Academic literature on the topic 'PBI membrane'
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Journal articles on the topic "PBI membrane"
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Jiang, Junqiao, Erli Qu, Min Xiao, Dongmei Han, Shuanjin Wang, and Yuezhong Meng. "3D Network Structural Poly (Aryl Ether Ketone)-Polybenzimidazole Polymer for High-Temperature Proton Exchange Membrane Fuel Cells." Advances in Polymer Technology 2020 (August 14, 2020): 1–13. http://dx.doi.org/10.1155/2020/4563860.
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Poor mechanical property is a critical problem for phosphoric acid-doped high-temperature proton exchange membranes (HT-PEMs). In order to address this concern, in this work, a 3D network structural poly (aryl ether ketone)-polybenzimidazole (PAEK-cr-PBI) polymer electrolyte membrane was successfully synthesized through crosslinking reaction between poly (aryl ether ketone) with the pendant carboxyl group (PAEK-COOH) and amino-terminated polybenzimidazole (PBI-4NH2). PAEK-COOH with a poly (aryl ether ketone) backbone endows superior thermal, mechanical, and chemical stability, while PBI-4NH2 serves as both a proton conductor and a crosslinker with basic imidazole groups to absorb phosphoric acid. Moreover, the composite membrane of PAEK-cr-PBI blended with linear PBI (PAEK-cr-PBI@PBI) was also prepared. Both membranes with a proper phosphoric acid (PA) uptake exhibit an excellent proton conductivity of around 50 mS cm-1 at 170°C, which is comparable to that of the well-documented PA-doped PBI membrane. Furthermore, the PA-doped PAEK-cr-PBI membrane shows superior mechanical properties of 17 MPa compared with common PA-doped PBI. Based upon these encouraging results, the as-synthesized PAEK-cr-PBI gives a highly practical promise for its application in high-temperature proton exchange membrane fuel cells (HT-PEMFCs).
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Jheng, Li-Cheng, Cheng-Wei Cheng, Ko-Shan Ho, Steve Lien-Chung Hsu, Chung-Yen Hsu, Bi-Yun Lin, and Tsung-Han Ho. "Dimethylimidazolium-Functionalized Polybenzimidazole and Its Organic–Inorganic Hybrid Membranes for Anion Exchange Membrane Fuel Cells." Polymers 13, no. 17 (August 26, 2021): 2864. http://dx.doi.org/10.3390/polym13172864.
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A quaternized polybenzimidazole (PBI) membrane was synthesized by grafting a dimethylimidazolium end-capped side chain onto PBI. The organic–inorganic hybrid membrane of the quaternized PBI was prepared via a silane-induced crosslinking process with triethoxysilylpropyl dimethylimidazolium chloride. The chemical structure and membrane morphology were characterized using NMR, FTIR, TGA, SEM, EDX, AFM, SAXS, and XPS techniques. Compared with the pristine membrane of dimethylimidazolium-functionalized PBI, its hybrid membrane exhibited a lower swelling ratio, higher mechanical strength, and better oxidative stability. However, the morphology of hydrophilic/hydrophobic phase separation, which facilitates the ion transport along hydrophilic channels, only successfully developed in the pristine membrane. As a result, the hydroxide conductivity of the pristine membrane (5.02 × 10−2 S cm−1 at 80 °C) was measured higher than that of the hybrid membrane (2.22 × 10−2 S cm−1 at 80 °C). The hydroxide conductivity and tensile results suggested that both membranes had good alkaline stability in 2M KOH solution at 80 °C. Furthermore, the maximum power densities of the pristine and hybrid membranes of dimethylimidazolium-functionalized PBI reached 241 mW cm−2 and 152 mW cm−2 at 60 °C, respectively. The fuel cell performance result demonstrates that these two membranes are promising as AEMs for fuel cell applications.
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Yu, Tzyy-Lung Leon, and Hsiu-Li Lin. "Preparation of PBI/H3PO4-PTFE Composite Membranes for High Temperature Fuel Cells." Open Fuels & Energy Science Journal 3, no. 1 (February 16, 2010): 1–7. http://dx.doi.org/10.2174/1876973x01003010001.
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The poly(benzimidazole) (PBI)/ poly(tetrafluoroethylene) (PTFE) composite membrane was prepared by impregnating a porous PTFE thin film in a PBI solution N,N’-dimethyl acetamide (DMAc) solution mixed with LiCl. LiCl was used as a stabilizer to avoid aggregations of PBI molecules in the DMAc solutions. In this paper, we report a 2 mg/ml PBI/ DMAc/ LiCl solution with a [LiCl]/[BI] molar ratio of ~8.0 (i.e. the LiCl/PBI is ~ 1.1 in wt ratio, where [BI] is the concentration of benzimidazole repeat unit in the solution) has a lowest PBI polymer aggregations and thus a lowest solutions viscosity. The PBI membrane and PBI/PTFE composite membrane prepared from the PBI/DMAc/LiCl solution with a [LiCl]/[BI] molar ratio of ~8.0 were used to dop H3PO4 and prepare membrane electrode assemblies (MEA). The unit cell performances of these MEAs were carried out at 150oC. Owing to the high mechanical strength of porous PTFE, the thickness of PBI/H3PO4-PTFE composite membrane is allowed to be lower than that of a PBI/H3PO4 membrane. The lower thickness of PBI/H3PO4-PTFE membrane than that of PBI/H3PO4 membrane results in a lower resistance of PBI/H3PO4-PTFE than PBI/H3PO4. Thus the MEA prepared from PBI/H3PO4-PTFE has a better fuel cell performance than that prepared from PBI.
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Cho, Hyeongrae, Henning Krieg, and Jochen Kerres. "Performances of Anion-Exchange Blend Membranes on Vanadium Redox Flow Batteries." Membranes 9, no. 2 (February 17, 2019): 31. http://dx.doi.org/10.3390/membranes9020031.
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Anion exchange blend membranes (AEBMs) were prepared for use in Vanadium Redox Flow Batteries (VRFBs). These AEBMs consisted of 3 polymer components. Firstly, PBI-OO (nonfluorinated PBI) or F6-PBI (partially fluorinated PBI) were used as a matrix polymer. The second polymer, a bromomethylated PPO, was quaternized with 1,2,4,5-tetramethylimidazole (TMIm) which provided the anion exchange sites. Thirdly, a partially fluorinated polyether or a non-fluorinated poly (ether sulfone) was used as an ionical cross-linker. While the AEBMs were prepared with different combinations of the blend polymers, the same weight ratios of the three components were used. The AEBMs showed similar membrane properties such as ion exchange capacity, dimensional stability and thermal stability. For the VRFB application, comparable or better energy efficiencies were obtained when using the AEBMs compared to the commercial membranes included in this study, that is, Nafion (cation exchange membrane) and FAP 450 (anion exchange membrane). One of the blend membranes showed no capacity decay during a charge-discharge cycles test for 550 cycles run at 40 mA/cm2 indicating superior performance compared to the commercial membranes tested.
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Meng, Chao, Sheng Huang, Dongmei Han, Shan Ren, Shuanjin Wang, and Min Xiao. "Semi-interpenetrating Network Membrane from Polyethyleneimine-Epoxy Resin and Polybenzimidazole for HT-PEM Fuel Cells." Advances in Polymer Technology 2020 (December 29, 2020): 1–8. http://dx.doi.org/10.1155/2020/3845982.
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In the present work, a semi-interpenetrating network (semi-IPN) high-temperature proton exchange membrane based on polyethyleneimine (PEI), epoxy resin (ER), and polybenzimidazole (PBI) was prepared and characterized, aiming at their future application in fuel cell devices. The physical properties of the semi-IPN membrane are characterized by thermogravimetric analysis (TGA) and tensile strength test. The results indicate that the as-prepared PEI-ER/PBI semi-IPN membranes possess excellent thermal stability and mechanical strength. After phosphoric acid (PA) doping treatment, the semi-IPN membranes show high proton conductivities. PA doping level and volume swelling ratio as well as proton conductivities of the semi-IPN membranes are found to be positively related to the PEI content. High proton conductivities of 3.9 ∽ 7.8 × 10 − 2 S c m − 1 are achieved at 160°C for these PA-doped PEI-ER/PBI series membranes. H2/O2 fuel cell assembled with PA-doped PEI-ER(1 : 2)/PBI membrane delivered a peak power density of 170 mW cm-2 at 160°C under anhydrous conditions.
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Zeng, L., T. S. Zhao, L. An, G. Zhao, and X. H. Yan. "A high-performance sandwiched-porous polybenzimidazole membrane with enhanced alkaline retention for anion exchange membrane fuel cells." Energy & Environmental Science 8, no. 9 (2015): 2768–74. http://dx.doi.org/10.1039/c5ee02047f.
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Polybenzimidazole (PBI)-based membrane electrode assemblies are fabricated with a sandwiched-porous PBI as the membrane and a new catalyst structure using PBI-decorated reduced graphene oxide as the supporting material for anion exchange membrane fuel cells.
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Yang, Jing Shuai, Xue Yuan Li, Yi Xin Xu, Quan Tong Che, Rong Huan He, and Qing Feng Li. "Polybenzimidazole Membranes Containing Benzimidazole Side Groups for High Temprature Polymer Electrolyte Membrane Fuel Cells." Advanced Materials Research 716 (July 2013): 310–13. http://dx.doi.org/10.4028/www.scientific.net/amr.716.310.
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Polybenzimidazole (PBI) with a high molecular weight of 69,000 was first synthesized. It was afterwards grafted with benzimidazole pendant groups on the backbones. The acid doped benzimidaozle grafted PBI membranes were investigated and characterized including fuel cell tests at elevated temperatures without humidification. At an acid doping level of 13.1 mol H3PO4 per average molar repeat unit, the PBI membranes with a benzimidazole grafting degree of 10.6% demonstrated a conductivity of 0.15 S cm-1 and a H2-air fuel cell peak power density of 378 mW cm-2 at 180 °C at ambient pressure without humidification.
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Seng, Leong Kok, Mohd Shahbudin Masdar, and Loh Kee Shyuan. "Ionic Liquid in Phosphoric Acid-Doped Polybenzimidazole (PA-PBI) as Electrolyte Membranes for PEM Fuel Cells: A Review." Membranes 11, no. 10 (September 24, 2021): 728. http://dx.doi.org/10.3390/membranes11100728.
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Increasing world energy demand and the rapid depletion of fossil fuels has initiated explorations for sustainable and green energy sources. High-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) are viewed as promising materials in fuel cell technology due to several advantages, namely improved kinetic of both electrodes, higher tolerance for carbon monoxide (CO) and low crossover and wastage. Recent technology developments showed phosphoric acid-doped polybenzimidazole (PA-PBI) membranes most suitable for the production of polymer electrolyte membrane fuel cells (PEMFCs). However, drawbacks caused by leaching and condensation on the phosphate groups hindered the application of the PA-PBI membranes. By phosphate anion adsorption on Pt catalyst layers, a higher volume of liquid phosphoric acid on the electrolyte–electrode interface and within the electrodes inhibits or even stops gas movement and impedes electron reactions as the phosphoric acid level grows. Therefore, doping techniques have been extensively explored, and recently ionic liquids (ILs) were introduced as new doping materials to prepare the PA-PBI membranes. Hence, this paper provides a review on the use of ionic liquid material in PA-PBI membranes for HT-PEMFC applications. The effect of the ionic liquid preparation technique on PA-PBI membranes will be highlighted and discussed on the basis of its characterization and performance in HT-PEMFC applications.
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Deng, Yuming, Gang Wang, Ming Ming Fei, Xin Huang, Jigui Cheng, Xiaoteng Liu, Lei Xing, Keith Scott, and Chenxi Xu. "A polybenzimidazole/graphite oxide based three layer membrane for intermediate temperature polymer electrolyte membrane fuel cells." RSC Advances 6, no. 76 (2016): 72224–29. http://dx.doi.org/10.1039/c6ra11307a.
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PBI/GO/PBI composite membrane exhibited acceptable proton conductivity and fuel cell performance at 150 °C. The graphite oxide as proton conductor layer enhanced the mechanical strength and reduced the swelling ratio of electrolyte at intermediate temperature.
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Lee, Sangrae, Ki-Ho Nam, Kwangwon Seo, Gunhwi Kim, and Haksoo Han. "Phase Inversion-Induced Porous Polybenzimidazole Fuel Cell Membranes: An Efficient Architecture for High-Temperature Water-Free Proton Transport." Polymers 12, no. 7 (July 19, 2020): 1604. http://dx.doi.org/10.3390/polym12071604.
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To cope with the demand for cleaner alternative energy, polymer electrolyte membrane fuel cells (PEMFCs) have received significant research attention owing to their high-power density, high fuel efficiency, and low polluting by-product. However, the water requirement of these cells has necessitated research on systems that do not require water and/or use other mediums with higher boiling points. In this work, a highly porous meta-polybenzimidazole (m-PBI) membrane was fabricated through the non-solvent induced phase inversion technique and thermal cross-linking for high-temperature PEMFC (HT-PEMFC) applications. Standard non-thermally treated porous membranes are susceptible to phosphoric acid (PA) even at low concentrations and are unsuitable as polymer electrolyte membranes (PEMs). With the porous structure of m-PBI membranes, higher PA uptake and minimal swelling, which is controlled via cross-linking, was achieved. In addition, the membranes exhibited partial asymmetrical morphology and are directly applicable to fuel cell systems without any further modifications. Membranes with insufficient cross-linking resulted in an unstable performance in HT-PEMFC environments. By optimizing thermal treatment, a high-performance membrane with limited swelling and improved proton conductivity was achieved. Finally, the m-PBI membrane exhibited enhanced acid retention, proton conductivity, and fuel cell performance.
Dissertations / Theses on the topic "PBI membrane"
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Kreisz, Aurélien. "Membranes PBI pour pile à combustible haute température." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT224.
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Cette thèse débute par une courte introduction traitant des principes et de l'état de l'art des PEMFC dans le but de situer le contexte des travaux. Le but des travaux présentés dans ce manuscrit est de développer une nouvelle méthode de préparation de membrane pour les piles à combustible haute température (> 120 °C). Le polybenzimidazole dopé à l'acide phosphorique est devenu la référence des PEM haute température. Un degré de dopage élevé est essentiel pour minimiser les pertes ohmiques dans la cellule. Malheureusement un degré de dopage élevé entraine aussi une plastification de la membrane détériorant aussi sa résistance mécanique. Il est donc essentiel d'atteindre un compromis entre conductivité protonique élevée et résistance mécanique en contrôlant le degré de dopage. Dans ce travail, nous avons développé une nouvelle méthode de préparation de membrane, basée sur la gélation thermoréversible d'une solution de PBI dans l'acide phosphorique ou polyphosphorique, dans le but d'obtenir des degrés de dopage élevés. Une modification chimique a été réalisée dans l'état dopé afin d'induire une réticulation du polymère. De plus, les résistances mécaniques ont été améliorées en introduisant dans la membrane un mat de PBI réticulé obtenu par filage électrostatique. La faisabilité des approches suivies dans ces travaux a été démontrée par des tests en cellule de pile à combustible jusqu'à une température de 180 °C. Les AMEs élaborés à partir de ces membranes ont montré une stabilité satisfaisante durant 900 - 1000 heures de fonctionnement sous conditions statiques (opération continue à 0.2 A.cm-2) et sous conditions dynamiques (cyclage en tension et courant) avec une décroissance de la tension de la cellule au cours du temps de 0.7 - 0.8 µV.h-1 à 0.2 A.cm-2. Les caractéristiques I-V de ces AMEs ont été comparées à des assemblages de référence PBI/H3PO4 commerciaux et ont présenté des performances améliorées par rapport aux assemblages commerciauxThe thesis begins with a short overview of the principles and the current state at the art of the PEMFC in order to give a background on the specific subject of high temperature PEM fuel cell. The aim of the work presented in this thesis is to develop a new method of preparation of membrane for high temperature fuel cell (T > 120 °C). Phosphoric acid doped PBI has become the reference for high temperature PEM. A high phosphoric acid content is essential to minimize the ohmic voltage loss in the fuel cell for high current density. Unfortunately high phosphoric acid content exerts a strong plasticizing effect resulting in poor mechanical properties of the membrane. Consequently the doping level of the membrane should be a compromise between the highest proton conductivity and mechanical strength. In this work we have presented a new method of preparation of membrane based on the thermoreversible gelation of a PBI solution in phosphoric or polyphosphoric acid in order to obtain high acid doping. The chemical modification of the membrane has been performed in the doped state in order to induce a chemical crosslinking. The mechanical strength of the membrane has been further improved by the introduction of PBI electrospun mat as reinforcement. The feasibility of the approaches followed in this work was demonstrated in fuel cell tests at temperature up to 180 °C. The MEA based on those membranes have shown a stability up to 900 - 1000 hours either under static (continuous operation at 0.2 A.cm-2) or dynamic (voltage and current cycling) operation with a small voltage decay of 0.7 - 0.8 µV.h-1 at 0.2 A.cm-2. The I-V characteristics of these MEA have been compared with reference commercial PBI/H3PO4 MEAs and shown improved performances
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Suarez, Matthew. "The Effect of Membrane Thickness on the Performance of PBI-Based High-Temperature Direct Methanol Fuel Cells." Digital WPI, 2013. https://digitalcommons.wpi.edu/etd-theses/1131.
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"This project investigates the effect of membrane thickness on the performance and durability of a Direct Methanol Fuel Cell (DMFC) using a commercially available Celtec®P-1000 PBI-based membrane electrode assembly (MEA). The PBI-based membranes tested were the 100µm, the standard thickness, 200µm and 250µm thick. With various methanol feed concentrations and cathode feeds, oxygen and air, the PBI-based MEAs were operated between 160 and 180°C with vaporized methanol feed. Results showed that the DMFC performance increased with temperature and with PBI membrane thickness. The optimal concentration for the 100µm membrane was at 5M while the best performance with the 200µm membrane was obtained at 3M. The 250µm membrane looked like it could have had better performance than the 200µm, but unfortunately experimental issues didn’t allow completion of these results."
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Gomes, Carlos André Mendonça. "Study of multi-component systems in polybenzimidazole membrane formation and their impact on membrane performance." Master's thesis, Faculdade de Ciências e Tecnologia, 2013. http://hdl.handle.net/10362/10651.
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Dissertação para obtenção do Grau de Mestre em
Engenharia Química e BioquímicaIntegrally skinned asymmetric polybenzimidazole (PBI) membranes suitable for organic solvent nanofiltration (OSN) were prepared via phase inversion and several changes were implemented in the dope solutions in order to control their molecular weight cut-off (MWCO). Initially, uncrosslinked membranes with different polymer concentrations were tested to investigate their impact on membrane performance. On a second approach, several co-solvents were added in the dope solutions of PBI membranes. Coupling this methodology with chemical crosslinking, using an aromatic bi-functional crosslinker, provided solvent stable membranes with several MWCOs in the nanofiltration range and high permeance. Further variation of membrane dope parameters was tested in order to study membrane formation impact on membrane performance. Total solubility parameters of the chosen co-solvents were calculated, and a correlation between this tool and membrane performance was studied. Even though it was not possible to withdraw conclusions on a fundamental level, from the correlation of the total solubility parameters with membrane performance, this work demonstrates the possibility of developing PBI OSN membranes using different co-solvents and opens up future possibilities for controlling the MWCO of these membranes. A post-treatment study was also conducted in order to examine its impact in membrane performance.
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Barrientos, Wilner Valenzuela. "Estudo dos parâmetros operacionais de uma célula a combustível de glicerol direto utilizando uma membrana de polibencimidazol impregnada com ácido fosfórico (PBI/H3PO4) ou 1-hexil-3-metilimidazol trifluorometanosulfo." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/75/75134/tde-15092015-135733/.
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Com o aumento da população mundial, o desenvolvimento de novas fontes e conversores de energia tornou-se uma necessidade. As células a combustível mostram-se como uma alternativa viável devido principalmente a duas razões, sua alta eficiência e a utilização de combustíveis renováveis. No presente trabalho se estuda a influência da temperatura de operação e o conteúdo de álcali no combustível sobre a densidade de potencia para uma célula a combustível de glicerol direto. Como combustível foi utilizado uma solução de glicerol:KOH (1M:xM, x=0, 1, 3, 5), como membranas foram utilizados filmes de polibencimidazol impregnado com ácido fosfórico (PBI/H3PO4, relação molar 1:11) ou 1-hexil-3-metilimidazol trifluorometanosulfonato (PBI/HMI-Tf relação molar 1:1.5), e finalmente, nano partículas de Pt suportadas em carbono (60% w/w) como catalizador no ânodo e no cátodo. Em geral, o incremento da temperatura e conteúdo de álcali no combustível mostra um efeito favorável na densidade de potencia do sistema. Numa célula a combustível unitária de glicerol direto utilizando membranas de PBI/ H3PO4 e PBI/HMI-Tf foram obtidas densidades de potencia de 0.54mW.cm-2 a 175°C e 0.599mW.cm-2 a 130°C, respectivamente, para uma solução de glicerol de (1M); enquanto que, para uma solução com um conteúdo maior de álcali, glicerol:KOH (1M:5M), foram obtidas densidades de potencia maiores, 44.1mW.cm-2 a 175°C e 29mW.cm-2 a 130°C, respectivamente. O efeito combinado do incremento da temperatura e concentração de álcali no combustível mostra um efeito maior em relação ao efeito só da temperatura.With the increasing world population, the development of new energy sources or energy converters has become a necessity. Fuel cells show up as a viable alternative due mainly to two reasons, their high efficiency and the use of renewable fuels. In the present work we study the influence of operating temperature and alkali content in the fuel on the power density for a direct glycerol fuel cell. A glycerol:KOH (1M: xM, x = 0, 1, 3, 5) solution was used as fuels, as membranes were used polibencimidazol films impregnated with phosphoric acid (PBI/H3PO4, molar ratio of 1:11) or 1-hexyl-3-methylimidazolium trifluoromethanesulfonate (PBI/HMI-Tf), and finally, Pt nanoparticles supported on carbon (60% w / w) as catalyst in the anode and cathode. In general, increasing the temperature and alkali content in the fuel shows a favorable effect in the system power density. In a direct glycerol fuel cell using PBI/H3PO4 and PBI /HMI-Tf membranes were obtained power density of 0.54mW.cm-2 at 175°C and 0.599mW.cm-2 at 130°C, respectively, for a 1M glycerol solution; while for a glycerol solution with a higher content of alkali, glycerol:KOH (1M: 5M), were obtained higher power densities, 44.1mW.cm-2 at 175 ° C and 29mW.cm-2 at 130 ° C, respectively. The combined effect of increased temperature and alkali concentration in the fuel shows a greater effect compared to the effect of temperature only.
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Lee, Jeong Kyu. "Direct Methanol Fuel Cell Membranes from Polymer Blends." Case Western Reserve University School of Graduate Studies / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=case1134316195.
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Basdemir, Merve. "Development Of Pbi Based Membranes For H2/co2 Separation." Master's thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615473/index.pdf.
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Recent developments have confirmed that in the future hydrogen demand in industrial applications will arise because of the growing requirements for H2 in chemical manufacturing, petroleum refining, and the newly emerging clean energy concepts. Hydrogen is mainly produced from the steam reforming of natural gas and water gas shift reactions. The major products of these processes are hydrogen and carbon dioxide. The selective removal of CO2 from the product gas is important because it poisons catalysts in the reactor and it is highly corrosive. Membrane separation processes for hydrogen purification may be employed as alternative for conventional methods such as adsorption, cryogenic distillation.
Mixed matrix membranes (MMMs) are composed of an insoluble phase dispersed homogeneously in a continuous polymer matrix. They have potential in gas separation applications by combining the advantageous properties of both phases. The objective of this study is to produce neat polybenzimidazole (PBI) membranes and PBI based mixed matrix membranes for separation of H2/CO2. Furthermore, to test the gas permeation performance of the prepared membranes at permeation temperatures of 35oC to 90oC.
Commercial PBI supplied from both Celanese and FumaTech were used as polymer matrix. PBI was selected based on its thermal, chemical stabilities and mechanical properties and its performance as a fuel-cell membrane produced by PBI.
Micro-sized Zeolite 3A and nano-sized SAPO-34 are zeolites with 0.30 nm and 0.38 nm pore size respectively have attracted considerable interest and employed as fillers in this study. Commercial Zeolite 3A and synthesized SAPO-34 by our group was used throughout the study. Membranes were prepared using N,N-dimethylacetamide as the solvent. Prepared membranes were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The effect of annealing procedure and operating temperature on gas separation performance of resultant neat PBI, PBI/Zeolite 3A and PBI/SAPO-34 membranes were investigated by gas permeation tests. Hydrogen and carbon dioxide gases were used for single gas permeation measurements. Two different annealing strategies were utilized namely in-line annealing and in-oven annealing. In-oven annealing was performed in an oven in nitrogen atmosphere at 120oC, 0.7 atm while in-line annealing was performed in the gas permeation set-up by feeding helium as permeating gas at 90oC and 3 bar.
Neat PBI and PBI/ Zeolite 3A membranes were in-oven annealed. The in-oven annealed membranes showed better selectivities with lower permeabilities, but the performance results of these membranes had low repeatability. On the other hand, in-line annealed membranes showed much higher permeabilities and lower selectivities with stable performance. By changing the annealing method hydrogen permeability increased from 5.16 Barrer to almost 7.77 barrer for neat membranes and for PBI/Zeolite 3A mixed matrix membranes increased from 5.55 to to 7.69 Barrer at 35oC. The selectivities were decreased from 6.21 to 2.31 for neat membranes and for PBI/Zeolite 3A from 5.55 to 2.63.
Effect of increasing operating temperature was investigated by using in-line annealed membranes. Increasing temperature from 35oC to 90o improved the performance of the both types of membranes and repeatable results were obtained. Besides neat PBI and PBI/Zeolite 3A, PBI/SAPO-34 membranes were prepared only via in-line annealing. The addition of nano-sized filer to the membranes provided homogeneous distribution in polymer matrix for PBI/SAPO-34 membranes. For this type of membrane hydrogen permeability increased from 8.01 to 26.73 Barrer and with no change in H2/CO2 selectivities via rising temperature. Consequently, it is better to study hydrogen and carbon dioxide separation at high temperature.
For all types of membranes hydrogen showed higher activation energies. In between all membranes magnitude of activation energies were the highest for PBI/SAPO-34 membrane which is an indication of good interaction between polymer and zeolite interface. In-line annealed membranes gave the best gas permeation results by providing repeatability of measurements. Among all studied membranes in-line annealed PBI/SAPO-34 membrane exhibited the best gas permeation results.
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Schoeman, Johannes Gerhardus. "H2SO4 stability of PBI–blend membranes for SO2 electrolysis Schoeman / H." Thesis, North-West University, 2011. http://hdl.handle.net/10394/7567.
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Alternative energy sources are needed if the current use of energy is to be sustained while
reducing global warming. A possible alternative energy source that has significant potential
is hydrogen. For hydrogen to become a serious contender for replacing fossil fuels, the
production thereof has to be further investigated. One such process, the membrane–based
Hybrid Sulphur (HyS) process, where hydrogen is produced from the electrolysis of SO2, has
received considerable interest recently.
Since H2SO4 is formed during SO2 electrolysis, H2SO4 stability is a prerequisite for any
membrane to be used in this process. In this study, pure as well as high and low
temperature blended polybenzimidazole (PBI), partially fluorinated poly(arylene ether) (sFS)
and nonfluorinated poly(arylene ethersulphone) (sPSU) membranes were investigated in
terms of their acid stability as a function of acid concentration by treating them in H2SO4 (30,
60 and 90wt%) for 120h at 1bar pressure. The high temperature blend membranes contain
the basic polymer in excess (70 wt% basic PBI and 30wt% acid sPSU/sFS polymer) and
require acid doping in order to conduct protons. In the doped state they are able to conduct
protons up to 200°C. The low temperature blend membranes are also composed of the
same PBI polymer used in the high temperature membranes, as well as the same acidic
polymers with one of the membranes containing a fluorinated polymer and the other a nonfluorinated
polymer (sFS or sPSU) in excess. These membranes do not require any acid
doping to conduct protons but they are only stable at temperatures below 80°C.
High temperature blend membranes were characterised using through–plane conductivity,
GPC and IEC, whilst low temperature membranes were characterised using in–plane and
through–plane proton conductivity, weight change, TGA, GPC, SEM, EDX and IEC
techniques. The conductivity determination techniques (especially the in–plane technique)
proved to be cumbersome, whilst all the other analysis techniques were deemed
appropriate.
H2SO4 exposure had a destabilising effect on the PBI membrane which presented as weight
gain at the 30 and 60wt% H2SO4 concentrations due to salt formation and dissolution at the
90wt% acid treatment due to sulphonation. In the sFS membrane dissolution was observed
at 30 and 60wt% as a result of oligomer loss that occurred during the post treatment
washing process and partial dissolution, as a result of sulphonation, at the 90wt% treated membrane. The sPSU membrane showed great stability at 30 and 60wt%, though
dissolution was observed at 90wt% because of membrane sulphonation due to a lack of
fluorination. The sFS–PBI membrane blend proved to be stable with only slight degradation
taking place at 90wt% treatment due to sulphonation. Similarly the sPSU–PBI blend
membrane showed great stability at the 30 and 60wt% H2SO4 treatment concentrations
however total dissolution occurred at 90wt% treatment again due to a lack of fluorination.
Although both the low temperature blended membranes showed superb stability to H2SO4
concentrations expected in the SO2 electrolyser (30–40wt%), the low temperature blended
sFS–PBI membrane seemed slightly more stable over the H2SO4 treatment concentration
range (30–90wt%), due to the protective role of the fluorinated polymer. The superior acid
stability of this membrane could prove vital for proper SO2 electrolysis, especially for
prolonged periods of operationThesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2012.
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Freitas, Mauricio Azevedo de. "Poli(indeno) fosfonado : síntese, propriedades e uso como eletrólito em membranas a base de PBI." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/181807.
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Neste trabalho, um polímero eletrólito derivado do poli(indeno) (PInd) foi desenvolvido como componente de membranas poliméricas a base de polibenzimidazol (PBI) para célula a combustível de média temperatura. Foi investigado o método de síntese, envolvendo a reação de fosfonação pelo método de Friedel-Crafts assistido por catalisador ácido de Lewis AlCl3. O polímero poli(indeno) fosfonado (PPInd) foi comparado com seu análogo sulfonado, o poli(indeno) sulfonado (SPInd), e usados nas blendas com 5, 7,5 e 10% em peso com o PBI. Os polímeros precursores foram caracterizados por espectroscopia de infravermelho, espectroscopia de ressonância magnética nuclear, espectroscopia de energia dispersiva, espectrometria de espalhamento Rutherford, análise termogravimétrica acoplada com espectrometria de massas e calorimetria exploratória diferencial. As blendas PPInd/PBI e SPInd/PBI foram caracterizadas por análise termogravimétrica, grau de dopagem e espectroscopia de impedância eletroquímica. A modificação realizada pelo método de Friedel-Crafts permitiu a obtenção do poli(indeno) fosfonado parcialmente solúvel em solventes orgânicos e água, com grau de modificação de 81%. Houve convergência dos teores de modificação encontrados pelas análises termogravimétrica, espectrometria de espalhamento Rutherford e espectroscopia de energia dispersiva. O polímero PPInd apresentou estabilidade química na temperatura de operação da célula a combustível de média temperatura, passando por processos de degradação típicos de sua estrutura aromática fosfonada. A degradação dos polímeros PInd, PPInd e SPInd ocorreu majoritariamente com cisão de unidades monoméricas de indeno não funcionalizado. A inserção dos polímeros modificados PPInd e SPInd no PBI resultou no aumento da condutividade iônica, tendo a blenda com 10% de PPInd apresentado o maior valor de condutividade protônica (0,015 S.cm-1), a 25 oC. O uso do poli(indeno) modificado com grupos ácido fosfônico visa aumentar a gama de eletrólitos para células a combustível de média temperatura.In this work a polymer electrolyte derivated from the poly(indene) (PInd) was developed to be used as polymer electrolyte membrane in medium-temperature fuel cells. The modification method, based on the AlCl3 assisted Friedel-Crafts reaction, was investigated as fosfonation strategy. The phosphonated poly(indene) was compared to its similar sulphonated poly(indene) and they were used in blends of 5, 7.5 and 10wt% in polybenzimidazole (PBI). Pristine polymers were characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, energy dispersive spectroscopy, Rutherford backscattering spectrometry, thermogravimetric analysis coupled with mass spectrometry and differential scanning calometry. The PPInd/PBI and SPInd/PBI blends were characterized by thermogravimetric analysis, doping level and electrochemical impedance spectroscopy. The modification by Friedel-Crafts reaction produced phophonated poly(indene) with degree of phosphonation of 81%, partially soluble in organic solvent and water. It was found convergence on the results for degree of phosphonation calculated by thermogravimetric analysis, Rutherford backscattering spectrometry and energy dispersive spectroscopy. PPInd presented chemical and thermal stabilities within the fuel cell operating temperature, passing by typical degradation processes of macromolecules made of phosphonated aromatic structures. The degradation of PPInd and SPInd occurred mainly by cleavage of monomeric units of non-funcionalized indene. Addition of modified polymers PPInd and SPInd resulted in increase of PBI’s ionic conductivity. 10PPInd/PBI blend presented the highest ionic conductivity (0.015 S.cm-1) at 25 oC. The use of phosphonated poly(indene) on PBI membranes enlarges the variety of available polymer electrolyte membranes for medium-temperature fuel cells.
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Petek, Tyler Joseph. "An Investigation of PBI/PA Membranes for Application in Pump Cells for the Purification and Pressurization of Hydrogen." Case Western Reserve University School of Graduate Studies / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=case1320704555.
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Fattori, Enrico. "Membrane elettrofilate ibride a base di PBS e cheratina per il rilascio controllato di farmaci." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amslaurea.unibo.it/18569/.
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Grazie agli sviluppi delle nanotecnologie biomedicali nell’ambito del rilascio controllato di farmaci, sta diventando sempre più concreta la possibilità di superare i principali limiti della medicina tradizionale, basata su somministrazioni frequenti e ripetute di quantità di principio attivo anche superiori rispetto a quelle necessarie, e che dopo poco tempo raggiungono livelli al di sotto della soglia di efficacia. Tramite lo studio dei biomateriali e delle loro proprietà è possibile realizzare soluzioni ad hoc per il rilascio mirato di farmaco nel sito in cui è richiesta la terapia, con cinetiche modulabili a seconda delle specifiche esigenze del paziente. Nel presente studio, è stato realizzato mediante elettrofilatura un cerotto (o patch) a partire da una blend fisica di poli(butilene succinato) (PBS) e cheratina. Il primo è un polimero sintetico biocompatibile e approvato dalla Food and Drug Administration, con buone resistenza meccanica e lavorabilità, ma tempi di degradazione piuttosto lenti, a differenza della cheratina, polimero naturale, che risulta troppo rigido e difficile da processare, ma con buoni tempi di degradazione ed un’ottima biocompatibilità. Il tappetino elettrofilato così ottenuto è stato sottoposto a caratterizzazione molecolare, termica e meccanica. Inoltre, in vista di possibili applicazioni nell’ambito del rilascio controllato di farmaco, alla stessa blend è stato aggiunto diclofenac, antinfiammatorio presente in commercio, per ottenere una patch contenente al suo interno la stessa quantità di principio attivo presente nei comuni cerotti medicati. Il tappetino è stato sottoposto anche a test di rilascio del farmaco in condizioni fisiologiche e a test di adesione alla pelle. In conclusione, ogni tipo di indagine, seppur preliminare, ha comprovato che l’unione tra il PBS e la cheratina ha dato vita ad un nuovo biomateriale facilmente processabile, adesivo, ed in grado di favorire il rilascio del farmaco contenuto al suo interno.
Books on the topic "PBI membrane"
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Abhishek, Abhishek, and Michael Doherty. Pathophysiology of calcium pyrophosphate deposition. Oxford University Press, 2016. http://dx.doi.org/10.1093/med/9780199668847.003.0049.
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Calcium pyrophosphate (CPP) dihydrate crystals form extracellularly. Their formation requires sufficient extracellular inorganic pyrophosphate (ePPi), calcium, and pro-nucleating factors. As inorganic pyrophosphate (PPi) cannot cross cell membranes passively due to its large size, ePPi results either from hydrolysis of extracellular ATP by the enzyme ectonucleotide pyrophosphatase/phosphodiesterase 1 (also known as plasma cell membrane glycoprotein 1) or from the transcellular transport of PPi by ANKH. ePPi is hydrolyzed to phosphate (Pi) by tissue non-specific alkaline phosphatase. The level of extracellular PPi and Pi is tightly regulated by several interlinked feedback mechanisms and growth factors. The relative concentration of Pi and PPi determines whether CPP or hydroxyapatite crystal is formed, with low Pi/PPi ratio resulting in CPP crystal formation, while a high Pi/PPi ratio promotes basic calcium phosphate crystal formation. CPP crystals are deposited in the cartilage matrix (preferentially in the middle layer) or in areas of chondroid metaplasia. Hypertrophic chondrocytes and specific cartilage matrix changes (e.g. high levels of dermatan sulfate and S-100 protein) are related to CPP crystal deposition and growth. CPP crystals cause inflammation by engaging with the NALP3 inflammasome, and with other components of the innate immune system, and is marked with a prolonged neutrophilic inflitrate. The pathogenesis of resolution of CPP crystal-induced inflammation is not well understood.
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Murer, Heini, Jürg Biber, and Carsten A. Wagner. Phosphate homeostasis. Edited by Robert Unwin. Oxford University Press, 2015. http://dx.doi.org/10.1093/med/9780199592548.003.0025.
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Inorganic phosphate ions (H2PO4−/ HPO42−) (abbreviated as Pi) are involved in formation of bone and generation of high-energy bonds (e.g. ATP), metabolic pathways, and regulation of cellular functions. In addition, Pi is a component of biological membranes and nucleic acids. Only about 1% of total body Pi content is present in extracellular fluids, at a plasma concentration in adults within the range 0.8–1.4 mMol/L (at pH 7.4 mostly as HPO42−), with diurnal variations of approximately 0.2 mM. A small amount of plasma Pi is bound to proteins or forms complexes with calcium. Under normal, balanced conditions, absorption of dietary Pi along the small intestine equals the output of Pi via kidney and faeces. Renal excretion of Pi represents the key determinant for the adjustment of normal Pi plasma concentrations. Renal reabsorption of Pi occurs along the proximal tubules by sodium-dependent Pi cotransporters that are strictly localized at the apical brush border membrane. Parathyroid hormone (PTH) and FGF23 are key regulators amongst a myriad of factors controlling excretion of Pi in urine, mostly by changes of the apical abundance of Na/Pi cotransporters. Hypophosphataemia may result in osteomalacia, rickets, muscle weakness, and haemolysis. Hyperphosphataemia can lead to hyperparathyroidism and severe calcifications in different tissues.
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Jancura, Daniel, and Erik Sedlák. Bioenergetika. Univerzita Pavla Jozefa Šafárika, Vydavateľstvo ŠafárikPress, 2021. http://dx.doi.org/10.33542/be2021-0022-6.
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Prekladaný vysokoškolský učebný text „Bioenergetika“ by mal slúžiť ako úvod do problematiky štúdia v oblasti bioenergetiky. Táto vedná oblast je v súčasnosti vysoko aktuálna, pretože výsledky získané bioenergetickým výskumom v uplynulých rokoch zreteľne ukazujú, že bioenergetické procesy prebiehajúce v živých systémoch neslúžia “len” na transformáciu energie, ale ovplyvňujú aj priebeh procesov ako sú apoptóza, starnutie, vznik a rozvoj mnohých ochorení (predovšetkým neurodegeneratívnych). Tieto skutočnosti jednoznačne naznačujú potrebu existencie kvalitných učebných textov, ktoré by prijateľným spôsobom umožnili študentom získať potrebné informácie a vedomosti v tejto vednej discipline. Z vyššie uvedených dôvodov sme sa rozhodli vytvoriť tieto učebné texty, ktoré sú vo forme desiatich samostatných kapitol, ktoré však na seba prirodzene a logicky nadväzujú. Jedna kapitola predstavuje v podstate jednu prednášku v rámci kurzu Bioenergetiky, ktorý je realizovaný na Prírodovedeckej fakulte Univerzity Pavla Jozefa Šafárika v Košiciach na magisterskom a doktorandskom stupni študijného programu „Biofyzika“. Zároveň tieto texty môžu poslúžiť aj pri výučbe v študijnom predmete Biochémia, ktorý je prednášaný v bakalárskych a magisterských stupňoch študijných programov “Biochémia” resp. “Biofyzika”. Dovoľujeme si vyjadriť presvedčenie, že tieto učebné texty by mohli byť istým spôsobom nápomocné aj vedeckým pracovníkom pracujúcim v oblasti výskumu týkajúcho sa problematiky transformáci energie v biologických organizmoch a fenoménoch spojených s touto transformáciou. V týchto učebných textoch sú postupne uvádzané poznatky týkajúce sa základných konceptov bioenergetiky, mechanizmov procesov ako sú glykolýza a Krebsov cyklus (okrem podrobného a uceleného popis týchto procesov je tu uvedený aj všeobecný náhľad o prepojenosti týchto procesov ako aj ich začlenenie do kompaktného pohľadu na celkový proces transformácie energie v biologických organizmoch), zloženia štruktúry a funkčnosti biologických membrán (táto oblast je nevyhnutná pre lepšie pochopenie poznatkov, ktoré sú uvedené v nasledujúcich kapitolách). V nasledujúcich kapitolách sa učebný text zaoberá popisom štruktúry a funkcie mitochondrií, pričom veľký dôraz je dávaný na popis vlastností a mechanizmov fungovania štyroch komplexov dýchacieho reťazca a ATP-syntázy. Tieto komplexy vytvárajú podmienky pre existenciu “najdôležitejšieho” bioenergetického procesu, oxidatívnej fosforylácie. V záverečných dvoch kapitolách sú uvedené mechanizmy procesov vytvárajúcich fotosyntézu, jej svetlej aj tmavej fázy. Sú tu relevantné informácie o tomto “druhom” najdôležitejšom bioenergetickom procese prebiehajúcom v mnohých biologických organizmoch a poskytujúcom možnosť transformácie enrgie elektromagnetického žiarenia na energiu “ukrytú” v chemických väzbách určitých chemických molekúl. Chceme vyjadriť naše presvedčenie, že predložené učebné texty “Bioenergetika” budú dobrým “pomocníkom a inšpirátorom” pre mnohých študentov, ktorí sa budú chcieť dozvedieť čo najviac o fascinujúcich štruktúrach a mechanizmoch umožňujúcich transformáciu energie v živých systémoch, bez ktorej by nebola možná existencia života ako ho poznáme. Želáme príjemné a podnetné čítanie a štúdium. URL: www.unibook.upjs.sk The textbook "Bioenergetics" should serve as an introduction to the study of bioenergetics. This field of science is currently highly actual, as the results of the bioenergetics research in recent years clearly show that bioenergetics processes in living systems can "serve" not only to transformation of energy, but also affect the course of processes such as apoptosis, aging, origin and development of many diseases (especially neurodegenerative). These facts clearly indicate the need for the existence of quality teaching texts that would allow students to acquire the necessary information and knowledge in this scientific discipline in an acceptable way. For the above mentioned reasons, we decided to create these textbooks, which are in the form of ten chapters, which naturally and logically follow each other. One chapter basically presents one lecture within the course of Bioenergetics, which is realized at the Faculty of Science of the Pavel Jozef Šafárik University in Košice at the master's and doctoral degree of the study program "Biophysics". At the same time, these texts can also be used for teaching in the study subject Biochemistry, which is taught in the bachelor's and master's degree programs of the study programs "Biochemistry" resp. “Biophysics”. We would like to express our conviction that these textbooks could in some way also help researchers working in the field of the energy transformation in biological organisms and the phenomena associated with this transformation. These textbooks present knowledge about the basic concepts of bioenergetics, the mechanisms of processes such as glycolysis and the Krebs cycle (in addition to a detailed and comprehensive description of these processes, there is also a general view of the interconnectedness of these processes and their incorporation into a compact view of the overall energy transformation in biological organisms), the structure and functionality of biological membranes (this area is necessary for a better understanding of the knowledge presented in the following chapters). In the following chapters, the textbook deals with the description of the structure and function of mitochondria, with great emphasis on the properties and mechanisms of functioning of the four complexes of the respiratory chain and ATP-synthase. These complexes create the basis for the existence of the "most important" process in bioenergetics, oxidative phosphorylation. In the final two chapters, the mechanisms of the processes that produce photosynthesis, its light and dark phases, are presented. There is relevant information about this "second" most important bioenergetics process taking place in many biological organisms and providing the possibility of transforming the energy of electromagnetic radiation into energy "hidden" in the chemical bonds of certain chemical molecules. We want to express our conviction that the textbooks "Bioenergetics" will be a good "helper and inspirer" for many students who want to learn as much as possible about the fascinating structures and mechanisms for energy transformation in living systems, without which it would not be possible existence of life as we know it.
Book chapters on the topic "PBI membrane"
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Linares, José J., Liliane C. Battirola, and Justo Lobato. "PBI-Based Composite Membranes." In High Temperature Polymer Electrolyte Membrane Fuel Cells, 275–95. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-17082-4_13.
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Henkensmeier, Dirk, and David Aili. "Techniques for PBI Membrane Characterization." In High Temperature Polymer Electrolyte Membrane Fuel Cells, 127–50. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-17082-4_6.
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Fishel, Kayley, Guoqing Qian, and Brian C. Benicewicz. "PBI Membranes Via the PPA Process." In High Temperature Polymer Electrolyte Membrane Fuel Cells, 217–38. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-17082-4_10.
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Jakobsen, Mark Tonny Dalsgaard, Jens Oluf Jensen, Lars Nilausen Cleemann, and Qingfeng Li. "Durability Issues and Status of PBI-Based Fuel Cells." In High Temperature Polymer Electrolyte Membrane Fuel Cells, 487–509. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-17082-4_22.
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Siegel, Christian, Sebastian Lang, Ed Fontes, and Peter Beckhaus. "Approaches for the Modeling of PBI/H3PO4 Based HT-PEM Fuel Cells." In High Temperature Polymer Electrolyte Membrane Fuel Cells, 387–424. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-17082-4_18.
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Baum, H., and M. Fusconi. "The Antimitochondrial Antibodies (AMA) of Primary Biliary Cirrhosis (PBC)." In Molecular Basis of Membrane-Associated Diseases, 323–34. Berlin, Heidelberg: Springer Berlin Heidelberg, 1989. http://dx.doi.org/10.1007/978-3-642-74415-0_27.
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Verma, D. P. S., C. I. Cheon, N. G. Lee, Z. Hong, and G. H. Miao. "Biogenesis of Peribacteroid Membrane (PBM) Forming a Subcellular Compartment Essential for Symbiotic Nitrogen Fixation." In New Horizons in Nitrogen Fixation, 269–74. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-017-2416-6_29.
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Grubinko, Vasil V., Angela I. Lutsiv, and Katherina V. Kostyuk. "Structural Reconstruction of a Membrane at Absorption of MN2+, ZN2+, CU2+, and PB2+ with Green Algae Chlorella Vulgaris Beij." In Heavy Metals and Other Pollutants in the Environment, 273–92. Toronto : Apple Academic Press, 2017.: Apple Academic Press, 2017. http://dx.doi.org/10.1201/9781315366029-14.
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Khan, Umraz, Graeme Perks, Rhidian Morgan-Jones, Peter James, Colin Esler, Vince Smyth, and Vanya Gant. "Case histories." In Pathways in Prosthetic Joint Infection, 55–64. Oxford University Press, 2018. http://dx.doi.org/10.1093/med/9780198791881.003.0009.
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This chapter provides several typical cases encountered in patients who develop infection in prosthetic joints after surgery. Both the assessment and the definitive management are considered, as well as the microbiology profiles and the need for protracted antibiotics. The aim is that the decision-making process is enhanced. Although the treatment pathways are specific to those cases outlined, the surgical principles should remain constant for all cases. Comprehensive membrane resection remains a key event when surgically eradicating prosthetic joint infection (PJI). This act improves with experience. To improve outcomes for cases of PJI we encourage data collection within networks.
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Becker, Richard C., and Frederick A. Spencer. "Platelet Antagonists." In Fibrinolytic and Antithrombotic Therapy. Oxford University Press, 2006. http://dx.doi.org/10.1093/oso/9780195155648.003.0039.
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Antithrombotic and fibrinolytic drugs impair normal hemostasis and, as a result, increase the risk for hemorrhage. It is important to consider that many treatment strategies include agents of differing classes (platelet antagonists, anticoagulants, fibrinolytics) and categories (aspirin, clopidogrel, glycoprotein [GP] IIb/IIIa receptor antagonists), creating a multisite and/or hemostatic phase defect. Platelet antagonists, by impairing primary hemostasis, are associated most often with hemorrhage involving the skin and mucous membranes; however, the gastrointestinal and genitourinary tracts may occasionally be involved. Fixed-dose unfractionated heparin (UFH) therapy is a modifiable risk factor associated with hemorrhage in patients receiving GPIIb/IIIa receptor antagonists. The Evaluation of c7E3 Fab in Preventing Ischemic Complications of High-Risk Angioplasty (EPIC) trial was a prospective, randomized, placebo-controlled trial examining the efficacy of treatment with abciximab (EPIC Investigators, 1994). A total of 2,099 patients were scheduled for coronary angioplasty or direct atherectomy and were considered to be at high risk for abrupt closure. The primary composite endpoint of the study at 30 days was death from any cause, nonfatal myocardial infarction (MI), coronary artery bypass grafting (CABG) or repeat percutaneous coronary intervention (PCI), or placement of an intraaortic balloon pump to relieve refractory ischemia. All patients received therapy with 325 mg of aspirin and bolus dosing of UFH between 10,000 and 12,000 U followed by additional boluses of 3,000 U every 15 minutes to maintain an activated clotting time (ACT) between 300 and 350 seconds. Patients were randomized to receive either abciximab 0.25 mg/kg as a bolus followed by placebo infusion, or a placebo bolus and infusion. A significant increase in the incidence of major hemorrhage was demonstrated in patients receiving abciximab bolus and infusion compared to placebo bolus and infusion. A total of 14% of patients receiving abciximab bolus and infusion experienced a major bleeding complication as compared to 7% in the placebo bolus and infusion group (p = .001). Analysis of major hemorrhage in patients treated with abciximab bolus and infusion as a function of UFH dose revealed a dose-dependent increased risk.
Conference papers on the topic "PBI membrane"
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Lin, Hsiu-Li, Chih-Ren Hu, Po-Hao Su, Yu-Cheng Chou, and Che-Yu Lin. "Proton Exchange Membranes Based on Blends of Poly(Benzimidazole) and Butylsulfonated Poly(Beznimidazole) for High Temperature PEMFC." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33031.
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Phosphoric acid doped poly(benzimidazole) (PBI) is one of excellent candidates of proton exchange membranes for high temperature (150–180°C) proton exchange membrane fuel cells (PEMFCs). However, the strong inter-polymer hydrogen bonds cause low elongation and brittleness of PBI membranes. In this work, we synthesize poly(benzimidazole) (PBI) and butylsulfonated poly(benzimidazole) (PBI-BS), in which around 22 mole% of imidazole –NH groups of PBI are grafted with sulfonated butyl groups. We show the elongation, phosphoric acid doping level, and proton conductivity of PBI can be improved by blending ∼ 20 wt% of PBI-BS in the PBI membrane, and the membrane electrode assembly prepared from PBI/PBI-BS (8/2 by wt) blend membrane has a better PEMFC performance at 140°C ∼ 180°C than that prepared from PBI membrane. It is believed that the crosslink interactions of imidazole -NH and -N=C-groups with side chain –C4H8−SO3H groups of PBI-BS reduces the inter-PBI hydrogen bonds and increases the free volume of polymers, which leads to the enhancements of the membrane toughness and phosphoric acid doping level and the PEMFC performance.
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Yu, Tzyy-Lung Leon, Shih-Hao Liu, Hsiu-Li Lin, and Po-Hao Su. "Nafion/PBI Nanofiber Composite Membranes for Fuel Cells Applications." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33025.
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The PBI (poly(benzimidazole)) nano-fiber thin film with thickness of 18–30 μm is prepared by electro-spinning from a 20 wt% PBI/DMAc (N, N′-dimethyl acetamide) solution. The PBI nano-fiber thin film is then treated with a glutaraldehyde liquid for 24h at room temperature to proceed chemical crosslink reaction. The crosslink PBI nano-fiber thin film is then immersed in Nafion solutions to prepare Nafion/PBI nano-fiber composite membranes (thickness 22–34 μm). The morphology of the composite membranes is observed using a scanning electron microscope (SEM). The mechanical properties, conductivity, and unit fuel cell performance of membrane electrode assembly (MEA) of the composite membrane are investigated and compared with those of Nafion-212 membrane (thickness ∼50 μm) and Nafion/porous PTFE (poly(tetrafluoro ethylene)) composite membrane (thickness ∼22 μm). We show the present composite membrane has a similar fuel cell performance to Nafion/PTFE and a better fuel cell performance than Du Pont Nafion-212.
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Das, Susanta K., and K. J. Berry. "Synthesis and Performance Evaluation of an S-POSS Based PBI Electrolyte for High Temperature PEM Fuel Cell Applications." In ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology collocated with the ASME 2016 Power Conference and the ASME 2016 10th International Conference on Energy Sustainability. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/fuelcell2016-59214.
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In this paper, using patented nano-additive based polymer synthesis technology, a novel approach to the design and fabrication of high temperature proton exchange membrane (PEM) has been developed. The presence of sulfonated octaphenyl POSS (S-POSS) in a PBI-PA (polybenzimidazole-phosphoric acid) membrane results in a 40–50% increase in conductivity at 120–200$deg relative to non-sulfonated silica or POSS control fillers at comparable weight percent filler loadings and PBI molecular masses, and also relative to unfilled PBI-PA membranes. In addition, the presence of S-POSS and silica both result in physical reinforcement of the membrane and increased its modulus and mechanical integrity, but only S-POSS offers the benefits of both increased conductivity and increased modulus. Isophthalic acid and 3,3’-diaminobenzidine (DAB) were polymerized in the presence of polyphosphoric acid (PPA) and S-POSS nanoadditive, and the degree of polymerization was monitored by viscosity and torque change measurements. Molecular mass was determined by inherent viscosity measurements of samples removed from the reaction solution. Membranes were prepared by casting the reaction solution and allowing PPA to hydrolyze to PA under ambient conditions. The membranes were characterized for acid content, in-plane conductivity, tensile modulus and shear modulus, and were roll-milled to achieve the desired thickness for membrane electrode assembly (MEA) fabrication.
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Bharath, Sudharsan. "Low-Temperature Direct Propane Polymer Electrolyte Membrane Fuel Cell (DPFC)." In ASME 2006 4th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2006. http://dx.doi.org/10.1115/fuelcell2006-97001.
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The low-temperature Direct Propane Polymer Electrolyte Membrane Fuel Cell (DPFC) based on low-cost modified membranes was demonstrated for the first time. The propane is fed into the fuel cell directly without the need for reforming. A PBI membrane doped with acid and a Nafion 117 membrane modified or non-modified with silicotungstic acid were used as the polymer membranes. The anode was based on Pt, Pt-Ru or Pt/CrO3 electro catalysts and the cathode was based on a Pt electro catalyst. For non-optimized fuel cells based on H2SO4 doped PBI membranes and Pt/CrO3 anode, the open circuit potential was 1.0 Volt and the current density at 0.40 Volt was 118 mA.cm-2 at 95°C. For fuel cells based on Nafion 117 membranes modified with silicotungstic acid and on Pt/CrO3, the open-circuit voltage was 0.98 Volt and the current density at 0.40 Volt was 108 mA.cm-2 while fuel cells based on non-modified Nafion 117 membranes exhibited an open-circuit voltage of 0.8 Volt and the current density at 0.40 Volt was 42 mA.cm-2. It was also shown that propane fuel cells using anodes based on Pt-Ru/C anode (42 mW.cm-2) exhibit a similar maximum power density to that exhibited by fuel cells based on Pt-CrO3/C-anode (46 mW.cm-2), while DPFC using a Pt/C-based anode exhibited lower maximum power density (18 mW.cm-2) than fuel cells based on the Pt-CrO3/C anode (46 mW.cm-2).
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Shi, Zhongying, and Xia Wang. "Three Dimensional Non-Isothermal Model of a High Temperature PEM Fuel Cell." In ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2009. http://dx.doi.org/10.1115/fuelcell2009-85082.
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The proton exchange membrane (PEM) fuel cell using a polybenzimidazole (PBI) membrane operates between 120 °C and 180 °C, higher than the PEM fuel cell with a Nafion based membrane (lower than 80°C). Few studies have been conducted in the theoretical modeling of the PEM fuel cell with a PBI membrane. Experimental results have shown that the conductivity of a PBI membrane is affected by the phosphoric acid doping level, the cell operating temperature and the relative humidity. The fuel cell performance is thus affected by these parameters as well. The objective of this paper is to develop a three dimensional non-isothermal model to investigate the performance of the fuel cell with a PBI membrane. This new model considers influences of the relative humidity of the inlet air, the phosphoric acid doping level, and the operating temperature on the performance of fuel cells. The model is validated using the experimental data. A high oxygen concentration is found under the flow channel, as well as a high temperature region. The performance of fuel cells increases with the increase of the phosphoric doping level, temperature or relative humidity. The fuel cell performance is found to be more sensitive to the doping level and temperature changes, and less sensitive to the change of relative humidity.
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Cheddie, Denver F., and Norman D. H. Munroe. "Computational Modeling of PEM Fuel Cells With PBI Membranes." In ASME 2006 4th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2006. http://dx.doi.org/10.1115/fuelcell2006-97127.
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A parametric model of a proton exchange membrane fuel cell (PEMFC) operating with a polybenzimidazole (PBI) membrane is presented. The model is three dimensional and applicable for PEMFCs operating at intermediate temperatures (120–150 °C). It accounts for all transport and polarization phenomena, and the results compare well with published experimental data for equivalent operating conditions. Results for oxygen concentration and temperature variations are presented. The model predicts the oxygen depletion, which occurs in the catalyst area under the ribs, and which gives an indication of the catalyst utilization. Results also predict that for an output power density of 1 kW m−2, a cell temperature rise of up to 30 K can be expected for typical laboratory operating conditions. Parametric analyses indicate that significant gain in fuel cell performance can be expected by increasing the conductivity of the PBI membrane. Further, results demonstrate that when the catalyst region is well utilized, increasing the catalyst activity results in only a small improvement in performance.
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Bhamidipati, Kanthi Latha, and Tequila A. L. Harris. "Numerical Analysis of the Effects of Processing Conditions on the Casting of High Temperature PEMFC Membrane Solutions." In ASME 2009 7th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2009. http://dx.doi.org/10.1115/fuelcell2009-85064.
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Polymer Electrolyte Membranes have numerous failure modes resulting from chemical, mechanical and thermal influences. The conventional state–of–the–art low temperature Nafion® membrane is susceptible to such failures due to its sensitivity to high temperatures and the presence of carbon monoxide (CO) in the reactant streams, which poisons the platinum catalyst at low temperatures. To circumvent these problems, novel, cost-effective membranes that operate at high temperatures (>120°C) and low humidity levels, such as phosphoric acid doped polybenzimidazole (PBI/PA) membranes, have been developed. However, an optimized manufacturing process for the PBI membranes is required to negate failure mechanisms that are mechanically and thermally induced; e.g., gas cross-over due to pinholes. This paper focuses on understanding defects arising in the fluid state during manufacturing, using Computational Fluid Dynamics (CFD) techniques. Simulations are performed to understand the effects of processing conditions (substrate velocity, inlet velocity and temperature) on the quality of the cast and pressure drop through the system. It is found that processing speeds affected both the cast quality and pressure drop, while temperature only affected the pressure drop.
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Krishnan, Lakshmi, Todd Snelson, Ray Puffer, and Daniel Walczyk. "Durability studies of PBI-based membrane elect rode assemblies for high temperature PEMFCs." In 2010 IEEE International Conference on Automation Science and Engineering (CASE 2010). IEEE, 2010. http://dx.doi.org/10.1109/coase.2010.5584497.
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Share, Dylan, Lakshmi Krishnan, David Lesperence, Daniel Walczyk, and Raymond Puffer. "Cold Pressing of Membrane Electrode Assemblies for High-Temperature PEM Fuel Cells." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33230.
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With the current economic and environmental situation, the development of affordable and clean energy sources is receiving much attention. One leading area of promise is PEM fuel cells. Presently, manufacture of high temperature Polybenzimidizole (PBI) based PEM Membrane Electrode Assemblies (MEAs) is usually performed by sealing in a thermal press. A typical sealing process requires heated tooling to press electrode-subgasket assemblies into a sol-gel PBI membrane. MEAs designed for transportation purposes have a large active area that requires expensive heated tooling, which in turn requires significant power to operate. A previous Design of Experiments (DoE) and analysis revealed that sealing temperature is a statistically insignificant sealing parameter with respect to MEA performance. To further investigate the effects of sealing temperature on MEA performance in hopes of reducing manufacturing costs, an additional DoE was performed in which MEAs were manufactured with the tooling at room temperature. This paper examines the effect of thermal sealing process parameters, namely: (1) sealing temperature; (2) percent compression, and; (3) seal time on the fuel cell performance. MEAs were manufactured using three different thickness membranes with these input process parameters. Polarization behavior during single cell operation, internal cell resistance and catalyst utilization were analyzed as performance parameters. This data is compared to MEAs made with traditional heated tooling. The analysis reveals the insignificance of sealing temperature on the initial performance of the MEA.
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Ubong, Etim U., Diana Phillips, and Matt Gieseke. "Regeneration of Pt Electrode Activity in H3PO4/PBI Doped PEMFC Membrane Following CO Poisoning." In ASME 2010 8th International Conference on Fuel Cell Science, Engineering and Technology. ASMEDC, 2010. http://dx.doi.org/10.1115/fuelcell2010-33333.
Full textAbstract:
An investigation has been made on a high temperature polybenzimidazole (PBI) proton exchange membrane doped with phosphoric acid. Two and five percent concentrations of CO in the hydrogen were evaluated to determine the effect of high CO concentrations on the performance of the PBI membrane under conditions that are representative of reformed fuels. A 3 × 3 matrix of fuel composition, temperature and air stoichiometry was studied at two pressures: one atmosphere and one bar gage. A controlled experiment using hydrogen of 99.997% purity was used as a baseline fuel before and after the exposure to higher CO concentrations. A comparison between the pure hydrogen runs and those where CO was also present in the fuel showed a significant reduction in cell performance. Subsequent runs with pure hydrogen restored the cell performance. The mechanism that led to the cell recovery with pure hydrogen will be discussed.
Reports on the topic "PBI membrane"
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Vogel, John, and Katrina Fritz Intwala. Demonstration of Next-Generation PEM CHP Systems for Global Markets Using PBI Membrane Technology. Office of Scientific and Technical Information (OSTI), August 2009. http://dx.doi.org/10.2172/1097545.
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Krishnan, Gopala N., Kathryn A. Berchtold, Indira Jayaweera, Richard Callahan, Kevin OBrien, Daryl-Lynn Roberts, and Will Johnson. Fabrication and Scale-up of Polybenzimidazole (PBI) Membrane Based System for Precombustion- Based Capture of Carbon Dioxide. Office of Scientific and Technical Information (OSTI), April 2013. http://dx.doi.org/10.2172/1073750.
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Krishnan, Gopala, Indira Jayaweera, Angel Sanjrujo, Kevin O'Brien, Richard Callahan, Kathryn Berchtold, Daryl-Lynn Roberts, and Will Johnson. Fabrication and Scale-up of Polybenzimidazole (PBI) Membrane Based System for Precombustion-Based Capture of Carbon Dioxide. Office of Scientific and Technical Information (OSTI), March 2012. http://dx.doi.org/10.2172/1050227.
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Jayaweera, Indira, and Palitha Jayaweera. Development of a Pre-combustion CO2 Capture Process Using High-Temperature PBI Hollow-Fiber Membranes. Office of Scientific and Technical Information (OSTI), November 2018. http://dx.doi.org/10.2172/1569766.
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