Methylene blue for surgical excision of digital myxoid cysts after sonography: Addressing the challenge of identifying the drainage tract

Digital mucous cysts are benign pseudocysts that frequently present as solitary lesions on the proximal nail folds, arising from the joint capsule and typically containing clear fluid. Although several therapeutic options exist for digital mucous cysts, the recurrence rate is high, and surgical excision remains the most effective choice1. Nevertheless, the use of ultrasound could assist in the identification of the drainage tract of the cyst within the join

«Presta los versos tú, yo el artificio»: Nuevos contrafacta espirituales de la poesía de Garcilaso

Este artículo trata de interpretar el sentido profundo que la recepción de la poesía garcilasiana adopta en una zona tan importante de nuestra literatura aurisecular como es la religiosa, donde fue objeto de numerosos intentos de reescritura desde presupuestos espirituales, adaptándola a un sentido cristiano. En nuestro trabajo se pasa revista a las versiones «a lo divino» conocidas de la lírica de Garcilaso, al tiempo que se enriquece el «corpus» de sus «contrafacta» con nuevas muestras halladas en fuentes documentales de índole muy diversa. This paper sets out to interpret the profound meaning that the reception of the Garcilaso's poetry adopts in such an important zone of the Spanish Golden Age literature as the religious one, where it was object of numerous attempts of rewriting from spiritual assumptions, making suitable for a Christian sense. In this work the known versions «a lo divino» of Garcilaso's lyric are reviewed, and at the same time the «corpus» of its «contrafacta» gets rich with new examples discovered in very diverse documentary sources

Relationships between depth and age, and recruitment indexes of hake on Galicia and Portugal shelf

In this paper it is studied the relations between the depth and the ages of the hake caugth in the six surveys done between 1974 and 1979 in the Divisions Vlllc and IXa, as soon as the recruitment levels in those years. It is observed a clear stratification of the ages and a significant bathimetric tendency to increase the mean age with the depth (1'=0.81). On the other hand, it is noticed a serious decrease in the following years over the recruitment level detected in 1974.Dans ce papier on a studie les relations entre l'âge et la profundeur du merlu capturée pendant six campagns realisées entre 1974 et 1979 dans subaire Vlllc et Division IXa du CIEM ainsi que les nivenux du recruitment durant ces annees. On observe une claire stratification entre la bathymetrie et l'âge et une tendence significatif a augmenter l'âge moyenne avec la profunder (r=0.81). D'antre coté, on constante une grave chute dans 1es anneés suivantes un relation avec le niveaux de recruitement detecté en 1974

Effect of phytase supplements on in vitro hydrolysis of proteins by rainbow trout Oncorhynchus mykiss (Walbaum, 1792)

The present paper evaluates the impact on plant meal and on an experimental feed product of supplementing them with four levels of phytase (0, 2 000, 4 000 and 6 000 FTU/kg), by assessing in vitro hydrolysis of protein in rainbow trout Oncorhynchus mykiss (Walbaum, 1792) using a pH-stat system. The effect on fish meal's digestibility of adding phytic acid was also evaluated. The highest degree of hydrolysis (DH) was obtained when phytase was added at 4 000 FTU/kg. The experimental diet's DH diminished when phytase was added at 6 000 FTU/kg. However, protein hydrolysis dropped as the percentage of phytic acid in the in vitro reaction mixture increased.En este trabajo se evaluó el efecto de la suplementación con 4 niveles de fitasa (0, 2 000, 4 000 y 6 000 FTU/kg) en un pienso experimental y sobre una harina vegetal, evaluando la hidrólisis in vitro de la proteína por pH-stat con extractos enzimáticos de trucha arcoiris Oncorhynchus mykiss (Walbaum, 1792). Además, se evaluó el efecto que ejerce la adición de ácido fítico sobre la digestibilidad de una harina de pescado. Se observó que, para el pienso experimental, el mayor grado de hidrólisis se obtiene cuando la inclusión de fitasa es de 4 000 FTU/kg, disminuyendo ligeramente cuando la inclusión es de 6 000 FTU/kg. En cambio, se observó una disminución de la hidrólisis proteica a medida que se incrementaba el porcentaje de ácido fítico en la mezcla de reacción in vitro.Instituto Español de Oceanografí

Comparison of different model solutions to simulate membrane fouling in the ultrafiltration of a secondary effluent from a municipal wastewater treatment plant

The quality of the secondary treatment effluent (STE) from a municipal wastewater treatment plant (MWWTP) is not good enough for some applications such as agriculture. Membrane ultrafiltration (UF) has been proven to be a reliable tertiary treatment to achieve the needed water quality. The productivity of the UF processes depends on the membrane fouling. The aim of this work is to prepare a model wastewater that could mimic the fouling trend of a STE wastewater from a MWWTP. Several model wastewaters consisting of different proteins and carbohydrates were used in the UF experiments. UF was also performed with a STE. The membrane used in the UF tests was a UFCM5 from Norit X-flow® hydrophilic polyethersulfone/polyvinylpyrrolidone blend hollow-fiber UF membrane of 200 KDa molecular weight cut-off with a fiber diameter of 1.5 mm. Membrane configuration was inside-out. UF tests with model wastewater and STE wastewater were compared. The results showed that the best model wastewater, which represents the fouling trend of STE wastewater is the model wastewater whose composition is 15 mg/l of bovine serum albumin and 5.5 mg/l of dextran.The authors of this work wish to gratefully acknowledge the financial support from the Generalitat Valenciana through the program "Ayudas para la realizacion de proyectos I+D para grupos de investigacion emergentes GV/2013."Tora Grau, M.; Soler Cabezas, JL.; Vincent Vela, MC.; Mendoza Roca, JA.; Martínez Francisco, FJ. (2014). Comparison of different model solutions to simulate membrane fouling in the ultrafiltration of a secondary effluent from a municipal wastewater treatment plant. Desalination and Water Treatment. 1-7. https://doi.org/10.1080/19443994.2014.939865S17Delgado, S., Dı́az, F., Vera, L., Dı́az, R., & Elmaleh, S. (2004). Modelling hollow-fibre ultrafiltration of biologically treated wastewater with and without gas sparging. Journal of Membrane Science, 228(1), 55-63. doi:10.1016/j.memsci.2003.09.011Qin, J.-J., Oo, M. H., Lee, H., & Kolkman, R. (2004). Dead-end ultrafiltration for pretreatment of RO in reclamation of municipal wastewater effluent. Journal of Membrane Science, 243(1-2), 107-113. doi:10.1016/j.memsci.2004.06.010Konieczny, K. (1998). Disinfection of surface and ground waters with polymeric ultrafiltration membranes. Desalination, 119(1-3), 251-258. doi:10.1016/s0011-9164(98)00166-0Madaeni, S. S., Fane, A. G., & Grohmann, G. S. (1995). Virus removal from water and wastewater using membranes. Journal of Membrane Science, 102, 65-75. doi:10.1016/0376-7388(94)00252-tArnal Arnal, J. M., Sancho Fernández, M., Martín Verdú, G., & Lora García, J. (2001). Design of a membrane facility for water potabilization and its application to Third World countries. Desalination, 137(1-3), 63-69. doi:10.1016/s0011-9164(01)00205-3Arévalo, J., Garralón, G., Plaza, F., Moreno, B., Pérez, J., & Gómez, M. Á. (2009). Wastewater reuse after treatment by tertiary ultrafiltration and a membrane bioreactor (MBR): a comparative study. Desalination, 243(1-3), 32-41. doi:10.1016/j.desal.2008.04.013Katsoufidou, K., Yiantsios, S. G., & Karabelas, A. J. (2008). An experimental study of UF membrane fouling by humic acid and sodium alginate solutions: the effect of backwashing on flux recovery. Desalination, 220(1-3), 214-227. doi:10.1016/j.desal.2007.02.038Muthukumaran, S., Nguyen, D. A., & Baskaran, K. (2011). Performance evaluation of different ultrafiltration membranes for the reclamation and reuse of secondary effluent. Desalination, 279(1-3), 383-389. doi:10.1016/j.desal.2011.06.040Henderson, R. K., Subhi, N., Antony, A., Khan, S. J., Murphy, K. R., Leslie, G. L., … Le-Clech, P. (2011). Evaluation of effluent organic matter fouling in ultrafiltration treatment using advanced organic characterisation techniques. Journal of Membrane Science, 382(1-2), 50-59. doi:10.1016/j.memsci.2011.07.041Fan, L., Nguyen, T., Roddick, F. A., & Harris, J. L. (2008). Low-pressure membrane filtration of secondary effluent in water reuse: Pre-treatment for fouling reduction. Journal of Membrane Science, 320(1-2), 135-142. doi:10.1016/j.memsci.2008.03.058Xiao, D., Li, W., Chou, S., Wang, R., & Tang, C. Y. (2012). A modeling investigation on optimizing the design of forward osmosis hollow fiber modules. Journal of Membrane Science, 392-393, 76-87. doi:10.1016/j.memsci.2011.12.006Kaya, Y., Barlas, H., & Arayici, S. (2011). Evaluation of fouling mechanisms in the nanofiltration of solutions with high anionic and nonionic surfactant contents using a resistance-in-series model. Journal of Membrane Science, 367(1-2), 45-54. doi:10.1016/j.memsci.2010.10.037Yu, C.-H., Fang, L.-C., Lateef, S. K., Wu, C.-H., & Lin, C.-F. (2010). Enzymatic treatment for controlling irreversible membrane fouling in cross-flow humic acid-fed ultrafiltration. Journal of Hazardous Materials, 177(1-3), 1153-1158. doi:10.1016/j.jhazmat.2010.01.022Gao, W., Liang, H., Ma, J., Han, M., Chen, Z., Han, Z., & Li, G. (2011). Membrane fouling control in ultrafiltration technology for drinking water production: A review. Desalination, 272(1-3), 1-8. doi:10.1016/j.desal.2011.01.051Amin Saad, M. (2004). Early discovery of RO membrane fouling and real-time monitoring of plant performance for optimizing cost of water. Desalination, 165, 183-191. doi:10.1016/j.desal.2004.06.021Jayalakshmi, A., Rajesh, S., & Mohan, D. (2012). Fouling propensity and separation efficiency of epoxidated polyethersulfone incorporated cellulose acetate ultrafiltration membrane in the retention of proteins. Applied Surface Science, 258(24), 9770-9781. doi:10.1016/j.apsusc.2012.06.028Qu, F., Liang, H., Wang, Z., Wang, H., Yu, H., & Li, G. (2012). Ultrafiltration membrane fouling by extracellular organic matters (EOM) of Microcystis aeruginosa in stationary phase: Influences of interfacial characteristics of foulants and fouling mechanisms. Water Research, 46(5), 1490-1500. doi:10.1016/j.watres.2011.11.051Wang, C., Li, Q., Tang, H., Yan, D., Zhou, W., Xing, J., & Wan, Y. (2012). Membrane fouling mechanism in ultrafiltration of succinic acid fermentation broth. Bioresource Technology, 116, 366-371. doi:10.1016/j.biortech.2012.03.099Nataraj, S., Schomäcker, R., Kraume, M., Mishra, I. M., & Drews, A. (2008). Analyses of polysaccharide fouling mechanisms during crossflow membrane filtration. Journal of Membrane Science, 308(1-2), 152-161. doi:10.1016/j.memsci.2007.09.060Zator, M., Ferrando, M., López, F., & Güell, C. (2007). Membrane fouling characterization by confocal microscopy during filtration of BSA/dextran mixtures. Journal of Membrane Science, 301(1-2), 57-66. doi:10.1016/j.memsci.2007.05.038Xiao, K., Wang, X., Huang, X., Waite, T. D., & Wen, X. (2009). Analysis of polysaccharide, protein and humic acid retention by microfiltration membranes using Thomas’ dynamic adsorption model. Journal of Membrane Science, 342(1-2), 22-34. doi:10.1016/j.memsci.2009.06.016Nigam, M. O., Bansal, B., & Chen, X. D. (2008). Fouling and cleaning of whey protein concentrate fouled ultrafiltration membranes. Desalination, 218(1-3), 313-322. doi:10.1016/j.desal.2007.02.027MOUROUZIDISMOUROUZIS, S., & KARABELAS, A. (2006). Whey protein fouling of microfiltration ceramic membranes—Pressure effects. Journal of Membrane Science, 282(1-2), 124-132. doi:10.1016/j.memsci.2006.05.012Carić, M. Đ., Milanović, S. D., Krstić, D. M., & Tekić, M. N. (2000). Fouling of inorganic membranes by adsorption of whey proteins. Journal of Membrane Science, 165(1), 83-88. doi:10.1016/s0376-7388(99)00221-5Tasselli, F., Cassano, A., & Drioli, E. (2007). Ultrafiltration of kiwifruit juice using modified poly(ether ether ketone) hollow fibre membranes. Separation and Purification Technology, 57(1), 94-102. doi:10.1016/j.seppur.2007.03.007Hao, Y., Moriya, A., Maruyama, T., Ohmukai, Y., & Matsuyama, H. (2011). Effect of metal ions on humic acid fouling of hollow fiber ultrafiltration membrane. Journal of Membrane Science, 376(1-2), 247-253. doi:10.1016/j.memsci.2011.04.035Marcos, B., Moresoli, C., Skorepova, J., & Vaughan, B. (2009). CFD modeling of a transient hollow fiber ultrafiltration system for protein concentration. Journal of Membrane Science, 337(1-2), 136-144. doi:10.1016/j.memsci.2009.03.036Chung, T.-S., Qin, J.-J., & Gu, J. (2000). Effect of shear rate within the spinneret on morphology, separation performance and mechanical properties of ultrafiltration polyethersulfone hollow fiber membranes. Chemical Engineering Science, 55(6), 1077-1091. doi:10.1016/s0009-2509(99)00371-1Nguyen, T.-A., Yoshikawa, S., Karasu, K., & Ookawara, S. (2012). A simple combination model for filtrate flux in cross-flow ultrafiltration of protein suspension. Journal of Membrane Science, 403-404, 84-93. doi:10.1016/j.memsci.2012.02.026Domínguez Chabaliná, L., Rodríguez Pastor, M., & Rico, D. P. (2013). Characterization of soluble and bound EPS obtained from 2 submerged membrane bioreactors by 3D-EEM and HPSEC. Talanta, 115, 706-712. doi:10.1016/j.talanta.2013.05.062Viebke, C. (2000). Determination of molecular mass distribution of κ-carrageenan and xanthan using asymmetrical flow field-flow fractionation. Food Hydrocolloids, 14(3), 265-270. doi:10.1016/s0268-005x(99)00066-1Kelly, S. T., & Zydney, A. L. (1995). Mechanisms for BSA fouling during microfiltration. Journal of Membrane Science, 107(1-2), 115-127. doi:10.1016/0376-7388(95)00108-oHwang, K.-J., & Sz, P.-Y. (2011). Membrane fouling mechanism and concentration effect in cross-flow microfiltration of BSA/dextran mixtures. Chemical Engineering Journal, 166(2), 669-677. doi:10.1016/j.cej.2010.11.04

Effects of mesh size and effort changes on the ibero-atlantic hake (Merluccius merluccius L.) fishery (Div. VIIIc (W) + IXa)

This paper concerns Hake fishery from the North of Galicia (Spain) to the South of Portugal. It represents one more attempt in obtaining more informations about the exploitation state of hake stock in this area. The aim of this study is to assess the immediate and long-term effects in this fishery with different fishing strategies. The models used were the following: a) increases in mesh-size: - Gulland (1961), Jones (1974), Ricker (1975), Cadima (1976,1978). b) increases in mesh-size and changes in fishing effort: - Jones (1974) and Ricker (1975). To apply such methods we used the data concerning the mean catches (from 1974 to 1977) belonging to the Galician and Portuguese fleets.Ce travail concerne la pêcherie du merlu de la côte nord de la Galice (Espagne), jusq'au sud du Portugal. Il répresente un essai en plus pour améliorer notre connaissance sur l'état d'exploitation du stock du merlu dans cette même region. Le but de cet étude c'est l'évaluation des effects immédiats et a long terme sur la pêcherie selon des stratégies de peche différentes. Les modeles appliqués ont été les suivants: a) pour les accroissements des maillages: Gulland (1961), Jones (1974), Ricker (1975), Cadima (1976,1978). b) pour les variations de l'effort et augmentations des mail lages: Jones (1974) et Ricker (1975). Pour l'application des méthodes mentionnées, nous avons utilisé les données rélatives a la moyenne des captures réalisées par les flotilles espagnole (Galicienne) et portugaise, pendant la période 1974-77

Study of the influence of operational conditions and hollow-fiber diameter on the ultrafiltration performance of a secondary treatment effluent

Secondary treatment effluents from municipal wastewater treatment plants (MWWTP) must achieve high water quality standards for their reuse in agriculture. To achieve these standards, ultrafiltration (UF) process, which is economically feasible, is carried out. However, UF has a drawback, membrane fouling, which causes operating difficulties and an increment of the operating cost. In order to minimize this phenomenon, it is important to determine the best operational conditions. Wastewater samples provided by MWWTP have a lot of variability in their composition due to factors such as temperature, efficiency of the secondary treatment, etc. Besides, the soluble microbial products of the secondary effluent are dependent on the type of the biological treatment implemented and its operating conditions. A model wastewater feed solution was prepared consisting of 15 mg/L of bovine serum albumin and 5.5 mg/L of dextran. In this research, UF tests were performed with the optimal simulated wastewater using two membranes UFCM5 Norit X-flow® hollow-fiber: one of them with a fiber diameter of 1.5 mm and the other one with a fiber diameter of 0.8 mm. The operational conditions, which influence membrane fouling, were varied in the range of 62 100 kPa for transmembrane pressure (TMP) and in the range of 0.8 1.2 m/s for cross-flow velocity (CFV). The best operational conditions were selected in terms of higher permeate flux. The highest permeate flux was obtained for the membrane of 0.8 mm and the lower energy consumption was achieved at a CFV of 1.2 m/s and a TMP of 62 kPa.Torà Grau, M.; Soler Cabezas, JL.; Vincent Vela, MC.; Mendoza Roca, JA.; Martínez Francisco, FJ. (2015). Study of the influence of operational conditions and hollow-fiber diameter on the ultrafiltration performance of a secondary treatment effluent. Desalination and Water Treatment. 1-7. doi:10.1080/19443994.2015.1118887S1

Ultrafiltration fouling trend simulation of a municipal wastewater treatment plant effluent with model wastewater

Secondary treatment effluents from Municipal Wastewater Treatment Plants require tertiary treatments to be reused in agriculture. Among tertiary treatment technologies, ultrafiltration has been proven to be a reliable reclamation process. Nevertheless this technique has an important disadvantage: membrane fouling. This phenomenon causes decline in permeate flux with time and increases the operational costs. Due to the fact that secondary effluents from Municipal Wastewater Treatment Plants contain a large amount of different compounds and that there is certain variability in their composition, the use of a simplified model wastewater consisting of only few compounds may help to simulate better the ultrafiltration fouling trend. The main secondary treatment effluent components responsible for fouling membrane during ultrafiltration tests are extracellular polymeric substances. These substances are mainly composed of proteins and polysaccharides, thus they are commonly used to prepare model wastewaters. This work consisted in two parts. Firstly, a model wastewater was selected among different model solutions mimicking secondary treatment effluent. Secondly, ultrafiltration behaviour of the selected model solution was compared with the behaviour of the secondary effluent in the ultrafiltration tests at different cross-flow velocities and transmembrane pressures. The membrane used in the ultrafiltration tests was UFCM5 Norit X-flow® hollow-fiber. To prepare model wastewaters, three parameters (proteins and carbohydrates concentrations and chemical oxygen demand) were considered. The model wastewater that represented the best the fouling trend of the secondary treatment effluent had a composition of 15 mg/l of bovine serum albumin and 5.5 mg/l of dextranThe authors wish to gratefully acknowledge the financial support of the Generalitat Valenciana through the project "Ayudas para la realizacion de proyectos I+D para grupos de investigacion emergentes GV/2013."Tora Grau, M.; Soler Cabezas, JL.; Vincent Vela, MC.; Mendoza Roca, JA.; Martínez Francisco, FJ. (2015). Ultrafiltration fouling trend simulation of a municipal wastewater treatment plant effluent with model wastewater. Desalination and Water Treatment. 1-9. doi:10.1080/19443994.2014.999714S19Qin, J.-J., Oo, M. H., Lee, H., & Kolkman, R. (2004). Dead-end ultrafiltration for pretreatment of RO in reclamation of municipal wastewater effluent. Journal of Membrane Science, 243(1-2), 107-113. doi:10.1016/j.memsci.2004.06.010Arévalo, J., Garralón, G., Plaza, F., Moreno, B., Pérez, J., & Gómez, M. Á. (2009). Wastewater reuse after treatment by tertiary ultrafiltration and a membrane bioreactor (MBR): a comparative study. Desalination, 243(1-3), 32-41. doi:10.1016/j.desal.2008.04.013Katsoufidou, K., Yiantsios, S. G., & Karabelas, A. J. (2008). An experimental study of UF membrane fouling by humic acid and sodium alginate solutions: the effect of backwashing on flux recovery. Desalination, 220(1-3), 214-227. doi:10.1016/j.desal.2007.02.038Muthukumaran, S., Nguyen, D. A., & Baskaran, K. (2011). Performance evaluation of different ultrafiltration membranes for the reclamation and reuse of secondary effluent. Desalination, 279(1-3), 383-389. doi:10.1016/j.desal.2011.06.040Henderson, R. K., Subhi, N., Antony, A., Khan, S. J., Murphy, K. R., Leslie, G. L., … Le-Clech, P. (2011). Evaluation of effluent organic matter fouling in ultrafiltration treatment using advanced organic characterisation techniques. Journal of Membrane Science, 382(1-2), 50-59. doi:10.1016/j.memsci.2011.07.041Muthukumaran, S., Jegatheesan, J. V., & Baskaran, K. (2013). Comparison of fouling mechanisms in low-pressure membrane (MF/UF) filtration of secondary effluent. Desalination and Water Treatment, 52(4-6), 650-662. doi:10.1080/19443994.2013.826324Yu, C.-H., Fang, L.-C., Lateef, S. K., Wu, C.-H., & Lin, C.-F. (2010). Enzymatic treatment for controlling irreversible membrane fouling in cross-flow humic acid-fed ultrafiltration. Journal of Hazardous Materials, 177(1-3), 1153-1158. doi:10.1016/j.jhazmat.2010.01.022Gao, W., Liang, H., Ma, J., Han, M., Chen, Z., Han, Z., & Li, G. (2011). Membrane fouling control in ultrafiltration technology for drinking water production: A review. Desalination, 272(1-3), 1-8. doi:10.1016/j.desal.2011.01.051Kaya, Y., Barlas, H., & Arayici, S. (2011). Evaluation of fouling mechanisms in the nanofiltration of solutions with high anionic and nonionic surfactant contents using a resistance-in-series model. Journal of Membrane Science, 367(1-2), 45-54. doi:10.1016/j.memsci.2010.10.037Delgado, S., Dı́az, F., Vera, L., Dı́az, R., & Elmaleh, S. (2004). Modelling hollow-fibre ultrafiltration of biologically treated wastewater with and without gas sparging. Journal of Membrane Science, 228(1), 55-63. doi:10.1016/j.memsci.2003.09.011Fan, L., Nguyen, T., Roddick, F. A., & Harris, J. L. (2008). Low-pressure membrane filtration of secondary effluent in water reuse: Pre-treatment for fouling reduction. Journal of Membrane Science, 320(1-2), 135-142. doi:10.1016/j.memsci.2008.03.058Xiao, D., Li, W., Chou, S., Wang, R., & Tang, C. Y. (2012). A modeling investigation on optimizing the design of forward osmosis hollow fiber modules. Journal of Membrane Science, 392-393, 76-87. doi:10.1016/j.memsci.2011.12.006Zator, M., Ferrando, M., López, F., & Güell, C. (2007). Membrane fouling characterization by confocal microscopy during filtration of BSA/dextran mixtures. Journal of Membrane Science, 301(1-2), 57-66. doi:10.1016/j.memsci.2007.05.038Nataraj, S., Schomäcker, R., Kraume, M., Mishra, I. M., & Drews, A. (2008). Analyses of polysaccharide fouling mechanisms during crossflow membrane filtration. Journal of Membrane Science, 308(1-2), 152-161. doi:10.1016/j.memsci.2007.09.060Nguyen, S. T., & Roddick, F. A. (2011). Chemical cleaning of ultrafiltration membrane fouled by an activated sludge effluent. Desalination and Water Treatment, 34(1-3), 94-99. doi:10.5004/dwt.2011.2790Xiao, K., Wang, X., Huang, X., Waite, T. D., & Wen, X. (2009). Analysis of polysaccharide, protein and humic acid retention by microfiltration membranes using Thomas’ dynamic adsorption model. Journal of Membrane Science, 342(1-2), 22-34. doi:10.1016/j.memsci.2009.06.016Hwang, K.-J., & Chiang, Y.-C. (2014). Comparisons of membrane fouling and separation efficiency in protein/polysaccharide cross-flow microfiltration using membranes with different morphologies. Separation and Purification Technology, 125, 74-82. doi:10.1016/j.seppur.2014.01.041Yamamura, H., Okimoto, K., Kimura, K., & Watanabe, Y. (2014). Hydrophilic fraction of natural organic matter causing irreversible fouling of microfiltration and ultrafiltration membranes. Water Research, 54, 123-136. doi:10.1016/j.watres.2014.01.024Nigam, M. O., Bansal, B., & Chen, X. D. (2008). Fouling and cleaning of whey protein concentrate fouled ultrafiltration membranes. Desalination, 218(1-3), 313-322. doi:10.1016/j.desal.2007.02.027MOUROUZIDISMOUROUZIS, S., & KARABELAS, A. (2006). Whey protein fouling of microfiltration ceramic membranes—Pressure effects. Journal of Membrane Science, 282(1-2), 124-132. doi:10.1016/j.memsci.2006.05.012Carić, M. Đ., Milanović, S. D., Krstić, D. M., & Tekić, M. N. (2000). Fouling of inorganic membranes by adsorption of whey proteins. Journal of Membrane Science, 165(1), 83-88. doi:10.1016/s0376-7388(99)00221-5Tasselli, F., Cassano, A., & Drioli, E. (2007). Ultrafiltration of kiwifruit juice using modified poly(ether ether ketone) hollow fibre membranes. Separation and Purification Technology, 57(1), 94-102. doi:10.1016/j.seppur.2007.03.007Vincent-Vela, M.-C., Álvarez-Blanco, S., Lora-García, J., & Bergantiños-Rodríguez, E. (2009). Estimation of the gel layer concentration in ultrafiltration: Comparison of different methods. Desalination and Water Treatment, 3(1-3), 157-161. doi:10.5004/dwt.2009.454Valiño, V., San Román, M. F., Ibáñez, R., Benito, J. M., Escudero, I., & Ortiz, I. (2014). Accurate determination of key surface properties that determine the efficient separation of bovine milk BSA and LF proteins. Separation and Purification Technology, 135, 145-157. doi:10.1016/j.seppur.2014.07.051Luck, P. J., Vardhanabhuti, B., Yong, Y. H., Laundon, T., Barbano, D. M., & Foegeding, E. A. (2013). Comparison of functional properties of 34% and 80% whey protein and milk serum protein concentrates. Journal of Dairy Science, 96(9), 5522-5531. doi:10.3168/jds.2013-6617Marcos, B., Moresoli, C., Skorepova, J., & Vaughan, B. (2009). CFD modeling of a transient hollow fiber ultrafiltration system for protein concentration. Journal of Membrane Science, 337(1-2), 136-144. doi:10.1016/j.memsci.2009.03.036Chung, T.-S., Qin, J.-J., & Gu, J. (2000). Effect of shear rate within the spinneret on morphology, separation performance and mechanical properties of ultrafiltration polyethersulfone hollow fiber membranes. Chemical Engineering Science, 55(6), 1077-1091. doi:10.1016/s0009-2509(99)00371-1Salahi, A., Mohammadi, T., Rahmat Pour, A., & Rekabdar, F. (2009). Oily wastewater treatment using ultrafiltration. Desalination and Water Treatment, 6(1-3), 289-298. doi:10.5004/dwt.2009.480Janssen, A. N., van Agtmaal, J., van den Broek, W. B. P., de Koning, J., Menkveld, H. W. H., Schrotter, J.-C., … van der Graaf, J. H. J. M. (2008). Monitoring of SUR to control and enhance the performance of dead-end ultrafiltration installations treating wwtp effluent. Desalination, 231(1-3), 99-107. doi:10.1016/j.desal.2007.10.024Torà-Grau, M., Soler-Cabezas, J. L., Vincent-Vela, M. C., Mendoza-Roca, J. A., & Martínez-Francisco, F. J. (2014). Comparison of different model solutions to simulate membrane fouling in the ultrafiltration of a secondary effluent from a municipal wastewater treatment plant. Desalination and Water Treatment, 1-7. doi:10.1080/19443994.2014.93986

Ultrafiltration of municipal wastewater: study on fouling models and fouling mechanisms

Ultrafiltration (UF) with hollow fiber membranes is a proven membrane technique that can achieve high water quality standards as a tertiary treatment in municipal wastewater treatment plants. However, UF has a major drawback, membrane fouling, which causes losses of productivity and increases operation costs. Thus, the aim of this work is to model membrane fouling in the UF of a secondary treatment effluent. The tests were carried out with a model wastewater solution that consisted of bovine serum albumin and dextran. Three different transmembrane pressures and three different crossflow velocities were tested. Several fouling models available in the literature, and new models proposed, were fitted to permeate flux decline experimental data. The models studied by other authors and considered in this study were: Hermia s models (complete, intermediate, standard pore blocking and gel layer) and Belfort s model. The new models proposed in this work were: modified Belfort s model, quadratic exponential model, logarithmic inversed model, double exponential model and tangent inversed model. The fitting accuracy of the models was determined in terms of the R-squared and standard deviation. The results showed that the model that had the higher fitting accuracy was the logarithmic inversed model. Among the Hermia s models, the model that had the higher fitting accuracy was the intermediate pore blocking model. Therefore, the predominant fouling mechanism was determined and it was the intermediate pore blocking modelThe authors wish to gratefully acknowledge the financial support of the Generalitat Valenciana through the project "Ayudas para la realizacion de proyectos I+D para grupos de investigacion emergentes GV/2013".Soler Cabezas, JL.; Tora Grau, M.; Vincent Vela, MC.; Mendoza Roca, JA.; Martínez Francisco, FJ. (2014). 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Incidencia de la forma de evaluar los docentes de Educación Primaria en el rendimiento de los estudiantes en España

La forma en cómo se evalúa a los estudiantes en el aula es un elemento fundamental que incide directamente en su desarrollo cognitivo y socio-afectivo. Esta investigación busca determinar la relación entre las actividades de evaluación que llevan a cabo los docentes de Educación primaria de escuelas españolas y el desarrollo en los alumnos de las siguientes competencias: Lingüística, Matemática, Científica, Social y Ciudadana. Para alcanzarlo se realiza una explotación especial de los datos de la Evaluación de Diagnóstico General (EDG) de 2009 a 28.708 estudiantes, 1.341 docentes, 887 centros españoles mediante el uso de Modelos Multinivel de tres de niveles. Los resultados muestran que los estudiantes cuyos docentes realizan en mayor medida controles después de cada tema o lección, corrigen los deberes y cuadernos y valoran el interés y la participación en clase de los estudiantes obtienen mejores resultados. Y, por el contrario, se ha encontrado una relación inversa entre realizar controles escritos trimestrales y el desarrollo de las competencias de los estudiantes.The way teachers assess in classroom impact over cognitive and socio-affective development of the students. This paper aims to determine the relationship between the teacher’s evaluation to their students, and the academic achievement of their students in four specific areas: Linguistic Competence, Mathematical Competence, Scientific Competence, and Social and Citizenship Competence. To reach our aim, this paper made a special analysis with the data of the Spanish General Diagnostic Evaluation –2009– to 28,708 students, and 1341 teachers of 887 schools. The use of Multilevel Model Analysis with three levels shows the impact of each evaluation strategy on the four competencies studied. Our study confirms those teachers who prepare exams after each lesson, give homework, review notebooks, and value the interest and participation of students in classroom do better. On the other side, we have found an inverse relationship between prepare quarterly exams and the skill development of the students