Academic literature on the topic 'Osmotic concentration'
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Journal articles on the topic "Osmotic concentration"
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Saranga, Yehoshua, Y. H. Kim, and Jules Janick. "Changes in Tolerance to Partial Desiccation and in Metabolite Content of Celery Somatic Embryos Induced by Reduced Osmotic Potential." Journal of the American Society for Horticultural Science 117, no. 2 (1992): 342–45. http://dx.doi.org/10.21273/jashs.117.2.342.
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Effects of reduced osmotic potential on somatic embryos of celery (Apium graveolens L.) were studied in an attempt to understand and improve their tolerance to partial desiccation. Embryos responded similarly to application of high osmoticum (384 mOs/kg H2O vs. 190 mOs/kg H2O in the control), achieved either by manipulation of sucrose or polyethylene glycol concentrations (PEG). Treatments of high osmotic concentration applied during the last 2 days of the embryo production cycle increased embryo survival and conversion after partial desiccation. The most striking effect of the high osmotic concentrations was the 4-fold increase in proline, while a 2-fold increase was obtained with 1 μm ABA alone. Application of high osmotica decreased reducing sugars, increased sucrose, but did not affect starch content of embryos; of these responses, only the change in sucrose was similar to that induced by ABA. Osmotic treatments did not affect total fatty acid content in the embryos compared to the 2-fold increase induced by ABA. Chemical name used: abscisic acid (ABA).
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LENART, A., and J. M. FLINK. "Osmotic concentration of potato." International Journal of Food Science & Technology 19, no. 1 (2007): 45–63. http://dx.doi.org/10.1111/j.1365-2621.1984.tb00326.x.
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LENART, A., and J. M. FLINK. "Osmotic concentration of potato." International Journal of Food Science & Technology 19, no. 1 (2007): 65–89. http://dx.doi.org/10.1111/j.1365-2621.1984.tb00327.x.
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Oymaci, Pelin, Pauline E. Offeringa, Zandrie Borneman, and Kitty Nijmeijer. "Effect of Osmotic Pressure on Whey Protein Concentration in Forward Osmosis." Membranes 11, no. 8 (2021): 573. http://dx.doi.org/10.3390/membranes11080573.
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Forward osmosis (FO) is an emerging process to dewater whey streams energy efficiently. The driving force for the process is the concentration gradient between the feed (FS) and the concentrated draw (DS) solution. Here we investigate not only the effect of the DS concentration on the performance, but also that of the FS is varied to maintain equal driving force at different absolute concentrations. Experiments with clean water as feed reveal a flux increase at higher osmotic pressure. When high product purities and thus low reverse salt fluxes are required, operation at lower DS concentrations is preferred. Whey as FS induces severe initial flux decline due to instantaneous protein fouling of the membrane. This is mostly due to reversible fouling, and to a smaller extent to irreversible fouling. Concentration factors in the range of 1.2–1.3 are obtained. When 0.5 M NaCl is added to whey as FS, clearly lower fluxes are obtained due to more severe concentration polarization. Multiple runs over longer times show though that irreversible fouling is fully suppressed due to salting in/out effects and flux decline is the result of reversible fouling only.
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Rathna, Ravichandran, and Ekambaram Nakkeeran. "Performance of High Molecular Weight Osmotic Solution for Opuntia Betacyanin Concentration by Forward Osmosis." Current Biotechnology 8, no. 2 (2020): 116–26. http://dx.doi.org/10.2174/2211550108666191025112221.
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Background: Forward osmosis is a sustainable membrane process employed for concentrating thermo-sensitive compounds to minimize storage and transportation costs with improved shelf life. Objective: In this study, the intervention of high molecular weight osmotic agents in the concentration of Opuntia betacyanin using forward osmosis was studied. Furthermore, the statistical model was used to estimate the probabilistic behavior of the forward osmosis process during concentration. Method: By using 2k-full factor analysis, the hydrodynamic variables, such as flow rate (50 and 150 mL/min) and temperature (20 and 50ºC) of the feed solution and osmotic agent solution (OAS) were selected. The study focused on inquiring and developing a statistically significant mathematical model using four independent variables on transmembrane flux, concentration factor and concentrate recovery. Results: Betacyanin feed flow rate of 50 mL/min at 28ºC, and OAS flow rate of 150 mL/min at 50ºC were determined as optimal conditions with a 2.5-fold increase in total soluble solids for a processing time of 4 h. Furthermore, forward osmosis enhanced the betacyanin concentration from 898 to 1004 mg/L and 98.7% recovery with 0.40 L/m2h transmembrane flux with comparable improvement in its physicochemical characteristics. The lower p-value of the main effects on the responses validated the significance of the process parameters on betacyanin concentration. Conclusion: The study suggested that a high molecular weight sucrose could be used as an osmotic agent for the concentration of Opuntia betacyanin during forward osmosis.
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Feher, J. J., and G. D. Ford. "A simple student laboratory on osmotic flow, osmotic pressure, and the reflection coefficient." Advances in Physiology Education 268, no. 6 (1995): S10. http://dx.doi.org/10.1152/advances.1995.268.6.s10.
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Osmosis is usually taught from the point of view of the osmotic pressure developed when solutions of different concentrations of solute are separated by an ideal semipermeable membrane. The osmotic pressure is defined at equilibrium when there is no net flow, and it takes some time to reach this equilibrium. Although the osmotic pressure is certainly important, teaching only this point of view implicitly diminishes the importance of osmotic flow, which begins almost instantaneously across a membrane. A device was constructed with which students could measure the flow across a model membrane (dialysis tubing) as a function of concentration for solutes of different sizes. The device produced flows that were linearly proportional to the concentration, providing a confirmation of van't Hoff's law. Separate student groups repeated these experiments using both different solutes and different dialysis membranes. The combined results of four student groups showed that the flow across these nonideal membranes depends on the solute and membrane as well as the concentration of solute. Given a value for area times filtration coefficient (A x Lp) for the membranes (determined beforehand by their instructor), the students could calculate the reflection coefficient (sigma) for three solutes and two membranes. The results showed that large solutes had large sigma and that less porous membranes had larger sigma. A concurrent demonstration using this device and membranes showed that the osmotic flow can generate large pressures. These experiments and demonstration provide a balanced view of osmotic flow and pressure.
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Petrotos, Konstantinos B., and Harris N. Lazarides. "Osmotic concentration of liquid foods." Journal of Food Engineering 49, no. 2-3 (2001): 201–6. http://dx.doi.org/10.1016/s0260-8774(00)00222-3.
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Grattoni, Alessandro, Manuele Merlo, and Mauro Ferrari. "Osmotic Pressure beyond Concentration Restrictions." Journal of Physical Chemistry B 111, no. 40 (2007): 11770–75. http://dx.doi.org/10.1021/jp075834j.
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Spinelli Barria, Michele, Cecilia Morales, Cristian Merino, and Waldo Quiroz. "Realist ontology and natural processes: a semantic tool to analyze the presentation of the osmosis concept in science texts." Chemistry Education Research and Practice 17, no. 4 (2016): 646–55. http://dx.doi.org/10.1039/c5rp00219b.
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In this work, we developed an ontological tool, based on the scientific realism of Mario Bunge, for the analysis of the presentation of natural processes in science textbooks. This tool was applied to analyze the presentation of the concept of osmosis in 16 chemistry and biology books at different educational levels. The results showed that more than 50% of the books present the process of osmosis connected just with concentration properties associated with the hydrodynamic state of the osmotic process, forgetting the properties of osmotic pressure to define the state of osmotic equilibrium. This omission creates confusion between the state of osmotic equilibrium with the isotonic state by reducing the entire osmosis process to a mere process of diffusion by differences in concentrations. Moreover, in 4 of the biology textbooks, the presentation of the osmosis concept and osmotic equilibrium in cell system illustrations generates confusion between hydrostatic pressure generated by gravityvs.hydrostatic pressure generated by membrane tension or turgor pressure. Our results show that in most of the texts, the osmotic process is not connected with the non-equilibrium state, macroscopic dynamic state or equilibrium state, whereas in other textbooks, equivalence between these states and hypo–hyper and isotonic states is incorrectly presented.
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Welti, J., E. Palou, A. Lopez-Malo, and A. Balseira. "Osmotic Concentration – Drying of Mango Slices." Drying Technology 13, no. 1-2 (1995): 405–16. http://dx.doi.org/10.1080/07373939508916960.
Full textDissertations / Theses on the topic "Osmotic concentration"
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Warczok, Justyna. "Concentration of Osmotic Dehydration Solutions using Membrane Separation Processes." Doctoral thesis, Universitat Rovira i Virgili, 2005. http://hdl.handle.net/10803/8534.
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El procesado de alimentos conlleva, en mayoría de los casos, la generación de subproductos o residuos que pueden ser reutilizados o revalorizados mediante la utilización de técnicas de separación por membrana. Estas técnicas ofrecen la posibilidad de tratar las soluciones en condiciones de operación muy suaves, y no comportan en mayoría de las ocasiones, una alteración de los componentes a recuperar. Actualmente, las técnicas de separación por membrana, debido a su alta calidad y relativamente bajos costes, se encuentran completamente integradas en la mayoría de procesos productivos que requieren de una etapa de separación. Sin embargo, la investigación en el área de las técnicas de separación por membrana sigue abriendo nuevos campos de aplicación, que surgen con la mejora de las condiciones tecnológicas de los equipos y la posibilidad de obtener nuevas membranas adaptables a necesidades específicas.<br/><br/>En concreto, en este proyecto se utilizaron técnicas de separación por membranas para concentrar soluciones de azúcar procedentes de deshidratación osmótica (en adelante OD). El principal objetivo fue estudiar el potencial de varias técnicas de separación, haciendo hincapié en los flujos obtenidos durante la reconcentración y en la calidad de la solución reconcentrada.<br/><br/>La deshidratación osmótica es un tratamiento que permite una eliminación parcial del agua en un alimento y/o la incorporación de solutos de una manera controlada, respetando la calidad inicial del producto. El proceso consiste en introducir los alimentos en una solución hipertónica, controlando las condiciones de operación para favorecer, en mayor o menor grado la incorporación de solutos y la deshidratación del alimento. La aplicación de OD puede resultar en la mejora de las propiedades nutricionales y funcionales de los alimentos y en la reducción de la energía requerida para la deshidratación. El principal problema de la aplicación industrial de la OD radica en la gestión de la solución procedente del proceso. La reutilización de esta solución plantea una doble ventaja: primero desde el punto de vista ambiental, ya que se elimina un efluente del proceso que a menudo no puede ser vertido directamente, y segundo el ahorro económico que representa la recuperación de las materias primas que muchas veces contienen solutos de importante valor económico. <br/><br/>Los métodos de separación por membrana utilizados para recuperar las soluciones de OD fueron los siguientes: nanofiltración, osmosis directa y destilación osmótica por membranas. La nanofiltración (NF) presenta altos niveles de retención y un menor gasto de energía que la osmosis inversa, y en la industria azucarera se aplica como uno de los pasos en la clarificación y concentración de jarabes. En los procesos de contactores de membranas: osmosis directa (DO) y destilación osmótica por membranas (OMD), a diferencia de los procesos basados en el tamizaje, el flujo depende solamente de la diferencia de potencial osmótico. Las únicas presiones hidráulicas requeridas son las necesarias para bombear la solución de azúcar y la solución osmótica hasta la superficie de la membrana. Estas características hacen que estos procesos presenten como muy prometedores para la reconcentración de soluciones de azúcar de concentraciones elevadas.<br/><br/>Los experimentos de filtración se llevaron a cabo utilizando plantas piloto diseñadas y construidas expresamente para el presente proyecto. Durante todos los procesos de separación por membranas, se empleó como solución modelo una solución de sacarosa a diferentes concentraciones (5-60 ºBrix), debido a que las soluciones aplicadas en la deshidratación osmótica de frutas son habitualmente soluciones de azucares (sacarosa, glucosa o jarabes). <br/><br/>Durante los experimentos de NF se evaluó el funcionamiento de las membranas planas: Desal5 DK (GE- Osmonics), MPF-34 (Koch Membrane), NFT-50 (DSS) y tubulares: MPT-34 (Koch Membrane) y AFC 80 (PCIMembranes). Además de la solución de azúcar de diferentes concentraciones (5-20 ºBrix), se concentraron zumos de pera y manzana.<br/><br/><br/>La reconcentración mediante osmosis directa se realizó utilizando dos modos de operación: off-site e on-site. En el modo off-site, la reconcentración por ósmosis directa se llevó a cabo en una planta de filtración provista de un módulo plano o tubular, dependiendo de la membrana. En el módulo se llevó a cabo la concentración. En el modo on-site, la deshidratación se realizaba conjuntamente con la reconcentración de la solución osmótica. La solución de reconcentración de la osmosis directa en off-site (offsiteDO) fue NaCl, mientras la solución de reconcentración de la osmosis directa on-site (on-site DO) fue una solución de sacarosa más concentrada que la solución osmótica (60 para una solución osmótica de 40 y 68 para una solución de 50 ºBrix). Para garantizar el flujo de agua entre las dos soluciones y altas retenciones de azúcar durante la off-site DO, se utilizaron membranas de NF planas (Desal5-DK y MPF-34) y tubulares (MPT-34 y AFC80). La reconcentración por osmosis directa on-site se levó a cabo empleando una membrana de microfiltración (Durapore, Millipore), ya que la solución de reconcentración (SS) es la misma que la solución osmótica y la alta viscosidad de la SS restringe mucho el flujo de agua si se utiliza una membrana más densa.<br/><br/>En la deshidratación por membranas (OMD) se utilizaron membranas hidrófobas (11806, Sartorius) que presentan una retención teórica del 100 %. Se comparó el rendimiento de dos soluciones de reconcentración: NaCl y CaCl2.<br/><br/>Con el fin de obtener información referente a la influencia de las propiedades de las membranas sobre el desarrollo del proceso de concentración de las soluciones procedentes de la deshidratación osmótica, se realizó un estudio detallado de las propiedades de las membranas aplicadas mediante AFM, SEM, FTIR, ángulo de contacto y medidas de potencial zeta. Con la finalidad de generar soluciones osmóticas para someterlas a reconcentración, y también para disponer de productos procedentes de deshidratación osmótica con soluciones frescas que pudieran compararse con aquellas procedentes de OD con solución reconcentrada, se deshidrataron diferentes lotes de manzana (Granny Smith) con soluciones de sacarosa de 40, 50 y 60 ºBrix. Estas pruebas permitieron determinar también el tímelo de operación para una máxima pérdida de agua con relativamente poca impregnación de las manzanas. Después de cada experimento se analizaron los siguientes parámetros: concentración de azúcar, pH, absorbancia a 420 nm de las soluciones y humedad de las manzanas.<br/><br/>La nanofiltración, aplicada en la primera fase del presente estudio, resultó ser viable solamente para la reconcentración de soluciones de concentraciones hasta 24 ºBrix. El aumento de la temperatura de 25 hasta 35 ºC para las dos membranas tubulares ocasionó un incremento del flujo de permeado, y el mismo efecto tuvo el aumento de presión transmembranaria de 8 a 12 bar.<br/><br/>Se comprobó que el factor más importante para la eficacia del proceso es disponer de una membrana que combine altos flujos y retenciones durante el proceso. La deposición de las partículas de sacarosa y/o los zumos se caracterizó mediante SEM y la topología de la capa filtrante de la membrana se identificó usando AFM. La topología de la capa filtrante de las membranas era diferente para cada una de ellas, a pesar de que todas estaban preparadas con el mismo material (poliamida). En las imágenes de los cortes transversales de las membranas realizados con SEM, se observaron los cambios en la estructura de las membranas producidos por la aplicación de presión durante los experimentos y las altas temperaturas empleadas durante su acondicionamiento. Gracias a las imágenes de SEM se pudo verificar también la eficacia del proceso de acondicionamiento de membranas.<br/><br/>A diferencia de NF, tanto la ósmosis directa como la destilación osmótica por membrana permiten la reconcentración de soluciones concentradas de sacarosa (hasta60 ºBrix). La eficacia de estas dos últimas técnicas se evaluó en unción de los flujos de agua obtenidos.<br/><br/>El sistema de ósmosis directa on-site propuesto para la reconcentración de las soluciones de OD permitió reutilizar las soluciones osmóticas como mínimo cuatro veces. Para la solución osmótica de 40 ºBrix la humedad de las manzanas fue similar utilizando solución fresca o reconcentrada. En cambio, una solución osmótica de 50 ºBrix, la pérdida de agua de las manzanas fue mayor cuando la deshidratación osmótica se llevó a cabo con reconcentración on-site de la solución osmótica. Los análisis de concentración de azúcar de las soluciones osmóticas y de la solución de reconcentración indican que la membrana elegida para los experimentos facilita el transporte óptimo de solutos y agua entre las dos soluciones. Además, el sistema de reconcentración por membrana propuesto es muy sencillo y de bajo coste porque no requiere presurización.<br/><br/>La osmosis directa en off-site proporcionó flujos mucho mayores que los obtenidos con el sistema on-site (1.3 kg/m2h para la solución osmótica de 50 ºBrix respecto a 0.0023 kg/m2h durante on-site DO para la misma solución). Sin embargo, el transporte de solutos de la solución de reconcentración hacía la solución osmótica puede ser considerado un obstáculo para su aplicación a escala industrial.<br/><br/>Los flujos de agua más elevados fueron obtenidos utilizando la OMD (2.01 kg/m2h para la solución osmótica de 50 ºBrix y con CaCl2 con la solución de reconcentración). Otra gran ventaja de este proceso es la retención de solutos que proporciona, hecho confirmado por los análisis realizados.<br/><br/>El estudio sobre el transporte durante los procesos de contactores de membranas indicó que la viscosidad es la propiedad limitante para la solución osmótica y la actividad de agua/alta presión osmótica como la propiedad más importante a la hora de elegir una solución de reconcentración. Para todos los procesos de separación aplicados, el aumento de la concentración de azúcar de la solución osmótica comporta una disminución notable del flujo de agua.<br/><br/>El desarrollo de un posible proceso de deshidratación osmótica con una etapa de reconcentración de la solución osmótica mediante procesos con contactores de membrana ha permitido calcular el área requerida para realizar la reconcentración: 3.6,9.7, 1608 m2 para OMD, off-site DO e on-site DO, respectivamente.<br/><br/>Las conclusiones del trabajo confirman la posibilidad de utilizar procesos por membrana para realizar la reconcentración de soluciones osmóticas. No obstante se ha constatado que técnicas más tradicionales basadas en diferencias de presión (NF) no son
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Bailey, Adelaide Fiona Grace. "The Concentration of Aqueous Solutions By Osmotic Distillation (OD)." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16006/.
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This study was to investigate theory and application of Osmotic Distillation (OD). OD is a new novel membrane separation process used for the concentration of aqueous solutions such as fruit juices without the application of heat. The present work was undertaken to investigate flux limitations focusing on feedside, membrane and stripper side characteristics of OD. Once the limiting areas were identified, further studies were undertaken to determine methods of minimizing those limitations without losing the quality and integrity of the liquid feed. A laboratory scale OD system was used to simulate the industrial process which takes place during the production of grape juice concentrate for the fruit juice industry. Results of a UF pretreatment study showed that the use of UF membranes with pore diameters of 0.1 fÝm or less as a pretreatment for the subsequent OD of grape juice resulted in significant increases in OD flux over that observed for juice not subjected to UF. The study of the physical properties of the feed played an important role in the explanation of the OD process. The increase in OD flux was attributed to a reduction in juice viscosity as the result of the removal of protein and other high molecular weight components. Apart from an increase in OD flux, UF pretreatment of the grape juice proved to be beneficial in other areas of the OD process. HPLC measurements showed that the normal concentration of fermentable sugars in standard 68 oBrix concentrate can be achieved at a lower Brix value in feed subjected to UF pretreatment, further reducing the need to handle highly viscous feeds. UF pretreatment also resulted in an increase in juice surface tension consequently reducing the tendency for membrane wet-out to occur. The study of the deoxygenation of the feed solution shows that the removal of dissolved gases by the pre boiling method and the perstraction with chemical reaction (PCR) method both had a positive affect on OD flux. Pre boiling the brine resulted in an indirect reduction in dissolved oxygen in the feed. Pre boiling both the feed and brine, further increased the flux. Throughout the PCR study, it was evident that stripper side mass transfer of O2 was not limited by flowrate but was limited by higher stripper concentration. However, the latter had an insignificant effect when the sulfite-oxygen reaction was catalysed. The use of a catalyst and increase in temperature gave a significant improvement in overall mass transfer coefficient. Ten types of hydrophobic microporous membranes were tested for their influence on OD flux. While the pore diameter is a considerable factor in mass transport of gases through the membrane, it was also noted that the type of membrane material used had an affect on the overall mass transfer. All top three performing membranes had pore diameters of 0.2 x 10-6 m and were made from polytetrafluoroethylene (PTFE). The choice of brine to use as the stripper was based on criteria that were confirmed by the brine studies performed here. The best performing stripper solutions demonstrating the greatest improvement in OD flux over the most commonly used brines, NaCl, CaCl2 and CH3COOK were aqueous solutions of potassium salts of phosphoric acid, pyrophosphoric acid and blends thereof. These salts agreed with all the required characteristics of a suitable brine, demonstrating high solubility rates, supporting the ability to lower water vapour pressure. The study of the corrosion effects of brine salts confirmed the phosphate salts are superior demonstrating some of the lowest corrosion rates and highest pH.
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Anh, Viet Bui, of Western Sydney Hawkesbury University, of Science Technology and Environment College, and of Science Food and Horticulture School. "A study of osmotic distillation in hollow fibre modul." THESIS_CSTE_SFH_Anh_V.xml, 2002. http://handle.uws.edu.au:8081/1959.7/4.
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Osmotic distillation is a process of removing water from an aqueous solution, driven by water vapour pressure gradient across a hydrophobic membrane. The process occurs at or below ambient temperature and under atmospheric pressure. This research project investigates the osmotic distillation process in hollow fibre modules using hollow fibres PP375, PV375 and PV660 supplied by Memcor Australia. Operating conditions such as temperature, feed concentration and brine cross flow velocity, but not the feed cross flow velocity, were found to have significant effect on the flux. Models for heat and mass transfers were used to study the polarisation phenomena in osmotic distillation. Temperature and concentration profiles at the membrane surfaces due to polarisation were quantified. Scholfield and Ordinary Diffusion models for flux prediction based on the bulk conditions were developed and validated. Models for water activity and viscosity of aqueous glucose and calcium chloride solutions were also developed and validated in this work.<br>Master of Science (Hons)
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Ventura, Fernanda Cardoso. "Desenvolvimento de doce de fruta em massa funcional de valor calorico reduzido, pela combinação de goiaba vermelha e yacon desidratados osmoticamente e acerola." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255236.
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Orientador: Nelson Horacio Pezoa Garcia<br>Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos<br>Made available in DSpace on 2018-08-03T21:38:54Z (GMT). No. of bitstreams: 1
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Previous issue date: 2004<br>Resumo: Ultimamente tem aumentado a preocupação pela relação entre dieta e saúde, estimulando o consumo de alimentos saudáveis, nutritivos e funcionais e ainda de valor calórico reduzido, que tenham nutrientes com potencial protetor de saúde. Esses alimentos além de satisfazer requerimentos nutricionais e sensoriais básicos desempenham efeitos fisiológicos benéficos que diminuiriam o risco de doenças crônicas cardiovasculares, cancerígenas ou outras. Existe uma grande variedade de produtos para fins especiais, sendo aqueles destinados a dietas de redução de açúcares um dos mais expressivos. Assim, as indústrias têm o desafio de desenvolver processamentos em condições amenas de operação, tempo e temperatura, provocando menores alterações de coloração, sabor e nutricionais. Com base nisso, a finalidade desse trabalho foi concentrar os nutrientes da goiaba vermelha e yacon, através da desidratação osmótica e desenvolver um doce em massa com as frutas desidratadas osmoticamente e acerola, de valor calórico reduzido através de processo contínuo. Primeiramente, foi realizado um estudo para otimizar a desidratação osmótica utilizando xarope de sorbitol e de sacarose. Os ensaios foram realizados utilizando planejamento fatorial completo, variando-se o tempo, temperatura e concentração da solução osmótica, visando a maximização da perda de umidade e minimização da incorporação de sólidos. Na desidratação osmótica utilizando xarope de sorbitol foram obtidas perdas de umidade de 35 a 43% % e incorporação de sólidos de 5,7 a 8% na goiaba vermelha e no yacon 53 a 55% de perdas de umidade e 6,02 a 6,46% de incorporação de sólidos. Os resultados obtidos mostraram que utilizando xarope de sorbitol se conseguem maiores perdas de umidade em relação ao xarope de sacarose, contudo há também uma maior incorporação de sólidos, mas isto seria irrelevante no caso de produtos de baixo valor calórico, nos quais o sorbitol é comumente utilizado, por apresentar um valor energético de 2,4kcal/g, enquanto que a sacarose fornece 4kcal/g. Outro objetivo foi também obter um doce em massa de goiaba vermelha, yacon e acerola, com um maior teor em sólidos de frutas que um produto convencional. Foram realizadas três formulações para análise sensorial, sendo utilizado o teste de aceitação. Os doces em massa tiveram boas médias de aceitação sensorial, variando de ¿gostei ligeiramente¿ a ¿gostei moderadamente¿, diferindo entre si (p< 0,05) nos atributos cor, sabor e impressão global, e não apresentando diferença significativa no atributo aroma. A formulação preferida foi com 50% goiaba vermelha, 30% acerola e 20% yacon, processada em tratamento térmico contínuo. Os resultados da caracterização química (pH, acidez e atividade de água) e física (sinerese, cor e textura) dos doces em massa mostraram concordância com os trabalhos encontrados na literatura. Através da avaliação microbiológica o produto foi considerado como ¿comercialmente estéril¿, indicando que o tratamento térmico foi eficiente para manter a estabilidade microbiológica do produto<br>Abstract: Concern about the relation between diet and health has greatly increased recently, stimulating the consumption of healthy, nutritive and functional foods, preferably of reduced caloric value, containing potentially health-protecting nutrients. In addition to satisfying the basic nutritional and sensory requirements, these foods play a beneficial physiological role in decreasing the risks of chronic cardiovascular diseases, cancer and other diseases. A great variety of special purpose foods exist, those destined for low sugar diets being the most prominent. Thus modern industry faces the challenge of developing processes operating under mild time/temperature conditions so as to minimize alterations in color, flavor and nutritional quality. Based on this idea, the objective of this research was to concentrate the nutrients of red guava and yacon by osmotic dehydration and develop a reduced calorie solid preserve using the osmotically dehydrated fruits plus West Indian cherry by way of a continuous process. Initially the osmotic dehydration process was optimized using sorbitol and sucrose syrups. A complete factorial experimental design was used for these trials, varying the time, temperature and concentration of the osmotic solution, aiming at maximizing moisture loss and minimizing solids incorporation. Osmotic dehydration using sorbitol syrup resulted in moisture losses of from 35 to 43% and solids incorporation between 5.7 and 8% for red guava and moisture losses of from 53 to 55% for yacon with solids incorporation from 6.02 to 6.46%. The results showed that higher moisture losses were obtained using the sorbitol syrup than with the sucrose syrup, although the solids incorporation was also higher. However, in low calorie products this is irrelevant since sorbitol is frequently used in such products due to its low energy value of 2.4kcal/g as compared to 4kcal/g for sucrose. A further objective was to prepare a solid preserve from red guava, yacon and West Indian cherry containing higher fruit solids content than the conventional product. Three formulations were prepared for the sensory acceptance test. The three formulations received good mean scores for acceptance, varying from ¿liked slightly¿ to ¿liked moderately¿, with significant differences (p£0.05) amongst the three for the attributes of color, flavor and overall impression but with no significant difference for aroma. The most preferred formulation was that containing 50% red guava, 30% West Indian cherry and 20% yacon, processed by a continuous heat treatment. The results of the chemical (pH, acidity and water activity) and physical (syneresis, color and texture) characterizations agreed with those of similar studies reported in the literature. The microbiological evaluation showed the product to be commercially sterile, indicating that the heat treatment was efficient in maintaining the microbiological stability of the product<br>Mestrado<br>Mestre em Tecnologia de Alimentos
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Bernales, chavez Braulio. "Modélisation de l'hydrodynamique et des transferts dans les procédés de filtration membranaire." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4779/document.
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L'accumulation du soluté à la surface d'une membrane entraîne le phénomène de polarisation de concentration. Ceci est un problème qui affecte tous les systèmes de filtration membranaire car il a pour effet une augmentation de la pression osmotique et par conséquence une réduction substantielle du flux de perméat. Afin de comprendre ce phénomène, nous avons d'abord mené une étude analytique de la filtration tangentielle en solvant pur prenant en compte de l'influence de la pression motrice locale sur le taux de perméation. Lors de cette étude, des solutions analytiques qui augmentent en précision avec l'ordre développé ont ete dérivées. Ensuite nous avons développé une approche analytique qui couple l'hydrodynamique aux transferts de matière pour le cas d'un système de filtration qui opère sous haute pression avec un taux de récupération faible. Dans le but d'intégrer à la fois la dépendance de la pression transmembranaire locale sur le flux de perméat et l'influence de la polarisation de concentration à travers leurs effets osmotiques sur la pression effective, nous avons développé un modèle numérique qui résout l'équation de conservation du soluté couplée aux équations de Navier-Stokes en régime stationnaire dans l'approximation de Prandtl. Nous avons validé cette approche grâce aux solutions analytiques précédemment dérivées. Ensuite, nous avons testé l'influence des principaux paramètres de fonctionnement sur la performance du système et comparé nos résultats avec ceux d'autres modèles numériques. Finalement, la pertinence du modèle a été quantitativement vérifiée grâce à des données tirées des expériences bien documentées en osmose inverse<br>Concentration polarization of solute at the membrane surface, because of osmotic pressure effects, is an important phenomenon that can cause substantial reductions in permeation. To understand these phenomena: we first analyze the filtration process for a pure solvent, imposing the influence of the driving pressure on permeation at the membrane. We obtain accurate analytical solutions for the flow fields. We then derive an analytical solution that coupled hydrodynamics to mass transfer for filtration systems working in a situation of High Pressure and Low Recovery. Second, we develop a numerical model that incorporates both physical aspects: the dependency of pressure on permeation and the influence of concentration polarization and their related osmotic effects in the effective pressure at the membrane. For that, the numerical approach solves the solute conservation equation coupled with the Navier-Stokes equations under the steady Prandtl approximation. The solution of the system is performed using a finite difference method of order 2. The validity of this approach is successfully demonstrated with the previous analytical solutions for hydrodynamics, as well as for the coupling with mass transfer. We then test the influence of the main operating parameters (inlet concentration, axial flow rate, operating pressure and membrane permeability) on the performance of the filtration system and compare the results with other numerical models that takes into account concentration polarization phenomenon. Finally, the validity of this model is quantitatively well-proved when using the reported data resulting from reverse osmosis experiments
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Pimentel, Rosangela Nascimento. "Desenvolvimento do pré-condicionamento por estresse hiperosmótico: estudo dos efeitos no modelo de camundongos endotoxêmicos." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/5/5164/tde-24022016-105845/.
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A tolerância ou pré-condicionamento é uma estratégia de defesa do hospedeiro que reduz o impacto negativo da infecção na saúde. Diminui a susceptibilidade a danos teciduais, causados pelos patógenos ou pela resposta imune. Um desbalanço no fluido e pressão osmótica intra e extracelular causa o estresse osmótico e liberação de mediadores inflamatórios. A solução salina hipertônica (SSH) tem sido utilizada na ressuscitação volêmica, mostrando-se benéfica em pacientes com danos cerebrais e pulmonares (3), melhora a contratilidade e perfusão microvascular. Utilizamos esta solução como possível agente indutor de pre-condicionamento ou tolerância. A SSH em doses crescentes de 4, 6 e 8 ml/kg levou a diminuição da mortalidade em camundongos endotoxêmicos o mesmo ocorrendo com outras soluções hiperosmóticas. Analisamos o padrão do perfil de produção de citocinas pró e anti-inflamatórias em períodos de 2 e 4 horas pós SSH e pós LPS. No estudo sistêmico do pré-condicionamento os resultados revelaram uma diminuição da resposta inflamatória causada pelo LPS nas dosagens plasmáticas, o mesmo ocorrendo nos tecidos estudados. Concluímos que o pré-condicionamento com SSH é promissor como um prétratamento na endotoxemia<br>The tolerance or preconditioning is a host defense strategy able to reduce the infection negative effect in health. Decrease the tissue damage susceptibility caused by the imune response. A fluid imbalance and osmotic pressure intra and extracellular cause the osmotic stress and inflammatory mediators release. The hypertonic saline solution (SSH) has been used in fluid resuscitation, with good results in patients with brain and lung damage, it improves microvascular perfusion and contractility. We used this solution as a possible induct agent of preconditioning or tolerance. The Hypertonic saline solution in increasing doses of 4,6 and 8ml/kg was able to stablish a decrease in endotoxemic mice mortality, the same happened with other hyperosmotic solutions. We analyzed the pattern profile of inflammatory and anti-inflammatory cytokines in a period of two and four hours after SSH. In the systemic study of the precondicioning, the results showed a decrease in the inflammatory response caused by LPS in the plasmatic dosage, the same was observed in the studied tissues. We concluded that the preconditioning with SSH is a promising pre-treatment in endotoxemia
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Pasquier, Coralie. "Interactions et structures dans les solutions hautement concentrées de protéines globulaires : étude du lysosyme et de l'ovalbumine." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S172/document.
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Les phases concentrées de protéines sont au centre de nombreuses études visant à identifier et caractériser les interactions et transitions de phases mises en jeu, en utilisant le large corpus de connaissances acquis sur les phases concentrées de colloïdes. Ces phases concentrées de protéines possèdent en outre une grande importance dans des domaines aussi variés que l’industrie agroalimentaire, l’industrie pharmaceutique et la médecine. L’établissement d’équations d’état présentant la pression osmotique (Π) en fonction de la fraction volumique (Φ) est une méthode efficace de caractérisation des interactions entre les composants d’un système. Nous l’avons appliquée à des solutions de deux protéines globulaires, le lysozyme et l’ovalbumine, en balayant une gamme de fractions volumiques allant d’une phase diluée (Φ < 0,01) à une phase concentrée, solide (Φ > 0,62). Les équations d’état obtenues, couplées à d’autres techniques (SAXS, simulations numériques), ont permis de mettre en évidence un comportement très différent des deux protéines lors de la concentration et ont montré leur complexité en comparaison avec des colloïdes modèles. La mise en relation des équations d’état et du comportement interfacial de ces deux protéines a montré des points de convergence et permis de formuler une nouvelle hypothèse expliquant certaines observations portant sur l’adsorption des protéines à l’interface air-eau<br>Concentrated phases of proteins are the subject of numerous studies aiming at identifying and characterizing the interactions and phase transitions at play, using the large corpus of knowledge in the field of concentrated colloids. Those concentrated phases of proteins have, in addition, a great importance in various fields, such as food industry, pharmaceutical industry and medicine. The establishment of equations of state relating osmotic pressure (Ð) and volume fraction (Φ) is an efficient way of characterization of the interactions between the components of a system. We applied this method to solutions of two globular proteins, lysozyme and ovalbumin, spanning volume fractions ranging from a dilute phase ( Φ < 0,01) to a concentrated, solid phase ( Φ > 0,62). The equations of state, coupled to other methods (SAXS, numerical simulations), enabled us to show that the two proteins carry a very different behavior when submitted to concentration and that their complexity is beyond that of colloids. Relating equations of state and interfacial behavior of these two proteins also showed points of convergence and enabled us to formulate a new hypothesis which explains some of the results obtained in the study of adsorption of proteins at the air-water interface
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Holloway, Ryan W. "Forward osmosis for concentration of anaerobic digester centrate." abstract and full text PDF (free order & download UNR users only), 2006. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1436020.
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Bouma, Andrew Thomas. "Split-feed counterflow reverse osmosis for brine concentration." Thesis, Massachusetts Institute of Technology, 2018. http://hdl.handle.net/1721.1/118668.
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Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.<br>This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.<br>Cataloged from student-submitted PDF version of thesis.<br>Includes bibliographical references (pages 73-77).<br>Brine concentration is a useful operation that allows for increased recovery ratios in water treatment systems, reduction of waste volumes, and the production of minerals from saline brines. As our world moves towards a more sustainable future, improvements in energy-efficient brine concentration will be important. While viable brine concentration technologies exist, current methods are often inefficient. In this thesis, a model is developed to simulate Counterflow Reverse Osmosis (CFRO), a membrane-based, pressure-driven brine concentration technology. Using this model, a single CFRO module is simulated and its performance characterized. Entropy generation within a single-stage system is analyzed, which provides insights for configuring and optimizing multistaged systems. Additionally, a parametric analysis of membrane parameters provides direction for the development of CFRO-specific membranes. Two existing configurations of CFRO are discussed, and compared with a new third configuration, split feed CFRO, which is presented for the first time here. Split feed CFRO systems are simulated and optimized to provide guidance for system design. A variety of multistage systems operating at a range of recovery ratios are simulated, and the results compared are with existing desalination and brine concentration technologies. Potential is shown for the maximum recovery ratio of RO systems to increase significantly when hybridized with split-feed CFRO brine concentration systems, while the energy requirements of these hybridized systems is similar to, or an improvement on, the expected performance of conventional RO systems operating at high pressures and the same conditions. A large reduction in energy usage when compared to commonly used evaporative brine concentrators is shown to be possible.<br>Funded by the Kuwait Foundation for the Advancement of Sciences (KFAS) Project No. P31475EC01<br>by Andrew Thomas Bouma.<br>S.M.
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Fiorenza, Francesca. "Investigation of high pressure reverse osmosis for the concentration of tomato juice." Thesis, University of Lincoln, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.269642.
Full textBooks on the topic "Osmotic concentration"
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Galeb, Abduljalil D. S. Use of ion-exchange and direct osmotic concentration technologies for processing cantaloupe juice. 1993.
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Galeb, Abduljalil D. S. Use of ion-exchange and direct osmotic concentration technologies for processing cantaloupe juice. 1993.
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Forry, Keith R. The starch content of roots and the osmotic concentration of expressed xylem sap as predictors of Douglas-fir seelding quality. 1992.
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C, Lynch S., and Health Effects Research Laboratory (Research Triangle Park, N.C.), eds. Isolation or concentration of organic substances from water: An evaluation of reverse osmosis concentration. U.S. Environmental Protection Agency, Health Effects Research Laboratory, 1985.
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Stachowska-Pietka, Joanna, Jacek Waniewski, and Bengt Lindholm. Peritoneal dialysis. Edited by Jonathan Himmelfarb. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0264.
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The principles of peritoneal dialysis are based on the physiological processes and their driving forces which permit the exchange of water (by ultrafiltration and fluid absorption) and solutes (by diffusion and convective transport) between the peritoneal microvasculature and the dialysate. In peritoneal dialysis, the peritoneal transport system—mesenchymal cells, interstitium, microvasculature, and lymphatics—is repeatedly exposed to high concentrations of an osmotic agent, and a volume load, leading to increased intraperitoneal hydrostatic and osmotic pressure. This results in immediate as well as long-term structural and functional changes of the peritoneal transport system. Clinical tests supplemented with mathematical modelling have been developed to monitor the quantitative characteristics of the peritoneal transport system, allowing detection and diagnosis of various problems and guidance when predicting consequences of changes in prescription.
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Sheppard, Charles R. C., Simon K. Davy, Graham M. Pilling, and Nicholas A. J. Graham. The abiotic environment. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198787341.003.0003.
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Coral reefs are largely restricted to shallow tropical seas, where water is warm, nutrient poor and well illuminated for photosynthesis and where sufficient calcium carbonate (aragonite) exists in seawater for the precipitation of coral skeletons (i.e. calcification). Extreme temperatures and salinities cause thermal and osmotic stress, while large amounts of sediment smother corals and block light. High concentrations of nutrients encourage algal growth at the expense of corals, while low seawater aragonite concentrations prevent net accretion of the reef framework. At local scales, the hydrodynamic regime influences reef growth, as corals are damaged by storms and wave surge. The typical abiotic environment in which reefs are found, and which determines reef distribution, is defined. The chapter also discusses marginal reefs, where corals live at the margins of their survival, for example in the warm, salty seas of the Persian Gulf and the relatively cold waters of Australia’s Lord Howe Island.
Book chapters on the topic "Osmotic concentration"
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Lazarides, Harris N. "Concentration – Direct Osmotic Concentration of Liquid Foods." In Experiments in Unit Operations and Processing of Foods. Springer US, 2008. http://dx.doi.org/10.1007/978-0-387-68642-4_5.
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Biswal, R. N., and M. Le Maguer. "Thermodynamic Modeling of the Osmotic Concentration Process." In Developments in Food Engineering. Springer US, 1994. http://dx.doi.org/10.1007/978-1-4615-2674-2_124.
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Amede, Tilahun, and Sven Schubert. "Solute-pool enlargement in drought-sensitive or -tolerant grain legumes: Concentration effect or osmotic adjustment?" In Plant Nutrition for Sustainable Food Production and Environment. Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-009-0047-9_35.
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Larsen, Erik Hviid, and Jens Nørkær Sørensen. "Stationary and Nonstationary Ion and Water Flux Interactions in Kidney Proximal Tubule: Mathematical Analysis of Isosmotic Transport by a Minimalistic Model." In Reviews of Physiology, Biochemistry and Pharmacology. Springer International Publishing, 2019. http://dx.doi.org/10.1007/112_2019_16.
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AbstractOur mathematical model of epithelial transport (Larsen et al. Acta Physiol. 195:171–186, 2009) is extended by equations for currents and conductance of apical SGLT2. With independent variables of the physiological parameter space, the model reproduces intracellular solute concentrations, ion and water fluxes, and electrophysiology of proximal convoluted tubule. The following were shown: Water flux is given by active Na+ flux into lateral spaces, while osmolarity of absorbed fluid depends on osmotic permeability of apical membranes. Following aquaporin “knock-out,” water uptake is not reduced but redirected to the paracellular pathway. Reported decrease in epithelial water uptake in aquaporin-1 knock-out mouse is caused by downregulation of active Na+ absorption. Luminal glucose stimulates Na+ uptake by instantaneous depolarization-induced pump activity (“cross-talk”) and delayed stimulation because of slow rise in intracellular [Na+]. Rate of fluid absorption and flux of active K+ absorption would have to be attuned at epithelial cell level for the [K+] of the absorbate being in the physiological range of interstitial [K+]. Following unilateral osmotic perturbation, time course of water fluxes between intraepithelial compartments provides physical explanation for the transepithelial osmotic permeability being orders of magnitude smaller than cell membranes’ osmotic permeability. Fluid absorption is always hyperosmotic to bath. Deviation from isosmotic absorption is increased in presence of glucose contrasting experimental studies showing isosmotic transport being independent of glucose uptake. For achieving isosmotic transport, the cost of Na+ recirculation is predicted to be but a few percent of the energy consumption of Na+/K+ pumps.
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Franco, Robert, Robin Barker-Gear, Edward Silberstein, et al. "Sickle Cells Modified by an Osmotic Pulse in the Presence of Inositol Hexaphosphate Have Decreased Intracellular Hemoglobin Concentration and Decreased in Vitro Sickling without Prolonged in Vivo Survival." In The Use of Resealed Erythrocytes as Carriers and Bioreactors. Springer US, 1992. http://dx.doi.org/10.1007/978-1-4615-3030-5_39.
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Porter, Mark C. "Concentration Polarization in Reverse Osmosis and Ultrafiltration." In Synthetic Membranes: Science, Engineering and Applications. Springer Netherlands, 1986. http://dx.doi.org/10.1007/978-94-009-4712-2_13.
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Shalini, H. N., and Chetan A. Nayak. "Forward Osmosis Membrane Concentration of Raw Sugarcane Juice." In Recent Advances in Chemical Engineering. Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-1633-2_10.
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Burgot, Jean-Louis. "Activities and Concentrations of Nonelectrolytes in Dilute Liquid Solutions Study of the Osmotic Pressure." In The Notion of Activity in Chemistry. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-46401-5_38.
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Malaiyandi, Murugan, R. H. Wightman, and C. LaFerriere. "Concentration of Selected Organic Pollutants: Comparison of Adsorption and Reverse-Osmosis Techniques." In Advances in Chemistry. American Chemical Society, 1986. http://dx.doi.org/10.1021/ba-1987-0214.ch008.
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Sharief, Shoaib A., and Chetan A. Nayak. "Concentration of C-Phycocyanin from Spirulina platensis Using Forward Osmosis Membrane Process." In Biotechnology and Biochemical Engineering. Springer Singapore, 2016. http://dx.doi.org/10.1007/978-981-10-1920-3_17.
Full textConference papers on the topic "Osmotic concentration"
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Flynn, Michael, Lance Delzeit, Sherwin Gormly, et al. "Development of the Direct Osmotic Concentration System." In 40th International Conference on Environmental Systems. American Institute of Aeronautics and Astronautics, 2010. http://dx.doi.org/10.2514/6.2010-6098.
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Flynn, Michael, Jesse Fusco, Mark Kliss, et al. "Advanced Development of the Direct Osmotic Concentration System." In International Conference On Environmental Systems. SAE International, 2008. http://dx.doi.org/10.4271/2008-01-2145.
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Flynn, Michael, Sherwin Gormly, Tzahi Y. Cath, V. Dean Adams, and Amy E. Childress. "Direct Osmotic Concentration System for Spacecraft Wastewater Recycling." In International Conference On Environmental Systems. SAE International, 2007. http://dx.doi.org/10.4271/2007-01-3035.
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Howlett, Larry D. "The Theory of Osmosis." In ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-55040.
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A fresh view for explaining the process of osmosis and the phenomenon of osmotic pressure is presented. The process of osmosis was identified and modeled more than 100 years ago. Others have unsuccessfully challenged the original model developed by J.H. van’t Hoff. We revisit the basic equations and assumptions used in the thermodynamic derivation of the osmosis model. And, we propose a small but significantly different view of the traditional theory of osmosis. From this new view of osmosis and the osmosis experiment, we conclude that osmosis occurs at atmospheric pressure. In cellular membranes, flow from the solvent to the solution is related to the vapor pressure difference determined from the concentration difference with Raoult’s law. Furthermore, we suggest that osmotic pressure as determined from the osmosis experiment is related to both the solution properties and the membrane characteristics. We suggest that the difference between experimental and theoretical determination of osmotic pressure can be attributed to capillary action that may occur in some man made membranes.
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Gulied, Mona Hersi, Ahmed Al Nouss, Tasneem ElMakki, Fathima Sifani Zavahir, and Dong Suk han. "Feasibility and Cost Optimization study of Osmotic Assisted Reverse Osmosis Process for Brine Management." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0031.
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Due to the excessive demand to desalinate seawater to satisfy the domestic need in Qatar, it was needed to develop safe and cost effective desalination processes with the consideration of stringent regulation for water quality production and wastewater/brine discharge quality. The direct disposal of brines to the environment raised potential negative impact to the aquatic system and therefore the best practice is to minimize the volume of brine production and reuse it for beneficiary application. Several brine-dewatering techniques include both evaporative and non-evaporative approaches, which are capable to dewater high salinity brines with 50-350 g/L of total dissolved solids (TDS). The commonly adopted technology for dewatering brine is mechanical vapor compression that is known for its significant energy consumption up to 25 kWh/m3 of produced water for 50% of water recovery1. Non-evaporative membrane base technologies are a promising approach to dewater brines with minimum energy usage. Osmotically assisted reverse osmosis (OARO) is an advance membrane based technology for energy efficient and high recovery desalination of saline brine. OARO differ from reverse osmosis (RO) by adding saline sweep on permeate side to reduce osmotic pressure difference across the membrane to generate more water flux. The ongoing research work are based on mathematical/numerical approach that focuses on finding the optimum OARO configuration, inlet hydraulic pressure to avoid membrane burst and cost analysis. However, most of these studies are conducted by considering ideal conditions. In this study, an algorithm for simulating OARO process based on MATLAB and Aspen Plus to model membrane calculation and to design process configuration is considered to the effect of concentration polarization (CP) and reverse solute flux (RSF). The objective is to study the effect of inlet feed concentration and flowrate, sweep concentration and flowrate, inlet hydraulic pressure, number of stages, membrane size and characteristics and module configuration flow. In addition, technical economic analysis to evaluate the economic feasibility of OARO process. The stopping criteria of this model is the quality of water permeating at the feasible operating conditions and the cost. This model demonstrated high potential simulating OARO process to be used as a palate form for the user to predict the behavior of the process by varying operating conditions to desired outcomes.
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"Increase the Sugar Concentration of the Solution Sugar by Reverse Osmotic Membrane." In International Seminar of Research Month Science and Technology in Publication, Implementation and Commercialization. Galaxy Science, 2018. http://dx.doi.org/10.11594/nstp.2018.0132.
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Jalab, Rem, Abdelrahman M. Awad, Mustafa S. Nasser, Joel Minier-Matar, and Samer Adham. "Pilot Scale Osmotic Concentration Process for Reducing Wastewater Volumes from Gas Processing Facilities in Qatar." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0080.
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Over the past 10-15 years, there has been increasing attention in the development of forward osmosis (FO) technology as a low-energy technical solution to wastewater treatment through the exploitation of the natural osmosis phenomenon across semi-permeable membrane. The significant energy benefit arises in applications where direct recovery of the permeate product from the draw solution (DS) is obviated such as in osmotic concentration (OC) process. In the current research, an OC FO-based pilot-scale unit was applied for wastewater volume reduction from oil and gas processing facilities in Qatar. The pilot unit uses seawater of 40 g/L salinity as a DS and wastewater generated during oil and gas operations as a feed. This feed water is of comparatively low conductivity (2 g/L salinity), making it unusually suited to treatment by OC. Based on FO technology principles, the feed gets concentrated at lower volume with the water permeation through the membrane, meanwhile the water transfer to DS side dilutes it. The diluted DS could be directly discharged into the ocean; so the energy intensive step of DS recovery is entirely eliminated. Two FO membranes (Toyobo and NTU) of hollow fiber configuration were tested to assess their performance and fouling propensity on both synthetic and real wastewaters. Results demonstrated that the membrane-based process can achieve feed water recoveries up to 90% without any scaling issues. Achieved water flux ranges between 1.5 to 12 LMH for feed recoveries between 60 and 90% using a constant dilution rate of the draw solution. Above all, the pilot unit maintained stable water flux of 1.62 and 6 LMH using at 75% feed recovery for over 48 hours of continuous operation Toyobo and NTU membranes respectively.
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Akram, Waqas, and Mostafa H. Sharqawy. "Power Generation With Pressure Retarded Osmosis." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-66590.
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Energy can be generated from two streams of different salt concentration using the osmotic pressure difference. Different methods have been proposed to harvest this energy. Pressure retarded osmosis (PRO) is investigated as a viable method and most promising technology. In PRO process, pure water permeates through a semi permeable membrane from the low hydrostatic pressure stream (feed solution) to the higher hydrostatic pressure stream (draw solution) due to the osmotic pressure difference. This increases the volume flow rate of the pressurized draw stream and energy is obtained by depressurizing the draw stream through a hydro turbine. In this study a one-dimensional computational model is developed to precisely estimate the power production under different operating conditions. Different feed and draw solution concentrations are used to estimate the power production from PRO. The maximum power density (power per unit membrane area), using available membrane characteristics, obtained from seawater–freshwater streams is 2.6 W/m2 and for the disposed brine–seawater streams is 9.1 W/m2. The performance of PRO process is very sensitive to the membrane characteristics in particular to the water permeability and PRO module configuration.
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Gormly, Sherwin, V. Dean Adams, Tzahi Cath, Amy Childress, Michael Flynn, and Edward Beaudry. "Direct Osmotic Concentration: A Primary Water Treatment Process for Space Life Support Applications." In International Conference On Environmental Systems. SAE International, 2003. http://dx.doi.org/10.4271/2003-01-2332.
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Panta, Yogendra M., Param C. Adhikari, and Sanket Aryal. "Development of a Electro-Osmotic Micromixer for Uniform and Rapid Mixing." In ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80641.
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Micro Total Analysis Systems (μTAS) require rapid yet homogeneous mixing of a number of fluid streams that carry bio/chemical species in the solution. Current analysis has been continued from our previously published work [1]. New models were designed by rendering some particular fluid and geometric variables from the original design and then analyzed for the degree of mixing effectiveness. A careful placement of obstacles in the mixing zone of the model and the electrodes in it showed enhancement in mixing performance. In addition, models with varied geometrical parameters such as converging inlet and diverging outlet yielded even better mixing capabilities. Concentration variances over time at the outlet were simultaneously compared in all models for mixing. Also average concentration was tracked over time so as to confirm the uniformity in mixing. The concentration variances at the outlet have been dramatically observed to be reduced by a factor of at least 10 from our designs as reported earlier [1].