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Sample records for ms pulsed electrolysis

  1. A comparative study of hair removal at an NHS hospital: Luminette intense pulsed light versus electrolysis.

    PubMed

    Harris, Karen; Ferguson, Janice; Hills, Samantha

    2014-04-01

    Twenty-five women, referred for hair removal by electrolysis, were enrolled in a split face study to treat facial hirsutism. Each patient was treated on six occasions: one-half of the face with electrolysis and the other side with an intense pulsed light source. Patients were evaluated with respect to reduction in hair counts, side effects and discomfort during treatment. Re-growth was assessed at 3, 6 and 9 months following treatment. All patients, except one with very sparse, fair hair growth, preferred treatment with the Intense Pulsed Light and rated their average hair reduction with this method as 77% after five treatments. The overall patient satisfaction rates as determined by visual analogue scales were 8.3 out of 10 for IPL and 5.4 out of 10 for electrolysis.

  2. Control of Analyte Electrolysis in Electrospray Ionization Mass Spectrometry Using Repetitively Pulsed High Voltage

    SciTech Connect

    Kertesz, Vilmos; Van Berkel, Gary J

    2011-01-01

    Analyte electrolysis using a repetitively pulsed high voltage ion source was investigated and compared to that using a regular, continuously operating direct current high voltage ion source in electrospray ionization mass spectrometry. The extent of analyte electrolysis was explored as a function of the length and frequency of the high voltage pulse using the model compound reserpine in positive ion mode. Using +5 kV as the maximum high voltage amplitude, reserpine was oxidized to its 2, 4, 6 and 8-electron oxidation products when direct current high voltage was employed. In contrast, when using a pulsed high voltage, oxidation of reserpine was eliminated by employing the appropriate high voltage pulse length and frequency. This effect was caused by inefficient mass transport of the analyte to the electrode surface during the duration of the high voltage pulse and the subsequent relaxation of the emitter electrode/ electrolyte interface during the time period when the high voltage was turned off. This mode of ESI source operation allows for analyte electrolysis to be quickly and simply switched on or off electronically via a change in voltage pulse variables.

  3. Pulsed voltage electrospray ion source and method for preventing analyte electrolysis

    DOEpatents

    Kertesz, Vilmos; Van Berkel, Gary

    2011-12-27

    An electrospray ion source and method of operation includes the application of pulsed voltage to prevent electrolysis of analytes with a low electrochemical potential. The electrospray ion source can include an emitter, a counter electrode, and a power supply. The emitter can include a liquid conduit, a primary working electrode having a liquid contacting surface, and a spray tip, where the liquid conduit and the working electrode are in liquid communication. The counter electrode can be proximate to, but separated from, the spray tip. The power system can supply voltage to the working electrode in the form of a pulse wave, where the pulse wave oscillates between at least an energized voltage and a relaxation voltage. The relaxation duration of the relaxation voltage can range from 1 millisecond to 35 milliseconds. The pulse duration of the energized voltage can be less than 1 millisecond and the frequency of the pulse wave can range from 30 to 800 Hz.

  4. Continuous harvest of marine microalgae using electrolysis: effect of pulse waveform of polarity exchange.

    PubMed

    Kim, Jungmin; Ryu, Byung-Gon; Lee, You-Jin; Han, Jong-In; Kim, Woong; Yang, Ji-Won

    2014-07-01

    Advances in harvesting of microalgae are needed for the efficient and economical production of microalgal biodiesel. In addition to improvements in recovery efficiency, developments in harvest technology should focus on reducing the adverse impact of subsequent processes, and should also allow water recycling. We investigated a continuous electrochemical approach for microalgal biodiesel production. Instead of conventional DC, pulsed DC was applied as a method of polarity exchange and its performance was analyzed in terms of recovery efficiency, electricity consumption, and residual Al concentration. Under optimized pulsed-DC conditions, 32 % less electricity was required and 7 % less Al was remained after continuous harvesting and there was no decrease in recovery efficiency compared to the continuous harvesting by conventional DC. We also examined the effect of this new protocol on biodiesel quality and water reusability. There were no differences in the microalgal oil composition before and after electrolytic harvesting. In addition, the harvested oil quality, based on four key parameters, was superior to that produced by other terrestrial crops. Lastly, there was no retardation of growth in recycled medium relative to that in fresh medium. PMID:24322506

  5. Improved liquid chromatography-MS/MS of heparan sulfate oligosaccharides via chip-based pulsed makeup flow.

    PubMed

    Huang, Yu; Shi, Xiaofeng; Yu, Xiang; Leymarie, Nancy; Staples, Gregory O; Yin, Hongfeng; Killeen, Kevin; Zaia, Joseph

    2011-11-01

    Microfluidic chip-based hydrophilic interaction chromatography (HILIC) is a useful separation system for liquid chromatography-mass spectrometry (LC-MS) in compositional profiling of heparan sulfate (HS) oligosaccharides; however, ions observed using HILIC LC-MS are low in charge. Tandem MS of HS oligosaccharide ions with low charge results in undesirable losses of SO(3) from precursor ions during collision induced dissociation. One solution is to add metal cations to stabilize sulfate groups. Another is to add a nonvolatile, polar compound such as sulfolane, a molecule known to supercharge proteins, to produce a similar effect for oligosaccharides. We demonstrate use of a novel pulsed makeup flow (MUF) HPLC-chip. The chip enables controlled application of additives during specified chromatographic time windows and thus minimizes the extent to which nonvolatile additives build up in the ion source. The pulsed MUF system was applied to LC-MS/MS of HS oligosaccharides. Metal cations and sulfolane were tested as additives. The most promising results were obtained for sulfolane, for which supercharging of the oligosaccharide ions increased their signal strengths relative to controls. Tandem MS of these supercharged precursor ions showed decreased abundances of product ions from sulfate losses yet more abundant product ions from backbone cleavages.

  6. L10 ordering of FePt thin films using sub-10 ms laser pulses

    NASA Astrophysics Data System (ADS)

    Inaba, Y.; Kang, S.; Izatt, J. R.; Harrell, J. W.; Thompson, G. B.; Kubota, Y.; Klemmer, T. J.

    2009-04-01

    The structural and magnetic properties of 10 nm FePt thin films annealed using a 1064 nm wavelength laser with 10, 7.5, 5.0, and 2.5 ms pulses have been examined. The A1 to L10 phase transformation was confirmed by x-ray diffraction (XRD). The maximum order parameter of 0.53 and coercivity of 5.36 kOe can be obtained with 10 ms pulse width laser annealing at a laser energy fluence of 10 J/cm2. The order parameter of the furnace annealed samples was approximately 1.0 suggesting that 10 ms is insufficient to obtain a fully ordered phase. The laser annealed grain size, as measured by in-plane XRD analysis, is 24 % smaller than that of furnace annealed sample for an equivalent order parameter demonstrating the merit of short time annealing.

  7. Water electrolysis

    NASA Technical Reports Server (NTRS)

    Schubert, Franz H. (Inventor); Grigger, David J. (Inventor)

    1992-01-01

    This disclosure is directed to an electrolysis cell forming hydrogen and oxygen at space terminals. The anode terminal is porous and able to form oxygen within the cell and permit escape of the gaseous oxygen through the anode and out through a flow line in the presence of backpressure. Hydrogen is liberated in the cell at the opposing solid metal cathode which is permeable to hydrogen but not oxygen so that the migratory hydrogen formed in the cell is able to escape from the cell. The cell is maintained at an elevated pressure so that the oxygen liberated by the cell is delivered at elevated pressure without pumping to raise the pressure of the oxygen.

  8. Anodes for alkaline electrolysis

    DOEpatents

    Soloveichik, Grigorii Lev

    2011-02-01

    A method of making an anode for alkaline electrolysis cells includes adsorption of precursor material on a carbonaceous material, conversion of the precursor material to hydroxide form and conversion of precursor material from hydroxide form to oxy-hydroxide form within the alkaline electrolysis cell.

  9. Combining Electrolysis and Electroporation for Tissue Ablation.

    PubMed

    Phillips, Mary; Rubinsky, Liel; Meir, Arie; Raju, Narayan; Rubinsky, Boris

    2015-08-01

    Electrolytic ablation is a method that operates by delivering low magnitude direct current to the target region over long periods of time, generating electrolytic products that destroy cells. This study was designed to explore the hypothesis stating that electrolytic ablation can be made more effective when the electrolysis-producing electric charges are delivered using electric pulses with field strength typical in reversible electroporation protocols. (For brevity we will refer to tissue ablation protocols that combine electroporation and electrolysis as E(2).) The mechanistic explanation of this hypothesis is related to the idea that products of electrolysis generated by E(2) protocols can gain access to the interior of the cell through the electroporation permeabilized cell membrane and therefore cause more effective cell death than from the exterior of an intact cell. The goal of this study is to provide a first-order examination of this hypothesis by comparing the charge dosage required to cause a comparable level of damage to a rat liver, in vivo, when using either conventional electrolysis or E(2) approaches. Our results show that E(2) protocols produce tissue damage that is consistent with electrolytic ablation. Furthermore, E(2) protocols cause damage comparable to that produced by conventional electrolytic protocols while delivering orders of magnitude less charge to the target tissue over much shorter periods of time.

  10. Synergistic Combination of Electrolysis and Electroporation for Tissue Ablation.

    PubMed

    Stehling, Michael K; Guenther, Enric; Mikus, Paul; Klein, Nina; Rubinsky, Liel; Rubinsky, Boris

    2016-01-01

    Electrolysis, electrochemotherapy with reversible electroporation, nanosecond pulsed electric fields and irreversible electroporation are valuable non-thermal electricity based tissue ablation technologies. This paper reports results from the first large animal study of a new non-thermal tissue ablation technology that employs "Synergistic electrolysis and electroporation" (SEE). The goal of this pre-clinical study is to expand on earlier studies with small animals and use the pig liver to establish SEE treatment parameters of clinical utility. We examined two SEE methods. One of the methods employs multiple electrochemotherapy-type reversible electroporation magnitude pulses, designed in such a way that the charge delivered during the electroporation pulses generates the electrolytic products. The second SEE method combines the delivery of a small number of electrochemotherapy magnitude electroporation pulses with a low voltage electrolysis generating DC current in three different ways. We show that both methods can produce lesion with dimensions of clinical utility, without the need to inject drugs as in electrochemotherapy, faster than with conventional electrolysis and with lower electric fields than irreversible electroporation and nanosecond pulsed ablation.

  11. Synergistic Combination of Electrolysis and Electroporation for Tissue Ablation

    PubMed Central

    Mikus, Paul; Klein, Nina; Rubinsky, Liel; Rubinsky, Boris

    2016-01-01

    Electrolysis, electrochemotherapy with reversible electroporation, nanosecond pulsed electric fields and irreversible electroporation are valuable non-thermal electricity based tissue ablation technologies. This paper reports results from the first large animal study of a new non-thermal tissue ablation technology that employs “Synergistic electrolysis and electroporation” (SEE). The goal of this pre-clinical study is to expand on earlier studies with small animals and use the pig liver to establish SEE treatment parameters of clinical utility. We examined two SEE methods. One of the methods employs multiple electrochemotherapy-type reversible electroporation magnitude pulses, designed in such a way that the charge delivered during the electroporation pulses generates the electrolytic products. The second SEE method combines the delivery of a small number of electrochemotherapy magnitude electroporation pulses with a low voltage electrolysis generating DC current in three different ways. We show that both methods can produce lesion with dimensions of clinical utility, without the need to inject drugs as in electrochemotherapy, faster than with conventional electrolysis and with lower electric fields than irreversible electroporation and nanosecond pulsed ablation. PMID:26866693

  12. Wind Electrolysis: Hydrogen Cost Optimization

    SciTech Connect

    Saur, G.; Ramsden, T.

    2011-05-01

    This report describes a hydrogen production cost analysis of a collection of optimized central wind based water electrolysis production facilities. The basic modeled wind electrolysis facility includes a number of low temperature electrolyzers and a co-located wind farm encompassing a number of 3MW wind turbines that provide electricity for the electrolyzer units.

  13. Hydrogen Generation From Electrolysis

    SciTech Connect

    Steven Cohen; Stephen Porter; Oscar Chow; David Henderson

    2009-03-06

    Small-scale (100-500 kg H2/day) electrolysis is an important step in increasing the use of hydrogen as fuel. Until there is a large population of hydrogen fueled vehicles, the smaller production systems will be the most cost-effective. Performing conceptual designs and analyses in this size range enables identification of issues and/or opportunities for improvement in approach on the path to 1500 kg H2/day and larger systems. The objectives of this program are to establish the possible pathways to cost effective larger Proton Exchange Membrane (PEM) water electrolysis systems and to identify areas where future research and development efforts have the opportunity for the greatest impact in terms of capital cost reduction and efficiency improvements. System design and analysis was conducted to determine the overall electrolysis system component architecture and develop a life cycle cost estimate. A design trade study identified subsystem components and configurations based on the trade-offs between system efficiency, cost and lifetime. Laboratory testing of components was conducted to optimize performance and decrease cost, and this data was used as input to modeling of system performance and cost. PEM electrolysis has historically been burdened by high capital costs and lower efficiency than required for large-scale hydrogen production. This was known going into the program and solutions to these issues were the focus of the work. The program provided insights to significant cost reduction and efficiency improvement opportunities for PEM electrolysis. The work performed revealed many improvement ideas that when utilized together can make significant progress towards the technical and cost targets of the DOE program. The cell stack capital cost requires reduction to approximately 25% of today’s technology. The pathway to achieve this is through part count reduction, use of thinner membranes, and catalyst loading reduction. Large-scale power supplies are available

  14. Membrane Cells for Brine Electrolysis.

    ERIC Educational Resources Information Center

    Tingle, M.

    1982-01-01

    Membrane cells were developed as alternatives to mercury and diaphragm cells for the electrolysis of brine. Compares the three types of cells, focusing on the advantages and disadvantages of membrane cells. (JN)

  15. Magnetic Resonance Imaging of Electrolysis.

    NASA Astrophysics Data System (ADS)

    Meir, Arie; Hjouj, Mohammad; Rubinsky, Liel; Rubinsky, Boris

    2015-02-01

    This study explores the hypothesis that Magnetic Resonance Imaging (MRI) can image the process of electrolysis by detecting pH fronts. The study has relevance to real time control of cell ablation with electrolysis. To investigate the hypothesis we compare the following MR imaging sequences: T1 weighted, T2 weighted and Proton Density (PD), with optical images acquired using pH-sensitive dyes embedded in a physiological saline agar solution phantom treated with electrolysis and discrete measurements with a pH microprobe. We further demonstrate the biological relevance of our work using a bacterial E. Coli model, grown on the phantom. The results demonstrate the ability of MRI to image electrolysis produced pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E. Coli model grown on the phantom. The results are promising and invite further experimental research.

  16. Electrolysis Propulsion for Spacecraft Applications

    NASA Technical Reports Server (NTRS)

    deGroot, Wim A.; Arrington, Lynn A.; McElroy, James F.; Mitlitsky, Fred; Weisberg, Andrew H.; Carter, Preston H., II; Myers, Blake; Reed, Brian D.

    1997-01-01

    Electrolysis propulsion has been recognized over the last several decades as a viable option to meet many satellite and spacecraft propulsion requirements. This technology, however, was never used for in-space missions. In the same time frame, water based fuel cells have flown in a number of missions. These systems have many components similar to electrolysis propulsion systems. Recent advances in component technology include: lightweight tankage, water vapor feed electrolysis, fuel cell technology, and thrust chamber materials for propulsion. Taken together, these developments make propulsion and/or power using electrolysis/fuel cell technology very attractive as separate or integrated systems. A water electrolysis propulsion testbed was constructed and tested in a joint NASA/Hamilton Standard/Lawrence Livermore National Laboratories program to demonstrate these technology developments for propulsion. The results from these testbed experiments using a I-N thruster are presented. A concept to integrate a propulsion system and a fuel cell system into a unitized spacecraft propulsion and power system is outlined.

  17. Electrolysis Performance Improvement and Validation Experiment

    NASA Technical Reports Server (NTRS)

    Schubert, Franz H.

    1992-01-01

    Viewgraphs on electrolysis performance improvement and validation experiment are presented. Topics covered include: water electrolysis: an ever increasing need/role for space missions; static feed electrolysis (SFE) technology: a concept developed for space applications; experiment objectives: why test in microgravity environment; and experiment description: approach, hardware description, test sequence and schedule.

  18. Vacuum electrolysis of quartz

    DOEpatents

    King, James Claude

    1976-01-13

    The disclosure is directed to a method for processing quartz used in fabricating crystal resonators such that transient frequency change of resonators exposed to pulse irradiation is virtually eliminated. The method involves heating the crystal quartz in a hydrogen-free atmosphere while simultaneously applying an electric field in the Z-axis direction of the crystal. The electric field is maintained during the cool-down phase of the process.

  19. Pulse

    MedlinePlus

    ... resting for at least 10 minutes. Take the exercise heart rate while you are exercising. ... pulse rate can help determine if the patient's heart is pumping. ... rate gives information about your fitness level and health.

  20. Nanotechnology makes biomass electrolysis more energy efficient than water electrolysis

    NASA Astrophysics Data System (ADS)

    Chen, Y. X.; Lavacchi, A.; Miller, H. A.; Bevilacqua, M.; Filippi, J.; Innocenti, M.; Marchionni, A.; Oberhauser, W.; Wang, L.; Vizza, F.

    2014-06-01

    The energetic convenience of electrolytic water splitting is limited by thermodynamics. Consequently, significant levels of hydrogen production can only be obtained with an electrical energy consumption exceeding 45 kWh kg-1H2. Electrochemical reforming allows the overcoming of such thermodynamic limitations by replacing oxygen evolution with the oxidation of biomass-derived alcohols. Here we show that the use of an original anode material consisting of palladium nanoparticles deposited on to a three-dimensional architecture of titania nanotubes allows electrical energy savings up to 26.5 kWh kg-1H2 as compared with proton electrolyte membrane water electrolysis. A net energy analysis shows that for bio-ethanol with energy return of the invested energy larger than 5.1 (for example, cellulose), the electrochemical reforming energy balance is advantageous over proton electrolyte membrane water electrolysis.

  1. Electrical Impedance Tomography of Electrolysis

    PubMed Central

    Meir, Arie; Rubinsky, Boris

    2015-01-01

    The primary goal of this study is to explore the hypothesis that changes in pH during electrolysis can be detected with Electrical Impedance Tomography (EIT). The study has relevance to real time control of minimally invasive surgery with electrolytic ablation. To investigate the hypothesis, we compare EIT reconstructed images to optical images acquired using pH-sensitive dyes embedded in a physiological saline agar gel phantom treated with electrolysis. We further demonstrate the biological relevance of our work using a bacterial E.Coli model, grown on the phantom. The results demonstrate the ability of EIT to image pH changes in a physiological saline phantom and show that these changes correlate with cell death in the E.coli model. The results are promising, and invite further experimental explorations. PMID:26039686

  2. Solid oxide electrolysis: Concluding remarks.

    PubMed

    Jun, Areum; Ju, Young-Wan; Kim, Guntae

    2015-01-01

    Renewable energy resources such as solar energy, wind energy, hydropower or geothermal energy have attracted significant attention in recent years. Renewable energy sources have to match supply with demand, therefore it is essential that energy storage devices (e.g., secondary batteries) are developed. However, secondary batteries are accompanied with critical problems such as high cost for the limited energy storage capacity and loss of charge over time. Energy storage in the form of chemical species, such as H2 or CO2, have no constraints on energy storage capacity and will also be essential. When plentiful renewable energy exists, for example, it could be used to convert H2O into hydrogen via water electrolysis. Also, renewable energy resources could be used to reduce CO2 into CO and recycle CO2 and H2O into sustainable hydrocarbon fuels in solid oxide electrolysis (SOE).

  3. Solid oxide electrolysis: Concluding remarks.

    PubMed

    Jun, Areum; Ju, Young-Wan; Kim, Guntae

    2015-01-01

    Renewable energy resources such as solar energy, wind energy, hydropower or geothermal energy have attracted significant attention in recent years. Renewable energy sources have to match supply with demand, therefore it is essential that energy storage devices (e.g., secondary batteries) are developed. However, secondary batteries are accompanied with critical problems such as high cost for the limited energy storage capacity and loss of charge over time. Energy storage in the form of chemical species, such as H2 or CO2, have no constraints on energy storage capacity and will also be essential. When plentiful renewable energy exists, for example, it could be used to convert H2O into hydrogen via water electrolysis. Also, renewable energy resources could be used to reduce CO2 into CO and recycle CO2 and H2O into sustainable hydrocarbon fuels in solid oxide electrolysis (SOE). PMID:26470860

  4. Electrolysis of a molten semiconductor.

    PubMed

    Yin, Huayi; Chung, Brice; Sadoway, Donald R

    2016-08-24

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

  5. Electrolysis of a molten semiconductor

    NASA Astrophysics Data System (ADS)

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-08-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides.

  6. Decoloration of aqueous Brilliant Green by using glow discharge electrolysis.

    PubMed

    Gao, Jinzhang; Yu, Jie; Li, Yan; He, Xiaoyan; Bo, Lili; Pu, Lumei; Yang, Wu; Lu, Quanfang; Yang, Zhiming

    2006-09-01

    This paper described a plasma degradation of Brilliant Green (BG) by glow discharge electrolysis. Various influencing factors such as the voltage, the distance between cathode and anode were examined. Ultraviolet (UV) absorption spectra, gas chromatogram-mass spectrum (GC-MS), and chemical oxygen demand (COD) were used to monitor the degradation process and to identify the major oxidation intermediates. It was confirmed that benzoic acid, 1,2,3,4,5,6-cyclohexanehexaol, and carboxylic acids (e.g., oxalic acid, succinic acid and hydroxyacetic acid) were produced in the degradation process. The results showed that BG rapidly underwent degradation and eventually mineralized into CO(2) and H(2)O. PMID:16603310

  7. The effect of the shape of single, sub-ms voltage pulses on the rates of surface immobilization and hybridization of DNA.

    PubMed

    Cabeça, R; Rodrigues, M; Prazeres, D M F; Chu, V; Conde, J P

    2009-01-01

    Electric fields generated by single square and sinusoidal voltage pulses with amplitudes below 2 V were used to assist the covalent immobilization of single-stranded, thiolated DNA probes, onto a chemically functionalized SiO2 surface and to assist the specific hybridization of single-stranded DNA targets with immobilized complementary probes. The single-stranded immobilized DNA probes were either covalently immobilized (chemisorption) or electrostatically adsorbed (physisorption) to a chemically functionalized surface. Comparing the speed of electric field assisted immobilization and hybridization with the corresponding control reactions (without electric field), an increase of several orders of magnitude is observed, with the reaction timescaled down from 1 to 2 h to a range between 100 ns and 1 ms. The influence of the shape of the voltage pulse (square versus sinusoidal) and its duration were studied for both immobilization and hybridization reactions. The results show that pulsed electric fields are a useful tool to achieve temporal and spatial control of surface immobilization and hybridization reactions of DNA. PMID:19417254

  8. Static feed water electrolysis module

    NASA Technical Reports Server (NTRS)

    Powell, J. D.; Schubert, F. H.; Jensen, F. C.

    1974-01-01

    An advanced static feed water electrolysis module (SFWEM) and associated instrumentation for generating breathable O2 was developed. The system also generates a H2 byproduct for use in an air revitalization system for O2 recovery from metabolic CO2. Special attention was given to: (1) eliminating water feed compartment degassing, (2) eliminating need for zero gravity condenser/separators, (3) increasing current density capability, and (4) providing a self contained module so that operation is independent of laboratory instrumentation and complicated startup/shutdown procedures.

  9. Electrolysis of a molten semiconductor.

    PubMed

    Yin, Huayi; Chung, Brice; Sadoway, Donald R

    2016-01-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides. PMID:27553525

  10. Electrolysis of a molten semiconductor

    PubMed Central

    Yin, Huayi; Chung, Brice; Sadoway, Donald R.

    2016-01-01

    Metals cannot be extracted by electrolysis of transition-metal sulfides because as liquids they are semiconductors, which exhibit high levels of electronic conduction and metal dissolution. Herein by introduction of a distinct secondary electrolyte, we reveal a high-throughput electro-desulfurization process that directly converts semiconducting molten stibnite (Sb2S3) into pure (99.9%) liquid antimony and sulfur vapour. At the bottom of the cell liquid antimony pools beneath cathodically polarized molten stibnite. At the top of the cell sulfur issues from a carbon anode immersed in an immiscible secondary molten salt electrolyte disposed above molten stibnite, thereby blocking electronic shorting across the cell. As opposed to conventional extraction practices, direct sulfide electrolysis completely avoids generation of problematic fugitive emissions (CO2, CO and SO2), significantly reduces energy consumption, increases productivity in a single-step process (lower capital and operating costs) and is broadly applicable to a host of electronically conductive transition-metal chalcogenides. PMID:27553525

  11. Studies in electron phenomena in MOS structures: The pulsed C-V method. M.S. Thesis. Abstract Only

    NASA Technical Reports Server (NTRS)

    Kaplan, G.

    1983-01-01

    The pulse hysteresis capacitance voltage (C-V) provides a straight forward technique for measuring the change of various charges in MOS structures and a tool for investigating the kinetics of various electron phenomena is developed and described. The method can be used for measuring the energy distribution and kinetics of surface states with the resolution of about 1/5 x 10 to the -9 power cm eV. Some transients in an MOS structure, particularly, the thermal generation of minority charge carriers via surface states and the relaxation of minority charge carriers supplied from the inversion layer outside the MOS structure are theoretically investigated. Analytical expressions which clearly present the physics of those electron phenomena are derived.

  12. ELECTROLYSIS OF THORIUM AND URANIUM

    DOEpatents

    Hansen, W.N.

    1960-09-01

    An electrolytic method is given for obtaining pure thorium, uranium, and thorium-uranium alloys. The electrolytic cell comprises a cathode composed of a metal selected from the class consisting of zinc, cadmium, tin, lead, antimony, and bismuth, an anode composed of at least one of the metals selected from the group consisting of thorium and uranium in an impure state, and an electrolyte composed of a fused salt containing at least one of the salts of the metals selected from the class consisting of thorium, uranium. zinc, cadmium, tin, lead, antimony, and bismuth. Electrolysis of the fused salt while the cathode is maintained in the molten condition deposits thorium, uranium, or thorium-uranium alloys in pure form in the molten cathode which thereafter may be separated from the molten cathode product by distillation.

  13. Water electrolysis system refurbishment and testing

    NASA Technical Reports Server (NTRS)

    Greenough, B. M.

    1972-01-01

    The electrolytic oxygen generator for the back-up water electrolysis system in a 90-day manned test was refurbished, improved and subjected to a 182-day bench test. The performance of the system during the test demonstrated the soundness of the basic electrolysis concept, the high development status of the automatic controls which allowed completely hands-off operation, and the capability for orbital operation. Some design improvements are indicated.

  14. Electrolysis of trichloromethylated organic compounds under aerobic conditions catalyzed by the B12 model complex for ester and amide formation.

    PubMed

    Shimakoshi, Hisashi; Luo, Zhongli; Inaba, Takuya; Hisaeda, Yoshio

    2016-06-21

    The electrolysis of benzotrichloride at -0.9 V vs. Ag/AgCl in the presence of the B12 model complex, heptamethyl cobyrinate perchlorate, in ethanol under aerobic conditions using an undivided cell equipped with a platinum mesh cathode and a zinc plate anode produced ethylbenzoate in 56% yield with 92% selectivity. The corresponding esters were obtained when the electrolysis was carried out in various alcohols such as methanol, n-propanol, and i-propanol. Benzoyl chloride was detected by GC-MS during the electrolysis as an intermediate for the ester formation. When the electrolysis was carried out under anaerobic conditions, partially dechlorinated products, 1,1,2,2-tetrachloro-1,2-diphenylethane and 1,2-dichlorostilibenes (E and Z forms), were obtained instead of an ester. ESR spin-trapping experiments using 5,5,-dimethylpyrroline N-oxide (DMPO) revealed that the corresponding oxygen-centered radical and carbon-centered radical were steadily generated during the electrolyses under aerobic and anaerobic conditions, respectively. Applications of the aerobic electrolysis to various organic halides, such as substituted benzotrichlorides, are described. Furthermore, the formation of amides with moderate yields by the aerobic electrolysis of benzotrichloride catalyzed by the B12 model complex in the presence of amines in acetonitrile is reported. PMID:27071703

  15. Degradation of 3,3'-iminobis-propanenitrile in aqueous solution by Fe(0)/GAC micro-electrolysis system.

    PubMed

    Lai, Bo; Zhou, Yuexi; Yang, Ping; Yang, Jinghui; Wang, Juling

    2013-01-01

    The degradation of 3,3'-iminobis-propanenitrile was investigated using the Fe(0)/GAC micro-electrolysis system. Effects of influent pH value, Fe(0)/GAC ratio and granular activated carbon (GAC) adsorption on the removal efficiency of the pollutant were studied in the Fe(0)/GAC micro-electrolysis system. The degradation of 3,3'-iminobis-propanenitrile was affected by influent pH, and a decrease of the influent pH values from 8.0 to 4.0 led to the increase of degradation efficiency. Granular activated carbon was added as cathode to form macroscopic galvanic cells between Fe(0) and GAC and enhance the current efficiency of the Fe(0)/GAC micro-electrolysis system. The GAC could only adsorb the pollutant and provide buffer capacity for the Fe(0)/GAC micro-electrolysis system, and the macroscopic galvanic cells of the Fe(0)/GAC micro-electrolysis system played a leading role in degradation of 3,3'-iminobis-propanenitrile. With the analysis of the degradation products with GC-MS, possible reaction pathway for the degradation of 3,3'-iminobis-propanenitrile by the Fe(0)/GAC micro-electrolysis system was suggested.

  16. Direct spectral analysis of tea samples using 266 nm UV pulsed laser-induced breakdown spectroscopy and cross validation of LIBS results with ICP-MS.

    PubMed

    Gondal, M A; Habibullah, Y B; Baig, Umair; Oloore, L E

    2016-05-15

    Tea is one of the most common and popular beverages spanning vast array of cultures all over the world. The main nutritional benefits of drinking tea are its anti-oxidant properties, presumed protection against certain cancers, inhibition of inflammation and possible protective effects against diabetes. Laser induced breakdown spectrometer (LIBS) was assembled as a powerful tool for qualitative and quantitative analysis of various brands of tea samples using 266 nm pulsed UV laser. LIBS spectra for six brands of tea samples in the wavelength range of 200-900 nm was recorded and all elements present in our tea samples were identified. The major toxic elements detected in several brands of tea samples were bromine, chromium and minerals like iron, calcium, potassium and silicon. The spectral assignment was conducted prior to the determination of concentration of each element. For quantitative analysis, calibration curves were drawn for each element using standard samples prepared in known concentration in the tea matrix. The plasma parameters (electron temperature and electron density) were also determined prior to the tea samples spectroscopic analysis. The concentration of iron, chromium, potassium, bromine, copper, silicon and calcium detected in all tea samples was between 378-656, 96-124, 1421-6785, 99-1476, 17-36, 2-11 and 92-130 mg L(-1) respectively. The limits of detection estimated for Fe, Cr, K, Br, Cu, Si, Ca in tea samples were 22, 12, 14, 11, 6, 1 and 12 mg L(-1) respectively. To further confirm the accuracy of our LIBS results, we determined the concentration of each element present in tea samples by using standard analytical technique like ICP-MS. The concentrations detected with our LIBS system are in excellent agreement with ICP-MS results. The system assembled for spectral analysis in this work could be highly applicable for testing the quality and purity of food and also pharmaceuticals products. PMID:26992530

  17. Production of Oxygen from Lunar Regolith using Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Sadoway, Donald R.; Sirk, Aislinn; Tripathy, Prabhat; Melendez, Orlando; Standish, Evan; Dominquez, Jesus A.; Stefanescu, Doru M.; Curreri, Peter A.; Poizeau, Sophie

    2009-01-01

    This slide presentation reviews the possible use of molten oxide electrolysis to extract oxygen from the Lunar Regolith. The presentation asserts that molten regolith electrolysis has advanced to be a useful method for production of oxygen and metals in situ on the Moon. The work has demonstrated an 8 hour batch of electrolysis at 5 amps using Iridium inert anodes.

  18. Contact glow discharge electrolysis: its origin, plasma diagnostics and non-faradaic chemical effects

    NASA Astrophysics Data System (ADS)

    Gupta, Susanta K. Sen

    2015-12-01

    Contact glow discharge electrolysis (CGDE) also termed plasma electrolysis is a novel electrolysis where a stable sheath of light emitting plasma develops around an electrode immersed well inside a relatively high-conductivity liquid electrolyte during normal electrolysis (NE) at several hundred volts. The phenomenon may develop in dc-, pulsed dc-, ac- as well as RF-driven electrolyses. The chemical effects of CGDE are remarkably non-faradaic in respect to the nature of the products as well as their yields. The article traces comprehensively the progress made in studies of CGDE in aqueous and non-aqueous solutions since 1844 and reviews the developments in the understanding of its origin, light emission, plasma state and non-faradaic effects leading to the elucidation of detailed mechanism of the origin of CGDE on the basis of the onset of hydrodynamic instabilities in local vaporization of the solvent near the working electrode during NE, and that of highly non-faradaic effects of CGDE based on a model of two reaction zones located within the electrode plasma and at the plasma-liquid interface producing solvent derived radicals at high local concentrations. Keeping in view the recent surge of interest in varied applications of CGDE, the article is appended with highlights of these applications across synthetic chemistry, waste water treatment, electrosurgical devices, nanoparticle fabrications, surface engineering and micro-machining.

  19. Lunar production of oxygen by electrolysis

    NASA Technical Reports Server (NTRS)

    Keller, Rudolf

    1991-01-01

    Two approaches to prepare oxygen from lunar resources by direct electrolysis are discussed. Silicates can be melted or dissolved in a fused salt and electrolyzed with oxygen evolved at the anode. Direct melting and electrolysis is potentially a very simple process, but high temperatures of 1400-1500 C are required, which aggravates materials problems. Operating temperatures can be lowered to about 1000 C by employing a molten salt flux. In this case, however, losses of electrolyte components must be avoided. Experimentation on both approaches is progressing.

  20. Pediatric MS

    MedlinePlus

    ... of the oral medications in the pediatric population. Network of Pediatric MS Centers The National MS Society ... MS Study Group (2004) and established a nationwide network of six Pediatric MS Centers of Excellence (2006) ...

  1. Base-acid hybrid water electrolysis.

    PubMed

    Chen, Long; Dong, Xiaoli; Wang, Fei; Wang, Yonggang; Xia, Yongyao

    2016-02-21

    A base-acid hybrid electrolytic system with a low onset voltage of 0.78 V for water electrolysis was developed by using a ceramic Li-ion exchange membrane to separate the oxygen-evolving reaction (OER) in a basic electrolyte solution containing the Li-ion and hydrogen-evolving reaction (HER) in an acidic electrolyte solution. PMID:26804323

  2. Evaluation of the alkaline electrolysis of zinc

    SciTech Connect

    Meisenhelder, J.H.; Brown, A.P.; Loutfy, R.O.; Yao, N.P.

    1981-05-01

    The alkaline leach and electrolysis process for zinc production is compared to the conventional acid-sulfate process in terms of both energy saving and technical merit. In addition, the potential for industrial application of the alkaline process is discussed on the basis of present market conditions, possible future zinc market scenarios, and the probability of increased secondary zinc recovery. In primary zinc production, the energy-saving potential for the alkaline process was estimated to be greater than 10%, even when significantly larger electrolysis current densities than those required for the sulfate process are used. The principal technical advantages of the alkaline process are that it can handle low-grade, high-iron-content or oxidized ores (like most of those found in the US) in a more cost- and energy-efficient manner than can the sulfate process. Additionally, in the electrowinning operation, the alkaline process should be technically superior because a dendritic or sponge deposit is formed that is amenable to automated collection without interruption of the electrolysis. Also, use of the higher current densities would result in significant capital cost reductions. Alkaline-based electrolytic recovery processes were considered for the recycling of zinc from smelter baghouse dusts and from the potential source of nickel/zinc electric-vehicle batteries. In all comparisons, an alkaline process was shown to be technically superior and, particularly for the baghouse dusts, energetically and economically superior to alternatively proposed recovery methods based on sulfate electrolysis. It is concluded that the alkaline zinc method is an important alternative technology to the conventional acid zinc process. (WHK)

  3. High temperature electrolysis for syngas production

    DOEpatents

    Stoots, Carl M.; O'Brien, James E.; Herring, James Stephen; Lessing, Paul A.; Hawkes, Grant L.; Hartvigsen, Joseph J.

    2011-05-31

    Syngas components hydrogen and carbon monoxide may be formed by the decomposition of carbon dioxide and water or steam by a solid-oxide electrolysis cell to form carbon monoxide and hydrogen, a portion of which may be reacted with carbon dioxide to form carbon monoxide. One or more of the components for the process, such as steam, energy, or electricity, may be provided using a nuclear power source.

  4. Economics of liquid hydrogen from water electrolysis

    NASA Technical Reports Server (NTRS)

    Lin, F. N.; Moore, W. I.; Walker, S. W.

    1985-01-01

    An economical model for preliminary analysis of LH2 cost from water electrolysis is presented. The model is based on data from vendors and open literature, and is suitable for computer analysis of different scenarios for 'directional' purposes. Cost data associated with a production rate of 10,886 kg/day are presented. With minimum modification, the model can also be used to predict LH2 cost from any electrolyzer once the electrolyzer's cost data are available.

  5. Electrolysis cell for the manufacture of persulfates

    NASA Technical Reports Server (NTRS)

    Cueto, J. M.

    1986-01-01

    A cell for the electrolytic generation of persulfates, characterized by the fact that a housing acts as cathode, is made of metal, and consists of a lower electrolytically active section and an upper electrolytically inactive section. It is designed so that there is produced the greatest possible current density suited to produce the desired electrolysis effect. This invention, compared to the devices used until now, exhibits considerable advantages whereby it is particularly suited for the production of potassium persulfate.

  6. A Study on the Preparation of Regular Multiple Micro-Electrolysis Filler and the Application in Pretreatment of Oil Refinery Wastewater

    PubMed Central

    Yang, Ruihong; ZHU, Jianzhong; Li, Yingliu; Zhang, Hui

    2016-01-01

    Through a variety of material screening experiments, Al was selected as the added metal and constituted a multiple micro-electrolysis system of Fe/C/Al. The metal proportion of alloy-structured filler was also analyzed with the best Fe/C/Al ratio of 3:1:1. The regular Fe/C/Al multiple micro-electrolysis fillers were prepared using a high-temperature anaerobic roasting method. The optimum conditions for oil refinery wastewater treated by Fe/C/Al multiple micro-electrolysis were determined to be an initial pH value of 3, reaction time of 80 min, and 0.05 mol/L Na2SO4 additive concentration. The reaction mechanism of the treatment of oil refinery wastewater by Fe/C/Al micro-electrolysis was investigated. The process of the treatment of oil refinery wastewater with multiple micro-electrolysis conforms to the third-order reaction kinetics. The gas chromatography–mass spectrometry (GC–MS) used to analyze the organic compounds of the oil refinery wastewater before and after treatment and the Ultraviolet–visible spectroscopy (UV–VIS) absorption spectrum analyzed the degradation process of organic compounds in oil refinery wastewater. The treatment effect of Fe/C/Al multiple micro-electrolysis was examined in the continuous experiment under the optimum conditions, which showed high organic compound removal and stable treatment efficiency. PMID:27136574

  7. Underwater microdischarge in arranged microbubbles produced by electrolysis in electrolyte solution using fabric-type electrode

    SciTech Connect

    Sakai, Osamu; Kimura, Masaru; Tachibana, Kunihide; Shirafuji, Tatsuru

    2008-12-08

    Pulsed microdischarge was generated in microbubbles produced by electrolysis in an electrolyte solution without external gas feed by using a fabric-type electrode. The electrode structure not only allowed low-voltage ignition of the atmospheric-pressure discharge in hydrogen or oxygen containing microbubbles but also worked effectively in producing and holding the bubbles on its surface. The generation of reactive species was verified by optical emissions from the produced microplasmas, and their transport into the solution was monitored by the change in hydrogen concentration.

  8. An electrospray ms-coupled microfluidic device for sub-second hydrogen/deuterium exchange pulse-labelling reveals allosteric effects in enzyme inhibition.

    PubMed

    Rob, Tamanna; Gill, Preet Kamal; Golemi-Kotra, Dasantila; Wilson, Derek J

    2013-07-01

    In this work, we introduce an integrated, electrospray mass spectrometry-coupled microfluidic chip that supports the complete workflow for 'bottom up' hydrogen/deuterium exchange (HDX) pulse labelling experiments. HDX pulse labelling is used to measure structural changes in proteins that occur after the initiation of a reaction, most commonly folding. In the present case, we demonstrate the device on the β-lactamase enzyme TEM-1, identifying active site changes that occur upon acylation by a covalent inhibitor and subtle changes in conformational dynamics that occur away from the active site over a period of several second after the inhibitor is bound. Our results demonstrate the power of microfluidics-enabled sub-second HDX pulse labelling as a tool for studying allostery and show some intriguing correlations with mutagenesis studies.

  9. Degradation in Solid Oxide Cells During High Temperature Electrolysis

    SciTech Connect

    Manohar Sohal

    2009-05-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells. One goal of that project is to address the technical and degradation issues associated with solid oxide electrolysis cells. This report covers a variety of these degradation issues, which were discussed during a workshop on “Degradation in Solid Oxide Electrolysis Cells and Strategies for its Mitigation,” held in Phoenix, AZ on October 27, 2008. Three major degradation issues related to solid oxide electrolysis cells discussed at the workshop are: • Delamination of O2-electrode and bond layer on steam/O2-electrode side • Contaminants (Ni, Cr, Si, etc.) on reaction sites (triple-phase boundary) • Loss of electrical/ionic conductivity of electrolyte. This list is not all inclusive, but the workshop summary can be useful in providing a direction for future research related to the degradation of solid oxide electrolysis cells.

  10. Liquid Fuel Production from Biomass via High Temperature Steam Electrolysis

    SciTech Connect

    Grant L. Hawkes; Michael G. McKellar

    2009-11-01

    A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-fed biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K. Parametric studies of system pressure, biomass moisture content and low temperature alkaline electrolysis are also presented.

  11. Solid-State Water Electrolysis with an Alkaline Membrane

    SciTech Connect

    Leng, YJ; Chen, G; Mendoza, AJ; Tighe, TB; Hickner, MA; Wang, CY

    2012-06-06

    We report high-performance, durable alkaline membrane water electrolysis in a solid-state cell. An anion exchange membrane (AEM) and catalyst layer ionomer for hydroxide ion conduction were used without the addition of liquid electrolyte. At 50 degrees C, an AEM electrolysis cell using iridium oxide as the anode catalyst and Pt black as the cathode catalyst exhibited a current density of 399 mA/cm(2) at 1.80 V. We found that the durability of the AEM-based electrolysis cell could be improved by incorporating a highly durable ionomer in the catalyst layer and optimizing the water feed configuration. We demonstrated an AEM-based electrolysis cell with a lifetime of > 535 h. These first-time results of water electrolysis in a solid-state membrane cell are promising for low-cost, scalable hydrogen production.

  12. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell.

    PubMed

    Huang, Xiao; Qu, Yan; Cid, Clément A; Finke, Cody; Hoffmann, Michael R; Lim, Keahying; Jiang, Sunny C

    2016-04-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source.

  13. Electrochemical disinfection of toilet wastewater using wastewater electrolysis cell

    PubMed Central

    Huang, Xiao; Qu, Yan; Cid, Clément A.; Finke, Cody; Hoffmann, Michael R.; Lim, Keahying; Jiang, Sunny C.

    2016-01-01

    The paucity of proper sanitation facilities has contributed to the spread of waterborne diseases in many developing countries. The primary goal of this study was to demonstrate the feasibility of using a wastewater electrolysis cell (WEC) for toilet wastewater disinfection. The treated wastewater was designed to reuse for toilet flushing and agricultural irrigation. Laboratory-scale electrochemical (EC) disinfection experiments were performed to investigate the disinfection efficiency of the WEC with four seeded microorganisms (Escherichia coli, Enterococcus, recombinant adenovirus serotype 5, and bacteriophage MS2). In addition, the formation of organic disinfection byproducts (DBPs) trihalomethanes (THMs) and haloacetic acids (HAA5) at the end of the EC treatment was also investigated. The results showed that at an applied cell voltage of +4 V, the WEC achieved 5-log10 reductions of all four seeded microorganisms in real toilet wastewater within 60 min. In contrast, chemical chlorination (CC) disinfection using hypochlorite [NaClO] was only effective for the inactivation of bacteria. Due to the rapid formation of chloramines, less than 0.5-log10 reduction of MS2 was observed in toilet wastewater even at the highest [NaClO] dosage (36 mg/L, as Cl2) over a 1 h reaction. Experiments using laboratory model waters showed that free reactive chlorine generated in situ during EC disinfection process was the main disinfectant responsible for the inactivation of microorganisms. However, the production of hydroxyl radicals [•OH], and other reactive oxygen species by the active bismuth-doped TiO2 anode were negligible under the same electrolytic conditions. The formation of THMs and HAA5 were found to increase with higher applied cell voltage. Based on the energy consumption estimates, the WEC system can be operated using solar energy stored in a DC battery as the sole power source. PMID:26854604

  14. Electrolysis-reducing electrodes for electrokinetic devices.

    PubMed

    Erlandsson, Per G; Robinson, Nathaniel D

    2011-03-01

    Direct current electrokinetic systems generally require Faradaic reactions to occur at a pair of electrodes to maintain an electric field in an electrolyte connecting them. The vast majority of such systems, e.g. electrophoretic separations (capillary electrophoresis) or electroosmotic pumps (EOPs), employ electrolysis of the solvent in these reactions. In many cases, the electrolytic products, such as H+ and OH⁻ in the case of water, can negatively influence the chemical or biological species being transported or separated, and gaseous products such as O₂ and H₂ can break the electrochemical circuit in microfluidic devices. This article presents an EOP that employs the oxidation/reduction of the conjugated polymer poly(3,4-ethylenedioxythiophene), rather than electrolysis of a solvent, to drive flow in a capillary. Devices made with poly(3,4-ethylenedioxythiophene) electrodes are compared with devices made with Pt electrodes in terms of flow and local pH change at the electrodes. Furthermore, we demonstrate that flow is driven for applied potentials under 2 V, and the electrodes are stable for potentials of at least 100 V. Electrochemically active electrodes like those presented here minimize the disadvantage of integrated EOP in, e.g. lab-on-a-chip applications, and may open new possibilities, especially for battery-powered disposable point-of-care devices. PMID:21425174

  15. Electrolysis-reducing electrodes for electrokinetic devices.

    PubMed

    Erlandsson, Per G; Robinson, Nathaniel D

    2011-03-01

    Direct current electrokinetic systems generally require Faradaic reactions to occur at a pair of electrodes to maintain an electric field in an electrolyte connecting them. The vast majority of such systems, e.g. electrophoretic separations (capillary electrophoresis) or electroosmotic pumps (EOPs), employ electrolysis of the solvent in these reactions. In many cases, the electrolytic products, such as H+ and OH⁻ in the case of water, can negatively influence the chemical or biological species being transported or separated, and gaseous products such as O₂ and H₂ can break the electrochemical circuit in microfluidic devices. This article presents an EOP that employs the oxidation/reduction of the conjugated polymer poly(3,4-ethylenedioxythiophene), rather than electrolysis of a solvent, to drive flow in a capillary. Devices made with poly(3,4-ethylenedioxythiophene) electrodes are compared with devices made with Pt electrodes in terms of flow and local pH change at the electrodes. Furthermore, we demonstrate that flow is driven for applied potentials under 2 V, and the electrodes are stable for potentials of at least 100 V. Electrochemically active electrodes like those presented here minimize the disadvantage of integrated EOP in, e.g. lab-on-a-chip applications, and may open new possibilities, especially for battery-powered disposable point-of-care devices.

  16. Design and Modelling of a Microfluidic Electro-Lysis Device with Controlling Plates

    NASA Technical Reports Server (NTRS)

    Jenkins, A.; Chen, C. P.; Spearing, S.; Monaco, L. A.; Steele, A.; Flores, G.

    2006-01-01

    Many Lab-on-Chip applications require sample pre-treatment systems. Using electric fields to perform cell-lysis in bio-MEMS systems has provided a powerful tool which can be integrated into Lab-on-a-Chip platforms. The major design considerations for electro-lysis devices include optimal geometry and placement of micro-electrodes, cell concentration, flow rates, optimal electric field (e.g. pulsed DC vs. AC), etc. To avoid electrolysis of the flowing solution at the exposed electrode surfaces, magnitudes and the applied voltages and duration of the DC pulse, or the AC frequency of the AC, have to be optimized for a given configuration. Using simulation tools for calculation of electric fields has proved very useful, for exploring alternative configurations and operating conditions for achieving electro cell-lysis. To alleviate the problem associated with low electric fields within the microfluidics channel and the high voltage demand on the contact electrode strips, two "control plates" are added to the microfluidics configuration. The principle of placing the two controlling plate-electrodes is based on the electric fields generated by a combined insulator/dielectric (gladwater) media. Surface charges are established at the insulator/dielectric interface. This paper discusses the effects of this interface charge on the modification of the electric field of the flowing liquid/cell solution.

  17. Static feed water electrolysis subsystem development

    NASA Technical Reports Server (NTRS)

    Schubert, Franz H. (Inventor); Grigger, David J. (Inventor)

    1991-01-01

    This disclosure is directed to an electrolysis cell forming hydrogen and oxygen at spaced terminals. The anode terminal is porous and able to form oxygen within the cell and permit escape of the gaseous oxygen through the anode and out through a flow line in the presence of backpressure. Hydrogen is liberated in the cell at the opposing solid metal cathode which is permeable to hydrogen but not oxygen so that the migratory hydrogen formed in the cell is able to escape from the cell. The cell is maintained at an elevated pressure so that oxygen liberated by the cell is delivered at elevated pressure without pumping to raise the pressure of the oxygen.

  18. Technology advancement of the static feed water electrolysis process

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Wynveen, R. A.

    1977-01-01

    A program to advance the technology of oxygen- and hydrogen-generating subsystems based on water electrolysis was studied. Major emphasis was placed on static feed water electrolysis, a concept characterized by low power consumption and high intrinsic reliability. The static feed based oxygen generation subsystem consists basically of three subassemblies: (1) a combined water electrolysis and product gas dehumidifier module; (2) a product gas pressure controller and; (3) a cyclically filled water feed tank. Development activities were completed at the subsystem as well as at the component level. An extensive test program including single cell, subsystem and integrated system testing was completed with the required test support accessories designed, fabricated, and assembled. Mini-product assurance activities were included throughout all phases of program activities. An extensive number of supporting technology studies were conducted to advance the technology base of the static feed water electrolysis process and to resolve problems.

  19. Electrolysis Production of Hydrogen from Wind and Hydropower Workshop Proceedings

    SciTech Connect

    2003-09-01

    This document summarizes the opportunities and challenges for low-cost renewable hydrogen production from wind and hydropower. The Workshop on Electrolysis Production of Hydrogen from Wind and Hydropower was held September 9-10, 2003.

  20. 21 CFR 886.4250 - Ophthalmic electrolysis unit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...) Identification. An ophthalmic electrolysis unit is an AC-powered or battery-powered device intended to destroy... battery-powered device. Class II for the AC-powered device. The battery-powered device is exempt from...

  1. Materials Degradation Studies for High Temperature Steam Electrolysis Systems

    SciTech Connect

    Paul Demkowicz; Pavel Medvedev; Kevin DeWall; Paul Lessing

    2007-06-01

    Experiments are currently in progress to assess the high temperature degradation behavior of materials in solid oxide electrolysis systems. This research includes the investigation of various electrolysis cell components and balance of plant materials under both anodic and cathodic gas atmospheres at temperatures up to 850°C. Current results include corrosion data for a high temperature nickel alloy used for the air-side flow field in electrolysis cells and a commercial ferritic stainless steel used as the metallic interconnect. Three different corrosion inhibiting coatings were also tested on the steel material. The samples were tested at 850ºC for 500 h in both air and H2O/H2 atmospheres. The results of this research will be used to identify degradation mechanisms and demonstrate the suitability of candidate materials for long-term operation in electrolysis cells.

  2. Hydrogen Production from Nuclear Energy via High Temperature Electrolysis

    SciTech Connect

    James E. O'Brien; Carl M. Stoots; J. Stephen Herring; Grant L. Hawkes

    2006-04-01

    This paper presents the technical case for high-temperature nuclear hydrogen production. A general thermodynamic analysis of hydrogen production based on high-temperature thermal water splitting processes is presented. Specific details of hydrogen production based on high-temperature electrolysis are also provided, including results of recent experiments performed at the Idaho National Laboratory. Based on these results, high-temperature electrolysis appears to be a promising technology for efficient large-scale hydrogen production.

  3. Evaluation of volatiles from Ampelopsis brevipedunculata var. heterophylla using GC-olfactometry, GC-MS and GC-pulsed flame photometric detector.

    PubMed

    Nakamura, Atsuhiko; Miyazawa, Mitsuo

    2013-01-01

    Ampelopsis brevipedunculata var. heterophylla is extensively cultivated in Asia, and the dried leaves and branches have a characteristic odor and have been used as a tea. To investigate the odorants contributing to the characteristic odor of A. brevipedunculata var. heterophylla, the aroma extraction dilution analysis method was performed through gas chromatography olfactometry. In addition, volatile sulfur compounds were evaluated using pulsed flame photometric detector. As a result, 86 compounds were identified in the oils of leaves and 78 in branches, accounting for 80.0% and 68.3%, respectively, of the compounds identified. The main compounds in the essential oil of leaves were palmitic acid (12.5%), phenylacetaldehyde (4.1%) and hexahydrofarnesyl acetone (3.9%). On the other hand, the essential oil of branches contained palmitic acid (12.7%), terpinen-4-ol (4.4%) and α-cadinol (3.7%). The total number of odor-active compounds identified in the leaf and branch oils was 39. The most odorous compounds of leaves and branches of A. brevipedunculata var. heterophylla were (E, Z)-2,6-nonadienal (melon, green odor), (E)-2-nonenal (grassy odor), phenylacetaldehyde (honey-like) and (E)-linalool oxide (woody odor). PMID:24005009

  4. Design of a water electrolysis flight experiment

    NASA Technical Reports Server (NTRS)

    Lee, M. Gene; Grigger, David J.; Thompson, C. Dean; Cusick, Robert J.

    1993-01-01

    Supply of oxygen (O2) and hydrogen (H2) by electolyzing water in space will play an important role in meeting the National Aeronautics and Space Administration's (NASA's) needs and goals for future space missios. Both O2 and H2 are envisioned to be used in a variety of processes including crew life support, spacecraft propulsion, extravehicular activity, electrical power generation/storage as well as in scientific experiment and manufacturing processes. The Electrolysis Performance Improvement Concept Study (EPICS) flight experiment described herein is sponsored by NASA Headquarters as a part of the In-Space Technology Experiment Program (IN-STEP). The objective of the EPICS is to further contribute to the improvement of the SEF technology, specifially by demonstrating and validating the SFE electromechanical process in microgravity as well as investigating perrformance improvements projected possible in a microgravity environment. This paper defines the experiment objective and presents the results of the preliminary design of the EPICS. The experiment will include testing three subscale self-contained SFE units: one containing baseline components, and two units having variations in key component materials. Tests will be conducted at varying current and thermal condition.

  5. Modeling Degradation in Solid Oxide Electrolysis Cells

    SciTech Connect

    Manohar S. Sohal; Anil V. Virkar; Sergey N. Rashkeev; Michael V. Glazoff

    2010-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic no equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential, , within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, no equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  6. Steam electrolysis by solid oxide electrolysis cells (SOECs) with proton-conducting oxides.

    PubMed

    Bi, Lei; Boulfrad, Samir; Traversa, Enrico

    2014-12-21

    Energy crisis and environmental problems caused by the conventional combustion of fossil fuels boost the development of renewable and sustainable energies. H2 is regarded as a clean fuel for many applications and it also serves as an energy carrier for many renewable energy sources, such as solar and wind power. Among all the technologies for H2 production, steam electrolysis by solid oxide electrolysis cells (SOECs) has attracted much attention due to its high efficiency and low environmental impact, provided that the needed electrical power is generated from renewable sources. However, the deployment of SOECs based on conventional oxygen-ion conductors is limited by several issues, such as high operating temperature, hydrogen purification from water, and electrode stability. To avoid these problems, proton-conducting oxides are proposed as electrolyte materials for SOECs. This review paper provides a broad overview of the research progresses made for proton-conducting SOECs, summarizing the past work and finding the problems for the development of proton-conducting SOECs, as well as pointing out potential development directions.

  7. Steam electrolysis by solid oxide electrolysis cells (SOECs) with proton-conducting oxides.

    PubMed

    Bi, Lei; Boulfrad, Samir; Traversa, Enrico

    2014-12-21

    Energy crisis and environmental problems caused by the conventional combustion of fossil fuels boost the development of renewable and sustainable energies. H2 is regarded as a clean fuel for many applications and it also serves as an energy carrier for many renewable energy sources, such as solar and wind power. Among all the technologies for H2 production, steam electrolysis by solid oxide electrolysis cells (SOECs) has attracted much attention due to its high efficiency and low environmental impact, provided that the needed electrical power is generated from renewable sources. However, the deployment of SOECs based on conventional oxygen-ion conductors is limited by several issues, such as high operating temperature, hydrogen purification from water, and electrode stability. To avoid these problems, proton-conducting oxides are proposed as electrolyte materials for SOECs. This review paper provides a broad overview of the research progresses made for proton-conducting SOECs, summarizing the past work and finding the problems for the development of proton-conducting SOECs, as well as pointing out potential development directions. PMID:25134016

  8. Gadolinia-Doped Ceria Cathodes for Electrolysis of CO2

    NASA Technical Reports Server (NTRS)

    Adler, Stuart B.

    2009-01-01

    Gadolinia-doped ceria, or GDC, (Gd(0.4)Ce(0.6)O(2-delta), where the value of delta in this material varies, depending on the temperature and oxygen concentration in the atmosphere in which it is being used) has shown promise as a cathode material for high-temperature electrolysis of carbon dioxide in solid oxide electrolysis cells. The polarization resistance of a GDC electrode is significantly less than that of an otherwise equivalent electrode made of any of several other materials that are now in use or under consideration for use as cathodes for reduction of carbon dioxide. In addition, GDC shows no sign of deterioration under typical temperature and gas-mixture operating conditions of a high-temperature electrolyzer. Electrolysis of CO2 is of interest to NASA as a way of generating O2 from the CO2 in the Martian atmosphere. On Earth, a combination of electrolysis of CO2 and electrolysis of H2O might prove useful as a means of generating synthesis gas (syngas) from the exhaust gas of a coal- or natural-gas-fired power plant, thereby reducing the emission of CO2 into the atmosphere. The syngas a mixture of CO and H2 could be used as a raw material in the manufacture, via the Fisher-Tropsch process, of synthetic fuels, lubrication oils, and other hydrocarbon prod

  9. A Small-Scale and Low-Cost Apparatus for the Electrolysis of Water

    ERIC Educational Resources Information Center

    Eggeen, Per-Odd; Kvittingen, Lise

    2004-01-01

    The construction of two simple, inexpensive apparatuses that clearly show the electrolysis of water are described. Traditionally the electrolysis of water is conducted in a Hofmann apparatus which is expensive and fragile.

  10. Process and apparatus for electrolysis of hydrochloric acid

    SciTech Connect

    Minz, F.; Wiechers, H.

    1980-12-02

    In the production of chlorine and hydrogen from hydrochloric acid by electrolysis in an electrolysis cell comprising a plurality of vertically arranged bipolar electrodes, a diaphragm arranged between each two electrodes to divide the electrolysis chambers formed between them into an anolyte chamber and a catholyte chamber, and outlet and inlet devices for the electrolyte, the improvement which comprises electrolyzing the hydrochloric acid in at least two successive stages, and degassing the hydrochloric acid. Advantageously the hydrochloric acid moves from bottom to top, first through an upper stage and then through a lower stage. As a result less electrode surface is needed, a higher current density and/or voltage is possible so existing apparatus can be modified to connect more bipolar electrodes in series.

  11. Development status of a preprototype water electrolysis subsystem

    NASA Technical Reports Server (NTRS)

    Martin, R. B.; Erickson, A. C.

    1981-01-01

    A preprototype water electrolysis subsystem was designed and fabricated for NASA's advanced regenerative life support program. A solid polymer is used for the cell electrolyte. The electrolysis module has 12 cells that can generate 5.5 kg/day of oxygen for the metabolic requirements of three crewmembers, for cabin leakage, and for the oxygen and hydrogen required for carbon dioxide collection and reduction processes. The subsystem can be operated at a pressure between 276 and 2760 kN/sq m and in a continuous constant-current, cyclic, or standby mode. A microprocessor is used to aid in operating the subsystem. Sensors and controls provide fault detection and automatic shutdown. The results of development, demonstration, and parametric testing are presented. Modifications to enhance operation in an integrated and manned test are described. Prospective improvements for the electrolysis subsystem are discussed.

  12. Water Electrolysis for In-Situ Resource Utilization (ISRU)

    NASA Technical Reports Server (NTRS)

    Lee, Kristopher A.

    2016-01-01

    Sending humans to Mars for any significant amount of time will require capabilities and technologies that enable Earth independence. To move towards this independence, the resources found on Mars must be utilized to produce the items needed to sustain humans away from Earth. To accomplish this task, NASA is studying In Situ Resource Utilization (ISRU) systems and techniques to make use of the atmospheric carbon dioxide and the water found on Mars. Among other things, these substances can be harvested and processed to make oxygen and methane. Oxygen is essential, not only for sustaining the lives of the crew on Mars, but also as the oxidizer for an oxygen-methane propulsion system that could be utilized on a Mars ascent vehicle. Given the presence of water on Mars, the electrolysis of water is a common technique to produce the desired oxygen. Towards this goal, NASA designed and developed a Proton Exchange Membrane (PEM) water electrolysis system, which was originally slated to produce oxygen for propulsion and fuel cell use in the Mars Atmosphere and Regolith COllector/PrOcessor for Lander Operations (MARCO POLO) project. As part of the Human Exploration Spacecraft Testbed for Integration and Advancement (HESTIA) project, this same electrolysis system, originally targeted at enabling in situ propulsion and power, operated in a life-support scenario. During HESTIA testing at Johnson Space Center, the electrolysis system supplied oxygen to a chamber simulating a habitat housing four crewmembers. Inside the chamber, oxygen was removed from the atmosphere to simulate consumption by the crew, and the electrolysis system's oxygen was added to replenish it. The electrolysis system operated nominally throughout the duration of the HESTIA test campaign, and the oxygen levels in the life support chamber were maintained at the desired levels.

  13. Installation of Ohio's First Electrolysis-Based Hydrogen Fueling Station

    NASA Technical Reports Server (NTRS)

    Scheidegger, Brianne T.; Lively, Michael L.

    2012-01-01

    This paper describes progress made towards the installation of a hydrogen fueling station in Northeast Ohio. In collaboration with several entities in the Northeast Ohio area, the NASA Glenn Research Center is installing a hydrogen fueling station that uses electrolysis to generate hydrogen on-site. The installation of this station is scheduled for the spring of 2012 at the Greater Cleveland Regional Transit Authority s Hayden bus garage in East Cleveland. This will be the first electrolysis-based hydrogen fueling station in Ohio.

  14. MS Detectors

    SciTech Connect

    Koppenaal, David W.; Barinaga, Charles J.; Denton, M Bonner B.; Sperline, Roger P.; Hieftje, Gary M.; Schilling, G. D.; Andrade, Francisco J.; Barnes IV., James H.

    2005-11-01

    Good eyesight is often taken for granted, a situation that everyone appreciates once vision begins to fade with age. New eyeglasses or contact lenses are traditional ways to improve vision, but recent new technology, i.e. LASIK laser eye surgery, provides a new and exciting means for marked vision restoration and improvement. In mass spectrometry, detectors are the 'eyes' of the MS instrument. These 'eyes' have also been taken for granted. New detectors and new technologies are likewise needed to correct, improve, and extend ion detection and hence, our 'chemical vision'. The purpose of this report is to review and assess current MS detector technology and to provide a glimpse towards future detector technologies. It is hoped that the report will also serve to motivate interest, prompt ideas, and inspire new visions for ion detection research.

  15. Hydrogen generation by electrolysis of aqueous organic solutions

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Valdez, Thomas I. (Inventor)

    2006-01-01

    A device for electrolysis of an aqueous solution of an organic fuel. The electrolyte is a solid-state polymer membrane with anode and cathode catalysts on both surfaces for electro-oxidization and electro-reduction. A low-cost and portable hydrogen generator can be made based on the device with organic fuels such as methanol.

  16. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    Minh, Nguyen Q.; Loutfy, Raouf O.; Yao, Neng-Ping

    1984-01-01

    Production of metallic aluminum by the electrolysis of Al.sub.2 S.sub.3 at 700.degree.-800.degree. C. in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  17. Production of aluminum metal by electrolysis of aluminum sulfide

    DOEpatents

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1982-04-01

    Metallic aluminum may be produced by the electrolysis of Al/sub 2/S/sub 3/ at 700 to 800/sup 0/C in a chloride melt composed of one or more alkali metal chlorides, and one or more alkaline earth metal chlorides and/or aluminum chloride to provide improved operating characteristics of the process.

  18. Electrolysis cell functions as water vapor dehumidifier and oxygen generator

    NASA Technical Reports Server (NTRS)

    Clifford, J. E.

    1971-01-01

    Water vapor is absorbed in hygroscopic electrolyte, and oxygen generated by absorbed water electrolysis at anode is added simultaneously to air stream. Cell applications include on-board aircraft oxygen systems, portable oxygen generators, oxygen concentration requirements, and commercial air conditioning and dehumidifying systems.

  19. PEM Electrolysis H2A Production Case Study Documentation

    SciTech Connect

    James, Brian; Colella, Whitney; Moton, Jennie; Saur, G.; Ramsden, T.

    2013-12-31

    This report documents the development of four DOE Hydrogen Analysis (H2A) case studies for polymer electrolyte membrane (PEM) electrolysis. The four cases characterize PEM electrolyzer technology for two hydrogen production plant sizes (Forecourt and Central) and for two technology development time horizons (Current and Future).

  20. Analysis of cavitation effect for water purifier using electrolysis

    NASA Astrophysics Data System (ADS)

    Shin, Dong Ho; Ko, Han Seo; Lee, Seung Ho

    2015-11-01

    Water is a limited and vital resource, so it should not be wasted by pollution. A development of new water purification technology is urgent nowadays since the original and biological treatments are not sufficient. The microbubble-aided method was investigated for removal of algal in this study since it overcomes demerits of the existing purification technologies. Thus, the cavitation effect in a venturi-type tube using the electrolysis was analyzed. Ruthenium-coated titanium plates were used as electrodes. Optimum electrode interval and applied power were determined for the electrolysis. Then, the optimized electrodes were installed in the venturi-type tube for generating cavitation. The cavitation effect could be enhanced without any byproduct by the bubbly flow induced by the electrolysis. The optimum mass flow rate and current were determined for the cavitation with the electrolysis. Finally, the visualization techniques were used to count the cell number of algal and microbubbles for the confirmation of the performance. As a result, the energy saving and high efficient water purifier was fabricated in this study. This work was supported by the Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Korean government (MEST) (No. 2013R1A2A2A01068653).

  1. Hydrogen generation by electrolysis of aqueous organic solutions

    NASA Technical Reports Server (NTRS)

    Narayanan, Sekharipuram R. (Inventor); Chun, William (Inventor); Jeffries-Nakamura, Barbara (Inventor); Valdez, Thomas I. (Inventor)

    2002-01-01

    A device for electrolysis of an aqueous solution of an organic fuel. The electrolyte is a solid-state polymer membrane with anode and cathode catalysts on both surfaces for electro-oxidization and electro-reduction. A low-cost and portable hydrogen generator can be made based on the device with organic fuels such as methanol.

  2. Endurance Test and Evaluation of Alkaline Water Electrolysis Cells

    NASA Technical Reports Server (NTRS)

    Kovach, Andrew J.; Schubert, Franz H.; Chang, B. J.; Larkins, Jim T.

    1985-01-01

    The overall objective of this program is to assess the state of alkaline water electrolysis cell technology and its potential as part of a Regenerative Fuel Cell System (RFCS) of a multikilowatt orbiting powerplant. The program evaluates the endurance capabilities of alkaline electrolyte water electrolysis cells under various operating conditions, including constant condition testing, cyclic testing and high pressure testing. The RFCS demanded the scale-up of existing cell hardware from 0.1 sq ft active electrode area to 1.0 sq ft active electrode area. A single water electrolysis cell and two six-cell modules of 1.0 sq ft active electrode area were designed and fabricated. The two six-cell 1.0 sq ft modules incorporate 1.0 sq ft utilized cores, which allow for minimization of module assembly complexity and increased tolerance to pressure differential. A water electrolysis subsystem was designed and fabricated to allow testing of the six-cell modules. After completing checkout, shakedown, design verification and parametric testing, a module was incorporated into the Regenerative Fuel Cell System Breadboard (RFCSB) for testing at Life Systems, Inc., and at NASA JSC.

  3. Production of oxygen from lunar soil by molten salt electrolysis

    NASA Technical Reports Server (NTRS)

    Keller, Rudolf

    1989-01-01

    A simple approach to utilizing lunar resources proposes to dissolve lunar soil, without or with little beneficiation, in a suitable molten salt and to electrolyze the oxides to oxygen and a metal byproduct. The envisioned process and the required technological advances are discussed. Promising electrolysis conditions have been identified in a recent experimental program to manufacture silicon and aluminum from anorthite.

  4. Oxygen from the lunar soil by molten silicate electrolysis

    NASA Technical Reports Server (NTRS)

    Colson, Russell O.; Haskin, Larry A.

    1992-01-01

    Accepting that oxygen, rather than gigantic gems or gold, is likely to make the Moon's Klondike, the extraction of oxygen from the lunar soil by molten silicate electrolysis has chosen to be investigated. Process theory and proposed lunar factory are addressed.

  5. HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION FROM NUCLEAR ENERGY

    SciTech Connect

    James E. O'Brien; Carl M. Stoots; J. Stephen Herring; Joseph J. Hartvigsen

    2005-10-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 90 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  6. Three-Man Solid Electrolyte Carbon Dioxide Electrolysis Breadboard

    NASA Technical Reports Server (NTRS)

    Isenberg, Arnold O.

    1989-01-01

    The development of the Three-Man (2.2 lb CO2/man-day) Solid Electrolyte CO2 Electrolysis Breadboard consisted of a Phase 1 and 2 effort. The Phase 1 effort constituted fabrication of three electrolysis cell types and performing parametric testing, off-design testing, and cell life testing. The Phase 2 consisted of the preliminary design, incorporation of palladium (Pd) tubes for hydrogen separation from the electrolyzer cathode feed gases, design support testing, final design, fabrication, and performance testing of the breadboard system. The results of performance tests demonstrated that CO2 electrolysis in an oxygen reclamation system for long duration space-based habitats is feasible. Closure of the oxygen system loop, therefore, can be achieved by CO2 electrolysis. In a two step process the metabolic CO2 and H2O vapor are electrolyzed into O2, H2, and CO. The CO can subsequently be disproportionated into carbon and CO2 in a carbon deposition reactor and the CO2 in turn be recycled and electrolyzed for total O2 recovery. The development effort demonstrated electrolyzer system can be designed and built to operate safely and reliably and the incorporation of Pd tubes for hydrogen diffusion can be integrated safely with predictable performance.

  7. Determination of the Electronics Charge--Electrolysis of Water Method.

    ERIC Educational Resources Information Center

    Venkatachar, Arun C.

    1985-01-01

    Presents an alternative method for measuring the electronic charge using data from the electrolysis of acidified distilled water. The process (carried out in a commercially available electrolytic cell) has the advantage of short completion time so that students can determine electron charge and mass in one laboratory period. (DH)

  8. HYDROGEN GENERATION FROM ELECTROLYSIS - REVISED FINAL TECHNICAL REPORT

    SciTech Connect

    IBRAHIM, SAMIR; STICHTER, MICHAEL

    2008-07-31

    DOE GO13028-0001 DESCRIPTION/ABSTRACT This report is a summary of the work performed by Teledyne Energy Systems to understand high pressure electrolysis mechanisms, investigate and address safety concerns related to high pressure electrolysis, develop methods to test components and systems of a high pressure electrolyzer, and produce design specifications for a low cost high pressure electrolysis system using lessons learned throughout the project. Included in this report are data on separator materials, electrode materials, structural cell design, and dissolved gas tests. Also included are the results of trade studies for active area, component design analysis, high pressure hydrogen/oxygen reactions, and control systems design. Several key pieces of a high pressure electrolysis system were investigated in this project and the results will be useful in further attempts at high pressure and/or low cost hydrogen generator projects. An important portion of the testing and research performed in this study are the safety issues that are present in a high pressure electrolyzer system and that they can not easily be simplified to a level where units can be manufactured at the cost goals specified, or operated by other than trained personnel in a well safeguarded environment. The two key objectives of the program were to develop a system to supply hydrogen at a rate of at least 10,000 scf/day at a pressure of 5000psi, and to meet cost goals of $600/ kW in production quantities of 10,000/year. On these two points TESI was not successful. The project was halted due to concerns over safety of high pressure gas electrolysis and the associated costs of a system which reduced the safety concerns.

  9. Development of a solid polymer electrolyte electrolysis cell module and ancillary components for a breadboard water electrolysis system

    NASA Technical Reports Server (NTRS)

    Porter, F. J., Jr.

    1972-01-01

    Solid polymer electrolyte technology in a water electrolysis system along with ancillary components to generate oxygen and hydrogen for a manned space station application are considered. Standard commercial components are utilized wherever possible. Presented are the results of investigations, surveys, tests, conclusions and recommendations for future development efforts.

  10. Removal of volatile fatty acids and ammonia recovery from unstable anaerobic digesters with a microbial electrolysis cell.

    PubMed

    Cerrillo, Míriam; Viñas, Marc; Bonmatí, August

    2016-11-01

    Continuous assays with a microbial electrolysis cell (MEC) fed with digested pig slurry were performed to evaluate its stability and robustness to malfunction periods of an anaerobic digestion (AD) reactor and its feasibility as a strategy to recover ammonia. When performing punctual pulses of volatile fatty acids (VFA) in the anode compartment of the MEC, simulating a malfunction of the AD process, an increase in the current density was produced (up to 14 times, reaching values of 3500mAm(-2)) as a result of the added chemical oxygen demand (COD), especially when acetate was used. Furthermore, ammonium diffusion from the anode to the cathode compartment was enhanced and the removal efficiency achieved up to 60% during daily basis VFA pulses. An AD-MEC combined system has proven to be a robust and stable configuration to obtain a high quality effluent, with a lower organic and ammonium content. PMID:27501031

  11. High Temperature Steam Electrolysis Materials Degradation: Preliminary Results of Corrosion Tests on Ceramatec Electrolysis Cell Components

    SciTech Connect

    Paul Demkowicz; Prateek Sachdev; Kevin DeWall; Pavel Medvedev

    2007-06-01

    Corrosion tests were performed on stainless steel and nickel alloy coupons in H2O/H2 mixtures and dry air to simulate conditions experienced in high temperature steam electrolysis systems. The stainless steel coupons were tested bare and with one of three different proprietary coatings applied. Specimens were corroded at 850°C for 500 h with weight gain data recorded at periodic intervals. Post-test characterization of the samples included surface and cross-section scanning electron microscopy, grazing incidence x-ray diffraction, and area-specific resistance measurements. The uncoated nickel alloy outperformed the ferritic stainless steel under all test conditions based on weight gain data. Parabolic rate constants for corrosion of these two uncoated alloys were consistent with values presented in the literature under similar conditions. The steel coatings reduced corrosion rates in H2O/H2 mixtures by as much as 50% compared to the untreated steel, but in most cases showed negligible corrosion improvement in air. The use of a rare-earth-based coating on stainless steel did not result in a significantly different area specific resistance values after corrosion compared to the untreated alloy. Characterization of the samples is still in progress and the findings will be revised when the complete data set is available.

  12. Pulsed Laser Tissue Interaction

    NASA Astrophysics Data System (ADS)

    Walsh, Joseph T.; van Leeuwen, Ton G.; Jansen, E. Duco; Motamedi, Massoud; Welch, Ashley J.

    Pulsed lasers, by virtue of their ability to deliver energy in a spatially and temporally confined fashion, are able to micromachine biological tissues. The clinical success of pulsed laser treatment, however, is often limited by the extent of damage that is caused to the tissue in the vicinity of the ablation crater. In general, pulsed ablation is a trade off between thermal damage to surrounding tissue, caused by relatively long pulses (>100 ms), and mechanical damage to surrounding tissue, caused by relatively short pulses (<1 ms). To identify the origin of pulsed laser induced damage, the possible laser tissue interactions and ablation are discussed here and in Chapter 14. The purpose of this chapter is to provide the reader with a condensed overview of the parameters that must be considered in the process of pulsed laser ablation of soft tissue. In this chapter, pulsed infrared ablation of biological soft tissue is used as a paradigm to illustrate the concepts and design considerations. Generally speaking, the absorption of laser light may lead to photothermal, photomechanical or photochemical interaction with the irradiated tissue [1-5]. The vast majority of therapeutic laser-tissue interactions is based on photothermal interactions where laser energy is converted into heat. Subsequent to thermalization of the absorbed optical energy, heat transfer mechanisms, in particular conduction allow thermal diffusion from high temperature areas to surrounding regions. When laser penetration depth is less than the laser spot radius, the thermal diffusion time, τ th, can be defined as:

  13. Composition Pulse Time-Of-Flight Mass Flow Sensor

    DOEpatents

    Mosier, Bruce P.; Crocker, Robert W.; Harnett, Cindy K. l

    2004-01-13

    A device for measuring fluid flow rates over a wide range of flow rates (<1 nL/min to >10 .mu.L/min) and at pressures at least as great as 10,000 psi. The invention is particularly adapted for use in microfluidic systems. The device operates by producing compositional variations in the fluid, or pulses, that are subsequently detected downstream from the point of creation to derive a flow rate. Each pulse, comprising a small fluid volume, whose composition is different from the mean composition of the fluid, can be created by electrochemical means, such as by electrolysis of a solvent, electrolysis of a dissolved species, or electrodialysis of a dissolved ionic species. Measurements of the conductivity of the fluid can be used to detect the arrival time of the pulses, from which the fluid flow rate can be determined

  14. On the generation of mini-clusters of microbubbles using water electrolysis

    NASA Astrophysics Data System (ADS)

    Medina-Palomo, Ana; Igualada-Villodre, Elena; Rodriguez-Rodriguez, Javier

    2014-11-01

    The interest on microbubbles and their behavior under ultrasound excitation has increased over the last years. Several phenomena can be observed when microbubbles interact with an ultrasound field. For instance, they can oscillate at their natural frequency, translate in the direction of the acoustic pulse (due to the well-known Bjerknes force) or coalesce (due to the secondary Bjerknes force). To study these effects, it is convenient to have an isolated bubble or a cloud consisting of a few bubbles. Using electrolysis we are able to produce mini-clusters of bubbles with controlled parameters, namely, bubble number and size distribution. We achieve this control using voltage pulses of well-defined properties. The most remarkable characteristics of this technique are its low cost and ease of implementation. We illustrate the applications of the technique with some academic examples, like the validation of the expressions for the primary and secondary Bjerknes forces. Funded by the Spanish Ministry of Economy and Competitiveness through grant DPI2011-28356-C03-02.

  15. Development of a static feed water electrolysis system

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Lantz, J. B.; Hallick, T. M.

    1982-01-01

    A one person level oxygen generation subsystem was developed and production of the one person oxygen metabolic requirements, 0.82 kg, per day was demonstrated without the need for condenser/separators or electrolyte pumps. During 650 hours of shakedown, design verification, and endurance testing, cell voltages averaged 1.62 V at 206 mA/sq cm and at average operating temperature as low as 326 K, virtually corresponding to the state of the art performance previously established for single cells. This high efficiency and low waste heat generation prevented maintenance of the 339 K design temperature without supplemental heating. Improved water electrolysis cell frames were designed, new injection molds were fabricated, and a series of frames was molded. A modified three fluid pressure controller was developed and a static feed water electrolysis that requires no electrolyte in the static feed compartment was developed and successfully evaluated.

  16. Natural gas anodes for aluminium electrolysis in molten fluorides.

    PubMed

    Haarberg, Geir Martin; Khalaghi, Babak; Mokkelbost, Tommy

    2016-08-15

    Industrial primary production of aluminium has been developed and improved over more than 100 years. The molten salt electrolysis process is still suffering from low energy efficiency and considerable emissions of greenhouse gases (CO2 and PFC). A new concept has been suggested where methane is supplied through the anode so that the CO2 emissions may be reduced significantly, the PFC emissions may be eliminated and the energy consumption may decrease significantly. Porous carbon anodes made from different graphite grades were studied in controlled laboratory experiments. The anode potential, the anode carbon consumption and the level of HF gas above the electrolyte were measured during electrolysis. In some cases it was found that the methane oxidation was effectively participating in the anode process. PMID:27210046

  17. Comparison of waste combustion and waste electrolysis - A systems analysis

    NASA Technical Reports Server (NTRS)

    Holtzapple, Mark T.; Little, Frank E.

    1989-01-01

    A steady state model of a closed environmental system has been developed which includes higher plant growth for food production, and is designed to allow wastes to be combusted or electrolyzed. The stoichiometric equations have been developed to evaluate various trash compositions, food items (both stored and produced), metabolic rates, and crew sizes. The advantages of waste electrolysis versus combustion are: (1) oxygen is not required (which reduces the load on the oxygen producing system); (2) the CO2 and H2 products are produced in pure form (reducing the load on the separators); and (3) nitrogen is converted to nitrate (which is directly usable by plants). Weight tradeoff studies performed using this model have shown that waste electrolysis reduces the life support weight of a 4-person crew by 1000 to 2000 kg.

  18. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    NASA Astrophysics Data System (ADS)

    Saksono, Nelson; Febiyanti, Irine Ayu; Utami, Nissa; Ibrahim

    2015-12-01

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H2O2 amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.

  19. Hydroxyl radical production in plasma electrolysis with KOH electrolyte solution

    SciTech Connect

    Saksono, Nelson; Febiyanti, Irine Ayu Utami, Nissa; Ibrahim

    2015-12-29

    Plasma electrolysis is an effective technology for producing hydroxyl radical (•OH). This method can be used for waste degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the plasma electrolysis system for producing hydroxyl radical. The materials of anode and cathode, respectively, were made from tungsten and stainless steel. KOH solution was used as the solution. Determination of hydroxyl radical production was done by measuring H{sub 2}O{sub 2} amount formed in plasma system using an iodometric titration method, while the electrical energy consumed was obtained by measuring the electrical current throughout the process. The highest hydroxyl radical production was 3.51 mmol reached with 237 kJ energy consumption in the power supply voltage 600 V, 0.02 M KOH, and 0.5 cm depth of anode.

  20. Direct Lit Electrolysis In A Metallic Lithium Fusion Blanket

    SciTech Connect

    Colon-Mercado, H.; Babineau, D.; Elvington, M.; Garcia-Diaz, B.; Teprovich, J.; Vaquer, A.

    2015-10-13

    A process that simplifies the extraction of tritium from molten lithium based breeding blankets was developed.  The process is based on the direct electrolysis of lithium tritide using a ceramic Li ion conductor that replaces the molten salt extraction step. Extraction of tritium in the form of lithium tritide in the blankets/targets of fission/fusion reactors is critical in order to maintained low concentrations.  This is needed to decrease the potential tritium permeation to the surroundings and large releases from unforeseen accident scenarios. Because of the high affinity of tritium for the blanket, extraction is complicated at the required low levels. This work identified, developed and tested the use of ceramic lithium ion conductors capable of recovering the hydrogen and deuterium thru an electrolysis step at high temperatures. 

  1. Degradation of linear alkylbenzene sulfonate with contact glow discharge electrolysis

    NASA Astrophysics Data System (ADS)

    Budikania, Trisutanti; Ibrahim, Febiyanti, Irine Ayu; Utami, Nissa; Saksono, Nelson

    2015-12-01

    Contact Glow Discharge Electrolysis (CGDE) is one of electrolysis plasma technologies. CGDE can produce the hydroxyl radical in a large amount that can be used for wastewater degradation process. This study was conducted to obtain the influence of applied voltage, electrolyte concentration, and anode depth in the LAS degradation using CGDE and review its energy consumption. The greatest LAS degradation is achieved up to 99.14% with low energy consumption of 1149.88 kJ/mmol of the energy consumption that is obtained during 120 minutes by using 600 Volt, 0.02 M of KOH, and 0.5 cm of the anode depth and initial concentration of LAS is 100 ppm.

  2. Hydrogen generation through static-feed water electrolysis

    NASA Technical Reports Server (NTRS)

    Jensen, F. C.; Schubert, F. H.

    1975-01-01

    A static-feed water electrolysis system (SFWES), developed under NASA sponsorship, is presented for potential applicability to terrestrial hydrogen production. The SFWES concept uses (1) an alkaline electrolyte to minimize power requirements and materials-compatibility problems, (2) a method where the electrolyte is retained in a thin porous matrix eliminating bulk electrolyte, and (3) a static water-feed mechanism to prevent electrode and electrolyte contamination and to promote system simplicity.

  3. Improving electrokinetic microdevice stability by controlling electrolysis bubbles.

    PubMed

    Lee, Hwi Yong; Barber, Cedrick; Minerick, Adrienne R

    2014-07-01

    The voltage-operating window for many electrokinetic microdevices is limited by electrolysis gas bubbles that destabilize microfluidic system causing noise and irreproducible responses above ∼3 V DC and less than ∼1 kHz AC at 3 Vpp. Surfactant additives, SDS and Triton X-100, and an integrated semipermeable SnakeSkin® membrane were employed to control and assess electrolysis bubbles from platinum electrodes in a 180 by 70 μm, 10 mm long microchannel. Stabilized current responses at 100 V DC were observed with surfactant additives or SnakeSkin® barriers. Electrolysis bubble behaviors, visualized via video microscopy at the electrode surface and in the microchannels, were found to be influenced by surfactant function and SnakeSkin® barriers. Both SDS and Triton X-100 surfactants promoted smaller bubble diameters and faster bubble detachment from electrode surfaces via increasing gas solubility. In contrast, SnakeSkin® membranes enhanced natural convection and blocked bubbles from entering the microchannels and thus reduced current disturbances in the electric field. This data illustrated that electrode surface behaviors had substantially greater impacts on current stability than microbubbles within microchannels. Thus, physically blocking bubbles from microchannels is less effective than electrode functionalization approaches to stabilize electrokinetic microfluidic systems. PMID:24648277

  4. Improving electrokinetic microdevice stability by controlling electrolysis bubbles.

    PubMed

    Lee, Hwi Yong; Barber, Cedrick; Minerick, Adrienne R

    2014-07-01

    The voltage-operating window for many electrokinetic microdevices is limited by electrolysis gas bubbles that destabilize microfluidic system causing noise and irreproducible responses above ∼3 V DC and less than ∼1 kHz AC at 3 Vpp. Surfactant additives, SDS and Triton X-100, and an integrated semipermeable SnakeSkin® membrane were employed to control and assess electrolysis bubbles from platinum electrodes in a 180 by 70 μm, 10 mm long microchannel. Stabilized current responses at 100 V DC were observed with surfactant additives or SnakeSkin® barriers. Electrolysis bubble behaviors, visualized via video microscopy at the electrode surface and in the microchannels, were found to be influenced by surfactant function and SnakeSkin® barriers. Both SDS and Triton X-100 surfactants promoted smaller bubble diameters and faster bubble detachment from electrode surfaces via increasing gas solubility. In contrast, SnakeSkin® membranes enhanced natural convection and blocked bubbles from entering the microchannels and thus reduced current disturbances in the electric field. This data illustrated that electrode surface behaviors had substantially greater impacts on current stability than microbubbles within microchannels. Thus, physically blocking bubbles from microchannels is less effective than electrode functionalization approaches to stabilize electrokinetic microfluidic systems.

  5. Endurance test and evaluation of alkaline water electrolysis cells

    NASA Technical Reports Server (NTRS)

    Burke, K. A.; Schubert, F. H.

    1981-01-01

    Utilization in the development of multi-kW low orbit power systems is discussed. The following technological developments of alkaline water electrolysis cells for space power application were demonstrated: (1) four 92.9 cm2 single water electrolysis cells, two using LST's advanced anodes and two using LST's super anodes; (2) four single cell endurance test stands for life testing of alkaline water electrolyte cells; (3) the solid performance of the advanced electrode and 355 K; (4) the breakthrough performance of the super electrode; (5) the four single cells for over 5,000 hours each significant cell deterioration or cell failure. It is concluded that the static feed water electrolysis concept is reliable and due to the inherent simplicity of the passive water feed mechanism coupled with the use of alkaline electrolyte has greater potential for regenerative fuel cell system applications than alternative electrolyzers. A rise in cell voltage occur after 2,000-3,000 hours which was attributed to deflection of the polysulfone end plates due to creepage of the thermoplastic. More end plate support was added, and the performance of the cells was restored to the initial performance level.

  6. Treatment of high salt oxidized modified starch waste water using micro-electrolysis, two-phase anaerobic aerobic and electrolysis for reuse

    NASA Astrophysics Data System (ADS)

    Yi, Xuenong; Wang, Yulin

    2016-08-01

    A combined process of micro-electrolysis, two-phase anaerobic, aerobic and electrolysis was investigated for the treatment of oxidized modified starch wastewater (OMSW). Optimum ranges for important operating variables were experimentally determined and the treated water was tested for reuse in the production process of corn starch. The optimum hydraulic retention time (HRT) of micro-electrolysis, methanation reactor, aerobic process and electrolysis process were 5, 24, 12 and 3 h, respectively. The addition of iron-carbon fillers to the acidification reactor was 200 mg/L while the best current density of electrolysis was 300 A/m2. The biodegradability was improved from 0.12 to 0.34 by micro-electrolysis. The whole treatment was found to be effective with removal of 96 % of the chemical oxygen demand (COD), 0.71 L/day of methane energy recovery. In addition, active chlorine production (15,720 mg/L) was obtained by electrolysis. The advantage of this hybrid process is that, through appropriate control of reaction conditions, effect from high concentration of salt on the treatment was avoided. Moreover, the process also produced the material needed in the production of oxidized starch while remaining emission-free and solved the problem of high process cost.

  7. Evaluation of an electrolysis apparatus for inactivating antineoplastics in clinical wastewater.

    PubMed

    Kobayashi, Toyohide; Hirose, Jun; Sano, Kouichi; Hiro, Naoki; Ijiri, Yoshio; Takiuchi, Hiroya; Tamai, Hiroshi; Takenaka, Hiroshi; Tanaka, Kazuhiko; Nakano, Takashi

    2008-06-01

    We recently reported a system for inactivating antineoplastics in which sodium hypochlorite is supplied by the electrolysis of sodium chloride solution. In this study, we designed an electrolysis apparatus for inactivating the cytotoxicity of antineoplastics in clinical wastewater using the system. The apparatus consists of an electrolysis cell with platinum-iridium electrodes, a pool tank, a circulating system for wastewater, a safety system for explosive gas and overflow, and an exhaust duct. The free chlorine concentration increased linearly up to 6500 mg l(-1), and pH also increased to 9.0-10.0 within 2h, when 0.9% sodium chloride solution was electrolyzed. We examined its efficacy with model and clinical wastewaters. The reciprocal of dilution factor for disappearance of cytotoxicity using Molt-4 cells was compared before and after electrolysis. In the model wastewater, that was 9.10 x 10(4) before electrolysis, and 3.56 x 10(2) after 2h of electrolysis. In the clinical wastewater (n=26), that was 6.90 x 10(3)-1.02 x 10(6) before electrolysis, and 1.08 x 10(2)-1.45 x 10(4) after 2h of electrolysis. Poisonous and explosive gases released by the electrolysis were measured; however, they were found to be negligible in terms of safety. The environmental load was evaluated by carbon dioxide generation as an index and it was found that the carbon dioxide generated by the electrolysis method was 1/70 lower than that by the dilution method with tap water. Moreover, the cost of the electrolysis method was 1/170 lower than that of the dilution method. This method was found to be both effective and economically valuable. PMID:18423519

  8. Iron migration from the anode surface in alumina electrolysis

    NASA Astrophysics Data System (ADS)

    Zhuravleva, Elena N.; Drozdova, Tatiana N.; Ponomareva, Svetlana V.; Kirik, Sergei D.

    2013-01-01

    Corrosion destruction of two-component iron-based alloys used as an anode in high-temperature alumina electrolysis in the melt of NaF/KF/AlF3 electrolyte has been considered. Ni, Si, Cu, Cr, Mn, Al, Ti in the amount of up to 10% have been tested as the dopants to an anode alloys. The composition of the corrosion products has been studied using X-ray diffraction, scanning electron microscopy and electron microprobe analysis. It has been established that the anode corrosion is induced by a surface electrochemical polarization and iron atom oxidation. Iron ions come into an exchange interaction with the fluoride components of the melted electrolyte, producing FeF2. The last interacts with oxyfluoride species transforming into the oxide forms: FeAl2O4, Fe3O4, Fe2O3. Due to the low solubility, the iron oxides are accumulated in the near-electrode sheath. The only small part of iron from anode migrates to cathode that makes an production of high purity aluminum of a real task. The alloy dopants are also subjected to corrosion in accordance with electromotive series resulting corrosion tunnels on the anode surface. The oxides are final compounds which collect in the same area. The corrosion products form an anode shell which is electronic conductor at electrolysis temperature. The electrolysis of alumina occurs beyond the corrosion shell. The rate limiting step in the corrosion is the electrolyte penetration through corrosion shell to the anode surface. The participation of the released oxygen in the corrosion has not been observed.

  9. Electrolysis Performance Improvement Concept Study (EPICS) flight experiment phase C/D

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Lee, M. G.

    1995-01-01

    The overall purpose of the Electrolysis Performance Improvement Concept Study flight experiment is to demonstrate and validate in a microgravity environment the Static Feed Electrolyzer concept as well as investigate the effect of microgravity on water electrolysis performance. The scope of the experiment includes variations in microstructural characteristics of electrodes and current densities in a static feed electrolysis cell configuration. The results of the flight experiment will be used to improve efficiency of the static feed electrolysis process and other electrochemical regenerative life support processes by reducing power and expanding the operational range. Specific technologies that will benefit include water electrolysis for propulsion, energy storage, life support, extravehicular activity, in-space manufacturing and in-space science in addition to other electrochemical regenerative life support technologies such as electrochemical carbon dioxide and oxygen separation, electrochemical oxygen compression and water vapor electrolysis. The Electrolysis Performance Improvement Concept Study flight experiment design incorporates two primary hardware assemblies: the Mechanical/Electrochemical Assembly and the Control/Monitor Instrumentation. The Mechanical/Electrochemical Assembly contains three separate integrated electrolysis cells along with supporting pressure and temperature control components. The Control/Monitor Instrumentation controls the operation of the experiment via the Mechanical/Electrochemical Assembly components and provides for monitoring and control of critical parameters and storage of experimental data.

  10. Electrolysis of Water in the Secondary School Science Laboratory with Inexpensive Microfluidics

    ERIC Educational Resources Information Center

    Davis, T. A.; Athey, S. L.; Vandevender, M. L.; Crihfield, C. L.; Kolanko, C. C. E.; Shao, S.; Ellington, M. C. G.; Dicks, J. K.; Carver, J. S.; Holland, L. A.

    2015-01-01

    This activity allows students to visualize the electrolysis of water in a microfluidic device in under 1 min. Instructional materials are provided to demonstrate how the activity meets West Virginia content standards and objectives. Electrolysis of water is a standard chemistry experiment, but the typical laboratory apparatus (e.g., Hoffman cell)…

  11. High School Students' Proficiency and Confidence Levels in Displaying Their Understanding of Basic Electrolysis Concepts

    ERIC Educational Resources Information Center

    Sia, Ding Teng; Treagust, David F.; Chandrasegaran, A. L.

    2012-01-01

    This study was conducted with 330 Form 4 (grade 10) students (aged 15-16 years) who were involved in a course of instruction on electrolysis concepts. The main purposes of this study were (1) to assess high school chemistry students' understanding of 19 major principles of electrolysis using a recently developed 2-tier multiple-choice diagnostic…

  12. Oxygen Production on Mars Using Solid Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Sridhar, K. R.

    1997-01-01

    If oxygen for propulsion and life support needs were to be extracted from martian resources, significant savings in launch mass and costs could be attained for both manned and unmanned missions. In addition to reduced cost the ability to produce oxygen from martian resources would decrease the risks associated with long duration stays on the surface of Mars. One method of producing the oxygen from the carbon dioxide rich atmosphere of Mars involves solid oxide electrolysis. A brief summary of the theory of operation will be presented followed by a schematic description of a Mars oxygen production pland and a discussion of its power consumption characteristics.

  13. Bio-Fuel Production Assisted with High Temperature Steam Electrolysis

    SciTech Connect

    Grant Hawkes; James O'Brien; Michael McKellar

    2012-06-01

    Two hybrid energy processes that enable production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure are presented. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), these two hybrid energy processes have the potential to provide a significant alternative petroleum source that could reduce dependence on imported oil. The first process discusses a hydropyrolysis unit with hydrogen addition from HTSE. Non-food biomass is pyrolyzed and converted to pyrolysis oil. The pyrolysis oil is upgraded with hydrogen addition from HTSE. This addition of hydrogen deoxygenates the pyrolysis oil and increases the pH to a tolerable level for transportation. The final product is synthetic crude that could then be transported to a refinery and input into the already used transportation fuel infrastructure. The second process discusses a process named Bio-Syntrolysis. The Bio-Syntrolysis process combines hydrogen from HTSE with CO from an oxygen-blown biomass gasifier that yields syngas to be used as a feedstock for synthesis of liquid synthetic crude. Conversion of syngas to liquid synthetic crude, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model

  14. Exhaustive breakdown of aqueous monochlorophenols by contact glow discharge electrolysis.

    PubMed

    Yang, Haiming; Matsumoto, Yuki; Tezuka, Meguru

    2009-01-01

    The aqueous monochlorophenols were degraded by contact glow discharge electrolysis (CGDE), in which plasma was generated in a localized zone between an electrolytic solution and an anode. With the decay of monochlorophenols, the amount of total organic carbon (TOC) also decreased smoothly, indicating that carbon atoms of benzene nucleus could be eventually converted to inorganic carbons. Meanwhile, it was also clarified that chlorine atoms in the organics were liberated as chloride ions. In addition, it was revealed that the disappearance of monochlorophenols obeyed the first-order rate law, depending on the isomeric structures. PMID:25084414

  15. Modeling of Sustainable Base Production by Microbial Electrolysis Cell.

    PubMed

    Blatter, Maxime; Sugnaux, Marc; Comninellis, Christos; Nealson, Kenneth; Fischer, Fabian

    2016-07-01

    A predictive model for the microbial/electrochemical base formation from wastewater was established and compared to experimental conditions within a microbial electrolysis cell. A Na2 SO4 /K2 SO4 anolyte showed that model prediction matched experimental results. Using Shewanella oneidensis MR-1, a strong base (pH≈13) was generated using applied voltages between 0.3 and 1.1 V. Due to the use of bicarbonate, the pH value in the anolyte remained unchanged, which is required to maintain microbial activity.

  16. Electrolysis: Information and Opportunities for Electric Power Utilities

    SciTech Connect

    Kroposki, B.; Levene, J.; Harrison, K.; Sen, P.K.; Novachek, F.

    2006-09-01

    Recent advancements in hydrogen technologies and renewable energy applications show promise for economical near- to mid-term conversion to a hydrogen-based economy. As the use of hydrogen for the electric utility and transportation sectors of the U.S. economy unfolds, electric power utilities need to understand the potential benefits and impacts. This report provides a historical perspective of hydrogen, discusses the process of electrolysis for hydrogen production (especially from solar and wind technologies), and describes the opportunities for electric power utilities.

  17. Production of Oxygen from Lunar Regolith by Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Curreri, Peter A.

    2009-01-01

    This paper describes the use of the molten oxide electrolysis (MOE) process for the extraction of oxygen for life support and propellant, and silicon and metallic elements for use in fabrication on the Moon. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis is ideal for extraction, since the electron is the only practical reducing agent. MOE has several advantages over other extraction methods. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. Alternatively, MOE requires no import of consumable reagents (e.g. fluorine and carbon) as other processes do, and does not rely on interfacing multiple processes to obtain refined products. Electrolytic processing has the advantage of selectivity of reaction in the presence of a multi-component feed. Products from lunar regolith can be extracted in sequence according to the stabilities of their oxides as expressed by the values of the free energy of oxide formation (e.g. chromium, manganese, Fe, Si, Ti, Al, magnesium, and calcium). Previous work has demonstrated the viability of producing Fe and oxygen from oxide mixtures similar in composition to lunar regolith by molten oxide electrolysis (electrowinning), also called magma electrolysis having shown electrolytic extraction of Si from regolith simulant. This paper describes recent advances in demonstrating the MOE process by a joint project with participation by NASA KSC and

  18. Experimental study of the electrolysis of silicate melts

    NASA Technical Reports Server (NTRS)

    Keller, R.; Larimer, K. T.

    1991-01-01

    To produce oxygen from lunar resources, it may be feasible to melt and electrolyze local silicate ores. This possibility was explored experimentally with synthesized melts of appropriate compositions. Platinum electrodes were employed at a melt temperature of 1425 C. When silicon components of the melt were reduced, the platinum cathode degraded rapidly, which prompted the substitution of a graphite cathode substrate. Discrete particles containing iron or titanium were found in the solidified electrolyte after three hours of electrolysis. Electrolyte conductivities did not decrease substantially, but the escape of gas bubbles, in some cases, appeared to be hindered by high viscosity of the melt.

  19. Formation of sulfonyl aromatic alcohols by electrolysis of a bisazo reactive dye.

    PubMed

    Elizalde-González, María P; Arroyo-Abad, Uriel; García-Díaz, Esmeralda; Brillas, Enric; Sirés, Ignasi; Dávila-Jiménez, Martín M

    2012-12-05

    Five sulfonyl aromatic alcohols, namely 4-((2-hydroxyethyl)sulfonyl)phenol, 4-((2-(2-((4-hydroxyphenyl)sulfonyl)ethoxy)vinyl)sulfonyl)phenol, 4-(ethylsulfonyl)phenol, 4-(vinylsulfonyl)phenol and 5-((4-aminophenyl)sulfonyl)-2-penten-1-ol were identified by LC-ESI-Qq-TOF-MS as products formed by electrolysis of the bisazo reactive dye Reactive Black 5 (RB5). Since electrolyses were performed in an undivided cell equipped with Ni electrodes in alkaline medium, amines like 4-(2-methoxyethylsulfonyl)benzene-amine (MEBA) with m/z 216 were also suspected to be formed due to the plausible chemical reaction in the bulk or the cathodic reduction of RB5 and its oxidation by-products. Aiming to check this hypothesis, a method was used for the preparation of MEBA with 98% purity, via chemical reduction also of the dye RB5. The logP of the synthesized sulfonyl aromatic compounds was calculated and their logkw values were determined chromatographically. These data were discussed in regard to the relationship between hydrophobicity/lipophilicity and toxicity.

  20. Aqueous p-chloronitrobenzene decomposition induced by contact glow discharge electrolysis.

    PubMed

    Liu, Yongjun

    2009-07-30

    Aqueous p-chloronitrobenzene (PCNB) decomposition induced by contact glow discharge electrolysis under various reaction conditions was investigated. Experimental results showed that, at voltage 450-550 V and initial concentration 50-500 mg/L, the decay of PCNB can be described by a first-order reaction kinetics of In(C(0)/C(t))=0.029 (I/V)t, where C(0), I, V and C(t) denote the initial PCNB concentration (mg/L), applied current (A), solution volume (L) and instantaneous PCNB concentration (mg/L) at treatment time t (min). Major intermediate products such as 4-nitrophenol, 2-chloro-5-nitrophenol, oxalic and formic acids, chloride and nitrate ions were identified by LC/MS and IC, respectively. No chlorophenols present indicated that the dechlorination was easier than denitration from the aromatic ring of PCNB. Formation of hydrogen peroxide during the degradation was observed and the role of Fenton's reaction was examined. Hydroxyl radicals may be the most responsible species for PCNB degradation. PMID:19179010

  1. Static Feed Water Electrolysis Subsystem Testing and Component Development

    NASA Technical Reports Server (NTRS)

    Koszenski, E. P.; Schubert, F. H.; Burke, K. A.

    1983-01-01

    A program was carried out to develop and test advanced electrochemical cells/modules and critical electromechanical components for a static feed (alkaline electrolyte) water electrolysis oxygen generation subsystem. The accomplishments were refurbishment of a previously developed subsystem and successful demonstration for a total of 2980 hours of normal operation; achievement of sustained one-person level oxygen generation performance with state-of-the-art cell voltages averaging 1.61 V at 191 ASF for an operating temperature of 128F (equivalent to 1.51V when normalized to 180F); endurance testing and demonstration of reliable performance of the three-fluid pressure controller for 8650 hours; design and development of a fluid control assembly for this subsystem and demonstration of its performance; development and demonstration at the single cell and module levels of a unitized core composite cell that provides expanded differential pressure tolerance capability; fabrication and evaluation of a feed water electrolyte elimination five-cell module; and successful demonstration of an electrolysis module pressurization technique that can be used in place of nitrogen gas during the standby mode of operation to maintain system pressure and differential pressures.

  2. Electrolysis Propulsion Provides High-Performance, Inexpensive, Clean Spacecraft Propulsion

    NASA Technical Reports Server (NTRS)

    deGroot, Wim A.

    1999-01-01

    An electrolysis propulsion system consumes electrical energy to decompose water into hydrogen and oxygen. These gases are stored in separate tanks and used when needed in gaseous bipropellant thrusters for spacecraft propulsion. The propellant and combustion products are clean and nontoxic. As a result, costs associated with testing, handling, and launching can be an order of magnitude lower than for conventional propulsion systems, making electrolysis a cost-effective alternative to state-of-the-art systems. The electrical conversion efficiency is high (>85 percent), and maximum thrust-to-power ratios of 0.2 newtons per kilowatt (N/kW), a 370-sec specific impulse, can be obtained. A further advantage of the water rocket is its dual-mode potential. For relatively high thrust applications, the system can be used as a bipropellant engine. For low thrust levels and/or small impulse bit requirements, cold gas oxygen can be used alone. An added innovation is that the same hardware, with modest modifications, can be converted into an energy-storage and power-generation fuel cell, reducing the spacecraft power and propulsion system weight by an order of magnitude.

  3. Technology advancement of the static feed water electrolysis process

    NASA Technical Reports Server (NTRS)

    Jensen, F. C.; Schubert, F. H.

    1977-01-01

    Some results are presented of a research and development program to continue the development of a method to generate oxygen for crew metabolic consumption during extended manned space flights. The concept being pursued is that of static feed water electrolysis. Specific major results of the work included: (1) completion of a 30-day electrode test using a Life Systems, Inc.-developed high performance catalyst. During startup the cell voltages were as low as 1.38 V at current densities of 108 mA/sq cm (100 ASF) and temperatures of 355 K (180 F). At the end of 30 days of testing the cell voltages were still only 1.42 V at 108 mA/sq cm, (2) determination that the Static Feed Water Electrolysis Module does not release an aerosol of the cell electrolyte into the product gas streams after a break-in period of 24 hours following a new electrolyte charge, and (3) completion of a detailed design analysis of an electrochemical Oxygen Generation Subsystem at a three-man level (4.19 kg/day (9.24 lb/day) of oxygen).

  4. Prediction of Production Power for High-pressure Hydrogen by High-pressure Water Electrolysis

    NASA Astrophysics Data System (ADS)

    Kyakuno, Takahiro; Hattori, Kikuo; Ito, Kohei; Onda, Kazuo

    Recently the high attention for fuel cell electric vehicle (FCEV) is pushing to construct the hydrogen supplying station for FCEV in the world. The hydrogen pressure supplied at the current test station is intended to be high for increasing the FCEV’s driving distance. The water electrolysis can produce cleanly the hydrogen by utilizing the electricity from renewable energy without emitting CO2 to atmosphere, when it is compared to be the popular reforming process of fossil fuel in the industry. The power required for the high-pressure water electrolysis, where water is pumped up to high-pressure, may be smaller than the power for the atmospheric water electrolysis, where the produced atmospheric hydrogen is pumped up by compressor, since the compression power for water is much smaller than that for hydrogen gas. In this study the ideal water electrolysis voltage up to 70MPa and 523K is estimated referring to both the results by LeRoy et al up to 10MPa and 523K, and to the latest steam table. By using this high-pressure water electrolysis voltage, the power required for high-pressure hydrogen produced by the high-pressure water electrolysis method is estimated to be about 5% smaller than that by the atmospheric water electrolysis method, by assuming the compressor and pump efficiency of 50%.

  5. Prediction of production power for high-pressure hydrogen by high-pressure water electrolysis

    NASA Astrophysics Data System (ADS)

    Onda, Kazuo; Kyakuno, Takahiro; Hattori, Kikuo; Ito, Kohei

    Recent attention focused on fuel cell electric vehicles (FCEVs) has created demand for the construction of hydrogen supply stations for FCEVs throughout the world. The hydrogen pressure supplied at the supply stations is intentionally high to increase the FCEVs driving mileage. Water electrolysis can produce clean hydrogen by utilizing electricity from renewable energy without CO 2 emission to the atmosphere when compared with the industrial fossil fuel reforming process. The power required for high-pressure water electrolysis, wherein water is pumped up to a high-pressure, may be less than the power required for atmospheric water electrolysis, wherein the produced atmospheric hydrogen is pumped by a compressor, since the compression power for water is much less than that for hydrogen-gas. In this study, the ideal water electrolysis voltage of up to 70 MPa and 250 °C is estimated by referring to both the results of LeRoy et al. up to 10 MPa and 250 °C, and the latest steam tables. Using this high-pressure water electrolysis voltage, the power required to produce high-pressure hydrogen by high-pressure water electrolysis is estimated to be about 5% less than that required for atmospheric water electrolysis, assuming compressor and pump efficiencies of 50%.

  6. Results Of Recent High Temperature Co-Electrolysis Studies At The Idaho National Laboratory

    SciTech Connect

    C. M. Stoots; James E. O'Brien; Joseph J. Hartvigsen

    2007-11-01

    For the past several years, the Idaho National Laboratory and Ceramatec, Inc. have been studying the feasibility of high temperature solid oxide electrolysis for large-scale, nuclear-powered hydrogen production. Parallel to this effort, the INL and Ceramatec have been researching high temperature solid oxide co-electrolysis of steam/CO2 mixtures to produce syngas, the raw material for synthetic fuels production. When powered by nuclear energy, high temperature co-electrolysis offers a carbon-neutral means of syngas production while consuming CO2. The INL has been conducting experiments to characterize the electrochemical performance of co-electrolysis, as well as validate INL-developed computer models. An inline methanation reactor has also been tested to study direct methane production from co-electrolysis products. Testing to date indicate that high temperature steam electrolysis cells perform equally well under co-electrolysis conditions. Process model predictions compare well with measurements for outlet product compositions. The process appears to be a promising technique for large-scale syngas production.

  7. Cooperative pulses

    NASA Astrophysics Data System (ADS)

    Braun, Michael; Glaser, Steffen J.

    2010-11-01

    We introduce the concept of cooperative (COOP) pulses which are designed to compensate each other's imperfections. In multi-scan experiments, COOP pulses can cancel undesired signal contributions, complementing and generalizing phase cycles. COOP pulses can be efficiently optimized using an extended version of the optimal-control-based gradient ascent pulse engineering (GRAPE) algorithm. The advantage of the COOP approach is experimentally demonstrated for broadband and band-selective pulses.

  8. Oxygen Handling and Cooling Options in High Temperature Electrolysis Plants

    SciTech Connect

    Manohar S. Sohal; J. Stephen Herring

    2008-07-01

    Idaho National Laboratory is working on a project to generate hydrogen by high temperature electrolysis (HTE). In such an HTE system, safety precautions need to be taken to handle high temperature oxygen at ~830°C. This report is aimed at addressing oxygen handling in a HTE plant.. Though oxygen itself is not flammable, most engineering material, including many gases and liquids, will burn in the presence of oxygen under some favorable physicochemical conditions. At present, an absolute set of rules does not exist that can cover all aspects of oxygen system design, material selection, and operating practices to avoid subtle hazards related to oxygen. Because most materials, including metals, will burn in an oxygen-enriched environment, hazards are always present when using oxygen. Most materials will ignite in an oxygen-enriched environment at a temperature lower than that in air, and once ignited, combustion rates are greater in the oxygen-enriched environment. Even many metals, if ignited, burn violently in an oxygen-enriched environment. However, these hazards do not preclude the operations and systems involving oxygen. Oxygen can be safely handled and used if all the materials in a system are not flammable in the end-use environment or if ignition sources are identified and controlled. In fact, the incidence of oxygen system fires is reported to be low with a probability of about one in a million. This report is a practical guideline and tutorial for the safe operation and handling of gaseous oxygen in high temperature electrolysis system. The intent is to provide safe, practical guidance that permits the accomplishment of experimental operations at INL, while being restrictive enough to prevent personnel endangerment and to provide reasonable facility protection. Adequate guidelines are provided to govern various aspects of oxygen handling associated with high temperature electrolysis system to generate hydrogen. The intent here is to present acceptable

  9. DESIGN OF A COMPACT HEAT EXCHANGER FOR HEAT RECUPERATION FROM A HIGH TEMPERATURE ELECTROLYSIS SYSTEM

    SciTech Connect

    G. K. Housley; J.E. O'Brien; G.L. Hawkes

    2008-11-01

    Design details of a compact heat exchanger and supporting hardware for heat recuperation in a high-temperature electrolysis application are presented. The recuperative heat exchanger uses a vacuum-brazed plate-fin design and operates between 300 and 800°C. It includes corrugated inserts for enhancement of heat transfer coefficients and extended heat transfer surface area. Two recuperative heat exchangers are required per each four-stack electrolysis module. The heat exchangers are mated to a base manifold unit that distributes the inlet and outlet flows to and from the four electrolysis stacks. Results of heat exchanger design calculations and assembly details are also presented.

  10. THE PRODUCTION OF SYNGAS VIA HIGH TEMPERATURE ELECTROLYSIS AND BIO-MASS GASIFICATION

    SciTech Connect

    M. G. McKellar; G. L. Hawkes; J. E. O'Brien

    2008-11-01

    A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to improve the hydrogen production efficiency of the steam electrolysis process. Hydrogen from electrolysis allows a high utilization of the biomass carbon for syngas production. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon dioxide and hydrogen). Assuming the thermal efficiency of the power cycle for electricity generation is 50%, (as expected from GEN IV nuclear reactors), the syngas production efficiency ranges from 70% to 73% as the gasifier temperature decreases from 1900 K to 1500 K.

  11. Novel process for recycling magnesium alloy employing refining and solid oxide membrane electrolysis

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei

    Magnesium is the least dense engineering metal, with an excellent stiffness-to-weight ratio. Magnesium recycling is important for both economic and environmental reasons. This project demonstrates feasibility of a new environmentally friendly process for recycling partially oxidized magnesium scrap to produce very pure magnesium at low cost. It combines refining and solid oxide membrane (SOM) based oxide electrolysis in the same reactor. Magnesium and its oxide are dissolved in a molten flux. This is followed by argon-assisted evaporation of dissolved magnesium, which is subsequently condensed in a separate condenser. The molten flux acts as a selective medium for magnesium dissolution, but not aluminum or iron, and therefore the magnesium collected has high purity. Potentiodynamic scans are performed to monitor the magnesium content change in the scrap as well as in solution in the flux. The SOM electrolysis is employed in the refining system to enable electrolysis of the magnesium oxide dissolved in the flux from the partially oxidized scrap. During the SOM electrolysis, oxygen anions are transported out of the flux through a yttria stabilized zirconia membrane to a liquid silver anode where they are oxidized. Simultaneously, magnesium cations are transported through the flux to a steel cathode where they are reduced. The combination of refining and SOM electrolysis yields close to 100% removal of magnesium metal from partially oxidized magnesium scrap. The magnesium recovered has a purity of 99.6w%. To produce pure oxygen it is critical to develop an inert anode current collector for use with the non-consumable liquid silver anode. In this work, an innovative inert anode current collector is successfully developed and used in SOM electrolysis experiments. The current collector employs a sintered strontium-doped lanthanum manganite (La0.8Sr0.2MnO 3-delta or LSM) bar, an Inconel alloy 601 rod, and a liquid silver contact in between. SOM electrolysis experiments

  12. High Temperature Electrolysis 4 kW Experiment Design, Operation, and Results

    SciTech Connect

    J.E. O'Brien; X. Zhang; K. DeWall; L. Moore-McAteer; G. Tao

    2012-09-01

    This report provides results of long-term stack testing completed in the new high-temperature steam electrolysis multi-kW test facility recently developed at INL. The report includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This facility has provided a demonstration of high-temperature steam electrolysis operation at the 4 kW scale with advanced cell and stack technology. This successful large-scale demonstration of high-temperature steam electrolysis will help to advance the technology toward near-term commercialization.

  13. Continuous microalgae recovery using electrolysis with polarity exchange.

    PubMed

    Kim, Jungmin; Ryu, Byung-Gon; Kim, Bo-Kyong; Han, Jong-In; Yang, Ji-Won

    2012-05-01

    There is increasing interest in the use of microalgae as a renewable source for the production of fuels and chemicals, but improvements are needed in all steps of this process, including harvesting. A continuous microalgae harvest system was developed based on electrolysis, referred to here as a continuous electrolytic microalgae (CEM) harvest system. This innovative system combines cultivation and harvesting and enables continuous and efficient concentration of microalgae. The electrodes were subject to a polarity exchange (PE) in the middle of the operation to further improve the harvest efficiency. Use of PE, rather than conventional electro-coagulation-flotation (ECF), led to more efficient cell recovery and more uniform recovery over the entire harvest chamber. In addition, PE increased the cell growth rate and the circulated cells remained intact after harvesting. PMID:22397823

  14. Alkaline Ammonia Electrolysis on Electrodeposited Platinum for Controllable Hydrogen Production.

    PubMed

    Gwak, Jieun; Choun, Myounghoon; Lee, Jaeyoung

    2016-02-19

    Ammonia is beginning to attract a great deal of attention as an alternative energy source carrier, because clean hydrogen can be produced through electrolytic processes without the emission of COx . In this study, we deposited various shapes of Pt catalysts under potentiostatic mode; the electrocatalytic oxidation behavior of ammonia using these catalysts was studied in alkaline media. The electrodeposited Pt was characterized by both qualitative and quantitative analysis. To discover the optimal structure and the effect of ammonia concentration, the bulk pH value, reaction temperature, and applied current of ammonia oxidation were investigated using potential sweep and galvanostatic methods. Finally, ammonia electrolysis was conducted using a zero-gap cell, producing highly pure hydrogen with an energy efficiency over 80 %.

  15. Study on the Inter-electrode Process of Aluminum Electrolysis

    NASA Astrophysics Data System (ADS)

    Yang, Youjian; Gao, Bingliang; Wang, Zhaowen; Shi, Zhongning; Hu, Xianwei

    2016-02-01

    The voltage distribution between carbon anode and aluminum cathode in cryolite electrolyte saturated with alumina was determined using a scanning reference electrode to investigate the inter-electrode process during aluminum electrolysis. The results showed that the anode-cathode-distance (ACD) is consisted of three parts: a relatively stable cathode boundary layer, bubble-free electrolyte layer, and gas-liquid layer near the anode. The aluminum diffusion layer with high electronic conductivity as well as the crystallization of cryolite was observed at the cathode boundary layer. The thickness of the aluminum diffusion layer varied with current density, which further determined the critical ACD. The thickness, coverage, and releasing frequency of the bubbles on both laboratory and industrial prebaked cells were derived, and it is found that the average bubble coverage decreases with current density, and the average coverage at 0.8 A cm-2 is approximately 50 pct.

  16. Alkaline Ammonia Electrolysis on Electrodeposited Platinum for Controllable Hydrogen Production.

    PubMed

    Gwak, Jieun; Choun, Myounghoon; Lee, Jaeyoung

    2016-02-19

    Ammonia is beginning to attract a great deal of attention as an alternative energy source carrier, because clean hydrogen can be produced through electrolytic processes without the emission of COx . In this study, we deposited various shapes of Pt catalysts under potentiostatic mode; the electrocatalytic oxidation behavior of ammonia using these catalysts was studied in alkaline media. The electrodeposited Pt was characterized by both qualitative and quantitative analysis. To discover the optimal structure and the effect of ammonia concentration, the bulk pH value, reaction temperature, and applied current of ammonia oxidation were investigated using potential sweep and galvanostatic methods. Finally, ammonia electrolysis was conducted using a zero-gap cell, producing highly pure hydrogen with an energy efficiency over 80 %. PMID:26530809

  17. Mineralization of aqueous pentachlorophenolate by anodic contact glow discharge electrolysis.

    PubMed

    Yang, Haiming; Tezuka, Meguru

    2011-01-01

    Exhaustive mineralization of pentachlorophenolate ion (PCP) in phosphate buffer was carried out using anodic contact glow discharge electrolysis (CGDE), in which plasma was sustained between the electrolyte and anode. During CGDE, PCP degraded smoothly. The amount of total organic carbon decreased significantly, indicating the eventual conversion of the carbon atoms of benzene nucleus to inorganic carbons. Furthermore, chlorine atoms in PCP were liberated as chloride ions. As a primary intermediate product, 2,3,5,6-tetrachloro-1,4-benzoquinone was detected, and oxalate and formate as byproducts were also found. It was revealed that disappearance of PCP obeyed first-order kinetics. The reaction rate was generally unaffected by both O2 and inert gases in the cell, although it decreased by raising initial pH of solution. In addition, a plausible reaction pathway involving hydroxyl radical was proposed. PMID:22066230

  18. Electrolysis of dilute sodium chloride solution in a diaphragm cell

    SciTech Connect

    Kubasov, V.L.; Ivanter, I.A.; Druzhinin, E.A.; Vorob'eva, V.B.

    1986-02-10

    In some cases, as in the production of iodine and bromine, dilute solutions of sodium chloride remain unutilized. In view of the existence of large amounts of unutilized spent sodium chloride solutions and their harmful effect when discharged into the environment, it is desirable to develop a process for production of chlorine and alkali with high current efficiencies, satisfying industrial requirements, from dilute sodium chloride solutions. The authors have therefore studied electrolysis of solutions containing 160 and 180 kg/m/sup 3/ of sodium chloride, having pH of 11.0-11.5, close in composition to solutions from the Cheleken chemical factory. The chlorine and alkali current efficiencies and the compositions of the anolyte, catholyte, and anode gas were determined.

  19. Perchlorate reduction in microbial electrolysis cell with polyaniline modified cathode.

    PubMed

    Li, Jia-Jia; Gao, Ming-Ming; Zhang, Gang; Wang, Xin-Hua; Wang, Shu-Guang; Song, Chao; Xu, Yan-Yan

    2015-02-01

    Excellent perchlorate reduction was obtained under various initial concentrations in a non-membrane microbial electrolysis cell with polyaniline (PANI) modified graphite cathode as sole electron donor. PANI modification is conducive to the formation of biofilm due to its porous structure and good electrocatalytic performance. Compared with cathode without biofilm, over 12% higher reduction rates were acquired in the presence of biocathode. The study demonstrates that, instead of perchlorate reduction, the main contribution of biofilm is involved in facilitate electron transfer from cathode to electrolyte. Interestingly, hairlike structure, referred as to pili-like, was observed in the biofilm as well as in the electrolyte. Additionally, the results show that pili were prone to formation under the condition of external electron field as sole electron donor. Analysis of microbial community suggests that perchlorate reduction bacteria community was most consistent with Azospiraoryzae strain DSM 13638 in the subdivision of the class Proteobacteria. PMID:25479396

  20. Continuous microalgae recovery using electrolysis with polarity exchange.

    PubMed

    Kim, Jungmin; Ryu, Byung-Gon; Kim, Bo-Kyong; Han, Jong-In; Yang, Ji-Won

    2012-05-01

    There is increasing interest in the use of microalgae as a renewable source for the production of fuels and chemicals, but improvements are needed in all steps of this process, including harvesting. A continuous microalgae harvest system was developed based on electrolysis, referred to here as a continuous electrolytic microalgae (CEM) harvest system. This innovative system combines cultivation and harvesting and enables continuous and efficient concentration of microalgae. The electrodes were subject to a polarity exchange (PE) in the middle of the operation to further improve the harvest efficiency. Use of PE, rather than conventional electro-coagulation-flotation (ECF), led to more efficient cell recovery and more uniform recovery over the entire harvest chamber. In addition, PE increased the cell growth rate and the circulated cells remained intact after harvesting.

  1. Impact of low gravity on water electrolysis operation

    NASA Technical Reports Server (NTRS)

    Powell, F. T.; Schubert, F. H.; Lee, M. G.

    1989-01-01

    Advanced space missions will require oxygen and hydrogen utilities for several important operations including the following: (1) propulsion; (2) electrical power generation and storage; (3) environmental control and life support; (4) extravehicular activity; (5) in-space manufacturing and (6) in-space science activities. An experiment suited to a Space Shuttle standard middeck payload has been designed for the Static Feed Water Electrolysis technology which has been viewed as being capable of efficient, reliable oxygen and hydrogen generation with few subsystem components. The program included: end use design requirements, phenomena to be studied, Space Shuttle Orbiter experiment constraints, experiment design and data requirements, and test hardware requirements. The objectives are to obtain scientific and engineering data for future research and development and to focus on demonstrating and monitoring for safety of a standard middeck payload.

  2. Advancements in water vapor electrolysis technology. [for Space Station ECLSS

    NASA Technical Reports Server (NTRS)

    Chullen, Cinda; Heppner, Dennis B.; Sudar, Martin

    1988-01-01

    The paper describes a technology development program whose goal is to develop water vapor electrolysis (WVE) hardware that can be used selectively as localized topping capability in areas of high metabolic activity without oversizing the central air revitalization system on long-duration manned space missions. The WVE will be used primarily to generate O2 for the crew cabin but also to provide partial humidity control by removing water vapor from the cabin atmosphere. The electrochemically based WVE interfaces with cabin air which is controlled in the following ranges: dry bulb temperature of 292 to 300 K; dew point temperature of 278 to 289 K; relative humidity of 25 to 75 percent; and pressure of 101 + or - 1.4 kPa. Design requirements, construction details, and results for both single-cell and multicell module testing are presented, and the preliminary sizing of a multiperson subsystem is discussed.

  3. A model-based understanding of solid-oxide electrolysis cells (SOECs) for syngas production by H2O/CO2 co-electrolysis

    NASA Astrophysics Data System (ADS)

    Menon, Vikram; Fu, Qingxi; Janardhanan, Vinod M.; Deutschmann, Olaf

    2015-01-01

    High temperature co-electrolysis of H2O and CO2 offers a promising route for syngas (H2, CO) production via efficient use of heat and electricity. The performance of a SOEC during co-electrolysis is investigated by focusing on the interactions between transport processes and electrochemical parameters. Electrochemistry at the three-phase boundary is modeled by a modified Butler-Volmer approach that considers H2O electrolysis and CO2 electrolysis, individually, as electrochemically active charge transfer pathways. The model is independent of the geometrical structure. A 42-step elementary heterogeneous reaction mechanism for the thermo-catalytic chemistry in the fuel electrode, the dusty gas model (DGM) to account for multi-component diffusion through porous media, and a plug flow model for flow through the channels are used in the model. Two sets of experimental data are reproduced by the simulations, in order to deduce parameters of the electrochemical model. The influence of micro-structural properties, inlet cathode gas velocity, and temperature are discussed. Reaction flow analysis is performed, at OCV, to study methane production characteristics and kinetics during co-electrolysis. Simulations are carried out for configurations ranging from simple one-dimensional electrochemical button cells to quasi-two-dimensional co-flow planar cells, to demonstrate the effectiveness of the computational tool for performance and design optimization.

  4. PULSE SORTER

    DOEpatents

    Wade, E.J.

    1958-07-29

    An apparatus is described for counting and recording the number of electrical pulses occurring in each of a timed sequence of groups of pulses. The particular feature of the invention resides in a novel timing circuit of the univibrator type which provides very accurately timed pulses for opening each of a series of coincidence channels in sequence. The univibrator is shown incorporated in a pulse analyzing system wherein a series of pulse counting channels are periodically opened in order, one at a time, for a predetermtned open time interval, so that only one channel will be open at the time of occurrence of any of the electrical pulses to be sorted.

  5. High-Speed MALDI MS/MS Imaging Mass Spectrometry Using Continuous Raster Sampling

    PubMed Central

    Prentice, Boone M.; Chumbley, Chad W.; Caprioli, Richard M.

    2015-01-01

    A matrix-assisted laser desorption/ionization time of flight/time of flight tandem mass spectrometer (MALDI TOF/TOF) has been used for high-speed precursor/fragment ion transition image acquisition. High throughput analysis is facilitated by a Nd:YLF solid state laser capable of pulse repetition rates up to 5 kHz, a high digitizer acquisition rate (up to 50 pixels/second), and continuous laser raster sampling. MS/MS experiments are enabled through the use of a precision timed ion selector, second source acceleration, and a dedicated collision cell. Continuous raster sampling is shown here to facilitate rapid MS/MS ion image acquisition from thin tissue sections for the drug rifampicin and of a common kidney lipid, SM4s(d18:1/24:1). The ability to confirm the structural identity of an analyte as part of the MS/MS imaging experiment is an essential part of the analysis. Additionally, the increase in sensitivity and specificity afforded by an MS/MS approach is highly advantageous, especially when interrogating complex chemical environments such as those in biological tissues. Herein, we report continuous laser raster sampling TOF/TOF imaging methodologies which demonstrate 8-14 fold increases in throughput compared to existing MS/MS instrumentation, an important advantage when imaging large areas on tissues. PMID:26149115

  6. A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

    PubMed

    Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

    2015-12-01

    The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors.

  7. THE HIGH-TEMPERATURE ELECTROLYSIS PROGRAM AT THE IDAHO NATIONAL LABORATORY: OBSERVATIONS ON PERFORMANCE DEGRADATION

    SciTech Connect

    J. E. O'Brien; C. M. Stoots; J. S. Herring; K. G. Condie; G. K. Housley

    2009-06-01

    This paper presents an overview of the high-temperature electrolysis research and development program at the Idaho National Laboratory, with selected observations of electrolysis cell degradation at the single-cell, small stack and large facility scales. The objective of the INL program is to address the technical and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for hydrogen production from steam. In the envisioned application, high-temperature electrolysis would be coupled to an advanced nuclear reactor for efficient large-scale non-fossil non-greenhouse-gas hydrogen production. The program supports a broad range of activities including small bench-scale experiments, larger scale technology demonstrations, detailed computational fluid dynamic modeling, and system modeling. A summary of the current status of these activities and future plans will be provided, with a focus on the problem of cell and stack degradation.

  8. A comparative evaluation of different types of microbial electrolysis desalination cells for malic acid production.

    PubMed

    Liu, Guangli; Zhou, Ying; Luo, Haiping; Cheng, Xing; Zhang, Renduo; Teng, Wenkai

    2015-12-01

    The aim of this study was to investigate different microbial electrolysis desalination cells for malic acid production. The systems included microbial electrolysis desalination and chemical-production cell (MEDCC), microbial electrolysis desalination cell (MEDC) with bipolar membrane and anion exchange membrane (BP-A MEDC), MEDC with bipolar membrane and cation exchange membrane (BP-C MEDC), and modified microbial desalination cell (M-MDC). The microbial electrolysis desalination cells performed differently in terms of malic acid production and energy consumption. The MEDCC performed best with the highest malic acid production rate (18.4 ± 0.6 mmol/Lh) and the lowest energy consumption (0.35 ± 0.14 kWh/kg). The best performance of MEDCC was attributable to the neutral pH condition in the anode chamber, the lowest internal resistance, and the highest Geobacter percentage of the anode biofilm population among all the reactors. PMID:26367771

  9. Advancements in oxygen generation and humidity control by water vapor electrolysis

    NASA Technical Reports Server (NTRS)

    Heppner, D. B.; Sudar, M.; Lee, M. C.

    1988-01-01

    Regenerative processes for the revitalization of manned spacecraft atmospheres or other manned habitats are essential for realization of long-term space missions. These processes include oxygen generation through water electrolysis. One promising technique of water electrolysis is the direct conversion of the water vapor contained in the cabin air to oxygen. This technique is the subject of the present program on water vapor electrolysis development. The objectives were to incorporate technology improvements developed under other similar electrochemical programs and add new ones; design and fabricate a mutli-cell electrochemical module and a testing facility; and demonstrate through testing the improvements. Each aspect of the water vapor electrolysis cell was reviewed. The materials of construction and sizing of each element were investigated analytically and sometime experimentally. In addition, operational considerations such as temperature control in response to inlet conditions were investigated. Three specific quantitative goals were established.

  10. Pulse Oximetry

    MedlinePlus

    ... www.thoracic.org amount of gases (oxygen and carbon dioxide) that are in your blood. To get an ... Also, a pulse oximeter does not measure your carbon dioxide level. How accurate is the pulse oximeter? The ...

  11. Stainless steel anodes for alkaline water electrolysis and methods of making

    SciTech Connect

    Soloveichik, Grigorii Lev

    2014-01-21

    The corrosion resistance of stainless steel anodes for use in alkaline water electrolysis was increased by immersion of the stainless steel anode into a caustic solution prior to electrolysis. Also disclosed herein are electrolyzers employing the so-treated stainless steel anodes. The pre-treatment process provides a stainless steel anode that has a higher corrosion resistance than an untreated stainless steel anode of the same composition.

  12. High performance of nitrogen and phosphorus removal in an electrolysis-integrated biofilter.

    PubMed

    Gao, Y; Xie, Y W; Zhang, Q; Yu, Y X; Yang, L Y

    2016-01-01

    A novel electrolysis-integrated biofilter system was developed in this study to evaluate the intensified removal of nitrogen and phosphorus from contaminated water. Two laboratory-scale biofilter systems were established, one with electrolysis (E-BF) and one without electrolysis (BF) as control. The dynamics of intensified nitrogen and phosphorus removal and the changes of inflow and outflow water qualities were also evaluated. The total nitrogen (TN) removal rate was 94.4% in our newly developed E-BF, but only 74.7% in the control BF. Ammonium removal rate was up to 95% in biofilters with or without electrolysis integration with an influent ammonium concentration of 40 mg/L, and the accumulation of nitrate and nitrite was much lower in the effluent of E-BF than that of BF. Thus electrolysis plays an important role in TN removal especially the nitrate and nitrite removal. Phosphorus removal was significantly enhanced, exceeding 90% in E-BF by chemical precipitation, physical adsorption, and flocculation of phosphorus because of the in situ formation of ferric ions by the anodizing of sacrificial iron anodes. Results from this study indicate that the electrolysis integrated biofilter is a promising solution for intensified nitrogen and phosphorus removal. PMID:27508376

  13. Inactivation characteristics of ozone and electrolysis process for ballast water treatment using B. subtilis spores as a probe.

    PubMed

    Jung, Youmi; Yoon, Yeojoon; Hong, Eunkyung; Kwon, Minhwan; Kang, Joon-Wun

    2013-07-15

    Since ballast water affects the ocean ecosystem, the International Maritime Organization (IMO) sets a standard for ballast water management and might impose much tighter regulations in the future. The aim of this study is to evaluate the inactivation efficiency of ozonation, electrolysis, and an ozonation-electrolysis combined process, using B. subtilis spores. In seawater ozonation, HOBr is the key active substance for inactivation, because of rapid reactivity of ozone with Br(-) in seawater. In seawater electrolysis, it is also HOBr, but not HOCl, because of the rapid reaction of HOCl with Br(-), which has not been recognized carefully, even though many electrolysis technologies have been approved by the IMO. Inactivation pattern was different in ozonation and electrolysis, which has some limitations with the tailing or lag-phase, respectively. However, each deficiency can be overcome with a combined process, which is most effective as a sequential application of ozonation followed by electrolysis.

  14. PULSE GENERATOR

    DOEpatents

    Roeschke, C.W.

    1957-09-24

    An improvement in pulse generators is described by which there are produced pulses of a duration from about 1 to 10 microseconds with a truly flat top and extremely rapid rise and fall. The pulses are produced by triggering from a separate input or by modifying the current to operate as a free-running pulse generator. In its broad aspect, the disclosed pulse generator comprises a first tube with an anode capacitor and grid circuit which controls the firing; a second tube series connected in the cathode circuit of the first tube such that discharge of the first tube places a voltage across it as the leading edge of the desired pulse; and an integrator circuit from the plate across the grid of the second tube to control the discharge time of the second tube, determining the pulse length.

  15. High Temperature Electrolysis Pressurized Experiment Design, Operation, and Results

    SciTech Connect

    J.E. O'Brien; X. Zhang; G.K. Housley; K. DeWall; L. Moore-McAteer

    2012-09-01

    A new facility has been developed at the Idaho National Laboratory for pressurized testing of solid oxide electrolysis stacks. Pressurized operation is envisioned for large-scale hydrogen production plants, yielding higher overall efficiencies when the hydrogen product is to be delivered at elevated pressure for tank storage or pipelines. Pressurized operation also supports higher mass flow rates of the process gases with smaller components. The test stand can accommodate planar cells with dimensions up to 8.5 cm x 8.5 cm and stacks of up to 25 cells. It is also suitable for testing other cell and stack geometries including tubular cells. The pressure boundary for these tests is a water-cooled spool-piece pressure vessel designed for operation up to 5 MPa. Pressurized operation of a ten-cell internally manifolded solid oxide electrolysis stack has been successfully demonstrated up 1.5 MPa. The stack is internally manifolded and operates in cross-flow with an inverted-U flow pattern. Feed-throughs for gas inlets/outlets, power, and instrumentation are all located in the bottom flange. The entire spool piece, with the exception of the bottom flange, can be lifted to allow access to the internal furnace and test fixture. Lifting is accomplished with a motorized threaded drive mechanism attached to a rigid structural frame. Stack mechanical compression is accomplished using springs that are located inside of the pressure boundary, but outside of the hot zone. Initial stack heatup and performance characterization occurs at ambient pressure followed by lowering and sealing of the pressure vessel and subsequent pressurization. Pressure equalization between the anode and cathode sides of the cells and the stack surroundings is ensured by combining all of the process gases downstream of the stack. Steady pressure is maintained by means of a backpressure regulator and a digital pressure controller. A full description of the pressurized test apparatus is provided in this

  16. Note: Emittance measurements of intense pulsed proton beam for different pulse length and repetition rate

    SciTech Connect

    Miracoli, R.; Gammino, S.; Celona, L.; Mascali, D.; Castro, G.; Gobin, R.; Delferriere, O.; Adroit, G.; Senee, F.; Ciavola, G.

    2012-05-15

    The high intensity ion source (SILHI), in operation at CEA-Saclay, has been used to produce a 90 mA pulsed proton beam with pulse length and repetition rates suitable for the European Spallation Source (ESS) linac. Typical r-r{sup '} rms normalized emittance values smaller than 0.2{pi} mm mrad have been measured for operation in pulsed mode (0.01 < duty cycle < 0.15 and 1 ms < pulse duration < 10 ms) that are relevant for the design update of the Linac to be used at the ESS in Lund.

  17. Systems Engineering Provides Successful High Temperature Steam Electrolysis Project

    SciTech Connect

    Charles V. Park; Emmanuel Ohene Opare, Jr.

    2011-06-01

    This paper describes two Systems Engineering Studies completed at the Idaho National Laboratory (INL) to support development of the High Temperature Stream Electrolysis (HTSE) process. HTSE produces hydrogen from water using nuclear power and was selected by the Department of Energy (DOE) for integration with the Next Generation Nuclear Plant (NGNP). The first study was a reliability, availability and maintainability (RAM) analysis to identify critical areas for technology development based on available information regarding expected component performance. An HTSE process baseline flowsheet at commercial scale was used as a basis. The NGNP project also established a process and capability to perform future RAM analyses. The analysis identified which components had the greatest impact on HTSE process availability and indicated that the HTSE process could achieve over 90% availability. The second study developed a series of life-cycle cost estimates for the various scale-ups required to demonstrate the HTSE process. Both studies were useful in identifying near- and long-term efforts necessary for successful HTSE process deployment. The size of demonstrations to support scale-up was refined, which is essential to estimate near- and long-term cost and schedule. The life-cycle funding profile, with high-level allocations, was identified as the program transitions from experiment scale R&D to engineering scale demonstration.

  18. Modeling Degradation in Solid Oxide Electrolysis Cells - Volume II

    SciTech Connect

    Manohar Motwani

    2011-09-01

    Idaho National Laboratory has an ongoing project to generate hydrogen from steam using solid oxide electrolysis cells (SOECs). To accomplish this, technical and degradation issues associated with the SOECs will need to be addressed. This report covers various approaches being pursued to model degradation issues in SOECs. An electrochemical model for degradation of SOECs is presented. The model is based on concepts in local thermodynamic equilibrium in systems otherwise in global thermodynamic non-equilibrium. It is shown that electronic conduction through the electrolyte, however small, must be taken into account for determining local oxygen chemical potential,, within the electrolyte. The within the electrolyte may lie out of bounds in relation to values at the electrodes in the electrolyzer mode. Under certain conditions, high pressures can develop in the electrolyte just near the oxygen electrode/electrolyte interface, leading to oxygen electrode delamination. These predictions are in accordance with the reported literature on the subject. Development of high pressures may be avoided by introducing some electronic conduction in the electrolyte. By combining equilibrium thermodynamics, non-equilibrium (diffusion) modeling, and first-principles, atomic scale calculations were performed to understand the degradation mechanisms and provide practical recommendations on how to inhibit and/or completely mitigate them.

  19. Electrolysis Performance Improvement Concept Study (EPICS) Flight Experiment-Reflight

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.

    1997-01-01

    The Electrolysis Performance Improvement Concept Study (EPICS) is a flight experiment to demonstrate and validate in a microgravity environment the Static Feed Electrolyzer (SFE) concept which was selected for the use aboard the International Space Station (ISS) for oxygen (O2) generation. It also is to investigate the impact of microgravity on electrochemical cell performance. Electrochemical cells are important to the space program because they provide an efficient means of generating O2 and hydrogen (H2) in space. Oxygen and H2 are essential not only for the survival of humans in space but also for the efficient and economical operation of various space systems. Electrochemical cells can reduce the mass, volume and logistical penalties associated with resupply and storage by generating and/or consuming these gases in space. An initial flight of the EPICS was conducted aboard STS-69 from September 7 to 8, 1995. A temperature sensor characteristics shift and a missing line of software code resulted in only partial success of this initial flight. Based on the review and recommendations of a National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC) review team a reflight activity was initiated to obtain the remaining desired results, not achieved during the initial flight.

  20. Oxygen production by electrolysis of molten lunar regolith

    NASA Technical Reports Server (NTRS)

    Haskin, Larry A.

    1990-01-01

    The goal of this study was threefold. First, the theoretical energy requirements of the process were to be defined. This includes studies of the relevant oxidation-reduction reactions in the melt, their kinetics and energies of reaction, and experimental determination of production efficiencies and melt resistivities as functions of melt composition and applied potential. Second, the product(s) of silicate electrolysis were to be characterized. This includes: (1) evaluating the phase relationships in the systems SiO2-TiO2-Al2O3-MgO-FeO-CaO and Fe-Si; (2) estimating the compositions of the metal products as a function of applied potential and feedstock composition based on phase equilibria in the Fe-Si system and free energy values for SiO2 and FeO reported in the literature; (3) definition of compositions of products in actual experiments; and (4) definition of the form the product takes (whether phases separate or remain fixed, whether crystals settle or float in the remaining melt, and how large crystals form). Third, materials for these highly corrosive high-temperature silicate melts were to be identified. This includes identifing materials that may be either inert or thermodynamically stable in these melts, and experimental testing of the materials to confirm that they do not deteriorate. The results are discussed within this framework.

  1. Aqueous organic dye discoloration induced by contact glow discharge electrolysis.

    PubMed

    Wang, Lei

    2009-11-15

    In this study, effects of applied voltage, types of electrolytes, initial substrate concentration, radical scavengers and iron salts on the aqueous polar brilliant B (PBB) discoloration induced by contact glow discharge electrolysis (CGDE) were examined. Experimental results showed that the PBB discoloration proceeded faster in chloride solution than in phosphate or sulfate solutions. Increasing the applied voltage from 450V to 550V did not enhance the discoloration when the applied current was kept constant. Addition of a small amount of hydroxyl scavengers (methanol) to the solution decreased the discoloration, whereas addition of a large amount of methanol increased the discoloration. During the treatment, TOC of the solution smoothly decreased whereas COD of the solution gradually increased due to the production of H(2)O(2) in the liquid phase. Iron salts enhanced the discoloration significantly due to the additional Fenton reaction. Higher initial PBB concentration resulted in lower color removal efficiency, indicating that the PBB discoloration by CGDE did not observe the first-order reaction kinetics in inert electrolytic solutions. PMID:19581050

  2. Electrode kinetics of a water vapor electrolysis cell

    NASA Technical Reports Server (NTRS)

    Jacobs, G.

    1974-01-01

    The anodic electrochemical behavior of the water vapor electrolysis cell was investigated. A theoretical review of various aspects of cell overvoltage is presented with special emphasis on concentration overvoltage and activation overvoltage. Other sources of overvoltage are described. The experimental apparatus controlled and measured anode potential and cell current. Potentials between 1.10 and 2.60 V (vs NHE) and currents between 0.1 and 3000 mA were investigated. Different behavior was observed between the standard cell and the free electrolyte cell. The free electrolyte cell followed typical Tafel behavior (i.e. activation overvoltage) with Tafel slopes of about 0.15, and the exchange current densities of 10 to the minus 9th power A/sq cm, both in good agreement with literature values. The standard cell exhibitied this same Tafel behavior at lower current densities but deviated toward lower than expected current densities at higher potentials. This behavior and other results were examined to determine their origin.

  3. Controlled Growth of one-dimensional zinc oxide nanostructures in the pulsed electrodeposition mode

    SciTech Connect

    Klochko, N. P. Khrypunov, G. S.; Myagchenko, Yu. O.; Melnychuk, E. E.; Kopach, V. R.; Klepikova, E. S.; Lyubov, V. M.; Kopach, A. V.

    2012-06-15

    Zinc oxide nanostructures are objects of study in the field of optoelectronics, solar power engineering, nanosensorics, and catalysis. For the purpose of the controlled growth of one-dimensional submicrometer zinc oxide structures in the pulsed electrodeposition mode, the effect of the pulse electrolysis parameters on the morphology of ZnO layers, their optical properties, and structural and substructural characteristics is determined using X-ray diffraction, optical spectrophotometry, and atomic-force microscopy. The possibility of fabricating arrays of ZnO nanowires with different geometrical shapes, perpendicular to the substrate surface, by varying the frequency of cathode-substrate potential pulses is shown.

  4. Pulse stretcher

    DOEpatents

    Horton, J.A.

    1994-05-03

    Apparatus for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse is disclosed. The apparatus uses a White cell having a plurality of optical delay paths of successively increasing number of passes between the field mirror and the objective mirrors. A pulse from a laser travels through a multi-leg reflective path between a beam splitter and a totally reflective mirror to the laser output. The laser pulse is also simultaneously injected through the beam splitter to the input mirrors of the optical delay paths. The pulses from the output mirrors of the optical delay paths go simultaneously to the laser output and to the input mirrors of the longer optical delay paths. The beam splitter is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output. 6 figures.

  5. Composition pulse time-of-flight mass flow sensor

    DOEpatents

    Harnett, Cindy K.; Crocker, Robert W.; Mosier, Bruce P.; Caton, Pamela F.; Stamps, James F.

    2007-06-05

    A device for measuring fluid flow rates over a wide range of flow rates (<1 nL/min to >10 .mu.L/min) and at pressures at least as great as 2,000 psi. The invention is particularly adapted for use in microfluidic systems. The device operates by producing compositional variations in the fluid, or pulses, that are subsequently detected downstream from the point of creation to derive a flow rate. Each pulse, comprising a small fluid volume, whose composition is different from the mean composition of the fluid, can be created by electrochemical means, such as by electrolysis of a solvent, electrolysis of a dissolved species, or electrodialysis of a dissolved ionic species. Measurements of the conductivity of the fluid can be used to detect the arrival time of the pulses, from which the fluid flow rate can be determined. A pair of spaced apart electrodes can be used to produce the electrochemical pulse. In those instances where it is desired to measure a wide range of fluid flow rates a three electrode configuration in which the electrodes are spaced at unequal distances has been found to be desirable.

  6. Sensitivity of GC-EI/MS, GC-EI/MS/MS, LC-ESI/MS/MS, LC-Ag(+) CIS/MS/MS, and GC-ESI/MS/MS for analysis of anabolic steroids in doping control.

    PubMed

    Cha, Eunju; Kim, Sohee; Kim, Ho Jun; Lee, Kang Mi; Kim, Ki Hun; Kwon, Oh-Seung; Lee, Jaeick

    2015-01-01

    This study compared the sensitivity of various separation and ionization methods, including gas chromatography with an electron ionization source (GC-EI), liquid chromatography with an electrospray ionization source (LC-ESI), and liquid chromatography with a silver ion coordination ion spray source (LC-Ag(+) CIS), coupled to a mass spectrometer (MS) for steroid analysis. Chromatographic conditions, mass spectrometric transitions, and ion source parameters were optimized. The majority of steroids in GC-EI/MS/MS and LC-Ag(+) CIS/MS/MS analysis showed higher sensitivities than those obtained with other analytical methods. The limits of detection (LODs) of 65 steroids by GC-EI/MS/MS, 68 steroids by LC-Ag(+) CIS/MS/MS, 56 steroids by GC-EI/MS, 54 steroids by LC-ESI/MS/MS, and 27 steroids by GC-ESI/MS/MS were below cut-off value of 2.0 ng/mL. LODs of steroids that formed protonated ions in LC-ESI/MS/MS analysis were all lower than the cut-off value. Several steroids such as unconjugated C3-hydroxyl with C17-hydroxyl structure showed higher sensitivities in GC-EI/MS/MS analysis relative to those obtained using the LC-based methods. The steroids containing 4, 9, 11-triene structures showed relatively poor sensitivities in GC-EI/MS and GC-ESI/MS/MS analysis. The results of this study provide information that may be useful for selecting suitable analytical methods for confirmatory analysis of steroids.

  7. Sensitivity of GC-EI/MS, GC-EI/MS/MS, LC-ESI/MS/MS, LC-Ag(+) CIS/MS/MS, and GC-ESI/MS/MS for analysis of anabolic steroids in doping control.

    PubMed

    Cha, Eunju; Kim, Sohee; Kim, Ho Jun; Lee, Kang Mi; Kim, Ki Hun; Kwon, Oh-Seung; Lee, Jaeick

    2015-01-01

    This study compared the sensitivity of various separation and ionization methods, including gas chromatography with an electron ionization source (GC-EI), liquid chromatography with an electrospray ionization source (LC-ESI), and liquid chromatography with a silver ion coordination ion spray source (LC-Ag(+) CIS), coupled to a mass spectrometer (MS) for steroid analysis. Chromatographic conditions, mass spectrometric transitions, and ion source parameters were optimized. The majority of steroids in GC-EI/MS/MS and LC-Ag(+) CIS/MS/MS analysis showed higher sensitivities than those obtained with other analytical methods. The limits of detection (LODs) of 65 steroids by GC-EI/MS/MS, 68 steroids by LC-Ag(+) CIS/MS/MS, 56 steroids by GC-EI/MS, 54 steroids by LC-ESI/MS/MS, and 27 steroids by GC-ESI/MS/MS were below cut-off value of 2.0 ng/mL. LODs of steroids that formed protonated ions in LC-ESI/MS/MS analysis were all lower than the cut-off value. Several steroids such as unconjugated C3-hydroxyl with C17-hydroxyl structure showed higher sensitivities in GC-EI/MS/MS analysis relative to those obtained using the LC-based methods. The steroids containing 4, 9, 11-triene structures showed relatively poor sensitivities in GC-EI/MS and GC-ESI/MS/MS analysis. The results of this study provide information that may be useful for selecting suitable analytical methods for confirmatory analysis of steroids. PMID:26489966

  8. Primary-Progressive MS (PPMS)

    MedlinePlus

    ... MS? Types of MS Primary progressive MS (PPMS) Primary progressive MS (PPMS) Share Smaller Text Larger Text Print In this article Overview PPMS is characterized by worsening neurologic function ( ...

  9. Pulse Voltammetry

    NASA Astrophysics Data System (ADS)

    Stojek, Zbigniew

    The idea of imposing potential pulses and measuring the currents at the end of each pulse was proposed by Barker in a little-known journal as early as in 1958 [1]. However, the first reliable trouble-free and affordable polarographs offering voltammetric pulse techniques appeared on the market only in the 1970s. This delay was due to some limitations on the electronic side. In the 1990s, again substantial progress in electrochemical pulse instrumentation took place. This was related to the introduction of microprocessors, computers, and advanced software.

  10. Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial

    PubMed Central

    Arias-Buría, José L.; Truyols-Domínguez, Sebastián; Valero-Alcaide, Raquel; Salom-Moreno, Jaime; Atín-Arratibel, María A.; Fernández-de-las-Peñas, César

    2015-01-01

    Objective. To compare effects of ultrasound- (US-) guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n = 17) group or exercise (n = 19) group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions). Shoulder pain (NPRS) and disability (DASH) were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P < 0.01): individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention. PMID:26649058

  11. Electrolysis byproduct D2O provides a third way to mitigate CO2

    SciTech Connect

    Schenewerk, William Ernest

    2009-09-01

    Rapid atomic power deployment may be possible without using fast breeder reactors or making undue demands on uranium resource. Using by-product D2O and thorium-U233 in CANDU and RBMK piles may circumvent need for either fast breeder reactors or seawater uranium. Atmospheric CO2 is presently increasing 2.25%/year in proportion to 2.25%/year exponential fossil fuel consumption increase. Roughly 1/3 anthropologic CO2 is removed by various CO2 sinks. CO2 removal is modelled as being proportional to 45-year-earlier CO2 amount above 280 ppm-C Water electrolysis produces roughly 0.1 kg-D20/kWe-y. Material balance assumes each electrolysis stage increases D2O bottoms concentration times 3. Except for first two electrolysis stages, all water from hydrogen consumption is returned to electrolysis. The unique characteristic of this process is the ability to economically burn all deuterium-enriched H2 in vehicles. Condensate from vehicles returns to appropriate electrolysis stage. Fuel cell condensate originally from reformed natural gas may augment second-sage feed. Atomic power expansion is 5%/year, giving 55000 GWe by 2100. World primary energy increases 2.25%/y, exceeding 4000 EJ/y by 2100. CO2 maximum is roughly 600 ppm-C around year 2085. CO2 declines back below 300 ppm-C by 2145 if the 45-year-delay seawater sink remains effective.

  12. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

    PubMed

    Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

    2014-08-01

    A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions. PMID:24784452

  13. Simultaneous treatment of washing, disinfection and sterilization using ultrasonic levitation, silver electrolysis and ozone oxidation.

    PubMed

    Ueda, Toyotoshi; Hara, Masanori; Odagawa, Ikumi; Shigihara, Takanori

    2009-03-01

    A new type of ultrasonic washer-disinfector-sterilizer, able to clean, disinfect and sterilize most kinds of reusable medical devices, has been developed by using the ultrasonic levitation function with umbrella-shape oscillators and ozone bubbling together with sterilization carried out by silver electrolysis. We have examined the biomedical and physicochemical performance of this instrument. Prokariotic and gram-negative Escherichia coli and eukariotic Saccharomyces cerevisiae were killed by silver electrolysis in 18 min and 1 min, respectively. Prokariotic and gram-positive Geobacillus stearothermophilus and Bacillus atrophaeus, which are most resistant to autoclave and gas sterilization, respectively, were killed by silver electrolysis within 20 min. Prokariotic and gram-negative Pseudomonas aeruginosa was also killed by silver electrolysis in 10 min. The intensity distribution of the ultrasonic levitation waves was homogeneous throughout the tank. The concentration of ozone gas was 2.57 mg/ kg. The concentration of dissolved silver ions was around 0.17 mg/L. The disulfide bond in proteins was confirmed to be destroyed by silver electrolysis. PMID:19344093

  14. Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial.

    PubMed

    Arias-Buría, José L; Truyols-Domínguez, Sebastián; Valero-Alcaide, Raquel; Salom-Moreno, Jaime; Atín-Arratibel, María A; Fernández-de-Las-Peñas, César

    2015-01-01

    Objective. To compare effects of ultrasound- (US-) guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n = 17) group or exercise (n = 19) group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions). Shoulder pain (NPRS) and disability (DASH) were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P < 0.01): individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention. PMID:26649058

  15. Performance Assessment of Single Electrode-Supported Solid Oxide Cells Operating in the Steam Electrolysis Mode

    SciTech Connect

    X. Zhang; J. E. O'Brien; R. C. O'Brien; N. Petigny

    2011-11-01

    An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production. Results presented in this paper were obtained from single cells, with an active area of 16 cm{sup 2} per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes ({approx}10 {mu}m thick), nickel-YSZ steam/hydrogen electrodes ({approx}1400 {mu}m thick), and modified LSM or LSCF air-side electrodes ({approx}90 {mu}m thick). The purpose of the present study is to document and compare the performance and degradation rates of these cells in the fuel cell mode and in the electrolysis mode under various operating conditions. Initial performance was documented through a series of voltage-current (VI) sweeps and AC impedance spectroscopy measurements. Degradation was determined through long-term testing, first in the fuel cell mode, then in the electrolysis mode. Results generally indicate accelerated degradation rates in the electrolysis mode compared to the fuel cell mode, possibly due to electrode delamination. The paper also includes details of an improved single-cell test apparatus developed specifically for these experiments.

  16. Ultrasound-Guided Percutaneous Electrolysis and Eccentric Exercises for Subacromial Pain Syndrome: A Randomized Clinical Trial.

    PubMed

    Arias-Buría, José L; Truyols-Domínguez, Sebastián; Valero-Alcaide, Raquel; Salom-Moreno, Jaime; Atín-Arratibel, María A; Fernández-de-Las-Peñas, César

    2015-01-01

    Objective. To compare effects of ultrasound- (US-) guided percutaneous electrolysis combined with an eccentric exercise program of the rotator cuff muscles in subacromial pain syndrome. Methods. Thirty-six patients were randomized and assigned into US-guided percutaneous electrolysis (n = 17) group or exercise (n = 19) group. Patients were asked to perform an eccentric exercise program of the rotator cuff muscles twice every day for 4 weeks. Participants assigned to US-guided percutaneous electrolysis group also received the application of galvanic current through acupuncture needle on each session once a week (total 4 sessions). Shoulder pain (NPRS) and disability (DASH) were assessed at baseline, after 2 sessions, and 1 week after the last session. Results. The ANOVA revealed significant Group∗Time interactions for shoulder pain and disability (all, P < 0.01): individuals receiving US-guided percutaneous electrolysis combined with the eccentric exercises experienced greater improvement than those receiving eccentric exercise alone. Conclusions. US-guided percutaneous electrolysis combined with eccentric exercises resulted in small better outcomes at short term compared to when only eccentric exercises were applied in subacromial pain syndrome. The effect was statistically and clinically significant for shoulder pain but below minimal clinical difference for function. Future studies should investigate the long-term effects and potential placebo effect of this intervention.

  17. Intensified nitrogen and phosphorus removal in a novel electrolysis-integrated tidal flow constructed wetland system.

    PubMed

    Ju, Xinxin; Wu, Shubiao; Zhang, Yansheng; Dong, Renjie

    2014-08-01

    A novel electrolysis-integrated tidal flow constructed wetland (CW) system was developed in this study. The dynamics of intensified nitrogen and phosphorus removal and that of hydrogen sulphide control were evaluated. Ammonium removal of up to 80% was achieved with an inflow concentration of 60 mg/L in wetland systems with and without electrolysis integration. Effluent nitrate concentration decreased from 2 mg/L to less than 0.5 mg/L with the decrease in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2) in the electrolysis-integrated wetland system, thus indicating that the current intensity of electrolysis plays an important role in nitrogen transformations. Phosphorus removal was significantly enhanced, exceeding 95% in the electrolysis-integrated CW system because of the in-situ formation of a ferric iron coagulant through the electro-dissolution of a sacrificial iron anode. Moreover, the electrolyzed wetland system effectively inhibits sulphide accumulation as a result of a sulphide precipitation coupled with ferrous-iron electro-dissolution and/or an inhibition of bacterial sulphate reduction under increased aerobic conditions.

  18. Design of an Integrated Laboratory Scale Test for Hydrogen Production via High Temperature Electrolysis

    SciTech Connect

    G.K. Housley; K.G. Condie; J.E. O'Brien; C. M. Stoots

    2007-06-01

    The Idaho National Laboratory (INL) is researching the feasibility of high-temperature steam electrolysis for high-efficiency carbon-free hydrogen production using nuclear energy. Typical temperatures for high-temperature electrolysis (HTE) are between 800º-900ºC, consistent with anticipated coolant outlet temperatures of advanced high-temperature nuclear reactors. An Integrated Laboratory Scale (ILS) test is underway to study issues such as thermal management, multiple-stack electrical configuration, pre-heating of process gases, and heat recuperation that will be crucial in any large-scale implementation of HTE. The current ILS design includes three electrolysis modules in a single hot zone. Of special design significance is preheating of the inlet streams by superheaters to 830°C before entering the hot zone. The ILS system is assembled on a 10’ x 16’ skid that includes electronics, power supplies, air compressor, pumps, superheaters, , hot zone, condensers, and dew-point sensor vessels. The ILS support system consists of three independent, parallel supplies of electrical power, sweep gas streams, and feedstock gas mixtures of hydrogen and steam to the electrolysis modules. Each electrolysis module has its own support and instrumentation system, allowing for independent testing under different operating conditions. The hot zone is an insulated enclosure utilizing electrical heating panels to maintain operating conditions. The target hydrogen production rate for the ILS is 5000 Nl/hr.

  19. Ms. Mentor Unmasked

    ERIC Educational Resources Information Center

    Krebs, Paula

    2008-01-01

    This article presents an interview with Emily Toth, who writes the monthly "Ms. Mentor" academic advice column in the "Chronicle of Higher Education" and teaches in the English department at Louisiana State University, in Baton Rouge. She is the author of "Ms. Mentor's Impeccable Advice for Women in Academia" (1997), "Inside Peyton Place: The Life…

  20. Overview of High-Temperature Electrolysis for Hydrogen Production

    SciTech Connect

    Herring, J. S.; O'Brien, J. E.; Stoots, C. M.; Hartvigsen, J. J.; Petri, M. C.; Carter, J. D.; Bischoff, B. L.

    2007-06-01

    Over the last five years there has been a growing interest in the use of hydrogen as an energy carrier, particularly to augment transportation fuels and thus reduce our dependence on imported petroleum. Hydrogen is now produced primarily via steam reforming of methane. However, in the long term, methane reforming is not a viable process for the large-scale hydrogen production since such fossil fuel conversion processes consume non-renewable resources and emit greenhouse gases. Nuclear energy can be used to produce hydrogen without consuming fossil fuels and without emitting greenhouse gases through the splitting of water into hydrogen and oxygen. The Nuclear Hydrogen Initiative of the DOE Office of Nuclear Energy is developing three general categories of high temperature processes for hydrogen production: thermochemical, electrolytic and hybrid thermo-electrolytic. This paper introduces the work being done in the development of high temperature electrolysis of steam. High Temperature Electrolysis (HTE) is built on the technology of solid oxide fuel cells (SOFCs), which were invented over a century ago, but which have been most vigorously developed during the last twenty years. SOFCs consume hydrogen and oxygen and produce steam and electricity. Solid Oxide Electrolytic Cells (SOECs) consume electricity and steam and produce hydrogen and oxygen. The purpose of the HTE research is to solve those problems unique to the electrolytic mode of operation, while building further on continuing fuel cell development. ORGANIZATION Experiments have been conducted for the last three years at the Idaho National Laboratory and at Ceramatec, Inc. on the operation of button cells and of progressively larger stacks of planar cells. In addition, the INL has been performing analyses of the cell-scale fluid dynamics and plant-scale flowsheets in order to determine optimum operating conditions and plant configurations. Argonne National Laboratory has been performing experiments for the

  1. PULSE AMPLIFIER

    DOEpatents

    Johnstone, C.W.

    1958-06-17

    The improvement of pulse amplifiers used with scintillation detectors is described. The pulse amplifier circuit has the advantage of reducing the harmful effects of overloading cause by large signal inputs. In general the pulse amplifier circuit comprises two amplifier tubes with the input pulses applied to one amplifier grid and coupled to the second amplifier tube through a common cathode load. The output of the second amplifier is coupled from the plate circuit to a cathode follower tube grid and a diode tube in connected from grid to cathode of the cathode follower tube. Degenerative feedback is provided in the second amplifier by coupling a signal from the cathode follower cathode to the second amplifier grid. The circuit proqides moderate gain stability, and overload protection for subsequent pulse circuits.

  2. MS/MS Automated Selected Ion Chromatograms

    2005-12-12

    This program can be used to read a LC-MS/MS data file from either a Finnigan ion trap mass spectrometer (.Raw file) or an Agilent Ion Trap mass spectrometer (.MGF and .CDF files) and create a selected ion chromatogram (SIC) for each of the parent ion masses chosen for fragmentation. The largest peak in each SIC is also identified, with reported statistics including peak elution time, height, area, and signal to noise ratio. It creates severalmore » output files, including a base peak intensity (BPI) chromatogram for the survey scan, a BPI for the fragmentation scans, an XML file containing the SIC data for each parent ion, and a "flat file" (ready for import into a database) containing summaries of the SIC data statistics.« less

  3. Combined uranous nitrate production consisting of undivided electrolytic cell and divided electrolytic cell (Electrolysis → Electrolytic cell)

    SciTech Connect

    Yuan, Zhongwei; Yan, Taihong; Zheng, Weifang; Li, Xiaodong; Yang, Hui; Xian, Liang

    2013-07-01

    The electrochemical reduction of uranyl nitrate is a green, mild way to make uranous ions. Undivided electrolyzers whose maintenance is less but their conversion ratio and current efficiency are low, have been chosen. However, at the beginning of undivided electrolysis, high current efficiency can also be maintained. Divided electrolyzers' conversion ratio and current efficiency is much higher because the re-oxidation of uranous on anode is avoided, but their maintenance costs are more, because in radioactive environment the membrane has to be changed after several operations. In this paper, a combined method of uranous production is proposed which consists of 2 stages: undivided electrolysis (early stage) and divided electrolysis (late stage) to benefit from the advantages of both electrolysis modes. The performance of the combined method was tested. The results show that in combined mode, after 200 min long electrolysis (80 min undivided electrolysis and 120 min divided electrolysis), U(IV) yield can achieve 92.3% (500 ml feed, U 199 g/l, 72 cm{sup 2} cathode, 120 mA/cm{sup 2}). Compared with divided mode, about 1/3 working time in divided electrolyzer is reduced to achieve the same U(IV) yield. If 120 min long undivided electrolysis was taken, more than 1/2 working time can be reduced in divided electrolyzer, which means that about half of the maintenance cost can also be reduced. (authors)

  4. Hydrogen production from switchgrass via a hybrid pyrolysis-microbial electrolysis process

    SciTech Connect

    Lewis, Alex J.; Ren, Shoujie; Ye, Philip; Kim, Pyoungchung; Labbe, Niki; Borole, Abhijeet P.

    2015-06-30

    A new approach to hydrogen production using a hybrid pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50 3.2% to76 0.5% while anode coulombic efficiency ranged from 54 6.5% to 96 0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%, respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass.

  5. Hydrogen production from switchgrass via an integrated pyrolysis-microbial electrolysis process.

    PubMed

    Lewis, A J; Ren, S; Ye, X; Kim, P; Labbe, N; Borole, A P

    2015-11-01

    A new approach to hydrogen production using an integrated pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L anode-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50±3.2% to 76±0.5% while anode Coulombic efficiency ranged from 54±6.5% to 96±0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%, respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass.

  6. Thermal and Electrochemical Performance of a High-Temperature Steam Electrolysis Stack

    SciTech Connect

    J. O'Brien; C. Stoots; G. Hawkes; J. Hartvigsen

    2006-11-01

    A research program is under way at the Idaho National Laboratory (INL) to simultaneously address the research and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for hydrogen production from steam. We are conducting a progression of electrolysis stack testing activities, at increasing scales, along with a continuation of supporting research activities in the areas of materials development, single-cell testing, detailed computational fluid dynamics (CFD) and systems modeling. This paper will present recent experimental results obtained from testing of planar solid-oxide stacks operating in the electrolysis mode. The hydrogen-production and electrochemical performance of these stacks will be presented, over a range of operating conditions. In addition, internal stack temperature measurements will be presented, with comparisons to computational fluid dynamic predictions.

  7. A Feasibility Study of Steelmaking by Molten Oxide Electrolysis (TRP9956)

    SciTech Connect

    Donald R. Sadoway; Gerbrand Ceder

    2009-12-31

    Molten oxide electrolysis (MOE) is an extreme form of molten salt electrolysis, a technology that has been used to produce tonnage metals for over 100 years - aluminum, magnesium, lithium, sodium and the rare earth metals specifically. The use of carbon-free anodes is the distinguishing factor in MOE compared to other molten salt electrolysis techniques. MOE is totally carbon-free and produces no CO or CO2 - only O2 gas at the anode. This project is directed at assessing the technical feasibility of MOE at the bench scale while determining optimum values of MOE operating parameters. An inert anode will be identified and its ability to sustain oxygen evalution will be demonstrated.

  8. Solid polymer electrolyte water electrolysis system development. [to generate oxygen for manned space station applications

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Solid polymer electrolyte technology used in a water electrolysis system (WES) to generate oxygen and hydrogen for manned space station applications was investigated. A four-man rated, low pressure breadboard water electrolysis system with the necessary instrumentation and controls was fabricated and tested. A six man rated, high pressure, high temperature, advanced preprototype WES was developed. This configuration included the design and development of an advanced water electrolysis module, capable of operation at 400 psig and 200 F, and a dynamic phase separator/pump in place of a passive phase separator design. Evaluation of this system demonstrated the goal of safe, unattended automated operation at high pressure and high temperature with an accumulated gas generation time of over 1000 hours.

  9. Microbial electrolysis cells for high yield hydrogen gas production from organic matter.

    PubMed

    Logan, Bruce E; Call, Douglas; Cheng, Shaoan; Hamelers, Hubertus V M; Sleutels, Tom H J A; Jeremiasse, Adriaan W; Rozendal, René A

    2008-12-01

    The use of electrochemically active bacteria to break down organic matter, combined with the addition of a small voltage (> 0.2 V in practice) in specially designed microbial electrolysis cells (MECs), can result in a high yield of hydrogen gas. While microbial electrolysis was invented only a few years ago, rapid developments have led to hydrogen yields approaching 100%, energy yields based on electrical energy input many times greater than that possible by water electrolysis, and increased gas production rates. MECs used to make hydrogen gas are similar in design to microbial fuel cells (MFCs) that produce electricity, but there are important differences in architecture and analytical methods used to evaluate performance. We review here the materials, architectures, performance, and energy efficiencies of these MEC systems that show promise as a method for renewable and sustainable energy production, and wastewater treatment.

  10. LARGE-SCALE HYDROGEN PRODUCTION FROM NUCLEAR ENERGY USING HIGH TEMPERATURE ELECTROLYSIS

    SciTech Connect

    James E. O'Brien

    2010-08-01

    Hydrogen can be produced from water splitting with relatively high efficiency using high-temperature electrolysis. This technology makes use of solid-oxide cells, running in the electrolysis mode to produce hydrogen from steam, while consuming electricity and high-temperature process heat. When coupled to an advanced high temperature nuclear reactor, the overall thermal-to-hydrogen efficiency for high-temperature electrolysis can be as high as 50%, which is about double the overall efficiency of conventional low-temperature electrolysis. Current large-scale hydrogen production is based almost exclusively on steam reforming of methane, a method that consumes a precious fossil fuel while emitting carbon dioxide to the atmosphere. Demand for hydrogen is increasing rapidly for refining of increasingly low-grade petroleum resources, such as the Athabasca oil sands and for ammonia-based fertilizer production. Large quantities of hydrogen are also required for carbon-efficient conversion of biomass to liquid fuels. With supplemental nuclear hydrogen, almost all of the carbon in the biomass can be converted to liquid fuels in a nearly carbon-neutral fashion. Ultimately, hydrogen may be employed as a direct transportation fuel in a “hydrogen economy.” The large quantity of hydrogen that would be required for this concept should be produced without consuming fossil fuels or emitting greenhouse gases. An overview of the high-temperature electrolysis technology will be presented, including basic theory, modeling, and experimental activities. Modeling activities include both computational fluid dynamics and large-scale systems analysis. We have also demonstrated high-temperature electrolysis in our laboratory at the 15 kW scale, achieving a hydrogen production rate in excess of 5500 L/hr.

  11. Annotation of glycomics MS and MS/MS spectra using the GlycoWorkbench software tool.

    PubMed

    Damerell, David; Ceroni, Alessio; Maass, Kai; Ranzinger, René; Dell, Anne; Haslam, Stuart M

    2015-01-01

    The GlycoWorkbench software tool allows users to semiautomatically annotate glycomics MS and MS/MS spectra and MS glycoproteomics spectra. The GlycanBuilder software tool is embedded within GlycoWorkbench allowing users to draw glycan structures and export images of the drawn structures. This chapter demonstrates to users how to draw glycan structures within GlycoWorkbench using the GlycanBuilder software tool. This chapter also demonstrates how to use GlycoWorkbench to import MS and MS/MS glycomics spectra and use the cascading annotation feature to annotate both the MS and MS/MS spectra with a single command.

  12. THERMODYNAMIC CONSIDERATIONS FOR THERMAL WATER SPLITTING PROCESSES AND HIGH TEMPERATURE ELECTROLYSIS

    SciTech Connect

    J. E. O'Brien

    2008-11-01

    A general thermodynamic analysis of hydrogen production based on thermal water splitting processes is presented. Results of the analysis show that the overall efficiency of any thermal water splitting process operating between two temperature limits is proportional to the Carnot efficiency. Implications of thermodynamic efficiency limits and the impacts of loss mechanisms and operating conditions are discussed as they pertain specifically to hydrogen production based on high-temperature electrolysis. Overall system performance predictions are also presented for high-temperature electrolysis plants powered by three different advanced nuclear reactor types, over their respective operating temperature ranges.

  13. Dimensionally stable electrodes for used salt electrolysis (substitute for petroleum coke)

    NASA Astrophysics Data System (ADS)

    Zoellner, C.; Kahl, K.

    1985-12-01

    An electrode system for anodes in aluminum fused salt electrolysis was developed and tested as regards electrochemical efficiency, corrosion resistance, possible design of large-scale anodes, and production costs. The anode, a water-cooled combination electrode, consists of a metal upper section incorporating a cooling system and serving as a current carrier and distributor, with refractory graphite protective elements, and a ceramic active lower section. The electrode system allows savings of raw materials of 0.655 ton of fuel per ton of aluminum produced. Operation of the aluminum electrolysis with inert anodes improves working conditions and environmental quality. The interpolation distance can be reduced with inert cathodes.

  14. Contact Electrification of Regolith Particles and Chloride Electrolysis: Synthesis of Perchlorates on Mars

    NASA Astrophysics Data System (ADS)

    Tennakone, K.

    2016-10-01

    Contact electrification of chloride-impregnated martian regolith particles due to eolian agitation and moisture condensation on coalesced oppositely charged grains may lead to spontaneous electrolysis that generates hypochlorite, chlorite, chlorate, and perchlorate with a concomitant reduction of water to hydrogen. This process is not curtailed even if moisture condenses as ice because chloride ionizes on the surface of ice. Limitations dictated by potentials needed for electrolysis and breakdown electric fields enable estimation of the required regolith grain size. The estimated dimension turns out to be of the same order of magnitude as the expected median size of martian regolith, and a simple calculation yields the optimum rate of perchlorate production.

  15. Improved enzymatic hydrolysis of lignocellulosic biomass through pretreatment with plasma electrolysis.

    PubMed

    Gao, Jing; Chen, Li; Zhang, Jian; Yan, Zongcheng

    2014-11-01

    A comprehensive research on plasma electrolysis as pretreatment method for water hyacinth (WH) was performed based on lignin content, crystalline structure, surface property, and enzymatic hydrolysis. A large number of active particles, such as HO and H2O2, generated by plasma electrolysis could decompose the lignin of the biomass samples and reduce the crystalline index. An efficient pretreatment process made use of WH pretreated at a load of 48 wt% (0.15-0.18 mm) in FeCl3 solution for 30 min at 450 V. After the pretreatment, the sugar yield of WH was increased by 126.5% as compared with unpretreated samples. PMID:25205055

  16. Solid polymer electrolyte water electrolysis preprototype subsystem. [oxygen production for life support systems on space stations

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Hardware and controls developed for an electrolysis demonstration unit for use with the life sciences payload program and in NASA's regenerative life support evaluation program are described. Components discussed include: the electrolysis module; power conditioner; phase separator-pump and hydrogen differential regulator; pressure regulation of O2, He, and N2; air-cooled heat exchanger; water accumulator; fluid flow sight gage assembly; catalytic O2/H2 sensor; gas flow sensors; low voltage power supply; 100 Amp DC contactor assembly; and the water purifier design.

  17. Alkaline water electrolysis technology for Space Station regenerative fuel cell energy storage

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Hoberecht, M. A.; Le, M.

    1986-01-01

    The regenerative fuel cell system (RFCS), designed for application to the Space Station energy storage system, is based on state-of-the-art alkaline electrolyte technology and incorporates a dedicated fuel cell system (FCS) and water electrolysis subsystem (WES). In the present study, emphasis is placed on the WES portion of the RFCS. To ensure RFCS availability for the Space Station, the RFCS Space Station Prototype design was undertaken which included a 46-cell 0.93 cu m static feed water electrolysis module and three integrated mechanical components.

  18. Fractional capacity electrolyzer development for CO2 and H2O electrolysis

    NASA Technical Reports Server (NTRS)

    Wynveen, R. A.

    1980-01-01

    The electrolyzer module was designed to produce 0.24 kg/d (0.53 lb/d) of breathable oxygen from the electrolysis of metabolic carbon dioxide and water vapor. The fractional capacity electrolyzer module is constructed from three electrochemical tube cells and contains only three critical seals. The module design illustrated an 84 percent reduction in the total number of seals for a one person capacity oxygen generating system based on the solid electrolyte carbon dioxide and water vapor electrolysis concept. The electrolyzer module was successfully endurance tested for 71 days.

  19. Managing Progressive MS

    MedlinePlus

    ... MS Society | 8 builders about renovations and home adaptations to support independence. OTs may also evaluate and ... Staying at home will mean making changes. Home adaptations do more than fight fatigue. They offer safety, ...

  20. Living with Advanced MS

    MedlinePlus

    ... Read More Read More Resource Edward M. Dowd Personal Advocate Program The Edward M. Dowd Personal Advocate ... Informed About the Society Vision Careers Leadership Cultural Values Financials News Press Room MS Prevalence Charitable Ratings ...

  1. MS Based Metabonomics

    SciTech Connect

    Want, Elizabeth J.; Metz, Thomas O.

    2010-03-01

    Metabonomics is the latest and least mature of the systems biology triad, which also includes genomics and proteomics, and has its origins in the early orthomolecular medicine work pioneered by Linus Pauling and Arthur Robinson. It was defined by Nicholson and colleagues in 1999 as the quantitative measurement of perturbations in the metabolite complement of an integrated biological system in response to internal or external stimuli, and is often used today to describe many non-global types of metabolite analyses. Applications of metabonomics are extensive and include toxicology, nutrition, pharmaceutical research and development, physiological monitoring and disease diagnosis. For example, blood samples from millions of neonates are tested routinely by mass spectrometry (MS) as a diagnostic tool for inborn errors of metabolism. The metabonome encompasses a wide range of structurally diverse metabolites; therefore, no single analytical platform will be sufficient. Specialized sample preparation and detection techniques are required, and advances in NMR and MS technologies have led to enhanced metabonome coverage, which in turn demands improved data analysis approaches. The role of MS in metabonomics is still evolving as instrumentation and software becomes more sophisticated and as researchers realize the strengths and limitations of current technology. MS offers a wide dynamic range, high sensitivity, and reproducible, quantitative analysis. These attributes are essential for addressing the challenges of metabonomics, as the range of metabolite concentrations easily exceeds nine orders of magnitude in biofluids, and the diversity of molecular species ranges from simple amino and organic acids to lipids and complex carbohydrates. Additional challenges arise in generating a comprehensive metabolite profile, downstream data processing and analysis, and structural characterization of important metabolites. A typical workflow of MS-based metabonomics is shown in Figure

  2. Pulse Data.

    ERIC Educational Resources Information Center

    Hands On!, 1998

    1998-01-01

    Presents an activity using computer software to investigate the role of the heart and blood, how the blood system responds to exercise, and how pulse rate is a good measure of physical condition. (ASK)

  3. IMS - MS Data Extractor

    SciTech Connect

    2015-10-20

    An automated drift time extraction and computed associated collision cross section software tool for small molecule analysis with ion mobility spectrometry-mass spectrometry (IMS-MS). The software automatically extracts drift times and computes associated collision cross sections for small molecules analyzed using ion mobility spectrometry-mass spectrometry (IMS-MS) based on a target list of expected ions provided by the user.

  4. Pulse stretcher

    DOEpatents

    Horton, James A.

    1994-01-01

    Apparatus (20) for increasing the length of a laser pulse to reduce its peak power without substantial loss in the average power of the pulse. The apparatus (20) uses a White cell (10) having a plurality of optical delay paths (18a-18d) of successively increasing number of passes between the field mirror (13) and the objective mirrors (11 and 12). A pulse (26) from a laser (27) travels through a multi-leg reflective path (28) between a beam splitter (21) and a totally reflective mirror (24) to the laser output (37). The laser pulse (26) is also simultaneously injected through the beam splitter (21) to the input mirrors (14a-14d) of the optical delay paths (18a-18d). The pulses from the output mirrors (16a-16d) of the optical delay paths (18a-18d) go simultaneously to the laser output (37) and to the input mirrors ( 14b-14d) of the longer optical delay paths. The beam splitter (21) is 50% reflective and 50% transmissive to provide equal attenuation of all of the pulses at the laser output (37).

  5. TESTING AND PERFORMANCE ANALYSIS OF NASA 5 CM BY 5 CM BI-SUPPORTED SOLID OXIDE ELECTROLYSIS CELLS OPERATED IN BOTH FUEL CELL AND STEAM ELECTROLYSIS MODES

    SciTech Connect

    R. C. O'Brien; J. E. O'Brien; C. M. Stoots; X. Zhang; S. C. Farmer; T. L. Cable; J. A. Setlock

    2011-11-01

    A series of 5 cm by 5 cm bi-supported Solid Oxide Electrolysis Cells (SOEC) were produced by NASA for the Idaho National Laboratory (INL) and tested under the INL High Temperature Steam Electrolysis program. The results from the experimental demonstration of cell operation for both hydrogen production and operation as fuel cells is presented. An overview of the cell technology, test apparatus and performance analysis is also provided. The INL High Temperature Steam Electrolysis laboratory has developed significant test infrastructure in support of single cell and stack performance analyses. An overview of the single cell test apparatus is presented. The test data presented in this paper is representative of a first batch of NASA's prototypic 5 cm by 5 cm SOEC single cells. Clearly a significant relationship between the operational current density and cell degradation rate is evident. While the performance of these cells was lower than anticipated, in-house testing at NASA Glenn has yielded significantly higher performance and lower degradation rates with subsequent production batches of cells. Current post-test microstructure analyses of the cells tested at INL will be published in a future paper. Modification to cell compositions and cell reduction techniques will be altered in the next series of cells to be delivered to INL with the aim to decrease the cell degradation rate while allowing for higher operational current densities to be sustained. Results from the testing of new batches of single cells will be presented in a future paper.

  6. Study of potassium DPAL operation in pulsed and CW mode

    NASA Astrophysics Data System (ADS)

    Zhdanov, Boris V.; Rotondaro, Matthew D.; Schaffer, Michael K.; Knize, Randall J.

    2014-10-01

    This paper presents the results of our experiments on development of the efficient hydrocarbon free Diode Pumped Alkali Laser based on potassium vapor buffered by He gas at 600 Torr. We studied the performance of this laser operating in pulsed mode with pulses up to 5 ms long at different pulse energies and cell temperatures. A slope efficiency of more than 50% was demonstrated with total optical efficiency about 30% for the pump pulses with duration about 30 μs. For the longer pump pulses the DPAL efficiency degraded in time with a characteristic time in the range from 0.5 ms to 4.5 ms depending on the pump pulse energy and cell temperature. The recorded spectrum of the side fluorescence indicates that multi-photon excitation, energy pooling collisions and ionization may be strong candidates for explaining the observed performance degradation.

  7. Progressive-Relapsing MS (PRMS)

    MedlinePlus

    ... the disease process in MS and in MRI technology. Individuals who were previously diagnosed with progressive-relapsing MS would now be ... The National MS Society is Here to Help Need More Information? We ...

  8. Development of electrolysis-cell separator for 125/sup 0/C operation. Advanced alkaline electrolysis cell development. Final report

    SciTech Connect

    Murray, J N

    1983-03-01

    This report contains the findings of a seven-month contracted effort. The major technical task involved a 125/sup 0/C operating temperature test of the 20 v/o polybenzimidazole (PBI) - 80 v/o potassium titanate (K/sub 2/TiO/sub 3/) separator in combination with the nickel-molybdenum cathode electrocatalyst system dubbed the C-AN cathode using the ARIES test system which was developed previously. The test of the PBI-K/sub 2/TiO/sub 3/ separator was only partially successful. The anticipated 1.85 (75/sup 0/C) and 1.75 volt per cell (100/sup 0/C) input requirement at 550 ma/cm/sup 2/ were surpassed slightly. The test module operated stably for about 550 hr. Although there were some mechanical difficulties with the ARIES test unit, testing at 125/sup 0/C proceeded from 745 hr on test until the test was terminated at 2318 operating hours to allow diagnostic disassembly. The input voltage degraded to a value of 1.82 volt per cell at 125/sup 0/C which is unacceptable. Diagnostic disassembly showed the PBI portion of the separator was no longer present. PBI had been shown to be stable in 123/sup 0/C, 45 w/o KOH solutions in a 1000-hr test. The attack is suggested to be attributable to a peroxide or perchlorate type oxidizer which would be unique to the electrolysis mode and probably not present in alkaline fuel cell applications. Recommendations for further testing include an evaluation of the chemical compatibility of PBI with alkaline/oxidizer solutions and endurance testing the C-AN cathode with new improved anode structures at 125/sup 0/C using asbestos separators in combination with a silicate saturated KOH electrolyte. Demonstration of the stability of this 1.65 volt per cell (90% voltage efficiency) technology at 500 ma/cm/sup 2/ will document an inexpensive and intelligent hydrogen production process which will satisfy the needs of the United States in the 1990s.

  9. A Review of Sealing Technologies Applicable to Solid Oxide Electrolysis Cells

    SciTech Connect

    Paul A. Lessing

    2007-05-01

    This article reviews designs and materials investigated for various seals in high temperature solid oxide fuel cell “stacks” and how they might be implemented in solid oxide electrolysis cells that decompose steam into hydrogen and oxygen. Materials include metals, glasses, glass–ceramics, cements, and composites. Sealing designs include rigid seals, compressive seals, and compliant seals.

  10. Water electrolysis on La1-xSrxCoO3-δ perovskite electrocatalysts

    DOE PAGES

    Mefford, J. Tyler; Rong, Xi; Abakumov, Artem M.; Hardin, William G.; Dai, Sheng; Kolpak, Alexie; Johnston, Keith P.; Stevenson, Keith J.

    2016-03-23

    Here, perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B–O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co–O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1–xSrxCoO3–δ. We attempt to rationalize the highmore » activities of La1–xSrxCoO3–δ through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.« less

  11. Hydrogen Production Performance of a 10-Cell Planar Solid-Oxide Electrolysis Stack

    SciTech Connect

    James O'Brien; Carl Stoots; Steve Herring; J. Hartvigsen

    2005-05-01

    An experimental study is under way to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from a ten-cell planar electrolysis stack, with an active area of 64 cm2 per cell. The electrolysis cells are electrolytesupported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. Cell operating potentials and cell current were varied using a programmable power supply. Hydrogen production rates up to 100 Normal liters per hour were demonstrated. Values of area-specific resistance and stack internal temperatures are presented as a function of current density. Stack performance is shown to be dependent on inlet steam flow rate.

  12. The Production and Characterization of Ceramic Carbon Electrode Materials for CuCl-HCl Electrolysis

    NASA Astrophysics Data System (ADS)

    Edge, Patrick

    Current H2 gas supplies are primarily produced through steam methane reforming and other fossil fuel based processes. This lack of viable large scale and environmentally friendly H2 gas production has hindered the wide spread adoption of H2 fuel cells. A potential solution to this problem is the Cu-Cl hybrid thermochemical cycle. The cycle captures waste heat to drive two thermochemical steps creating CuCl as well as O2 gas and HCl from CuCl2 and water. The CuCl is oxidized in HCl to produce H2 gas and regenerate CuCl2, this process occurs at potentials well below those required for water electrolysis. The electrolysis process occurs in a traditional PEM fuel-cell. In the aqueous anolyte media Cu(I) will form anionic complexes such as CuCl 2 - or CuCl32-. The slow transport of these species to the anode surface limits the overall electrolysis process. To improve this transport process we have produced ceramic carbon electrode (CCE) materials through a sol-gel method incorporating a selection of amine containing silanes with increasing numbers of primary and secondary amines. When protonated these amines allow for improved transport of anionic copper complexes. The electrochemical and physical characterization of these CCE materials in a half and full-cell electrolysis environment will be presented. Electrochemical analysis was performed using cell polarization, cyclic voltammetry, and electrochemical impedance spectroscopy.

  13. Water electrolysis on La1-xSrxCoO3-δ perovskite electrocatalysts

    NASA Astrophysics Data System (ADS)

    Mefford, J. Tyler; Rong, Xi; Abakumov, Artem M.; Hardin, William G.; Dai, Sheng; Kolpak, Alexie M.; Johnston, Keith P.; Stevenson, Keith J.

    2016-03-01

    Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1-xSrxCoO3-δ. We attempt to rationalize the high activities of La1-xSrxCoO3-δ through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.

  14. Water electrolysis on La(1-x)Sr(x)CoO(3-δ) perovskite electrocatalysts.

    PubMed

    Mefford, J Tyler; Rong, Xi; Abakumov, Artem M; Hardin, William G; Dai, Sheng; Kolpak, Alexie M; Johnston, Keith P; Stevenson, Keith J

    2016-01-01

    Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B-O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co-O bond and the concentration of oxygen vacancies are controlled through Sr(2+) substitution into La(1-x)Sr(x)CoO(3-δ) . We attempt to rationalize the high activities of La(1-x)Sr(x)CoO(3-δ) through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis.

  15. Electrolysis of neodymium oxide. Final report for the period August 19, 1991 through February 28, 1997

    SciTech Connect

    Keller, R.; Larimer, K.T.

    1997-05-01

    The objective of this research was to develop an electrolytic process for the continuous and economic production of neodymium alloys from neodymium oxide. The electrolysis of neodymium oxide continued to show promise for implementation as a low-cost process to produce high- quality neodymium or neodymium-iron alloy.

  16. An impulse-driven liquid-droplet deposition interface for combining LC with MALDI MS and MS/MS.

    PubMed

    Young, J Bryce; Li, Liang

    2006-03-01

    A simple and robust impulse-driven droplet deposition system was developed for off-line liquid chromatography matrix-assisted laser desorption ionization mass spectrometry (LC-MALDI MS). The system uses a solenoid operated with a pulsed voltage power supply to generate impulses that dislodge the hanging droplets from the LC outlet directly to a MALDI plate via a momentum transfer process. There is no contact between the LC outlet and the collection surface. The system is compatible with solvents of varying polarity and viscosity, and accommodates the use of hydrophobic and hydrophilic MALDI matrices. MALDI spots are produced on-line with the separation, and do not require further processing before MS analysis. It is shown that high quality MALDI spectra from 5 fmol of pyro-Glu-fibrinopeptide deposition after LC separation could be obtained using the device, indicating that there was no sample loss in the interface. To demonstrate the analytical performance of the system as a proteome analysis tool, a range of BSA digest concentrations covering about 3 orders of magnitude, from 5 fmol to 1 pmol, were analyzed by LC-MALDI quadrupole time-of-flight MS, yielding 6 and 57% amino acid sequence coverage, respectively. In addition, a complex protein mixture of an E. coli cell extract was tryptically digested and analyzed by LC-MALDI MS, resulting in the detection of a total of 409 unique peptides from 100 fractions of 15-s intervals.

  17. Lithium batteries for pulse power

    NASA Astrophysics Data System (ADS)

    Redey, Laszlo

    New designs of lithium batteries having bipolar construction and thin cell components possess the very low impedance that is necessary to deliver high-intensity current pulses. The research and development and understanding of the fundamental properties of these pulse batteries have reached an advanced level. Ranges of 50 to 300 kW/kg specific power and 80 to 130 Wh/kg specific energy have been demonstrated with experimental high-temperature lithium alloy/transition-metal disulfide rechargeable bipolar batteries in repeated 1- to 100-ms long pulses. Other versions are designed for repetitive power bursts that may last up to 20 or 30 s and yet may attain high specific power (1 to 10 kW/kg). Primary high-temperature Li-alloy/FeS2 pulse batteries (thermal batteries) are already commercially available. Other high-temperature lithium systems may use chlorine or metal-oxide positive electrodes. Also under development are low-temperature pulse batteries: a 50-kW Li/SOCl2 primary batter and an all solid-state, polymer-electrolyte secondary battery. Such pulse batteries could find use in commercial and military applications in the near future.

  18. Lithium batteries for pulse power

    SciTech Connect

    Redey, L.

    1990-01-01

    New designs of lithium batteries having bipolar construction and thin cell components possess the very low impedance that is necessary to deliver high-intensity current pulses. The R D and understanding of the fundamental properties of these pulse batteries have reached an advanced level. Ranges of 50--300 kW/kg specific power and 80--130 Wh/kg specific energy have been demonstrated with experimental high-temperature lithium alloy/transition-metal disulfide rechargeable bipolar batteries in repeated 1- to 100-ms long pulses. Other versions are designed for repetitive power bursts that may last up to 20 or 30 s and yet may attain high specific power (1--10 kW/kg). Primary high-temperature Li-alloy/FeS{sub 2} pulse batteries (thermal batteries) are already commercially available. Other high-temperature lithium systems may use chlorine or metal-oxide positive electrodes. Also under development are low-temperature pulse batteries: a 50-kW Li/SOCl{sub 2} primary batter and an all solid-state, polymer-electrolyte secondary battery. Such pulse batteries could find use in commercial and military applications in the near future. 21 refs., 8 figs.

  19. Optimization of the LCLS Single Pulse Shutter

    SciTech Connect

    Adera, Solomon; /Georgia Tech., Atlanta /SLAC

    2010-08-25

    A mechanical shutter which operates on demand is used to isolate a single pulse from a 120 Hz X-ray source. This is accomplished with a mechanical shutter which is triggered on demand with frequencies ranging from 0 to 10 Hz. The single pulse shutter is an iron blade that oscillates on a pivot in response to a force generated by a pair of pulsed electromagnets (current driven teeter-totter). To isolate an individual pulse from the X-ray beam, the motion of the mechanical shutter should be synchronized in such a way that it allows a single pulse to pass through the aperture and blocks the other incoming pulses. Two consecutive pulses are only {approx} 8 ms apart and the shutter is required to complete one full cycle such that no two pulses pass through the opening. Also the opening of the shutter blade needs to be at least 4 mm so that a 1 mm diameter rms Gaussian beam can pass through without modulation. However, the 4 mm opening is difficult to obtain due to blade rebound and oscillation of the blade after colliding with the electromagnet. The purpose of this project is to minimize and/or totally eliminate the rebound of the shutter blade in pursuit of maximizing the aperture while keeping the open window interval < {approx}12 ms.

  20. ICP-MS Workshop

    SciTech Connect

    Carman, April J.; Eiden, Gregory C.

    2014-11-01

    This is a short document that explains the materials that will be transmitted to LLNL and DNN HQ regarding the ICP-MS Workshop held at PNNL June 17-19th. The goal of the information is to pass on to LLNL information regarding the planning and preparations for the Workshop at PNNL in preparation of the SIMS workshop at LLNL.

  1. PULSE COUNTER

    DOEpatents

    Trumbo, D.E.

    1959-02-10

    A transistorized pulse-counting circuit adapted for use with nuclear radiation detecting detecting devices to provide a small, light weight portable counter is reported. The small size and low power requirements of the transistor are of particular value in this instance. The circuit provides an adjustable count scale with a single transistor which is triggered by the accumulated charge on a storage capacitor.

  2. Water rocket - Electrolysis propulsion and fuel cell power

    SciTech Connect

    Carter, P H; Dittman, M D; Kare, J T; Militsky, F; Myers, B; Weisberg, A H

    1999-07-24

    Water Rocket is the collective name for an integrated set of technologies that offer new options for spacecraft propulsion, power, energy storage, and structure. Low pressure water stored on the spacecraft is electrolyzed to generate, separate, and pressurize gaseous hydrogen and oxygen. These gases, stored in lightweight pressure tanks, can be burned to generate thrust or recombined to produce electric power. As a rocket propulsion system, Water Rocket provides the highest feasible chemical specific impulse (-400 seconds). Even higher specific impulse propulsion can be achieved by combining Water Rocket with other advanced propulsion technologies, such as arcjet or electric thrusters. With innovative pressure tank technology, Water Rocket's specific energy [Wh/kg] can exceed that of the best foreseeable batteries by an order of magnitude, and the tanks can often serve as vehicle structural elements. For pulsed power applications, Water Rocket propellants can be used to drive very high power density generators, such as MHD devices or detonation-driven pulse generators. A space vehicle using Water Rocket propulsion can be totally inert and non-hazardous during assembly and launch. These features are particularly important for the timely development and flight qualification of new classes of spacecraft, such as microsats, nanosats, and refuelable spacecraft.

  3. The Interconversion of Electrical and Chemical Energy: The Electrolysis of Water and the Hydrogen-Oxygen Fuel Cell.

    ERIC Educational Resources Information Center

    Roffia, Sergio; And Others

    1988-01-01

    Discusses some of the drawbacks of using a demonstration of the electrolysis of water to illustrate the interconversion between electrical and chemical energy. Illustrates a simple apparatus allowing demonstration of this concept while overcoming these drawbacks. (CW)

  4. PROGRESS IN HIGH-TEMPERATURE ELECTROLYSIS FOR HYDROGEN PRODUCTION USING PLANAR SOFC TECHNOLOGY

    SciTech Connect

    O'Brien, J. E.; Herring, J. S.; Stoots, C. M.; Hawkes, G. L.; Hartvigsen, J., J.; Mehrdad Shahnam

    2005-04-01

    A research program is under way at the Idaho National Laboratory to assess the performance of solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. The research program includes both experimental and modeling activities. Selected results from both activities are presented in this paper. Experimental results were obtained from a ten-cell planar electrolysis stack, fabricated by Ceramatec , Inc. The electrolysis cells are electrolyte-supported, with scandia-stabilized zirconia electrolytes (~140 µm thick), nickel-cermet steam/hydrogen electrodes, and manganite air-side electrodes. The metallic interconnect plates are fabricated from ferritic stainless steel. The experiments were performed over a range of steam inlet mole fractions (0.1 - 0.6), gas flow rates (1000 - 4000 sccm), and current densities (0 to 0.38 A/cm2). Hydrogen production rates up to 90 Normal liters per hour were demonstrated. Stack performance is shown to be dependent on inlet steam flow rate. A three-dimensional computational fluid dynamics (CFD) model was also created to model high-temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell as it would exist in the experimental electrolysis stack. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT1. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with

  5. Preliminary study of the electrolysis of aluminum sulfide in molten salts

    SciTech Connect

    Minh, N.Q.; Loutfy, R.O.; Yao, N.P.

    1983-02-01

    A preliminary laboratory-scale study of the electrolysis of aluminum sulfide in molten salts investigated the (1) solubility of Al/sub 2/S/sub 3/ in molten salts, (2) electrochemical behavior of Al/sub 2/S/sub 3/, and (3) electrolysis of Al/sub 2/S/sub 3/ with the determination of current efficiency as a function of current density. The solubility measurements show that MgCl/sub 2/-NaCl-KCl eutectic electrolyte at 1023 K can dissolve up to 3.3 mol % sulfide. The molar ratio of sulfur to aluminum in the eutectic is about one, which suggests that some sulfur remains undissolved, probably in the form of MgS. The experimental data and thermodynamic calculations suggest that Al/sub 2/S/sub 3/ dissolves in the eutectic to form AlS/sup +/ species in solution. Addition of AlCl/sub 3/ to the eutectic enhances the solubility of Al/sub 2/S/sub 3/; the solubility increases with increasing AlCl/sub 3/ concentration. The electrode reaction mechanism for the electrolysis of Al/sub 2/S/sub 3/ was elucidated by using linear sweep voltammetry. The cathodic reduction of aluminum-ion-containing species to aluminum proceeds by a reversible, diffusion-controlled, three-electron reaction. The anodic reaction involves the two-electron discharge of sulfide-ion-containing species, followed by the fast dimerization of sulfur atoms to S/sub 2/. Electrolysis experiments show that Al/sub 2/S/sub 3/ dissolved in molten MgCl/sub 2/-NaCl-KCl eutectic or in eutectic containing AlCl/sub 3/ can be electrolyzed to produce aluminum and sulfur. In the eutectic at 1023 K, the electrolysis can be conducted up to about 300 mA/cm/sup 2/ for the saturation solubility of Al/sub 2/S/sub 3/. Although these preliminary results are promising, additional studies are needed to elucidate many critical operating parameters before the technical potential of the electrolysis can be accurately assessed. 20 figures, 18 tables.

  6. Al/sub 2/S/sub 3/ preparation and use in electrolysis process for aluminum production

    DOEpatents

    Hsu, C.C.; Loutfy, R.O.; Yao, N.P.

    A continuous process for producing aluminum sulfide and for electrolyzing the aluminum sulfide to form metallic aluminum in which the aluminum sulfide is produced from aluminum oxide and COS or CS/sub 2/ in the presence of a chloride melt which also serves as the electrolysis bath. Circulation between the reactor and electrolysis cell is carried out to maintain the desired concentration of aluminum sulfide in the bath.

  7. Standardization of Rocket Engine Pulse Time Parameters

    NASA Technical Reports Server (NTRS)

    Larin, Max E.; Lumpkin, Forrest E.; Rauer, Scott J.

    2001-01-01

    Plumes of bipropellant thrusters are a source of contamination. Small bipropellant thrusters are often used for spacecraft attitude control and orbit correction. Such thrusters typically operate in a pulse mode, at various pulse lengths. Quantifying their contamination effects onto spacecraft external surfaces is especially important for long-term complex-geometry vehicles, e.g. International Space Station. Plume contamination tests indicated the presence of liquid phase contaminant in the form of droplets. Their origin is attributed to incomplete combustion. Most of liquid-phase contaminant is generated during the startup and shutdown (unsteady) periods of thruster pulse. These periods are relatively short (typically 10-50 ms), and the amount of contaminant is determined by the thruster design (propellant valve response, combustion chamber size, thruster mass flow rate, film cooling percentage, dribble volume, etc.) and combustion process organization. Steady-state period of pulse is characterized by much lower contamination rates, but may be lengthy enough to significantly conh'ibute to the overall contamination effect. Because there was no standard methodology for thruster pulse time division, plume contamination tests were conducted at various pulse durations, and their results do not allow quantifying contaminant amounts from each portion of the pulse. At present, the ISS plume contamination model uses an assumption that all thrusters operate in a pulse mode with the pulse length being 100 ms. This assumption may lead to a large difference between the actual amounts of contaminant produced by the thruster and the model predictions. This paper suggests a way to standardize thruster startup and shutdown period definitions, and shows the usefulness of this approach to better quantify thruster plume contamination. Use of the suggested thruster pulse time-division technique will ensure methodological consistency of future thruster plume contamination test programs

  8. Pulsed hydrojet

    DOEpatents

    Bohachevsky, I.O.; Torrey, M.D.

    1986-06-10

    An underwater pulsed hydrojet propulsion system is provided for accelerating and propelling a projectile or other vessel. A reactant, such as lithium, is fluidized and injected into a water volume. The resulting reaction produces an energy density in a time effective to form a steam pocket. Thrust flaps or baffles direct the pressure from the steam pocket toward an exit nozzle for accelerating a water volume to create thrust. A control system regulates the dispersion of reactant to control thrust characteristics.

  9. NAPS-MS

    PubMed Central

    Gudesblatt, Mark; Kresa-Reahl, Kiren; Brandes, David W.; Sater, Pamela

    2016-01-01

    Background: Patients with multiple sclerosis (MS) have higher rates of fatigue, mood disturbance, and cognitive impairments than healthy populations. Disease-modifying agents may affect sleep. Although patients taking natalizumab often show improvement in fatigue during the first year of therapy, the mechanism behind this effect is unknown. The aim of the NAPS-MS study was to investigate whether natalizumab affected objective measures of sleep as determined by polysomnography (PSG) and multiple sleep latency testing (MSLT) in patients with MS with fatigue or sleepiness initiating therapy. Additional goals were to evaluate changes in measures of fatigue, mood, and cognition and to correlate these measures with objective sleep measures. Methods: Patients underwent PSG and MSLT before their first natalizumab infusion and after their seventh. Patients completed the Modified Fatigue Impact Scale, Fatigue Severity Scale (FSS), Epworth Sleepiness Scale (ESS), and visual analogue scale for fatigue (VAS-F) at their first, fourth, and seventh natalizumab infusions. NeuroTrax cognitive tests and the Hospital Anxiety and Depression Scale (HADS) were performed at the first and seventh natalizumab infusions. Results: Changes in sleep efficiency, wakefulness after sleep onset, and multiple sleep latency from baseline to 6 months of therapy did not reach significance. The FSS, VAS-F, ESS, and HADS scores were significantly improved after 6 months of therapy; cognitive scores were not significantly improved. Conclusions: Although treatment with natalizumab was associated with improvements in fatigue, sleepiness, and mood, changes in objective measures of sleep were not significant. PMID:27551242

  10. Advances in Molten Oxide Electrolysis for the Production of Oxygen and Metals from Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Sadoway, Donald R.; Sirk, Aislinn; Sibille, Laurent; Melendez, Orlando; Lueck, Dale; Curreri, Peter; Dominquez, Jesus; Whitlow, Jonathan

    2008-01-01

    As part of an In-Situ Resource Utilization infrastructure to sustain long term-human presence on the lunar surface, the production of oxygen and metals by electrolysis of lunar regolith has been the subject of major scrutiny. There is a reasonably large body of literature characterizing the candidate solvent electrolytes, including ionic liquids, molten salts, fluxed oxides, and pure molten regolith itself. In the light of this information and in consideration of available electrolytic technologies, the authors have determined that direct molten oxide electrolysis at temperatures of approx 1600 C is the most promising avenue for further development. Results from ongoing studies as well as those of previous workers will be presented. Topics include materials selection and testing, electrode stability, gas capture and analysis, and cell operation during feeding and tapping.

  11. Solid oxide electrolysis cell analysis by means of electrochemical impedance spectroscopy: A review

    NASA Astrophysics Data System (ADS)

    Nechache, A.; Cassir, M.; Ringuedé, A.

    2014-07-01

    High temperature water electrolysis based on Solid Oxide Electrolysis Cell (SOEC) is a very promising solution to produce directly pure hydrogen. However, degradation issues occurring during operation still represent a scientific and technological barrier in view of its development at an industrial scale. Electrochemical Impedance Spectroscopy (EIS) is a powerful in-situ fundamental tool adapted to the study of SOEC systems. Hence, after a quick presentation of EIS principle and data analysis methods, this review demonstrates how EIS can be used: (i) to characterize the performance and mechanisms of SOEC electrodes; (ii) as a complementary tool to study SOEC degradation processes for different cell configurations, in addition to post-test tools such as scanning electron microscopy (SEM) or X-ray diffraction (XRD). The use of EIS to establish a systematic SOEC analysis is introduced as well.

  12. Conversion of laser energy to chemical energy by the photoassisted electrolysis of water

    NASA Technical Reports Server (NTRS)

    Wrighton, M. S.

    1976-01-01

    Ultraviolet irradiation of the n-type semiconductor TiO2 crystal electrode of an aqueous electrochemical cell evolves O2 at the TiO2 electrode and H2 at the Pt electrode. The gases are typically evolved in a 2:1 (H2:O2) volume ratio. The photoassisted reaction seems to require applied voltages, but values as low as 0.25 V do allow the photoassisted electrolysis to proceed. Prolonged irradiation in either acid or base evolves the gaseous products in amounts which clearly demonstrate that the reaction is catalytic with respect to the TiO2. The wavelength response of the TiO2 and the correlation of product yield and current are reported. The results support the claim that TiO2 is a true photoassistance agent for the electrolysis of water. Minimum optical storage efficiencies of the order of 1 percent can be achieved by the production of H2.

  13. Microbial fuel cells and microbial electrolysis cells for the production of bioelectricity and biomaterials.

    PubMed

    Zhou, Minghua; Yang, Jie; Wang, Hongyu; Jin, Tao; Xu, Dake; Gu, Tingyue

    2013-01-01

    Today's global energy crisis requires a multifaceted solution. Bioenergy is an important part of the solution. The microbial fuel cell (MFC) technology stands out as an attractive potential technology in bioenergy. MFCs can convert energy stored in organic matter directly into bioelectricity. MFCs can also be operated in the electrolysis mode as microbial electrolysis cells to produce bioproducts such as hydrogen and ethanol. Various wastewaters containing low-grade organic carbons that are otherwise unutilized can be used as feed streams for MFCs. Despite major advances in the past decade, further improvements in MFC power output and cost reduction are needed for MFCs to be practical. This paper analysed MFC operating principles using bioenergetics and bioelectrochemistry. Several major issues were explored to improve the MFC performance. An emphasis was placed on the use of catalytic materials for MFC electrodes. Recent advances in the production of various biomaterials using MFCs were also investigated.

  14. Experiments on a ceramic electrolysis cell and a palladium diffuser at the tritium systems test assembly

    SciTech Connect

    Konishi, Satoshi; Yoshida, Hiroshi; Ohno, Hideo; Naruse, Yuji; Coffin, D.O.; Walthers, C.R.; Binning, K.E.

    1985-01-01

    A ceramic electrolysis cell and a palladium diffuser are developed in Japan and is tested with tritium in Tritium Systems Test Assembly (TSTA) of the Los Alamos National Laboratory, in order to confirm the feasibility as possible upgrades for the fuel cleanup system (PCU). The ceramic electrolysis cell made of stabilized zirconia was operated at 630/sup 0/C for an extended period with a mixture of 3% T/sub 2/O in He carrier gas in the circulation system with oxidizing catalyst bed. The palladium diffuser was tested with circulated pure tritium gas at 280/sup 0/C to verify the compatibility of the alloy with tritium, since the /sup 3/He produced in the metal could cause a degradation. The isotopic effects were also measured for both devices.

  15. Hydrogen from renewable energy - Photovoltaic/water electrolysis as an exemplary approach

    NASA Astrophysics Data System (ADS)

    Sprafka, R. J.; Tison, R. R.; Escher, W. J. D.

    A feasibility study has been conducted for a NASA Kennedy Space Center liquid hydrogen/liquid oxygen production facility using solar cell arrays as the power source for electrolysis. The 100 MW output of the facility would be split into 67.6 and 32 MW portions for electrolysis and liquefaction, respectively. The solar cell array would cover 1.65 sq miles, and would be made up of 249 modular 400-kW arrays. Hydrogen and oxygen are generated at either dispersed or centralized water electrolyzers. The yearly hydrogen output is projected to be 5.76 million lbs, with 8 times that much oxygen; these fuel volumes can support approximately 18 Space Shuttle launches/year.

  16. Test results of six-month test of two water electrolysis systems

    NASA Technical Reports Server (NTRS)

    Mills, E. S.; Wells, G. W.

    1972-01-01

    The two water electrolysis systems used in the NASA space station simulation 90-day manned test of a regenerative life support system were refurbished as required and subjected to 26-weeks of testing. The two electrolysis units are both promising systems for oxygen and hydrogen generation and both needed extensive long-term testing to evaluate the performance of the respective cell design and provide guidance for further development. Testing was conducted to evaluate performance in terms of current, pressure, variable oxygen demands, and orbital simulation. An automatic monitoring system was used to record, monitor and printout performance data at one minute, ten minute or one-hour intervals. Performance data is presented for each day of system operation for each module used during the day. Failures are analyzed, remedial action taken to eliminate problems is discussed and recommendations for redesign for future space applications are stated.

  17. Recent Progress At The Idaho National Laboratory In High Temperature Electrolysis For Hydrogen And Syngas Production

    SciTech Connect

    C. Stoots; J. O'Brien; J. Herring; J. Hartvigsen

    2008-11-01

    This paper presents the most recent results of experiments conducted at the Idaho National Laboratory (INL) studying electrolysis of steam and coelectrolysis of steam / carbon dioxide in solid-oxide electrolysis stacks. Single button cell tests as well as multi-cell stack testing have been conducted. Multi-cell stack testing used 10 x 10 cm cells (8 x 8 cm active area) supplied by Ceramatec, Inc (Salt Lake City, Utah, USA) and ranged from 10 cell short stacks to 240 cell modules. Tests were conducted either in a bench-scale test apparatus or in a newly developed 5 kW Integrated Laboratory Scale (ILS) test facility. Gas composition, operating voltage, and operating temperature were varied during testing. The tests were heavily instrumented, and outlet gas compositions were monitored with a gas chromatograph. The ILS facility is currently being expanded to 15 kW testing capacity (H2 production rate based upon lower heating value).

  18. Hydrogen from renewable energy - Photovoltaic/water electrolysis as an exemplary approach

    NASA Technical Reports Server (NTRS)

    Sprafka, R. J.; Tison, R. R.; Escher, W. J. D.

    1984-01-01

    A feasibility study has been conducted for a NASA Kennedy Space Center liquid hydrogen/liquid oxygen production facility using solar cell arrays as the power source for electrolysis. The 100 MW output of the facility would be split into 67.6 and 32 MW portions for electrolysis and liquefaction, respectively. The solar cell array would cover 1.65 sq miles, and would be made up of 249 modular 400-kW arrays. Hydrogen and oxygen are generated at either dispersed or centralized water electrolyzers. The yearly hydrogen output is projected to be 5.76 million lbs, with 8 times that much oxygen; these fuel volumes can support approximately 18 Space Shuttle launches/year.

  19. Development of solid electrolytes for water electrolysis at intermediate temperatures. Task 3 report; Annual report

    SciTech Connect

    Linkous, C.A.; Anderson, R.; Kopitzke, R.W.

    1995-12-01

    This project is an attempt to synthesize and fabricate proton exchange membranes for hydrogen production via water electrolysis that can take advantage of the better kinetic and thermodynamic conditions that exist at higher temperatures. Current PEM technology is limited to the 125--150 C range. Based on previous work evaluating thermohydrolytic stability, some 5 families of polymers were chosen as viable candidates: polyether ketones, polyether sulfones, fluorinated polyimides, polybenzimidazoles, and polyphenyl quinoxalines. Several of these have been converted into ionomers via sulfonation and fashioned into membranes for evaluation. In particular, the sulfonated polyetheretherketone, or SPEEK, was tested for water uptake, thermo-conductimetric analysis, and performance as the solid electrolyte material in an electrolysis cell. Results comparable to commercial perfluorocarbon sulfonates were obtained.

  20. Life cycle assessment of high-rate anaerobic treatment, microbial fuel cells, and microbial electrolysis cells.

    PubMed

    Foley, Jeffrey M; Rozendal, René A; Hertle, Christopher K; Lant, Paul A; Rabaey, Korneel

    2010-05-01

    Existing wastewater treatment options are generally perceived as energy intensive and environmentally unfriendly. Much attention has been focused on two new approaches in the past years, (i) microbial fuel cells and (ii) microbial electrolysis cells, which directly generate electrical current or chemical products, respectively, during wastewater treatment. These systems are commonly denominated as bioelectrochemical systems, and a multitude of claims have been made in the past regarding the environmental impact of these treatment options. However, an in-depth study backing these claims has not been performed. Here, we have conducted a life cycle assessment (LCA) to compare the environmental impact of three industrial wastewater treatment options, (i) anaerobic treatment with biogas generation, (ii) a microbial fuel cell treatment, with direct electricity generation, and (iii) a microbial electrolysis cell, with hydrogen peroxide production. Our analysis showed that a microbial fuel cell does not provide a significant environmental benefit relative to the "conventional" anaerobic treatment option. However, a microbial electrolysis cell provides significant environmental benefits through the displacement of chemical production by conventional means. Provided that the target conversion level of 1000 A.m(-3) can be met, the decrease in greenhouse gas emissions and other environmentally harmful emissions (e.g., aromatic hydrocarbons) of the microbial electrolysis cell will be a key driver for the development of an industrial standard for this technology. Evidently, this assessment is highly dependent on the underlying assumptions, such as the used reactor materials and target performance. This provides a challenge and an opportunity for researchers in the field to select and develop appropriate and environmentally benign materials of construction, as well as demonstrate the required 1000 A.m(-3) performance at pilot and full scale.

  1. Solid oxide electrolysis--a key enabling technology for sustainable energy scenarios.

    PubMed

    Hansen, John Bøgild

    2015-01-01

    Production of fuels and chemicals from steam and/or CO2 with solid oxide electrolysis cells (SOEC) and electricity have attracted considerable interest recently. This paper is an extended version of the introductory lecture presented at the first Faraday Discussions meeting on the subject. The focus is on the state of the art of cells, stacks and systems. Thermodynamics, performance and degradation are addressed. Remaining challenges and potential application of the technology are discussed from an industrial perspective.

  2. 3D CFD ELECTROCHEMICAL AND HEAT TRANSFER MODEL OF AN INTERNALLY MANIFOLDED SOLID OXIDE ELECTROLYSIS CELL

    SciTech Connect

    Grant L. Hawkes; James E. O'Brien; Greg Tao

    2011-11-01

    A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in an internally manifolded planar solid oxide electrolysis cell (SOEC) stack. This design is being evaluated at the Idaho National Laboratory for hydrogen production from nuclear power and process heat. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, operating potential, steam-electrode gas composition, oxygen-electrode gas composition, current density and hydrogen production over a range of stack operating conditions. Single-cell and five-cell results will be presented. Flow distribution through both models is discussed. Flow enters from the bottom, distributes through the inlet plenum, flows across the cells, gathers in the outlet plenum and flows downward making an upside-down ''U'' shaped flow pattern. Flow and concentration variations exist downstream of the inlet holes. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, oxygen-electrode and steam-electrode current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal

  3. Feasibility Analysis of Liquefying Oxygen Generated from Water Electrolysis Units on Lunar Surface

    NASA Technical Reports Server (NTRS)

    Jeng, Frank F.

    2009-01-01

    Concepts for liquefying oxygen (O2) generated from water electrolysis subsystems on the Lunar surface were explored. Concepts for O2 liquefaction units capable of generating 1.38 lb/hr (0.63 kg/hr) liquid oxygen (LOX) were developed. Heat and mass balance calculations for the liquefaction concepts were conducted. Stream properties, duties of radiators, heat exchangers and compressors for the selected concepts were calculated and compared.

  4. THERMAL AND ELECTROCHEMICAL THREE DIMENSIONAL CFD MODEL OF A PLANAR SOLID OXIDE ELECTROLYSIS CELL

    SciTech Connect

    Grant Hawkes; Jim O'Brien; Carl Stoots; Steve Herring; Mehrdad Shahnam

    2005-07-01

    A three-dimensional computational fluid dynamics (CFD) model has been created to model high-temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell, as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec , Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL.

  5. Electricity and H2 generation from hemicellulose by sequential fermentation and microbial fuel/electrolysis cell

    NASA Astrophysics Data System (ADS)

    Yan, Di; Yang, Xuewei; Yuan, Wenqiao

    2015-09-01

    Electricity and hydrogen generation by bacteria Geobacter sulfurreducens in a dual-chamber microbial fuel/electrolysis cell following the fermentation of hemicellulose by bacteria Moorella thermoacetica was investigated. Experimental results showed that 10 g l-1 xylose under 60 °C was appropriate for the fermentation of xylose by M. thermoacetica, yielding 0.87 g-acetic acid per gram of xylose consumed. Corncob hydrolysate could also be fermented to produce acetic acid, but with lower yield (0.74 g-acid per g-xylose). The broths of xylose and corncob hydrolysate fermented by M. thermoacetica containing acetic acid were fed to G. sulfurreducens in a dual-chamber microbial fuel/electrolysis cell for electricity and hydrogen generation. The highest open-circuit cell voltages generated were 802 and 745 mV, and hydrogen yields were 41.7 and 23.3 mmol per mol-acetate, in xylose and corncob hydrolysate fermentation broth media, respectively. The internal resistance of the microbial fuel/electrolysis cell fed with corncob hydrolysate fermentation broth (3472 Ω) was much higher than that with xylose fermentation broth (1993 Ω) or sodium acetate medium (467 Ω), which was believed to be the main cause of the variation in hydrogen yield of the three feeding media.

  6. Summary Report on Solid-oxide Electrolysis Cell Testing and Development

    SciTech Connect

    J.E. O'Brien; X. Zhang; R.C. O'Brien; G.L. Hawkes

    2012-01-01

    Idaho National Laboratory (INL) has been researching the application of solid-oxide electrolysis cells (SOECs) for large-scale hydrogen production from steam over a temperature range of 800 to 900 C. From 2003 to 2009, this work was sponsored by the United States Department of Energy Nuclear Hydrogen Initiative, under the Office of Nuclear Energy. Starting in 2010, the high-temperature electrolysis (HTE) research program has been sponsored by the INL Next Generation Nuclear Plant Project. This report provides a summaryof program activities performed in Fiscal Year (FY) 2011 and the first quarter of FY-12, with a focus on small-scale testing and cell development activities. HTE research priorities during this period have included the development and testing of SOEC and stack designs that exhibit high-efficiency initial performance and low, long-term degradation rates. This report includes contributions from INL and five industry partners: Materials and Systems Research, Incorporated (MSRI); Versa Power Systems, Incorporated (VPS); Ceramatec, Incorporated; National Aeronautics and Space Administration - Glenn Research Center (NASA - GRC); and the St. Gobain Advanced Materials Division. These industry partners have developed SOEC cells and stacks for in-house testing in the electrolysis mode and independent testing at INL. Additional fundamental research and post-test physical examinations have been performed at two university partners: Massachusetts Institute of Technology (MIT) and the University of Connecticut. Summaries of these activities and test results are also presented in this report.

  7. Nanostructured F doped IrO2 electro-catalyst powders for PEM based water electrolysis

    NASA Astrophysics Data System (ADS)

    Kadakia, Karan Sandeep; Jampani, Prashanth H.; Velikokhatnyi, Oleg I.; Datta, Moni Kanchan; Park, Sung Kyoo; Hong, Dae Ho; Chung, Sung Jae; Kumta, Prashant N.

    2014-12-01

    Fluorine doped iridium oxide (IrO2:F) powders with varying F content ranging from 0 to 20 wt.% has been synthesized by using a modification of the Adams fusion method. The precursors (IrCl4 and NH4F) are mixed with NaNO3 and heated to elevated temperatures to form high surface area nanomaterials as electro-catalysts for PEM based water electrolysis. The catalysts were then coated on a porous Ti substrate and have been studied for the oxygen evolution reaction in PEM based water electrolysis. The IrO2:F with an optimum composition of IrO2:10 wt.% F shows remarkably superior electrochemical activity and chemical stability compared to pure IrO2. The results have also been supported via kinetic studies by conducting rotating disk electrode (RDE) experiments. The RDE studies confirm that the electro-catalysts follow the two electron transfer reaction for electrolysis with calculated activation energy of ∼25 kJ mol-1. Single full cell tests conducted also validate the superior electrochemical activity of the 10 wt.% F doped IrO2.

  8. Performance of Single Electrode-Supported Cells Operating in the Electrolysis Mode

    SciTech Connect

    J. E. O'Brien; G. K. Housley; D. G. Milobar

    2009-11-01

    An experimental study is under way to assess the performance of electrode-supported solid-oxide cells operating in the steam electrolysis mode for hydrogen production over a temperature range of 800 to 900ºC. Results presented in this paper were obtained from single cells, with an active area of 16 cm2 per cell. The electrolysis cells are electrode-supported, with yttria-stabilized zirconia (YSZ) electrolytes (~10 µm thick), nickel-YSZ steam/hydrogen electrodes (~1400 µm thick), and manganite (LSM) air-side electrodes. The experiments were performed over a range of steam inlet mole fractions (0.1 – 0.6), gas flow rates, and current densities (0 to 0.6 A/cm2). Steam consumption rates associated with electrolysis were measured directly using inlet and outlet dewpoint instrumentation. On a molar basis, the steam consumption rate is equal to the hydrogen production rate. Cell performance was evaluated by performing DC potential sweeps at 800, 850, and 900°C. The voltage-current characteristics are presented, along with values of area-specific resistance as a function of current density. Long-term cell performance is also assessed to evaluate cell degradation. Details of the custom single-cell test apparatus developed for these experiments are also presented.

  9. Hydrogen production from switchgrass via a hybrid pyrolysis-microbial electrolysis process

    DOE PAGES

    Lewis, Alex J.; Ren, Shoujie; Ye, Philip; Kim, Pyoungchung; Labbe, Niki; Borole, Abhijeet P.

    2015-06-30

    A new approach to hydrogen production using a hybrid pyrolysis-microbial electrolysis process is described. The aqueous stream generated during pyrolysis of switchgrass was used as a substrate for hydrogen production in a microbial electrolysis cell, achieving a maximum hydrogen production rate of 4.3 L H2/L-day at a loading of 10 g COD/L-anode-day. Hydrogen yields ranged from 50 3.2% to76 0.5% while anode coulombic efficiency ranged from 54 6.5% to 96 0.21%, respectively. Significant conversion of furfural, organic acids and phenolic molecules was observed under both batch and continuous conditions. The electrical and overall energy efficiency ranged from 149-175% and 48-63%,more » respectively. The results demonstrate the potential of the pyrolysis-microbial electrolysis process as a sustainable and efficient route for production of renewable hydrogen with significant implications for hydrocarbon production from biomass.« less

  10. Diagnosis of sources of current inefficiency in industrial molten salt electrolysis cells by Raman spectroscopy

    SciTech Connect

    Sadoway, D.R.

    1988-07-29

    The purpose of this project was to employ Raman spectroscopy in the study of industrial molten salt electrolysis cells. The objective was to improve the understanding of the chemistry and electrochemistry of the relevant melt systems and, in turn, of energy loss mechanisms in the industrial processes. On this basis new ways to improve the energy efficiency of these industrial reactors might be identified. The research plan has several principal elements. First, there was the design and construction of laboratory scale representations of industrial molten salt electrolysis cells that would at the same time serve a spectrocells. Secondly, there was the mastery of the preparation of the molten salt electrolytes, what in industry is called the ''front end.'' Thirdly, there was the adaptation of commercially available Raman instrumentation in order to facilitate the proposed studies. It is the nature of the specimens that so dramatically distinguished this work from conventional Raman studies for which commercial instrumentation is designed: first, the laboratory scale electrolysis cells are large compared to typical spectrocells; and secondly, the cells operate at, what for Raman studies are, extremely high temperatures. 4 refs., 2 figs.

  11. Status of the INL high-temperature electrolysis research program –experimental and modeling

    SciTech Connect

    J. E. O'Brien; C. M. Stoots; M. G. McKellar; E. A. Harvego; K. G. Condie; G. K. Housley; J. S. Herring; J. J. Hartvigsen

    2009-04-01

    This paper provides a status update on the high-temperature electrolysis (HTE) research and development program at the Idaho National Laboratory (INL), with an overview of recent large-scale system modeling results and the status of the experimental program. System analysis results have been obtained using the commercial code UniSim, augmented with a custom high-temperature electrolyzer module. The process flow diagrams for the system simulations include an advanced nuclear reactor as a source of high-temperature process heat, a power cycle and a coupled steam electrolysis loop. Several reactor types and power cycles have been considered, over a range of reactor coolant outlet temperatures. In terms of experimental research, the INL has recently completed an Integrated Laboratory Scale (ILS) HTE test at the 15 kW level. The initial hydrogen production rate for the ILS test was in excess of 5000 liters per hour. Details of the ILS design and operation will be presented. Current small-scale experimental research is focused on improving the degradation characteristics of the electrolysis cells and stacks. Small-scale testing ranges from single cells to multiple-cell stacks. The INL is currently in the process of testing several state-of-the-art anode-supported cells and is working to broaden its relationship with industry in order to improve the long-term performance of the cells.

  12. 3D CFD Model of a Multi-Cell High Temperature Electrolysis Stack

    SciTech Connect

    G.L. Hawkes; J. E. O'Brien; C. M. Stoots

    2007-11-01

    A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis stack performance and steam electrolysis in the Idaho National Laboratory Integrated Lab Scale (ILS) experiment. The model is made of 60 planar cells stacked on top of each other operated as Solid Oxide Electrolysis Cells (SOEC). Details of the model geometry are specific to a stack that was fabricated by Ceramatec, Inc1. and tested at the Idaho National Laboratory. Inlet and outlet plenum flow and distribution are considered. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC userdefined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation overpotential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Variations in flow distribution, and species concentration are discussed. End effects of flow and per-cell voltage are also considered.

  13. Conceptual study of on orbit production of cryogenic propellants by water electrolysis

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.

    1991-01-01

    The feasibility is assessed of producing cryogenic propellants on orbit by water electrolysis in support of NASA's proposed Space Exploration Initiative (SEI) missions. Using this method, water launched into low earth orbit (LEO) would be split into gaseous hydrogen and oxygen by electrolysis in an orbiting propellant processor spacecraft. The resulting gases would then be liquified and stored in cryogenic tanks. Supplying liquid hydrogen and oxygen fuel to space vehicles by this technique has some possible advantages over conventional methods. The potential benefits are derived from the characteristics of water as a payload, and include reduced ground handling and launch risk, denser packaging, and reduced tankage and piping requirements. A conceptual design of a water processor was generated based on related previous studies, and contemporary or near term technologies required. Extensive development efforts would be required to adapt the various subsystems needed for the propellant processor for use in space. Based on the cumulative results, propellant production by on orbit water electrolysis for support of SEI missions is not recommended.

  14. CFD Model Of A Planar Solid Oxide Electrolysis Cell For Hydrogen Production From Nuclear Energy

    SciTech Connect

    Grant L. Hawkes; James E. O'Brien; Carl M. Stoots; J. Stephen Herring

    2005-10-01

    A three-dimensional computational fluid dynamics (CFD) model has been created to model hightemperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec2, Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL.

  15. Composite cathode based on doped vanadate enhanced with loaded metal nanoparticles for steam electrolysis

    NASA Astrophysics Data System (ADS)

    Li, Yuanxin; Wu, Guojian; Ruan, Cong; Zhou, Qi; Wang, Yan; Doherty, Winston; Xie, Kui; Wu, Yucheng

    2014-05-01

    The use of composite electrodes based on La0.7Sr0.3VO3 (LSV) for steam electrolysis has uncovered the tremendous potential and capacity inherent in this material. Unfortunately, this material has a major setback of inefficient electrolysis triggered by limited electrocatalytic activity. In this work, an infiltration method is employed to load catalytic-active metal nanoparticles onto the composite electrodes in order to achieve an activity-enhanced electrode performance. The electrical properties of LSV are methodically explored and correlated to electrode performance. At 800 °C in either pure H2 or low hydrogen partial pressure (pH2) of 5%H2/N2, the polarization resistance of symmetrical cells with Ni-loaded LSV (LSV-Ni) cathode is largely enhanced, in contrast to bare LSV cathode. Similar improvement is also achieved for the Fe-loaded LSV (LSV-Fe) cathode in a wide range of hydrogen partial pressures of 5%-100%. The Faraday efficiencies of LSV-Ni and LSV-Fe composite cathodes were remarkably improved for electrolysis in either 3%H2O/4.7H2/Ar or 3%H2O/Ar at 800 °C.

  16. Pulsed Plasma Thruster Contamination

    NASA Technical Reports Server (NTRS)

    Myers, Roger M.; Arrington, Lynn A.; Pencil, Eric J.; Carter, Justin; Heminger, Jason; Gatsonis, Nicolas

    1996-01-01

    Pulsed Plasma Thrusters (PPT's) are currently baselined for the Air Force Mightysat II.1 flight in 1999 and are under consideration for a number of other missions for primary propulsion, precision positioning, and attitude control functions. In this work, PPT plumes were characterized to assess their contamination characteristics. Diagnostics included planar and cylindrical Langmuir probes and a large number of collimated quartz contamination sensors. Measurements were made using a LES 8/9 flight PPT at 0.24, 0.39, 0.55, and 1.2 m from the thruster, as well as in the backflow region behind the thruster. Plasma measurements revealed a peak centerline ion density and velocity of approx. 6 x 10(exp 12) cm(exp -3) and 42,000 m/s, respectively. Optical transmittance measurements of the quartz sensors after 2 x 10(exp 5) pulses showed a rapid decrease in plume contamination with increasing angle from the plume axis, with a barely measurable transmittance decrease in the ultraviolet at 90 deg. No change in optical properties was detected for sensors in the backflow region.

  17. Design of a Pulsed Flux Concentrator for the ILC Positron Source

    SciTech Connect

    Gronberg, J; Abbott, R; Brown, C; Javedani, J; Piggott, W T; Clarke, J

    2010-05-17

    The Positron Source for the International Linear Collider requires an optical matching device after the target to increase the capture efficiency for positrons. Pulsed flux concentrators have been used by previous machines to improve the capture efficiency but the ILC has a 1 ms long pulse train which is too long for a standard flux concentrator. A pulsed flux concentrator with a 40 ms flat top was created for a hyperon experiment in 1965 which used liquid nitrogen cooling to reduce the resistance of the concentrating plates and extend the lifetime of the pulse. We report on a design for a 1 ms device based on this concept.

  18. PULSE COLUMN

    DOEpatents

    Grimmett, E.S.

    1964-01-01

    This patent covers a continuous countercurrent liquidsolids contactor column having a number of contactor states each comprising a perforated plate, a layer of balls, and a downcomer tube; a liquid-pulsing piston; and a solids discharger formed of a conical section at the bottom of the column, and a tubular extension on the lowest downcomer terminating in the conical section. Between the conical section and the downcomer extension is formed a small annular opening, through which solids fall coming through the perforated plate of the lowest contactor stage. This annular opening is small enough that the pressure drop thereacross is greater than the pressure drop upward through the lowest contactor stage. (AEC)

  19. Effects of pulse duration on magnetostimulation thresholds

    SciTech Connect

    Saritas, Emine U.; Goodwill, Patrick W.; Conolly, Steven M.

    2015-06-15

    Purpose: Medical imaging techniques such as magnetic resonance imaging and magnetic particle imaging (MPI) utilize time-varying magnetic fields that are subject to magnetostimulation limits, which often limit the speed of the imaging process. Various human-subject experiments have studied the amplitude and frequency dependence of these thresholds for gradient or homogeneous magnetic fields. Another contributing factor was shown to be number of cycles in a magnetic pulse, where the thresholds decreased with longer pulses. The latter result was demonstrated on two subjects only, at a single frequency of 1.27 kHz. Hence, whether the observed effect was due to the number of cycles or due to the pulse duration was not specified. In addition, a gradient-type field was utilized; hence, whether the same phenomenon applies to homogeneous magnetic fields remained unknown. Here, the authors investigate the pulse duration dependence of magnetostimulation limits for a 20-fold range of frequencies using homogeneous magnetic fields, such as the ones used for the drive field in MPI. Methods: Magnetostimulation thresholds were measured in the arms of six healthy subjects (age: 27 ± 5 yr). Each experiment comprised testing the thresholds at eight different pulse durations between 2 and 125 ms at a single frequency, which took approximately 30–40 min/subject. A total of 34 experiments were performed at three different frequencies: 1.2, 5.7, and 25.5 kHz. A solenoid coil providing homogeneous magnetic field was used to induce stimulation, and the field amplitude was measured in real time. A pre-emphasis based pulse shaping method was employed to accurately control the pulse durations. Subjects reported stimulation via a mouse click whenever they felt a twitching/tingling sensation. A sigmoid function was fitted to the subject responses to find the threshold at a specific frequency and duration, and the whole procedure was repeated at all relevant frequencies and pulse durations

  20. LIQUID BIO-FUEL PRODUCTION FROM NON-FOOD BIOMASS VIA HIGH TEMPERATURE STEAM ELECTROLYSIS

    SciTech Connect

    G. L. Hawkes; J. E. O'Brien; M. G. McKellar

    2011-11-01

    Bio-Syntrolysis is a hybrid energy process that enables production of synthetic liquid fuels that are compatible with the existing conventional liquid transportation fuels infrastructure. Using biomass as a renewable carbon source, and supplemental hydrogen from high-temperature steam electrolysis (HTSE), bio-syntrolysis has the potential to provide a significant alternative petroleum source that could reduce US dependence on imported oil. Combining hydrogen from HTSE with CO from an oxygen-blown biomass gasifier yields syngas to be used as a feedstock for synthesis of liquid transportation fuels via a Fischer-Tropsch process. Conversion of syngas to liquid hydrocarbon fuels, using a biomass-based carbon source, expands the application of renewable energy beyond the grid to include transportation fuels. It can also contribute to grid stability associated with non-dispatchable power generation. The use of supplemental hydrogen from HTSE enables greater than 90% utilization of the biomass carbon content which is about 2.5 times higher than carbon utilization associated with traditional cellulosic ethanol production. If the electrical power source needed for HTSE is based on nuclear or renewable energy, the process is carbon neutral. INL has demonstrated improved biomass processing prior to gasification. Recyclable biomass in the form of crop residue or energy crops would serve as the feedstock for this process. A process model of syngas production using high temperature electrolysis and biomass gasification is presented. Process heat from the biomass gasifier is used to heat steam for the hydrogen production via the high temperature steam electrolysis process. Oxygen produced form the electrolysis process is used to control the oxidation rate in the oxygen-blown biomass gasifier. Based on the gasifier temperature, 94% to 95% of the carbon in the biomass becomes carbon monoxide in the syngas (carbon monoxide and hydrogen). Assuming the thermal efficiency of the power

  1. 3D CFD Model of High Temperature H2O/CO2 Co-electrolysis

    SciTech Connect

    Grant Hawkes; James O'Brien; Carl Stoots; Stephen Herring; Joe Hartvigsen

    2007-06-01

    3D CFD Model of High Temperature H2O/CO2 Co-Electrolysis Grant Hawkes1, James O’Brien1, Carl Stoots1, Stephen Herring1 Joe Hartvigsen2 1 Idaho National Laboratory, Idaho Falls, Idaho, grant.hawkes@inl.gov 2 Ceramatec Inc, Salt Lake City, Utah INTRODUCTION A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature co-electrolysis of steam and carbon dioxide in a planar solid oxide electrolyzer (SOE) using solid oxide fuel cell technology. A research program is under way at the Idaho National Laboratory (INL) to simultaneously address the research and scale-up issues associated with the implementation of planar solid-oxide electrolysis cell technology for syn-gas production from CO2 and steam. Various runs have been performed under different run conditions to help assess the performance of the SOE. This paper presents CFD results of this model compared with experimental results. The Idaho National Laboratory (INL), in conjunction with Ceramatec Inc. (Salt Lake City, USA) has been researching for several years the use of solid-oxide fuel cell technology to electrolyze steam for large-scale nuclear-powered hydrogen production. Now, an experimental research project is underway at the INL to produce syngas by simultaneously electrolyzing at high-temperature steam and carbon dioxide (CO2) using solid oxide fuel cell technology. A strong interest exists in the large-scale production of syn-gas from CO2 and steam to be reformed into a usable transportation fuel. If biomass is used as the carbon source, the overall process is climate neutral. Consequently, there is a high level of interest in production of syn-gas from CO2 and steam electrolysis. With the price of oil currently around $60 / barrel, synthetically-derived hydrocarbon fuels (synfuels) have become economical. Synfuels are typically produced from syngas – hydrogen (H2) and carbon monoxide (CO) -- using the Fischer-Tropsch process, discovered by Germany before World

  2. Ion acceleration in the RPA regime by shaped pulses

    NASA Astrophysics Data System (ADS)

    Kim, Young-Kuk; Hur, Min Sup

    2012-10-01

    Recently we presented a controllable pulse shaping by relativistic transparency in non-uniform, overdense plasmas [1]. In this shaping scheme, by tapering the density and thickness of an overdense plasma slab, the pulse front can be carved into various figures such as transversely flat or concave shape with longitudinally sharp pulse fronts. As an application of such a novel scheme of the pulse shaping, we studied the effects of the shaped pulse on ion beam energy, charge, and energy spread in the radiation pressure dominant regime. From the 2-dimensional PIC simulations, we observed that the flat pulse produces more energetic proton beam than a usual Gaussian beam, and concave pulse yields even more abundant proton beam. [4pt] [1] M.S. Hur et al., ``Versatile shaping of a relativistic laser pulse from a nonuniform overdense plasma,'' Phys. Plasmas, (accepted, to appear in 2012).

  3. Tapered pulse tube for pulse tube refrigerators

    DOEpatents

    Swift, Gregory W.; Olson, Jeffrey R.

    1999-01-01

    Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

  4. An Environmentally Friendly Process Involving Refining and Membrane-Based Electrolysis for Magnesium Recovery from Partially Oxidized Scrap Alloy

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei; Pal, Uday B.; Powell, Adam C.

    2013-10-01

    Magnesium is recovered from partially oxidized scrap alloy by combining refining and solid oxide membrane (SOM) electrolysis. In this combined process, a molten salt eutectic flux (45 wt.% MgF2-55 wt.% CaF2) containing 10 wt.% MgO and 2 wt.% YF3 was used as the medium for magnesium recovery. During refining, magnesium and its oxide are dissolved from the scrap into the molten flux. Forming gas is bubbled through the flux and the dissolved magnesium is removed via the gas phase and condensed in a separate condenser at a lower temperature. The molten flux has a finite solubility for magnesium and acts as a selective medium for magnesium dissolution, but not aluminum or iron, and therefore the magnesium recovered has high purity. After refining, SOM electrolysis is performed in the same reactor to enable electrolysis of the dissolved magnesium oxide in the molten flux producing magnesium at the cathode and oxygen at the SOM anode. During SOM electrolysis, it is necessary to decrease the concentration of the dissolved magnesium in the flux to improve the faradaic current efficiency and prevent degradation of the SOM. Thus, for both refining and SOM electrolysis, it is very important to measure and control the magnesium solubility in the molten flux. High magnesium solubility facilitates refining whereas lower solubility benefits the SOM electrolysis process. Computational fluid dynamics modeling was employed to simulate the flow behavior of the flux stirred by the forming gas. Based on the modeling results, an optimized design of the stirring tubes and its placement in the flux are determined for efficiently removing the dissolved magnesium and also increasing the efficiency of the SOM electrolysis process.

  5. LC-MS/MS quantitation of plasma progesterone in cattle.

    PubMed

    Fernandes, R M T; Gomes, G C; Porcari, A M; Pimentel, J R V; Porciúncula, P M; Martins-Júnior, H A; Miguez, P H P; da Costa, J L; Amaral, P H; Perecin, F; Meurer, E C; Furtado, P V; Simas, R C; Eberlin, M N; Ferreira, C R; Madureira, E H

    2011-10-15

    Quantitation of progesterone (P(4)) in biological fluids is often performed by radioimmunoassay (RIA), whereas liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has been used much less often. Due to its autoconfirmatory nature, LC-MS/MS greatly minimizes false positives and interference. Herein we report and compare with RIA an optimized LC-MS/MS method for rapid, efficient, and cost-effective quantitation of P(4) in plasma of cattle with no sample derivatization. The quantitation of plasma P(4) released from three nonbiodegradable, commercial, intravaginal P(4)-releasing devices (IPRD) over 192 h in six ovariectomized cows was compared in a pairwise study as a test case. Both techniques showed similar P(4) kinetics (P > 0.05) whereas results of P(4) quantitation by RIA were consistently higher compared with LC-MS/MS (P < 0.05) due to interference and matrix effects. The LC-MS/MS method was validated according to the recommended analytical standards and displayed P(4) limits of detection (LOD) and quantitation (LOQ) of 0.08 and a 0.25 ng/mL, respectively. The high selective LC-MS/MS method proposed herein for P(4) quantitation eliminates the risks associated with radioactive handling; it also requires no sample derivatization, which is a common requirement for LC-MS/MS quantitation of steroid hormones. Its application to multisteroid assays is also viable, and it is envisaged that it may provide a gold standard technique for hormone quantitation in animal reproductive science studies. PMID:21798587

  6. Polyamine analysis by LC-MS.

    PubMed

    Häkkinen, Merja R

    2011-01-01

    This chapter describes a protocol to analyze polyamines without any derivatization steps utilizing LC-MS/MS. Polyamines are separated by reversed phase LC prior MS analysis using heptafluorobutyric acid as MS compatible volatile ion-pairing agent, and selective and sensitive MS detection is performed using MS/MS in selected reaction monitoring mode.

  7. Electrostatic Changes Observed with Narrow Bipolar Pulses

    NASA Astrophysics Data System (ADS)

    Karunarathne, S.; Marshall, T. C.; Stolzenburg, M.; Karunarathna, N.

    2015-12-01

    Narrow bipolar pulses (NBPs) or compact intracloud discharges are impulsive discharges that are considered to be the strongest natural emitters in the HF radio band; they usually occur at high altitudes in some thunderstorms. In the summer of 2011, we collected E-change data with wideband flat-plate antennas (0.16 Hz - 2.5 MHz) at ten stations covering an area of nearly 70 km x 100 km in and around Kennedy Space Center, Florida, USA. On one thunderstorm day, 14 August 2011, we detected 226 positive NBPs, and some observations of these pulses were published in Karunarathne et al. [2015, JGR-atmospheres]. Of these 226 NBPs, 50 (22.1 %) occurred within 10 km horizontally of at least one sensor. All of these closer sensors show electrostatic changes associated with corresponding NBPs, with a net electrostatic change in the main bipolar pulse and with a slower electrostatic change after the bipolar pulse that seems similar to short continuing current immediately after some cloud-to-ground return strokes. Although NBPs have been considered as short duration pulses (10 - 20 microseconds), the electrostatic changes after the main bipolar pulse ranged from 0.7 ms to 34 ms and associated charge moments were calculated. The total duration of the electrostatic E-change was strongly dependent on the distance to the sensors. In this presentation, we will present data for these electrostatic changes, some statistics, and physical background and reasoning for the electrostatic changes.

  8. Solids sampling using double-pulse laser ablation inductivelycoupled plasma mass spectrometry

    SciTech Connect

    Gonzalez, Jhanis; Liu, Chunyi; Yoo, Jong; Mao, Xianglei; Russo,RickRick

    2003-07-01

    This paper describes the use of double-pulse laser ablation to improve ICP-MS internal precision (temporal relative standard deviation, %TRSD). Double pulse laser ablation offers reduced fractionation, increased sensitivity, and improved signal to noise ratios. The first pulse is used to ablate a large quantity of mass from the sample surface. The second pulse is applied with a variable time delay after the first pulse to break the ablated mass into a finer aerosol, which is more readily transported to and digested in the ICP-MS.

  9. Mathematical Analysis of High-Temperature Co-electrolysis of CO2 and O2 Production in a Closed-Loop Atmosphere Revitalization System

    SciTech Connect

    Michael G. McKellar; Manohar S. Sohal; Lila Mulloth; Bernadette Luna; Morgan B. Abney

    2010-03-01

    NASA has been evaluating two closed-loop atmosphere revitalization architectures based on Sabatier and Bosch carbon dioxide, CO2, reduction technologies. The CO2 and steam, H2O, co-electrolysis process is another option that NASA has investigated. Utilizing recent advances in the fuel cell technology sector, the Idaho National Laboratory, INL, has developed a CO2 and H2O co-electrolysis process to produce oxygen and syngas (carbon monoxide, CO and hydrogen, H2 mixture) for terrestrial (energy production) application. The technology is a combined process that involves steam electrolysis, CO2 electrolysis, and the reverse water gas shift (RWGS) reaction. A number of process models have been developed and analyzed to determine the theoretical power required to recover oxygen, O2, in each case. These models include the current Sabatier and Bosch technologies and combinations of those processes with high-temperature co-electrolysis. The cases of constant CO2 supply and constant O2 production were evaluated. In addition, a process model of the hydrogenation process with co-electrolysis was developed and compared. Sabatier processes require the least amount of energy input per kg of oxygen produced. If co-electrolysis replaces solid polymer electrolyte (SPE) electrolysis within the Sabatier architecture, the power requirement is reduced by over 10%, but only if heat recuperation is used. Sabatier processes, however, require external water to achieve the lower power results. Under conditions of constant incoming carbon dioxide flow, the Sabatier architectures require more power than the other architectures. The Bosch, Boudouard with co-electrolysis, and the hydrogenation with co-electrolysis processes require little or no external water. The Bosch and hydrogenation processes produce water within their reactors, which aids in reducing the power requirement for electrolysis. The Boudouard with co-electrolysis process has a higher electrolysis power requirement because carbon

  10. Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water

    NASA Astrophysics Data System (ADS)

    Graves, Christopher Ronald

    Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co-electrolysis

  11. A Vivens Ex Vivo Study on the Synergistic Effect of Electrolysis and Freezing on the Cell Nucleus.

    PubMed

    Lugnani, Franco; Zanconati, Fabrizio; Marcuzzo, Thomas; Bottin, Cristina; Mikus, Paul; Guenther, Enric; Klein, Nina; Rubinsky, Liel; Stehling, Michael K; Rubinsky, Boris

    2015-01-01

    Freezing-cryosurgery, and electrolysis-electrochemical therapy (EChT), are two important minimally invasive surgery tissue ablation technologies. Despite major advantages they also have some disadvantages. Cryosurgery cannot induce cell death at high subzero freezing temperatures and requires multiple freeze thaw cycles, while EChT requires high concentrations of electrolytic products-which makes it a lengthy procedure. Based on the observation that freezing increases the concentration of solutes (including products of electrolysis) in the frozen region and permeabilizes the cell membrane to these products, this study examines the hypothesis that there could be a synergistic effect between freezing and electrolysis in their use together for tissue ablation. Using an animal model we refer to as vivens ex vivo, which may be of value in reducing the use of animals for experiments, combined with a Hematoxylin stain of the nucleus, we show that there are clinically relevant protocols in which the cell nucleus appears intact when electrolysis and freezing are used separately but is affected by certain combinations of electrolysis and freezing.

  12. Analysis of Biomolecules by Atmospheric Pressure Visible-Wavelength MALDI-Ion Trap-MS in Transmission Geometry

    NASA Astrophysics Data System (ADS)

    West, Raymond E.; Findsen, Eric W.; Isailovic, Dragan

    2013-10-01

    We report the development of a new AP visible-wavelength MALDI-ion trap-MS instrument with significantly improved performance over our previously reported system ( Int. J. Mass Spectrom. 315, 66-73 (2012)). A Nd:YAG pulsed laser emitting light at 532 nm was used to desorb and ionize oligosaccharides and peptides in transmission geometry through a glass slide. Limits of detection (LODs) achieved in MS mode correspond to picomole quantities of oligosaccharides and femtomole quantities of peptides. Tandem MS (MS/MS) experiments enabled identification of enzymatically digested proteins and oligosaccharides by comparison of MS/MS spectra with data found in protein and glycan databases. Moreover, the softness of ionization, LODs, and fragmentation spectra of biomolecules by AP visible-wavelength MALDI-MS were compared to those obtained by AP UV MALDI-MS using a Nd:YAG laser emitting light at 355 nm. AP visible-wavelength MALDI appears to be a softer ionization technique then AP UV MALDI for the analysis of sulfated peptides, while visible-wavelength MALDI-MS, MS/MS, and MS/MS/MS spectra of other biomolecules analyzed were mostly similar to those obtained by AP UV MALDI-MS. Therefore, the methodology presented will be useful for MS and MSn analyses of biomolecules at atmospheric pressure. Additionally, the AP visible-wavelength MALDI developed can be readily used for soft ionization of analytes on various mass spectrometers.

  13. Three Dimensional CFD Model of a Planar Solid Oxide Electrolysis Cell for Co-Electrolysis of Steam and Carbon-Dioxide

    SciTech Connect

    G. Hawkes; J. O'Brien; C. Stoots; S. Herring; R. Jones

    2006-11-01

    A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature co-electrolysis of steam and carbon dioxide in a planar solid oxide electrolyzer (SOE). A research program is under way at the Idaho National Laboratory (INL) to simultaneously address the research and scale-up issues associated with the implementation of planar solid-oxide electrolysis cell technology for syn-gas production from CO2 and steam. Various runs have been performed under different run conditions to help assess the performance of the SOE. An experimental study is also being performed at the INL to assess the SOE. Model results provide detailed profiles of temperature, Nernst potential, operating potential, anode-side gas composition, cathode-side gas composition, current density and syn-gas production over a range of stack operating conditions. Typical results of current density versus cell potential, cell current versus H2 and CO production, temperature, and voltage potential are all presented within this paper. Plots of mole fraction of CO2, CO, H2, H2O, O2, are presented. Currently there is strong interest in the large-scale production of syn-gas from CO2 and steam to be reformed into a usable transportation fuel. This process takes the carbon-neutral approach where the amount of CO2 in the atmosphere does not increase. Consequently, there is a high level of interest in production of syn-gas from CO2 and steam electrolysis. Worldwide, the demand for light hydrocarbon fuels like gasoline and diesel oil is increasing. To satisfy this demand, oil companies have begun to utilize oil deposits of lower hydrogen. In the mean time, with the price of oil currently over $70 / barrel, synthetically-derived hydrocarbon fuels (synfuels) have become economical. Synfuels are typically produced from syngas – hydrogen (H2) and carbon monoxide (CO) -- using the Fischer-Tropsch process, discovered by Germany before World War II. South Africa has used synfuels to

  14. MS-DIAL: Data Independent MS/MS Deconvolution for Comprehensive Metabolome Analysis

    PubMed Central

    Tsugawa, Hiroshi; Cajka, Tomas; Kind, Tobias; Ma, Yan; Higgins, Brendan; Ikeda, Kazutaka; Kanazawa, Mitsuhiro; VanderGheynst, Jean; Fiehn, Oliver; Arita, Masanori

    2015-01-01

    Data-independent acquisition (DIA) in liquid chromatography tandem mass spectrometry (LC-MS/MS) provides more comprehensive untargeted acquisition of molecular data. Here we provide an open-source software pipeline, MS-DIAL, to demonstrate how DIA improves simultaneous identification and quantification of small molecules by mass spectral deconvolution. For reversed phase LC-MS/MS, our program with an enriched LipidBlast library identified total 1,023 lipid compounds from nine algal strains to highlight their chemotaxonomic relationships. PMID:25938372

  15. Integrated LC-MS/MS system for plant metabolomics

    PubMed Central

    Sawada, Yuji; Hirai, Masami Yokota

    2013-01-01

    Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is highly sensitive, selective, and enables extensive detection of metabolites within a sample. The result allows us to characterize comprehensive metabolite accumulation patterns without dependence on authentic standard compounds and isolation of the individual metabolites. A reference database search is essential for the structural assignment process of un-targeted MS and MS/MS data. Moreover, the characterization of unknown metabolites is challenging, since these cannot be assigned a candidate structure by using a reference database. In this case study, integrated LC-MS/MS based plant metabolomics allows us to detect several hundred metabolites in a sample; and integrated omics analyses, e.g., large-scale reverse genetics, linkage mapping, and association mapping, provides a powerful tool for candidate structure selection or rejection. We also examine emerging technology and applications for LC-MS/MS-based un-targeted plant metabolomics. These activities promote the characterization of massive extended detectable metabolites. PMID:24688692

  16. Analysis of Improved Reference Design for a Nuclear-Driven High Temperature Electrolysis Hydrogen Production Plant

    SciTech Connect

    Edwin A. Harvego; James E. O'Brien; Michael G. McKellar

    2010-06-01

    The use of High Temperature Electrolysis (HTE) for the efficient production of hydrogen without the greenhouse gas emissions associated with conventional fossil-fuel hydrogen production techniques has been under investigation at the Idaho National Engineering Laboratory (INL) for the last several years. The activities at the INL have included the development, testing and analysis of large numbers of solid oxide electrolysis cells, and the analyses of potential plant designs for large scale production of hydrogen using an advanced Very-High Temperature Reactor (VHTR) to provide the process heat and electricity to drive the electrolysis process. The results of these system analyses, using the UniSim process analysis software, have shown that the HTE process, when coupled to a VHTR capable of operating at reactor outlet temperatures of 800 °C to 950 °C, has the potential to produce the large quantities of hydrogen needed to meet future energy and transportation needs with hydrogen production efficiencies in excess of 50%. In addition, economic analyses performed on the INL reference plant design, optimized to maximize the hydrogen production rate for a 600 MWt VHTR, have shown that a large nuclear-driven HTE hydrogen production plant can to be economically competitive with conventional hydrogen production processes, particularly when the penalties associated with greenhouse gas emissions are considered. The results of this research led to the selection in 2009 of HTE as the preferred concept in the U.S. Department of Energy (DOE) hydrogen technology down-selection process. However, the down-selection process, along with continued technical assessments at the INL, has resulted in a number of proposed modifications and refinements to improve the original INL reference HTE design. These modifications include changes in plant configuration, operating conditions and individual component designs. This paper describes the resulting new INL reference design and presents

  17. Nonlinear time-series analysis of current signal in cathodic contact glow discharge electrolysis

    NASA Astrophysics Data System (ADS)

    Allagui, Anis; Rojas, Andrea Espinel; Bonny, Talal; Elwakil, Ahmed S.; Abdelkareem, Mohammad Ali

    2016-05-01

    In the standard two-electrode configuration employed in electrolytic process, when the control dc voltage is brought to a critical value, the system undergoes a transition from conventional electrolysis to contact glow discharge electrolysis (CGDE), which has also been referred to as liquid-submerged micro-plasma, glow discharge plasma electrolysis, electrode effect, electrolytic plasma, etc. The light-emitting process is associated with the development of an irregular and erratic current time-series which has been arbitrarily labelled as "random," and thus dissuaded further research in this direction. Here, we examine the current time-series signals measured in cathodic CGDE configuration in a concentrated KOH solution at different dc bias voltages greater than the critical voltage. We show that the signals are, in fact, not random according to the NIST SP. 800-22 test suite definition. We also demonstrate that post-processing low-pass filtered sequences requires less time than the native as-measured sequences, suggesting a superposition of low frequency chaotic fluctuations and high frequency behaviors (which may be produced by more than one possible source of entropy). Using an array of nonlinear time-series analyses for dynamical systems, i.e., the computation of largest Lyapunov exponents and correlation dimensions, and re-construction of phase portraits, we found that low-pass filtered datasets undergo a transition from quasi-periodic to chaotic to quasi-hyper-chaotic behavior, and back again to chaos when the voltage controlling-parameter is increased. The high frequency part of the signals is discussed in terms of highly nonlinear turbulent motion developed around the working electrode.

  18. Quantitative aspects of electrolysis in electromembrane extractions of acidic and basic analytes.

    PubMed

    Šlampová, Andrea; Kubáň, Pavel; Boček, Petr

    2015-08-01

    Electrolysis is omnipresent in all electrochemical processes including electromembrane extraction (EME). The effects of electrolysis on quantitative aspects of EME were comprehensively evaluated for a set of acidic (substituted phenols) and basic (basic drugs) analytes. EMEs were carried out across supported liquid membranes formed by 1-ethyl-2-nitrobenzene at standard EME conditions, i.e., acidic analytes were extracted from alkaline into alkaline solutions and basic analytes were extracted from acidic into acidic solutions. Electric potential applied across the EME systems was 50 V and extraction recoveries of analytes as well as pH values of donor and acceptor solutions were determined after each EME. It has been proven that electrolysis plays a more significant role than has ever been thought before in EME. Electrolytically produced H(+) and OH(-) ions had a significant effect on pH values of acceptor solutions and variations of up to 8.5 pH units were obtained at standard EME conditions. pH values of donor solutions were affected only negligibly due to their significantly higher volumes. The observed variations in pH values of acceptor solutions had fatal consequences on quantitative EME results of weak and medium strong acidic/basic analytes. A direct relation was observed between the decrease in extraction recoveries of the analytes, their pKa values and the acceptor solution pH values. Acceptor solutions consisting of high concentrations of weak bases or acids were thus proposed as suitable EME operational solutions since they efficiently eliminated the electrolytically induced pH variations, offered stable EME performances and were easily compatible with subsequent analytical methods.

  19. CHALLENGES IN GENERATING HYDROGEN BY HIGH TEMPERATURE ELECTROLYSIS USING SOLID OXIDE CELLS

    SciTech Connect

    M. S. Sohal; J. E. O'Brien; C. M. Stoots; M. G. McKellar; J. S. Herring; E. A. Harvego

    2008-03-01

    Idaho National Laboratory’s (INL) high temperature electrolysis research to generate hydrogen using solid oxide electrolysis cells is presented in this paper. The research results reported here have been obtained in a laboratory-scale apparatus. These results and common scale-up issues also indicate that for the technology to be successful in a large industrial setting, several technical, economical, and manufacturing issues have to be resolved. Some of the issues related to solid oxide cells are stack design and performance optimization, identification and evaluation of cell performance degradation parameters and processes, integrity and reliability of the solid oxide electrolysis (SOEC) stacks, life-time prediction and extension of the SOEC stack, and cost reduction and economic manufacturing of the SOEC stacks. Besides the solid oxide cells, balance of the hydrogen generating plant also needs significant development. These issues are process and ohmic heat source needed for maintaining the reaction temperature (~830°C), high temperature heat exchangers and recuperators, equal distribution of the reactants into each cell, system analysis of hydrogen and associated energy generating plant, and cost optimization. An economic analysis of this plant was performed using the standardized H2A Analysis Methodology developed by the Department of Energy (DOE) Hydrogen Program, and using realistic financial and cost estimating assumptions. The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a cost of $3.23/kg of hydrogen assuming an internal rate of return of 10%. These issues need interdisciplinary research effort of federal laboratories, solid oxide cell manufacturers, hydrogen consumers, and other such stakeholders. This paper discusses research and development accomplished by INL on such issues and highlights associated challenges that need to

  20. The effects of electrolysis on operational solutions in electromembrane extraction: The role of acceptor solution.

    PubMed

    Kubáň, Pavel; Boček, Petr

    2015-06-12

    Fundamental operational principle and instrumental set-up of electromembrane extraction (EME) suggest that electrolysis may play an important role in this recently developed micro-extraction technique. In the present study, the effect of electrolysis in EME is described comprehensively for the first time and it is demonstrated that electrolysis considerably influences EME performance. Micro-electromembrane extraction (μ-EME) across free liquid membrane formed by 1-pentanol was utilized for real-time monitoring of the electrolytically induced changes in composition of μ-EME solutions. These changes were visualized with a set of acid-base indicators. Changes in colours of their aqueous solutions revealed serious variations in their pH values, which occurred within seconds to minutes of the μ-EME process. Variations of up to eight pH units were observed for indicator solutions initially prepared in 1, 5 and 10mM hydrochloric acid. No or only negligible pH changes (less than 0.15 pH unit) were observed for indicator solutions prepared in 50 and 100mM acetic acid demonstrating that initial composition of the aqueous solutions was the crucial parameter. These results were also confirmed by theoretical calculations of maximum pH variations in the solutions, which were based on total electric charge transfers measured in the μ-EME systems, and by exact measurements of their pH values after μ-EMEs. Acceptor solutions that, in the current practice, consist predominantly of low concentrations of strong mineral acids or alkali hydroxides may thus not always ensure adequate EME performance, which was manifested by decrease in extraction recoveries of a basic drug papaverine. A suitable remedy to the observed effects is the application of acceptor solutions containing high concentrations of weak acids or bases. These solutions not only eliminate the decrease in recoveries but also serve well as matrices of extracted samples for subsequent analysis by capillary

  1. The effects of electrolysis on operational solutions in electromembrane extraction: The role of acceptor solution.

    PubMed

    Kubáň, Pavel; Boček, Petr

    2015-06-12

    Fundamental operational principle and instrumental set-up of electromembrane extraction (EME) suggest that electrolysis may play an important role in this recently developed micro-extraction technique. In the present study, the effect of electrolysis in EME is described comprehensively for the first time and it is demonstrated that electrolysis considerably influences EME performance. Micro-electromembrane extraction (μ-EME) across free liquid membrane formed by 1-pentanol was utilized for real-time monitoring of the electrolytically induced changes in composition of μ-EME solutions. These changes were visualized with a set of acid-base indicators. Changes in colours of their aqueous solutions revealed serious variations in their pH values, which occurred within seconds to minutes of the μ-EME process. Variations of up to eight pH units were observed for indicator solutions initially prepared in 1, 5 and 10mM hydrochloric acid. No or only negligible pH changes (less than 0.15 pH unit) were observed for indicator solutions prepared in 50 and 100mM acetic acid demonstrating that initial composition of the aqueous solutions was the crucial parameter. These results were also confirmed by theoretical calculations of maximum pH variations in the solutions, which were based on total electric charge transfers measured in the μ-EME systems, and by exact measurements of their pH values after μ-EMEs. Acceptor solutions that, in the current practice, consist predominantly of low concentrations of strong mineral acids or alkali hydroxides may thus not always ensure adequate EME performance, which was manifested by decrease in extraction recoveries of a basic drug papaverine. A suitable remedy to the observed effects is the application of acceptor solutions containing high concentrations of weak acids or bases. These solutions not only eliminate the decrease in recoveries but also serve well as matrices of extracted samples for subsequent analysis by capillary

  2. Quantitative aspects of electrolysis in electromembrane extractions of acidic and basic analytes.

    PubMed

    Šlampová, Andrea; Kubáň, Pavel; Boček, Petr

    2015-08-01

    Electrolysis is omnipresent in all electrochemical processes including electromembrane extraction (EME). The effects of electrolysis on quantitative aspects of EME were comprehensively evaluated for a set of acidic (substituted phenols) and basic (basic drugs) analytes. EMEs were carried out across supported liquid membranes formed by 1-ethyl-2-nitrobenzene at standard EME conditions, i.e., acidic analytes were extracted from alkaline into alkaline solutions and basic analytes were extracted from acidic into acidic solutions. Electric potential applied across the EME systems was 50 V and extraction recoveries of analytes as well as pH values of donor and acceptor solutions were determined after each EME. It has been proven that electrolysis plays a more significant role than has ever been thought before in EME. Electrolytically produced H(+) and OH(-) ions had a significant effect on pH values of acceptor solutions and variations of up to 8.5 pH units were obtained at standard EME conditions. pH values of donor solutions were affected only negligibly due to their significantly higher volumes. The observed variations in pH values of acceptor solutions had fatal consequences on quantitative EME results of weak and medium strong acidic/basic analytes. A direct relation was observed between the decrease in extraction recoveries of the analytes, their pKa values and the acceptor solution pH values. Acceptor solutions consisting of high concentrations of weak bases or acids were thus proposed as suitable EME operational solutions since they efficiently eliminated the electrolytically induced pH variations, offered stable EME performances and were easily compatible with subsequent analytical methods. PMID:26320790

  3. Efficient treatment of azo dye containing wastewater in a hybrid acidogenic bioreactor stimulated by biocatalyzed electrolysis.

    PubMed

    Wang, Hong-Cheng; Cheng, Hao-Yi; Wang, Shu-Sen; Cui, Dan; Han, Jing-Long; Hu, Ya-Ping; Su, Shi-Gang; Wang, Ai-Jie

    2016-01-01

    In this study, a novel scaled-up hybrid acidogenic bioreactor (HAB) was designed and adopted to evaluate the performance of azo dye (acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time (HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD (chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis (AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3%±2.5%, 86.2%±3.8% and 93.5%±1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS (61.1%±4.7%, 75.4%±5.0% and 82.1%±2.1%, respectively). Moreover, larger TCV/TV (total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2%±3.7% and 28.30±1.48 mA, respectively. They were significantly increased to 62.1%±2.0% and 34.55±0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater. PMID:26899658

  4. CFD Model of a Planar Solid Oxide Electrolysis Cell: Base Case and Variations

    SciTech Connect

    G. L. Hawkes; J. E. O'Brien; C. M. Stoots; J. S. Herring; R. W. Jones

    2007-07-01

    A three-dimensional computational fluid dynamics (CFD) model has been created to model high-temperature steam electrolysis in a planar solid oxide electrolysis cell (SOEC). The model represents a single cell, as it would exist in an electrolysis stack. Details of the model geometry are specific to a stack that was fabricated by Ceramatec, Inc. and tested at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean model results are shown to compare favorably with experimental results obtained from an actual ten-cell stack tested at INL. Mean per-cell area-specific-resistance (ASR) values decrease with increasing current density, consistent with experimental data. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, cathode and anode exchange current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicated the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal efficiency, cell electrical efficiency, and Gibbs free energy are discussed and reported herein.

  5. Lunar Metal Oxide Electrolysis with Oxygen and Photovoltaic Array Production Applications

    NASA Technical Reports Server (NTRS)

    Curreri, P. A.; Ethridge, E.; Hudson, S.; Sen, S.

    2006-01-01

    This paper presents the results of a Marshall Space Flight Center funded effort to conduct an experimental demonstration of the processing of simulated lunar resources by the molten oxide electrolysis (MOE) process to produce oxygen and metal from lunar resources to support human exploration of space. Oxygen extracted from lunar materials can be used for life support and propellant, and silicon and metallic elements produced can be used for in situ fabrication of thin-film solar cells for power production. The Moon is rich in mineral resources, but it is almost devoid of chemical reducing agents, therefore, molten oxide electrolysis, MOE, is chosen for extraction, since the electron is the most practical reducing agent. MOE was also chosen for following reasons. First, electrolytic processing offers uncommon versatility in its insensitivity to feedstock composition. Secondly, oxide melts boast the twin key attributes of highest solubilizing capacity for regolith and lowest volatility of any candidate electrolytes. The former is critical in ensuring high productivity since cell current is limited by reactant solubility, while the latter simplifies cell design by obviating the need for a gas-tight reactor to contain evaporation losses as would be the case with a gas or liquid phase fluoride reagent operating at such high temperatures. In the experiments reported here, melts containing iron oxide were electrolyzed in a low temperature supporting oxide electrolyte (developed by D. Sadoway, MIT). The production of oxygen and reduced iron were observed. Electrolysis was also performed on the supporting electrolyte with JSC-1 Lunar Simulant. The cell current for the supporting electrolyte alone is negligible while the current for the electrolyte with JSC-1 shows significant current and a peak at about -0.6 V indicating reductive reaction in the simulant.

  6. Results of tritium experiments on ceramic electrolysis cells and palladium diffusers for application to fusion reactor fuel cleanup systems

    SciTech Connect

    Carlson, R.V.; Binning, K.E.; Konishi, S.; Yoshida, H.; Naruse, Y.

    1987-01-01

    Tritium tests at the Tritium Systems Test Assembly have demonstrated that ceramic electrolysis cells and palladium alloy diffuser developed in Japan are possible components for a fusion reactor fuel cleanup system. Both components have been successfully operated with tritium for over a year. A failure of the first electrolysis cell was most likely the result of an over voltage on the ceramic. A simple circuit was developed to eliminate this mode of failure. The palladium diffusers tubes exhibited some degradation of mechanical properties as a result of the build up of helium from the tritium decay, after 450 days of operation with tritium, however the effects were not significant enough to affect the performance. New models of the diffuser and electrolysis cell, providing higher flow rates and more tritium compatible designs are currently being tested with tritium. 8 refs., 5 figs.

  7. Production of anhydrous aluminum chloride composition and process for electrolysis thereof

    DOEpatents

    Vandegrift, George F.; Krumpelt, Michael; Horwitz, E. Philip

    1983-01-01

    A process for producing an anhydrous aluminum chloride composition from a water-based aluminous material such as a slurry of aluminum hydroxide in a multistage extraction process in which the aluminum ion is first extracted into an organic liquid containing an acidic extractant and then extracted from the organic phase into an alkali metal chloride or chlorides to form a melt containing a mixture of chlorides of alkali metal and aluminum. In the process, the organic liquid may be recycled. In addition, the process advantageously includes an electrolysis cell for producing metallic aluminum and the alkali metal chloride or chlorides may be recycled for extraction of the aluminum from the organic phase.

  8. In-Situ Propellant Production on Mars: A Sabatier/Electrolysis Demonstration Plant

    NASA Astrophysics Data System (ADS)

    Clark, David L.

    1997-01-01

    An efficient, reliable propellant production plant has been developed for use on Mars. Using a Sabatier reactor in conjunction with a water electrolysis system, a complete demonstration plant has produced methane and liquid oxygen from simulated Martian atmosphere. The production plant has demonstrated high efficiency, extended duration production and autonomous operations. This paper presents the results and conclusions relating to eventual use in a Mars sample return mission. This work was funded by the Jet Propulsion Laboratory (JPL). The production plant was built and tested at the Propulsion Center of Lockheed Martin at the Denver Colorado facility.

  9. Energy storage using high pressure electrolysis and methods for reconversion. [in automobile fuel synthesis

    NASA Technical Reports Server (NTRS)

    Hughes, W. L.

    1973-01-01

    Theoretical and experimental studies on high pressure electrolysis producing hydrogen and oxygen for energy storage and reconversion are reported. Moderate temperature, high pressure hydrogen/oxygen fuel cells with nickel electrodes are investigated for effects of pressure, temperature, and membrane porosity. Test results from an aphodid burner turbine generator combination obtained 40 percent kilowatt hours out of the fuel cell divided by kilowatt hours into the electrolyzer. It is concluded that high pressure hydrogenation of organic materials can be used to synthesize hydrozenes and methanes for making synthetic vehicular fuels.

  10. Investigation of multi-metal catalysts for stable hydrogen production via urea electrolysis

    NASA Astrophysics Data System (ADS)

    King, Rebecca L.; Botte, Gerardine G.

    It has been shown that urea electrolysis is a viable method for wastewater remediation and simultaneous production of valuable hydrogen. Inexpensive nickel catalyst is optimal for the oxidation of urea in alkaline media but improvements are needed to minimize surface blockage and increase current density. Multi-metal catalysts were investigated by depositing platinum group metals on a nickel substrate. Rhodium and nickel proved synergistic to reduce surface blockage and increase catalyst stability. Rh-Ni electrodes reduced the overpotential for the electro-oxidation of urea and improved the current density by a factor of 200 compared to a Ni catalyst.

  11. From Oxygen Generation to Metals Production: In Situ Resource Utilization by Molten Oxide Electrolysis

    NASA Technical Reports Server (NTRS)

    Khetpal, Deepak; Ducret, Andrew C.; Sadoway, Donald R.

    2003-01-01

    For the exploration of other bodies in the solar system, electrochemical processing is arguably the most versatile technology for conversion of local resources into usable commodities: by electrolysis one can, in principle, produce (1) breathable oxygen, (2) silicon for the fabrication of solar cells, (3) various reactive metals for use as electrodes in advanced storage batteries, and (4) structural metals such as steel and aluminum. Even so, to date there has been no sustained effort to develop such processes, in part due to the inadequacy of the database. The objective here is to identify chemistries capable of sustaining molten oxide electrolysis in the cited applications and to examine the behavior of laboratory-scale cells designed to generate oxygen and to produce metal. The basic research includes the study of the underlying high-temperature physical chemistry of oxide melts representative of lunar regolith and of Martian soil. To move beyond empirical approaches to process development, the thermodynamic and transport properties of oxide melts are being studied to help set the limits of composition and temperature for the processing trials conducted in laboratory-scale electrolysis cells. The goal of this investigation is to deliver a working prototype cell that can use lunar regolith and Martian soil to produce breathable oxygen along with metal by-product. Additionally, the process can be generalized to permit adaptation to accommodate different feedstock chemistries, such as those that will be encountered on other bodies in the solar system. The expected results of this research include: (1) the identification of appropriate electrolyte chemistries; (2) the selection of candidate anode and cathode materials compatible with electrolytes named above; and (3) performance data from a laboratory-scale cell producing oxygen and metal. On the strength of these results it should be possible to assess the technical viability of molten oxide electrolysis for in

  12. ADJUSTABLE DOUBLE PULSE GENERATOR

    DOEpatents

    Gratian, J.W.; Gratian, A.C.

    1961-08-01

    >A modulator pulse source having adjustable pulse width and adjustable pulse spacing is described. The generator consists of a cross coupled multivibrator having adjustable time constant circuitry in each leg, an adjustable differentiating circuit in the output of each leg, a mixing and rectifying circuit for combining the differentiated pulses and generating in its output a resultant sequence of negative pulses, and a final amplifying circuit for inverting and square-topping the pulses. (AEC)

  13. High velocity pulsed wire-arc spray

    NASA Technical Reports Server (NTRS)

    Witherspoon, F. Douglas (Inventor); Massey, Dennis W. (Inventor); Kincaid, Russell W. (Inventor)

    1999-01-01

    Wire arc spraying using repetitively pulsed, high temperature gas jets, usually referred to as plasma jets, and generated by capillary discharges, substantially increases the velocity of atomized and entrained molten droplets. The quality of coatings produced is improved by increasing the velocity with which coating particles impact the coated surface. The effectiveness of wire-arc spraying is improved by replacing the usual atomizing air stream with a rapidly pulsed high velocity plasma jet. Pulsed power provides higher coating particle velocities leading to improved coatings. 50 micron aluminum droplets with velocities of 1500 m/s are produced. Pulsed plasma jet spraying provides the means to coat the insides of pipes, tubes, and engine block cylinders with very high velocity droplet impact.

  14. Innovative methodology to transfer conventional GC-MS heroin profiling to UHPLC-MS/MS.

    PubMed

    Debrus, B; Broséus, J; Guillarme, D; Lebrun, P; Hubert, P; Veuthey, J-L; Esseiva, P; Rudaz, S

    2011-03-01

    Nowadays, in forensic laboratories, heroin profiling is frequently carried out by gas chromatography coupled with mass spectrometry (GC-MS). This analytical technique is well established, provides good sensitivity and reproducibility, and allows the use of large databases. Despite those benefits, recently introduced analytical techniques, such as ultra-high-pressure liquid chromatography (UHPLC), could offer better chromatographic performance, which needs to be considered to increase the analysis throughput for heroin profiling. With the latter, chromatographic conditions were optimized through commercial modeling software and two atmospheric pressure ionization sources were evaluated. Data obtained from UHPLC-MS/MS were thus transferred, thanks to mathematical models to mimic GC-MS data. A calibration and a validation set of representative heroin samples were selected among the database to establish a transfer methodology and assess the models' abilities to transfer using principal component analysis and hierarchical classification analysis. These abilities were evaluated by computing the frequency of successful classification of UHPLC-MS/MS data among GC-MS database. Seven mathematical models were tested to adjust UHPLC-MS/MS data to GC-MS data. A simplified mathematical model was finally selected and offered a frequency of successful transfer equal to 95%.

  15. Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping

    PubMed Central

    D’Ostilio, Kevin; Rothwell, John C; Murphy, David L

    2014-01-01

    Objective This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with lower voltage rating than prior cTMS devices. Main results cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The near-zero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (<10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in 10 healthy volunteers. Significance The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool. PMID:25242286

  16. Controllable pulse parameter transcranial magnetic stimulator with enhanced circuit topology and pulse shaping

    NASA Astrophysics Data System (ADS)

    Peterchev, Angel V.; DʼOstilio, Kevin; Rothwell, John C.; Murphy, David L.

    2014-10-01

    Objective. This work aims at flexible and practical pulse parameter control in transcranial magnetic stimulation (TMS), which is currently very limited in commercial devices. Approach. We present a third generation controllable pulse parameter device (cTMS3) that uses a novel circuit topology with two energy-storage capacitors. It incorporates several implementation and functionality advantages over conventional TMS devices and other devices with advanced pulse shape control. cTMS3 generates lower internal voltage differences and is implemented with transistors with a lower voltage rating than prior cTMS devices. Main results. cTMS3 provides more flexible pulse shaping since the circuit topology allows four coil-voltage levels during a pulse, including approximately zero voltage. The near-zero coil voltage enables snubbing of the ringing at the end of the pulse without the need for a separate active snubber circuit. cTMS3 can generate powerful rapid pulse sequences (\\lt 10 ms inter pulse interval) by increasing the width of each subsequent pulse and utilizing the large capacitor energy storage, allowing the implementation of paradigms such as paired-pulse and quadripulse TMS with a single pulse generation circuit. cTMS3 can also generate theta (50 Hz) burst stimulation with predominantly unidirectional electric field pulses. The cTMS3 device functionality and output strength are illustrated with electrical output measurements as well as a study of the effect of pulse width and polarity on the active motor threshold in ten healthy volunteers. Significance. The cTMS3 features could extend the utility of TMS as a research, diagnostic, and therapeutic tool.

  17. Relapsing-Remitting MS (RRMS)

    MedlinePlus

    ... pdf) Download Brochure Taming Stress (.pdf) Download Brochure Multiple Sclerosis and Your Emotions (.pdf) Download Brochure Disease Modifying Therapies Overview (.pdf) Download Document Pediatric MS Learn More ...

  18. X-ray Photoelectron Spectroscopy ofGaP_{1-x}N_x Photocorroded as a Result of Hydrogen Productionthrough Water Electrolysis

    SciTech Connect

    Mayer, Marie A.; /Illinois U., Urbana /SLAC

    2006-09-27

    Photoelectrochemical (PEC) cells produce hydrogen gas through the sunlight driven electrolysis of water. By extracting hydrogen and oxygen from water and storing solar energy in the H-H bond, they offer a promising renewable energy technology. Addition of dilute amounts of nitrogen to III-V semiconductors has been shown to dramatically increase the stability of these materials for hydrogen production. In an effort to learn more about the origin of semiconductor photocorrosion in PEC cells, three samples of p-type GaP with varying levels of nitrogen content (0%, 0.2%, 2%) were photocorroded and examined by X-ray Photoelectron Spectroscopy (XPS). GaPN samples were observed to be more efficient during the hydrogen production process than the pure GaP samples. Sample surfaces contained gallium oxides in the form of Ga{sub 2}O{sub 3} and Ga(OH){sub 3} and phosphorus oxide (P{sub 2}O{sub 5}), as well as surface oxides from exposure to air. A significant shift in intensity from bulk to surface peaks dramatic nitrogen segregation to the surface during photoelectrochemical hydrogen production. Further investigations, including using a scanning electron microscope to investigate sample topography and inductively coupled plasma mass spectroscopy (ICP-MS) analysis for solution analyses, are under way to determine the mechanism for these changes.

  19. Investigation of Fe:ZnSe laser in pulsed and repetitively pulsed regimes

    SciTech Connect

    Velikanov, S D; Zaretskiy, N A; Zotov, E A; Maneshkin, A A; Chuvatkin, R S; Yutkin, I M; Kozlovsky, V I; Korostelin, Yu V; Krokhin, O N; Podmar'kov, Yu P; Savinova, S A; Skasyrsky, Ya K; Frolov, M P

    2015-01-31

    The characteristics of a Fe:ZnSe laser pumped by a single-pulse free-running Er : YAG laser and a repetitively pulsed HF laser are presented. An output energy of 4.9 J is achieved in the case of liquid-nitrogen cooling of the Fe{sup 2+}:ZnSe active laser element longitudinally pumped by an Er:YAG laser with a pulse duration of 1 ms and an energy up to 15 J. The laser efficiency with respect to the absorbed energy is 47%. The output pulse energy at room temperature is 53 mJ. The decrease in the output energy is explained by a strong temperature dependence of the upper laser level lifetime and by pulsed heating of the active element. The temperature dependence of the upper laser level lifetime is used to determine the pump parameters needed to achieve high pulse energies at room temperature. Stable repetitively-pulsed operation of the Fe{sup 2+}:ZnSe laser at room temperature with an average power of 2.4 W and a maximum pulse energy of 14 mJ is achieved upon pumping by a 1-s train of 100-ns HF laser pulses with a repetition rate of 200 Hz. (lasers)

  20. Hydrogen Rearrangement Rules: Computational MS/MS Fragmentation and Structure Elucidation Using MS-FINDER Software.

    PubMed

    Tsugawa, Hiroshi; Kind, Tobias; Nakabayashi, Ryo; Yukihira, Daichi; Tanaka, Wataru; Cajka, Tomas; Saito, Kazuki; Fiehn, Oliver; Arita, Masanori

    2016-08-16

    Compound identification from accurate mass MS/MS spectra is a bottleneck for untargeted metabolomics. In this study, we propose nine rules of hydrogen rearrangement (HR) during bond cleavages in low-energy collision-induced dissociation (CID). These rules are based on the classic even-electron rule and cover heteroatoms and multistage fragmentation. We evaluated our HR rules by the statistics of MassBank MS/MS spectra in addition to enthalpy calculations, yielding three levels of computational MS/MS annotation: "resolved" (regular HR behavior following HR rules), "semiresolved" (irregular HR behavior), and "formula-assigned" (lacking structure assignment). With this nomenclature, 78.4% of a total of 18506 MS/MS fragment ions in the MassBank database and 84.8% of a total of 36370 MS/MS fragment ions in the GNPS database were (semi-) resolved by predicted bond cleavages. We also introduce the MS-FINDER software for structure elucidation. Molecular formulas of precursor ions are determined from accurate mass, isotope ratio, and product ion information. All isomer structures of the predicted formula are retrieved from metabolome databases, and MS/MS fragmentations are predicted in silico. The structures are ranked by a combined weighting score considering bond dissociation energies, mass accuracies, fragment linkages, and, most importantly, nine HR rules. The program was validated by its ability to correctly calculate molecular formulas with 98.0% accuracy for 5063 MassBank MS/MS records and to yield the correct structural isomer with 82.1% accuracy within the top-3 candidates. In a test with 936 manually identified spectra from an untargeted HILIC-QTOF MS data set of human plasma, formulas were correctly predicted in 90.4% of the cases, and the correct isomer structure was retrieved at 80.4% probability within the top-3 candidates, including for compounds that were absent in mass spectral libraries. The MS-FINDER software is freely available at http

  1. Hydrogen Rearrangement Rules: Computational MS/MS Fragmentation and Structure Elucidation Using MS-FINDER Software.

    PubMed

    Tsugawa, Hiroshi; Kind, Tobias; Nakabayashi, Ryo; Yukihira, Daichi; Tanaka, Wataru; Cajka, Tomas; Saito, Kazuki; Fiehn, Oliver; Arita, Masanori

    2016-08-16

    Compound identification from accurate mass MS/MS spectra is a bottleneck for untargeted metabolomics. In this study, we propose nine rules of hydrogen rearrangement (HR) during bond cleavages in low-energy collision-induced dissociation (CID). These rules are based on the classic even-electron rule and cover heteroatoms and multistage fragmentation. We evaluated our HR rules by the statistics of MassBank MS/MS spectra in addition to enthalpy calculations, yielding three levels of computational MS/MS annotation: "resolved" (regular HR behavior following HR rules), "semiresolved" (irregular HR behavior), and "formula-assigned" (lacking structure assignment). With this nomenclature, 78.4% of a total of 18506 MS/MS fragment ions in the MassBank database and 84.8% of a total of 36370 MS/MS fragment ions in the GNPS database were (semi-) resolved by predicted bond cleavages. We also introduce the MS-FINDER software for structure elucidation. Molecular formulas of precursor ions are determined from accurate mass, isotope ratio, and product ion information. All isomer structures of the predicted formula are retrieved from metabolome databases, and MS/MS fragmentations are predicted in silico. The structures are ranked by a combined weighting score considering bond dissociation energies, mass accuracies, fragment linkages, and, most importantly, nine HR rules. The program was validated by its ability to correctly calculate molecular formulas with 98.0% accuracy for 5063 MassBank MS/MS records and to yield the correct structural isomer with 82.1% accuracy within the top-3 candidates. In a test with 936 manually identified spectra from an untargeted HILIC-QTOF MS data set of human plasma, formulas were correctly predicted in 90.4% of the cases, and the correct isomer structure was retrieved at 80.4% probability within the top-3 candidates, including for compounds that were absent in mass spectral libraries. The MS-FINDER software is freely available at http://prime.psc.riken.jp/ .

  2. Ablation and analysis of small cell populations and single cells by consecutive laser pulses

    NASA Astrophysics Data System (ADS)

    Shrestha, Bindesh; Nemes, Peter; Vertes, Akos

    2010-10-01

    Laser ablation of single cells through a sharpened optical fiber is used for the detection of metabolites by laser ablation electrospray ionization (LAESI) mass spectrometry (MS). Ablation of the same Allium cepa epidermal cell by consecutive pulses indicates the rupture of the cell wall by the second shot. Intracellular sucrose heterogeneity is detected by subsequent laser pulses pointing to rupturing the vacuolar membrane by the third exposure. Ion production by bursts of laser pulses shows that the drying of ruptured A. cepa cells occurs in ˜50 s at low pulse rates (10 pulses/s bursts) and significantly faster at high pulse rates (100 pulses/s bursts). These results point to the competing role of cytoplasm ejection and evaporative drying in diminishing the LAESI-MS signal in ˜50 s or 100 laser pulses, whichever occurs first.

  3. Analysis of acrylamide by LC-MS/MS and GC-MS in processed Japanese foods.

    PubMed

    Ono, H; Chuda, Y; Ohnishi-Kameyama, M; Yada, H; Ishizaka, M; Kobayashi, H; Yoshida, M

    2003-03-01

    Acrylamide concentrations in processed foods (63 samples covering 31 product types) from Japan were analysed by LC-MS/MS and GC-MS methods. The limit of detection and limit of quantification of acrylamide were 0.2 ng x ml(-1) (6 fmol) and 0.8 ng x ml(-1) (22 fmol), respectively, by LC-MS/MS, and those of 2,3-dibromopropionamide derived from acrylamide were 12 ng x ml(-1) (52 fmol) and 40 ng x ml(-1) (170 fmol), respectively, by GC-MS. Repeatability given as RSD was <5 and <15% for the LC-MS/MS and GC-MS methods, respectively. High correlation (r(2) - 0.946) was observed between values obtained by the two methods. Most potato crisps and whole potato-based fried snacks showed acrylamide concentrations >1000 microg x kg(-1). The concentrations in non-whole potato-based snacks, rice crackers processed by grilling or frying, and candied sweet potatoes were lower compared with those in the potato crisps and the whole potato-based fried snacks. One of the whole potato-based fried snacks, however, showed low acrylamide concentration (<50 microg x kg(-1)) suggesting the formation of acrylamide is strongly influenced by processing conditions. Acrylamide concentrations in instant precooked noodles and won-tons were <100 microg x kg(-1) with only one exception. Roasted barley grains for 'Mugi-cha' tea contained 200-600 microg x kg(-1) acrylamide.

  4. Long pulse production from short pulses

    DOEpatents

    Toeppen, John S.

    1994-01-01

    A method of producing a long output pulse (SA) from a short pump pulse (P), using an elongated amplified fiber (11) having a doped core (12) that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding 13. A seed beam (S) of the longer wavelength is injected into the core (12) at one end of the fiber (11) and a pump pulse (P) of the shorter wavelength is injected into the cladding (13) at the other end of the fiber (11). The counter-propagating seed beam (S) and pump pulse (P) will produce an amplified output pulse (SA) having a time duration equal to twice the transit time of the pump pulse (P) through the fiber (11) plus the length of the pump pulse (P).

  5. Long pulse production from short pulses

    DOEpatents

    Toeppen, J.S.

    1994-08-02

    A method of producing a long output pulse from a short pump pulse is disclosed, using an elongated amplified fiber having a doped core that provides an amplifying medium for light of one color when driven into an excited state by light of a shorter wavelength and a surrounding cladding. A seed beam of the longer wavelength is injected into the core at one end of the fiber and a pump pulse of the shorter wavelength is injected into the cladding at the other end of the fiber. The counter-propagating seed beam and pump pulse will produce an amplified output pulse having a time duration equal to twice the transit time of the pump pulse through the fiber plus the length of the pump pulse. 3 figs.

  6. Effects of pulse duration on magnetostimulation thresholds

    PubMed Central

    Saritas, Emine U.; Goodwill, Patrick W.; Conolly, Steven M.

    2015-01-01

    Purpose: Medical imaging techniques such as magnetic resonance imaging and magnetic particle imaging (MPI) utilize time-varying magnetic fields that are subject to magnetostimulation limits, which often limit the speed of the imaging process. Various human-subject experiments have studied the amplitude and frequency dependence of these thresholds for gradient or homogeneous magnetic fields. Another contributing factor was shown to be number of cycles in a magnetic pulse, where the thresholds decreased with longer pulses. The latter result was demonstrated on two subjects only, at a single frequency of 1.27 kHz. Hence, whether the observed effect was due to the number of cycles or due to the pulse duration was not specified. In addition, a gradient-type field was utilized; hence, whether the same phenomenon applies to homogeneous magnetic fields remained unknown. Here, the authors investigate the pulse duration dependence of magnetostimulation limits for a 20-fold range of frequencies using homogeneous magnetic fields, such as the ones used for the drive field in MPI. Methods: Magnetostimulation thresholds were measured in the arms of six healthy subjects (age: 27 ± 5 yr). Each experiment comprised testing the thresholds at eight different pulse durations between 2 and 125 ms at a single frequency, which took approximately 30–40 min/subject. A total of 34 experiments were performed at three different frequencies: 1.2, 5.7, and 25.5 kHz. A solenoid coil providing homogeneous magnetic field was used to induce stimulation, and the field amplitude was measured in real time. A pre-emphasis based pulse shaping method was employed to accurately control the pulse durations. Subjects reported stimulation via a mouse click whenever they felt a twitching/tingling sensation. A sigmoid function was fitted to the subject responses to find the threshold at a specific frequency and duration, and the whole procedure was repeated at all relevant frequencies and pulse durations

  7. Determination of Glyphosate Levels in Breast Milk Samples from Germany by LC-MS/MS and GC-MS/MS.

    PubMed

    Steinborn, Angelika; Alder, Lutz; Michalski, Britta; Zomer, Paul; Bendig, Paul; Martinez, Sandra Aleson; Mol, Hans G J; Class, Thomas J; Pinheiro, Nathalie Costa

    2016-02-17

    This study describes the validation and application of two independent analytical methods for the determination of glyphosate in breast milk. They are based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) and gas chromatography-tandem mass spectrometry (GC-MS/MS), respectively. For LC-MS/MS, sample preparation involved an ultrafiltration followed by chromatography on an anion exchange column. The analysis by GC-MS/MS involved an extraction step, cleanup on a cation exchange column, and derivatization with heptafluorobutanol and trifluoroacetic acid anhydride. Both methods were newly developed for breast milk and are able to quantify glyphosate residues at concentrations as low as 1 ng/mL. The methods were applied to quantify glyphosate levels in 114 breast milk samples, which had been collected from August to September of 2015 in Germany. The mothers participated at their own request and thus do not form a representative sample. In none of the investigated samples were glyphosate residues above the limit of detection found.

  8. Alkali doped poly (2,5-benzimidazole) membrane for alkaline water electrolysis: Characterization and performance

    NASA Astrophysics Data System (ADS)

    Diaz, Liliana A.; Hnát, Jaromír; Heredia, Nayra; Bruno, Mariano M.; Viva, Federico A.; Paidar, Martin; Corti, Horacio R.; Bouzek, Karel; Abuin, Graciela C.

    2016-04-01

    The properties and performance of linear and cross-linked KOH doped ABPBI membranes as electrolyte/separator for zero gap alkaline water electrolysis cells are evaluated and compared with a commercial Zirfon® diaphragm. Stability in alkaline environment, swelling, thermal properties, water sorption, KOH uptake and conductivity of linear (L-ABPBI) and cross-linked (C-ABPBI) membranes doped with different concentrations of KOH are analyzed. Linear membranes show stability up to 3.0 mol·dm-3 KOH doping, while cross-linked membranes are stable up to 4.2 mol·dm-3 KOH doping. Both kinds of membranes exhibit good thermal stability and reasonable specific ionic conductivity at 22 °C in the range between 7 and 25 mS·cm-1, being slightly higher the conductivity of C-ABPBI membranes than that of L-ABPBI ones. In short-term electrolysis tests both L-ABPBI and C-ABPBI membranes show better performance than Zirfon diaphragm in the range from 50 to 70 °C. A current density of 335 mA·cm-2 at a cell voltage of 2.0 V is attained with C-ABPBI membranes doped in 3 mol·dm-3 KOH at 70 °C, a performance comparable with that of commercial units operating at temperatures ca. 80 °C and 30 wt% KOH (6.7 mol·dm-3) as electrolyte.

  9. Microbial electrolysis cells turning to be versatile technology: recent advances and future challenges.

    PubMed

    Zhang, Yifeng; Angelidaki, Irini

    2014-06-01

    Microbial electrolysis cells (MECs) are an electricity-mediated microbial bioelectrochemical technology, which is originally developed for high-efficiency biological hydrogen production from waste streams. Compared to traditional biological technologies, MECs can overcome thermodynamic limitations and achieve high-yield hydrogen production from wide range of organic matters at relatively mild conditions. This approach greatly reduces the electric energy cost for hydrogen production in contrast to direct water electrolysis. In addition to hydrogen production, MECs may also support several energetically unfavorable biological/chemical reactions. This unique advantage of MECs has led to several alternative applications such as chemicals synthesis, recalcitrant pollutants removal, resources recovery, bioelectrochemical research platform and biosensors, which have greatly broaden the application scopes of MECs. MECs are becoming a versatile platform technology and offer a new solution for emerging environmental issues related to waste streams treatment and energy and resource recovery. Different from previous reviews that mainly focus on hydrogen production, this paper provides an up-to-date review of all the new applications of MECs and their resulting performance, current challenges and prospects of future. PMID:24631941

  10. Estimating Hydrogen Production Potential in Biorefineries Using Microbial Electrolysis Cell Technology

    SciTech Connect

    Borole, Abhijeet P; Mielenz, Jonathan R

    2011-01-01

    Microbial electrolysis cells (MECs) are devices that use a hybrid biocatalysis-electrolysis process for production of hydrogen from organic matter. Future biofuel and bioproducts industries are expected to generate significant volumes of waste streams containing easily degradable organic matter. The emerging MEC technology has potential to derive added- value from these waste streams via production of hydrogen. Biorefinery process streams, particularly the stillage or distillation bottoms contain underutilized sugars as well as fermentation and pretreatment byproducts. In a lignocellulosic biorefinery designed for producing 70 million gallons of ethanol per year, up to 7200 m3/hr of hydrogen can be generated. The hydrogen can either be used as an energy source or a chemical reagent for upgrading and other reactions. The energy content of the hydrogen generated is sufficient to meet 57% of the distillation energy needs. We also report on the potential for hydrogen production in existing corn mills and sugar-based biorefineries. Removal of the organics from stillage has potential to facilitate water recycle. Pretreatment and fermentation byproducts generated in lignocellulosic biorefinery processes can accumulate to highly inhibitory levels in the process streams, if water is recycled. The byproducts of concern including sugar- and lignin- degradation products such as furans and phenolics can also be converted to hydrogen in MECs. We evaluate hydrogen production from various inhibitory byproducts generated during pretreatment of various types of biomass. Finally, the research needs for development of the MEC technology and aspects particularly relevant to the biorefineries are discussed.

  11. Production of hydrogen by photovoltaic-powered electrolysis. Task 1 report

    SciTech Connect

    Block, D.L.

    1995-12-01

    The report presents results of a cooperative effort among the Florida Energy Office, NASA/Kennedy Space Center, the US Department of Energy and the Florida Solar Energy Center (FSEC). It reports on a task to evaluate hydrogen production from photovoltaic (PV)-powered electrolysis. The resulting activities covered five years of effort funded at a total of $216,809. The results represent a successful, coordinated effort among two state agencies and two federal agencies. Results are reported on two separate investigations. The first investigation looked at the use of line focus concentrating photovoltaics coupled with single-cell electrolyzers to produce gaseous hydrogen. The concept, and its design, construction and operation, are presented. The objectives of the line focusing PV system are to reduce overall system cost under the assumptions that lenses and mirrors are cheaper to deploy than are PV cells, and that low-voltage, high-current dc electricity can efficiently power a single-cell elctrolyzer to produce hydrogen. The second investigation evaluated a base case cost of PV electrolysis hydrogen production based on present-day PV and electrolyzer costs and efficiencies. A second step analyzed the hydrogen costs based on a best prediction of where PV costs and efficiencies will be in 10 years. These results set the minimum cost standards that other renewable production technologies must meet or better.

  12. The recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor.

    PubMed

    Ren, Xiulian; Wei, Qifeng; Hu, Surong; Wei, Sijie

    2010-09-15

    This paper reports the optimization of the process parameters for recovery of zinc from hot galvanizing slag in an anion-exchange membrane electrolysis reactor. The experiments were carried out in an ammoniacal ammonium chloride system. The influence of composition of electrolytes, pH, stirring rate, current density and temperature, on cathodic current efficiency, specific power consumption and anodic dissolution of Zn were investigated. The results indicate that the cathode current efficiency increases and the hydrogen evolution decreased with increasing the cathode current density. The partial current for electrodeposition of Zn has liner relationship with omega(1/2) (omega: rotation rate). The highest current efficiency for dissolving zinc was obtained when NH(4)Cl concentration was 53.46 g L(-1) and the anodic dissolution of zinc was determined by mass transfer rate at stirring rate 0-300 r min(-1). Increase in temperature benefits to improve CE and dissolution of Zn, and reduce cell voltage. Initial pH of electrolytes plays an important role in the deposition and anodic dissolution of Zn. The results of single factor experiment show that about 50% energy consumption was saved for electrodeposition of Zn in the anion-exchange membrane electrolysis reactor.

  13. Direct anodic hydrochloric acid and cathodic caustic production during water electrolysis

    NASA Astrophysics Data System (ADS)

    Lin, Hui-Wen; Cejudo-Marín, Rocío; Jeremiasse, Adriaan W.; Rabaey, Korneel; Yuan, Zhiguo; Pikaar, Ilje

    2016-02-01

    Hydrochloric acid (HCl) and caustic (NaOH) are among the most widely used chemicals by the water industry. Direct anodic electrochemical HCl production by water electrolysis has not been successful as current commercially available electrodes are prone to chlorine formation. This study presents an innovative technology simultaneously generating HCl and NaOH from NaCl using a Mn0.84Mo0.16O2.23 oxygen evolution electrode during water electrolysis. The results showed that protons could be anodically generated at a high Coulombic efficiency (i.e. ≥ 95%) with chlorine formation accounting for 3 ~ 5% of the charge supplied. HCl was anodically produced at moderate strengths at a CE of 65 ± 4% together with a CE of 89 ± 1% for cathodic caustic production. The reduction in CE for HCl generation was caused by proton cross-over from the anode to the middle compartment. Overall, this study showed the potential of simultaneous HCl and NaOH generation from NaCl and represents a major step forward for the water industry towards on-site production of HCl and NaOH. In this study, artificial brine was used as a source of sodium and chloride ions. In theory, artificial brine could be replaced by saline waste streams such as Reverse Osmosis Concentrate (ROC), turning ROC into a valuable resource.

  14. Experimental design, operation, and results of a 4 kW high temperature steam electrolysis experiment

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoyu; O'Brien, James E.; Tao, Greg; Zhou, Can; Housley, Gregory K.

    2015-11-01

    High temperature steam electrolysis (HTSE) is a promising technology for large-scale hydrogen production. However, research on HTSE performance above the kW level is limited. This paper presents the results of 4 kW HTSE long-term test completed in a multi-kW test facility recently developed at the Idaho National Laboratory (INL). The 4 kW HTSE unit consisted of two solid oxide electrolysis stacks electrically connected in parallel, each of which included 40 electrode-supported planar cells. A current density of 0.41 A cm-2 was used for the long-term operating at a constant current mode, resulting in a theoretical hydrogen production rate about 23 slpm. A demonstration of 830 h stable operation was achieved with a degradation rate of 3.1% per 1000 h. The paper also includes detailed descriptions of the piping layout, steam generation and delivery system, test fixture, heat recuperation system, hot zone, instrumentation, and operating conditions. This successful demonstration of multi-kW scale HTSE unit will help to advance the technology toward near-term commercialization.

  15. Numerical simulation of plasma-induced electrolysis utilizing dc glow discharge

    NASA Astrophysics Data System (ADS)

    Tochikubo, Fumiyoshi; Shirai, Naoki; Uchida, Satoshi; Shirafuji, Tatsuru

    2014-10-01

    In this work, we carried out one-dimensional numerical simulation of plasma-induced electrolysis, which consists of atmospheric pressure dc glow discharge and electrolyte solution connected in series. Grounded metal electrode is placed at the bottom of NaCl solution with 1 mm depth while powered electrode is placed at 1 mm above the solution surface. The gap is filled with helium. Continuity equations of charged species both in gas and in liquid were simultaneously calculated with Poisson's equation. Current continuity is considered at plasma-liquid interface. That is, hydrated electrons equivalent to electron flux from plasma, or H2O+ ions equivalent to positive ion flux from plasma are supplied in the liquid at plasma-liquid interface. The calculated gas-phase discharge structure is essentially the same as that between two metal electrodes. In front of the metal electrode in liquid, the electric double layer (EDL) with thickness of approximately 10 nm was formed to maintain the electrode reaction. However, the EDL was not formed at the liquid surface in contact with dc glow discharge, because charges are forcibly supplied from plasma to liquid. In other words, plasma-induced electrolysis is controlled at plasma-liquid interface by plasma. This work was partly supported by KAKENHI (Nos. 21110003 and 21110007).

  16. Development of an advanced static feed water electrolysis module. [for spacecraft

    NASA Technical Reports Server (NTRS)

    Schubert, F. H.; Wynveen, R. A.; Jensen, F. C.; Quattrone, P. D.

    1975-01-01

    A Static Feed Water Electrolysis Module (SFWEM) was developed to produce 0.92 kg/day (2.0 lb/day) of oxygen (O2). Specific objectives of the program's scope were to (1) eliminate the need for feed water cavity degassing, (2) eliminate the need for subsystem condenser/separators, (3) increase current density capability while decreasing electrolysis cell power (i.e., cell voltage) requirements, and (4) eliminate subsystem rotating parts and incorporate control and monitor instrumentation. A six-cell, one-man capacity module having an active area of 0.00929 sq m (0.10 sq ft) per cell was designed, fabricated, assembled, and subjected to 111 days (2664 hr) of parametric and endurance testing. The SFWEM was successfully operated over a current density range of 0 to 1076 mA/sq cm (0 to 1000 ASF), pressures of ambient to 2067 kN/sq m (300 psia), and temperatures of ambient to 366 K (200 F). During a 94-day endurance test, the SFWEM successfully demonstrated operation without the need for feed water compartment degassing.

  17. Electrolysis within anaerobic bioreactors stimulates breakdown of toxic products from azo dye treatment.

    PubMed

    Gavazza, Sávia; Guzman, Juan J L; Angenent, Largus T

    2015-04-01

    Azo dyes are the most widely used coloring agents in the textile industry, but are difficult to treat. When textile effluents are discharged into waterways, azo dyes and their degradation products are known to be environmentally toxic. An electrochemical system consisting of a graphite-plate anode and a stainless-steel mesh cathode was placed into a lab-scale anaerobic bioreactor to evaluate the removal of an azo dye (Direct Black 22) from synthetic textile wastewater. At applied potentials of 2.5 and 3.0 V when water electrolysis occurs, no improvement in azo dye removal efficiency was observed compared to the control reactor (an integrated system with electrodes but without an applied potential). However, applying such electric potentials produces oxygen via electrolysis and promoted the aerobic degradation of aromatic amines, which are toxic, intermediate products of anaerobic azo dye degradation. The removal of these amines indicates a decrease in overall toxicity of the effluent from a single-stage anaerobic bioreactor, which warrants further optimization in anaerobic digestion.

  18. Direct anodic hydrochloric acid and cathodic caustic production during water electrolysis

    PubMed Central

    Lin, Hui-Wen; Cejudo-Marín, Rocío; Jeremiasse, Adriaan W.; Rabaey, Korneel; Yuan, Zhiguo; Pikaar, Ilje

    2016-01-01

    Hydrochloric acid (HCl) and caustic (NaOH) are among the most widely used chemicals by the water industry. Direct anodic electrochemical HCl production by water electrolysis has not been successful as current commercially available electrodes are prone to chlorine formation. This study presents an innovative technology simultaneously generating HCl and NaOH from NaCl using a Mn0.84Mo0.16O2.23 oxygen evolution electrode during water electrolysis. The results showed that protons could be anodically generated at a high Coulombic efficiency (i.e. ≥ 95%) with chlorine formation accounting for 3 ~ 5% of the charge supplied. HCl was anodically produced at moderate strengths at a CE of 65 ± 4% together with a CE of 89 ± 1% for cathodic caustic production. The reduction in CE for HCl generation was caused by proton cross-over from the anode to the middle compartment. Overall, this study showed the potential of simultaneous HCl and NaOH generation from NaCl and represents a major step forward for the water industry towards on-site production of HCl and NaOH. In this study, artificial brine was used as a source of sodium and chloride ions. In theory, artificial brine could be replaced by saline waste streams such as Reverse Osmosis Concentrate (ROC), turning ROC into a valuable resource. PMID:26848031

  19. Design Criteria, Operating Conditions, and Nickel-Iron Hydroxide Catalyst Materials for Selective Seawater Electrolysis.

    PubMed

    Dionigi, Fabio; Reier, Tobias; Pawolek, Zarina; Gliech, Manuel; Strasser, Peter

    2016-05-10

    Seawater is an abundant water resource on our planet and its direct electrolysis has the advantage that it would not compete with activities demanding fresh water. Oxygen selectivity is challenging when performing seawater electrolysis owing to competing chloride oxidation reactions. In this work we propose a design criterion based on thermodynamic and kinetic considerations that identifies alkaline conditions as preferable to obtain high selectivity for the oxygen evolution reaction. The criterion states that catalysts sustaining the desired operating current with an overpotential <480 mV in alkaline pH possess the best chance to achieve 100 % oxygen/hydrogen selectivity. NiFe layered double hydroxide is shown to satisfy this criterion at pH 13 in seawater-mimicking electrolyte. The catalyst was synthesized by a solvothermal method and the activity, surface redox chemistry, and stability were tested electrochemically in alkaline and near-neutral conditions (borate buffer at pH 9.2) and under both fresh seawater conditions. The Tafel slope at low current densities is not influenced by pH or presence of chloride. On the other hand, the addition of chloride ions has an influence in the temporal evolution of the nickel reduction peak and on both the activity and stability at high current densities at pH 9.2. Faradaic efficiency close to 100 % under the operating conditions predicted by our design criteria was proven using in situ electrochemical mass spectrometry.

  20. Separating hydrogen and oxygen evolution in alkaline water electrolysis using nickel hydroxide

    PubMed Central

    Chen, Long; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2016-01-01

    Low-cost alkaline water electrolysis has been considered a sustainable approach to producing hydrogen using renewable energy inputs, but preventing hydrogen/oxygen mixing and efficiently using the instable renewable energy are challenging. Here, using nickel hydroxide as a redox mediator, we decouple the hydrogen and oxygen production in alkaline water electrolysis, which overcomes the gas-mixing issue and may increase the use of renewable energy. In this architecture, the hydrogen production occurs at the cathode by water reduction, and the anodic Ni(OH)2 is simultaneously oxidized into NiOOH. The subsequent oxygen production involves a cathodic NiOOH reduction (NiOOH→Ni(OH)2) and an anodic OH− oxidization. Alternatively, the NiOOH formed during hydrogen production can be coupled with a zinc anode to form a NiOOH-Zn battery, and its discharge product (that is, Ni(OH)2) can be used to produce hydrogen again. This architecture brings a potential solution to facilitate renewables-to-hydrogen conversion. PMID:27199009

  1. Urea Monitor Based on Chemiluminescence and Electrolysis as a Marker for Dialysis Efficiency

    NASA Astrophysics Data System (ADS)

    Ozaki, Masahiro; Okabayashi, Tohru; Ishimaru, Teppei; Hayashi, Kunihito; Hori, Jun'ya; Yamamoto, Isao; Nakagawa, Masuo

    We have developed a practical urea monitor based on a chemiluminescent (CL) reaction of urea and hypobromous acid produced by electrolysis of sodium bromide (NaBr) for measuring urea concentration in spent dialysate at set intervals. A reagent containing 4×10-2 M hypobromous acid is produced by electrolysis of an electrolyte containing 5.9 M NaBr and 0.2 M sodium hydroxide (NaOH). Chemiluminescence is emitted by injection of spent hemodialysis fluid (0.11 ml) into the reagent, and the CL-intensity is measured by a photomultiplier tube using the photon counting technique. The CL-intensity is proportional to the 0.9th power of the urea concentration between 7×10-4 and 2×10-2 M. The urea monitor can determine the urea concentration in spent dialysate samples collected from the waste line of a dialyzer, and the time for the intermittent measurements including the cleaning cycle of the reaction chamber is 3 min. The urea concentrations measured by the monitor are in close agreement with those measured by the conventional enzyme colorimetric method using urease for the spent dialysate collected during a hemodialysis treatment, and the correlation coefficient is 0.93.

  2. Microbial electrolysis cells turning to be versatile technology: recent advances and future challenges.

    PubMed

    Zhang, Yifeng; Angelidaki, Irini

    2014-06-01

    Microbial electrolysis cells (MECs) are an electricity-mediated microbial bioelectrochemical technology, which is originally developed for high-efficiency biological hydrogen production from waste streams. Compared to traditional biological technologies, MECs can overcome thermodynamic limitations and achieve high-yield hydrogen production from wide range of organic matters at relatively mild conditions. This approach greatly reduces the electric energy cost for hydrogen production in contrast to direct water electrolysis. In addition to hydrogen production, MECs may also support several energetically unfavorable biological/chemical reactions. This unique advantage of MECs has led to several alternative applications such as chemicals synthesis, recalcitrant pollutants removal, resources recovery, bioelectrochemical research platform and biosensors, which have greatly broaden the application scopes of MECs. MECs are becoming a versatile platform technology and offer a new solution for emerging environmental issues related to waste streams treatment and energy and resource recovery. Different from previous reviews that mainly focus on hydrogen production, this paper provides an up-to-date review of all the new applications of MECs and their resulting performance, current challenges and prospects of future.

  3. Separating hydrogen and oxygen evolution in alkaline water electrolysis using nickel hydroxide.

    PubMed

    Chen, Long; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2016-05-20

    Low-cost alkaline water electrolysis has been considered a sustainable approach to producing hydrogen using renewable energy inputs, but preventing hydrogen/oxygen mixing and efficiently using the instable renewable energy are challenging. Here, using nickel hydroxide as a redox mediator, we decouple the hydrogen and oxygen production in alkaline water electrolysis, which overcomes the gas-mixing issue and may increase the use of renewable energy. In this architecture, the hydrogen production occurs at the cathode by water reduction, and the anodic Ni(OH)2 is simultaneously oxidized into NiOOH. The subsequent oxygen production involves a cathodic NiOOH reduction (NiOOH→Ni(OH)2) and an anodic OH(-) oxidization. Alternatively, the NiOOH formed during hydrogen production can be coupled with a zinc anode to form a NiOOH-Zn battery, and its discharge product (that is, Ni(OH)2) can be used to produce hydrogen again. This architecture brings a potential solution to facilitate renewables-to-hydrogen conversion.

  4. Performance of single chamber biocatalyzed electrolysis with different types of ion exchange membranes.

    PubMed

    Rozendal, René A; Hamelers, Hubertus V M; Molenkamp, Redmar J; Buisman, Cees J N

    2007-05-01

    In this paper hydrogen production through biocatalyzed electrolysis was studied for the first time in a single chamber configuration. Single chamber biocatalyzed electrolysis was tested in two configurations: (i) with a cation exchange membrane (CEM) and (ii) with an anion exchange membrane (AEM). Both configurations performed comparably and produced over 0.3 m3 H2/m3 reactor liquid volume/day at 1.0 V applied voltage (overall hydrogen efficiencies around 23%). Analysis of the water that permeated through the membrane revealed that a large part of potential losses in the system were associated with a pH gradient across the membrane (CEM DeltapH=6.4; AEM DeltapH=4.4). These pH gradient associated potential losses were lower in the AEM configuration (CEM 0.38 V; AEM 0.26 V) as a result of its alternative ion transport properties. This benefit of the AEM, however, was counteracted by the higher cathode overpotentials occurring in the AEM configuration (CEM 0.12 V at 2.39 A/m2; AEM 0.27 V at 2.15 A/m2) as a result of a less effective electroless plating method for the AEM membrane electrode assembly (MEA).

  5. Three-Dimensional Computational Fluid Dynamics Modeling of Solid Oxide Electrolysis Cells and Stacks

    SciTech Connect

    Grant Hawkes; James O'Brien; Carl Stoots; Stephen Herring

    2008-07-01

    A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created for detailed analysis of a high-temperature electrolysis stack (solid oxide fuel cells operated as electrolyzers). Inlet and outlet plenum flow distributions are discussed. Maldistribution of plena flow show deviations in per-cell operating conditions due to non-uniformity of species concentrations. Models have also been created to simulate experimental conditions and for code validation. Comparisons between model predictions and experimental results are discussed. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the electrolysis mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Variations in flow distribution, and species concentration are discussed. End effects of flow and per-cell voltage are also considered. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition.

  6. Investigations on degradation of the long-term proton exchange membrane water electrolysis stack

    NASA Astrophysics Data System (ADS)

    Sun, Shucheng; Shao, Zhigang; Yu, Hongmei; Li, Guangfu; Yi, Baolian

    2014-12-01

    A 9-cell proton exchange membrane (PEM) water electrolysis stack is developed and tested for 7800 h. The average degradation rate of 35.5 μV h-1 per cell is measured. The 4th MEA of the stack is offline investigated and characterized. The electrochemical impedance spectroscopy (EIS) shows that the charge transfer resistance and ionic resistance of the cell both increase. The linear sweep scan (LSV) shows the hydrogen crossover rate of the membrane has slight increase. The electron probe X-ray microanalyze (EPMA) illustrates further that Ca, Cu and Fe elements distribute in the membrane and catalyst layers of the catalyst-coated membranes (CCMs). The cations occupy the ion exchange sites of the Nafion polymer electrolyte in the catalyst layers and membrane, which results in the increase in the anode and the cathode overpotentials. The metallic impurities originate mainly from the feed water and the components of the electrolysis unit. Fortunately, the degradation was reversible and can be almost recovered to the initial performance by using 0.5 M H2SO4. This indicates the performance degradation of the stack running 7800 h is mainly caused by a recoverable contamination.

  7. Design Criteria, Operating Conditions, and Nickel-Iron Hydroxide Catalyst Materials for Selective Seawater Electrolysis.

    PubMed

    Dionigi, Fabio; Reier, Tobias; Pawolek, Zarina; Gliech, Manuel; Strasser, Peter

    2016-05-10

    Seawater is an abundant water resource on our planet and its direct electrolysis has the advantage that it would not compete with activities demanding fresh water. Oxygen selectivity is challenging when performing seawater electrolysis owing to competing chloride oxidation reactions. In this work we propose a design criterion based on thermodynamic and kinetic considerations that identifies alkaline conditions as preferable to obtain high selectivity for the oxygen evolution reaction. The criterion states that catalysts sustaining the desired operating current with an overpotential <480 mV in alkaline pH possess the best chance to achieve 100 % oxygen/hydrogen selectivity. NiFe layered double hydroxide is shown to satisfy this criterion at pH 13 in seawater-mimicking electrolyte. The catalyst was synthesized by a solvothermal method and the activity, surface redox chemistry, and stability were tested electrochemically in alkaline and near-neutral conditions (borate buffer at pH 9.2) and under both fresh seawater conditions. The Tafel slope at low current densities is not influenced by pH or presence of chloride. On the other hand, the addition of chloride ions has an influence in the temporal evolution of the nickel reduction peak and on both the activity and stability at high current densities at pH 9.2. Faradaic efficiency close to 100 % under the operating conditions predicted by our design criteria was proven using in situ electrochemical mass spectrometry. PMID:27010750

  8. Composite membranes for alkaline electrolysis based on polysulfone and mineral fillers

    NASA Astrophysics Data System (ADS)

    Burnat, Dariusz; Schlupp, Meike; Wichser, Adrian; Lothenbach, Barbara; Gorbar, Michal; Züttel, Andreas; Vogt, Ulrich F.

    2015-09-01

    Mineral-based membranes for high temperature alkaline electrolysis were developed by a phase inversion process with polysulfone as binder. The long-term stability of new mineral fillers: wollastonite, forsterite and barite was assessed by 8000 h-long leaching experiments (5.5 M KOH, 85 °C) combined with thermodynamic modelling. Barite has released only 6.22 10-4 M of Ba ions into the electrolyte and was selected as promising filler material, due to its excellent stability. Barite-based membranes, prepared by the phase inversion process, were further studied. The resistivity of these membranes in 5.5 M KOH was investigated as a function of membrane thickness and total porosity, hydrodynamic porosity as well as gas purities determined by conducting electrolysis at ambient conditions. It was found that a dense top layer resulting from the phase inversion process, shows resistivity values up to 451.0 ± 22 Ω cm, which is two orders of magnitude higher than a porous bulk membrane microstructure (3.89 Ω cm). Developed membranes provided hydrogen purity of 99.83 at 200 mA cm-2, which is comparable to previously used chrysotile membranes and higher than commercial state-of-the-art Zirfon 500utp membrane. These cost-effective polysulfone - barite membranes are promising candidates as asbestos replacement for commercial applications.

  9. Separating hydrogen and oxygen evolution in alkaline water electrolysis using nickel hydroxide

    NASA Astrophysics Data System (ADS)

    Chen, Long; Dong, Xiaoli; Wang, Yonggang; Xia, Yongyao

    2016-05-01

    Low-cost alkaline water electrolysis has been considered a sustainable approach to producing hydrogen using renewable energy inputs, but preventing hydrogen/oxygen mixing and efficiently using the instable renewable energy are challenging. Here, using nickel hydroxide as a redox mediator, we decouple the hydrogen and oxygen production in alkaline water electrolysis, which overcomes the gas-mixing issue and may increase the use of renewable energy. In this architecture, the hydrogen production occurs at the cathode by water reduction, and the anodic Ni(OH)2 is simultaneously oxidized into NiOOH. The subsequent oxygen production involves a cathodic NiOOH reduction (NiOOH-->Ni(OH)2) and an anodic OH- oxidization. Alternatively, the NiOOH formed during hydrogen production can be coupled with a zinc anode to form a NiOOH-Zn battery, and its discharge product (that is, Ni(OH)2) can be used to produce hydrogen again. This architecture brings a potential solution to facilitate renewables-to-hydrogen conversion.

  10. Control of the electrode metal transfer by means of the welding current pulse generator

    NASA Astrophysics Data System (ADS)

    Knyaz'kov, A.; Pustovykh, O.; Verevkin, A.; Terekhin, V.; Shachek, A.; Knyaz'kov, S.; Tyasto, A.

    2016-04-01

    The paper presents a generator of welding current pulses to transfer an electrode metal into the molten pool. A homogeneous artificial line is used to produce near rectangular pulses. The homogeneous artificial line provides the minimum heat input with in the pulse to transfer the electrode metal, and it significantly decreases the impact of disturbances affecting this transfer. The pulse frequency does not exceed 300 Hz, and the duration is 0.6 ÷ 0.9 ms.

  11. Amplified reference pulse storage for low-coherence pulsed Doppler lidar.

    PubMed

    Shen, Jyi-Lai; Künnemeyer, Rainer

    2006-11-10

    We present a lidar concept for wind-speed measurements, in which a pulsed laser is used as the source for measurement and reference beams. A fraction of the transmitted pulse is stored in a fiber-optic ring resonator with a path length longer than the pulse. The output of the resonator is a pulse train that is used as the reference beam and can be mixed with the Doppler-shifted measurement signal. Because this reference has traveled a distance equivalent to the measurement beam's path length, low-coherence sources can be used. Inserting an erbium-doped fiber amplifier into the resonator ensures that the stored pulses do not decay in amplitude. Experiments prove that 16 reference pulses of sufficiently constant amplitude and stability can be generated. This would correspond to a measurement range of 240 m in free air over which the returned signal is sampled at equal intervals. Velocity measurements of a hard target have been carried out in the range of 1-10 m/s. The Doppler-measured velocities agree with tachometer reference measurements within +/-0.09 m/s.

  12. Amplified reference pulse storage for low-coherence pulsed Doppler lidar.

    PubMed

    Shen, Jyi-Lai; Künnemeyer, Rainer

    2006-11-10

    We present a lidar concept for wind-speed measurements, in which a pulsed laser is used as the source for measurement and reference beams. A fraction of the transmitted pulse is stored in a fiber-optic ring resonator with a path length longer than the pulse. The output of the resonator is a pulse train that is used as the reference beam and can be mixed with the Doppler-shifted measurement signal. Because this reference has traveled a distance equivalent to the measurement beam's path length, low-coherence sources can be used. Inserting an erbium-doped fiber amplifier into the resonator ensures that the stored pulses do not decay in amplitude. Experiments prove that 16 reference pulses of sufficiently constant amplitude and stability can be generated. This would correspond to a measurement range of 240 m in free air over which the returned signal is sampled at equal intervals. Velocity measurements of a hard target have been carried out in the range of 1-10 m/s. The Doppler-measured velocities agree with tachometer reference measurements within +/-0.09 m/s. PMID:17068580

  13. Fast initial continuous current pulses versus return stroke pulses in tower-initiated lightning

    NASA Astrophysics Data System (ADS)

    Azadifar, Mohammad; Rachidi, Farhad; Rubinstein, Marcos; Rakov, Vladimir A.; Paolone, Mario; Pavanello, Davide; Metz, Stefan

    2016-06-01

    We present a study focused on pulses superimposed on the initial continuous current of upward negative discharges. The study is based on experimental data consisting of correlated lightning current waveforms recorded at the instrumented Säntis Tower in Switzerland and electric fields recorded at a distance of 14.7 km from the tower. Two different types of pulses superimposed on the initial continuous current were identified: (1) M-component-type pulses, for which the microsecond-scale electric field pulse occurs significantly earlier than the onset of the current pulse, and (2) fast pulses, for which the onset of the field matches that of the current pulse. We analyze the currents and fields associated with these fast pulses (return-stroke type (RS-type) initial continuous current (ICC) pulses) and compare their characteristics with those of return strokes. A total of nine flashes containing 44 RS-type ICC pulses and 24 return strokes were analyzed. The median current peaks associated with RS-type ICC pulses and return strokes are, respectively, 3.4 kA and 8 kA. The associated median E-field peaks normalized to 100 km are 1.5 V/m and 4.4 V/m, respectively. On the other hand, the electric field peaks versus current peaks for the two data sets (RS-type ICC pulses and return strokes) are characterized by very similar linear regression slopes, namely, 3.67 V/(m kA) for the ICC pulses and 3.77 V/(m kA) for the return strokes. Assuming the field-current relation based on the transmission line model, we estimated the apparent speed of both the RS-type ICC pulses and return strokes to be about 1.4 × 108 m/s. A strong linear correlation is observed between the E-field risetime and the current risetime for the ICC pulses, similar to the relation observed between the E-field risetime and current risetime for return strokes. The similarity of the RS-type ICC pulses with return strokes suggests that these pulses are associated with the mixed mode of charge transfer to ground.

  14. GeLC-MS/MS Analysis of Complex Protein Mixtures

    PubMed Central

    Dzieciatkowska, Monika; Hill, Ryan; Hansen, Kirk C.

    2015-01-01

    Discovery-based proteomics has found its place in nearly every facet of biological research. A key objective of this approach is to maximize sequence coverage for proteins across a wide concentration range. Fractionating samples at the protein level is one of the most common ways to circumvent challenges due to sample complexity and improve proteome coverage. Of the available methods, one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by liquid chromatography-tandem mass spectrometry (GeLC-MS/MS) is a robust and reproducible method for qualitative and quantitative proteomic analysis. Here we describe a general GeLC-MS/MS protocol and include technical advice and outline caveats to increase the probability of a successful analysis. PMID:24791981

  15. METLIN: MS/MS metabolite data from the MAGGIE Project

    DOE Data Explorer

    METLIN is a metabolite database for metabolomics containing over 50,000 structures, it also represents a data management system designed to assist in a broad array of metabolite research and metabolite identification by providing public access to its repository of current and comprehensive MS/MS metabolite data. An annotated list of known metabolites and their mass, chemical formula, and structure are available on the METLIN website. Each metabolite is conveniently linked to outside resources such as the the Kyoto Encyclopedia of Genes and Genomes (KEGG) for further reference and inquiry. MS/MS data is also available on many of the metabolites. The list is expanding continuously as more metabolite information is being deposited and discovered. [from http://metlin.scripps.edu/] Metlin is a component of the MAGGIE Project. MAGGIE is funded by the DOE Genomics: GTL and is an acronym for "Molecular Assemblies, Genes, and Genomics Integrated Efficiently."

  16. Effects of Lecture, Teacher Demonstrations, Discussion and Practical Work on 10th Graders' Attitudes to Chemistry and Understanding of Electrolysis.

    ERIC Educational Resources Information Center

    Thompson, Jerome; Soyibo, Kola

    2002-01-01

    Investigates whether the use of the combination of lecture, teacher demonstrations, class discussion, and student practical work in small groups significantly improved experimental subjects' attitudes to chemistry and understanding of electrolysis more than their control group counterparts who were not exposed to practical work. Examines whether…

  17. Water electrolysis on La1−xSrxCoO3−δ perovskite electrocatalysts

    PubMed Central

    Mefford, J. Tyler; Rong, Xi; Abakumov, Artem M.; Hardin, William G.; Dai, Sheng; Kolpak, Alexie M.; Johnston, Keith P.; Stevenson, Keith J.

    2016-01-01

    Perovskite oxides are attractive candidates as catalysts for the electrolysis of water in alkaline energy storage and conversion systems. However, the rational design of active catalysts has been hampered by the lack of understanding of the mechanism of water electrolysis on perovskite surfaces. Key parameters that have been overlooked include the role of oxygen vacancies, B–O bond covalency, and redox activity of lattice oxygen species. Here we present a series of cobaltite perovskites where the covalency of the Co–O bond and the concentration of oxygen vacancies are controlled through Sr2+ substitution into La1−xSrxCoO3−δ. We attempt to rationalize the high activities of La1−xSrxCoO3−δ through the electronic structure and participation of lattice oxygen in the mechanism of water electrolysis as revealed through ab initio modelling. Using this approach, we report a material, SrCoO2.7, with a high, room temperature-specific activity and mass activity towards alkaline water electrolysis. PMID:27006166

  18. How the novel integration of electrolysis in tidal flow constructed wetlands intensifies nutrient removal and odor control.

    PubMed

    Ju, Xinxin; Wu, Shubiao; Huang, Xu; Zhang, Yansheng; Dong, Renjie

    2014-10-01

    Intensified nutrient removal and odor control in a novel electrolysis-integrated tidal flow constructed wetland were evaluated. The average removal efficiencies of COD and NH4(+)-N were above 85% and 80% in the two experimental wetlands at influent COD concentration of 300 mg/L and ammonium nitrogen concentration of 60 mg/L regardless of electrolysis integration. Effluent nitrate concentration decreased from 2.5mg/L to 0.5mg/L with the reduction in current intensity from 1.5 mA/cm(2) to 0.57 mA/cm(2). This result reveals the important role of current intensity in nitrogen transformation. Owing to the ferrous and ferric iron coagulant formed through the electro-dissolution of the iron anode, electrolysis integration not only exerted a positive effect on phosphorus removal but also effectively inhibited sulfide accumulation for odor control. Although electrolysis operation enhanced nutrient removal and promoted the emission of CH4, no significant difference was observed in the microbial communities and abundance of the two experimental wetlands. PMID:25103037

  19. HIGH-TEMPERATURE ELECTROLYSIS FOR LARGE-SCALE HYDROGEN AND SYNGAS PRODUCTION FROM NUCLEAR ENERGY – SYSTEM SIMULATION AND ECONOMICS

    SciTech Connect

    J. E. O'Brien; M. G. McKellar; E. A. Harvego; C. M. Stoots

    2009-05-01

    A research and development program is under way at the Idaho National Laboratory (INL) to assess the technological and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for efficient high-temperature hydrogen production from steam. This work is supported by the US Department of Energy, Office of Nuclear Energy, under the Nuclear Hydrogen Initiative. This paper will provide an overview of large-scale system modeling results and economic analyses that have been completed to date. System analysis results have been obtained using the commercial code UniSim, augmented with a custom high-temperature electrolyzer module. Economic analysis results were based on the DOE H2A analysis methodology. The process flow diagrams for the system simulations include an advanced nuclear reactor as a source of high-temperature process heat, a power cycle and a coupled steam electrolysis loop. Several reactor types and power cycles have been considered, over a range of reactor outlet temperatures. Pure steam electrolysis for hydrogen production as well as coelectrolysis for syngas production from steam/carbon dioxide mixtures have both been considered. In addition, the feasibility of coupling the high-temperature electrolysis process to biomass and coal-based synthetic fuels production has been considered. These simulations demonstrate that the addition of supplementary nuclear hydrogen to synthetic fuels production from any carbon source minimizes emissions of carbon dioxide during the production process.

  20. The Concept and Analytical Investigation of CO2 and Steam Co-Electrolysis for Resource Utilization in Space Exploration

    NASA Technical Reports Server (NTRS)

    McKellar, Michael G.; Stoots, Carl M.; Sohal, Manohar S.; Mulloth, Lila M.; Luna, Bernadette; Abney, Morgan B.

    2010-01-01

    CO2 acquisition and utilization technologies will have a vital role in designing sustainable and affordable life support and in situ fuel production architectures for human and robotic exploration of Moon and Mars. For long-term human exploration to be practical, reliable technologies have to be implemented to capture the metabolic CO2 from the cabin air and chemically reduce it to recover oxygen. Technologies that enable the in situ capture and conversion of atmospheric CO2 to fuel are essential for a viable human mission to Mars. This paper describes the concept and mathematical analysis of a closed-loop life support system based on combined electrolysis of CO2 and steam (co-electrolysis). Products of the coelectrolysis process include oxygen and syngas (CO and H2) that are suitable for life support and synthetic fuel production, respectively. The model was developed based on the performance of a co-electrolysis system developed at Idaho National Laboratory (INL). Individual and combined process models of the co-electrolysis and Sabatier, Bosch, Boudouard, and hydrogenation reactions are discussed and their performance analyses in terms of oxygen production and CO2 utilization are presented.

  1. Enhanced hydroxyl radical generation in the combined ozonation and electrolysis process using carbon nanotubes containing gas diffusion cathode.

    PubMed

    Wu, Donghai; Lu, Guanghua; Zhang, Ran; Lin, Qiuhong; Yan, Zhenhua; Liu, Jianchao; Li, Yi

    2015-10-01

    Combination of ozone together with electrolysis (ozone-electrolysis) is a promising wastewater treatment technology. This work investigated the potential use of carbon nanotube (CNT)-based gas diffusion cathode (GDC) for ozone-electrolysis process employing hydroxyl radicals (·OH) production as an indicator. Compared with conventional active carbon (AC)-polytetrafluoroethylene (PTFE) and carbon black (CB)-PTFE cathodes, the production of ·OH in the coupled process was improved using CNTs-PTFE GDC. Appropriate addition of acetylene black (AB) and pore-forming agent Na2SO4 could enhance the efficiency of CNTs-PTFE GDC. The optimum GDC composition was obtained by response surface methodology (RSM) analysis and was determined as CNTs 31.2 wt%, PTFE 60.6 wt%, AB 3.5 wt%, and Na2SO4 4.7 wt%. Moreover, the optimized CNT-based GDC exhibited much more effective than traditional Ti and graphite cathodes in Acid Orange 7 (AO7) mineralization and possessed the desirable stability without performance decay after ten times reaction. The comparison tests revealed that peroxone reaction was the main pathway of ·OH production in the present system, and cathodic reduction of ozone could significantly promote ·OH generation. These results suggested that application of CNT-based GDC offers considerable advantages in ozone-electrolysis of organic wastewater. PMID:26036588

  2. A Vivens Ex Vivo Study on the Synergistic Effect of Electrolysis and Freezing on the Cell Nucleus

    PubMed Central

    Lugnani, Franco; Zanconati, Fabrizio; Marcuzzo, Thomas; Bottin, Cristina; Mikus, Paul; Guenther, Enric; Klein, Nina; Rubinsky, Liel; Stehling, Michael K.; Rubinsky, Boris

    2015-01-01

    Freezing—cryosurgery, and electrolysis—electrochemical therapy (EChT), are two important minimally invasive surgery tissue ablation technologies. Despite major advantages they also have some disadvantages. Cryosurgery cannot induce cell death at high subzero freezing temperatures and requires multiple freeze thaw cycles, while EChT requires high concentrations of electrolytic products—which makes it a lengthy procedure. Based on the observation that freezing increases the concentration of solutes (including products of electrolysis) in the frozen region and permeabilizes the cell membrane to these products, this study examines the hypothesis that there could be a synergistic effect between freezing and electrolysis in their use together for tissue ablation. Using an animal model we refer to as vivens ex vivo, which may be of value in reducing the use of animals for experiments, combined with a Hematoxylin stain of the nucleus, we show that there are clinically relevant protocols in which the cell nucleus appears intact when electrolysis and freezing are used separately but is affected by certain combinations of electrolysis and freezing. PMID:26695185

  3. Highlights from Faraday Discussion 182: Solid Oxide Electrolysis: Fuels and Feedstocks from Water and Air, York, UK, July 2015.

    PubMed

    Stefan, Elena; Norby, Truls

    2016-01-31

    The rising importance of converting high peak electricity from renewables to fuels has urged field specialists to organize this Faraday Discussion on Solid Oxide Electrolysis. The topic is of essential interest in order to achieve a greater utilization of renewable energy and storage at higher densities. PMID:26758816

  4. Transducing Energy Loss in Water Electrolysis with a 0D Ion-Sensitive Field-Effect Transistor

    NASA Astrophysics Data System (ADS)

    Clement, Nicolas; Nishiguchi, Katsuhiko; Dufrêche, Jean-François; Guérin, David; Patriarche, Gilles; Troadec, David; Fujiwara, Akira; Vuillaume, Dominique

    2013-03-01

    In order to produce hydrogen as a fuel source of the future, water electrolysis is one of the most ``promising'' green approaches. Although electrolysis efficiency can be as high as 80%, it still means that at least 20% of the energy is lost. The use of transducers to collect the energy loss in water electrolysis is attractive. Among the various transducers, several ideas have been proposed such as an air bubble powered rotary driving apparatus or a microcantilever vibrating after impact of each bubble. However, the main source of energy lost appears at electrode interfaces with the presence of a double layer of ions acting as a resistor and capacitor. In this study, we show that using a 0D - ultra low noise - ISFET, allows getting the energy coming from the double layer fluctuation at each H2 bubble emission. Interestingly, the output signal that can be tuned with salt concentration and electrolysis current exactly corresponds to that of action potential which could be useful for bio-applications. In addition, electrical detection of bubbles emission at single bubble level also opens the door to optimization of hydrolysis efficiency and further save energy for hydrogen production.

  5. A pulsed mode electrolytic drug delivery device

    NASA Astrophysics Data System (ADS)

    Yi, Ying; Buttner, Ulrich; Carreno, Armando A. A.; Conchouso, David; Foulds, Ian G.

    2015-10-01

    This paper reports the design of a proof-of-concept drug delivery device that is actuated using the bubbles formed during electrolysis. The device uses a platinum (Pt) coated nickel (Ni) metal foam and a solid drug in reservoir (SDR) approach to improve the device’s performance. This electrochemically-driven pump has many features that are unlike conventional drug delivery devices: it is capable of pumping periodically and being refilled automatically; it features drug release control; and it enables targeted delivery. Pt-coated metal foam is used as a catalytic reforming element, which reduces the period of each delivery cycle. Two methods were used for fabricating the Pt-coated metal: sputtering and electroplating. Of these two methods, the sputtered Pt-coated metal foam has a higher pumping rate; it also has a comparable recombination rate when compared to the electroplated Pt-coated metal foam. The only drawback of this catalytic reformer is that it consumes nickel scaffold. Considering long-term applications, the electroplated Pt metal foam was selected for drug delivery, where a controlled drug release rate of 2.2 μg  ±  0.3 μg per actuation pulse was achieved using 4 mW of power.

  6. Qualitative identification of rodenticide anticoagulants by LC-MS/MS.

    PubMed

    Middleberg, Robert A; Homan, Joseph

    2012-01-01

    Rodenticide anticoagulants are used in the control of rodent populations. In addition to accidental ingestions in humans, such agents have also been used for homicidal and suicidal purposes. There are two major groups of rodenticide anticoagulants - hydroxycoumarins and indanediones. Before the advent of LC-MS/MS, analysis for such agents was relegated to such techniques as TLC and HPLC with nonspecific modes of detection. LC-MS/MS has been used to determine any given number of rodenticide anticoagulants in animal tissues, foods, plasma, etc. Use of this technique allows for the simultaneous identification of individual compounds within both classes of rodenticide anticoagulants. The LC-MS/MS method presented allows for simultaneous qualitative identification of brodifacoum, bromadiolone, chlorphacinone, dicumarol, difenacoum, diphacinone, and warfarin in blood, serum, and plasma using ESI in the negative mode. Two transitions are monitored for each analyte after a simple sample preparation. Chromatographic separation is accomplished using a gradient of ammonium hydroxide in water and ammonium hydroxide in methanol. Chloro-warfarin is used as internal standard. PMID:22767114

  7. Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water

    NASA Astrophysics Data System (ADS)

    Graves, Christopher Ronald

    Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co-electrolysis

  8. Chirped-pulse amplification with narrowband pulses.

    PubMed

    Shverdin, M Y; Albert, F; Anderson, S G; Betts, S M; Gibson, D J; Messerly, M J; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-15

    We demonstrate a compact hyperdispersion stretcher and compressor pair that permit chirped-pulse amplification in Nd:YAG. We generate 750 mJ, 0.2 nm FWHM, 10 Hz pulses recompressed to an 8 ps near-transform-limited duration. The dispersion-matched pulse compressor and stretcher impart a chirp of 7300 ps/nm, in a 3 m x 1 m footprint.

  9. Chirped-pulse amplification with narrowband pulses.

    PubMed

    Shverdin, M Y; Albert, F; Anderson, S G; Betts, S M; Gibson, D J; Messerly, M J; Hartemann, F V; Siders, C W; Barty, C P J

    2010-07-15

    We demonstrate a compact hyperdispersion stretcher and compressor pair that permit chirped-pulse amplification in Nd:YAG. We generate 750 mJ, 0.2 nm FWHM, 10 Hz pulses recompressed to an 8 ps near-transform-limited duration. The dispersion-matched pulse compressor and stretcher impart a chirp of 7300 ps/nm, in a 3 m x 1 m footprint. PMID:20634869

  10. Control of cavitation activity by different shockwave pulsing regimes.

    PubMed

    Huber, P; Debus, J; Jöchle, K; Simiantonakis, I; Jenne, J; Rastert, R; Spoo, J; Lorenz, W J; Wannenmacher, M

    1999-06-01

    The aim of the study was to control the number of inertial cavitation bubbles in the focal area of an electromagnetic lithotripter in water independently of peak intensity, averaged intensity or pressure waveform. To achieve this, the shockwave pulses were applied in double pulse sequences, which were administered at a fixed pulse repetition frequency (PRF) of 0.33 Hz. The two pulses of a double pulse were separated by a variable short pulse separation time (PST) ranging from 200 micros to 1500 ms. The number and size of the cavitation bubbles were monitored by scattered laser light and stroboscopic photographs. We found that the number of inertial cavitation bubbles as a measure of cavitation dose was substantially influenced by variation of the PST, while the pressure pulse waveform, averaged acoustic intensity and bubble size were kept constant. The second pulse of each double pulse generated more cavitation bubbles than the first. At 14 kV capacitor voltage, the total number of cavitation bubbles generated by the double pulses increased with shorter PST down to approximately 400 micros, the cavitation lifespan. The results can be explained by cavitation nuclei generated by the violently imploding inertial cavitation bubbles. This method of pulse administration and cavitation monitoring could be useful to establish a cavitation dose-effect relationship independently of other acoustic parameters.

  11. DIFFERENTIAL PULSE HEIGHT DISCRIMINATOR

    DOEpatents

    Test, L.D.

    1958-11-11

    Pulse-height discriminators are described, specifically a differential pulse-height discriminator which is adapted to respond to pulses of a band of amplitudes, but to reject pulses of amplitudes greater or less than tbe preselected band. In general, the discriminator includes a vacuum tube having a plurality of grids adapted to cut off plate current in the tube upon the application of sufficient negative voltage. One grid is held below cutoff, while a positive pulse proportional to the amplltude of each pulse is applled to this grid. Another grid has a negative pulse proportional to the amplitude of each pulse simultaneously applied to it. With this arrangement the tube will only pass pulses which are of sufficlent amplitude to counter the cutoff bias but not of sufficlent amplitude to cutoff the tube.

  12. Evidence of thermal additivity during short laser pulses in an in vitro retinal model

    NASA Astrophysics Data System (ADS)

    Denton, Michael L.; Tijerina, Amanda J.; Dyer, Phillip N.; Oian, Chad A.; Noojin, Gary D.; Rickman, John M.; Shingledecker, Aurora D.; Clark, Clifton D.; Castellanos, Cherry C.; Thomas, Robert J.; Rockwell, Benjamin A.

    2015-03-01

    Laser damage thresholds were determined for exposure to 2.5-ms 532-nm pulses in an established in vitro retinal model. Single and multiple pulses (10, 100, 1000) were delivered to the cultured cells at three different pulse repetition frequency (PRF) values, and overt damage (membrane breach) was scored 1 hr post laser exposure. Trends in the damage data within and across the PRF range identified significant thermal additivity as PRF was increased, as evidenced by drastically reduced threshold values (< 40% of single-pulse value). Microthermography data that were collected in real time during each exposure also provided evidence of thermal additivity between successive laser pulses. Using thermal profiles simulated at high temporal resolution, damage threshold values were predicted by an in-house computational model. Our simulated ED50 value for a single 2.5-ms pulse was in very good agreement with experimental results, but ED50 predictions for multiple-pulse trains will require more refinement.

  13. Pulmonary Capillary Hemorrhage Induced by Fixed-Beam Pulsed Ultrasound.

    PubMed

    Miller, Douglas L; Dou, Chunyan; Raghavendran, Krishnan

    2015-08-01

    The induction of pulmonary capillary hemorrhage (PCH) by pulsed ultrasound was discovered 25 y ago, but early research used fixed-beam systems rather than actual diagnostic ultrasound machines. In this study, results of exposure of rats to fixed-beam focused ultrasound for 5 min at 1.5 and 7.5 MHz were compared with recent research on diagnostic ultrasound. One exposure condition at each frequency used 10-μs pulses delivered at 25-ms intervals. Three conditions involved Gaussian modulation of the pulse amplitudes at 25-ms intervals to simulate diagnostic scanning: 7.5 MHz with 0.3- and 1.5-μs pulses at 100- and 500-μs pulse repetition periods, respectively, and 1.5 MHz with 1.7-μs pulses at 500-μs repetition periods. Four groups were tested for each condition to assess PCH areas at different exposure levels and to determine occurrence thresholds. The conditions with identical pulse timing resulted in smaller PCH areas for the smaller 7.5-MHz beam, but both had thresholds of 0.69-0.75 MPa in situ peak rarefactional pressure amplitude. The Gaussian modulation conditions for both 7.5 MHz with 0.3-μs pulses and 1.5 MHz with 1.7-μs pulses had thresholds of 1.12-1.20 MPa peak rarefactional pressure amplitude, although the relatively long 1.5-μs pulses at 7.5 MHz yielded a threshold of 0.75 MPa. The fixed-beam pulsed ultrasound exposures produced lower thresholds than diagnostic ultrasound. There was no clear tendency for thresholds to increase with increasing ultrasonic frequency when pulse timing conditions were similar.

  14. Laser pulse stacking method

    DOEpatents

    Moses, E.I.

    1992-12-01

    A laser pulse stacking method is disclosed. A problem with the prior art has been the generation of a series of laser beam pulses where the outer and inner regions of the beams are generated so as to form radially non-synchronous pulses. Such pulses thus have a non-uniform cross-sectional area with respect to the outer and inner edges of the pulses. The present invention provides a solution by combining the temporally non-uniform pulses in a stacking effect to thus provide a more uniform temporal synchronism over the beam diameter. 2 figs.

  15. Nerve-pulse interactions

    SciTech Connect

    Scott, A.C.

    1982-01-01

    Some recent experimental and theoretical results on mechanisms through which individual nerve pulses can interact are reviewed. Three modes of interactions are considered: (1) interaction of pulses as they travel along a single fiber which leads to velocity dispersion; (2) propagation of pairs of pulses through a branching region leading to quantum pulse code transformations; and (3) interaction of pulses on parallel fibers through which they may form a pulse assembly. This notion is analogous to Hebb's concept of a cell assembly, but on a lower level of the neural hierarchy.

  16. Removal of fluoride from fluoride contaminated industrial waste water by electrolysis.

    PubMed

    Joshi, Vijaya A; Nanoti, Madan V

    2003-01-01

    Wastewater containing fluoride are generally treated with lime or calcium salt supplemented with aluminium salts. Wastewater generated from different industries does not always behave in the same way due to the presence of interfering contaminants. A number of techniques have been developed and studied for the removal of excessive fluoride. Most of these are based on use of aluminium salt. In alum coagulation the sorption properties of product of hydrolysis of aluminium salts and capacity of fluoride for complex formation plays a very important role. These hydrolysis products of aluminium can be produced by passing direct current through aluminium electrode. The text presented in the paper deals with the various aspect of removal of fluoride by electrolysis using aluminium electrode from fluoride chemical based industrial wastewater. PMID:14672366

  17. Treatability studies on different refinery wastewater samples using high-throughput microbial electrolysis cells (MECs).

    PubMed

    Ren, Lijiao; Siegert, Michael; Ivanov, Ivan; Pisciotta, John M; Logan, Bruce E

    2013-05-01

    High-throughput microbial electrolysis cells (MECs) were used to perform treatability studies on many different refinery wastewater samples all having appreciably different characteristics, which resulted in large differences in current generation. A de-oiled refinery wastewater sample from one site (DOW1) produced the best results, with 2.1±0.2 A/m(2) (maximum current density), 79% chemical oxygen demand removal, and 82% headspace biological oxygen demand removal. These results were similar to those obtained using domestic wastewater. Two other de-oiled refinery wastewater samples also showed good performance, with a de-oiled oily sewer sample producing less current. A stabilization lagoon sample and a stripped sour wastewater sample failed to produce appreciable current. Electricity production, organics removal, and startup time were improved when the anode was first acclimated to domestic wastewater. These results show mini-MECs are an effective method for evaluating treatability of different wastewaters.

  18. Size-dependent capacitance of NiO nanoparticles synthesized with cathodic contact glow discharge electrolysis

    NASA Astrophysics Data System (ADS)

    Allagui, Anis; Alami, Abdul Hai; Baranova, Elena A.; Wüthrich, Rolf

    2014-09-01

    NiO nanoparticles of 70, 91 and 107 nm average diameter are synthesized by cathodic contact glow discharge electrolysis at 30, 36 and 42 VDC respectively, in 2 M H2SO4 + 0.5 M ethanol + 2.5 mg ml-1 of PVP, and are investigated for electrochemical energy storage. From the cyclic voltammetry and galvanostatic charge-discharge measurements in 1 M KOH, it was found that a maximum specific capacitance of 218 F g-1 is achieved with the 70 nm NiO nanoparticles at 2.7 A g-1. Larger nanoparticles of 91 and 107 nm diameter exhibit specific capacitances of 106 and 63 F g-1, respectively, suggesting a size-dependent capacitive performance enhanced with decreasing particles size.

  19. Electrolysis of water in the diffusion layer: first-principles molecular dynamics simulation.

    PubMed

    Hofbauer, Florian; Frank, Irmgard

    2012-01-01

    With Car-Parrinello molecular dynamics simulations the elementary reaction steps of the electrolysis of bulk water are investigated. To simulate the reactions occurring near the anode and near the cathode, electrons are removed or added, respectively. The study focuses on the reactions in pure water. Effects depending on a particular electrode surface or a particular electrolyte are ignored. Under anodic conditions, the reaction continues till molecular oxygen is formed, under cathodic conditions the formation of molecular hydrogen is observed. In addition the formation of hydrogen peroxide is observed as an intermediate of the anodic reaction. The simulations demonstrate that the electrochemistry of oxygen formation without direct electrode contact can be explained by radical reactions in a solvent. These reactions may involve the intermediate formation of ions. The hydrogen formation is governed by rapid proton transfers between water molecules. PMID:22162243

  20. Microbial electrolysis cells for waste biorefinery: A state of the art review.

    PubMed

    Lu, Lu; Ren, Zhiyong Jason

    2016-09-01

    Microbial electrolysis cells (MECs) is an emerging technology for energy and resource recovery during waste treatment. MECs can theoretically convert any biodegradable waste into H2, biofuels, and other value added products, but the system efficacy can vary significantly when using different substrates or are operated in different conditions. To understand the application niches of MECs in integrative waste biorefineries, this review provides a critical analysis of MEC system performance reported to date in terms of H2 production rate, H2 yield, and energy efficiency under a variety of substrates, applied voltages and other crucial factors. It further discusses the mutual benefits between MECs and dark fermentation and argues such integration can be a viable approach for efficient H2 production from renewable biomass. Other marketable products and system integrations that can be applied to MECs are also summarized, and the challenges and prospects of the technology are highlighted.

  1. High temperature electrolysis: zinc from zinc oxide using a solar furnace

    SciTech Connect

    MacDonald, F.J.

    1986-01-01

    Exploratory research was conducted in high temperature metal extraction using a concentrating solar furnace for process heat. Electrolysis of zinc oxide was performed using various molten salts as electrolytes; 13% AlF/sub 3//87% NaF, 45% AlF/sub 3//55% NaF, 33% ZnF/sub 2//67% NaF and NaOH. The temperature range investigated was 600 to 1400 K. Several materials were tried as crucibles and electrodes with the best being graphite for the cathode and crucible, and platinum for the anode. Experiments were performed where the zinc produced was collected and the current and voltage were measured. From this data, current efficiencies were calculated and decomposition potentials were determined.

  2. Suppression of methanogenesis for hydrogen production in single-chamber microbial electrolysis cells using various antibiotics.

    PubMed

    Catal, Tunc; Lesnik, Keaton Larson; Liu, Hong

    2015-01-01

    Methanogens can utilize the hydrogen produced in microbial electrolysis cells (MECs), thereby decreasing the hydrogen generation efficiency. However, various antibiotics have previously been shown to inhibit methanogenesis. In the present study antibiotics, including neomycin sulfate, 2-bromoethane sulfonate, 2-chloroethane sulfonate, 8-aza-hypoxanthine, were examined to determine if hydrogen production could be improved through inhibition of methanogenesis but not hydrogen production in MECs. 1.1mM neomycin sulfate inhibited both methane and hydrogen production while 2-chloroethane sulfonate (20mM), 2-bromoethane sulfonate (20mM), and 8-aza-hypoxanthine (3.6mM) can inhibited methane generation and with concurrent increases in hydrogen production. Our results indicated that adding select antibiotics to the mixed species community in MECs could be a suitable method to enhance hydrogen production efficiency.

  3. Aqueous 4-nitrophenol decomposition and hydrogen peroxide formation induced by contact glow discharge electrolysis.

    PubMed

    Liu, Yongjun; Wang, Degao; Sun, Bing; Zhu, Xiaomei

    2010-09-15

    Liquid-phase decomposition of 4-nitrophenol (4-NP) and formation of hydrogen peroxide (H(2)O(2)) induced by contact glow discharge electrolysis (CGDE) were investigated. Experimental results showed that the decays of 4-NP and total organic carbon (TOC) obeyed the first-order and pseudo-first-order reaction kinetics, respectively. The major intermediate products were 4-nitrocatechol, hydroquinone, benzoquinone, hydroxyhydroquinone, organic acids and nitrite ion. The final products were carbon dioxide and nitrate ion. The initial formation rate of H(2)O(2) decreased linearly with increasing initial concentration of 4-NP. Addition of iron ions, especially ferric ion, to the solution significantly enhanced the 4-NP removal due to the additional hydroxyl radical formation through Fenton's reaction. A reaction pathway is proposed based on the degradation kinetics and the distribution of intermediate products.

  4. Hydrogen production in microbial reverse-electrodialysis electrolysis cells using a substrate without buffer solution.

    PubMed

    Song, Young-Hyun; Hidayat, Syarif; Kim, Han-Ki; Park, Joo-Yang

    2016-06-01

    The aim of this work was to use substrate without buffer solution in a microbial reverse-electrodialysis electrolysis cell (MREC) for hydrogen production under continuous flow condition (10 cell pairs of RED stacks, HRT=5, 7.5, and 15h). Decreasing in the HRT (increasing in the organic matter) made cell current stable and increased. Hydrogen gas was produced at a rate of 0.61m(3)-H2/m(3)-Van/d in H-MREC, with a COD removal efficiency of 81% (1.55g/L/d) and a Coulombic efficiency of 41%. This MREC system without buffer solution could successfully produce hydrogen gas at a consistent rate. PMID:26888336

  5. Mineralization of alkylbenzenesulfonates in water by means of contact glow discharge electrolysis.

    PubMed

    Amano, Ryo; Tezuka, Meguru

    2006-05-01

    Mineralization of aqueous alkylbenzenesulfonates (ABS) was investigated by means of contact glow discharge electrolysis (CGDE). Toluenesulfonic and dodecylbenzenesulfonic acids in a neutral phosphate buffer solution were smoothly degraded and eventually converted to inorganic carbon and sulfate ion when CGDE was conducted under the applied DC voltage of 500 V and current of ca. 90 mA. As the intermediate products, some phenolic compounds were detected as well as carboxylic acids such as oxalate, formate and so on. It was demonstrated that the decay of ABS followed the first-order rate law. Based on the detailed analysis of the hydroxylation products and kinetic consideration, it was assumed that hydroxyl radicals would play a crucial role in the oxidative degradation of aqueous ABS. The features of CGDE as a tool for the removal of organic pollutants in water were discussed in comparison with other physicochemical methods. PMID:16616949

  6. Aqueous 4-nitrophenol decomposition and hydrogen peroxide formation induced by contact glow discharge electrolysis.

    PubMed

    Liu, Yongjun; Wang, Degao; Sun, Bing; Zhu, Xiaomei

    2010-09-15

    Liquid-phase decomposition of 4-nitrophenol (4-NP) and formation of hydrogen peroxide (H(2)O(2)) induced by contact glow discharge electrolysis (CGDE) were investigated. Experimental results showed that the decays of 4-NP and total organic carbon (TOC) obeyed the first-order and pseudo-first-order reaction kinetics, respectively. The major intermediate products were 4-nitrocatechol, hydroquinone, benzoquinone, hydroxyhydroquinone, organic acids and nitrite ion. The final products were carbon dioxide and nitrate ion. The initial formation rate of H(2)O(2) decreased linearly with increasing initial concentration of 4-NP. Addition of iron ions, especially ferric ion, to the solution significantly enhanced the 4-NP removal due to the additional hydroxyl radical formation through Fenton's reaction. A reaction pathway is proposed based on the degradation kinetics and the distribution of intermediate products. PMID:20576351

  7. Plasma degradation of Cationic Blue dye with contact glow discharge electrolysis.

    PubMed

    Jin, Xing-long; Wang, Xiao-yan; Wang, Qing-feng; Yue, Jun-jie; Cai, Ya-qi

    2010-01-01

    Contact glow discharge electrolysis (CGDE) of Cationic Blue SD-GTL (CB) was investigated by determining degradation rates and rate constants under different voltages, pH, temperature and initial concentrations. The results indicated that 500 V was the optimum voltage for CGDE of CB under experimental conditions. The effect of pH was not appreciable. Fe²(+) and Fe³(+) had a remarkable catalytic effect on the degradation of CB. The degradation rate was up to 99.7% after 3 minutes CGDE treatment when the concentration of Fe²(+) was 20.0 mg/L. And when the concentration of Fe³ (+) was 5.0 mg/L, the degradation rate was only 68.6% after 10 minutes CGDE treatment. The reaction mechanisms were also well illustrated by relative reactions and their rate constants. It had been demonstrated that CB underwent oxidative degradation in CGDE. PMID:20935361

  8. Development status of solid polymer electrolyte water electrolysis for manned spacecraft life support systems

    NASA Technical Reports Server (NTRS)

    Nuttall, L. J.; Titterington, W. A.

    1974-01-01

    Details of the design and system verification test results are presented for a six-man-rated oxygen generation system. The system configuration incorporates components and instrumentation for computer-controlled operation with automatic start-up/shutdown sequencing, fault detection and isolation, and with self-contained sensors and controls for automatic safe emergency shutdown. All fluid and electrical components, sensors, and electronic controls are designed to be easily maintainable under zero-gravity conditions. On-board component spares are utilized in the system concept to sustain long-term operation (six months minimum) in a manned spacecraft application. The system is centered on a 27-cell solid polymer electrolyte water electrolysis module which, combined with the associated system components and controls, forms a total system envelope 40 in. high, 40 in. wide, and 30 in. deep.

  9. Generation of High Pressure Oxygen via Electrochemical Pumping in a Multi-stage Electrolysis Stack

    NASA Technical Reports Server (NTRS)

    Setlock, John A (Inventor); Green, Robert D (Inventor); Farmer, Serene (Inventor)

    2016-01-01

    An oxygen pump can produce high-purity high-pressure oxygen. Oxygen ions (O.sup.2-) are electrochemically pumped through a multi-stage electrolysis stack of cells. Each cell includes an oxygen-ion conducting solid-state electrolyte between cathode and anode sides. Oxygen dissociates into the ions at the cathode side. The ions migrate across the electrolyte and recombine at the anode side. An insulator is between adjacent cells to electrically isolate each individual cell. Each cell receives a similar volt potential. Recombined oxygen from a previous stage can diffuse through the insulator to reach the cathode side of the next stage. Each successive stage similarly incrementally pressurizes the oxygen to produce a final elevated pressure.

  10. Initial Operation of the High Temperature Electrolysis Integrated Laboratory Scale Experiment at INL

    SciTech Connect

    C. M. Stoots; J. E. O'Brien; K. G. Condie; J. S. Herring; J. J. Hartvigsen

    2008-06-01

    An integrated laboratory scale, 15 kW high-temperature electrolysis facility has been developed at the Idaho National Laboratory under the U.S. Department of Energy Nuclear Hydrogen Initiative. Initial operation of this facility resulted in over 400 hours of operation with an average hydrogen production rate of approximately 0.9 Nm3/hr. The integrated laboratory scale facility is designed to address larger-scale issues such as thermal management (feed-stock heating, high-temperature gas handling), multiple-stack hot-zone design, multiple-stack electrical configurations, and other “integral” issues. This paper documents the initial operation of the ILS, with experimental details about heat-up, initial stack performance, as well as long-term operation and stack degradation.

  11. Lunar oxygen and metal for use in near-Earth space: Magma electrolysis

    NASA Technical Reports Server (NTRS)

    Colson, Russell O.; Haskin, Larry A.

    1990-01-01

    Because it is energetically easier to get material from the Moon to Earth orbit than from the Earth itself, the Moon is a potentially valuable source of materials for use in space. The unique conditions on the Moon, such as vacuum, absence of many reagents common on the Earth, and the presence of very nontraditional ores suggest that a unique and nontraditional process for extracting materials from the ores may prove the most practical. With this in mind, an investigation of unfluxed silicate electrolysis as a method for extracting oxygen, iron, and silicon from lunar regolith was initiated and is discussed. The advantages of the process include simplicity of concept, absence of need to supply reagents from Earth, and low power and mass requirements for the processing plant. Disadvantages include the need for uninterrupted high temperature and the highly corrosive nature of the high-temperature silicate melts which has made identifying suitable electrode and container materials difficult.

  12. Increased performance of hydrogen production in microbial electrolysis cells under alkaline conditions.

    PubMed

    Rago, Laura; Baeza, Juan A; Guisasola, Albert

    2016-06-01

    This work reports the first successful enrichment and operation of alkaline bioelectrochemical systems (microbial fuel cells, MFC, and microbial electrolysis cells, MEC). Alkaline (pH=9.3) bioelectrochemical hydrogen production presented better performance (+117%) compared to conventional neutral conditions (2.6 vs 1.2 litres of hydrogen gas per litre of reactor per day, LH2·L(-1)REACTOR·d(-1)). Pyrosequencing results of the anodic biofilm showed that while Geobacter was mainly detected under conventional neutral conditions, Geoalkalibacter sp. was highly detected in the alkaline MFC (21%) and MEC (48%). This is the first report of a high enrichment of Geoalkalibacter from an anaerobic mixed culture using alkaline conditions in an MEC. Moreover, Alkalibacter sp. was highly present in the anodic biofilm of the alkaline MFC (37%), which would indicate its potentiality as a new exoelectrogen.

  13. Increased performance of hydrogen production in microbial electrolysis cells under alkaline conditions.

    PubMed

    Rago, Laura; Baeza, Juan A; Guisasola, Albert

    2016-06-01

    This work reports the first successful enrichment and operation of alkaline bioelectrochemical systems (microbial fuel cells, MFC, and microbial electrolysis cells, MEC). Alkaline (pH=9.3) bioelectrochemical hydrogen production presented better performance (+117%) compared to conventional neutral conditions (2.6 vs 1.2 litres of hydrogen gas per litre of reactor per day, LH2·L(-1)REACTOR·d(-1)). Pyrosequencing results of the anodic biofilm showed that while Geobacter was mainly detected under conventional neutral conditions, Geoalkalibacter sp. was highly detected in the alkaline MFC (21%) and MEC (48%). This is the first report of a high enrichment of Geoalkalibacter from an anaerobic mixed culture using alkaline conditions in an MEC. Moreover, Alkalibacter sp. was highly present in the anodic biofilm of the alkaline MFC (37%), which would indicate its potentiality as a new exoelectrogen. PMID:26855359

  14. Hydrogen production from continuous flow, microbial reverse-electrodialysis electrolysis cells treating fermentation wastewater.

    PubMed

    Watson, Valerie J; Hatzell, Marta; Logan, Bruce E

    2015-11-01

    A microbial reverse-electrodialysis electrolysis cell (MREC) was used to produce hydrogen gas from fermentation wastewater without the need for additional electrical energy. Increasing the number of cell pairs in the reverse electrodialysis stack from 5 to 10 doubled the maximum current produced from 60 A/m(3) to 120 A/m(3) using acetate. However, more rapid COD removal required a decrease in the anolyte hydraulic retention time (HRT) from 24 to 12 h to stabilize anode potentials. Hydrogen production using a fermentation wastewater (10 cell pairs, HRT=8 h) reached 0.9±0.1 L H2/Lreactor/d (1.1±0.1 L H2/g-COD), with 58±5% COD removal and a coulombic efficiency of 74±5%. These results demonstrated that consistent rates of hydrogen gas production could be achieved using an MREC if effluent anolyte COD concentrations are sufficient to produce stable anode potentials.

  15. Drinking Water Disinfection by In-line Electrolysis: Product and Inorganic By-Product Formation

    NASA Astrophysics Data System (ADS)

    Bergmann, M. E. Henry

    This section covers peculiarities of so-called in-line electrolysis when drinking water is electrolysed to produce disinfection species killing microorganisms. Mainly mixed oxide electrodes (MIO) based on IrO2 and/or RuO2 coatings and boron-doped diamond electrodes were used in the studies. Artificial and real drinking water systems were electrolysed in continuous and discontinuous operating mode, varying water composition, current density and electrode materials. Results show, besides the ability of producing active chlorine, risks of inorganic disinfection by-products (DBPs) such as chlorate, perchlorate, nitrite, ammonium, chloramines, hydrogen peroxide and others. DBPs are responsible for analysis errors using DPD method for active chlorine measurements. Geometry may influence by-product yield. As a conclusion, the necessity of developing test routines for practical cell applications must be underlined.

  16. NiFe2O4-based cermet inert anodes for aluminum electrolysis

    NASA Astrophysics Data System (ADS)

    Li, Wangxing; Zhang, Gang; Li, Jie; Lai, Yanqing

    2009-05-01

    Recent developments in the preparation, sintering process, mechanical properties, and thermal shock resistance of cermet inert anodes for aluminum electrolysis are reviewed in this paper. To obtain the desired technologies of low-temperature activated sintering of cermet inert anodes, the effects of material composition, sintering atmosphere, sintering temperature, and sintering aids on the densifi cation and microstructure of NiFe2O4-10NiO- based ceramics and cermets were studied. To obtain the toughening and strengthening technology of the cermet, the effects of material composition including ceramic and metallic phases are discussed. The cermet inert anodes with high density and mechanical properties were prepared through adjustment of material composition and sintering technology and selection of feasible sintering aids.

  17. Test Results From The Idaho National Laboratory 15kW High Temperature Electrolysis Test Facility

    SciTech Connect

    Carl M. Stoots; Keith G. Condie; James E. O'Brien; J. Stephen Herring; Joseph J. Hartvigsen

    2009-07-01

    A 15kW high temperature electrolysis test facility has been developed at the Idaho National Laboratory under the United States Department of Energy Nuclear Hydrogen Initiative. This facility is intended to study the technology readiness of using high temperature solid oxide cells for large scale nuclear powered hydrogen production. It is designed to address larger-scale issues such as thermal management (feed-stock heating, high temperature gas handling, heat recuperation), multiple-stack hot zone design, multiple-stack electrical configurations, etc. Heat recuperation and hydrogen recycle are incorporated into the design. The facility was operated for 1080 hours and successfully demonstrated the largest scale high temperature solid-oxide-based production of hydrogen to date.

  18. The repetitive high energy pulsed power module

    SciTech Connect

    Harjes, H.C.; Reed, K.W.; Buttram, M.T.; Turman, B.N.; Neau, E.L.; Martinez, L.; Adcock, J.; Weinbrecht, E.A.; Mann, G.A.; Morgan, F.A.; Laderach, G.E.; Pena, G.; Butler, M.; Schneider, L.X.; Wavrik, R.W.; Penn, K.J.; Weber, G.J.

    1990-01-01

    High average power magnetic pulse compression systems are being considered for use in several applications. One of the key issues in the design of a pulsed power driver for these applications is component reliability, efficiency, and lifetime. In the Repetitive High Energy Pulsed Power (RHEPP) module, pulse compression is done exclusively with magnetic switches (saturable reactors) because such switches have the potential of performing efficiently and reliably for >10{sup 10} shots. The objective of the RHEPP project is to explore the feasibility of using magnetic pulse compression technology in continuous high average power applications. The RHEPP system consists of a compressor which drives a linear induction voltage adder with a diode load. Prime power for the module is supplied by a 600 kW, 120 Hz, alternator (furnished by Westinghouse Electric Corporation). At present, construction and initial testing in a bipolar mode of the first two stages of the compressor has been completed. This system has operated for a total of 332 minutes (4.8 {times} 10{sup 6} pulses) at full power (600 kW) with an efficiency of 94+/{minus}3%. The first stage magnetic switch (MS1) has a pulse compression factor of 8.4 (4.2 ms to 500 {mu}s time to peak). It has two, parallel connected, 67 turn copper coils and a 760 kg core of 2 mil silicon steel with a magnetic cross sectional area of 0. 065 m{sup 2}. The second stage magnetic switch (MS2) has a pulse compression factor of 3 (500 {mu}s to 170 {mu}s). It has two, parallel connected, 36 turn copper coils and a 361 kg core of field annealed 2605CO Metglas with a magnetic area of 0.019 m{sup 2}. A discussion of RHEPP compressor design effort and its baseline design is given. In addition, initial results from the operation of the first two stages are presented. 11 refs., 8 figs., 4 tabs.

  19. Suspension of Atoms Using Optical Pulses, and Application to Gravimetry

    SciTech Connect

    Hughes, K. J.; Burke, J. H. T.; Sackett, C. A.

    2009-04-17

    Atoms from a {sup 87}Rb condensate are suspended against gravity using repeated reflections from a pulsed optical standing wave. Up to 100 reflections are observed, yielding suspension times of over 100 ms. The local gravitational acceleration can be determined from the pulse rate required to achieve suspension. Further, a gravitationally sensitive atom interferometer was implemented using the suspended atoms. This technique could potentially provide a precision measurement of gravity without requiring the atoms to fall a large distance.

  20. Pulse to pulse klystron diagnosis system

    SciTech Connect

    Nowak, J.; Davidson, V.; Genova, L.; Johnson, R.; Reagan, D.

    1981-03-01

    This report describes a system used to study the behavior of SLAC high powered klystrons operating with a twice normal pulse width of 5 ..mu..s. At present, up to eight of the klystrons installed along the accelerator can be operated with long pulses and monitored by this system. The report will also discuss some of the recent findings and investigations.

  1. U.S. Geographic Analysis of the Cost of Hydrogen from Electrolysis

    SciTech Connect

    Saur, G.; Ainscough, C.

    2011-12-01

    This report summarizes U.S. geographic analysis of the cost of hydrogen from electrolysis. Wind-based water electrolysis represents a viable path to renewably-produced hydrogen production. It might be used for hydrogen-based transportation fuels, energy storage to augment electricity grid services, or as a supplement for other industrial hydrogen uses. This analysis focuses on the levelized production, costs of producing green hydrogen, rather than market prices which would require more extensive knowledge of an hourly or daily hydrogen market. However, the costs of hydrogen presented here do include a small profit from an internal rate of return on the system. The cost of renewable wind-based hydrogen production is very sensitive to the cost of the wind electricity. Using differently priced grid electricity to supplement the system had only a small effect on the cost of hydrogen; because wind electricity was always used either directly or indirectly to fully generate the hydrogen. Wind classes 3-6 across the U.S. were examined and the costs of hydrogen ranged from $3.74kg to $5.86/kg. These costs do not quite meet the 2015 DOE targets for central or distributed hydrogen production ($3.10/kg and $3.70/kg, respectively), so more work is needed on reducing the cost of wind electricity and the electrolyzers. If the PTC and ITC are claimed, however, many of the sites will meet both targets. For a subset of distributed refueling stations where there is also inexpensive, open space nearby this could be an alternative to central hydrogen production and distribution.

  2. Constant potential pulse polarography

    USGS Publications Warehouse

    Christie, J.H.; Jackson, L.L.; Osteryoung, R.A.

    1976-01-01

    The new technique of constant potential pulse polarography, In which all pulses are to be the same potential, is presented theoretically and evaluated experimentally. The response obtained is in the form of a faradaic current wave superimposed on a constant capacitative component. Results obtained with a computer-controlled system exhibit a capillary response current similar to that observed In normal pulse polarography. Calibration curves for Pb obtained using a modified commercial pulse polarographic instrument are in good accord with theoretical predictions.

  3. Alternate drop pulse polarography

    USGS Publications Warehouse

    Christie, J.H.; Jackson, L.L.; Osteryoung, R.A.

    1976-01-01

    The new technique of alternate drop pulse polarography is presented. An experimental evaluation of alternate drop pulse polarography shows complete compensation of the capacitative background due to drop expansion. The capillary response phenomenon was studied in the absence of faradaic reaction and the capillary response current was found to depend on the pulse width to the -0.72 power. Increased signal-to-noise ratios were obtained using alternate drop pulse polarography at shorter drop times.

  4. Optically pulsed electron accelerator

    DOEpatents

    Fraser, John S.; Sheffield, Richard L.

    1987-01-01

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radio frequency powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  5. Optically pulsed electron accelerator

    DOEpatents

    Fraser, J.S.; Sheffield, R.L.

    1985-05-20

    An optically pulsed electron accelerator can be used as an injector for a free electron laser and comprises a pulsed light source, such as a laser, for providing discrete incident light pulses. A photoemissive electron source emits electron bursts having the same duration as the incident light pulses when impinged upon by same. The photoemissive electron source is located on an inside wall of a radiofrequency-powered accelerator cell which accelerates the electron burst emitted by the photoemissive electron source.

  6. Electrical pulse generator

    DOEpatents

    Norris, Neil J.

    1979-01-01

    A technique for generating high-voltage, wide dynamic range, shaped electrical pulses in the nanosecond range. Two transmission lines are coupled together by resistive elements distributed along the length of the lines. The conductance of each coupling resistive element as a function of its position along the line is selected to produce the desired pulse shape in the output line when an easily produced pulse, such as a step function pulse, is applied to the input line.

  7. Pulsed Laval nozzle with a large optical path length of 50 cm

    NASA Astrophysics Data System (ADS)

    Okada, Yoshiki; Isomura, Shohei; Satooka, Sakae; Takeuchi, Kazuo

    1994-07-01

    This note describes the design and performance of a pulsed valve developed as a gas source for a 500 mm long supersonic Laval nozzle with a 3 mm wide throat. The valve consists of a rotating drum with a slit, which allows an opening duration of approximately 14 ms. The duration of quasi-steady-state expansion is measured to be 10 ms at the nozzle throat when the pulsed valve is filled with 200 Torr of Ar gas.

  8. 12 CFR Appendix Ms-3 to Part 1024 - Appendix MS-3 to Part 1024

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Appendix MS-3 to Part 1024 MS Appendix MS-3 to... ACT (REGULATION X) Pt. 1024, App. MS-3 Appendix MS-3 to Part 1024 Model Force-Placed Insurance Notice Forms Table of Contents MS-3(A)—Model Form for Force-Placed Insurance Notice Containing...

  9. A PC-controlled voltage pulse generator for electroanalytical applications

    NASA Astrophysics Data System (ADS)

    Heredia-López, Francisco J.; Góngora-Alfaro, José L.; Alvarez-Cervera, Fernando J.; Bata-García, José Luis

    1997-04-01

    We present the design of a voltage pulse generator controlled by an IBM or compatible AT Personal Computer (PC) capable of synthesizing some of the voltage pulse wave forms commonly used in electrochemical studies. The included signals are: differential pulse voltametry, differential normal pulse voltametry, and differential pulse amperometry. Additionally, a triangular wave form and a constant-voltage signal, used in the pretreatment of carbon fiber microelectrodes for neurochemical analysis, are also available. Operating the generator imposes a minimum of restrictions on the specification of the duration, amplitude, and type of wave shapes. Low-cost PC-based design allows for compatibility, portability, and versatility. The operating ranges of the wave form parameters for the three voltametric signals are: initial voltage, -0.9-+0.9 V; step amplitude, 0.1-900 mV; period, 6 ms-60 s; measuring pulse amplitude, 0.1-900 mV; measuring pulse duration, 2 ms-20 s; prepulse duration, 2 ms-20 s. In the electrode pretreatment mode, the operating ranges are: amplitude, 0-±5 V; duration, unlimited; frequency, 15-240 Hz. The generator uses its own time base for the generation of all signals, thereby rendering it independent of processor clock speed or power-line frequency. The results of the experimental evaluation indicate that the system is accurate within ±10% of the expected values, taking into account the errors associated with the signal synthesis and the digitizing process. The maximum achievable scan rate is 500 V/s, and the highest frequency for the triangular wave form is 240 Hz. Therefore, the pulse generator could be used for fast cyclic voltametry (FCV). FCV and other wave forms could be added through software modules, without any hardware changes. We conclude that the PC-based electrochemistry pulse generator represents an economical and flexible alternative for electroanalytical applications.

  10. Giant Crab pulses at low frequency: statistics, scattering, polarization

    SciTech Connect

    Smirnova, T. V.

    2010-01-01

    We carried out observations of Crab giant pulses at frequency 112 MHz from 2005 till 2008 on the Large Phased Array of the Pushchino Radio Astronomy Observatory. The scattering of pulses observed in various series varies by a factor of 3: from 11 ms in November 2005 till 34 ms in September 2008. The cumulative probability distribution for the peak intensities of the giant pulses for each of these series shows that the distribution is stable and is a power law with a single slope (n = -2.3). This testifies to stability of the mechanism generating the giant pulses. The energy in the pulses is conserved; i.e., the increase in the pulse intensity is proportional to the decrease in the scattering. Refractive scintillations at low frequencies in measurements with large time separation lead to variations in the relative number of giant pulses exceeding a given amplitude, proportional to the ratio of the mean flux densities of the pulsar in the corresponding observational series. The maximum energy of the recorded giant pulses is 2.5x10{sup 7} Jy mus. Analysis of the giant pulses observed at other frequencies shows that the frequency dependence of the maximum energy of the giant pulses in the range of 23 MHz-9 GHz is a power-law with index -2.2+-0.2. We measured the rotation measure using GP which is RM (-47.5+-0.4) rad/m{sup 2}, and the degree of linear polarization for pulses with measured frequency modulation was 9% divide 17% for November 2005.

  11. Diagnosis of sources of current inefficiency in industrial molten salt electrolysis cells by Raman spectroscopy: A topical report on chlorides: Topical report, June 1982-June 1987

    SciTech Connect

    Sadoway, D. R.

    1987-06-01

    Molten salt electrolysis, a very energy-intensive process, is used in the extraction of light metals. Aluminum production by the Hall process and magnesium production in the Dow and I.G. Farbenindustrie cells constitute the major commercial applications of metal electrowinning from molten-salt media at present. The energy input into the electrolysis cell is in the form of direct current, and the energy efficiencies in the magnesium or aluminum processes are only in the 30 to 40% range. Major energy reductions are achieved by reducing the cell voltage or by increasing the current efficiency. Goal of the research is to identify the sources of the current losses occurring in molten salt electrolysis. This research worked on the systems of I.G. Farben magnesium chloride and Alcoa smelting aluminum chloride processes. Raman spectra were measured and analyzed for each component or their mixtures of the electrolyte for magnesium and aluminum reduction in chloride melts. Raman measurements were also conducted on the melts of industrial composition for aluminum and magnesium electrolysis. In laboratory-scale cells which imitated industrial practice, Raman spectra were measured in situ during electrolysis in attempts to identify the streamers, coloration of electrolyte, and any subvalent species. They were known to occur only during electrolysis, and they have been reported to be possible current losses. Cyclic voltammetry was conducted to obtain information about the generation of subvalent species which were not detected by Raman measurement. These were thought to be kinetic entities present only during electrolysis. Results of Raman spectroscopy and electrochemistry of magnesium and aluminum reduction from molten chloride bath are presented. The results would be useful to establish the basis for the study of electrolysis of aluminum from molten fluoride media. 119 refs., 66 figs.

  12. MS-MS Approaches for the Analysis of Environmental Pollutants

    EPA Science Inventory

    Concern about the environment and the start of environmental analysis coincided with the rise of gas chromatography-mass spectrometry (GC-MS). The United States Environmental Protection Agency (U.S. EPA) was founded in 1970, and as the need for techniques to analyze environmental...

  13. Hybrid chirped pulse amplification system

    DOEpatents

    Barty, Christopher P.; Jovanovic, Igor

    2005-03-29

    A hybrid chirped pulse amplification system wherein a short-pulse oscillator generates an oscillator pulse. The oscillator pulse is stretched to produce a stretched oscillator seed pulse. A pump laser generates a pump laser pulse. The stretched oscillator seed pulse and the pump laser pulse are directed into an optical parametric amplifier producing an optical parametric amplifier output amplified signal pulse and an optical parametric amplifier output unconverted pump pulse. The optical parametric amplifier output amplified signal pulse and the optical parametric amplifier output laser pulse are directed into a laser amplifier producing a laser amplifier output pulse. The laser amplifier output pulse is compressed to produce a recompressed hybrid chirped pulse amplification pulse.

  14. Attenuated total reflectance spectroscopy with chirped-pulse upconversion.

    PubMed

    Shirai, Hideto; Duchesne, Constance; Furutani, Yuji; Fuji, Takao

    2014-12-01

    Chirped-pulse upconversion technique has been applied to attenuated total reflectance (ATR) infrared spectroscopy. An extremely broadband infrared pulse was sent to an ATR diamond prism and the reflected pulse was converted to the visible by using four-wave mixing in krypton gas. Absorption spectra of liquids in the range from 200 to 5500 cm(-1) were measured with a visible spectrometer on a single-shot basis. The system was applied to observe the dynamics of exchanging process of two solvents, water and acetone, which give clear vibrational spectral contrast. We observed that the exchange was finished within ∼ 10 ms. PMID:25606893

  15. Stress pulse phenomena

    SciTech Connect

    McGlaun, M.

    1993-08-01

    This paper is an introductory discussion of stress pulse phenomena in simple solids and fluids. Stress pulse phenomena is a very rich and complex field that has been studied by many scientists and engineers. This paper describes the behavior of stress pulses in idealized materials. Inviscid fluids and simple solids are realistic enough to illustrate the basic behavior of stress pulses. Sections 2 through 8 deal with the behavior of pressure pulses. Pressure is best thought of as the average stress at a point. Section 9 deals with shear stresses which are most important in studying solids.

  16. Laser fusion pulse shape controller

    DOEpatents

    Siebert, Larry D.

    1977-01-01

    An apparatus for controlling the pulse shape, i.e., the pulse duration and intensity pattern, of a pulsed laser system, and which is particularly well adapted for controlling the pellet ignition pulse in a laser-driven fusion reaction system. The apparatus comprises a laser generator for providing an optical control pulse of the shape desired, a pulsed laser triggered by the control pulse, and a plurality of optical Kerr-effect gates serially disposed at the output of the pulsed laser and selectively triggered by the control pulse to pass only a portion of the pulsed laser output generally corresponding in shape to the control pulse.

  17. 10 years of MS instrumental developments--impact on LC-MS/MS in clinical chemistry.

    PubMed

    Himmelsbach, Markus

    2012-02-01

    The combination of liquid chromatography and mass spectrometry (LC-MS) is a powerful and indispensable analytical tool that is widely applied in many areas of chemistry, medicine, pharmaceutics and biochemistry. In this review recent MS instrumental developments are presented as part of a special issue covering various aspects of liquid chromatography tandem mass spectrometry (LC-MS/MS) in clinical chemistry. Improvements, new inventions as well as new combinations in ion source technology are described focusing on dual or multimode sources and atmospheric pressure photoionization (APPI). Increasing demands regarding sensitivity, accuracy, resolution and both quantitation and identification guarantee on-going improvements in mass analyzer technology. This paper discusses new hybrid MS instruments that can perform novel scan modes as well as high-resolution mass spectrometers (HRMS) that finally seem to be able to overcome, or at least significantly reduce, their weaknesses in quantitative applications. Ion mobility-mass spectrometry (IMMS) itself is not an invention of the last 10 years, but a lot of progress was made within the last decade that reveals the potential benefits of this combination. This is clearly reflected by the increased number of commercially available instruments and the various designs of IMMS are covered in detail in this review. Selected applications for all these instrumental developments are given focusing on the perspective of clinical chemistry.

  18. Quantitative attachment and detachment of bacterial spores from fine wires through continuous and pulsed DC electrophoretic deposition.

    PubMed

    Zhou, Wenbo; Watt, Sarah K; Tsai, De-Hao; Lee, Vincent T; Zachariah, Michael R

    2013-02-14

    We demonstrate the uniform attachment of bacterial spores electrophoretically onto fine wires in liquids and subsequently quantitatively detached back into suspension. It was found that the use of a pulsed voltage method resulted in a uniform coverage of spores and prevented visible bubble formation resulting from water electrolysis which tended to dislodge the spores from the wires. By monitoring the electrophoretically derived current, this method could also be used to quantitatively measure the surface charges on spores and the deposition rate. The method is generic and should be applicable to the deposition of any charged biological material (e.g., spores, bacteria, viruses) onto metal surfaces.

  19. PULSE DURATION LENGTHENER

    DOEpatents

    Aiken, W.R.

    1958-02-01

    This patent pertains to pulse modifying apparatus and, more particularly, describes a device to provide a rise time and time base expander for signal pulses having a very short duration. The basic element of the device is a vacuum tube comprising a charged particie beam, grid control means, an accelerating electrode, a drift tube, and a collector electrode. As the short duration input pulse modulates the particle beam through the grid control means, the voltage between the drift tube and accelerating electrode is caused to vary, whereby the output signal from the collector is a pulse having longer rise time, expanded duration and proportionate characteristics of the original pulse. The invention is particuiarly useful where subsequent pulse circultry does not have the frequency bandwidth to handle the short duration pulse without distorting it.

  20. ELECTRICAL PULSE COUNTER APPARATUS

    DOEpatents

    Kaufman, W.M.; Jeeves, T.A.

    1962-09-01

    A progressive electrical pulse counter circuit rs designed for the counting of a chain of input pulses. The circuit employs a series of direct connected bistable counting stages simultaneously pulsed by each input pulse and a delay means connected between each of the stages. Each bistable stage has two d-c operative states, which stage, when in its initial state, prevents the next succeeding stage from changing its condition when the latter stage is pulsed. Since the delay circuits between the stages prevents the immediate decay of the d-c state of each stage when the stages are pulsed, only one stage will change its state for each input pulse, thereby providing progressive stage-by-stage counting. (AEC)

  1. LIBS and LA-ICP-MS; Old techniques, new approaches

    NASA Astrophysics Data System (ADS)

    Mueller, P. A.; Foster, D. A.; Gonzalez, J.; Colucci, M.; Russo, R.

    2012-12-01

    Over the past decade laser ablation in-situ solid sampling for chemical analysis with an ICP-MS analyzer (LA-ICP-MS, single and multi-collector) has become a generally accepted technique across a wide range of disciplines (geochemistry, forensic science, life sciences, etc). More recently, Laser Induced Breakdown Spectrometry (LIBS) has developed into a complementary technique that offers full spectral analysis of the laser plasma without the need for a mass spectrometer. Both techniques provide in-situ solid sample elemental and isotopic analysis at high spatial resolution (<5 microns) with minimal sample preparation. LA-ICP-MS affords the analyst low detection limits (ppb) and the ability to optimize across a specific mass range for high precision element or isotope ratios. LIBS, while providing slightly higher detection limits (ppm), allows for simultaneous and near complete spectral coverage of the laser plasma. Both techniques are capable of producing semi-quantitative and quantitative data. Integration of a LA and LIBS system could be a powerful tool to allow full spectral element and isotope/element ratio data on the same laser plume (plasma and particulates). Although LIBS and LA typically operate under different conditions of pulse length, spot size, and energy, the ability to capture elemental abundance information from the light that is otherwise wasted during LA makes an important complement to the limited number of ions measured in multi-collector ICP-MS analyses. Such an approach would not require the compromises in sampled volume associated with either split-streams (two ICP-MS systems required; diluted aerosol streams) or with peak switching in the MS (magnetic or electrostatic) because extraction of light-based information does not impact the number of ions measured for isotope ratios. We present LIBS experiments with UV-nanosecond lasers at 17mJ energies delivered to spot sizes of <100 μm and light directed to an ICCD detection system on NIST

  2. Joule-Heated Molten Regolith Electrolysis Reactor Concepts for Oxygen and Metals Production on the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Dominques, Jesus A.

    2012-01-01

    The maturation of Molten Regolith Electrolysis (MRE) as a viable technology for oxygen and metals production on explored planets relies on the realization of the self-heating mode for the reactor. Joule heat generated during regolith electrolysis creates thermal energy that should be able to maintain the molten phase (similar to electrolytic Hall-Heroult process for aluminum production). Self-heating via Joule heating offers many advantages: (1) The regolith itself is the crucible material, it protects the vessel walls (2) Simplifies the engineering of the reactor (3) Reduces power consumption (no external heating) (4) Extends the longevity of the reactor. Predictive modeling is a tool chosen to perform dimensional analysis of a self-heating reactor: (1) Multiphysics modeling (COMSOL) was selected for Joule heat generation and heat transfer (2) Objective is to identify critical dimensions for first reactor prototype.

  3. Ab-initio study of fluorine-doped tin dioxide: A prospective catalyst support for water electrolysis

    NASA Astrophysics Data System (ADS)

    Velikokhatnyi, Oleg I.; Kumta, Prashant N.

    2011-02-01

    In an attempt to identify new electrochemically stable catalyst supports for electrolysis of water, the electronic structure of SnO 2 doped with different fluorine concentrations has been calculated using the Vienna ab-initio simulation package (VASP) in the projector-augmented wave (PAW) method with the general gradient approximation (GGA) for conducting the exchange-correlation corrections. The role of fluorine in improving the electronic conductivity is discussed. An increase in the density of electronic states at the Fermi level with increase in the concentration of fluorine incorporated into the main SnO 2 matrix agrees well with published experimental observations. Despite a gradual decrease in the cohesive energies for the fluorine-doped tin oxide with increase in fluorine concentration, the doped material still remains an appropriate candidate for use as catalyst supports in water electrolysis warranting further experimental validation.

  4. Ammonia synthesis. Ammonia synthesis by N₂ and steam electrolysis in molten hydroxide suspensions of nanoscale Fe₂O₃.

    PubMed

    Licht, Stuart; Cui, Baochen; Wang, Baohui; Li, Fang-Fang; Lau, Jason; Liu, Shuzhi

    2014-08-01

    The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm(-2)) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm(-2) current density decreased to 1.0 V.

  5. Ammonia synthesis. Ammonia synthesis by N₂ and steam electrolysis in molten hydroxide suspensions of nanoscale Fe₂O₃.

    PubMed

    Licht, Stuart; Cui, Baochen; Wang, Baohui; Li, Fang-Fang; Lau, Jason; Liu, Shuzhi

    2014-08-01

    The Haber-Bosch process to produce ammonia for fertilizer currently relies on carbon-intensive steam reforming of methane as a hydrogen source. We present an electrochemical pathway in which ammonia is produced by electrolysis of air and steam in a molten hydroxide suspension of nano-Fe2O3. At 200°C in an electrolyte with a molar ratio of 0.5 NaOH/0.5 KOH, ammonia is produced at 1.2 volts (V) under 2 milliamperes per centimeter squared (mA cm(-2)) of applied current at coulombic efficiency of 35% (35% of the applied current results in the six-electron conversion of N2 and water to ammonia, and excess H2 is cogenerated with the ammonia). At 250°C and 25 bar of steam pressure, the electrolysis voltage necessary for 2 mA cm(-2) current density decreased to 1.0 V. PMID:25104378

  6. Effect of the cathode material on the removal of nitrates by electrolysis in non-chloride media.

    PubMed

    Lacasa, Engracia; Cañizares, Pablo; Llanos, Javier; Rodrigo, Manuel A

    2012-04-30

    In this work, the effect of the cathode material (conductive diamond, stainless steel, silicon carbide, graphite or lead) and the current density (150-1400 A m(-2)) on the removal of nitrates from aqueous solutions is studied by electrolysis in non-divided electrochemical cells equipped with conductive diamond anodes, using sodium sulphate as the electrolyte. The results show that the cathode material very strongly influences both the process performance and the product distribution. The main products obtained are gaseous nitrogen (NO, N(2)O and NO(2)) and ammonium ions. Nitrate removal follows first order kinetics, which indicates that the electrolysis process is controlled by mass transfer. Furthermore, the stainless steel and graphite cathodes show a great selectivity towards the production of ammonium ions, whereas the silicon carbide cathode leads to the highest formation of gaseous nitrogen, which production is promoted at low current densities.

  7. 3D CFD Electrochemical and Heat Transfer Model of an Integrated-Planar Solid Oxide Electrolysis Cells

    SciTech Connect

    Grant Hawkes; James E. O'Brien

    2008-10-01

    A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in a new novel integrated planar porous-tube supported solid oxide electrolysis cell (SOEC). The model is of several integrated planar cells attached to a ceramic support tube. This design is being evaluated with modeling at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean per-cell area-specific-resistance (ASR) values decrease with increasing current density. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, cathode and anode exchange current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicated the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal efficiency, cell electrical efficiency, and Gibbs free energy are discussed and reported herein.

  8. Treatment of concentrated industrial wastewaters originating from oil shale and the like by electrolysis polyurethane foam interaction

    DOEpatents

    Tiernan, Joan E.

    1991-01-01

    Highly concentrated and toxic petroleum-based and synthetic fuels wastewaters such as oil shale retort water are treated in a unit treatment process by electrolysis in a reactor containing oleophilic, ionized, open-celled polyurethane foams and subjected to mixing and l BACKGROUND OF THE INVENTION The invention described herein arose in the course of, or under, Contract No. DE-AC03-76SF00098 between the U.S. Department of Energy and the University of California.

  9. Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence characteristics of Microcystis aeruginosa.

    PubMed

    Lin, Li; Feng, Cong; Li, Qingyun; Wu, Min; Zhao, Liangyuan

    2015-10-01

    Effects of electrolysis by low-amperage electric current on the chlorophyll fluorescence characteristics of Microcystis aeruginosa were investigated in order to reveal the mechanisms of electrolytic inhibition of algae. Threshold of current density was found under a certain initial no. of algae cell. When current density was equal to or higher than the threshold (fixed electrolysis time), growth of algae was inhibited completely and the algae lost the ability to survive. Effect of algal solution volume on algal inhibition was insignificant. Thresholds of current density were 8, 10, 14, 20, and 22 mA cm(-2) at 2.5 × 10(7), 5 × 10(7), 1 × 10(8), 2.5 × 10(8), and 5 × 10(8) cells mL(-1) initial no. of algae cell, respectively. Correlativity between threshold of current and initial no. of algae cells was established for scale-up and determining operating conditions. Changes of chlorophyll fluorescence parameters demonstrated that photosystem (PS) II of algae was damaged by electrolysis but still maintained relatively high activity when algal solution was treated by current densities lower than the threshold. The activity of algae recovered completely after 6 days of cultivation. On the contrary, when current density was higher than the threshold, connection of phycobilisome (PBS) and PS II core complexes was destroyed, PS II system of algae was damaged irreversibly, and algae could not survive thoroughly. The inactivation of M. aeruginosa by electrolysis can be attributed to irreversible separation of PBS from PS II core complexes and the damage of PS II of M. aeruginosa.

  10. Fabrication and Performance of Zirconia Electrolysis Cells for Carbon Dioxide Reduction for Mars In Situ Resource Utilization Applications

    NASA Technical Reports Server (NTRS)

    Minh, N. Q.; Chung, B. W.; Doshi, R.; Lear, G. R.; Montgomery, K.; Ong, E. T.

    1999-01-01

    The use of the Martian atmosphere (95% CO2) to produce oxygen (for propellant and life support) can significantly lower the required launch mass and dramatically reduce the total cost for Mars missions. Zirconia electrolysis cells are one of the technologies being considered for oxygen generation from carbon dioxide in Mars In Situ Resource Utilization (ISRU) production plants. The attractive features of the zirconia cell for this application include simple operation and lightweight, low volume system.

  11. Phosphoprotein profiling by PA-GeLC-MS/MS.

    PubMed

    Kristjansdottir, Kolbrun; Wolfgeher, Donald; Lucius, Nick; Angulo, David Sigfredo; Kron, Stephen J

    2008-07-01

    A significant consequence of protein phosphorylation is to alter protein-protein interactions, leading to dynamic regulation of the components of protein complexes that direct many core biological processes. Recent proteomic studies have populated databases with extensive compilations of cellular phosphoproteins and phosphorylation sites and a similarly deep coverage of the subunit compositions and interactions in multiprotein complexes. However, considerably less data are available on the dynamics of phosphorylation, composition of multiprotein complexes or that define their interdependence. We describe a method to identify candidate phosphoprotein complexes by combining phosphoprotein affinity chromatography, separation by size, denaturing gel electrophoresis, protein identification by tandem mass spectrometry, and informatics analysis. Toward developing phosphoproteome profiling, we have isolated native phosphoproteins using a phosphoprotein affinity matrix, Pro-Q Diamond resin (Molecular Probes-Invitrogen). This resin quantitatively retains phosphoproteins and associated proteins from cell extracts. Pro-Q Diamond purification of a yeast whole cell extract followed by 1-D PAGE separation, proteolysis and ESI LC-MS/MS, a method we term PA-GeLC-MS/MS, yielded 108 proteins, a majority of which were known phosphoproteins. To identify proteins that were purified as parts of phosphoprotein complexes, the Pro-Q eluate was separated into two fractions by size, <100 kDa and >100 kDa, before analysis by PAGE and ESI LC-MS/MS and the component proteins queried against databases to identify protein-protein interactions. The <100 kDa fraction was enriched in phosphoproteins indicating the presence of monomeric phosphoproteins. The >100 kDa fraction contained 171 proteins of 20-80 kDa, nearly all of which participate in known protein-protein interactions. Of these 171, few are known phosphoproteins, consistent with their purification by participation in protein complexes. By

  12. Evaluating GC/MS Performance

    SciTech Connect

    Alcaraz, A; Dougan, A

    2006-11-26

    Evaluating the chemical background in the GC/MS system (system background) and solvent purity. This procedure will allow the analyst to verify that the GC/MS is free of chemical interferences or contamination and verify the solvent being utilized is free of interferences - Conduct a GC/MS analysis without injecting a solvent (system background) and Conduct a GC/MS analysis inject 1uL of CH2Cl2 solvent (Solvent background). GC conditions: (1) Injector Temperature (C): Injector Temperature is typically set at 250; (2) Transferline Temperature (C) - The Transferline Temperature is typically set at 280 C; (3) Constant flow (Sec./cm2) - This value, in seconds per cubic cm. Typically, set at 32; (4) Splitless mode (Sec.) - This value, in seconds, is the time before the purge valve opens. Typically, set at 45 seconds; (5) Starting Temperature (C): The Starting Temperature value can be set at 40 C; (6) Hold Time 1 (Min.) - Hold Time 1 is the amount of time, in minutes at the Starting Temperature that Ramp 1 Temperature is held. Typically set at 3 minutes; (7) Ramp 1 Rate (C/Min.) - Ramp 1 Rate is the temperature rise per unit time and has a typically value of 8 C per minute to 300 C; and (8) Hold Time 2 (Min.): Hold Time 2 is the amount of time, in minutes at the final Temperature that Ramp 1 Temperature is held. Temperature is held at 300 C for 3 minutes. MS conditions: Electronic - 40 to 500 amu, Scan Range - 30-600 m/z, Scan time - 0.7 sec, Mass Resolution - 07u, and Electron energy 1 - 70 eV. The total ion chromatograms (TIC) from a bakeout and solvent should be void of any large chromatographic peaks (see figure 1). Autotune using the PFTBA calibrant: First selecting the autotune option and click on standard autotune. The software program will generate final tune report similar to figure 2. If there are any MS tuning problems (e.g., dirty source, air leak, etc.) the tuning process will fail. Be sure to save the tune file before proceeding to the next step. Run an 'Air

  13. A composite cathode based on scandium doped titanate with enhanced electrocatalytic activity towards direct carbon dioxide electrolysis.

    PubMed

    Yang, Liming; Xie, Kui; Wu, Lan; Qin, Qingqing; Zhang, Jun; Zhang, Yong; Xie, Ting; Wu, Yucheng

    2014-10-21

    A composite cathode based on redox-stable La0.2Sr0.8TiO(3+δ) (LSTO) can perform direct carbon dioxide electrolysis; however, the insufficient electro-catalytic activity limits the electrode performances and current efficiencies. In this work, catalytically active scandium is doped into LSTO to enhance the electro-catalytic activity for CO2 electrolysis. The structures, electronic conductivities and ionic conductivities of La0.2Sr0.8Ti(1-x)Sc(x)O (LSTS(x)O) (x = 0, 0.05, 0.1, 0.15 and 0.2) are systematically studied and further correlated with electrode performances. The ionic conductivities of single-phase LSTS(x)O (x = 0, 0.05, 0.1 and 0.15) remarkably improve versus the scandium doping contents though the electrical conductivities gradually change in an adverse trend. Electrochemical measurements demonstrate promising electrode polarisation of LSTS(x)O electrodes and increasing scandium doping contents accordingly improve electrode performances. The Faradic efficiencies of carbon dioxide electrolysis are enhanced by 20% with LSTS0.15O in contrast to bare LSTO electrodes in a solid oxide electrolyser at 800 °C.

  14. Performance evaluation of a bipolar electrolysis/electrocoagulation (EL/EC) reactor to enhance the sludge dewaterability.

    PubMed

    Gharibi, Hamed; Sowlat, Mohammad Hossein; Mahvi, Amir Hossein; Keshavarz, Morteza; Safari, Mohammad Hossein; Lotfi, Saeedeh; Bahram Abadi, Mahnaz; Alijanzadeh, Azim

    2013-01-01

    The present study aimed to evaluate the performance of a bipolar electrolysis/electrocoagulation reactor designed to enhance the sludge dewaterability. The reactor was 15 L in volume, with two series of plates used in it; Ti/RuO(2) plates for the electrolysis of the sludge, and also aluminum and iron plates for electrocoagulation process. The dewaterability of the sludge was determined in terms of its capillary suction time (CST) and specific resistance to filtration (SRF), while the degree of sludge disintegration was determined based on the value of degree of sludge disintegration (DD(SCOD)). The maximum reduction in CST and SRF was observed at a detention time of 20 min and a voltage of 30 V. However, increasing of both detention time and voltage significantly increased the values of CST and SRF even to an extent that they both exceeded those of the untreated sludge. The optimal degree of sludge disintegration achieved by the present study was 2.5%, which was also achieved at a detention time of 20 min and a voltage of 30V. As reported previously, increased DD(SCOD) values led to increasing CST and SRF values, due primarily to the disruption of the sludge flocs. According to the results from the present study, it can be concluded that simultaneous application of electrocoagulation and electrolysis is effective in enhancing the sludge dewaterability, because electrocoagulation helps to achieve a higher degree of sludge disintegration while maintaining the desired sludge dewaterability.

  15. Prediction of Low-Voltage Tetrafluoromethane Emissions Based on the Operating Conditions of an Aluminium Electrolysis Cell

    NASA Astrophysics Data System (ADS)

    Dion, Lukas; Kiss, László I.; Poncsák, Sándor; Lagacé, Charles-Luc

    2016-08-01

    Greenhouse gas (GHG) generation is inherent in the production of aluminium by a technology that uses carbon anodes. Most of those GHG are composed of CO2 produced by redox reaction that occurs in the cell. However, a significant fraction of the annual GHG production is composed of perfluorocarbons (PFC) resulting from anode effects (AE). Multiple investigations have shown that tetrafluoromethane (CF4) can be generated under low-voltage conditions in the electrolysis cells, without global anode effect. The aim of this paper is to find a quantitative relationship between monitored cell parameters and the emissions of CF4. To achieve this goal, a predictive algorithm has been developed using seven cell indicators. These indicators are based on the cell voltage, the noise level and other parameters calculated from individual anode current monitoring. The predictive algorithm is structured into three different steps. The first two steps give qualitative information while the third one quantitatively describes the expected CF4 concentration at the duct end of the electrolysis cells. Validations after each step are presented and discussed. Finally, a sensitivity analysis was performed to understand the effect of each indicator on the onset of low-voltage PFC emissions. The standard deviation of individual anode currents was found to be the dominant variable. Cell voltage, noise level, and maximum individual anode current also showed a significant correlation with the presence of CF4 in the output gas of an electrolysis cell.

  16. Multi-Physics Modeling of Molten Salt Transport in Solid Oxide Membrane (SOM) Electrolysis and Recycling of Magnesium

    SciTech Connect

    Powell, Adam; Pati, Soobhankar

    2012-03-11

    Solid Oxide Membrane (SOM) Electrolysis is a new energy-efficient zero-emissions process for producing high-purity magnesium and high-purity oxygen directly from industrial-grade MgO. SOM Recycling combines SOM electrolysis with electrorefining, continuously and efficiently producing high-purity magnesium from low-purity partially oxidized scrap. In both processes, electrolysis and/or electrorefining take place in the crucible, where raw material is continuously fed into the molten salt electrolyte, producing magnesium vapor at the cathode and oxygen at the inert anode inside the SOM. This paper describes a three-dimensional multi-physics finite-element model of ionic current, fluid flow driven by argon bubbling and thermal buoyancy, and heat and mass transport in the crucible. The model predicts the effects of stirring on the anode boundary layer and its time scale of formation, and the effect of natural convection at the outer wall. MOxST has developed this model as a tool for scale-up design of these closely-related processes.

  17. Development of the microbial electrolysis desalination and chemical-production cell for desalination as well as acid and alkali productions.

    PubMed

    Chen, Shanshan; Liu, Guangli; Zhang, Renduo; Qin, Bangyu; Luo, Yong

    2012-02-21

    By combining the microbial electrolysis cell and the microbial desalination cell, the microbial electrolysis desalination cell (MEDC) becomes a novel device to desalinate salty water. However, several factors, such as sharp pH decrease and Cl(-) accumulation in the anode chamber, limit the MEDC development. In this study, a microbial electrolysis desalination and chemical-production cell (MEDCC) was developed with four chambers using a bipolar membrane. Results showed that the pH in the anode chamber of the MEDCC always remained near 7.0, which greatly enhanced the microbial activities in the cell. With applied voltages of 0.3-1.0 V, 62%-97% of Coulombic efficiencies were achieved from the MEDCC, which were 1.5-2.0 times of those from the MEDC. With 10 mL of 10 g/L NaCl in the desalination chamber, desalination rates of the MEDCC reached 46%-86% within 18 h. Another unique feature of the MEDCC was the simultaneous production of HCl and NaOH in the cell. With 1.0 V applied voltage, the pH values at 18 h in the acid-production chamber and cathode chamber were 0.68 and 12.9, respectively. With the MEDCC, the problem with large pH changes in the anode chamber was resolved, and products of the acid and alkali were obtained.

  18. Prediction of Low-Voltage Tetrafluoromethane Emissions Based on the Operating Conditions of an Aluminium Electrolysis Cell

    NASA Astrophysics Data System (ADS)

    Dion, Lukas; Kiss, László I.; Poncsák, Sándor; Lagacé, Charles-Luc

    2016-09-01

    Greenhouse gas (GHG) generation is inherent in the production of aluminium by a technology that uses carbon anodes. Most of those GHG are composed of CO2 produced by redox reaction that occurs in the cell. However, a significant fraction of the annual GHG production is composed of perfluorocarbons (PFC) resulting from anode effects (AE). Multiple investigations have shown that tetrafluoromethane (CF4) can be generated under low-voltage conditions in the electrolysis cells, without global anode effect. The aim of this paper is to find a quantitative relationship between monitored cell parameters and the emissions of CF4. To achieve this goal, a predictive algorithm has been developed using seven cell indicators. These indicators are based on the cell voltage, the noise level and other parameters calculated from individual anode current monitoring. The predictive algorithm is structured into three different steps. The first two steps give qualitative information while the third one quantitatively describes the expected CF4 concentration at the duct end of the electrolysis cells. Validations after each step are presented and discussed. Finally, a sensitivity analysis was performed to understand the effect of each indicator on the onset of low-voltage PFC emissions. The standard deviation of individual anode currents was found to be the dominant variable. Cell voltage, noise level, and maximum individual anode current also showed a significant correlation with the presence of CF4 in the output gas of an electrolysis cell.

  19. Oxygen evolution reaction characteristics of synthetic nickel-cobalt-oxide electrodes for alkaline anion-exchange membrane water electrolysis

    NASA Astrophysics Data System (ADS)

    Koo, Tae Woo; Park, ChanSu; Kim, Yang Do; Lee, Dooyong; Park, Sungkyun; Lee, Jae Ho; Choi, Sung Mook; Choi, Chul Young

    2015-11-01

    A polymer electrolyte membrane water electrolysis system can produce high-purity hydrogen gases in a highly efficient manner. However, the level of hydrogen gas production is still small. In addition, noble-metal catalysts for the reaction in acidic environments, as well as an additional drying step to remove water contained in the hydrogen, are required. Therefore, water electrolysis system with high efficiency and lower cost, an alkaline anion-exchange membrane system that can produce high-purity hydrogen without a noble-metal catalyst, is needed. Nano-size NiCo2O4 powders were prepared by using a sol-gel method to achieve an efficient and economical water electrolysis system. When the powder was calcined at 450 °C, the crystallinity and the cyclic voltammogram measurement showed the best values. In addition, the 15-wt.% polytetrafluoroethylene mixed NiCo2O4 powders exhibited the largest cyclic voltammetry active area and the highest oxygen evolution reaction activity with the appropriate stability.

  20. Mechanism of enhanced nitrate reduction via micro-electrolysis at the powdered zero-valent iron/activated carbon interface.

    PubMed

    Luo, Jinghuan; Song, Guangyu; Liu, Jianyong; Qian, Guangren; Xu, Zhi Ping

    2014-12-01

    Nitrate reduction by zero-valent iron (Fe(0)) powder always works well only at controlled pH lower than 4 due to the formation of iron (hydr)oxides on its surface. Fe(0) powder combined with activated carbon (AC), i.e., Fe(0)/AC micro-electrolysis system, was first introduced to enhance nitrate reduction in aqueous solution. Comparative study was carried out to investigate nitrate reduction by Fe(0)/AC system and Fe(0) under near-neutral conditions, showing that the Fe(0)/AC system successfully reduced nitrate even at initial pH 6 with the reduction efficiency of up to 73%, whereas for Fe(0) only ∼10%. The effect of Fe(0) to AC mass ratio on nitrate reduction efficiency was examined. Easier nitrate reduction was achieved with more contact between Fe(0) and AC as the result of decreasing Fe(0) to AC mass ratio. Ferrous ion and oxidation-reduction potential were measured to understand the mechanism of enhanced nitrate reduction by Fe(0)/AC micro-electrolysis. The results suggest that a relative potential difference drives much more electrons from Fe(0) to AC, thus generating adsorbed atomic hydrogen which makes it possible for nitrate to be reduced at near-neural pH. Fe(0)/AC micro-electrolysis thus presents a great potential for practical application in nitrate wastewater treatment without excessive pH adjustment. PMID:25217726

  1. High performance robust F-doped tin oxide based oxygen evolution electro-catalysts for PEM based water electrolysis

    SciTech Connect

    Datta, Moni Kanchan; Kadakia, Karan; Velikokhatnyi, Oleg I; Jampani, Prashanth H; Chung, Sung Jae; Poston, James A; Manivannan, Ayyakkannu; Kumta, Prashant N

    2013-01-01

    Identification and development of non-noble metal based electro-catalysts or electro-catalysts comprising compositions with significantly reduced amounts of expensive noble metal contents (e.g. IrO{sub 2}, Pt) with comparable electrochemical performance to the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would signify a major breakthrough in hydrogen generation via water electrolysis. Development of such systems would lead to two primary outcomes: first, a reduction in the overall capital costs of PEM based water electrolyzers, and second, attainment of the targeted hydrogen production costs (<$3.00/gge delivered by 2015) comparable to conventional liquid fuels. In line with these goals, by exploiting a two-pronged theoretical first principles and experimental approach herein, we demonstrate for the very first time a solid solution of SnO{sub 2}:10 wt% F containing only 20 at.% IrO{sub 2} [e.g. (Sn{sub 0.80}Ir{sub 0.20})O{sub 2}:10F] displaying remarkably similar electrochemical activity and comparable or even much improved electrochemical durability compared to pure IrO{sub 2}, the accepted gold standard in oxygen evolution electro-catalysts for PEM based water electrolysis. We present the results of these studies.

  2. LONG-TERM PERFORMANCE OF SOLID OXIDE STACKS WITH ELECTRODE-SUPPORTED CELLS OPERATING IN THE STEAM ELECTROLYSIS MODE

    SciTech Connect

    J. E. O'Brien; R. C. O'Brien; X. Zhang; G. Tao; B. J. Butler

    2011-11-01

    Performance characterization and durability testing have been completed on two five-cell high-temperature electrolysis stacks constructed with advanced cell and stack technologies. The solid oxide cells incorporate a negative-electrode-supported multi-layer design with nickel-zirconia cermet negative electrodes, thin-film yttria-stabilized zirconia electrolytes, and multi-layer lanthanum ferrite-based positive electrodes. The per-cell active area is 100 cm2. The stack is internally manifolded with compliant mica-glass seals. Treated metallic interconnects with integral flow channels separate the cells. Stack compression is accomplished by means of a custom spring-loaded test fixture. Initial stack performance characterization was determined through a series of DC potential sweeps in both fuel cell and electrolysis modes of operation. Results of these sweeps indicated very good initial performance, with area-specific resistance values less than 0.5 ?.cm2. Long-term durability testing was performed with A test duration of 1000 hours. Overall performance degradation was less than 10% over the 1000-hour period. Final stack performance characterization was again determined by a series of DC potential sweeps at the same flow conditions as the initial sweeps in both electrolysis and fuel cell modes of operation. A final sweep in the fuel cell mode indicated a power density of 0.356 W/cm2, with average per-cell voltage of 0.71 V at a current of 50 A.

  3. Supergiant pulses from extragalactic neutron stars

    NASA Astrophysics Data System (ADS)

    Cordes, J. M.; Wasserman, Ira

    2016-03-01

    We consider radio bursts that originate from extragalactic neutron stars (NSs) by addressing three questions about source distances. What are the physical limitations on coherent radiation at GHz frequencies? Do they permit detection at cosmological distances? How many bursts per NS are needed to produce the inferred burst rate ˜103-104sky-1 d-1? The burst rate is comparable to the NS formation rate in a Hubble volume, requiring only one per NS if they are bright enough. Radiation physics suggests a closer population, requiring more bursts per NS and increasing the chances for repeats. Bursts comprise sub-ns, coherent shot pulses superposed incoherently to produce ms-duration ˜1 Jy amplitudes; each shot pulse can be much weaker than 1 Jy, placing less restrictive requirements on the emission process. None the less, single shot pulses are similar to the extreme, unresolved (<0.4 ns) MJy shot pulse seen from the Crab pulsar, consistent with coherent curvature radiation emitted near the light cylinder by an almost neutral clump with net charge ˜± 1021e and total energy ≳ 1023 erg. Bursts from Gpc distances require incoherent superposition of {˜ } 10^{12}d_Gpc^2 shot pulses or a total energy ≳ 10^{35} d_Gpc^2 erg. The energy reservoir near the light cylinder limits the detection distance to ≲ few × 100 Mpc for a fluence ˜1 Jy ms unless conditions are more extreme than for the Crab pulsar, such as in magnetars. We discuss contributions to dispersion measures from galaxy clusters and we propose tests for the overall picture presented.

  4. ANALYSIS OF A HIGH TEMPERATURE GAS-COOLED REACTOR POWERED HIGH TEMPERATURE ELECTROLYSIS HYDROGEN PLANT

    SciTech Connect

    M. G. McKellar; E. A. Harvego; A. M. Gandrik

    2010-11-01

    An updated reference design for a commercial-scale high-temperature electrolysis (HTE) plant for hydrogen production has been developed. The HTE plant is powered by a high-temperature gas-cooled reactor (HTGR) whose configuration and operating conditions are based on the latest design parameters planned for the Next Generation Nuclear Plant (NGNP). The current HTGR reference design specifies a reactor power of 600 MWt, with a primary system pressure of 7.0 MPa, and reactor inlet and outlet fluid temperatures of 322°C and 750°C, respectively. The reactor heat is used to produce heat and electric power to the HTE plant. A Rankine steam cycle with a power conversion efficiency of 44.4% was used to provide the electric power. The electrolysis unit used to produce hydrogen includes 1.1 million cells with a per-cell active area of 225 cm2. The reference hydrogen production plant operates at a system pressure of 5.0 MPa, and utilizes a steam-sweep system to remove the excess oxygen that is evolved on the anode (oxygen) side of the electrolyzer. The overall system thermal-to-hydrogen production efficiency (based on the higher heating value of the produced hydrogen) is 42.8% at a hydrogen production rate of 1.85 kg/s (66 million SCFD) and an oxygen production rate of 14.6 kg/s (33 million SCFD). An economic analysis of this plant was performed with realistic financial and cost estimating The results of the economic analysis demonstrated that the HTE hydrogen production plant driven by a high-temperature helium-cooled nuclear power plant can deliver hydrogen at a competitive cost. A cost of $3.03/kg of hydrogen was calculated assuming an internal rate of return of 10% and a debt to equity ratio of 80%/20% for a reactor cost of $2000/kWt and $2.41/kg of hydrogen for a reactor cost of $1400/kWt.

  5. Critical Causes of Degradation in Integrated Laboratory Scale Cells during High Temperature Electrolysis

    SciTech Connect

    M.S. Sohal; J.E. O'Brien; C.M. Stoots; J. J. Hartvigsen; D. Larsen; S. Elangovan; J.S. Herring; J.D. Carter; V.I. Sharma; B. Yildiz

    2009-05-01

    An ongoing project at Idaho National Laboratory involves generating hydrogen from steam using solid oxide electrolysis cells (SOEC). This report describes background information about SOECs, the Integrated Laboratory Scale (ILS) testing of solid-oxide electrolysis stacks, ILS performance degradation, and post-test examination of SOECs by various researchers. The ILS test was a 720- cell, three-module test comprised of 12 stacks of 60 cells each. A peak H2 production rate of 5.7 Nm3/hr was achieved. Initially, the module area-specific resistance ranged from 1.25 Ocm2 to just over 2 Ocm2. Total H2 production rate decreased from 5.7 Nm3/hr to a steady state value of 0.7 Nm3/hr. The decrease was primarily due to cell degradation. Post test examination by Ceramatec showed that the hydrogen electrode appeared to be in good condition. The oxygen evolution electrode does show delamination in operation and an apparent foreign layer deposited at the electrolyte interface. Post test examination by Argonne National Laboratory showed that the O2-electrode delaminated from the electrolyte near the edge. One possible reason for this delamination is excessive pressure buildup with high O2 flow in the over-sintered region. According to post test examination at the Massachusetts Institute of Technology, the electrochemical reactions have been recognized as one of the prevalent causes of their degradation. Specifically, two important degradation mechanisms were examined: (1) transport of Crcontaining species from steel interconnects into the oxygen electrode and LSC bond layers in SOECs, and (2) cation segregation and phase separation in the bond layer. INL conducted a workshop October 27, 2008 to discuss possible causes of degradation in a SOEC stack. Generally, it was agreed that the following are major degradation issues relating to SOECs: • Delamination of the O2-electrode and bond layer on the steam/O2-electrode side • Contaminants (Ni, Cr, Si, etc.) on reaction sites

  6. PULSE RATE DIVIDER

    DOEpatents

    McDonald, H.C. Jr.

    1962-12-18

    A compact pulse-rate divider circuit affording low impedance output and high input pulse repetition rates is described. The circuit features a single secondary emission tube having a capacitor interposed between its dynode and its control grid. An output pulse is produced at the anode of the tube each time an incoming pulse at the control grid drives the tube above cutoff and the duration of each output pulse corresponds to the charging time of the capacitor. Pulses incoming during the time the grid bias established by the discharging capacitor is sufficiently negative that the pulses are unable to drive the tube above cutoff do not produce output pulses at the anode; these pulses are lost and a dividing action is thus produced by the circuit. The time constant of the discharge path may be vanied to vary in turn the division ratio of the circuit; the time constant of the charging circuit may be varied to vary the width of the output pulses. (AEC)

  7. PULSE HEIGHT ANALYZER

    DOEpatents

    Goldsworthy, W.W.

    1958-06-01

    A differential pulse-height discriminator circuit is described which is readily adaptable for operation in a single-channel pulse-height analyzer. The novel aspect of the circuit lies in the specific arrangement of differential pulse-height discriminator which includes two pulse-height discriminators having a comnnon input and an anticoincidence circuit having two interconnected vacuum tubes with a common cathode resistor. Pulses from the output of one discriminator circuit are delayed and coupled to the grid of one of the anticoincidence tubes by a resistor. The output pulses from the other discriminator circuit are coupled through a cathode follower circuit, which has a cathode resistor of such value as to provide a long time constant with the interelectrode capacitance of the tube, to lenthen the output pulses. The pulses are then fed to the grid of the other anticoincidence tube. With such connections of the circuits, only when the incoming pulse has a pesk value between the operating levels of the two discriminators does an output pulse occur from the anticoincidence circuit.

  8. Alternative pulse shapes in electrical hearing.

    PubMed

    van Wieringen, Astrid; Macherey, Olivier; Carlyon, Robert P; Deeks, John M; Wouters, Jan

    2008-08-01

    Cochlear implants (CIs) stimulate the auditory nerve with trains of symmetric biphasic (BI) pulses. We review studies showing that more efficient stimulation can be achieved by modifying these pulses by (1) increasing the inter-phase gap (IPG) between the two phases of each pulse, thereby delaying the recovery of charge, (2) increasing the duration and decreasing the amplitude of one phase - so-called "pseudomonophasic (PS)" waveforms, and (3) combining the pseudomonophasic stimulus with an IPG in a "delayed pseudomonophasic" waveform (PS_IPG). These efficiency gains, measured using changes in threshold and loudness, occur at a wide range of pulse rates, including those commonly used in current CI systems. In monopolar mode, dynamic ranges are larger for PS and for long-IPG pulse shapes than for BI pulses, but this increase in DR is not accompanied by a higher number of discriminable loudness steps, and hence, in a better coding of loudness. Moreover, waveforms with relatively short and long interphase gaps do not yield different patterns of excitation despite the relatively large differences in threshold. Two important findings are that, contrary to data obtained in animal experiments, anodic currents are more effective than cathodic stimulation for human CI patients and that the thresholds decrease with increases in IPG over a much longer time course (more than 3 ms) than for animals. In this review it is discussed how these alternative pulse shapes may be beneficial in terms of reducing power consumption and channel interactions, which issues remain to be addressed, and how models contribute to guiding our research.

  9. Do All Lightning Flashes Have Initial Breakdown Pulses?

    NASA Astrophysics Data System (ADS)

    Marshall, Thomas; Stolzenburg, Maribeth; Karunarathne, Sumedhe; Karunarathna, Nadeeka

    2013-04-01

    The initial breakdown (IB) stage of lightning flashes typically occurs in the first 5-15 ms of a flash. The IB stage is characterized in electric field change (E-change) records by a sequence of pulses (called "classic" IB pulses), each with relatively large amplitude and duration of tens of microseconds. Nag and Rakov [JGR, 2008] investigated the IB stage of cloud to ground (CG) lightning flashes in Florida thunderstorms and found that only 18% of CG flashes had classic IB pulses. Nag and Rakov [GRL, 2009] hypothesized that CG flashes without classic IB pulses initiated in thunderstorms with a weak or non-existent lower positive cloud charge. In this presentation we show the results of studying E-change data of 127 negative CG flashes and 90 intracloud (IC) flashes recorded at the Kennedy Space Center in Florida in the summers of 2010 and 2011. In 2011 we deployed 10 E-change sensors spread across an area of 70 km x 100 km; in 2010 5 E-change sensors were deployed over a smaller area. The bandwidth of the E-change sensors was 0.16 Hz - 2.6 MHz; the data were digitized at 12 bits with a sampling rate of 1, 5, or 10 MHz and a typical record length of 500 ms, including 150 ms of pre-trigger data. The analysis focuses on flashes that occurred within 30 km of at least one sensor. We find that all 127 CG flashes and all 90 IC flashes began with classic IB pulses, though the amplitude of these pulses varies significantly from flash to flash. For flashes with weak IB pulses, the more distant sensors did not always detect the IB pulses seen by closer sensors.

  10. Determination of drugs in hair using GC/MS/MS.

    PubMed

    Uhl, M

    1997-01-17

    An important task for the forensic toxicologist and expert witness is the detection of the noxa in biological matrices. Because of this, the identification and quantification of residues of illegal drugs in human hair is still of growing interest. Utilizing the advantages of GC/MS/MS testing human hair is performed for most common drugs of abuse like heroin and other opioides, cocaine, cannabis and amphetamine derivatives. Analyzing hair specimens for substances that present a toxicological risk is another challenge. Several quality control parameters must be observed to avoid false positive or false negative results and to gain additional information. Blank sample, blank hair as well as the combined wash extracts are tested for the presence of the relevant compounds within every series. Careful evaluation of the findings can provide an approximate measure of the intensity of drug use in the majority of cases.

  11. Therapeutic drug monitoring of tamoxifen using LC-MS/MS.

    PubMed

    Tchu, Simone M; Lynch, Kara L; Wu, Alan H B

    2012-01-01

    Tamoxifen is a selective estrogen receptor modulator (SERM) that is used widely in the treatment of estrogen receptor positive breast cancer (ER+). Therapeutic monitoring of tamoxifen, and its metabolites N-desmethyltamoxifen (NDTam) and 4-hydroxy-N-desmethyltamoxifen (endoxifen), may be clinically useful for guiding treatment decisions. Two significant barriers to tamoxifen efficacy are: (1) variability in conversion of tamoxifen into the potent antiestrogenic metabolite, endoxifen, and (2) poor compliance and adherence to tamoxifen therapy. Therapeutic monitoring can be used to address both of these issues. Low levels of endoxifen indicate either poor compliance or poor metabolism of tamoxifen. Low tamoxifen levels would suggest poor compliance while a low ratio of endoxifen to NDTam would be indicative of poor metabolism. Solid phase extraction of patient serum followed by liquid chromatography tandem mass spectrometry (LC-MS/MS) detection enables rapid, accurate, detection of tamoxifen, N-desmethyltamoxifen, and endoxifen. PMID:22767121

  12. Development of Electrolysis System Powered by Solar-Cell Array to Supply Hydrogen Gas for Fuel-Cell Energy Resource Systems

    NASA Astrophysics Data System (ADS)

    Priambodo, Purnomo Sidi; Yusivar, Feri; Subiantoro, Aries; Gunawan, Ridwan

    2009-09-01

    The huge demand of energy worldwide and the depletion of fossil based energy, is a strong reason to rapidly develop any kind of renewable energy resources, which has economical advantages and zero pollution effect. One of the renewable energy technologies aimed in this paper is the generation of electric-energy based on fuel-cell technology, where the input hydrogen (H2) gas is supplied by electrolysis system powered by renewable energy system based on solar cell. In this paper, the authors explain the development of electrolysis system which is powered by solar cell array to supply hydrogen for fuel-cell system. The authors explain in detail how to design an efficient electrolysis system to obtain high ratio conversion of electric energy to hydrogen gas volume. It includes the explanation of the usage of multiple anodes with a single cathode for many solar cell inputs in a single electrolysis system. Hereinafter this is referred as multiple anode electrolysis system. This multiple anode electrolysis system makes the management of hydrogen gas becomes more efficient and effective by using only a single hydrogen gas storage system. This paper also explain the careful design of the resistance value of the electrolysis system to protect or avoid the solar cell panel to deliver excessive current to the electrolysis system which can cause damage on the solar cell panel. Moreover, the electrolyte volume detector is applied on the system as a tool to measure the electrolyte concentration to assure the system resistance is still in the allowed range. Further, the hydrogen gas produced by electrolysis system is stored into the gas storage which consists of silica-gel purifier, first stage low pressure gas bottle, vacuum pump, and second stage high pressure gas bottle. In the first step, the pump will vacuum the first bottle. The first bottle will collect the hydrogen from the electrolysis system through the silica gel to get rid of water vapor. When the first bottle

  13. Quantitative acylcarnitine determination by UHPLC-MS/MS--Going beyond tandem MS acylcarnitine "profiles".

    PubMed

    Minkler, Paul E; Stoll, Maria S K; Ingalls, Stephen T; Kerner, Janos; Hoppel, Charles L

    2015-12-01

    Tandem MS "profiling" of acylcarnitines and amino acids was conceived as a first-tier screening method, and its application to expanded newborn screening has been enormously successful. However, unlike amino acid screening (which uses amino acid analysis as its second-tier validation of screening results), acylcarnitine "profiling" also assumed the role of second-tier validation, due to the lack of a generally accepted second-tier acylcarnitine determination method. In this report, we present results from the application of our validated UHPLC-MS/MS second-tier method for the quantification of total carnitine, free carnitine, butyrobetaine, and acylcarnitines to patient samples with known diagnoses: malonic acidemia, short-chain acyl-CoA dehydrogenase deficiency (SCADD) or isobutyryl-CoA dehydrogenase deficiency (IBD), 3-methyl-crotonyl carboxylase deficiency (3-MCC) or ß-ketothiolase deficiency (BKT), and methylmalonic acidemia (MMA). We demonstrate the assay's ability to separate constitutional isomers and diastereomeric acylcarnitines and generate values with a high level of accuracy and precision. These capabilities are unavailable when using tandem MS "profiles". We also show examples of research interest, where separation of acylcarnitine species and accurate and precise acylcarnitine quantification is necessary.

  14. Pulsed-field magnetometry for rock magnetism

    NASA Astrophysics Data System (ADS)

    Kodama, Kazuto

    2015-07-01

    An improved method is proposed for measuring dynamic magnetizations of bulk volcanic rock samples induced by a pulsed-field of 0.7 T and a duration of 10 ms. The transient magnetization is measured by a sensing system that consists of a pair of inductive differential coils, an analog preamplifier and integrator, and a high-speed digital storage scope. The system was calibrated using a paramagnetic salt (Gd2O3) and was tested to different kinds of volcanic rocks with their magnetic properties well-documented previously. The results were comparable with those measured by a quasi-static method using a vibrating sample magnetometer, although there were small discrepancies in hysteresis parameters suggesting the time-dependence of the magnetic properties. The proposed system provides not only the magnetization over the short interval of a pulse but also the rapid (~3 ms) exponential decay after a pulse. The decay time constant was different among the samples under study, indicating the variations of their magnetic relaxation time. Although the present system is not sensitive enough to characterize varieties of natural samples including sediments, it has the potential as a versatile and convenient tool for rock magnetism.

  15. PULSE AMPLITUDE ANALYZER

    DOEpatents

    Greenblatt, M.H.

    1958-03-25

    This patent pertains to pulse amplitude analyzers for sorting and counting a serles of pulses, and specifically discloses an analyzer which ls simple in construction and presents the puise height distribution visually on an oscilloscope screen. According to the invention, the pulses are applied to the vertical deflection plates of an oscilloscope and trigger the horizontal sweep. Each pulse starts at the same point on the screen and has a maximum amplitude substantially along the same vertical line. A mask is placed over the screen except for a slot running along the line where the maximum amplitudes of the pulses appear. After the slot has been scanned by a photocell in combination with a slotted rotating disk, the photocell signal is displayed on an auxiliary oscilloscope as vertical deflection along a horizontal time base to portray the pulse amplitude distribution.

  16. PULSE AMPLITUDE ANALYSERS

    DOEpatents

    Lewis, I.A.D.

    1956-05-15

    This patent pentains to an electrical pulse amplitude analyzer, capable of accepting input pulses having a separation between adjacent pulses in the order of one microsecond while providing a large number of channels of classification. In its broad aspect the described pulse amplitude analyzer utilizes a storage cathode ray tube und control circuitry whereby the amplitude of the analyzed pulses controls both the intensity and vertical defiection of the beam to charge particular spots in horizontal sectors of the tube face as the beam is moved horizontally across the tube face. As soon as the beam has swept the length of the tube the information stored therein is read out by scanning individually each horizontal sector corresponding to a certain range of pulse amplitudes and applying the output signal from each scan to separate indicating means.

  17. Depth profile characterization of Zn-TiO2 nanocomposite films by pulsed radiofrequency glow discharge-optical emission spectrometry.

    PubMed

    Alberts, Deborah; Fernández, Beatriz; Frade, Tania; Gomes, Anabela; Pereira, Maria Isabel da Silva; Pereiro, Rosario; Sanz-Medel, Alfredo

    2011-04-15

    In recent years particular effort is being devoted towards the development of radiofrequency (rf) pulsed glow discharges (GDs) coupled to optical emission spectrometry (OES) for depth profile analysis of materials with technological interest. In this work, pulsed rf-GD-OES is investigated for the fast and sensitive depth characterization of Zn-TiO(2) nanocomposite films deposited on conductive substrates (Ti and steel). The first part of this work focuses on assessing the advantages of pulsed GDs, in comparison with the continuous GD, in terms of analytical emission intensities and emission yields. Next, the capability of pulsed rf-GD-OES for determination of thickness and compositional depth profiles is demonstrated by resorting to a simple multi-matrix calibration procedure. A rf forward power of 75 W, a pressure of 600 Pa, 10 kHz pulse frequency and 50% duty cycle were selected as GD operation parameters.Quantitative depth profiles obtained with the GD proposed methodology for Zn-TiO(2) nanocomposite films, prepared by the occlusion electrodeposition method using pulsed reverse current electrolysis, have proved to be in good agreement with results achieved by complementary techniques, including scanning electron microscopy and inductively coupled plasma-mass spectrometry. The work carried out demonstrates that pulsed rf-GD-OES is a promising tool for the fast analytical characterization of nanocomposite films. PMID:21376989

  18. SISGR-Fundamental Experimental and Theoretical Studies on a Novel Family of Oxide Catalyst Supports for Water Electrolysis

    SciTech Connect

    Kumta, Prashant

    2014-10-03

    Identification and development of non-noble metal based electro-catalysts or electro-catalysts with significant reduction of expensive noble metal contents (E.g. IrO2, Pt) with comparable electrochemical performance as the standard noble metal/metal oxide for proton exchange membrane (PEM) based water electrolysis would constitute a major breakthrough in the generation of hydrogen by water electrolysis. Accomplishing such a system would not only result reduction of the overall capital costs of PEM based water electrolyzers, but also help attain the targeted hydrogen production cost [< $ 3.0 / gallon gasoline equivalent (gge)] comparable to conventional liquid fuels. In line with these goals, it was demonstrated that fluorine doped IrO2 thin films and nanostructured high surface area powders display remarkably higher electrochemical activity, and comparable durability as pure IrO2 electro-catalyst for the oxygen evolution reaction (OER) in PEM based water electrolysis. Furthermore, corrosion resistant SnO2 and NbO2 support has been doped with F and coupled with IrO2 or RuO2 for use as an OER electro-catalyst. A solid solution of SnO2:F or NbO2:F with only 20 - 30 mol.% IrO2 or RuO2 yielding a rutile structure in the form of thin films and bulk nanoparticles displays similar electrochemical activity and stability as pure IrO2/RuO2. This would lead to more than 70 mol.% reduction in the noble metal oxide content. Novel nanostructured ternary (Ir,Sn,Nb)O2 thin films of different compositions FUNDAMENTAL STUDY OF NANOSTRUCTURED ELECTRO-CATALYSTS WITH REDUCED NOBLE METAL CONTENT FOR PEM BASED WATER ELECTROLYSIS 4 have also been studied. It has been shown that (Ir0.40Sn0.30Nb0.30)O2 shows similar electrochemical activity and enhanced chemical robustness as compared to pure IrO2. F doping of the ternary (Ir,Sn,Nb)O2 catalyst helps in further decreasing the noble metal oxide content of the catalyst. As a result, these reduced noble metal oxide catalyst systems would

  19. PulseSoar

    SciTech Connect

    Carter, P.; Peglow, S.

    1992-07-21

    This paper is an introduction to the PulseSoar concept. PulseSoar is a hypervelocity airplane that uses existing airport facilities and current technologies to fly at the very edge of space. It will be shown that PulseSoar can fly between any two points on the globe in less than two hours with fuel efficiency exceeding current state of the art commercial airliners. In addition, it will be shown that PulseSoar avoids environmental issues concerning the ozone layer and sonic booms because of its unique flight profile. All of this can be achieved with current technology. PulseSoar does not require the development of enabling technology. It is a concept which can be demonstrated today. The importance of this idea goes beyond the technical significance`s of PulseSoar in terms of feasibility and performance. PulseSoar could provide a crucial economic advantage to America`s largest export market: commercial aircraft. PulseSoar is a breakthrough concept for addressing the emerging markets of long range and high speed aircraft. Application of PulseSoar to commercial transport could provide the US Aerospace industry a substantial lead in offering high speed/long range aircraft to the world`s airlines. The rapid emergence of a US developed high speed aircraft could also be important to our competitiveness in the Pacific Rim and South American economies. A quick and inexpensive demonstration vehicle is proposed to bang the concept to reality within two years. This discussion will address all the major technical subjects encompassed by PulseSoar and identifies several near-term, and low risk, applications which may be further explored with the initial demonstration vehicle. What is PulseSoar? PulseSoar could enable high speed, high altitude and long range flight without many of the difficulties encountered by traditional hypersonic vehicles.

  20. PULSED INDICATOR CIRCUIT

    DOEpatents

    Linlor, W.I.; Kerns, Q.A.

    1960-11-15

    A system is given for detecting incremental changes in a transducer impedance terminating a transmission line. Principal novelty resides in the transducer impedance terminating the line in a mismatch and a pulse generator being provided to apply discrete pulses to the input end of the line. The amplitudes of the pulses reflected to the input end of the line from the mismatched transducer impedance are then observed as a very accurate measure of the instantaneous value of the latter.

  1. High voltage pulse conditioning

    DOEpatents

    Springfield, Ray M.; Wheat, Jr., Robert M.

    1990-01-01

    Apparatus for conditioning high voltage pulses from particle accelerators in order to shorten the rise times of the pulses. Flashover switches in the cathode stalk of the transmission line hold off conduction for a determinable period of time, reflecting the early portion of the pulses. Diodes upstream of the switches divert energy into the magnetic and electrostatic storage of the capacitance and inductance inherent to the transmission line until the switches close.

  2. 12 CFR Appendix Ms-1 to Part 1024 - Appendix MS-1 to Part 1024

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 8 2014-01-01 2014-01-01 false Appendix MS-1 to Part 1024 MS Appendix MS-1 to Part 1024 Banks and Banking BUREAU OF CONSUMER FINANCIAL PROTECTION REAL ESTATE SETTLEMENT PROCEDURES ACT (REGULATION X) Pt. 1024, App. MS-1 Appendix MS-1 to Part 1024 SERVICING DISCLOSURE...

  3. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  4. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  5. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  6. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 5 2013-04-01 2013-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  7. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 5 2012-04-01 2012-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  8. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 5 2014-04-01 2014-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  9. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  10. 24 CFR Appendix Ms-1 to Part 3500 - Appendix MS-1 to Part 3500

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Appendix MS-1 to Part 3500 MS Appendix MS-1 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-1 Appendix MS-1...

  11. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  12. 24 CFR Appendix Ms-2 to Part 3500 - Appendix MS-2 to Part 3500

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Appendix MS-2 to Part 3500 MS Appendix MS-2 to Part 3500 Housing and Urban Development Regulations Relating to Housing and Urban... HOUSING AND URBAN DEVELOPMENT REAL ESTATE SETTLEMENT PROCEDURES ACT Pt. 3500, App. MS-2 Appendix MS-2...

  13. Application of ceramic membrane in molten salt electrolysis of CaO-CaCl{sub 2}

    SciTech Connect

    Ferro, P.D.; Mishra, B.; Olson, D.L.; Averill, W.A.

    1998-09-01

    Calciothermic reduction of radioactive metal oxides and halides produces calcium compounds as the by-product which require subsequent processing to mitigate and control a potential source of waste generation. Attempts to recover elemental calcium by direct molten salt electrolysis of calcium compounds using carbon anodes have met with very limited success due to severe process limitations and stringent cell design requirements. A feasible process to win calcium in a modified cell is discussed where a porous anodic diaphragm has been used around the carbon anode. The effective diffusion coefficient for steady state cell operation has been estimated and is found to depend on the porosity and morphology of the anode sheath. An expression for the maximum electrowinning rate, incorporating an effective diffusion coefficient, has been developed and can be used to determine the limiting current density under steady-state conditions. The possibility of enhancing the current efficiency to an acceptable level by in situ application of calcium as a reductant is suggested.

  14. The use of rotating electrodes in the electrolysis of molten zinc chloride electrolytes

    NASA Astrophysics Data System (ADS)

    Copham, P. M.; Fray, D. J.

    1990-12-01

    In order to decrease the resistive losses in molten salt electrowinning cells, it is necessary to reduce the interelectrode spacing. Under stationary conditions, this can only be achieved at the detriment of the current efficiency. However, by rotating 100-mm-diameter electrodes, it was found for plane disc electrodes that at a current density of 10,000 A m-2, a separation of 4 mm, and a rotation speed of 100 rpm, a current efficiency of 75.5 pct for the electrolysis of zinc from a zinc chloride, sodium chloride, potassium chloride electrolyte was achieved. This was 31 pct above that of the equivalent stationary case. The use of conical electrodes which combined centrifugal and gravitational separation increased the current efficiency to 85.7 pct at a rotation speed of 44 rpm. Increasing the scale of the electrodes to 200 mm in diameter resulted in similar efficiencies. These results and a low temperature study using perspex discs and cones in water indicated that the removal of the anode gas may be the rate-limiting step.

  15. A Parametric Sizing Model for Molten Regolith Electrolysis Reactors to Produce Oxygen from Lunar Regolith

    NASA Technical Reports Server (NTRS)

    Schreiner, Samuel S.; Dominguez, Jesus A.; Sibille, Laurent; Hoffman, Jeffrey A.

    2015-01-01

    We present a parametric sizing model for a Molten Electrolysis Reactor that produces oxygen and molten metals from lunar regolith. The model has a foundation of regolith material properties validated using data from Apollo samples and simulants. A multiphysics simulation of an MRE reactor is developed and leveraged to generate a vast database of reactor performance and design trends. A novel design methodology is created which utilizes this database to parametrically design an MRE reactor that 1) can sustain the required mass of molten regolith, current, and operating temperature to meet the desired oxygen production level, 2) can operate for long durations via joule heated, cold wall operation in which molten regolith does not touch the reactor side walls, 3) can support a range of electrode separations to enable operational flexibility. Mass, power, and performance estimates for an MRE reactor are presented for a range of oxygen production levels. The effects of several design variables are explored, including operating temperature, regolith type/composition, batch time, and the degree of operational flexibility.

  16. High Temperature Electrolysis for Hydrogen Production from Nuclear Energy – TechnologySummary

    SciTech Connect

    J. E. O'Brien; C. M. Stoots; J. S. Herring; M. G. McKellar; E. A. Harvego; M. S. Sohal; K. G. Condie

    2010-02-01

    The Department of Energy, Office of Nuclear Energy, has requested that a Hydrogen Technology Down-Selection be performed to identify the hydrogen production technology that has the best potential for timely commercial demonstration and for ultimate deployment with the Next Generation Nuclear Plant (NGNP). An Independent Review Team has been assembled to execute the down-selection. This report has been prepared to provide the members of the Independent Review Team with detailed background information on the High Temperature Electrolysis (HTE) process, hardware, and state of the art. The Idaho National Laboratory has been serving as the lead lab for HTE research and development under the Nuclear Hydrogen Initiative. The INL HTE program has included small-scale experiments, detailed computational modeling, system modeling, and technology demonstration. Aspects of all of these activities are included in this report. In terms of technology demonstration, the INL successfully completed a 1000-hour test of the HTE Integrated Laboratory Scale (ILS) technology demonstration experiment during the fall of 2008. The HTE ILS achieved a hydrogen production rate in excess of 5.7 Nm3/hr, with a power consumption of 18 kW. This hydrogen production rate is far larger than has been demonstrated by any of the thermochemical or hybrid processes to date.

  17. Engineering Process Model for High-Temperature Electrolysis System Performance Evaluation

    SciTech Connect

    Carl M. Stoots; James E. O'Brien; Michael G. McKellar; Grant L. Hawkes

    2005-11-01

    In order to evaluate the potential hydrogen production performance of large-scale High-Temperature Electrolysis (HTE) operations, we have developed an engineering process model at INL using the commercial systems-analysis code HYSYS. Using this code, a detailed process flowsheet has been defined that includes all of the components that would be present in an actual plant such as pumps, compressors, heat exchangers, turbines, and the electrolyzer. Since the electrolyzer is not a standard HYSYS component, a custom one-dimensional electrolyzer model was developed for incorporation into the overall HYSYS process flowsheet. This electrolyzer model allows for the determination of the operating voltage, gas outlet temperatures, and electrolyzer efficiency for any specified inlet gas flow rates, current density, cell active area, and external heat loss or gain. The one-dimensional electrolyzer model was validated by comparison with results obtained from a fully 3-D computational fluid dynamics model developed using FLUENT. This report provides details on the one-dimensional electrolyzer model, the HYSYS process model for a 300 MW HTE plant, and some representative results of parametric studies performed using the HYSYS process model.

  18. Test Plan for Long-Term Operation of a Ten-Cell High Temperature Electrolysis Stack

    SciTech Connect

    James E. O'Brien; Carl M. Stoots; J. Stephen Herring

    2008-07-01

    This document defines a test plan for a long-term (2500 Hour) test of a ten-cell high-temperature electrolysis stack to be performed at INL during FY09 under the Nuclear Hydrogen Initiative. This test was originally planned for FY08, but was removed from our work scope as a result of the severe budget cuts in the FY08 NHI Program. The purpose of this test is to evaluate stack performance degradation over a relatively long time period and to attempt to identify some of the degradation mechanisms via post-test examination. This test will be performed using a planar ten-cell Ceramatec stack, with each cell having dimensions of 10 cm × 10 cm. The specific makeup of the stack will be based on the results of a series of shorter duration ten-cell stack tests being performed during FY08, funded by NGNP. This series of tests was aimed at evaluating stack performance with different interconnect materials and coatings and with or without brazed edge rails. The best performing stack from the FY08 series, in which five different interconnect/coating/edge rail combinations were tested, will be selected for the FY09 long-term test described herein.

  19. Removal of oxyfluorfen from ex-situ soil washing fluids using electrolysis with diamond anodes.

    PubMed

    dos Santos, Elisama Vieira; Sáez, Cristina; Martínez-Huitle, Carlos Alberto; Cañizares, Pablo; Rodrigo, Manuel Andres

    2016-04-15

    In this research, firstly, the treatment of soil spiked with oxyfluorfen was studied using a surfactant-aided soil-washing (SASW) process. After that, the electrochemical treatment of the washing liquid using boron doped diamond (BDD) anodes was performed. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing the pesticide completely by using dosages below 5 g of sodium dodecyl sulfate (SDS) per Kg of soil. After that, complete mineralization of organic matter (oxyflourfen, SDS and by-products) was attained (100% of total organic carbon and chemical oxygen demand removals) when the washing liquids were electrolyzed using BDD anodes, but the removal rate depends on the size of the particles in solution. Electrolysis of soil washing fluids occurs via the reduction in size of micelles until their complete depletion. Lower concentrations of intermediates are produced (sulfate, chlorine, 4-(trifluoromethyl)-phenol and ortho-nitrophenol) during BDD-electrolyzes. Finally, it is important to indicate that, sulfate (coming from SDS) and chlorine (coming from oxyfluorfen) ions play an important role during the electrochemical organic matter removal. PMID:26846982

  20. Effect of electrolysis conditions on photocatalytic activities of the anodized TiO{sub 2} films

    SciTech Connect

    Onoda, Kinji; Yoshikawa, Susumu

    2007-12-15

    Photocatalytic activities of anodized TiO{sub 2} films for decomposition of gaseous acetaldehyde were investigated. The anodized TiO{sub 2} films were fabricated by galvanostatic anodization in a mixed electrolyte composed of H{sub 2}SO{sub 4}, H{sub 3}PO{sub 4}, and H{sub 2}O{sub 2}. Pre-nitridation treatment effectively enhanced the photocatalytic activity of the anodized TiO{sub 2} films. The electrolysis parameters such as anodization time, current density, electrolyte temperature, and electrolyte composition significantly affected the photocatalytic activity of the anodized TiO{sub 2} films. The improvement of photocatalytic activity of the anodized films is attributed to increase in surface areas of the anodized specimens. - Graphical abstract: The effect of concentration of H{sub 3}PO{sub 4} on the photocatalytic activity of the anodized TiO{sub 2} films was investigated. The pre-nitrided titanium plates were anodized in electrolyte of 1.5 M H{sub 3}PO{sub 4} and 0.3 M H{sub 2}O{sub 2} with varying H{sub 3}PO{sub 4} concentration in the range from 0 to 0.5 M. The highest photocatalytic activity was obtained at H{sub 3}PO{sub 4} concentration of 0.1 M.

  1. Evaluation of low-cost cathode catalysts for high yield biohydrogen production in microbial electrolysis cell.

    PubMed

    Wang, L; Chen, Y; Ye, Y; Lu, B; Zhu, S; Shen, S

    2011-01-01

    As an ideal fuel due to the advantages of no pollution, high combustion heat and abundant sources, hydrogen gas can be produced from organic matter through the electrohydrogenesis process in microbial electrolysis cells. But in many MECs, platinum is often used as catalyst, which limits the practical applications of MECs. To reduce the cost of the MECs, Ni-based alloy cathodes were developed by electrodepositing. In this paper hydrogen production using Ni-W-P cathode was studied for the first time in a single-chamber membrane-free MEC. At an applied voltage of 0.9 V, MECs with Ni-W-P cathodes obtained a hydrogen production rate of 1.09 m3/m3/day with an cathodic hydrogen recovery of 74%, a Coulombic efficiency of 56% and an electrical energy efficiency relative to electrical input of 139%, which was the best result of reports in this study. The Ni-W-P cathode demonstrated a better electrocatalytic activity than the Ni-Ce-P cathode and achieved a comparable performance to the Pt cathode in terms of hydrogen production rate, Coulombic efficiency, cathodic hydrogen recovery and electrical energy efficiency at 0.9 V. PMID:21278465

  2. A new anode material for oxygen evolution in molten oxide electrolysis.

    PubMed

    Allanore, Antoine; Yin, Lan; Sadoway, Donald R

    2013-05-16

    Molten oxide electrolysis (MOE) is an electrometallurgical technique that enables the direct production of metal in the liquid state from oxide feedstock, and compared with traditional methods of extractive metallurgy offers both a substantial simplification of the process and a significant reduction in energy consumption. MOE is also considered a promising route for mitigation of CO2 emissions in steelmaking, production of metals free of carbon, and generation of oxygen for extra-terrestrial exploration. Until now, MOE has been demonstrated using anode materials that are consumable (graphite for use with ferro-alloys and titanium) or unaffordable for terrestrial applications (iridium for use with iron). To enable metal production without process carbon, MOE requires an anode material that resists depletion while sustaining oxygen evolution. The challenges for iron production are threefold. First, the process temperature is in excess of 1,538 degrees Celsius (ref. 10). Second, under anodic polarization most metals inevitably corrode in such conditions. Third, iron oxide undergoes spontaneous reduction on contact with most refractory metals and even carbon. Here we show that anodes comprising chromium-based alloys exhibit limited consumption during iron extraction and oxygen evolution by MOE. The anode stability is due to the formation of an electronically conductive solid solution of chromium(iii) and aluminium oxides in the corundum structure. These findings make practicable larger-scale evaluation of MOE for the production of steel, and potentially provide a key material component enabling mitigation of greenhouse-gas emissions while producing metal of superior metallurgical quality.

  3. Evaluation of hydrogen production and internal resistance in forward osmosis membrane integrated microbial electrolysis cells.

    PubMed

    Lee, Mi-Young; Kim, Kyoung-Yeol; Yang, Euntae; Kim, In S

    2015-01-01

    In order to enhance hydrogen production by facilitated proton transport through a forward osmosis (FO) membrane, the FO membrane was integrated into microbial electrolysis cells (MECs). An improved hydrogen production rate was obtained in the FO-MEC (12.5±1.84×10(-3)m(3)H2/m(3)/d) compared to that of the cation exchange membrane (CEM) - MEC (4.42±0.04×10(-3)m(3)H2/m(3)/d) during batch tests (72h). After an internal resistance analysis, it was confirmed that the enhanced hydrogen production in FO-MEC was attributed to the smaller charge transfer resistance than in the CEM-MEC (90.3Ω and 133.4Ω respectively). The calculation of partial internal resistance concluded that the transport resistance can be substantially reduced by replacing a CEM with a FO membrane; decrease of the resistance from 0.069Ωm(2) to 5.99×10(-4)Ωm(2). PMID:25841189

  4. 3D CFD Model of a Tubular Porous-Metal Supported Solid Oxide Electrolysis Cell

    SciTech Connect

    G.L. Hawkes; B.D. Hawkes; M.S. Sohal; P.T. Torgerson; T. Armstrong; M.C. Williams

    2007-10-01

    Currently there is strong interest in the large-scale production of hydrogen as an energy carrier for the non-electrical market [1, 2, and 3]. High-temperature nuclear reactors have the potential for substantially increasing the efficiency of hydrogen production from water splitting, with no consumption of fossil fuels, no production of greenhouse gases, and no other forms of air pollution. A high-temperature advanced nuclear reactor coupled with a high-efficiency high-temperature electrolyzer could achieve a competitive thermal-to-hydrogen conversion efficiency of 45 to 55%. A research program is under way at the INL to simultaneously address the research and scale-up issues associated with the implementation of solid-oxide electrolysis cell technology for hydrogen production from steam. The future SOEC market includes the 1200MW GEN4 reactor which has projected 40-50% efficiency, 400 tones H2 production per day (at 5kg H2/car/300 mile day this corresponds to 80,000 cars/day). DOE is planning for 26GW of nuclear hydrogen production by 2025.

  5. The dynamic-state effects of sodium ion contamination on the solid polymer electrolyte water electrolysis

    NASA Astrophysics Data System (ADS)

    Zhang, Linsong; Jie, Xiao; Shao, Zhi-Gang; Wang, Xunying; Yi, Baolian

    2013-11-01

    Na+ is a likely intrinsic impurity in water and is a potential cation impurity in the solid polymer electrolyte water electrolysis. In this paper, the dynamic-state effect of low concentration of Na+ is studied by adding Na+ into the deionized water fed in the SPE water electrolyser. The dynamic variation of cell voltage results show that the cell performance degraded more severely in the presence of Na+ impurity by anode poisoning than by cathode poisoning. The severity and poisoning rate of the cell depend on the Na+ concentration, water flow rate and cell temperature. However, the current density does not impact the extent of the cell voltage increase. In the meantime, an external reference electrode is used to measure the anode and cathode potentials. The performance degradation is mainly ascribed to the increase in cathode overpotential by anode poisoning. EIS measurements show that the performance difference primarily comes from the kinetics loss rather than the ohmic loss. The decrease of available protons in the three phase boundaries may lead to the increase in charge transfer resistance. The electron probe microanalysis tests show that Na+ remains in CCM even recovered with deionized water, which results in only partially recovered cell performance.

  6. High Temperature Gas-Cooled Reactor Coupled with High Temperature Steam Electrolysis

    SciTech Connect

    Oh, Chang H.; Davis, Cliff; Kim, Eung S.; Sherman, Steven; Barner, Robert; Vilim, R.

    2007-07-01

    The US Department of Energy is investigating the use of high-temperature gas-cooled reactors (HTGR) to produce electricity and hydrogen. Although the hydrogen production processes using the nuclear energy are in an early stage of development, coupling hydrogen plant to HTGR requires both efficient heat transfer and adequate separation of the facilities to assure that off-normal events in the production facility do not impact the nuclear plant. In anticipation of the design, development and procurement of an advanced power conversion system for HTGR, this study was initiated to identify the major design and technology options and their tradeoffs in the evaluation of power conversion unit (PCU) coupled to the hydrogen plant. In this study, we investigated a number of design configurations and performed thermal hydraulic analyses using various working fluids and various conditions. Also using the high temperature steam electrolysis process (HTSE), we calculated the energy requirement for the operation of the HTSE. The balance of the plant of the HTSE was developed and the HTGR was modeled to be coupled with the HTSE. This paper presents a portion of results obtained from this study. (authors)

  7. The presence of hydrogenotrophic methanogens in the inoculum improves methane gas production in microbial electrolysis cells.

    PubMed

    Siegert, Michael; Li, Xiu-Fen; Yates, Matthew D; Logan, Bruce E

    2014-01-01

    High current densities in microbial electrolysis cells (MECs) result from the predominance of various Geobacter species on the anode, but it is not known if archaeal communities similarly converge to one specific genus. MECs were examined here on the basis of maximum methane production and current density relative to the inoculum community structure. We used anaerobic digester (AD) sludge dominated by acetoclastic Methanosaeta, and an anaerobic bog sediment where hydrogenotrophic methanogens were detected. Inoculation using solids to medium ratio of 25% (w/v) resulted in the highest methane production rates (0.27 mL mL(-1) cm(-2), gas volume normalized by liquid volume and cathode projected area) and highest peak current densities (0.5 mA cm(-2)) for the bog sample. Methane production was independent of solid to medium ratio when AD sludge was used as the inoculum. 16S rRNA gene community analysis using pyrosequencing and quantitative PCR confirmed the convergence of Archaea to Methanobacterium and Methanobrevibacter, and of Bacteria to Geobacter, despite their absence in AD sludge. Combined with other studies, these findings suggest that Archaea of the hydrogenotrophic genera Methanobacterium and Methanobrevibacter are the most important microorganisms for methane production in MECs and that their presence in the inoculum improves the performance. PMID:25642216

  8. Evaluation of hydrogen production and internal resistance in forward osmosis membrane integrated microbial electrolysis cells.

    PubMed

    Lee, Mi-Young; Kim, Kyoung-Yeol; Yang, Euntae; Kim, In S

    2015-01-01

    In order to enhance hydrogen production by facilitated proton transport through a forward osmosis (FO) membrane, the FO membrane was integrated into microbial electrolysis cells (MECs). An improved hydrogen production rate was obtained in the FO-MEC (12.5±1.84×10(-3)m(3)H2/m(3)/d) compared to that of the cation exchange membrane (CEM) - MEC (4.42±0.04×10(-3)m(3)H2/m(3)/d) during batch tests (72h). After an internal resistance analysis, it was confirmed that the enhanced hydrogen production in FO-MEC was attributed to the smaller charge transfer resistance than in the CEM-MEC (90.3Ω and 133.4Ω respectively). The calculation of partial internal resistance concluded that the transport resistance can be substantially reduced by replacing a CEM with a FO membrane; decrease of the resistance from 0.069Ωm(2) to 5.99×10(-4)Ωm(2).

  9. Removal of oxyfluorfen from ex-situ soil washing fluids using electrolysis with diamond anodes.

    PubMed

    dos Santos, Elisama Vieira; Sáez, Cristina; Martínez-Huitle, Carlos Alberto; Cañizares, Pablo; Rodrigo, Manuel Andres

    2016-04-15

    In this research, firstly, the treatment of soil spiked with oxyfluorfen was studied using a surfactant-aided soil-washing (SASW) process. After that, the electrochemical treatment of the washing liquid using boron doped diamond (BDD) anodes was performed. Results clearly demonstrate that SASW is a very efficient approach in the treatment of soil, removing the pesticide completely by using dosages below 5 g of sodium dodecyl sulfate (SDS) per Kg of soil. After that, complete mineralization of organic matter (oxyflourfen, SDS and by-products) was attained (100% of total organic carbon and chemical oxygen demand removals) when the washing liquids were electrolyzed using BDD anodes, but the removal rate depends on the size of the particles in solution. Electrolysis of soil washing fluids occurs via the reduction in size of micelles until their complete depletion. Lower concentrations of intermediates are produced (sulfate, chlorine, 4-(trifluoromethyl)-phenol and ortho-nitrophenol) during BDD-electrolyzes. Finally, it is important to indicate that, sulfate (coming from SDS) and chlorine (coming from oxyfluorfen) ions play an important role during the electrochemical organic matter removal.

  10. Destruction of 4-phenolsulfonic acid in water by anodic contact glow discharge electrolysis.

    PubMed

    Yang, Haiming; An, Baigang; Wang, Shaoyan; Li, Lixiang; Jin, Wenjie; Li, Lihua

    2013-06-01

    Destruction of 4-phenolsulfonic acid (4-PSA) in water was carried out using anodic contact glow discharge electrolysis. Accompanying the decay of 4-PSA, the amount of total organic carbon (TOC) in water correspondingly decreased, while the sulfonate group of 4-PSA was released as sulfate ion. Oxalate and formate were obtained as minor by-products. Additionally, phenol, 1,4-hydroquinone, hydroxyquinol and 1,4-benzoquinone were detected as primary intermediates in the initial stages of decomposition of 4-PSA. A reaction pathway involving successive attacks of hydroxyl and hydrogen radicals was assumed on the basis of the observed products and kinetics. It was revealed that the decay of both 4-PSA and TOC obeyed a first-order rate law. The effects of different Fe ions and initial concentrations of 4-PSA on the degradation rate were investigated. It was found that the presence of Fe ions could increase the degradation rate of 4-PSA, while initial concentrations lower than 80 mmol/L had no significant effect on kinetic behaviour. The disappearance rate of 4-PSA was significantly affected by pH. PMID:24191593

  11. Application of microbial electrolysis cells to treat spent yeast from an alcoholic fermentation.

    PubMed

    Sosa-Hernández, Ornella; Popat, Sudeep C; Parameswaran, Prathap; Alemán-Nava, Gibrán Sidney; Torres, César I; Buitrón, Germán; Parra-Saldívar, Roberto

    2016-01-01

    Spent yeast (SY), a major challenge for the brewing industry, was treated using a microbial electrolysis cell to recover energy. Concentrations of SY from bench alcoholic fermentation and ethanol were tested, ranging from 750 to 1500mgCOD/L and 0 to 2400mgCOD/L respectively. COD removal efficiency (RE), coulombic efficiency (CE), coulombic recovery (CR), hydrogen production and current density were evaluated. The best treatment condition was 750mgCOD/LSY+1200mgCOD/L ethanol giving higher COD RE, CE, CR (90±1%, 90±2% and 81±1% respectively), as compared with 1500mgCOD/LSY (76±2%, 63±7% and 48±4% respectively); ethanol addition was significantly favorable (p value=0.011), possibly due to electron availability and SY autolysis. 1500mgCOD/LSY+1200mgCOD/L ethanol achieved higher current density (222.0±31.3A/m(3)) and hydrogen production (2.18±0.66 [Formula: see text] ) but with lower efficiencies (87±2% COD RE, 71.0±.4% CE). Future work should focus on electron sinks, acclimation and optimizing SY breakdown. PMID:26512857

  12. Recycling of Magnesium Alloy Employing Refining and Solid Oxide Membrane (SOM) Electrolysis

    NASA Astrophysics Data System (ADS)

    Guan, Xiaofei; Zink, Peter A.; Pal, Uday B.; Powell, Adam C.

    2013-04-01

    Pure magnesium was recycled from partially oxidized 50.5 wt pct Mg-Al scrap alloy and AZ91 Mg alloy (9 wt pct Al, 1 wt pct Zn). Refining experiments were performed using a eutectic mixture of MgF2-CaF2 molten salt (flux). During the experiments, potentiodynamic scans were performed to determine the electrorefining potentials for magnesium dissolution and magnesium bubble nucleation in the flux. The measured electrorefining potential for magnesium bubble nucleation increased over time as the magnesium content inside the magnesium alloy decreased. Potentiostatic holds and electrochemical impedance spectroscopy were employed to measure the electronic and ionic resistances of the flux. The electronic resistivity of the flux varied inversely with the magnesium solubility. Up to 100 pct of the magnesium was refined from the Mg-Al scrap alloy by dissolving magnesium and its oxide into the flux followed by argon-assisted evaporation of dissolved magnesium and subsequently condensing the magnesium vapor. Solid oxide membrane electrolysis was also employed in the system to enable additional magnesium recovery from magnesium oxide in the partially oxidized Mg-Al scrap. In an experiment employing AZ91 Mg alloy, only the refining step was carried out. The calculated refining yield of magnesium from the AZ91 alloy was near 100 pct.

  13. Nitrogen removal from wastewater through microbial electrolysis cells and cation exchange membrane

    PubMed Central

    2014-01-01

    Vulnerability of water resources to nutrients led to progressively stricter standards for wastewater effluents. Modification of the conventional procedures to meet the new standards is inevitable. New technologies should give a priority to nitrogen removal. In this paper, ammonium chloride and urine as nitrogen sources were used to investigate the capacity of a microbial electrolysis cell (MEC) configured by cation exchange membrane (CEM) for electrochemical removal of nitrogen over open-and closed-circuit potentials (OCP and CCP) during biodegradation of organic matter. Results obtained from this study indicated that CEM was permeable to both organic and ammonium nitrogen over OCP. Power substantially mediated ammonium migration from anodic wastewater to the cathode, as well. With a urine rich wastewater in the anode, the maximum rate of ammonium intake into the cathode varied from 34.2 to 40.6 mg/L.h over CCP compared to 10.5-14.9 mg/L.h over OCP. Ammonium separation over CCP was directly related to current. For 1.46-2.12 mmol electron produced, 20.5-29.7 mg-N ammonium was removed. Current also increased cathodic pH up to 12, a desirable pH for changing ammonium ion to ammonia gas. Results emphasized the potential for MEC in control of ammonium through ammonium separation and ammonia volatilization provided that membrane characteristic is considered in their development. PMID:24533446

  14. Preparation and use of electrodes in the electrolysis of alkali halides

    SciTech Connect

    Beaver, R.N.; Byrd, C.E.; Alexander, L.E.

    1986-02-25

    A process is described for electrolysis of aqueous solutions of sodium chloride in an electrolytic cell comprising an anolyte compartment and catholyte compartment separated by a diaphragm to produce an aqueous solution of sodium hydroxide in the catholyte compartment, and chlorine in the anolyte compartment. The cathode of the process is a low hydrogen overvoltage cathode made by applying to an electroconductive substrate a coating solution of nickel oxide and ruthenium oxide precursor compounds and an etchant capable of etching the surface of the substrate and/or any previously applied coating. Heating is done to remove volatiles from the so-coated substrate to cause the metal values of the precursor compounds and those etched from the substrate or previously applied coating. Further, heating is performed in the presence of oxygen, air or an oxidizing agent, to a temperature sufficient to oxidize the metal values, thereby obtaining on the substrate an electrocatalytically-active heaterogeneous metal oxide structure comprising RuO/sub 2/ and NiO.

  15. Enhancement of hydrogen production in a single chamber microbial electrolysis cell through anode arrangement optimization.

    PubMed

    Liang, Da-Wei; Peng, Si-Kan; Lu, Shan-Fu; Liu, Yan-Yan; Lan, Fei; Xiang, Yan

    2011-12-01

    Reducing the inner resistances is crucial for the enhancement of hydrogen generation in microbial electrolysis cells (MECs). This study demonstrates that the optimization of the anode arrangement is an effective strategy to reduce the system resistances. By changing the normal MEC configuration into a stacking mode, namely separately placing the contacted anodes from one side to both sides of cathode in parallel, the solution, biofilm and polarization resistances of MECs were greatly reduced, which was also confirmed with electrochemical impedance spectroscopy analysis. After the anode arrangement optimization, the current and hydrogen production rate (HPR) of MEC could be enhanced by 72% and 118%, reaching 621.3±20.6 A/m3 and 5.56 m3/m3 d respectively, under 0.8 V applied voltage. A maximum current density of 1355 A/m3 with a HPR of 10.88 m3/m3 d can be achieved with 1.5 V applied voltage.

  16. Microbial electrolysis cell scale-up for combined wastewater treatment and hydrogen production.

    PubMed

    Gil-Carrera, L; Escapa, A; Mehta, P; Santoyo, G; Guiot, S R; Morán, A; Tartakovsky, B

    2013-02-01

    This study demonstrates microbial electrolysis cell (MEC) scale-up from a 50mL to a 10L cell. Initially, a 50mL membraneless MEC with a gas diffusion cathode was operated on synthetic wastewater at different organic loads. It was concluded that process scale-up might be best accomplished using a "reactor-in-series" concept. Consequently, 855mL and 10L MECs were built and operated. By optimizing the hydraulic retention time (HRT) of the 855mL MEC and individually controlling the applied voltages of three anodic compartments with a real-time optimization algorithm, a COD removal of 5.7g L(R)(-1)d(-1) and a hydrogen production of 1.0-2.6L L(R)(-1)d(-1) was achieved. Furthermore, a two MECs in series 10L setup was constructed and operated on municipal wastewater. This test showed a COD removal rate of 0.5g L(R)(-1)d(-1), a removal efficiency of 60-76%, and an energy consumption of 0.9Whperg of COD removed. PMID:23334014

  17. Improved performance of the microbial electrolysis desalination and chemical-production cell using the stack structure.

    PubMed

    Chen, Shanshan; Liu, Guangli; Zhang, Renduo; Qin, Bangyu; Luo, Yong; Hou, Yanping

    2012-07-01

    The microbial electrolysis desalination and chemical-production cell (MEDCC) is a device to desalinate seawater, and produce acid and alkali. The objective of this study was to enhance the desalination and chemical-production performance of the MEDCC using two types of stack structure. Experiments were conducted with different membrane spacings, numbers of desalination chambers and applied voltages. Results showed that the stack construction in the MEDCC enhanced the desalination and chemical-production rates. The maximal desalination rate of 0.58 ± 0.02 mmol/h, which was 43% higher than that in the MEDCC, was achieved in the four-desalination-chamber MEDCC with the AEM-CEM stack structure and the membrane spacing of 1.5mm. The maximal acid- and alkali-production rates of 0.079 ± 0.006 and 0.13 ± 0.02 mmol/h, which were 46% and 8% higher than that in the MEDCC, respectively, were achieved in the two-desalination-chamber MEDCC with the BPM-AEM-CEM stack structure and the membrane spacing of 3mm.

  18. Concurrent desalination and hydrogen generation using microbial electrolysis and desalination cells.

    PubMed

    Luo, Haiping; Jenkins, Peter E; Ren, Zhiyong

    2011-01-01

    The versatility of bioelectrochemical systems (BESs) makes them promising for various applications, and good combinations could make the system more applicable and economically effective. An integrated BES called microbial electrolysis and desalination cell (MEDC) was developed to concurrently desalinate salt water, produce hydrogen gas, and potentially treat wastewater. The reactor is divided into three chambers by inserting a pair of ion exchange membranes, with each chamber serving one of the three functions. With an added voltage of 0.8 V, lab scale batch study shows the MEDC achieved the highest H(2) production rate of 1.5 m(3)/m(3) d (1.6 mL/h) from the cathode chamber, while also removing 98.8% of the 10 g/L NaCl from the middle chamber. The anode recirculation alleviated pH and high salinity inhibition on bacterial activity and further increased system current density from 87.2 to 140 A/m(3), leading to an improved desalination rate by 80% and H(2) production by 30%. Compared to slight changes in desalination, H(2) production was more significantly affected by the applied voltage and cathode buffer capacity, suggesting cathode reactions were likely affected by the external power supply in addition to the anode microbial activity.

  19. Role of Iron Anode Oxidation on Transformation of Chromium by Electrolysis

    PubMed Central

    Sarahney, Hussam; Mao, Xuhui; Alshawabkeh, Akram N.

    2012-01-01

    The potential for chemical reduction of hexavalent chromium Cr(VI) in contaminated water and formation of a stable precipitate by Zero Valent Iron (ZVI) anode electrolysis is evaluated in separated electrodes system. Oxidation of iron electrodes produces ferrous ions causing the development of a reducing environment in the anolyte, chemical reduction of Cr(VI) to Cr(III) and formation of stable iron-chromium precipitates. Cr(VI) transformation rates are dependent on the applied electric current density. Increasing the electric current increases the transformation rates; however, the process is more efficient under lower volumetric current density (for example 1.5 mA L−1 in this study). The transformation follows a zero order rate that is dependent on the electric current density. Cr(VI) transformation occurs in the anolyte when the electrodes are separated as well as when the electrolytes (anolyte/catholyte) are mixed, as used in electrocoagulation. The study shows that the transformation occurs in the anolyte as a result of ferrous ion formation and the product is a stable Fe15Cr5(OH)60 precipitate. PMID:23284182

  20. Role of Iron Anode Oxidation on Transformation of Chromium by Electrolysis.

    PubMed

    Sarahney, Hussam; Mao, Xuhui; Alshawabkeh, Akram N

    2012-12-30

    The potential for chemical reduction of hexavalent chromium Cr(VI) in contaminated water and formation of a stable precipitate by Zero Valent Iron (ZVI) anode electrolysis is evaluated in separated electrodes system. Oxidation of iron electrodes produces ferrous ions causing the development of a reducing environment in the anolyte, chemical reduction of Cr(VI) to Cr(III) and formation of stable iron-chromium precipitates. Cr(VI) transformation rates are dependent on the applied electric current density. Increasing the electric current increases the transformation rates; however, the process is more efficient under lower volumetric current density (for example 1.5 mA L(-1) in this study). The transformation follows a zero order rate that is dependent on the electric current density. Cr(VI) transformation occurs in the anolyte when the electrodes are separated as well as when the electrolytes (anolyte/catholyte) are mixed, as used in electrocoagulation. The study shows that the transformation occurs in the anolyte as a result of ferrous ion formation and the product is a stable Fe(15)Cr(5)(OH)(60) precipitate.

  1. Improvement of bioelectrochemical property and energy recovery by acylhomoserine lactones (AHLs) in microbial electrolysis cells (MECs)

    NASA Astrophysics Data System (ADS)

    Liu, Wenzong; Cai, Weiwei; Ma, Anzhou; Ren, Ge; Li, Zhiling; Zhuang, Guoqiang; Wang, Aijie

    2015-06-01

    Quorum sensing (QS) has been extensively studied as a cell-cell communication system, where small chemical signal molecules (acylhomoserine lactones, AHLs) can regulate the bacterial communications in bioelectrochemical systems via chemical signaling and electric signaling. In this study, electrochemical activity of bio-anode is substantially promoted by adding two kinds of AHLs with different chain length at the stage of community formation in microbial electrolysis cells (MECs). Hydrogen yield increase is observed by adding of two chain length AHLs, 3-oxo-hexanoyl-homoserine lactone (3OC6-HSL) and 3-oxo-dodecanoyl homoserine lactone (3OC12-HSL). A higher MEC current is acquired with addition of 3OC6-HSL than 3OC12-HSL at a fixed voltage of 0.8 V (vs. SHE). The highest yield is up to 3.8 ± 0.2 mol H2 mol-1 acetate at 10 μM 3OC6-HSL, which is increased 29% over control MECs. Evaluated on applied voltage, energy efficiency is increased to 171.6 ± 21.3% with short chain AHL, however, no significant improvement is performed on energy efficiency and coulombic efficiency with long-chain AHL. The study shows that bioelectrochemical characteristics of MECs varied on the chain length of AHL signal molecules and short-chain AHLs have a more positive effect on electron transfer and energy recovery in MECs.

  2. Performance of microbial electrolysis cells with bioanodes grown at different external resistances.

    PubMed

    Rago, Laura; Monpart, Nuria; Cortés, Pilar; Baeza, Juan A; Guisasola, Albert

    2016-01-01

    Bioelectrochemical systems need an anode with a high abundance of exoelectrogenic bacteria for an optimal performance. Among all possible operational parameters for an efficient enrichment, the role of external resistance in microbial fuel cell (MFC) has gained a lot of interest since it indirectly poises an anode potential, a key parameter for biofilm distribution and morphology. Thus, this work aims at investigating and discussing whether bioanodes selected at different external resistances under MFC operation present different responses under both MFC and microbial electrolysis cell (MEC) operation. A better MEC performance (i.e. shorter start-up time, higher current intensity and higher H2 production rate) was obtained with an anode from an MFC developed under low external resistance. Quantitative real-time polymerase chain reaction (qPCR) confirmed that a low external resistance provides an MFC anodic biofilm with the highest content of Geobacter because it allows higher current intensity, which is correlated to exoelectrogenic activity. High external resistances such as 1,000 Ω led to a slower start-up time under MEC operation.

  3. Hydrogen generation in microbial reverse-electrodialysis electrolysis cells using a heat-regenerated salt solution.

    PubMed

    Nam, Joo-Youn; Cusick, Roland D; Kim, Younggy; Logan, Bruce E

    2012-05-01

    Hydrogen gas can be electrochemically produced in microbial reverse-electrodialysis electrolysis cells (MRECs) using current derived from organic matter and salinity-gradient energy such as river water and seawater solutions. Here, it is shown that ammonium bicarbonate salts, which can be regenerated using low-temperature waste heat, can also produce sufficient voltage for hydrogen gas generation in an MREC. The maximum hydrogen production rate was 1.6 m(3) H(2)/m(3)·d, with a hydrogen yield of 3.4 mol H(2)/mol acetate at a salinity ratio of infinite. Energy recovery was 10% based on total energy applied with an energy efficiency of 22% based on the consumed energy in the reactor. The cathode overpotential was dependent on the catholyte (sodium bicarbonate) concentration, but not the salinity ratio, indicating high catholyte conductivity was essential for maximizing hydrogen production rates. The direction of the HC and LC flows (co- or counter-current) did not affect performance in terms of hydrogen gas volume, production rates, or stack voltages. These results show that the MREC can be successfully operated using ammonium bicarbonate salts that can be regenerated using conventional distillation technologies and waste heat making the MREC a useful method for hydrogen gas production from wastes. PMID:22463373

  4. Radiation-Grafted Polymer Electrolyte Membranes for Water Electrolysis Cells: Evaluation of Key Membrane Properties.

    PubMed

    Albert, Albert; Barnett, Alejandro O; Thomassen, Magnus S; Schmidt, Thomas J; Gubler, Lorenz

    2015-10-14

    Radiation-grafted membranes can be considered an alternative to perfluorosulfonic acid (PFSA) membranes, such as Nafion, in a solid polymer electrolyte electrolyzer. Styrene, acrylonitrile, and 1,3-diisopropenylbenzene monomers are cografted into preirradiated 50 μm ethylene tetrafluoroethylene (ETFE) base film, followed by sulfonation to introduce proton exchange sites to the obtained grafted films. The incorporation of grafts throughout the thickness is demonstrated by scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) analysis of the membrane cross-sections. The membranes are analyzed in terms of grafting kinetics, ion-exchange capacity (IEC), and water uptake. The key properties of radiation-grafted membranes and Nafion, such as gas crossover, area resistance, and mechanical properties, are evaluated and compared. The plot of hydrogen crossover versus area resistance of the membranes results in a property map that indicates the target areas for membrane development for electrolyzer applications. Tensile tests are performed to assess the mechanical properties of the membranes. Finally, these three properties are combined to establish a figure of merit, which indicates that radiation-grafted membranes obtained in the present study are promising candidates with properties superior to those of Nafion membranes. A water electrolysis cell test is performed as proof of principle, including a comparison to a commercial membrane electrode assembly (MEA).

  5. An analysis of degradation phenomena in polymer electrolyte membrane water electrolysis

    NASA Astrophysics Data System (ADS)

    Rakousky, Christoph; Reimer, Uwe; Wippermann, Klaus; Carmo, Marcelo; Lueke, Wiebke; Stolten, Detlef

    2016-09-01

    The durability of a polymer electrolyte membrane (PEM) water electrolysis single cell, assembled with regular porous transport layers (PTLs) is investigated for just over 1000 h. We observe a significant degradation rate of 194 μV h-1 and conclude that 78% of the detectable degradation can be explained by an increase in ohmic resistance, arising from the anodic Ti-PTL. Analysis of the polarization curves also indicates a decrease in the anodic exchange current density, j0, that results from the over-time contamination of the anode with Ti species. Furthermore, the average Pt-cathode particle size increases during the test, but we do not believe this phenomenon makes a significant contribution to increased cell voltages. To validate the anode Ti-PTL as a crucial source of increasing resistance, a second cell is assembled using Pt-coated Ti-PTLs. This yields a substantially reduced degradation rate of only 12 μV h-1, indicating that a non-corroding anode PTL is vital for PEM electrolyzers. It is our hope that forthcoming tailored PTLs will not only contribute to fast progress on cost-efficient stacks, but also to its long-term application of PEM electrolyzers involved in industrial processes.

  6. Performance of microbial electrolysis cells with bioanodes grown at different external resistances.

    PubMed

    Rago, Laura; Monpart, Nuria; Cortés, Pilar; Baeza, Juan A; Guisasola, Albert

    2016-01-01

    Bioelectrochemical systems need an anode with a high abundance of exoelectrogenic bacteria for an optimal performance. Among all possible operational parameters for an efficient enrichment, the role of external resistance in microbial fuel cell (MFC) has gained a lot of interest since it indirectly poises an anode potential, a key parameter for biofilm distribution and morphology. Thus, this work aims at investigating and discussing whether bioanodes selected at different external resistances under MFC operation present different responses under both MFC and microbial electrolysis cell (MEC) operation. A better MEC performance (i.e. shorter start-up time, higher current intensity and higher H2 production rate) was obtained with an anode from an MFC developed under low external resistance. Quantitative real-time polymerase chain reaction (qPCR) confirmed that a low external resistance provides an MFC anodic biofilm with the highest content of Geobacter because it allows higher current intensity, which is correlated to exoelectrogenic activity. High external resistances such as 1,000 Ω led to a slower start-up time under MEC operation. PMID:26942536

  7. Hydrogen generation in microbial reverse-electrodialysis electrolysis cells using a heat-regenerated salt solution.

    PubMed

    Nam, Joo-Youn; Cusick, Roland D; Kim, Younggy; Logan, Bruce E

    2012-05-01

    Hydrogen gas can be electrochemically produced in microbial reverse-electrodialysis electrolysis cells (MRECs) using current derived from organic matter and salinity-gradient energy such as river water and seawater solutions. Here, it is shown that ammonium bicarbonate salts, which can be regenerated using low-temperature waste heat, can also produce sufficient voltage for hydrogen gas generation in an MREC. The maximum hydrogen production rate was 1.6 m(3) H(2)/m(3)·d, with a hydrogen yield of 3.4 mol H(2)/mol acetate at a salinity ratio of infinite. Energy recovery was 10% based on total energy applied with an energy efficiency of 22% based on the consumed energy in the reactor. The cathode overpotential was dependent on the catholyte (sodium bicarbonate) concentration, but not the salinity ratio, indicating high catholyte conductivity was essential for maximizing hydrogen production rates. The direction of the HC and LC flows (co- or counter-current) did not affect performance in terms of hydrogen gas volume, production rates, or stack voltages. These results show that the MREC can be successfully operated using ammonium bicarbonate salts that can be regenerated using conventional distillation technologies and waste heat making the MREC a useful method for hydrogen gas production from wastes.

  8. Hydrogen production in single chamber microbial electrolysis cells with different complex substrates.

    PubMed

    Montpart, Nuria; Rago, Laura; Baeza, Juan A; Guisasola, Albert

    2015-01-01

    The use of synthetic wastewater containing carbon sources of different complexity (glycerol, milk and starch) was evaluated in single chamber microbial electrolysis cell (MEC) for hydrogen production. The growth of an anodic syntrophic consortium between fermentative and anode respiring bacteria was operationally enhanced and increased the opportunities of these complex substrates to be treated with this technology. During inoculation, current intensities achieved in single chamber microbial fuel cells were 50, 62.5, and 9 A m⁻³ for glycerol, milk and starch respectively. Both current intensities and coulombic efficiencies were higher than other values reported in previous works. The simultaneous degradation of the three complex substrates favored power production and COD removal. After three months in MEC operation, hydrogen production was only sustained with milk as a single substrate and with the simultaneous degradation of the three substrates. The later had the best results in terms of current intensity (150 A m⁻³), hydrogen production (0.94 m³ m⁻³ d⁻¹) and cathodic gas recovery (91%) at an applied voltage of 0.8 V. Glycerol and starch as substrates in MEC could not avoid the complete proliferation of hydrogen scavengers, even under low hydrogen retention time conditions induced by continuous nitrogen sparging.

  9. Enhanced succinic acid production from corncob hydrolysate by microbial electrolysis cells.

    PubMed

    Zhao, Yan; Cao, Weijia; Wang, Zhen; Zhang, Bowen; Chen, Kequan; Ouyang, Pingkai

    2016-02-01

    In this study, Actinobacillus succinogenes NJ113 microbial electrolysis cells (MECs) were used to enhance the reducing power responsible for succinic acid production from corncob hydrolysate. During corncob hydrolysate fermentation, electric MECs resulted in a 1.31-fold increase in succinic acid production and a 1.33-fold increase in the reducing power compared with those in non-electric MECs. When the hydrolysate was detoxified by combining Ca(OH)2, NaOH, and activated carbon, succinic acid production increased from 3.47 to 6.95 g/l. Using a constant potential of -1.8 V further increased succinic acid production to 7.18 g/l. A total of 18.09 g/l of succinic acid and a yield of 0.60 g/g total sugar were obtained after a 60-h fermentation when NaOH was used as a pH regulator. The improved succinic acid yield from corncob hydrolysate fermentation using A. succinogenes NJ113 in electric MECs demonstrates the great potential of using biomass as a feedstock to cost-effectively produce succinate. PMID:26708482

  10. Catalytic dechlorination of diclofenac by biogenic palladium in a microbial electrolysis cell

    PubMed Central

    Gusseme, Bart De; Soetaert, Maarten; Hennebel, Tom; Vanhaecke, Lynn; Boon, Nico; Verstraete, Willy

    2012-01-01

    Summary Diclofenac is one of the most commonly detected pharmaceuticals in wastewater treatment plant (WWTP) effluents and the receiving water bodies. In this study, biogenic Pd nanoparticles (‘bio‐Pd’) were successfully applied in a microbial electrolysis cell (MEC) for the catalytic reduction of diclofenac. Hydrogen gas was produced in the cathodic compartment, and consumed as a hydrogen donor by the bio‐Pd on the graphite electrodes. In this way, complete dechlorination of 1 mg diclofenac l−1 was achieved during batch recirculation experiments, whereas no significant removal was observed in the absence of the biocatalyst. The complete dechlorination of diclofenac was demonstrated by the concomitant production of 2‐anilinophenylacetate (APA). Through the addition of −0.8 V to the circuit, continuous and complete removal of diclofenac was achieved in synthetic medium at a minimal HRT of 2 h. Continuous treatment of hospital WWTP effluent containing 1.28 µg diclofenac l−1 resulted in a lower removal efficiency of 57%, which can probably be attributed to the affinity of other environmental constituents for the bio‐Pd catalyst. Nevertheless, reductive catalysis coupled to sustainable hydrogen production in a MEC offers potential to lower the release of micropollutants from point‐sources such as hospital WWTPs. PMID:22221490

  11. Improved hydrogen production in the microbial electrolysis cell by inhibiting methanogenesis using ultraviolet irradiation.

    PubMed

    Hou, Yanping; Luo, Haiping; Liu, Guangli; Zhang, Renduo; Li, Jiayi; Fu, Shiyu

    2014-09-01

    Methanogenesis inhibition is essential for the improvement of hydrogen (H2) yield and energy recovery in the microbial electrolysis cell (MEC). In this study, ultraviolet (UV) irradiation was proposed as an efficient method for methanogenesis control in a single chamber MEC. With 30 cycles of operation with UV irradiation in the MEC, high H2 concentrations (>91%) were maintained, while without UV irradiation, CH4 concentrations increased significantly and reached up to 94%. In the MEC, H2 yields ranged from 2.87 ± 0.03 to 3.70 ± 0.11 mol H2/mol acetate with UV irradiation and from 3.78 ± 0.12 to 0.03 ± 0.004 mol H2/mol acetate without UV irradiation. Average energy efficiencies from the UV-irradiated MEC were 1.5 times of those without UV irradiation. Energy production from the MEC without UV irradiation was a negative energy yield process because of large amount of CH4 produced over time, which was mainly attributable to cathodic hydrogenotrophic methanogenesis. Our results clearly showed that UV irradiation could effectively inhibit methanogenesis and improve MEC performance to produce H2.

  12. Results from electrolysis test of a prototype inert anode: Inert Electrode Program

    SciTech Connect

    Strachan, D.M.; Windisch, C.F. Jr.; Koski, O.H.; Morgan, L.G. ); Peterson, R.D.; Richards, N.E.; Tabereaux, A.T. . Mfg. Technology Lab.)

    1990-05-01

    Nonconsumable or inert anodes are being developed at the Pacific Northwest Laboratory (PNL)({sup a}) for use in the electrolytic production of aluminum. A series of laboratory test on the laboratory scale (Hart et al. 1987; Strachan et al. 1989; Marschman 1989) has shown the technology to be potentially feasible. A series of larger-scale experiments are now being run to determine the viability of the technology on a commercial scale. The results reported here are from a test performed at the Reynolds Metals Company, Manufacturing Technology Laboratory, Sheffield, Alabama, using a prototype anode. The prototype anode was approximately 15 cm in diameter and 20 cm high (Figure 1.1). The objectives of the test were to determine if an anode, produced by a commercial vendor, could survive in a test under conditions approximating those found in a commercial electrolysis cell; to familiarize the Reynolds staff with the operation of such an anode in a subsequent pilot cell test of the inert anode technology; and to familiarize the PNL staff with the operations at the Reynolds Metals Company facility. 8 refs., 39 figs., 9 tabs.

  13. A parametric sizing model for Molten Regolith Electrolysis reactors to produce oxygen on the Moon

    NASA Astrophysics Data System (ADS)

    Schreiner, Samuel S.; Sibille, Laurent; Dominguez, Jesus A.; Hoffman, Jeffrey A.

    2016-04-01

    We present a parametric sizing model for a Molten Regolith Electrolysis (MRE) reactor that produces oxygen and molten metals from lunar regolith. The model has a foundation of regolith material property models validated using data from Apollo samples and simulants. A multiphysics simulation of an MRE reactor is developed and leveraged to generate a database linking reactor design and performance trends. A novel design methodology is created which utilizes this database to parametrically design an MRE reactor that can (1) sustain the required current, operating temperature, and mass of molten regolith to meet a desired oxygen production level, (2) operate for long periods of time by protecting the reactor walls from the corrosive molten regolith with a layer of solid "frozen" regolith, and (3) support a range of electrode separations to enable operational flexibility. Mass, power, and performance estimates for an MRE reactor are presented for a range of oxygen production levels. Sensitivity analyses are presented for several design variables, including operating temperature, regolith feedstock composition, and the degree of operational flexibility.

  14. Catalytic dechlorination of diclofenac by biogenic palladium in a microbial electrolysis cell.

    PubMed

    De Gusseme, Bart; Soetaert, Maarten; Hennebel, Tom; Vanhaecke, Lynn; Boon, Nico; Verstraete, Willy

    2012-05-01

    Diclofenac is one of the most commonly detected pharmaceuticals in wastewater treatment plant (WWTP) effluents and the receiving water bodies. In this study, biogenic Pd nanoparticles ('bio-Pd') were successfully applied in a microbial electrolysis cell (MEC) for the catalytic reduction of diclofenac. Hydrogen gas was produced in the cathodic compartment, and consumed as a hydrogen donor by the bio-Pd on the graphite electrodes. In this way, complete dechlorination of 1 mg diclofenac l(-1) was achieved during batch recirculation experiments, whereas no significant removal was observed in the absence of the biocatalyst. The complete dechlorination of diclofenac was demonstrated by the concomitant production of 2-anilinophenylacetate (APA). Through the addition of -0.8 V to the circuit, continuous and complete removal of diclofenac was achieved in synthetic medium at a minimal HRT of 2 h. Continuous treatment of hospital WWTP effluent containing 1.28 µg diclofenac l(-1) resulted in a lower removal efficiency of 57%, which can probably be attributed to the affinity of other environmental constituents for the bio-Pd catalyst. Nevertheless, reductive catalysis coupled to sustainable hydrogen production in a MEC offers potential to lower the release of micropollutants from point-sources such as hospital WWTPs. PMID:22221490

  15. Microbial electrolysis desalination and chemical-production cell for CO2 sequestration.

    PubMed

    Zhu, Xiuping; Logan, Bruce E

    2014-05-01

    Mineral carbonation can be used for CO2 sequestration, but the reaction rate is slow. In order to accelerate mineral carbonation, acid generated in a microbial electrolysis desalination and chemical-production cell (MEDCC) was examined to dissolve natural minerals rich in magnesium/calcium silicates (serpentine), and the alkali generated by the same process was used to absorb CO2 and precipitate magnesium/calcium carbonates. The concentrations of Mg(2+) and Ca(2+) dissolved from serpentine increased 20 and 145 times by using the acid solution. Under optimal conditions, 24 mg of CO2 was absorbed into the alkaline solution and 13 mg of CO2 was precipitated as magnesium/calcium carbonates over a fed-batch cycle (24h). Additionally, the MEDCC removed 94% of the COD (initially 822 mg/L) and achieved 22% desalination (initially 35 g/L NaCl). These results demonstrate the viability of this process for effective CO2 sequestration using renewable organic matter and natural minerals.

  16. TRENTA Facility for Trade-Off Studies Between Combined Electrolysis Catalytic Exchange and Cryogenic Distillation Processes

    SciTech Connect

    Cristescu, I.; Cristescu, I.R.; Doerr, L.; Glugla, M.; Hellriegel, G.; Schaefer, P.; Welte, S.; Kveton, O.; Murdoch, D

    2005-07-15

    One of the most used methods for tritium recovery from different sources of tritiated water is based on the combination between Combined Electrolysis Catalytic Exchange (CECE) and Cryogenic Distillation (CD) processes. The development, i.e. configuration, design and performance testing of critical components, of a tritium recovery system based on the combination CECE-CD is essential for both JET and ITER. For JET, a Water Detritiation System (WDS) is not only needed to process tritiated water which has already been accumulated from operation, but also for the tritiated water which will be generated during decommissioning. For ITER, the WDS is one of the key systems to control the tritium content in the effluents streams, to recover as much tritium as possible and consequently to minimize the impact on the environment. A cryogenic distillation facility with the aim to investigate the trade-off between CECE-CD, to validate different components and mathematical modelling software is current under development at Tritium Laboratory Karlsruhe (TLK) as an extension of the existing CECE facility.

  17. Femtosecond polarization pulse shaping.

    PubMed

    Brixner, T; Gerber, G

    2001-04-15

    We report computer-controlled femtosecond polarization pulse shaping where intensity, momentary frequency, and light polarization are varied as functions of time. For the first time to our knowledge, a pulse shaper is used to modulate the degree of ellipticity as well as the orientation of the elliptical principal axes within a single laser pulse by use of a 256-pixel two-layer liquid-crystal display inside a zero-dispersion compressor. Interferometric stability of the setup is not required. Complete pulse characterization is achieved by dual-channel spectral interferometry. This technology has a large range of applications, especially in the field of quantum control.

  18. Femtosecond polarization pulse shaping.

    PubMed

    Brixner, T; Gerber, G

    2001-04-15

    We report computer-controlled femtosecond polarization pulse shaping where intensity, momentary frequency, and light polarization are varied as functions of time. For the first time to our knowledge, a pulse shaper is used to modulate the degree of ellipticity as well as the orientation of the elliptical principal axes within a single laser pulse by use of a 256-pixel two-layer liquid-crystal display inside a zero-dispersion compressor. Interferometric stability of the setup is not required. Complete pulse characterization is achieved by dual-channel spectral interferometry. This technology has a large range of applications, especially in the field of quantum control. PMID:18040384

  19. The New High Magnetic Field Laboratory at Dresden: a Pulsed-Field Laboratory at an IR Free-Electron-Laser

    SciTech Connect

    Pobell, F.; Bianchi, A. D.; Herrmannsdoerfer, T.; Krug, H.; Zherlitsyn, S.; Zvyagin, S.; Wosnitza, J.

    2006-09-07

    We report on the construction of a new high magnetic field user laboratory which will offer pulsed-field coils in the range (60 T, 500 ms, 40 mm) to (100 T, 10 ms, 20 mm) for maximum field, pulse time, and bore diameter of the coils. These coils will be energized by a modular 50 MJ/24 kV capacitor bank. Besides many other experimental techniques, as unique possibilities NMR in pulsed fields as well as infrared spectroscopy at 5 to 150 {mu}m will be available by connecting the pulsed field laboratory to a nearby free-electron-laser facility.

  20. Analysis of 136 pesticides in avocado using a modified QuEChERS method with LC-MS/MS and GC-MS/MS.

    PubMed

    Chamkasem, Narong; Ollis, Lisa W; Harmon, Tiffany; Lee, Sookwang; Mercer, Greg

    2013-03-13

    A simple and high-throughput screening method for the analysis of 136 pesticides in avocado ( Persea americana ) by LC-(+)-ESI-MS/MS and GC-MS/MS is presented. A modified QuEChERS sample preparation method was developed to improve the extraction recovery of highly lipophilic pesticides. Extracts from minced avocados after acetonitrile (MeCN) extraction were directly injected to LC-MS/MS, whereas other GC-amenable compounds were treated with the modified QuEChERS procedure for GC-MS/MS analysis. The average recoveries for 79 pesticides quantified by LC-MS/MS at 10, 50, and 200 ng/g fortifying levels were 86.1% or better (with maximum RSD at 9.2%), whereas GC-MS/MS analysis demonstrated 70.2% or better (RSD < 18%) for average recovery from 57 compounds at the same spike levels. The application of LC- and GC-MS/MS combined with the improved extraction procedures led to the current method, which can quantitate these pesticides even if they are present in avocados below the targeted action level by FDA. This method demonstrated the improved recovery of several challenging lipophilic pesticides in highly fat-rich avocados. PMID:23362971