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Sample records for oxygen-enriching membrane system

  1. Novel Membranes and Processes for Oxygen Enrichment

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Haiqing

    2011-11-15

    The overall goal of this project is to develop a membrane process that produces air containing 25-35% oxygen, at a cost of $25-40/ton of equivalent pure oxygen (EPO2). Oxygen-enriched air at such a low cost will allow existing air-fueled furnaces to be converted economically to oxygen-enriched furnaces, which in turn will improve the economic and energy efficiency of combustion processes significantly, and reduce the cost of CO{sub 2} capture and sequestration from flue gases throughout the U.S. manufacturing industries. During the 12-month Concept Definition project: We identified a series of perfluoropolymers (PFPs) with promising oxygen/nitrogen separation properties, which were successfully made into thin film composite membranes. The membranes showed oxygen permeance as high as 1,200 gpu and oxygen/nitrogen selectivity of 3.0, and the permeance and selectivity were stable over the time period tested (60 days). We successfully scaled up the production of high-flux PFP-based membranes, using MTR's commercial coaters. Two bench-scale spiral-wound modules with countercurrent designs were made and parametric tests were performed to understand the effect of feed flow rate and pressure, permeate pressure and sweep flow rate on the membrane module separation properties. At various operating conditions that modeled potential industrial operating conditions, the module separation properties were similar to the pure-gas separation properties in the membrane stamps. We also identified and synthesized new polymers [including polymers of intrinsic microporosity (PIMs) and polyimides] with higher oxygen/nitrogen selectivity (3.5-5.0) than the PFPs, and made these polymers into thin film composite membranes. However, these membranes were susceptible to severe aging; pure-gas permeance decreased nearly six-fold within two weeks, making them impractical for industrial applications of oxygen enrichment. We tested the effect of oxygen-enriched air on NO{sub x} emissions

  2. Oxygen enriched air using membrane for palm oil wastewater treatment

    Directory of Open Access Journals (Sweden)

    Ramlah Mohd Tajuddin

    2002-11-01

    Full Text Available A research aimed to explore new method of aeration using oxygen enriched air performance on BOD reduction of palm oil wastewater was conducted. The oxygen enriched air was obtained from an Oxygen Enriched System (OES developed using asymmetric polysulfone hollow fiber membrane with composition consisting of PSF: 22%, DMAc: 31.8%, THF: 31.8%, EtOH: 14.4%. Palm oil wastewater samples were taken from facultative pond effluent. These samples were tested for its initial biochemical oxygen demand (BOD, total suspended solids (TSS, pH, conductivity, turbidity, dissolved oxygen (DO, suspended solids (SS, and total dissolved solids (TDS before being subjected to two modes of aeration system, that is diffused air and oxygen enriched air. These water quality concentrations were tested for every 20 minutes for two-hour period during the aeration process. Results of BOD, TSS, pH, conductivity, DO, SS and TDS concentrations against time of samples from the two modes of aeration were then compared. It was found that DO concentration achieved in oxygen enriched air aeration was better than aeration using diffused air system. Aeration using OES improve the DO concentration in the wastewater and thus improve the BOD reduction and also influence other physical characteristics of wastewater. This phenomenon indicates the advantage of using air with higher oxygen concentration for wastewater aeration instead of diffused air system.

  3. Review of Membrane Oxygen Enrichment for Efficient Combustion

    Science.gov (United States)

    Ariono, Danu; Kusuma Wardani, Anita

    2017-07-01

    Oxygen enrichment from air is a simple way of increasing the efficiency of combustion process, as in oxy-combustion. Oxy-combustion has become one of the most attracting combustion technologies because of its potential to address both pollutant reduction and CO2 capture. In oxy-combustion, the fuel and recycled flue gas are combusted with oxygen enriched air (OEA). By using OEA, many benefits can be obtained, such as increasing available heat, improving ignition characteristics, flue gas reduction, increasing productivity, energy efficiency, turndown ratio, and flame stability. Membrane-based gas separation for OEA production becomes an attractive technology over the conventional technology due to the some advantages, including low capital cost, low energy consumption, compact size, and modularity. A single pass through membrane usually can enrich O2 concentration in the air up to 35% and a 50% concentration can be achieved with a double pass of membrane. The use of OEA in the combustion process eliminates the presence of nitrogen in the flue gas. Hence, the flue gas is mainly composed of CO2 and condensable water that can be easily separated. This paper gives an overview of oxy-combustion with membrane technology for oxygen enrichment process. Special attention is given to OEA production and the effect of OEA to the efficiency of combustion.

  4. Primary study of ethyl cellulose nanofiber for oxygen-enrichment membrane

    Directory of Open Access Journals (Sweden)

    Shen Jing

    2016-01-01

    Full Text Available Ethyl cellulose is widely used for oxygen-enrichment membrane, however, its nanofiber membrane was rarely developed though it behaves more excellent performance. This paper gives a preliminary study to produce oxygen-enrichment membrane by bubbfil spinning.

  5. Oxygen enriched combustion system performance study. Phase 2: 100 percent oxygen enriched combustion in regenerative glass melters, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Tuson, G.B.; Kobayashi, H.; Campbell, M.J.

    1994-08-01

    The field test project described in this report was conducted to evaluate the energy and environmental performance of 100% oxygen enriched combustion (100% OEC) in regenerative glass melters. Additional objectives were to determine other impacts of 100% OEC on melter operation and glass quality, and to verify on a commercial scale that an on-site Pressure Swing Adsorption oxygen plant can reliably supply oxygen for glass melting with low electrical power consumption. The tests constituted Phase 2 of a cooperative project between the United States Department of Energy, and Praxair, Inc. Phase 1 of the project involved market and technical feasibility assessments of oxygen enriched combustion for a range of high temperature industrial heating applications. An assessment of oxygen supply options for these applications was also performed during Phase 1, which included performance evaluation of a pilot scale 1 ton per day PSA oxygen plant. Two regenerative container glass melters were converted to 100% OEC operation and served as host sites for Phase 2. A 75 ton per day end-fired melter at Carr-Lowrey Glass Company in Baltimore, Maryland, was temporarily converted to 100% OEC in mid- 1990. A 350 tpd cross-fired melter at Gallo Glass Company in Modesto, California was rebuilt for permanent commercial operation with 100% OEC in mid-1991. Initially, both of these melters were supplied with oxygen from liquid storage. Subsequently, in late 1992, a Pressure Swing Adsorption oxygen plant was installed at Gallo to supply oxygen for 100% OEC glass melting. The particular PSA plant design used at Gallo achieves maximum efficiency by cycling the adsorbent beds between pressurized and evacuated states, and is therefore referred to as a Vacuum/Pressure Swing Adsorption (VPSA) plant.

  6. Development of Nanofiller-Modulated Polymeric Oxygen Enrichment Membranes for Reduction of Nitrogen Oxides in Coal Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Jianzhong Lou; Shamsuddin Ilias

    2010-12-31

    North Carolina A&T State University in Greensboro, North Carolina, has undertaken this project to develop the knowledge and the material to improve the oxygen-enrichment polymer membrane, in order to provide high-grade oxygen-enriched streams for coal combustion and gasification applications. Both experimental and theoretical approaches were used in this project. The membranes evaluated thus far include single-walled carbon nano-tube, nano-fumed silica polydimethylsiloxane (PDMS), and zeolite-modulated polyimide membranes. To document the nanofiller-modulated polymer, molecular dynamics simulations have been conducted to calculate the theoretical oxygen molecular diffusion coefficient and nitrogen molecular coefficient inside single-walled carbon nano-tube PDMS membranes, in order to predict the effect of the nano-tubes on the gas-separation permeability. The team has performed permeation and diffusion experiments using polymers with nano-silica particles, nano-tubes, and zeolites as fillers; studied the influence of nano-fillers on the self diffusion, free volume, glass transition, oxygen diffusion and solubility, and perm-selectivity of oxygen in polymer membranes; developed molecular models of single-walled carbon nano-tube and nano-fumed silica PDMS membranes, and zeolites-modulated polyimide membranes. This project partially supported three graduate students (two finished degrees and one transferred to other institution). This project has resulted in two journal publications and additional publications will be prepared in the near future.

  7. Oxygen enrichment incineration

    International Nuclear Information System (INIS)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested

  8. Oxygen enrichment incineration

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jeong Guk; Yang, Hee Chul; Park, Geun Il; Kim, Joon Hyung

    2000-10-01

    Oxygen enriched combustion technology has recently been used in waste incineration. To apply the oxygen enrichment on alpha-bearing waste incineration, which is being developed, a state-of-an-art review has been performed. The use of oxygen or oxygen-enriched air instead of air in incineration would result in increase of combustion efficiency and capacity, and reduction of off-gas product. Especially, the off-gas could be reduced below a quarter, which might reduce off-gas treatment facilities, and also increase an efficiency of off-gas treatment. However, the use of oxygen might also lead to local overheating and high nitrogen oxides (NOx) formation. To overcome these problems, an application of low NOx oxy-fuel burner and recycling of a part of off-gas to combustion chamber have been suggested.

  9. Study on Characteristics of Co-firing Ammonia/Methane Fuels under Oxygen Enriched Combustion Conditions

    Science.gov (United States)

    Xiao, Hua; Wang, Zhaolin; Valera-Medina, Agustin; Bowen, Philip J.

    2018-06-01

    Having a background of utilising ammonia as an alternative fuel for power generation, exploring the feasibility of co-firing ammonia with methane is proposed to use ammonia to substitute conventional natural gas. However, improvement of the combustion of such fuels can be achieved using conditions that enable an increase of oxygenation, thus fomenting the combustion process of a slower reactive molecule as ammonia. Therefore, the present study looks at oxygen enriched combustion technologies, a proposed concept to improve the performance of ammonia/methane combustion. To investigate the characteristics of ammonia/methane combustion under oxygen enriched conditions, adiabatic burning velocity and burner stabilized laminar flame emissions were studied. Simulation results show that the oxygen enriched method can help to significantly enhance the propagation of ammonia/methane combustion without changing the emission level, which would be quite promising for the design of systems using this fuel for practical applications. Furthermore, to produce low computational-cost flame chemistry for detailed numerical analyses for future combustion studies, three reduced combustion mechanisms of the well-known Konnov's mechanism were compared in ammonia/methane flame simulations under practical gas turbine combustor conditions. Results show that the reduced reaction mechanisms can provide good results for further analyses of oxygen enriched combustion of ammonia/methane. The results obtained in this study also allow gas turbine designers and modellers to choose the most suitable mechanism for further combustion studies and development.

  10. Examinations of the process of hard coal and biomass blend combustion in OEA (oxygen enriched atmosphere)

    International Nuclear Information System (INIS)

    Pawlak-Kruczek, Halina; Ostrycharczyk, Michał; Czerep, Michał; Baranowski, Marcin; Zgóra, Jacek

    2015-01-01

    The benefits of oxygen enrichment have been demonstrated in a variety of industrial combustion applications, but to date no implementation of oxygen enrichment in boilers has been reported, primarily due to their already high thermal efficiencies and a very large scale of such systems, which require significant amounts of oxygen. But recently, oxygen combustion in boilers has become one of the CCS technologies which can be an effective tool for reducing greenhouse gases emissions, and oxygen enriched combustion is suitable for low-calorific fuels, including biomass. This paper analyses the use of oxygen enrichment in a furnace for co-firing of different kinds of biomass with hard coal in terms of emission and burnout impact (LOI). As a part of this research, the effect of injection oxygen mode and total oxygen concentration on the flue gas emission (SO_2, NO_x) and burnout from co-firing of straw and wooden biomass in different proportions (20% and 40%) with hard coal were studied. The co-firing tests were carried out in an isothermal flow reactor. One of the benefits from the OEA (oxygen enriched atmosphere) technology is more effective separation of CO_2 owing to the higher CO_2 concentration in the flue gas. The additional advantage of the OEA combustion technology in comparison with oxy-fuel combustion is that the OEA process needs lower O_2 purities and therefore it is cost-effective. Experimental tests on co-firing of 20% straw-hard coal blend were conducted in oxygen enriched (up to 25 and 30%) atmospheres with three variants of O_2 injection modes. NO_x, SO_2 emissions and burnout for the various atmospheres in the combustion chamber were studied. Moreover, co-firing tests were performed with 40% share of wooden biomass to examine the effect of the biomass share and a type on emission of NO_x and SO_2 in OEA. The two O_2 injection modes were investigated. In each case, the emission of SO_2 increases alongside an increase of oxygen concentration in

  11. Effect of Oxygen Enrichment in Propane Laminar Diffusion Flames under Microgravity and Earth Gravity Conditions

    Science.gov (United States)

    Bhatia, Pramod; Singh, Ravinder

    2017-06-01

    Diffusion flames are the most common type of flame which we see in our daily life such as candle flame and match-stick flame. Also, they are the most used flames in practical combustion system such as industrial burner (coal fired, gas fired or oil fired), diesel engines, gas turbines, and solid fuel rockets. In the present study, steady-state global chemistry calculations for 24 different flames were performed using an axisymmetric computational fluid dynamics code (UNICORN). Computation involved simulations of inverse and normal diffusion flames of propane in earth and microgravity condition with varying oxidizer compositions (21, 30, 50, 100 % O2, by mole, in N2). 2 cases were compared with the experimental result for validating the computational model. These flames were stabilized on a 5.5 mm diameter burner with 10 mm of burner length. The effect of oxygen enrichment and variation in gravity (earth gravity and microgravity) on shape and size of diffusion flames, flame temperature, flame velocity have been studied from the computational result obtained. Oxygen enrichment resulted in significant increase in flame temperature for both types of diffusion flames. Also, oxygen enrichment and gravity variation have significant effect on the flame configuration of normal diffusion flames in comparison with inverse diffusion flames. Microgravity normal diffusion flames are spherical in shape and much wider in comparison to earth gravity normal diffusion flames. In inverse diffusion flames, microgravity flames were wider than earth gravity flames. However, microgravity inverse flames were not spherical in shape.

  12. Studies of MHD generator performance with oxygen enriched coal combustion

    Science.gov (United States)

    Wormhoudt, J.; Yousefian, V.; Kolb, C. E.; Martinez-Sanchez, M.

    1980-07-01

    This paper presents calculations made using the Aerodyne PACKAGE (Plasma Analysis, Chemical Kinetics, and Generator Efficiency) computer code which bear on two questions which arise in connection with choices between oxygen enrichment and air preheating to attain the high combustion temperatures needed for open-cycle, coal-fired MHD power generation. The first question is which method produces the highest enthalpy extraction per unit channel length. The second is, in test facilities intended to study tradeoffs between oxygen enrichment and preheated air, can good generator performance be obtained from the same physical channel for different combustor compositions. The answer to the first question is found to depend on what combustor conditions are taken to be comparable. As for the second question, it is found that operation with channel input from off-design combustor conditions can cause serious problems, which can be partially alleviated by changing the channel load factors.

  13. Decommissioning Combustible Waste Treatment using Oxygen-Enriched Incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Min, Byungyoun; Lee, Yoonji; Yun, Gyoungsu; Lee, Kiwon; Moon, Jeikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    The aim of the paper is current status of treatment for the decommissioning combustible waste in KAERI and for the purpose of the volume reduction and clearance for decommissioning combustible wastes generated by the decommissioning projects. The incineration technology has been selected for the treatment of combustible wastes. About 34 tons of decommissioning combustible waste has been treated using Oxygen Enriched incineration. Temperature, pressure of major components, stack gas concentration, i. e., SOx, NOx, CO, CO{sub 2} and HCl, and the residual oxygen were measured. Measured major parameters during normal operation were sustained on a stable status within a criteria operation condition. Oxygen enriched air, 22vol. % (dry basis) was used for stable incineration. The volume reduction ratio has achieved about 1/117. The incineration with decommissioning radioactive combustible waste is possible with moderate oxygen enrichment of 22 vol.% (dry basis) into the supply air. The incineration facility operated quite smoothly through the analysis major critical parameters of off-gas. The pressure, off-gas flow and temperature of major components remained constant within the range specified. The measures gases and particulate materials in stack were considerably below the regulatory limits. The achieved volume reduction ratio through incineration is about 1/117.

  14. Modeling the effects of late cycle oxygen enrichment on diesel engine combustion and emissions

    International Nuclear Information System (INIS)

    Mather, D. K.; Foster, D. E.; Poola, R. B.; Longman, D. E.; Chanda, A.; Vachon, T. J.

    2002-01-01

    A multidimensional simulation of Auxiliary Gas Injection (AGI) for late cycle oxygen enrichment was exercised to assess the merits of AGI for reducing the emissions of soot from heavy duty diesel engines while not adversely affecting the NO(sub x) emissions of the engine. Here, AGI is the controlled enhancement of mixing within the diesel engine combustion chamber by high speed jets of air or another gas. The engine simulated was a Caterpillar 3401 engine. For a particular operating condition of this engine, the simulated soot emissions of the engine were reduced by 80% while not significantly affecting the engine-out NO(sub x) emissions compared to the engine operating without AGI. The effects of AGI duration, timing, and orientation are studied to confirm the window of opportunity for realizing lower engine-out soot while not increasing engine out NO(sub x) through controlled enhancement of in-cylinder mixing. These studies have shown that this window occurs during the late combustion cycle, from 20 to 60 crank angle degrees after top-dead-center. During this time, the combustion chamber temperatures are sufficiently high that soot oxidation increases in response in increased mixing, but the temperature is low enough that NO(sub x) reactions are quenched. The effect of the oxygen composition of the injected air is studied for the range of compositions between 21% and 30% oxygen by volume. This is the range of oxygen enrichment that is practical to produce from an air separation membrane. Simulations showed that this level of oxygen enrichment is insufficient to provide an additional benefit by either increasing the level of soot oxidation or prolonging the window of opportunity for increasing soot oxidation through enhanced mixing

  15. Volume Reduction of Decommissioning Burnable Waste with Oxygen Enrich Incinerator

    Energy Technology Data Exchange (ETDEWEB)

    Min, B. Y.; Yang, D. S.; Lee, K. W.; Choi, J. W. [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The incineration technology is an effective treatment method that contains hazardous chemicals as well as radioactive contamination. The volume reduction of the combustible wastes through the incineration technologies has merits from the view point of a decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost. Incineration is generally accepted as a method of reducing the volume of radioactive waste. The incineration technology is an effective treatment method that contains hazardous chemicals as well as radioactive contamination. This paper covers the general facility operation of an oxygen-enriched incinerator for the treatment of decommissioning wastes generated from a decommissioning project. The combustible wastes have been treated by the utilization of incinerator the capacity of the average 20 kg/hr. The decommissioning combustible waste of about 31 tons has been treated using Oxygen Enriched incinerator by at the end of 2016. The off-gas flow and temperature were maintained constant or within the desired range. The measured gases and particulate materials in the stack were considerably below the regulatory limits.

  16. Volume Reduction of Decommissioning Burnable Waste with Oxygen Enrich Incinerator

    International Nuclear Information System (INIS)

    Min, B. Y.; Yang, D. S.; Lee, K. W.; Choi, J. W.

    2016-01-01

    The incineration technology is an effective treatment method that contains hazardous chemicals as well as radioactive contamination. The volume reduction of the combustible wastes through the incineration technologies has merits from the view point of a decrease in the amount of waste to be disposed of resulting in a reduction of the disposal cost. Incineration is generally accepted as a method of reducing the volume of radioactive waste. The incineration technology is an effective treatment method that contains hazardous chemicals as well as radioactive contamination. This paper covers the general facility operation of an oxygen-enriched incinerator for the treatment of decommissioning wastes generated from a decommissioning project. The combustible wastes have been treated by the utilization of incinerator the capacity of the average 20 kg/hr. The decommissioning combustible waste of about 31 tons has been treated using Oxygen Enriched incinerator by at the end of 2016. The off-gas flow and temperature were maintained constant or within the desired range. The measured gases and particulate materials in the stack were considerably below the regulatory limits.

  17. Hybrid membrane--PSA system for separating oxygen from air

    Science.gov (United States)

    Staiger, Chad L [Albuquerque, NM; Vaughn, Mark R [Albuquerque, NM; Miller, A Keith [Albuquerque, NM; Cornelius, Christopher J [Blackburg, VA

    2011-01-25

    A portable, non-cryogenic, oxygen generation system capable of delivering oxygen gas at purities greater than 98% and flow rates of 15 L/min or more is described. The system consists of two major components. The first component is a high efficiency membrane capable of separating argon and a portion of the nitrogen content from air, yielding an oxygen-enriched permeate flow. This is then fed to the second component, a pressure swing adsorption (PSA) unit utilizing a commercially available, but specifically formulated zeolite compound to remove the remainder of the nitrogen from the flow. The system is a unique gas separation system that can operate at ambient temperatures, for producing high purity oxygen for various applications (medical, refining, chemical production, enhanced combustion, fuel cells, etc . . . ) and represents a significant advance compared to current technologies.

  18. High Pressure and High Temperature State of Oxygen Enriched Ice

    Science.gov (United States)

    LI, M.; Zhang, S.; Jeanloz, R.; Militzer, B.

    2016-12-01

    Interior models for Uranus and Neptune include a hydrogen/helium/water outer envelope and a core of rock and metal at the center, with superionic water-rich ice proposed as comprising an intermediate layer. Here we consider an oxygen-enriched ice, such as H2O2 hydrogen peroxide (± water), that could form through chemical reaction between water-rich and underlying rocky (i.e., oxygen-rich) layers. As oxygen and its compounds (e.g., H2O, SiO2) form metallic fluids at pressures above 100-150 GPa, the problem amounts to considering oxygen alloying of semiconducting or metallic water. The density of H2O2 is 1.45 g/cc at ambient pressure and 0° C, increasing to 1.71 g/cc in the solid state at about -20° C. There are no Hugoniot data beyond 30 GPa, so we estimated Hugoniots for H2O2 with different initial densities, using both a mixing model based on Hugoniot data for H2O2 and 1/2 O2 (molar volume summation under pressure) and ab initio calculations for unreacted H2O2. The results agree with each other to pressures of about 200 GPa, and the ab initio calculations show evidence of a superionic state at temperatures as low as 500 K, much lower than for water ice. Hydrogen peroxide is expected to be liquid along planetary isentropes for Uranus and Neptune, suggesting that H2O2 may not be present as a pure compound in these planets. Instead, oxygen-enriched H2O ice may be the relevant form of water and oxygen, and might be produced in the laboratory by way of dynamic compression of H2O2 or laser-heating of statically compressed H2O + O2 and/or H2O2.

  19. Test Operation of Oxygen-Enriched Incinerator for Wastes From Nuclear Fuel Fabrication Facility

    International Nuclear Information System (INIS)

    Kim, J.-G.; Yang, H.cC.; Park, G.-I.; Kim, I.-T.; Kim, J.-K.

    2002-01-01

    The oxygen-enriched combustion concept, which can minimize off-gas production, has been applied to the incineration of combustible uranium-containing wastes from a nuclear fuel fabrication facility. A simulation for oxygen combustion shows the off-gas production can be reduced by a factor of 6.7 theoretically, compared with conventional air combustion. The laboratory-scale oxygen enriched incineration (OEI) process with a thermal capacity of 350 MJ/h is composed of an oxygen feeding and control system, a combustion chamber, a quencher, a ceramic filter, an induced draft fan, a condenser, a stack, an off-gas recycle path, and a measurement and control system. Test burning with cleaning paper and office paper in this OEI process shows that the thermal capacity is about 320 MJ/h, 90 % of design value and the off-gas reduces by a factor of 3.5, compared with air combustion. The CO concentration for oxygen combustion is lower than that of air combustion, while the O2 concentration in off-gas is kept above 25 vol % for a simple incineration process without any grate. The NOx concentration in an off-gas stream does not reduce significantly due to air incoming by leakage, and the volume and weight reduction factors are not changed significantly, which suggests a need for an improvement in sealing

  20. Numeric Simulation of Oxygen Enriched Combustion in a Frit Melting Kiln

    Directory of Open Access Journals (Sweden)

    Bernardo A. Herrera-Múnera

    2013-11-01

    Full Text Available In this paper, a numerical study of air enriched combustion on a natural gas rotary furnace for frita melting is presented. This study was done with the aim of determining an oxygen concentration to ensure economic feasibility of the process without affecting quality requirements. The simulations were conducted using the commercial software ANSYS FLUENT as a design tool to predict the behavior of the thermal system and to establish operations conditions with different oxygen enrichment levels. Finite Rate / Eddy Dissipation model was used for combustion simulation, while k - ε Realizable and Discrete Ordinates models were utilized for turbulence and radiation simulation, respectively. It was found that an enrichment level close to 31% of oxygen in the air allows for reaching temperatures for frita melting larger than 1700 K. In this way, current consumption of high purity oxygen can be diminished without affecting the production levels and the quality of the product.

  1. Influence of oxygen enrichment on compression ignition engines using biodiesel blends

    Directory of Open Access Journals (Sweden)

    Vaiyapuri Senthil Murugan

    2017-01-01

    Full Text Available The influence of oxygen enrichment on performance and emission characteristics of a single cylinder diesel engine operated with biodiesel blends have been investigated in this work. The methyl ester of jatropha biodiesel was selected as bio-diesel and four blends (B10, B20, B30, and B40 were selected for experimental investigations. The performance and emission characteristics were obtained for the these blends along with three oxygen enrichment flow rates (1, 3, and 5 L per minute using an oxygen cylinder at the air intake in the diesel engine. The performance and emission characteristics were studied and compared with the diesel and biodiesel. It was observed that, oxygen enrichment enhances the brake thermal efficiency, HC, CO, and smoke. B10 biodiesel with 5 L per minute oxygen enrichment was found to be the best fuel for biodiesel operation.

  2. An Elementary Overview of the Selection of Materials for Service in Oxygen-Enriched Environments

    Science.gov (United States)

    Davis, Samuel Eddie

    2012-01-01

    The process for selecting materials for use in oxygen or oxygen-enriched environments is one that continues to be investigated by many industries due to the importance to those industries of oxygen systems. There are several excellent resources available to assist oxygen systems design engineers and end-users, with the most comprehensive being ASTM MNL-36, Safe Use of Oxygen and Oxygen Systems: Handbook for Design, Operation and Maintenance, 2nd Edition. ASTM also makes available several standards for oxygen systems. However, the ASTM publications are extremely detailed, and typically designed for professionals who already possess a working knowledge of oxygen systems. No notable resource exists, whether an ASTM or other organizational publication, which can be used to educate engineers or technicians who have no prior knowledge of the nuances of oxygen system design and safety. This paper will fill the void for information needed by organizations that design or operate oxygen systems. The information in this paper is not new information, but is a concise and easily understood summary of selecting materials for oxygen systems. This paper will serve well as an employee s first introduction to oxygen system materials selection, and probably the employee s first introduction to ASTM.

  3. Effect of oxygen enrichment in air on acid gas combustion under Claus conditions

    KAUST Repository

    Ibrahim, Salisu

    2013-09-01

    Results are presented to examine the combustion of acid gas (H2S and CO2) in hydrogen-fueled flames using a mixture of oxygen and nitrogen under Claus conditions (Φ = 3). Specifically the effect of oxygen enrichment in the above flames is examined. The compositions of acid gas examined are100% H2S and 50% H2S/50% CO2 with different percentages of oxygen enrichment (0%, 19.3% and 69.3%) in the oxygen/nitrogen mixtures. The results revealed that combustion of acid gas formed SO2 wherein the mole fraction of SO2 increased to an asymptotic value at all the oxygen concentrations examined. In addition, increase in oxygen enrichment of the air resulted in increased amounts of SO2 rather than the formation of more desirable elemental sulfur. In case of 50% H2S/50% CO2 acid gas, carbon monoxide mole fraction increased with oxygen enrichment which is an indicator to the availability of additional amounts of oxygen into the reaction pool. This gas mixture resulted in the formation of other sulfurous–carbonaceous compounds (COS and CS2) due to the presence of carbon monoxide. The results showed that the rate of COS formation increased with oxygen enrichment due to the availability of higher amounts of CO while that of CS2 reduced. The global reactions responsible for this observed phenomenon are presented.

  4. Preliminary analysis of 500 MWt MHD power plant with oxygen enrichment

    Science.gov (United States)

    1980-04-01

    An MHD Engineering Test Facility design concept is analyzed. A 500 MWt oxygen enriched MHD topping cycle integrated for combined cycle operation with a 400 MWe steam plant is evaluated. The MHD cycle uses Montana Rosebud coal and air enriched to 35 mole percent oxygen preheated to 1100 F. The steam plant is a 2535 psia/1000 F/1000 F reheat recycle that was scaled down from the Gilbert/Commonwealth Reference Fossil Plant design series. Integration is accomplished by blending the steam generated in the MHD heat recovery system with steam generated by the partial firing of the steam plant boiler to provide the total flow requirement of the turbine. The major MHD and steam plant auxiliaries are driven by steam turbines. When the MHD cycle is taken out of service, the steam plant is capable of stand-alone operation at turbine design throttle flow. This operation requires the full firing of the steam plant boiler. A preliminary feasibility assessment is given, and results on the system thermodynamics, construction scheduling, and capital costs are presented.

  5. High Temperature Oxidation of Steel in an Oxygen-enriched Low NOX Furnace Environment

    Energy Technology Data Exchange (ETDEWEB)

    Poirier, D.; Grandmaison, E.W. [Department of Chemical Engineering, Queen' s University, Kingston, ON K7L 3N6 (Canada); Matovic, M.D. [Department of Mechanical and Materials Engineering, Queen' s University, Kingston, ON K7L 3N6 (Canada); Barnes, K.R. [KB Technical Services, Inc (formerly) Stelco Inc, Research Manager, Stelco Inc., P.O. Box 2030, Hamilton, ON L8N 3T1 (Canada); Nelson, B.D. [Department of Chemical Engineering, Senior Researcher, Dofasco Inc., P.O. Box 2460, Hamilton, ON L8N 3J5 (Canada)

    2006-09-15

    Steel scaling tests have been performed in a research furnace utilizing an oxygen-enriched, low NOX, burner. This work was performed in conjunction with a study of the combustion characteristics for the Canadian Gas Research Institute (CGRI) low NOX burner. The furnace (a facility of the Centre for Advanced Gas Combustion Technology (CAGCT)) was fired with the burner mounted in a sidewall configuration similar to the geometry encountered in steel reheat furnaces. Scale habit, intactness, adhesion and oxidation rates were examined for five grades of steel over a range of stack oxygen concentrations ({approx}0.8% - {approx}4.3%) and oxygen enrichment levels (0-90%) at 1100C. Steel grade had the largest effect on scaling properties examined in this work. Within the tests for each grade, stack oxygen concentration had the largest effect on the scaling properties while oxygen enrichment level had only a small effect.

  6. Simulation and experiment for oxygen-enriched combustion engine using liquid oxygen to solidify CO2

    Science.gov (United States)

    Liu, Yongfeng; Jia, Xiaoshe; Pei, Pucheng; Lu, Yong; Yi, Li; Shi, Yan

    2016-01-01

    For capturing and recycling of CO2 in the internal combustion engine, Rankle cycle engine can reduce the exhaust pollutants effectively under the condition of ensuring the engine thermal efficiency by using the techniques of spraying water in the cylinder and optimizing the ignition advance angle. However, due to the water spray nozzle need to be installed on the cylinder, which increases the cylinder head design difficulty and makes the combustion conditions become more complicated. In this paper, a new method is presented to carry out the closing inlet and exhaust system for internal combustion engines. The proposed new method uses liquid oxygen to solidify part of cooled CO2 from exhaust system into dry ice and the liquid oxygen turns into gas oxygen which is sent to inlet system. The other part of CO2 is sent to inlet system and mixed with oxygen, which can reduce the oxygen-enriched combustion detonation tendency and make combustion stable. Computing grid of the IP52FMI single-cylinder four-stroke gasoline-engine is established according to the actual shape of the combustion chamber using KIVA-3V program. The effects of exhaust gas recirculation (EGR) rate are analyzed on the temperatures, the pressures and the instantaneous heat release rates when the EGR rate is more than 8%. The possibility of enclosing intake and exhaust system for engine is verified. The carbon dioxide trapping device is designed and the IP52FMI engine is transformed and the CO2 capture experiment is carried out. The experimental results show that when the EGR rate is 36% for the optimum EGR rate. When the liquid oxygen of 35.80-437.40 g is imported into the device and last 1-20 min, respectively, 21.50-701.30 g dry ice is obtained. This research proposes a new design method which can capture CO2 for vehicular internal combustion engine.

  7. Effects of oxygen enriched combustion on pollution and performance characteristics of a diesel engine

    Directory of Open Access Journals (Sweden)

    P. Baskar

    2016-03-01

    Full Text Available Oxygen enriched combustion is one of the attractive combustion technologies to control pollution and improve combustion in diesel engines. An experimental test was conducted on a single cylinder direct injection diesel engine to study the impact of oxygen enrichment on pollution and performance parameters by increasing the oxygen concentration of intake air from 21 to 27% by volume. The tests results show that the combustion process was improved as there is an increase in thermal efficiency of 4 to 8 percent and decrease in brake specific fuel consumption of 5 to 12 percent. There is also a substantial decrease in unburned hydro carbon, carbon mono-oxide and smoke density levels to the maximum of 40, 55 and 60 percent respectively. However, there is a considerable increase in nitrogen oxide emissions due to increased combustion temperature and extra oxygen available which needs to be addressed.

  8. Thermogravimetric analysis of rice and wheat straw catalytic combustion in air- and oxygen-enriched atmospheres

    International Nuclear Information System (INIS)

    Yu Zhaosheng; Ma Xiaoqian; Liu Ao

    2009-01-01

    By thermogravimetric analysis (TGA) study, the influences of different catalysts on the ignition and combustion of rice and wheat straw in air- and oxygen-enriched atmospheres have been investigated in this paper. Straw combustion is divided into two stages. One is the emission and combustion of volatiles and the second is the combustion of fixed carbon. The existence of catalysts in the first step enhances the emission of volatiles from the straw. The action of catalysts in the second step of straw combustion may be as a carrier of oxygen to the fixed carbon. Two parameters have been used to compare the characteristics of ignition and combustion of straw under different catalysts and in various oxygen concentrations. One is the temperature when the conversion degree combustible (CDC) of straw is 5%, the other is the CDC when the temperature is 900 deg. C. By comparing the different values of the two parameters, the different influences of the catalysts and oxygen concentration on the ignition and combustion of straw have been studied, the action of these catalysts for straw ignition and combustion in air and oxygen-enriched atmosphere is effective except the oxygen-enriched catalytic combustion of wheat straw fixed carbon

  9. Staged membrane oxidation reactor system

    Science.gov (United States)

    Repasky, John Michael; Carolan, Michael Francis; Stein, VanEric Edward; Chen, Christopher Ming-Poh

    2012-09-11

    Ion transport membrane oxidation system comprising (a) two or more membrane oxidation stages, each stage comprising a reactant zone, an oxidant zone, one or more ion transport membranes separating the reactant zone from the oxidant zone, a reactant gas inlet region, a reactant gas outlet region, an oxidant gas inlet region, and an oxidant gas outlet region; (b) an interstage reactant gas flow path disposed between each pair of membrane oxidation stages and adapted to place the reactant gas outlet region of a first stage of the pair in flow communication with the reactant gas inlet region of a second stage of the pair; and (c) one or more reactant interstage feed gas lines, each line being in flow communication with any interstage reactant gas flow path or with the reactant zone of any membrane oxidation stage receiving interstage reactant gas.

  10. Memcomputing with membrane memcapacitive systems

    International Nuclear Information System (INIS)

    Pershin, Y V; Traversa, F L; Ventra, M Di

    2015-01-01

    We show theoretically that networks of membrane memcapacitive systems—capacitors with memory made out of membrane materials—can be used to perform a complete set of logic gates in a massively parallel way by simply changing the external input amplitudes, but not the topology of the network. This polymorphism is an important characteristic of memcomputing (computing with memories) that closely reproduces one of the main features of the brain. A practical realization of these membrane memcapacitive systems, using, e.g., graphene or other 2D materials, would be a step forward towards a solid-state realization of memcomputing with passive devices. (paper)

  11. Operation of staged membrane oxidation reactor systems

    Science.gov (United States)

    Repasky, John Michael

    2012-10-16

    A method of operating a multi-stage ion transport membrane oxidation system. The method comprises providing a multi-stage ion transport membrane oxidation system with at least a first membrane oxidation stage and a second membrane oxidation stage, operating the ion transport membrane oxidation system at operating conditions including a characteristic temperature of the first membrane oxidation stage and a characteristic temperature of the second membrane oxidation stage; and controlling the production capacity and/or the product quality by changing the characteristic temperature of the first membrane oxidation stage and/or changing the characteristic temperature of the second membrane oxidation stage.

  12. Effectiveness of oxygen enriched hydrogen-HHO gas addition on DI diesel engine performance, emission and combustion characteristics

    Directory of Open Access Journals (Sweden)

    Premkartikkumar S.R.

    2014-01-01

    Full Text Available Nowadays, more researches focus on protecting the environment. Present investigation concern with the effectiveness of Oxygen Enriched hydrogen- HHO gas addition on performance, emission and combustion characteristics of a DI diesel engine. Here the Oxygen Enriched hydrogen-HHO gas was produced by the process of water electrolysis. When potential difference is applied across the anode and cathode electrodes of the electrolyzer, water is transmuted into Oxygen Enriched hydrogen-HHO gas. The produced gas was aspirated into the cylinder along with intake air at the flow rates of 1 lpm and 3.3 lpm. The results show that when Oxygen Enriched hydrogen-HHO gas was inducted, the brake thermal efficiency of the engine increased by 11.06%, Carbon monoxide decreased by 15.38%, Unburned hydrocarbon decreased by 18.18%, Carbon dioxide increased by 6.06%, however, the NOX emission increased by 11.19%.

  13. Oxygen-enriched fermentation of sodium gluconate by Aspergillus niger and its impact on intracellular metabolic flux distributions.

    Science.gov (United States)

    Shen, Yuting; Tian, Xiwei; Zhao, Wei; Hang, Haifeng; Chu, Ju

    2018-01-01

    Different concentrations of oxygen-enriched air were utilized for sodium gluconate (SG) fermentation by Aspergillus niger. The fermentation time shortened from 20 to 15.5 h due to the increase of volumetric oxygen transfer coefficient (K L a) and the formation of more dispersed mycelia when inlet oxygen concentration ascended from 21 to 32%. According to metabolic flux analysis, during the growth phase, extracellular glucose for SG synthesis accounted for 79.0 and 85.3% with air and oxygen-enriched air (25%), respectively, whereas the proportions were 89.4 and 93.0% in the stationary phase. Intracellular glucose consumption decreased in oxygen-enriched fermentation, as cell respiration was more high-efficiently performed. Metabolic profiling indicated that most intermediates in TCA cycle and EMP pathway had smaller pool sizes in oxygen-enriched fermentations. Moreover, the main by-product of citric acid dramatically decreased from 1.36 to 0.34 g L -1 in oxygen-enriched fermentation. And the sodium gluconate yield increased from 0.856 to 0.903 mol mol -1 .

  14. Fraction Reduction in Membrane Systems

    Directory of Open Access Journals (Sweden)

    Ping Guo

    2014-01-01

    Full Text Available Fraction reduction is a basic computation for rational numbers. P system is a new computing model, while the current methods for fraction reductions are not available in these systems. In this paper, we propose a method of fraction reduction and discuss how to carry it out in cell-like P systems with the membrane structure and the rules with priority designed. During the application of fraction reduction rules, synchronization is guaranteed by arranging some special objects in these rules. Our work contributes to performing the rational computation in P systems since the rational operands can be given in the form of fraction.

  15. The use of oxygen-enriched air for biomass gasification: initial scoping study

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The article reports an initial scoping study which is aimed at assessing the potential impact of using non-cryogenic oxygen, or oxygen-enriched air, for biomass gasification with respect to cost, design and operation of stationary biomass-fuelled generators in the range 5 to 15 MW(e). The study is expected to lead to identification of options worthy of more detailed study. The format of the scoping study is as follows: (i) using data on performance and cost from the manufacturers, minimum cost-saving potential is assessed; (ii) the performance and component costs of various gasifier types and engine types are reviewed to identify possible savings in monetary cost; (iii) an assessment of the likely impact of low-cost fuels is made and (iv) areas for detailed investigation are highlighted.

  16. Biofouling of spiral wound membrane systems

    NARCIS (Netherlands)

    Vrouwenvelder, J.S.

    2009-01-01

    Biofouling of spiral wound membrane systems High quality drinking water can be produced with membrane filtration processes like reverse osmosis (RO) and nanofiltration (NF). Because the global demand for fresh clean water is increasing, these membrane technologies will increase in importance in the

  17. Thermodynamic Analysis of Oxygen-Enriched Direct Smelting of Jamesonite Concentrate

    Science.gov (United States)

    Zhang, Zhong-Tang; Dai, Xi; Zhang, Wen-Hai

    2017-12-01

    Thermodynamic analysis of oxygen-enriched direct smelting of jamesonite concentrate is reported in this article. First, the occurrence state of lead, antimony and other metallic elements in the smelting process was investigated theoretically. Then, the verification test was carried out. The results indicate that lead and antimony mainly exist in the alloy in the form of metallic lead and metallic antimony. Simultaneously, lead and antimony were also oxidized into the slag in the form of lead-antimony oxide. Iron and copper could be oxidized into the slag in the form of oxides in addition to combining with antimony in the alloy, while zinc was mainly oxidized into the slag in the form of zinc oxide. The verification test indicates that the main phases in the alloy contain metallic lead, metallic antimony and a small amount of Cu2Sb, FeSb2 intermetallic compounds, and the slag is mainly composed of kirschsteinite, fayalite and zinc oxide, in agreement with the thermodynamic analysis.

  18. Minerals in the Ash and Slag from Oxygen-Enriched Underground Coal Gasification

    Directory of Open Access Journals (Sweden)

    Shuqin Liu

    2016-03-01

    Full Text Available Underground coal gasification (UCG is a promising option for the recovery of low-rank and inaccessible coal resources. Detailed mineralogical information is essential to understand underground reaction conditions far from the surface and optimize the operation parameters during the UCG process. It is also significant in identifying the environmental effects of UCG residue. In this paper, with regard to the underground gasification of lignite, UCG slag was prepared through simulation tests of oxygen-enriched gasification under different atmospheric conditions, and the minerals were identified by X-Ray diffraction (XRD and a scanning electron microscope coupled to an energy-dispersive spectrometer (SEM-EDS. Thermodynamic calculations performed using FactSage 6.4 were used to help to understand the transformation of minerals. The results indicate that an increased oxygen concentration is beneficial to the reformation of mineral crystal after ash fusion and the resulting crystal structures of minerals also tend to be more orderly. The dominant minerals in 60%-O2 and 80%-O2 UCG slag include anorthite, pyroxene, and gehlenite, while amorphous substances almost disappear. In addition, with increasing oxygen content, mullite might react with the calcium oxide existed in the slag to generate anorthite, which could then serve as a calcium source for the formation of gehlenite. In 80%-O2 UCG slag, the iron-bearing mineral is transformed from sekaninaite to pyroxene.

  19. Potential benefits of oxygen-enriched intake air in a vehicle powered by a spark-ignition engine

    Science.gov (United States)

    Ng, H. K.; Sekar, R. R.

    1994-04-01

    A production vehicle powered by a spark-ignition engine (3.1-L Chevrolet Lumina, model year 1990) was tested. The test used oxygen-enriched intake air containing 25 and 28% oxygen by volume to determine (1) if the vehicle would run without difficulties and (2) if emissions benefits would result. Standard Federal Test Procedure (FTP) emissions test cycles were run satisfactorily. Test results of catalytic converter-out emissions (emissions out of the converter) showed that both carbon monoxide and hydrocarbons were reduced significantly in all three phases of the emissions test cycle. Test results of engine-out emissions (emissions straight out of the engine, with the converter removed) showed that carbon monoxide was significantly reduced in the cold phase. All emission test results were compared with those for normal air (21% oxygen). The catalytic converter also had an improved carbon monoxide conversion efficiency under the oxygen-enriched-air conditions. Detailed results of hydrocarbon speciation indicated large reductions in 1,3-butadiene, formaldehyde, acetaldehyde, and benzene from the engine with the oxygen-enriched air. Catalytic converter-out ozone was reduced by 60% with 25%-oxygen-content air. Although NO(x) emissions increased significantly, both for engine-out and catalytic converter-out emissions, we anticipate that they can be ameliorated in the near future with new control technologies. The automotive industry currently is developing exhaust-gas control technologies for an oxidizing environment; these technologies should reduce NO(x) emissions more efficiently in vehicles that use oxygen-enriched intake air. On the basis of estimates made from current data, several production vehicles that had low NO(x) emissions could meet the 2004 Tier 2 emissions standards with 25%-oxygen-content air.

  20. Hybrid Membrane System for Industrial Water Reuse

    Energy Technology Data Exchange (ETDEWEB)

    None

    2016-08-01

    This factsheet describes a project that developed and demonstrated a new hybrid system for industrial wastewater treatment that synergistically combines a forward osmosis system with a membrane distillation technology and is powered by waste heat.

  1. Membrane tethering complexes in the endosomal system

    Directory of Open Access Journals (Sweden)

    Anne eSpang

    2016-05-01

    Full Text Available Vesicles that are generated by endocytic events at the plasma membrane are destined to early endosomes. A prerequisite for proper fusion is the tethering of two membrane entities. Tethering of vesicles to early endosomes is mediated by the CORVET complex, while fusion of late endosomes with lysosomes depends on the HOPS complex. Recycling through the TGN and to the plasma membrane is facilitated by the GARP and EARP complexes, respectively. However, there are other tethering functions in the endosomal system as there are multiple pathways through which proteins can be delivered from endosomes to either the TGN or the plasma membrane. Furthermore, complexes that may be part of novel tethering complexes have been recently identified. Thus it is likely that more tethering factors exist. In this review, I will provide an overview of different tethering complexes of the endosomal system and discuss how they may provide specificity in membrane traffic.

  2. Measurement of Soot Volume Fraction and Temperature for Oxygen-Enriched Ethylene Combustion Based on Flame Image Processing

    Directory of Open Access Journals (Sweden)

    Weijie Yan

    2017-05-01

    Full Text Available A method for simultaneously visualizing the two-dimensional distributions of temperature and soot volume fraction in an ethylene flame was presented. A single-color charge-coupled device (CCD camera was used to capture the flame image in the visible spectrum considering the broad-response spectrum of the R and G bands of the camera. The directional emissive power of the R and G bands were calibrated and used for measurement. Slightly increased temperatures and reduced soot concentration were predicted in the central flame without self-absorption effects considered, an iterative algorithm was used for eliminating the effect of self-absorption. Nine different cases were presented in the experiment to demonstrate the effects of fuel mass flow rate and oxygen concentration on temperature and soot concentration in three different atmospheres. For ethylene combustion in pure-air atmosphere, as the fuel mass flow rate increased, the maximum temperature slightly decreased, and the maximum soot volume fraction slightly increased. For oxygen fractions of 30%, 40%, and 50% combustion in O2/N2 oxygen-enhanced atmospheres, the maximum flame temperatures were 2276, 2451, and 2678 K, whereas combustion in O2/CO2 atmospheres were 1916, 2322, and 2535 K. The maximum soot volume fractions were 4.5, 7.0, and 9.5 ppm in oxygen-enriched O2/N2 atmosphere and 13.6, 15.3, and 14.8 ppm in oxygen-enriched O2/CO2 atmosphere. Compared with the O2/CO2 atmosphere, combustion in the oxygen-enriched O2/N2 atmosphere produced higher flame temperature and larger soot volume fraction. Preliminary results indicated that this technique is reliable and can be used for combustion diagnosis.

  3. Effect of oxygen enriched combustion and water–diesel emulsion on the performance and emissions of turbocharged diesel engine

    International Nuclear Information System (INIS)

    Liang, Youcai; Shu, Gequn; Wei, Haiqiao; Zhang, Wei

    2013-01-01

    Highlights: • Emulsion is effective to mitigate increased NOx caused by OEC. • OEC and WDE have significant influence on particle mode formation. • OEC and WDE have significant influence on combustion characteristics. • The application potential of combination of OEC and WDE has been proved. - Abstract: Oxygen enriched combustion (OEC) is potential to improve emissions, thermal efficiency and brake power output of diesel engine. The purpose of this investigation is to study whether it is feasible to apply water diesel emulsion to mitigate the increasing NOx caused by OEC with comparable BSFC and power output. Effect of OEC on particle size and number concentration was also analyzed in this paper. Oxygen concentration of intake air varied from 21% to 24% by volume. Water content in tested fuels was 0%, 10%, 20%, and 30% by volume respectively. The result indicated that lower BSFC, higher cylinder pressure and shorter ignition delay were observed when OEC was applied, while opposite trends were found when using WDE. Reduction of PM and NOx can be realized simultaneously by applying OE combined with WDE. Particle number concentration of nucleation mode increases with increasing oxygen concentration, while that of accumulation mode decreases. Optimal operating condition was realized when water content in emulsion was below 20% along with low oxygen enrichment

  4. Novel, Ceramic Membrane System For Hydrogen Separation

    Energy Technology Data Exchange (ETDEWEB)

    Elangovan, S.

    2012-12-31

    Separation of hydrogen from coal gas represents one of the most promising ways to produce alternative sources of fuel. Ceramatec, teamed with CoorsTek and Sandia National Laboratories has developed materials technology for a pressure driven, high temperature proton-electron mixed conducting membrane system to remove hydrogen from the syngas. This system separates high purity hydrogen and isolates high pressure CO{sub 2} as the retentate, which is amenable to low cost capture and transport to storage sites. The team demonstrated a highly efficient, pressure-driven hydrogen separation membrane to generate high purity hydrogen from syngas using a novel ceramic-ceramic composite membrane. Recognizing the benefits and limitations of present membrane systems, the all-ceramic system has been developed to address the key technical challenges related to materials performance under actual operating conditions, while retaining the advantages of thermal and process compatibility offered by the ceramic membranes. The feasibility of the concept has already been demonstrated at Ceramatec. This project developed advanced materials composition for potential integration with water gas shift rectors to maximize the hydrogenproduction.

  5. Sustainability of thermoplastic vinyl roofing membrane systems

    Energy Technology Data Exchange (ETDEWEB)

    Graveline, S. P. [Sika Sanarfil, Canton, (United States)

    2010-07-01

    The International Council for Research and Innovation in Building and Construction (CIB-RILEM) has developed a framework for sustainable roofing based on a series of tenets divided into three key areas: preservation of the environment, conservation of energy, and extended roof life. This paper investigated the sustainability of thermoplastic vinyl roof membranes using these guidelines and the relevant tenets for roof system selection. Several tenets provided alternatives for minimizing the burden on the environment using non-renewable raw materials, conserving energy with thermal insulation, and extending the lifespan of all roof components by using long lasting membranes. A life cycle assessment was carried out to provide a quantitative framework for assessing the sustainability of roofing materials. It was found that the PVC membrane systems had a lesser impact on the environment than other competing systems.

  6. Fundamentals of membrane bioreactors materials, systems and membrane fouling

    CERN Document Server

    Ladewig, Bradley

    2017-01-01

    This book provides a critical, carefully researched, up-to-date summary of membranes for membrane bioreactors. It presents a comprehensive and self-contained outline of the fundamentals of membrane bioreactors, especially their relevance as an advanced water treatment technology. This outline helps to bring the technology to the readers’ attention, and positions the critical topic of membrane fouling as one of the key impediments to its more widescale adoption. The target readership includes researchers and industrial practitioners with an interest in membrane bioreactors.

  7. How to express tumours using membrane systems

    Institute of Scientific and Technical Information of China (English)

    Miguel A. Gutiérrez-Naranjo; Mario J. Pérez-Jiménez; Agustín Riscos-Nú(n)ez; Francisco J. Romero-Campero

    2007-01-01

    In this paper we discuss the potential usefulness of membrane systems as tools for modelling tumours. The approach is followed both from a macroscopic and a microscopic point of view. In the first case, one considers the tumour as a growing mass of cells,focusing on its external shape. In the second case, one descends to the microscopic level, studying molecular signalling pathways that are crucial to determine if a cell is cancerous or not. In each of these approaches we work with appropriate variants of membrane systems.

  8. Application of dynamic membranes in anaerobic membranes in anaerobic membrane bioreactor systems

    NARCIS (Netherlands)

    Erşahin, M.E.

    2015-01-01

    Anaerobic membrane bioreactors (AnMBRs) physically ensure biomass retention by the application of a membrane filtration process. With growing application experiences from aerobic membrane bioreactors (MBRs), the combination of membrane and anaerobic processes has received much attention and become

  9. Improved wound management by regulated negative pressure-assisted wound therapy and regulated, oxygen- enriched negative pressure-assisted wound therapy through basic science research and clinical assessment

    Directory of Open Access Journals (Sweden)

    Moris Topaz

    2012-01-01

    Full Text Available Regulated negative pressure-assisted wound therapy (RNPT should be regarded as a state-of-the-art technology in wound treatment and the most important physical, nonpharmaceutical, platform technology developed and applied for wound healing in the last two decades. RNPT systems maintain the treated wound′s environment as a semi-closed, semi-isolated system applying external physical stimulations to the wound, leading to biological and biochemical effects, with the potential to substantially influence wound-host interactions, and when properly applied may enhance wound healing. RNPT is a simple, safe, and affordable tool that can be utilized in a wide range of acute and chronic conditions, with reduced need for complicated surgical procedures, and antibiotic treatment. This technology has been shown to be effective and safe, saving limbs and lives on a global scale. Regulated, oxygen-enriched negative pressure-assisted wound therapy (RO-NPT is an innovative technology, whereby supplemental oxygen is concurrently administered with RNPT for their synergistic effect on treatment and prophylaxis of anaerobic wound infection and promotion of wound healing. Understanding the basic science, modes of operation and the associated risks of these technologies through their fundamental clinical mechanisms is the main objective of this review.

  10. Molten salt synthesis of nitrogen and oxygen enriched hierarchically porous carbons derived from biomass via rapid microwave carbonization for high voltage supercapacitors

    Science.gov (United States)

    Cheng, Yinfeng; Li, Baoqiang; Huang, Yanjuan; Wang, Yaming; Chen, Junchen; Wei, Daqing; Feng, Yujie; Jia, Dechang; Zhou, Yu

    2018-05-01

    Nitrogen and oxygen enriched hierarchically porous carbons (NOHPCs) derived from biomass have been successfully prepared by rapid microwave carbonization coupled with molten salt synthesis method in only 4 min. ZnCl2 plays important roles as microwave absorber, chemical activation agent and porogen in this process. NOHPC-1:10 sample possesses the maximum specific surface area of 1899 m2 g-1 with a pore volume of 1.16 cm3 g-1 and mesopore ratio of 70%, as well as nitrogen content of 5.30 wt% and oxygen content of 14.12 wt%. When evaluated as an electrode in a three-electrode system with 6 M KOH electrolyte, the material exhibits a high specific capacitance of 276 F g-1 at 0.2 A g-1, with a good rate capability of 90.9% retention at 10 A g-1. More importantly, the symmetric supercapacitor based on NOHPC-1:10 in 1 M Na2SO4 electrolyte exhibits a high energy density of 13.9 Wh kg-1 at a power density of 120 W kg-1 in a wide voltage window of 0-1.6 V, an excellent cycling stability with 95% of capacitance retention after 10,000 cycles. Our strategy provides a facile and rapid way for the preparation of advanced carbon materials derived from biomass towards energy storage applications.

  11. Survey of technological trends in functional membrane materials; Kinosei makuzai ni kansuru gijutsu doko chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1979-03-01

    Materials for membranes with novel functions are surveyed. The survey is focused on 10 subjects, which are high-performance RO (reverse osmosis)/UF (ultrafiltration) membranes; development of an energy-efficient secondary treatment system for urban wastewater using pollution-free membranes; high-performance ion exchange membranes; artificial lung membranes; hydrogen separation membranes (hydrogen as energy); development of an energy-efficient combustion system using gas separation membranes (oxygen-enriched membranes); organic matter separation membranes; enzyme-aided chemical reaction membranes and their application; development of a distilling ship; and functional membranes making use of photosynthesis. Discussed in this connection are the outlines of the technologies, the need of their development, methods and contents of the development efforts, and the effects and impacts of their development. The survey further concerns the particulars of the trends in novel technologies about functional membrane materials development, covering gas separation and liquid separation technologies; chemical reaction membranes; and enzyme-aided chemical reaction membranes and their application systems. As for their application, the survey covers the field of application of desalinated or ultrapure water; field of application of food fermentation technologies; industrial wastewater, valuable materials recovery, and urban wastewater treatment; and application to medical systems. (NEDO)

  12. Textural properties of chars as determined by petrographic analysis: comparison between air-blown, oxygen-blown and oxygen-enriched gasification

    CSIR Research Space (South Africa)

    Oboirien, BO

    2012-11-01

    Full Text Available In this study, the textural properties of chars generated from a vitrinite, high ash coal in a fluidised bed gasifier under air-blown, oxygen-blown and oxygen-enriched conditions were determined by detailed petrographic analysis. The char samples...

  13. Efficient preparation and analysis of membrane and membrane protein systems

    Czech Academy of Sciences Publication Activity Database

    Javanainen, M.; Martinez-Seara, Hector

    2016-01-01

    Roč. 1858, č. 10 (2016), s. 2468-2482 ISSN 0005-2736 Institutional support: RVO:61388963 Keywords : tools and software * membrane building * protein insertion * molecular dynamics * lipid bilayer Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.498, year: 2016

  14. Experimental investigation on performance characteristics of a diesel engine using diesel-water emulsion with oxygen enriched air

    Directory of Open Access Journals (Sweden)

    P. Baskar

    2017-03-01

    Full Text Available Diesel engines occupy a crucial position in automobile industry due to their high thermal efficiency and high power to weight ratio. However, they lag behind in controlling air polluting components coming out of the engine exhaust. Therefore, diesel consumption should be analyzed for future energy consumption and this can be primarily controlled by the petroleum fuel substitution techniques for existing diesel engines, which include biodiesel, alcohol-diesel emulsions and diesel water emulsions. Among them the diesel water emulsion is found to be most suitable fuel due to reduction in particulate matter and NOx emission, besides that it also improves the brake thermal efficiency. But the major problem associated with emulsions is the ignition delay, since this is responsible for the power and torque loss. A reduction in NOx emission was observed due to reduction in combustion chamber temperature as the water concentration increases. However the side effect of emulsified diesel is a reduction in power which can be compensated by oxygen enrichment. The present study investigates the effects of oxygen concentration on the performance characteristics of a diesel engine when the intake air is enriched to 27% of oxygen and fueled by 10% of water diesel emulsion. It was found that the brake thermal efficiency was enhanced, combustion characteristics improved and there is also a reduction in HC emissions.

  15. Effects of oxygen-enriched air on cognitive performance during SCUBA-diving - an open-water study.

    Science.gov (United States)

    Brebeck, Anne-Kathrin; Deussen, Andreas; Schmitz-Peiffer, Henning; Range, Ursula; Balestra, Costantino; Cleveland, Sinclair; Schipke, Jochen D

    2017-01-01

    Backround: Nitrogen narcosis impairs cognitive function, a fact relevant during SCUBA-diving. Oxygen-enriched air (nitrox) became popular in recreational diving, while evidence of its advantages over air is limited. Compare effects of nitrox28 and air on two psychometric tests. In this prospective, double-blind, open-water study, 108 advanced divers (38 females) were randomized to an air or a nitrox-group for a 60-min dive to 24 m salt water. Breathing gas effects on cognitive performance were assessed during the dive using a short- and long-term memory test and a number connection test. Nitrox28 divers made fewer mistakes only on the long-term memory test (p = 0.038). Female divers remembered more items than male divers (p < 0.001). There were no significant differences in the number connection test between the groups. Likely owing to the comparatively low N 2 reduction and the conservative dive, beneficial nitrox28 effects to diver performance were moderate but could contribute to diving safety.

  16. The effect of intraoral suction on oxygen-enriched surgical environments: a mechanism for reducing the risk of surgical fires.

    Science.gov (United States)

    VanCleave, Andrea M; Jones, James E; McGlothlin, James D; Saxen, Mark A; Sanders, Brian J; Vinson, LaQuia A

    2014-01-01

    In this study, a mechanical model was applied in order to replicate potential surgical fire conditions in an oxygen-enriched environment with and without high-volume suction typical for dental surgical applications. During 41 trials, 3 combustion events were measured: an audible pop, a visible flash of light, and full ignition. In at least 11 of 21 trials without suction, all 3 conditions were observed, sometimes with an extent of fire that required early termination of the experimental trial. By contrast, in 18 of 20 with-suction trials, ignition did not occur at all, and in the 2 cases where ignition did occur, the fire was qualitatively a much smaller, candle-like flame. Statistically comparing these 3 combustion events in the no-suction versus with-suction trials, ignition (P = .0005), audible pop (P = .0211), and flash (P = .0092) were all significantly more likely in the no-suction condition. These results suggest a possible significant and new element to be added to existing surgical fire safety protocols toward making surgical fires the "never-events" they should be.

  17. Membrane Lipid Oscillation: An Emerging System of Molecular Dynamics in the Plant Membrane.

    Science.gov (United States)

    Nakamura, Yuki

    2018-03-01

    Biological rhythm represents a major biological process of living organisms. However, rhythmic oscillation of membrane lipid content is poorly described in plants. The development of lipidomic technology has led to the illustration of precise molecular profiles of membrane lipids under various growth conditions. Compared with conventional lipid signaling, which produces unpredictable lipid changes in response to ever-changing environmental conditions, lipid oscillation generates a fairly predictable lipid profile, adding a new layer of biological function to the membrane system and possible cross-talk with the other chronobiological processes. This mini review covers recent studies elucidating membrane lipid oscillation in plants.

  18. Soft sensing of system parameters in membrane distillation

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-01-01

    Various examples of methods and systems are provided for soft sensing of system parameters in membrane distillation (MD). In one example, a system includes a MD module comprising a feed side and a permeate side separated by a membrane boundary layer

  19. Membrane Tethering Complexes in the Endosomal System

    OpenAIRE

    Spang, Anne

    2016-01-01

    Vesicles that are generated by endocytic events at the plasma membrane are destined to early endosomes. A prerequisite for proper fusion is the tethering of two membrane entities. Tethering of vesicles to early endosomes is mediated by the class C core vacuole/endosome tethering (CORVET) complex, while fusion of late endosomes with lysosomes depends on the homotypic fusion and vacuole protein sorting (HOPS) complex. Recycling through the trans-Golgi network (TGN) and to the plasma membrane is...

  20. Processing radioactive wastes using membrane (UF/HF/RO) systems

    International Nuclear Information System (INIS)

    Doyle, R.D.

    1988-01-01

    Over the years many technologies have been utilized to process low level radioactive waste streams generated by the nuclear industry, including: demineralization, evaporation, reverse osmosis and filtration. In the early 1980's interest was generated in membrane technologies and their application to radioactive wastes. This interest was generated based on the capabilities shown by membrane systems in non-radioactive environments and the promise that reverse osmosis systems showed in early testing with radioactive wastes. Membrane technologies have developed from the early development of reverse osmosis system to also include specifically designed membranes for ultrafiltration and hyperfiltration applications

  1. New Electrorelease Systems Based on Microporous Membranes

    Science.gov (United States)

    1990-08-02

    correspondence (6) we demonstrated the validity of the concept by showing that insulin and vitamin B-12 can be electroreleased from a composite membrane...applied to the membrane. The dye reservoir contained an aqueous solution of either methylene blue dye (Aldrich), K3 Fe(CN)6 (Baker), or bovine insulin

  2. Development of divertor pumping system with superpermeable membrane

    International Nuclear Information System (INIS)

    Nakamura, Y.; Ohyabu, N.; Suzuki, H.; Nakahara, Y.; Livshits, A.; Notkin, M.; Alimov, V.; Busnyuk, A.

    2000-01-01

    A new divertor pumping system with superpermeable membranes of group Va-metals (Nb, V) is now under research and development. Properties of membrane pumping were investigated with the use of a plasma device simulating divertor plasma conditions. The deposition of metal (Fe) and non-metal (C) impurities on the membrane upstream surface results in a degradation of plasma driven superpermeation at the membrane temperature T m m ≥800 deg. C. The same temperature effect on superpermeation is observed at sputtering of membrane surface by energetic plasma ions. In addition, the first application of the membrane pumping to fusion devices has been carried out and a deuterium pumping through the membrane was demonstrated under the conditions of divertor plasma in the JFT-2M tokamak

  3. Techno-economical evaluation of membrane based biogas upgrading system: A comparison between polymeric membrane and carbon membrane technology

    Directory of Open Access Journals (Sweden)

    Shamim Haider

    2016-10-01

    Full Text Available A shift to renewable energy sources will reduce emissions of greenhouse gases and secure future energy supplies. In this context, utilization of biogas will play a prominent role. Focus of this work is upgrading of biogas to fuel quality by membrane separation using a carbon hollow fibre (CHF membrane and compare with a commercially available polymeric membrane (polyimide through economical assessment. CHF membrane modules were prepared for pilot plant testing and performance measured using CO2, O2, N2. The CHF membrane was modified through oxidation, chemical vapour deposition (CVD and reduction process thus tailoring pores for separation and increased performance. The post oxidized and reduced carbon hollow fibres (PORCHFs significantly exceeded CHF performance showing higher CO2 permeance (0.021 m3(STP/m2 h bar and CO2/CH4 selectivity of 246 (5 bar feed vs 50 mbar permeate pressure. The highest performance recorded through experiments (CHF and PORCHF was used as simulation basis. A membrane simulation model was used and interfaced to 8.6 V Aspen HYSYS. A 300 Nm3/h mixture of CO2/CH4 containing 30–50% CO2 at feed pressures 6, 8 and 10 bar, was simulated and process designed to recover 99.5% CH4 with 97.5% purity. Net present value (NPV was calculated for base case and optimal pressure (50 bar for CHF and PORCHF. The results indicated that recycle ratio (recycle/feed ranged from 0.2 to 10, specific energy from 0.15 to 0.8 (kW/Nm3feed and specific membrane area from 45 to 4700 (m2/Nm3feed. The high recycle ratio can create problems during start-up, as it would take long to adjust volumetric flow ratio towards 10. The best membrane separation system employs a three-stage system with polyimide at 10 bar, and a two-stage membrane system with PORCHF membranes at 50 bar with recycle. Considering biomethane price of 0.78 $/Nm3 and a lifetime of 15 years, the techno-economic analysis showed that payback time for

  4. Utilization of membranes for H2O recycle system

    Science.gov (United States)

    Ohya, H.; Oguchi, M.

    1986-01-01

    Conceptual studies of closed ecological life support systems (CELSS) carried out at NAL in Japan for a water recycle system using membranes are reviewed. The system will treat water from shower room, urine, impure condensation from gas recycle system, and so on. The H2O recycle system is composed of prefilter, ultrafiltration membrane, reverse osmosis membrane, and distillator. Some results are shown for a bullet train of toilet-flushing water recycle equipment with an ultraviltration membrane module. The constant value of the permeation rate with a 4.7 square meters of module is about 70 1/h after 500th of operation. Thermovaporization with porous polytetrafluorocarbon membrane is also proposed to replce the distillator.

  5. Robust membrane systems for actinide separations

    International Nuclear Information System (INIS)

    Jarvinen, Gordon D.; McCleskey, T. Mark; Bluhm, Elizabeth A.; Abney, Kent D.; Ehler, Deborah S.; Bauer, Eve; Le, Quyen T.; Young, Jennifer S.; Ford, Doris K.; Pesiri, David R.; Dye, Robert C.; Robison, Thomas W.; Jorgensen, Betty S.; Redondo, Antonio; Pratt, Lawrence R.; Rempe, Susan L.

    2000-01-01

    Our objective in this project is to develop very stable thin membrane structures containing ionic recognition sites that facilitate the selective transport of target metal ions, especially the actinides

  6. High anisotropy of flow-aligned bicellar membrane systems

    KAUST Repository

    Kogan, Maxim; Nordé n, Bengt; Beke-Somfai, Tamá s

    2013-01-01

    In recent years, multi-lipid bicellar systems have emerged as promising membrane models. The fast orientational diffusion and magnetic alignability made these systems very attractive for NMR investigations. However, their alignment was so far

  7. Membrane-Organized Chemical Photoredox Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, James K.

    2014-09-18

    This project has three interrelated goals relevant to solar water photolysis, which are to develop: (1) vesicle-organized assemblies for H2 photoproduction that utilize pyrylium and structurally related compounds as combined photosensitizers and cyclic electroneutral transmembrane electron carriers; (2) transmembrane redox systems whose reaction rates can be modulated by light; and (3) homogeneous catalysts for water oxidation. . In area (1), initial efforts to photogenerate H2 from vectorially-organized vesicles containing occluded colloidal Pt and commonly available pyrylium ions as transmembrane redox mediators were unsuccessful. New pyrylium compounds with significantly lower reduction potentials have been synthesized to address this problem, their apparent redox potentials in functioning systems have been now evaluated by using a series of occluded viologens, and H2 photoproduction has been demonstrated in continuous illumination experiments. In area (2), spirooxazine-quinone dyads have been synthesized and their capacity to function as redox mediators across bilayer membranes has been evaluated through continuous photolysis and transient spectrophotometric measurements. Photoisomerization of the spiro moiety to the ring-open mero form caused net quantum yields to decrease significantly, providing a basis for photoregulation of transmembrane redox. Research on water oxidation (area 3) has been directed at understanding mechanisms of catalysis by cis,cis-[(bpy)2Ru(OH2)]2O4+ and related polyimine complexes. Using a variety of physical techniques, we have: (i) identified the redox state of the complex ion that is catalytically active; (ii) shown using 18O isotopic labeling that there are two reaction pathways, both of which involve participation of solvent H2O; and (iii) detected and characterized by EPR and resonance Raman spectroscopies new species which may be key intermediates in the catalytic cycle.

  8. Turing Incompleteness of Asynchronous P Systems with Active Membranes

    OpenAIRE

    Leporati, Alberto; Manzoni, Luca; Porreca, Antonio E.

    2013-01-01

    We prove that asynchronous P systems with active membranes without divi- sion rules can be simulated by place/transition Petri nets, and hence are computationally weaker than Turing machines. This result holds even if the synchronisation mechanisms provided by electrical charges and membrane dissolution are exploited.

  9. Biogenesis of the demarcation membrane system (DMS) in megakaryocytes

    NARCIS (Netherlands)

    Eckly, A.; Heijnen, H.F.G.; Pertuy, F.; Geerts, W.J.C.; Proamer, F.; Rinckel, J.Y.; Leon, C.; Lanza, F; Gachet, C.

    2014-01-01

    The demarcation membrane system (DMS) in megakaryocytes forms the plasma membrane (PM) of future platelets. Using confocal microscopy, electron tomography, and large volume focused ion beam/scanning electron microscopy (FIB/SEM), we determined the sequential steps of DMS formation. We identified a

  10. System analysis of membrane facilitated water generation from air humidity

    NARCIS (Netherlands)

    Bergmair, D.; Metz, S.J.; Lange, de H.C.; Steenhoven, van A.A.

    2014-01-01

    The use of water vapor selective membranes can reduce the energy requirement for extracting water out of humid air by more than 50%. We performed a system analysis of a proposed unit, that uses membranes to separate water vapor from other atmospheric gases. This concentrated vapor can then be

  11. Renewable energy powered membrane technology. 2. The effect of energy fluctuations on performance of a photovoltaic hybrid membrane system

    OpenAIRE

    Richards, B.S.; Capão, D.P.S.; Schäfer, Andrea

    2008-01-01

    This paper reports on the performance fluctuations during the operation of a batteryless hybrid ultrafiltration-nanofiltration/reverse osmosis (UF-NF/RO) membrane desalination system powered by photovoltaics treating brackish groundwater in outback Australia. The renewable energy powered membrane (RE-membrane) system is designed to supply clean drinking water to a remote community of about 50 inhabitants. The performance of the RE-membrane system over four different solar days is summarized u...

  12. Empirical membrane lifetime model for heavy duty fuel cell systems

    Science.gov (United States)

    Macauley, Natalia; Watson, Mark; Lauritzen, Michael; Knights, Shanna; Wang, G. Gary; Kjeang, Erik

    2016-12-01

    Heavy duty fuel cells used in transportation system applications such as transit buses expose the fuel cell membranes to conditions that can lead to lifetime-limiting membrane failure via combined chemical and mechanical degradation. Highly durable membranes and reliable predictive models are therefore needed in order to achieve the ultimate heavy duty fuel cell lifetime target of 25,000 h. In the present work, an empirical membrane lifetime model was developed based on laboratory data from a suite of accelerated membrane durability tests. The model considers the effects of cell voltage, temperature, oxygen concentration, humidity cycling, humidity level, and platinum in the membrane using inverse power law and exponential relationships within the framework of a general log-linear Weibull life-stress statistical distribution. The obtained model is capable of extrapolating the membrane lifetime from accelerated test conditions to use level conditions during field operation. Based on typical conditions for the Whistler, British Columbia fuel cell transit bus fleet, the model predicts a stack lifetime of 17,500 h and a membrane leak initiation time of 9200 h. Validation performed with the aid of a field operated stack confirmed the initial goal of the model to predict membrane lifetime within 20% of the actual operating time.

  13. Development of compact tritium confinement system using gas separation membrane

    International Nuclear Information System (INIS)

    Hayashi, Takumi; Okuno, Kenji

    1994-01-01

    In order to develop more compact and cost-effective tritium confinement system for fusion reactor, a new system using gas separation membranes has been studied at the Tritium Process Laboratory in the Japan Atomic Energy Research Institute. The preliminary result showed that the gas separation membrane system could reduce processing volume of tritium contaminated gas to more than one order of magnitude compared with the conventional system, and that most of tritiated water vapor (humidity) could be directly recovered by water condenser before passing through dryer such as molecular sieves. More detail investigations of gas separation characteristics of membrane were started to design ITER Atmospheric Detritiation System (ADS). Furthermore, a scaled polyimide membrane module (hollow-filament type) loop was just installed to investigate the actual tritium confinement performance under various ITER-ADS conditions. (author)

  14. Long term analysis of the biomass content in the feed of a waste-to-energy plant with oxygen-enriched combustion air.

    Science.gov (United States)

    Fellner, Johann; Cencic, Oliver; Zellinger, Günter; Rechberger, Helmut

    2011-10-01

    Thermal utilization of municipal solid waste and commercial wastes has become of increasing importance in European waste management. As waste materials are generally composed of fossil and biogenic materials, a part of the energy generated can be considered as renewable and is thus subsidized in some European countries. Analogously, CO(2) emissions of waste incinerators are only partly accounted for in greenhouse gas inventories. A novel approach for determining these fractions is the so-called balance method. In the present study, the implementation of the balance method on a waste-to-energy plant using oxygen-enriched combustion air was investigated. The findings of the 4-year application indicate on the one hand the general applicability and robustness of the method, and on the other hand the importance of reliable monitoring data. In particular, measured volume flows of the flue gas and the oxygen-enriched combustion air as well as corresponding O(2) and CO(2) contents should regularly be validated. The fraction of renewable (biogenic) energy generated throughout the investigated period amounted to between 27 and 66% for weekly averages, thereby denoting the variation in waste composition over time. The average emission factor of the plant was approximately 45 g CO(2) MJ(-1) energy input or 450 g CO(2) kg(-1) waste incinerated. The maximum error of the final result was about 16% (relative error), which was well above the error (<8%) of the balance method for plants with conventional oxygen supply.

  15. Applications of membrane computing in systems and synthetic biology

    CERN Document Server

    Gheorghe, Marian; Pérez-Jiménez, Mario

    2014-01-01

    Membrane Computing was introduced as a computational paradigm in Natural Computing. The models introduced, called Membrane (or P) Systems, provide a coherent platform to describe and study living cells as computational systems. Membrane Systems have been investigated for their computational aspects and employed to model problems in other fields, like: Computer Science, Linguistics, Biology, Economy, Computer Graphics, Robotics, etc. Their inherent parallelism, heterogeneity and intrinsic versatility allow them to model a broad range of processes and phenomena, being also an efficient means to solve and analyze problems in a novel way. Membrane Computing has been used to model biological systems, becoming with time a thorough modeling paradigm comparable, in its modeling and predicting capabilities, to more established models in this area. This book is the result of the need to collect, in an organic way, different facets of this paradigm. The chapters of this book, together with the web pages accompanying th...

  16. Estimation of membrane hydration status for standby proton exchange membrane fuel cell systems by impedance measurement

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Rugholt, Mark; Nielsen, Morten Busk

    2014-01-01

    Fuel cells are getting growing interest in both backup systems and electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However, the membrane of which PEMFCs are made tends to dry out when...

  17. Integration of oxygen membranes for oxygen production in cement plants

    DEFF Research Database (Denmark)

    Puig Arnavat, Maria; Søgaard, Martin; Hjuler, Klaus

    2015-01-01

    The present paper describes the integration of oxygen membranes in cement plants both from an energy, exergy and economic point of view. Different configurations for oxygen enrichment of the tertiary air for combustion in the pre-calciner and full oxy-fuel combustion in both pre-calciner and kiln...

  18. Microfluidic systems with ion-selective membranes.

    Science.gov (United States)

    Slouka, Zdenek; Senapati, Satyajyoti; Chang, Hsueh-Chia

    2014-01-01

    When integrated into microfluidic chips, ion-selective nanoporous polymer and solid-state membranes can be used for on-chip pumping, pH actuation, analyte concentration, molecular separation, reactive mixing, and molecular sensing. They offer numerous functionalities and are hence superior to paper-based devices for point-of-care biochips, with only slightly more investment in fabrication and material costs required. In this review, we first discuss the fundamentals of several nonequilibrium ion current phenomena associated with ion-selective membranes, many of them revealed by studies with fabricated single nanochannels/nanopores. We then focus on how the plethora of phenomena has been applied for transport, separation, concentration, and detection of biomolecules on biochips.

  19. Membrane separation systems---A research and development needs assessment

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W. (Membrane Technology and Research, Inc., Menlo Park, CA (USA)); Cussler, E.L. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemical Engineering and Materials Science); Eykamp, W. (California Univ., Berkeley, CA (USA)); Koros, W.J. (Texas Univ., Austin, TX (USA)); Riley, R.L. (Separation Systems Technology, San Diego, CA (USA)); Strathmann, H. (Fraunhofer-Institut fuer Grenzflaech

    1990-04-01

    Industrial separation processes consume a significant portion of the energy used in the United States. A 1986 survey by the Office of Industrial Programs estimated that about 4.2 quads of energy are expended annually on distillation, drying and evaporation operations. This survey also concluded that over 0.8 quads of energy could be saved in the chemical, petroleum and food industries alone if these industries adopted membrane separation systems more widely. Membrane separation systems offer significant advantages over existing separation processes. In addition to consuming less energy than conventional processes, membrane systems are compact and modular, enabling easy retrofit to existing industrial processes. The present study was commissioned by the Department of Energy, Office of Program Analysis, to identify and prioritize membrane research needs in light of DOE's mission. Each report will be individually cataloged.

  20. Membrane separation systems---A research and development needs assessment

    Energy Technology Data Exchange (ETDEWEB)

    Baker, R.W. (Membrane Technology and Research, Inc., Menlo Park, CA (USA)); Cussler, E.L. (Minnesota Univ., Minneapolis, MN (USA). Dept. of Chemical Engineering and Materials Science); Eykamp, W. (California Univ., Berkeley, CA (USA)); Koros, W.J. (Texas Univ., Austin, TX (USA)); Riley, R.L. (Separation Systems Technology, San Diego, CA (USA)); Strathmann, H. (Fraunhofer-Institut fuer Grenzflaech

    1990-03-01

    Membrane based separation technology, a relative newcomer on the separations scene, has demonstrated the potential of saving enormous amounts of energy in the processing industries if substituted for conventional separation systems. Over 1 quad annually, out of 2.6, can possibly be saved in liquid-to-gas separations, alone, if membrane separation systems gain wider acceptance, according to a recent DOE/OIP (DOE/NBM-80027730 (1986)) study. In recent years great strides have been made in the field and offer even greater energy savings in the future when substituted for other conventional separation techniques such as distillation, evaporation, filtration, sedimentation, and absorption. An assessment was conducted by a group of six internationally known membrane separations experts who examined the worldwide status of research in the seven major membrane areas. This encompassed four mature technology areas: reverse osmosis, micorfiltration, ultrafiltration, and electrodialysis; two developing areas: gas separation and and pervaporation; and one emerging technology: facilitated transport. Particular attention was paid to identifying the innovative processes currently emerging, and even further improvements which could gain wider acceptance for the more mature membrane technology. The topics that were pointed out as having the greatest research emphasis are pervaporation for organic-organic separations; gas separation; micorfiltration; an oxidant-resistant reverse osmosis membrane; and a fouling-resistant ultrafiltration membrane. 35 refs., 6 figs., 22 tabs.

  1. Effect of breathing oxygen-enriched air on exercise performance in patients with precapillary pulmonary hypertension: randomized, sham-controlled cross-over trial.

    Science.gov (United States)

    Ulrich, Silvia; Hasler, Elisabeth D; Saxer, Stéphanie; Furian, Michael; Müller-Mottet, Séverine; Keusch, Stephan; Bloch, Konrad E

    2017-04-14

    The purpose of the current trial was to test the hypothesis that breathing oxygen-enriched air increases exercise performance of patients with pulmonary arterial or chronic thrombo-embolic pulmonary hypertension (PAH/CTEPH) and to investigate involved mechanisms. Twenty-two patients with PAH/CTEPH, eight women, means ± SD 61 ± 14 years, resting mPAP 35 ± 9mmHg, PaO2 ambient air >7.3 kPa, underwent four bicycle ergospirometries to exhaustion on different days, while breathing oxygen-enriched (FiO2 0.50, hyperoxia) or ambient air (FiO2 0.21, normoxia) using progressively increased or constant load protocols (with 75% maximal work rate under FiO2 0.21), according to a randomized, sham-controlled, single-blind, cross-over design. ECG, pulmonary gas-exchange, arterial blood gases, cerebral and quadriceps muscle tissue oxygenation (CTO and QMTO) by near-infrared spectroscopy were measured. In ramp exercise, maximal work rate increased from 113 ± 38 W with normoxia to 132 ± 48 W with hyperoxia, mean difference 19.7 (95% CI 10.5-28.9) W, P endurance increased from 571 ± 443 to 1242 ± 514 s, mean difference 671 (95% CI 392-951) s, P < 0.001. At end-exercise with hyperoxia PaO2, CTO, QMTO, and PaCO2 were increased, and ventilatory equivalents for CO2 were reduced while the physiological dead space/tidal volume ratio remained unchanged. In patients with PAH/CTEPH, breathing oxygen-enriched air provides major increases in exercise performance. This is related to an improved arterial oxygenation that promotes oxygen availability in muscles and brain and to a reduction of the excessive ventilatory response to exercise thereby enhancing ventilatory efficiency. Patients with PAH/CTEPH may therefore benefit from oxygen therapy during daily physical activities and training. clinicaltrials.gov Identifier: NCT01748474. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions

  2. Biogenesis of the demarcation membrane system (DMS) in megakaryocytes.

    Science.gov (United States)

    Eckly, Anita; Heijnen, Harry; Pertuy, Fabien; Geerts, Willie; Proamer, Fabienne; Rinckel, Jean-Yves; Léon, Catherine; Lanza, François; Gachet, Christian

    2014-02-06

    The demarcation membrane system (DMS) in megakaryocytes forms the plasma membrane (PM) of future platelets. Using confocal microscopy, electron tomography, and large volume focused ion beam/scanning electron microscopy (FIB/SEM), we determined the sequential steps of DMS formation. We identified a pre-DMS that initiated at the cell periphery and was precisely located between the nuclear lobes. At all developmental stages, the DMS remained continuous with the cell surface. The number of these connections correlated well with the nuclear lobulation, suggesting a relationship with cleavage furrow formation and abortive cytokinesis. On DMS expansion, Golgi complexes assembled around the pre-DMS, and fusion profiles between trans-golgi network-derived vesicles and the DMS were observed. Brefeldin-A reduced DMS expansion, indicating that the exocytic pathway is essential for DMS biogenesis. Close contacts between the endoplasmic reticulum (ER) and the DMS were detected, suggesting physical interaction between the 2 membrane systems. FIB/SEM revealed that the DMS forms an intertwined tubular membrane network resembling the platelet open canalicular system. We thus propose the following steps in DMS biogenesis: (1) focal membrane assembly at the cell periphery; (2) PM invagination and formation of a perinuclear pre-DMS; (3) expansion through membrane delivery from Golgi complexes; and (4) ER-mediated lipid transfer.

  3. Dynamic nanoplatforms in biosensor and membrane constitutional systems.

    Science.gov (United States)

    Mahon, Eugene; Aastrup, Teodor; Barboiu, Mihail

    2012-01-01

    Molecular recognition in biological systems occurs mainly at interfacial environments such as membrane surfaces, enzyme active sites, or the interior of the DNA double helix. At the cell membrane surface, carbohydrate-protein recognition principles apply to a range of specific non-covalent interactions including immune response, cell proliferation, adhesion and death, cell-cell interaction and communication. Protein-protein recognition meanwhile accounts for signalling processes and ion channel structure. In this chapter we aim to describe such constitutional dynamic interfaces for biosensing and membrane transport applications. Constitutionally adaptive interfaces may mimic the recognition capabilities intrinsic to natural recognition processes. We present some recent examples of 2D and 3D constructed sensors and membranes of this type and describe their sensing and transport capabilities.

  4. Development of novel nano-composite membranes as introduction systems for mass spectrometers: Contrasting nano-composite membranes and conventional inlet systems

    Science.gov (United States)

    Miranda, Luis Diego

    This dissertation presents the development of novel nano-composite membranes as introduction systems for mass spectrometers. These nano-composite membranes incorporate anodic aluminum oxide (AAO) membranes as templates that can be used by themselves or modified by a variety of chemical deposition processes. Two types of nano-composite membranes are presented. The first nano-composite membrane has carbon deposited within the pores of an AAO membrane. The second nano-composite membrane is made by coating an AAO membrane with a thin polymer film. The following chapters describe the transmission properties these nano-composite membranes and compare them to conventional mass spectrometry introduction systems. The nano- composite membranes were finally coupled to the inlet system of an underwater mass spectrometer revealing their utility in field deployments.

  5. Thermo-osmosis in Membrane Systems: A Review

    Science.gov (United States)

    Barragán, V. María; Kjelstrup, Signe

    2017-06-01

    We give a first review of experimental results for a phenomenon little explored in the literature, namely thermal osmosis or thermo-osmosis. Such systems are now getting increased attention because of their ability to use waste heat for separation purposes. We show that this volume transport of a solution or a pure liquid caused by a temperature difference across a membrane can be understood as a property of the membrane system, i. e. the membrane with its adjacent solutions. We present experimental values found in the literature of thermo-osmotic coefficients of neutral and hydrophobic as well as charged and hydrophilic membranes, with water and other permeant fluids as well as electrolyte solutions. We propose that the coefficient can be qualitatively explained by a formula that contains the entropy of adsorption of permeant into the membrane, the hydraulic permeability, and a factor that depends on the interface resistance to heat transfer. A variation in the entropy of adsorption with hydrophobic/hydrophilic membranes and structure breaking/structure making cations could then explain the sign of the permeant flux. Systematic experiments in the field are lacking and we propose an experimental program to mend this situation.

  6. Biofilm spatial organization by the emerging pathogen Campylobacter jejuni: comparison between NCTC 11168 and 81-176 strains under microaerobic and oxygen-enriched conditions.

    Science.gov (United States)

    Turonova, Hana; Briandet, Romain; Rodrigues, Ramila; Hernould, Mathieu; Hayek, Nabil; Stintzi, Alain; Pazlarova, Jarmila; Tresse, Odile

    2015-01-01

    During the last years, Campylobacter has emerged as the leading cause of bacterial foodborne infections in developed countries. Described as an obligate microaerophile, Campylobacter has puzzled scientists by surviving a wide range of environmental oxidative stresses on foods farm to retail, and thereafter intestinal transit and oxidative damage from macrophages to cause human infection. In this study, confocal laser scanning microscopy (CLSM) was used to explore the biofilm development of two well-described Campylobacter jejuni strains (NCTC 11168 and 81-176) prior to or during cultivation under oxygen-enriched conditions. Quantitative and qualitative appraisal indicated that C. jejuni formed finger-like biofilm structures with an open ultrastructure for 81-176 and a multilayer-like structure for NCTC 11168 under microaerobic conditions (MAC). The presence of motile cells within the biofilm confirmed the maturation of the C. jejuni 81-176 biofilm. Acclimation of cells to oxygen-enriched conditions led to significant enhancement of biofilm formation during the early stages of the process. Exposure to these conditions during biofilm cultivation induced an even greater biofilm development for both strains, indicating that oxygen demand for biofilm formation is higher than for planktonic growth counterparts. Overexpression of cosR in the poorer biofilm-forming strain, NCTC 11168, enhanced biofilm development dramatically by promoting an open ultrastructure similar to that observed for 81-176. Consequently, the regulator CosR is likely to be a key protein in the maturation of C. jejuni biofilm, although it is not linked to oxygen stimulation. These unexpected data advocate challenging studies by reconsidering the paradigm of fastidious requirements for C. jejuni growth when various subpopulations (from quiescent to motile cells) coexist in biofilms. These findings constitute a clear example of a survival strategy used by this emerging human pathogen.

  7. Biofilm spatial organization by the emerging pathogen Campylobacter jejuni: comparison between NCTC 11168 and 81-176 strains under microaerobic and oxygen-enriched conditions

    Directory of Open Access Journals (Sweden)

    Hana eTuronova

    2015-07-01

    Full Text Available During the last years, Campylobacter has emerged as the leading cause of bacterial foodborne infections in developed countries. Described as an obligate microaerophile, Campylobacter has puzzled scientists by surviving a wide range of environmental oxidative stresses on foods farm to retail, and thereafter intestinal transit and oxidative damage from macrophages to cause human infection. In this study, confocal laser scanning microscopy was used to explore the biofilm development of two well-described Campylobacter jejuni strains (NCTC 11168 and 81-176 prior to or during cultivation under oxygen-enriched conditions. Quantitative and qualitative appraisal indicated that C. jejuni formed finger-like biofilm structures with an open ultrastructure for 81-176 and a multilayer-like structure for NCTC 11168 under microaerobic conditions. The presence of motile cells within the biofilm confirmed the maturation of the C. jejuni 81-176 biofilm. Acclimation of cells to oxygen-enriched conditions led to significant enhancement of biofilm formation during the early stages of the process. Exposure to these conditions during biofilm cultivation induced an even greater biofilm development for both strains, indicating that oxygen demand for biofilm formation is higher than for planktonic growth counterparts. Overexpression of cosR in the poorer biofilm-forming strain, NCTC 11168, enhanced biofilm development dramatically by promoting an open ultrastructure similar to that observed for 81-176. Consequently, the regulator CosR is likely to be a key protein in the maturation of C. jejuni biofilm, although it is not linked to oxygen stimulation. These unexpected data advocate challenging studies by reconsidering the paradigm of fastidious requirements for C. jejuni growth when various subpopulations (from quiescent to motile cells coexist in biofilms. These findings constitute a clear example of a survival strategy used by this emerging human pathogen.

  8. Experimental study on the mechanism of SO2 emission and calcium-based desulfurization in the coal oxygen-enriched combustion

    International Nuclear Information System (INIS)

    Tian, Luning; Chen, Hanping; Yang, Haiping; Wang, Xianhua; Zhang, Shihong

    2010-01-01

    Full text: The emission of SO 2 , CO 2 brings serious harm to the ecological environment, human health and the global climate change. The largest source of SO 2 , CO 2 is the combustion of fossil fuels for power generation. So developing the new technology for controlling pollutants emissions from coal combustion was imperative. Oxygen-enriched combustion technology is such a new technology which can realize CO 2 zero emission, enhance the combustion efficiency and reduce pollutants emission. Due to the high concentration of CO 2 , it has many different aspects in the SO 2 emission and calcium-based desulfurization compare with the conventional combustion. In this article, experiments have been done to investigate the behavior and mechanism of SO 2 emissions and removal in oxygen-enriched combustion. First, in TGA and fixed bed reactor, the SO 2 emission characteristics were investigated under various bed temperature, particle size and O 2 / CO 2 concentration. It was observed that SO 2 released faster and the emission peak was higher than air atmosphere. SO 2 emission concentration increased with the reaction temperature increasing. Simultaneously, the mechanism of SO 2 emission was obtained by analyzing the sulfur compounds in the gas products and solid products in different reaction times. Then, the impacts of reaction temperature, particle size, O 2 / CO 2 concentration and SO 2 concentration etc. on the efficiency of SO 2 removal were analyzed. The phase analysis, pore diameter distribution and microstructure of the solid product were investigated. The experimental results showed that the sulphur capture takes place by direct sulphation reaction at high CO 2 concentration which attributes to light sinter, better porous structure, higher optimal desulfurization temperature and high desulfurization efficiency of calcium-based sorbent. (author)

  9. Soft sensing of system parameters in membrane distillation

    KAUST Repository

    Laleg-Kirati, Taous-Meriem

    2017-03-23

    Various examples of methods and systems are provided for soft sensing of system parameters in membrane distillation (MD). In one example, a system includes a MD module comprising a feed side and a permeate side separated by a membrane boundary layer; and processing circuitry configured to estimate feed solution temperatures and permeate solution temperatures of the MD module using monitored outlet temperatures of the feed side and the permeate side. In another example, a method includes monitoring outlet temperatures of a feed side and a permeate side of a MD module to determine a current feed outlet temperature and a current permeate outlet temperature; and determining a plurality of estimated temperature states of a membrane boundary layer separating the feed side and the permeate side of the MD module using the current feed outlet temperature and the current permeate outlet temperature.

  10. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System.

    Science.gov (United States)

    Zhao, Baiwang; Peng, Na; Liang, Canzeng; Yong, Wai Fen; Chung, Tai-Shung

    2015-11-16

    In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18-22 g/m³ to a range of 13.5-18.3 g/m³. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  11. Hollow Fiber Membrane Dehumidification Device for Air Conditioning System

    Directory of Open Access Journals (Sweden)

    Baiwang Zhao

    2015-11-01

    Full Text Available In order to provide a comfortable living and working environment indoors in tropical countries, the outdoor air often needs to be cooled and dehumidified before it enters the rooms. Membrane separation is an emerging technology for air dehumidification and it is based on the solution diffusion mechanism. Water molecules are preferentially permeating through the membranes due to its smaller kinetic diameter and higher condensability than the other gases. Compared to other dehumidification technologies such as direct cooling or desiccation, there is no phase transition involved in membrane dehumidification, neither the contact between the fresh air stream and the desiccants. Hence, membrane dehumidification would not only require less energy consumption but also avoid cross-contamination problems. A pilot scale air dehumidification system is built in this study which comprises nine pieces of one-inch PAN/PDMS hollow fiber membrane modules. A 150 h long-term test shows that the membrane modules has good water vapor transport properties by using a low vacuum force of only 0.78 bar absolute pressure at the lumen side. The water vapor concentration of the feed humid air decreases dramatically from a range of 18–22 g/m3 to a range of 13.5–18.3 g/m3. Most importantly, the total energy saving is up to 26.2% compared with the conventional air conditioning process.

  12. A mini-scale mass production and separation system for secretory heterologous proteins by perfusion culture of recombinant Pichia pastoris using a shaken ceramic membrane flask.

    Science.gov (United States)

    Ohashi, R; Mochizuki, E; Suzuki, T

    1999-01-01

    The perfusion culture technique using a shaken ceramic membrane flask (SCM flask) was applied to the production of a secretory heterologous protein. A recombinant methylotrophic yeast strain, Pichia pastoris, was cultured aerobically on a reciprocal shaker using an SCM flask. High-level production of human serum albumin (HSA) was attempted by increasing both the cell concentration and the expression level of the recombinant gene. In the two-stage culture method, the cell concentration was first raised to 17 g/l by feeding glycerol, after which the expression of HSA was induced by feeding methanol. However, the concentration of HSA in the effluent filtrate was as low as 0.15 g/l, while the cell concentration continued to increase. In contrast, HSA was effectively produced by feeding methanol from an early stage of the culture. In this case, the HSA concentration reached 0.24 and 0.46 g/l, respectively, using the growth-associated production method without and with aeration into the head space of the SCM flask. The results showed that supplying sufficient oxygen together with the growth-associated induction method are effective for obtaining high-level expression of the methanol-inducible recombinant gene of P. pastoris. An HSA concentration in the filtrate of 1.5 g/l was finally achieved when the cell concentration was increased to 53 g/l by supplying oxygen-enriched gas to the SCM flask. The yield and productivity of HSA reached 2.6-fold and 10-fold those obtained in an ordinary fed-batch culture using a shake flask, and these levels were readily achieved by continuous replenishment of the culture supernatant. The achievements made in this study should contribute to the development of a handy bioreactor system for mini-scale mass production of target proteins with separation at high purity.

  13. Anion-exchange membranes in electrochemical energy systems

    NARCIS (Netherlands)

    Varcoe, J.R.; Atanassov, P.; Dekel, D.R.; Herring, A.M.; Hickner, M.A.; Kohl, P.A.; Kucernak, A. R.; Mustain, W.E.; Nijmeijer, K.; Scott, Keith; Xu, Tongwen; Zhuang, Lin

    2014-01-01

    This article provides an up-to-date perspective on the use of anion-exchange membranes in fuel cells, electrolysers, redox flow batteries, reverse electrodialysis cells, and bioelectrochemical systems (e.g. microbial fuel cells). The aim is to highlight key concepts, misconceptions, the current

  14. Analysis of hollow fibre membrane systems for multicomponent gas separation

    KAUST Repository

    Khalilpour, Rajab

    2013-02-01

    This paper analysed the performance of a membrane system over key design/operation parameters. A computation methodology is developed to solve the model of hollow fibre membrane systems for multicomponent gas feeds. The model represented by a nonlinear differential algebraic equation system is solved via a combination of backward differentiation and Gauss-Seidel methods. Natural gas sweetening problem is investigated as a case study. Model parametric analyses of variables, namely feed gas quality, pressure, area, selectivity and permeance, resulted in better understanding of operating and design optima. Particularly, high selectivities and/or permeabilities are shown not to be necessary targets for optimal operation. Rather, a medium selectivity (<60 in the given example) combined with medium permeance (∼300-500×10-10mol/sm2Pa in the given case study) is more advantageous. This model-based membrane systems engineering approach is proposed for the synthesis of efficient and cost-effective multi-stage membrane networks. © 2012 The Institution of Chemical Engineers.

  15. Feed gas contaminant control in ion transport membrane systems

    Science.gov (United States)

    Carolan, Michael Francis [Allentown, PA; Minford, Eric [Laurys Station, PA; Waldron, William Emil [Whitehall, PA

    2009-07-07

    Ion transport membrane oxidation system comprising an enclosure having an interior and an interior surface, inlet piping having an internal surface and adapted to introduce a heated feed gas into the interior of the enclosure, and outlet piping adapted to withdraw a product gas from the interior of the enclosure; one or more planar ion transport membrane modules disposed in the interior of the enclosure, each membrane module comprising mixed metal oxide material; and a preheater adapted to heat a feed gas to provide the heated feed gas to the inlet piping, wherein the preheater comprises an interior surface. Any of the interior surfaces of the enclosure, the inlet piping, and the preheater may be lined with a copper-containing metal lining. Alternatively, any of the interior surfaces of the inlet piping and the preheater may be lined with a copper-containing metal lining and the enclosure may comprise copper.

  16. Evaluation for membrane components of water recycling system. Mizu saisei junkan system yoso no tokusei hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Tanemura, T; Otsubo, K; Oguchi, M [National Aerospace Laboratory, Tokyo (Japan); Ashida, A; Hamano, N; Mitani, K [Hitachi, Ltd., Tokyo (Japan)

    1992-04-01

    The configuration of water recycling systems with membrane filters was studied to purify waste water discharged from human beings, animals and plants which is a key subsystem for closed ecological life support systems (CELSS) essential to long-term manned space activity. The filter performance test apparatus with three kinds of filters such as pre-filter, reverse osmosis membrane filter and ultra membrane filter was fabricated to conduct long-term cycling high-concentration tests using artificial urine as original waste water. As a result, since every membrane filter offered their nominal performance incompletely in high-concentration tests, it was necessary to add an NaCl removing apparatus to the system as primary treated water should be used for vegetation. It was also required to test the membrane performance preliminarily because the performance such as membrane life was different between various waste waters. 7 refs., 32 figs., 9 tabs.

  17. Cell-free system for synthesizing membrane proteins cell free method for synthesizing membrane proteins

    Science.gov (United States)

    Laible, Philip D; Hanson, Deborah K

    2013-06-04

    The invention provides an in vitro method for producing proteins, membrane proteins, membrane-associated proteins, and soluble proteins that interact with membrane-associated proteins for assembly into an oligomeric complex or that require association with a membrane for proper folding. The method comprises, supplying intracytoplasmic membranes from organisms; modifying protein composition of intracytoplasmic membranes from organism by modifying DNA to delete genes encoding functions of the organism not associated with the formation of the intracytoplasmic membranes; generating appropriate DNA or RNA templates that encode the target protein; and mixing the intracytoplasmic membranes with the template and a transcription/translation-competent cellular extract to cause simultaneous production of the membrane proteins and encapsulation of the membrane proteins within the intracytoplasmic membranes.

  18. Modeling Of Proton Exchange Membrane Fuel Cell Systems

    DEFF Research Database (Denmark)

    Nielsen, Mads Pagh

    The objective of this doctoral thesis was to develop reliable steady-state and transient component models suitable to asses-, develop- and optimize proton exchange membrane (PEM) fuel cell systems. Several components in PEM fuel cell systems were characterized and modeled. The developed component...... cell systems. Consequences of indirectly fueling PEM stacks with hydrocarbons using reforming technology were investigated using a PEM stack model including CO poisoning kinetics and a transient Simulink steam reforming system model. Aspects regarding the optimization of PEM fuel cell systems...

  19. Cellulose Nanocrystal Membranes as Excipients for Drug Delivery Systems

    Directory of Open Access Journals (Sweden)

    Ananda M. Barbosa

    2016-12-01

    Full Text Available In this work, cellulose nanocrystals (CNCs were obtained from flax fibers by an acid hydrolysis assisted by sonochemistry in order to reduce reaction times. The cavitation inducted during hydrolysis resulted in CNC with uniform shapes, and thus further pretreatments into the cellulose are not required. The obtained CNC exhibited a homogeneous morphology and high crystallinity, as well as typical values for surface charge. Additionally, CNC membranes were developed from CNC solution to evaluation as a drug delivery system by the incorporation of a model drug. The drug delivery studies were carried out using chlorhexidine (CHX as a drug and the antimicrobial efficiency of the CNC membrane loaded with CHX was examined against Gram-positive bacteria Staphylococcus aureus (S. Aureus. The release of CHX from the CNC membranes is determined by UV-Vis. The obtaining methodology of the membranes proved to be simple, and these early studies showed a potential use in antibiotic drug delivery systems due to the release kinetics and the satisfactory antimicrobial activity.

  20. Continuous Membrane-Based Screening System for Biocatalysis

    Directory of Open Access Journals (Sweden)

    Matthias Kraume

    2011-02-01

    Full Text Available The use of membrane reactors for enzymatic and co-factor regenerating reactions offers versatile advantages such as higher conversion rates and space-time-yields and is therefore often applied in industry. However, currently available screening and kinetics characterization systems are based on batch and fed-batch operated reactors and were developed for whole cell biotransformations rather than for enzymatic catalysis. Therefore, the data obtained from such systems has only limited transferability for continuous membrane reactors. The aim of this study is to evaluate and to improve a novel screening and characterization system based on the membrane reactor concept using the enzymatic hydrolysis of cellulose as a model reaction. Important aspects for the applicability of the developed system such as long-term stability and reproducibility of continuous experiments were very high. The concept used for flow control and fouling suppression allowed control of the residence time with a high degree of precision (±1% accuracy in a long-term study (>100 h.

  1. Dynamic nuclear polarization methods in solids and solutions to explore membrane proteins and membrane systems.

    Science.gov (United States)

    Cheng, Chi-Yuan; Han, Songi

    2013-01-01

    Membrane proteins regulate vital cellular processes, including signaling, ion transport, and vesicular trafficking. Obtaining experimental access to their structures, conformational fluctuations, orientations, locations, and hydration in membrane environments, as well as the lipid membrane properties, is critical to understanding their functions. Dynamic nuclear polarization (DNP) of frozen solids can dramatically boost the sensitivity of current solid-state nuclear magnetic resonance tools to enhance access to membrane protein structures in native membrane environments. Overhauser DNP in the solution state can map out the local and site-specific hydration dynamics landscape of membrane proteins and lipid membranes, critically complementing the structural and dynamics information obtained by electron paramagnetic resonance spectroscopy. Here, we provide an overview of how DNP methods in solids and solutions can significantly increase our understanding of membrane protein structures, dynamics, functions, and hydration in complex biological membrane environments.

  2. The chloroplast thylakoid membrane system is a molecular conveyor belt.

    Science.gov (United States)

    Critchley, C

    1988-10-01

    Light drives photosynthesis, but paradoxically light is also the most variable environmental factor influencing photosynthesis both qualitatively and quantitatively. The photosynthetic apparatus of higher plants is adaptable in the extreme, as exemplified by its capacity for acclimation to very bright sunny or deeply shaded conditions. It can also respond to rapid changes in light such as sunflecks. In this paper I offer a model that i) explains the thylakoid membrane organisation into grana stacks and stroma lamellae, ii) proposes a role for rapid D1 protein turnover and LHCII phosphorylation, and iii) suggests a mechanism for photoinhibition. I argue that the photosynthetic membrane system is dynamic in three dimensions, so much so that, in the light, it is in constant motion and operates in a manner somewhat analogous to a conveyor belt. D1 protein degradation is proposed to be the motor that drives this system. Photoinhibition is suggested to be due to the arrest of D1 protein turnover.

  3. Development of a proton exchange membrane fuel cell cogeneration system

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jenn Jiang; Zou, Meng Lin [Department of Greenergy, National University of Tainan, Tainan 700 (China)

    2010-05-01

    A proton exchange membrane fuel cell (PEMFC) cogeneration system that provides high-quality electricity and hot water has been developed. A specially designed thermal management system together with a microcontroller embedded with appropriate control algorithm is integrated into a PEM fuel cell system. The thermal management system does not only control the fuel cell operation temperature but also recover the heat dissipated by FC stack. The dynamic behaviors of thermal and electrical characteristics are presented to verify the stability of the fuel cell cogeneration system. In addition, the reliability of the fuel cell cogeneration system is proved by one-day demonstration that deals with the daily power demand in a typical family. Finally, the effects of external loads on the efficiencies of the fuel cell cogeneration system are examined. Results reveal that the maximum system efficiency was as high as 81% when combining heat and power. (author)

  4. Polymeric membrane systems of potential use for battery separators

    Science.gov (United States)

    Philipp, W. H.

    1977-01-01

    Two membrane systems were investigated that may have potential use as alkaline battery separators. One system comprises two miscible polymers: a support polymer (e.g., polyvinyl formal) and an ion conductor such as polyacrylic acid. The other system involves a film composed of two immiscible polymers: a conducting polymer (e.g., calcium polyacrylate) suspended in an inert polymer support matrix, polyphenylene oxide. Resistivities in 45-percent potassium hydroxide and qualitative mechanical properties are presented for films comprising various proportions of conducting and support polymers. In terms of these parameters, the results are encouraging for optimum ratios of conducting to support polymers.

  5. Renewable energy powered membrane technology. 2. The effect of energy fluctuations on performance of a photovoltaic hybrid membrane system.

    Science.gov (United States)

    Richards, B S; Capão, D P S; Schäfer, A I

    2008-06-15

    This paper reports on the performance fluctuations during the operation of a batteryless hybrid ultrafiltration--nanofiltration/reverse osmosis (UF-NF/RO) membrane desalination system powered by photovoltaics treating brackish groundwater in outback Australia. The renewable energy powered membrane (RE-membrane) system is designed to supply clean drinking water to a remote community of about 50 inhabitants. The performance of the RE-membrane system over four different solar days is summarized using four different NF membranes (BW30, NF90, ESPA4, TFC-S), and examined in more detail for the BW30 membrane. On an Australian spring day, the system produced 1.1 m3 of permeate with an average conductivity of 0.28 mS x cm(-1), recovering 28% of the brackish (8.29 mS x cm(-1) conductivity) feedwater with an average specific energy consumption of 2.3 kWh x m(-3). The RE-membrane system tolerated large fluctuations in solar irradiance (500--1200 W x m(-2)), resulting in only small increases in the permeate conductivity. When equipped with the NF90 (cloudy day) and ESPA4 (rainy day) membranes, the system was still able to produce 1.36 m(-3) and 0.85 m(-3) of good quality permeate, respectively. The TFC-S membrane was not able to produce adequate water quality from the bore water tested. It is concluded that batteryless operation is a simple and robust way to operate such systems under conditions ranging from clear skies to medium cloud cover.

  6. High anisotropy of flow-aligned bicellar membrane systems

    KAUST Repository

    Kogan, Maxim

    2013-10-01

    In recent years, multi-lipid bicellar systems have emerged as promising membrane models. The fast orientational diffusion and magnetic alignability made these systems very attractive for NMR investigations. However, their alignment was so far achieved with a strong magnetic field, which limited their use with other methods that require macroscopic orientation. Recently, it was shown that bicelles could be aligned also by shear flow in a Couette flow cell, making it applicable to structural and biophysical studies by polarized light spectroscopy. Considering the sensitivity of this lipid system to small variations in composition and physicochemical parameters, efficient use of such a flow-cell method with coupled techniques will critically depend on the detailed understanding of how the lipid systems behave under flow conditions. In the present study we have characterized the flow alignment behavior of the commonly used dimyristoyl phosphatidylcholine/dicaproyl phosphatidylcholine (DMPC/DHPC) bicelle system, for various temperatures, lipid compositions, and lipid concentrations. We conclude that at optimal flow conditions the selected bicellar systems can produce the most efficient flow alignment out of any lipid systems used so far. The highest degree of orientation of DMPC/DHPC samples is noticed in a narrow temperature interval, at a practical temperature around 25 C, most likely in the phase transition region characterized by maximum sample viscosity. The change of macroscopic orientation factor as function of the above conditions is now described in detail. The increase in macroscopic alignment observed for bicelles will most likely allow recording of higher resolution spectra on membrane systems, which provide deeper structural insight and analysis into properties of biomolecules interacting with solution phase lipid membranes. © 2013 Elsevier Ireland Ltd.

  7. Silver nanoparticles delivery system based on natural rubber latex membranes

    International Nuclear Information System (INIS)

    Guidelli, Éder José; Kinoshita, Angela; Ramos, Ana Paula; Baffa, Oswaldo

    2013-01-01

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV–Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane (∼0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are sterically

  8. Silver nanoparticles delivery system based on natural rubber latex membranes

    Energy Technology Data Exchange (ETDEWEB)

    Guidelli, Eder Jose, E-mail: ederguidelli@gmail.com [Universidade de Sao Paulo/FFCLRP-DF (Brazil); Kinoshita, Angela [Universidade do Sagrado Coracao (Brazil); Ramos, Ana Paula [Universidade de Sao Paulo/FFCLRP-DQ (Brazil); Baffa, Oswaldo [Universidade de Sao Paulo/FFCLRP-DF (Brazil)

    2013-04-15

    The search for new materials for biomedical applications is extremely important. Here, we present results on the performance of a silver nanoparticles delivery system using natural rubber latex (NRL) as the polymeric matrix. Our aim was to obtain an optimized wound dressing by combining materials with potential healing action. The synthesis of silver nanoparticles and their characterization by UV-Vis spectroscopy, transmission electron microscopy, zeta potential, dynamic light scattering, and Fourier transform infrared spectroscopy (FTIR) are depicted. The NRL membranes are good matrix for silver nanoparticles and allow for their gradual release. The release of 30 nm silver nanoparticles by the NRL membranes depends on their mass percentage in NRL membranes. The total concentration of AgNP released by the NRL membranes was calculated. The AgNP attached to the cis-isoprene molecules in the NRL matrix remain attached to the membrane ({approx}0.1 % w/w). So, only the AgNP bound to the non-rubber molecules are released. FTIR spectra suggest that non-rubber molecules, like aminoacids and proteins, associated with the serum fraction of the NRL may be attached to the surfaces of the released nanoparticles, thereby increasing the release of such molecules. The released silver nanoparticles are sterically stabilized, more stable and well dispersed. Because the serum fraction of the NRL is responsible for the angiogenic properties of the matrix, the silver nanoparticles could increment the angiogenic properties of NRL. This biomaterial has desirable properties for the fabrication of a wound dressing with potential healing action, since it combines the angiogenic and antibacterial properties of the silver nanoparticles with the increased angiogenic properties of the NRL.Graphical AbstractThe AgNP attached to the cis-isoprene molecules remain in the NRL matrix and only the AgNP bound to the non-rubber molecules (NRL serum fraction) are released. The released AgNP are

  9. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    Membrane filtration technologies have emerged as cost competitive and viable techniques in drinking and industrial water production. Despite advancements in membrane manufacturing and technology, membrane scaling and fouling remain major problems and may limit future growth in the industry. Scaling

  10. Valero Refinery Oxygen Enrichment Project

    Science.gov (United States)

    This document may be of assistance in applying the New Source Review (NSR) air permitting regulations including the Prevention of Significant Deterioration (PSD) requirements. This document is part of the NSR Policy and Guidance Database. Some documents in the database are a scanned or retyped version of a paper photocopy of the original. Although we have taken considerable effort to quality assure the documents, some may contain typographical errors. Contact the office that issued the document if you need a copy of the original.

  11. Hydrogen-1 NMR relaxation time studies in membrane: anesthetic systems

    International Nuclear Information System (INIS)

    Pinto, L.M.A.; Fraceto, L.; Paula, E. de; Franzoni, L.; Spisni, A.

    1997-01-01

    The study of local anesthetics'(LA) interaction with model phospholipid membranes is justified by the direct correlation between anesthetic's hydrophobicity and its potency/toxicity. By the same reason, uncharged LA species seems to play a crucial role in anesthesia. Most clinically used LA are small amphiphilics with a protonated amine group (pKa around 8). Although both charged (protonated) and uncharged forms can coexist at physiological pH, it has been shown (Lee, Biochim. Biophys. Acta 514:95, 1978; Screier et al. Biochim. Biophys. Acta 769:231, 1984) that the real anesthetic pka can be down-shifted, due to differential partition into membranes, increasing the ratio of uncharged species at pH 7.4. We have measured 1 H-NMR longitudinal relaxation times (T 1 ) for phospholipid and three local anesthetics (tetracaine, lidocaine, benzocaine), in sonicated vesicles at a 3:1 molar ratio. All the LA protons have shown smaller T 1 in this system than in isotropic phases, reflecting LA immobilization caused by insertion in the membrane. T 1 values for the lipid protons in the presence of LA were analyzed, in an attempt to identify specific LA:lipid contact regions. (author)

  12. Nonlinear Effects in Osmotic Volume Flows of Electrolyte Solutions through Double-Membrane System

    NARCIS (Netherlands)

    Slezak, A.; Jasik-Slezak, J.; Grzegorczyn, S.; Slezak-Prochazka, I.

    The results of experimental study of volume osmotic flows in a double-membrane system are presented in this article. The double-membrane system consists of two membranes (M-u, M-d) oriented in horizontal planes and three identical compartments (u, m, d), containing unstirred binary or ternary ionic

  13. Development of solid supports for electrochemical study of biomimetic membrane systems

    DEFF Research Database (Denmark)

    Mech-Dorosz, Agnieszka

    cushion directly on a gold electrode microchip and on a polyethersulfone (PES) support grafted by in situ polymerized hydrogel. Both strategies proved to be suitable for immobilization of functional bRh loaded lipo-polymersomes. Amperometric monitoring showed that the PES membrane support facilitated......Biomimetic membranes are model membrane systems used as an experimental tool to study fundamental cellular membrane physics and functionality of reconstituted membrane proteins. By exploiting the properties of biomimetic membranes resembling the functions of biological membranes, it is possible...... to construct biosensors for high-throughput screening of potential drug candidates. Among a variety of membrane model systems used for biomimetic approach, lipid bilayers in the form of black lipid membranes (BLMs) and lipo-polymersomes (vesicle structures composed of lipids and polymers), both...

  14. How synthetic membrane systems contribute to the understanding of lipid-driven endocytosis.

    Science.gov (United States)

    Schubert, Thomas; Römer, Winfried

    2015-11-01

    Synthetic membrane systems, such as giant unilamellar vesicles and solid supported lipid bilayers, have widened our understanding of biological processes occurring at or through membranes. Artificial systems are particularly suited to study the inherent properties of membranes with regard to their components and characteristics. This review critically reflects the emerging molecular mechanism of lipid-driven endocytosis and the impact of model membrane systems in elucidating the complex interplay of biomolecules within this process. Lipid receptor clustering induced by binding of several toxins, viruses and bacteria to the plasma membrane leads to local membrane bending and formation of tubular membrane invaginations. Here, lipid shape, and protein structure and valency are the essential parameters in membrane deformation. Combining observations of complex cellular processes and their reconstitution on minimal systems seems to be a promising future approach to resolve basic underlying mechanisms. This article is part of a Special Issue entitled: Mechanobiology. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Biofouling investigation in membrane filtration systems using Optical Coherence Tomography (OCT)

    KAUST Repository

    Fortunato, Luca

    2017-01-01

    Biofouling represents the main problem in membrane filtration systems. Biofouling arises when the biomass growth negatively impacts the membrane performance parameters (i.e. flux decrease and feed channel pressure drop). Most of the available

  16. Comparison between moving bed-membrane bioreactor (MB-MBR) and membrane bioreactor (MBR) systems: influence of wastewater salinity variation.

    Science.gov (United States)

    Di Trapani, Daniele; Di Bella, Gaetano; Mannina, Giorgio; Torregrossa, Michele; Viviani, Gaspare

    2014-06-01

    Two pilot plant systems were investigated for the treatment of wastewater subject to a gradual increase of salinity. In particular, a membrane bioreactor (MBR) and a moving bed biofilm membrane bioreactor (MB-MBR) were analyzed. Carbon and ammonium removal, kinetic constants and membranes fouling rates have been assessed. Both plants showed very high efficiency in terms of carbon and ammonium removal and the gradual salinity increase led to a good acclimation of the biomass, as confirmed by the respirometric tests. Significant biofilm detachments from carriers were experienced, which contributed to increase the irreversible superficial cake deposition. However, this aspect prevented the pore fouling tendency in the membrane module of MB-MBR system. On the contrary, the MBR pilot, even showing a lower irreversible cake deposition, was characterized by a higher pore fouling tendency. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Catalytic membrane reactor for tritium extraction system from He purge

    International Nuclear Information System (INIS)

    Santucci, Alessia; Incelli, Marco; Sansovini, Mirko; Tosti, Silvano

    2016-01-01

    Highlights: • In the HCBB blanket, the produced tritium is recovered by purging with helium; membrane technologies are able to separate tritium from helium. • The paper presents the results of two experimental campaigns. • In the first, a Pd–Ag diffuser for hydrogen separation is tested at several operating conditions. • In the second, the ability of a Pd–Ag membrane reactor for water decontamination is assessed by performing isotopic swamping and water gas shift reactions. - Abstract: In the Helium Cooled Pebble Bed (HCPB) blanket concept, the produced tritium is recovered purging the breeder with helium at low pressure, thus a tritium extraction system (TES) is foreseen to separate the produced tritium (which contains impurities like water) from the helium gas purge. Several R&D activities are running in parallel to experimentally identify most promising TES technologies: particularly, Pd-based membrane reactors (MR) are under investigation because of their large hydrogen selectivity, continuous operation capability, reliability and compactness. The construction and operation under DEMO relevant conditions (that presently foresee a He purge flow rate of about 10,000 Nm 3 /h and a H 2 /He ratio of 0.1%) of a medium scale MR is scheduled for next year, while presently preliminary experiments on a small scale reactor are performed to identify most suitable operative conditions and catalyst materials. This work presents the results of an experimental campaign carried out on a Pd-based membrane aimed at measuring the capability of this device in separating hydrogen from the helium. Many operative conditions have been investigated by considering different He/H 2 feed flow ratios, several lumen pressures and reactor temperatures. Moreover, the performances of a membrane reactor (composed of a Pd–Ag tube having a wall thickness of about 113 μm, length 500 mm and diameter 10 mm) in processing the water contained in the purge gas have been measured by using

  18. Catalytic membrane reactor for tritium extraction system from He purge

    Energy Technology Data Exchange (ETDEWEB)

    Santucci, Alessia, E-mail: alessia.santucci@enea.it [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy); Incelli, Marco [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy); DEIM, University of Tuscia, Via del Paradiso 47, 01100 Viterbo (Italy); Sansovini, Mirko; Tosti, Silvano [ENEA for EUROfusion, Via E. Fermi 45, 00044 Frascati, Roma (Italy)

    2016-11-01

    Highlights: • In the HCBB blanket, the produced tritium is recovered by purging with helium; membrane technologies are able to separate tritium from helium. • The paper presents the results of two experimental campaigns. • In the first, a Pd–Ag diffuser for hydrogen separation is tested at several operating conditions. • In the second, the ability of a Pd–Ag membrane reactor for water decontamination is assessed by performing isotopic swamping and water gas shift reactions. - Abstract: In the Helium Cooled Pebble Bed (HCPB) blanket concept, the produced tritium is recovered purging the breeder with helium at low pressure, thus a tritium extraction system (TES) is foreseen to separate the produced tritium (which contains impurities like water) from the helium gas purge. Several R&D activities are running in parallel to experimentally identify most promising TES technologies: particularly, Pd-based membrane reactors (MR) are under investigation because of their large hydrogen selectivity, continuous operation capability, reliability and compactness. The construction and operation under DEMO relevant conditions (that presently foresee a He purge flow rate of about 10,000 Nm{sup 3}/h and a H{sub 2}/He ratio of 0.1%) of a medium scale MR is scheduled for next year, while presently preliminary experiments on a small scale reactor are performed to identify most suitable operative conditions and catalyst materials. This work presents the results of an experimental campaign carried out on a Pd-based membrane aimed at measuring the capability of this device in separating hydrogen from the helium. Many operative conditions have been investigated by considering different He/H{sub 2} feed flow ratios, several lumen pressures and reactor temperatures. Moreover, the performances of a membrane reactor (composed of a Pd–Ag tube having a wall thickness of about 113 μm, length 500 mm and diameter 10 mm) in processing the water contained in the purge gas have been

  19. Sorting of bacterial lipoproteins to the outer membrane by the Lol system.

    Science.gov (United States)

    Narita, Shin-ichiro; Tokuda, Hajime

    2010-01-01

    Bacterial lipoproteins comprise a subset of membrane proteins with a lipid-modified cysteine residue at their amino termini through which they are anchored to the membrane. In Gram-negative bacteria, lipoproteins are localized on either the inner or the outer membrane. The Lol system is responsible for the transport of lipoproteins to the outer membrane.The Lol system comprises an inner-membrane ABC transporter LolCDE complex, a periplasmic carrier protein, LolA, and an outer membrane receptor protein, LolB. Lipoproteins are synthesized as precursors in the cytosol and then translocated across the inner membrane by the Sec translocon to the outer leaflet of the inner membrane, where lipoprotein precursors are processed to mature lipoproteins. The LolCDE complex then mediates the release of outer membrane-specific lipoproteins from the inner membrane while the inner membrane-specific lipoproteins possessing Asp at position 2 are not released by LolCDE because it functions as a LolCDE avoidance signal, causing the retention of these lipoproteins in the inner membrane. A water-soluble lipoprotein-LolA complex is formed as a result of the release reaction mediated by LolCDE. This complex traverses the hydrophilic periplasm to reach the outer membrane, where LolB accepts a lipoprotein from LolA and then catalyzes its incorporation into the inner leaflet of the outer membrane.

  20. RECENT PROGRESS OF OXYGEN/NITROGEN SEPARATION USING MEMBRANE TECHNOLOGY

    OpenAIRE

    K. C. CHONG; S. O. LAI; H. S. THIAM; H. C. TEOH; S. L. HENG

    2016-01-01

    The oxygen-enriched air is highly demanded for various industrial applications such as medical, chemical and enhanced combustion processes. The conventional oxygen/nitrogen production is either cryogenic distillation or pressure swing adsorption (PSA). Both of these techniques possess the production capability of 20 to 300 tonnes of oxygen per day and oxygen purity of more than 95%. However, these techniques are energy intensive. Alternatively, membrane technology is an emerging technology...

  1. Advanced Wastewater Treatment Engineering—Investigating Membrane Fouling in both Rotational and Static Membrane Bioreactor Systems Using Empirical Modelling

    Directory of Open Access Journals (Sweden)

    Parneet Paul

    2016-01-01

    Full Text Available Advanced wastewater treatment using membranes are popular environmental system processes since they allow reuse and recycling. However, fouling is a key limiting factor and so proprietary systems such as Avanti’s RPU-185 Flexidisks membrane bioreactor (MBR use novel rotating membranes to assist in ameliorating it. In earlier research, this rotating process was studied by creating a simulation model based on first principles and traditional fouling mechanisms. In order to directly compare the potential benefits of this rotational system, this follow-up study was carried out using Avanti’s newly developed static (non-rotating Flexidisks MBR system. The results from operating the static pilot unit were simulated and modelled using the rotational fouling model developed earlier however with rotational switching functions turned off and rotational parameters set to a static mode. The study concluded that a rotating MBR system could increase flux throughput when compared against a similar static system. It is thought that although the slowly rotating spindle induces a weak crossflow shear, it is still able to even out cake build up across the membrane surface, thus reducing the likelihood of localised critical flux being exceeded at the micro level and lessening the potential of rapid trans-membrane pressure increases at the macro level.

  2. Hybrid membrane contactor system for creating semi-breathing air

    Science.gov (United States)

    Timofeev, D. V.

    2012-02-01

    Typically, the equipment to create an artificial climate does not involve changing the composition of the respiratory air. In particular in medical institutions assumes the existence of plant of artificial climate and disinfection in operating rooms and intensive care wards. The use of a hybrid membrane-absorption systems for the generation of artificial atmospheres are improving the respiratory system, blood is enriched or depleted of various gases, resulting in increased stamina, there is a better, faster or slower metabolism, improves concentration and memory. Application of the system contributes to easy and rapid recovery after the operation. By adding a special component, with drug activity, air ionization, and adjust its composition, you can create a special, more favorable for patients with the atmosphere. These factors allow for the treatment and rehabilitation of patients and reduce mortality of heavy patients.

  3. Modulation of Erythrocyte Plasma Membrane Redox System Activity by Curcumin

    Directory of Open Access Journals (Sweden)

    Prabhakar Singh

    2016-01-01

    Full Text Available Plasma membrane redox system (PMRS is an electron transport chain system ubiquitously present throughout all cell types. It transfers electron from intracellular substrates to extracellular acceptors for regulation of redox status. Curcumin, isolated from Curcuma longa, has modulatory effects on cellular physiology due to its membrane interaction ability and antioxidant potential. The present study investigates the effect of curcumin on PMRS activity of erythrocytes isolated from Wistar rats in vitro and in vivo and validated through an in silico docking simulation study using Molegro Virtual Docker (MVD. Effects of curcumin were also evaluated on level of glutathione (GSH and the oxidant potential of plasma measured in terms of plasma ferric equivalent oxidative potentials (PFEOP. Results show that curcumin significantly (p<0.01 downregulated the PMRS activity in a dose-dependent manner. Molecular docking results suggest that curcumin interacts with amino acids at the active site cavity of cytochrome b5 reductase, a key constituent of PMRS. Curcumin also increased the GSH level in erythrocytes and plasma while simultaneously decreasing the oxidant potential (PFEOP of plasma. Altered PMRS activity and redox status are associated with the pathophysiology of several health complications including aging and diabetes; hence, the above finding may explain part of the role of curcumin in health beneficial effects.

  4. An investigation of co-combustion municipal sewage sludge with biomass in a 20kW BFB combustor under air-fired and oxygen-enriched condition.

    Science.gov (United States)

    Kumar, Rajesh; Singh, Ravi Inder

    2017-12-01

    The behavior of municipal sewage sludge (MSS) with biomass (Guar stalks (GS), Mustard Husk (MH), Prosopis Juliflora Wood (PJW)) has been investigated in a 20kW bubbling fluidized bed (BFB) combustor under both air-fired (A-F) and oxygen-enriched (O-E) conditions. The work presented is divided into three parts, first part cover the thermogravimetric analysis (TGA), second part cover the experimental investigation of BFB combustor, and third part covers the ash analysis. TGA was performed with a ratio of 50%MSS/50%biomass (GS, MH, PJW) and results show that 50%MSS/50%GS has highest combustion characteristic factor (CCF). The experimental investigation of BFB combustor was performed for two different ratios of MSS/biomass (50%/50% and 25%/75%) and the combustion characteristics of blends were distinctive under both A-F and O-E condition. Despite 50%MSS/50%GS showing the highest combustion performance in TGA analysis, it formed agglomerates during burning in BFB. Due to this formation of large amount of agglomerates, de-fluidization was observed in the combustor bed after 65-75min in A-F conditions. The rate of de-fluidization increased under O-E condition. The de-fluidization problem disappeared when the share of MSS was reduced to 25%, but small amounts of the agglomerate were still present in the bed. With oxygen enhancement, the combustion efficiency of BFB combustor was improved and flue gasses were found within permissible limit. The maximum conceivable combustion efficiency (97.1%) for BFB combustor was accomplished by using 50% MSS/50%PJW under O-E condition. Results show that a ratio of 25%MSS/75%biomass combusted successfully inside the BFB combustor and extensive work is required for efficient utilization of significant share of MSS with biomass. SEM/EDS analyses were performed for agglomerate produced and for the damaged heater to study the surface morphology and compositions. The elemental heterogeneity of fly ash generated during MSS/biomass combustion

  5. Fouling in a MBR system with rotating membrane discs

    DEFF Research Database (Denmark)

    Jørgensen, Mads Koustrup; Bentzen, Thomas Ruby; Christensen, Morten Lykkegaard

    concentrations and a clear effluent with no bacteria present in the permeate [1]. However, the process performance is limited by membrane fouling, which results in a lower productivity and higher energy demand and hence places demands for limitation of fouling and/or cleaning of the membranes. One way to do...... uses rotating ceramic membrane discs for creation of shear, which can be changed by controlling the membrane rotation speed of the membrane. Furthermore, the influence of shear on fouling is studied at different radii from the center of rotation, by dividing membranes into different concentric rings......Membrane bioreactors (MBR) are an attractive alternative solution for municipal and industrial wastewater treatment. The MBR, which is a combination of a bioreactor for sludge degradation and a membrane for separation, has the advantages of a low footprint, ability to handle high sludge...

  6. Effects of Bloom-Forming Algae on Fouling of Integrated Membrane Systems in Seawater Desalination

    Science.gov (United States)

    Ladner, David Allen

    2009-01-01

    Combining low- and high-pressure membranes into an integrated membrane system is an effective treatment strategy for seawater desalination. Low-pressure microfiltration (MF) and ultrafiltration (UF) membranes remove particulate material, colloids, and high-molecular-weight organics leaving a relatively foulant-free salt solution for treatment by…

  7. Detection of inhomogeneities in membrane ohmic resistance in geometrically complex systems

    DEFF Research Database (Denmark)

    Svirskis, G; Hounsgaard, J; Gutman, A

    2000-01-01

    DC field-evoked transients in arbitrarily shaped neurons and syncytia were analyzed theoretically. In systems with homogeneous passive membrane properties, the transients develop much faster than the membrane discharges. Conductance of the proximal membrane could be larger due to the injury impos...

  8. Coarctation induces alterations in basement membranes in the cardiovascular system

    DEFF Research Database (Denmark)

    Lipke, D W; McCarthy, K J; Elton, T S

    1993-01-01

    ventricular hypertrophy was maximal within 5 days. In immunohistochemical studies, fibronectin and laminin were increased and the basement membrane chondroitin sulfate proteoglycan decreased in both the subendothelial space and smooth muscle cell basement membranes of the aorta above the clip compared...... membrane components in the heart and vasculature peaked before maximal cardiac hypertrophy (5 days). These studies indicate that alterations in basement membrane component deposition in the hypertrophied vasculature occur at both transcriptional and translational levels and suggest that the cell attachment...

  9. Automatic design of deterministic and non-halting membrane systems by tuning syntactical ingredients.

    Science.gov (United States)

    Zhang, Gexiang; Rong, Haina; Ou, Zhu; Pérez-Jiménez, Mario J; Gheorghe, Marian

    2014-09-01

    To solve the programmability issue of membrane computing models, the automatic design of membrane systems is a newly initiated and promising research direction. In this paper, we propose an automatic design method, Permutation Penalty Genetic Algorithm (PPGA), for a deterministic and non-halting membrane system by tuning membrane structures, initial objects and evolution rules. The main ideas of PPGA are the introduction of the permutation encoding technique for a membrane system, a penalty function evaluation approach for a candidate membrane system and a genetic algorithm for evolving a population of membrane systems toward a successful one fulfilling a given computational task. Experimental results show that PPGA can successfully accomplish the automatic design of a cell-like membrane system for computing the square of n ( n ≥ 1 is a natural number) and can find the minimal membrane systems with respect to their membrane structures, alphabet, initial objects, and evolution rules for fulfilling the given task. We also provide the guidelines on how to set the parameters of PPGA.

  10. Electrical equivalent circuit of an ion-exchange membrane system

    Energy Technology Data Exchange (ETDEWEB)

    Nikonenko, Victor V., E-mail: v_nikonenko@mail.r [Membrane Institute, Kuban State University, Krasnodar (Russian Federation); Kozmai, Anton E. [Membrane Institute, Kuban State University, Krasnodar (Russian Federation)

    2011-01-01

    Usually, the current flowing through an electrochemical cell is divided into the faradaic current going to an electrochemical interface reaction, and the current charging electric double layer (EDL). This division leads to the Randles-Ershler equivalent circuit with an EDL capacitance in one branch, and the faradaic impedance in the other, specific for each particular system. However, the physics of the separation of the impedance into faradaic and capacitive components for different electrochemical systems is not sufficiently clear. The most of derivations resulting in the formal construction of the Randles-Ershler or similar equivalent circuits are based on the a priori separation of the electroneutral and the double-layer regions. In this paper, we derive an equation for the impedance of a three-layer system consisted of an ion-exchange membrane and two adjoining diffusion boundary layers (DBL) starting from the Poisson equation. The system is polarized by a constant electric current over which a small sinusoidal signal is applied. The equation shows that the impedance of the considered system can be formally interpreted via an equivalent circuit with a frequency dependent capacitance in one branch and a finite-length Warburg-type impedance in the other. To take into account this dependence, the impedance of the system may be presented as a series connection of five circuits. Three of them are consisted of a geometric capacitance connected in parallel with an ohmic resistance, respectively, for both diffusion layers and for the membrane bulk; the two others being the double-layer capacitance in parallel with the finite-length Warburg impedance for the left and the right interfaces, respectively. The comparison of the impedance spectra calculated within our analytical approach with those obtained by the full numerical solution of the Nernst-Planck-Poisson (NPP) equations shows a good agreement. Different possible situations, which might arise in real systems

  11. Natural Organic Matter Removal and Fouling in a Low Pressure Hybrid Membrane Systems

    Directory of Open Access Journals (Sweden)

    Vedat Uyak

    2014-01-01

    Full Text Available The objective of this study was to investigate powdered activated carbon (PAC contribution to natural organic matter (NOM removal by a submerged MF and UF hybrid systems. It was found that filtration of surface waters by a bare MF and UF membranes removed negligible TOC; by contrast, significant amounts of TOC were removed when daily added PAC particles were predeposited on the membrane surfaces. These results support the assumption that the membranes surface properties and PAC layer structure might have considerably influential factor on NOM removal. Moreover, it was concluded that the dominant removal mechanism of hybrid membrane system is adsorption of NOM within PAC layer rather than size exclusion of NOM by both of membrane pores. Transmembrane pressure (TMP increases with PAC membrane systems support the view that PAC adsorption pretreatment will not prevent the development of membrane pressure; on the contrary, PAC particles themselves caused membrane fouling by blocking the entrance of pores of MF and UF membranes. Although all three source waters have similar HPI content, it appears that the PAC interaction with the entrance of membrane pores was responsible for offsetting the NOM fractional effects on membrane fouling for these source waters.

  12. The plasma membrane transport systems and adaptation to salinity.

    Science.gov (United States)

    Mansour, Mohamed Magdy F

    2014-11-15

    Salt stress represents one of the environmental challenges that drastically affect plant growth and yield. Evidence suggests that glycophytes and halophytes have a salt tolerance mechanisms working at the cellular level, and the plasma membrane (PM) is believed to be one facet of the cellular mechanisms. The responses of the PM transport proteins to salinity in contrasting species/cultivars were discussed. The review provides a comprehensive overview of the recent advances describing the crucial roles that the PM transport systems have in plant adaptation to salt. Several lines of evidence were presented to demonstrate the correlation between the PM transport proteins and adaptation of plants to high salinity. How alterations in these transport systems of the PM allow plants to cope with the salt stress was also addressed. Although inconsistencies exist in some of the information related to the responses of the PM transport proteins to salinity in different species/cultivars, their key roles in adaptation of plants to high salinity is obvious and evident, and cannot be precluded. Despite the promising results, detailed investigations at the cellular/molecular level are needed in some issues of the PM transport systems in response to salinity to further evaluate their implication in salt tolerance. Copyright © 2014 Elsevier GmbH. All rights reserved.

  13. System and method for air temperature control in an oxygen transport membrane based reactor

    Science.gov (United States)

    Kelly, Sean M

    2016-09-27

    A system and method for air temperature control in an oxygen transport membrane based reactor is provided. The system and method involves introducing a specific quantity of cooling air or trim air in between stages in a multistage oxygen transport membrane based reactor or furnace to maintain generally consistent surface temperatures of the oxygen transport membrane elements and associated reactors. The associated reactors may include reforming reactors, boilers or process gas heaters.

  14. Endogenous glycosphingolipid acceptor specificity of sialosyltransferase systems in intact golgi membranes, synaptosomes, and synaptic plasma membranes from rat brain

    International Nuclear Information System (INIS)

    Durrie, R.; Saito, M.; Rosenberg, A.

    1988-01-01

    Preparations highly enriched in Golgi complex membranes, synaptosomes, and synaptic plasma membranes (SPM) by marker enzyme analysis and electron microscopic morphology were made from the brains of 28-day-old rats. These were incubated with cytidine 5'-monophosphate-N-acetyl[ 14 C]neuraminic acid (CMP-NeuAc) in a physiologic buffer, without detergents. Glycolipid sialosyltransferase activities (SATs) were measured by analyzing incorporation of radiolabeled NeuAc into endogenous membrane gangliosides. Golgi SAT was diversified in producing all the various molecular species of labeled gangliosides. Synaptosomal SAT exhibited a lower activity, but it was highly specific in its labeling pattern, with a marked preference for labeling NeuAcα2 → 8NeuAcα2 → 3Galβ1 → 4Glcβ1 → 1Cer (GD3 ganglioside). SPM prepared from the synaptosomes retained the GD3-related SAT (or SAT-2), and the total specific activity increased, which suggests that the location of the synaptosomal activity is in the SPM. These results indicate that SAT activity in Golgi membranes differs from that in synaptosomes with regard to endogenous acceptor substrate specificity and SAT activity of synaptosomes should be located in the synaptosomal plasma membrane. This SAT could function as an ectoenzyme in concert with ecto-sialidase to modulate the GD3 and other ganglioside population in situ at the SPM of the central nervous system

  15. A Pilot-Scale System for Carbon Molecular Sieve Hollow Fiber Membrane Manufacturing

    KAUST Repository

    Karvan, O.; Johnson, J. R.; Williams, P. J.; Koros, W. J.

    2012-01-01

    research on these materials with a variety of applications being studied. The results from a pilot-scale CMS production system are presented. This system was designed based on extensive laboratory research, and hollow fiber membranes produced in this system

  16. Attainability and minimum energy of multiple-stage cascade membrane Systems

    KAUST Repository

    Alshehri, Ali

    2015-08-12

    Process design and simulation of multi-stage membrane systems have been widely studied in many gas separation systems. However, general guidelines have not been developed yet for the attainability and the minimum energy consumption of a multi-stage membrane system. Such information is important for conceptual process design and thus it is the topic of this work. Using a well-mixed membrane model, it was determined that the attainability curve of multi-stage systems is defined by the pressure ratio and membrane selectivity. Using the constant recycle ratio scheme, the recycle ratio can shift the attainability behavior between single-stage and multi-stage membrane systems. When the recycle ratio is zero, all of the multi-stage membrane processes will decay to a single-stage membrane process. When the recycle ratio approaches infinity, the required selectivity and pressure ratio reach their absolute minimum values, which have a simple relationship with that of a single-stage membrane process, as follows: View the MathML sourceSn=S1, View the MathML sourceγn=γ1, where n is the number of stages. The minimum energy consumption of a multi-stage membrane process is primarily determined by the membrane selectivity and recycle ratio. A low recycle ratio can significantly reduce the required membrane selectivity without substantial energy penalty. The energy envelope curve can provide a guideline from an energy perspective to determine the minimum required membrane selectivity in membrane process designs to compete with conventional separation processes, such as distillation.

  17. Membrane Systems Engineering for Post-combustion Carbon Capture

    KAUST Repository

    Alshehri, Ali; Khalilpour, Rajab; Abbas, Ali; Lai, Zhiping

    2013-01-01

    This study proposes a strategy for optimal design of hollow fiber membrane networks for post combustion carbon capture from power plant multicomponent flue gas. A mathematical model describing multicomponent gas permeation through a separation membrane was customized into the flowsheet modeling package ASPEN PLUS. An N-stage membrane network superstructure was defined considering all possible flowsheeting configurations. An optimization formulation was then developed and solved using an objective function that minimizes the costs associated with operating and capital expenses. For a case study of flue gas feed flow rate of 298 m3/s with 13% CO2 and under defined economic parameters, the optimization resulted in the synthesis of a membrane network structure consisting of two stages in series. This optimal design was found while also considering feed and permeate pressures as well as recycle ratios between stages. The cost of carbon capture for this optimal membrane network is estimated to be $28 per tonne of CO2 captured, considering a membrane permeance of 1000 GPU and membrane selectivity of 50. Following this approach, a reduction in capture cost to less than $20 per tonne CO2 captured is possible if membranes with permeance of 2000 GPU and selectivity higher than 70 materialize.

  18. Membrane Systems Engineering for Post-combustion Carbon Capture

    KAUST Repository

    Alshehri, Ali

    2013-08-05

    This study proposes a strategy for optimal design of hollow fiber membrane networks for post combustion carbon capture from power plant multicomponent flue gas. A mathematical model describing multicomponent gas permeation through a separation membrane was customized into the flowsheet modeling package ASPEN PLUS. An N-stage membrane network superstructure was defined considering all possible flowsheeting configurations. An optimization formulation was then developed and solved using an objective function that minimizes the costs associated with operating and capital expenses. For a case study of flue gas feed flow rate of 298 m3/s with 13% CO2 and under defined economic parameters, the optimization resulted in the synthesis of a membrane network structure consisting of two stages in series. This optimal design was found while also considering feed and permeate pressures as well as recycle ratios between stages. The cost of carbon capture for this optimal membrane network is estimated to be $28 per tonne of CO2 captured, considering a membrane permeance of 1000 GPU and membrane selectivity of 50. Following this approach, a reduction in capture cost to less than $20 per tonne CO2 captured is possible if membranes with permeance of 2000 GPU and selectivity higher than 70 materialize.

  19. A Pilot-Scale System for Carbon Molecular Sieve Hollow Fiber Membrane Manufacturing

    KAUST Repository

    Karvan, O.

    2012-12-21

    Carbon molecular sieve (CMS) membranes offer advantages over traditional polymeric membrane materials, but scale-up of manufacturing systems has not received much attention. In the recent decade, there has been a dramatic increase in fundamental research on these materials with a variety of applications being studied. The results from a pilot-scale CMS production system are presented. This system was designed based on extensive laboratory research, and hollow fiber membranes produced in this system show similar performance compared to membranes produced using a smaller bench-scale system. After optimizing the system design, a 93% recovery of the precursor fibers for use in membrane module preparation were obtained. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Biofouling Control in Spiral-Wound Membrane Systems: Impact of Feed Spacer Modification and Biocides

    KAUST Repository

    Siddiqui, Amber

    2016-12-01

    High-quality drinking water can be produced with membrane-based filtration processes like reverse osmosis and nanofiltration. One of the major problems in these membrane systems is biofouling that reduces the membrane performance, increasing operational costs. Current biofouling control strategies such as pre-treatment, membrane modification, and chemical cleaning are not sufficient in all cases. Feed spacers are thin (0.8 mm), complex geometry meshes that separate membranes in a module. The main objective of this research was to evaluate whether feed spacer modification is a suitable strategy to control biofouling. Membrane fouling simulator studies with six feed spacers showed differences in biofouled spacer performance, concluding that (i) spacer geometry influences biofouling impact and (ii) biofouling studies are essential for evaluation of spacer biofouling impact. Computed tomography (CT) was found as a suitable technique to obtain three-dimensional (3D) measurements of spacers, enabling more representative mathematical modeling of hydraulic behavior of spacers in membrane systems. A strategy for developing, characterizing, and testing of spacers by numerical modeling, 3D printing of spacers and experimental membrane fouling simulator studies was developed. The combination of modeling and experimental testing of 3D printed spacers is a promising strategy to develop advanced spacers aiming to reduce the impact of biofilm formation on membrane performance and to improve the cleanability of spiral-wound membrane systems.

  1. Root cause analysis of pump valve failures of three membrane pump systems

    NARCIS (Netherlands)

    Buijs, L.J.; Eijk, A.; Hooft, L. van

    2014-01-01

    This paper will present the root cause analysis and the solution of fatigue failures of the pump valves of three membrane pump systems installed on a chemical plant of Momentive in Pernis, the Netherlands. The membrane pumps were installed approximately 30 years ago. Each system has encountered

  2. Membrane heat exchanger in HVAC energy recovery systems, systems energy analysis

    Energy Technology Data Exchange (ETDEWEB)

    Nasif, M. [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Opus International Consultants (New Zealand); AL-Waked, R. [Mechanical Engineering Department, Prince Mohammad Bin Fahd University (PMU), P.O. Box 1614, AlKhobar 31952 (Saudi Arabia); Morrison, G. [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney, NSW 2052 (Australia); Behnia, M. [School of Aerospace, Mechanical and Mechatronic Engineering, University of Sydney, NSW 2006 (Australia)

    2010-10-15

    The thermal performance of an enthalpy/membrane heat exchanger is experimentally investigated. The heat exchanger utilizes a 60gsm Kraft paper as the heat and moisture transfer surface for HVAC energy recovery. The heat exchanger sensible, latent and total effectiveness have been determined through temperature and moisture content measurements. The annual energy consumption of an air conditioner coupled with an enthalpy/membrane heat exchanger is also studied and compared with a conventional air conditioning cycle using in-house modified HPRate software. The heat exchanger effectiveness are used as thermal performance indicators and incorporated in the modified software. Energy analysis showed that an air conditioning system coupled with a membrane heat exchanger consumes less energy than a conventional air conditioning system in hot and humid climates where the latent load is high. It has been shown that in humid climate a saving of up to 8% in annual energy consumption can be achieved when membrane heat exchanger is used instead of a conventional HVAC system. (author)

  3. Hydrogen selective membrane for the natural gas system. Development of CO{sub 2}-selective biogas membrane. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Vestboe, A.P.

    2012-02-15

    The project started as a literature study and technology development project for a hydrogen selective membrane for the natural gas system. The introduction of hydrogen (for example produced from wind turbines by surplus electricity) in the gas system makes it possible to store energy which can be selectively used with high energy conversion in fuel cells directly located at the end users. In order to make this possible, it is necessary to have a separating unit that can selectively remove hydrogen from the gas mixture and deliver it as fuel to the electrical generator (a fuel cell). In the project, several existing technologies were evaluated with regard to the application in view. It was concluded that while other technologies are ripe, they are costly in energy and unsuitable for the relatively low capacity application that are in question close to the end users. Membrane technology was evaluated to be the most suitable, although the technology is still under development in many cases. In the project it was found that metallic membranes in the form of palladium coated stainless discs would answer the needs for the high purity needed. Laboratory development yielded discs that could separate hydrogen from natural gas, however, the flux was low compared to the needs of the application. It was found that at least 2 bar pressure difference of hydrogen would be needed to get a high enough flux. The way to achieve this pressure would necessitate a compressor which would consume an energy amount high enough to invalidate the concept. When concluding on the results and the study it was found that the direction of the project could be changed towards developing CO{sub 2}-selective membranes with the goal of developing membrane technology that could upgrade biogas by removing CO{sub 2}. The laboratory equipment and setup that were developed in the first part of the project could be used directly in this second part of the project. In this second part of the project it was

  4. Membrane fusion

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    At Stanford University, Boxer lab, I worked on membrane fusion of small unilamellar lipid vesicles to flat membranes tethered to glass surfaces. This geometry closely resembles biological systems in which liposomes fuse to plasma membranes. The fusion mechanism was studied using DNA zippering...... between complementary strands linked to the two apposing membranes closely mimicking the zippering mechanism of SNARE fusion complexes....

  5. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    Energy Technology Data Exchange (ETDEWEB)

    Stoica-Guzun, Anicuta [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania)], E-mail: astoica@mt.pub.ro; Stroescu, Marta; Tache, Florin [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania); Zaharescu, Traian [Advanced Research Institute for Electrical Engineering, 313 Splaiul Unirii, 030138 Bucharest (Romania)], E-mail: zaharescut@icpe-ca.ro; Grosu, Elena [Department of Chemical Engineering, ' Politehnica' University Bucharest, 313 Splaiul Independentei, 060042 Bucharest (Romania)

    2007-12-15

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of {gamma}-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell.

  6. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    International Nuclear Information System (INIS)

    Stoica-Guzun, Anicuta; Stroescu, Marta; Tache, Florin; Zaharescu, Traian; Grosu, Elena

    2007-01-01

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of γ-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell

  7. Effect of electron beam irradiation on bacterial cellulose membranes used as transdermal drug delivery systems

    Science.gov (United States)

    Stoica-Guzun, Anicuta; Stroescu, Marta; Tache, Florin; Zaharescu, Traian; Grosu, Elena

    2007-12-01

    Ionizing radiation is an effective energetic source for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. In this work, gamma rays have been applied to induce changes in bacterial cellulose membranes. Permeation of drug (tetracycline) was theoretically and experimentally investigated starting from the effect of γ-irradiation on membranes permeability. Release and permeation of drug from irradiated and non-irradiated membranes have been performed using a diffusion cell.

  8. Nutrient utilization and oxygen production by Chlorella Vulgaris in a hybrid membrane bioreactor and algal membrane photobioreactor system

    KAUST Repository

    Najm, Yasmeen Hani Kamal

    2017-02-17

    This work studied oxygen production and nutrient utilization by Chlorella Vulgaris at different organic/inorganic carbon (OC/IC) and ammonium/nitrate (NH4+-N/NO3--N) ratios to design a hybrid aerobic membrane bioreactor (MBR) and membrane photobioreactor (MPBR) system. Specific oxygen production by C. vulgaris was enough to support the MBR if high growth is accomplished. Nearly 100% removal (or utilization) of PO43--P and IC was achieved under all conditions tested. Optimal growth was achieved at mixotrophic carbon conditions (0.353 d-1) and the highest NH4+-N concentration (0.357 d-1), with preferable NH4+-N utilization rather than NO3--N. The results indicate the potential of alternative process designs to treat domestic wastewater by coupling the hybrid MBR - MPBR systems.

  9. Nutrient utilization and oxygen production by Chlorella Vulgaris in a hybrid membrane bioreactor and algal membrane photobioreactor system

    KAUST Repository

    Najm, Yasmeen Hani Kamal; Jeong, Sanghyun; Leiknes, TorOve

    2017-01-01

    This work studied oxygen production and nutrient utilization by Chlorella Vulgaris at different organic/inorganic carbon (OC/IC) and ammonium/nitrate (NH4+-N/NO3--N) ratios to design a hybrid aerobic membrane bioreactor (MBR) and membrane photobioreactor (MPBR) system. Specific oxygen production by C. vulgaris was enough to support the MBR if high growth is accomplished. Nearly 100% removal (or utilization) of PO43--P and IC was achieved under all conditions tested. Optimal growth was achieved at mixotrophic carbon conditions (0.353 d-1) and the highest NH4+-N concentration (0.357 d-1), with preferable NH4+-N utilization rather than NO3--N. The results indicate the potential of alternative process designs to treat domestic wastewater by coupling the hybrid MBR - MPBR systems.

  10. Experimental performance of indirect air–liquid membrane contactors for liquid desiccant cooling systems

    International Nuclear Information System (INIS)

    Das, Rajat Subhra; Jain, Sanjeev

    2013-01-01

    Owing to the stringent indoor air quality (IAQ) requirements and high cost of desiccants, one of the major concerns in liquid desiccant technology has been the carryover, which can be eliminated through indirect contact between desiccant and air. Membrane contactors using microporous semipermeable hydrophobic membranes have a great potential in this regard. This communication investigates the performance of semipermeable membrane based indirect contactors as dehumidifiers in liquid desiccant cooling applications. Experiments on different types of membrane contactors are carried out using lithium chloride (LiCl) solution as desiccant. The membrane contactors consist of alternate channels of air and liquid desiccant flowing in cross-flow direction. Hydrophobic membranes form a liquid tight, vapor permeable porous barrier between hygroscopic solution and moist air, thus eliminating carryover of desiccant droplets. In order to provide maximum contact area for air–desiccant interaction, a wicking material is sandwiched between two membranes in the liquid channel. It is observed that vapor flux upto 1300 g/m 2 h can be achieved in a membrane contactor with polypropylene (PP) membranes, although the dehumidification effectiveness remains low. The effect of key parameters on the transmembrane vapor transport is presented in the paper. - Highlights: • Indirect membrane contactors developed to avoid carryover in liquid desiccant system. • Dehumidification effectiveness and vapor flux reported under varying conditions. • Vapor flux upto 1295 g/m 2 h in polypropylene contactor with high area density. • Dehumidification effectiveness with LiCl solution varies within 23% to 45%

  11. Spatial heterogeneity of biofouling under different cross-flow velocities in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia

    2016-09-06

    The spatially heterogeneous distribution of biofouling in spiral wound membrane systems restricts (i) the water distribution over the membrane surface and therefore (ii) the membrane-based water treatment. The objective of the study was to assess the spatial heterogeneity of biofilm development over the membrane fouling simulator (MFS) length (inlet and outlet part) at three different cross-flow velocities (0.08, 0.12 and 0.16 m/s). The MFS contained sheets of membrane and feed spacer and simulated the first 0.20 m of spiral-wound membrane modules where biofouling accumulates the most in practice. In-situ non-destructive oxygen imaging using planar optodes was applied to determine the biofilm spatially resolved activity and heterogeneity.

  12. Modeling and parametric analysis of hollow fiber membrane system for carbon capture from multicomponent flue gas

    KAUST Repository

    Khalilpour, Rajab

    2011-08-12

    The modeling and optimal design/operation of gas membranes for postcombustion carbon capture (PCC) is presented. A systematic methodology is presented for analysis of membrane systems considering multicomponent flue gas with CO 2 as target component. Simplifying assumptions is avoided by namely multicomponent flue gas represented by CO 2/N 2 binary mixture or considering the co/countercurrent flow pattern of hollow-fiber membrane system as mixed flow. Optimal regions of flue gas pressures and membrane area were found within which a technoeconomical process system design could be carried out. High selectivity was found to not necessarily have notable impact on PCC membrane performance, rather, a medium selectivity combined with medium or high permeance could be more advantageous. © 2011 American Institute of Chemical Engineers (AIChE).

  13. Review on strategies for biofouling mitigation in spiral wound membrane systems

    KAUST Repository

    Bucs, Szilard; Farhat, Nadia; Kruithof, Joop C.; Picioreanu, Cristian; van Loosdrecht, Mark C.M.; Vrouwenvelder, Johannes S.

    2018-01-01

    . However, in many cases membrane performance is restricted by biofouling. The objective of this review is to provide an overview on the state of the art strategies to control biofouling in spiral wound reverse osmosis membrane systems and point to possible

  14. Estimation of Membrane Hydration Status for Standby Proton Exchange Membrane Fuel Cell Systems by Impedance Measurement: First Results on Variable Temperature Stack Characterization

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Kær, Søren Knudsen

    2013-01-01

    Fuel cells are getting growing interest in both backup systems and electric vehicles. Although these systems are characterized by periods of standby, they must be able to start at any instant in the shortest possible time. However, the membranes of which proton exchange membrane fuel cells are made...

  15. Modeling of Hollow-Fiber Membrane System During Ultrafiltration

    International Nuclear Information System (INIS)

    EI-Bialy, S.H.

    2004-01-01

    The present study aims to evaluate the performance of hollow fiber membrane module during ultrafiltration of aqueous solutions. The model is represented by a set of differential equations for permeate and residue pressure drop and volumetric flow rates in the axial direction, beside the principle equations of both solvent and solute fluxes through the membrane, while osmotic pressure was neglected in model equations. The shell and tube module type was considered where feed pass in the shell and permeate in the bore side. Tortousily factor of membrane pores in addition to concentration polarization modulus were taken into account in calculations. The model was solved numerically with the help of suitable program in both co current and countercurrent flow pattern and comparison of results were carried out

  16. NMR spectroscopic studies of membrane-bound biological systems

    International Nuclear Information System (INIS)

    Hohlweg, W.

    2013-01-01

    In the course of this thesis, biological NMR spectroscopy was employed in studying membrane-bound peptides and proteins, for which structural information is still comparatively hard to obtain. Initial work focused on various model peptides bound to membrane-mimicking micelles, studying the protonation state of arginine in a membrane environment. Strong evidence for a cation-π complex was found in TM7, a peptide which forms the seventh transmembrane helix of subunit a of the vacuolar-type H+-ATPase (V-ATPase). V-ATPase is a physiologically highly relevant proton pump, which is present in intracellular membranes of all eukaryotic organisms, as well as the plasma membrane of several specialized cells. Loss of functional V-ATPase is associated with human diseases such as osteopetrosis, distal renal tubular acidosis or the spreading of cancer. V-ATPase is considered a potential drug target in the treatment of osteoporosis and cancer, or in the development of novel contraceptives. Results from NMR solution structure determination, NMR titration experiments, paramagnetic relaxation enhancement experiments and tryptophan fluorescence spectroscopy confirm the existence of a buried cation-? complex formed between arginine residue R735, which is essential for proton transport, and neighbouring tryptophan and tyrosine residues. In vivo experiments in the yeast Saccharomyces cerevisiae using selective growth tests and fluorescence microscopy showed that formation of the cation-π complex is essential for V-ATPase function. Deletion of both aromatic residues, as well as only the one tryptophan residue leads to growth defects and inability to maintain vacuolar pH homeostasis. These findings shine new light on the still elusive mechanism of proton transport in V-ATPase, and show that arginine R735 may be directly involved in proton transfer across the membrane. (author) [de

  17. Extracorporeal Circulation Using an Extracorporeal Membrane Oxygenation System and an Autotransfusion System

    Directory of Open Access Journals (Sweden)

    Yu. A. Bakhareva

    2010-01-01

    Full Text Available The authors draw attention to the fact that complete cardiopulmonary bypass can be made in the emergency situation in order to perform an extracorporeal membrane oxygenation (ECMO procedure in a 5-year-old boy weighing 15 kg, diagnosed as having Fallot tetrad. By taking into account the technological features of the system for ECMO, there is an additional need for a blood cell separator to be applied.

  18. Ion transport membrane reactor systems and methods for producing synthesis gas

    Science.gov (United States)

    Repasky, John Michael

    2015-05-12

    Embodiments of the present invention provide cost-effective systems and methods for producing a synthesis gas product using a steam reformer system and an ion transport membrane (ITM) reactor having multiple stages, without requiring inter-stage reactant injections. Embodiments of the present invention also provide techniques for compensating for membrane performance degradation and other changes in system operating conditions that negatively affect synthesis gas production.

  19. [Effect of solution environments on ceramic membrane microfiltration of model system of Chinese medicines].

    Science.gov (United States)

    Zhang, Lianjun; Lu, Jin; Le, Kang; Fu, Tingming; Guo, Liwei

    2010-07-01

    To investigate the effect of differents solution environments on the ceramic membrane microfiltration of model system of Chinese medicines. Taking binary system of soybean protein-berberine as the research object, flux, transmittance of berberine and traping rate of protein as indexes, different solution environment on membrane process were investigated. When the concentration of soybean protein was under 1 g x L(-1), the membrane flux was minimum with the traping of berberine decreased slightly as the concentration increased. When pH was 4, the flux was maximum with the traping rate of protein was 99%, and the transmittance of berberine reached above 60%. The efficiency of membrane separation can be improved by optimizing the solution environment of water-extraction of chinese medicines. The efficiency of membrane separation is the best when adjust the pH to the isoelectric point of proteins for the proteins as the main pollutant in aqueous solution.

  20. Research on mass transfer and actual performance of the membrane regeneration air-conditioning system

    International Nuclear Information System (INIS)

    Li, Xiu-Wei; Zhang, Xiao-Song; Chen, Qing

    2015-01-01

    Highlights: • Experimental research has been made on the membrane air-conditioning system. • We develop mass transfer models for the membrane regeneration process. • The paper exposes the actual performance of the system. • Increase of membrane pairs improves the performance. - Abstract: Absorption air-conditioning system has great advantages in energy conservation and environmental protection. To improve the performance of the traditional system, the membrane regeneration absorption system was proposed. Its COP could approach 6 by regenerating absorbent solution with the ion exchange membranes. However, the theoretical conclusion has not been supported by the experiment. This paper presents the experimental research of the membrane regeneration process. It has investigated the mass transfer process, energy efficiency and actual performance under different working conditions. Based on that, a mass transfer model has been developed and the influences of some key parameters have been exposed. It found the regeneration performance is mainly influenced by the current intensity. The calculation results with the model agree well the experimental data. The actual efficiency was lower than 50%, caused by energy loss in heat and electrochemical reactions. The actual COP is between 1 and 3, lower current intensity and more membrane pairs could improve it.

  1. Design and simulation of the surface shape control system for membrane mirror

    Science.gov (United States)

    Zhang, Gengsheng; Tang, Minxue

    2009-11-01

    The surface shape control is one of the key technologies for the manufacture of membrane mirror. This paper presents a design of membrane mirror's surface shape control system on the basis of fuzzy logic control. The system contains such function modules as surface shape design, surface shape control, surface shape analysis, and etc. The system functions are realized by using hybrid programming technology of Visual C# and MATLAB. The finite element method is adopted to simulate the surface shape control of membrane mirror. The finite element analysis model is established through ANSYS Parametric Design Language (APDL). ANSYS software kernel is called by the system in background running mode when doing the simulation. The controller is designed by means of controlling the sag of the mirror's central crosssection. The surface shape of the membrane mirror and its optical aberration are obtained by applying Zernike polynomial fitting. The analysis of surface shape control and the simulation of disturbance response are performed for a membrane mirror with 300mm aperture and F/2.7. The result of the simulation shows that by using the designed control system, the RMS wavefront error of the mirror can reach to 142λ (λ=632.8nm), which is consistent to the surface accuracy of the membrane mirror obtained by the large deformation theory of membrane under the same condition.

  2. A conceptual design of catalytic gasification fuel cell hybrid power plant with oxygen transfer membrane

    Science.gov (United States)

    Shi, Wangying; Han, Minfang

    2017-09-01

    A hybrid power generation system integrating catalytic gasification, solid oxide fuel cell (SOFC), oxygen transfer membrane (OTM) and gas turbine (GT) is established and system energy analysis is performed. In this work, the catalytic gasifier uses steam, recycled anode off-gas and pure oxygen from OTM system to gasify coal, and heated by hot cathode off-gas at the same time. A zero-dimension SOFC model is applied and verified by fitting experimental data. Thermodynamic analysis is performed to investigate the integrated system performance, and system sensitivities on anode off-gas back flow ratio, SOFC fuel utilization, temperature and pressure are discussed. Main conclusions are as follows: (1) System overall electricity efficiency reaches 60.7%(HHV) while the gasifier operates at 700 °C and SOFC at 850 °C with system pressure at 3.04 bar; (2) oxygen enriched combustion simplify the carbon-dioxide capture process, which derives CO2 of 99.2% purity, but results in a penalty of 6.7% on system electricity efficiency; (3) with SOFC fuel utilization or temperature increasing, the power output of SOFC increases while GT power output decreases, and increasing system pressure can improve both the performance of SOFC and GT.

  3. Models of natural computation : gene assembly and membrane systems

    NARCIS (Netherlands)

    Brijder, Robert

    2008-01-01

    This thesis is concerned with two research areas in natural computing: the computational nature of gene assembly and membrane computing. Gene assembly is a process occurring in unicellular organisms called ciliates. During this process genes are transformed through cut-and-paste operations. We

  4. Membrane formation : diffusion induced demixing processes in ternary polymeric systems

    NARCIS (Netherlands)

    Reuvers, Albertus Johannes

    1987-01-01

    In this thesis the mechanism of membrane formation by means of immersion precipitation is studied. Immersion of a concentrated polymer solution film into a nonsolvent bath induces an exchange of solvent and nonsolvent in the film by means of diffusion. This process results in an asymmetric polymer

  5. Scaling and particulate fouling in membrane filtration systems

    NARCIS (Netherlands)

    Boerlage, S.F.E.

    2001-01-01

    In the last decade, pressure driven membrane filtration processes; reverse osmosis, nano, ultra and micro-filtration have undergone steady growth. Drivers for this growth include desalination to combat water scarcity and the removal of various material from water to comply with increasingly

  6. Thermal Behavior and Hydrogen Production of Methanol Autothermal Reforming Performed Using Oxygen Enrichment and Cu/ZnO/Al2O3/Cr2O3/CeO2 Catalyst

    Directory of Open Access Journals (Sweden)

    Donny Lesmana

    2015-07-01

    Full Text Available A fixed-bed reactor designed for the autothermal reforming (ATR of methanol under adiabatic conditions was constructed to experimentally determine the profile of temperature and catalyst activity generated using the Cu/ZnO/Al2O3/Cr2O3/CeO2 catalyst. The effect of oxygen enrichment in this experiment was investigated, and the experimental results showed that an increase in oxygen concentration correlated with an increase in the temperature of the catalytic bed; by contrast, this increase in oxygen concentration resulted in a reduction of the startup time of the catalyst. Moreover, the reaction temperature was determined to vary with the position within the catalytic fixed bed. © 2015 BCREC UNDIP. All rights reservedReceived: 29th August 2014; Revised: 19th March 2015; Accepted: 19th March 2015

  7. Colorimetric test-systems for creatinine detection based on composite molecularly imprinted polymer membranes.

    Science.gov (United States)

    Sergeyeva, T A; Gorbach, L A; Piletska, E V; Piletsky, S A; Brovko, O O; Honcharova, L A; Lutsyk, O D; Sergeeva, L M; Zinchenko, O A; El'skaya, A V

    2013-04-03

    An easy-to-use colorimetric test-system for the efficient detection of creatinine in aqueous samples was developed. The test-system is based on composite molecularly imprinted polymer (MIP) membranes with artificial receptor sites capable of creatinine recognition. A thin MIP layer was created on the surface of microfiltration polyvinylidene fluoride (PVDF) membranes using method of photo-initiated grafting polymerization. The MIP layer was obtained by co-polymerization of a functional monomer (e.g. 2-acrylamido-2-methyl-1-propanesulfonic acid, itaconic acid or methacrylic acid) with N, N'-methylenebisacrylamide as a cross-linker. The choice of the functional monomer was based on the results of computational modeling. The creatinine-selective composite MIP membranes were used for measuring creatinine in aqueous samples. Creatinine molecules were selectively adsorbed by the MIP membranes and quantified using color reaction with picrates. The intensity of MIP membranes staining was proportional to creatinine concentration in an analyzed sample. The colorimetric test-system based on the composite MIP membranes was characterized with 0.25 mM detection limit and 0.25-2.5mM linear dynamic range. Storage stability of the MIP membranes was estimated as at least 1 year at room temperature. As compared to the traditional methods of creatinine detection the developed test-system is characterized by simplicity of operation, small size and low cost. Copyright © 2013 Elsevier B.V. All rights reserved.

  8. Membrane morphology and topology for fouling control in Reverse Osmosis filtration systems

    Science.gov (United States)

    Ling, Bowen; Battiato, Ilenia

    2017-11-01

    Reverse Osmosis Membrane (ROM) filtration systems are widely utilized in waste-water recovery, seawater desalination, landfill water treatment, etc. During filtration, the system performance is dramatically affected by membrane fouling which causes a significant decrease in permeate flux as well as an increase in the energy input required to operate the system. Design and optimization of ROM filtration systems aim at reducing membrane fouling by studying the coupling between membrane structure, local flow field and foulant adsorption patterns. Yet, current studies focus exclusively on oversimplified steady-state models that ignore any dynamic coupling between fluid flow and transport through the membrane. In this work, we develop a customized solver (SUMembraneFoam) under OpenFOAM to solve the transient equations. The simulation results not only predict macroscopic quantities (e.g. permeate flux, pressure drop, etc.) but also show an excellent agreement with the fouling patterns observed in experiments. It is observed that foulant deposition is strongly controlled by the local shear stress on the membrane, and channel morphology or membrane topology can be modified to control the shear stress distribution and reduce fouling. Finally, we identify optimal regimes for design.

  9. Interactions of sugar-based bolaamphiphiles with biomimetic systems of plasma membranes.

    Science.gov (United States)

    Nasir, Mehmet Nail; Crowet, Jean-Marc; Lins, Laurence; Obounou Akong, Firmin; Haudrechy, Arnaud; Bouquillon, Sandrine; Deleu, Magali

    2016-11-01

    Glycolipids constitute a class of molecules with various biological activities. Among them, sugar-based bolaamphiphiles characterized by their biocompatibility, biodegradability and lower toxicity, became interesting for the development of efficient and low cost lipid-based drug delivery systems. Their activity seems to be closely related to their interactions with the lipid components of the plasma membrane of target cells. Despite many works devoted to the chemical synthesis and characterization of sugar-based bolaamphiphiles, their interactions with plasma membrane have not been completely elucidated. In this work, two sugar-based bolaamphiphiles differing only at the level of their sugar residues were chemically synthetized. Their interactions with membranes have been investigated using model membranes containing or not sterol and with in silico approaches. Our findings indicate that the nature of sugar residues has no significant influence for their membrane interacting properties, while the presence of sterol attenuates the interactions of both bolaamphiphiles with the membrane systems. The understanding of this distinct behavior of bolaamphiphiles towards sterol-containing membrane systems could be useful for their applications as drug delivery systems. Copyright © 2016. Published by Elsevier B.V.

  10. Quantitative measurement and visualization of biofilm O 2 consumption rates in membrane filtration systems

    KAUST Repository

    Prest, Emmanuelle I E C; Staal, Marc J.; Kü hl, Michael; van Loosdrecht, Mark C.M.; Vrouwenvelder, Johannes S.

    2012-01-01

    There is a strong need for techniques enabling direct assessment of biological activity of biofouling in membrane filtration systems. Here we present a new quantitative and non-destructive method for mapping O 2 dynamics in biofilms during

  11. Biofouling investigation in membrane filtration systems using Optical Coherence Tomography (OCT)

    KAUST Repository

    Fortunato, Luca

    2017-10-01

    Biofouling represents the main problem in membrane filtration systems. Biofouling arises when the biomass growth negatively impacts the membrane performance parameters (i.e. flux decrease and feed channel pressure drop). Most of the available techniques for characterization of biofouling involve membrane autopsies, providing information ex-situ destructively at the end of the process. OCT, is non-invasive imaging technique, able to acquire scans in-situ and non-destructively. The objective of this study was to evaluate the suitability of OCT as in-situ and non-destructive tool to gain a better understanding of biofouling behavior in membrane filtration systems. The OCT was employed to study the fouling behavior in two different membrane configurations: (i) submerged flat sheet membrane and (ii) spacer filled channel. Through the on-line acquisition of OCT scans and the study of the biomass morphology, it was possible to relate the impact of the fouling on the membrane performance. The on-line monitoring of biofilm formation on a flat sheet membrane was conducted in a gravity-driven submerged membrane bioreactor (SMBR) for 43 d. Four different phases were observed linking the variations in permeate flux with changes in biofilm morphology. Furthermore, the biofilm morphology was used in computational fluid dynamics (CFD) simulation to better understand the role of biofilm structure on the filtration mechanisms. The time-resolved OCT analysis was employed to study the biofouling development at the early stage. Membrane coverage and average biofouling layer thickness were found to be linearly correlated with the permeate flux pattern. An integrated characterization methodology was employed to characterize the fouling on a flat sheet membrane, involving the use of OCT as first step followed by membrane autopsies, revealing the presence of a homogeneous layer on the surface. In a spacer filled channel a 3D OCT time series analysis of biomass development under

  12. Transient response simulation of gas separation membrane module for an atmosphere detritiation system

    International Nuclear Information System (INIS)

    Sugiyama, Takahiko; Tanaka, Masahiro; Munakata, Kenzo; Yamamoto, Ichiro

    2012-01-01

    Transient response of a gas separation membrane module for the atmosphere detritiation system was numerically simulated with a mass transfer model. The module contains thousands of hollow fiber type polyimide membranes. The simulation model took into account permeation of water vapor through the dense layer of the membrane, diffusive transfer through the porous support layer and adsorption/desorption of water vapor into the matrix of the porous layer. The slow responses of the water vapor concentration in the retentate and the permeation rate were well reproduced by the present simulation, and transient changes in a follow fiber membrane were investigated in detail. The inventory and the mean residence time of water vapor at 303 K were estimated for the commercial membrane module (UMS-B2, Ube industries, Ltd.) as 5.7 × 10 −3 mol and 380 s, respectively.

  13. Protein secretion and membrane insertion systems in gram-negative bacteria.

    Science.gov (United States)

    Saier, Milton H

    2006-01-01

    In contrast to other organisms, gram-negative bacteria have evolved numerous systems for protein export. Eight types are known that mediate export across or insertion into the cytoplasmic membrane, while eight specifically mediate export across or insertion into the outer membrane. Three of the former secretory pathway (SP) systems, type I SP (ISP, ABC), IIISP (Fla/Path) and IVSP (Conj/Vir), can export proteins across both membranes in a single energy-coupled step. A fourth generalized mechanism for exporting proteins across the two-membrane envelope in two distinct steps (which we here refer to as type II secretory pathways [IISP]) utilizes either the general secretory pathway (GSP or Sec) or the twin-arginine targeting translocase for translocation across the inner membrane, and either the main terminal branch or one of several protein-specific export systems for translocation across the outer membrane. We here survey the various well-characterized protein translocation systems found in living organisms and then focus on the systems present in gram-negative bacteria. Comparisons between these systems suggest specific biogenic, mechanistic and evolutionary similarities as well as major differences.

  14. Mini-review: novel non-destructivein situbiofilm characterization techniques in membrane systems

    KAUST Repository

    Valladares Linares, Rodrigo; Fortunato, Luca; Farhat, Nadia; Bucs, Szilard; Staal, M.; Fridjonsson, E.O.; Johns, M.L.; Vrouwenvelder, Johannes S.; Leiknes, TorOve

    2016-01-01

    Membrane systems are commonly used in the water industry to produce potable water and for advanced wastewater treatment. One of the major drawbacks of membrane systems is biofilm formation (biofouling), which results in an unacceptable decline in membrane performance. Three novel in situ biofouling characterization techniques were assessed: (i) optical coherence tomography (OCT), (ii) planar optodes, and (iii) nuclear magnetic resonance (NMR). The first two techniques were assessed using a biofilm grown on the surface of nanofiltration (NF) membranes using a transparent membrane fouling simulator that accurately simulates spiral wound modules, modified for in situ biofilm imaging. For the NMR study, a spiral wound reverse osmosis membrane module was used. Results show that these techniques can provide information to reconstruct the biofilm accurately, either with 2-D (OCT, planar optodes and NMR), or 3-D (OCT and NMR) scans. These non-destructive tools can elucidate the interaction of hydrodynamics and mass transport on biofilm accumulation in membrane systems. Oxygen distribution in the biofilm can be mapped and linked to water flow and substrate characteristics; insights on the effect of crossflow velocity, flow stagnation, and feed spacer presence can be obtained, and in situ information on biofilm structure, thickness, and spatial distribution can be quantitatively assessed. The combination of these novel non-destructive in situ biofilm characterization techniques can provide real-time observation of biofilm formation at the mesoscale. The information obtained with these tools could potentially be used for further improvement in the design of membrane systems and operational parameters to reduce impact of biofouling on membrane performance. © 2016 Balaban Desalination Publications. All rights reserved.

  15. Mini-review: novel non-destructivein situbiofilm characterization techniques in membrane systems

    KAUST Repository

    Valladares Linares, R.

    2016-05-12

    Membrane systems are commonly used in the water industry to produce potable water and for advanced wastewater treatment. One of the major drawbacks of membrane systems is biofilm formation (biofouling), which results in an unacceptable decline in membrane performance. Three novel in situ biofouling characterization techniques were assessed: (i) optical coherence tomography (OCT), (ii) planar optodes, and (iii) nuclear magnetic resonance (NMR). The first two techniques were assessed using a biofilm grown on the surface of nanofiltration (NF) membranes using a transparent membrane fouling simulator that accurately simulates spiral wound modules, modified for in situ biofilm imaging. For the NMR study, a spiral wound reverse osmosis membrane module was used. Results show that these techniques can provide information to reconstruct the biofilm accurately, either with 2-D (OCT, planar optodes and NMR), or 3-D (OCT and NMR) scans. These non-destructive tools can elucidate the interaction of hydrodynamics and mass transport on biofilm accumulation in membrane systems. Oxygen distribution in the biofilm can be mapped and linked to water flow and substrate characteristics; insights on the effect of crossflow velocity, flow stagnation, and feed spacer presence can be obtained, and in situ information on biofilm structure, thickness, and spatial distribution can be quantitatively assessed. The combination of these novel non-destructive in situ biofilm characterization techniques can provide real-time observation of biofilm formation at the mesoscale. The information obtained with these tools could potentially be used for further improvement in the design of membrane systems and operational parameters to reduce impact of biofouling on membrane performance. © 2016 Balaban Desalination Publications. All rights reserved.

  16. Evaluation of mechanical and morphologic features of PLLA membranes as supports for perfusion cells culture systems

    Energy Technology Data Exchange (ETDEWEB)

    Montesanto, S., E-mail: salvatore.montesanto1985@gmail.com [Department of Civil, Environmental, Aerospace, Materials Engineering (DICAM), University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo (Italy); Brucato, V. [Department of Civil, Environmental, Aerospace, Materials Engineering (DICAM), University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo (Italy); La Carrubba, V. [Department of Civil, Environmental, Aerospace, Materials Engineering (DICAM), University of Palermo, Viale delle Scienze Ed. 8, 90128 Palermo (Italy); Euro-Mediterranean Institute of Science and Technology (IEMEST), Via Michele Miraglia, 20, 90128 Palermo (Italy)

    2016-12-01

    Porous biodegradable PLLA membranes, which can be used as supports for perfusion cell culture systems were designed, developed and characterized. PLLA membranes were prepared via diffusion induced phase separation (DIPS). A glass slab was coated with a binary PLLA–dioxane solution (8 wt.% PLLA) via dip coating, then pool immersed in two subsequent coagulation baths, and finally dried in a humidity-controlled environment. Surface and mechanical properties were evaluated by measuring pore size, porosity via scanning electron microscopy, storage modulus, loss modulus and loss angle by using a dynamic mechanical analysis (DMA). Cell adhesion assays on different membrane surfaces were also performed by using a standard count method. Results provide new insights into the foaming methods for producing polymeric membranes and supply indications on how to optimise the fabrication parameters to design membranes for tissue cultures and regeneration. - Highlights: • Design, development and characterization of porous biodegradable PLLA membranes via DIPS technology. • Easy-to-tune processing parameters in terms of surface and volumetric properties and cell adhesion. • Evaluation of the impact of the interconnection degree on membrane's mechanical properties. • Evaluation of cell adhesion on different membrane surface textures.

  17. Evaluation of mechanical and morphologic features of PLLA membranes as supports for perfusion cells culture systems

    International Nuclear Information System (INIS)

    Montesanto, S.; Brucato, V.; La Carrubba, V.

    2016-01-01

    Porous biodegradable PLLA membranes, which can be used as supports for perfusion cell culture systems were designed, developed and characterized. PLLA membranes were prepared via diffusion induced phase separation (DIPS). A glass slab was coated with a binary PLLA–dioxane solution (8 wt.% PLLA) via dip coating, then pool immersed in two subsequent coagulation baths, and finally dried in a humidity-controlled environment. Surface and mechanical properties were evaluated by measuring pore size, porosity via scanning electron microscopy, storage modulus, loss modulus and loss angle by using a dynamic mechanical analysis (DMA). Cell adhesion assays on different membrane surfaces were also performed by using a standard count method. Results provide new insights into the foaming methods for producing polymeric membranes and supply indications on how to optimise the fabrication parameters to design membranes for tissue cultures and regeneration. - Highlights: • Design, development and characterization of porous biodegradable PLLA membranes via DIPS technology. • Easy-to-tune processing parameters in terms of surface and volumetric properties and cell adhesion. • Evaluation of the impact of the interconnection degree on membrane's mechanical properties. • Evaluation of cell adhesion on different membrane surface textures.

  18. Design of a tubular ceramic membrane for gas separation in a PEMFC system

    Energy Technology Data Exchange (ETDEWEB)

    Kamarudin, S.K.; Daud, W.R.W.; Mohammad, A.W.; Som, A.Md.; Takriff, M.S. [Department of Chemical and Process Engineering, National University of Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2004-01-01

    The objective of this study is to introduce a shortcut in the method of design for a tubular ceramic membrane (TCM) for gas separation. Generally, it explains the permeation of the multi component gas using cross flow models in a porous membrane and the surface area of the membrane required. The novel aspect of this method is that the expression for the length of the membrane is simplified to a number unit (NTU) and a height of transfer unit (HTU). The HTU term for porous membranes is characterised by the physical properties of the membrane; the feed flow rate, n{sub F}, membrane thickness, l{sub M}, feed pressure, P{sub F}, K the permeability of gas and the diameter of the membrane, D{sub M}. The integral for NTU of a porous membrane is the solution for the local permeate along the length of the membrane. It is found that, NTU mainly depends on the rejection stream, x{sub R,}, along the membrane and it describes the relative degree of separation. The Proton Electrolyte Membrane Fuel Cell (PEMFC) system is taken as the case study. CO is the main culprit in reducing the performance of the PEMFC and will act as a catalyst poison for the fuel cell anode at a concentration as low as 100 ppm. Thus, the reformate, from primary reforming, contains a significant amount of CO and must be purified. The effect of some important parameters such as temperature, pressure and the thickness of membrane to the degree of separation are presented in this paper. From the results, it can be seen that the system could reduce the CO concentration from 2000 - 500 ppm. Basically the TCM will operate, in series, with a pressure swing adsorber in order to further reduce the concentration of CO to less than 10 ppm before entering the fuel cell stack. However, this paper only focuses on the design of the TCM. Besides this, it is observed that the purity of the hydrogen increased from 72.8 - 96% (at {theta} = 0.5) after the membrane. (Abstract Copyright [2003], Wiley Periodicals, Inc.)

  19. Design study of fuel circulating system using Pd-alloy membrane isotope separation method

    International Nuclear Information System (INIS)

    Naito, T.; Yamada, T.; Yamanaka, T.; Aizawa, T.; Kasahara, T.; Nishikawa, M.; Asami, N.

    1980-01-01

    Design study on the fuel circulating system (FCS) for a tokamak experimental fusion reactor (JXFR) has been carried out to establish the system concept, to plan the development program, and to evaluate the feasibility of diffusion system. The FCS consists of main vacuum system, fuel gas refiners, isotope separators, fuel feeders, and auxiliary systems. In the system design, Pd-alloy membrane permeation method is adopted for fuel refining and isotope separating. All impurities are effectively removed and hydrogen isotopes are sufficiently separated by Pd-alloy membrane. The isotope separation system consists of 1st (47 separators) and 2nd (46 separators) cascades for removing protium and separating deuterium, respectively. In the FCS, while cryogenic distillation method appears to be practicable, Pd-alloy membrane diffusion method is attractive for isotope separation and refining of fuel gas. The choice will have to be based on reliability, economic, and safety analyses

  20. Estimation of membrane hydration status for active proton exchange membrane fuel cell systems by impedance measurement

    DEFF Research Database (Denmark)

    Török, Lajos; Sahlin, Simon Lennart; Kær, Søren Knudsen

    2016-01-01

    Fuel cells are getting growing interest in industrial areas like backup systems for telecom applications or power source for electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However, the memb......Fuel cells are getting growing interest in industrial areas like backup systems for telecom applications or power source for electric vehicles. Although these systems are characterized by long periods of inactivity, they must be able to start at any instant in the shortest time. However...

  1. Optimization Study of Small-Scale Solar Membrane Distillation Desalination Systems (s-SMDDS

    Directory of Open Access Journals (Sweden)

    Hsuan Chang

    2014-11-01

    Full Text Available Membrane distillation (MD, which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS is a potential technology for resolving energy and water resource problems. Small-scale SMDDS (s-SMDDS is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo-steady-state approach for equipment sizing and dynamic optimization using overall system mathematical models. Two s-SMDDS employing an air gap membrane distillation module with membrane areas of 11.5 m2 and 23 m2 are analyzed. The lowest water production costs are $5.92/m3 and $5.16/m3 for water production rates of 500 kg/day and 1000 kg/day, respectively. For these two optimal cases, the performance ratios are 0.85 and 0.91; the recovery ratios are 4.07% and 4.57%. The effect of membrane characteristics on the production cost is investigated. For the commercial membrane employed in this study, the increase of the membrane mass transfer coefficient up to two times is beneficial for cost reduction.

  2. Dermal-epidermal membrane systems by using human keratinocytes and mesenchymal stem cells isolated from dermis

    Energy Technology Data Exchange (ETDEWEB)

    Salerno, Simona, E-mail: s.salerno@itm.cnr.it [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy); Messina, Antonietta [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy); Giordano, Francesca [Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, I-87036 Rende, (CS) (Italy); Bader, Augustinus [Biomedical-Biotechnological Center, BBZ, University of Leipzig, D-04103 Leipzig (Germany); Drioli, Enrico [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy); WCU Energy Engineering Department, Hanyang University, Seoul (Korea, Republic of); De Bartolo, Loredana, E-mail: l.debartolo@itm.cnr.it [Institute on Membrane Technology, National Research Council of Italy, ITM-CNR, c/o University of Calabria, via P. Bucci cubo 17/C, I-87036, Rende (CS) (Italy)

    2017-02-01

    Dermal-epidermal membrane systems were developed by co-culturing human keratinocytes with Skin derived Stem Cells (SSCs), which are Mesenchymal Stem Cells (MSCs) isolated from dermis, on biodegradable membranes of chitosan (CHT), polycaprolactone (PCL) and a polymeric blend of CHT and PCL. The membranes display physico-chemical, morphological, mechanical and biodegradation properties that could satisfy and fulfil specific requirements in skin tissue engineering. CHT membrane exhibits an optimal biodegradation rate for acute wounds; CHT-PCL for the chronic ones. On the other hand, PCL membrane in spite of its very slow biodegradation rate exhibits mechanical properties similar to in vivo dermis, a lower hydrophilic character, and a surface roughness, all properties that make it able to sustain cell adhesion and proliferation for in vitro skin models. Both CHT–PCL and PCL membranes guided epidermal and dermal differentiation of SSCs as pointed out by the expression of cytokeratins and the deposition of the ECM protein fibronectin, respectively. In the dermal-epidermal membrane systems, a more suitable microenvironment for the SSCs differentiation was promoted by the interactions and the mutual interplay with keratinocytes. Being skin tissue-biased stem cells committed to their specific final dermal and/or epidermal cell differentiation, SSCs are more suitable for skin tissue engineering than other adult MSCs with different origin. For this reason, they represent a useful autologous cell source for engineering skin substitutes for both in vivo and in vitro applications.

  3. Review on strategies for biofouling mitigation in spiral wound membrane systems

    KAUST Repository

    Bucs, Szilard

    2018-02-01

    Because of the uneven distribution of fresh water in time and space, a large number of regions are experiencing water scarcity and stress. Membrane based desalination technologies have the potential to solve the fresh water crisis in coastal areas. However, in many cases membrane performance is restricted by biofouling. The objective of this review is to provide an overview on the state of the art strategies to control biofouling in spiral wound reverse osmosis membrane systems and point to possible future research directions. A critical review on biofouling control strategies such as feed water pre-treatment, membrane surface modification, feed spacer geometry optimization and hydrodynamics in spiral wound membrane systems is presented. In conclusion, biofouling cannot be avoided in the long run, and thus biofouling control strategies should focus on delaying the biofilm formation, reducing its impact on membrane performance and enhancing biofilm removal by advanced cleaning strategies. Therefore, future studies should aim on: (i) biofilm structural characterization; (ii) understanding to what extent biofilm properties affect membrane filtration performance, and (iii) developing methods to engineer biofilm properties such that biofouling would have only a low or delayed impact on the filtration process and accumulated biomass can be easily removed.

  4. Ion transport membrane module and vessel system with directed internal gas flow

    Science.gov (United States)

    Holmes, Michael Jerome; Ohrn, Theodore R.; Chen, Christopher Ming-Poh

    2010-02-09

    An ion transport membrane system comprising (a) a pressure vessel having an interior, an inlet adapted to introduce gas into the interior of the vessel, an outlet adapted to withdraw gas from the interior of the vessel, and an axis; (b) a plurality of planar ion transport membrane modules disposed in the interior of the pressure vessel and arranged in series, each membrane module comprising mixed metal oxide ceramic material and having an interior region and an exterior region; and (c) one or more gas flow control partitions disposed in the interior of the pressure vessel and adapted to change a direction of gas flow within the vessel.

  5. Development of membrane moisture separator for BWR off-gas system

    International Nuclear Information System (INIS)

    Ogata, H.; Kawamura, S.; Kumasaka, M.; Nishikubo, M.

    2001-01-01

    In BWR plant off-gas treatment systems, dehumidifiers are used to maintain noble gas adsorption efficiency in the first half of the charcoal hold-up units. From the perspective of simplifying and reducing the cost of such a dehumidification system, Japanese BWR utilities and plant fabricators have been developing a dehumidification system employing moisture separation membrane of the type already proven in fields such as medical instrumentation and precision measuring apparatus. The first part of this development involved laboratory testing to simulate the conditions found in an actual off-gas system, the results of which demonstrated satisfactory results in terms of moisture separation capability and membrane durability, and suggested favorable prospects for application in actual off-gas systems. Further, in-plant testing to verify moisture separation capability and membrane durability in the presence of actual gases is currently underway, with results so far suggesting that the system is capable of obtaining good moisture separation capability. (author)

  6. First order actions for gravitational systems, strings and membranes

    International Nuclear Information System (INIS)

    Lindstrom, U.

    1988-01-01

    The authors discuss first order actions in general and the construction of first order actions by eliminating Lagrange multipliers in particular. A number of first order actions for gravitational theories are presented. Part of the article reviews first order actions, some of them well-known and some lesser known. New examples of first order actions include Weyl-invariant actions for membranes, with and without rigidity terms, as well as for Abelian and non-Abelian Born-Infeld actions in two dimensions

  7. Cost effectiveness analysis of the SEAMIST trademark membrane system technology

    International Nuclear Information System (INIS)

    Henriksen, A.D.; Booth, S.R.

    1993-01-01

    This report describes the cost and performance characteristics of SEAMIST trademark, an innovative technology that facilitates measurements of contaminants in both vertical and horizontal vadose zone boreholes. This new technology consists of an airtight membrane linear that is pneumatically emplaced inside the borehole structure. Sampling ports with attached tubing, absorbent collectors, or various in situ measuring devices can be fabricated into the linear and used for monitoring volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), pesticides, herbicides, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, or radioactive substances. In addition, small instruments can be guided through the lined borehole and measurements taken inside at specified intervals

  8. In-situ Non-destructive Studies on Biofouling Processes in Reverse Osmosis Membrane Systems

    KAUST Repository

    Farhat, Nadia

    2016-12-01

    Reverse osmosis (RO) and nanofiltration (NF) membrane systems are high-pressure membrane filtration processes that can produce high quality drinking water. Biofouling, biofilm formation that exceeds a certain threshold, is a major problem in spiral wound RO and NF membrane systems resulting in a decline in membrane performance, produced water quality, and quantity. In practice, detection of biofouling is typically done indirectly through measurements of performance decline. Existing direct biofouling detection methods are mainly destructive, such as membrane autopsies, where biofilm samples can be contaminated, damaged and resulting in biofilm structural changes. The objective of this study was to test whether transparent luminescent planar oxygen sensing optodes, in combination with a simple imaging system, can be used for in-situ, non-destructive biofouling characterization. Aspects of the study were early detection of biofouling, biofilm spatial patterning in spacer filled channels, and the effect of feed cross-flow velocity, and feed flow temperature. Oxygen sensing optode imaging was found suitable for studying biofilm processes and gave detailed spatial and quantitative biofilm development information enabling better understanding of the biofouling development process. The outcome of this study attests the importance of in-situ, non-destructive imaging in acquiring detailed knowledge on biofilm development in membrane systems contributing to the development of effective biofouling control strategies.

  9. The extraction of uranium from wet process phosphoric acid using a liquid surfactant membrane system

    International Nuclear Information System (INIS)

    Dickens, N.; Davies, G.A.

    1984-01-01

    A liquid membrane extraction process is examined for the extraction of uranium from wet process phosphoric acid. Uranium is present in the acid in concentrations up to 100 ppm which in principle makes it ideal for treatment with a membrane process. The membrane system studied is based on extraction using DEHPA-TOPO reagents which are contained within the organic phase of a water in oil emulsion. Formulations of the emulsion membrane system have been studied, the limitations of acid temperature, P 2 O 5 concentration and solid dispersed impurities in the acid have been studied in laboratory batch experiments and in a continuous pilot plant unit capable of treating 5l of concentrated acid per minute. Data from the pilot plant work has been used to develop a flowsheet for a commercial unit based on this process. (author)

  10. Spin chain from membrane and the Neumann-Rosochatius integrable system

    International Nuclear Information System (INIS)

    Bozhilov, P.

    2007-01-01

    We find membrane configurations in AdS 4 xS 7 , which correspond to the continuous limit of the SU(2) integrable spin chain, considered as a limit of the SU(3) spin chain, arising in N=4 SYM in four dimensions, dual to strings in AdS 5 xS 5 . We also discuss the relationship with the Neumann-Rosochatius integrable system at the level of Lagrangians, comparing the string and membrane cases

  11. Fluid transportation mechanisms by a coupled system of elastic membranes and magnetic fluids

    International Nuclear Information System (INIS)

    Ido, Y.; Tanaka, K.; Sugiura, Y.

    2002-01-01

    The basic properties of the fluid transportation mechanism that is produced by the coupled waves propagating along a thin elastic membrane covering a magnetic fluid layer in a shallow and long rectangular vessel are investigated. It is shown that the progressive magnetic field induced by the rectangular pulses generates sinusoidal vibration of the displacement of elastic membrane and makes the system work more efficiently than the magnetic field induced by the pulse-width-modulation method

  12. Lactococcus lactis, an alternative system for functional expression of peripheral and intrinsic Arabidopsis membrane proteins.

    Directory of Open Access Journals (Sweden)

    Annie Frelet-Barrand

    Full Text Available BACKGROUND: Despite their functional and biotechnological importance, the study of membrane proteins remains difficult due to their hydrophobicity and their low natural abundance in cells. Furthermore, into established heterologous systems, these proteins are frequently only produced at very low levels, toxic and mis- or unfolded. Lactococcus lactis, a gram-positive lactic bacterium, has been traditionally used in food fermentations. This expression system is also widely used in biotechnology for large-scale production of heterologous proteins. Various expression vectors, based either on constitutive or inducible promoters, are available for this system. While previously used to produce bacterial and eukaryotic membrane proteins, the ability of this system to produce plant membrane proteins was until now not tested. METHODOLOGY/PRINCIPAL FINDINGS: The aim of this work was to test the expression, in Lactococcus lactis, of either peripheral or intrinsic Arabidopsis membrane proteins that could not be produced, or in too low amount, using more classical heterologous expression systems. In an effort to easily transfer genes from Gateway-based Arabidopsis cDNA libraries to the L. lactis expression vector pNZ8148, we first established a cloning strategy compatible with Gateway entry vectors. Interestingly, the six tested Arabidopsis membrane proteins could be produced, in Lactococcus lactis, at levels compatible with further biochemical analyses. We then successfully developed solubilization and purification processes for three of these proteins. Finally, we questioned the functionality of a peripheral and an intrinsic membrane protein, and demonstrated that both proteins were active when produced in this system. CONCLUSIONS/SIGNIFICANCE: Altogether, these data suggest that Lactococcus lactis might be an attractive system for the efficient and functional production of difficult plant membrane proteins.

  13. Membrane systems and their use in nuclear power plants. Treatment of primary coolant

    Energy Technology Data Exchange (ETDEWEB)

    Kus, Pavel; Bartova, Sarka; Skala, Martin; Vonkova, Katerina [Research Centre Rez, Husinec-Rez (Czech Republic). Technological Circuits Innovation Dept.; Zach, Vaclav; Kopa, Roman [CEZ a.s., Temelin (Czech Republic). Nuclear Power Plant Temelin

    2016-03-15

    In nuclear power plants, drained primary coolant containing boric acid is currently treated in the system of evaporators and by ion exchangers. Replacement of the system of evaporators by membrane system (MS) will result in lower operating cost mainly due to lower operation temperature. In membrane systems the feed primary coolant is separated into two output streams: retentate and permeate. Retentate stream consists of the concentrated boric acid solution together with other components, while permeate stream consists of purified water. Results are presented achieved by testing a pilot-plant unit of reverse osmosis in nuclear power plant (NPP) Temelin.

  14. Planar ceramic membrane assembly and oxidation reactor system

    Science.gov (United States)

    Carolan, Michael Francis; Dyer, legal representative, Kathryn Beverly; Wilson, Merrill Anderson; Ohm, Ted R.; Kneidel, Kurt E.; Peterson, David; Chen, Christopher M.; Rackers, Keith Gerard; Dyer, deceased, Paul Nigel

    2007-10-09

    Planar ceramic membrane assembly comprising a dense layer of mixed-conducting multi-component metal oxide material, wherein the dense layer has a first side and a second side, a porous layer of mixed-conducting multi-component metal oxide material in contact with the first side of the dense layer, and a ceramic channeled support layer in contact with the second side of the dense layer. The planar ceramic membrane assembly can be used in a ceramic wafer assembly comprising a planar ceramic channeled support layer having a first side and a second side; a first dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the first side of the ceramic channeled support layer; a first outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the first dense layer; a second dense layer of mixed-conducting multi-component metal oxide material having an inner side and an outer side, wherein the inner side is in contact with the second side of the ceramic channeled layer; and a second outer support layer comprising porous mixed-conducting multi-component metal oxide material and having an inner side and an outer side, wherein the inner side is in contact with the outer side of the second dense layer.

  15. Water-Permeable Dialysis Membranes for Multi-Layered Micro Dialysis System

    Directory of Open Access Journals (Sweden)

    Naoya eTo

    2015-06-01

    Full Text Available This paper presents the development of water-permeable dialysis membranes that are suitable for an implantable microdialysis system that does not use dialysis fluid. We developed a microdialysis system integrating microfluidic channels and nanoporous filtering membranes made of polyethersulfone (PES, aiming at a fully implantable system that drastically improves the quality of life of patients. Simplicity of the total system is crucial for the implantable dialysis system, where the pumps and storage tanks for the dialysis fluid pose problems. Hence, we focus on hemofiltration, which does not require the dialysis fluid but water-permeable membranes. We investigated the water-permeability of the PES membrane with respect to the concentrations of the PES, the additives, and the solvents in the casting solution. Sufficiently water-permeable membranes were found through in vitro experiments using whole bovine blood. The filtrate was verified to have the concentrations of low-molecular-weight molecules, such as sodium, potassium, urea, and creatinine, while proteins, such as albumin, were successfully blocked by the membrane. We conducted in vivo experiments using rats, where the system was connected to the femoral artery and jugular vein. The filtrate was successfully collected without any leakage of blood inside the system and it did not contain albumin but low-molecular-weight molecules whose concentrations were identical to those of the blood. The rat model with renal failure showed 100% increase of creatinine in 5 h, while rats connected to the system showed only a 7.4% increase, which verified the effectiveness of the proposed microdialysis system.

  16. Fluorescent sensor systems based on nanostructured polymeric membranes for selective recognition of Aflatoxin B1.

    Science.gov (United States)

    Sergeyeva, Tetyana; Yarynka, Daria; Piletska, Elena; Lynnik, Rostyslav; Zaporozhets, Olga; Brovko, Oleksandr; Piletsky, Sergey; El'skaya, Anna

    2017-12-01

    Nanostructured polymeric membranes for selective recognition of aflatoxin B1 were synthesized in situ and used as highly sensitive recognition elements in the developed fluorescent sensor. Artificial binding sites capable of selective recognition of aflatoxin B1 were formed in the structure of the polymeric membranes using the method of molecular imprinting. A composition of molecularly imprinted polymer (MIP) membranes was optimized using the method of computational modeling. The MIP membranes were synthesized using the non-toxic close structural analogue of aflatoxin B1, ethyl-2-oxocyclopentanecarboxylate as a dummy template. The MIP membranes with the optimized composition demonstrated extremely high selectivity towards aflatoxin B1 (AFB1). Negligible binding of close structural analogues of AFB1 - aflatoxins B2 (AFB2), aflatoxin G2 (AFG2), and ochratoxin A (OTA) was demonstrated. Binding of AFB1 by the MIP membranes was investigated as a function of both type and concentration of the functional monomer in the initial monomer composition used for the membranes' synthesis, as well as sample composition. The conditions of the solid-phase extraction of the mycotoxin using the MIP membrane as a stationary phase (pH, ionic strength, buffer concentration, volume of the solution, ratio between water and organic solvent, filtration rate) were optimized. The fluorescent sensor system based on the optimized MIP membranes provided a possibility of AFB1 detection within the range 14-500ngmL -1 demonstrating detection limit (3Ϭ) of 14ngmL -1 . The developed technique was successfully applied for the analysis of model solutions and waste waters from bread-making plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Converting differential-equation models of biological systems to membrane computing.

    Science.gov (United States)

    Muniyandi, Ravie Chandren; Zin, Abdullah Mohd; Sanders, J W

    2013-12-01

    This paper presents a method to convert the deterministic, continuous representation of a biological system by ordinary differential equations into a non-deterministic, discrete membrane computation. The dynamics of the membrane computation is governed by rewrite rules operating at certain rates. That has the advantage of applying accurately to small systems, and to expressing rates of change that are determined locally, by region, but not necessary globally. Such spatial information augments the standard differentiable approach to provide a more realistic model. A biological case study of the ligand-receptor network of protein TGF-β is used to validate the effectiveness of the conversion method. It demonstrates the sense in which the behaviours and properties of the system are better preserved in the membrane computing model, suggesting that the proposed conversion method may prove useful for biological systems in particular. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  18. Use of a parallel artificial membrane system to evaluate passive absorption and elimination in small fish.

    Science.gov (United States)

    Kwon, Jung-Hwan; Katz, Lynn E; Liljestrand, Howard M

    2006-12-01

    A parallel artificial lipid membrane system was developed to mimic passive mass transfer of hydrophobic organic chemicals in fish. In this physical model system, a membrane filter-supported lipid bilayer separates two aqueous phases that represent the external and internal aqueous environments of fish. To predict bioconcentration kinetics in small fish with this system, literature absorption and elimination rates were analyzed with an allometric diffusion model to quantify the mass transfer resistances in the aqueous and lipid phases of fish. The effect of the aqueous phase mass transfer resistance was controlled by adjusting stirring intensity to mimic bioconcentration rates in small fish. Twenty-three simple aromatic hydrocarbons were chosen as model compounds for purposes of evaluation. For most of the selected chemicals, literature absorption/elimination rates fall into the range predicted from measured membrane permeabilities and elimination rates of the selected chemicals determined by the diffusion model system.

  19. Computer aided design, analysis and experimental investigation of membrane assisted batch reaction-separation systems

    DEFF Research Database (Denmark)

    Mitkowski, Piotr Tomasz; Buchaly, Carsten; Kreis, Peter

    2009-01-01

    Membrane assisted batch reaction operation offers an interesting option for equilibrium limited reaction systems in chemical and biochemical manufacturing by selective removal of one of the products and thereby increasing the product yield. The design of such hybrid systems need to take into acco......Membrane assisted batch reaction operation offers an interesting option for equilibrium limited reaction systems in chemical and biochemical manufacturing by selective removal of one of the products and thereby increasing the product yield. The design of such hybrid systems need to take...... into account the performance of each constituent element and the optimisation of the design must take into consideration their interdependency. In this paper use of a membrane, to assist in the synthesis of propyl-propionate is investigated through the use of a hybrid process design framework, which consists...... and separation functionalities and to design/analyse the hybrid scheme. The generated hybrid scheme has been validated through experiments involving an esterification reaction....

  20. Effect of Electron-Beam Irradiation on Bacterial Cellulose Membranes Used as Transdermal Drug Delivery Systems

    International Nuclear Information System (INIS)

    Stoica-Guzun, A.

    2006-01-01

    Multiple methods are used to modify material surfaces. Radiation is an effective tool for polymer surfaces modification in order to obtain transdermal systems with different controlled release properties. Bacterial cellulose is a promising biomaterial synthesized by Acetobacter xylinum. It has a distinctive ultrafine reticulated structure that may become a perfect matrix as an optimal wound healing environment. In this work, high energy irradiation (γ rays from 137 C s) was applied to modify bacterial cellulose membranes. The effect of varying irradiation doses on membranes permeability was studied. Tetracycline was involved in the study of diffusivity as model drug. Release and permeation of drug from irradiated and non-irradiated membranes were done using a diffusion cell. The membrane permeability was determined using a psudo-steady state analysis based on Fick's law

  1. Modeling the ion transfer and polarization of ion exchange membranes in bioelectrochemical systems.

    Science.gov (United States)

    Harnisch, Falk; Warmbier, Robert; Schneider, Ralf; Schröder, Uwe

    2009-06-01

    An explicit numerical model for the charge balancing ion transfer across monopolar ion exchange membranes under conditions of bioelectrochemical systems is presented. Diffusion and migration equations have been solved according to the Nernst-Planck Equation and the resulting ion concentrations, pH values and the resistance values of the membrane for different conditions were computed. The modeling results underline the principle limitations of the application of ion exchange membranes in biological fuel cells and electrolyzers, caused by the inherent occurrence of a pH-gradient between anode and cathode compartment, and an increased ohmic membrane resistance at decreasing electrolyte concentrations. Finally, the physical and numerical limitations of the model are discussed.

  2. Structure, Dynamics, and Phase Behavior of DOPC/DSPC Mixture Membrane Systems: Molecular Dynamics Simulation Studies

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Seonghan; Chang, Rakwoo [Kwangwoon University, Seoul (Korea, Republic of)

    2016-07-15

    Full atomistic molecular dynamics simulations have been performed for model mixture bilayer membrane systems consisting of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) phospholipids to understand the effects of two essential parameters such as lipid composition and temperature on the structural, dynamical, and phase behavior of mixture membrane systems. Although pure DSPC membranes are in the gel-like (L{sub β}' or P{sub β}') phase at 323 K, raising the temperature by only 10 K or replacing 20% of DSPC lipids by DOPC lipids can change the gel-like phase into the completely liquid-crystalline phase (L{sub α}). This phase change is accompanied by dramatic change in both structural properties such as area per lipid, membrane thickness, deuterium order parameter, and tail angle distribution, and dynamics properties such as mobility map. We also observe that the full width at half-maximum (FWHM) data of tail angle distribution as well as area per lipid (or membrane thickness)can be used as order parameters for the membrane phase transition.

  3. Structure, Dynamics, and Phase Behavior of DOPC/DSPC Mixture Membrane Systems: Molecular Dynamics Simulation Studies

    International Nuclear Information System (INIS)

    Kim, Seonghan; Chang, Rakwoo

    2016-01-01

    Full atomistic molecular dynamics simulations have been performed for model mixture bilayer membrane systems consisting of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) and 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) phospholipids to understand the effects of two essential parameters such as lipid composition and temperature on the structural, dynamical, and phase behavior of mixture membrane systems. Although pure DSPC membranes are in the gel-like (L_β' or P_β') phase at 323 K, raising the temperature by only 10 K or replacing 20% of DSPC lipids by DOPC lipids can change the gel-like phase into the completely liquid-crystalline phase (L_α). This phase change is accompanied by dramatic change in both structural properties such as area per lipid, membrane thickness, deuterium order parameter, and tail angle distribution, and dynamics properties such as mobility map. We also observe that the full width at half-maximum (FWHM) data of tail angle distribution as well as area per lipid (or membrane thickness)can be used as order parameters for the membrane phase transition.

  4. Control of membrane fouling during hyperhaline municipal wastewater treatment using a pilot-scale anoxic/aerobic-membrane bioreactor system

    Institute of Scientific and Technical Information of China (English)

    Jingmei Sun; Jiangxiu Rong; Lifeng Dai; Baoshan Liu; Wenting Zhu

    2011-01-01

    Membrane fouling limits the effects of long-term stable operation of membrane bioreactor (MBR).Control of membrane foulin can extend the membrane life and reduce water treatment cost effectively.A pilot scale anoxic/aerobic-membrane bioreactor (A/O MBR,40 L/hr) was used to treat the hyperhaline municipal sewage from a processing zone of Tianjin,China.Impact factors including mixed liquid sludge suspension (MLSS),sludge viscosity (μ),microorganisms,extracellular polymeric substances (EPS),aeration intensity and suction/suspended time on membrane fouling and pollution control were studied.The relationships among various factors associated with membrane fouling were analyzed.Results showed that there was a positive correlation among MLSS,sludge viscosity and trans-membrane pressure (TMP).Considering water treatment efficiency and stable operation of the membrane module,MLSS of 5 g/L was suggested for the process.There was a same trend among EPS,sludge viscosity and TMP.Numbers and species of microorganisms affected membrane fouling.Either too high or too low aeration intensity was not conducive to membrane fouling control.Aeration intensity of 1.0 m3/hr (gas/water ratio of 25:1) is suggested for the process.A long suction time caused a rapid increase in membrane resistance.However,long suspended time cannot prevent the increase of membrane resistance effectively even though a suspended time was necessary for scale off particles from the membrane surface.The suction/suspended time of 12 min/3 min was selected for the process.The interaction of various environmental factors and operation conditions must be considered synthetically.

  5. Research on ration selection of mixed absorbent solution for membrane air-conditioning system

    International Nuclear Information System (INIS)

    Li, Xiu-Wei; Zhang, Xiao-Song; Wang, Fang; Zhao, Xiao; Zhang, Zhuo

    2015-01-01

    Highlights: • We derive models of the membrane air-conditioning system with mixed absorbents. • We make analysis on system COP, cost-effectiveness and economy. • The paper provides a new method for ideal absorbent selection. • The solutes concentration of 50% achieves the best cost-effectiveness and the economy. - Abstract: Absorption air-conditioning system is a good alternative to vapor compression system for developing low carbon society. To improve the performance of the traditional absorption system, the membrane air-conditioning system is configured and its COP can reach as high as 6. Mixed absorbents are potential for cost reduction of the membrane system while maintaining a high COP. On the purpose of finding ideal mixed absorbent groups, this paper makes analysis on COP, cost-effectiveness and economy of the membrane system with mixed LiBr–CaCl 2 absorbent solution. The models of the system have been developed for the analysis. The results show the COP is higher for the absorbent groups with lower concentration of the total solute and higher concentration ratio of LiBr. It also reveals when the total solutes concentration is about 50%, it achieves the best cost-effectiveness and the economy. The process of the analysis provides a useful method for mixed absorbents selection

  6. Pilot testing of a membrane system for postcombustion CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Merkel, Tim [Membrane Technology And Research, Incorporated, Newark, CA (United States); Kniep, Jay [Membrane Technology And Research, Incorporated, Newark, CA (United States); Wei, Xiaotong [Membrane Technology And Research, Incorporated, Newark, CA (United States); Carlisle, Trevor [Membrane Technology And Research, Incorporated, Newark, CA (United States); White, Steve [Membrane Technology And Research, Incorporated, Newark, CA (United States); Pande, Saurabh [Membrane Technology And Research, Incorporated, Newark, CA (United States); Fulton, Don [Membrane Technology And Research, Incorporated, Newark, CA (United States); Watson, Robert [Membrane Technology And Research, Incorporated, Newark, CA (United States); Hoffman, Thomas [Membrane Technology And Research, Incorporated, Newark, CA (United States); Freeman, Brice [Membrane Technology And Research, Incorporated, Newark, CA (United States); Baker, Richard [Membrane Technology And Research, Incorporated, Newark, CA (United States)

    2015-09-30

    This final report summarizes work conducted for the U.S. Department of Energy, National Energy Technology Laboratory (DOE) to scale up an efficient post-combustion CO2 capture membrane process to the small pilot test stage (award number DE-FE0005795). The primary goal of this research program was to design, fabricate, and operate a membrane CO2 capture system to treat coal-derived flue gas containing 20 tonnes CO2/day (20 TPD). Membrane Technology and Research (MTR) conducted this project in collaboration with Babcock and Wilcox (B&W), the Electric Power Research Institute (EPRI), WorleyParsons (WP), the Illinois Sustainable Technology Center (ISTC), Enerkem (EK), and the National Carbon Capture Center (NCCC). In addition to the small pilot design, build and slipstream testing at NCCC, other project efforts included laboratory membrane and module development at MTR, validation field testing on a 1 TPD membrane system at NCCC, boiler modeling and testing at B&W, a techno-economic analysis (TEA) by EPRI/WP, a case study of the membrane technology applied to a ~20 MWe power plant by ISTC, and an industrial CO2 capture test at an Enerkem waste-to-biofuel facility. The 20 TPD small pilot membrane system built in this project successfully completed over 1,000 hours of operation treating flue gas at NCCC. The Polaris™ membranes used on this system demonstrated stable performance, and when combined with over 10,000 hours of operation at NCCC on a 1 TPD system, the risk associated with uncertainty in the durability of postcombustion capture membranes has been greatly reduced. Moreover, next-generation Polaris membranes with higher performance and lower cost were validation tested on the 1 TPD system. The 20 TPD system also demonstrated successful operation of a new low-pressure-drop sweep module that will reduce parasitic energy losses at full scale by as much as 10 MWe. In modeling and pilot boiler testing, B&W confirmed the

  7. Development of metal catalyst impregnation technology for membrane-based oxygen removal system

    International Nuclear Information System (INIS)

    Kim, Mun Soo; Lee, Doo Ho; Kang, Duk Won

    2005-01-01

    Dissolved oxygen(DO) is a primary cause of PWSCC and its content in reactor coolant system in NPPs has been strictly controlled by various DO removal methods. There are several removal methods of DO, such as vacuum degasification, thermal deaeration, and reductive removal by oxygen scavengers. Although the operation principles of vacuum degasification and thermal deaeration are simple, these methods require a lot of energy for operation and show lower efficiency. And these methods have a few handicaps such as temperature, pH, toxicity, high cost of installation and so on. For the purpose of developing the best method for DO removal from make-up water storage tank, it is necessary to overcome the disadvantages of hydrazine treatment. From this point of view, membrane-based oxygen removal system (MORS) has many advantages than other methods for example, friendly environmental process, versatility of operation conditions with high temperature and low pressure, small space, low cost, etc. Recently de-gassing membrane is widely used in power plant's feed water system for DO removal. De-gassing membrane has some advantages; it removes other dissolved gases such as CO2, N2, as well as O2, and is more economical than Catalytic resin-based Oxygen Removal System. In this study, to obtain better efficiency of MORS, we modified the polypropylene (PP) hollow fiber membrane by plasma treatment and ion beam irradiation supported platinum(Pt), palladium(Pd) as metal catalyst on the surface of the membrane

  8. Emergency membrane contactor based absorption system for ammonia leaks in water treatment plants.

    Science.gov (United States)

    Shao, Jiahui; Fang, Xuliang; He, Yiliang; Jin, Qiang

    2008-01-01

    Abstract Because of the suspected health risks of trihalomethanes (THMs), more and more water treatment plants have replaced traditional chlorine disinfection process with chloramines but often without the proper absorption system installed in the case of ammonia leaks in the storage room. A pilot plant membrane absorption system was developed and installed in a water treatment plant for this purpose. Experimentally determined contact angle, surface tension, and corrosion tests indicated that the sulfuric acid was the proper choice as the absorbent for leaking ammonia using polypropylene hollow fiber membrane contactor. Effects of several operating conditions on the mass transfer coefficient, ammonia absorption, and removal efficiency were examined, including the liquid concentration, liquid velocity, and feed gas concentration. Under the operation conditions investigated, the gas absorption efficiency over 99.9% was achieved. This indicated that the designed pilot plant membrane absorption system was effective to absorb the leaking ammonia in the model storage room. The removal rate of the ammonia in the model storage room was also experimentally and theoretically found to be primarily determined by the ammonia suction flow rate from the ammonia storage room to the membrane contactor. The ammonia removal rate of 99.9% was expected to be achieved within 1.3 h at the ammonia gas flow rate of 500 m3/h. The success of the pilot plant membrane absorption system developed in this study illustrated the potential of this technology for ammonia leaks in water treatment plant, also paved the way towards a larger scale application.

  9. MEMBRANE SYSTEM FOR RECOVERY OF VOLATILE ORGANIC COMPOUNDS FROM REMEDIATION OFF-GASES

    International Nuclear Information System (INIS)

    Wijmans, J.G.

    2003-01-01

    In situ vacuum extraction, air or steam sparging, and vitrification are widely used to remediate soil contaminated with volatile organic compounds (VOCs). All of these processes produce a VOC-laden air stream from which the VOC must be removed before the air can be discharged or recycled to the generating process. Treatment of these off-gases is often a major portion of the cost of the remediation project. Currently, carbon adsorption and catalytic incineration are the most common methods of treating these gas streams. Membrane Technology and Research, Inc. (MTR) proposed an alternative treatment technology based on selective membranes that separate the organic components from the gas stream, producing a VOC-free air stream. This technology can be applied to off-gases produced by various remediation activities and the systems can be skid-mounted and automated for easy transportation and unattended operation. The target performance for the membrane systems is to produce clean air (less than 10 ppmv VOC) for discharge or recycle, dischargeable water (less than 1 ppmw VOC), and a concentrated liquid VOC phase. This report contains the results obtained during Phase II of a two-phase project. In Phase I, laboratory experiments were carried out to demonstrate the feasibility of the proposed approach. In the subsequent Phase II project, a demonstration system was built and operated at the McClellan Air Force Base near Sacramento, California. The membrane system was fed with off-gas from a Soil Vacuum Extraction (SVE) system. The work performed in Phase II demonstrated that the membrane system can reduce the VOC concentration in remediation off-gas to 10 ppmv, while producing a concentrated VOC phase and dischargeable water containing less than 1 ppmw VOC. However, the tests showed that the presence of 1 to 3% carbon dioxide in the SVE off-gas reduced the treatment capacity of the system by a factor of three to four. In an economic analysis, treatment costs of the membrane

  10. Contaminant Permeation in the Ionomer-Membrane Water Processor (IWP) System

    Science.gov (United States)

    Kelsey, Laura K.; Finger, Barry W.; Pasadilla, Patrick; Perry, Jay

    2016-01-01

    The Ionomer-membrane Water Processor (IWP) is a patented membrane-distillation based urine brine water recovery system. The unique properties of the IWP membrane pair limit contaminant permeation from the brine to the recovered water and purge gas. A paper study was conducted to predict volatile trace contaminant permeation in the IWP system. Testing of a large-scale IWP Engineering Development Unit (EDU) with urine brine pretreated with the International Space Station (ISS) pretreatment formulation was then conducted to collect air and water samples for quality analysis. Distillate water quality and purge air GC-MS results are presented and compared to predictions, along with implications for the IWP brine processing system.

  11. Comparison of Four Types of Membrane Bioreactor Systems in Terms of Shear Stress over the Membrane Surface using Computational Fluid Dynamics

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Bentzen, Thomas Ruby

    2013-01-01

    Membrane bioreactors (MBRs) have been used successfully in biological wastewater treatment to solve the perennial problem of effective solids–liquid separation. A common problem with MBR systems is clogging of the modules and fouling of the membrane, resulting in frequent cleaning and replacement...... and requires knowledge of the membrane fouling, hydrodynamics and biokinetics. Modern tools such as computational fluid dynamics (CFD) can be used to diagnose and understand the two-phase flow in an MBR. Four cases of different MBR configurations are presented in this work, using CFD as a tool to develop...

  12. Multiaction antibacterial nanofibrous membranes fabricated by electrospinning: an excellent system for antibacterial applications

    International Nuclear Information System (INIS)

    Wu Yiguang; Jia Weijie; An Qi; Li Guangtao; Liu Yuanfeng; Chen Jinchun

    2009-01-01

    In this paper, novel multiaction antibacterial nanofibrous membranes containing apatite, Ag, AgBr and TiO 2 as four active components were fabricated by an electrospinning technique. In this antibacterial membrane, each component serves a different function: the hydroxyapatite acts as the adsorption material for capturing bacteria, the Ag nanoparticles act as the release-active antibacterial agent, the AgBr nanoparticles act as the visible sensitive and release-active antibacterial agent, and the TiO 2 acts as the UV sensitive antibacterial material and substrate for other functional components. Using E. coli as the typical testing organism, such multicomponent membranes exhibit excellent antimicrobial activity under UV light, visible light or in a dark environment. The significant antibacterial properties may be due to the synergetic action of the four major functional components, and the unique porous structure and high surface area of the nanofibrous membrane. It takes only 20 min for the bacteria to be completely (99.9%) destroyed under visible light. Even in a dark environment, about 50 min is enough to kill all of the bacteria. Compared to the four component system in powder form reported previously, the addition of the electrospun membrane could significantly improve the antibacterial inactivation of E. coli under the same evaluation conditions. Besides the superior antimicrobial capability, the permanence of the antibacterial activity of the prepared free-standing membranes was also demonstrated in repeated applications.

  13. Double liquid membrane system for the removal of actinides and lanthanides from acidic nuclear wastes

    International Nuclear Information System (INIS)

    Chiarizia, R.; Danesi, P.R.

    1985-01-01

    Supported liquid membranes (SLM), consisting of an organic solution of n-octyl-(phenyl)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) and tributyl-phosphate (TBP) in decalin are able to perform selective separation and concentration of actinide and lanthanide ions from aqueous nitrate feed solutions and synthetic nuclear wastes. In the membrane process a possible strip solution is a mixture of formic acid and hydroxylammonium formate (HAF). The effectiveness of this strip solution is reduced and eventually nullified by the simultaneous transfer through the SLM of nitric acid which accumulates in the strip solution. A possible way to overcome this drawback is to make use of a second SLM consisting of a primary amine which is able to extract only HNO 3 from the strip solution. In this work the results obtained by experimentally studying the membrane system: synthetic nuclear waste/CMPO-TBP membrane/HCOOH-HAF strip solution/primary amine membrane/NaOH solution, are reported. They show that the use of a second liquid membrane is effective in controlling the HNO 3 concentration in the strip solution, thus allowing the actinide and lanthanide ions removal from the feed solution to proceed to completion. 15 refs., 10 figs., 1 tab

  14. Natural membranes of Hevea brasiliensis latex as delivery system for Casearia sylvestris leaf components

    Directory of Open Access Journals (Sweden)

    Flávio A. Carvalho

    Full Text Available ABSTRACT Natural latex from Hevea brasiliensis (Wild. ex A.Juss Müll.Arg., Euphorbiaceae, showed angiogenic action and Casearia sylvestris Sw., Salicaceae, leaf derivatives presented anti-inflammatory and wound healing activities. Therefore, an association of these effects was interesting for wound healing applications. The aims of this study were the development of membranes of natural latex incorporated with C. sylvestris leaf derivatives (ethanolic extract, diterpene concentrated fraction and casearin J, their chemical and physical characterization, and the evaluation of in vitro skin permeation and retention of C. sylvestris bioactive secondary metabolites (diterpenes and phenolic compounds. The membranes were developed mixing hydroethanolic solutions of C. sylvestris derivatives with latex and drying them in a desiccator. They were characterized by infrared spectroscopy, scanning electron microscopy, water vapor permeability and mechanical resistance assays, demonstrating that all membranes were permeable, resistant and homogeneous in surfaces. The permeation and retention assays demonstrated dermal penetration of phenolic compounds for ethanolic extract membrane and of casearin-like clerodane diterpenes for all membranes, indicating that these membranes have great potential for therapeutical application as a topical system for C. sylvestris components releasing.

  15. Advanced, Energy-Efficient Hybrid Membrane System for Industrial Water Reuse

    Energy Technology Data Exchange (ETDEWEB)

    Toy, Lora [RTI International, Research Triangle Park, NC (United States); Choi, Young Chul [RTI International, Research Triangle Park, NC (United States); Hendren, Zachary [RTI International, Research Triangle Park, NC (United States); Kim, Gyu Dong [RTI International, Research Triangle Park, NC (United States)

    2017-03-31

    In the U.S. manufacturing sector, current industrial water use practices are energy-intensive and utilize and discharge high volumes of waters, rendering them not sustainable especially in light of the growing scarcity of suitable water supplies. To help address this problem, the goal of this project was to develop an advanced, cost-effective, hybrid membrane-based water treatment system that can improve the energy efficiency of industrial wastewater treatment while allowing at least 50% water reuse efficiency. This hybrid process would combine emerging Forward Osmosis (FO) and Membrane Distillation (MD) technology components into an integrated FO-MD system that can beneficially utilize low-grade waste heat (i.e., T < 450 °F) in industrial facilities to produce distilled-quality product water for reuse. In this project, laboratory-, bench-, and pilot-scale experiments on the hybrid FO-MD system were conducted for industrial wastewater treatment. It was demonstrated at laboratory, bench, and pilot scales that FO-MD membrane technology can concentrate brine to very high total dissolved solids (TDS) levels (>200,000 ppm) that are at least 2.5 times higher than the TDS level to which RO can achieve. In laboratory testing, currently available FO and MD membranes were tested to select for high-performing membranes with high salt rejection and high water flux. Multiple FO membrane/draw-salt solution combinations that gave high water flux with higher than 98% salt rejection were also identified. Reverse draw-salt fluxes were observed to be much lower for divalent salts than for monovalent salts. MD membranes were identified that had 99.9+% salt rejection and water flux as high as 50-90 L/(m2·h) for flat-sheet membranes and >20 L/(m2·h) for hollow fibers. In bench-scale testing, a single unit of commercially available FO and MD membrane modules were evaluated for continuous, integrated operation. Using the laboratory- and bench-scale test data

  16. Development of a PVAl/chitosan composite membrane compatible with the dermo-epidermic system

    International Nuclear Information System (INIS)

    Almeida, Tiago Luiz de

    2009-03-01

    surface, thus obtaining a composite membrane compatible with the dermo-epidermic system. (author)

  17. Multilayer affinity adsorption of albumin on polymer brushes modified membranes in a continuous-flow system.

    Science.gov (United States)

    Hu, Meng-Xin; Li, Xiang; Li, Ji-Nian; Huang, Jing-Jing; Ren, Ge-Rui

    2018-02-23

    Polymer brushes modified surfaces have been widely used for protein immobilization and isolation. Modification of membranes with polymer brushes increases the surface concentration of affinity ligands used for protein binding. Albumin is one of the transporting proteins and shows a high affinity to bile acids. In this work, the modified membranes with cholic acid-containing polymer brushes can be facilely prepared by the immobilization of cholic acid on the poly(2-hydroxyethyl methacrylate) grafted microporous polypropylene membranes (MPPMs) for affinity adsorption of albumin. ATR/FT-IR and X-ray photoelectron spectroscopy were used to characterize the chemical composition of the modified membranes. Water contact angle measurements were used to analyze the hydrophilic/hydrophobic properties of the membrane surface. The modified MPPMs show a high affinity to albumin and have little non-specific adsorption of hemoglobin. The dynamic binding capacity of albumin in the continous-flow system increases with the cycle number and feed rate as the binding degree of cholic acid is moderate. The highest binding capacity of affinity membranes is about 52.49 g/m 2 membrane, which is about 24 times more than the monolayer binding capacity. These results reveal proteins could be captured in multilayers by the polymer brushes containing affinity ligands similar to the polymer brushes containing ion-exchange groups, which open up the potential of the polymer brushes containing affinity ligands in protein or another components separation. And the cholic acid containing polymer brushes modified membranes has the promising potential for albumin separation and purification rapidly from serum or fermented solution in medical diagnosis and bioseparation. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. Discussion on cleaning and maintenance of YA system reverse osmosis membrane

    International Nuclear Information System (INIS)

    Zhu Yidong

    2012-01-01

    According to the overproof of pollution data of YA system reverse osmosis membrane in extension project, the daily maintenance company is using chemical cleaning on reverse osmosis unit to eliminate the pollution blindly, the fixed prescription, fixed dosage and high frequency of the chemical cleaning. The writer analyzed the cause of the membrane pollution and commended several chemical cleaning methods by the long-period study of the system, and also some suggestion, according to the status of operational site, for the daily maintenance. (author)

  19. New approaches to characterizing and understanding biofouling of spiral wound membrane systems

    KAUST Repository

    van Loosdrecht, Mark C.M.

    2012-06-01

    Historically, biofouling research on spiral wound membrane systems is typically problem solving oriented. Membrane modules are studied as black box systems, investigated by autopsies. Biofouling is not a simple process. Many factors influence each other in a non-linear fashion. These features make biofouling a subject which is not easy to study using a fundamental scientific approach. Nevertheless to solve or minimize the negative impacts of biofouling, a clear understanding of the interacting basic principles is needed. Recent research into microbiological characterizing of biofouling, small scale test units, application of in situ visualization methods, and model approaches allow such an integrated study of biofouling. © IWA Publishing 2012.

  20. New approaches to characterizing and understanding biofouling of spiral wound membrane systems

    KAUST Repository

    van Loosdrecht, Mark C.M.; Bereschenko, Ludmilla A.; Radu, Andrea I.; Kruithof, Joop C.; Picioreanu, Cristian; Johns, Michael L.; Vrouwenvelder, Johannes S.

    2012-01-01

    Historically, biofouling research on spiral wound membrane systems is typically problem solving oriented. Membrane modules are studied as black box systems, investigated by autopsies. Biofouling is not a simple process. Many factors influence each other in a non-linear fashion. These features make biofouling a subject which is not easy to study using a fundamental scientific approach. Nevertheless to solve or minimize the negative impacts of biofouling, a clear understanding of the interacting basic principles is needed. Recent research into microbiological characterizing of biofouling, small scale test units, application of in situ visualization methods, and model approaches allow such an integrated study of biofouling. © IWA Publishing 2012.

  1. Effects of upgrading systems on energy conversion efficiency of a gasifier - fuel cell - gas turbine power plant

    International Nuclear Information System (INIS)

    Pedrazzi, Simone; Allesina, Giulio; Tartarini, Paolo

    2016-01-01

    Highlights: • An advanced gasifier-SOFC-MGT system is modeled. • An overall electrical efficiency of 32.81% is reached. • Influence of all the sub-system modeled on the power plant efficiency is discussed. • Compression storage of syngas is taken into account. - Abstract: This work focuses on a DG-SOFC-MGT (downdraft gasifier - solid oxide fuel cell - micro gas turbine) power plant for electrical energy production and investigates two possible performance-upgrading systems: polyphenylene oxide (PPO) membrane and zeolite filters. The first is used to produce oxygen-enriched air used in the reactor, while the latter separates the CO_2 content from the syngas. In order to prevent power plant shutdowns during the gasifier reactor scheduled maintenance, the system is equipped with a gas storage tank. The generation unit consists of a SOFC-MGT system characterized by higher electrical efficiency when compared to conventional power production technology (IC engines, ORC and EFGT). Poplar wood chips with 10% of total moisture are used as feedstock. Four different combinations with and without PPO and zeolite filtrations are simulated and discussed. One-year energy and power simulation were used as basis for comparison between all the cases analyzed. The modeling of the gasification reactions gives results consistent with literature about oxygen-enriched processes. Results showed that the highest electrical efficiency obtained is 32.81%. This value is reached by the power plant equipped only with PPO membrane filtration. Contrary to the PPO filtering, zeolite filtration does not increase the SOFC-MGT unit performance while it affects the energy balance with high auxiliary electrical consumption. This solution can be considered valuable only for future work coupling a CO_2 sequestration system to the power plant.

  2. Membrane systems for energy efficient separation of light gases

    Energy Technology Data Exchange (ETDEWEB)

    Devlin, D.J.; Archuleta, T.; Barbero, R. [Los Alamos National Lab., NM (United States)] [and others

    1997-04-01

    Ethylene and propylene are two of the largest commodity chemicals in the United States and are major building blocks for the petrochemicals industry. These olefins are separated currently by cryogenic distillation which demands extremely low temperatures and high pressures. Over 75 billion pounds of ethylene and propylene are distilled annually in the US at an estimated energy requirement of 400 trillion BTU`s. Non-domestic olefin producers are rapidly constructing state-of-the-art plants. These energy-efficient plants are competing with an aging United States olefins industry in which 75% of the olefins producers are practicing technology that is over twenty years old. New separation opportunities are therefore needed to continually reduce energy consumption and remain competitive. Amoco has been a leader in incorporating new separation technology into its olefins facilities and has been aggressively pursuing non-cryogenic alternatives to light gas separations. The largest area for energy reduction is the cryogenic isolation of the product hydrocarbons from the reaction by-products, methane and hydrogen. This separation requires temperatures as low as {minus}150{degrees}F and pressures exceeding 450 psig. This CRADA will focus on developing a capillary condensation process to separate olefinic mixtures from light gas byproducts at temperatures that approach ambient conditions and at pressures less than 250 psig; this technology breakthrough will result in substantial energy savings. The key technical hurdle in the development of this novel separation concept is the precise control of the pore structure of membrane materials. These materials must contain specially-shaped channels in the 20-40A range to provide the driving force necessary to remove the condensed hydrocarbon products. In this project, Amoco is the technology end-user and provides the commercialization opportunity and engineering support.

  3. Design study of fuel circulating system using Pd alloy membrane isotope separation method

    International Nuclear Information System (INIS)

    Naito, T.; Yamada, T.; Aizawa, T.; Kasahara, T.; Yamanaka, T.

    1981-01-01

    It is expected that the method of permeating through Pd-alloy membrances is effective for isotope separation and the refining of fuel gas. In this paper, the design study of the Fuel Circulating System (FCS) using Pb-alloy membranes is described. The study is mainly focused on the main vacuum, fuel gas refining, isotope separating, and tritium containment systems. In the fuel gas refining system, impurities are effectively removed by using Pd-alloy membranes. For the isotope separation system, the diffusion method through Pd-alloy membranes was adopted. From the standpoint of the safety and economy, a three-stage tritium containment system was adopted to control tritium release to the environment as low as possible. The principal conclusion drawn from the design study was as follows. In the FCS, while cryogenic distillation method appears to be practicable, Pd-alloy membrane method is attractive for isotope separation and the refining of fuel gas. For a large amount of tritium inventory, handling and control technologies should be completed by the experimental evaluation and development of the components and materials used for the FCS. A three-stage containment system was adopted to control tritium release to environment as low as possible. Consideration to prevent tritium escape will be necessary for fuel gas refiners and isotope separators. (Kato, T.)

  4. Isolation of plasma membranes from the nervous system by countercurrent distribution in aqueous polymer two-phase systems.

    Science.gov (United States)

    Schindler, Jens; Nothwang, Hans Gerd

    2009-01-01

    The plasma membrane separates the cell-interior from the cell's environment. To maintain homeostatic conditions and to enable transfer of information, the plasma membrane is equipped with a variety of different proteins such as transporters, channels, and receptors. The kind and number of plasma membrane proteins are a characteristic of each cell type. Owing to their location, plasma membrane proteins also represent a plethora of drug targets. Their importance has entailed many studies aiming at their proteomic identification and characterization. Therefore, protocols are required that enable their purification in high purity and quantity. Here, we report a protocol, based on aqueous polymer two-phase systems, which fulfils these demands. Furthermore, the protocol is time-saving and protects protein structure and function.

  5. Treatment of coal gasification wastewater by membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system.

    Science.gov (United States)

    Jia, Shengyong; Han, Hongjun; Hou, Baolin; Zhuang, Haifeng; Fang, Fang; Zhao, Qian

    2014-12-01

    A laboratory-scale membrane bioreactor hybrid powdered activated carbon (MBR–PAC) system was developed to treat coal gasification wastewater to enhance the COD, total phenols (TPh), NH4+ removals and migrate the membrane fouling. Since the MBR–PAC system operated with PAC dosage of 4 g L−1, the maximum removal efficiencies of COD, TPh and NH4+ reached 93%, 99% and 63%, respectively with the corresponding influent concentrations of 2.27 g L−1, 497 mg L−1 and 164 mg N L−1; the PAC extraction efficiencies of COD, TPh and NH4+ were 6%, 3% and 13%, respectively; the transmembrane pressure decreased 34% with PAC after 50 d operation. The results demonstrate that PAC played a key role in the enhancement of biodegradability and mitigation of membrane fouling.

  6. An energetic analysis of CO2 capture on a gas turbine combining flue gas recirculation and membrane separation

    International Nuclear Information System (INIS)

    Belaissaoui, Bouchra; Cabot, Gilles; Cabot, Marie-Sophie; Willson, David; Favre, Eric

    2012-01-01

    Post-combustion Carbon Capture and Storage (CCS) is currently intensively investigated as a key issue for the mitigation of greenhouse gases emissions. A very large number of studies is dedicated to coal power plants. In this paper, the possibility to achieve carbon capture on a gas turbine, based on a combination of flue gas recycle and membrane separation is reported. Membrane processes are effectively known to offer attractive performances in terms of energy efficiency, as soon as concentrated and/or pressure mixtures have to be treated. Two different flow schemes have been simulated and compared: flue gas recycle with air combustion and flue gas recycle with an oxygen enriched feed mixture. The energy requirement of the different processes, expressed in GJ (thermal basis) per ton of recovered CO 2 , and the size of the membrane capture process (expressed in m 2 of membrane area) have been systematically estimated for different membrane separation performances. It is shown that an overall energy requirement down to 2.6 GJ per ton can possibly be achieved when optimal operating conditions, based on oxygen enriched air (OEA) combustion together with a highly selective membrane (CO 2 /N 2 selectivity of 200) are combined. Additional possibilities in order to minimise the energy penalty of the process are discussed. -- Highlights: ► A carbon capture process for gas turbine has been investigated for the first time, with membrane separation unit. ► Air combustion systematically induces CO 2 capture specific energy requirement far above alternative capture processes. ► Remarkably, a very low energy requirement can be achieved (down to 2.6 GJ/ton) with Oxygen Enriched Air combustion. ► Target membrane selectivities and optimal oxygen content for combustion have been identified.

  7. The mechanism of uncoupling by picrate in Escherichia coli K-12 membrane systems.

    Science.gov (United States)

    Michels, M; Bakker, E P

    1981-06-01

    The mechanism of action of the uncoupler picrate on intact cells and everted membrane vesicles of Escherichia coli K-12 was investigated. Like in mitochondria [Hanstein, W. G. and Hatefi, Y. (1974) Proc. Natl Acad. Sci. USA, 71, 288-292], it was observed that picrate uncoupled energy-linked functions only in everted, but not in intact membrane systems. In the vesicles picrate also decreased the magnitude of the transmembrane proton-motive force at concentrations similar to those at which it caused uncoupling. Experiments with 14C-labelled picrate showed that this compound bound both to deenergized intact cells and everted vesicles. However, upon energization of the membrane, picrate was extruded from the intact cell and taken up to a larger extent by the vesicles. These energy-dependent changes in picrate uptake correlated with the magnitude of the transmembrane electrical potential, delta psi. It is therefore proposed that picrate is a permeant uncoupler, that delta psi is the driving force for picrate movement across biological membranes, and that the uncoupling activity of picrate in everted membrane systems is due to its protonophoric action.

  8. Novel Composite Membrane for Space Life Supporting System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Space life-supporting systems require effective removal of metabolic CO2 from the cabin atmosphere with minimal loss of O2. Conventional techniques, using either...

  9. Analysis of hollow fibre membrane systems for multicomponent gas separation

    KAUST Repository

    Khalilpour, Rajab; Abbas, Ali; Lai, Zhiping; Pinnau, Ingo

    2013-01-01

    nonlinear differential algebraic equation system is solved via a combination of backward differentiation and Gauss-Seidel methods. Natural gas sweetening problem is investigated as a case study. Model parametric analyses of variables, namely feed gas quality

  10. Economics of Direct Hydrogen Polymer Electrolyte Membrane Fuel Cell Systems

    Energy Technology Data Exchange (ETDEWEB)

    Mahadevan, Kathyayani

    2011-10-04

    Battelle's Economic Analysis of PEM Fuel Cell Systems project was initiated in 2003 to evaluate the technology and markets that are near-term and potentially could support the transition to fuel cells in automotive markets. The objective of Battelle?s project was to assist the DOE in developing fuel cell systems for pre-automotive applications by analyzing the technical, economic, and market drivers of direct hydrogen PEM fuel cell adoption. The project was executed over a 6-year period (2003 to 2010) and a variety of analyses were completed in that period. The analyses presented in the final report include: Commercialization scenarios for stationary generation through 2015 (2004); Stakeholder feedback on technology status and performance status of fuel cell systems (2004); Development of manufacturing costs of stationary PEM fuel cell systems for backup power markets (2004); Identification of near-term and mid-term markets for PEM fuel cells (2006); Development of the value proposition and market opportunity of PEM fuel cells in near-term markets by assessing the lifecycle cost of PEM fuel cells as compared to conventional alternatives used in the marketplace and modeling market penetration (2006); Development of the value proposition of PEM fuel cells in government markets (2007); Development of the value proposition and opportunity for large fuel cell system application at data centers and wastewater treatment plants (2008); Update of the manufacturing costs of PEM fuel cells for backup power applications (2009).

  11. Optimal design and control of solar driven air gap membrane distillation desalination systems

    International Nuclear Information System (INIS)

    Chen, Yih-Hang; Li, Yu-Wei; Chang, Hsuan

    2012-01-01

    Highlights: ► Air gap membrane distillation unit was used in the desalination plants. ► Aspen Custom Molder was used to simulate each unit of desalination plants. ► Design parameters were investigated to obtain the minimum total annual cost. ► The control structure was proposed to operate desalination plants all day long. -- Abstract: A solar heated membrane distillation desalination system is constructed of solar collectors and membrane distillation devices for increasing pure water productivity. This technically and economically feasible system is designed to use indirect solar heat to drive membrane distillation processes to overcome the unstable supply of solar radiation from sunrise to sunset. The solar heated membrane distillation desalination system in the present study consisted of hot water storage devices, heat exchangers, air gap membrane distillation units, and solar collectors. Aspen Custom Molder (ACM) software was used to model and simulate each unit and establish the cost function of a desalination plant. From Design degree of freedom (DOF) analysis, ten design parameters were investigated to obtain the minimum total annual cost (TAC) with fixed pure water production rate. For a given solar energy density profile of typical summer weather, the minimal TAC per 1 m 3 pure water production can be found at 500 W/m 2 by varying the solar energy intensity. Therefore, we proposed two modes for controlling the optimal design condition of the desalination plant; day and night. In order to widen the operability range of the plant, the sensitivity analysis was used to retrofit the original design point to lower the effluent temperature from the solar collector by increasing the hot water recycled stream. The simulation results show that the pure water production can be maintained at a very stable level whether in sunny or cloudy weather.

  12. The membrane attack complex of the complement system is essential for rapid wallerian degeneration

    NARCIS (Netherlands)

    Ramaglia, Valeria; King, Rosalind Helen Mary; Nourallah, Michelle; Wolterman, Ruud; de Jonge, Rosalein; Ramkema, Marja; Vigar, Miriam Ann; van der Wetering, Sandra; Morgan, Brian Paul; Troost, Dirk; Baas, Frank

    2007-01-01

    The complement (C) system plays an important role in myelin breakdown during Wallerian degeneration (WD). The pathway and mechanism involved are, however, not clear. In a crush injury model of the sciatic nerve, we show that C6, necessary for the assembly of the membrane attack complex (MAC), is

  13. Integrable systems from membranes on AdS4 x S7

    International Nuclear Information System (INIS)

    Bozhilov, P.

    2008-01-01

    We describe how Neumann and Neumann-Rosochatius type integrable systems, as well as the continuous limit of the SU(2) integrable spin chain, can be obtained from membranes on AdS 4 x S 7 background, in the framework of AdS/CFT correspondence. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

  14. Small Water System Alternatives: Media and Membrane Filtration Alternatives for Small Communities and Households

    Science.gov (United States)

    This webinar presentation will highlight research case studies on innovative drinking water treatment alternatives for small community water systems. Emphasis will be placed on media and membrane filtration technologies capable of meeting the requirements of the Long-Term 2 Enha...

  15. Equilibrium thermodynamics of the ternary membrane-forming system nylon, formic acid and water

    NARCIS (Netherlands)

    Bulte, A.M.W.; Bulte, A.M.W.; Naafs, E.M.; van Eeten, F.; Mulder, M.H.V.; Smolders, C.A.; Smolders, C.A.; Strathmann, H.

    1996-01-01

    The binary Flory-Huggins interaction parameters for the ternary membrane-forming system nylon, formic acid and water have been obtained from literature data, swelling values and melting point depression. Nylon 4,6 nylon 6 and a copolymer of nylon 4,6 and 6 were examined. The isothermal

  16. Computational fluid dynamics simulations of flow and concentration polarization in forward osmosis membrane systems

    DEFF Research Database (Denmark)

    Gruber, M.F.; Johnson, C.J.; Tang, C.Y.

    2011-01-01

    is inspired by previously published CFD models for pressure-driven systems and the general analytical theory for flux modeling in asymmetric membranes. Simulations reveal a non-negligible external concentration polarization on the porous support, even when accounting for high cross-flow velocity and slip...

  17. Integrated nitrogen removal biofilter system with ceramic membrane for advanced post-treatment of municipal wastewater.

    Science.gov (United States)

    Son, Dong-Jin; Yun, Chan-Young; Kim, Woo-Yeol; Zhang, Xing-Ya; Kim, Dae-Gun; Chang, Duk; Sunwoo, Young; Hong, Ki-Ho

    2016-12-01

    The pre-denitrification biofilm process for nitrogen removal was combined with ceramic membrane with pore sizes of 0.05-0.1 µm as a system for advanced post-treatment of municipal wastewater. The system was operated under an empty bed hydraulic retention time of 7.8 h, recirculation ratio of 3, and transmembrane pressure of 0.47 bar. The system showed average removals of organics, total nitrogen, and solids as high as 93%, 80%, and 100%, respectively. Rapid nitrification could be achieved and denitrification was performed in the anoxic filter without external carbon supplements. The residual particulate organics and nitrogen in effluent from biofilm process could be also removed successfully through membrane filtration and the removal of total coliform was noticeably improved after membrane filtration. Thus, a system composed of the pre-denitrification biofilm process with ceramic membrane would be a compact and flexible option for advanced post-treatment of municipal wastewater.

  18. New Approach for Description of Sorption and Swelling phenomena in Liquid + Polymer Membrane Systems.

    Czech Academy of Sciences Publication Activity Database

    Randová, A.; Bartovská, L.; Hovorka, Š.; Bartovský, T.; Izák, Pavel; Kárászová, Magda; Vopička, O.; Lindnerová, V.

    2017-01-01

    Roč. 179, MAY (2017), s. 475-485 ISSN 1383-5866 R&D Projects: GA MŠk(CZ) LD14094 Institutional support: RVO:67985858 Keywords : description of sorption * polymer membranes systems * new method Subject RIV: CI - Industrial Chemistry, Chemical Engineering OBOR OECD: Chemical process engineering Impact factor: 3.359, year: 2016

  19. MEMBRANOUS FLOWS IN GAS-LIQUID COLLECTORS-REGENERATORS OF SOLAR ABSORPTIVE SYSTEMS FEATURES

    Directory of Open Access Journals (Sweden)

    Doroshenko А.V.

    2009-12-01

    Full Text Available Article is devoted to the creation of new generation of solar collectors of the gas-liquid type, intended for use in alternative refrigerating and conditioning systems of drying-evaporating type with direct solar regeneration of absorbent. Special attention is given to the study of membranous flows features on inclined surfaces, including questions of such flows stability.

  20. Gas-permeable hydrophobic tubular membranes for ammonia recovery in bio-electrochemical systems

    NARCIS (Netherlands)

    Kuntke, P.; Zamora, P.; Saakes, M.; Buisman, C.J.N.; Hamelers, H.V.M.

    2016-01-01

    The application of a gas-permeable hydrophobic tubular membrane in bio-electrochemical systems enables efficient recovery of ammonia (NH3) from their cathode compartments. Due to a hydrogen evolution reaction at the cathode, no chemical addition was required to increase the pH for

  1. Dynamic Simulation of a Proton Exchange Membrane Fuel Cell System For Automotive Applications

    DEFF Research Database (Denmark)

    Rabbani, Raja Abid; Rokni, Masoud

    2012-01-01

    parameters have been adjusted specifically for a 21.2 kW Ballard stack [1]. This model also incorporates the effects of water cross-over in the fuel cell membrane. Controls for temperatures, pressures, reactant stoichiometry and flows are implemented to simulate the system behaviour for different loads...

  2. Energy-producing system of the membrane potential generation in γ-irradiated Streptococcus faecalis

    International Nuclear Information System (INIS)

    Fomenko, B.S.

    1976-01-01

    γ-irradiated (20-100 krads) Str. faecalis cells exhibited increased glycolytic and ATPase activity whereas the ATP level remained unaffected by radiation. It is concluded that the radiation-induced reduction of the membrane potential in Str. faecalis, that has been earlier described, is not connected with the impairment of the energy-producing system of the potential generation

  3. Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

    DEFF Research Database (Denmark)

    Toft-Hansen, Henrik; Babcock, Alicia A; Millward, Jason M

    2007-01-01

    BACKGROUND: Matrix metalloproteinases (MMPs) are thought to mediate cellular infiltration in central nervous system (CNS) inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (M...

  4. High Performance Fuel Cell and Electrolyzer Membrane Electrode Assemblies (MEAs) for Space Energy Storage Systems

    Science.gov (United States)

    Valdez, Thomas I.; Billings, Keith J.; Kisor, Adam; Bennett, William R.; Jakupca, Ian J.; Burke, Kenneth; Hoberecht, Mark A.

    2012-01-01

    Regenerative fuel cells provide a pathway to energy storage system development that are game changers for NASA missions. The fuel cell/ electrolysis MEA performance requirements 0.92 V/ 1.44 V at 200 mA/cm2 can be met. Fuel Cell MEAs have been incorporated into advanced NFT stacks. Electrolyzer stack development in progress. Fuel Cell MEA performance is a strong function of membrane selection, membrane selection will be driven by durability requirements. Electrolyzer MEA performance is catalysts driven, catalyst selection will be driven by durability requirements. Round Trip Efficiency, based on a cell performance, is approximately 65%.

  5. Development of a stealth carrier system for structural studies of membrane proteins in solution

    DEFF Research Database (Denmark)

    Maric, Selma

    Structural studies of membrane proteins remain a great experimental challenge. Functional reconstitution into artificial carriers that mimic the native bilayer environment allows for the handling of membrane proteins in solution and enables the use of small-angle scattering techniques for fast...... and reliable structural analysis. The difficulty with this approach is that the carrier discs contribute to the measured scattering intensity in a highly non-trivial fashion, making subsequent data analysis challenging. This thesis presents the development of a specifically deuterated, stealth nanodisc system...

  6. Invariant-based inverse engineering for fluctuation transfer between membranes in an optomechanical cavity system

    Science.gov (United States)

    Chen, Ye-Hong; Shi, Zhi-Cheng; Song, Jie; Xia, Yan

    2018-02-01

    In this paper, by invariant-based inverse engineering, we design classical driving fields to transfer quantum fluctuations between two suspended membranes in an optomechanical cavity system. The transfer can be quickly attained through a nonadiabatic evolution path determined by a so-called dynamical invariant. Such an evolution path allows one to optimize the occupancies of the unstable "intermediate" states; thus, the influence of cavity decays can be suppressed. Numerical simulation demonstrates that a perfect fluctuation transfer between two membranes can be rapidly achieved in one step, and the transfer is robust to both the amplitude noises and cavity decays.

  7. Controlling Biofouling in Seawater Reverse Osmosis Membrane Systems

    NARCIS (Netherlands)

    Dhakal, N.

    2017-01-01

    Seawater desalination is a rapidly growing coastal industry that is increasingly threatened by algal blooms. Depending on the severity of algal blooms, desalination systems may be forced to shut down because of clogging and/or poor feed water quality. To maintain stable operation and provide good

  8. Innovative cross-flow membrane system for volume reduction of mixed waste

    Energy Technology Data Exchange (ETDEWEB)

    Greene, W. [SpinTek Membrane Systems, Huntington Beach, CA (United States)

    1997-10-01

    In this task, SpinTek Membrane Systems, Inc., and the Institute of Gas Technology are completing engineering development leading to a full-scale demonstration of the SpinTek ST-II High Shear Rotary Membrane Filtration System (ST-II) under a Program Research and Development Agreement (PRDA) with the Federal Energy Technology Center-Morgantown. The SpinTek ST-II technology will be scaled-up, and a two-stage ST-II system will be designed, constructed, and operated on both surrogate and actual feed at the Los Alamos National Laboratory (LANL) Liquid Radioactive Waste Treatment Facility (LRWTF). Results from these studies on both surrogate and actual wastewater streams will also be used by LANL personnel to produce a model for determining the applicability and economics of the SpinTek ST-II system to other DOE waste and process streams. The ST-II is a unique, compact cross-flow membrane system having several advantages in performance and cost compared to currently available systems. Staff at LANL have performed pilot-scale testing with the SpinTek technology to evaluate its feasibility for enhanced radionuclide removal from wastewater at its 5- to 8-million-gallon-per-year LRWTF. Recent data have shown the system`s capabilities to remove radionuclides from the waste stream at concentration factors greater than 2000:1, and performance has exceeded both conventional and all other advanced technologies examined.

  9. Neutron scattering to study membrane systems: from lipid vesicles to living cells.

    Energy Technology Data Exchange (ETDEWEB)

    Nickels, Jonathan D. [ORNL; Chatterjee, Sneha [ORNL; Stanley, Christopher B. [ORNL; Qian, Shuo [ORNL; Cheng, Xiaolin [ORNL; Myles, Dean A A [ORNL; Standaert, Robert F. [ORNL; Elkins, James G. [ORNL; Katsaras, John [ORNL

    2017-03-01

    The existence and role of lateral lipid organization in biological membranes has been studied and contested for more than 30 years. Lipid domains, or rafts, are hypothesized as scalable compartments in biological membranes, providing appropriate physical environments to their resident membrane proteins. This implies that lateral lipid organization is associated with a range of biological functions, such as protein co-localization, membrane trafficking, and cell signaling, to name just a few. Neutron scattering techniques have proven to be an excellent tool to investigate these structural features in model lipids, and more recently, in living cells. I will discuss our recent work using neutrons to probe the structure and mechanical properties in model lipid systems and our current efforts in using neutrons to probe the structure and organization of the bilayer in a living cell. These efforts in living cells have used genetic and biochemical strategies to generate a large neutron scattering contrast, making the membrane visible. I will present our results showing in vivo bilayer structure and discuss the outlook for this approach.

  10. Gravity-driven membrane system for secondary wastewater effluent treatment: Filtration performance and fouling characterization

    KAUST Repository

    Wang, Yiran; Fortunato, Luca; Jeong, Sanghyun; Leiknes, TorOve

    2017-01-01

    Gravity-driven membrane (GDM) filtration is one of the promising membrane bioreactor (MBR) configurations. It operates at an ultra-low pressure by gravity, requiring a minimal energy. The objective of this study was to understand the performance of GDM filtration system and characterize the biofouling formation on a flat sheet membrane. This submerged GDM reactor was operated at constant gravitational pressure in treating of two different concentrations of secondary wastewater effluent. Morphology of biofilm layer was acquired by an in-situ and on-line optical coherence tomography (OCT) scanning in a fixed position at regular intervals. The thickness and roughness calculated from OCT images were related to the variation of flux, fouling resistance and permeate quality. At the end of experiment, fouling was quantified by total organic carbon (TOC) and adenosine tri-phosphate (ATP) method. Confocal laser scanning microscopy (CLSM) was also applied for biofouling morphology observation. The biofouling formed on membrane surface was mostly removed by physical cleaning confirmed by contact angle measurement before and after cleaning. This demonstrated that fouling on the membrane under ultra-low pressure operation was highly reversible. The superiority and sustainability of GDM in both flux maintaining and long-term operation with production of high quality effluent was demonstrated.

  11. Effect of water temperature on biofouling development in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia

    2016-07-14

    Understanding the factors that determine the spatial and temporal biofilm development is a key to formulate effective control strategies in reverse osmosis membrane systems for desalination and wastewater reuse. In this study, biofilm development was investigated at different water temperatures (10, 20, and 30 °C) inside a membrane fouling simulator (MFS) flow cell. The MFS studies were done at the same crossflow velocity with the same type of membrane and spacer materials, and the same feed water type and nutrient concentration, differing only in water temperature. Spatially resolved biofilm parameters such as oxygen decrease rate, biovolume, biofilm spatial distribution, thickness and composition were measured using in-situ imaging techniques. Pressure drop (PD) increase in time was used as a benchmark as to when to stop the experiments. Biofilm measurements were performed daily, and experiments were stopped once the average PD increased to 40 mbar/cm. The results of the biofouling study showed that with increasing feed water temperature (i) the biofilm activity developed faster, (ii) the pressure drop increased faster, while (iii) the biofilm thickness decreased. At an average pressure drop increase of 40 mbar/cm over the MFS for the different feed water temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high temperature feed water are more susceptible to biofouling than installations fed with low temperature feed water.

  12. Effect of Biological Contact Filters (BCFs on Membrane Fouling in Drinking Water Treatment Systems

    Directory of Open Access Journals (Sweden)

    Susumu Hasegawa

    2017-12-01

    Full Text Available Membrane fouling is a serious problem in drinking water treatment systems. Biological contact filters (BCFs are often used as a pretreatment to remove ammonia, dissolved organic matter (DOM, and metal ions such as iron and manganese. In this study, the effect of BCF as a pretreatment for membrane fouling was evaluated using a laboratory-scale mini module consisting of a mini BCF column and a mini MF column. Initially, it was confirmed that the main foulant was a biopolymer (at low concentration in the raw water. Subsequently, the biopolymer concentrations in the BCF influent and effluent were measured with the excitation emission matrix (EEM fluorescence spectroscopy and the liquid chromatograph organic carbon detector (LC-OCD. The fouling potential of the BCF influent and effluent was also measured to evaluate MF membrane fouling rate. The results demonstrate that application of the BCF reduced the biopolymer concentration of the effluent and reduced membrane fouling. The effect of BCF was also established in an actual drinking water treatment plant. It was found that optimizing the contact time of raw water with the BCF was crucial to reduce membrane fouling.

  13. Gravity-driven membrane system for secondary wastewater effluent treatment: Filtration performance and fouling characterization

    KAUST Repository

    Wang, Yiran

    2017-04-21

    Gravity-driven membrane (GDM) filtration is one of the promising membrane bioreactor (MBR) configurations. It operates at an ultra-low pressure by gravity, requiring a minimal energy. The objective of this study was to understand the performance of GDM filtration system and characterize the biofouling formation on a flat sheet membrane. This submerged GDM reactor was operated at constant gravitational pressure in treating of two different concentrations of secondary wastewater effluent. Morphology of biofilm layer was acquired by an in-situ and on-line optical coherence tomography (OCT) scanning in a fixed position at regular intervals. The thickness and roughness calculated from OCT images were related to the variation of flux, fouling resistance and permeate quality. At the end of experiment, fouling was quantified by total organic carbon (TOC) and adenosine tri-phosphate (ATP) method. Confocal laser scanning microscopy (CLSM) was also applied for biofouling morphology observation. The biofouling formed on membrane surface was mostly removed by physical cleaning confirmed by contact angle measurement before and after cleaning. This demonstrated that fouling on the membrane under ultra-low pressure operation was highly reversible. The superiority and sustainability of GDM in both flux maintaining and long-term operation with production of high quality effluent was demonstrated.

  14. Characterization of Type Three Secretion System Translocator Interactions with Phospholipid Membranes.

    Science.gov (United States)

    Adam, Philip R; Barta, Michael L; Dickenson, Nicholas E

    2017-01-01

    In vitro characterization of type III secretion system (T3SS) translocator proteins has proven challenging due to complex purification schemes and their hydrophobic nature that often requires detergents to provide protein solubility and stability. Here, we provide experimental details for several techniques that overcome these hurdles, allowing for the direct characterization of the Shigella translocator protein IpaB with respect to phospholipid membrane interaction. The techniques specifically discussed in this chapter include membrane interaction/liposome flotation, liposome sensitive fluorescence quenching, and protein-mediated liposome disruption assays. These assays have provided valuable insight into the role of IpaB in T3SS-mediated phospholipid membrane interactions by Shigella and should readily extend to other members of this important class of proteins.

  15. Development of a Comprehensive Fouling Model for a Rotating Membrane Bioreactor System Treating Wastewater

    Directory of Open Access Journals (Sweden)

    Parneet Paul

    2015-01-01

    Full Text Available Membrane bioreactors (MBRs are now main stream wastewater treatment technologies. In recent times, novel pressure driven rotating membrane disc modules have been specially developed that induce high shear on the membrane surface, thereby reducing fouling. Previous research has produced dead-end filtration fouling model which combines all three classical mechanisms that was later used by another researcher as a starting point for a greatly refined model of a cross flow side-stream MBR that incorporated both hydrodynamics and soluble microbial products’ (SMP effects. In this study, a comprehensive fouling model was created based on this earlier work that incorporated all three classical fouling mechanisms for a rotating MBR system. It was tested and validated for best fit using appropriate data sets. The initial model fit appeared good for all simulations, although it still needs to be calibrated using further appropriate data sets.

  16. Effects of prolonged recombinant human erythropoietin administration on muscle membrane transport systems and metabolic marker enzymes

    DEFF Research Database (Denmark)

    Juel, C; Thomsen, J J; Rentsch, R L

    2007-01-01

    on the expression of muscle membrane transport proteins. Likewise, improvements in performance may involve upregulation of metabolic enzymes. Since Epo is known to augment performance we tested the effect of rHuEpo on some marker enzymes that are related to aerobic capacity. For these purposes eight subjects...... performance by approximately 54%. Membrane transport systems and carbonic anhydrases involved in pH regulation remained unchanged. Of the Na(+), K(+)-pump isoforms only the density of the alpha2 subunit was decreased (by 22%) after treatment. The marker enzymes cytochrom c and hexokinase remained unchanged......Adaptations to chronic hypoxia involve changes in membrane transport proteins. The underlying mechanism of this response may be related to concomitant occurring changes in erythropoietin (Epo) levels. We therefore tested the direct effects of recombinant human erythropoietin (rHuEpo) treatment...

  17. Membrane-membrane interactions in a lipid-containing bacteriophage system. Progress report, October 1, 1978-September 30, 1979

    International Nuclear Information System (INIS)

    Snipes, W.

    1979-06-01

    Progress is reported on research on two aspects of the life cycle of PM2, a lipid-containing bacteriophage. The first concerns the initial interaction of PM2 with the outer membrane of its host cell, Pseudomonas BAL-31. The second concerns the assembly of PM2 in infected cells and the structural features of hydrophobic membrane perturbers that inhibit PM2 assembly. Several other projects have been completed: distribution of PM2 receptors; effects of adamantance derivatives on PM2 production; hydrophobic membrane perturbers as antiviral and virucidal agents; hydrophobic photosensitizers; and other technique development

  18. A study on the silica removal in primary system using the membrane process

    International Nuclear Information System (INIS)

    Kim, Bong Jin; Lee, Sang Jin; Yang, Ho Yeon; Kim, Kyung Duk; Jung, Hee Chul; Jo, Hang Rae

    2005-01-01

    Silica in primary system combines with an alkali grammatical particle metal and forms the zeolite layer which is hindering the heat transfer on the surface of the cladding. Zeolite layer becomes the cause of the damage in this way. The problems of the NPP's primary system have been issued steadily by EPRI. Through a series of experiments of the laboratory scale, we confirmed the applicability of NF membrane for silica removal, as silica rejection rate of NF membrane is about 60 ∼ 70% and boron rejection rate is about 10 ∼ 20%. We accomplished a site experiment about four NF membranes manufactured by FilmTec and Osmonics Inc. In experiment using 400L of SFP water, when operation pressure is 10kg f /cm 2 , we confirmed that the silica rejection rate of NF90-2540 manufactured by FilmTec Inc. is about 98%, boron rejection rate is about 43%. The silica rejection rate of NF270-2540 is about 38%, boron rejection rate is about 3.5%. Afterward, through additional experiments, such as long term characteristic experiments, we are going to design a optimum NF membrane system for silica removal

  19. A study on the silica removal in primary system using the membrane process

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Jin; Lee, Sang Jin; Yang, Ho Yeon; Kim, Kyung Duk [Korea Hydro and Nuclear Power Co., LTD., Taejeon (Korea, Republic of); Jung, Hee Chul; Jo, Hang Rae [Korea Hydro and Nuclear Power Co., LTD., Uljin (Korea, Republic of)

    2005-06-15

    Silica in primary system combines with an alkali grammatical particle metal and forms the zeolite layer which is hindering the heat transfer on the surface of the cladding. Zeolite layer becomes the cause of the damage in this way. The problems of the NPP's primary system have been issued steadily by EPRI. Through a series of experiments of the laboratory scale, we confirmed the applicability of NF membrane for silica removal, as silica rejection rate of NF membrane is about 60 {approx} 70% and boron rejection rate is about 10 {approx} 20%. We accomplished a site experiment about four NF membranes manufactured by FilmTec and Osmonics Inc. In experiment using 400L of SFP water, when operation pressure is 10kg{sub f}/cm{sup 2}, we confirmed that the silica rejection rate of NF90-2540 manufactured by FilmTec Inc. is about 98%, boron rejection rate is about 43%. The silica rejection rate of NF270-2540 is about 38%, boron rejection rate is about 3.5%. Afterward, through additional experiments, such as long term characteristic experiments, we are going to design a optimum NF membrane system for silica removal.

  20. Quantitative measurement and visualization of biofilm O 2 consumption rates in membrane filtration systems

    KAUST Repository

    Prest, Emmanuelle I E C

    2012-03-01

    There is a strong need for techniques enabling direct assessment of biological activity of biofouling in membrane filtration systems. Here we present a new quantitative and non-destructive method for mapping O 2 dynamics in biofilms during biofouling studies in membrane fouling simulators (MFS). Transparent planar O 2 optodes in combination with a luminescence lifetime imaging system were used to map the two-dimensional distribution of O 2 concentrations and consumption rates inside the MFS. The O 2 distribution was indicative for biofilm development. Biofilm activity was characterized by imaging of O 2 consumption rates, where low and high activity areas could be clearly distinguished. The spatial development of O 2 consumption rates, flow channels and stagnant areas could be determined. This can be used for studies on concentration polarization, i.e. salt accumulation at the membrane surface resulting in increased salt passage and reduced water flux. The new optode-based O 2 imaging technique applied to MFS allows non-destructive and spatially resolved quantitative biological activity measurements (BAM) for on-site biofouling diagnosis and laboratory studies. The following set of complementary tools is now available to study development and control of biofouling in membrane systems: (i) MFS, (ii) sensitive pressure drop measurement, (iii) magnetic resonance imaging, (iv) numerical modelling, and (v) biological activity measurement based on O 2 imaging methodology. © 2011 Elsevier B.V.

  1. The influence of oscillating electromagnetic fields on membrane structure and function: Synthetic liposome and natural membrane bilayer systems with direct application to the controlled delivery of chemical agents

    International Nuclear Information System (INIS)

    Liburdy, R.P.; de Manincor, D.; Fingado, B.

    1989-09-01

    Investigations have been conducted to determine if an imposed electromagnetic field can influence membrane transport, and ion and drug permeability in both synthetic and natural cell membrane systems. Microwave fields enhance accumulation of sodium in the lymphocyte and induce protein shedding at Tc. Microwaves also trigger membrane permeability of liposome systems under specific field exposure conditions. Sensitivity varies in a defined way in bilayers displaying a membrane structural phase transition temperature, Tc; maximal release was observed at or near Tc. Significantly, liposome systems without a membrane phase transition were also found to experience permeability increases but, in contrast, this response was temperature independent. The above results indicate that field-enhanced drug release occurs in liposome vesicles that possess a Tc as well as non-Tc liposomes. Additional studies extend non-Tc liposome responses to the in vivo case in which microwaves trigger Gentamicin release from a liposome ''depot'' placed subcutaneously in the rat hind leg. In addition, evidence is provided that cell surface sequestered liposomes can be triggered by microwave fields to release drugs directly into target cells. 24 refs., 6 figs

  2. Stakeholder acceptance analysis: In-well vapor stripping, in-situ bioremediation, gas membrane separation system (membrane separation)

    International Nuclear Information System (INIS)

    Peterson, T.

    1995-12-01

    This document provides stakeholder evaluations on innovative technologies to be used in the remediation of volatile organic compounds from soils and ground water. The technologies evaluated are; in-well vapor stripping, in-situ bioremediation, and gas membrane separation

  3. A comparison of BNR activated sludge systems with membrane and settling tank solid-liquid separation.

    Science.gov (United States)

    Ramphao, M C; Wentzel, M C; Ekama, G A; Alexander, W V

    2006-01-01

    Installing membranes for solid-liquid separation into biological nutrient removal (BNR) activated sludge (AS) systems makes a profound difference not only to the design of the membrane bio-reactor (MBR) BNR system itself, but also to the design approach for the whole wastewater treatment plant (WWTP). In multi-zone BNR systems with membranes in the aerobic reactor and fixed volumes for the anaerobic, anoxic and aerobic zones (i.e. fixed volume fractions), the mass fractions can be controlled (within a range) with the inter-reactor recycle ratios. This zone mass fraction flexibility is a significant advantage of MBR BNR systems over BNR systems with secondary settling tanks (SSTs), because it allows changing the mass fractions to optimise biological N and P removal in conformity with influent wastewater characteristics and the effluent N and P concentrations required. For PWWF/ADWF ratios (fq) in the upper range (fq approximately 2.0), aerobic mass fractions in the lower range (f(maer) settling and long sludge age). However, the volume reduction compared with equivalent BNR systems with SSTs will not be large (40-60%), but the cost of the membranes can be offset against sludge thickening and stabilisation costs. Moving from a flow unbalanced raw wastewater system to a flow balanced (fq = 1) low (usually settled) wastewater strength system can double the ADWF capacity of the biological reactor, but the design approach of the WWTP changes away from extended aeration to include primary sludge stabilisation. The cost of primary sludge treatment then has to be offset against the savings of the increased WWTP capacity.

  4. 35-We polymer electrolyte membrane fuel cell system for notebook computer using a compact fuel processor

    Science.gov (United States)

    Son, In-Hyuk; Shin, Woo-Cheol; Lee, Yong-Kul; Lee, Sung-Chul; Ahn, Jin-Gu; Han, Sang-Il; kweon, Ho-Jin; Kim, Ju-Yong; Kim, Moon-Chan; Park, Jun-Yong

    A polymer electrolyte membrane fuel cell (PEMFC) system is developed to power a notebook computer. The system consists of a compact methanol-reforming system with a CO preferential oxidation unit, a 16-cell PEMFC stack, and a control unit for the management of the system with a d.c.-d.c. converter. The compact fuel-processor system (260 cm 3) generates about 1.2 L min -1 of reformate, which corresponds to 35 We, with a low CO concentration (notebook computers.

  5. 35-We polymer electrolyte membrane fuel cell system for notebook computer using a compact fuel processor

    Energy Technology Data Exchange (ETDEWEB)

    Son, In-Hyuk; Shin, Woo-Cheol; Lee, Sung-Chul; Ahn, Jin-Gu; Han, Sang-Il; kweon, Ho-Jin; Kim, Ju-Yong; Park, Jun-Yong [Energy 1 Group, Energy Laboratory at Corporate R and D Center in Samsung SDI Co., Ltd., 575, Shin-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do 443-731 (Korea); Lee, Yong-Kul [Department of Chemical Engineering, Dankook University, Youngin 448-701 (Korea); Kim, Moon-Chan [Department of Environmental Engineering, Chongju University, Chongju 360-764 (Korea)

    2008-10-15

    A polymer electrolyte membrane fuel cell (PEMFC) system is developed to power a notebook computer. The system consists of a compact methanol-reforming system with a CO preferential oxidation unit, a 16-cell PEMFC stack, and a control unit for the management of the system with a d.c.-d.c. converter. The compact fuel-processor system (260 cm{sup 3}) generates about 1.2 L min{sup -1} of reformate, which corresponds to 35 We, with a low CO concentration (<30 ppm, typically 0 ppm), and is thus proven to be capable of being targetted at notebook computers. (author)

  6. Preliminary design of fusion reactor fuel cleanup system by palladium alloy membrane method

    International Nuclear Information System (INIS)

    Yoshida, Hiroshi; Konishi, Satoshi; Naruse, Yuji

    1981-10-01

    A design of palladium diffuser and Fuel Cleanup System (FCU) for D-T fusion reactor is proposed. Feasibility of palladium alloy membrane method is discussed based on the early studies by the authors. Operating conditions of the palladium diffuser are determined experimentally. Dimensions of the diffuser are estimated from computer simulation. FCU system is designed under the feed conditions of Tritium Systems Test Assembly (TSTA) at Los Alamos Scientific Laboratory. The system is composed of Pd-diffusers, catalytic oxidizer, freezer and zink beds, and has some advantages in system layout and operation. This design can readily be extended to other conditions of plasma exhaust gases. (author)

  7. Integrated Wireless Monitoring and Control System in Reverse Osmosis Membrane Desalination Plants

    Directory of Open Access Journals (Sweden)

    Al Haji Ahmad

    2015-01-01

    Full Text Available The operational processes of the Reverse Osmosis (RO membrane desalination plants require continuous monitoring through the constant attendance of operators to ensure proper productivity and minimize downtime and prevent membrane failure. Therefore, the plant must be equipped with a control system that monitors and controls the operational variables. Monitoring and controlling the affecting parameters are critical to the evaluation of the performance of the desalination plant, which will help the operator find and resolve problems immediately. Therefore, this paper was aimed at developing an RO unit by utilizing a wireless sensor network (WSN system. Hence, an RO pilot plant with a feed capacity of 1.2 m3/h was utilized, commissioned, and tested in Kuwait to assess and verify the performance of the integrated WSN in RO membrane desalination system. The investigated system allowed the operators to remotely monitor the operational process of the RO system. The operational data were smoothly recorded and monitored. Furthermore, the technical problems were immediately determined, which reduced the time and effort in rectifying the technical problems relevant to the RO performance. The manpower requirements of such treatment system were dramatically reduced by about 50%. Based on a comparison between manual and wireless monitoring operational processes, the availability of the integrated RO unit with a wireless monitoring was increased by 10%

  8. Proton-sensing transistor systems for detecting ion leakage from plasma membranes under chemical stimuli.

    Science.gov (United States)

    Imaizumi, Yuki; Goda, Tatsuro; Schaffhauser, Daniel F; Okada, Jun-Ichi; Matsumoto, Akira; Miyahara, Yuji

    2017-03-01

    The membrane integrity of live cells is routinely evaluated for cytotoxicity induced by chemical or physical stimuli. Recent progress in bioengineering means that high-quality toxicity validation is required. Here, we report a pH-sensitive transistor system developed for the continuous monitoring of ion leakage from cell membranes upon challenge by toxic compounds. Temporal changes in pH were generated with high reproducibility via periodic flushing of HepG2 cells on a gate insulator of a proton-sensitive field-effect transistor with isotonic buffer solutions with/without NH 4 Cl. The pH transients at the point of NH 4 Cl addition/withdrawal originated from the free permeation of NH 3 across the semi-permeable plasma membranes, and the proton sponge effect produced by the ammonia equilibrium. Irreversible attenuation of the pH transient was observed when the cells were subjected to a membrane-toxic reagent. Experiments and simulations proved that the decrease in the pH transient was proportional to the area of the ion-permeable pores on the damaged plasma membranes. The pH signal was correlated with the degree of hemolysis produced by the model reagents. The pH assay was sensitive to the formation of molecularly sized pores that were otherwise not measurable via detection of the leakage of hemoglobin, because the hydrodynamic radius of hemoglobin was greater than 3.1nm in the hemolysis assay. The pH transient was not disturbed by inherent ion-transporter activity. The ISFET assay was applied to a wide variety of cell types. The system presented here is fast, sensitive, practical and scalable, and will be useful for validating cytotoxins and nanomaterials. The plasma membrane toxicity and hemolysis are widely and routinely evaluated in biomaterials science and biomedical engineering. Despite the recent development of a variety of methods/materials for efficient gene/drug delivery systems to the cytosol, the methodologies for safety validation remain unchanged in

  9. Sympathetic cooling of a membrane oscillator in a hybrid mechanical-atomic system

    Science.gov (United States)

    Jöckel, Andreas; Faber, Aline; Kampschulte, Tobias; Korppi, Maria; Rakher, Matthew T.; Treutlein, Philipp

    2015-01-01

    Sympathetic cooling with ultracold atoms and atomic ions enables ultralow temperatures in systems where direct laser or evaporative cooling is not possible. It has so far been limited to the cooling of other microscopic particles, with masses up to 90 times larger than that of the coolant atom. Here, we use ultracold atoms to sympathetically cool the vibrations of a Si3N4 nanomembrane, the mass of which exceeds that of the atomic ensemble by a factor of 1010. The coupling of atomic and membrane vibrations is mediated by laser light over a macroscopic distance and is enhanced by placing the membrane in an optical cavity. We observe cooling of the membrane vibrations from room temperature to 650 ± 230 mK, exploiting the large atom-membrane cooperativity of our hybrid optomechanical system. With technical improvements, our scheme could provide ground-state cooling and quantum control of low-frequency oscillators such as nanomembranes or levitated nanoparticles, in a regime where purely optomechanical techniques cannot reach the ground state.

  10. Rapid antibiotic efficacy screening with aluminum oxide nanoporous membrane filter-chip and optical detection system.

    Science.gov (United States)

    Tsou, Pei-Hsiang; Sreenivasappa, Harini; Hong, Sungmin; Yasuike, Masayuki; Miyamoto, Hiroshi; Nakano, Keiyo; Misawa, Takeyuki; Kameoka, Jun

    2010-09-15

    We have developed a filter-chip and optical detection system for rapid antibiotic efficacy screening. The filter-chip consisted of a 1-mL reservoir and an anodic aluminum oxide (AAO) nanoporous membrane. Sample solution with liquid growth media, bacteria, and antibiotics was incubated in the reservoir for a specific period of time. The number of live bacteria on the surface of membrane was counted after the incubation with antibiotics and filtration. Using this biosensing system, we have demonstrated a 1-h antibiotic screening for patients' clinical samples, significantly faster than the conventional antibiotic susceptibility tests that typically take more than 24h. This rapid screening nature makes the filter-chip and detection system ideal for tailoring antibiotic treatment to individual patients by reducing the microbial antibiotic resistance, and improving the survival rate for patients suffering from postoperative infections. Published by Elsevier B.V.

  11. Novel Water Treatment Processes Based on Hybrid Membrane-Ozonation Systems: A Novel Ceramic Membrane Contactor for Bubbleless Ozonation of Emerging Micropollutants

    Directory of Open Access Journals (Sweden)

    Stylianos K. Stylianou

    2015-01-01

    Full Text Available The aim of this study is the presentation of novel water treatment systems based on ozonation combined with ceramic membranes for the treatment of refractory organic compounds found in natural water sources such as groundwater. This includes, firstly, a short review of possible membrane based hybrid processes for water treatment from various sources. Several practical and theoretical aspects for the application of hybrid membrane-ozonation systems are discussed, along with theoretical background regarding the transformation of target organic pollutants by ozone. Next, a novel ceramic membrane contactor, bringing into contact the gas phase (ozone and water phase without the creation of bubbles (bubbleless ozonation, is presented. Experimental data showing the membrane contactor efficiency for oxidation of atrazine, endosulfan, and methyl tert-butyl ether (MTBE are shown and discussed. Almost complete endosulfan degradation was achieved with the use of the ceramic contactor, whereas atrazine degradation higher than 50% could not be achieved even after 60 min of reaction time. Single ozonation of water containing MTBE could not result in a significant MTBE degradation. MTBE mineralization by O3/H2O2 combination increased at higher pH values and O3/H2O2 molar ratio of 0.2 reaching a maximum of around 65%.

  12. Dynamic solar-powered multi-stage direct contact membrane distillation system: Concept design, modeling and simulation

    KAUST Repository

    Lee, Jung Gil; Kim, Woo-Seung; Choi, June-Seok; Ghaffour, NorEddine; Kim, Young-Deuk

    2017-01-01

    This paper presents a theoretical analysis of the monthly average daily and hourly performances of a solar-powered multi-stage direct contact membrane distillation (SMDCMD) system with an energy recovery scheme and dynamic operating system. Mid

  13. Porosity of spacer-filled channels in spiral-wound membrane systems: Quantification methods and impact on hydraulic characterization

    KAUST Repository

    Siddiqui, Amber; Lehmann, S.; Haaksman, V.; Ogier, J.; Schellenberg, C.; van Loosdrecht, M.C.M.; Kruithof, J.C.; Vrouwenvelder, Johannes S.

    2017-01-01

    The porosity of spacer-filled feed channels influences the hydrodynamics of spiral-wound membrane systems and impacts the overall performance of the system. Therefore, an exact measurement and a detailed understanding of the impact of the feed

  14. Development and characterization of 3D-printed feed spacers for spiral wound membrane systems

    KAUST Repository

    Siddiqui, Amber

    2016-01-02

    Feed spacers are important for the impact of biofouling on the performance of spiral-wound reverse osmosis (RO) and nanofiltration (NF) membrane systems. The objective of this study was to propose a strategy for developing, characterizing, and testing of feed spacers by numerical modeling, three-dimensional (3D) printing of feed spacers and experimental membrane fouling simulator (MFS) studies. The results of numerical modeling on the hydraulic behavior of various feed spacer geometries suggested that the impact of spacers on hydraulics and biofouling can be improved. A good agreement was found for the modeled and measured relationship between linear flow velocity and pressure drop for feed spacers with the same geometry, indicating that modeling can serve as first step in spacer characterization. An experimental comparison study of a feed spacer currently applied in practice and a 3D printed feed spacer with the same geometry showed (i) similar hydraulic behavior, (ii) similar pressure drop development with time and (iii) similar biomass accumulation during MFS biofouling studies, indicating that 3D printing technology is an alternative strategy for development of thin feed spacers with a complex geometry. Based on the numerical modeling results, a modified feed spacer with low pressure drop was selected for 3D printing. The comparison study of the feed spacer from practice and the modified geometry 3D printed feed spacer established that the 3D printed spacer had (i) a lower pressure drop during hydraulic testing, (ii) a lower pressure drop increase in time with the same accumulated biomass amount, indicating that modifying feed spacer geometries can reduce the impact of accumulated biomass on membrane performance. The combination of numerical modeling of feed spacers and experimental testing of 3D printed feed spacers is a promising strategy (rapid, low cost and representative) to develop advanced feed spacers aiming to reduce the impact of biofilm formation on

  15. Continual Energy Management System of Proton Exchange Membrane Fuel Cell Hybrid Power Electric Vehicles

    Directory of Open Access Journals (Sweden)

    Ren Yuan

    2016-01-01

    Full Text Available Current research status in energy management of Proton Exchange Membrane (PEM fuel cell hybrid power electric vehicles are first described in this paper, and then build the PEMFC/ lithium-ion battery/ ultra-capacitor hybrid system model. The paper analysis the key factors of the continuous power available in PEM fuel cell hybrid power electric vehicle and hybrid power system working status under different driving modes. In the end this paper gives the working flow chart of the hybrid power system and concludes the three items of the system performance analysis.

  16. Ultra-thin and strong formvar-based membranes with controlled porosity for micro- and nano-scale systems

    Science.gov (United States)

    Auchter, Eric; Marquez, Justin; Stevens, Garrison; Silva, Rebecca; Mcculloch, Quinn; Guengerich, Quintessa; Blair, Andrew; Litchfield, Sebastian; Li, Nan; Sheehan, Chris; Chamberlin, Rebecca; Yarbro, Stephen L.; Dervishi, Enkeleda

    2018-05-01

    We present a methodology for developing ultra-thin and strong formvar-based membranes with controlled morphologies. Formvar is a thin hydrophilic and oleophilic polymer inert to most chemicals and resistant to radiation. The formvar-based membranes are viable materials as support structures in micro- and macro-scale systems depending on thinness and porosity control. Tunable sub-micron thick porous membranes with 20%–65% porosity were synthesized by controlling the ratios of formvar, glycerol, and chloroform. This synthesis process does not require complex separation or handling methods and allows for the production of strong, thin, and porous formvar-based membranes. An expansive array of these membrane characterizations including chemical compatibility, mechanical responses, wettability, as well as the mathematical simulations as a function of porosity has been presented. The wide range of chemical compatibility allows for membrane applications in various environments, where other polymers would not be suitable. Our formvar-based membranes were found to have an elastic modulus of 7.8 GPa, a surface free energy of 50 mN m‑1 and an average thickness of 125 nm. Stochastic model simulations indicate that formvar with the porosity of ∼50% is the optimal membrane formulation, allowing the most material transfer across the membrane while also withstanding the highest simulated pressure loadings before tearing. Development of novel, resilient and versatile membranes with controlled porosity offers a wide range of exciting applications in the fields of nanoscience, microfluidics, and MEMS.

  17. Application of CO{sub 2} selective membrane reactors in pre-combustion decarbonisation systems for power production

    Energy Technology Data Exchange (ETDEWEB)

    Steven C.A. Kluiters; Virginie C. Feuillade; Jan Wilco Dijkstra; Daniel Jansen; Wim G. Haije [Energy research Centre of the Netherlands (ECN), Petten (Netherlands)

    2006-07-01

    For pre-combustion decarbonisation of fuels for large-scale power production or H{sub 2} generation both CO{sub 2} and H{sub 2} selective membranes are viable candidates for use in steam reforming and water gas shift membrane reactors. It will be shown that the choice between either option is not a matter of taste, but dictated by the fuel used and, to a lesser extent, the total system layout. Hydrotalcites, clay-like materials, are shown to be promising candidates as membrane material for low temperature, below 400{sup o}C, membrane shift reactors. 7 refs., 6 figs., 1 tab.

  18. A hypothesis for the minimal overall structure of the mammalian plasma membrane redox system.

    Science.gov (United States)

    de Grey, Aubrey D N J

    2003-05-01

    After a long period of frustration, many components of the mammalian plasma membrane redox system are now being identified at the molecular level. Some are apparently ubiquitous but are necessary only for a subset of electron donors or acceptors; some are present only in certain cell types; some appear to be associated with proton extrusion; some appear to be capable of superoxide production. The volume and variety of data now available have begun to allow the formulation of tentative models for the overall network of interactions of enzymes and substrates that together make up the plasma membrane redox system. Such a model is presented here. The structure discussed here is of the mammalian system, though parts of it may apply more or less accurately to fungal and plant cells too. Judging from the history of mitochondrial oxidative phosphorylation, it may be hoped that the development of models of the whole system - even if they undergo substantial revision thereafter - will markedly accelerate the pace of research in plasma membrane redox, by providing a coherent basis for the design of future experiments.

  19. Seawater desalination with solar-energy-integrated vacuum membrane distillation system

    Directory of Open Access Journals (Sweden)

    Fang Wang

    2017-03-01

    Full Text Available This study designed and tested a novel type of solar-energy-integrated vacuum membrane distillation (VMD system for seawater desalination under actual environmental conditions in Wuhan, China. The system consists of eight parts: a seawater tank, solar collector, solar cooker, inclined VMD evaporator, circulating water vacuum pump, heat exchanger, fresh water tank, and brine tank. Natural seawater was used as feed and a hydrophobic hollow-fiber membrane module was used to improve seawater desalination. The experiment was conducted during a typical summer day. Results showed that when the highest ambient temperature was 33 °C, the maximum value of the average solar intensity was 1,080 W/m2. The system was able to generate 36 kg (per m2 membrane module distilled fresh water during 1 day (7:00 am until 6:00 pm, the retention rate was between 99.67 and 99.987%, and electrical conductivity was between 0.00276 and 0.0673 mS/cm. The average salt rejection was over 90%. The proposed VMD system shows favorable potential application in desalination of brackish waters or high-salt wastewater treatment, as well.

  20. Coulometric sodium chloride removal system with Nafion membrane for seawater sample treatment.

    Science.gov (United States)

    Grygolowicz-Pawlak, Ewa; Sohail, Manzar; Pawlak, Marcin; Neel, Bastien; Shvarev, Alexey; de Marco, Roland; Bakker, Eric

    2012-07-17

    Seawater analysis is one of the most challenging in the field of environmental monitoring, mainly due to disparate concentration levels between the analyte and the salt matrix causing interferences in a variety of analytical techniques. We propose here a miniature electrochemical sample pretreatment system for a rapid removal of NaCl utilizing the coaxial arrangement of an electrode and a tubular Nafion membrane. Upon electrolysis, chloride is deposited at the Ag electrode as AgCl and the sodium counterions are transported across the membrane. This cell was found to work efficiently at potentials higher than 400 mV in both stationary and flow injection mode. Substantial residual currents observed during electrolysis were found to be a result of NaCl back diffusion from the outer side of the membrane due to insufficient permselectivity of the Nafion membrane. It was demonstrated that the residual current can be significantly reduced by adjusting the concentration of the outer solution. On the basis of ion chromatography results, it was found that the designed cell used in flow injection electrolysis mode reduced the NaCl concentration from 0.6 M to 3 mM. This attempt is very important in view of nutrient analysis in seawater where NaCl is a major interfering agent. We demonstrate that the pretreatment of artificial seawater samples does not reduce the content of nitrite or nitrate ions upon electrolysis. A simple diffusion/extraction steady state model is proposed for the optimization of the electrolysis cell characteristics.

  1. Synthetic nanoparticles camouflaged with biomimetic erythrocyte membranes for reduced reticuloendothelial system uptake

    International Nuclear Information System (INIS)

    Rao, Lang; Xu, Jun-Hua; Cai, Bo; Liu, Huiqin; Li, Ming; Jia, Yan; Xiao, Liang; Guo, Shi-Shang; Liu, Wei; Zhao, Xing-Zhong

    2016-01-01

    Suppression of the reticuloendothelial system (RES) uptake is one of the most challenging tasks in nanomedicine. Coating stratagems using polymers, such as poly(ethylene glycol) (PEG), have led to great success in this respect. Nevertheless, recent observations of immunological response toward these synthetic polymers have triggered a search for better alternatives. In this work, natural red blood cell (RBC) membranes are camouflaged on the surface of Fe 3 O 4 nanoparticles for reducing the RES uptake. In vitro macrophage uptake, in vivo biodistribution and pharmacokinetic studies demonstrate that the RBC membrane is a superior alternative to the current gold standard PEG for nanoparticle ‘stealth’. Furthermore, we systematically investigate the in vivo potential toxicity of RBC membrane-coated nanoparticles by blood biochemistry, whole blood panel examination and histology analysis based on animal models. The combination of synthetic nanoparticles and natural cell membranes embodies a novel and biomimetic nanomaterial design strategy and presents a compelling property of functional materials for a broad range of biomedical applications. (paper)

  2. Collecting soil vapor from the Vadose Zone with an instrumented membrane system

    International Nuclear Information System (INIS)

    Martins, S.A.

    1992-07-01

    As part of an on-going program to monitor ground water pollution, the SEAMIST instrumented membrane system was purchased and installed in two boreholes at the Lawrence Livermore National Laboratory (LLNL). SEAMIST is a flexible, removable, polyvinylchloride-coated, nylon membrane tube used to seal the sides of a borehole and to which sampling devices and other types of instrumentation may be attached. This paper describes a method to sample soil vapor (a component of soil gas) with the SEAMIST system from a borehole at several depths simultaneously. The cryotraps used with this technique were tested for their collection efficiency, and those data are presented. Data on the integrity of the SEAMIST borehole seal are also reported

  3. An integrated membrane system for the biocatalytic production of 3′-sialyllactose from dairy by-products

    DEFF Research Database (Denmark)

    Luo, Jianquan; Nordvang, Rune Thorbjørn; Morthensen, Sofie Thage

    2014-01-01

    An integrated membrane system was investigated for the production of 30-sialyllactose by an engineered sialidase using casein glycomacropeptide (CGMP) and lactose as substrates. CGMP was purified by ultrafiltration (UF) to remove any small molecules present and then an enzymatic membrane reactor ...

  4. A Fluid Membrane-Based Soluble Ligand Display System for Live CellAssays

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jwa-Min; Nair, Pradeep N.; Neve, Richard M.; Gray, Joe W.; Groves, Jay T.

    2005-10-14

    Cell communication modulates numerous biological processes including proliferation, apoptosis, motility, invasion and differentiation. Correspondingly, there has been significant interest in the development of surface display strategies for the presentation of signaling molecules to living cells. This effort has primarily focused on naturally surface-bound ligands, such as extracellular matrix components and cell membranes. Soluble ligands (e.g. growth factors and cytokines) play an important role in intercellular communications, and their display in a surface-bound format would be of great utility in the design of array-based live cell assays. Recently, several cell microarray systems that display cDNA, RNAi, or small molecules in a surface array format were proven to be useful in accelerating high-throughput functional genetic studies and screening therapeutic agents. These surface display methods provide a flexible platform for the systematic, combinatorial investigation of genes and small molecules affecting cellular processes and phenotypes of interest. In an analogous sense, it would be an important advance if one could display soluble signaling ligands in a surface assay format that allows for systematic, patterned presentation of soluble ligands to live cells. Such a technique would make it possible to examine cellular phenotypes of interest in a parallel format with soluble signaling ligands as one of the display parameters. Herein we report a ligand-modified fluid supported lipid bilayer (SLB) assay system that can be used to functionally display soluble ligands to cells in situ (Figure 1A). By displaying soluble ligands on a SLB surface, both solution behavior (the ability to become locally enriched by reaction-diffusion processes) and solid behavior (the ability to control the spatial location of the ligands in an open system) could be combined. The method reported herein benefits from the naturally fluid state of the supported membrane, which allows

  5. Ethanol production in an integrated fermentation/membrane system. Process simulations and economics

    Energy Technology Data Exchange (ETDEWEB)

    Groot, W J; Kraayenbrink, M R; Lans, R.G.J.M. van der; Luyben, K C.A.M. [Delft Univ. of Technology (Netherlands). Dept. of Biochemical Engineering

    1993-01-01

    Four systems comprising of an ethanol fermentation integrated with microfiltration and/or pervaporation, and a conventional continuous culture, were compared with respect to the performance of the fermentation and economics. The processes are compared on the basis of the same kinetic model. It is found that cell retention by microfiltration leads to lower production costs, compared to a conventional continuous culture. Pervaporation becomes profitable at a high selectivity of ethanol/water separation and low membrane prices. (orig.).

  6. A hybrid system of a membrane oscillator coupled to ultracold atoms

    Science.gov (United States)

    Kampschulte, Tobias

    2015-05-01

    The control over micro- and nanomechanical oscillators has recently made impressive progress. First experiments demonstrated ground-state cooling and single-phonon control of high-frequency oscillators using cryogenic cooling and techniques of cavity optomechanics. Coupling engineered mechanical structures to microscopic quantum system with good coherence properties offers new possibilities for quantum control of mechanical vibrations, precision sensing and quantum-level signal transduction. Ultracold atoms are an attractive choice for such hybrid systems: Mechanical can either be coupled to the motional state of trapped atoms, which can routinely be ground-state cooled, or to the internal states, for which a toolbox of coherent manipulation and detection exists. Furthermore, atomic collective states with non-classical properties can be exploited to infer the mechanical motion with reduced quantum noise. Here we use trapped ultracold atoms to sympathetically cool the fundamental vibrational mode of a Si3N4 membrane. The coupling of membrane and atomic motion is mediated by laser light over a macroscopic distance and enhanced by an optical cavity around the membrane. The observed cooling of the membrane from room temperature to 650 +/- 230 mK shows that our hybrid mechanical-atomic system operates at a large cooperativity. Our scheme could provide ground-state cooling and quantum control of low-frequency oscillators such as levitated nanoparticles, in a regime where purely optomechanical techniques cannot reach the ground state. Furthermore, we will present a scheme where an optomechanical system is coupled to internal states of ultracold atoms. The mechanical motion is translated into a polarization rotation which drives Raman transitions between atomic ground states. Compared to the motional-state coupling, the new scheme enables to couple atoms to high-frequency structures such as optomechanical crystals.

  7. Hybrid membrane system for desalination and wastewater treatment: Integrating forward osmosis and low pressure reverse osmosis

    OpenAIRE

    Valladares Linares, R.

    2014-01-01

    Since more than 97% of the water in the world is seawater, desalination technologies have the potential to solve the fresh water crisis. The most used desalination technology nowadays is seawater reverse osmosis (SWRO), where a membrane is used as a physical barrier to separate the salts from the water, using high hydraulic pressure as the driving force. However, the use of high hydraulic pressure imposes a high cost on operation of these systems, in addition to the known persistent fouling p...

  8. Efficient treatment of aniline containing wastewater in bipolar membrane microbial electrolysis cell-Fenton system.

    Science.gov (United States)

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan; Angelidaki, Irini; Zhang, Yifeng

    2017-08-01

    Aniline-containing wastewater can cause significant environmental problems and threaten the humans's life. However, rapid degradation of aniline with cost-efficient methods remains a challenge. In this work, a novel microbial electrolysis cell with bipolar membrane was integrated with Fenton reaction (MEC-Fenton) for efficient treatment of real wastewater containing a high concentration (4460 ± 52 mg L -1 ) of aniline. In this system, H 2 O 2 was in situ electro-synthesized from O 2 reduction on the graphite cathode and was simultaneously used as source of OH for the oxidation of aniline wastewater under an acidic condition maintained by the bipolar membrane. The aniline was effectively degraded following first-order kinetics at a rate constant of 0.0166 h -1 under an applied voltage of 0.5 V. Meanwhile, a total organic carbon (TOC) removal efficiency of 93.1 ± 1.2% was obtained, revealing efficient mineralization of aniline. The applicability of bipolar membrane MEC-Fenton system was successfully demonstrated with actual aniline wastewater. Moreover, energy balance showed that the system could be a promising technology for removal of biorefractory organic pollutants from wastewaters. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. MEMBRANE ACTION IN PROFILED STEEL SHEETING DRY BOARD (PSSDB FLOOR SLAB SYSTEM

    Directory of Open Access Journals (Sweden)

    MAHMOOD SERAJI

    2013-02-01

    Full Text Available Profiled steel sheeting dry board (PSSDB system is a lightweight composite structural system that made of the profiled steel sheeting (PSS connected to the dry board (DB by self-drilling and self-tapping screws. The objective of this paper is to study the effect of membrane action in improving the flexural capacities of the PSSDB system. According to the literatures, common failure of the PSSDB floor is due to local buckling in the top flanges of steel sheeting at the centre of a simply supported slab. Restraining the horizontal movement at supports may develop the membrane action (MA in the slab that can remarkably enhance the flexural rigidities of the floor. Experimental tests were conducted along with developing nonlinear finite element model to explore the effect of MA in the PSSDB floor. Experimental results of the PSSDB panel with simply end support were exploited to verify the nonlinear finite element results. The developed finite element model was then modified by restraining the horizontal movement of the slab at the supports. The obtained results disclosed that the developed compressive membrane action enhanced the stiffness of the slab at serviceability load by about 240%.

  10. EFFECTS OF PRESSURE AND TEMPERATURE ON ULTRAFILTRATION HOLLOW FIBER MEMBRANE IN MOBILE WATER TREATMENT SYSTEM

    Directory of Open Access Journals (Sweden)

    ROSDIANAH RAMLI

    2016-07-01

    Full Text Available In Sabah, Malaysia, there are still high probability of limited clean water access in rural area and disaster site. Few villages had been affected in Pitas due to improper road access, thus building a water treatment plant there might not be feasible. Recently, Kundasang area had been affected by earthquake that caused water disruption to its people due to the damage in the underground pipes and water tanks. It has been known that membrane technology brought ease in making mobile water treatment system that can be transported to rural or disaster area. In this study, hollow fiber membrane used in a mobile water treatment system due to compact and ease setup. Hollow fiber membrane was fabricated into small module at 15 and 30 fibers to suit the mobile water treatment system for potable water production of at least 80 L/day per operation. The effects of transmembrane pressure (TMP and feed water temperature were investigated. It was found that permeate flux increases by more than 96% for both 15 and 30 fiber bundles with increasing pressure in the range of 0.25 to 3.0 bar but dropped when the pressure reached maximum. Lower temperature of 17 to 18˚C increase the water viscosity by 15% from normal temperature of water at 24˚C, making the permeate flux decreases. The fabricated modules effectively removed 96% turbidity of the surface water sample tested.

  11. Effect of water temperature on biofouling development in reverse osmosis membrane systems.

    Science.gov (United States)

    Farhat, N M; Vrouwenvelder, J S; Van Loosdrecht, M C M; Bucs, Sz S; Staal, M

    2016-10-15

    Understanding the factors that determine the spatial and temporal biofilm development is a key to formulate effective control strategies in reverse osmosis membrane systems for desalination and wastewater reuse. In this study, biofilm development was investigated at different water temperatures (10, 20, and 30 °C) inside a membrane fouling simulator (MFS) flow cell. The MFS studies were done at the same crossflow velocity with the same type of membrane and spacer materials, and the same feed water type and nutrient concentration, differing only in water temperature. Spatially resolved biofilm parameters such as oxygen decrease rate, biovolume, biofilm spatial distribution, thickness and composition were measured using in-situ imaging techniques. Pressure drop (PD) increase in time was used as a benchmark as to when to stop the experiments. Biofilm measurements were performed daily, and experiments were stopped once the average PD increased to 40 mbar/cm. The results of the biofouling study showed that with increasing feed water temperature (i) the biofilm activity developed faster, (ii) the pressure drop increased faster, while (iii) the biofilm thickness decreased. At an average pressure drop increase of 40 mbar/cm over the MFS for the different feed water temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high temperature feed water are more susceptible to biofouling than installations fed with low temperature feed water. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Use of membrane vesicles as a simplified system for studying auxin transport of auxin: Progress report

    International Nuclear Information System (INIS)

    Goldsmith, M.H.M.

    1986-01-01

    Indoleacetic acid (IAA), the auxin regulating growth, is transported polarly in plants. IAA stimulates a rapid increase in the rate of electrogenic proton secretion by the plasma membrane. This not only increases the magnitude of the pH and electrical gradients providing the driving force for polar auxin transport and uptake of sugars, amino acids and inorganic ions, but, by acidifying the cell wall, also leads to growth. We find that auxin uptake by membrane vesicles isolated from actively growing plant tissues exhibits some of the same properties as by cells: the accumulation depends on the pH gradient, is saturable and specific for auxin, and enhanced by herbicides that inhibit polar auxin transport. We are using accumulation of a radioactive weak acid to quantify the pH gradient and distribution of fluorescent cyanine dyes to monitor the membrane potential. The magnitude of IAA accumulation exceeds that predicted from the pH gradient, and in the absence of a pH gradient, a membrane potential fails to support any auxin accumulation, leading to the conclusion that the transmembrane potential is not a significant driving force for auxin accumulation in this system. Since increasing the external ionic strength decreases saturable auxin accumulation, we are investigating how modifying the surface potential of the vesicles affects the interaction of the amphipathic IAA molecules with the membranes and whether protein modifying reagents affect the saturability and stimulation by NPA. These studies should provide information on the location and function of the auxin binding site and may enable us to identify the solubilized protein. 5 refs

  13. Control and experimental characterization of a methanol reformer for a 350W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    suited for reformer systems, where high CO tolerance is required. This enables the use fuels based on e.g. liquid alcohols. This work presents the control strategies of a methanol refoermer for a 350W HTPEM FC system. The system examined is the Serenergy H3-350 Mobile Battery Charger, an integrated......High temperature polymer electrolyte membrane(HTPEM) fuel cells offer many advantages due to their increased operating tempera-tures compared to similar Nafion-based membrane tech-nologies, that rely on the conductive abilities of liquid water. The polybenzimidazole (PBI) membranes are especially...

  14. Membranous nephropathy

    Science.gov (United States)

    ... skin-lightening creams Systemic lupus erythematosus , rheumatoid arthritis, Graves disease, and other autoimmune disorders The disorder occurs at ... diagnosis. The following tests can help determine the cause of membranous nephropathy: Antinuclear antibodies test Anti-double- ...

  15. Analytical solutions for a single vertical drain with time-dependent vacuum combined surcharge preloading in membrane and membraneless systems

    International Nuclear Information System (INIS)

    Geng, X Y; Indraratna, B; Rujikiatkamjorn, C

    2010-01-01

    Vertical drains combined with vacuum pressure and surcharge preloading are widely used to accelerate the consolidation process of soft clay in order to decrease the pore pressure as well as to increase the effective stress. Currently there are two types of vacuum preloading systems commercially available; (a) membrane system with an airtight membrane over the drainage layer and, (b) membraneless system where a vacuum system is connected to individual drain. Their effectiveness varies from site to site depending on the type of soil treated and the characteristics of the drain-vacuum system. This study presents the analytical solutions of vertical drains with vacuum preloading for both membrane and membraneless systems. According to the field and laboratory observations, the vacuum in both of the membraneless and membrane system was assumed to be decreasing along the drain whereas in the membrane system, it was maintained at a constant level. This model was verified by using the measured settlements and excess pore pressures obtained from large-scale laboratory testing and case studies in Australia. The analytical solutions improved the accuracy of predicting the dissipation of pore water pressure and the associated settlement. The effects of the permeability of the sand blanket in a membrane system and the possible loss of vacuum were also discussed.

  16. A Linear Time Complexity of Breadth-First Search Using P System with Membrane Division

    Directory of Open Access Journals (Sweden)

    Einallah Salehi

    2013-01-01

    Full Text Available One of the known methods for solving the problems with exponential time complexity such as NP-complete problems is using the brute force algorithms. Recently, a new parallel computational framework called Membrane Computing is introduced which can be applied in brute force algorithms. The usual way to find a solution for the problems with exponential time complexity with Membrane Computing techniques is by P System with active membrane using division rule. It makes an exponential workspace and solves the problems with exponential complexity in a polynomial (even linear time. On the other hand, searching is currently one of the most used methods for finding solution for problems in real life, that the blind search algorithms are accurate, but their time complexity is exponential such as breadth-first search (BFS algorithm. In this paper, we proposed a new approach for implementation of BFS by using P system with division rule technique for first time. The theorem shows time complexity of BSF in this framework on randomly binary trees reduced from O(2d to O(d.

  17. Application of vacuum membrane distillation to lithium bromide absorption refrigeration system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Zanshe; Feng, Shiyu; Li, Yun [School of Energy and Power Engineering, Xi' an Jiaotong University, Xi' an 710049 (China); Gu, Zhaolin [School of Human Settlement and Civil Engineering, Xi' an Jiaotong University, Xi' an 710049 (China)

    2009-11-15

    Conventional generator in lithium bromide absorption refrigeration system is too bulky and heavy to be fitted into small scale device, and the temperature of the driving heater in the generator seems much higher than low grade energy such as regenerative energy or waste heat energy. In this paper, desorption of aqueous lithium bromide solution by vacuum membrane distillation process was presented. Hollow fiber membrane module made by polyvinylidene fluoride was used as desorption device of aqueous lithium bromide solution. Influencing factors of feed flux, feed temperature in lumen side and vacuum pressure in shell side were tested and analyzed with orthogonal test. The results showed that permeation flux of water vapor increased with the feed temperature increasing and the feed flux increasing in lumen side, and the permeation flux also went up along with absolute pressure drop in shell side. Feasibility and potential application analysis shows that the temperature of the driving heat was low and the volume and weight of the desorption device was light. In this study, vacuum membrane distillation to the lithium bromide absorption refrigeration system has proved to be an efficient and cheap desorption mode. (author)

  18. Phosphorus and water recovery by a novel osmotic membrane bioreactor-reverse osmosis system.

    Science.gov (United States)

    Luo, Wenhai; Hai, Faisal I; Price, William E; Guo, Wenshan; Ngo, Hao H; Yamamoto, Kazuo; Nghiem, Long D

    2016-01-01

    An osmotic membrane bioreactor-reverse osmosis (OMBR-RO) hybrid system integrated with periodic microfiltration (MF) extraction was evaluated for simultaneous phosphorus and clean water recovery from raw sewage. In this hybrid system, the forward osmosis membrane effectively retained inorganic salts and phosphate in the bioreactor, while the MF membrane periodically bled them out for phosphorus recovery with pH adjustment. The RO process was used for draw solute recovery and clean water production. Results show that phosphorus recuperation from the MF permeate was most effective when the solution pH was adjusted to 10, whereby the recovered precipitate contained 15-20% (wt/wt) of phosphorus. Periodic MF extraction also limited salinity build-up in the bioreactor, resulting in a stable biological performance and an increase in water flux during OMBR operation. Despite the build-up of organic matter and ammonia in the draw solution, OMBR-RO allowed for the recovery of high quality reused water. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  19. Further Improvement and System Integration of High Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Jensen, Jens Oluf; Li, Qingfeng

    Polymer electrolyte membrane fuel cell (PEMFC) technology based on Nafion membranes can operate at temperatures around 80°C. The new development in the field is high temperature PEMFC for operation above 100°C, which has been successfully demonstrated through the previous EC Joule III and the 5th......, and system integration of the high temperature PEMFC. The strategic developments of the FURIM are in three steps: (1) further improvement of the high temperature polymer membranes and related materials; (2) development of technological units including fuel cell stack, hydrocarbon reformer, afterburner...... and power management system, that are compatible with the HT-PEMFC; and (3) integration of the HT-PEMFC stack with these compatible subunits. The main goal of the project is a 2kWel HT-PEMFC stack operating in a temperature range of 120-220°C, with a single cell performance target of 0.7 A/cm² at a cell...

  20. Polyethersulfone-based ultrafiltration hollow fibre membrane for drinking water treatment systems

    Science.gov (United States)

    Chew, Chun Ming; Ng, K. M. David; Ooi, H. H. Richard

    2017-12-01

    Conventional media/sand filtration has been the mainstream water treatment process for most municipal water treatment plants in Malaysia. Filtrate qualities of conventional media/sand filtration are very much dependent on the coagulation-flocculation process prior to filtration and might be as high as 5 NTU. However, the demands for better quality of drinking water through public piped-water supply systems are growing. Polymeric ultrafiltration (UF) hollow fibre membrane made from modified polyethersulfone (PES) material is highly hydrophilic with high tensile strength and produces excellent quality filtrate of below 0.3 NTU in turbidity. This advanced membrane filtration material is also chemical resistance which allows a typical lifespan of 5 years. Comparisons between the conventional media/sand filtration and PES-based UF systems are carried out in this paper. UF has been considered as the emerging technology in municipal drinking water treatment plants due to its consistency in producing high quality filtrates even without the coagulation-flocculation process. The decreasing cost of PES-based membrane due to mass production and competitive pricing by manufacturers has made the UF technology affordable for industrial-scale water treatment plants.

  1. Therapeutic drug monitoring of flucytosine in serum using a SERS-active membrane system

    Science.gov (United States)

    Berger, Adam G.; White, Ian M.

    2017-02-01

    A need exists for near real-time therapeutic drug monitoring (TDM), in particular for antibiotics and antifungals in patient samples at the point-of-care. To truly fit the point-of-care need, techniques must be rapid and easy to use. Here we report a membrane system utilizing inkjet-fabricated surface enhanced Raman spectroscopy (SERS) sensors that allows sensitive and specific analysis despite the elimination of sophisticated chromatography equipment, expensive analytical instruments, and other systems relegated to the central lab. We utilize inkjet-fabricated paper SERS sensors as substrates for 5FC detection; the use of paper-based SERS substrates leverages the natural wicking ability and filtering properties of microporous membranes. We investigate the use of microporous membranes in the vertical flow assay to allow separation of the flucytosine from whole blood. The passive vertical flow assay serves as a valuable method for physical separation of target analytes from complex biological matrices. This work further establishes a platform for easy, sensitive, and specific TDM of 5FC from whole blood.

  2. Ancient Systems of Sodium/Potassium Homeostasis as Predecessors of Membrane Bioenergetics.

    Science.gov (United States)

    Dibrova, D V; Galperin, M Y; Koonin, E V; Mulkidjanian, A Y

    2015-05-01

    Cell cytoplasm of archaea, bacteria, and eukaryotes contains substantially more potassium than sodium, and potassium cations are specifically required for many key cellular processes, including protein synthesis. This distinct ionic composition and requirements have been attributed to the emergence of the first cells in potassium-rich habitats. Different, albeit complementary, scenarios have been proposed for the primordial potassium-rich environments based on experimental data and theoretical considerations. Specifically, building on the observation that potassium prevails over sodium in the vapor of inland geothermal systems, we have argued that the first cells could emerge in the pools and puddles at the periphery of primordial anoxic geothermal fields, where the elementary composition of the condensed vapor would resemble the internal milieu of modern cells. Marine and freshwater environments generally contain more sodium than potassium. Therefore, to invade such environments, while maintaining excess of potassium over sodium in the cytoplasm, primordial cells needed means to extrude sodium ions. The foray into new, sodium-rich habitats was the likely driving force behind the evolution of diverse redox-, light-, chemically-, or osmotically-dependent sodium export pumps and the increase of membrane tightness. Here we present a scenario that details how the interplay between several, initially independent sodium pumps might have triggered the evolution of sodium-dependent membrane bioenergetics, followed by the separate emergence of the proton-dependent bioenergetics in archaea and bacteria. We also discuss the development of systems that utilize the sodium/potassium gradient across the cell membranes.

  3. Molecular dynamics simulations of Na+/Cl--dependent neurotransmitter transporters in a membrane-aqueous system

    DEFF Research Database (Denmark)

    Jørgensen, Anne Marie; Tagmose, L.; Jørgensen, A.M.M.

    2007-01-01

    We have performed molecular dynamics simulations of a homology model of the human serotonin transporter (hSERT) in a membrane environment and in complex with either the natural substrate S-HT or the selective serotonin reuptake inhibitor escitaloprom. We have also included a transporter homologue......, the Aquifex aeolicus leucine transporter (LeuT), in our study to evaluate the applicability of a simple and computationally attractive membrane system. Fluctuations in LeuT extracted from simulations are in good agreement with crystal logrophic B factors. Furthermore, key interactions identified in the X....... Specific interactions responsible for ligand recognition, are identified in the hSERT-5HT and hSERT-escitaloprom complexes. Our finding5 are in good agreement with predictions from mutagenesis studies....

  4. Bromate formation in a hybrid ozonation-ceramic membrane filtration system.

    Science.gov (United States)

    Moslemi, Mohammadreza; Davies, Simon H; Masten, Susan J

    2011-11-01

    The effect of pH, ozone mass injection rate, initial bromide concentration, and membrane molecular weight cut off (MWCO) on bromate formation in a hybrid membrane filtration-ozonation reactor was studied. Decreasing the pH, significantly reduced bromate formation. Bromate formation increased with increasing gaseous ozone mass injection rate, due to increase in dissolved ozone concentrations. Greater initial bromide concentrations resulted in higher bromate concentrations. An increase in the bromate concentration was observed by reducing MWCO, which resulted in a concomitant increase in the retention time in the system. A model to estimate the rate of bromate formation was developed. Good correlation between the model simulation and the experimental data was achieved. Copyright © 2011 Elsevier Ltd. All rights reserved.

  5. Further Improvement and System Integration of High Temperature Polymer Electrolyte Membrane Fuel Cells

    DEFF Research Database (Denmark)

    Li, Qingfeng; Jensen, Jens Oluf

    The new development in the field of polymer electrolyte membrane fuel cell (PEMFC) is high temperature PEMFC for operation above 100°C, which has been successfully demonstrated through the previous EC Joule III and the 5th framework programme. New challenges are encountered, bottlenecks for the new...... technology have been identified, and new concepts and solutions have been provisionally identified. FURIM is directed at tackling these key issues by concentrating on the further materials development, compatible technologies, and system integration of the high temperature PEMFC. The strategic developments...... of the FURIM are in three steps: (1) further improvement of the high temperature polymer membranes and related materials; (2) development of technological units including fuel cell stack, hydrocarbon reformer and afterburner, that are compatible with the HT-PEMFC; and (3) integration of the HT-PEMFC stack...

  6. Optical Biosensor with Multienzyme System Immobilized onto Hybrid Membrane for Pesticides Determination

    Directory of Open Access Journals (Sweden)

    Lyubov Yotova

    2011-12-01

    Full Text Available A construction of optical biosensor based on simultaneous immobilization of acetylcholinesterase and choline oxidase enzymes for the detection of pesticides residues is described. Different kinds of novel SiO2 hybrid membranes were synthesized to be suitable for optical biosensors using sol-gel techniques. The bioactive component of the sensor consists of a multi-enzyme system including acetylcholinesterase and choline oxidase covalently immobilized on new hybrid membranes. The sensor exhibited a linear response to acetylcholine in a concentration range of 2.5 - 30 mM. Inhibition plots obtained from testing carbamate (carbofuran pesticides exhibited concentration dependent behaviour and showed linear profiles in concentration ranges between 5x10-8 - 5x10-7 M for carbofuran. The factors affecting the constructed optical biosensors were investigated.

  7. Exergoeconomic analysis of vehicular PEM (proton exchange membrane) fuel cell systems with and without expander

    International Nuclear Information System (INIS)

    Sayadi, Saeed; Tsatsaronis, George; Duelk, Christian

    2014-01-01

    In this paper we perform an exergoeconomic analysis to a PEM (proton exchange membrane) vehicular fuel cell system used in the latest generation of environmentally friendly cars. Two alternative configurations of a fuel cell system are considered (with and without an expander), and two alternative design concepts for each configuration: BoL (Begin of Life) and EoL (End of Life). The system including an expander generates additional power from the exhaust gases leaving the fuel cell stack, which might increase the system efficiency. However the total investment costs for this case are higher than for the other system configuration without an expander, due to the investment costs associated with the expander and its accessories. The fuel cell stack area in the EoL-sized systems is larger than in the BoL-sized systems. A larger stack area on one hand raises the investment costs, but on the other hand decreases the fuel consumption due to a higher cell efficiency. In this paper, exergoeconomic analyses have been implemented to consider a trade-off between positive and negative effects of using an expander in the system and to select the proper design concept. The results from the exergoeconomic analysis show that (a) an EoL-sized system with an expander is the most cost effective system, (b) the compression and humidification of air are very expensive processes, (c) the stack is by far the most important component from the economic viewpoint, and (d) the thermodynamic efficiency of almost all components must be improved to increase the cost effectiveness of the overall system. - Highlights: • Two vehicular PEM (proton exchange membrane) fuel cell system configurations are studied in this paper. • Exergoeconomics has been performed to compare these two system configurations. • The compression and humidification of air are very expensive processes. • The stack is by far the most important component from the economic viewpoint. • The thermodynamic efficiencies

  8. Estimation of Membrane Hydration Status for Standby Proton Exchange Membrane Fuel Cell Systems by Impedance Measurement: First Results on Stack Characterization

    DEFF Research Database (Denmark)

    Bidoggia, Benoit; Kær, Søren Knudsen

    Fuel cells have started replacing traditional lead-acid battery banks in backup systems. Although these systems are characterized by long periods of standby, they must be able to start at any instant in the shortest time. In the case of low temperature proton exchange membrane fuel cell systems......, a precise estimation of hydration status of the fuel cell during standby is important for a fast and safe startup. In this article, the measurement of the complex impedance of the fuel cell is suggested as a method to estimate the membrane hydration status. A 56-cell fuel cell stack has been symmetrically...... fed with air whose temperature and relative humidity were controlled, and its complex impedance was measured at different frequencies and for different values of relative humidity. After showing that the experiment was repeatable, the fuel cell stack was characterized, a power regression model...

  9. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi; N'Doye, Ibrahima; Laleg-Kirati, Taous-Meriem

    2015-01-01

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  10. [Successful treatment of surgically induced necrotizing sclerokeratitis (SINS) with systemic immunosuppresive agents and amniotic membrane grafting].

    Science.gov (United States)

    Cordero-Coma, M; Franco-Benito, M; García-Ruiz-de-Morales, J M; Alonso-Orcajo, N; Del Barrio-Manso, I

    2009-11-01

    We report the case of a 74-year-old female who developed a necrotizing sclerokeratitis affecting her left eye after uncomplicated cataract surgery. She had no previous history of systemic autoimmune disease. Histopathology of the lesion revealed necrotic granulomatosis with an increased number of plasma cells. Surgically induced necrotizing sclerokeratitis (SINS) is a serious entity which requires prompt and aggressive therapy to prevent its potential devastating ocular consequences. Conjunctival resection and amniotic membrane grafting may be necessary to temporarily interrupt local immunologic events in severe cases. However, associated systemic immunomodulatory therapy seems to be mandatory (Arch Soc Esp Oftalmol 2009; 84: 577-580).

  11. Boiler feedwater quality improvement by replacing conventional pre-treatment with advanced membrane systems

    Energy Technology Data Exchange (ETDEWEB)

    Doll, Bernhard [Process Systems Pall GmbH, Dreieich (Germany). Marketing; Venkatadri, Ramraj [Pall Corporation, Port Washington, NY (United States). Global Marketing Energy

    2013-09-01

    Two case studies in different application fields highlight significant economical and operational improvements that were achieved by replacing conventional water treatment technologies by highly-sophisticated membrane systems. The first case study deals with boiler feedwater in a power plant, focusing on the challenges faced as well as the direct and indirect benefits gained by the new system within a utility station. The second case study deals with the conventional water treatment scheme for groundwater from 13 wells at a major oil sands facility. Operational performance as well as the cost improvements gained in both cases will be presented. (orig.)

  12. Feedback control for distributed heat transfer mechanisms in direct-contact membrane distillation system

    KAUST Repository

    Eleiwi, Fadi

    2015-09-21

    In this paper, the problem of stabilization and production rate reference tracking for a Direct-Contact Membrane Distillation (DCMD) system is addressed. Sufficient conditions for the asymptotic and exponential stabilization for DCMD system are presented using the Gronwall-Bellman lemma and Linear Matrix Inequalities (LMIs) approaches, respectively. A nonlinear observer is then proposed to estimate the temperature distribution among the DCMD domain. This contributes to propose a reference production rate control design for the DCMD process via observer-based output control approach. Finally, numerical simulations are given to show the effectiveness of the proposed methods.

  13. Modeling and operation optimization of a proton exchange membrane fuel cell system for maximum efficiency

    International Nuclear Information System (INIS)

    Han, In-Su; Park, Sang-Kyun; Chung, Chang-Bock

    2016-01-01

    Highlights: • A proton exchange membrane fuel cell system is operationally optimized. • A constrained optimization problem is formulated to maximize fuel cell efficiency. • Empirical and semi-empirical models for most system components are developed. • Sensitivity analysis is performed to elucidate the effects of major operating variables. • The optimization results are verified by comparison with actual operation data. - Abstract: This paper presents an operation optimization method and demonstrates its application to a proton exchange membrane fuel cell system. A constrained optimization problem was formulated to maximize the efficiency of a fuel cell system by incorporating practical models derived from actual operations of the system. Empirical and semi-empirical models for most of the system components were developed based on artificial neural networks and semi-empirical equations. Prior to system optimizations, the developed models were validated by comparing simulation results with the measured ones. Moreover, sensitivity analyses were performed to elucidate the effects of major operating variables on the system efficiency under practical operating constraints. Then, the optimal operating conditions were sought at various system power loads. The optimization results revealed that the efficiency gaps between the worst and best operation conditions of the system could reach 1.2–5.5% depending on the power output range. To verify the optimization results, the optimal operating conditions were applied to the fuel cell system, and the measured results were compared with the expected optimal values. The discrepancies between the measured and expected values were found to be trivial, indicating that the proposed operation optimization method was quite successful for a substantial increase in the efficiency of the fuel cell system.

  14. Field-scale electrolysis/ceramic membrane system for the treatment of sewage from decentralized small communities.

    Science.gov (United States)

    Son, Dong-Jin; Kim, Woo-Yeol; Yun, Chan-Young; Kim, Dae-Gun; Chang, Duk; Sunwoo, Young; Hong, Ki-Ho

    2017-07-05

    The electrolysis process adopting copper electrodes and ceramic membrane with pore sizes of 0.1-0.2 μm were consisted to a system for the treatment of sewage from decentralized small communities. The system was operated under an HRT of 0.1 hour, voltage of 24 V, and TMP of 0.05 MPa. The system showed average removals of organics, nitrogen, phosphorus, and solids of up to 80%, 52%, 92%, and 100%, respectively. Removal of organics and nitrogen dramatically increased in proportion to increment of influent loading. Phosphorus and solids were remarkably eliminated by both electro-coagulation and membrane filtration. The residual particulate constituents could also be removed successfully through membrane process. A system composed of electrolysis process with ceramic membrane would be a compact, reliable, and flexible option for the treatment of sewage from decentralized small communities.

  15. Cost and Performance Report for Tri-Service Site Characterization and Analysis Penetrometer System (SCAPS) Membrane Interface Probe

    National Research Council Canada - National Science Library

    Myers, Karen

    2002-01-01

    The SCAPS ion trap mass spectrometer-Membrane Interface Probe (ITMS-MIP) system was developed to respond to the need for real-time, in situ measurements of subsurface volatile organic compounds (VOC...

  16. Oxygen transport membrane reactor based method and system for generating electric power

    Science.gov (United States)

    Kelly, Sean M.; Chakravarti, Shrikar; Li, Juan

    2017-02-07

    A carbon capture enabled system and method for generating electric power and/or fuel from methane containing sources using oxygen transport membranes by first converting the methane containing feed gas into a high pressure synthesis gas. Then, in one configuration the synthesis gas is combusted in oxy-combustion mode in oxygen transport membranes based boiler reactor operating at a pressure at least twice that of ambient pressure and the heat generated heats steam in thermally coupled steam generation tubes within the boiler reactor; the steam is expanded in steam turbine to generate power; and the carbon dioxide rich effluent leaving the boiler reactor is processed to isolate carbon. In another configuration the synthesis gas is further treated in a gas conditioning system configured for carbon capture in a pre-combustion mode using water gas shift reactors and acid gas removal units to produce hydrogen or hydrogen-rich fuel gas that fuels an integrated gas turbine and steam turbine system to generate power. The disclosed method and system can also be adapted to integrate with coal gasification systems to produce power from both coal and methane containing sources with greater than 90% carbon isolation.

  17. Organic semiconductor wastewater treatment using a four-stage Bardenpho with membrane system.

    Science.gov (United States)

    Chung, Jinwook; Fleege, Daniel; Ong, Say Kee; Lee, Yong-Woo

    2014-01-01

    Electronic wastewater from a semiconductor plant was treated with a pilot-scale four-stage Bardenpho process with membrane system. The system was operated over a 14-month period with an overall hydraulic retention time (HRT) ranging from 9.5 to 30 h. With a few exceptions, the pilot plant consistently treated the electronic wastewater with an average removal efficiency of chemical oxygen demand (COD) and total nitrogen of 97% and 93%, respectively, and achieving effluent quality of COD<15 mg/L, turbidity<1, and silt density index<1. Based on removal efficiencies of the pilot plant, it is possible to lower the HRT to less than 9.5 h to achieve comparable removal efficiencies. An energy-saving configuration where an internal recycle line was omitted and the biomass recycle was rerouted to the pre-anoxic tank, can reduce energy consumption by 8.6% and gave removal efficiencies that were similar to the Bardenpho process. The system achieved pre-anoxic and post-anoxic specific denitrification rate values with a 95% confidence interval of 0.091 ± 0.011 g NO₃-N/g MLVSS d and 0.087 ± 0.016 g NO₃-N/g MLVSS d, respectively. The effluent from the four-stage Bardenpho with membrane system can be paired with a reverse osmosis system to provide further treatment for reuse purposes.

  18. Exergy Analysis of Air-Gap Membrane Distillation Systems for Water Purification Applications

    Directory of Open Access Journals (Sweden)

    Daniel Woldemariam

    2017-03-01

    Full Text Available Exergy analyses are essential tools for the performance evaluation of water desalination and other separation systems, including those featuring membrane distillation (MD. One of the challenges in the commercialization of MD technologies is its substantial heat demand, especially for large scale applications. Identifying such heat flows in the system plays a crucial role in pinpointing the heat loss and thermal integration potential by the help of exergy analysis. This study presents an exergetic evaluation of air-gap membrane distillation (AGMD systems at a laboratory and pilot scale. A series of experiments were conducted to obtain thermodynamic data for the water streams included in the calculations. Exergy efficiency and destruction for two different types of flat-plate AGMD were analyzed for a range of feed and coolant temperatures. The bench scale AGMD system incorporating condensation plate with more favorable heat conductivity contributed to improved performance parameters including permeate flux, specific heat demand, and exergy efficiency. For both types of AGMD systems, the contributions of the major components involved in exergy destruction were identified. The result suggested that the MD modules caused the highest fraction of destructions followed by re-concentrating tanks.

  19. Primordial membranes

    DEFF Research Database (Denmark)

    Hanczyc, Martin M; Monnard, Pierre-Alain

    2017-01-01

    Cellular membranes, which are self-assembled bilayer structures mainly composed of lipids, proteins and conjugated polysaccharides, are the defining feature of cell physiology. It is likely that the complexity of contemporary cells was preceded by simpler chemical systems or protocells during...... the various evolutionary stages that led from inanimate to living matter. It is also likely that primitive membranes played a similar role in protocell 'physiology'. The composition of such ancestral membranes has been proposed as mixtures of single hydrocarbon chain amphiphiles, which are simpler versions...

  20. Periodic mesoporous organosilica-doped nanocomposite membranes and systems including same

    KAUST Repository

    Hammami, Mohamed Amen

    2017-12-28

    A periodic mesoporous organosilica (PMO) nanoparticle functionalized nanocomposite membrane (NCM) for membrane distillation, the NCM including: polymer fibers such as polyetherimide fibers aggregated into a matrix; and hydrophobic PMO nanoparticles disposed on the polymer fibers. The PMO nanoparticles include a framework connected by organic groups and pentafluorophenyl groups. Good membrane flux and anti-fouling was demonstrated. Membranes can be prepared by electrospinning.

  1. Periodic mesoporous organosilica-doped nanocomposite membranes and systems including same

    KAUST Repository

    Hammami, Mohamed Amen; Francis, Lijo; Croissant, Jonas; Ghaffour, NorEddine; Alsaiari, Shahad; Khashab, Niveen M.

    2017-01-01

    A periodic mesoporous organosilica (PMO) nanoparticle functionalized nanocomposite membrane (NCM) for membrane distillation, the NCM including: polymer fibers such as polyetherimide fibers aggregated into a matrix; and hydrophobic PMO nanoparticles disposed on the polymer fibers. The PMO nanoparticles include a framework connected by organic groups and pentafluorophenyl groups. Good membrane flux and anti-fouling was demonstrated. Membranes can be prepared by electrospinning.

  2. Systems and methods for using a boehmite bond-coat with polyimide membranes for gas separation

    Science.gov (United States)

    Polishchuk, Kimberly Ann

    2013-03-05

    The subject matter disclosed herein relates to gas separation membranes and, more specifically, to polyimide gas separation membranes. In an embodiment, a gas separation membrane includes a porous substrate, a substantially continuous polyimide membrane layer, and one or more layers of boehmite nanoparticles disposed between the porous substrate and the polyimide membrane layer to form a bond-coat layer. The bond-coat layer is configured to improve the adhesion of the polyimide membrane layer to the porous substrate, and the polyimide membrane layer has a thickness approximately 100 nm or less.

  3. A heat pump driven and hollow fiber membrane-based liquid desiccant air dehumidification system: Modeling and experimental validation

    International Nuclear Information System (INIS)

    Zhang, Li-Zhi; Zhang, Ning

    2014-01-01

    A compression heat pump driven and membrane-based liquid desiccant air dehumidification system is presented. The dehumidifier and the regenerator are made of two hollow fiber membrane bundles packed in two shells. Water vapor can permeate through these membranes effectively, while the liquid desiccant droplets are prevented from cross-over. Simultaneous heating and cooling of the salt solution are realized with a heat pump system to improve energy efficiency. In this research, the system is built up and a complete modeling is performed for the system. Heat and mass transfer processes in the membrane modules, as well as in the evaporator, the condenser, and other key components are modeled in detail. The whole model is validated by experiment. The performances of SDP (specific dehumidification power), dehumidification efficiency, EER (energy efficiency ratio) of heat pump, and the COP (coefficient of performance) of the system are investigated numerically and experimentally. The results show that the model can predict the system accurately. The dehumidification capabilities and the energy efficiencies of the system are high. Further, it performs well even under the harsh hot and humid South China weather conditions. - Highlights: • A membrane-based and heat pump driven air dehumidification system is proposed. • A real experimental set up is built and used to validate the model for the whole system. • Performance under design and varying operation conditions is investigated. • The system performs well even under harsh hot and humid conditions

  4. Ten years of industrial and municipal membrane bioreactor (MBR) systems - lessons from the field.

    Science.gov (United States)

    Larrea, Asun; Rambor, Andre; Fabiyi, Malcolm

    2014-01-01

    The use of membrane bioreactors (MBRs) in activated sludge wastewater treatment has grown significantly in the last decade. While there is growing awareness and knowledge about the application of MBR technology in municipal wastewater treatment, not much information is available on the application of MBRs in industrial wastewater treatment. A comparative study of design data, operating conditions and the major challenges associated with MBR operations in 24 MBR plants treating both municipal and industrial wastewater, built by and/or operated by Praxair, Inc., is presented. Of the 24 MBR systems described, 12 of the plants used high purity oxygen (HPO). By enabling a wide range of food/microorganism ratios and loading conditions in the same system, HPO MBR systems can extend the options available to industrial plant operators to meet the challenges of wide fluctuations in organic loading and footprint limitations. While fouling in industrial MBR systems can be an issue, adequate flux and permeability values can be reliably maintained by the use of good maintenance strategies and effective process controls (pretreatment, cleaning and membrane autopsies).

  5. Hybrid systems with lead-acid battery and proton-exchange membrane fuel cell

    Science.gov (United States)

    Jossen, Andreas; Garche, Juergen; Doering, Harry; Goetz, Markus; Knaupp, Werner; Joerissen, Ludwig

    Hybrid systems, based on a lead-acid battery and a proton-exchange membrane fuel cell (PEMFC) give the possibility to combine the advantages of both technologies. The benefits for different applications are discussed and the practical realisation of such systems is shown. Furthermore a numerical model for such a hybrid system is described and results are shown and discussed. The results show that the combination of lead-acid batteries and PEMFC shows advantages in case of applications with high peak power requirements (i.e. electric scooter) and applications where the fuel cell is used as auxiliary power supply to recharge the battery. The high efficiency of fuel cells at partial load operation results in a good fuel economy for recharging of lead-acid batteries with a fuel cell system.

  6. A New Hybrid Proton-Exchange-Membrane Fuel Cells-Battery Power System with Efficiencies Considered

    Science.gov (United States)

    Chao, Chung-Hsing; Shieh, Jenn-Jong

    Hybrid systems, based on lead-acid or lithium-ion batteries and proton-exchange-membrane fuel cells (PEMFCs), give the possibility of combining the benefit of both technologies. The merits of high energy density and power density for different applications are discussed in this paper in recognition of the practical realization of such hybrid power systems. Furthermore, experimental data for such a hybrid system is described and the results are shown and discussed. The results show that the combination of lead-acid batteries or lithium-ion batteries and PEMFCs shows advantages in cases of applications with high peak power requirements, such as electric scooters and applications where the fuel cell (FC) is used as an auxiliary power-supply to recharge the battery. The high efficiency of FCs operating with a partial load results in a good fuel economy for the purpose of recharging batteries within a FC system.

  7. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jurgen

    2013-10-31

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  8. Magnetically controlled permeability membranes

    KAUST Repository

    Kosel, Jü rgen; Khashab, Niveen M.; Zaher, Amir

    2013-01-01

    A bioactive material delivery system can include a thermoresponsive polymer membrane and nanowires distributed within the thermoresponsive polymer membrane. Magnetic activation of a thermoresponsive polymer membrane can take place via altering the magnetization or dimensions of nanowires dispersed or ordered within the membrane matrix.

  9. Advances in biotreatment of acid mine drainage and biorecovery of metals: 2. Membrane bioreactor system for sulfate reduction.

    Science.gov (United States)

    Tabak, Henry H; Govind, Rakesh

    2003-12-01

    Several biotreatmemt techniques for sulfate conversion by the sulfate reducing bacteria (SRB) have been proposed in the past, however few of them have been practically applied to treat sulfate containing acid mine drainage (AMD). This research deals with development of an innovative polypropylene hollow fiber membrane bioreactor system for the treatment of acid mine water from the Berkeley Pit, Butte, MT, using hydrogen consuming SRB biofilms. The advantages of using the membrane bioreactor over the conventional tall liquid phase sparged gas bioreactor systems are: large microporous membrane surface to the liquid phase; formation of hydrogen sulfide outside the membrane, preventing the mixing with the pressurized hydrogen gas inside the membrane; no requirement of gas recycle compressor; membrane surface is suitable for immobilization of active SRB, resulting in the formation of biofilms, thus preventing washout problems associated with suspended culture reactors; and lower operating costs in membrane bioreactors, eliminating gas recompression and gas recycle costs. Information is provided on sulfate reduction rate studies and on biokinetic tests with suspended SRB in anaerobic digester sludge and sediment master culture reactors and with SRB biofilms in bench-scale SRB membrane bioreactors. Biokinetic parameters have been determined using biokinetic models for the master culture and membrane bioreactor systems. Data are presented on the effect of acid mine water sulfate loading at 25, 50, 75 and 100 ml/min in scale-up SRB membrane units, under varied temperatures (25, 35 and 40 degrees C) to determine and optimize sulfate conversions for an effective AMD biotreatment. Pilot-scale studies have generated data on the effect of flow rates of acid mine water (MGD) and varied inlet sulfate concentrations in the influents on the resultant outlet sulfate concentration in the effluents and on the number of SRB membrane modules needed for the desired sulfate conversion in

  10. Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling Systems for the Advanced Extravehicular Mobility Unit Portable Life Support System

    Science.gov (United States)

    Bue, Grant C.; Makinen, Janice V.; Miller, Sean.; Campbell, Colin; Lynch, Bill; Vogel, Matt; Craft, Jesse; Petty, Brian

    2014-01-01

    Spacesuit Water Membrane Evaporator - Baseline heat rejection technology for the Portable Life Support System of the Advanced EMU center dot Replaces sublimator in the current EMU center dot Contamination insensitive center dot Can work with Lithium Chloride Absorber Radiator in Spacesuit Evaporator Absorber Radiator (SEAR) to reject heat and reuse evaporated water The Spacesuit Water Membrane Evaporator (SWME) is being developed to replace the sublimator for future generation spacesuits. Water in LCVG absorbs body heat while circulating center dot Warm water pumped through SWME center dot SWME evaporates water vapor, while maintaining liquid water - Cools water center dot Cooled water is then recirculated through LCVG. center dot LCVG water lost due to evaporation (cooling) is replaced from feedwater The Independent TCV Manifold reduces design complexity and manufacturing difficulty of the SWME End Cap. center dot The offset motor for the new BPV reduces the volume profile of the SWME by laying the motor flat on the End Cap alongside the TCV.

  11. Methods and systems for Raman and optical cross-interrogation in flow-through silicon membranes

    Science.gov (United States)

    Bond, Tiziana C.; Letant, Sonia E.

    2014-09-09

    Cross-interrogating photonic detection systems and methods are shown. A flow through photonic crystal membrane with a surface enhanced Raman scattering (SERS) substrate is provided with pores which are distributed along multiple regions. The pores of one region have walls to which a first type of target specific anchor can be attached, while pores of another region have walls to which a second type of target specific anchor can be attached. An optical arrangement out-of-plane to the SERS substrate is also provided for enhanced sensitivity and identification of target organisms.

  12. Viability in the production of a drug extracted from Ananas comosus by a flat membrane system

    Directory of Open Access Journals (Sweden)

    Francisco Luiz Gumes Lopes

    2012-06-01

    Full Text Available The aim of this work was to study the production of e bromelain from the Ananas comosus L. Merril, by determining the process conditions using flat membranes. The production system modeling generated a hyperbolical curve and the optimization by response surfaces showed an influence of the transmembrane pressure higher than the pH influence. The cost of the production of bromelain from A. comosus was estimated 9 to 13 times lower than Sigma's retail sales price and 6.5 to 8.5 times lower than when this enzyme was obtained through a liquid-liquid extraction, which showed the economical feasibility of the process.

  13. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    International Nuclear Information System (INIS)

    Wibowo,; Zakaria,; Lambang, Lullus; Triyono,; Muhayat, Nurul

    2016-01-01

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  14. Study on antilock brake system with elastic membrane vibration generated by controlled solenoid excitation

    Energy Technology Data Exchange (ETDEWEB)

    Wibowo,, E-mail: wibowo-uns@yahoo.com; Zakaria,, E-mail: zakaaria27@gmail.com; Lambang, Lullus, E-mail: lulus-l@yahoo.com; Triyono,, E-mail: tyon-bila@yahoo.co.id; Muhayat, Nurul, E-mail: nurulmuhayat@ymail.com [Mechanical Engineering Department, Sebelas Maret University, Surakarta 57128 (Indonesia)

    2016-03-29

    The most effective chassis control system for improving vehicle safety during severe braking is anti-lock braking system (ABS). Antilock effect can be gained by vibrate the pad brake at 7 to 20 cycle per second. The aim of this study is to design a new method of antilock braking system with membrane elastic vibrated by solenoid. The influence of the pressure fluctuations of brake fluid is investigated. Vibration data is collected using a small portable accelerometer-slam stick. The experiment results that the vibration of brake pad caused by controlled solenoid excitation at 10 Hz is obtained by our new method. The result of measurements can be altered by varying brake fluid pressure.

  15. Open absorption system for cooling and air conditioning using membrane contactors. 2006 annual report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R. [Materials Science and Technology (EMPA), Abteilung Bautechnologien, Duebendorf (Switzerland)

    2006-11-15

    This illustrated annual report for 2006 for the Swiss Federal Office of Energy (SFOE) reports on work being done on the development of an open absorption system for cooling and air-conditioning. The report reviews the construction of a first prototype and the manufacture of its components. The conceptual design of this new type of air handling unit (AHU), operating with a liquid desiccant, is discussed. The AHU is to be autonomous and the system will not require additional mechanical refrigeration. It is to be thermally driven at temperatures below 80 {sup o}C. Waste heat sources, solar collectors, district heating plants and co-generation systems are targeted as providers of thermal energy at this temperature level. Work carried out is reported on, including that on two-stream membrane contactors.

  16. Impact of organic nutrient load on biomass accumulation, feed channel pressure drop increase and permeate flux decline in membrane systems

    KAUST Repository

    Bucs, Szilard

    2014-12-01

    The influence of organic nutrient load on biomass accumulation (biofouling) and pressure drop development in membrane filtration systems was investigated. Nutrient load is the product of nutrient concentration and linear flow velocity. Biofouling - excessive growth of microbial biomass in membrane systems - hampers membrane performance. The influence of biodegradable organic nutrient load on biofouling was investigated at varying (i) crossflow velocity, (ii) nutrient concentration, (iii) shear, and (iv) feed spacer thickness. Experimental studies were performed with membrane fouling simulators (MFSs) containing a reverse osmosis (RO) membrane and a 31 mil thick feed spacer, commonly applied in practice in RO and nanofiltration (NF) spiral-wound membrane modules. Numerical modeling studies were done with identical feed spacer geometry differing in thickness (28, 31 and 34 mil). Additionally, experiments were done applying a forward osmosis (FO) membrane with varying spacer thickness (28, 31 and 34 mil), addressing the permeate flux decline and biofilm development. Assessed were the development of feed channel pressure drop (MFS studies), permeate flux (FO studies) and accumulated biomass amount measured by adenosine triphosphate (ATP) and total organic carbon (TOC).Our studies showed that the organic nutrient load determined the accumulated amount of biomass. The same amount of accumulated biomass was found at constant nutrient load irrespective of linear flow velocity, shear, and/or feed spacer thickness. The impact of the same amount of accumulated biomass on feed channel pressure drop and permeate flux was influenced by membrane process design and operational conditions. Reducing the nutrient load by pretreatment slowed-down the biofilm formation. The impact of accumulated biomass on membrane performance was reduced by applying a lower crossflow velocity and/or a thicker and/or a modified geometry feed spacer. The results indicate that cleanings can be delayed

  17. Low CO2-emissions hybrid solar combined-cycle power system with methane membrane reforming

    International Nuclear Information System (INIS)

    Li, Yuanyuan; Zhang, Na; Cai, Ruixian

    2013-01-01

    Based on the principle of cascade utilization of multiple energy resources, a gas-steam combined cycle power system integrated with solar thermo-chemical fuel conversion and CO 2 capture has been proposed and analyzed. The collected solar heat at 550 °C drives the endothermic methane reforming and is converted to the produced syngas chemical exergy, and then released as high-temperature thermal energy via combustion for power generation, achieving its high-efficiency heat-power conversion. The reforming reaction is integrated with a hydrogen separation membrane, which continuously withdraws hydrogen from the reaction zone and enables nearly full methane conversion. The CO 2 enriched gas being concentrated in the retentate zone is collected and processed with pre-combustion decarbonization. The system is thermodynamically simulated using the ASPEN PLUS code. The results show that with 91% CO 2 captured, the specific CO 2 emission is 25 g/kWh. An exergy efficiency of 58% and thermal efficiency of 51.6% can be obtained. A fossil fuel saving ratio of 31.2% is achievable with a solar thermal share of 28.2%, and the net solar-to-electricity efficiency based on the gross solar heat incident on the collector is about 36.4% compared with the same gas-steam combined cycle system with an equal CO 2 removal ratio obtained by post-combustion decarbonization. - Highlights: ► A solar-assisted hybrid combined cycle power system has been proposed and analyzed. ► The system integrates power generation with solar-driven reforming and CO 2 capture. ► solar heat upgrading and high-efficiency heat-to-power conversion are achieved. ► membrane reforming enables high CH 4 conversion and pre-combustion CO 2 capture. ► The system thermodynamic performances have been investigated and compared

  18. Effluent quality of a conventional activated sludge and a membrane bioreactor system treating hospital wastewater

    International Nuclear Information System (INIS)

    Pauwels, B.; Ngwa, F.; Deconinck, S.; Verstraete, W.

    2005-01-01

    Two lab scale wastewater treatment plants treating hospital wastewater in parallel were compared in terms of performance characteristics. One plant consisted of a conventional activated sludge system (CAS) and comprised In anoxic and aerobic compartment followed by a settling tank with recycle loop. The second pilot plant was a -late membrane bioreactor (MBR). The wastewater as obtained from the hospital had a variable COD (Chemical Oxygen Demand) ranging from 250 to 2300 mg/L. Both systems were operated at a similar hydraulic residence time of 12 hours. The reference conventional activated sludge system did not meet the regulatory standard for effluent COD of 125 mg /L most of the time. Its COD removal efficiency was 88%. The plate MBR delivered an effluent with a COD value of 50 mg/L or less, and attained an efficiency of 93%. The effluent contained no suspended particles. In addition, the MBR resulted in consistent operational parameters with a flux remaining around 8 -10 L/m/sup 2/.h and a trans membrane pressure <0.1 bar without the need for backwash or chemical cleaning. The CAS and the MBR system performed equally good in terms of TAN removal and EE2 removal. The CAS system typically decreased bacterial groups for about 1 log unit, whereas the MBR decreased these groups for about 3 log units. Enterococci were decreased below the detection limit in the MBR and indicator organisms such as fecal coliforms were decreased for 1.4 log units in the CAS system compared to a 3.6 log removal in the MBR. (author)

  19. Three-dimensional dynamic modelling of Polymer-Electrolyte-Membrane-Fuel-Cell-Systems; Dreidimensionale dynamische Modellierung und Berechnung von Polymer-Elektrolyt-Membran-Brennstoffzellen

    Energy Technology Data Exchange (ETDEWEB)

    Vath, Andreas

    2008-12-15

    This thesis deals with dynamic and multi-dimensional modelling of Polymer- Electrolyte-Membrane-Fuel-Cells (PEMFC). The developed models include all the different layers of the fuel cell e.g. flow field, gas diffusion layer, catalyst layer and membrane with their particular physical, chemical and electrical characteristics. The simulation results have been verified by detailed measurements performed at the research centre for hydrogen and solar energy in Ulm (ZSW Ulm). The developed three dimensional model describes the time- and spatial-dependent charge and mass transport in a fuel cell. Additionally, this model allows the analysis of critical operating conditions. For example, the current density distribution for different membranes is shown during insufficient humidification which results in local overstraining and degradation. The model also allows to analyse extreme critical operating conditions, e.g. short time breakdown of the humidification. Furthermore, the model shows the available potential of improvement opportunities in power density and efficiency of PEMFC due to optimisation of the gas diffusion layer, the catalyst and membrane. In the second part of the work the application of PEMFC systems for combined heat and power units is described by one-dimensional models for an electrical power range between 1 kW and 5 kW. This model contains the necessary components, e.g. gas processing, humidification, gas supply, fuel cell stack, heat storage, pumps, auxiliary burner, power inverter und additional aggregates. As a main result, it is possible to distinctly reduce the energy demand and the carbon dioxide exhaust for different load profiles. Today the costs for fuel cell systems are considerably higher than that of the conventional electrical energy supply. (orig.)

  20. Control and experimental characterization of a methanol reformer for a 350 W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart

    2013-01-01

    is the water and methanol mixture fuel flow and the burner fuel/air ratio and combined flow. An experimental setup is presented capable of testing the methanol reformer used in the Serenergy H3 350 Mobile Battery Charger; a high temperature polymer electrolyte membrane (HTPEM) fuel cell system......This work presents a control strategy for controlling the methanol reformer temperature of a 350 W high temperature polymer electrolyte membrane fuel cell system, by using a cascade control structure for reliable system operation. The primary states affecting the methanol catalyst bed temperature....... The experimental system consists of a fuel evaporator utilizing the high temperature waste gas from the cathode air cooled 45 cell HTPEM fuel cell stack. The fuel cells used are BASF P1000 MEAs which use phosphoric acid doped polybenzimidazole membranes. The resulting reformate gas output of the reformer system...

  1. Integral design method for simple and small Mars lander system using membrane aeroshell

    Science.gov (United States)

    Sakagami, Ryo; Takahashi, Ryohei; Wachi, Akifumi; Koshiro, Yuki; Maezawa, Hiroyuki; Kasai, Yasko; Nakasuka, Shinichi

    2018-03-01

    To execute Mars surface exploration missions, spacecraft need to overcome the difficulties of the Mars entry, descent, and landing (EDL) sequences. Previous landing missions overcame these challenges with complicated systems that could only be executed by organizations with mature technology and abundant financial resources. In this paper, we propose a novel integral design methodology for a small, simple Mars lander that is achievable even by organizations with limited technology and resources such as universities or emerging countries. We aim to design a lander (including its interplanetary cruise stage) whose size and mass are under 1 m3 and 150 kg, respectively. We adopted only two components for Mars EDL process: a "membrane aeroshell" for the Mars atmospheric entry and descent sequence and one additional mechanism for the landing sequence. The landing mechanism was selected from the following three candidates: (1) solid thrusters, (2) aluminum foam, and (3) a vented airbag. We present a reasonable design process, visualize dependencies among parameters, summarize sizing methods for each component, and propose the way to integrate these components into one system. To demonstrate the effectiveness, we applied this methodology to the actual Mars EDL mission led by the National Institute of Information and Communications Technology (NICT) and the University of Tokyo. As a result, an 80 kg class Mars lander with a 1.75 m radius membrane aeroshell and a vented airbag was designed, and the maximum landing shock that the lander will receive was 115 G.

  2. Effect of different commercial feed spacers on biofouling of reverse osmosis membrane systems: A numerical study

    KAUST Repository

    Bucs, Szilard; Radu, Andrea I.; Lavric, Vasile; Vrouwenvelder, Johannes S.; Picioreanu, Cristian

    2014-01-01

    Feed spacers and hydrodynamics have been found relevant for the impact of biofouling on performance in reverse osmosis (RO) and nanofiltration (NF) membrane systems.The objectives of this study on biofouling development were to determine the impact of (i) linear flow velocity and bacterial cell load, (ii) biomass location and (iii) various feed spacer geometries as applied in practice as well as a modified geometry spacer.A three-dimensional mathematical model for biofouling of feed spacer channels including hydrodynamics, solute mass transport and biofilm formation was developed in COMSOL Multiphysics and MATLAB software.Results of this study indicate that the feed channel pressure drop increase caused by biofilm formation can be reduced by using thicker and/or modified feed spacer geometry and/or a lower flow rate in the feed channel. The increase of feed channel pressure drop by biomass accumulation is shown to be strongly influenced by the location of biomass. Results of numerical simulations are in satisfactory agreement with experimental data, indicating that this micro-scale mechanistic model is representative for practice. The developed model can help to understand better the biofouling process of spiral-wound RO and NF membrane systems and to develop strategies to reduce and control biofouling. © 2013 Elsevier B.V.

  3. Effect of different commercial feed spacers on biofouling of reverse osmosis membrane systems: A numerical study

    KAUST Repository

    Bucs, Szilard

    2014-06-01

    Feed spacers and hydrodynamics have been found relevant for the impact of biofouling on performance in reverse osmosis (RO) and nanofiltration (NF) membrane systems.The objectives of this study on biofouling development were to determine the impact of (i) linear flow velocity and bacterial cell load, (ii) biomass location and (iii) various feed spacer geometries as applied in practice as well as a modified geometry spacer.A three-dimensional mathematical model for biofouling of feed spacer channels including hydrodynamics, solute mass transport and biofilm formation was developed in COMSOL Multiphysics and MATLAB software.Results of this study indicate that the feed channel pressure drop increase caused by biofilm formation can be reduced by using thicker and/or modified feed spacer geometry and/or a lower flow rate in the feed channel. The increase of feed channel pressure drop by biomass accumulation is shown to be strongly influenced by the location of biomass. Results of numerical simulations are in satisfactory agreement with experimental data, indicating that this micro-scale mechanistic model is representative for practice. The developed model can help to understand better the biofouling process of spiral-wound RO and NF membrane systems and to develop strategies to reduce and control biofouling. © 2013 Elsevier B.V.

  4. A dense cell retention culture system using stirred ceramic membrane reactor.

    Science.gov (United States)

    Suzuki, T; Sato, T; Kominami, M

    1994-11-20

    A novel reactor design incorporating porous ceramic tubes into a stirred jar fermentor was developed. The stirred ceramic membrane reactor has two ceramic tubular membrane units inside the vessel and maintains high filtration flux by alternating use for filtering and recovering from clogging. Each filter unit was linked for both extraction of culture broth and gas sparging. High permeability was maintained for long periods by applying the periodical control between filtering and air sparging during the stirred retention culture of Saccharomyces cerevisiae. The ceramic filter aeration system increased the k(L)a to about five times that of ordinary gas sparing. Using the automatic feeding and filtering system, cell mass concentration reached 207 g/L in a short time, while it was 64 g/L in a fed-batch culture. More than 99% of the growing cells were retained in the fermentor by the filtering culture. Both yield and productivity of cells were also increased by controlling the feeding of fresh medium and filtering the supernatant of the dense cells culture. (c) 1994 John Wiley & Sons, Inc.

  5. Performance of Hybrid Photocatalytic-Ceramic Membrane System for the Treatment of Secondary Effluent.

    Science.gov (United States)

    Song, Lili; Zhu, Bo; Gray, Stephen; Duke, Mikel; Muthukumaran, Shobha

    2017-03-28

    Evaluation of an advanced wastewater treatment system that combines photocatalysis with ceramic membrane filtration for the treatment of secondary effluent was undertaken. The results showed that, after photocatalysis and ceramic membrane filtration, the removal of dissolved organic carbon and UV 254 was 60% and 54%, respectively, at a concentration of 4 g/L of TiO₂. Dissolved organic matter (DOM) present in the secondary effluent was characterised with a liquid chromatography-organic carbon detector (LC-OCD) technique. The results showed low removal of humics, building blocks, the other oxidation by-products and no removal of biopolymers after TiO₂/UV photocatalytic treatment. This suggested that the radical non-selective oxidation mechanisms of TiO₂/UV process resulted in secondary effluent in which all of the DOM fractions were present. However, the hybrid system was effective for removing biopolymers with the exception of low molecular weight (LMW) compounds acids, which accumulated from the beginning of the reaction. In addition, monitoring of the DOM fractions with LC-OCD analysis demonstrated that the reduction of the effluent aromaticity was not firmly correlated with the removal of humic substances for the combined processes.

  6. High speed municipal sewage treatment in microbial fuel cell integrated with anaerobic membrane filtration system.

    Science.gov (United States)

    Lee, Y; Oa, S W

    2014-01-01

    A cylindrical two chambered microbial fuel cell (MFC) integrated with an anaerobic membrane filter was designed and constructed to evaluate bioelectricity generation and removal efficiency of organic substrate (glucose or domestic wastewater) depending on organic loading rates (OLRs). The MFC was continuously operated with OLRs 3.75, 5.0, 6.25, and 9.38 kg chemical oxygen demand (COD)/(m(3)·d) using glucose as a substrate, and the cathode chamber was maintained at 5-7 mg/L of dissolved oxygen. The optimal OLR was found to be 6.25 kgCOD/(m(3)·d) (hydraulic retention time (HRT) 1.9 h), and the corresponding voltage and power density averaged during the operation were 0.15 V and 13.6 mW/m(3). With OLR 6.25 kgCOD/(m(3)·d) using domestic wastewater as a substrate, the voltage and power reached to 0.13 V and 91 mW/m(3) in the air cathode system. Even though a relatively short HRT of 1.9 h was applied, stable effluent could be obtained by the membrane filtration system and the following air purging. In addition, the short HRT would provide economic benefit in terms of reduction of construction and operating costs compared with a conventional aerobic treatment process.

  7. Identification of immunogenic outer membrane proteins of Haemophilus influenzae type b in the infant rat model system

    International Nuclear Information System (INIS)

    Hansen, E.J.; Frisch, C.F.; McDade, R.L. Jr.; Johnston, K.H.

    1981-01-01

    Outer membrane proteins of Haemophilus influenzae type b which are immunogenic in infant rats were identified by a radioimmunoprecipitation method. Intact cells of H. influenzae type b were radioiodinated by a lactoperoxidase-catalyzed procedure, and an outer membrane-containing fraction was prepared from these cells. These radioiodinated outer membranes were mixed with sera obtained from rats convalescing from systemic H. influenzae type b disease induced at 6 days of age, and the resultant (antibody-outer membrane protein antigen) complexes were extracted from these membranes by treatment with nonionic detergent and ethylenediaminetetraacetic acid. These soluble antibody-antigen complexes were isolated by means of adsorption to protein A-bearing staphylococci, and the radioiodinated protein antigens were identified by gel electrophoresis followed by autoradiography. Infant rats were shown to mount a readily detectable antibody response to several different proteins present in the outer membrane of H. influenzae type b. Individual infant rats were found to vary both qualitatively and quantitatively in their immune response to these immunogenic outer membrane proteins

  8. Application of the mass-based UNIQUAC model to membrane systems: A critical revision

    International Nuclear Information System (INIS)

    Chovau, S.; Van der Bruggen, B.; Luis, P.

    2012-01-01

    Highlights: ► UNIQUAC model in mass-based terms is considered for the description of sorption equilibria in membrane systems. ► Model validation of molar and mass-based model is performed on simple (vapor + liquid) equilibrium. ► Discrepancy is found between molar and mass-based model, which is attributed to an incorrect conversion. ► Novel model based on correct thermodynamics is provided for future research. - Abstract: The UNIQUAC model is very suitable in describing (liquid + liquid) as well as (vapor + liquid) equilibrium for a wide range of systems. It can be extended to (solvent + polymer) systems for describing sorption equilibria. The original model is expressed in molar-based terms, but requires knowledge of structural parameters and molar masses of all components. Since these cannot always be easily determined for membranes, a conversion to mass-based terms is often performed, which eliminates this issue. Many studies use this model to calculate sorption equilibria in (solvent + polymer) systems. Nevertheless, in this work the conversion from molar to mass-based parameters is postulated to be erroneous. This even leads to an incorrect description of simple (vapor + liquid) equilibrium of pure liquid mixtures and hence it is advised not to use this model for further modeling of sorption equilibrium in (solvent + polymer) systems. In this paper, the errors in the conversion are pinpointed, and the effects it can have on the description of (vapor + liquid) equilibrium, if used improvident, are demonstrated. Furthermore, it is shown that in fact a simple and straightforward conversion can be performed. Finally, in the case when polymers are involved, an adaption and simplification to the model was successfully applied.

  9. Development of an Electrochemical Ceramic Membrane Filtration System for Efficient Contaminant Removal from Waters.

    Science.gov (United States)

    Zheng, Junjian; Wang, Zhiwei; Ma, Jinxing; Xu, Shaoping; Wu, Zhichao

    2018-04-03

    Inability to remove low-molecular-weight anthropogenic contaminants is a critical issue in low-pressure membrane filtration processes for water treatment. In this work, a novel electrochemical ceramic membrane filtration (ECMF) system using TiO 2 @SnO 2 -Sb anode was developed for removing persistent p-chloroaniline (PCA). Results showed that the ECMF system achieved efficient removal of PCA from contaminated waters. At a charging voltage of 3 V, the PCA removal rate of TiO 2 @SnO 2 -Sb ECMF system under flow-through mode was 2.4 times that of flow-by mode. The energy consumption for 50% of PCA removal for TiO 2 @SnO 2 -Sb ECMF at 3 V under flow-through mode was 0.38 Wh/L, much lower than that of flow-by operation (1.5 Wh/L), which was attributed to the improved utilization of the surface adsorbed HO· and dissociated HO· driven by the enhanced mass transfer of PCA toward the anode surface. Benefiting from the increased production of reactive oxygen species such as O 2 •- , H 2 O 2 , and HO· arising from excitation of anatase TiO 2 , TiO 2 @SnO 2 -Sb ECMF exhibited a superior electrocatalytic activity to the SnO 2 -Sb ECMF system. The degradation pathways of PCA initiated by OH· attack were further proposed, with the biodegradable short-chain carboxylic acids (mainly formic, acetic, and oxalic acids) identified as the dominant oxidized products. These results highlight the potential of the ECMF system for cost-effective water purification.

  10. Novel Membranes and Systems for Industrial and Municipal Water Purification and Reuse

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-01-01

    This factsheet describes a project that developed nano-engineered, high-permeance membrane materials with more than double the permeance of current reverse osmosis membranes as well as manufacturing technologies for large-scale production of the novel materials.

  11. Characterization of antibacterial polyethersulfone membranes using the respiration activity monitoring system (RAMOS)

    NARCIS (Netherlands)

    Kochan, J.; Scheidle, M.; Erkel, J. van; Bikel, M.; Büchs, J.; Wong, J.E.; Melin, T.; Wessling, M.

    2012-01-01

    Membranes with antibacterial properties were developed using surface modification of polyethersulfone ultrafiltration membranes. Three different modification strategies using polyelectrolyte layer-by-layer (LbL) technique are described. The first strategy relying on the intrinsic antibacterial

  12. Effect of water temperature on biofouling development in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia; Vrouwenvelder, Johannes S.; van Loosdrecht, Mark C.M.; Bucs, Szilard; Staal, Marc

    2016-01-01

    temperatures, different biofilm activities, structures, and quantities were found, indicating that diagnosis of biofouling of membranes operated at different or varying (seasonal) feed water temperatures may be challenging. Membrane installations with a high

  13. Axionic membranes

    International Nuclear Information System (INIS)

    Aurilia, A.; Spallucci, E.

    1992-01-01

    A metal ring removed from a soap-water solution encloses a film of soap which can be mathematically described as a minimal surface having the ring as its only boundary. This is known to everybody. In this letter we suggest a relativistic extension of the above fluidodynamic system where the soap film is replaced by a Kalb-Ramand gauge potential B μν (x) and the ring by a closed string. The interaction between the B μν field and the string current excites a new configuration of the system consisting of a relativistic membrane bounded by the string. We call such a classical solution of the equation of motion an axionic membrane. As a dynamical system, the axionic membrane admits a Hamilton-Jacobi formulation which is an extension of the HJ theory of electromagnetic strings. (orig.)

  14. An anaerobic membrane bioreactor - membrane distillation hybrid system for energy recovery and water reuse: Removal performance of organic carbon, nutrients, and trace organic contaminants.

    Science.gov (United States)

    Song, Xiaoye; Luo, Wenhai; McDonald, James; Khan, Stuart J; Hai, Faisal I; Price, William E; Nghiem, Long D

    2018-07-01

    In this study, a direct contact membrane distillation (MD) unit was integrated with an anaerobic membrane bioreactor (AnMBR) to simultaneously recover energy and produce high quality water for reuse from wastewater. Results show that AnMBR could produce 0.3-0.5L/g COD added biogas with a stable methane content of approximately 65%. By integrating MD with AnMBR, bulk organic matter and phosphate were almost completely removed. The removal of the 26 selected trace organic contaminants by AnMBR was compound specific, but the MD process could complement AnMBR removal, leading to an overall efficiency from 76% to complete removal by the integrated system. The results also show that, due to complete retention, organic matter (such as humic-like and protein-like substances) and inorganic salts accumulated in the MD feed solution and therefore resulted in significant fouling of the MD unit. As a result, the water flux of the MD process decreased continuously. Nevertheless, membrane pore wetting was not observed throughout the operation. Crown Copyright © 2018. Published by Elsevier B.V. All rights reserved.

  15. Limbic system associated membrane protein as a potential target for neuropsychiatric disorders

    Directory of Open Access Journals (Sweden)

    Eero eVasar

    2013-03-01

    Full Text Available The studies performed in laboratory animals and psychiatric patients suggest a possible role of limbic system associated membrane protein (LAMP in the mechanisms of psychiatric disorders. Stressful manipulations and genetic invalidation have revealed a role of the Lsamp gene in the regulation of anxiety in rodents. Besides that, Lsamp deficient mice display reduced aggressiveness and impaired adaptation in novel and stressful environments. The behavioural effects of amphetamine were blunted in genetically modified mice. Recent pharmacological and biochemical studies point towards altered function of GABA-, 5-hydroxytryptamine- and dopaminergic systems in Lsamp deficient mice. Moreover, we found an association between the gene polymorphisms of LSAMP and major depressive disorder. Patients suffering from major depressive disorder had significantly increased ratio between risk and protective haplotypes of the LSAMP gene compared to healthy volunteers. However, the impact of these haplotypes for the function of LAMP is not clear and remains to be elucidated in future studies.

  16. Asymmetric bi-layer PFSA membranes as model systems for the study of water management in the PEMFC.

    Science.gov (United States)

    Peng, Z; Peng, A Z; Morin, A; Huguet, P; Lanteri, Y; Deabate, S

    2014-10-14

    New bi-layer PFSA membranes made of Nafion® NRE212 and Aquivion™ E79-05s with different equivalent weights are prepared with the aim of managing water repartition in the PEMFC. The membrane water transport properties, i.e. back-diffusion and electroosmosis, as well as the electrochemical performances, are compared to those of state-of-art materials. The actual water content (the inner water concentration profile across the membrane thickness) is measured under operation in the fuel cell by in situ Raman microspectroscopy. The orientation of the equivalent weight gradient with respect to the water external gradient and to the proton flow direction affects the membrane water content, the water transport ability and, thus, the fuel cell performances. Higher power outputs, related to lower ohmic losses, are observed when the membrane is assembled with the lower equivalent weight layer (Aquivion™) at the anode side. This orientation, corresponding to enhanced water transport by back-flow while electroosmosis remains unaffected, results in the higher hydration of the membrane and of the anode active layer during operation. Also, polarization data suggest a different water repartition in the fuel cell along the on-plane direction. Even if the interest in multi-layer PFSA membranes as perspective electrolytes for PEMFCs is not definitively attested, these materials appear to be excellent model systems to establish relationships between the membrane transport properties, the water distribution in the fuel cell and the electrochemical performances. Thanks to the micrometric resolution, in situ Raman microspectroscopy proves to be a unique tool to measure the actual hydration of the membrane at the surface swept by the hydrated feed gases during operation, so that it can be used as a local probe of the water concentration evolution along the gas distribution channels according to changing working conditions.

  17. Experimental and theoretical investigations of Lantana camara oil diffusion from polyacrylonitrile membrane for pulsatile drug delivery system

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Vivek [Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008 (India); Balasubramanian, K., E-mail: meetkbs@gmail.com [Department of Materials Engineering, Defence Institute of Advance Technology (DIAT), Ministry of Defence, Girinagar, Pune 411025 (India)

    2014-08-01

    Porous composite membrane of polyacrylonitrile (PAN) and Lantana camara essential oil was synthesized by solvent casting method. Stability of oil in PAN solution was measured by XiGo nano tool indicating constant relaxation time of 1487 time/s. Pore size of few microns confirmed by electron microscopy was supported by atomic force microscopy indicating roughness factor of 0.9 nm. Contact angle of 2° inveterates superhydrophilicity of the composite membrane. Membrane showed excellent antibacterial activity against both Gram-positive Bacillus subtilis and Gram-negative Escherichia coli with a 7–10 mm zone of inhibition. In vitro release of Lantana oil from the composite membrane was carried out in isotonic phosphate buffer solution (pH = 7.4). Lantana oil was released for 9 h, lag time of 3 h with constant 33% release confirmed PAN membranes as potential system for pulsatile drug delivery applications. Diffusion of E-caryophyllene (antibacterial component of oil) which was studied through molecular simulation using Material Studio software ensued diffusion coefficient value of 1.11 ∗ 10{sup −9} m{sup 2}/s. Biocompatibility of the composite membrane was assessed by mouse embryonic fibroblast cell line (NIH 3T3) through MTT assay indicating more than 91% viable cell even at 200 μg/mL concentration. Such membranes can be efficiently used in biomedical applications as antibacterial and antifungal agent. - Highlights: • Pulsatile release • Lantana oil–PAN composite membrane as antibacterial material • Enhanced bactericidal activity of the membrane.

  18. Mathematical Modelling of Nitrate Removal from Water Using a Submerged Membrane Adsorption Hybrid System with Four Adsorbents

    Directory of Open Access Journals (Sweden)

    Mahatheva Kalaruban

    2018-01-01

    Full Text Available Excessive concentrations of nitrate in ground water are known to cause human health hazards. A submerged membrane adsorption hybrid system that includes a microfilter membrane and four different adsorbents (Dowex 21K XLT ion exchange resin (Dowex, Fe-coated Dowex, amine-grafted (AG corn cob and AG coconut copra operated at four different fluxes was used to continuously remove nitrate. The experimental data obtained in this study was simulated mathematically with a homogeneous surface diffusion model that incorporated membrane packing density and membrane correlation coefficient, and applied the concept of continuous flow stirred tank reactor. The model fit with experimental data was good. The surface diffusion coefficient was constant for all adsorbents and for all fluxes. The mass transfer coefficient increased with flux for all adsorbents and generally increased with the adsorption capacity of the adsorbents.

  19. A hyaluronic acid membrane delivery system for cultured keratinocytes: clinical "take" rates in the porcine kerato-dermal model.

    Science.gov (United States)

    Myers, S R; Grady, J; Soranzo, C; Sanders, R; Green, C; Leigh, I M; Navsaria, H A

    1997-01-01

    The clinical take rates of cultured keratinocyte autografts are poor on a full-thickness wound unless a dermal bed is provided. Even under these circumstances two important problems are the time delay in growing autografts and the fragility of the grafts. A laser-perforated hyaluronic acid membrane delivery system allows grafting at early confluence without requiring dispase digestion to release grafts from their culture dishes. We designed this study to investigate the influence of this membrane on clinical take rates in an established porcine kerato-dermal grafting model. The study demonstrated a significant reduction in take as a result of halving the keratinocyte seeding density onto the membrane. The take rates, however, of grafts grown on the membrane at half or full conventional seeding density and transplanted to a dermal wound bed were comparable, if not better, than those of keratinocyte sheet grafts.

  20. Significance of membrane bioreactor design on the biocatalytic performance of glucose oxidase and catalase: Free vs. immobilized enzyme systems

    DEFF Research Database (Denmark)

    Morthensen, Sofie Thage; Meyer, Anne S.; Jørgensen, Henning

    2017-01-01

    Membrane separation of xylose and glucose can be accomplished via oxidation of glucose to gluconic acid by enzymatic glucose oxidase catalysis. Oxygen for this reaction can be supplied via decomposition of hydrogen peroxide by enzymatic catalase catalysis. In order to maximize the biocatalytic...... productivity of glucose oxidase and catalase (gluconic acid yield per total amount of enzyme) the following system set-ups were compared: immobilization of glucose oxidase alone; co-immobilization of glucose oxidase and catalase; glucose oxidase and catalase free in the membrane bioreactor. Fouling......-induced enzyme immobilization in the porous support of an ultrafiltration membrane was used as strategy for entrapment of glucose oxidase and catalase. The biocatalytic productivity of the membrane reactor was found to be highly related to the oxygen availability, which in turn depended on the reactor...

  1. Power Generation from Concentration Gradient by Reverse Electrodialysis in Dense Silica Membranes for Microfluidic and Nanofluidic Systems

    Directory of Open Access Journals (Sweden)

    Sang Woo Lee

    2016-01-01

    Full Text Available In this study, we investigate power generation by reverse electrodialysis in a dense silica membrane that is between two NaCl solutions with various combinations of concentrations. Each silica membrane is fabricated by depositing a silica layer on a porous alumina substrate via chemical vapor deposition. The measured potential-current (V-I characteristics of the silica membrane are used to obtain the transference number, diffusion potential, and electrical resistance. We develop empirical correlations for the transference number and the area-specific resistance, and present the results of power generation by reverse electrodialysis using the fabricated silica membranes. The highest measured power density is 0.98 mW/m2. In addition, we develop a contour map of the power density as a function of NaCl concentrations on the basis of the empirical correlations. The contour map shows that a power output density of 1.2 mW/m2 is achievable with the use of silica membranes and is sufficient to drive nanofluidic and microfluidic systems. The dense silica membrane has the potential for use in micro power generators in nanofluidic and microfluidic systems.

  2. Vacuumed gap membrane distillation (vagmed) module, multi-stage vagmed systems, and vagmed processes

    KAUST Repository

    Ghaffour, NorEddine; Alsaadi, Ahmad Salem; Francis, Lijo

    2016-01-01

    Vacuumed gap membrane distillation (VAGMED) modules, and multi-stage VAGMED systems and processes using the modules are provided. In an embodiment, the membrane distillation modules (10) can comprise: a) a condenser (12) including a condensation surface (15); b) a first passageway (13) having an inlet for receiving a first feed stream (14) and an outlet through which the first stream can pass out of the first passageway, the first passageway configured to bring the first feed stream into thermal communication with the condensation surface; c) an evaporator (17) including a permeable evaporation surface allowing condensable gas to pass there through; d) a second passageway (18) having an inlet for receiving a second feed stream (19) and an outlet through which the second feed stream can pass out of the second passageway, the second passageway configured to bring the second feed stream into communication with the permeable evaporation surface; and e) an enclosure (24) providing a vacuum compartment within which the condenser, the evaporator and the first and second passageways of the module are contained.

  3. Saponin Interactions with Model Membrane Systems - Langmuir Monolayer Studies, Hemolysis and Formation of ISCOMs.

    Science.gov (United States)

    de Groot, Carolin; Müller-Goymann, Christel C

    2016-12-01

    Saponins are used in medicine due to their pharmacological and immunological effects. To better understand interactions of saponins with model membranes and natural membranes of, for example, erythrocytes, Langmuir film balance experiments are well established. For most saponins, a strong interaction with cholesterol was demonstrated in dependence of both the aglycone part and the sugar moieties and is suggested to be correlated with a strong hemolytic activity, high toxicity, and high surface activity, as was demonstrated for the steroid saponin digitonin. In general, changes in the sugar chain or in substituents of the aglycone result in a modification of the saponin properties. A promising saponin with regard to fairly low hemolytic activity and high adjuvant effect is α -tomatine, which still shows a high affinity for cholesterol. An interaction with cholesterol and lipids has also been proven for the Quillaja saponin from the bark of Quillaja saponaria Molina. This triterpene saponin was approved in marketed vaccines as an adjuvant due to the formation of immunostimulating complexes. Immunostimulating complexes consist of a Quillaja saponin, cholesterol, phospholipids, and a corresponding antigen. Recently, another saponin from Quillaja brasiliensis was successfully tested in immunostimulating complexes, too. Based on the results of interaction studies, the formation of drug delivery systems such as immunostimulating complexes or similar self-assembled colloids is postulated for a variety of saponins. Georg Thieme Verlag KG Stuttgart · New York.

  4. Vacuumed gap membrane distillation (vagmed) module, multi-stage vagmed systems, and vagmed processes

    KAUST Repository

    Ghaffour, Noreddine

    2016-06-30

    Vacuumed gap membrane distillation (VAGMED) modules, and multi-stage VAGMED systems and processes using the modules are provided. In an embodiment, the membrane distillation modules (10) can comprise: a) a condenser (12) including a condensation surface (15); b) a first passageway (13) having an inlet for receiving a first feed stream (14) and an outlet through which the first stream can pass out of the first passageway, the first passageway configured to bring the first feed stream into thermal communication with the condensation surface; c) an evaporator (17) including a permeable evaporation surface allowing condensable gas to pass there through; d) a second passageway (18) having an inlet for receiving a second feed stream (19) and an outlet through which the second feed stream can pass out of the second passageway, the second passageway configured to bring the second feed stream into communication with the permeable evaporation surface; and e) an enclosure (24) providing a vacuum compartment within which the condenser, the evaporator and the first and second passageways of the module are contained.

  5. Using adaptive neuro fuzzy inference system (ANFIS) for proton exchange membrane fuel cell (PEMFC) performance modeling

    International Nuclear Information System (INIS)

    Rezazadeh, S.; Mirzaee, I.; Mehrabi, M.

    2012-01-01

    In this paper, an adaptive neuro fuzzy inference system (ANFIS) is used for modeling proton exchange membrane fuel cell (PEMFC) performance using some numerically investigated and compared with those to experimental results for training and test data. In this way, current density I (A/cm 2 ) is modeled to the variation of pressure at the cathode side P C (atm), voltage V (V), membrane thickness (mm), Anode transfer coefficient α an , relative humidity of inlet fuel RH a and relative humidity of inlet air RH c which are defined as input (design) variables. Then, we divided these data into train and test sections to do modeling. We instructed ANFIS network by 80% of numerical validated data. 20% of primary data which had been considered for testing the appropriateness of the models was entered ANFIS network models and results were compared by three statistical criterions. Considering the results, it is obvious that our proposed modeling by ANFIS is efficient and valid and it can be expanded for more general states

  6. Using adaptive neuro fuzzy inference system (ANFIS) for proton exchange membrane fuel cell (PEMFC) performance modeling

    Energy Technology Data Exchange (ETDEWEB)

    Rezazadeh, S.; Mirzaee, I. [Urmia Univ., Urmia (Iran, Islamic Republic of); Mehrabi, M. [University of Pretoria, Pretoria (South Africa)

    2012-11-15

    In this paper, an adaptive neuro fuzzy inference system (ANFIS) is used for modeling proton exchange membrane fuel cell (PEMFC) performance using some numerically investigated and compared with those to experimental results for training and test data. In this way, current density I (A/cm{sup 2}) is modeled to the variation of pressure at the cathode side P{sup C} (atm), voltage V (V), membrane thickness (mm), Anode transfer coefficient {alpha}{sup an}, relative humidity of inlet fuel RH{sup a} and relative humidity of inlet air RH{sup c} which are defined as input (design) variables. Then, we divided these data into train and test sections to do modeling. We instructed ANFIS network by 80% of numerical validated data. 20% of primary data which had been considered for testing the appropriateness of the models was entered ANFIS network models and results were compared by three statistical criterions. Considering the results, it is obvious that our proposed modeling by ANFIS is efficient and valid and it can be expanded for more general states.

  7. Characteristic of ascorbic acid in crosslinked chitosan edible film as drug delivery system membrane

    Directory of Open Access Journals (Sweden)

    Kistriyani Lilis

    2018-01-01

    Full Text Available Chitosan is a polysaccharide compound in the form of a linear polysaccharide consisting of N-acetyl glucosamine (GlcNAc and D-glucosamine (GlcN monomer, which is a derivative of deacetylization of chitin polymer. Chitin is one of common type of polysaccharide on earth after the excess cellulose from inveterbrata skeletons. Chitosan has anti-microbial properties. Based on this properties, chitosan is potentially used to be an edible film as drug delivery system membrane. Edible film was made by dissolving chitosan in 100 mL acetic acid 1%, then the plasticizer and crosslinker was added while heated at 60° C. It was molded and dried in oven at 50°C for 48 hours. Drug loading in the edible film could be controlled by remodeling membrane characteristics in the presence of crosslinker additions. The purpose of this study was to estimate the mass transfer coefficient (kCa of drug loading in various concentrations of ascorbic acid in the edible film. The characteristics of ascorbic acid in chitosan edible film could be seen from the number of drugs that could be loaded through the uv-vis spectrophotometric analysis. The higher concentration of ascorbic acid was added, the drug would be loaded more into edible film.

  8. Liquid membrane system for the removal and concentration of transuranic elements

    International Nuclear Information System (INIS)

    Timmins, M.R.; Wysk, S.R.; Smolensky, L.A.; Jiang, D.; Lumetta, G.J.

    1996-01-01

    The goal of this program is to develop an efficient, reliable, and radiation-resistant modified liquid membrane system (MLMS) for the selective removal and concentration of transuranic elements (TRUs) and strontium-90 from dissolved Hanford sludge wastes. The efforts are divided into three categories: (1) demonstration and optimization of the MLMS for the TRUEX and SREX processes using simulant waste solution; (2) development of a radiation-resistant microporous divider and membrane module for testing with actual waste solutions; and (3) demonstration of the MLMS for the TRUEX and SREX processes using actual Hanford waste. Successful completion of these development efforts will yield a compact, versatile, and reliable MLMS for implementation with the TRUEX and SREX processes. The MLMS is simple, stable, more efficient, and easier to control and operate than conventional solvent-extraction processes, such as those employing centrifugal contactors. In addition, the MLMS process offers operational cost savings over the conventional technology, by exhibiting at least a 10% reduction in the consumption of extractant chemicals

  9. A novel cogeneration system: A proton exchange membrane fuel cell coupled to a heat transformer

    International Nuclear Information System (INIS)

    Huicochea, A.; Romero, R.J.; Rivera, W.; Gutierrez-Urueta, G.; Siqueiros, J.; Pilatowsky, I.

    2013-01-01

    This study focuses on the potential of a novel cogeneration system which consists of a 5 kW proton exchange membrane fuel cell (PEMFC) and an absorption heat transformer (AHT). The dissipation heat resulting from the operation of the PEMFC would be used to feed the absorption heat transformer, which is integrated to a water purification system. Therefore, the products of the proposed cogeneration system are heat, electricity and distilled water. The study includes a simulation for the PEMFC as well as experimental results obtained with an experimental AHT facility. Based on the simulation results, experimental tests were performed in order to estimate the performance parameters of the overall system. This is possible due to the matching in power and temperatures between the outlet conditions of the simulated fuel cell and the inlet requirements of the AHT. Experimental coefficients of performance are reported for the AHT as well as the overall cogeneration efficiency for the integrated system. The results show that experimental values of coefficient of performance of the AHT and the overall cogeneration efficiency, can reach up to 0.256 and 0.571, respectively. This represents an increment in 12.4% of efficiency, compared to the fuel cell efficiency working individually. This study shows that the combined use of AHT systems with a PEMFC is possible and it is a very feasible project to be developed in the Centro de Investigación en Energía (Centre of Energy Research), México.

  10. Essential Role of the ESX-5 Secretion System in Outer Membrane Permeability of Pathogenic Mycobacteria

    KAUST Repository

    Ates, Louis S.

    2015-05-04

    Mycobacteria possess different type VII secretion (T7S) systems to secrete proteins across their unusual cell envelope. One of these systems, ESX-5, is only present in slow-growing mycobacteria and responsible for the secretion of multiple substrates. However, the role of ESX-5 substrates in growth and/or virulence is largely unknown. In this study, we show that esx-5 is essential for growth of both Mycobacterium marinum and Mycobacterium bovis. Remarkably, this essentiality can be rescued by increasing the permeability of the outer membrane, either by altering its lipid composition or by the introduction of the heterologous porin MspA. Mutagenesis of the first nucleotide-binding domain of the membrane ATPase EccC5 prevented both ESX-5-dependent secretion and bacterial growth, but did not affect ESX-5 complex assembly. This suggests that the rescuing effect is not due to pores formed by the ESX-5 membrane complex, but caused by ESX-5 activity. Subsequent proteomic analysis to identify crucial ESX-5 substrates confirmed that all detectable PE and PPE proteins in the cell surface and cell envelope fractions were routed through ESX-5. Additionally, saturated transposon-directed insertion-site sequencing (TraDIS) was applied to both wild-type M. marinum cells and cells expressing mspA to identify genes that are not essential anymore in the presence of MspA. This analysis confirmed the importance of esx-5, but we could not identify essential ESX-5 substrates, indicating that multiple of these substrates are together responsible for the essentiality. Finally, examination of phenotypes on defined carbon sources revealed that an esx-5 mutant is strongly impaired in the uptake and utilization of hydrophobic carbon sources. Based on these data, we propose a model in which the ESX-5 system is responsible for the transport of cell envelope proteins that are required for nutrient uptake. These proteins might in this way compensate for the lack of MspA-like porins in slow

  11. Essential Role of the ESX-5 Secretion System in Outer Membrane Permeability of Pathogenic Mycobacteria.

    Directory of Open Access Journals (Sweden)

    Louis S Ates

    2015-05-01

    Full Text Available Mycobacteria possess different type VII secretion (T7S systems to secrete proteins across their unusual cell envelope. One of these systems, ESX-5, is only present in slow-growing mycobacteria and responsible for the secretion of multiple substrates. However, the role of ESX-5 substrates in growth and/or virulence is largely unknown. In this study, we show that esx-5 is essential for growth of both Mycobacterium marinum and Mycobacterium bovis. Remarkably, this essentiality can be rescued by increasing the permeability of the outer membrane, either by altering its lipid composition or by the introduction of the heterologous porin MspA. Mutagenesis of the first nucleotide-binding domain of the membrane ATPase EccC5 prevented both ESX-5-dependent secretion and bacterial growth, but did not affect ESX-5 complex assembly. This suggests that the rescuing effect is not due to pores formed by the ESX-5 membrane complex, but caused by ESX-5 activity. Subsequent proteomic analysis to identify crucial ESX-5 substrates confirmed that all detectable PE and PPE proteins in the cell surface and cell envelope fractions were routed through ESX-5. Additionally, saturated transposon-directed insertion-site sequencing (TraDIS was applied to both wild-type M. marinum cells and cells expressing mspA to identify genes that are not essential anymore in the presence of MspA. This analysis confirmed the importance of esx-5, but we could not identify essential ESX-5 substrates, indicating that multiple of these substrates are together responsible for the essentiality. Finally, examination of phenotypes on defined carbon sources revealed that an esx-5 mutant is strongly impaired in the uptake and utilization of hydrophobic carbon sources. Based on these data, we propose a model in which the ESX-5 system is responsible for the transport of cell envelope proteins that are required for nutrient uptake. These proteins might in this way compensate for the lack of Msp

  12. Essential Role of the ESX-5 Secretion System in Outer Membrane Permeability of Pathogenic Mycobacteria

    KAUST Repository

    Ates, Louis S.; Ummels, Roy; Commandeur, Susanna; van der Weerd, Robert; Sparrius, Marion; Weerdenburg, Eveline; Alber, Marina; Kalscheuer, Rainer; Piersma, Sander R.; Abdallah, Abdallah; Abd El Ghany, Moataz; Abdel-Haleem, Alyaa M.; Pain, Arnab; Jimé nez, Connie R.; Bitter, Wilbert; Houben, Edith N.G.

    2015-01-01

    Mycobacteria possess different type VII secretion (T7S) systems to secrete proteins across their unusual cell envelope. One of these systems, ESX-5, is only present in slow-growing mycobacteria and responsible for the secretion of multiple substrates. However, the role of ESX-5 substrates in growth and/or virulence is largely unknown. In this study, we show that esx-5 is essential for growth of both Mycobacterium marinum and Mycobacterium bovis. Remarkably, this essentiality can be rescued by increasing the permeability of the outer membrane, either by altering its lipid composition or by the introduction of the heterologous porin MspA. Mutagenesis of the first nucleotide-binding domain of the membrane ATPase EccC5 prevented both ESX-5-dependent secretion and bacterial growth, but did not affect ESX-5 complex assembly. This suggests that the rescuing effect is not due to pores formed by the ESX-5 membrane complex, but caused by ESX-5 activity. Subsequent proteomic analysis to identify crucial ESX-5 substrates confirmed that all detectable PE and PPE proteins in the cell surface and cell envelope fractions were routed through ESX-5. Additionally, saturated transposon-directed insertion-site sequencing (TraDIS) was applied to both wild-type M. marinum cells and cells expressing mspA to identify genes that are not essential anymore in the presence of MspA. This analysis confirmed the importance of esx-5, but we could not identify essential ESX-5 substrates, indicating that multiple of these substrates are together responsible for the essentiality. Finally, examination of phenotypes on defined carbon sources revealed that an esx-5 mutant is strongly impaired in the uptake and utilization of hydrophobic carbon sources. Based on these data, we propose a model in which the ESX-5 system is responsible for the transport of cell envelope proteins that are required for nutrient uptake. These proteins might in this way compensate for the lack of MspA-like porins in slow

  13. Technical assessment of a micro-cogeneration system based on polymer electrolyte membrane fuel cell and fluidized bed autothermal reformer

    International Nuclear Information System (INIS)

    Di Marcoberardino, Gioele; Roses, Leonardo; Manzolini, Giampaolo

    2016-01-01

    Highlights: • Performances of an ATR membrane reactor within a PEM FC micro-CHP system of 5 kWel. • Analysis of two different options for the H_2 permeate side: sweep and vacuum pump. • Optimization of operating conditions in terms of efficiency and membrane area. • Distribution of power and thermal consumptions and losses were discussed in detail. • A sensitivity analysis highlights the relevant design parameters of the CHP system. - Abstract: This work investigates the integration of an autothermal membrane reformer within a micro-CHP system of 5 kWel based on PEM fuel cell. The system modeled is based on a prototype developed within Reforcell European project. The optimization of the micro-CHP system is performed from a thermodynamic point of view aiming at the target of 40% of net electric efficiency and 90% of total system efficiency comparing different configuration and operating conditions. In particular, two hydrogen permeate side options as vacuum or sweep steam are evaluated together with different combination of feed temperature and pressures. A good compromise between electric efficiency (40%) and membrane surface area (0.3 m"2) was obtained for the sweep gas case at reaction side conditions of 8 bar, 600 °C and S/C of 2.5. Higher electric efficiency (40.5%) could be achieved by increasing the membrane surface area. The adoption of a vacuum pump simplifies the reactor design and manufacturing, but reduces the net electric efficiency by about 2% points with a membrane surface area of 0.15 m"2. Finally, the sensitivity analysis highlighted the influence of the main parameters and the design criteria for the definition of the CHP system.

  14. The effect of acid rain stress on membrane protective system of spinach and the conservation of rare earth elements

    International Nuclear Information System (INIS)

    Chongling, Y; Yetang, H.

    1998-01-01

    Full text: Based on pot experiments, the effect of acid rain stress on membrane protective system of spinach and the effect of rare earth elements has been studied. The results showed, stress of acid rain resulted in decrease of over all level of superoxide dismutase activity, catalase activity and increase of peroxidase (POD) activity. After being treated by rare earth elements, the overall level of superoxide dismutase activity and catalase activity were increased and the peak value of activity variation curve moved toward to the direction of higher acidity. POD activity increased slightly, comparing with the plants that hadn't been treated by rare earth elements under same acid rain condition; the three important enzymes of membrane protective system could be kept on a relatively stable level. It was clear that in relative lower acidity condition, rare earth elements can reduce the impact of acid rain on the membrane protective system

  15. A microbial fuel cell–membrane bioreactor integrated system for cost-effective wastewater treatment

    International Nuclear Information System (INIS)

    Wang, Yong-Peng; Liu, Xian-Wei; Li, Wen-Wei; Li, Feng; Wang, Yun-Kun; Sheng, Guo-Ping; Zeng, Raymond J.; Yu, Han-Qing

    2012-01-01

    Highlights: ► An MFC–MBR integrated system for wastewater treatment and electricity generation. ► Stable electricity generation during 1000-h continuous operation. ► Low-cost electrode, separator and filter materials were adopted. -- Abstract: Microbial fuel cell (MFC) and membrane bioreactor (MBR) are both promising technologies for wastewater treatment, but both with limitations. In this study, a novel MFC–MBR integrated system, which combines the advantages of the individual systems, was proposed for simultaneous wastewater treatment and energy recovery. The system favored a better utilization of the oxygen in the aeration tank of MBR by the MFC biocathode, and enabled a high effluent quality. Continuous and stable electricity generation, with the average current of 1.9 ± 0.4 mA, was achieved over a long period of about 40 days. The maximum power density reached 6.0 W m −3 . Moreover, low-cost materials were used for the reactor construction. This integrated system shows great promise for practical wastewater treatment application.

  16. Study of Hydrogen Consumption by Control System in Proton Exchange Membrane Fuel Cell

    International Nuclear Information System (INIS)

    Ros Emilia Rosli; Edy Herianto Majlan; Siti Afiqah Abd Hamid; Wan Ramli Wan Daud; Ramizi Mohamed; Dedi Rohendi

    2016-01-01

    Efficient operation results from a proper control strategy. In the operation and performance of a Proton Exchange Membrane Fuel Cell (PEMFC), the hydrogen gas flow rate is one of the most essential control parameter in addition to operating pressure, water management, temperature and humidity. This is because of the high cost and amount of energy are required to produce the purity hydrogen gas. In this paper, a Proportional Integral Derivative (PID) feedback control system is used to control the hydrogen flow rate. A strategy is adapted to balance the hydrogen use based on the loading requirements, especially during start-ups and sudden power demands. This system is implemented using National Instrument (NI) devices powered by the LabVIEW program. This is due to its simplicity and customization flexibility for measuring, processing and recording data. Designed structure allows the real-time implementation of a robust control law that is able to address the related nonlinearities and uncertainties without incurring a heavy computational load for the controller algorithm. While it facilitating a fast sampling rate according to the needs of the power system. Test results from the controller show that the new fuel control system provides good performance by reducing the amount of wasted hydrogen gas compared with that of the previous open loop system by 30 % to over 80 % saved by the varied load. This improvement is beneficial for any PEMFC that experiences fluctuating power demand, especially for vehicle applications. (author)

  17. Characterization of a poly(ether urethane)-based controlled release membrane system for delivery of ketoprofen

    International Nuclear Information System (INIS)

    Macocinschi, Doina; Filip, Daniela; Vlad, Stelian; Oprea, Ana Maria; Gafitanu, Carmen Anatolia

    2012-01-01

    Highlights: ► Ketoprofen incorporation in poly(ether urethane) microporous membrane. ► Moisture sorption properties of as-cast membrane. ► Drug release mechanisms in function of pH and composition of membranes. - Abstract: A poly(ether urethane) based on polytetrahydrofuran containing hydroxypropyl cellulose for biomedical applications was tested for its biocompatibility. Ketoprofen was incorporated (3% and 6%) in the polyurethane matrix as an anti-inflammatory drug. Kinetic and drug release mechanisms were studied. The pore size and pore size distribution of the polyurethane membranes were investigated by scanning electron microscopy. Surface tension characteristics as well as moisture sorption properties such as diffusion coefficients and equilibrium moisture contents of the membrane material were studied. It was found that kinetics and release mechanisms are in function of medium pH, composition of polymer–drug system, pore morphology and pore size distribution. Prolonged nature of release of ketoprofen is assured by low amount of drug in polyurethane membrane and physiological pH.

  18. Colorimetric biomimetic sensor systems based on molecularly imprinted polymer membranes for highly-selective detection of phenol in environmental samples

    Directory of Open Access Journals (Sweden)

    Sergeyeva T. A.

    2014-05-01

    Full Text Available Aim. Development of an easy-to-use colorimetric sensor system for fast and accurate detection of phenol in envi- ronmental samples. Methods. Technique of molecular imprinting, method of in situ polymerization of molecularly imprinted polymer membranes. Results. The proposed sensor is based on free-standing molecularly imprinted polymer (MIP membranes, synthesized by in situ polymerization, and having in their structure artificial binding sites capable of selective phenol recognition. The quantitative detection of phenol, selectively adsorbed by the MIP membranes, is based on its reaction with 4-aminoantipyrine, which gives a pink-colored product. The intensity of staining of the MIP membrane is proportional to phenol concentration in the analyzed sample. Phenol can be detected within the range 50 nM–10 mM with limit of detection 50 nM, which corresponds to the concentrations that have to be detected in natural and waste waters in accordance with environmental protection standards. Stability of the MIP-membrane-based sensors was assessed during 12 months storage at room temperature. Conclusions. The sensor system provides highly-selective and sensitive detection of phenol in both mo- del and real (drinking, natural, and waste water samples. As compared to traditional methods of phenol detection, the proposed system is characterized by simplicity of operation and can be used in non-laboratory conditions.

  19. Neumann and Neumann-Rosochatius integrable systems from membranes on AdS4 x S7

    International Nuclear Information System (INIS)

    Bozhilov, Plamen

    2007-01-01

    It is known that large class of classical string solutions in the type IIB AdS 5 x S 5 background is related to the Neumann and Neumann-Rosochatius integrable systems, including spiky strings and giant magnons. It is also interesting if these integrable systems can be associated with some membrane configurations in M-theory. We show here that this is indeed the case by presenting explicitly several types of membrane embedding in AdS 4 x S 7 with the searched properties

  20. Mixed Matrix Membranes for O2/N2 Separation: The Influence of Temperature

    Directory of Open Access Journals (Sweden)

    Ana Fernández-Barquín

    2016-05-01

    Full Text Available In this work, mixed matrix membranes (MMMs composed of small-pore zeolites with various topologies (CHA (Si/Al = 5, LTA (Si/Al = 1 and 5, and Rho (Si/Al = 5 as dispersed phase, and the hugely permeable poly(1-trimethylsilyl-1-propyne (PTMSP as continuous phase, have been synthesized via solution casting, in order to obtain membranes that could be attractive for oxygen-enriched air production. The O2/N2 gas separation performance of the MMMs has been analyzed in terms of permeability, diffusivity, and solubility in the temperature range of 298–333 K. The higher the temperature of the oxygen-enriched stream, the lower the energy required for the combustion process. The effect of temperature on the gas permeability, diffusivity, and solubility of these MMMs is described in terms of the Arrhenius and Van’t Hoff relationships with acceptable accuracy. Moreover, the O2/N2 permselectivity of the MMMs increases with temperature, the O2/N2 selectivities being considerably higher than those of the pure PTMSP. In consequence, most of the MMMs prepared in this work exceeded the Robeson’s upper bound for the O2/N2 gas pair in the temperature range under study, with not much decrease in the O2 permeabilities, reaching O2/N2 selectivities of up to 8.43 and O2 permeabilities up to 4,800 Barrer at 333 K.

  1. Performance investigation of a solar-assisted direct contact membrane distillation system

    KAUST Repository

    Kim, Youngdeuk

    2013-01-01

    This paper presents a solar-assisted direct contact membrane distillation (DCMD) system with novel energy recovery concepts for a continuous 24-h-a-day operation. A temperature modulating scheme is introduced to the solar-thermal system that supplies feed seawater to the DCMD modules. This scheme attenuates extreme temperature fluctuations of the feed water by storing the collected energy during solar-peak hours and reutilizing it throughout the day. Thus, the energy savings is realized yet the feed seawater temperature is maintained within the desired range. Additionally, the system employs heat recovery from the permeate and brine streams to the feed seawater. The simulations for such a system with a shell-and-tube type DCMD modules are carried out to examine the spatial property variations and the sensitivity of system performance (i.e., transmembrane pressure, permeate flux and performance ratio) to the operating conditions (inlet temperature and flow rate) and the fiber dimensions (fiber length and packing density). It is found that there are trade-offs between mean permeate flux and performance ratio with respect to permeate inlet temperature and flow rate and between total distillate production and performance ratio with respect to packing density. For the solar-assisted DCMD system having evacuated-tube collectors of 3360m2 with 160m3 seawater storage tanks and 50 DCMD modules, the annual solar fraction and the collector efficiency are found to be 77% and 53%, respectively, whilst the overall permeate production capacity is 31m3/day. The overall specific thermal energy consumption of the DCMD system with heat recovery is found to be 436kWh/m3 and it is about 43% lower as compared to the system without heat recovery. It is observed that the specific thermal energy consumption decreases significantly by 55% with increased collector area from 1983m2 to 3360m2 whereas the specific electrical energy consumption increases slightly by 16%. © 2012 Elsevier B.V.

  2. Comparative study of the active cadmium efflux systems operating at the plasma membrane and tonoplast of cucumber root cells.

    Science.gov (United States)

    Migocka, Magdalena; Papierniak, Anna; Kosatka, Ewelina; Klobus, Grazyna

    2011-10-01

    The strategies developed by plants to avoid the toxicity of cadmium (Cd) and other heavy metals involve active sequestration of metals into the apoplast and vacuoles. The protein systems excluding heavy metals from the cell cytosol localize to the plasma membrane and tonoplast and are energized either by ATP or by the electrochemical gradient generated by H(+)-ATPase or by V-ATPase and pyrophosphatase (PPase), respectively. In this work, a comparative study on the contribution of both the plasma membrane and tonoplast in the active detoxification of plant cells after treatment with Cd was performed. The studies using plants treated and untreated with Cd reveal that both, H(+)-coupled and MgATP-driven efflux of Cd across plasma membranes and tonoplast is markedly stimulated in the presence of Cd in the environment. Previous studies on plasma-membrane localized H(+)-coupled Cd efflux together with the present data demonstrating tonoplast H(+)/Cd(2+) antiport activity suggest that H(+)-coupled secondary transport of Cd displays a lower affinity for Cd when compared with Cd primary pumps driven by MgATP. In addition, it is shown that MgATP-energized Cd efflux across both membranes is significantly enhanced by cysteine, dithiothreitol, and glutathione. These results suggest that Cd is excluded from the cytosol through an energy-dependent system as a free ion as well as a complexed form. Although both membranes contribute in the active exclusion of ionized and complexed Cd from the cytosol, the overall calculation of Cd accumulation in the everted plasma membranes and vacuolar vesicles suggests that the tonoplast and vacuole have a major function in Cd efflux from the cytosol in the roots of cucumber subjected to Cd stress.

  3. Offshore Membrane Enclosures for Growing Algae (OMEGA: A System for Biofuel Production, Wastewater Treatment, and CO2 Sequestration

    Science.gov (United States)

    Trent, Jonathan; Embaye, Tsegereda; Buckwalter, Patrick; Richardson, Tra-My; Kagawa, Hiromi; Reinsch, Sigrid; Martis, Mary

    2010-01-01

    We are developing Offshore Membrane Enclosures for Growing Algae (OMEGA). OMEGAs are closed photo-bioreactors constructed of flexible, inexpensive, and durable plastic with small sections of semi-permeable membranes for gas exchange and forward osmosis (FO). Each OMEGA modules is filled with municipal wastewater and provided with CO2 from coastal CO2 sources. The OMEGA modules float just below the surface, and the surrounding seawater provides structural support, temperature control, and mixing for the freshwater algae cultures inside. The salinit7 gradient from inside to outside drives forward osmosis through the patches of FO membranes. This concentrates nutrients in the wastewater, which enhances algal growth, and slowly dewaters the algae, which facilitates harvesting. Thy concentrated algal biomass is harvested for producing biofuels and fertilizer. OMEGA system cleans the wastewater released into the surrounding coastal waters and functions as a carbon sequestration system.

  4. Parametric analysis of an irreversible proton exchange membrane fuel cell/absorption refrigerator hybrid system

    International Nuclear Information System (INIS)

    Yang, Puqing; Zhang, Houcheng

    2015-01-01

    A hybrid system mainly consisting of a PEMFC (proton exchange membrane fuel cell) and an absorption refrigerator is proposed, where the PEMFC directly converts the chemical energy contained in the hydrogen into electrical and thermal energies, and the thermal energy is transferred to drive the bottoming absorption refrigerator for cooling purpose. By considering the existing irreversible losses in the hybrid system, the operating current density region of the PEMFC permits the absorption refrigerator to exert its function is determined and the analytical expressions for the equivalent power output and efficiency of the hybrid system under different operating conditions are specified. Numerical calculations show that the equivalent maximum power density and the corresponding efficiency of the hybrid system can be respectively increased by 5.3% and 6.8% compared to that of the stand-alone PEMFC. Comprehensive parametric analyses are conducted to reveal the effects of the internal irreversibility of the absorption refrigerator, operating current density, operating temperature and operating pressure of the PEMFC, and some integrated parameters related to the thermodynamic losses on the performance of the hybrid system. The model presented in the paper is more general than previous study, and the results for some special cases can be directly derived from this paper. - Highlights: • A CHP system composed of a PEMFC and an absorption refrigerator is proposed. • Current density region enables the absorption refrigerator to work is determined. • Multiple irreversible losses in the system are analytically characterized. • Maximum power density and corresponding efficiency can be increased by 5.3% and 6.8%. • Effects of some designing and operating parameters on the performance are discussed

  5. Fouling-Resistant Membranes for Treating Concentrated Brines for Water Reuse in Advanced Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Hendren, Zachary [RTI International, Research Triangle Park, NC (United States); Choi, Young Chul [RTI International, Research Triangle Park, NC (United States)

    2014-10-14

    The high total dissolved solids (TDS) levels in the wastewater quality generated from unconventional oil and gas development make the current state-of-the art approach to water treatment/disposal untenable. Our proposed membrane technology approach addresses the two major challenges associated with this water: 1) the membrane distillation process removes the high TDS content, which is often 8 times higher than that of seawater, and 2) our novel membrane coating prevents the formation of scale that would otherwise pose a significant operational hurdle. This is accomplished through next-generation electrically conductive membranes that mitigate fouling beyond what is currently possible, and allow for the flexibility to treat to the water to levels desirable for multiple reuse options, thus reducing fresh water withdrawal, all the way to direct disposal into the environment. The overall project objective was to demonstrate the efficacy of membrane distillation (MD) as a cost-savings technology to treat concentrated brines (such as, but not limited to, produced waters generated from fossil fuel extraction) that have high levels of TDS for beneficial water reuse in power production and other industrial operations as well as agricultural and municipal water uses. In addition, a novel fouling-resistant nanocomposite membrane was developed to reduce the need for chemicals to address membrane scaling due to the precipitation of divalent ions in high-TDS waters and improve overall MD performance via an electrically conductive membrane distillation process (ECMD). This anti-fouling membrane technology platform is based on incorporating carbon nanotubes (CNTs) into the surface layer of existing, commercially available MD membranes. The CNTs impart electrical conductivity to the membrane surface to prevent membrane scaling and fouling when an electrical potential is applied.

  6. Inflammatory Response of Human Gestational Membranes to Ureaplasma parvum Using a Novel Dual-Chamber Tissue Explant System.

    Science.gov (United States)

    Potts, Lauren C; Feng, Liping; Seed, Patrick C; Jayes, Friederike L; Kuchibhatla, Maragatha; Antczak, Brian; Nazzal, Matthew K; Murtha, Amy P

    2016-05-01

    Preterm premature rupture of membranes (PPROM) is often associated with intra-amniotic inflammation and infection. Current understanding of the pathogenesis of PPROM includes activation of pro-inflammatory cytokines and proteolytic enzymes leading to compromise of membrane integrity. The impact of exposure to bacterial pathogens, including Ureaplasma parvum, on gestational membranes is poorly understood. Our objective was to develop a dual-chamber system to characterize the inflammatory response of gestational membranes to U. parvum in a directional nature. Full-thickness human gestational membrane explants, with either choriodecidua or amnion oriented superiorly, were suspended between two washers in a cylindrical device, creating two distinct compartments. Brilliant green dye was introduced into the top chamber to assess the integrity of the system. Tissue viability was evaluated after 72 h using a colorimetric cell proliferation assay. Choriodecidua or amnion was exposed to three doses of U. parvum and incubated for 24 h. Following treatment, media from each compartment were used for quantification of U. parvum (quantitative PCR), interleukin (IL)-8 (enzyme-linked immunosorbent assay), and matrix metalloproteinase (MMP)-2 and MMP-9 activity (zymography). We observed that system integrity and explant viability were maintained over 72 h. Dose-dependent increases in recovered U. parvum, IL-8 concentration, and MMP-2 activity were detected in both compartments. Significant differences in IL-8 concentration and MMP-9 activity were found between the choriodecidua and amnion. This tissue explant system can be used to investigate the inflammatory consequences of directional bacterial exposure for gestational membranes and provides insight into the pathogenesis of PPROM and infectious complications of pregnancy. © 2016 by the Society for the Study of Reproduction, Inc.

  7. Application of new nuclear track microporous membrane in transdermal therapeutic system (TTS)

    International Nuclear Information System (INIS)

    Risheng Wu; Jian Zhou; Wei Ke

    1993-01-01

    Newly-developed Nuclear Track Microporous Membrane, which is formed by alpha particle irradiation with greatly reduced cost, is first used as the drug release rate controlling membrane for TTS patch. It shows good zero order release kinetics and its released quantity of drugs can be regulated conveniently by changing its porosity instead of changing the area of other control membrane used abroad. Its high benefit-cost ratio and improved TTS performances manifest the superiority and great potential of the newly developed Nuclear Track Microporous membrane. (Author)

  8. Heat-And-Mass Transfer Relationship to Determine Shear Stress in Tubular Membrane Systems

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Nopens, Ingmar

    2012-01-01

    The main drawback of Membrane Bioreactors (MBRs) is the fouling of the membrane. One way to reduce this fouling is through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. It has been proven in literature that the slug flow pattern has a higher scouring effect...... to remove particulates due to the high shear rates and high mass transfer between the membrane surface and the bulk region. However, to calculate the mass transfer coefficient in an efficient and accurate way is not straightforward. Indeed, for accurate determination, numerous complex experimental...

  9. Catalytic, Conductive Bipolar Membrane Interfaces through Layer-by-Layer Deposition for the Design of Membrane-Integrated Artificial Photosynthesis Systems.

    Science.gov (United States)

    McDonald, Michael B; Freund, Michael S; Hammond, Paula T

    2017-11-23

    In the presence of an electric field, bipolar membranes (BPMs) are capable of initiating water disassociation (WD) within the interfacial region, which can make water splitting for renewable energy in the presence of a pH gradient possible. In addition to WD catalytic efficiency, there is also the need for electronic conductivity in this region for membrane-integrated artificial photosynthesis (AP) systems. Graphene oxide (GO) was shown to catalyze WD and to be controllably reduced, which resulted in electronic conductivity. Layer-by-layer (LbL) film deposition was employed to improve GO film uniformity in the interfacial region to enhance WD catalysis and, through the addition of a conducting polymer in the process, add electronic conductivity in a hybrid film. Three different deposition methods were tested to optimize conducting polymer synthesis with the oxidant in a metastable solution and to yield the best film properties. It was found that an approach that included substrate dipping in a solution containing the expected final monomer/oxidant ratio provided the most predictable film growth and smoothest films (by UV/Vis spectroscopy and atomic force microscopy/scanning electron microscopy, respectively), whereas dipping in excess oxidant or co-spraying the oxidant and monomer produced heterogeneous films. Optimized films were found to be electronically conductive and produced a membrane ohmic drop that was acceptable for AP applications. Films were integrated into the interfacial region of BPMs and revealed superior WD efficiency (≥1.4 V at 10 mA cm -2 ) for thinner films (<10 bilayers≈100 nm) than for either the pure GO catalyst or conducting polymer individually, which indicated that there was a synergistic effect between these materials in the structure configured by the LbL method. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Bioenergetic coupling between membrane transport systems and biosynthetic pathways essential for cell cycle progression

    International Nuclear Information System (INIS)

    Leister, K.J.; Cutry, A.F.; Wenner, C.E.

    1986-01-01

    Recently, it has been shown that there exists a point in the cell cycle (approximately 2 h prior to S phase entry) when (Na + /K + )ATPase pump activity is no longer needed for progression through the cycle. These data suggests that pump activity is critical in the biosynthetic processes which enables the cell to proceed through the G 1 phase. A scheme is proposed which is currently being tested that (Na + /K + )ATPase pump activity serves as the driving force in the regulation of other membrane transport processes critical for cell proliferation. For example, in post-confluent quiescent C3H-10T1/2 fibroblasts, when [K + ]/sub o/ is lowered just below the K/sub m/ of the pump for K + there is a 10-fold increase in 3 H-uridine uptake into both acid soluble and insoluble cell fractions. By modulation of the pump in this manner, glucose utilization is enhanced whereas inhibition of the pump by ouabain suppresses glucose utilization. In both methods of affecting the pump, 3 H-leucine incorporation is inhibited. Electron acceptors that influence the redox state of the cell have been shown to both stimulate or inhibit cell cycle progression. Under conditions where [K + ]/sub o/ is lowered, the nucleoside uptake responses observed were modified by electron acceptors depending on the ability to oxidize NAD(P)H directly or to interact with a cytochrome-like component, (e.g. phenazine methosulfate) reversed the enhanced uridine uptake and p-phenylene diamine further enhanced the uridine uptake response. These findings suggest that a plasma membrane redox system (presumably cyt-c like) is linked to nucleoside transport which is subject to (Na + /K + )ATPase activity

  11. Rheological, mechanical and membrane penetration properties of novel dual drug systems for percutaneous delivery.

    Science.gov (United States)

    Woolfson, A D; Malcolm, R K; Campbell, K; Jones, D S; Russell, J A

    2000-07-03

    In this study it has been demonstrated that mixtures of two solid drugs, ibuprofen and methyl nicotinate, with different but complementary pharmacological activities and which exist as a single liquid phase over a wide composition range at skin temperature, can be formulated as o/w emulsions without the use of an additional hydrophobic carrier. These novel dual drug systems provided significantly enhanced in vitro penetration rates through a model lipophilic barrier membrane compared to conventional individual formulations of each active. Thus, for ibuprofen, drug penetration flux enhancements of three- and 10-fold were observed when compared to an aqueous ibuprofen suspension and a commercial alcohol-based ibuprofen formulation, respectively. Methyl nicotinate penetration rates were shown to be similar for aqueous gels and emulsified systems. Mechanisms explaining these observations are proposed. Novel dual drug formulations of ibuprofen and methyl nicotinate, formulated within the liquid range at skin temperature, were investigated by oscillatory rheology and texture profile analysis, demonstrating the effects of drug and viscosity enhancer concentrations, and disperse phase type upon the rheological, mechanical and drug penetration properties of these systems.

  12. Laboratory information management system for membrane protein structure initiative--from gene to crystal.

    Science.gov (United States)

    Troshin, Petr V; Morris, Chris; Prince, Stephen M; Papiz, Miroslav Z

    2008-12-01

    Membrane Protein Structure Initiative (MPSI) exploits laboratory competencies to work collaboratively and distribute work among the different sites. This is possible as protein structure determination requires a series of steps, starting with target selection, through cloning, expression, purification, crystallization and finally structure determination. Distributed sites create a unique set of challenges for integrating and passing on information on the progress of targets. This role is played by the Protein Information Management System (PIMS), which is a laboratory information management system (LIMS), serving as a hub for MPSI, allowing collaborative structural proteomics to be carried out in a distributed fashion. It holds key information on the progress of cloning, expression, purification and crystallization of proteins. PIMS is employed to track the status of protein targets and to manage constructs, primers, experiments, protocols, sample locations and their detailed histories: thus playing a key role in MPSI data exchange. It also serves as the centre of a federation of interoperable information resources such as local laboratory information systems and international archival resources, like PDB or NCBI. During the challenging task of PIMS integration, within the MPSI, we discovered a number of prerequisites for successful PIMS integration. In this article we share our experiences and provide invaluable insights into the process of LIMS adaptation. This information should be of interest to partners who are thinking about using LIMS as a data centre for their collaborative efforts.

  13. A review of fault tolerant control strategies applied to proton exchange membrane fuel cell systems

    Science.gov (United States)

    Dijoux, Etienne; Steiner, Nadia Yousfi; Benne, Michel; Péra, Marie-Cécile; Pérez, Brigitte Grondin

    2017-08-01

    Fuel cells are powerful systems for power generation. They have a good efficiency and do not generate greenhouse gases. This technology involves a lot of scientific fields, which leads to the appearance of strongly inter-dependent parameters. This makes the system particularly hard to control and increases fault's occurrence frequency. These two issues call for the necessity to maintain the system performance at the expected level, even in faulty operating conditions. It is called "fault tolerant control" (FTC). The present paper aims to give the state of the art of FTC applied to the proton exchange membrane fuel cell (PEMFC). The FTC approach is composed of two parts. First, a diagnosis part allows the identification and the isolation of a fault; it requires a good a priori knowledge of all the possible faults. Then, a control part allows an optimal control strategy to find the best operating point to recover/mitigate the fault; it requires the knowledge of the degradation phenomena and their mitigation strategies.

  14. Tools for designing the cooling system of a proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Soupremanien, Ulrich; Le Person, Stéphane; Favre-Marinet, Michel; Bultel, Yann

    2012-01-01

    Proton exchange membrane fuel cell (PEMFC) requires a careful management of the heat distribution inside the stack. The proton exchange membrane is the most sensitive element of this thermal management and it must operate under specific conditions in order to increase the lifetime and also the output power of the fuel cell. These last decades, the enhancement of the output power of the PEMFC has led the manufacturers to greatly improve the heat transfer effectiveness for cooling such systems. In addition, homogenizing the bipolar plate temperature increases the lifetime of the system by limiting the occurrence of strong thermal gradients. In this context, using a fluid in boiling conditions to cool down the PEMFC seems to be very suitable for this purpose. In order to compare the thermal performances between a coolant used in single-phase flow or in boiling flow conditions, we have built an experimental set-up allowing the investigation of cooling flows for these two conditions. Moreover, the geometry of the cooling channels is one of the key parameters which allows the improvement of the thermal performances. Indeed, the size or the aspect ratio of these channels could be designed in order to decrease the thermal system response. The sizing of the fuel cell cooling system is of paramount importance in boiling flow conditions because it can modify, not only the pressure losses along the channel and the heat transfer coefficient like in a single-phase flow but also, the onset of nucleate boiling (ONB) and the dryout point or critical heat flux (CHF). Thus, in order to understand some heat transfer mechanisms, which are geometry-dependent, a parametric study was completed by considering flows in four different rectangular channels. Finally, this study allows a better insight on the optimization of the geometrical parameters which improve the thermal performances of a PEMFC, from a cooling strategy aspect point of view. - Highlights: ► Parameters for the using of a

  15. Preparation, characterisation and critical flux determination of graphene oxide blended polysulfone (PSf) membranes in an MBR system.

    Science.gov (United States)

    Ravishankar, Harish; Roddick, Felicity; Navaratna, Dimuth; Jegatheesan, Veeriah

    2018-05-01

    Microfiltration membranes having different blends of graphene-oxide (GO) (0-1 wt%) and Polysulfone (PSf) (15-20 wt%) were prepared using the classical non-solvent induced phase inversion process. The prepared membranes were characterised for their structural morphology, surface properties, mechanical strength, porosity and pure water flux. Based on the initial characterisation results, four membranes (15 wt% PSf, 15 wt% PSf + 0.25 wt% GO, 15 wt% PSf + 1 wt% GO and 20 wt% PSf + 1 wt% GO) were chosen for critical flux study, that was conducted using flux-step method in a lab scale MBR system. In order to study the application potential of GO blended membranes, the critical flux of each membrane was evaluated in two operational modes i.e., continuous and intermittent modes with backwash. The membranes with maximal GO concentration (15 wt% PSf + 1 wt% GO and 20 wt% PSf + 1 wt% GO) showed higher critical flux (16.5, 12.8 L/m 2 h and 19, 15 L/m 2 h for continuous and intermittent mode, respectively). It was observed that the operational modes did not have a significant effect on the critical flux of the membranes with low GO concentration (15 wt% PSf and 15 wt% PSf + 0.25 wt% GO), indicating a minimal of 1 wt% GO was required for an observable effect that favoured intermittent mode of operation. Through these results, ideal operating condition was arrived (i.e., flux maintained at 6.4 L/m 2 h operated under intermittent mode) and the membranes 15 wt% PSf and 15 wt% PSf + 1 wt% GO were studied for their long-term operation. The positive effect of GO on filtration time, cleaning frequency and against fouling was demonstrated through long term TMP profile of the membranes, indicating the suitability of GO blended membrane for real time wastewater treatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

  16. RECENT PROGRESS OF OXYGEN/NITROGEN SEPARATION USING MEMBRANE TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    K. C. CHONG

    2016-07-01

    Full Text Available The oxygen-enriched air is highly demanded for various industrial applications such as medical, chemical and enhanced combustion processes. The conventional oxygen/nitrogen production is either cryogenic distillation or pressure swing adsorption (PSA. Both of these techniques possess the production capability of 20 to 300 tonnes of oxygen per day and oxygen purity of more than 95%. However, these techniques are energy intensive. Alternatively, membrane technology is an emerging technology in gas separation as it requires low energy consumption and relatively moderate production volume, if compared to the conventional gas production techniques. These advantages have spurred much interest from industries and academics to speed up the commercial viability of the O2/N2 separation via membrane technology. In this review, the conventional and membrane technologies in O2/N2 separation, as well as recent development of membrane fabrication techniques and materials are reviewed. The latest membrane performance in O2/N2 separation is also tabulated and discussed.

  17. Membrane dynamics

    DEFF Research Database (Denmark)

    Bendix, Pól Martin

    2015-01-01

    Current topics include membrane-protein interactions with regard to membrane deformation or curvature sensing by BAR domains. Also, we study the dynamics of membrane tubes of both cells and simple model membrane tubes. Finally, we study membrane phase behavior which has important implications...... for the lateral organization of membranes as wells as for physical properties like bending, permeability and elasticity...

  18. An artificial neural network ensemble method for fault diagnosis of proton exchange membrane fuel cell system

    International Nuclear Information System (INIS)

    Shao, Meng; Zhu, Xin-Jian; Cao, Hong-Fei; Shen, Hai-Feng

    2014-01-01

    The commercial viability of PEMFC (proton exchange membrane fuel cell) systems depends on using effective fault diagnosis technologies in PEMFC systems. However, many researchers have experimentally studied PEMFC (proton exchange membrane fuel cell) systems without considering certain fault conditions. In this paper, an ANN (artificial neural network) ensemble method is presented that improves the stability and reliability of the PEMFC systems. In the first part, a transient model giving it flexibility in application to some exceptional conditions is built. The PEMFC dynamic model is built and simulated using MATLAB. In the second, using this model and experiments, the mechanisms of four different faults in PEMFC systems are analyzed in detail. Third, the ANN ensemble for the fault diagnosis is built and modeled. This model is trained and tested by the data. The test result shows that, compared with the previous method for fault diagnosis of PEMFC systems, the proposed fault diagnosis method has higher diagnostic rate and generalization ability. Moreover, the partial structure of this method can be altered easily, along with the change of the PEMFC systems. In general, this method for diagnosis of PEMFC has value for certain applications. - Highlights: • We analyze the principles and mechanisms of the four faults in PEMFC (proton exchange membrane fuel cell) system. • We design and model an ANN (artificial neural network) ensemble method for the fault diagnosis of PEMFC system. • This method has high diagnostic rate and strong generalization ability

  19. Distinct human and mouse membrane trafficking systems for sweet taste receptors T1r2 and T1r3.

    Science.gov (United States)

    Shimizu, Madoka; Goto, Masao; Kawai, Takayuki; Yamashita, Atsuko; Kusakabe, Yuko

    2014-01-01

    The sweet taste receptors T1r2 and T1r3 are included in the T1r taste receptor family that belongs to class C of the G protein-coupled receptors. Heterodimerization of T1r2 and T1r3 is required for the perception of sweet substances, but little is known about the mechanisms underlying this heterodimerization, including membrane trafficking. We developed tagged mouse T1r2 and T1r3, and human T1R2 and T1R3 and evaluated membrane trafficking in human embryonic kidney 293 (HEK293) cells. We found that human T1R3 surface expression was only observed when human T1R3 was coexpressed with human T1R2, whereas mouse T1r3 was expressed without mouse T1r2 expression. A domain-swapped chimera and truncated human T1R3 mutant showed that the Venus flytrap module and cysteine-rich domain (CRD) of human T1R3 contain a region related to the inhibition of human T1R3 membrane trafficking and coordinated regulation of human T1R3 membrane trafficking. We also found that the Venus flytrap module of both human T1R2 and T1R3 are needed for membrane trafficking, suggesting that the coexpression of human T1R2 and T1R3 is required for this event. These results suggest that the Venus flytrap module and CRD receive taste substances and play roles in membrane trafficking of human T1R2 and T1R3. These features are different from those of mouse receptors, indicating that human T1R2 and T1R3 are likely to have a novel membrane trafficking system.

  20. Preliminary study on application of Pd composite membrane in helium purification system of high-temperature gas-cooled reactor

    International Nuclear Information System (INIS)

    Cai Jianhua; Yang Xiaoyong; Wang Jie; Yu Suyuan

    2008-01-01

    Helium purification system (HPS) is the main part of the helium auxiliary system of high-temperature gas-cooled reactors (HTGR), also in fusion reactors. Some exploratory work was carried out on the application of Pd composite membrane in the separation of He and H 2 . A typical single stripper permeator with recycle (SSP) system was designed, based on the design parameters of a small scale He purification test system CIGNE in CADARACHE, CEA, France, and finite element analysis method was used to solve the model. The total length of membrane module is fixed to 0.5 m. The results show that the concentration of H 2 is found to reduce from 1 000 μL/L in feed gas to 5 μL/L in the product He (the upper limitation of HPS in HTGR). And the molar ratio of product He to feed gas is 96.18% with the optimized ratio of sweep gas to retentive gas 0. 3970. It's an exponential distribution of H 2 concentration along the membrane module. The results were also compared with the other two popular designs, two stripper in series permeator (TSSP) and continuous membrane column (CMC). (authors)

  1. Evaluation of a membrane bioreactor system as post-treatment waste water treatment for better removal of micropollutants

    DEFF Research Database (Denmark)

    Arriaga, Sonia; de Jonge, Nadieh; Lund Nielsen, Marc

    2016-01-01

    Organic micropollutants such as pharmaceuticals are persistent pollutants that are only partially degraded in waste water treatment plants (WWTPs). In this study, a membrane bioreactor (MBR) system was used as a polishing step on a full-scale WWTP, and its ability to remove micropollutants...

  2. Fabrication and Scale-up of Polybenzimidazole (PBI) Membrane Based System for Precombustion-Based Capture of Carbon Dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Krishnan, Gopala; Jayaweera, Indira; Sanjrujo, Angel; O' Brien, Kevin; Callahan, Richard; Berchtold, Kathryn; Roberts, Daryl-Lynn; Johnson, Will

    2012-03-31

    The primary objectives of this project are to (1) demonstrate the performance and fabrication of a technically and economically viable pre-combustion-based CO{sub 2} capture system based on the high temperature stability and permeance of PBI membranes, (2) optimize a plan for integration of PBI capture system into an IGCC plant and (3) develop a commercialization plan that addresses technical issues and business issues to outline a clear path for technology transfer of the PBI membrane technology. This report describes research conducted from April 1, 2007 to March 30, 2012 and focused on achieving the above objectives. PBI-based hollow fibers have been fabricated at kilometer lengths and bundled as modules at a bench-scale level for the separation of CO{sub 2} from H{sub 2} at high temperatures and pressures. Long term stability of these fibers has been demonstrated with a relatively high H{sub 2}/CO{sub 2} selectivity (35 to 50) and H{sub 2} permeance (80 GPU) at temperatures exceeding 225°C. Membrane performance simulations and systems analysis of an IGCC system incorporating a PBI hollow fiber membrane modules have demonstrated that the cost of electricity for CO{sub 2} capture (<10%) using such a high temperature separator. When the cost of transporting, storing, and monitoring the CO{sub 2} is accounted for, the increase in the COE is only 14.4%.

  3. Modeling and optimization of the air system in polymer exchange membrane fuel cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Bao, Cheng; Ouyang, Minggao [State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084 (China); Yi, Baolian [Dalian Institute of Chemical Physics, CAS, Dalian 116023 (China)

    2006-06-01

    Stack and air system are the two most important components in the fuel cell system (FCS). It is meaningful to study their properties and the trade-off between them. In this paper, a modified one-dimensional steady-state analytical fuel cell model is used. The logarithmic mean of the inlet and the outlet oxygen partial pressure is adopted to avoid underestimating the effect of air stoichiometry. And the pressure drop model in the grid-distributed flow field is included in the stack analysis. Combined with the coordinate change preprocessing and analog technique, neural network is used to treat the MAP of compressor and turbine in the air system. Three kinds of air system topologies, the pure screw compressor, serial booster and exhaust expander are analyzed in this article. A real-code genetic algorithm is programmed to obtain the global optimum air stoichiometric ratio and the cathode outlet pressure. It is shown that the serial booster and expander with the help of exhaust recycling, can improve more than 3% in the FCS efficiency comparing to the pure screw compressor. As the net power increases, the optimum cathode outlet pressure keeps rising and the air stoichiometry takes on the concave trajectory. The working zone of the proportional valve is also discussed. This presented work is helpful to the design of the air system in fuel cell system. The steady-state optimum can also be used in the dynamic control. (author)

  4. Modeling and optimization of the air system in polymer exchange membrane fuel cell systems

    Science.gov (United States)

    Bao, Cheng; Ouyang, Minggao; Yi, Baolian

    Stack and air system are the two most important components in the fuel cell system (FCS). It is meaningful to study their properties and the trade-off between them. In this paper, a modified one-dimensional steady-state analytical fuel cell model is used. The logarithmic mean of the inlet and the outlet oxygen partial pressure is adopted to avoid underestimating the effect of air stoichiometry. And the pressure drop model in the grid-distributed flow field is included in the stack analysis. Combined with the coordinate change preprocessing and analog technique, neural network is used to treat the MAP of compressor and turbine in the air system. Three kinds of air system topologies, the pure screw compressor, serial booster and exhaust expander are analyzed in this article. A real-code genetic algorithm is programmed to obtain the global optimum air stoichiometric ratio and the cathode outlet pressure. It is shown that the serial booster and expander with the help of exhaust recycling, can improve more than 3% in the FCS efficiency comparing to the pure screw compressor. As the net power increases, the optimum cathode outlet pressure keeps rising and the air stoichiometry takes on the concave trajectory. The working zone of the proportional valve is also discussed. This presented work is helpful to the design of the air system in fuel cell system. The steady-state optimum can also be used in the dynamic control.

  5. Analysis of Shear Stress and Energy Consumption in a Tubular Airlift Membrane System

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Chan, C.C.V.; Berube, P.R.

    2011-01-01

    of fouling by imposing high shear stress near the surface of the membrane. Previously, shear stress histograms (SSH) have been introduced to summarize results from an experimental setup developed to investigate the shear stress imposed on the surface of a membrane under different two-phase flow conditions...

  6. Dynamical and structural properties of lipid membranes in relation to liposomal drug delivery systems

    DEFF Research Database (Denmark)

    Jørgensen, Kent; Høyrup, Lise Pernille Kristine; Pedersen, Tina B.

    2001-01-01

    The structural and dynamical properties of DPPC liposomes containing lipopolymers (PEG-lipids) and charged DPPS lipids have been,studied in relation to the lipid membrane interaction of enzymes and peptides. The results suggest that both the lipid membrane structure and dynamics and in particular...

  7. Attainability and minimum energy of multiple-stage cascade membrane Systems

    KAUST Repository

    Alshehri, Ali; Lai, Zhiping

    2015-01-01

    : View the MathML sourceSn=S1, View the MathML sourceγn=γ1, where n is the number of stages. The minimum energy consumption of a multi-stage membrane process is primarily determined by the membrane selectivity and recycle ratio. A low recycle ratio can

  8. Model cell membranes

    DEFF Research Database (Denmark)

    Günther-Pomorski, Thomas; Nylander, Tommy; Cardenas Gomez, Marite

    2014-01-01

    The high complexity of biological membranes has motivated the development and application of a wide range of model membrane systems to study biochemical and biophysical aspects of membranes in situ under well defined conditions. The aim is to provide fundamental understanding of processes control...

  9. Meniscus Membranes For Separation

    Science.gov (United States)

    Dye, Robert C.; Jorgensen, Betty; Pesiri, David R.

    2005-09-20

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  10. Meniscus membranes for separations

    Science.gov (United States)

    Dye, Robert C [Irvine, CA; Jorgensen, Betty [Jemez Springs, NM; Pesiri, David R [Aliso Viejo, CA

    2004-01-27

    Gas separation membranes, especially meniscus-shaped membranes for gas separations are disclosed together with the use of such meniscus-shaped membranes for applications such as thermal gas valves, pre-concentration of a gas stream, and selective pre-screening of a gas stream. In addition, a rapid screening system for simultaneously screening polymer materials for effectiveness in gas separation is provided.

  11. Integration of sand and membrane filtration systems for iron and pesticide removal without chemical addition

    DEFF Research Database (Denmark)

    Kowalski, Krysztof; Madsen, Henrik Tækker; Søgaard, Erik Gydesen

    2013-01-01

    the content of key foulants, the techniques can be used as a pre-treatment for nanofiltration and low pressure reverse osmosis that has proved to be capable of removing pesticides. It was found that a lower fouling potential could be obtained by using the membranes, but that sand filter was better at removing......Pilot plant investigations of sand and membrane filtration (MF/UF/NF/LPRO) have been performed to treat groundwater polluted with pesticides. The results show that simple treatment, with use of aeration and sand filtration or MF/UF membranes, does not remove pesticides. However, by reducing...... manganese and dissolved organic matter. The results indicate that combining aeration; sand filtration and membrane techniques might be a good option for pesticide removal without any addition of chemicals and minimized membrane maintenance....

  12. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    Science.gov (United States)

    Kelly, Sean M; Kromer, Brian R; Litwin, Michael M; Rosen, Lee J; Christie, Gervase Maxwell; Wilson, Jamie R; Kosowski, Lawrence W; Robinson, Charles

    2014-01-07

    A method and apparatus for producing heat used in a synthesis gas production is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the stream reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5.

  13. Oxygen transport membrane system and method for transferring heat to catalytic/process reactors

    Science.gov (United States)

    Kelly, Sean M.; Kromer, Brian R.; Litwin, Michael M.; Rosen, Lee J.; Christie, Gervase Maxwell; Wilson, Jamie R.; Kosowski, Lawrence W.; Robinson, Charles

    2016-01-19

    A method and apparatus for producing heat used in a synthesis gas production process is provided. The disclosed method and apparatus include a plurality of tubular oxygen transport membrane elements adapted to separate oxygen from an oxygen containing stream contacting the retentate side of the membrane elements. The permeated oxygen is combusted with a hydrogen containing synthesis gas stream contacting the permeate side of the tubular oxygen transport membrane elements thereby generating a reaction product stream and radiant heat. The present method and apparatus also includes at least one catalytic reactor containing a catalyst to promote the steam reforming reaction wherein the catalytic reactor is surrounded by the plurality of tubular oxygen transport membrane elements. The view factor between the catalytic reactor and the plurality of tubular oxygen transport membrane elements radiating heat to the catalytic reactor is greater than or equal to 0.5

  14. Multi-objective Optimization of Solar-driven Hollow-fiber Membrane Distillation Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nenoff, Tina M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Moore, Sarah E. [Univ. of Arizona, Tucson, AZ (United States); Mirchandani, Sera [Univ. of Arizona, Tucson, AZ (United States); Karanikola, Vasiliki [Univ. of Arizona, Tucson, AZ (United States); Arnold, Robert G. [Univ. of Arizona, Tucson, AZ (United States); Saez, Eduardo [Univ. of Arizona, Tucson, AZ (United States)

    2017-09-01

    Securing additional water sources remains a primary concern for arid regions in both the developed and developing world. Climate change is causing fluctuations in the frequency and duration of precipitation, which can be can be seen as prolonged droughts in some arid areas. Droughts decrease the reliability of surface water supplies, which forces communities to find alternate primary water sources. In many cases, ground water can supplement the use of surface supplies during periods of drought, reducing the need for above-ground storage without sacrificing reliability objectives. Unfortunately, accessible ground waters are often brackish, requiring desalination prior to use, and underdeveloped infrastructure and inconsistent electrical grid access can create obstacles to groundwater desalination in developing regions. The objectives of the proposed project are to (i) mathematically simulate the operation of hollow fiber membrane distillation systems and (ii) optimize system design for off-grid treatment of brackish water. It is anticipated that methods developed here can be used to supply potable water at many off-grid locations in semi-arid regions including parts of the Navajo Reservation. This research is a collaborative project between Sandia and the University of Arizona.

  15. A role for the membrane protein M6 in the Drosophila visual system.

    Science.gov (United States)

    Zappia, María Paula; Bernabo, Guillermo; Billi, Silvia C; Frasch, Alberto C; Ceriani, María Fernanda; Brocco, Marcela Adriana

    2012-07-04

    Members of the proteolipid protein family, including the four-transmembrane glycoprotein M6a, are involved in neuronal plasticity in mammals. Results from our group previously demonstrated that M6, the only proteolipid protein expressed in Drosophila, localizes to the cell membrane in follicle cells. M6 loss triggers female sterility, which suggests a role for M6 in follicular cell remodeling. These results were the basis of the present study, which focused on the function and requirements of M6 in the fly nervous system. The present study identified two novel, tissue-regulated M6 isoforms with variable N- and C- termini, and showed that M6 is the functional fly ortholog of Gpm6a. In the adult brain, the protein was localized to several neuropils, such as the optic lobe, the central complex, and the mushroom bodies. Interestingly, although reduced M6 levels triggered a mild rough-eye phenotype, hypomorphic M6 mutants exhibited a defective response to light. Based on its ability to induce filopodium formation we propose that M6 is key in cell remodeling processes underlying visual system function. These results bring further insight into the role of M6/M6a in biological processes involving neuronal plasticity and behavior in flies and mammals.

  16. Application of DBNPA dosage for biofouling control in spiral wound membrane systems

    KAUST Repository

    Siddiqui, Amber

    2017-05-30

    Biocides may be used to control biofouling in spiral-wound reverse osmosis (RO) and nanofiltration (NF) systems. The objective of this study was to investigate the effect of biocide 2,2-dibromo-3-ni-trilopropionamide (DBNPA) dosage on biofouling control. Preventive biofouling control was studied applying a continuous dosage of substrate (0.5 mg/L) and DBNPA (1 mg/L). Curative biofouling control was studied on pre-grown biofilms, once again applying a continuous dosage of substrate (0.5 mg acetate C/L) and DBNPA (1 and 20 mg/L). Biofouling studies were performed in membrane fouling simulators (MFSs) supplied with biodegradable substrate and DBNPA. The pressure drop was monitored in time and at the end of the study, the accumulated biomass in MFS was quantified by adenosine triphosphate (ATP) and total organic carbon (TOC) analysis. Continuous dosage of DBNPA (1 mg/L) prevented pressure drop increase and biofilm accumulation in the MFSs during a run time of 7 d, showing that biofouling can be managed by preventive DBNPA dosage. For biofouled systems, continuous dosage of DBNPA (1 and 20 mg/L) inactivated the accumulated biomass but did not restore the original pressure drop and did not remove the accumulated inactive cells and extracellular polymeric substances (EPS), indicating DBNPA dosage is not suitable for curative biofouling control.

  17. Pd based ultrathin membranes for the tritiated water gas shift reaction in the ITER breeder recovery system

    International Nuclear Information System (INIS)

    Tosti, S.; Bettinali, L.; Violante, V.; Basile, A.; Chiappetta, M.; Criscuoli, A.; Drioli, E.; Rizzelo, C.

    1998-01-01

    A mathematical model of a catalytic membrane reactor (CMR) for the water gas shift reaction has been carried out. Based on the model, a new closed loop process for the tritium removal system for the ITER test module of helium cooled pebble bed blanket concept has been studied. A CMR is the main equipment of the proposed process. The main advantages of the closed loop process are related to the absence of secondary wastes, low tritium inventories, moderate operating temperatures and pressures, low dilution of the stream to be processed by isotopic separation. As permeating membranes in the CMR ultra-thin metallic membranes of Pd and PdAg (50-70 μm thick) have been studied. A ceramic porous tube, containing the catalyst in the lumen, has been put in the metallic tube to obtain the CMR for the water gas shifting. Experimental tests, carried out both on ultra-thin membranes and CMRs for the water gas shift reaction, confirmed the behavior studied by the theoretical model and showed a long live of the membrane. (authors)

  18. Membranous nephropathy (bubbling appearance and spike formation) without immunoglobulin deposition in a patient with systemic lupus erythematosus.

    Science.gov (United States)

    Miura, Naoto; Mori, Yuki; Yoshino, Masabumi; Suga, Norihiro; Kitagawa, Wataru; Yamada, Harutaka; Nishikawa, Kazuhiro; Imai, Hirokazu

    2008-12-01

    A 53-year-old Japanese man with systemic lupus erythematosus developed proteinuria and hematuria after a urinary stone episode. A light microscopic study of a kidney biopsy specimen demonstrated a bubbling appearance and spike formation of the basement membrane. Immunofluorescent studies revealed that there were no significant depositions of immunoglobulins, such as IgG (-), IgA (-), IgM (+/-), kappa light chain (+/-), lambda light chain (+/-), or C3 (-) in the glomerular capillary wall, though C1q was present as one-plus positive staining in mesangial areas. Electron microscopic studies showed that the thickness of the basement membrane varied from thin to thick without electron dense deposits, and that the cellular components of the podocyte were irregularly present in the basement membrane. Urinary protein decreased after the usage of prednisolone and mizoribine; however, proteinuria aggravated after an episode of urinary stone during the same treatment.

  19. Conceptual design of primary coolant purification system using cylindrical membrane for nuclear energy system base on HTGR

    International Nuclear Information System (INIS)

    Piping Supriatna

    2011-01-01

    The recent progress of reactor technology design for next generation reactor will be implemented on cogeneration reactor, which the aim of reactor operation not only for generating electrical energy, but also for other application like desalination, industrial manufacturing process, hydrogen production, Enhanced Oil Recovery (EOR), etc. The cogeneration reactor concept developed for generate energy effectively, efficiently and sustainable, which reserve of uranium and thorium nuclear fuel for cogeneration reactor is supply able for world energy demand until next thousand years. The cogeneration reactor produce temperature output higher than commonly Nuclear Power Plant (NPP), and need special Heat Exchanger with helium gas as coolant. In order to preserve heat transfer with high efficiency, constant purity of the gas must be maintained as well as possible, especially contamination from its impurities. In this research has been designed modeling and assessment of primary coolant gas purification system with purify and fill up helium gas continuously, by using Cylindrical Helium Splitting Membrane and helium gas inventory system. The result of flow rate helium assessment for the purification system is 0.844x10 -3 kg/sec, where helium flow rate of reactor primary coolant is 120 kg/sec. The result of study show that the Primary Coolant Gas Purification System is enable to be implemented on Cogeneration Reactor HTGR200C. (author)

  20. Performance Validation and Scaling of a Capillary Membrane Solid-Liquid Separation System

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, S; Cook, J; Juratovac, J; Goodwillie, J; Burke, T

    2011-10-25

    Algaeventure Systems (AVS) has previously demonstrated an innovative technology for dewatering algae slurries that dramatically reduces energy consumption by utilizing surface physics and capillary action. Funded by a $6M ARPA-E award, transforming the original Harvesting, Dewatering and Drying (HDD) prototype machine into a commercially viable technology has required significant attention to material performance, integration of sensors and control systems, and especially addressing scaling issues that would allow processing extreme volumes of algal cultivation media/slurry. Decoupling the harvesting, dewatering and drying processes, and addressing the rate limiting steps for each of the individual steps has allowed for the development individual technologies that may be tailored to the specific needs of various cultivation systems. The primary performance metric used by AVS to assess the economic viability of its Solid-Liquid Separation (SLS) dewatering technology is algae mass production rate as a function of power consumption (cost), cake solids/moisture content, and solids capture efficiency. An associated secondary performance metric is algae mass loading rate which is dependent on hydraulic loading rate, area-specific hydraulic processing capacity (gpm/in2), filter:capillary belt contact area, and influent algae concentration. The system is capable of dewatering 4 g/L (0.4%) algae streams to solids concentrations up to 30% with capture efficiencies of 80+%, however mass production is highly dependent on average cell size (which determines filter mesh size and percent open area). This paper will present data detailing the scaling efforts to date. Characterization and performance data for novel membranes, as well as optimization of off-the-shelf filter materials will be examined. Third party validation from Ohio University on performance and operating cost, as well as design modification suggestions will be discussed. Extrapolation of current productivities

  1. Modeling and analysis of cell membrane systems with probabilistic model checking

    Science.gov (United States)

    2011-01-01

    Background Recently there has been a growing interest in the application of Probabilistic Model Checking (PMC) for the formal specification of biological systems. PMC is able to exhaustively explore all states of a stochastic model and can provide valuable insight into its behavior which are more difficult to see using only traditional methods for system analysis such as deterministic and stochastic simulation. In this work we propose a stochastic modeling for the description and analysis of sodium-potassium exchange pump. The sodium-potassium pump is a membrane transport system presents in all animal cell and capable of moving sodium and potassium ions against their concentration gradient. Results We present a quantitative formal specification of the pump mechanism in the PRISM language, taking into consideration a discrete chemistry approach and the Law of Mass Action aspects. We also present an analysis of the system using quantitative properties in order to verify the pump reversibility and understand the pump behavior using trend labels for the transition rates of the pump reactions. Conclusions Probabilistic model checking can be used along with other well established approaches such as simulation and differential equations to better understand pump behavior. Using PMC we can determine if specific events happen such as the potassium outside the cell ends in all model traces. We can also have a more detailed perspective on its behavior such as determining its reversibility and why its normal operation becomes slow over time. This knowledge can be used to direct experimental research and make it more efficient, leading to faster and more accurate scientific discoveries. PMID:22369714

  2. Study of basic biopolymer as proton membrane for fuel cell systems

    International Nuclear Information System (INIS)

    Ramirez-Salgado, Joel

    2007-01-01

    Up to now, many research groups work to improve the electrical and mechanical properties of membranes with a low cost of production. The biopolymers could be an answer to produce proton membranes at low cost. This work demonstrates that the intrinsic membrane polymer and clays properties can help to develop a novel proton exchange membranes. Biopolymer composites (chitosan-oxide compounds) present conductivity between 10 -3 and 10 -2 S cm -1 . The measurements were calculated by EIS (1 MHz-0.05 Hz) using the two-electrode configuration. Different oxides were used: MgO, CaO, SiO 2 , Al 2 O 3 . The ionic conductivities were compared with Nafion (registered)'s in the same conditions of P and T. The catalyst layer/membrane ensemble was made during the design with the subsequent demonstration as membrane electrode assemblies and finally the fuel cell was built. Our focus was to increase the compatibility between the proton basic polymer exchange membrane and basic clays as CaO and test a new kind of fuel cell

  3. [Relationship between the changes in ischemia/reperfusion cerebro-microvessel basement membrane injury and gelatinase system in senile rat].

    Science.gov (United States)

    Li, Jian-sheng; Liu, Ke; Liu, Jing-xia; Wang, Ming-hang; Zhao, Yue-wu; Liu, Zheng-guo

    2008-11-01

    To study the relationship of cerebro-microvessel basement membrane injury and gelatinase system after cerebral ischemia/reperfusion (I/R) in aged rats. Cerebral I/R injury model was reproduced by intraluminal silk ligature thrombosis of the middle cerebral artery occlusion (MCAO). Rats were divided randomly into sham control and I/R groups in young rats [ischemia 3 hours (I 3 h) and reperfusion 6 hours (I/R 6 h), 12 hours (I/R 12 h), 24 hours (I/R 24 h), 3 days (I/R 3 d), 6 days (I/R 6 d)], and sham control group and I/R group in aged rats (I 3 h and I/R 6 h, I/R 12 h, I/R 24 h , I/R 3 d, I/R 6 d). The change in cerebro-cortex microvessel basement membrane structure, basement membrane type IV collagen (Col IV) and laminin (LN) contents, matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) expression in every group were determined with immunohistochemical method and zymogram analysis. With the increase in age, Col IV and LN contents of the microvessel basement membrane were increased, and MMP-2 and MMP-9 expressions were stronger. With prolongation of I/R, the degradation of microvessel basement membrane components (Col IV and LN) was positively correlated with the duration of cerebral I/R. MMP-2 expression was increased gradually, and MMP-9 and TIMP-1 expression increased at the beginning and decreased subsequently. Col IV(I 3 h, I/R 6 h , I/R 12 h), LN (I 3 h, I/R 6-24 h), MMP-2 (I 3 h, I/R 6 h-6 d) and MMP-9 (I 3 h, I/R 6-24 h) expression level in aged rats with I/R injury were higher, and TIMP-1 (I/R 24 h) expression was lower than those in young rats (Pcerebro-microvessel basement membrane in rats is related with MMPs and TIMP. Cerebro-microvessel basement membrane injury is more serious in aged rats than that of young rats. Changes in cerebro-microvessel basement membrane injury in aged rats is related with gelatinase system change.

  4. Development of the pilot system for radioactive laundry waste treatment using UV photo-oxidation process and reverse osmosis membrane

    International Nuclear Information System (INIS)

    Park, S. M.; Park, J. K.; Kim, J. B.; Shin, S. W.; Lee, M. C.

    1999-01-01

    The pilot system for radioactive liquid laundry waste was developed with treatment capacity 1ton/hr and set up in the Yonkwang unit No.4. The system is composed of tank module, reverse osmosis membrane system and UV/H2O2 photo-oxidation process unit. The R/O system consists of the BW unit for low concentration and the SW unit for high concentration. The BW unit possesses 4 of R/O membranes and it can concentrate the feed water volume down to 1/10. This concentrated feed water can be reduced again 1/10 in its volume in the SW unit which is composed of 4 of R/O membranes. The UV/H2O2 photo-oxidation process unit was determined for the detergent removal process. The pilot system was verified in its capability through the continuous operation and enrichment operation using the actual liquid waste of the power plant. The design criteria and data for the industrial system were yielded. The efficiency of the UV/H2O2 photo-oxidation process and the optimum operational procedure were analysed. The decontamination factor of radionuclides, cobalt and cesium was measured. This on-site test showed the experimental result of the DF more than 100 and concentration rate more than 100

  5. Recent palladium membrane reactor development at the tritium systems test assembly

    International Nuclear Information System (INIS)

    Willms, R.S.; Birdsell, S.A.; Wilhelm, R.C.

    1995-01-01

    The palladium membrane reactor (PMR) is proving to be a simple and effective means for recovering hydrogen isotopes from fusion fuel impurities such as methane and water. This device directly combines two techniques which have long been utilized for hydrogen processing, namely catalytic shift reactions and palladium/silver permeators. A proof-of-principle (PMR) has been constructed and tested at the Tritium Systems Test Assembly of Los Alamos National Laboratory. The first tests with this device showed that is was effective for the proposed purpose. Initial work concluded that a nickel catalyst was an appropriate choice for use in a PMR. More detailed testing of the PMR with such a catalyst was performed and reported in other works. It was shown that a nickel catalyst-packed PMR did, indeed, recover hydrogen from water and methane with efficiencies approaching 100% in a single processing pass. These experiments were conducted over an extended period of time and no failure or need for regeneration was encountered. These positive results have prompted further PMR development. Topics addressed include alternate PMR geometries and initial testing of the PMR with tritium. These are the subjects of this paper

  6. Cost-effectiveness analysis of the SEAMIST trademark membrane system technology

    International Nuclear Information System (INIS)

    Henriksen, A.D.; Booth, S.R.

    1995-01-01

    SEAMIST trademark is a new technology that consists of an airtight membrane liner that is pneumatically emplaced inside the borehole. The positive air pressure inside the liner maintains the integrity of the borehole structure. Sampling ports with attached tubing, absorbent collectors, or various in situ measuring devices can be fabricated into the liner and used for monitoring volatile organic compounds (VOCs), semivolatile organic compounds (SVOCs), pesticides, herbicides, polynuclear aromatic hydrocarbons, polychlorinated biphenyls, or radioactive substances. In addition, small instruments can be guided through the lined borehole and measurements taken inside at specified intervals. The purpose of this study is to analyze the cost and performance effectiveness of this new technology. To do so, the authors constructed five hypothetical scenarios in which utilization of the SEAMIST trademark system can address various needs of the Department of Energy's environmental remediation program. Two of the scenarios involve vertical boreholes (or vertical instrument configurations) and two involve horizontal boreholes (or horizontal instrument configurations). The four scenarios jointly address contamination by VOCS, SVOCS, various water-soluble toxic substances, and low-level radioactive waste. One of the scenarios involves towing an instrument through a borehole and taking measurements of moisture levels in the surrounding soil

  7. A knowledge-based control system for air-scour optimisation in membrane bioreactors.

    Science.gov (United States)

    Ferrero, G; Monclús, H; Sancho, L; Garrido, J M; Comas, J; Rodríguez-Roda, I

    2011-01-01

    Although membrane bioreactors (MBRs) technology is still a growing sector, its progressive implementation all over the world, together with great technical achievements, has allowed it to reach a mature degree, just comparable to other more conventional wastewater treatment technologies. With current energy requirements around 0.6-1.1 kWh/m3 of treated wastewater and investment costs similar to conventional treatment plants, main market niche for MBRs can be areas with very high restrictive discharge limits, where treatment plants have to be compact or where water reuse is necessary. Operational costs are higher than for conventional treatments; consequently there is still a need and possibilities for energy saving and optimisation. This paper presents the development of a knowledge-based decision support system (DSS) for the integrated operation and remote control of the biological and physical (filtration and backwashing or relaxation) processes in MBRs. The core of the DSS is a knowledge-based control module for air-scour consumption automation and energy consumption minimisation.

  8. Proton Exchange Membrane Fuel Cell/Supercapasitor Hybrid Power Management System for a Golf Cart

    International Nuclear Information System (INIS)

    Siti Afiqah Abd Hamid; Ros Emilia Rosli; Edy Herianto Majlan; Wan Ramli Wan Daud; Ramizi Mohamed; Ramli Sitanggang

    2016-01-01

    This paper presented the transformation of a golf cart system powered lead acid battery into an environmental friendly hybrid vehicle. The design developed by using an advantage contributes by the uprising alternative power source candidate which is Proton Exchange Membrane Fuel Cell (PEMFC) and the maintenance free energy storage device, a supercapacitor (SC). The fuel cell (FC) stack was an in house manufactured with 450 W (36 V, 12.5 A) power, while the SC was from Maxwell Technologies (48 V, 165 F). This two power sources were controlled by the mechanical relay, meanwhile the reactant (hydrogen) are control by mass flow controller (MFC) both signaled by a National Instrument (NI) devices. The power management controller are programmed in the LabVIEW environment and then downloaded to the NI devices. The experimental result of the power trend was compared before and after the transformation with the same route to validate the effectiveness of the proposed power management strategy. The power management successfully controls the power sharing between power sources and satisfies the load transient. While the reactant control managed to vary the hydrogen mass flow rate feed according to the load demand in vehicular applications. (author)

  9. Hydrodynamic Study of a Hollow Fiber Membrane System Using Experimental and Numerical Derived Surface Shear Stresses

    DEFF Research Database (Denmark)

    Ratkovich, Nicolas Rios; Hunze, M.; Nopens, I.

    2012-01-01

    .39 – 0.69 Pa) were in good agreement, with an error less that 15 %. Based on comparison of the cumulative frequency distribution of shear stresses from experiments and simulation: (i) moderate shear stresses (i.e. 50th percentile) were found to be accurately predicted (model: 0.24 – 0.45 Pa; experimental......Computational Fluids Dynamics (CFD) models can be used to gain insight into the shear stresses induced by air sparging on submerged hollow fiber Membrane BioReactor (MBR) systems. It was found that the average range of shear stresses obtained by the CFD model (0.30 – 0.60 Pa) and experimentally (0......: 0.25 – 0.49 Pa) with an error of less than 5 %; (ii) high shear stresses (i.e. 90th percentile) predictions were much less accurate (model: 0.60 – 1.23 Pa; experimental: 1.04 – 1.90 Pa) with an error up to 38 %. This was attributed to the fact that the CFD model only considers the two-phase flow (50...

  10. Expression of progesterone receptor membrane component-1 in bovine reproductive system during estrous cycle

    Directory of Open Access Journals (Sweden)

    A.M. Luciano

    2011-09-01

    Full Text Available Several reports suggest the participation of progesterone receptor membrane component 1 (PGRMC1 in progesterone signaling in the reproductive system. This study aimed at investigating the presence and localization of PGRMC1 in bovine ovary, oviduct and uterus, during the follicular and luteal phases of the estrous cycle. In the ovary, PGRMC1 has been detected in surface germinal epithelium, granulosa cells, theca cells and in the germinal vesicle of the oocytesat all stages of folliculogenesis. In the corpus luteum the expression of PGRMC1 was influenced by the stage of the estrous cycle. In the oviducts and in the uterus horns, PGRMC1 was immunolocalized in the luminal epithelium, in the muscle layer cells and in the endothelial cells. In the uterus, PGRMC1 was intensely localized also in the glandular endometrium. However, in the oviducts and in the uterus horns, the localization of PGRMC1 was independent on the stage of the estrous cycle and on whether evaluating the ipsilateral or the contralateral organ. In conclusion, the present immunohistochemical study showed that PGRMC1 is located in various compartments of the bovine female reproductive organs. With the exception of the corpora lutea, PGRMC1 localization showed similar pattern during different stage of the estrous cycle.

  11. A stowing and deployment strategy for large membrane space systems on the example of Gossamer-1

    Science.gov (United States)

    Seefeldt, Patric

    2017-09-01

    Deployment systems for innovative space applications such as solar sails require a technique for a controlled and autonomous deployment in space. The deployment process has a strong impact on the mechanism and structural design and sizing. On the example of the design implemented in the Gossamer-1 project of the German Aerospace Center (DLR), such a stowing and deployment process is analyzed. It is based on a combination of zig-zag folding and coiling of triangular sail segments spanned between crossed booms. The deployment geometry and forces introduced by the mechanism considered are explored in order to reveal how the loads are transferred through the membranes to structural components such as the booms. The folding geometry and force progressions are described by function compositions of an inverse trigonometric function with the considered trigonometric function itself. If these functions are evaluated over several periods of the trigonometric function, a non-smooth oscillating curve occurs. Depending on the trigonometric function, these are often vividly described as zig-zag or sawtooth functions. The developed functions are applied to the Gossamer-1 design. The deployment geometry reveals a tendency that the loads are transferred along the catheti of the sail segments and therefore mainly along the boom axes. The load introduced by the spool deployment mechanism is described. By combining the deployment geometry with that load, a prediction of the deployment load progression is achieved. The mathematical description of the stowing and deployment geometry, as well as the forces inflicted by the mechanism provides an understanding of how exactly the membrane deploys and through which edges the deployment forces are transferred. The mathematical analysis also gives an impression of sensitive parameters that could be influenced by manufacturing tolerances or unsymmetrical deployment of the sail segments. While the mathematical model was applied on the design of

  12. Removal of Pharmaceutical and Personal Care Products (PPCPs) from Municipal Waste Water with Integrated Membrane Systems, MBR-RO/NF.

    Science.gov (United States)

    Wang, Yonggang; Wang, Xu; Li, Mingwei; Dong, Jing; Sun, Changhong; Chen, Guanyi

    2018-02-05

    This study focuses on the application of combining membrane bioreactor (MBR) treatment with reverse osmosis (RO) or nanofiltration (NF) membrane treatment for removal of pharmaceuticals and personal care products (PPCPs) in municipal wastewater. Twenty-seven PPCPs were measured in real influent with lowest average concentration being trimethoprim (7.12 ng/L) and the highest being caffeine (18.4 ng/L). The results suggest that the MBR system effectively removes the PPCPs with an efficiency of between 41.08% and 95.41%, and that the integrated membrane systems, MBR-RO/NF, can achieve even higher removal rates of above 95% for most of them. The results also suggest that, due to the differences in removal mechanisms of NF/RO membrane, differences of removal rates exist. In this study, the combination of MBR-NF resulted in the removal of 13 compounds to below detection limits and MBR-RO achieved even better results with removal of 20 compounds to below detection limits.

  13. Evaluation of the Membrane Permeability (PAMPA and Skin) of Benzimidazoles with Potential Cannabinoid Activity and their Relation with the Biopharmaceutics Classification System (BCS)

    OpenAIRE

    Alvarez-Figueroa, M. Javiera; Pessoa-Mahana, C. David; Palavecino-González, M. Elisa; Mella-Raipán, Jaime; Espinosa-Bustos, Cristián; Lagos-Muñoz, Manuel E.

    2011-01-01

    The permeability of five benzimidazole derivates with potential cannabinoid activity was determined in two models of membranes, parallel artificial membrane permeability assay (PAMPA) and skin, in order to study the relationship of the physicochemical properties of the molecules and characteristics of the membranes with the permeability defined by the Biopharmaceutics Classification System. It was established that the PAMPA intestinal absorption method is a good predictor for classifying thes...

  14. Key steps in type III secretion system (T3SS) towards translocon assembly with potential sensor at plant plasma membrane.

    Science.gov (United States)

    Ji, Hongtao; Dong, Hansong

    2015-09-01

    Many plant- and animal-pathogenic Gram-negative bacteria employ the type III secretion system (T3SS) to translocate effector proteins from bacterial cells into the cytosol of eukaryotic host cells. The effector translocation occurs through an integral component of T3SS, the channel-like translocon, assembled by hydrophilic and hydrophobic proteinaceous translocators in a two-step process. In the first, hydrophilic translocators localize to the tip of a proteinaceous needle in animal pathogens, or a proteinaceous pilus in plant pathogens, and associate with hydrophobic translocators, which insert into host plasma membranes in the second step. However, the pilus needs to penetrate plant cell walls in advance. All hydrophilic translocators so far identified in plant pathogens are characteristic of harpins: T3SS accessory proteins containing a unitary hydrophilic domain or an additional enzymatic domain. Two-domain harpins carrying a pectate lyase domain potentially target plant cell walls and facilitate the penetration of the pectin-rich middle lamella by the bacterial pilus. One-domain harpins target plant plasma membranes and may play a crucial role in translocon assembly, which may also involve contrapuntal associations of hydrophobic translocators. In all cases, sensory components in the target plasma membrane are indispensable for the membrane recognition of translocators and the functionality of the translocon. The conjectural sensors point to membrane lipids and proteins, and a phosphatidic acid and an aquaporin are able to interact with selected harpin-type translocators. Interactions between translocators and their sensors at the target plasma membrane are assumed to be critical for translocon assembly. © 2014 BSPP AND JOHN WILEY & SONS LTD.

  15. Surface modification of poly(vinylidene fluoride) hollow fibre membranes for biogas purification in a gas-liquid membrane contactor system.

    Science.gov (United States)

    Jin, Pengrui; Huang, Chuan; Li, Jiaxiang; Shen, Yadong; Wang, Liao

    2017-11-01

    The wetting of hollow fibre membranes decreases the performance of the liquid-gas membrane contactor for CO 2 capture in biogas upgrading. To solve this problem, in this work, a poly(vinylidene fluoride) (PVDF) hollow fibre membrane for a liquid-gas membrane contactor was coated with a superhydrophobic layer composed of a combination of hydrophobic SiO 2 nanoparticles and polydimethylsiloxane (PDMS) by the method of spray deposition. A rough layer of SiO 2 deposited on the PVDF membrane resulted in an enhanced surface hydrophobicity. The surface structure of the pristine PVDF significantly affected the homogeneity of the generated SiO 2 layer. A uniform surface coating on the PVDF upper layer resulted from the presence of micrometre and nanometre-sized roughness on the surface of the PVDF membrane, which was achieved with a SiO 2 concentration of 4.44 mg ml -1 (0.2 g/45 ml) in the coating solution. As a result, the water contact angle of the modified surface was recorded as 155 ± 3°, which is higher than that of the pristine surface. The high contact angle is advantageous for reducing the wetting of the membrane. Additional mass transfer resistance was introduced by the superhydrophobic layer. In addition, continuous CO 2 absorption tests were carried out in original and modified PVDF hollow fibre membrane contactors, using monoethanolamine (MEA) solution as the absorbent. A long-term stability test revealed that the modified PVDF hollow fibre membrane contactor was able to outperform the original membrane contactor and demonstrated outstanding long-term stability, suggesting that spray deposition is a promising approach to obtain superhydrophobic PVDF membranes for liquid-gas membrane absorption.

  16. Liquid Membrane System for Extraction and Electrodeposition of Lead(II During Electrodialysis

    Directory of Open Access Journals (Sweden)

    Sadyrbaeva Tatiana

    2017-05-01

    Full Text Available A novel method for lead(II removal from aqueous acidic solutions is presented. The method involves electrodialysis through bulk liquid membranes accompanied by electrodeposition of metal from the cathodic solution. Solutions of di(2-ethylhexylphosphoric acid with admixtures of tri-n-octylamine in 1,2-dichloroethane were used as the liquid membranes. The effects of the main electrodialysis parameters as well as of the composition of the liquid membranes and aqueous solutions on the lead(II transport rate are studied. The optimal conditions are determined. A possibility of effective single-stage transfer of lead(II through the liquid membrane into dilute solutions of perchloric, nitric and acetic acids is demonstrated. Dense and adherent lead electrodeposits are obtained from perchloric acid solutions. Maximum extraction degree of 93 % and electrodeposition degree of ~60 % are obtained during 5 h of electrodialysis.

  17. Copper recovery in a bench-scale carrier facilitated tubular supported liquid membrane system

    Directory of Open Access Journals (Sweden)

    Makaka S.

    2010-01-01

    Full Text Available The extraction of copper ions in a tubular supported liquid membrane using LIX 984NC as a mobile carrier was studied, evaluating the effect of the feed characteristics (flowrate, density, viscosity on the feedside laminar layer of the membrane. A vertical countercurrent, double pipe perspex benchscale reactor consisting of a single hydrophobic PVDF tubular membrane mounted inside was used in all test work. The membrane was impregnated with LIX 984NC and became the support for this organic transport medium. Dilute Copper solution passed through the centre pipe and sulphuric acid as strippant passed through the shell side. Copper was successfully transported from the feedside to the stripside and from the data obtained, a relationship between Schmidt, Reynolds and Sherwood number was achieved of.

  18. Refillable and magnetically actuated drug delivery system using pear-shaped viscoelastic membrane

    KAUST Repository

    So, Hongyun; Seo, Young Ho; Pisano, Albert P.

    2014-01-01

    We report a refillable and valveless drug delivery device actuated by an external magnetic field for on-demand drug release to treat localized diseases. The device features a pear-shaped viscoelastic magnetic membrane inducing asymmetrical

  19. Analysis of hybrid membrane and chemical absorption systems for CO2 capture

    International Nuclear Information System (INIS)

    Binns, Michael; Oh, Se-Young; Kwak, Dong-Hun; Kim, Jin-Kuk

    2015-01-01

    Amine-based absorption of CO 2 is currently the industry standard technology for capturing CO 2 emitted from power plants, refineries and other large chemical plants. However, more recently there have been a number of competing technologies under consideration, including the use of membranes for CO 2 separation and purification. We constructed and analyzed two different hybrid configurations combining and connecting chemical absorption with membrane separation. For a particular flue gas which is currently treated with amine-based chemical absorption at a pilot plant we considered and tested how membranes could be integrated to improve the performance of the CO 2 capture. In particular we looked at the CO 2 removal efficiency and the energy requirements. Sensitivity analysis was performed varying the size of the membranes and the solvent flow rate

  20. Enhanced Membrane System for Recovery of Water from Gas-Liquid Mixtures, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Gas-Liquid separation is an acute microgravity problem. Existing devices use centrifugal motion on microporous membranes to separate the two phases. Centrifugal...

  1. In-situ Non-destructive Studies on Biofouling Processes in Reverse Osmosis Membrane Systems

    KAUST Repository

    Farhat, Nadia

    2016-01-01

    biofouling detection methods are mainly destructive, such as membrane autopsies, where biofilm samples can be contaminated, damaged and resulting in biofilm structural changes. The objective of this study was to test whether transparent luminescent planar

  2. Biofouling Control in Spiral-Wound Membrane Systems: Impact of Feed Spacer Modification and Biocides

    KAUST Repository

    Siddiqui, Amber

    2016-01-01

    was developed. The combination of modeling and experimental testing of 3D printed spacers is a promising strategy to develop advanced spacers aiming to reduce the impact of biofilm formation on membrane performance and to improve the cleanability of spiral

  3. A continuous membrane microbioreactor system for development of integrated pectin modification and separation processes

    DEFF Research Database (Denmark)

    Zainal Alam, Muhd Nazrul Hisham Bin; Pinelo, Manuel; Samanta, Kama

    2011-01-01

    present a continuous membrane microbioreactor prototype for development of enzyme catalyzed degradation of pectin. Membrane reactors are becoming increasingly important for the novel ‘biorefining’ type of processes that either require product removal to avoid product inhibition or rest on partial...... hydrolysis of the substrate to obtain e.g. value-added oligosaccharides from complex biopolymers. The microbioreactor prototype was fabricated from poly(methylmethacrylate) (PMMA) and poly(dimethylsiloxane) (PDMS) and designed as a loop reactor (working volume approximately 190μL) integrated...... with a regenerated cellulose membrane for separation of low molecular weight products. The main technical considerations and challenges related to establishing the continuous membrane microbioreactor are discussed. The workability of the prototype was validated by comparing the process data at microscale to those...

  4. Decoupling of the nernst-planck and poisson equations. Application to a membrane system at overlimiting currents.

    Science.gov (United States)

    Urtenov, Mahamet A-Kh; Kirillova, Evgeniya V; Seidova, Natalia M; Nikonenko, Victor V

    2007-12-27

    This paper deals with one-dimensional stationary Nernst-Planck and Poisson (NPP) equations describing ion electrodiffusion in multicomponent solution/electrode or ion-conductive membrane systems. A general method for resolving ordinary and singularly perturbed problems with these equations is developed. This method is based on the decoupling of NPP equations that results in deduction of an equation containing only the terms with different powers of the electrical field and its derivatives. Then, the solution of this equation, analytical in several cases or numerical, is substituted into the Nernst-Planck equations for calculating the concentration profile for each ion present in the system. Different ionic species are grouped in valency classes that allows one to reduce the dimension of the original set of equations and leads to a relatively easy treatment of multi-ion systems. When applying the method developed, the main attention is paid to ion transfer at limiting and overlimiting currents, where a significant deviation from local electroneutrality occurs. The boundary conditions and different approximations are examined: the local electroneutrality (LEN) assumption and the original assumption of quasi-uniform distribution of the space charge density (QCD). The relations between the ion fluxes at limiting and overlimiting currents are discussed. In particular, attention is paid to the "exaltation" of counterion transfer toward an ion-exchange membrane by co-ion flux leaking through the membrane or generated at the membrane/solution interface. The structure of the multi-ion concentration field in a depleted diffusion boundary layer (DBL) near an ion-exchange membrane at overlimiting currents is analyzed. The presence of salt ions and hydrogen and hydroxyl ions generated in the course of the water "splitting" reaction is considered. The thickness of the DBL and its different zones, as functions of applied current density, are found by fitting experimental current

  5. Microbial community structure characteristics associated membrane fouling in A/O-MBR system.

    Science.gov (United States)

    Gao, Da-Wen; Wen, Zhi-Dan; Li, Bao; Liang, Hong

    2014-02-01

    The study demonstrated the potential relationship between microbial community structure and membrane fouling in an anoxic-oxic membrane bioreactor (A/O-MBR). The results showed that the microbial community structure in biocake was different with aerobic mixture, and the dominant populations were out of sync during the fouling process. Based on microbial community structure and metabolites analysis, the results showed that the succession of microbial community might be the leading factor to the variation of metabolites, and it might be the primary cause of membrane fouling. The rise of Shannon diversity index (H) of the microbial community in A/O-MBR went with the gradually serious membrane fouling. Pareto-Lorenz curve was used to describe the evenness of microbial distribution in A/O-MBR, and the result indicated when community evenness was low, the membrane fouling took place smoothly or slightly, otherwise, high evenness of microbial community would lead to more seriously membrane fouling. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. A natural driven membrane process for brackish and wastewater treatment: photovoltaic powered ED and FO hybrid system.

    Science.gov (United States)

    Zhang, Yang; Pinoy, Luc; Meesschaert, Boudewijn; Van der Bruggen, Bart

    2013-09-17

    In isolated locations, remote areas, or islands, potable water is precious because of the lack of drinking water treatment facilities and energy supply. Thus, a robust and reliable water treatment system based on natural energy is needed to reuse wastewater or to desalinate groundwater/seawater for provision of drinking water. In this work, a hybrid membrane system combining electrodialysis (ED) and forward osmosis (FO), driven by renewable energy (solar energy), denoted as EDFORD (ED-FO Renewable energy Desalination), is proposed to produce high-quality water (potable) from secondary wastewater effluent or brackish water. In this hybrid membrane system, feedwater (secondary wastewater effluent or synthetic brackish water) was drawn to the FO draw solution while the organic and inorganic substances (ions, compounds, colloids and particles) were rejected. The diluted draw solution was then pumped to the solar energy driven ED. In the ED unit, the diluted draw solution was desalted and high-quality water was produced; the concentrate was recycled to the FO unit and reused as the draw solution. Results show that the water produced from this system contains a low concentration of total organic carbon (TOC), carbonate, and cations derived from the feedwater; had a low conductivity; and meets potable water standards. The water production cost considering the investment for membranes and solar panel is 3.32 to 4.92 EUR m(-3) (for 300 days of production per year) for a small size potable water production system.

  7. Open absorption system for cooling and air conditioning using membrane contactors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Conde-Petit, M. [M. Conde Engineering, Zuerich (Switzerland); Weber, R.; Dorer, V. [Swiss Federal Laboratories for Materials Testing and Research (EMPA), Duebendorf (Switzerland)

    2008-07-01

    Air conditioning systems based upon the open absorption principle, essentially an absorption device operating at atmospheric pressure, have been proposed and investigated at many instances in the past eighty years. Their potential for improving energy efficiency is clearly recognized in the earliest research reports. By the mid 1950ies, solar thermal energy was being applied to drive open absorption-based air conditioning systems. For several reasons, however, the open absorption technology was not mature enough to take place in the mainstream. In the past two decades, vigorous efforts have been undertaken to reverse this situation, but success continued to elude, despite the fact that the main problems, such as corrosion, aerosols in the supply air, etc., have been identified. This report details the work and the main results from the MemProDEC Project. In this project innovative solutions were proposed, and successfully investigated, for the corrosion problem and the improvement of efficiency of the absorption process, in particular a new method to cool a very compact absorber. The practically uniform flow distribution for all three streams in the absorber (air, water and desiccant) warrants the contact of the air to be dehumidified with the desiccant over the whole surface of exchange (across a porous membrane). This, together with the cooling with water in counter flow to the air, are the key factors for the excellent effectiveness of the absorber. As the results show, the dehydration effectiveness of the prototype absorber is up to 150 % higher than that previously obtained by others. The solutions developed for compactness and modularity represent an important step in the way to flexible manufacturing, i.e. using a single element size to assemble autonomous air handling units of various nominal capacities. And although the manufacturing methods of the individual elements require improvement, namely by avoiding adhesive bonding, the choice of materials and the

  8. Evaluation of hydroacid complex in the forward osmosis–membrane distillation (FO–MD) system for desalination

    KAUST Repository

    Wang, Peng; Cui, Yue; Ge, Qingchun; Fern Tew, Tjin; Chung, Neal Tai-Shung

    2015-01-01

    The incorporation of membrane distillation (MD) into forward osmosis (FO) provides process sustainability to regenerate the draw solution and to produce clean water simultaneously. However, the reverse salt flux is the major hurdle in the FO-MD system because it not only reduces the effective osmotic driving force across the membrane but also increases the replenishment cost and scaling issue. For the first time, a hydroacid complex with abundant hydrophilic groups and ionic species is evaluated as the draw solutes in the hybrid FO-MD system consisting of multi-bore PVDF MD membranes for seawater/brackish desalination. In order to evaluate the practicality of the hydroacid complex in the FO-MD system, FO and MD experiments were conducted at elevated temperatures and concentrations. The hydroacid complex has displayed desired properties such as high solubility, low viscosity, excellent thermal stability and minimal reverse salt flux suitable for FO and MD operations. FO-MD desalination process was demonstrated with a highest seawater desalination flux of 6/32 LMH (FO/MD). This study may open up the prospective of employing the hydroacid complex as the draw solute in FO-MD hybrid systems for seawater /brackish desalination. © 2015 Elsevier B.V.

  9. Thermal and water management of low temperature Proton Exchange Membrane Fuel Cell in fork-lift truck power system

    International Nuclear Information System (INIS)

    Hosseinzadeh, Elham; Rokni, Masoud; Rabbani, Abid; Mortensen, Henrik Hilleke

    2013-01-01

    Highlights: ► Developing a general zero dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model for a forklift. ► System performance with different cooling fluids. ► Water and thermal management of fuel cell system. ► Effect of inlet temperature, outlet temperature and temperature gradient on system performance. - Abstract: A general zero-dimensional Proton Exchange Membrane Fuel Cell (PEMFC) model has been developed for forklift truck application. The balance of plant (BOP) comprises of a compressor, an air humidifier, a set of heat exchangers and a recirculation pump. Water and thermal management of the fuel cell stack and BOP has been investigated in this study. The results show that humidification of the inlet air is of great importance. By decreasing the relative humidity of inlet air from 95% to 25%, the voltage can drop by 29%. In addition, elevated stack temperature can lead to a higher average cell voltage when membrane is fully hydrated otherwise it causes a drastic voltage drop in the stack. Furthermore, by substituting liquid water with water–ethylene glycol mixture of 50%, the mass flow of coolant increases by about 32–33% in the inner loop and 60–65% in the outer loop for all ranges of current. The system can then be started up at about −25 °C with negligible change in the efficiency

  10. Effect of operation parameters on the flux stabilization of gravity-driven membrane (GDM) filtration system for decentralized water supply.

    Science.gov (United States)

    Tang, Xiaobin; Ding, An; Qu, Fangshu; Jia, Ruibao; Chang, Haiqing; Cheng, Xiaoxiang; Liu, Bin; Li, Guibai; Liang, Heng

    2016-08-01

    A pilot-scale gravity-driven membrane (GDM) filtration system under low gravitational pressure without any pre-treatment, backwash, flushing, or chemical cleaning was carried out to investigate the effect of operation parameters (including operation pressure, aeration mode, and intermittent filtration) on the effluent quality and permeability development. The results revealed that GDM system exhibited an efficient performance for the removal of suspended substances and organic compounds. The stabilization of flux occurred and the average values of stable flux were 6.6, 8.1, and 8.6 Lm(-2) h(-1) for pressures of 65, 120, and 200 mbar, respectively. In contrast, flux stabilization was not observed under continuous and intermittent aeration conditions. However, aeration (especially continuous aeration) was effective to improve flux and alleviate membrane fouling during 1-month operation. Moreover, intermittent filtration would influence the stabilization of permeate flux, resulting in a higher stable flux (ranging from 6 to 13 Lm(-2) h(-1)). The stable flux significantly improved with the increase of intermittent period. Additionally, GDM systems exhibited an efficient recovery of flux after simple physical cleaning and the analyses of resistance reversibility demonstrated that most of the total resistance was hydraulic reversible resistance (50-75 %). Therefore, it is expected that the results of this study can develop strategies to increase membrane permeability and reduce energy consumption in GDM systems for decentralized water supply.

  11. Evaluation of hydroacid complex in the forward osmosis–membrane distillation (FO–MD) system for desalination

    KAUST Repository

    Wang, Peng

    2015-11-01

    The incorporation of membrane distillation (MD) into forward osmosis (FO) provides process sustainability to regenerate the draw solution and to produce clean water simultaneously. However, the reverse salt flux is the major hurdle in the FO-MD system because it not only reduces the effective osmotic driving force across the membrane but also increases the replenishment cost and scaling issue. For the first time, a hydroacid complex with abundant hydrophilic groups and ionic species is evaluated as the draw solutes in the hybrid FO-MD system consisting of multi-bore PVDF MD membranes for seawater/brackish desalination. In order to evaluate the practicality of the hydroacid complex in the FO-MD system, FO and MD experiments were conducted at elevated temperatures and concentrations. The hydroacid complex has displayed desired properties such as high solubility, low viscosity, excellent thermal stability and minimal reverse salt flux suitable for FO and MD operations. FO-MD desalination process was demonstrated with a highest seawater desalination flux of 6/32 LMH (FO/MD). This study may open up the prospective of employing the hydroacid complex as the draw solute in FO-MD hybrid systems for seawater /brackish desalination. © 2015 Elsevier B.V.

  12. Brackish groundwater membrane system design for sustainable irrigation: Optimal configuration selection using analytic hierarchy process and multi-dimension scaling

    Directory of Open Access Journals (Sweden)

    Beni eLew

    2014-12-01

    Full Text Available The recent high demands for reuse of salty water for irrigation affected membrane producers to assess new potential technologies for undesirable physical, chemical and biological contaminants removal. This paper studies the assembly options by the analytic hierarchy process (AHP model and the multi-dimension scaling (MDS techniques. A specialized form of MDS (CoPlot software enables presentation of the AHP outcomes in a two dimensional space and the optimal model can be visualized clearly. Four types of 8 membranes were selected: (i Nanofiltration low rejection and high flux (ESNA1-LF-LD, 86% rejection, 10,500gpd; (ii Nanofiltration medium rejection and medium flux (ESNA1-LF2-LD, 91% rejection, 8,200gpd; (iii Reverse Osmosis high rejection and high flux (CPA5-MAX, 99.7 rejection, 12,000gpd ; and (iv Reverse Osmosis medium rejection and extreme high flux (ESPA4-MAX, 99.2 rejection, 13,200gpd. The results indicate that: (i Nanofiltration membrane (High flux and Low rejection can produce water for irrigation with valuable levels of nutrient ions and a reduction in the sodium absorption ratio (SAR, minimizing soil salinity; this is an attractive option for agricultural irrigation and is the optimal solution; and (ii implementing the MDS approach with reference to the variables is consequently useful to characterize membrane system design.

  13. Assessing the removal of organic micropollutants by a novel baffled osmotic membrane bioreactor-microfiltration hybrid system

    KAUST Repository

    Pathak, Nirenkumar

    2018-04-14

    A novel approach was employed to study removal of organic micropollutants (OMPs) in a baffled osmotic membrane bioreactor-microfiltration (OMBR-MF) hybrid system under oxic–anoxic conditions. The performance of OMBR-MF system was examined employing three different draw solutes (DS), and three model OMPs. The highest forward osmosis (FO) membrane rejection was attained with atenolol (100 %) due to its higher molar mass and positive charge. With inorganic DS caffeine (94-100 %) revealed highest removal followed by atenolol (89-96 %) and atrazine (16-40 %) respectively. All three OMPs exhibited higher removal with organic DS as compared to inorganic DS. Significant anoxic removal was observed for atrazine under very different redox conditions with extended anoxic cycle time. This can be linked with possible development of different microbial consortia responsible for diverse enzymes secretion. Overall, the OMBR-MF process showed effective removal of total organic carbon (98%) and nutrients (phosphate 97% and total nitrogen 85%), respectively.

  14. Assessing the removal of organic micropollutants by a novel baffled osmotic membrane bioreactor-microfiltration hybrid system

    KAUST Repository

    Pathak, Nirenkumar; Li, Sheng; Kim, Youngjin; Chekli, Laura; Phuntsho, Sherub; Jang, Am; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2018-01-01

    A novel approach was employed to study removal of organic micropollutants (OMPs) in a baffled osmotic membrane bioreactor-microfiltration (OMBR-MF) hybrid system under oxic–anoxic conditions. The performance of OMBR-MF system was examined employing three different draw solutes (DS), and three model OMPs. The highest forward osmosis (FO) membrane rejection was attained with atenolol (100 %) due to its higher molar mass and positive charge. With inorganic DS caffeine (94-100 %) revealed highest removal followed by atenolol (89-96 %) and atrazine (16-40 %) respectively. All three OMPs exhibited higher removal with organic DS as compared to inorganic DS. Significant anoxic removal was observed for atrazine under very different redox conditions with extended anoxic cycle time. This can be linked with possible development of different microbial consortia responsible for diverse enzymes secretion. Overall, the OMBR-MF process showed effective removal of total organic carbon (98%) and nutrients (phosphate 97% and total nitrogen 85%), respectively.

  15. A yeast-based model system for cloning secreted and membrane proteins

    Directory of Open Access Journals (Sweden)

    MARCELO J. SURPILI

    2002-12-01

    Full Text Available The targeting of proteins to cell organelles and membranes, or of proteins destined to secretion, is coordinated by signal sequences located at the 5´-end of their respective genes. A signal sequence trap system was envisaged in which a truncated version of the yeast acid phosphatase pho5 gene lacking the start codon and signal sequence could serve as a reporter gene. A fraction enriched in 5´-end fragments obtained by PCR from a potato guard-cell cDNA library was cloned in frame to the acid phosphatase gene and the acid phosphatase activity was assayed directly in yeast colonies grown on selective medium. Putative signal sequences targeting the acid phosphatase to the membrane or to the outside of the cell were used to screen the cDNA bank in order to recover the original full-size sequence which gave rise to the signal sequence. Two unknown sequences displaying marked tissue-specific expression were retrieved, one of them (YE139 with a higher expression level in green buds and stem cells, and the other one (YE290 with a higher expression level in androceum, gyneceum, and roots. The limitations of the system are further analyzed using other sequences as control.O direcionamento de proteínas a organelas e à membrana celular, ou de proteínas a serem secretadas, é coordenado por seqüências sinalizadoras localizadas na extremidade 5´ de seus respectivos genes que codificam peptídeos-sinal. Este trabalho analisa um sistema para seleção de seqüências sinalizadoras utilizando uma fosfatase ácida de levedura, enzima reconhecidamente secretada por estes organismos, desprovida de seu códon de iniciação e de sua seqüência sinalizadora, como gene repórter. Uma fração enriquecida em fragmentos provenientes da região 5´ de uma biblioteca de cDNA de células-guarda de batata foi inserida in frame ao gene truncado da fosfatase ácida em vetores apropriados. Após a transformação em leveduras, a atividade da fosfatase ácida foi

  16. Phosphoenolpyruvate-Dependent Fructose Phosphotransferase System of Rhodopseudomonas sphaeroides : Purification and Physicochemical and Immunochemical Characterization of a Membrane-Associated Enzyme I

    NARCIS (Netherlands)

    Brouwer, Marius; Elferink, Marieke G.L.; Robillard, George T.

    1982-01-01

    The phosphotransferase system (PTS) of the phototrophic bacterium Rhodopseudomonas sphaeroides consists of a component located in the cytoplasmic membrane and a membrane-associated enzyme called “soluble factor” (SF). SF has been partially purified by a combination of hydrophobic interaction and

  17. Definition of validated membrane reactor model for 5 kW power output CHP system for different natural gas compositions

    NARCIS (Netherlands)

    Di Marcoberardino, Gioele; Gallucci, Fausto; Manzolini, Giampaolo; van Sint Annaland, Martin

    2016-01-01

    Over the last years, many studies focused on the development of membrane reactors for micro-cogeneration systems based on PEM fuel cells, thanks to its unique feature of separating pure hydrogen. This work deals with (i) the design of a fluidized bed membrane reactor flexible towards different

  18. Economic Assessment of an Integrated Membrane System for Secondary Effluent Polishing for Unrestricted Reuse

    Directory of Open Access Journals (Sweden)

    Gideon Oron

    2012-03-01

    Full Text Available Extra treatment stages are required to polish the secondary effluent for unrestricted reuse, primarily for agricultural irrigation. Improved technology for the removal of particles, turbidity, bacteria and cysts, without the use of disinfectants is based on MicroFiltration (MF and UltraFiltration (UF membrane technology and in series with Reverse Osmosis (RO for dissolved solids removal. Field experiments were conducted using a mobile UF and RO membrane pilot unit at a capacity of around 1.0 m3/hr. A management model was defined and tested towards optimal polishing of secondary effluent. The two major purposes of the management model are: (i to delineate a methodology for economic assessment of optimal membrane technology implementation for secondary effluent upgrading for unrestricted use, and; (ii to provide guidelines for optimal RO membrane selection in regards to the pretreatment stage. The defined linear model takes into account the costs of the feed secondary effluent, the UF pretreatment and the RO process. Technological constraints refer primarily to the longevity of the membrane and their performance. Final treatment cost (the objective function includes investment, operation and maintenance expenses, UF pretreatment, RO treatment, post treatment and incentive for low salinity permeate use. The cost range of water for irrigation according to the model is between 15 and 42 US cents per m3.

  19. Spacesuit Water Membrane Evaporator; An Enhanced Evaporative Cooling System for the Advanced Extravehicular Mobility Unit Portable Life Support System

    Science.gov (United States)

    Bue, Grant C.; Makinen, Janice V.; Miller, Sean; Campbell, Colin; Lynch, Bill; Vogel, Matt; Craft, Jesse; Wilkes, Robert; Kuehnel, Eric

    2014-01-01

    Development of the Advanced Extravehicular Mobility Unit (AEMU) portable life support subsystem (PLSS) is currently under way at NASA Johnson Space Center. The AEMU PLSS features a new evaporative cooling system, the Generation 4 Spacesuit Water Membrane Evaporator (Gen4 SWME). The SWME offers several advantages when compared with prior crewmember cooling technologies, including the ability to reject heat at increased atmospheric pressures, reduced loop infrastructure, and higher tolerance to fouling. Like its predecessors, Gen4 SWME provides nominal crew member and electronics cooling by flowing water through porous hollow fibers. Water vapor escapes through the hollow fiber pores, thereby cooling the liquid water that remains inside of the fibers. This cooled water is then recirculated to remove heat from the crew member and PLSS electronics. Test results from the backup cooling system which is based on a similar design and the subject of a companion paper, suggested that further volume reductions could be achieved through fiber density optimization. Testing was performed with four fiber bundle configurations ranging from 35,850 fibers to 41,180 fibers. The optimal configuration reduced the Gen4 SWME envelope volume by 15% from that of Gen3 while dramatically increasing the performance margin of the system. A rectangular block design was chosen over the Gen3 cylindrical design, for packaging configurations within the AEMU PLSS envelope. Several important innovations were made in the redesign of the backpressure valve which is used to control evaporation. A twin-port pivot concept was selected from among three low profile valve designs for superior robustness, control and packaging. The backpressure valve motor, the thermal control valve, delta pressure sensors and temperature sensors were incorporated into the manifold endcaps, also for packaging considerations. Flight-like materials including a titanium housing were used for all components. Performance testing

  20. Membrane System for the Recovery of Volatile Organic Compounds from Remediation Off-Gases. Innovative Technology Summary Report

    International Nuclear Information System (INIS)

    2001-01-01

    Membrane Technology and Research, Inc.'s (MTR's) membrane-based off-gas treatment technology separates the organic components from the off-gas stream, producing a VOC-free air stream that can be discharged or recycled to the gas-generating process. The membrane system produces a constant, high-quality air discharge stream irrespective of the feed-air composition. The system also produces a concentrated liquid VOC stream for disposal. Any water vapor present in the off-gas is removed as condensed dischargeable water. Benefits: Applicable to a broad range of off-gas generating sources. Target streams are off-gas from soil remediation by in situ vacuum extraction or air and steam sparging, and soil vitrification Suitable for remote sites: systems require minimal site preparation, little operator attention once installed, electrical power but no other utilities, and no expendable chemicals Minimizes waste volume: dischargeable air and water are produced, and VOCs removed from the feed gas ar e concentrated into a condensed liquid. No other waste streams result Treats off-gases containing both flammable and nonflammable and chlorinated and nonchlorinated VOCs Cost competitive with other technologies in the VOC concentration range 100-1,000 ppm and offers significant cost reduction at higher VOC concentrations Systems are easily moved and transported to new sites with a minimum of refurbishing or modification Generates no air emissions, minimizing permitting issues and speeding up the start of a clean-up operation Technology: Removal of VOCs from air streams with membranes is a relatively new technology

  1. Thermoresponsive Membrane Based on Thermotropic Liquid Crystalline Cholesteryl - (L-lacticacidn System: Study of Its Drug Permeability

    Directory of Open Access Journals (Sweden)

    Massoumeh Bagheri

    2013-01-01

    Full Text Available The rapidly increasing interest in functional materials with reversibly switchable physico- chemical properties has led to significant work on the development of stimuli responsive membranes. Thermotropic liquid crystals with their exceptional properties have potentials for drug-delivery applications. Thermoresponsive liquid-crystal-embedded membranes were investigated for the purpose of developing the drug delivery systems with thermal stimuli response. Drug release occurs at temperatures above the phase transition temperature of thermotropic liquid crystals. Therefore, they can control drug release in response to small temperature changes. In this work, the biocompatible and thermotropic liquid crystalline polymer cholesteryl-(L-lactic acidn ,CLAn (n=30, was synthesized with accurate control of molecular weight via ring opening polymerization method. Polymerization of L-lactide was carried out in the presence of cholesterol as an initiator and catalytic amount of tin (II octoate (Sn(Oct2 at 150°C in 5 h. The number-average degree of polymerization of CLA 30 was obtained from 1H NMR spectroscopy. The phase transition behavior of liquid crystalline CLA30 was established by differential scanning calorimetry and polarizing optical microscopy. The resulting liquid crystalline CLA30 was subsequently utilized to prepare CLA30 -embedded cellulose nitrate membrane by adsorption method. The CLA30-embedded cellulose nitrate membrane was used by an in-vitro drug penetration studies. Acetaminophen was used as a model drug. The permeation study was carried out at different temperatures around glass transition temperature of polymer CLA30 (37, 45 and 40°C, respectively. The results show that the CLA30 -embedded cellulose nitrate membranes exhibit thermo-responsive sensitivity with controlled drug permeation.

  2. Spatial heterogeneity of biofouling under different cross-flow velocities in reverse osmosis membrane systems

    KAUST Repository

    Farhat, Nadia; Staal, M.; Bucs, Szilard; Van Loosdrecht, M.C.M.; Vrouwenvelder, Johannes S.

    2016-01-01

    the spatial heterogeneity of biofilm development over the membrane fouling simulator (MFS) length (inlet and outlet part) at three different cross-flow velocities (0.08, 0.12 and 0.16 m/s). The MFS contained sheets of membrane and feed spacer and simulatedComparison of the inlet and outlet position of the MFS showed a more (i) heterogeneous biofilm distribution and a (ii) higher biological activity at the inlet side (first 2.5 cm) for all cross-flow velocities. The lowest cross-flow velocity had

  3. A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results.

    Science.gov (United States)

    Kim, Young-Deuk; Thu, Kyaw; Ng, Kim Choon; Amy, Gary L; Ghaffour, Noreddine

    2016-09-01

    In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m(2) of evacuated-tube collectors and 10 m(3) seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. A novel integrated thermal-/membrane-based solar energy-driven hybrid desalination system: Concept description and simulation results

    KAUST Repository

    Kim, Youngdeuk

    2016-05-03

    In this paper, a hybrid desalination system consisting of vacuum membrane distillation (VMD) and adsorption desalination (AD) units, designated as VMD-AD cycle, is proposed. The synergetic integration of the VMD and AD is demonstrated where a useful effect of the AD cycle is channelled to boost the operation of the VMD process, namely the low vacuum environment to maintain the high pressure gradient across the microporous hydrophobic membrane. A solar-assisted multi-stage VMD-AD hybrid desalination system with temperature modulating unit is first designed, and its performance is then examined with a mathematical model of each component in the system and compared with the VMD-only system with temperature modulating and heat recovery units. The total water production and water recovery ratio of a solar-assisted 24-stage VMD-AD hybrid system are found to be about 21% and 23% higher, respectively, as compared to the VMD-only system. For the solar-assisted 24-stage VMD-AD desalination system having 150 m2 of evacuated-tube collectors and 10 m3 seawater storage tanks, both annual collector efficiency and solar fraction are close to 60%.

  5. Efficient treatment of aniline containing wastewater in bipolar membrane microbial electrolysis cell-Fenton system

    DEFF Research Database (Denmark)

    Li, Xiaohu; Jin, Xiangdan; Zhao, Nannan

    2017-01-01

    wastewater under an acidic condition maintained by the bipolar membrane. The aniline was effectively degraded following first-order kinetics at a rate constant of 0.0166 h−1 under an applied voltage of 0.5 V. Meanwhile, a total organic carbon (TOC) removal efficiency of 93.1 ± 1.2% was obtained, revealing...

  6. Thermal Regulation of Membrane Lipid Fluidity by a Two-Component System in "Bacillus Subtilis"

    Science.gov (United States)

    Bredeston, L. M.; Marciano, D.; Albanesi, D.; De Mendoza, D.; Delfino, J. M.

    2011-01-01

    This article describes a simple and robust laboratory exercise on the regulation of membrane unsaturated fatty acid composition in bacteria by a decrease in growth temperature. We take advantage of the well characterized Des pathway of "Bacillus subtilis", composed of a [delta]5-desaturase (encoded by the "des" gene) and the canonical…

  7. Membrane separation principle used for gas drying processes in fuel cells and life support systems

    International Nuclear Information System (INIS)

    Nigsch, H.A.; Fleck, W.U.

    1991-07-01

    Different membrane separation principles as applied to fuel cell powerplants and ECLSS are described. A new separator type that enables smaller weight and geometries and requires less energy than conventional mechanical separator techniques for space applications is presented. Module optimization and investigations concerning ECLSS applications are discussed. 5 refs

  8. Iron oxide nanoparticle synthesis in aqueous and membrane systems for oxidative degradation of trichloroethylene from water

    Energy Technology Data Exchange (ETDEWEB)

    Gui Minghui; Smuleac, Vasile [University of Kentucky, Department of Chemical and Materials Engineering (United States); Ormsbee, Lindell E. [University of Kentucky, Department of Civil Engineering (United States); Sedlak, David L. [University of California at Berkeley, Department of Civil and Environmental Engineering (United States); Bhattacharyya, Dibakar, E-mail: db@engr.uky.edu [University of Kentucky, Department of Chemical and Materials Engineering (United States)

    2012-05-15

    The potential for using hydroxyl radical (OH{sup Bullet }) reactions catalyzed by iron oxide nanoparticles (NPs) to remediate toxic organic compounds was investigated. Iron oxide NPs were synthesized by controlled oxidation of iron NPs prior to their use for contaminant oxidation (by H{sub 2}O{sub 2} addition) at near-neutral pH values. Cross-linked polyacrylic acid (PAA) functionalized polyvinylidene fluoride (PVDF) microfiltration membranes were prepared by in situ polymerization of acrylic acid inside the membrane pores. Iron and iron oxide NPs (80-100 nm) were directly synthesized in the polymer matrix of PAA/PVDF membranes, which prevented the agglomeration of particles and controlled the particle size. The conversion of iron to iron oxide in aqueous solution with air oxidation was studied based on X-ray diffraction, Moessbauer spectroscopy and BET surface area test methods. Trichloroethylene (TCE) was selected as the model contaminant because of its environmental importance. Degradations of TCE and H{sub 2}O{sub 2} by NP surface generated OH{sup Bullet} were investigated. Depending on the ratio of iron and H{sub 2}O{sub 2}, TCE conversions as high as 100 % (with about 91 % dechlorination) were obtained. TCE dechlorination was also achieved in real groundwater samples with the reactive membranes.

  9. Iron oxide nanoparticle synthesis in aqueous and membrane systems for oxidative degradation of trichloroethylene from water

    International Nuclear Information System (INIS)

    Gui Minghui; Smuleac, Vasile; Ormsbee, Lindell E.; Sedlak, David L.; Bhattacharyya, Dibakar

    2012-01-01

    The potential for using hydroxyl radical (OH • ) reactions catalyzed by iron oxide nanoparticles (NPs) to remediate toxic organic compounds was investigated. Iron oxide NPs were synthesized by controlled oxidation of iron NPs prior to their use for contaminant oxidation (by H 2 O 2 addition) at near-neutral pH values. Cross-linked polyacrylic acid (PAA) functionalized polyvinylidene fluoride (PVDF) microfiltration membranes were prepared by in situ polymerization of acrylic acid inside the membrane pores. Iron and iron oxide NPs (80–100 nm) were directly synthesized in the polymer matrix of PAA/PVDF membranes, which prevented the agglomeration of particles and controlled the particle size. The conversion of iron to iron oxide in aqueous solution with air oxidation was studied based on X-ray diffraction, Mössbauer spectroscopy and BET surface area test methods. Trichloroethylene (TCE) was selected as the model contaminant because of its environmental importance. Degradations of TCE and H 2 O 2 by NP surface generated OH • were investigated. Depending on the ratio of iron and H 2 O 2 , TCE conversions as high as 100 % (with about 91 % dechlorination) were obtained. TCE dechlorination was also achieved in real groundwater samples with the reactive membranes.

  10. Hybrid membrane system for desalination and wastewater treatment : Integrating forward osmosis and low pressure reverse osmosis

    NARCIS (Netherlands)

    Valladares Linares, R.

    2014-01-01

    Since more than 97% of the water in the world is seawater, desalination technologies have the potential to solve the fresh water crisis. The most used desalination technology nowadays is seawater reverse osmosis (SWRO), where a membrane is used as a physical barrier to separate the salts from the

  11. MITO-Porter: A liposome-based carrier system for delivery of macromolecules into mitochondria via membrane fusion.

    Science.gov (United States)

    Yamada, Yuma; Akita, Hidetaka; Kamiya, Hiroyuki; Kogure, Kentaro; Yamamoto, Takenori; Shinohara, Yasuo; Yamashita, Kikuji; Kobayashi, Hideo; Kikuchi, Hiroshi; Harashima, Hideyoshi

    2008-02-01

    Mitochondria are the principal producers of energy in higher cells. Mitochondrial dysfunction is implicated in a variety of human diseases, including cancer and neurodegenerative disorders. Effective medical therapies for such diseases will ultimately require targeted delivery of therapeutic proteins or nucleic acids to the mitochondria, which will be achieved through innovations in the nanotechnology of intracellular trafficking. Here we describe a liposome-based carrier that delivers its macromolecular cargo to the mitochondrial interior via membrane fusion. These liposome particles, which we call MITO-Porters, carry octaarginine surface modifications to stimulate their entry into cells as intact vesicles (via macropinocytosis). We identified lipid compositions for the MITO-Porter which promote both its fusion with the mitochondrial membrane and the release of its cargo to the intra-mitochondrial compartment in living cells. Thus, the MITO-Porter holds promise as an efficacious system for the delivery of both large and small therapeutic molecules into mitochondria.

  12. Development and characterization of membrane surface display system using molecular chaperon, prsA, of Bacillus subtilis

    International Nuclear Information System (INIS)

    Kim, June-Hyung; Park, In-Suk; Kim, Byung-Gee

    2005-01-01

    We report a new membrane surface display system based on molecular chaperon, prsA, of Bacillus subtilis. Clostridium thermocellum cellulase, celA, was fused to C-terminal end of PrsA. Cellulase activity of B. subtilis protoplast, which expressed PrsA-CelA was 15 times higher compared to control strain. More than 85% of total cellulase activity was observed in surface displayed format and less than 15% of total cellulase activity was found in supernatant. Flow cytometric analysis of protoplast of PrsA-CelA fusion expressing bacteria provided another proof of uniform expression of fusion protein onto cytoplasmic membrane of B. subtilis. Without lysozyme treatment, only part of cellulase activity (10%) was observed in whole cell fraction

  13. Forward osmosis membrane modular configurations for osmotic dilution of seawater by forward osmosis and reverse osmosis hybrid system.

    Science.gov (United States)

    Kim, Jung Eun; Phuntsho, Sherub; Ali, Syed Muztuza; Choi, Joon Young; Shon, Ho Kyong

    2018-01-01

    This study evaluates various options for full-scale modular configuration of forward osmosis (FO) process for osmotic dilution of seawater using wastewater for simultaneous desalination and water reuse through FO-reverse osmosis (RO) hybrid system. Empirical relationship obtained from one FO membrane element operation was used to simulate the operational performances of different FO module configurations. The main limiting criteria for module operation is to always maintain the feed pressure higher than the draw pressure throughout the housing module for safe operation without affecting membrane integrity. Experimental studies under the conditions tested in this study show that a single membrane housing cannot accommodate more than four elements as the draw pressure exceeds the feed pressure. This then indicates that a single stage housing with eight elements is not likely to be practical for safe FO operation. Hence, six different FO modular configurations were proposed and simulated. A two-stage FO configuration with multiple housings (in parallel) in the second stage using same or larger spacer thickness reduces draw pressure build-up as the draw flow rates are reduced to half in the second stage thereby allowing more than four elements in the second stage housing. The loss of feed pressure (pressure drop) and osmotic driving force in the second stage are compensated by operating under the pressure assisted osmosis (PAO) mode, which helps enhance permeate flux and maintains positive pressure differences between the feed and draw chamber. The PAO energy penalty is compensated by enhanced permeate throughput, reduced membrane area, and plant footprint. The contribution of FO/PAO to total energy consumption was not significant compared to post RO desalination (90%) indicating that the proposed two-stage FO modular configuration is one way of making the FO full-scale operation practical for FO-RO hybrid system. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. Applicability of short-term accelerated biofouling studies to predict long-term biofouling accumulation in reverse osmosis membrane systems

    KAUST Repository

    Sanawar, Huma

    2018-02-02

    Biofouling studies addressing biofouling control are mostly executed in short-term studies. It is unclear whether data collected from these experiments are representative for long-term biofouling as occurring in full-scale membrane systems. This study investigated whether short-term biofouling studies accelerated by biodegradable nutrient dosage to feed water were predictive for long-term biofouling development without nutrient dosage. Since the presence of a feed spacer has an strong effect on the degree of biofouling, this study employed six geometrically different feed spacers. Membrane fouling simulators (MFSs) were operated with the same (i) membrane, (ii) feed flow and (iii) feed water, but with feed spacers varying in geometry. For the short-term experiment, biofilm formation was enhanced by nutrient dosage to the MFS feed water, whereas no nutrient dosage was applied in the long-term experiment. Pressure drop development was monitored to characterize the extent of biofouling, while the accumulated viable biomass content at the end of the experimental run was quantified by adenosine triphosphate (ATP) measurements. Impact of feed spacer geometry on biofouling was compared for the short-term and long-term biofouling study. The results of the study revealed that the feed spacers exhibited the same biofouling behavior for (i) the short-term (9-d) study with nutrient dosage and (ii) the long-term (96-d) study without nutrient dosage. For the six different feed spacers, the accumulated viable biomass content (pg ATP.cm) was roughly the same, but the biofouling impact in terms of pressure drop increase in time was significantly different. The biofouling impact ranking of the six feed spacers was the same for the short-term and long-term biofouling studies. Therefore, it can be concluded that short-term accelerated biofouling studies in MFSs are a representative and suitable approach for the prediction of biofouling in membrane filtration systems after long

  15. Downregulation of membrane type-matrix metalloproteinases in the inflamed or injured central nervous system

    Directory of Open Access Journals (Sweden)

    Millward Jason M

    2007-09-01

    Full Text Available Abstract Background Matrix metalloproteinases (MMPs are thought to mediate cellular infiltration in central nervous system (CNS inflammation by cleaving extracellular matrix proteins associated with the blood-brain barrier. The family of MMPs includes 23 proteinases, including six membrane type-MMPs (MT-MMPs. Leukocyte infiltration is an integral part of the pathogenesis of autoimmune inflammation in the CNS, as occurs in multiple sclerosis and its animal model experimental autoimmune encephalomyelitis (EAE, as well as in the response to brain trauma and injury. We have previously shown that gene expression of the majority of MMPs was upregulated in the spinal cord of SJL mice with severe EAE induced by adoptive transfer of myelin basic protein-reactive T cells, whereas four of the six MT-MMPs (MMP-15, 16, 17 and 24 were downregulated. The two remaining MT-MMPs (MMP-14 and 25 were upregulated in whole tissue. Methods We used in vivo models of CNS inflammation and injury to study expression of MT-MMP and cytokine mRNA by real-time RT-PCR. Expression was also assessed in microglia sorted from CNS by flow cytometry, and in primary microglia cultures following treatment with IFNγ. Results We now confirm the expression pattern of MT-MMPs in the B6 mouse, independent of effects of adjuvant. We further show expression of all the MT-MMPs, except MMP-24, in microglia. Microglia isolated from mice with severe EAE showed statistically significant downregulation of MMP-15, 17 and 25 and lack of increase in levels of other MT-MMPs. Downregulation of MT-MMPs was also apparent following CNS injury. The pattern of regulation of MT-MMPs in neuroinflammation showed no association with expression of the proinflammatory cytokines TNFα, IL-1β, or IFNγ. Conclusion CNS inflammation and injury leads to downregulation in expression of the majority of MT-MMPs. Microglia in EAE showed a general downregulation of MT-MMPs, and our findings suggest that MT-MMP levels may

  16. Novel, energy-optimized membrane design for biological waste water treatment systems; Ein neuentwickeltes Niedrig-Energie-Membransystem fuer Membran-Biologien

    Energy Technology Data Exchange (ETDEWEB)

    Luebbecke, S. [Preussag Wassertechnik GmbH, Bremen (Germany)

    1999-07-01

    In industrial waste water treatment, circular movement of waste water, scarcity of space for erecting waste water treatment plants, and economy are factors of eminent importance, calling for innovative, efficient process techniques. Up to now, separation of activated sludge from cleaned waste water has been done almost exclusively by means of sedimentation. But because of the slight difference in density between water and biomass, large final sedimentation tanks are indispensable, and attainable biomass concentrations in an activated sludge tank (or bioreactor) are low (3-4g/l). Given that cleaning performance is directly proportional to biomass concentration, achieving higher biomass concentrations spells substantially enhanced efficiency per unit of space of biological systems, thus saving reaction volume. For this task, membrane techniques are suitable, which, contrary to sedimentation, permit random-selection, operationally stable retention and concentration of biomass with a definitely smaller space requirement. (orig.) [German] Bei der industriellen Abwasserbehandlung stehen die Kreislauffuehrung des Abwassers, beengte Platzverhaeltnisse fuer die Errichtung von Abwasserbehandlungsanlagen und die Wirtschaftlichkeit im Vordergrund, so dass dort innovative, effiziente Verfahrenstechniken gefragt sind. Zur Abtrennung des Belebtschlammes vom gereinigten Abwasser wird bisher fast ausschliesslich die Sedimentation eingesetzt. Der geringe Dichteunterschied zwischen Wasser und Biomasse macht jedoch grosse Nachklaerbecken notwendig und die erreichbaren Biomassekonzentrationen im Belebungsbecken (bzw. Bioreaktor) sind gering (3-4 g/l). Da die Reinigungsleistung der Biomassekonzentration direkt proportional ist, kann mit der Einstellung hoeherer Biomassekonzentrationen die Raumumsatzleistung biologischer Systeme erheblich gesteigert und somit Reaktionsvolumen eingespart werden. Fuer diese Aufgabe koennen Membranverfahren eingesetzt werden, die im Gegensatz zur

  17. Molecular-based detection of potentially pathogenic bacteria in membrane bioreactor (MBR) systems treating municipal wastewater: a case study.

    Science.gov (United States)

    Harb, Moustapha; Hong, Pei-Ying

    2017-02-01

    Although membrane bioreactor (MBR) systems provide better removal of pathogens compared to conventional activated sludge processes, they do not achieve total log removal. The present study examines two MBR systems treating municipal wastewater, one a full-scale MBR plant and the other a lab-scale anaerobic MBR. Both of these systems were operated using microfiltration (MF) polymeric membranes. High-throughput sequencing and digital PCR quantification were utilized to monitor the log removal values (LRVs) of associated pathogenic species and their abundance in the MBR effluents. Results showed that specific removal rates vary widely regardless of the system employed. Each of the two MBR effluents' microbial communities contained genera associated with opportunistic pathogens (e.g., Pseudomonas, Acinetobacter) with a wide range of log reduction values (5.5). Digital PCR further confirmed that these bacterial groups included pathogenic species, in several instances at LRVs different than those for their respective genera. These results were used to evaluate the potential risks associated both with the reuse of the MBR effluents for irrigation purposes and with land application of the activated sludge from the full-scale MBR system.

  18. Molecular-based detection of potentially pathogenic bacteria in membrane bioreactor (MBR) systems treating municipal wastewater: a case study

    KAUST Repository

    Harb, Moustapha

    2016-12-24

    Although membrane bioreactor (MBR) systems provide better removal of pathogens compared to conventional activated sludge processes, they do not achieve total log removal. The present study examines two MBR systems treating municipal wastewater, one a full-scale MBR plant and the other a lab-scale anaerobic MBR. Both of these systems were operated using microfiltration (MF) polymeric membranes. High-throughput sequencing and digital PCR quantification were utilized to monitor the log removal values (LRVs) of associated pathogenic species and their abundance in the MBR effluents. Results showed that specific removal rates vary widely regardless of the system employed. Each of the two MBR effluents’ microbial communities contained genera associated with opportunistic pathogens (e.g., Pseudomonas, Acinetobacter) with a wide range of log reduction values (< 2 to >5.5). Digital PCR further confirmed that these bacterial groups included pathogenic species, in several instances at LRVs different than those for their respective genera. These results were used to evaluate the potential risks associated both with the reuse of the MBR effluents for irrigation purposes and with land application of the activated sludge from the full-scale MBR system.

  19. Radioimmunoassay of adjuvant-associated porcine parvovirus using a monoclonal antibody in a nitrocellulose membrane system

    International Nuclear Information System (INIS)

    Katz, J.B.; Van Deusen, R.A.

    1985-01-01

    A quantitative and simple indirect radioimmunoassay (IRIA) was developed for porcine parvovirus (PPV), employing a monoclonal antibody directed against PPV adsorbed to nitrocellulose membrane. The IRIA was equally sensitive to live or inactivated PPV. There was a linear relationship between membrane-bound radioactivity and PPV quantity within a range of 10-80 hemagglutinating (HA) units of virus. Two commercially used adjuvants, aluminum hydroxide (AH) and carboxyvinyl polymer (CP), reduced bound radioactivity in a concentration-dependent manner. At fixed adjuvant concentrations, there were, nevertheless, linear relationships between bound radioactivity and HA units of PPV. Known amounts of PPV were prepared in adjuvants according to commercial vaccine formulations. Using these standards, the PPV content of 16 commercial PPV vaccines was estimated by IRIA. The IRIA may be one practical method of in vitro estimation of antigenic mass in adjuvanted vaccines. (Auth.)

  20. Proposal of the system for the biogas purification using vitreous and natural zeolite membranes

    International Nuclear Information System (INIS)

    Ortega Viera, Lianys; Fernández SantanI, Elina; Alfonso Martínez, Félix Enrique; Aguiar RoqueI, Yania; Rodríguez Muñoz, Susana

    2017-01-01

    One way to reduce the effects of climate change is to replace fossil fuels with renewable energy such as biogas, but the amount of hydrogen sulphide in it represents an impediment to its use, because of its negative impacts on human health, materials of construction and the environment, being essential its reduction or elimination. For this reason, it was defined as aim to propose an effective method for the purification of biogas using membranes constructed from vitreous waste materials and natural cuban zeolite. This treatment requires four membranes with their supports and eight valves and could be used by small farmers for the purification of 1.4 m 3 of biogas per day, an amount necessary for the cooking of three meals of a family of five people, being the cost of the biogas purification process equal to 0.06%/m 3 . (author)

  1. Ionic liquids in proton exchange membrane fuel cells: Efficient systems for energy generation

    Energy Technology Data Exchange (ETDEWEB)

    Padilha, Janine C.; Basso, Juliana; da Trindade, Leticia G.; Martini, Emilse M.A.; de Souza, Michele O.; de Souza, Roberto F. [Institute of Chemistry, UFRGS, Av. Bento Goncalves 9500, Porto Alegre 91501-970, P.O. Box 15003 (Brazil)

    2010-10-01

    Proton exchange membrane fuel cells (PEMFCs) are used in portable devices to generate electrical energy; however, the efficiency of the PEMFC is currently only 40%. This study demonstrates that the efficiency of a PEMFC can be increased to 61% when 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF{sub 4}) ionic liquid (IL) is used together with the membrane electrode assembly (MEA). The results for ionic liquids (ILs) 1-butyl-3-methylimidazolium chloride (BMI.Cl) and 1-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF{sub 4}) in aqueous solutions are better than those obtained with pure water. The current and the power densities with IL are at least 50 times higher than those obtained for the PEMFC wetted with pure water. This increase in PEMFC performance can greatly facilitate the use of renewable energy sources. (author)

  2. Evaluation of Zosteric Acid for Mitigating Biofilm Formation of Pseudomonas putida Isolated from a Membrane Bioreactor System

    Directory of Open Access Journals (Sweden)

    Andrea Polo

    2014-05-01

    Full Text Available This study provides data to define an efficient biocide-free strategy based on zosteric acid to counteract biofilm formation on the membranes of submerged bioreactor system plants. 16S rRNA gene phylogenetic analysis showed that gammaproteobacteria was the prevalent taxa on fouled membranes of an Italian wastewater plant. Pseudomonas was the prevalent genus among the cultivable membrane-fouler bacteria and Pseudomonas putida was selected as the target microorganism to test the efficacy of the antifoulant. Zosteric acid was not a source of carbon and energy for P. putida cells and, at 200 mg/L, it caused a reduction of bacterial coverage by 80%. Biofilm experiments confirmed the compound caused a significant decrease in biomass (−97% and thickness (−50%, and it induced a migration activity of the peritrichous flagellated P. putida over the polycarbonate surface not amenable to a biofilm phenotype. The low octanol-water partitioning coefficient and the high water solubility suggested a low bioaccumulation potential and the water compartment as its main environmental recipient and capacitor. Preliminary ecotoxicological tests did not highlight direct toxicity effects toward Daphnia magna. For green algae Pseudokirchneriella subcapitata an effect was observed at concentrations above 100 mg/L with a significant growth of protozoa that may be connected to a concurrent algal growth inhibition.

  3. Performance Evaluation of Waterproofing Membrane Systems Subject to the Concrete Joint Load Behavior of Below-Grade Concrete Structures

    Directory of Open Access Journals (Sweden)

    Jaeyoung Song

    2017-11-01

    Full Text Available Below-grade structures such as parking lots, underground subway tunnels, and basements are growing in scale and reaching deeper below-ground levels. In this type of environment, they become subject to higher water pressure. The concrete material of the structures is exposed to wet conditions for longer periods of time, which makes the proper adhesion of waterproofing membranes difficult. Joint movements from increased structural settlement, thermal expansion/shrinkage, and physical loads from external sources (e.g., vehicles make securing durable waterproofing challenging. While ASTM Guides, Korean Codes, and BS Practice Codes on below-grade waterproofing stress the importance of manufacturer specification for quality control, ensuring high quality waterproofing for the ever-changing scale of construction remains a challenge. This study proposes a new evaluation method and criteria which allow for the selection of waterproofing membranes based on specific performance attributes and workmanship. It subjects six different waterproofing membrane systems (installed on dry and wet surface conditioned mortar slab specimens with an artificial joint to different cyclic movement widths to 300 cycles in water to demonstrate that inadequate material properties and workmanship are key causes for leakages.

  4. Electrophysiological study of transport systems in isolated perfused pancreatic ducts: properties of the basolateral membrane

    DEFF Research Database (Denmark)

    Novak, I; Greger, R

    1988-01-01

    - concentration from 0 to 25 mmol/l produced fast and sustained depolarization of PDbl by 8.5 +/- 1.0 mV (n = 149). It was investigated whether the effect of HCO3- was due to a Na+-dependent transport mechanism on the basolateral membrane, where the ion complex transferred into the cell would be positively...... was monitored by electrophysiological techniques. In this report some properties of the basolateral membrane of pancreatic duct cells are described. The transepithelial potential difference (PDte) in ducts bathed in HCO3(-)-free and HCO3(-)-containing solution was -0.8 and -2.6 mV, respectively. The equivalent...... short circuit current (Isc) under similar conditions was 26 and 50 microA . cm-2. The specific transepithelial resistance (Rte) was 88 omega cm2. In control solutions the PD across the basolateral membrane (PDbl) was -63 +/- 1 mV (n = 314). Ouabain (3 mmol/l) depolarized PDbl by 4.8 +/- 1.1 mV (n = 6...

  5. Development and Testing of a Fully Adaptable Membrane Bioreactor Fouling Model for a Sidestream Configuration System

    Directory of Open Access Journals (Sweden)

    Parneet Paul

    2013-04-01

    Full Text Available A dead-end filtration model that includes the three main fouling mechanisms mentioned in Hermia (i.e., cake build-up, complete pore blocking, and pore constriction and that was based on a constant trans-membrane pressure (TMP operation was extensively modified so it could be used for a sidestream configuration membrane bioreactor (MBR situation. Modifications and add-ons to this basic model included: alteration so that it could be used for varying flux and varying TMP operations; inclusion of a backwash mode; it described pore constriction (i.e., irreversible fouling in relation to the concentration of soluble microbial products (SMP in the liquor; and, it could be used in a cross flow scenario by the addition of scouring terms in the model formulation. The additional terms in this modified model were checked against an already published model to see if they made sense, physically speaking. Next this modified model was calibrated and validated in Matlab© using data collected by carrying out flux stepping tests on both a pilot sidestream MBR plant, and then a pilot membrane filtration unit. The model fit proved good, especially for the pilot filtration unit data. In conclusion, this model formulation is of the right level of complexity to be used for most practical MBR situations.

  6. Ultrasensitive Detection of Ebola Virus Oligonucleotide Based on Upconversion Nanoprobe/Nanoporous Membrane System.

    Science.gov (United States)

    Tsang, Ming-Kiu; Ye, WeiWei; Wang, Guojing; Li, Jingming; Yang, Mo; Hao, Jianhua

    2016-01-26

    Ebola outbreaks are currently of great concern, and therefore, development of effective diagnosis methods is urgently needed. The key for lethal virus detection is high sensitivity, since early-stage detection of virus may increase the probability of survival. Here, we propose a luminescence scheme of assay consisting of BaGdF5:Yb/Er upconversion nanoparticles (UCNPs) conjugated with oligonucleotide probe and gold nanoparticles (AuNPs) linked with target Ebola virus oligonucleotide. As a proof of concept, a homogeneous assay was fabricated and tested, yielding a detection limit at picomolar level. The luminescence resonance energy transfer is ascribed to the spectral overlapping of upconversion luminescence and the absorption characteristics of AuNPs. Moreover, we anchored the UCNPs and AuNPs on a nanoporous alumina (NAAO) membrane to form a heterogeneous assay. Importantly, the detection limit was greatly improved, exhibiting a remarkable value at the femtomolar level. The enhancement is attributed to the increased light-matter interaction throughout the nanopore walls of the NAAO membrane. The specificity test suggested that the nanoprobes were specific to Ebola virus oligonucleotides. The strategy combining UCNPs, AuNPs, and NAAO membrane provides new insight into low-cost, rapid, and ultrasensitive detection of different diseases. Furthermore, we explored the feasibility of clinical application by using inactivated Ebola virus samples. The detection results showed great potential of our heterogeneous design for practical application.

  7. Plasma membrane events associated with the meiotic divisions in the amphibian oocyte: insights into the evolution of insulin transduction systems and cell signaling

    Directory of Open Access Journals (Sweden)

    Morrill Gene A

    2013-01-01

    Full Text Available Abstract Background Insulin and its plasma membrane receptor constitute an ancient response system critical to cell growth and differentiation. Studies using intact Rana pipiens oocytes have shown that insulin can act at receptors on the oocyte surface to initiate resumption of the first meiotic division. We have reexamined the insulin-induced cascade of electrical and ion transport-related plasma membrane events using both oocytes and intact plasma membranes in order to characterize the insulin receptor-steroid response system associated with the meiotic divisions. Results [125I]Insulin binding (Kd = 54 ± 6 nM at the oocyte plasma membrane activates membrane serine protease(s, followed by the loss of low affinity ouabain binding sites, with a concomitant 3–4 fold increase in high affinity ouabain binding sites. The changes in protease activity and ouabain binding are associated with increased Na+/Ca2+ exchange, increased endocytosis, decreased Na+ conductance resulting in membrane hyperpolarization, increased 2-deoxy-D-glucose uptake and a sustained elevation of intracellular pH (pHi. Hyperpolarization is largely due to Na+-channel inactivation and is the main driving force for glucose uptake by the oocyte via Na+/glucose cotransport. The Na+ sym- and antiporter systems are driven by the Na+ free energy gradient generated by Na+/K+-ATPase. Shifts in α and/or β Na+-pump subunits to caveolar (lipid raft membrane regions may activate Na/K-ATPase and contribute to the Na+ free energy gradient and the increase in both Na+/glucose co-transport and pHi. Conclusions Under physiological conditions, resumption of meiosis results from the concerted action of insulin and progesterone at the cell membrane. Insulin inactivates Na+ channels and mobilizes fully functional Na+-pumps, generating a Na+ free energy gradient which serves as the energy source for several membrane anti- and symporter systems.

  8. Inward cholesterol gradient of the membrane system in P. falciparum-infected erythrocytes involves a dilution effect from parasite-produced lipids

    Directory of Open Access Journals (Sweden)

    Fuyuki Tokumasu

    2014-05-01

    Full Text Available Plasmodium falciparum (Pf infection remodels the human erythrocyte with new membrane systems, including a modified host erythrocyte membrane (EM, a parasitophorous vacuole membrane (PVM, a tubulovesicular network (TVN, and Maurer's clefts (MC. Here we report on the relative cholesterol contents of these membranes in parasitized normal (HbAA and hemoglobin S-containing (HbAS, HbAS erythrocytes. Results from fluorescence lifetime imaging microscopy (FLIM experiments with a cholesterol-sensitive fluorophore show that membrane cholesterol levels in parasitized erythrocytes (pRBC decrease inwardly from the EM, to the MC/TVN, to the PVM, and finally to the parasite membrane (PM. Cholesterol depletion of pRBC by methyl-β-cyclodextrin treatment caused a collapse of this gradient. Lipid and cholesterol exchange data suggest that the cholesterol gradient involves a dilution effect from non-sterol lipids produced by the parasite. FLIM signals from the PVM or PM showed little or no difference between parasitized HbAA vs HbS-containing erythrocytes that differed in lipid content, suggesting that malaria parasites may regulate the cholesterol contents of the PVM and PM independently of levels in the host cell membrane. Cholesterol levels may affect raft structures and the membrane trafficking and sorting functions that support Pf survival in HbAA, HbAS and HbSS erythrocytes.

  9. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  10. A Disulfide Bond in the Membrane Protein IgaA Is Essential for Repression of the RcsCDB System

    Directory of Open Access Journals (Sweden)

    M. Graciela Pucciarelli

    2017-12-01

    Full Text Available IgaA is an integral inner membrane protein that was discovered as repressor of the RcsCDB phosphorelay system in the intracellular pathogen Salmonella enterica serovar Typhimurium. The RcsCDB system, conserved in many members of the family Enterobacteriaceae, regulates expression of varied processes including motility, biofilm formation, virulence and response to envelope stress. IgaA is an essential protein to which, in response to envelope perturbation, the outer membrane lipoprotein RcsF has been proposed to bind in order to activate the RcsCDB phosphorelay. Envelope stress has also been reported to be sensed by a surface exposed domain of RcsF. These observations support a tight control of the RcsCDB system by RcsF and IgaA via mechanisms that, however, remain unknown. Interestingly, RcsF and IgaA have four conserved cysteine residues in loops exposed to the periplasmic space. Two non-consecutive disulfide bonds were shown to be required for RcsF function. Here, we report mutagenesis studies supporting the presence of one disulfide bond (C404-C425 in the major periplasmic loop of IgaA that is essential for repression of the RcsCDB phosphorelay. Our data therefore suggest that the redox state of the periplasm may be critical for the control of the RcsCDB system by its two upstream regulators, RcsF and IgaA.

  11. Functional reconstitution of an ATP-driven Ca2+-transport system from the plasma membrane of Commelina communis L

    International Nuclear Information System (INIS)

    Graef, P.; Weiler, E.W.

    1990-01-01

    The protein(s) that constitute(s) the ATP-driven Ca 2+ -translocator of plasma membrane enriched vesicles obtained by aqueous two-phase partitioning from leaves of Commelina communis L. has/have been solubilized and reincorporated into tightly sealed liposomes. The reconstituted Ca 2+ -transport system was studied using ATP-driven 45 Ca 2+ import into the proteoliposomes as a measure of activity. The detergent, 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate proved to be the most suitable and was used at 10 millimolar concentration, i.e. just above its critical micellar concentration. The presence of additional phospholipid and ATP improved the solubilization and/or reconstitution. The characteristics of the reconstituted system were similar to those of the plasma membrane-bound activity, including the apparent K m for Ca 2+ inhibition by relatively high levels of vanadate and lacking response to added calmodulin. The reconstituted transport system was very strongly inhibited by erythrosine B and had a low apparent K m for ATP levels of the Ca 2+ -ionophore A 23187 instantaneously discharged 90% of the Ca 2+ associated with the vesicles, proving that it had been accumulated in the intravesicular volume in soluble, freely exchangeable form. Ca 2+ -transport in the reconstituted system was thus primary active, through a Ca 2+ -translocating ATPase

  12. A hybrid system using a regenerative electrochemical cycle to harvest waste heat from the proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Long, Rui; Li, Baode; Liu, Zhichun; Liu, Wei

    2015-01-01

    A new hybrid system consisting of a PEMFC (proton exchange membrane fuel cell) subsystem and a TREC (thermally regenerative electrochemical cycle) subsystem is proposed to convert the waste heat produced by the PEMFC system into electricity. The performance of the hybrid system and its corresponding subsystems is analyzed. Results reveal that there exists optimal current densities of the PEMFC and TREC systems leading to the maximum power output of the hybrid system. With the maximum power output as the objective function, an optimization of the hybrid system based on genetic algorithm method is conducted under different operating temperatures of the PEMFC subsystem. The power output of the hybrid system is 6.85%–20.59% larger than that of the PEMFC subsystem. And the total electrical efficiency is improved by 2.74%–8.27%. The corresponding electrical efficiency of the TREC is 4.56%–13.81%. The hybrid system proposed in this paper could contribute to utilizing the fuel energy more efficiently and sufficiently. - Highlights: • A hybrid power system consisting of a PEMFC and a TREC subsystems is proposed. • Parameters' impacts on performance of the hybrid system have been analyzed. • The maximum power output of the hybrid system is investigated based on genetic algorithm. • Total power output of the hybrid system is 7.63%–18.84% larger than that of the PEMFC subsystem.

  13. Design and implementation of fixed-order robust controllers for a proton exchange membrane fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Fu-Cheng; Chen, Hsuan-Tsung [Department of Mechanical Engineering, National Taiwan University, No.1, Sec. 4, Roosevelt Road, 10617 Taipei (China)

    2009-03-15

    This paper applies fixed-order multivariable robust control strategies to a proton exchange membrane fuel cell (PEMFC) system, and implements the designed controllers on a microchip for system miniaturization. In previous studies, robust control was applied to guarantee system stability and to reduce hydrogen consumption for a PEMFC system. It was noted that for standard robust control design, the order of resulting H{sub {infinity}} controllers is dictated by the plants and weighting functions. However, for hardware implementation, controllers with lower orders are preferable in terms of computing efforts and cost. Therefore, in this paper the PEMFC is modeled as multivariable transfer matrices, then three fixed-order robust control algorithms are applied to design controllers with specified orders for a PEMFC. Finally, the designed controllers are implemented on a microchip to regulate the air and hydrogen flow rates. From the experimental results, fixed-order robust control is deemed effective in supplying steady power and reducing fuel consumption. (author)

  14. Novel carbon fiber cathode membrane with Fe/Mn/C/F/O elements in bio-electrochemical system (BES) to enhance wastewater treatment

    Science.gov (United States)

    Gao, Changfei; Liu, Lifen; Yang, Fenglin

    2018-03-01

    A novel conductive membrane with Fe/Mn/C/F/O elements is developed, it functions as the catalytic cathode of MFC and the antifouling filter of MBR simultaneously, in a newly designed integrated wastewater treatment system, without proton exchange membrane (PEM). The optimal conductive membrane is characterized using SEM-EDX, XRD and XPS. BET and porous structure analysis of the grounded membrane material indicate a narrow and small pore size (2-7 nm). The membrane surface is rich in Fe species (Fe - Fe2O3- Fe3O4) and manganese oxide (MnO2). Its characteristics such as excellent electro-chemical oxygen reduction reaction (ORR) activity, high clear water flux (>240 L/(m2·h)) and better antifouling filtration performance are further confirmed. The new system features bio-electrochemical system (BES) and integrates bio-filtration (trickling filter and air contact oxidation bed) and proton transfer through quartz sand chamber (QSC) which eliminates the use of expensive proton exchange membrane. The system removes chemical oxygen demand (>97.4%), ammonia nitrogen (>96.7%), total phosphorus (>98.0%) effectively, and it simultaneously generates electricity (446 mW/m3). The low cost and high performances, economic and advantageous system has good compatibility with existing wastewater treatment facilities and a wide application prospect.

  15. Treatment of poultry slaughterhouse wastewater using a static granular bed reactor (SGBR) coupled with ultrafiltration (UF) membrane system.

    Science.gov (United States)

    Basitere, M; Rinquest, Z; Njoya, M; Sheldon, M S; Ntwampe, S K O

    2017-07-01

    The South African poultry industry has grown exponentially in recent years due to an increased demand for their products. As a result, poultry plants consume large volumes of high quality water to ensure that hygienically safe poultry products are produced. Furthermore, poultry industries generate high strength wastewater, which can be treated successfully at low cost using anaerobic digesters. In this study, the performance of a bench-scale mesophilic static granular bed reactor (SGBR) containing fully anaerobic granules coupled with an ultrafiltration (UF) membrane system, as a post-treatment system, was investigated. The poultry slaughterhouse wastewater was characterized by a chemical oxygen demand (COD) range between 1,223 and 9,695mg/L, average biological oxygen demand of 2,375mg/L and average fats, oil and grease (FOG) of 554mg/L. The SGBR anaerobic reactor was operated for 9 weeks at different hydraulic retention times (HRTs), i.e. 55 and 40 h, with an average organic loading rate (OLR) of 1.01 and 3.14g COD/L.day. The SGBR results showed an average COD, total suspended solids (TSS) and FOG removal of 93%, 95% and 90% respectively, for both OLR. The UF post-treatment results showed an average of COD, TSS and FOG removal of 64%, 88% and 48%, respectively. The overall COD, TSS and FOG removal of the system (SGBR and UF membrane) was 98%, 99.8%, and 92.4%, respectively. The results of the combined SGBR reactor coupled with the UF membrane showed a potential to ensure environmentally friendly treatment of poultry slaughterhouse wastewater.

  16. The structure of Serratia marcescens Lip, a membrane-bound component of the type VI secretion system

    Energy Technology Data Exchange (ETDEWEB)

    Rao, Vincenzo A.; Shepherd, Sharon M.; English, Grant; Coulthurst, Sarah J.; Hunter, William N., E-mail: w.n.hunter@dundee.ac.uk [College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland (United Kingdom)

    2011-12-01

    The high-resolution crystal structure of S. marcescens Lip reveals a new member of the transthyretin family of proteins. Lip, a core component of the type VI secretion apparatus, is localized to the outer membrane and is positioned to interact with other proteins forming this complex system. Lip is a membrane-bound lipoprotein and a core component of the type VI secretion system found in Gram-negative bacteria. The structure of a Lip construct (residues 29–176) from Serratia marcescens (SmLip) has been determined at 1.92 Å resolution. Experimental phases were derived using a single-wavelength anomalous dispersion approach on a sample cocrystallized with iodide. The membrane localization of the native protein was confirmed. The structure is that of the globular domain lacking only the lipoprotein signal peptide and the lipidated N-terminus of the mature protein. The protein fold is dominated by an eight-stranded β-sandwich and identifies SmLip as a new member of the transthyretin family of proteins. Transthyretin and the only other member of the family fold, 5-hydroxyisourate hydrolase, form homotetramers important for their function. The asymmetric unit of SmLip is a tetramer with 222 symmetry, but the assembly is distinct from that previously noted for the transthyretin protein family. However, structural comparisons and bacterial two-hybrid data suggest that the SmLip tetramer is not relevant to its role as a core component of the type VI secretion system, but rather reflects a propensity for SmLip to participate in protein–protein interactions. A relatively low level of sequence conservation amongst Lip homologues is noted and is restricted to parts of the structure that might be involved in interactions with physiological partners.

  17. The structure of Serratia marcescens Lip, a membrane-bound component of the type VI secretion system

    International Nuclear Information System (INIS)

    Rao, Vincenzo A.; Shepherd, Sharon M.; English, Grant; Coulthurst, Sarah J.; Hunter, William N.

    2011-01-01

    The high-resolution crystal structure of S. marcescens Lip reveals a new member of the transthyretin family of proteins. Lip, a core component of the type VI secretion apparatus, is localized to the outer membrane and is positioned to interact with other proteins forming this complex system. Lip is a membrane-bound lipoprotein and a core component of the type VI secretion system found in Gram-negative bacteria. The structure of a Lip construct (residues 29–176) from Serratia marcescens (SmLip) has been determined at 1.92 Å resolution. Experimental phases were derived using a single-wavelength anomalous dispersion approach on a sample cocrystallized with iodide. The membrane localization of the native protein was confirmed. The structure is that of the globular domain lacking only the lipoprotein signal peptide and the lipidated N-terminus of the mature protein. The protein fold is dominated by an eight-stranded β-sandwich and identifies SmLip as a new member of the transthyretin family of proteins. Transthyretin and the only other member of the family fold, 5-hydroxyisourate hydrolase, form homotetramers important for their function. The asymmetric unit of SmLip is a tetramer with 222 symmetry, but the assembly is distinct from that previously noted for the transthyretin protein family. However, structural comparisons and bacterial two-hybrid data suggest that the SmLip tetramer is not relevant to its role as a core component of the type VI secretion system, but rather reflects a propensity for SmLip to participate in protein–protein interactions. A relatively low level of sequence conservation amongst Lip homologues is noted and is restricted to parts of the structure that might be involved in interactions with physiological partners

  18. Innovative Design of Solar-Powered Desalination (SPD System using Vacuum-Multi Effect Membrane Distillation (V-MEMD Process

    Directory of Open Access Journals (Sweden)

    Chafidz Achmad

    2018-01-01

    Full Text Available This research focused on the development of an innovative design of solar-powered desalination (SPD system which was expected to solve the water and energy problem simultaneously. We have developed a portable and hybrid solar-powered desalination (SPD system for producing potable water from saline water. It is a self-contained and integrated system which combines solar-thermal collector and solar-photovoltaic for its operation, and thus the system can operate to produce water by only using solar energy. Therefore, the system is highly suitable to be implemented in remote arid and coastal areas without infrastructures or connection to the grid (water and power, but blessed with abundant solar irradiation, like in Saudi Arabia. A Memsys Vacuum Multi-Effect Membrane Distillation (V-MEMD unit was used as the core of the SPD system. A heat pump was also integrated into the SPD system for energy recovery and to improve the performance of the system. The system could be considered as sustainable and “green” desalination technology, which will be very useful for the Kingdom of Saudi Arabia. To study the performance of the system, small-scale tests have been carried out at the Engineering College - King Saud University, Saudi Arabia. Based on the experimental results, the system has run successfully by only utilizing solar energy.

  19. Control and Experimental Characterization of a Methanol Reformer for a 350 W High Temperature Polymer Electrolyte Membrane Fuel Cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    , i.e. cathode and anode gas flows and temperature by using mass flow controllers and controlled heaters. Using this system the methanol reformer is characterized in its different operating points, both steady-state but also dynamically. Methanol steam reforming is a well known process, and provides...... and burner and the behaviour of the CO concentration of the reformate gas....... the high temperature waste gas from a cathode air cooled 45 cell HTPEM fuel cell stack. The MEAs used are BASF P2100 which use phosphoric acid doped polybenzimidazole type membranes; an MEA with high CO tolerance and no complex humidity requirements. The methanol reformer used is integrated into a compact...

  20. Porosity of spacer-filled channels in spiral-wound membrane systems: Quantification methods and impact on hydraulic characterization

    KAUST Repository

    Siddiqui, Amber

    2017-04-13

    The porosity of spacer-filled feed channels influences the hydrodynamics of spiral-wound membrane systems and impacts the overall performance of the system. Therefore, an exact measurement and a detailed understanding of the impact of the feed channel porosity is required to understand and improve the hydrodynamics of spiral-wound membrane systems applied for desalination and wastewater reuse. The objectives of this study were to assess the accuracy of porosity measurement techniques for feed spacers differing in geometry and thickness and the consequences of using an inaccurate method on hydrodynamic predictions, which may affect permeate production. Six techniques were applied to measure the porosity namely, three volumetric calculations based on spacer strand count together with cuboidal (SC), cylindrical (VCC) and ellipsoidal volume calculation (VCE) and three independent techniques based on volume displacement (VD), weight and density (WD) and computed tomography scanning (CT). The CT method was introduced as an alternative for the other five already existing and applied methods in practice.Six feed spacers used for the porosity measurement differed in filament thickness, angle between the filaments and mesh-size. The results of the studies showed differences between the porosities, measured by the six methods. The results of the microscopic techniques SC, VCC and VCE deviated significantly from measurements by VD, WD and CT, which showed similar porosity values for all spacer types.Depending on the maximum deviation of the porosity measurement techniques from –6% to +6%, (i) the linear velocity deviations were −5.6% and +6.4% respectively and (ii) the pressure drop deviations were –31% and +43% respectively, illustrating the importance of an accurate porosity measurement. Because of the accuracy and standard deviation, the VD and WD method should be applied for the porosity determination of spacer-filled channels, while the CT method is recommended for