Tesis sobre el tema "Electrodialysis with bipolar membranes"
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Balster, Jörg Henning. "Membrane module and process development for monopolar and bipolar membrane electrodialysis". Enschede : University of Twente [Host], 2006. http://doc.utwente.nl/57595.
Xia, Jiabing [Verfasser] y Ulrich [Akademischer Betreuer] Nieken. "Reverse electrodialysis with bipolar membranes (REDBP) as an energy storage system / Jiabing Xia ; Betreuer: Ulrich Nieken". Stuttgart : Universitätsbibliothek der Universität Stuttgart, 2018. http://d-nb.info/1175951293/34.
Lundblad, Helena. "Split of sodium and sulfur in a Kraft mill and internal production of sulfuric acid and sodium hydroxide". Thesis, KTH, Skolan för kemivetenskap (CHE), 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-158486.
Abou-Diab, Mira. "Production éco-circulaire de peptides antibactériens, antifongiques et antioxydants déminéralisés à partir d'hémoglobine bovine par électrodialyse avec membranes bipolaires : étude de faisabilité, mécanisme enzymatique, optimisation des paramètres, comparaison avec l'hydrolyse conventionnelle et prévention du colmatage". Electronic Thesis or Diss., Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUR031.
Bovine cruor, a slaughterhouse waste, is produced in large quantities all around the world. This co-product was mainly composed of hemoglobin, a protein rich in bioactive peptides after its enzymatic hydrolysis. However, during conventional hydrolysis, chemical agents are necessary to adjust/regulate the pH of the solution and the final hydrolysates produced contain high levels of mineral salts. Therefore, in this study, it is proposed to apply, for the first time, a green technology, named electrodialysis with bipolar membrane (EDBM), as an alternative method to the conventional enzymatic hydrolysis of hemoglobin to obtain purified bioactive peptides. The main objectives of the present thesis were to test the feasibility of this new process to produce bioactive peptides from bovine hemoglobin, to establish the optimal conditions, to avoid membrane fouling and to apply a new original « multiple-step » EDMB process allowing the production of demineralized bioactive peptides without the addition of chemical salts. Bipolar/monopolar (anionic or cationic) configurations using the H+ and OH- generated by the bipolar membranes to regulate the pH were investigated and compared to a conventional process using chemical acid and base. The EDBM configuration formed with cationic membranes allowed the production of hydrolysates containing a low concentration of mineral salts but with fouling formation on the cationic membrane, while EDBM configuration formed with anionic membranes allowed the production of hydrolysates without fouling but with a similar salt concentration than the control. Based on these results, a new 3 compartments EDBM configuration was carried-out for denaturing the hemoglobin, inactivating the enzymatic reaction and demineralizing up to 85% the hemoglobin hydrolysate simultaneously. However, a fouling was still observed on the anionic membrane due to hem precipitation. For this reason, an additional step of discoloration was tested before the demineralization to avoid fouling using the electrogenerated acid. The discolored and demineralized peptides recovered showed antioxidant activity, antibacterial activity against many bacterial strains (Gram + and Gram -) and for the first time antifungal activity against many molds and yeasts strains. Moving towards a circular economy, this sustainable technology has found to be effective in performing multiple operations simultaneously and has a great potential for industrial hydrolysis of blood, since it produces purified biopeptides with a low mineral content and can be used as natural preservatives on meat
Lu, Wei. "Étude de l'échange d'ions modulé électriquement : application du couplage échange d'ions-électrodialyse à la séparation de biomolécules". Thesis, Vandoeuvre-les-Nancy, INPL, 2010. http://www.theses.fr/2010INPL027N/document.
The present work aims to study the coupling of ion exchange and electrodialysis. This study is applied to the separation of biomolecules. One objective is to reduce the generation of saline wastewater produced by the ion exchange steps used conventionally in bioseparations. One approach has led to the design of architecture with a cyclic mode in 3 steps to purify some families of peptides without using a buffer pH or generate wastes. The experimental device consists of an electrodialysis cell in which are introduced anion exchange resins. The three steps are: loading of biomolecules on the resin initially in the carbonate form, elution with a solution of carbon dioxide dissolved in water, electroregeneration of the resin in its original form leading simultaneously to the regeneration of the carbonic acid solution. Using a modelling of the electroregeneration step, simulations can improve the understanding of coupled processes as the ion exchange equilibria, the equilibria in solution, the electromigration. A second approach has then been to study the possibilities of controlling the pH by electrochemical means to limit the use of buffers. The dissociation of water, leading to the formation of protons and hydroxyl ions, has been particularly studied by accounting the properties of contacts called « bipolar » as a result of an electric field. It was established that the choice of resin type and the current density can modify the pH. However this work must be pursued through research of architectures and operating procedures that deliver appropriate buffer capacity
CULCASI, Andrea. "ELECTRICAL ENERGY STORAGE DEVICES BASED ON pH AND SALINITY GRADIENTS: MODELLING, EXPERIMENTS AND PILOTING". Doctoral thesis, Università degli Studi di Palermo, 2021. http://hdl.handle.net/10447/478993.
Davis, Jake Ryan. "Production of Expendable Reagents from Raw Waters and Industrial Wastes". Diss., The University of Arizona, 2014. http://hdl.handle.net/10150/344216.
Jaouadi, Meyssa. "Étude d'un procédé hybride de séparation couplant l’électrodialyse à membrane bipolaire et l’échange d'ions : application à la valorisation de solutions diluées d'acide organique". Thesis, Université de Lorraine, 2016. http://www.theses.fr/2016LORR0208/document.
This work is dedicated to the study of a hybrid separation process involving bipolar membrane electrodialysis and ion exchange. This study is applied to the treatment of diluted effluents. The aim is first to acquire a theoretical understanding of transfer processes and mechanisms that affect energy consumption of this hybrid system. Then, in a more applied way, the objective is to be able to propose a cell configuration that allows to remove the acid from the treated solution by transferring it to a concentration compartment. This configuration must allow to obtain the highest purification rates as possible while minimizing energy consumption. Criteria aiming at optimizing ion exchange resins (strong or weak) in dilution compartment are proposed. The interest of the introduction of strong cationic resin under H+ form in the concentrated compartment is highlighted, as it enables reducing compartment resistance and hence energy consumption. Furthermore, experimental measurements successively conducted with “decoupled” and “coupled” systems identified resistive contributions of the different elements of the stack. This approach led to the determination of parameters of a model which predicts the resin bed electrical resistance in a given solution. Specific energy consumption (kWh/Kg transferred acid) was evaluated as a function of the desired purification rate. All the work led to recommendations for the cell design and for the choice of operating parameters
Schab, Frédéric. "Étude comparative des procédés d'électrodialyse et d'électrodéionisation : application à la fabrication d'acide lactique". Thesis, Vandoeuvre-les-Nancy, INPL, 2007. http://www.theses.fr/2007INPL035N/document.
This work deals with the comparative study of electrodialysis and electrodeionization. The possibilities to integrate the electro-membrane processes in the lactic acid fermentive production lines are investigated. Two main research ways are chosen : the first one lies in the continuous extraction of natrium lactate out of the fermentation middle. For this, an electrodialysis stack of only anionic membranes is coupled with the fermenter : approximately 95 % of lactate are removed during the operation. By comparison with a standard fermentation in batch mode, no inhibition is observed, and the productivity is increased by 13. The second way is to convert the natrium lactate in lactic acid : a high purity rate is seeked. A continuous electrodeioniation process including bipolar membranes, leading to 99,9% conversion rate, is elaborated for the treatment of diluted solutions. Finally is presented the mathematic calculation of an electrodeionization compartment : experimental points and calculated values are very similar
Gabrielsson, Erik O. "Monopolar and Bipolar Membranes in Organic Bioelectronic Devices". Doctoral thesis, Linköpings universitet, Fysik och elektroteknik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-110406.
Hong, Jin Gi. "Development of process-based model and novel nanocomposite cation exchange membranes for salinity gradient power production". Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53530.
Willson, Terrence R. "Synthesis of ion exchange membranes for reverse electrodialysis via radiation induced graft co-polymerisation". Thesis, University of Surrey, 2018. http://epubs.surrey.ac.uk/846392/.
Jesus, Juliana Mendonça Silva de. "Estudo do envelhecimento de membranas trocadoras de íons em contato com soluções sintéticas à base de HEDP". Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3137/tde-05092017-105121/.
The use of cyanide in electrodeposition processes provides industrial practice environmental and occupational risk. Thereby, studies have looked for alternatives for the substitution of this noxious agent. The Institute of Technological Research (ITR) developed an alkaline copper bath cyanide-free, which used HEDP (1-hydroxyethane- 1,1-diphosphonic) as a substitute. For the recovery of this acid the electrodialysis was evaluated, which consists of the use of an ion-exchange membrane (IEM) system and electric current as the driving force. Oxidizing, corrosive and organic materials favor membrane degradation, inhibiting their separation ability. Maintenance alternatives have been studied to increase the shelf life of membranes, such as the use of cleaning agents. The ageing study provides the evaluation of a material under specific conditions, in order to monitor changes as a function of the time of contact with the medium. The present study proposes the ageing of commercial anionic membranes in dilute solutions from the synthetic copper bath with HEDP. The purpose of the study was selected two membranes, being a heterogeneous and homogeneous membrane. These were aged in three distinct concentrations (CuHEDP 1%, 5%, 10% v/v) for 400 hours of contact, under stirring. The possible structural modifications were evaluated by techniques such as scanning electron microscopy coupled to X-ray dispersive energy spectroscopy (SEM-EDS), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR-ATR). The intrinsic properties of the membranes are directly related to their selective and morphological character. To evaluate such properties, chronopotentiometric assays and potentiometric titration were used. The investigated properties were swelling degree, ion-exchange capacity, electrical resistance, current density, and permselectivity. In parallel, the heterogeneous membrane was subjected to ageing in an electrodialysis system for 400h, monitoring the changes in its current density and electrical resistance every 100h of the test. In addition, acid and basic cleaning agents were evaluated in different concentrations. The agent that achieved the best performance in removing the ionic incorporation was applied to the membranes aged in 100h of ageing. These were then reevaluated from electrochemical tests. It was observed that there was interaction between the ions in solution and the membranes studied, which provided alterations in its structure and properties, but without provide modifications that indicated the need of disposal for both membranes.
Nguyen, Duy Linh. "La technologie des membranes pour le traitement des eaux de surface dans le delta du Mékong". Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT211/document.
Access to clean water is one of the most important problems that is encountered worldwide even in countries as water-rich. For instance, the Mekong Delta (MD)’s coastal provinces have to face up to alternated flooding and drought periods. Moreover, climate changes inducing less rainfall and salt water intrusion water severely affect the water quality of the area. The main sources of pollution come from the human and farming wastes including fish, livestock and poultry. Pesticide pollution can also be a serious problem in some areas. The deterioration of water quality in the MD and the lack of access to clean water via safe supply systems in the rural communes entail an increase of waterborne diseases related to the salinity, the presence of microorganism and organic pollutants. The study is aimed at investigating the membrane technology to treat surface water in the MD region in order to produce good drinking water. The study was focused on brackish waters containing pesticides. Two synthetic model water samples were chosen as representative of surface waters found in the Mekong Delta. Desalination and pollutant removal were performed using nanofiltration (NF) integrated with electrodialysis. The Nanoflux® software was used to explain the experimental performance of two NF membranes (NF90 and 270). On the other hand, energy consumption of the two coupled processes was also estimated depending on the quality of water feed. All the data obtained should be used in the future to design a demonstrator pilot for the family-sized production of drinking water
Strand, Robin Viktor. "Characterization of ion selective membranes for application in reverse electrodialysis systems : Concentration dependency of the apparent transport number". Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for kjemi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-25836.
Manenda, Mahder Seifu. "Separation of bioactive peptides by electrodialysis with ultrafiltration membranes: membrane characteristics, ex-situ and in-situ digestion and their impact on peptide migration". Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10410.
Trypsic hydrolysis of whey protein isolate was performed simultaneously with (in-situ) and before (ex-situ) fractionation by electrodialysis with ultrafiltration membrane (EDUF) to obtain bioactive peptides. Two ultrafiltration membrane (UFM) materials, PES and PVDF, were used for a 120 minute EDUF fractionation of the hydrolysate. The two membranes showed similar zeta potential measurements at the pH of operation, 7.8, but had significantly different conductivity which decreased significantly after use in EDUF. Peptide migration to anionic (A-RC) and cationic (C+RC) peptide recovery compartment was strongly dependent on the electrical conductivity of the UFMs than their types or the digestion strategy used. For UFMs with close values of conductivity, peptide migration to the A-RC was observed to be higher with in-situ digestion while peptide migration to the C+RC was higher in an ex-situ digestion. When the two membrane types, PES and PVDF, have closer values of conductivities, PVDF was observed to exhibit more migration than PES. Peptide migration to the C+RC varied from 16.56 ± 5.36 μg/mL to 103.10 ± 2.76 μg/mL for PVDF membrane with significantly different conductivities: 2.73 ± 0.32 mS/cm and 5.47 ± 0.56 mS/cm, respectively. Peptide migration to the A-RC varied from 4.41 ± 0.86 μg/mL to 49.65 ± 6.13 μg/ml for PVDF membrane with significantly different conductivities: 3.163 ± 0.12 mS/cm and 5.23 ± 0.04 mS/cm, respectively. HPLC-MS studies showed 23 major peaks that were generated on whey protein isolate digestion by trypsin. 9 of these peaks migrated to the A-RC while 3 migrated to the C+RC. Among the anionic peptides 3 peptides are known to have hypocholesterolemic effect, 1 is antibacterial and 1 is antihypertensive. Among the cationic peptides 1 is antihypertensive. EDUF appears to be a powerful new technique that can fractionate bioactive peptides in terms of mass and charge.
The EM3E Master is an Education Programme supported by the European Commission, the European Membrane Society (EMS), the European Membrane House (EMH), and a large international network of industrial companies, research centres and universities
Glabman, Shira. "Effect of inorganic filler size on nanocomposite ion exchange membranes for salinity gradient power generation". Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/54311.
Le, Xuan Tuan. "Contribution à l'étude électrochimique des propriétés de membranes échangeuses cationiques en milieu acide sulfurique". Doctoral thesis, Universite Libre de Bruxelles, 2006. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210782.
Kadel, Sabita. "Impact of physicochemical properties of filtration membranes on peptide migration and selectivity during electrodialysis with filtration membranes : development of predictive statistical models and understanding of mechanisms involved". Doctoral thesis, Université Laval, 2020. http://hdl.handle.net/20.500.11794/66602.
During electrodialysis with filtration membranes (EDFM), charged peptides selectively migrate through filtration membranes (FMs) to their respective anionic (ARC) or cationic (C + RC) peptide recovery compartments. Consequently, the type of interactions occurring between FM and peptide at the interface, due to their physicochemical properties, must have significant impact on overall EDFM performances (peptide migration and selectivity). Therefore, the main objective of this doctoral thesis was to investigate the major FM properties that contribute to peptide-membrane interactions at the interface, which either facilitates or hinders global migration and selective separation of peptides during EDFM, and to understand the mechanisms involved behind those interactions. Thus, in this study, 16 FMs, characterized in terms of their physicochemical properties (zeta potential, conductivity, hydrophilic/hydrophobic nature of the surface and pores, thickness, roughness, porosity and percentage of macropores distribution in filtrating layer) were tested during EDFM to simultaneously separate anionic and cationic peptides from a well-characterized complex whey protein hydrolysate. In the first study, 6 FMs were tested, differing in terms of membrane materials, including one ultrafiltration (polyethersulfone (PES)) as a control and 5 microfiltration ( one polyvinylidene fluoride (PVDF) and four polyvinyl chloride (PVC)-silica: two functionalized (sulfonyl or amino) or two non-functionalized). Redundancy analysis (RDA) and multivariate regression analysis demonstrated that at least two FM properties among zeta potential, pore/surface hydrophilicity, porosity and roughness significantly impacted the migration of any charged peptide. In addition, the important effect of pore size on peptide selectivity was also reported. Finally, predictive statistical models that link each peptide migration with significant FM properties were proposed. In the second study, which was carried out on PES membranes with a wide range of molecular weight cut-offs (MWCOs) (5 kDa to 300 kDa), a linear relation was noticed between MWCO and global peptide migration (GPM) to both recovery compartments. However, the selective peptide migration to A - RC or C + RC was found to be influenced by the vi MWCO of FMs as well as physicochemical properties (charge and molecular weight (MW)) of peptides. For instance, the migration of a peptide having low MW and low charge (positive or negative) was favored when a FM with small MWCO was used, while the opposite was observed for a peptide having high MW and high charge. In the third study, the effect of combination of membrane material (PAN, PES and PVDF)/MWCO (30 and 50 kDa) on peptide migration and selectivity was first studied. The simple effect of membrane material and MWCO on GPM to C+ RC was observed, while the combined effect of membrane materials/MWCO on GPM to A - RC and selective peptide migration to both recovery compartments was observed. Secondly, a RDA was performed on the data obtained for all the selective FMs tested in this doctoral research, which demonstrated the significant impact of zeta potential, conductivity, roughness and percentage of macropores distribution in the filtrating layer of FMs on GPM. Concerning selective peptide migration, in addition to the aforementioned FM properties, the significant impact of contact angle was noticed for at least one anionic and/or cationic peptide migration to their respective recovery compartments. These significant FM properties were found to trigger different interactions such as electrostatic, size exclusion and hydrophilic/hydrophobic between FM and peptide at the interface resulting in either facilitation or inhibition of peptide migration. Finally, global predictive statistical models were developed for GPM and each individual peptide migration to ARC and/or C+ RC based on these significant FM properties, which allow the estimation of their migration behavior when FMs having a wide range of physicochemical properties are used during EDFM. The results obtained in this Ph.D. thesis demonstrated, for the first time, the significant correlation between physicochemical properties of FMs, and peptide migration and selectivity during EDFM. The predictive models developed in this study can be used for the range of peptides and FMs tested. Moreover, the types of interactions occurring between FMs and peptide at the interface, and mechanisms and explanations proposed in this study can be applied to understand all types of peptide/membrane interactions. Validation of such models vii by using different sources of hydrolysates or different FMs or a hydrolysate produced by other enzymes will be the main perspectives of this research work.
Proença, Marcela Pinheiro. "Desenvolvimento de membranas íon-seletivas com poliestireno sulfonado e polianilina dopada para a aplicação em eletrodiálise". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/18585.
Nowadays the concern with the reduction of industrial pollution has motivated researchers to found out new technologies for treatment of industrial waste. The clean technologies, as electrodialysis, are capable of treating some these residues, as for example the galvanoplasty’s waste, minimizing the impacts that would happen to them if they were discarded directly on the environment. The main component of this technique is the membrane on which occurs the ions removal stage of the solution. The membranes are imported and expensive what justifies the development of efficient and accessible membranes. In this sense, in the present work membranes of sulfonated polystyrene / high impact polystyrene (SPS/HIPS), polyaniline doped with camphorsulfonic acid / sulfonated polystyrene / high impact polystyrene (PAniCSA/SPS/HIPS), sulfonated polyaniline/ sulfonated polystyrene / high impact polystyrene (SPAN/SPS/HIPS), and polyaniline doped with p-toluenesulfonic acid / sulfonated polystyrene / high impact polystyrene (PAniTSA/SPS/HIPS) were developed using chemical mixture method. Membranes were characterized by Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Dynamic Mechanical Analysis (DMA) and Scanning Electronic Microscopy (SEM). Membranes were submitted to current-voltage curves and electrodialysis experiments with NaCl and KCl solutions, in order to determine ionic transport through them. Results were compared with a commercial membrane, Selemion CMT. The average percent extraction for Na+ ions obtained by membranes developed were beyond 20%.
Garcia-Vasquez, Wendy. "Etude du comportement à long terme des membranes échangeuses d’ions utilisées dans les procédés d’électrodialyse". Thesis, Paris Est, 2013. http://www.theses.fr/2013PEST1111/document.
The long term behavior of anion and cation-exchange membranes used in conventional electrodialysis for food industry applications was investigated. Some of these membranes were homogeneous and some others were heterogeneous. The approach of this thesis is based upon the analysis of several physico-chemical, structural and mechanical properties of new samples and aged ones in electrodialysis stacks (in-situ) or under artificial ageing protocols at laboratory scale (ex-situ).The in-situ investigation of different ion-exchange membranes used in the purification of organic acids and in whey demineralization confirmed that anion-exchange membranes are more prone to degradation than the cation-exchange membranes. It was observed, as well, that changes in the transport properties, and subsequently in the membrane performance, are dependant of the modifications of the membrane microstructure. The microheterogeneous model was improved and applied for the interpretation and quantification of the ageing consequences on ion-exchange membranes. Assessment of the cleaning process effect on the long term behavior of ion-exchange membranes used in electrodialysis for the food industry applications was the objective of the ex-situ investigation. The ageing protocols were performed using acidic or alkaline solutions or by alternating both of them, as well as in oxidant bleach solutions. Among other findings, it was proven that the damage caused by the acid-base cleaning cycles provoked severe degradation to anion-exchange membranes. Furthermore this cleaning process was the main cause of ageing of homogeneous anion-exchange membranes in electrodialysis for whey demineralization. Comparisons between results obtained by in-situ and ex-situ ageing protocols confirmed their similarity. Therefore, it may be considered that under well-chosen operation conditions, ex-situ investigation is a well adapted method for the artificial ageing
Jiang, Di. "Synthesis of novel hybrid cation exchange membranes for reverse electrodialysis using sulfonated poly(vinyl alcohol) (sPVA)/ poly (2,6-dimethyl-1,4-phenylene oxide) (sPPO)". Thesis, Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/54240.
Bdiri, Myriam. "Etude du décolmatage, par procédés chimiques et biologiques, des membranes échangeuses d'ions utilisées en électrodialyse dans le domaine agroalimentaire". Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1070.
Conventional electrodialysis (ED) is mainly based on the specific action of ion exchange membranes (IEMs) and is widely used in food industry for tartaric stabilization of wines, deacidification and treatment of fruit juices, demineralization of whey or elimination and fractionation of milk proteins. The organic fouling, accentuated by the complex composition of the food effluents and their richness in phenolic compounds, represents a major limitative factor of the process efficiency and the IEMs performance. This phenomenon causes a decrease in the selectivity of membranes, an increase in their electrical resistance and reduces the energy efficiency of the process leading to economic losses in industry. This study mainly consists in studying the IEMs cleaning by chemical and biological methods. Two batches of new membranes (cation- (CEMs) and anion-exchange membranes (AEMs)) and five batches of used ones (3 CEMs and 2 AEM) with different durations of use in ED units in food industry -confidential application- have been studied. All the samples have been previously characterized to determine their physicochemical parameters (ion-exchange capacity (IEC), thickness (Tm), electrical conductivity (km), contact angle (θ), water content (WC) and the volume fraction of the inter-gel solution (f2) resulting from the study of the micro heterogeneous model), structure and morphology by FTIR spectroscopy, optical microscopy, scanning electron microscopy and mechanical by tensile strength tests. The direct and indirect effects (caused by the regular cleaning operations in industry) of fouling as well as the anisotropy of the membranes mechanical properties have been highlighted. Non-aggressive and environmentally friendly cleaning methods have been experimentally tested in ex-situ static mode: Saline solutions (35 g.L-1 NaCl and reconstituted seawater), hydro-alcoholic solution (12% water-ethanol mixture, pH = 3,5) and biological solutions using 3 categories of enzymatic agents (Rohalase BX-BXL, β-glucanase / Corolase 7089, endo-peptidase / Tyrosinase, polyphenol oxidase) whose operating conditions of optimal enzymatic activity have been determined. The evolution of IEC, km, θ and f2 were followed in function of the cleaning duration. Saline solutions have a negligible effect on intern cleaning but remain efficient for extern cleaning. However, the application of the hydro-alcoholic solution and enzyme solutions have been found to be efficient for both intern and extern cleaning and led to significant recoveries of the studied parameters. It has been shown that phenolic compounds, the principal constituents of treated effluents, are mainly responsible for MEIs fouling. Apparently, they form dense colloidal nanoparticles not permeable for ions within membrane meso- and macropores, not penetrating into micropores. A modification of the micro heterogeneous model under this assumption allowed an adequate interpretation of km and the modelization of structural modifications of the inter-gel phase generated by the fouling mechanisms by polyphenols and explained the reasons why the f2app decreases. An extraction method using a mixture of solvents (25% V/V, acetone/methanol/ isopropanol/water) was developed and made it possible to extract certain phenolic compounds from different batches of used CEMs and AEMs that were identified by high performance liquid chromatography. It has also been demonstrated that the interactions between the phenolic compounds and the polymer matrix are mainly governed by the stacking of aromatic rings and electrostatic interactions of the CH-pi and pi-pi type as well as the hydrogen bonds
Babíková, Barbora. "Membránové separace". Master's thesis, Vysoké učení technické v Brně. Fakulta chemická, 2018. http://www.nusl.cz/ntk/nusl-376883.
Andreeva, Marina. "Etude du colmatage des membranes échangeuses d'ions lors de l'électrodialyse de solutions de sels de Ca2+ et Mg2+ : influence des propriétés de surface". Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1018/document.
Scaling on the surface and in the bulk of ion-exchange membranes is a considerable locker for electrodialysis. The scale reduces the effective surface area of the membrane and leads to additional resistance to the mass transfer and solution flow.Three cation-exchange membranes are used in this study: a heterogeneous commercial MK-40 membrane and two of its modifications. The MK-40/Nafion membrane is obtained by mechanical coating the MK-40 membrane surface with a homogeneous ion-conductive Nafion® film. Modification of the MK-40/PANI membrane is carried out by polyaniline synthesis on the membrane surface. The solutions used in the study are 0.02 and 0.04 mol/L CaCl2 and MgCl2 solutions, as well as the solution, imitating the mineral composition of milk, concentrated 3 times. The visualization of the membrane surface is made using optical and scanning electron microscopy. The elemental analysis of the scale on the membrane surface is made by X-ray analysis. The hydrophobic-hydrophilic balance of the membrane surface is estimated by the contact angle measurements. To characterize the cation transport through and the water splitting rate, chronopotentiometry and voltammetry methods are used, pH measurement of the diluate solution is conducted at the same time.It is shown that the relatively high hydrophobicity of the membrane surface, its electrical and geometric heterogeneity, create conditions for the development of electroconvection. The electroconvection intensity in the case of MK-40/Nafion is significantly higher, and in the case of MK-40/PANI is lower in comparison with that of the unmodified membrane. Electroconvection vortexes cause the mixing of the solution at the membrane surface in a 10 µm thick layer. This effect significantly increases mass transfer in intensive current modes and prevents or reduces the scaling process, as well as reduces the water splitting rate at the membrane surface. The rate of electroconvection essentially depends on the counterion hydration degree, it increases with increasing the counterion Stokes radius. The rate of the scale formation on the membrane surface is determined by the slope of the chronopotentiogramme. The formation of Mg(OH)2, Ca(OH)2 and CaCO3 scales is observed. It is experimentally established that the scaling rate on the surface of MK-40/Nafion is smaller, and on the surface of the MK-40/PANI is larger in comparison with the MK-40 membrane. The scaling rate is significantly reduced when the pulsed electric current mode is applied. Such mode allows the reduction of the potential drop more than twice and achievement of a quasi steady-state because an unstable periodically crumbling scale occurs
Valerdi, Pérez Ramón. "Caracterización, evaluación y optimización de una planta de desalación por electrodiálisis reversible". Doctoral thesis, Universidad de Murcia, 1999. http://hdl.handle.net/10803/10848.
Narang, Gurtej Singh. "Synthesis and Characterization of Novel Pol(arylene ethers) for Gas Separation and Water Desalination Membranes". Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/95968.
PHD
Daryaei, Amin. "Synthesis and Characterization of Linear and Crosslinked Sulfonated Poly(arylene ether sulfone)s: Hydrocarbon-based Copolymers as Ion Conductive Membranes for Electrochemical Systems". Diss., Virginia Tech, 2017. http://hdl.handle.net/10919/86439.
Ph. D.
Martí, Calatayud Manuel César. "STUDY OF THE TRANSPORT OF HEAVY METAL IONS THROUGH CATION-EXCHANGE MEMBRANES APPLIED TO THE TREATMENT OF INDUSTRIAL EFFLUENTS". Doctoral thesis, Universitat Politècnica de València, 2015. http://hdl.handle.net/10251/46004.
Martí Calatayud, MC. (2014). STUDY OF THE TRANSPORT OF HEAVY METAL IONS THROUGH CATION-EXCHANGE MEMBRANES APPLIED TO THE TREATMENT OF INDUSTRIAL EFFLUENTS [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/46004
TESIS
Premiado
Boulehdid, Hanae. "Elaboration et caractérisation d'une membrane cationique monosélective par modification chimique d'un film ETFE". Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210555.
La synthèse de la membrane cationique de base a été réalisée en passant par différentes étapes à savoir :le greffage du styrène - divinylbenzène (DVB), la chlorosulfonation et l’hydrolyse.
Au cours de ce travail, nous avons mis au point un protocole de greffage du styrène-DVB dans le film d’ETFE qui permet l’obtention d’un film ayant un taux de greffage reproductible assurant à la membrane cationique finale une bonne conductivité électrique et une capacité d’échange acceptable pour une membrane d’électrodialyse. Une étude de la réaction de greffage en fonction de la concentration en réticulant a été réalisée.
Nous avons procédé par la suite à la modification de la surface du film d’ETFE greffé styrène-DVB par la formation d’une couche superficielle mince fixée par des liens covalents. Les membranes modifiées ont été obtenues par la réaction d’une seule face du film d’ETFE greffé chlorosulfoné avec la 3-diméthylaminopropylamine. La modification chimique de la surface du film ETFE greffé chlorosulfoné a été suivie par la technique FTIR-ATR. L’effet de la concentration de la diamine sur les propriétés électrochimiques des différentes membranes modifiées a été étudié. La résistance électrique des membranes modifiées équilibrées au contact de solutions de chlorure de sodium et d'acide sulfurique a été mesurée par la technique d’impédance. La détermination du nombre de transport du proton et de l’ion sodium a été réalisée à partir de mesures du potentiel de membrane. La densité de courant limite des membranes a été évaluée sur base des courbes courant-tension. Les mesures de chronopotentiométrie ont été également effectuées sur les différentes membranes synthétisées.
Les résultats de ces caractérisations montrent que la modification de la surface engendre des changements considérables au niveau des propriétés électrochimiques des membranes résultantes. La résistance électrique, la densité de courant limite ainsi que les propriétés de transport de la membrane dépendent d’une part de la concentration de la diamine utilisée et d’autre part de la solution dans laquelle la membrane modifiée est équilibrée.
La sélectivité préférentielle des différentes membranes vis-à-vis des protons par rapport aux ions bivalents a été testée en réalisant des électrodialyses d’un milieu mixte H2SO4-NiSO4. Nos résultats montrent que la modification chimique de la surface de la membrane affecte d’une manière significative le transport des ions nickel tout en respectant le passage des protons. Une meilleure séparation a été obtenue pour une membrane modifiée en utilisant la diamine pure.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
Souza, Jadison Fabricio de. "Desenvolvimento de membranas de polissulfona para imobilização de lipase". reponame:Repositório Institucional da UCS, 2006. https://repositorio.ucs.br/handle/11338/168.
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Preparation and characterization of polysulfone (PSU) membranes and the immobilization of lipase enzyme in these membranes to produce enantioselective membranes, in order to separate chiral compounds, is the subject of the present work. PSU membranes were prepared by phase inversion, using chloroform as solvent and water as nonsolvent. Membranes with different thickness were prepared and phase inversion parameters such as (solution concentrations, solvent evaporation time, drying and thermal treatment) were investigated. Membranes were characterized, in order to use them in electrodialysis process (ED) and in the lipase PS enzyme immobilization. For immobilization, bifunctional agent glutaraldehyde was used to link the enzyme to the polymer. On immobilization, the kinetic constants (Km e Vmax), the amount of immobilized enzyme with Bradford method and the activity of free and immobilized enzyme with p-nitrophenyl acetate (PNPA) hydrolysis, were determined. PSU membranes prepared by phase inversion are hydrophobic and, when compared with Selemion®; CMT and CMV commercial membranes, present lower permeselectivity, lower ion exchange capability and higher resistance. Membranes pore diameter is lower than 100 nm. The maximum amount of immobilized enzyme in the membranes reached 2.35 mg per gram of polymer after 18 hours of immobilization with a 61,2% yield . Enzyme activity decays after immobilization , from 14780 U.g-1 (free enzyme) to 1184 U.g-1 (immobilized enzyme).
Patil, Rahul. "Membrane Processes for Sustainable Energy Applications". University of Toledo / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1353077392.
Catonné, Jean-Claude. "Contribution à l'étude du défaut de sélectivité présenté par les membranes échangeuses d'anions, dans le cadre de leurs applications au traitement électrochimique de régénération des solutions aqueuses d'acides minéraux". Paris 6, 1986. http://www.theses.fr/1986PA066030.
Io-MengFok y 霍耀明. "Treatment of High Salinity RO Concentrated Wastewater Using Bipolar Membrane Electrodialysis". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/g2ntjw.
Jiang, Chi-Lung y 江其龍. "Energy Generation from a Salinity Gradient by Reverse Electrodialysis in Nanopores with Outer Membranes Modified with Bipolar Polyelectrolyte Brushes". Thesis, 2015. http://ndltd.ncl.edu.tw/handle/x4d5xg.
國立雲林科技大學
化學工程與材料工程系
103
Inspired by biological power conversion system, we theoretically investigate the power generation by the reverse electrodialysis (RED) through a salinity gradient in a solid-state nanopore with its outer membranes modified with biopolar surface charges and polyelectrolyte brushes, referred to as the bipolar solid-state and soft nanopores, respectively. In addition to salinity gradients, the influences of the nanopore length and the surface charge property of the inner pore wall are comprehensively discussed. Our results demonstrate that the surface modification of bipolar charges is capable of enhancing the energy density and the energy conversion efficiency. Compared to the conventional solid-state nanopore, the proposed bipolar soft nanopore exhibits a much higher energy output and conversion efficiency. If the inner wall of the nanopore is negatively charged, the energy output in the bipolar soft nanopore gets largest at a moderate pore length. A gaint osmotic energy density along with a maximum conversion efficiency up as high as 53.2 and 14.3 %, respectively, for a single biopolar soft nanopore with its inner pore wall of negative charges at are discovered. The results gathered suggest that the proposed bipolar soft nanopore can be a possible candidate used as membranes for osmotic power genrtation by the RED.
Hattingh, Cornelius Johannes. "Electrodialysis in flow injection systems". Thesis, 2000. http://upetd.up.ac.za/thesis/available/etd-12042006-132952/.
Ribeiro, Pedro Daniel Porfírio. "Multistage Reverse Electrodialysis for Energy Production". Master's thesis, 2020. http://hdl.handle.net/10362/105718.
Tsung-ChenTsai y 蔡宗承. "Power Generation by Reverse Electrodialysis in Nanopore Membranes from a Microfluidic and Nanofluidic System". Thesis, 2016. http://ndltd.ncl.edu.tw/handle/02664774512989023119.
Kotoka, Francis. "Fouling Monitoring and Mitigation of Monovalent Selective Anion Exchange Membranes to Be Used in Reverse Electrodialysis". Master's thesis, 2020. http://hdl.handle.net/10362/128904.
Organic fouling phenomena predominantly restricts the behavior of Anion Exchange membranes (AEMs), thus reducing the obtainable net power density in reverse electrodialysis (RED). Consequently, we propose a monolayer surface modification of heterogeneous Ralex-AEMs with biocompatible poly(acrylic) acid (PAA) to enhance organic antifouling and monovalent membrane permselectivity. The AEMs were immersed in PAA aqueous solution for 24 h for surface modification. The modified membranes were physicochemical characterized via water contact angle (WCA), water uptake, ion exchange capacity, fixed charge density and swelling degree measurements. Their electrochemical characteristics were evaluated through cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The impact of recurring fouling and cleaning was assessed. Membrane fouling behavior and sulfate rejection were studied in the presence of humic acid (HA), using model NaCl aqueous solutions in a diffusion cell. The modified AEMs (PAA-AEMs) showed a sulfate rejection improvement by 36%-54%, and their hydrophilicity was enhanced by > 15 % with respective to their WCA values. The 3 g/L PAA based AEM achieved an antifouling resistance of 65.8% towards HA in comparison with the unmodified membrane. Recurring fouling and cleaning of the membranes was investigated using 25 ppm HA as the model foulant, and 0.1 M NaOH(aq) as the cleaning agent. In this case, the NaOH cleaning solution restored the membrane resistances almost to their original values after the first fouling and cleaning cycle. However, it failed in the second and third cycles due to the predominance of irreversible fouling and adsorption caused by the HA, leading to higher membrane resistance. Overall, the results demonstrate the technical feasibility of the proposed membrane surface modification procedure, and the need for efficient cleaning agents to mitigate fouling of AEMs. This study may therefore provide a viable approach to enhance RED process efficiency.
Mufula, Alain Ilunga. "Production of ion exchange membrane for hydrogen fuel cell". Thesis, 2017. https://hdl.handle.net/10539/24237.
Among of the components of the fuel cell, the polymer electrolyte membrane is critical to the performance and life time of the cell. Over the years the mechanical properties of the membrane, water management have tended to limit its wide spread commercialization as an alternative source of the renewable energy for portable power units. Fuel cell continues to attract extensive research interest as potential source of renewable energy. This work focuses on the production of ionexchange membrane (IEM) for hydrogen fuel cell, using cheap and locally available starting materials. The polystyrene-butadiene rubber (SBR) of different styrene and butadiene compositions, have been explored for functionality in fuel cell application. The production process was conducted in three stages: the first stage involved hydrogenation process followed by sulfonation process. The second stage entailed the production of carbon nano-spheres for the blending in the hydrogenated sulfonated polystyrene-butadiene rubber. The blending was also done between hybrid nanoparticles and hydrogenated sulfonated polystyrenebutadiene rubber. The third stage was the casting in thin film of blended solutions employing the evaporative method and the use of casting tape machine technique. The thin film was later on characterized and tested in a single fuel cell stack. Controlled hydrogenation of SBR employing catalytic method was achieved with maximum degree of hydrogenation in the range of: 90 – 92% for SBR with 23.5% styrene content and for SBR 25% styrene content 76 – 80% for SBR with 40% styrene content and 82 – 92% for SBR with 52% styrene content. The optimum conditions of this process were obtained using the Design of Experiments. SBR was also hydrogenated using a photocatalytic method and the percentage of hydrogenation for all SBR compositions used was found in the range between 60 and 74%. The hydrogenation results using the catalyst were higher compared to those obtained with the photocatalytic method. Therefore they were used to develop the kinetic model for prediction of hydrogenation process. Langmuir – Hinshelwood models were reviewed in this project as they explain these heterogeneous catalytic processes. Data from the kinetic tests were fitted to Langmuir – Hinshelwood models and reaction constants were found in the range between 0.445 h-1 and 0.610 h-1 for the reaction temperature between 20 and 30°C. The hydrogenated SBR of different compositions were effectively sulfonated with chlorosulphonic acid employed as first sulfonating agent of concentrations 0.15, 0.175 and 0.25M for SBR 23.5 and 25% styrene content, for SBR 40% styrene content and for SBR 52% styrene content, respectively. The degree of sulfonation was found in the range between 56 and 72% depending on the rubber composition. Trimethylsilyl chlorosulfonate used as the second sulfonating agent was like wise attached to the same polymer back bone and the degree of sulfonation was between 59 and 74% depending on the rubber’s styrene content. Non-conductive carbon nanospheres (CNS) of uniform size of about 46 nm were produced employing the non-catalytic chemical vapour deposition method at 1000°C. Acetylene and argon were respectively used as carbon source and carrier gas, in a reactor of 16 mm in diameter. Successful blending of 4 wt% nanoparticles and hydrogenated sulfonated styrene butadiene solution was accomplished by magnetic stirring technique combined with ultrasonication at 60% amplitude. The blended solution was casted to produce a thin film membrane of 156 μm thickness. Further the tensile strength test of the membranes has shown an increase in Young’s Modulus by 72-120% for all the rubbers. This test was done using TA.XTplus, Texture Analyser machine. The water uptake increment was in the range of 20-27% and thermal stability in the range of 2-20% depending on the rubber composition. Purchased electrodes from FuelCellsEtc (USA), were pasted on both sides of the membranes by the means of hot press at 125oC for about 5 minutes at a pressure of 40 kPa. The Membrane Electrode Assembly (MEAs) fabricated were tested in the fuel cell stack. The highest power density of approximately 85mW/cm2 was obtained for 52% styrene nanocomposite membrane with 4% hybrid nanoparticles at the current density of 212.41mA/cm2 and the efficiency was between 41 and 43%. MEA fabricated with Nafion112 membrane was tested and yielded the open cell voltage of 0.79V, power density of about 77.34mW/cm2 and efficiency of 45%. Results obtained disclose that the MEA with nanocomposites based SBR 52% styrene composition yielded higher power density and higher voltage than the one with Nafion 112 which is one of the fuel cell membranes available on the market. The results obtained revealed that the nanocomposite membranes with 4% hybrid nanoparticles (CNS + SiO2) had higher voltage than the one with 4% CNS. These optimum conditions obtained in this work may be adopted for a typical continuous production of the membrane for hydrogen fuel cell.
MT2018
Chang, Chien-Yu y 張倩瑜. "The Separation and Purification of Recombinant Proteins from Transgenic Rice Cell Culture by Electrodialysis with Filtration Membranes". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/e2s9k6.
元智大學
化學工程與材料科學學系
107
It is expected that electrodialysis with filtration membranes (EDFM) can effectively separate protein macromolecules based on the combined effect of molecular size and charge differences with filtration membranes and electrodialysis.A system of EDFM with proper selection of ultrafiltration (UF) membranes was established to test the feasibility of separation and purification of human serum albumin (HSA) from the medium of rice cell culture. The effects of the operating conditions such as operating voltage, current density, pH value on the performance were evaluated. The concentrations of proteins in the feed and permeate chambers were monitored by RP-HPLC. In a preliminary study, bovine serum albumin (BSA) as model, and is negatively charged with pH higher than pI in the feed solution. Therefore, BSA could be driven to the permeate side (anode) by an electric field at higher pH.BSA has higher electrophoretic coefficient (31.3 10-5 mg/V cm2 h) because of negative charge. HSA could be recovered from the medium of rice cell culture by our technology at right conditions.The results demonstrate that recovery of HSA from rice cell culture would be possible with proper selections of filtration membranes, pH, and operating electrical field by EDFM process.
Rankin, Daniel Justin. "Entrance effects on solution transport through nanoporous membranes". Thesis, 2019. http://hdl.handle.net/2440/119956.
Thesis (MPhil) -- University of Adelaide, School of Physical Sciences, 2019
Pereira, Ana Catarina de Jesus Pais. "Deregulated inflammasome in Bipolar Disorder (BD): a matter of stress?" Master's thesis, 2018. http://hdl.handle.net/10316/86272.
Os problemas de saúde mental constituem a principal fonte de carga económica mundial, estimando-se que o custo global seja superior ao das doenças cardiovasculares, cancro ou diabetes, quando consideradas individualmente. Na União Europeia, as doenças mentais afetam milhões de pessoas e prevê-se que esses números aumentem devido ao envelhecimento da população. A doença bipolar (DB) é um distúrbio mental que se caracteriza por oscilações de humor entre depressão e mania, resultando em danos cognitivos e funcionais que requerem tratamento contínuo. No entanto, os escassos tratamentos atualmente disponíveis apresentam eficácia limitada e o diagnóstico tardio é frequente devido à ausência de marcadores biológicos. Assim, é fundamental compreender a fisiopatologia da DB para a implementação de novos fármacos na prática clínica, bem como para o desenvolvimento de biomarcadores que possibilitem um diagnóstico mais preciso e precoce. Dado que a DB parece estar intimamente associada ao stresse do retículo endoplasmático (RE) e aos mecanismos para o enfrentar ao longo da sua progressão, propôs-se que as estratégias de resiliência celular desenvolvidas pelas células para lidar com o stresse desempenham um papel crucial na DB. Interessantemente, demonstrou-se que as junções RE-mitocôndria, designadas “Mitochondria-Associated Membranes” (MAMs), são fundamentais nas respostas ao stresse uma vez que modulam a função mitocondrial, a sinalização de cálcio, a via Unfolded Protein Response (UPR) induzida pelo stresse do RE e a ativação do inflamassoma, os quais representam marcadores fisiopatológicos da DB. Estas premissas constituíram o ponto de partida para este trabalho, que é focado na “hipótese MAM” proposta pelo nosso grupo para a fisiopatologia da DB, e que pretende investigar o papel do stresse do RE na ativação do inflamassoma NLRP3 e na subsequente libertação de mediadores pró-inflamatórios que certamente sustentam o estado pro-inflamatório associado à DB. As MAMs foram avaliadas como o elo de ligação subjacente ao eixo RE-inflamassoma na DB. Neste sentido, utilizou-se um modelo celular do sistema imune inato, nomeadamente monócitos isolados de doentes bipolares versus controlos saudáveis em condições basais ou expostos a stresse do RE, assim como a linha celular de monócitos humanos THP-1 que foi usada como um modelo in vitro para elucidar as consequências funcionais e morfológicas do stresse do RE. Os nossos resultados sugerem que o stresse do RE induz a ativação do inflamassoma NLRP3 em monócitos THP-1 e em monócitos de indivíduos com diagnóstico de DB (fase precoce). Enquanto que nas células THP-1 o stresse do RE atua como sinal 2 para a ativação do inflamassoma, nos monócitos primários de doentes bipolares e de controlos saudáveis atua como sinal 1 e 2. Além disso, apurámos que os monócitos de doentes previamente expostos a LPS são mais sensíveis ao stresse do RE do que os monócitos controlo o que, juntamente com os parâmetros analíticos analisados, sugere que os doentes bipolares são mais suscetíveis a um estado pró-inflamatório. Evidenciámos ainda que os contactos RE-mitocôndria ao nível das MAMs, em particular a chaperona Sigma-1R e a proteína de ligação Mitofusina 2, são afetados pelo stresse do RE tanto nas células THP-1 como nos monócitos de doentes bipolares. Os resultados obtidos nos monócitos THP-1 sugerem que a comunicação RE-mitocôndria em células submetidas ao stresse promove a ativação do NLRP3 através de um mecanismo independente da produção mitocondrial de espécies reativas de oxigénio, o qual parece ser parcialmente mediado pela despolarização da membrana mitocondrial e subsequente externalização de cardiolipina. Também se observou que o stresse do RE provoca alterações morfológicas em monócitos THP-1 compatíveis com RE dilatado, indução da autofagia/mitofagia e modulação da dinâmica mitocondrial. Este trabalho evidenciou a disfunção das MAMs como um potencial elo fisiopatológico entre o stresse do RE e a ativação do inflamassoma NLRP3 no sistema imune inato, abrindo assim novos horizontes para o desenvolvimento de estratégias terapêuticas ajustadas à DB.
Mental health problems constitute the largest single source of world economic burden, with an estimated global cost greater than cardiovascular disease, cancer or diabetes individually. In the European Union, mental disorders affect millions of people and these numbers are expected to rise due to population ageing. Bipolar disorder (BD) is a mental illness characterized by mood swings between depression and mania resulting in cognitive and functional impairments that require lifetime treatment. However, few treatments are currently available with limited efficacy and delayed diagnosis is frequent because biomarkers are absent. Therefore, a better understanding of BD pathophysiology is crucial for new drugs design and implementation in clinical settings as well as to develop biomarkers for a more accurate and earlier diagnosis.Given that BD may be intimately associated with endoplasmic reticulum (ER) stress and coping mechanisms over the illness course, it has been proposed that cellular resilience strategies developed by cells to cope with stress play a key role in BD. Interestingly, it was shown that ER-mitochondria junctions, the so-called “Mitochondria-Associated Membranes” (MAMs), are relevant for stress-related responses by modulating mitochondrial function, Ca2+ signaling, ER stress-induced Unfolded Protein Response (UPR) and inflammasome activation, which are pathophysiological hallmarks of BD. These assumptions were the starting point for this work, which is focused on the “MAM hypothesis” proposed by our group for BD pathophysiology that intends to unveil the role of ER stress in NLRP3 inflammasome activation and subsequent release of pro-inflammatory mediators that will certainly sustain a pro-inflammatory status, as well as to evaluate MAMs as the link behind the ER stress-inflammasome axis in BD. For this purpose, a patient-derived cellular model of the innate immune system was used, namely monocytes isolated from BD patients versus healthy controls exposed to basal or ER stressful conditions and, the THP-1 monocytic cell line was used as in vitro model to decipher the functional and morphological consequences of ER stress. Altogether, our results suggest that ER stress induces NLRP3 inflammasome activation in THP-1 monocytes and BD patient-derived monocytes (early-stage). While in THP-1 cells ER stress acts as signal 2 for NLRP3 inflammasome activation, in control and BD monocytes it works as signal 1 and 2. In addition, LPS primed-BD patients’ monocytes are more responsive to ER stress than control monocytes, which together with the analytical parameters analyzed indicate that BD patients are more susceptible to develop a pro-inflammatory status. Furthermore, we uncovered that ER-mitochondria contacts at MAMs, particularly the chaperone Sigma-1R and the tethering protein Mitofusin 2, are affected in THP-1 cells as well as in BD monocytes upon ER stress. Data obtained in THP-1 monocytes suggest that ER-mitochondria communication in ER stressed cells promotes NLRP3 activation by a mitochondrial reactive oxygen species (ROS)-independent mechanism and, might be partially mediated by mitochondria membrane depolarization and subsequent externalization of cardiolipin. It was also observed in THP-1 monocytes that ER stress evoked morphological alterations consistent with dilated ER, autophagy/mitophagy induction and modulation of mitochondrial dynamics. This work pointed out MAM’s dysfunction as a potential pathophysiological link between ER stress and NLRP3 inflammasome activation in the innate immune system thus opening new avenues for the development of fine-tuned therapeutic strategies for BD.
Sheng-DeLi y 李聖德. "Preparation of Bipolar Membranes Using Plasma-Induced Polymerization Method on Hydrogen Production from Water Electrolysis". Thesis, 2010. http://ndltd.ncl.edu.tw/handle/86052989427337492612.
國立成功大學
化學工程學系碩博士班
98
Bipolar membranes have a lot of industrial applications because of their extraordinary properties. Generally speaking, they could be used to the fields of producing acid/base solutions, water treatment (ex. Separate to recycle and purify inorganic acid/base solution, organic acid and organic materials) and food industry. Therefore, industrial and academic researchers have attracted considerable attentions on this field. It is emphasized that bipolar membranes possess a characteristic property of the electrical field-enhanced water dissociation. As a result, the aim of the research is to investigate the surface modification of the PVDF membrane to form the bipolar membranes after plasma treatment and subsequently using the bipolar membranes to hydrogen production from water electrolysis. In the first section of this study, the G-I, AA and SSS monomers were grafted onto the respective side of the PVDF or PES membranes after plasma treatment and then, the four kinds of the bipolar membranes have been successfully prepared by plasma-induced polymerization method (PVDF-g-G-I, AA-PVDF-G-I, SSS-PVDF-G-I and PES-g-G-I bipolar membranes). PES membrane as diaphragms was used as background experiment and marked as“Water”. The reason is that the result of the electrochemical properties for PES membrane used was the same as that for no membrane between the electrodes. Take PVDF-g-G-I bipolar membrane as an example, it was carried out the measurements of the ability to produce acid/base solution and hydrogen production from water electrolysis. In producing acid/base solution, the critical voltage of water splitting to H+ and OH- could be reduced to 0.88 V by using the PVDF-g-G-I bipolar membrane. In addition, the value of the critical voltage by using the PVDF-g-G-I bipolar membrane was the same when the electrolyte concentration was increased or the kinds of the electrolyte was altered. On the other hand, the value of the limiting current density was increased with the KCl concentration and the diffusion coefficient of the electrolyte. There are two reasons for lower current efficiency of the PVDF-g-G-I bipolar membrane. (1) when water dissociation was occurred, H2O was dissociated into H+ and OH- within it. H+ was migrated to cathode electrode and OH- was moved to anode electrode under the electrical field. The negative charge on cation exchange layer was neutralized by H+ ion. Contractly, the positive charge on anion exchange layer was neutralized by OH- ion. (2) The fixed charge concentration on the PVDF-g-G-I bipolar membrane was reduced in the solution phase due to high swelling ratio. It is divided from two part of hydrogen production from water electrolysis. One part is to change the base membranes and second part is to alter cation exchange layers of the PVDF-g-G-I bipolar membrane (using AA (-COO-) and SSS (HSO3- ) monomers). The performance of water electrolysis for the cell operated with or without the self-made bipolar membranes is demonstrated by measuring the cell voltage, H2 production efficiency and the energy consumption of the H2 generation. The cell voltage using the self-made bipolar membranes is obviously lower than that of Water. The data demonstrates that the bipolar membranes prepared by plasma-induced polymerization had a great ability to reduce the cell voltage of water electrolysis and H2 production efficiency was improved 10-20 % by using them (compared with Water). The reason is due to the effect of the electrical field-enhanced water dissociation. From the energy consumption of H2 production, an energy saving of 30 % could be reached for the cell operated with the self-made bipolar membranes (compared with Water). In the second section of this study, it was the design of the reactor of water electrolysis. The ultrasonic field was applied into water electrolysis to remove the bubbles gas adhering onto the surface of the electrodes, membrane and in the solution. By removing the bubbles gas, the ohmic drop was reduced. The performance for the cell operated with or without an ultrasonic field is demonstrated by measuring the reduction in cell voltage, the efficiency and energy consumption of the generated gas (Water system). The reference sample was based on Water system for the cell operated without an ultrasonic field. The reduction in cell voltage was 320, 100 and 75 mV under 0.1, 0.5 and 1.0 M NaOH when current density is 200 mA/cm2, respectively. H2 production efficiency was improved 5-18 % in the presence of an ultrasonic field and however, O2 production efficiency was reduced a little bit. It is due to the difference between the dynamic behavior of H2 and O2 gas adhering onto the electrodes. For the energy consumption of H2 production, it could be reduced 10-25 % under an ultrasonic field. From economic consideration, the ultrasonic field applied into alkaline water electrolysis was beneficial to energy efficiency of water electrolysis. Finally, the ultrasonic field and the self-made bipolar membranes were combined to improve H2 production from water electrolysis. Take the PVDF-g-G-I bipolar membrane as an example, the energy consumption of H2 production was obviously reduced 4-8 % for the cell operated with the ultrasonic field (in comparison with Water), respectively.
JouLi y 李柔. "Preparation of various ionic bipolar membranes using plasma-induced polymerization method on hydrogen production from water electrolysis". Thesis, 2012. http://ndltd.ncl.edu.tw/handle/40208559048294440720.
國立成功大學
化學工程學系碩博士班
100
Bipolar membranes are widely used in industry. They were usually used to produce the acid/base solutions and water treatment. Therefore, bipolar membranes have been attracted industrial and academic research. Reducing the cell voltage of water electrolysis by using bipolar membrane had proved by our laboratory. Consequently, the aim of this research is to investigate the surface modification of PVDF membranes by plasma treatment and alter various ionic monomers to form four kinds of bipolar membranes for hydrogen production from water electrolysis. In this study, the N,N-Dimethyl amino ethyl acrylate (DMAEA)、4-Vinyl pyridine (4-VP), 4-Styrene sulfonic acid sodium salt hydrate (SSS)、acrylic acid (AA) monomers were grafted onto the respective side of the PVDF membranes through the plasma treatment. Four kinds of bipolar membranes, DMAEA-PVDF-SSS、DMAEA-PVDF-AA、4VP-PVDF-SSS and 4VP-PVDF-AA bipolar membranes, have been successfully prepared by plasma-induced polymerization method after characteristic of FTIR and SEM. Poly-ethersulfonate (PES) membranes were used as background experiment (Water). In water electrolysis experiment, the cell voltage using four kinds of bipolar membranes is lower than PES membrane (Water). Among those bipolar membranes, DMAEA-PVDF-SSS bipolar membrane has lowest critical voltage of water splitting to H+ and OH- as 0.92V. On the other hand, the limiting current density was increased with the increasing of KCl concentration. Furthermore, H2 production efficiency can be improved 10-30% (compared with Water). When using the DMAEA-PVDF-SSS bipolar membranes in water electrolysis, the H2 production efficiency can be as high as 92% but it is just only 74% by 4VP-PVDF-SSS bipolar membranes. The result is attributed from the electrical field, water dissociation constant ratio and their physical properties. In the energy consumption of H2 production, DMAEA-PVDF-SSS bipolar membranes have great outcome, it can save 48% energy. Consequently, the effect of anion exchange layer on the water electrolysis is larger than that of cation exchange layer of bipolar membranes.
Jhih-JyunMai y 麥智鈞. "Preparation of bipolar membranes by plasma-induced polymerization for the application of hydrogen production from water electrolysis". Thesis, 2019. http://ndltd.ncl.edu.tw/handle/hw8kjz.
Cunha, Ana Rita Azevedo Henriques da. "Perturbation of ER-mitochondria crosstalk in bipolar disorder: effect of Sigma-1 receptor modulation". Master's thesis, 2021. http://hdl.handle.net/10316/98013.
Os distúrbios psiquiátricos têm um enorme impacto tanto na qualidade de vida dos doentes, como a economia global. Só na Europa existem cerca de 164 milhões de pessoas com diagnóstico de algum tipo de distúrbio psiquiátrico. O distúrbio bipolar é uma perturbação de humor caracterizada pelas alterações entre episódios depressivos e maníacos ou hipomaníacos. O conhecimento relativo aos mecanismos celulares e moleculares subjacentes ao distúrbio bipolar são ainda muito limitados. Até então, a maioria dos estudos foram realizados em tecido post-mortem de doentes ou em animais, possuindo grandes limitações para o desenvolvimento de terapias e biomarcadores. No entanto, a literatura aponta para que existam alterações da resposta ao stress do retículo endoplasmático, disfunção mitocondrial, e alterações nos processos de inflamação, sinalização de Ca2+, bioenergética, autofagia e apoptose. Estes processos são regulados por zonas de junção entre o retículo endoplasmático e a mitocôndria, denominadas mitochondria-associated membranes (MAMs) cuja relevância em diferentes doenças do cérebro tem vindo a ser desvendada. Tendo isto em conta, este trabalho visou revelar se os alguns dos eventos regulados pelas MAM se encontram alterados em fibroblastos derivados de doentes com distúrbio bipolar, nomeadamente na resposta ao stress do retículo endoplasmático, ao nível do contacto entre este organelo e a mitocôndria, na disfunção mitocondrial, e na sinalização de Ca2+. Para este fim, foram usados fibroblastos da derme a partir de biópsias de pele realizadas em doentes com BD ou sujeitos saudáveis (n=3 homens, com idades compreendidas entre os 18-25 anos) após consentimento informado, de acordo com as diretrizes do Comité de Ética. As células foram sujeitas a tratamentos com tapsigargina, um indutor clássico do stress do retículo endoplasmático, e com pridopidina, um agonista do recetor Sigma-1, que é uma proteína envolvida nos mecanismos das MAM. Em condições basais e em stress induzido pela tapsigargina, analisamos os níveis proteicos de marcadores de unfolded protein response (UPR) por Western-blotting. A viabilidade celular foi avaliada pelo ensaio de redução do MTT, e o potencial da membrana mitocondrial foi avaliado utilizando TMRE. A libertação de Ca2+ do retículo endoplasmático mediada por IP3R e a transferência de Ca2+ do retículo endoplasmático para a mitocôndria foram analisados através das sondas fluorescentes Fura-2 e Rhod-2, respetivamente. A ligação do retículo endoplasmático às mitocôndrias foi analisada utilizando proximity ligation assay. Em fibroblastos provenientes de doentes com distúrbio bipolar detetámos diferenças nos níveis de proteínas envolvidas na resposta ao stress do retículo endoplasmático, na ligação entre este organelo e a mitocôndria, e ainda na sinalização de Ca2+ para a mitocôndria, tanto em condições basais como em stress. No entanto, observámos que a ativação farmacológica do recetor Sigma-1 não alterou a reposta das células dos doentes bipolares. Os nossos estudos revelaram mecanismos celulares e moleculares alterados nos fibroblastos de doentes relativamente aos fibroblastos controlo. Estes resultados contribuirão para o desenvolvimento de biomarcadores fidedignos e de estratégias terapêuticas.
Psychiatric disorders greatly impact both the quality of life of patients and the global economy. Only in Europe, there are about 164 million people diagnosed with some type of psychiatric disorder. Bipolar disorder (BD) is a mood disorder characterised by changes between depressive and manic or hypomanic episodes. Knowledge regarding the cellular and molecular mechanisms underlying bipolar disorder are still very limited. Until then, most studies have been carried out in post-mortem tissue of patients or in animals, with major limitations for the development of therapies and biomarkers. However, the literature points to altered endoplasmic reticulum stress response, mitochondrial dysfunction, and abnormalities in the processes of inflammation, Ca2+ signaling, bioenergetics, autophagy, and apoptosis. These processes are regulated by mitochondria-associated membranes (MAMs) and their relevance in different brain diseases is being unravelled. Taking this into account, this work aimed to reveal whether some of the events regulated by MAMs are altered in fibroblasts derived from patients with bipolar disorder, namely in the endoplasmic reticulum (ER) stress response, the contacts between this organelle and mitochondria, in mitochondrial dysfunction, and in Ca2+ signaling. For this purpose, dermal fibroblasts were generated from skin biopsies performed in BD patients or age- and sex-matched control subjects (n=3 males, aged 18-25 years) after informed consent in accordance with Ethics Committee’s guidelines. The cells were subjected to treatments with thapsigargin, a classical inducer of ER stress, and with pridopidine, an agonist of the Sigma-1 receptor which is a protein involved in MAMs mechanisms. Under basal and thapsigargin exposure, protein levels of ER stress- induced unfolded protein response (UPR) markers were measured by Western-blotting. Cell survival was assessed by the MTT reduction assay, and the mitochondrial membrane potential was evaluated using TMRE. IP3R-mediated ER Ca2+ release and ER-mitochondria Ca2+ transfer were studied with the Fura-2 and Rhod-2 fluorescent dyes, respectively. ER-mitochondria tethering was analysed using the proximity ligand assay. In BD patients-derived fibroblasts we detected differences in the levels of proteins involved in the ER stress response, in ER-mitochondria tethering, and in Ca2+ signaling to mitochondria, both in basal and stress conditions. However, we found that pharmacological activation of the Sigma-1 receptor did not alter the response of bipolar patients’ cells. Our studies have revealed abnormal cellular and molecular mechanisms in bipolar patients’ fibroblasts that could contribute to the development of reliable biomarkers and therapeutic strategies.
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