Comparison of porosity assessment techniques for low-cost ceramic membranes | Boletín de la Sociedad Española de Cerámica y Vidrio

array:24 ["pii" => "S0366317516300723" "issn" => "03663175" "doi" => "10.1016/j.bsecv.2016.09.002" "estado" => "S300" "fechaPublicacion" => "2017-01-01" "aid" => "66" "copyright" => "SECV" "copyrightAnyo" => "2016" "documento" => "article" "crossmark" => 1 "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/" "subdocumento" => "fla" "cita" => "Bol Soc Esp Ceram Vidr. 2017;56:29-38" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 1835 "formatos" => array:3 [ "EPUB" => 78 "HTML" => 1413 "PDF" => 344 ] ] "itemSiguiente" => array:19 [ "pii" => "S0366317516300346" "issn" => "03663175" "doi" => "10.1016/j.bsecv.2016.04.003" "estado" => "S300" "fechaPublicacion" => "2017-01-01" "aid" => "54" "copyright" => "SECV" "documento" => "article" "crossmark" => 1 "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/" "subdocumento" => "fla" "cita" => "Bol Soc Esp Ceram Vidr. 2017;56:39-46" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 1600 "formatos" => array:3 [ "EPUB" => 62 "HTML" => 991 "PDF" => 547 ] ] "en" => array:12 [ "idiomaDefecto" => true "titulo" => "Low-temperature synthesis of silicon carbide powder using shungite" "tienePdf" => "en" "tieneTextoCompleto" => "en" "tieneResumen" => array:2 [ 0 => "en" 1 => "es" ] "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "39" "paginaFinal" => "46" ] ] "titulosAlternativos" => array:1 [ "es" => array:1 [ "titulo" => "Síntesis de baja temperatura de polvo de carburo de silicio utilizando shunguita" ] ] "contieneResumen" => array:2 [ "en" => true "es" => true ] "contieneTextoCompleto" => array:1 [ "en" => true ] "contienePdf" => array:1 [ "en" => true ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:7 [ "identificador" => "fig0025" "etiqueta" => "Fig. 5" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr5.jpeg" "Alto" => 4111 "Ancho" => 3369 "Tamanyo" => 585672 ] ] "descripcion" => array:1 [ "en" => "IR spectra of syntheses products of various reaction bed: (a) aggregates; (b) pellets and (c) powder." ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "Agnieszka Gubernat, Waldemar Pichór, Radosław Lach, Dariusz Zientara, Maciej Sitarz, Maria Springwald" "autores" => array:6 [ 0 => array:2 [ "nombre" => "Agnieszka" "apellidos" => "Gubernat" ] 1 => array:2 [ "nombre" => "Waldemar" "apellidos" => "Pichór" ] 2 => array:2 [ "nombre" => "Radosław" "apellidos" => "Lach" ] 3 => array:2 [ "nombre" => "Dariusz" "apellidos" => "Zientara" ] 4 => array:2 [ "nombre" => "Maciej" "apellidos" => "Sitarz" ] 5 => array:2 [ "nombre" => "Maria" "apellidos" => "Springwald" ] ] ] ] ] "idiomaDefecto" => "en" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S0366317516300346?idApp=UINPBA00004N" "url" => "/03663175/0000005600000001/v1_201702110054/S0366317516300346/v1_201702110054/en/main.assets" ] "itemAnterior" => array:19 [ "pii" => "S0366317516300553" "issn" => "03663175" "doi" => "10.1016/j.bsecv.2016.07.001" "estado" => "S300" "fechaPublicacion" => "2017-01-01" "aid" => "62" "copyright" => "SECV" "documento" => "article" "crossmark" => 1 "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/" "subdocumento" => "ssu" "cita" => "Bol Soc Esp Ceram Vidr. 2017;56:19-28" "abierto" => array:3 [ "ES" => true "ES2" => true "LATM" => true ] "gratuito" => true "lecturas" => array:2 [ "total" => 1560 "formatos" => array:3 [ "EPUB" => 50 "HTML" => 1194 "PDF" => 316 ] ] "es" => array:12 [ "idiomaDefecto" => true "titulo" => "Comportamiento ferroeléctrico de una nanoesfera de titanato de plomo debido a campos de despolarización y a esfuerzos mecánicos" "tienePdf" => "es" "tieneTextoCompleto" => "es" "tieneResumen" => array:2 [ 0 => "es" 1 => "en" ] "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "19" "paginaFinal" => "28" ] ] "titulosAlternativos" => array:1 [ "en" => array:1 [ "titulo" => "Ferroelectric behavior of a lead titanate nanosphere due to depolarization fields and mechanical stresses" ] ] "contieneResumen" => array:2 [ "es" => true "en" => true ] "contieneTextoCompleto" => array:1 [ "es" => true ] "contienePdf" => array:1 [ "es" => true ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:7 [ "identificador" => "fig0030" "etiqueta" => "Figura 6" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr6.jpeg" "Alto" => 1421 "Ancho" => 1662 "Tamanyo" => 98523 ] ] "descripcion" => array:1 [ "es" => "Polarización en función del diámetro de la nanopartícula de PT para T=298,15K y n=3. Las líneas son las predicciones de este trabajo. Los puntos han sido extraídos de un modelo para películas delgadas de Junquera et al. <a class="elsevierStyleCrossRef" href="#bib0410">[32]</a>. En las películas D se refiere a su grosor." ] ] ] "autores" => array:1 [ 0 => array:2 [ "autoresLista" => "Julio Andrade Landeta, Luis Lascano" "autores" => array:2 [ 0 => array:2 [ "nombre" => "Julio" "apellidos" => "Andrade Landeta" ] 1 => array:2 [ "nombre" => "Luis" "apellidos" => "Lascano" ] ] ] ] ] "idiomaDefecto" => "es" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S0366317516300553?idApp=UINPBA00004N" "url" => "/03663175/0000005600000001/v1_201702110054/S0366317516300553/v1_201702110054/es/main.assets" ] "en" => array:20 [ "idiomaDefecto" => true "titulo" => "Comparison of porosity assessment techniques for low-cost ceramic membranes" "tieneTextoCompleto" => true "paginas" => array:1 [ 0 => array:2 [ "paginaInicial" => "29" "paginaFinal" => "38" ] ] "autores" => array:1 [ 0 => array:4 [ "autoresLista" => "Maria-Magdalena Lorente-Ayza, Olga Pérez-Fernández, Raquel Alcalá, Enrique Sánchez, Sergio Mestre, Joaquin Coronas, Miguel Menéndez" "autores" => array:7 [ 0 => array:4 [ "nombre" => "Maria-Magdalena" "apellidos" => "Lorente-Ayza" "email" => array:1 [ 0 => "magda.lorente@itc.uji.es" ] "referencia" => array:2 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "aff0005" ] 1 => array:2 [ "etiqueta" => "*" "identificador" => "cor0005" ] ] ] 1 => array:3 [ "nombre" => "Olga" "apellidos" => "Pérez-Fernández" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "b" "identificador" => "aff0010" ] ] ] 2 => array:3 [ "nombre" => "Raquel" "apellidos" => "Alcalá" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "b" "identificador" => "aff0010" ] ] ] 3 => array:3 [ "nombre" => "Enrique" "apellidos" => "Sánchez" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "aff0005" ] ] ] 4 => array:3 [ "nombre" => "Sergio" "apellidos" => "Mestre" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "a" "identificador" => "aff0005" ] ] ] 5 => array:3 [ "nombre" => "Joaquin" "apellidos" => "Coronas" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "c" "identificador" => "aff0015" ] ] ] 6 => array:3 [ "nombre" => "Miguel" "apellidos" => "Menéndez" "referencia" => array:1 [ 0 => array:2 [ "etiqueta" => "b" "identificador" => "aff0010" ] ] ] ] "afiliaciones" => array:3 [ 0 => array:3 [ "entidad" => "Instituto Universitario de Tecnología Cerámica (ITC), Universitat Jaume I, Castellón, Spain" "etiqueta" => "a" "identificador" => "aff0005" ] 1 => array:3 [ "entidad" => "Instituto de Investigación en Ingeniería de Aragón (I3A), Universidad de Zaragoza, Zaragoza, Spain" "etiqueta" => "b" "identificador" => "aff0010" ] 2 => array:3 [ "entidad" => "Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, Spain" "etiqueta" => "c" "identificador" => "aff0015" ] ] "correspondencia" => array:1 [ 0 => array:3 [ "identificador" => "cor0005" "etiqueta" => "⁎" "correspondencia" => "Corresponding author." ] ] ] ] "titulosAlternativos" => array:1 [ "es" => array:1 [ "titulo" => "Comparación de técnicas de medida de la porosidad en membranas cerámicas de bajo coste" ] ] "resumenGrafico" => array:2 [ "original" => 0 "multimedia" => array:7 [ "identificador" => "fig0020" "etiqueta" => "Fig. 4" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr4.jpeg" "Alto" => 754 "Ancho" => 1750 "Tamanyo" => 223443 ] ] "descripcion" => array:1 [ "en" => "FEG-ESEM micrographs of pressed and extruded membranes with high clay content (magnification: 1500×). Pores present a dark color in the micrographs." ] ] ] "textoCompleto" => "IntroductionMembrane bioreactors (MBR) combine a biological degradation process with the direct separation of activated sludge and liquid-solid by filtration membranes <a class="elsevierStyleCrossRef" href="#bib0170">[1]</a>. In addition, MBRs have important advantages such as space reduction relative to conventional activated sludge process, which leads to a decrease in their environmental impact, the capability of operating with higher concentrations of suspended solids, and the production of better quality effluent. However, one of the main drawbacks of MBR is membrane fouling. Despite the high cost of commonly used ceramic membranes (made of alumina, zirconia or titania), it is known that they are more hydrophilic than polymeric membranes, which means that ceramic membranes have a lower membrane fouling rate. Ceramic membranes are also more chemically, mechanically and thermally resistant. Other characteristics that influence membrane fouling are pore size and configuration (tubular, flat or hollow fiber) <a class="elsevierStyleCrossRefs" href="#bib0175">[2,3]</a>. Currently, polymeric hollow fiber membranes are the most widely used in the industry because the manufacturing cost of ceramic membranes based on high purity oxides is higher than that of their polymeric counterparts. However, hollow fiber membranes are more likely to develop higher fouling rates and consequently give rise to higher maintenance costs <a class="elsevierStyleCrossRef" href="#bib0170">[1]</a>. As an alternative, low cost ceramic membranes whose composition is mainly based on clays and organic pore formers are cheaper, similar to the cost of polymeric membranes. The preparation of low cost ceramic membranes was described in a previous paper <a class="elsevierStyleCrossRef" href="#bib0185">[4]</a>.This work attempts to characterize two key parameters of low cost ceramic membranes: mean pore diameter and permeability. Several techniques can be used to measure the pore size distribution and average pore size (d50) of a membrane: nitrogen adsorption, intrusion mercury porosimetry, permporometry, the bubble point method, solute resistance tests and electronic microscopy (SEM, TEM). In this work, we will compare the results obtained by intrusion mercury porosimetry and the bubble point method. Both are simple and rapid techniques which have been widely used to evaluate the pore size of ceramic materials. They are standardized, repeatable and reproducible test methods.The goal of this study is to draw a comparison between the average pore size results obtained using bubble point and intrusion mercury porosimetry characterization techniques applied to a set of low cost symmetrical ceramic membranes. As mercury manipulation has been restricted, this comparison could open up an alternative to intrusion mercury porosimetry. This work also addresses the relationship between the water and air permeabilities of the membranes.Experimental methodMembrane preparationLow cost ceramic membranes were prepared from raw materials normally used in the ceramic tile sector (clays, chamotte, feldspar and calcium carbonate) and organic pore formers (different starches provided by Roquette Laisa España, S.A.). The components were mixed in suitable proportions so that they could be easily processed by uniaxial dry pressing or extrusion. To obtain membranes with a broad range of porosity and pore sizes, the forming methods were combined with the addition of different proportions of starch to some compositions. <a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a> shows the compositional range used to obtain the ceramic membranes, where the proportion of clay, chamotte, feldspar, calcite and starch have been modified. Four different groups of membranes were prepared in this way, referred to as P, PS, E and ES (<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>).<elsevierMultimedia ident="tbl0005"></elsevierMultimedia><elsevierMultimedia ident="tbl0010"></elsevierMultimedia>The process for producing the pressed membranes started with dry homogenization (manually and by means of an automatic mixer) of the different raw materials. The resulting compositions were moistened to 5.5kg H2O/100kg dry solid. Cylindrical test specimens, 0.7cm thick and 5cm in diameter, were formed from this powder by uniaxial dry pressing using an automatic laboratory press (Nannetti SpA, Italy). The test samples were oven-dried at 110°C to a constant weight.Each batch of raw materials for the extruded membranes was kneaded to a consistency of 5kg, determined by penetrometry (using a cylinder with 1.5cm diameter) (Analogic penetrometer Geotester 0-6kg, Novatest S.r.l., Italy) <a class="elsevierStyleCrossRef" href="#bib0190">[5]</a>, and allowed to stand for 24h to achieve uniform moisture in the mass. The water content of the compositions varies between 20 and 32wt%. Test pieces 1cm thick and 5cm in diameter were shaped from an extruded sheet, using a laboratory auger with a de-airing chamber (Model 050 C, Talleres Felipe Verdés, S.A., Spain). The test samples were weighed and afterwards dried at room temperature for 24h, and oven-dried at 110°C to a constant weight.After drying, all the samples were weighed and the bulk density was measured by the mercury immersion method <a class="elsevierStyleCrossRef" href="#bib0195">[6]</a>. Next, the membranes were sintered with different thermal cycles, depending on their composition and the final properties required (sintering temperatures ranged from 1060 to 1160°C and dwelling time from 6 to 120min). After sintering, the membrane properties were determined. These properties included density, thickness, microstructure (observed by Scanning Electron Microscopy, FEG-ESEM Quanta 200 F, FEI, USA), and air and water permeability. Moreover, the average pore diameter and pore size distribution were determined by two techniques: intrusion mercury porosimetry and the bubble point method.The present study was carried out with a large number of membranes with different pore sizes: 15 different compositions (classified in four series, as shown in <a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>) and 36 samples were tested to compare average pore size values obtained by both methods. In order to compare the permeability for air and water, 9 different compositions and 36 tests were carried out.Characterization: bubble point and intrusion mercury porosimetryThe bubble point method allows the determination of membrane air permeability and, unlike the most common techniques used in the study of porous solids (nitrogen adsorption and intrusion mercury porosimetry), provides information about the pores that control the permeation <a class="elsevierStyleCrossRefs" href="#bib0200">[7–12]</a>. This method is used to measure pores with size above 50nm and it is standardized by ASTM F316-03 <a class="elsevierStyleCrossRef" href="#bib0230">[13]</a>, ISO 2942 <a class="elsevierStyleCrossRef" href="#bib0235">[14]</a> and ISO 4003 <a class="elsevierStyleCrossRef" href="#bib0240">[15]</a>. It consists of filling the porous structure of the membrane with a liquid and measuring the air pressure necessary to displace the liquid inside the pores. The minimum pressure necessary to blow the first observed air bubble corresponds to the largest pore size of the membrane; this value is known as the bubble point <a class="elsevierStyleCrossRefs" href="#bib0240">[15–18]</a>. The mathematical relationship between pressure and pore size is given by Washburn equation:<elsevierMultimedia ident="eq0005"></elsevierMultimedia>where ΔP is the pressure drop (bar), dp is the pore size (μm), φ is the contact angle between the fluid and pore walls and γ is the liquid surface stress. In order to be able to use the Washburn equation, the pores are assumed to be cylindrical.During the bubble point test, liquid intrusion will first occur through the largest pores. If the pores were cylindrical, the flow (m3s−1) through the membrane, considered as laminar, would be given by Hagen–Poiseuille equation <a class="elsevierStyleCrossRefs" href="#bib0215">[10,17,19]</a>:<elsevierMultimedia ident="eq0010"></elsevierMultimedia>where Qv is the volumetric flow through the membrane, ΔP is the transmembrane pressure, n is the number of pores, r is the pore size, μ is the liquid viscosity and l is the pore length. If the above equation is employed for a gas, the volumetric flow rate should be expressed at the mean pressure, i.e. Qv should be calculated as the volumetric flow measured at Pm, where Pm is the mean pressure at both sides of the membrane. This is slightly different from the usual way of calculating the gas permeation through porous membranes (e.g. <a class="elsevierStyleCrossRef" href="#bib0265">[20]</a>). In laminar flow conditions, the molar flow rate is proportional to (P12−P22), where P1 is the pressure in the retentate and P2 is the pressure in the permeate. However, if the volumetric flow measured at the mean pressure (P1+P2)/2 is employed, it may easily be found that this volumetric flow rate is given by Eq. <a class="elsevierStyleCrossRef" href="#eq0010">(2)</a>, where ΔP is (P1−P2) (see Appendix). This formulation of the gas permeation allows the same equation <a class="elsevierStyleCrossRef" href="#eq0010">(2)</a> to be used for liquids and gases.The average pore size (d50) is calculated using Eq. <a class="elsevierStyleCrossRef" href="#eq0005">(1)</a> from the pressure at the intersection point of the line that represents 50% of the air flow (mLmin−1) through the dry membrane versus the applied pressure with the equivalent curve for the wet membrane (<a class="elsevierStyleCrossRef" href="#fig0005">Fig. 1</a>). The pore sizes corresponding to 16% and 84% of the dry flow (named d16 and d84) are calculated in the same manner, giving an insight into the standard deviation of the pore size distribution.<elsevierMultimedia ident="fig0005"></elsevierMultimedia>Intrusion mercury porosimetry is also based on the Washburn equation, but in this technique mercury is the liquid used to fill the pores. By this method the mercury intrusion volume is recorded as a function of pressure or pore size <a class="elsevierStyleCrossRefs" href="#bib0205">[8,21]</a>. This technique is normalized within DIN 66133 and ISO 15901 <a class="elsevierStyleCrossRef" href="#bib0275">[22]</a>, but restrictions on the use of mercury may lead to its disappearance in the near future. Finally, the total volume of pores (Vf) and characteristic pore diameters (d16, d50 and d84) are calculated from experimental data.The main difference between both methods is that the bubble point, besides being a non-destructive technique, measures the air flow through the pores, while intrusion mercury porosimetry records the intrusion volume of mercury coming into the membrane pores. Intrusion mercury porosimetry works with higher pressure, which is considered a limitation because it can lead to sample deformation in the case of polymeric membranes <a class="elsevierStyleCrossRef" href="#bib0210">[9]</a>. Another limitation in the case of asymmetric membranes is the inability of this method to distinguish between the pores which determine the flux (usually in the selective layer) and the larger pores in the support <a class="elsevierStyleCrossRef" href="#bib0280">[23]</a>. In addition, intrusion mercury porosimetry also measures pores that do not participate in the permeation (non-connected pores).Bubble pointIn order to measure the pore size of the membranes by the bubble point method, two sets of air flow measurements were carried out. The first was performed with the dry membrane, measuring the air flow through the membrane while the transmembrane pressure (TMP) was gradually increased. A second set of measurements was performed with the same procedure, but the porous network of the membrane was previously filled with water (surface tension at the water/air interface, γ, is 72.75mN/m at 20°C <a class="elsevierStyleCrossRef" href="#bib0285">[24]</a>); this method is based on the fact that an air bubble will penetrate through the pore when its radius is equal to that of the pore, meaning that the contact angle is 0° (and cosφ=1) <a class="elsevierStyleCrossRef" href="#bib0290">[25]</a>. For this procedure, a steel module suitable for disk ceramic membranes with a diameter of 5cm was made and a set-up was designed as shown in <a class="elsevierStyleCrossRef" href="#fig0010">Fig. 2</a>. The sealing between the membrane and the module was made with Viton o-rings.<elsevierMultimedia ident="fig0010"></elsevierMultimedia>Intrusion mercury porosimetryThe pore size distribution for each membrane was also obtained by intrusion mercury porosimetry (Autopore IV 9500, Micromeritics Inc. USA). This technique is based on the measurement of the intrusion volume of a non-wetting liquid in order to calculate data related with the pore structure of the sample. Thus, the equipment continuously registers the variation of the intrusion volume of the mercury inside the sample depending on the pressure applied over the sample. Next, it calculates the pore diameter with the intrusion pressure, by means of the Washburn equation (surface tension at the mercury/air interface, γ, is 487mN/m at 20°C and contact angle, φ, is 135°), obtaining a graphic of cumulative pore volume versus pore size. Finally, the characteristic pore diameters (d16, d50 and d84) are calculated from experimental data.Permeability: air and waterAir and water permeabilities were calculated by measuring the fluid flow (mLmin−1) through the membrane at room temperature while the applied pressure was gradually increased. The permeation was determined from the slope of the straight line obtained from the graphical plot of the air/water flux against applied pressure, per membrane area unit (m3h−1m−2bar−1). Air permeability was measured in the same module as described for the bubble point measurements, while water permeability was determined by means of two different pieces of equipment: an automatic liquid permeameter (LEP-1101-A, PMI, Ithaca, NY, USA) for membranes with higher permeability and a manual liquid permeameter for membranes with lower permeability.Results and discussionMembrane structure (SEM)Micrographs of polished sections of examples of the four types of membranes described in <a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a> are shown in <a class="elsevierStyleCrossRef" href="#fig0015">Fig. 3</a>. It can be seen that a continuous porous structure was created, the pores being larger when starch was employed as the pore generator in the preparation of the membrane (membranes PS and ES, compared with those without starch addition, P and S). The addition of starch increases porosity and pore size as well as pore connectivity, owed to the increase in the amount of interconnected pores created by starch burnout, which should result in an increase in permeability. This effect has been reported previously in the literature. Starch additions greater than 10wt% have been shown to increase the amount of interconnected pores created by starch burnout during the sintering step <a class="elsevierStyleCrossRefs" href="#bib0185">[4,26–28]</a>.<elsevierMultimedia ident="fig0015"></elsevierMultimedia>Samples obtained by extrusion (E and ES) have a lower pore size than the pressed samples owing to the different shaping processes (see <a class="elsevierStyleCrossRef" href="#fig0015">Fig. 3</a>). <a class="elsevierStyleCrossRef" href="#fig0020">Fig. 4</a> shows the microstructures of two membranes of the same composition (high clay content and no starch), which have been obtained by extrusion and pressing. As can be seen, they differ mainly in the oriented and scarcely connected pore structure which is typical from the extruded materials. Pores from the pressed membrane are rounder and highly connected, whereas pores from the extruded membrane show a long shape and reduced connection. This characteristic microstructure is more evident in the surface of the membranes, where the oriented clay particles create a superficial layer that closes many pores near the surface. This effect have already been observed by several authors <a class="elsevierStyleCrossRefs" href="#bib0185">[4,29,30]</a>, who have reported that clay products manufactured by extrusion have a microstructure characterized by an orientated pore distribution. This is a consequence of the movement of the colloidal clay particles traveling through the auger extruder during the shaping step. Moreover, these pores have a reduced connectivity. In short, both the shaping method and the starch addition have a great influence on the microstructure of the support, modifying the pore size, porosity and pore connectivity and, consequently, the permeability, as it will be explained in Section “Air–water permeability”.<elsevierMultimedia ident="fig0020"></elsevierMultimedia>Bubble point and intrusion mercury porosimetryA graphical representation of the mean pore size obtained from the bubble point and intrusion mercury porosimetry characterization shows an approximate linear relationship between both methods with a coefficient R2 of 0.93 (<a class="elsevierStyleCrossRef" href="#fig0025">Fig. 5</a>) and a slope close to 1 (0.84). This suggests that both methods provide mean pore diameters of the same order in spite of the differences in the experimental approach. Small differences between the mean pore size measured by both methods are expected since in the bubble point method the mean pore diameter corresponds to a flow of a value of half as great as that in the absence of water (as it has been explained in <a class="elsevierStyleCrossRef" href="#fig0005">Fig. 1</a>), while in intrusion mercury porosimetry the mean pore diameter corresponds to the cut off pore size under which 50% of the total pore volume lies. In addition, since the real pores are not cylindrical, parallel and equal, the differences in both methods would affect the calculation of the mean value in different ways. The bubble point method measures pores that affect the liquid flow, which are pores that are connected to the surface and between them, but closed pores are not measured. On the other hand, intrusion mercury porosimetry technique measures all pores that mercury can reach with pressure, both open and non-connected pores. Moreover, because of the high pressures used, intrusion mercury porosimetry technique is able to reach smaller pores, which are no measurable for the bubble point method. Deviation between both methods have also been found by other authors, but the nature of the measured material affects to this deviation: Bhatia et al. <a class="elsevierStyleCrossRef" href="#bib0320">[31]</a> found that the mercury pore-size distributed results showed much larger pores in the geotextiles than did the bubble point method, whereas Calvo et al. <a class="elsevierStyleCrossRef" href="#bib0210">[9]</a> observed that mean pore diameters were lower for the intrusion mercury porosimetry curves when polycarbonate filters were analyzed.<elsevierMultimedia ident="fig0025"></elsevierMultimedia>The good agreement, in spite of the differences between both methods, can be considered as confirmation of the validity of the bubble point method; which allows the replacement of intrusion mercury porosimetry technique by bubble point method to reduce the mercury use in characterization laboratories.Finally, it is worth noting that the extruded samples show results closer to the linear relationship than the pressed samples. This could be due to the different microstructure that both shaping methods give to the supports, as described in Section “Membrane structure”. Supports obtained by means of the addition of starch in their composition also show a higher deviation from the linear relationship, probably owing to the fact that the big pores generated by the starch provide higher variability, being higher the error associated to the measurement. As it has been stated before, intrusion mercury porosimety provide the same status to all pores; on the other hand, bubble point method measures the effective diameter, which is affected by the pore size, since it influences the necessary energy to empty the pores. This has also been reported by Calvo et al. <a class="elsevierStyleCrossRef" href="#bib0210">[9]</a>, who observed a better accordance for both characterizations (pore size distributions obtained by intrusion mercury posimetry and bubble point method) when pore size decreased.The comparison between characteristic diameters (d16 and d84) calculated by bubble point method and intrusion mercury porosimetry shows the same tend that d50, so it has not been plotted in the present paper. A good agreement was achieved between the values obtained by these two different methods, which again is confirmation of the validity of the bubble point method. It is clear that the agreement was achieved because these membranes are symmetric. In the case of asymmetric membranes, the measurement of pore size distribution by intrusion mercury porosimetry would not reflect the size of the pores controlling the flow. In addition, the d84 pores generate the worst correlation (R2=0.919). This could be explained by the fact that mercury intrusion can measure very small and non-connected pores that take no part in the permeation, as it has been described previously.Air–water permeabilityAccording to Eq. <a class="elsevierStyleCrossRef" href="#eq0010">(2)</a>, a plot of the air flow (using the volume measured at the mean pressure) versus the transmembrane pressure (ΔP) should show a straight line (<a class="elsevierStyleCrossRef" href="#fig0030">Fig. 6</a>a). The slopes of these lines allow the permeation of each membrane to air to be calculated. On the other hand, water permeability is calculated by means of the slope of the straight line that appears when the water flow is represented versus ΔP (<a class="elsevierStyleCrossRef" href="#fig0030">Fig. 6</a>b). As <a class="elsevierStyleCrossRef" href="#fig0030">Fig. 6</a>a and b shows, pressed membranes show higher slopes (and permeabilities) than the extruded membranes. The permeability of the membranes obtained by uniaxial pressing is higher than those obtained by extrusion, confirming the results on microstructural features set out in Section “Membrane structure”: extruded membranes have smaller and less connected pores than pressed ones, which provokes a reduction in water and air permeability, effect that have been reported by the authors in previous works about low-cost ceramic membranes <a class="elsevierStyleCrossRef" href="#bib0185">[4]</a>.<elsevierMultimedia ident="fig0030"></elsevierMultimedia>The addition of starch to the initial composition greatly improves the permeability, because compositions with starch have higher slopes than those without starch, as can be seen in <a class="elsevierStyleCrossRef" href="#fig0030">Fig. 6</a>a and b. The results are consistent with the microstructure observed in Section “Membrane structure”, where it has been stated that the addition of starch to the membrane's composition increase the pore size and the connectivity of the pores, owed to the porosity created when starch is burnt out during the sintering step, increasing the membrane's permeability (air and water). This is especially effective for starch percentages higher than 10wt%, since a connected coarse pore network is developed, as has been detailed in previous works <a class="elsevierStyleCrossRef" href="#bib0325">[32]</a>.A graphical representation of air and water permeability obtained from the experimental values shows a linear relationship between both measurements with a coefficient R2 of 0.96 (<a class="elsevierStyleCrossRef" href="#fig0035">Fig. 7</a>). As has been pointed out previously, samples with higher permeability (membranes PS, shaped by pressing and with starch addition) do not follow the general trend as well as the rest of the samples. This is expected, since these samples exhibit permeability values that are twice or three times higher than those of the rest of samples. Moreover, mean pore size of PS samples follow the same pattern, since they do not fit to the general trend as well as the other compositions. Similar conclusions have been found in previous researches carried out by the same authors <a class="elsevierStyleCrossRef" href="#bib0185">[4]</a>.<elsevierMultimedia ident="fig0035"></elsevierMultimedia>The slope of the straight line in <a class="elsevierStyleCrossRef" href="#fig0035">Fig. 7</a> (value 63) confirms the relationship between both measurements. The relationship between air and water permeabilities is close to the theoretical value of 56 calculated for the ratio of air and water permeation from the Hagen–Poiseuille equation, using the viscosities of air (1.837×10−5Nsm−2) and water (1.002×10−3Nsm−2) at 20°C (Eq. <a class="elsevierStyleCrossRef" href="#eq0015">(3)</a>):<elsevierMultimedia ident="eq0015"></elsevierMultimedia>where f is the ratio of air and water permeation, J is the flux and μ is the viscosity of every fluid (air or water).This good agreement between the ratio of permeabilities for air and water with the ratio of viscosities suggests that it could be possible to estimate the permeability for a fluid from the permeability experimentally measured with the other and vice versa, as <a class="elsevierStyleCrossRef" href="#tbl0015">Table 3</a> confirms.<elsevierMultimedia ident="tbl0015"></elsevierMultimedia>Finally, the influence of the pore size (obtained by the bubble point method and intrusion mercury porosimetry) over the water and air permeability coefficient (Kp) has been evaluated. As reported in a previous research study <a class="elsevierStyleCrossRef" href="#bib0330">[33]</a>, the Hagen–Poiseuille (Eq. <a class="elsevierStyleCrossRef" href="#eq0020">(4)</a>) relates the permeability coefficient with the pore radius (r), the water viscosity (μ), the surface porosity (¿sf) and the tortuosity factor (τ):<elsevierMultimedia ident="eq0020"></elsevierMultimedia>Assuming that the ratio ¿sf/τ varies little between the membranes, the model predicts an approximately linear relationship between Kp and r2. This relationship has been represented in <a class="elsevierStyleCrossRef" href="#fig0040">Fig. 8</a> for both d16 (a) and d50 (b), obtained by the bubble point method. The correlation is slightly better with the mean diameter (d50) obtained with the bubble point method, which indicates that d50 is a good parameter for defining the properties of the support as a membrane. The differences found between this trend and the trend obtained in the referenced work <a class="elsevierStyleCrossRef" href="#bib0330">[33]</a>, where the correlation was slightly better with the d16 parameter (obtained with the mercury porosimeter), may be due to the different measuring techniques. Since mercury porosimeter measures all the pores of the membrane (connected and non-connected), the pore diameter d16 represents the pores of bigger diameter, which are the pores that have higher influence over the fluid permeability. On the other hand, bubble point method measures the pores that participate in the fluid flux, so the d50 is representative of the effective pore size. This possibly explains the differences obtained in the diameter that correlates better with the permeability.<elsevierMultimedia ident="fig0040"></elsevierMultimedia>ConclusionsA study of the relationship between mean pore sizes measured by two different methods (bubble point and intrusion mercury porosimetry) has been carried out using a set of low cost ceramic membranes prepared using different procedures and compositions. The air and water permeabilities of the tested membranes were compared, achieving a good correlation between both experimental values. These permeabilities were related by the Hagen–Poiseuille model with the ratio of the viscosities for air and water. Moreover, both permeabilities have a relationship with the square pore diameter, as the Hagen–Poiseuille equation predicts.SEM images showed a higher porosity of the membranes prepared with starch, which also had higher permeability. This result confirms the suitability of starch as a pore former in the preparation of low cost ceramic membranes. Membranes prepared with uniaxial pressing provided higher permeability than those obtained by extrusion, for the same composition of the starting mixture.To sum up, a good correlation between both methods was found. The consistency between the two methods opens up the possibility of replacing mercury intrusion in some applications. Good agreement was also obtained in the measurements of the pore size distribution width (d16 and d84)." "textoCompletoSecciones" => array:1 [ "secciones" => array:10 [ 0 => array:3 [ "identificador" => "xres800270" "titulo" => "Abstract" "secciones" => array:1 [ 0 => array:1 [ "identificador" => "abst0005" ] ] ] 1 => array:2 [ "identificador" => "xpalclavsec798763" "titulo" => "Keywords" ] 2 => array:3 [ "identificador" => "xres800271" "titulo" => "Resumen" "secciones" => array:1 [ 0 => array:1 [ "identificador" => "abst0010" ] ] ] 3 => array:2 [ "identificador" => "xpalclavsec798764" "titulo" => "Palabras clave" ] 4 => array:2 [ "identificador" => "sec0005" "titulo" => "Introduction" ] 5 => array:3 [ "identificador" => "sec0010" "titulo" => "Experimental method" "secciones" => array:3 [ 0 => array:2 [ "identificador" => "sec0015" "titulo" => "Membrane preparation" ] 1 => array:3 [ "identificador" => "sec0020" "titulo" => "Characterization: bubble point and intrusion mercury porosimetry" "secciones" => array:2 [ 0 => array:2 [ "identificador" => "sec0025" "titulo" => "Bubble point" ] 1 => array:2 [ "identificador" => "sec0030" "titulo" => "Intrusion mercury porosimetry" ] ] ] 2 => array:2 [ "identificador" => "sec0035" "titulo" => "Permeability: air and water" ] ] ] 6 => array:3 [ "identificador" => "sec0040" "titulo" => "Results and discussion" "secciones" => array:3 [ 0 => array:2 [ "identificador" => "sec0045" "titulo" => "Membrane structure (SEM)" ] 1 => array:2 [ "identificador" => "sec0050" "titulo" => "Bubble point and intrusion mercury porosimetry" ] 2 => array:2 [ "identificador" => "sec0055" "titulo" => "Air–water permeability" ] ] ] 7 => array:2 [ "identificador" => "sec0060" "titulo" => "Conclusions" ] 8 => array:2 [ "identificador" => "xack268094" "titulo" => "Acknowledgements" ] 9 => array:1 [ "titulo" => "References" ] ] ] "pdfFichero" => "main.pdf" "tienePdf" => true "fechaRecibido" => "2016-02-09" "fechaAceptado" => "2016-09-06" "PalabrasClave" => array:2 [ "en" => array:1 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Keywords" "identificador" => "xpalclavsec798763" "palabras" => array:5 [ 0 => "Membranes" 1 => "Porosity" 2 => "Shaping" 3 => "Bubble point method" 4 => "Intrusion mercury porosimetry" ] ] ] "es" => array:1 [ 0 => array:4 [ "clase" => "keyword" "titulo" => "Palabras clave" "identificador" => "xpalclavsec798764" "palabras" => array:5 [ 0 => "Membranas" 1 => "Porosidad" 2 => "Conformado" 3 => "Método de punto de burbuja" 4 => "Porosimetría de intrusión de mercurio" ] ] ] ] "tieneResumen" => true "resumen" => array:2 [ "en" => array:2 [ "titulo" => "Abstract" "resumen" => "Several characterization methods were applied to low cost ceramic membranes developed for wastewater treatment in membrane bioreactors (MBRs) and/or tertiary treatments. The membranes were prepared by four different procedures (uniaxial pressing and extrusion, both with and without starch addition to generate pores). The pore size of these symmetric ceramic membranes was measured by two different methods: bubble point and intrusion mercury porosimetry. A good agreement between both methods was achieved, confirming the validity of the bubble point method for the measurement of the mean pore size of membranes. Air and water permeations of these ceramic membranes were also studied. The relationship between the permeation of both fluids is consistent with the ratio of viscosities, according to the Hagen–Poiseuille equation." ] "es" => array:2 [ "titulo" => "Resumen" "resumen" => "En el presente trabajo se han caracterizado mediante diferentes métodos membranas cerámicas de bajo coste desarrolladas para tratar aguas residuales en reactores biológicos de membrana (MBR) o mediante tratamientos terciarios. Las membranas se prepararon mediante diferentes procedimientos (prensado uniaxial y extrusión, con o sin adición de almidón como material generador de poros). El tamaño del poro de estas membranas cerámicas simétricas se determinó mediante 2 métodos diferentes: punto de burbuja y porosimetría de intrusión de mercurio. Los resultados obtenidos mediante ambos métodos mostraban concordancia, lo que confirma la validez del método de punto de burbuja para la medida del tamaño del poro medio de las membranas. Además, se ha estudiado la permeabilidad al aire y agua de estas membranas cerámicas: la relación entre la permeabilidad de ambos fluidos es consistente con el ratio de viscosidades, de acuerdo con la ecuación de Hagen-Poiseuille." ] ] "apendice" => array:1 [ 0 => array:1 [ "seccion" => array:1 [ 0 => array:4 [ "apendice" => "The Hagen–Poiseuille equation <a class="elsevierStyleCrossRef" href="#eq0010">(2)</a> was deduced for a non-compressible fluid. For a compressible fluid it can be expressed as:<elsevierMultimedia ident="eq0025"></elsevierMultimedia> Since the gas is compressible, the volumetric flow varies with the pressure, and it is preferable to give the volumetric flow as a function of the molar flow. According to the ideal gas equation we have:<elsevierMultimedia ident="eq0030"></elsevierMultimedia>where F is the molar flow. Substituting Eq. <a class="elsevierStyleCrossRef" href="#eq0030">(A.2)</a> in Eq. <a class="elsevierStyleCrossRef" href="#eq0025">(A.1)</a> we obtain:<elsevierMultimedia ident="eq0035"></elsevierMultimedia> By separating variables and integrating, with P2 and P1 as the pressure in retentate and permeate side respectively, we obtain:<elsevierMultimedia ident="eq0040"></elsevierMultimedia>Eq. <a class="elsevierStyleCrossRef" href="#eq0040">(A.4)</a> has been extensively used to describe the laminar flow in a porous membrane (e.g. <a class="elsevierStyleCrossRef" href="#bib0265">[20]</a>). However, if the volumetric flow measured at the mean pressure (Pm=(P1+P2)/2) is defined by:<elsevierMultimedia ident="eq0045"></elsevierMultimedia>it is possible to rewrite Eq. <a class="elsevierStyleCrossRef" href="#eq0040">(A.4)</a> as:<elsevierMultimedia ident="eq0050"></elsevierMultimedia>Thus Eq. <a class="elsevierStyleCrossRef" href="#eq0050">(A.6)</a> allows the same form of the Hagen–Poiseuille equation employed for liquids (Eq. <a class="elsevierStyleCrossRef" href="#eq0010">(2)</a>), but using as volumetric flow the value calculated at the mean pressure in the membrane (Eq. <a class="elsevierStyleCrossRef" href="#eq0045">(A.5)</a>)." "etiqueta" => "Appendix A" "titulo" => "Appendix" "identificador" => "sec0065" ] ] ] ] "multimedia" => array:21 [ 0 => array:7 [ "identificador" => "fig0005" "etiqueta" => "Fig. 1" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr1.jpeg" "Alto" => 1135 "Ancho" => 1352 "Tamanyo" => 114825 ] ] "descripcion" => array:1 [ "en" => "Air flow-pressure representation." ] ] 1 => array:7 [ "identificador" => "fig0010" "etiqueta" => "Fig. 2" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr2.jpeg" "Alto" => 1178 "Ancho" => 1571 "Tamanyo" => 155487 ] ] "descripcion" => array:1 [ "en" => "Scheme of the bubble point experimental equipment." ] ] 2 => array:7 [ "identificador" => "fig0015" "etiqueta" => "Fig. 3" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr3.jpeg" "Alto" => 1512 "Ancho" => 1750 "Tamanyo" => 615100 ] ] "descripcion" => array:1 [ "en" => "FEG-ESEM micrographs of pressed and extruded membranes, with and without starch addition (magnification: 400×). Pores present a dark color in the micrographs." ] ] 3 => array:7 [ "identificador" => "fig0020" "etiqueta" => "Fig. 4" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr4.jpeg" "Alto" => 754 "Ancho" => 1750 "Tamanyo" => 223443 ] ] "descripcion" => array:1 [ "en" => "FEG-ESEM micrographs of pressed and extruded membranes with high clay content (magnification: 1500×). Pores present a dark color in the micrographs." ] ] 4 => array:7 [ "identificador" => "fig0025" "etiqueta" => "Fig. 5" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr5.jpeg" "Alto" => 1607 "Ancho" => 1332 "Tamanyo" => 114165 ] ] "descripcion" => array:1 [ "en" => "Comparison of average pore size measured by bubble point (BP) and intrusion mercury porosimetry (MP) methods (2 samples evaluated for each point)." ] ] 5 => array:7 [ "identificador" => "fig0030" "etiqueta" => "Fig. 6" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr6.jpeg" "Alto" => 1475 "Ancho" => 2500 "Tamanyo" => 193859 ] ] "descripcion" => array:1 [ "en" => "Plot of air flow (measured at the mean pressure) (a) and water flow (b) versus transmembrane pressure for one example of each kind of membranes (1 sample evaluated for each curve)." ] ] 6 => array:7 [ "identificador" => "fig0035" "etiqueta" => "Fig. 7" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr7.jpeg" "Alto" => 1554 "Ancho" => 1340 "Tamanyo" => 148850 ] ] "descripcion" => array:1 [ "en" => "Comparison between water and air membrane permeabilities (2 samples evaluated for each point)." ] ] 7 => array:7 [ "identificador" => "fig0040" "etiqueta" => "Fig. 8" "tipo" => "MULTIMEDIAFIGURA" "mostrarFloat" => true "mostrarDisplay" => false "figura" => array:1 [ 0 => array:4 [ "imagen" => "gr8.jpeg" "Alto" => 1455 "Ancho" => 2499 "Tamanyo" => 199109 ] ] "descripcion" => array:1 [ "en" => "Comparison of water and air permeability coefficients versus d16 (a) and d50 (b) pore size measured by bubble point (BP) method (2 samples evaluated for each point)." ] ] 8 => array:8 [ "identificador" => "tbl0005" "etiqueta" => "Table 1" "tipo" => "MULTIMEDIATABLA" "mostrarFloat" => true "mostrarDisplay" => false "detalles" => array:1 [ 0 => array:3 [ "identificador" => "at1" "detalle" => "Table " "rol" => "short" ] ] "tabla" => array:1 [ "tablatextoimagen" => array:1 [ 0 => array:2 [ "tabla" => array:1 [ 0 => """ <table border="0" frame="\n \t\t\t\t\tvoid\n \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Raw material \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Compositional range (wt%) \t\t\t\t\t\t\n \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Clay \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">40–85 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Chamotte \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">0–20 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Feldspar \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">0–15 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Calcium carbonate \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">7–20 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Starch (different sources) \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">0–20 \t\t\t\t\t\t\n \t\t\t\t</td></tr></tbody></table> """ ] "imagenFichero" => array:1 [ 0 => "xTab1342665.png" ] ] ] ] "descripcion" => array:1 [ "en" => "Compositional range used to obtain ceramic membranes with very different porosity characteristics (total pore volume and size distribution)." ] ] 9 => array:8 [ "identificador" => "tbl0010" "etiqueta" => "Table 2" "tipo" => "MULTIMEDIATABLA" "mostrarFloat" => true "mostrarDisplay" => false "detalles" => array:1 [ 0 => array:3 [ "identificador" => "at2" "detalle" => "Table " "rol" => "short" ] ] "tabla" => array:1 [ "tablatextoimagen" => array:1 [ 0 => array:2 [ "tabla" => array:1 [ 0 => """ <table border="0" frame="\n \t\t\t\t\tvoid\n \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Membranes series \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Forming method \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Composition \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Number of specimens \t\t\t\t\t\t\n \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">P \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">Uniaxial dry pressing \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">Without starch \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">10 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">PS \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">Uniaxial dry pressing \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">With starch \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">4 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">E \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">Extrusion \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">Without starch \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">2 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">ES \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">Extrusion \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="left" valign="top">With starch \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">5 \t\t\t\t\t\t\n \t\t\t\t</td></tr></tbody></table> """ ] "imagenFichero" => array:1 [ 0 => "xTab1342666.png" ] ] ] ] "descripcion" => array:1 [ "en" => "Membranes classification." ] ] 10 => array:8 [ "identificador" => "tbl0015" "etiqueta" => "Table 3" "tipo" => "MULTIMEDIATABLA" "mostrarFloat" => true "mostrarDisplay" => false "detalles" => array:1 [ 0 => array:3 [ "identificador" => "at3" "detalle" => "Table " "rol" => "short" ] ] "tabla" => array:1 [ "tablatextoimagen" => array:1 [ 0 => array:2 [ "tabla" => array:1 [ 0 => """ <table border="0" frame="\n \t\t\t\t\tvoid\n \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Composition \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Experimental air permeability (m3h−1m−2bar−1) \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Calculated air permeability (m3h−1m−2bar−1) \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Deviation ratio (%) \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Experimental water permeability (m3h−1m−2bar−1) \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Calculated water permeability (m3h−1m−2bar−1) \t\t\t\t\t\t\n \t\t\t\t</th><th class="td" title="table-head " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Deviation ratio (%) \t\t\t\t\t\t\n \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">P \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">231 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">269 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">17 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">4.3 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">3.7 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">14 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">PS \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">2280 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">2859 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">25 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">46.0 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">36.0 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">20 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">E \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">112 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">93 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">17 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">1.5 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">1.8 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">21 \t\t\t\t\t\t\n \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">ES \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">483 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">526 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">9 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">8.4 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">7.7 \t\t\t\t\t\t\n \t\t\t\t</td><td class="td" title="table-entry " align="char" valign="top">8 \t\t\t\t\t\t\n \t\t\t\t</td></tr></tbody></table> """ ] "imagenFichero" => array:1 [ 0 => "xTab1342664.png" ] ] ] ] "descripcion" => array:1 [ "en" => "Examples of permeability estimation based Eq. <a class="elsevierStyleCrossRef" href="#eq0015">(3)</a> for compositions of each series." ] ] 11 => array:6 [ "identificador" => "eq0005" "etiqueta" => "(1)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "ΔP=4γ cos φdp" "Fichero" => "STRIPIN_si1.jpeg" "Tamanyo" => 1271 "Alto" => 35 "Ancho" => 97 ] ] 12 => array:6 [ "identificador" => "eq0010" "etiqueta" => "(2)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "Qv=nπr4 ΔP8μl" "Fichero" => "STRIPIN_si2.jpeg" "Tamanyo" => 1315 "Alto" => 36 "Ancho" => 92 ] ] 13 => array:6 [ "identificador" => "eq0015" "etiqueta" => "(3)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "ftheor=JairJwater=μwaterμair" "Fichero" => "STRIPIN_si3.jpeg" "Tamanyo" => 1809 "Alto" => 34 "Ancho" => 151 ] ] 14 => array:6 [ "identificador" => "eq0020" "etiqueta" => "(4)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "Kp=εsf8μτr2" "Fichero" => "STRIPIN_si4.jpeg" "Tamanyo" => 1008 "Alto" => 31 "Ancho" => 79 ] ] 15 => array:6 [ "identificador" => "eq0025" "etiqueta" => "(A.1)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "Qv=nπr48μdPdl" "Fichero" => "STRIPIN_si5.jpeg" "Tamanyo" => 1437 "Alto" => 36 "Ancho" => 90 ] ] 16 => array:6 [ "identificador" => "eq0030" "etiqueta" => "(A.2)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "PQv=FRT" "Fichero" => "STRIPIN_si6.jpeg" "Tamanyo" => 736 "Alto" => 14 "Ancho" => 73 ] ] 17 => array:6 [ "identificador" => "eq0035" "etiqueta" => "(A.3)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "FRT=nπr48μPdPdl" "Fichero" => "STRIPIN_si7.jpeg" "Tamanyo" => 1554 "Alto" => 36 "Ancho" => 108 ] ] 18 => array:6 [ "identificador" => "eq0040" "etiqueta" => "(A.4)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "F=nπr416RTμ(P22−P12)l" "Fichero" => "STRIPIN_si8.jpeg" "Tamanyo" => 1930 "Alto" => 36 "Ancho" => 136 ] ] 19 => array:6 [ "identificador" => "eq0045" "etiqueta" => "(A.5)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "Qm=FRTPm" "Fichero" => "STRIPIN_si9.jpeg" "Tamanyo" => 1010 "Alto" => 33 "Ancho" => 71 ] ] 20 => array:6 [ "identificador" => "eq0050" "etiqueta" => "(A.6)" "tipo" => "MULTIMEDIAFORMULA" "mostrarFloat" => false "mostrarDisplay" => true "Formula" => array:5 [ "Matematica" => "Qm=nπr48μ(P2−P1)l" "Fichero" => "STRIPIN_si10.jpeg" "Tamanyo" => 1714 "Alto" => 36 "Ancho" => 134 ] ] ] "bibliografia" => array:2 [ "titulo" => "References" "seccion" => array:1 [ 0 => array:2 [ "identificador" => "bibs0005" "bibliografiaReferencia" => array:33 [ 0 => array:3 [ "identificador" => "bib0170" "etiqueta" => "[1]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Fouling in membrane bioreactors used in wastewater treatment" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "P. Le-Clech" 1 => "V. Chen" 2 => "T.A.G. Fane" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "2006" "volumen" => "284" "paginaInicial" => "17" "paginaFinal" => "53" ] ] ] ] ] ] 1 => array:3 [ "identificador" => "bib0175" "etiqueta" => "[2]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "The status of membrane bioreactor technology" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "S. Judd" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1016/j.tibtech.2007.11.005" "Revista" => array:6 [ "tituloSerie" => "Trends Biotechnol." "fecha" => "2008" "volumen" => "26" "paginaInicial" => "109" "paginaFinal" => "116" "link" => array:1 [ 0 => array:2 [ "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18191260" "web" => "Medline" ] ] ] ] ] ] ] ] 2 => array:3 [ "identificador" => "bib0180" "etiqueta" => "[3]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Membrane fouling in membrane bioreactors – characterisation, contradictions, cause and cures" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "A. Drews" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "2010" "volumen" => "363" "paginaInicial" => "1" "paginaFinal" => "28" ] ] ] ] ] ] 3 => array:3 [ "identificador" => "bib0185" "etiqueta" => "[4]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Comparison of extruded and pressed low cost ceramic supports for microfiltration membranes" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "M.-M. Lorente-Ayza" 1 => "S. Mestre" 2 => "M. Menéndez" 3 => "E. Sánchez" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Eur. Ceram. Soc." "fecha" => "2015" "volumen" => "35" "paginaInicial" => "3681" "paginaFinal" => "3691" ] ] ] ] ] ] 4 => array:3 [ "identificador" => "bib0190" "etiqueta" => "[5]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Measuring the plasticity of clays: a review" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "F.A. Andrade" 1 => "H.A. Al-Qureshi" 2 => "D. Hotza" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Appl. Clay Sci." "fecha" => "2011" "volumen" => "51" "paginaInicial" => "1" "paginaFinal" => "7" ] ] ] ] ] ] 5 => array:3 [ "identificador" => "bib0195" "etiqueta" => "[6]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Técnicas experimentales del control de la compactación de pavimentos y revestimientos cerámicos" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:5 [ 0 => "J.L. Amorós" 1 => "V. Beltrán" 2 => "A. Blasco" 3 => "C. Feliu" 4 => "M. Sancho-Tello" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Técnica Cerámica" "fecha" => "1983" "volumen" => "116" "paginaInicial" => "1234" "paginaFinal" => "1246" ] ] ] ] ] ] 6 => array:3 [ "identificador" => "bib0200" "etiqueta" => "[7]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Characterisation of polymeric UF membranes by liquid–liquid displacement porosimetry" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:5 [ 0 => "R.I. Peinador" 1 => "J.I. Calvo" 2 => "P. Pradanos" 3 => "L. Palacio" 4 => "A. Hernandez" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "2010" "volumen" => "348" "paginaInicial" => "238" "paginaFinal" => "244" ] ] ] ] ] ] 7 => array:3 [ "identificador" => "bib0205" "etiqueta" => "[8]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Pore size distribution of ceramic UF membranes by liquid–liquid displacement porosimetry" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "J.I. Calvo" 1 => "A. Bottino" 2 => "G. Capannelli" 3 => "A. Hernandez" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "2008" "volumen" => "310" "paginaInicial" => "531" "paginaFinal" => "538" ] ] ] ] ] ] 8 => array:3 [ "identificador" => "bib0210" "etiqueta" => "[9]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Pore size distributions in microporous membranes II. Bulk characterization of track-etched filters by air porometry and mercury porosimetry" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "J.I. Calvo" 1 => "A. Hernandez" 2 => "P. Pradanos" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Colloid Interface Sci." "fecha" => "1995" "volumen" => "478" "paginaInicial" => "467" "paginaFinal" => "478" ] ] ] ] ] ] 9 => array:3 [ "identificador" => "bib0215" "etiqueta" => "[10]" "referencia" => array:1 [ 0 => array:3 [ "comentario" => "<a class="elsevierStyleInterRef" id="intr0005" href="http://ceramicayvidrio.revistas.csic.es/index.php/ceramicayvidrio/article/viewArticle/956">http://ceramicayvidrio.revistas.csic.es/index.php/ceramicayvidrio/article/viewArticle/956</a>" "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Membranas cerámicas y su utilidad en procesos de separación" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "A. Hernandez" 1 => "P. Pradanos" 2 => "J.I. Calvo" 3 => "L. Palacio" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Bol. Soc. Esp. Ceram." "fecha" => "1999" "volumen" => "38" "paginaInicial" => "185" "paginaFinal" => "192" ] ] ] ] ] ] 10 => array:3 [ "identificador" => "bib0220" "etiqueta" => "[11]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Pore size distributions in microporous membranes. A critical analysis of the bubble point extended method" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "A. Hernandez" 1 => "J.I. Calvo" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "1996" "volumen" => "112" "paginaInicial" => "1" "paginaFinal" => "12" ] ] ] ] ] ] 11 => array:3 [ "identificador" => "bib0225" "etiqueta" => "[12]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Ceramic Membranes for Separation and Reaction" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "K. Li" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Libro" => array:3 [ "fecha" => "2007" "editorial" => "John Wiley" "editorialLocalizacion" => "Hoboken, NJ" ] ] ] ] ] ] 12 => array:3 [ "identificador" => "bib0230" "etiqueta" => "[13]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "ASTM F316-03, Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test, ASTM F316-03" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "ASTM International" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Libro" => array:1 [ "fecha" => "2003" ] ] ] ] ] ] 13 => array:3 [ "identificador" => "bib0235" "etiqueta" => "[14]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Hydraulic Fluid Power – Filter Elements – Verification of Fabrication Integrity and Determination of the First Bubble Point (ISO 2942), ISO 2942" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "International Standard" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Libro" => array:1 [ "fecha" => "2004" ] ] ] ] ] ] 14 => array:3 [ "identificador" => "bib0240" "etiqueta" => "[15]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Permeable Sintered Metal Materials: Determination of Bubble Point Test Pore Size (ISO 4003), ISO 4003" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "International Standard" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Libro" => array:1 [ "fecha" => "1977" ] ] ] ] ] ] 15 => array:3 [ "identificador" => "bib0245" "etiqueta" => "[16]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Membranas cerámicas. Tipos, métodos de obtención y caracterización" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "J.M. Benito" 1 => "A. Conesa" 2 => "M.A. Rodríguez" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Bol. Soc. Esp. Ceram." "fecha" => "2004" "volumen" => "43" "paginaInicial" => "829" "paginaFinal" => "842" ] ] ] ] ] ] 16 => array:3 [ "identificador" => "bib0250" "etiqueta" => "[17]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "A modification of the bubble-point method to determine the pore-mouth size distribution of porous materials" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "J. Yu" 1 => "X. Hu" 2 => "Y. Huang" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Sep. Purif. Technol." "fecha" => "2010" "volumen" => "70" "paginaInicial" => "314" "paginaFinal" => "319" ] ] ] ] ] ] 17 => array:3 [ "identificador" => "bib0255" "etiqueta" => "[18]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Ceramic membrane characterization via the bubble point technique" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "E. Jakobs" 1 => "W. Koros" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "1997" "volumen" => "124" "paginaInicial" => "149" "paginaFinal" => "159" ] ] ] ] ] ] 18 => array:3 [ "identificador" => "bib0260" "etiqueta" => "[19]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Neck-size distributions of through-pores in polymer membranes" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:7 [ 0 => "C. Agarwal" 1 => "A.K. Pandey" 2 => "S. Das" 3 => "M.K. Sharma" 4 => "D. Pattyn" 5 => "P. Ares" 6 => "A. Goswami" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "2012" "volumen" => "415–416" "paginaInicial" => "608" "paginaFinal" => "615" ] ] ] ] ] ] 19 => array:3 [ "identificador" => "bib0265" "etiqueta" => "[20]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Gas separation mechanisms in microporous modified γ-Al2O3 membranes" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "K. Keizer" 1 => "R.J.R. Uhlhorn" 2 => "R.J. Van vuren" 3 => "A.J. Burggraaf" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "1988" "volumen" => "39" "paginaInicial" => "285" "paginaFinal" => "300" ] ] ] ] ] ] 20 => array:3 [ "identificador" => "bib0270" "etiqueta" => "[21]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Pore size distribution determination from liquid permeation through microporous membranes" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "K.S. McGuire" 1 => "K.W. Lawson" 2 => "D.R. Lloyd" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "1995" "volumen" => "99" "paginaInicial" => "127" "paginaFinal" => "137" ] ] ] ] ] ] 21 => array:3 [ "identificador" => "bib0275" "etiqueta" => "[22]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Pore Size Distribution and Porosity of Solid Materials by Mercury Porosimetry and Gas Adsorption. Mercury Porosimetry (ISO 15901), ISO 15901" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "International Standard" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Libro" => array:2 [ "fecha" => "2006" "paginaInicial" => "28" ] ] ] ] ] ] 22 => array:3 [ "identificador" => "bib0280" "etiqueta" => "[23]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Permporometry characterization of microporous ceramic membranes" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "T. Tsuru" 1 => "T. Hino" 2 => "T. Yoshioka" 3 => "M. Asaeda" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Membr. Sci." "fecha" => "2001" "volumen" => "186" "paginaInicial" => "257" "paginaFinal" => "265" ] ] ] ] ] ] 23 => array:3 [ "identificador" => "bib0285" "etiqueta" => "[24]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "International tables of the surface tension of water" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "N.B. Vargaftik" 1 => "B.N. Volkov" 2 => "L.D. Voljak" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Phys. Chem. Ref. Data" "fecha" => "1983" "volumen" => "12" "paginaInicial" => "817" "paginaFinal" => "820" ] ] ] ] ] ] 24 => array:3 [ "identificador" => "bib0290" "etiqueta" => "[25]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Basic Principes of Membrane Technology" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:1 [ 0 => "M. Mulder" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Libro" => array:4 [ "edicion" => "2nd ed." "fecha" => "1996" "editorial" => "Kluwer Academic Publishers" "editorialLocalizacion" => "Dordrecht, The Netherlands" ] ] ] ] ] ] 25 => array:3 [ "identificador" => "bib0295" "etiqueta" => "[26]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Effects of starch addition on characteristics of tubular porous ceramic membrane substrates" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "G.C.C. Yang" 1 => "C.-M. Tsai" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Desalination" "fecha" => "2008" "volumen" => "233" "paginaInicial" => "129" "paginaFinal" => "136" ] ] ] ] ] ] 26 => array:3 [ "identificador" => "bib0300" "etiqueta" => "[27]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Processing of porous cordierite bodies by starch consolidation" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "H.M. Alves" 1 => "G. Tarì" 2 => "A.T. Fonseca" 3 => "J.M.F. Ferreira" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Mater. Res. Bull." "fecha" => "1998" "volumen" => "33" "paginaInicial" => "1439" "paginaFinal" => "1448" ] ] ] ] ] ] 27 => array:3 [ "identificador" => "bib0305" "etiqueta" => "[28]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Processing of porous ceramics by starch consolidation" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "O. Lyckfeldt" 1 => "J.M.F. Ferreira" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Eur. Ceram. Soc." "fecha" => "1998" "volumen" => "18" "paginaInicial" => "131" "paginaFinal" => "140" ] ] ] ] ] ] 28 => array:3 [ "identificador" => "bib0310" "etiqueta" => "[29]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Multitechnique investigation of extruded clay brick microstructure" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:3 [ 0 => "K.J. Krakowiak" 1 => "P.B. Lourenço" 2 => "F.J. Ulm" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Am. Ceram. Soc." "fecha" => "2011" "volumen" => "94" "paginaInicial" => "3012" "paginaFinal" => "3022" ] ] ] ] ] ] 29 => array:3 [ "identificador" => "bib0315" "etiqueta" => "[30]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Effects of the anisotropy of extruded earth bricks on their hygrothermal properties" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "P. Maillard" 1 => "J.E. Aubert" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Constr. Build. Mater." "fecha" => "2014" "volumen" => "63" "paginaInicial" => "56" "paginaFinal" => "61" ] ] ] ] ] ] 30 => array:3 [ "identificador" => "bib0320" "etiqueta" => "[31]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Comparative study of bubble point method and mercury intrusion porosimetry techniques for characterizing the pore-size distribution of geotextiles" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:2 [ 0 => "S.K. Bhatia" 1 => "J.L. Smith" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "Geotext. Geomembr." "fecha" => "1994" "volumen" => "13" "paginaInicial" => "679" "paginaFinal" => "702" ] ] ] ] ] ] 31 => array:3 [ "identificador" => "bib0325" "etiqueta" => "[32]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Influence of starch content on the properties of low-cost microfiltration ceramic membranes" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "M.-M. Lorente-Ayza" 1 => "E. Sánchez" 2 => "V. Sanz" 3 => "S. Mestre" ] ] ] ] ] "host" => array:1 [ 0 => array:2 [ "doi" => "10.1016/j.ceramint.2015.07.092" "Revista" => array:2 [ "tituloSerie" => "Ceram. Int." "fecha" => "2015" ] ] ] ] ] ] 32 => array:3 [ "identificador" => "bib0330" "etiqueta" => "[33]" "referencia" => array:1 [ 0 => array:2 [ "contribucion" => array:1 [ 0 => array:2 [ "titulo" => "Role of starch characteristics in the properties of low-cost ceramic membranes" "autores" => array:1 [ 0 => array:2 [ "etal" => false "autores" => array:4 [ 0 => "M.-M. Lorente-Ayza" 1 => "M.J. Orts" 2 => "V. Pérez-Herranz" 3 => "S. Mestre" ] ] ] ] ] "host" => array:1 [ 0 => array:1 [ "Revista" => array:5 [ "tituloSerie" => "J. Eur. Ceram. Soc." "fecha" => "2015" "volumen" => "35" "paginaInicial" => "2333" "paginaFinal" => "2341" ] ] ] ] ] ] ] ] ] ] "agradecimientos" => array:1 [ 0 => array:4 [ "identificador" => "xack268094" "titulo" => "Acknowledgements" "texto" => "This paper includes results of the NITRAMEM (IPT-2012-0069-310000) project, funded with a total amount of 870,455.39 Euros by the Ministry of Economy and Competitiveness and the European Regional Development Fund (ERDF) of the European Union, INNPACTO through the program, which the authors show their gratitude." "vista" => "all" ] ] ] "idiomaDefecto" => "en" "url" => "/03663175/0000005600000001/v1_201702110054/S0366317516300723/v1_201702110054/en/main.assets" "Apartado" => null "PDF" => "https://static.elsevier.es/multimedia/03663175/0000005600000001/v1_201702110054/S0366317516300723/v1_201702110054/en/main.pdf?idApp=UINPBA00004N&text.app=https://www.elsevier.es/" "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S0366317516300723?idApp=UINPBA00004N"]

Statistics

Comparison of porosity assessment techniques for low-cost ceramic membranes

Comparación de técnicas de medida de la porosidad en membranas cerámicas de bajo coste

Maria-Magdalena Lorente-Ayzaa,

Corresponding author

magda.lorente@itc.uji.es

Corresponding author.

, Olga Pérez-Fernándezb, Raquel Alcaláb, Enrique Sáncheza, Sergio Mestrea, Joaquin Coronasc, Miguel Menéndezb

a Instituto Universitario de Tecnología Cerámica (ITC), Universitat Jaume I, Castellón, Spain

b Instituto de Investigación en Ingeniería de Aragón (I3A), Universidad de Zaragoza, Zaragoza, Spain

c Instituto de Nanociencia de Aragón (INA), Universidad de Zaragoza, Zaragoza, Spain

Read

7917

Times
was read the article

1690

Total PDF

6227

Total HTML

Share statistics

 array:24 [
  "pii" => "S0366317516300723"
  "issn" => "03663175"
  "doi" => "10.1016/j.bsecv.2016.09.002"
  "estado" => "S300"
  "fechaPublicacion" => "2017-01-01"
  "aid" => "66"
  "copyright" => "SECV"
  "copyrightAnyo" => "2016"
  "documento" => "article"
  "crossmark" => 1
  "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/"
  "subdocumento" => "fla"
  "cita" => "Bol Soc Esp Ceram Vidr. 2017;56:29-38"
  "abierto" => array:3 [
    "ES" => true
    "ES2" => true
    "LATM" => true
  ]
  "gratuito" => true
  "lecturas" => array:2 [
    "total" => 1835
    "formatos" => array:3 [
      "EPUB" => 78
      "HTML" => 1413
      "PDF" => 344
    ]
  ]
  "itemSiguiente" => array:19 [
    "pii" => "S0366317516300346"
    "issn" => "03663175"
    "doi" => "10.1016/j.bsecv.2016.04.003"
    "estado" => "S300"
    "fechaPublicacion" => "2017-01-01"
    "aid" => "54"
    "copyright" => "SECV"
    "documento" => "article"
    "crossmark" => 1
    "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/"
    "subdocumento" => "fla"
    "cita" => "Bol Soc Esp Ceram Vidr. 2017;56:39-46"
    "abierto" => array:3 [
      "ES" => true
      "ES2" => true
      "LATM" => true
    ]
    "gratuito" => true
    "lecturas" => array:2 [
      "total" => 1600
      "formatos" => array:3 [
        "EPUB" => 62
        "HTML" => 991
        "PDF" => 547
      ]
    ]
    "en" => array:12 [
      "idiomaDefecto" => true
      "titulo" => "Low-temperature synthesis of silicon carbide powder using shungite"
      "tienePdf" => "en"
      "tieneTextoCompleto" => "en"
      "tieneResumen" => array:2 [
        0 => "en"
        1 => "es"
      ]
      "paginas" => array:1 [
        0 => array:2 [
          "paginaInicial" => "39"
          "paginaFinal" => "46"
        ]
      ]
      "titulosAlternativos" => array:1 [
        "es" => array:1 [
          "titulo" => "S&#237;ntesis de baja temperatura de polvo de carburo de silicio utilizando shunguita"
        ]
      ]
      "contieneResumen" => array:2 [
        "en" => true
        "es" => true
      ]
      "contieneTextoCompleto" => array:1 [
        "en" => true
      ]
      "contienePdf" => array:1 [
        "en" => true
      ]
      "resumenGrafico" => array:2 [
        "original" => 0
        "multimedia" => array:7 [
          "identificador" => "fig0025"
          "etiqueta" => "Fig&#46; 5"
          "tipo" => "MULTIMEDIAFIGURA"
          "mostrarFloat" => true
          "mostrarDisplay" => false
          "figura" => array:1 [
            0 => array:4 [
              "imagen" => "gr5.jpeg"
              "Alto" => 4111
              "Ancho" => 3369
              "Tamanyo" => 585672
            ]
          ]
          "descripcion" => array:1 [
            "en" => "<p id="spar0035" class="elsevierStyleSimplePara elsevierViewall">IR spectra of syntheses products of various reaction bed&#58; &#40;a&#41; aggregates&#59; &#40;b&#41; pellets and &#40;c&#41; powder&#46;</p>"
          ]
        ]
      ]
      "autores" => array:1 [
        0 => array:2 [
          "autoresLista" => "Agnieszka Gubernat, Waldemar Pich&#243;r, Rados&#322;aw Lach, Dariusz Zientara, Maciej Sitarz, Maria Springwald"
          "autores" => array:6 [
            0 => array:2 [
              "nombre" => "Agnieszka"
              "apellidos" => "Gubernat"
            ]
            1 => array:2 [
              "nombre" => "Waldemar"
              "apellidos" => "Pich&#243;r"
            ]
            2 => array:2 [
              "nombre" => "Rados&#322;aw"
              "apellidos" => "Lach"
            ]
            3 => array:2 [
              "nombre" => "Dariusz"
              "apellidos" => "Zientara"
            ]
            4 => array:2 [
              "nombre" => "Maciej"
              "apellidos" => "Sitarz"
            ]
            5 => array:2 [
              "nombre" => "Maria"
              "apellidos" => "Springwald"
            ]
          ]
        ]
      ]
    ]
    "idiomaDefecto" => "en"
    "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S0366317516300346?idApp=UINPBA00004N"
    "url" => "/03663175/0000005600000001/v1_201702110054/S0366317516300346/v1_201702110054/en/main.assets"
  ]
  "itemAnterior" => array:19 [
    "pii" => "S0366317516300553"
    "issn" => "03663175"
    "doi" => "10.1016/j.bsecv.2016.07.001"
    "estado" => "S300"
    "fechaPublicacion" => "2017-01-01"
    "aid" => "62"
    "copyright" => "SECV"
    "documento" => "article"
    "crossmark" => 1
    "licencia" => "http://creativecommons.org/licenses/by-nc-nd/4.0/"
    "subdocumento" => "ssu"
    "cita" => "Bol Soc Esp Ceram Vidr. 2017;56:19-28"
    "abierto" => array:3 [
      "ES" => true
      "ES2" => true
      "LATM" => true
    ]
    "gratuito" => true
    "lecturas" => array:2 [
      "total" => 1560
      "formatos" => array:3 [
        "EPUB" => 50
        "HTML" => 1194
        "PDF" => 316
      ]
    ]
    "es" => array:12 [
      "idiomaDefecto" => true
      "titulo" => "Comportamiento ferroel&#233;ctrico de una nanoesfera de titanato de plomo debido a campos de despolarizaci&#243;n y a esfuerzos mec&#225;nicos"
      "tienePdf" => "es"
      "tieneTextoCompleto" => "es"
      "tieneResumen" => array:2 [
        0 => "es"
        1 => "en"
      ]
      "paginas" => array:1 [
        0 => array:2 [
          "paginaInicial" => "19"
          "paginaFinal" => "28"
        ]
      ]
      "titulosAlternativos" => array:1 [
        "en" => array:1 [
          "titulo" => "Ferroelectric behavior of a lead titanate nanosphere due to depolarization fields and mechanical stresses"
        ]
      ]
      "contieneResumen" => array:2 [
        "es" => true
        "en" => true
      ]
      "contieneTextoCompleto" => array:1 [
        "es" => true
      ]
      "contienePdf" => array:1 [
        "es" => true
      ]
      "resumenGrafico" => array:2 [
        "original" => 0
        "multimedia" => array:7 [
          "identificador" => "fig0030"
          "etiqueta" => "Figura 6"
          "tipo" => "MULTIMEDIAFIGURA"
          "mostrarFloat" => true
          "mostrarDisplay" => false
          "figura" => array:1 [
            0 => array:4 [
              "imagen" => "gr6.jpeg"
              "Alto" => 1421
              "Ancho" => 1662
              "Tamanyo" => 98523
            ]
          ]
          "descripcion" => array:1 [
            "es" => "<p id="spar0040" class="elsevierStyleSimplePara elsevierViewall">Polarizaci&#243;n en funci&#243;n del di&#225;metro de la nanopart&#237;cula de PT para T<span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>298&#44;15K y n<span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>3&#46; Las l&#237;neas son las predicciones de este trabajo&#46; Los puntos han sido extra&#237;dos de un modelo para pel&#237;culas delgadas de Junquera et al&#46; <a class="elsevierStyleCrossRef" href="#bib0410">&#91;32&#93;</a>&#46; En las pel&#237;culas D se refiere a su grosor&#46;</p>"
          ]
        ]
      ]
      "autores" => array:1 [
        0 => array:2 [
          "autoresLista" => "Julio Andrade Landeta, Luis Lascano"
          "autores" => array:2 [
            0 => array:2 [
              "nombre" => "Julio"
              "apellidos" => "Andrade Landeta"
            ]
            1 => array:2 [
              "nombre" => "Luis"
              "apellidos" => "Lascano"
            ]
          ]
        ]
      ]
    ]
    "idiomaDefecto" => "es"
    "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S0366317516300553?idApp=UINPBA00004N"
    "url" => "/03663175/0000005600000001/v1_201702110054/S0366317516300553/v1_201702110054/es/main.assets"
  ]
  "en" => array:20 [
    "idiomaDefecto" => true
    "titulo" => "Comparison of porosity assessment techniques for low-cost ceramic membranes"
    "tieneTextoCompleto" => true
    "paginas" => array:1 [
      0 => array:2 [
        "paginaInicial" => "29"
        "paginaFinal" => "38"
      ]
    ]
    "autores" => array:1 [
      0 => array:4 [
        "autoresLista" => "Maria-Magdalena Lorente-Ayza, Olga P&#233;rez-Fern&#225;ndez, Raquel Alcal&#225;, Enrique S&#225;nchez, Sergio Mestre, Joaquin Coronas, Miguel Men&#233;ndez"
        "autores" => array:7 [
          0 => array:4 [
            "nombre" => "Maria-Magdalena"
            "apellidos" => "Lorente-Ayza"
            "email" => array:1 [
              0 => "magda&#46;lorente&#64;itc&#46;uji&#46;es"
            ]
            "referencia" => array:2 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">a</span>"
                "identificador" => "aff0005"
              ]
              1 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">&#42;</span>"
                "identificador" => "cor0005"
              ]
            ]
          ]
          1 => array:3 [
            "nombre" => "Olga"
            "apellidos" => "P&#233;rez-Fern&#225;ndez"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">b</span>"
                "identificador" => "aff0010"
              ]
            ]
          ]
          2 => array:3 [
            "nombre" => "Raquel"
            "apellidos" => "Alcal&#225;"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">b</span>"
                "identificador" => "aff0010"
              ]
            ]
          ]
          3 => array:3 [
            "nombre" => "Enrique"
            "apellidos" => "S&#225;nchez"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">a</span>"
                "identificador" => "aff0005"
              ]
            ]
          ]
          4 => array:3 [
            "nombre" => "Sergio"
            "apellidos" => "Mestre"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">a</span>"
                "identificador" => "aff0005"
              ]
            ]
          ]
          5 => array:3 [
            "nombre" => "Joaquin"
            "apellidos" => "Coronas"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">c</span>"
                "identificador" => "aff0015"
              ]
            ]
          ]
          6 => array:3 [
            "nombre" => "Miguel"
            "apellidos" => "Men&#233;ndez"
            "referencia" => array:1 [
              0 => array:2 [
                "etiqueta" => "<span class="elsevierStyleSup">b</span>"
                "identificador" => "aff0010"
              ]
            ]
          ]
        ]
        "afiliaciones" => array:3 [
          0 => array:3 [
            "entidad" => "Instituto Universitario de Tecnolog&#237;a Cer&#225;mica &#40;ITC&#41;&#44; Universitat Jaume I&#44; Castell&#243;n&#44; Spain"
            "etiqueta" => "a"
            "identificador" => "aff0005"
          ]
          1 => array:3 [
            "entidad" => "Instituto de Investigaci&#243;n en Ingenier&#237;a de Arag&#243;n &#40;I3A&#41;&#44; Universidad de Zaragoza&#44; Zaragoza&#44; Spain"
            "etiqueta" => "b"
            "identificador" => "aff0010"
          ]
          2 => array:3 [
            "entidad" => "Instituto de Nanociencia de Arag&#243;n &#40;INA&#41;&#44; Universidad de Zaragoza&#44; Zaragoza&#44; Spain"
            "etiqueta" => "c"
            "identificador" => "aff0015"
          ]
        ]
        "correspondencia" => array:1 [
          0 => array:3 [
            "identificador" => "cor0005"
            "etiqueta" => "&#8270;"
            "correspondencia" => "<span class="elsevierStyleItalic">Corresponding author</span>&#46;"
          ]
        ]
      ]
    ]
    "titulosAlternativos" => array:1 [
      "es" => array:1 [
        "titulo" => "Comparaci&#243;n de t&#233;cnicas de medida de la porosidad en membranas cer&#225;micas de bajo coste"
      ]
    ]
    "resumenGrafico" => array:2 [
      "original" => 0
      "multimedia" => array:7 [
        "identificador" => "fig0020"
        "etiqueta" => "Fig&#46; 4"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr4.jpeg"
            "Alto" => 754
            "Ancho" => 1750
            "Tamanyo" => 223443
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0030" class="elsevierStyleSimplePara elsevierViewall">FEG-ESEM micrographs of pressed and extruded membranes with high clay content &#40;magnification&#58; 1500&#215;&#41;&#46; Pores present a dark color in the micrographs&#46;</p>"
        ]
      ]
    ]
    "textoCompleto" => "<span class="elsevierStyleSections"><span id="sec0005" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0025">Introduction</span><p id="par0005" class="elsevierStylePara elsevierViewall">Membrane bioreactors &#40;MBR&#41; combine a biological degradation process with the direct separation of activated sludge and liquid-solid by filtration membranes <a class="elsevierStyleCrossRef" href="#bib0170">&#91;1&#93;</a>&#46; In addition&#44; MBRs have important advantages such as space reduction relative to conventional activated sludge process&#44; which leads to a decrease in their environmental impact&#44; the capability of operating with higher concentrations of suspended solids&#44; and the production of better quality effluent&#46; However&#44; one of the main drawbacks of MBR is membrane fouling&#46; Despite the high cost of commonly used ceramic membranes &#40;made of alumina&#44; zirconia or titania&#41;&#44; it is known that they are more hydrophilic than polymeric membranes&#44; which means that ceramic membranes have a lower membrane fouling rate&#46; Ceramic membranes are also more chemically&#44; mechanically and thermally resistant&#46; Other characteristics that influence membrane fouling are pore size and configuration &#40;tubular&#44; flat or hollow fiber&#41; <a class="elsevierStyleCrossRefs" href="#bib0175">&#91;2&#44;3&#93;</a>&#46; Currently&#44; polymeric hollow fiber membranes are the most widely used in the industry because the manufacturing cost of ceramic membranes based on high purity oxides is higher than that of their polymeric counterparts&#46; However&#44; hollow fiber membranes are more likely to develop higher fouling rates and consequently give rise to higher maintenance costs <a class="elsevierStyleCrossRef" href="#bib0170">&#91;1&#93;</a>&#46; As an alternative&#44; low cost ceramic membranes whose composition is mainly based on clays and organic pore formers are cheaper&#44; similar to the cost of polymeric membranes&#46; The preparation of low cost ceramic membranes was described in a previous paper <a class="elsevierStyleCrossRef" href="#bib0185">&#91;4&#93;</a>&#46;</p><p id="par0010" class="elsevierStylePara elsevierViewall">This work attempts to characterize two key parameters of low cost ceramic membranes&#58; mean pore diameter and permeability&#46; Several techniques can be used to measure the pore size distribution and average pore size &#40;<span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span>&#41; of a membrane&#58; nitrogen adsorption&#44; intrusion mercury porosimetry&#44; permporometry&#44; the bubble point method&#44; solute resistance tests and electronic microscopy &#40;SEM&#44; TEM&#41;&#46; In this work&#44; we will compare the results obtained by intrusion mercury porosimetry and the bubble point method&#46; Both are simple and rapid techniques which have been widely used to evaluate the pore size of ceramic materials&#46; They are standardized&#44; repeatable and reproducible test methods&#46;</p><p id="par0015" class="elsevierStylePara elsevierViewall">The goal of this study is to draw a comparison between the average pore size results obtained using bubble point and intrusion mercury porosimetry characterization techniques applied to a set of low cost symmetrical ceramic membranes&#46; As mercury manipulation has been restricted&#44; this comparison could open up an alternative to intrusion mercury porosimetry&#46; This work also addresses the relationship between the water and air permeabilities of the membranes&#46;</p></span><span id="sec0010" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0030">Experimental method</span><span id="sec0015" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0035">Membrane preparation</span><p id="par0020" class="elsevierStylePara elsevierViewall">Low cost ceramic membranes were prepared from raw materials normally used in the ceramic tile sector &#40;clays&#44; chamotte&#44; feldspar and calcium carbonate&#41; and organic pore formers &#40;different starches provided by Roquette Laisa Espa&#241;a&#44; S&#46;A&#46;&#41;&#46; The components were mixed in suitable proportions so that they could be easily processed by uniaxial dry pressing or extrusion&#46; To obtain membranes with a broad range of porosity and pore sizes&#44; the forming methods were combined with the addition of different proportions of starch to some compositions&#46; <a class="elsevierStyleCrossRef" href="#tbl0005">Table 1</a> shows the compositional range used to obtain the ceramic membranes&#44; where the proportion of clay&#44; chamotte&#44; feldspar&#44; calcite and starch have been modified&#46; Four different groups of membranes were prepared in this way&#44; referred to as P&#44; PS&#44; E and ES &#40;<a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>&#41;&#46;</p><elsevierMultimedia ident="tbl0005"></elsevierMultimedia><elsevierMultimedia ident="tbl0010"></elsevierMultimedia><p id="par0025" class="elsevierStylePara elsevierViewall">The process for producing the pressed membranes started with dry homogenization &#40;manually and by means of an automatic mixer&#41; of the different raw materials&#46; The resulting compositions were moistened to 5&#46;5<span class="elsevierStyleHsp" style=""></span>kg H<span class="elsevierStyleInf">2</span>O&#47;100<span class="elsevierStyleHsp" style=""></span>kg dry solid&#46; Cylindrical test specimens&#44; 0&#46;7<span class="elsevierStyleHsp" style=""></span>cm thick and 5<span class="elsevierStyleHsp" style=""></span>cm in diameter&#44; were formed from this powder by uniaxial dry pressing using an automatic laboratory press &#40;Nannetti SpA&#44; Italy&#41;&#46; The test samples were oven-dried at 110<span class="elsevierStyleHsp" style=""></span>&#176;C to a constant weight&#46;</p><p id="par0030" class="elsevierStylePara elsevierViewall">Each batch of raw materials for the extruded membranes was kneaded to a consistency of 5<span class="elsevierStyleHsp" style=""></span>kg&#44; determined by penetrometry &#40;using a cylinder with 1&#46;5<span class="elsevierStyleHsp" style=""></span>cm diameter&#41; &#40;Analogic penetrometer Geotester 0-6<span class="elsevierStyleHsp" style=""></span>kg&#44; Novatest S&#46;r&#46;l&#46;&#44; Italy&#41; <a class="elsevierStyleCrossRef" href="#bib0190">&#91;5&#93;</a>&#44; and allowed to stand for 24<span class="elsevierStyleHsp" style=""></span>h to achieve uniform moisture in the mass&#46; The water content of the compositions varies between 20 and 32<span class="elsevierStyleHsp" style=""></span>wt&#37;&#46; Test pieces 1<span class="elsevierStyleHsp" style=""></span>cm thick and 5<span class="elsevierStyleHsp" style=""></span>cm in diameter were shaped from an extruded sheet&#44; using a laboratory auger with a de-airing chamber &#40;Model 050 C&#44; Talleres Felipe Verd&#233;s&#44; S&#46;A&#46;&#44; Spain&#41;&#46; The test samples were weighed and afterwards dried at room temperature for 24<span class="elsevierStyleHsp" style=""></span>h&#44; and oven-dried at 110<span class="elsevierStyleHsp" style=""></span>&#176;C to a constant weight&#46;</p><p id="par0035" class="elsevierStylePara elsevierViewall">After drying&#44; all the samples were weighed and the bulk density was measured by the mercury immersion method <a class="elsevierStyleCrossRef" href="#bib0195">&#91;6&#93;</a>&#46; Next&#44; the membranes were sintered with different thermal cycles&#44; depending on their composition and the final properties required &#40;sintering temperatures ranged from 1060 to 1160<span class="elsevierStyleHsp" style=""></span>&#176;C and dwelling time from 6 to 120<span class="elsevierStyleHsp" style=""></span>min&#41;&#46; After sintering&#44; the membrane properties were determined&#46; These properties included density&#44; thickness&#44; microstructure &#40;observed by Scanning Electron Microscopy&#44; FEG-ESEM Quanta 200 F&#44; FEI&#44; USA&#41;&#44; and air and water permeability&#46; Moreover&#44; the average pore diameter and pore size distribution were determined by two techniques&#58; intrusion mercury porosimetry and the bubble point method&#46;</p><p id="par0040" class="elsevierStylePara elsevierViewall">The present study was carried out with a large number of membranes with different pore sizes&#58; 15 different compositions &#40;classified in four series&#44; as shown in <a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a>&#41; and 36 samples were tested to compare average pore size values obtained by both methods&#46; In order to compare the permeability for air and water&#44; 9 different compositions and 36 tests were carried out&#46;</p></span><span id="sec0020" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0040">Characterization&#58; bubble point and intrusion mercury porosimetry</span><p id="par0045" class="elsevierStylePara elsevierViewall">The bubble point method allows the determination of membrane air permeability and&#44; unlike the most common techniques used in the study of porous solids &#40;nitrogen adsorption and intrusion mercury porosimetry&#41;&#44; provides information about the pores that control the permeation <a class="elsevierStyleCrossRefs" href="#bib0200">&#91;7&#8211;12&#93;</a>&#46; This method is used to measure pores with size above 50<span class="elsevierStyleHsp" style=""></span>nm and it is standardized by ASTM F316-03 <a class="elsevierStyleCrossRef" href="#bib0230">&#91;13&#93;</a>&#44; ISO 2942 <a class="elsevierStyleCrossRef" href="#bib0235">&#91;14&#93;</a> and ISO 4003 <a class="elsevierStyleCrossRef" href="#bib0240">&#91;15&#93;</a>&#46; It consists of filling the porous structure of the membrane with a liquid and measuring the air pressure necessary to displace the liquid inside the pores&#46; The minimum pressure necessary to blow the first observed air bubble corresponds to the largest pore size of the membrane&#59; this value is known as the bubble point <a class="elsevierStyleCrossRefs" href="#bib0240">&#91;15&#8211;18&#93;</a>&#46; The mathematical relationship between pressure and pore size is given by Washburn equation&#58;<elsevierMultimedia ident="eq0005"></elsevierMultimedia>where &#916;<span class="elsevierStyleItalic">P</span> is the pressure drop &#40;bar&#41;&#44; <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">p</span> is the pore size &#40;&#956;m&#41;&#44; <span class="elsevierStyleItalic">&#966;</span> is the contact angle between the fluid and pore walls and <span class="elsevierStyleItalic">&#947;</span> is the liquid surface stress&#46; In order to be able to use the Washburn equation&#44; the pores are assumed to be cylindrical&#46;</p><p id="par0050" class="elsevierStylePara elsevierViewall">During the bubble point test&#44; liquid intrusion will first occur through the largest pores&#46; If the pores were cylindrical&#44; the flow &#40;m<span class="elsevierStyleSup">3</span><span class="elsevierStyleHsp" style=""></span>s<span class="elsevierStyleSup">&#8722;1</span>&#41; through the membrane&#44; considered as laminar&#44; would be given by Hagen&#8211;Poiseuille equation <a class="elsevierStyleCrossRefs" href="#bib0215">&#91;10&#44;17&#44;19&#93;</a>&#58;<elsevierMultimedia ident="eq0010"></elsevierMultimedia>where <span class="elsevierStyleItalic">Q</span><span class="elsevierStyleInf">v</span> is the volumetric flow through the membrane&#44; &#916;<span class="elsevierStyleItalic">P</span> is the transmembrane pressure&#44; <span class="elsevierStyleItalic">n</span> is the number of pores&#44; <span class="elsevierStyleItalic">r</span> is the pore size&#44; <span class="elsevierStyleItalic">&#956;</span> is the liquid viscosity and <span class="elsevierStyleItalic">l</span> is the pore length&#46; If the above equation is employed for a gas&#44; the volumetric flow rate should be expressed at the mean pressure&#44; i&#46;e&#46; <span class="elsevierStyleItalic">Q</span><span class="elsevierStyleInf">v</span> should be calculated as the volumetric flow measured at <span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">m</span>&#44; where <span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">m</span> is the mean pressure at both sides of the membrane&#46; This is slightly different from the usual way of calculating the gas permeation through porous membranes &#40;e&#46;g&#46; <a class="elsevierStyleCrossRef" href="#bib0265">&#91;20&#93;</a>&#41;&#46; In laminar flow conditions&#44; the molar flow rate is proportional to &#40;<span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">1</span><span class="elsevierStyleSup">2</span><span class="elsevierStyleHsp" style=""></span>&#8722;<span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">2</span><span class="elsevierStyleSup">2</span>&#41;&#44; where <span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">1</span> is the pressure in the retentate and <span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">2</span> is the pressure in the permeate&#46; However&#44; if the volumetric flow measured at the mean pressure &#40;<span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">1</span><span class="elsevierStyleHsp" style=""></span>&#43;<span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">2</span>&#41;&#47;2 is employed&#44; it may easily be found that this volumetric flow rate is given by Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0010">&#40;2&#41;</a>&#44; where &#916;<span class="elsevierStyleItalic">P</span> is &#40;<span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">1</span><span class="elsevierStyleHsp" style=""></span>&#8722;<span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">2</span>&#41; &#40;see Appendix&#41;&#46; This formulation of the gas permeation allows the same equation <a class="elsevierStyleCrossRef" href="#eq0010">&#40;2&#41;</a> to be used for liquids and gases&#46;</p><p id="par0055" class="elsevierStylePara elsevierViewall">The average pore size &#40;<span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span>&#41; is calculated using Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0005">&#40;1&#41;</a> from the pressure at the intersection point of the line that represents 50&#37; of the air flow &#40;mL<span class="elsevierStyleHsp" style=""></span>min<span class="elsevierStyleSup">&#8722;1</span>&#41; through the dry membrane versus the applied pressure with the equivalent curve for the wet membrane &#40;<a class="elsevierStyleCrossRef" href="#fig0005">Fig&#46; 1</a>&#41;&#46; The pore sizes corresponding to 16&#37; and 84&#37; of the dry flow &#40;named <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span> and <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">84</span>&#41; are calculated in the same manner&#44; giving an insight into the standard deviation of the pore size distribution&#46;</p><elsevierMultimedia ident="fig0005"></elsevierMultimedia><p id="par0060" class="elsevierStylePara elsevierViewall">Intrusion mercury porosimetry is also based on the Washburn equation&#44; but in this technique mercury is the liquid used to fill the pores&#46; By this method the mercury intrusion volume is recorded as a function of pressure or pore size <a class="elsevierStyleCrossRefs" href="#bib0205">&#91;8&#44;21&#93;</a>&#46; This technique is normalized within DIN 66133 and ISO 15901 <a class="elsevierStyleCrossRef" href="#bib0275">&#91;22&#93;</a>&#44; but restrictions on the use of mercury may lead to its disappearance in the near future&#46; Finally&#44; the total volume of pores &#40;<span class="elsevierStyleItalic">V</span><span class="elsevierStyleInf">f</span>&#41; and characteristic pore diameters &#40;<span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span>&#44; <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span> and <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">84</span>&#41; are calculated from experimental data&#46;</p><p id="par0065" class="elsevierStylePara elsevierViewall">The main difference between both methods is that the bubble point&#44; besides being a non-destructive technique&#44; measures the air flow through the pores&#44; while intrusion mercury porosimetry records the intrusion volume of mercury coming into the membrane pores&#46; Intrusion mercury porosimetry works with higher pressure&#44; which is considered a limitation because it can lead to sample deformation in the case of polymeric membranes <a class="elsevierStyleCrossRef" href="#bib0210">&#91;9&#93;</a>&#46; Another limitation in the case of asymmetric membranes is the inability of this method to distinguish between the pores which determine the flux &#40;usually in the selective layer&#41; and the larger pores in the support <a class="elsevierStyleCrossRef" href="#bib0280">&#91;23&#93;</a>&#46; In addition&#44; intrusion mercury porosimetry also measures pores that do not participate in the permeation &#40;non-connected pores&#41;&#46;</p><span id="sec0025" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0045">Bubble point</span><p id="par0070" class="elsevierStylePara elsevierViewall">In order to measure the pore size of the membranes by the bubble point method&#44; two sets of air flow measurements were carried out&#46; The first was performed with the dry membrane&#44; measuring the air flow through the membrane while the transmembrane pressure &#40;TMP&#41; was gradually increased&#46; A second set of measurements was performed with the same procedure&#44; but the porous network of the membrane was previously filled with water &#40;surface tension at the water&#47;air interface&#44; <span class="elsevierStyleItalic">&#947;</span>&#44; is 72&#46;75<span class="elsevierStyleHsp" style=""></span>mN&#47;m at 20<span class="elsevierStyleHsp" style=""></span>&#176;C <a class="elsevierStyleCrossRef" href="#bib0285">&#91;24&#93;</a>&#41;&#59; this method is based on the fact that an air bubble will penetrate through the pore when its radius is equal to that of the pore&#44; meaning that the contact angle is 0&#176; &#40;and cos<span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">&#966;</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>1&#41; <a class="elsevierStyleCrossRef" href="#bib0290">&#91;25&#93;</a>&#46; For this procedure&#44; a steel module suitable for disk ceramic membranes with a diameter of 5<span class="elsevierStyleHsp" style=""></span>cm was made and a set-up was designed as shown in <a class="elsevierStyleCrossRef" href="#fig0010">Fig&#46; 2</a>&#46; The sealing between the membrane and the module was made with Viton o-rings&#46;</p><elsevierMultimedia ident="fig0010"></elsevierMultimedia></span><span id="sec0030" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0050">Intrusion mercury porosimetry</span><p id="par0075" class="elsevierStylePara elsevierViewall">The pore size distribution for each membrane was also obtained by intrusion mercury porosimetry &#40;Autopore IV 9500&#44; Micromeritics Inc&#46; USA&#41;&#46; This technique is based on the measurement of the intrusion volume of a non-wetting liquid in order to calculate data related with the pore structure of the sample&#46; Thus&#44; the equipment continuously registers the variation of the intrusion volume of the mercury inside the sample depending on the pressure applied over the sample&#46; Next&#44; it calculates the pore diameter with the intrusion pressure&#44; by means of the Washburn equation &#40;surface tension at the mercury&#47;air interface&#44; <span class="elsevierStyleItalic">&#947;</span>&#44; is 487<span class="elsevierStyleHsp" style=""></span>mN&#47;m at 20<span class="elsevierStyleHsp" style=""></span>&#176;C and contact angle&#44; <span class="elsevierStyleItalic">&#966;</span>&#44; is 135&#176;&#41;&#44; obtaining a graphic of cumulative pore volume versus pore size&#46; Finally&#44; the characteristic pore diameters &#40;<span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span>&#44; <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span> and <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">84</span>&#41; are calculated from experimental data&#46;</p></span></span><span id="sec0035" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0055">Permeability&#58; air and water</span><p id="par0080" class="elsevierStylePara elsevierViewall">Air and water permeabilities were calculated by measuring the fluid flow &#40;mL<span class="elsevierStyleHsp" style=""></span>min<span class="elsevierStyleSup">&#8722;1</span>&#41; through the membrane at room temperature while the applied pressure was gradually increased&#46; The permeation was determined from the slope of the straight line obtained from the graphical plot of the air&#47;water flux against applied pressure&#44; per membrane area unit &#40;m<span class="elsevierStyleSup">3</span><span class="elsevierStyleHsp" style=""></span>h<span class="elsevierStyleSup">&#8722;1</span><span class="elsevierStyleHsp" style=""></span>m<span class="elsevierStyleSup">&#8722;2</span><span class="elsevierStyleHsp" style=""></span>bar<span class="elsevierStyleSup">&#8722;1</span>&#41;&#46; Air permeability was measured in the same module as described for the bubble point measurements&#44; while water permeability was determined by means of two different pieces of equipment&#58; an automatic liquid permeameter &#40;LEP-1101-A&#44; PMI&#44; Ithaca&#44; NY&#44; USA&#41; for membranes with higher permeability and a manual liquid permeameter for membranes with lower permeability&#46;</p></span></span><span id="sec0040" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0060">Results and discussion</span><span id="sec0045" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0065">Membrane structure &#40;SEM&#41;</span><p id="par0085" class="elsevierStylePara elsevierViewall">Micrographs of polished sections of examples of the four types of membranes described in <a class="elsevierStyleCrossRef" href="#tbl0010">Table 2</a> are shown in <a class="elsevierStyleCrossRef" href="#fig0015">Fig&#46; 3</a>&#46; It can be seen that a continuous porous structure was created&#44; the pores being larger when starch was employed as the pore generator in the preparation of the membrane &#40;membranes PS and ES&#44; compared with those without starch addition&#44; P and S&#41;&#46; The addition of starch increases porosity and pore size as well as pore connectivity&#44; owed to the increase in the amount of interconnected pores created by starch burnout&#44; which should result in an increase in permeability&#46; This effect has been reported previously in the literature&#46; Starch additions greater than 10<span class="elsevierStyleHsp" style=""></span>wt&#37; have been shown to increase the amount of interconnected pores created by starch burnout during the sintering step <a class="elsevierStyleCrossRefs" href="#bib0185">&#91;4&#44;26&#8211;28&#93;</a>&#46;</p><elsevierMultimedia ident="fig0015"></elsevierMultimedia><p id="par0090" class="elsevierStylePara elsevierViewall">Samples obtained by extrusion &#40;E and ES&#41; have a lower pore size than the pressed samples owing to the different shaping processes &#40;see <a class="elsevierStyleCrossRef" href="#fig0015">Fig&#46; 3</a>&#41;&#46; <a class="elsevierStyleCrossRef" href="#fig0020">Fig&#46; 4</a> shows the microstructures of two membranes of the same composition &#40;high clay content and no starch&#41;&#44; which have been obtained by extrusion and pressing&#46; As can be seen&#44; they differ mainly in the oriented and scarcely connected pore structure which is typical from the extruded materials&#46; Pores from the pressed membrane are rounder and highly connected&#44; whereas pores from the extruded membrane show a long shape and reduced connection&#46; This characteristic microstructure is more evident in the surface of the membranes&#44; where the oriented clay particles create a superficial layer that closes many pores near the surface&#46; This effect have already been observed by several authors <a class="elsevierStyleCrossRefs" href="#bib0185">&#91;4&#44;29&#44;30&#93;</a>&#44; who have reported that clay products manufactured by extrusion have a microstructure characterized by an orientated pore distribution&#46; This is a consequence of the movement of the colloidal clay particles traveling through the auger extruder during the shaping step&#46; Moreover&#44; these pores have a reduced connectivity&#46; In short&#44; both the shaping method and the starch addition have a great influence on the microstructure of the support&#44; modifying the pore size&#44; porosity and pore connectivity and&#44; consequently&#44; the permeability&#44; as it will be explained in Section &#8220;Air&#8211;water permeability&#8221;&#46;</p><elsevierMultimedia ident="fig0020"></elsevierMultimedia></span><span id="sec0050" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0070">Bubble point and intrusion mercury porosimetry</span><p id="par0095" class="elsevierStylePara elsevierViewall">A graphical representation of the mean pore size obtained from the bubble point and intrusion mercury porosimetry characterization shows an approximate linear relationship between both methods with a coefficient <span class="elsevierStyleItalic">R</span><span class="elsevierStyleSup">2</span> of 0&#46;93 &#40;<a class="elsevierStyleCrossRef" href="#fig0025">Fig&#46; 5</a>&#41; and a slope close to 1 &#40;0&#46;84&#41;&#46; This suggests that both methods provide mean pore diameters of the same order in spite of the differences in the experimental approach&#46; Small differences between the mean pore size measured by both methods are expected since in the bubble point method the mean pore diameter corresponds to a flow of a value of half as great as that in the absence of water &#40;as it has been explained in <a class="elsevierStyleCrossRef" href="#fig0005">Fig&#46; 1</a>&#41;&#44; while in intrusion mercury porosimetry the mean pore diameter corresponds to the cut off pore size under which 50&#37; of the total pore volume lies&#46; In addition&#44; since the real pores are not cylindrical&#44; parallel and equal&#44; the differences in both methods would affect the calculation of the mean value in different ways&#46; The bubble point method measures pores that affect the liquid flow&#44; which are pores that are connected to the surface and between them&#44; but closed pores are not measured&#46; On the other hand&#44; intrusion mercury porosimetry technique measures all pores that mercury can reach with pressure&#44; both open and non-connected pores&#46; Moreover&#44; because of the high pressures used&#44; intrusion mercury porosimetry technique is able to reach smaller pores&#44; which are no measurable for the bubble point method&#46; Deviation between both methods have also been found by other authors&#44; but the nature of the measured material affects to this deviation&#58; Bhatia et al&#46; <a class="elsevierStyleCrossRef" href="#bib0320">&#91;31&#93;</a> found that the mercury pore-size distributed results showed much larger pores in the geotextiles than did the bubble point method&#44; whereas Calvo et al&#46; <a class="elsevierStyleCrossRef" href="#bib0210">&#91;9&#93;</a> observed that mean pore diameters were lower for the intrusion mercury porosimetry curves when polycarbonate filters were analyzed&#46;</p><elsevierMultimedia ident="fig0025"></elsevierMultimedia><p id="par0100" class="elsevierStylePara elsevierViewall">The good agreement&#44; in spite of the differences between both methods&#44; can be considered as confirmation of the validity of the bubble point method&#59; which allows the replacement of intrusion mercury porosimetry technique by bubble point method to reduce the mercury use in characterization laboratories&#46;</p><p id="par0105" class="elsevierStylePara elsevierViewall">Finally&#44; it is worth noting that the extruded samples show results closer to the linear relationship than the pressed samples&#46; This could be due to the different microstructure that both shaping methods give to the supports&#44; as described in Section &#8220;Membrane structure&#8221;&#46; Supports obtained by means of the addition of starch in their composition also show a higher deviation from the linear relationship&#44; probably owing to the fact that the big pores generated by the starch provide higher variability&#44; being higher the error associated to the measurement&#46; As it has been stated before&#44; intrusion mercury porosimety provide the same status to all pores&#59; on the other hand&#44; bubble point method measures the effective diameter&#44; which is affected by the pore size&#44; since it influences the necessary energy to empty the pores&#46; This has also been reported by Calvo et al&#46; <a class="elsevierStyleCrossRef" href="#bib0210">&#91;9&#93;</a>&#44; who observed a better accordance for both characterizations &#40;pore size distributions obtained by intrusion mercury posimetry and bubble point method&#41; when pore size decreased&#46;</p><p id="par0110" class="elsevierStylePara elsevierViewall">The comparison between characteristic diameters &#40;<span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span> and <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">84</span>&#41; calculated by bubble point method and intrusion mercury porosimetry shows the same tend that <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span>&#44; so it has not been plotted in the present paper&#46; A good agreement was achieved between the values obtained by these two different methods&#44; which again is confirmation of the validity of the bubble point method&#46; It is clear that the agreement was achieved because these membranes are symmetric&#46; In the case of asymmetric membranes&#44; the measurement of pore size distribution by intrusion mercury porosimetry would not reflect the size of the pores controlling the flow&#46; In addition&#44; the <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">84</span> pores generate the worst correlation &#40;<span class="elsevierStyleItalic">R</span><span class="elsevierStyleSup">2</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>0&#46;919&#41;&#46; This could be explained by the fact that mercury intrusion can measure very small and non-connected pores that take no part in the permeation&#44; as it has been described previously&#46;</p></span><span id="sec0055" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0075">Air&#8211;water permeability</span><p id="par0115" class="elsevierStylePara elsevierViewall">According to Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0010">&#40;2&#41;</a>&#44; a plot of the air flow &#40;using the volume measured at the mean pressure&#41; versus the transmembrane pressure &#40;&#916;<span class="elsevierStyleItalic">P</span>&#41; should show a straight line &#40;<a class="elsevierStyleCrossRef" href="#fig0030">Fig&#46; 6</a>a&#41;&#46; The slopes of these lines allow the permeation of each membrane to air to be calculated&#46; On the other hand&#44; water permeability is calculated by means of the slope of the straight line that appears when the water flow is represented versus &#916;<span class="elsevierStyleItalic">P</span> &#40;<a class="elsevierStyleCrossRef" href="#fig0030">Fig&#46; 6</a>b&#41;&#46; As <a class="elsevierStyleCrossRef" href="#fig0030">Fig&#46; 6</a>a and b shows&#44; pressed membranes show higher slopes &#40;and permeabilities&#41; than the extruded membranes&#46; The permeability of the membranes obtained by uniaxial pressing is higher than those obtained by extrusion&#44; confirming the results on microstructural features set out in Section &#8220;Membrane structure&#8221;&#58; extruded membranes have smaller and less connected pores than pressed ones&#44; which provokes a reduction in water and air permeability&#44; effect that have been reported by the authors in previous works about low-cost ceramic membranes <a class="elsevierStyleCrossRef" href="#bib0185">&#91;4&#93;</a>&#46;</p><elsevierMultimedia ident="fig0030"></elsevierMultimedia><p id="par0120" class="elsevierStylePara elsevierViewall">The addition of starch to the initial composition greatly improves the permeability&#44; because compositions with starch have higher slopes than those without starch&#44; as can be seen in <a class="elsevierStyleCrossRef" href="#fig0030">Fig&#46; 6</a>a and b&#46; The results are consistent with the microstructure observed in Section &#8220;Membrane structure&#8221;&#44; where it has been stated that the addition of starch to the membrane&#39;s composition increase the pore size and the connectivity of the pores&#44; owed to the porosity created when starch is burnt out during the sintering step&#44; increasing the membrane&#39;s permeability &#40;air and water&#41;&#46; This is especially effective for starch percentages higher than 10<span class="elsevierStyleHsp" style=""></span>wt&#37;&#44; since a connected coarse pore network is developed&#44; as has been detailed in previous works <a class="elsevierStyleCrossRef" href="#bib0325">&#91;32&#93;</a>&#46;</p><p id="par0125" class="elsevierStylePara elsevierViewall">A graphical representation of air and water permeability obtained from the experimental values shows a linear relationship between both measurements with a coefficient <span class="elsevierStyleItalic">R</span><span class="elsevierStyleSup">2</span> of 0&#46;96 &#40;<a class="elsevierStyleCrossRef" href="#fig0035">Fig&#46; 7</a>&#41;&#46; As has been pointed out previously&#44; samples with higher permeability &#40;membranes PS&#44; shaped by pressing and with starch addition&#41; do not follow the general trend as well as the rest of the samples&#46; This is expected&#44; since these samples exhibit permeability values that are twice or three times higher than those of the rest of samples&#46; Moreover&#44; mean pore size of PS samples follow the same pattern&#44; since they do not fit to the general trend as well as the other compositions&#46; Similar conclusions have been found in previous researches carried out by the same authors <a class="elsevierStyleCrossRef" href="#bib0185">&#91;4&#93;</a>&#46;</p><elsevierMultimedia ident="fig0035"></elsevierMultimedia><p id="par0130" class="elsevierStylePara elsevierViewall">The slope of the straight line in <a class="elsevierStyleCrossRef" href="#fig0035">Fig&#46; 7</a> &#40;value 63&#41; confirms the relationship between both measurements&#46; The relationship between air and water permeabilities is close to the theoretical value of 56 calculated for the ratio of air and water permeation from the Hagen&#8211;Poiseuille equation&#44; using the viscosities of air &#40;1&#46;837<span class="elsevierStyleHsp" style=""></span>&#215;<span class="elsevierStyleHsp" style=""></span>10<span class="elsevierStyleSup">&#8722;5</span><span class="elsevierStyleHsp" style=""></span>N<span class="elsevierStyleHsp" style=""></span>s<span class="elsevierStyleHsp" style=""></span>m<span class="elsevierStyleSup">&#8722;2</span>&#41; and water &#40;1&#46;002<span class="elsevierStyleHsp" style=""></span>&#215;<span class="elsevierStyleHsp" style=""></span>10<span class="elsevierStyleSup">&#8722;3</span><span class="elsevierStyleHsp" style=""></span>N<span class="elsevierStyleHsp" style=""></span>s<span class="elsevierStyleHsp" style=""></span>m<span class="elsevierStyleSup">&#8722;2</span>&#41; at 20<span class="elsevierStyleHsp" style=""></span>&#176;C &#40;Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0015">&#40;3&#41;</a>&#41;&#58;<elsevierMultimedia ident="eq0015"></elsevierMultimedia>where <span class="elsevierStyleItalic">f</span> is the ratio of air and water permeation&#44; <span class="elsevierStyleItalic">J</span> is the flux and <span class="elsevierStyleItalic">&#956;</span> is the viscosity of every fluid &#40;air or water&#41;&#46;</p><p id="par0135" class="elsevierStylePara elsevierViewall">This good agreement between the ratio of permeabilities for air and water with the ratio of viscosities suggests that it could be possible to estimate the permeability for a fluid from the permeability experimentally measured with the other and vice versa&#44; as <a class="elsevierStyleCrossRef" href="#tbl0015">Table 3</a> confirms&#46;</p><elsevierMultimedia ident="tbl0015"></elsevierMultimedia><p id="par0140" class="elsevierStylePara elsevierViewall">Finally&#44; the influence of the pore size &#40;obtained by the bubble point method and intrusion mercury porosimetry&#41; over the water and air permeability coefficient &#40;<span class="elsevierStyleItalic">K</span><span class="elsevierStyleInf">p</span>&#41; has been evaluated&#46; As reported in a previous research study <a class="elsevierStyleCrossRef" href="#bib0330">&#91;33&#93;</a>&#44; the Hagen&#8211;Poiseuille &#40;Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0020">&#40;4&#41;</a>&#41; relates the permeability coefficient with the pore radius &#40;<span class="elsevierStyleItalic">r</span>&#41;&#44; the water viscosity &#40;<span class="elsevierStyleItalic">&#956;</span>&#41;&#44; the surface porosity &#40;<span class="elsevierStyleItalic">¿</span><span class="elsevierStyleInf">sf</span>&#41; and the tortuosity factor &#40;<span class="elsevierStyleItalic">&#964;</span>&#41;&#58;<elsevierMultimedia ident="eq0020"></elsevierMultimedia></p><p id="par0145" class="elsevierStylePara elsevierViewall">Assuming that the ratio <span class="elsevierStyleItalic">¿</span><span class="elsevierStyleInf">sf</span>&#47;<span class="elsevierStyleItalic">&#964;</span> varies little between the membranes&#44; the model predicts an approximately linear relationship between <span class="elsevierStyleItalic">K</span><span class="elsevierStyleInf">p</span> and <span class="elsevierStyleItalic">r</span><span class="elsevierStyleSup">2</span>&#46; This relationship has been represented in <a class="elsevierStyleCrossRef" href="#fig0040">Fig&#46; 8</a> for both <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span> &#40;a&#41; and <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span> &#40;b&#41;&#44; obtained by the bubble point method&#46; The correlation is slightly better with the mean diameter &#40;<span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span>&#41; obtained with the bubble point method&#44; which indicates that <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span> is a good parameter for defining the properties of the support as a membrane&#46; The differences found between this trend and the trend obtained in the referenced work <a class="elsevierStyleCrossRef" href="#bib0330">&#91;33&#93;</a>&#44; where the correlation was slightly better with the <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span> parameter &#40;obtained with the mercury porosimeter&#41;&#44; may be due to the different measuring techniques&#46; Since mercury porosimeter measures all the pores of the membrane &#40;connected and non-connected&#41;&#44; the pore diameter <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span> represents the pores of bigger diameter&#44; which are the pores that have higher influence over the fluid permeability&#46; On the other hand&#44; bubble point method measures the pores that participate in the fluid flux&#44; so the <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span> is representative of the effective pore size&#46; This possibly explains the differences obtained in the diameter that correlates better with the permeability&#46;</p><elsevierMultimedia ident="fig0040"></elsevierMultimedia></span></span><span id="sec0060" class="elsevierStyleSection elsevierViewall"><span class="elsevierStyleSectionTitle" id="sect0080">Conclusions</span><p id="par0150" class="elsevierStylePara elsevierViewall">A study of the relationship between mean pore sizes measured by two different methods &#40;bubble point and intrusion mercury porosimetry&#41; has been carried out using a set of low cost ceramic membranes prepared using different procedures and compositions&#46; The air and water permeabilities of the tested membranes were compared&#44; achieving a good correlation between both experimental values&#46; These permeabilities were related by the Hagen&#8211;Poiseuille model with the ratio of the viscosities for air and water&#46; Moreover&#44; both permeabilities have a relationship with the square pore diameter&#44; as the Hagen&#8211;Poiseuille equation predicts&#46;</p><p id="par0155" class="elsevierStylePara elsevierViewall">SEM images showed a higher porosity of the membranes prepared with starch&#44; which also had higher permeability&#46; This result confirms the suitability of starch as a pore former in the preparation of low cost ceramic membranes&#46; Membranes prepared with uniaxial pressing provided higher permeability than those obtained by extrusion&#44; for the same composition of the starting mixture&#46;</p><p id="par0160" class="elsevierStylePara elsevierViewall">To sum up&#44; a good correlation between both methods was found&#46; The consistency between the two methods opens up the possibility of replacing mercury intrusion in some applications&#46; Good agreement was also obtained in the measurements of the pore size distribution width &#40;<span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span> and <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">84</span>&#41;&#46;</p></span></span>"
    "textoCompletoSecciones" => array:1 [
      "secciones" => array:10 [
        0 => array:3 [
          "identificador" => "xres800270"
          "titulo" => "Abstract"
          "secciones" => array:1 [
            0 => array:1 [
              "identificador" => "abst0005"
            ]
          ]
        ]
        1 => array:2 [
          "identificador" => "xpalclavsec798763"
          "titulo" => "Keywords"
        ]
        2 => array:3 [
          "identificador" => "xres800271"
          "titulo" => "Resumen"
          "secciones" => array:1 [
            0 => array:1 [
              "identificador" => "abst0010"
            ]
          ]
        ]
        3 => array:2 [
          "identificador" => "xpalclavsec798764"
          "titulo" => "Palabras clave"
        ]
        4 => array:2 [
          "identificador" => "sec0005"
          "titulo" => "Introduction"
        ]
        5 => array:3 [
          "identificador" => "sec0010"
          "titulo" => "Experimental method"
          "secciones" => array:3 [
            0 => array:2 [
              "identificador" => "sec0015"
              "titulo" => "Membrane preparation"
            ]
            1 => array:3 [
              "identificador" => "sec0020"
              "titulo" => "Characterization&#58; bubble point and intrusion mercury porosimetry"
              "secciones" => array:2 [
                0 => array:2 [
                  "identificador" => "sec0025"
                  "titulo" => "Bubble point"
                ]
                1 => array:2 [
                  "identificador" => "sec0030"
                  "titulo" => "Intrusion mercury porosimetry"
                ]
              ]
            ]
            2 => array:2 [
              "identificador" => "sec0035"
              "titulo" => "Permeability&#58; air and water"
            ]
          ]
        ]
        6 => array:3 [
          "identificador" => "sec0040"
          "titulo" => "Results and discussion"
          "secciones" => array:3 [
            0 => array:2 [
              "identificador" => "sec0045"
              "titulo" => "Membrane structure &#40;SEM&#41;"
            ]
            1 => array:2 [
              "identificador" => "sec0050"
              "titulo" => "Bubble point and intrusion mercury porosimetry"
            ]
            2 => array:2 [
              "identificador" => "sec0055"
              "titulo" => "Air&#8211;water permeability"
            ]
          ]
        ]
        7 => array:2 [
          "identificador" => "sec0060"
          "titulo" => "Conclusions"
        ]
        8 => array:2 [
          "identificador" => "xack268094"
          "titulo" => "Acknowledgements"
        ]
        9 => array:1 [
          "titulo" => "References"
        ]
      ]
    ]
    "pdfFichero" => "main.pdf"
    "tienePdf" => true
    "fechaRecibido" => "2016-02-09"
    "fechaAceptado" => "2016-09-06"
    "PalabrasClave" => array:2 [
      "en" => array:1 [
        0 => array:4 [
          "clase" => "keyword"
          "titulo" => "Keywords"
          "identificador" => "xpalclavsec798763"
          "palabras" => array:5 [
            0 => "Membranes"
            1 => "Porosity"
            2 => "Shaping"
            3 => "Bubble point method"
            4 => "Intrusion mercury porosimetry"
          ]
        ]
      ]
      "es" => array:1 [
        0 => array:4 [
          "clase" => "keyword"
          "titulo" => "Palabras clave"
          "identificador" => "xpalclavsec798764"
          "palabras" => array:5 [
            0 => "Membranas"
            1 => "Porosidad"
            2 => "Conformado"
            3 => "M&#233;todo de punto de burbuja"
            4 => "Porosimetr&#237;a de intrusi&#243;n de mercurio"
          ]
        ]
      ]
    ]
    "tieneResumen" => true
    "resumen" => array:2 [
      "en" => array:2 [
        "titulo" => "Abstract"
        "resumen" => "<span id="abst0005" class="elsevierStyleSection elsevierViewall"><p id="spar0005" class="elsevierStyleSimplePara elsevierViewall">Several characterization methods were applied to low cost ceramic membranes developed for wastewater treatment in membrane bioreactors &#40;MBRs&#41; and&#47;or tertiary treatments&#46; The membranes were prepared by four different procedures &#40;uniaxial pressing and extrusion&#44; both with and without starch addition to generate pores&#41;&#46; The pore size of these symmetric ceramic membranes was measured by two different methods&#58; bubble point and intrusion mercury porosimetry&#46; A good agreement between both methods was achieved&#44; confirming the validity of the bubble point method for the measurement of the mean pore size of membranes&#46; Air and water permeations of these ceramic membranes were also studied&#46; The relationship between the permeation of both fluids is consistent with the ratio of viscosities&#44; according to the Hagen&#8211;Poiseuille equation&#46;</p></span>"
      ]
      "es" => array:2 [
        "titulo" => "Resumen"
        "resumen" => "<span id="abst0010" class="elsevierStyleSection elsevierViewall"><p id="spar0010" class="elsevierStyleSimplePara elsevierViewall">En el presente trabajo se han caracterizado mediante diferentes m&#233;todos membranas cer&#225;micas de bajo coste desarrolladas para tratar aguas residuales en reactores biol&#243;gicos de membrana &#40;MBR&#41; o mediante tratamientos terciarios&#46; Las membranas se prepararon mediante diferentes procedimientos &#40;prensado uniaxial y extrusi&#243;n&#44; con o sin adici&#243;n de almid&#243;n como material generador de poros&#41;&#46; El tama&#241;o del poro de estas membranas cer&#225;micas sim&#233;tricas se determin&#243; mediante 2 m&#233;todos diferentes&#58; punto de burbuja y porosimetr&#237;a de intrusi&#243;n de mercurio&#46; Los resultados obtenidos mediante ambos m&#233;todos mostraban concordancia&#44; lo que confirma la validez del m&#233;todo de punto de burbuja para la medida del tama&#241;o del poro medio de las membranas&#46; Adem&#225;s&#44; se ha estudiado la permeabilidad al aire y agua de estas membranas cer&#225;micas&#58; la relaci&#243;n entre la permeabilidad de ambos fluidos es consistente con el ratio de viscosidades&#44; de acuerdo con la ecuaci&#243;n de Hagen-Poiseuille&#46;</p></span>"
      ]
    ]
    "apendice" => array:1 [
      0 => array:1 [
        "seccion" => array:1 [
          0 => array:4 [
            "apendice" => "<p id="par0170" class="elsevierStylePara elsevierViewall">The Hagen&#8211;Poiseuille equation <a class="elsevierStyleCrossRef" href="#eq0010">&#40;2&#41;</a> was deduced for a non-compressible fluid&#46; For a compressible fluid it can be expressed as&#58;<elsevierMultimedia ident="eq0025"></elsevierMultimedia></p> <p id="par0175" class="elsevierStylePara elsevierViewall">Since the gas is compressible&#44; the volumetric flow varies with the pressure&#44; and it is preferable to give the volumetric flow as a function of the molar flow&#46; According to the ideal gas equation we have&#58;<elsevierMultimedia ident="eq0030"></elsevierMultimedia>where <span class="elsevierStyleItalic">F</span> is the molar flow&#46; Substituting Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0030">&#40;A&#46;2&#41;</a> in Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0025">&#40;A&#46;1&#41;</a> we obtain&#58;<elsevierMultimedia ident="eq0035"></elsevierMultimedia></p> <p id="par0180" class="elsevierStylePara elsevierViewall">By separating variables and integrating&#44; with <span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">2</span> and <span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">1</span> as the pressure in retentate and permeate side respectively&#44; we obtain&#58;<elsevierMultimedia ident="eq0040"></elsevierMultimedia>Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0040">&#40;A&#46;4&#41;</a> has been extensively used to describe the laminar flow in a porous membrane &#40;e&#46;g&#46; <a class="elsevierStyleCrossRef" href="#bib0265">&#91;20&#93;</a>&#41;&#46; However&#44; if the volumetric flow measured at the mean pressure &#40;<span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">m</span><span class="elsevierStyleHsp" style=""></span>&#61;<span class="elsevierStyleHsp" style=""></span>&#40;<span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">1</span><span class="elsevierStyleHsp" style=""></span>&#43;<span class="elsevierStyleHsp" style=""></span><span class="elsevierStyleItalic">P</span><span class="elsevierStyleInf">2</span>&#41;&#47;2&#41; is defined by&#58;<elsevierMultimedia ident="eq0045"></elsevierMultimedia>it is possible to rewrite Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0040">&#40;A&#46;4&#41;</a> as&#58;<elsevierMultimedia ident="eq0050"></elsevierMultimedia>Thus Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0050">&#40;A&#46;6&#41;</a> allows the same form of the Hagen&#8211;Poiseuille equation employed for liquids &#40;Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0010">&#40;2&#41;</a>&#41;&#44; but using as volumetric flow the value calculated at the mean pressure in the membrane &#40;Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0045">&#40;A&#46;5&#41;</a>&#41;&#46;</p>"
            "etiqueta" => "Appendix A"
            "titulo" => "Appendix"
            "identificador" => "sec0065"
          ]
        ]
      ]
    ]
    "multimedia" => array:21 [
      0 => array:7 [
        "identificador" => "fig0005"
        "etiqueta" => "Fig&#46; 1"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr1.jpeg"
            "Alto" => 1135
            "Ancho" => 1352
            "Tamanyo" => 114825
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0015" class="elsevierStyleSimplePara elsevierViewall">Air flow-pressure representation&#46;</p>"
        ]
      ]
      1 => array:7 [
        "identificador" => "fig0010"
        "etiqueta" => "Fig&#46; 2"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr2.jpeg"
            "Alto" => 1178
            "Ancho" => 1571
            "Tamanyo" => 155487
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0020" class="elsevierStyleSimplePara elsevierViewall">Scheme of the bubble point experimental equipment&#46;</p>"
        ]
      ]
      2 => array:7 [
        "identificador" => "fig0015"
        "etiqueta" => "Fig&#46; 3"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr3.jpeg"
            "Alto" => 1512
            "Ancho" => 1750
            "Tamanyo" => 615100
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0025" class="elsevierStyleSimplePara elsevierViewall">FEG-ESEM micrographs of pressed and extruded membranes&#44; with and without starch addition &#40;magnification&#58; 400&#215;&#41;&#46; Pores present a dark color in the micrographs&#46;</p>"
        ]
      ]
      3 => array:7 [
        "identificador" => "fig0020"
        "etiqueta" => "Fig&#46; 4"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr4.jpeg"
            "Alto" => 754
            "Ancho" => 1750
            "Tamanyo" => 223443
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0030" class="elsevierStyleSimplePara elsevierViewall">FEG-ESEM micrographs of pressed and extruded membranes with high clay content &#40;magnification&#58; 1500&#215;&#41;&#46; Pores present a dark color in the micrographs&#46;</p>"
        ]
      ]
      4 => array:7 [
        "identificador" => "fig0025"
        "etiqueta" => "Fig&#46; 5"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr5.jpeg"
            "Alto" => 1607
            "Ancho" => 1332
            "Tamanyo" => 114165
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0035" class="elsevierStyleSimplePara elsevierViewall">Comparison of average pore size measured by bubble point &#40;BP&#41; and intrusion mercury porosimetry &#40;MP&#41; methods &#40;2 samples evaluated for each point&#41;&#46;</p>"
        ]
      ]
      5 => array:7 [
        "identificador" => "fig0030"
        "etiqueta" => "Fig&#46; 6"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr6.jpeg"
            "Alto" => 1475
            "Ancho" => 2500
            "Tamanyo" => 193859
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0040" class="elsevierStyleSimplePara elsevierViewall">Plot of air flow &#40;measured at the mean pressure&#41; &#40;a&#41; and water flow &#40;b&#41; versus transmembrane pressure for one example of each kind of membranes &#40;1 sample evaluated for each curve&#41;&#46;</p>"
        ]
      ]
      6 => array:7 [
        "identificador" => "fig0035"
        "etiqueta" => "Fig&#46; 7"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr7.jpeg"
            "Alto" => 1554
            "Ancho" => 1340
            "Tamanyo" => 148850
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0045" class="elsevierStyleSimplePara elsevierViewall">Comparison between water and air membrane permeabilities &#40;2 samples evaluated for each point&#41;&#46;</p>"
        ]
      ]
      7 => array:7 [
        "identificador" => "fig0040"
        "etiqueta" => "Fig&#46; 8"
        "tipo" => "MULTIMEDIAFIGURA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "figura" => array:1 [
          0 => array:4 [
            "imagen" => "gr8.jpeg"
            "Alto" => 1455
            "Ancho" => 2499
            "Tamanyo" => 199109
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0050" class="elsevierStyleSimplePara elsevierViewall">Comparison of water and air permeability coefficients versus <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">16</span> &#40;a&#41; and <span class="elsevierStyleItalic">d</span><span class="elsevierStyleInf">50</span> &#40;b&#41; pore size measured by bubble point &#40;BP&#41; method &#40;2 samples evaluated for each point&#41;&#46;</p>"
        ]
      ]
      8 => array:8 [
        "identificador" => "tbl0005"
        "etiqueta" => "Table 1"
        "tipo" => "MULTIMEDIATABLA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "detalles" => array:1 [
          0 => array:3 [
            "identificador" => "at1"
            "detalle" => "Table "
            "rol" => "short"
          ]
        ]
        "tabla" => array:1 [
          "tablatextoimagen" => array:1 [
            0 => array:2 [
              "tabla" => array:1 [
                0 => """
                  <table border="0" frame="\n
                  \t\t\t\t\tvoid\n
                  \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head  " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Raw material&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Compositional range &#40;wt&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Clay&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">40&#8211;85&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Chamotte&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">0&#8211;20&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Feldspar&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">0&#8211;15&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Calcium carbonate&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">7&#8211;20&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">Starch &#40;different sources&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">0&#8211;20&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr></tbody></table>
                  """
              ]
              "imagenFichero" => array:1 [
                0 => "xTab1342665.png"
              ]
            ]
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0055" class="elsevierStyleSimplePara elsevierViewall">Compositional range used to obtain ceramic membranes with very different porosity characteristics &#40;total pore volume and size distribution&#41;&#46;</p>"
        ]
      ]
      9 => array:8 [
        "identificador" => "tbl0010"
        "etiqueta" => "Table 2"
        "tipo" => "MULTIMEDIATABLA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "detalles" => array:1 [
          0 => array:3 [
            "identificador" => "at2"
            "detalle" => "Table "
            "rol" => "short"
          ]
        ]
        "tabla" => array:1 [
          "tablatextoimagen" => array:1 [
            0 => array:2 [
              "tabla" => array:1 [
                0 => """
                  <table border="0" frame="\n
                  \t\t\t\t\tvoid\n
                  \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head  " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Membranes series&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Forming method&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Composition&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Number of specimens&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">P&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">Uniaxial dry pressing&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">Without starch&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">10&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">PS&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">Uniaxial dry pressing&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">With starch&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">4&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">E&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">Extrusion&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">Without starch&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">2&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">ES&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">Extrusion&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="left" valign="top">With starch&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">5&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr></tbody></table>
                  """
              ]
              "imagenFichero" => array:1 [
                0 => "xTab1342666.png"
              ]
            ]
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0060" class="elsevierStyleSimplePara elsevierViewall">Membranes classification&#46;</p>"
        ]
      ]
      10 => array:8 [
        "identificador" => "tbl0015"
        "etiqueta" => "Table 3"
        "tipo" => "MULTIMEDIATABLA"
        "mostrarFloat" => true
        "mostrarDisplay" => false
        "detalles" => array:1 [
          0 => array:3 [
            "identificador" => "at3"
            "detalle" => "Table "
            "rol" => "short"
          ]
        ]
        "tabla" => array:1 [
          "tablatextoimagen" => array:1 [
            0 => array:2 [
              "tabla" => array:1 [
                0 => """
                  <table border="0" frame="\n
                  \t\t\t\t\tvoid\n
                  \t\t\t\t" class=""><thead title="thead"><tr title="table-row"><th class="td" title="table-head  " align="left" valign="top" scope="col" style="border-bottom: 2px solid black">Composition&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Experimental air permeability &#40;m<span class="elsevierStyleSup">3</span><span class="elsevierStyleHsp" style=""></span>h<span class="elsevierStyleSup">&#8722;1</span><span class="elsevierStyleHsp" style=""></span>m<span class="elsevierStyleSup">&#8722;2</span><span class="elsevierStyleHsp" style=""></span>bar<span class="elsevierStyleSup">&#8722;1</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Calculated air permeability &#40;m<span class="elsevierStyleSup">3</span><span class="elsevierStyleHsp" style=""></span>h<span class="elsevierStyleSup">&#8722;1</span><span class="elsevierStyleHsp" style=""></span>m<span class="elsevierStyleSup">&#8722;2</span><span class="elsevierStyleHsp" style=""></span>bar<span class="elsevierStyleSup">&#8722;1</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Deviation ratio &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Experimental water permeability &#40;m<span class="elsevierStyleSup">3</span><span class="elsevierStyleHsp" style=""></span>h<span class="elsevierStyleSup">&#8722;1</span><span class="elsevierStyleHsp" style=""></span>m<span class="elsevierStyleSup">&#8722;2</span><span class="elsevierStyleHsp" style=""></span>bar<span class="elsevierStyleSup">&#8722;1</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Calculated water permeability &#40;m<span class="elsevierStyleSup">3</span><span class="elsevierStyleHsp" style=""></span>h<span class="elsevierStyleSup">&#8722;1</span><span class="elsevierStyleHsp" style=""></span>m<span class="elsevierStyleSup">&#8722;2</span><span class="elsevierStyleHsp" style=""></span>bar<span class="elsevierStyleSup">&#8722;1</span>&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th><th class="td" title="table-head  " align="center" valign="top" scope="col" style="border-bottom: 2px solid black">Deviation ratio &#40;&#37;&#41;&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</th></tr></thead><tbody title="tbody"><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">P&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">231&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">269&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">17&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">4&#46;3&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">3&#46;7&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">14&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">PS&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">2280&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">2859&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">25&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">46&#46;0&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">36&#46;0&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">20&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">E&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">112&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">93&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">17&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">1&#46;5&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">1&#46;8&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">21&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr><tr title="table-row"><td class="td-with-role" title="table-entry ; entry_with_role_rowhead " align="left" valign="top">ES&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">483&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">526&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">9&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">8&#46;4&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">7&#46;7&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td><td class="td" title="table-entry  " align="char" valign="top">8&nbsp;\t\t\t\t\t\t\n
                  \t\t\t\t</td></tr></tbody></table>
                  """
              ]
              "imagenFichero" => array:1 [
                0 => "xTab1342664.png"
              ]
            ]
          ]
        ]
        "descripcion" => array:1 [
          "en" => "<p id="spar0065" class="elsevierStyleSimplePara elsevierViewall">Examples of permeability estimation based Eq&#46; <a class="elsevierStyleCrossRef" href="#eq0015">&#40;3&#41;</a> for compositions of each series&#46;</p>"
        ]
      ]
      11 => array:6 [
        "identificador" => "eq0005"
        "etiqueta" => "&#40;1&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "&#916;P&#61;4&#947;&#8201;cos&#8201;&#966;dp"
          "Fichero" => "STRIPIN_si1.jpeg"
          "Tamanyo" => 1271
          "Alto" => 35
          "Ancho" => 97
        ]
      ]
      12 => array:6 [
        "identificador" => "eq0010"
        "etiqueta" => "&#40;2&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "Qv&#61;n&#960;r4&#8201;&#916;P8&#956;l"
          "Fichero" => "STRIPIN_si2.jpeg"
          "Tamanyo" => 1315
          "Alto" => 36
          "Ancho" => 92
        ]
      ]
      13 => array:6 [
        "identificador" => "eq0015"
        "etiqueta" => "&#40;3&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "ftheor&#61;JairJwater&#61;&#956;water&#956;air"
          "Fichero" => "STRIPIN_si3.jpeg"
          "Tamanyo" => 1809
          "Alto" => 34
          "Ancho" => 151
        ]
      ]
      14 => array:6 [
        "identificador" => "eq0020"
        "etiqueta" => "&#40;4&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "Kp&#61;&#949;sf8&#956;&#964;r2"
          "Fichero" => "STRIPIN_si4.jpeg"
          "Tamanyo" => 1008
          "Alto" => 31
          "Ancho" => 79
        ]
      ]
      15 => array:6 [
        "identificador" => "eq0025"
        "etiqueta" => "&#40;A&#46;1&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "Qv&#61;n&#960;r48&#956;dPdl"
          "Fichero" => "STRIPIN_si5.jpeg"
          "Tamanyo" => 1437
          "Alto" => 36
          "Ancho" => 90
        ]
      ]
      16 => array:6 [
        "identificador" => "eq0030"
        "etiqueta" => "&#40;A&#46;2&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "PQv&#61;FRT"
          "Fichero" => "STRIPIN_si6.jpeg"
          "Tamanyo" => 736
          "Alto" => 14
          "Ancho" => 73
        ]
      ]
      17 => array:6 [
        "identificador" => "eq0035"
        "etiqueta" => "&#40;A&#46;3&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "FRT&#61;n&#960;r48&#956;PdPdl"
          "Fichero" => "STRIPIN_si7.jpeg"
          "Tamanyo" => 1554
          "Alto" => 36
          "Ancho" => 108
        ]
      ]
      18 => array:6 [
        "identificador" => "eq0040"
        "etiqueta" => "&#40;A&#46;4&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "F&#61;n&#960;r416RT&#956;&#40;P22&#8722;P12&#41;l"
          "Fichero" => "STRIPIN_si8.jpeg"
          "Tamanyo" => 1930
          "Alto" => 36
          "Ancho" => 136
        ]
      ]
      19 => array:6 [
        "identificador" => "eq0045"
        "etiqueta" => "&#40;A&#46;5&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "Qm&#61;FRTPm"
          "Fichero" => "STRIPIN_si9.jpeg"
          "Tamanyo" => 1010
          "Alto" => 33
          "Ancho" => 71
        ]
      ]
      20 => array:6 [
        "identificador" => "eq0050"
        "etiqueta" => "&#40;A&#46;6&#41;"
        "tipo" => "MULTIMEDIAFORMULA"
        "mostrarFloat" => false
        "mostrarDisplay" => true
        "Formula" => array:5 [
          "Matematica" => "Qm&#61;n&#960;r48&#956;&#40;P2&#8722;P1&#41;l"
          "Fichero" => "STRIPIN_si10.jpeg"
          "Tamanyo" => 1714
          "Alto" => 36
          "Ancho" => 134
        ]
      ]
    ]
    "bibliografia" => array:2 [
      "titulo" => "References"
      "seccion" => array:1 [
        0 => array:2 [
          "identificador" => "bibs0005"
          "bibliografiaReferencia" => array:33 [
            0 => array:3 [
              "identificador" => "bib0170"
              "etiqueta" => "&#91;1&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Fouling in membrane bioreactors used in wastewater treatment"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "P&#46; Le-Clech"
                            1 => "V&#46; Chen"
                            2 => "T&#46;A&#46;G&#46; Fane"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "2006"
                        "volumen" => "284"
                        "paginaInicial" => "17"
                        "paginaFinal" => "53"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            1 => array:3 [
              "identificador" => "bib0175"
              "etiqueta" => "&#91;2&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "The status of membrane bioreactor technology"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "S&#46; Judd"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1016/j.tibtech.2007.11.005"
                      "Revista" => array:6 [
                        "tituloSerie" => "Trends Biotechnol&#46;"
                        "fecha" => "2008"
                        "volumen" => "26"
                        "paginaInicial" => "109"
                        "paginaFinal" => "116"
                        "link" => array:1 [
                          0 => array:2 [
                            "url" => "https://www.ncbi.nlm.nih.gov/pubmed/18191260"
                            "web" => "Medline"
                          ]
                        ]
                      ]
                    ]
                  ]
                ]
              ]
            ]
            2 => array:3 [
              "identificador" => "bib0180"
              "etiqueta" => "&#91;3&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Membrane fouling in membrane bioreactors &#8211; characterisation&#44; contradictions&#44; cause and cures"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "A&#46; Drews"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "2010"
                        "volumen" => "363"
                        "paginaInicial" => "1"
                        "paginaFinal" => "28"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            3 => array:3 [
              "identificador" => "bib0185"
              "etiqueta" => "&#91;4&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Comparison of extruded and pressed low cost ceramic supports for microfiltration membranes"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "M&#46;-M&#46; Lorente-Ayza"
                            1 => "S&#46; Mestre"
                            2 => "M&#46; Men&#233;ndez"
                            3 => "E&#46; S&#225;nchez"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Eur&#46; Ceram&#46; Soc&#46;"
                        "fecha" => "2015"
                        "volumen" => "35"
                        "paginaInicial" => "3681"
                        "paginaFinal" => "3691"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            4 => array:3 [
              "identificador" => "bib0190"
              "etiqueta" => "&#91;5&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Measuring the plasticity of clays&#58; a review"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "F&#46;A&#46; Andrade"
                            1 => "H&#46;A&#46; Al-Qureshi"
                            2 => "D&#46; Hotza"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Appl&#46; Clay Sci&#46;"
                        "fecha" => "2011"
                        "volumen" => "51"
                        "paginaInicial" => "1"
                        "paginaFinal" => "7"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            5 => array:3 [
              "identificador" => "bib0195"
              "etiqueta" => "&#91;6&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "T&#233;cnicas experimentales del control de la compactaci&#243;n de pavimentos y revestimientos cer&#225;micos"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:5 [
                            0 => "J&#46;L&#46; Amor&#243;s"
                            1 => "V&#46; Beltr&#225;n"
                            2 => "A&#46; Blasco"
                            3 => "C&#46; Feliu"
                            4 => "M&#46; Sancho-Tello"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "T&#233;cnica Cer&#225;mica"
                        "fecha" => "1983"
                        "volumen" => "116"
                        "paginaInicial" => "1234"
                        "paginaFinal" => "1246"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            6 => array:3 [
              "identificador" => "bib0200"
              "etiqueta" => "&#91;7&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Characterisation of polymeric UF membranes by liquid&#8211;liquid displacement porosimetry"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:5 [
                            0 => "R&#46;I&#46; Peinador"
                            1 => "J&#46;I&#46; Calvo"
                            2 => "P&#46; Pradanos"
                            3 => "L&#46; Palacio"
                            4 => "A&#46; Hernandez"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "2010"
                        "volumen" => "348"
                        "paginaInicial" => "238"
                        "paginaFinal" => "244"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            7 => array:3 [
              "identificador" => "bib0205"
              "etiqueta" => "&#91;8&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Pore size distribution of ceramic UF membranes by liquid&#8211;liquid displacement porosimetry"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "J&#46;I&#46; Calvo"
                            1 => "A&#46; Bottino"
                            2 => "G&#46; Capannelli"
                            3 => "A&#46; Hernandez"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "2008"
                        "volumen" => "310"
                        "paginaInicial" => "531"
                        "paginaFinal" => "538"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            8 => array:3 [
              "identificador" => "bib0210"
              "etiqueta" => "&#91;9&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Pore size distributions in microporous membranes II&#46; Bulk characterization of track-etched filters by air porometry and mercury porosimetry"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "J&#46;I&#46; Calvo"
                            1 => "A&#46; Hernandez"
                            2 => "P&#46; Pradanos"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Colloid Interface Sci&#46;"
                        "fecha" => "1995"
                        "volumen" => "478"
                        "paginaInicial" => "467"
                        "paginaFinal" => "478"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            9 => array:3 [
              "identificador" => "bib0215"
              "etiqueta" => "&#91;10&#93;"
              "referencia" => array:1 [
                0 => array:3 [
                  "comentario" => "<a class="elsevierStyleInterRef" id="intr0005" href="http://ceramicayvidrio.revistas.csic.es/index.php/ceramicayvidrio/article/viewArticle/956">http&#58;&#47;&#47;ceramicayvidrio&#46;revistas&#46;csic&#46;es&#47;index&#46;php&#47;ceramicayvidrio&#47;article&#47;viewArticle&#47;956</a>"
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Membranas cer&#225;micas y su utilidad en procesos de separaci&#243;n"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "A&#46; Hernandez"
                            1 => "P&#46; Pradanos"
                            2 => "J&#46;I&#46; Calvo"
                            3 => "L&#46; Palacio"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Bol&#46; Soc&#46; Esp&#46; Ceram&#46;"
                        "fecha" => "1999"
                        "volumen" => "38"
                        "paginaInicial" => "185"
                        "paginaFinal" => "192"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            10 => array:3 [
              "identificador" => "bib0220"
              "etiqueta" => "&#91;11&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Pore size distributions in microporous membranes&#46; A critical analysis of the bubble point extended method"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "A&#46; Hernandez"
                            1 => "J&#46;I&#46; Calvo"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "1996"
                        "volumen" => "112"
                        "paginaInicial" => "1"
                        "paginaFinal" => "12"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            11 => array:3 [
              "identificador" => "bib0225"
              "etiqueta" => "&#91;12&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Ceramic Membranes for Separation and Reaction"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "K&#46; Li"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Libro" => array:3 [
                        "fecha" => "2007"
                        "editorial" => "John Wiley"
                        "editorialLocalizacion" => "Hoboken&#44; NJ"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            12 => array:3 [
              "identificador" => "bib0230"
              "etiqueta" => "&#91;13&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "ASTM F316-03&#44; Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test&#44; ASTM F316-03"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "ASTM International"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Libro" => array:1 [
                        "fecha" => "2003"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            13 => array:3 [
              "identificador" => "bib0235"
              "etiqueta" => "&#91;14&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Hydraulic Fluid Power &#8211; Filter Elements &#8211; Verification of Fabrication Integrity and Determination of the First Bubble Point &#40;ISO 2942&#41;&#44; ISO 2942"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "International Standard"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Libro" => array:1 [
                        "fecha" => "2004"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            14 => array:3 [
              "identificador" => "bib0240"
              "etiqueta" => "&#91;15&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Permeable Sintered Metal Materials&#58; Determination of Bubble Point Test Pore Size &#40;ISO 4003&#41;&#44; ISO 4003"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "International Standard"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Libro" => array:1 [
                        "fecha" => "1977"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            15 => array:3 [
              "identificador" => "bib0245"
              "etiqueta" => "&#91;16&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Membranas cer&#225;micas&#46; Tipos&#44; m&#233;todos de obtenci&#243;n y caracterizaci&#243;n"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "J&#46;M&#46; Benito"
                            1 => "A&#46; Conesa"
                            2 => "M&#46;A&#46; Rodr&#237;guez"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Bol&#46; Soc&#46; Esp&#46; Ceram&#46;"
                        "fecha" => "2004"
                        "volumen" => "43"
                        "paginaInicial" => "829"
                        "paginaFinal" => "842"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            16 => array:3 [
              "identificador" => "bib0250"
              "etiqueta" => "&#91;17&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "A modification of the bubble-point method to determine the pore-mouth size distribution of porous materials"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "J&#46; Yu"
                            1 => "X&#46; Hu"
                            2 => "Y&#46; Huang"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Sep&#46; Purif&#46; Technol&#46;"
                        "fecha" => "2010"
                        "volumen" => "70"
                        "paginaInicial" => "314"
                        "paginaFinal" => "319"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            17 => array:3 [
              "identificador" => "bib0255"
              "etiqueta" => "&#91;18&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Ceramic membrane characterization via the bubble point technique"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "E&#46; Jakobs"
                            1 => "W&#46; Koros"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "1997"
                        "volumen" => "124"
                        "paginaInicial" => "149"
                        "paginaFinal" => "159"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            18 => array:3 [
              "identificador" => "bib0260"
              "etiqueta" => "&#91;19&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Neck-size distributions of through-pores in polymer membranes"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:7 [
                            0 => "C&#46; Agarwal"
                            1 => "A&#46;K&#46; Pandey"
                            2 => "S&#46; Das"
                            3 => "M&#46;K&#46; Sharma"
                            4 => "D&#46; Pattyn"
                            5 => "P&#46; Ares"
                            6 => "A&#46; Goswami"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "2012"
                        "volumen" => "415&#8211;416"
                        "paginaInicial" => "608"
                        "paginaFinal" => "615"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            19 => array:3 [
              "identificador" => "bib0265"
              "etiqueta" => "&#91;20&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Gas separation mechanisms in microporous modified &#947;-Al<span class="elsevierStyleInf">2</span>O<span class="elsevierStyleInf">3</span> membranes"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "K&#46; Keizer"
                            1 => "R&#46;J&#46;R&#46; Uhlhorn"
                            2 => "R&#46;J&#46; Van vuren"
                            3 => "A&#46;J&#46; Burggraaf"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "1988"
                        "volumen" => "39"
                        "paginaInicial" => "285"
                        "paginaFinal" => "300"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            20 => array:3 [
              "identificador" => "bib0270"
              "etiqueta" => "&#91;21&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Pore size distribution determination from liquid permeation through microporous membranes"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "K&#46;S&#46; McGuire"
                            1 => "K&#46;W&#46; Lawson"
                            2 => "D&#46;R&#46; Lloyd"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "1995"
                        "volumen" => "99"
                        "paginaInicial" => "127"
                        "paginaFinal" => "137"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            21 => array:3 [
              "identificador" => "bib0275"
              "etiqueta" => "&#91;22&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Pore Size Distribution and Porosity of Solid Materials by Mercury Porosimetry and Gas Adsorption&#46; Mercury Porosimetry &#40;ISO 15901&#41;&#44; ISO 15901"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "International Standard"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Libro" => array:2 [
                        "fecha" => "2006"
                        "paginaInicial" => "28"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            22 => array:3 [
              "identificador" => "bib0280"
              "etiqueta" => "&#91;23&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Permporometry characterization of microporous ceramic membranes"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "T&#46; Tsuru"
                            1 => "T&#46; Hino"
                            2 => "T&#46; Yoshioka"
                            3 => "M&#46; Asaeda"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Membr&#46; Sci&#46;"
                        "fecha" => "2001"
                        "volumen" => "186"
                        "paginaInicial" => "257"
                        "paginaFinal" => "265"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            23 => array:3 [
              "identificador" => "bib0285"
              "etiqueta" => "&#91;24&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "International tables of the surface tension of water"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "N&#46;B&#46; Vargaftik"
                            1 => "B&#46;N&#46; Volkov"
                            2 => "L&#46;D&#46; Voljak"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Phys&#46; Chem&#46; Ref&#46; Data"
                        "fecha" => "1983"
                        "volumen" => "12"
                        "paginaInicial" => "817"
                        "paginaFinal" => "820"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            24 => array:3 [
              "identificador" => "bib0290"
              "etiqueta" => "&#91;25&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Basic Principes of Membrane Technology"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:1 [
                            0 => "M&#46; Mulder"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Libro" => array:4 [
                        "edicion" => "2nd ed&#46;"
                        "fecha" => "1996"
                        "editorial" => "Kluwer Academic Publishers"
                        "editorialLocalizacion" => "Dordrecht&#44; The Netherlands"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            25 => array:3 [
              "identificador" => "bib0295"
              "etiqueta" => "&#91;26&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Effects of starch addition on characteristics of tubular porous ceramic membrane substrates"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "G&#46;C&#46;C&#46; Yang"
                            1 => "C&#46;-M&#46; Tsai"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Desalination"
                        "fecha" => "2008"
                        "volumen" => "233"
                        "paginaInicial" => "129"
                        "paginaFinal" => "136"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            26 => array:3 [
              "identificador" => "bib0300"
              "etiqueta" => "&#91;27&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Processing of porous cordierite bodies by starch consolidation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "H&#46;M&#46; Alves"
                            1 => "G&#46; Tar&#236;"
                            2 => "A&#46;T&#46; Fonseca"
                            3 => "J&#46;M&#46;F&#46; Ferreira"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Mater&#46; Res&#46; Bull&#46;"
                        "fecha" => "1998"
                        "volumen" => "33"
                        "paginaInicial" => "1439"
                        "paginaFinal" => "1448"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            27 => array:3 [
              "identificador" => "bib0305"
              "etiqueta" => "&#91;28&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Processing of porous ceramics by starch consolidation"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "O&#46; Lyckfeldt"
                            1 => "J&#46;M&#46;F&#46; Ferreira"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Eur&#46; Ceram&#46; Soc&#46;"
                        "fecha" => "1998"
                        "volumen" => "18"
                        "paginaInicial" => "131"
                        "paginaFinal" => "140"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            28 => array:3 [
              "identificador" => "bib0310"
              "etiqueta" => "&#91;29&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Multitechnique investigation of extruded clay brick microstructure"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:3 [
                            0 => "K&#46;J&#46; Krakowiak"
                            1 => "P&#46;B&#46; Louren&#231;o"
                            2 => "F&#46;J&#46; Ulm"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Am&#46; Ceram&#46; Soc&#46;"
                        "fecha" => "2011"
                        "volumen" => "94"
                        "paginaInicial" => "3012"
                        "paginaFinal" => "3022"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            29 => array:3 [
              "identificador" => "bib0315"
              "etiqueta" => "&#91;30&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Effects of the anisotropy of extruded earth bricks on their hygrothermal properties"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "P&#46; Maillard"
                            1 => "J&#46;E&#46; Aubert"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Constr&#46; Build&#46; Mater&#46;"
                        "fecha" => "2014"
                        "volumen" => "63"
                        "paginaInicial" => "56"
                        "paginaFinal" => "61"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            30 => array:3 [
              "identificador" => "bib0320"
              "etiqueta" => "&#91;31&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Comparative study of bubble point method and mercury intrusion porosimetry techniques for characterizing the pore-size distribution of geotextiles"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:2 [
                            0 => "S&#46;K&#46; Bhatia"
                            1 => "J&#46;L&#46; Smith"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "Geotext&#46; Geomembr&#46;"
                        "fecha" => "1994"
                        "volumen" => "13"
                        "paginaInicial" => "679"
                        "paginaFinal" => "702"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            31 => array:3 [
              "identificador" => "bib0325"
              "etiqueta" => "&#91;32&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Influence of starch content on the properties of low-cost microfiltration ceramic membranes"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "M&#46;-M&#46; Lorente-Ayza"
                            1 => "E&#46; S&#225;nchez"
                            2 => "V&#46; Sanz"
                            3 => "S&#46; Mestre"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:2 [
                      "doi" => "10.1016/j.ceramint.2015.07.092"
                      "Revista" => array:2 [
                        "tituloSerie" => "Ceram&#46; Int&#46;"
                        "fecha" => "2015"
                      ]
                    ]
                  ]
                ]
              ]
            ]
            32 => array:3 [
              "identificador" => "bib0330"
              "etiqueta" => "&#91;33&#93;"
              "referencia" => array:1 [
                0 => array:2 [
                  "contribucion" => array:1 [
                    0 => array:2 [
                      "titulo" => "Role of starch characteristics in the properties of low-cost ceramic membranes"
                      "autores" => array:1 [
                        0 => array:2 [
                          "etal" => false
                          "autores" => array:4 [
                            0 => "M&#46;-M&#46; Lorente-Ayza"
                            1 => "M&#46;J&#46; Orts"
                            2 => "V&#46; P&#233;rez-Herranz"
                            3 => "S&#46; Mestre"
                          ]
                        ]
                      ]
                    ]
                  ]
                  "host" => array:1 [
                    0 => array:1 [
                      "Revista" => array:5 [
                        "tituloSerie" => "J&#46; Eur&#46; Ceram&#46; Soc&#46;"
                        "fecha" => "2015"
                        "volumen" => "35"
                        "paginaInicial" => "2333"
                        "paginaFinal" => "2341"
                      ]
                    ]
                  ]
                ]
              ]
            ]
          ]
        ]
      ]
    ]
    "agradecimientos" => array:1 [
      0 => array:4 [
        "identificador" => "xack268094"
        "titulo" => "Acknowledgements"
        "texto" => "<p id="par0165" class="elsevierStylePara elsevierViewall">This paper includes results of the NITRAMEM &#40;IPT-2012-0069-310000&#41; project&#44; funded with a total amount of 870&#44;455&#46;39 Euros by the <span class="elsevierStyleGrantSponsor" id="gs1">Ministry of Economy and Competitiveness</span> and the <span class="elsevierStyleGrantSponsor" id="gs2">European Regional Development Fund &#40;ERDF&#41; of the European Union</span>&#44; INNPACTO through the program&#44; which the authors show their gratitude&#46;</p>"
        "vista" => "all"
      ]
    ]
  ]
  "idiomaDefecto" => "en"
  "url" => "/03663175/0000005600000001/v1_201702110054/S0366317516300723/v1_201702110054/en/main.assets"
  "Apartado" => null
  "PDF" => "https://static.elsevier.es/multimedia/03663175/0000005600000001/v1_201702110054/S0366317516300723/v1_201702110054/en/main.pdf?idApp=UINPBA00004N&text.app=https://www.elsevier.es/"
  "EPUB" => "https://multimedia.elsevier.es/PublicationsMultimediaV1/item/epub/S0366317516300723?idApp=UINPBA00004N"
]

Article information

ISSN: 03663175
Original language: English

DOI:10.1016/j.bsecv.2016.09.002

The statistics are updated each day

Year/Month	Html	Pdf	Total

2024 October	25	15	40
2024 September	57	28	85
2024 August	61	19	80
2024 July	49	21	70
2024 June	51	35	86
2024 May	68	80	148
2024 April	74	33	107
2024 March	77	25	102
2024 February	42	55	97
2024 January	70	47	117
2023 December	61	40	101
2023 November	82	42	124
2023 October	111	46	157
2023 September	65	8	73
2023 August	69	12	81
2023 July	36	16	52
2023 June	68	12	80
2023 May	90	11	101
2023 April	139	11	150
2023 March	55	11	66
2023 February	63	9	72
2023 January	44	14	58
2022 December	52	17	69
2022 November	80	23	103
2022 October	57	20	77
2022 September	44	18	62
2022 August	66	17	83
2022 July	60	30	90
2022 June	58	18	76
2022 May	83	28	111
2022 April	105	18	123
2022 March	169	29	198
2022 February	196	27	223
2022 January	183	32	215
2021 December	92	27	119
2021 November	99	34	133
2021 October	79	34	113
2021 September	76	25	101
2021 August	83	18	101
2021 July	58	23	81
2021 June	64	28	92
2021 May	59	24	83
2021 April	156	48	204
2021 March	109	18	127
2021 February	75	14	89
2021 January	543	24	567
2020 December	49	25	74
2020 November	77	25	102
2020 October	48	8	56
2020 September	36	16	52
2020 August	49	15	64
2020 July	205	19	224
2020 June	53	11	64
2020 May	72	6	78
2020 April	44	20	64
2020 March	55	15	70
2020 February	53	8	61
2020 January	35	2	37
2019 December	35	12	47
2019 November	39	8	47
2019 October	36	3	39
2019 September	50	7	57
2019 August	28	5	33
2019 July	42	7	49
2019 June	60	19	79
2019 May	125	12	137
2019 April	88	12	100
2019 March	31	12	43
2019 February	35	7	42
2019 January	28	2	30
2018 December	15	1	16
2018 November	34	3	37
2018 October	31	6	37
2018 September	46	10	56
2018 August	37	11	48
2018 July	32	11	43
2018 June	31	5	36
2018 May	32	5	37
2018 April	25	6	31
2018 March	16	1	17
2018 February	21	4	25
2018 January	18	2	20
2017 December	21	5	26
2017 November	22	11	33
2017 October	24	2	26
2017 September	24	6	30
2017 August	27	6	33
2017 July	31	3	34
2017 June	42	9	51
2017 May	53	9	62
2017 April	58	14	72
2017 March	55	28	83
2017 February	40	24	64
2017 January	1	13	14
2016 December	7	16	23
2016 November	7	16	23
2016 October	1	3	4

Show all

Indexed in:

Follow us:

Statistics

Indexed in:

Follow us:

Statistics

Subscribe to our newsletter