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Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
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1

Membraneless Vanadium Redox Fuel Cell Using Laminar Flow Rosaria Ferrigno, Abraham D. Stroock, Thomas D. Clark, Michael Mayer, and  

E-Print Network [OSTI]

Membraneless Vanadium Redox Fuel Cell Using Laminar Flow Rosaria Ferrigno, Abraham D. Stroock This communication describes a small redox fuel cell fabricated using a design that omits the membrane normally used this concept by operating a millimeter-scale redox fuel cell that uses the redox couples V(V)/V(IV) (cathodic

Prentiss, Mara

2

Cascade redox flow battery systems  

DOE Patents [OSTI]

A reduction/oxidation ("redox") flow battery system includes a series of electrochemical cells arranged in a cascade, whereby liquid electrolyte reacts in a first electrochemical cell (or group of cells) before being directed into a second cell (or group of cells) where it reacts before being directed to subsequent cells. The cascade includes 2 to n stages, each stage having one or more electrochemical cells. During a charge reaction, electrolyte entering a first stage will have a lower state-of-charge than electrolyte entering the nth stage. In some embodiments, cell components and/or characteristics may be configured based on a state-of-charge of electrolytes expected at each cascade stage. Such engineered cascades provide redox flow battery systems with higher energy efficiency over a broader range of current density than prior art arrangements.

Horne, Craig R.; Kinoshita, Kim; Hickey, Darren B.; Sha, Jay E.; Bose, Deepak

2014-07-22T23:59:59.000Z

3

Redox Flow Batteries, a Review  

SciTech Connect (OSTI)

Redox flow batteries are enjoying a renaissance due to their ability to store large amounts of electrical energy relatively cheaply and efficiently. In this review, we examine the components of redox flow batteries with a focus on understanding the underlying physical processes. The various transport and kinetic phenomena are discussed along with the most common redox couples.

U. Tennessee Knoxville; U. Texas Austin; McGill U; Weber, Adam Z.; Mench, Matthew M.; Meyers, Jeremy P.; Ross, Philip N.; Gostick, Jeffrey T.; Liu, Qinghua

2011-07-15T23:59:59.000Z

4

Optimization of electrode characteristics for the Br2/H2 redox flow cell  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The Br2/H2 redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (?) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (?) catalyst layer on the membrane instead of on the carbon paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm?2 and a peak power density of 1.4 W cm?2. Maximum energy efficiency of 79 % is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br? reversibly adsorbs at the Pt (?) electrode for potentials exceeding a critical value, and the extent of Br? coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.

Tucker, Michael C.; Cho, Kyu Taek; Weber, Adam Z.; Lin, Guangyu; Nguyen, Trung V.

2014-10-01T23:59:59.000Z

5

Rebalancing electrolytes in redox flow battery systems  

DOE Patents [OSTI]

Embodiments of redox flow battery rebalancing systems include a system for reacting an unbalanced flow battery electrolyte with a rebalance electrolyte in a first reaction cell. In some embodiments, the rebalance electrolyte may contain ferrous iron (Fe.sup.2+) which may be oxidized to ferric iron (Fe.sup.3+) in the first reaction cell. The reducing ability of the rebalance reactant may be restored in a second rebalance cell that is configured to reduce the ferric iron in the rebalance electrolyte back into ferrous iron through a reaction with metallic iron.

Chang, On Kok; Pham, Ai Quoc

2014-12-23T23:59:59.000Z

6

Redox Flow Batteries: An Engineering Perspective  

SciTech Connect (OSTI)

Redox flow batteries are well suited to provide modular and scalable energy storage systems for a wide range of energy storage applications. In this paper, we review the development of redox flow battery technology including recent advances in new redox active materials and systems. We discuss cost, performance, and reliability metrics that are critical for deployment of large flow battery systems. The technology, while relatively young, has the potential for significant improvement through reduced materials costs, improved energy and power efficiency, and significant reduction in the overall system cost.

Chalamala, Babu R.; Soundappan, Thiagarajan; Fisher, Graham R.; Anstey, Mitchell A.; Viswanathan, Vilayanur V.; Perry, Mike L.

2014-10-01T23:59:59.000Z

7

High energy density redox flow device  

DOE Patents [OSTI]

Redox flow devices are described in which at least one of the positive electrode or negative electrode-active materials is a semi-solid or is a condensed ion-storing electroactive material, and in which at least one of the electrode-active materials is transported to and from an assembly at which the electrochemical reaction occurs, producing electrical energy. The electronic conductivity of the semi-solid is increased by the addition of conductive particles to suspensions and/or via the surface modification of the solid in semi-solids (e.g., by coating the solid with a more electron conductive coating material to increase the power of the device). High energy density and high power redox flow devices are disclosed. The redox flow devices described herein can also include one or more inventive design features. In addition, inventive chemistries for use in redox flow devices are also described.

Chiang, Yet-Ming; Carter, W. Craig; Ho, Bryan Y; Duduta, Mihai; Limthongkul, Pimpa

2014-05-13T23:59:59.000Z

8

High energy density redox flow device  

DOE Patents [OSTI]

Redox flow devices are described including a positive electrode current collector, a negative electrode current collector, and an ion-permeable membrane separating said positive and negative current collectors, positioned and arranged to define a positive electroactive zone and a negative electroactive zone; wherein at least one of said positive and negative electroactive zone comprises a flowable semi-solid composition comprising ion storage compound particles capable of taking up or releasing said ions during operation of the cell, and wherein the ion storage compound particles have a polydisperse size distribution in which the finest particles present in at least 5 vol % of the total volume, is at least a factor of 5 smaller than the largest particles present in at least 5 vol % of the total volume.

Chiang, Yet-Ming; Carter, William Craig; Duduta, Mihai; Limthongkul, Pimpa

2014-05-13T23:59:59.000Z

9

Numerical modeling of an all vanadium redox flow battery.  

SciTech Connect (OSTI)

We develop a capability to simulate reduction-oxidation (redox) flow batteries in the Sierra Multi-Mechanics code base. Specifically, we focus on all-vanadium redox flow batteries; however, the capability is general in implementation and could be adopted to other chemistries. The electrochemical and porous flow models follow those developed in the recent publication by [28]. We review the model implemented in this work and its assumptions, and we show several verification cases including a binary electrolyte, and a battery half-cell. Then, we compare our model implementation with the experimental results shown in [28], with good agreement seen. Next, a sensitivity study is conducted for the major model parameters, which is beneficial in targeting specific features of the redox flow cell for improvement. Lastly, we simulate a three-dimensional version of the flow cell to determine the impact of plenum channels on the performance of the cell. Such channels are frequently seen in experimental designs where the current collector plates are borrowed from fuel cell designs. These designs use a serpentine channel etched into a solid collector plate.

Clausen, Jonathan R.; Brunini, Victor E.; Moffat, Harry K.; Martinez, Mario J.

2014-01-01T23:59:59.000Z

10

Redox Flow Batteries, a Review  

E-Print Network [OSTI]

and water. For a fuel cell, hydrogen oxidizes at the anode5. 2.1.5 Hydrogen-based systems A fuel cell takes a fuel (

Weber, Adam Z.

2013-01-01T23:59:59.000Z

11

Advanced Redox Flow Batteries for Stationary Electrical Energy Storage  

SciTech Connect (OSTI)

This report describes the status of the advanced redox flow battery research being performed at Pacific Northwest National Laboratories for the U.S. Department of Energy’s Energy Storage Systems Program. The Quarter 1 of FY2012 Milestone was completed on time. The milestone entails completion of evaluation and optimization of single cell components for the two advanced redox flow battery electrolyte chemistries recently developed at the lab, the all vanadium (V) mixed acid and V-Fe mixed acid solutions. All the single cell components to be used in future kW-scale stacks have been identified and optimized in this quarter, which include solution electrolyte, membrane or separator; carbon felt electrode and bi-polar plate. Varied electrochemical, chemical and physical evaluations were carried out to assist the component screening and optimization. The mechanisms of the battery capacity fading behavior for the all vanadium redox flow and the Fe/V battery were discovered, which allowed us to optimize the related cell operation parameters and continuously operate the system for more than three months without any capacity decay.

Li, Liyu; Kim, Soowhan; Xia, Guanguang; Wang, Wei; Yang, Zhenguo

2012-03-19T23:59:59.000Z

12

Fe-V redox flow batteries  

DOE Patents [OSTI]

A redox flow battery having a supporting solution that includes Cl.sup.- anions is characterized by an anolyte having V.sup.2+ and V.sup.3+ in the supporting solution, a catholyte having Fe.sup.2+ and Fe.sup.3+ in the supporting solution, and a membrane separating the anolyte and the catholyte. The anolyte and catholyte can have V cations and Fe cations, respectively, or the anolyte and catholyte can each contain both V and Fe cations in a mixture. Furthermore, the supporting solution can contain a mixture of SO.sub.4.sup.2- and Cl.sup.- anions.

Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Xia, Guanguang

2014-07-08T23:59:59.000Z

13

Iron-sulfide redox flow batteries  

DOE Patents [OSTI]

Iron-sulfide redox flow battery (RFB) systems can be advantageous for energy storage, particularly when the electrolytes have pH values greater than 6. Such systems can exhibit excellent energy conversion efficiency and stability and can utilize low-cost materials that are relatively safer and more environmentally friendly. One example of an iron-sulfide RFB is characterized by a positive electrolyte that comprises Fe(III) and/or Fe(II) in a positive electrolyte supporting solution, a negative electrolyte that comprises S.sup.2- and/or S in a negative electrolyte supporting solution, and a membrane, or a separator, that separates the positive electrolyte and electrode from the negative electrolyte and electrode.

Xia, Guan-Guang; Yang, Zhenguo; Li, Liyu; Kim, Soowhan; Liu, Jun; Graff, Gordon L

2013-12-17T23:59:59.000Z

14

Recent Progress in Redox Flow Battery Research and Development  

SciTech Connect (OSTI)

With the increase need to seamlessly integrate the renewable energy with the current grid which itself is evolving into a more intelligent, efficient, and capable electrical power system, it is envisioned that the energy storage system will play a more prominent role in bridging the gap between the current technology and a clean sustainable future in grid reliability and utilization. Redox flow battery technology is leading the way in this perspective in providing a well balanced approach for current challenges. Recent progress in the research and development of redox flow battery technology is reviewed here with a focus on new chemistries and systems.

Wang, Wei; Luo, Qingtao; Li, Bin; Wei, Xiaoliang; Li, Liyu; Yang, Zhenguo

2013-02-20T23:59:59.000Z

15

A Stable Vanadium Redox-Flow Battery with High Energy Density...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Stable Vanadium Redox-Flow Battery with High Energy Density for Large-scale Energy Storage. A Stable Vanadium Redox-Flow Battery with High Energy Density for Large-scale Energy...

16

Redox flow batteries based on supporting solutions containing chloride  

DOE Patents [OSTI]

Redox flow battery systems having a supporting solution that contains Cl.sup.- ions can exhibit improved performance and characteristics. Furthermore, a supporting solution having mixed SO.sub.4.sup.2- and Cl.sup.- ions can provide increased energy density and improved stability and solubility of one or more of the ionic species in the catholyte and/or anolyte. According to one example, a vanadium-based redox flow battery system is characterized by an anolyte having V.sup.2+ and V.sup.3+ in a supporting solution and a catholyte having V.sup.4+ and V.sup.5+ in a supporting solution. The supporting solution can contain Cl.sup.- ions or a mixture of SO.sub.4.sup.2- and Cl.sup.- ions.

Li, Liyu; Kim, Soowhan; Yang, Zhenguo; Wang, Wei; Zhang, Jianlu; Chen, Baowei; Nie, Zimin; Xia, Guanguang

2014-01-14T23:59:59.000Z

17

Investigation of Local Environments in Nafion-SiO2 Composite Membranes used in Vanadium Redox Flow Batteries  

SciTech Connect (OSTI)

The proton conducting polymer composite membranes are of technological interest in many energy devices such as fuel cells and redox flow batteries. In particular, the polymer composite membranes such as SiO2 incorporated Nafion membranes are recently reported as highly promising for the redox flow batteries. However, there is conflicting reports regarding the performance of this Nafion-SiO2 composite membrane in the redox flow cell. This paper presents results of the analysis of the Nafion-SiO2 composite membrane used in a vanadium redox flow battery by nuclear magnetic resonance (NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Fourier Transformed Infra Red (FTIR) spectroscopy, and ultraviolet visible spectroscopy. The XPS study reveals the chemical identity and environment of vanadium cations accumulated at the surface. On the other hand, the 19F and 29Si NMR measurement explores the nature of the interaction between the silica particles, Nafion side chains and diffused vanadium cations. The 29Si NMR shows that the silica particles interaction via hydrogen bonds to the sulfonic groups of Nafion and diffused vanadium cations. Based on these spectroscopic studies, the chemical environment of the silica particles inside the Nafion membrane and their interaction with diffusing vanadium cations during flow cell operations are discussed. This study discusses the origin of performance degradation of the Nafion-SiO2 composite membrane materials in vanadium redox flow batteries.

Vijayakumar, M.; Schwenzer, Birgit; Kim, Soowhan; Yang, Zhenguo; Thevuthasan, Suntharampillai; Liu, Jun; Graff, Gordon L.; Hu, Jian Z.

2012-04-01T23:59:59.000Z

18

Cost and Performance Model for Redox Flow Batteries  

SciTech Connect (OSTI)

A cost model was developed for all vanadium and iron-vanadium redox flow batteries. Electrochemical performance modeling was done to estimate stack performance at various power densities as a function of state of charge. This was supplemented with a shunt current model and a pumping loss model to estimate actual system efficiency. The operating parameters such as power density, flow rates and design parameters such as electrode aspect ratio, electrolyte flow channel dimensions were adjusted to maximize efficiency and minimize capital costs. Detailed cost estimates were obtained from various vendors to calculate cost estimates for present, realistic and optimistic scenarios. The main drivers for cost reduction for various chemistries were identified as a function of the energy to power ratio of the storage system. Levelized cost analysis further guided suitability of various chemistries for different applications.

Viswanathan, Vilayanur V.; Crawford, Aladsair J.; Stephenson, David E.; Kim, Soowhan; Wang, Wei; Li, Bin; Coffey, Greg W.; Thomsen, Edwin C.; Graff, Gordon L.; Balducci, Patrick J.; Kintner-Meyer, Michael CW; Sprenkle, Vincent L.

2014-02-01T23:59:59.000Z

19

Anthraquinone with Tailored Structure for Nonaqueous Metal-Organic Redox Flow Battery  

SciTech Connect (OSTI)

A nonaqueous, hybrid metal-organic redox flow battery based on tailored anthraquinone structure is demonstrated to have an energy efficiency of {approx}82% and a specific discharge energy density similar to aqueous redox flow batteries, which is due to the significantly improved solubility of anthraquinone in supporting electrolytes.

Wang, Wei; Xu, Wu; Cosimbescu, Lelia; Choi, Daiwon; Li, Liyu; Yang, Zhenguo

2012-06-08T23:59:59.000Z

20

SFTEL: Flow Cell | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Flow Cell EMSL's Subsurface Flow and Transport Experimental Laboratory offers several meter-scale flow cells and columns for research in saturated and unsaturated porous media....

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries  

SciTech Connect (OSTI)

We will present a novel design lithium-organic non-aqueous redox flow battery based on a TEMPO catholyte. This RFB produced desired electrochemical performance exceeding most of the currently reported nonaqueous RFB systems.

Wei, Xiaoliang; Xu, Wu; Vijayakumar, M.; Cosimbescu, Lelia; Liu, Tianbiao L.; Sprenkle, Vincent L.; Wang, Wei

2014-12-03T23:59:59.000Z

22

Redox and ATP control of photosynthetic cyclic electron flow in Chlamydomonas reinhardtii (I) aerobic conditions  

E-Print Network [OSTI]

Redox and ATP control of photosynthetic cyclic electron flow in Chlamydomonas reinhardtii (I, requires the production of ATP and NADPH in a ratio of 3:2. The oxygenic photosynthetic chain can function following two different modes: the linear electron flow which produces reducing power and ATP

23

Lithium borate cluster salts as novel redox shuttles for overcharge protection of lithium-ion cells.  

SciTech Connect (OSTI)

Redox shuttle is a promising mechanism for intrinsic overcharge protection in lithium-ion cells and batteries. Two lithium borate cluster salts are reported to function as both the main salt for a nonaqueous electrolyte and the redox shuttle for overcharge protection. Lithium borate cluster salts with a tunable redox potential are promising candidates for overcharge protection for most positive electrodes in state-of-the-art lithium-ion cells.

Chen, Z.; Liu, J.; Jansen, A. N.; Casteel, B.; Amine, K.; GirishKumar, G.; Air Products and Chemicals, Inc.

2010-01-01T23:59:59.000Z

24

Electrochimica Acta 52 (2007) 49424946 High-performance microfluidic vanadium redox fuel cell  

E-Print Network [OSTI]

vanadium redox fuel cell Erik Kjeanga,c, Brenton T. Proctora,c, Alexandre G. Brolob,c, David A. Harringtonb a new microfluidic fuel cell design with high-surface area porous carbon electrodes and high aspect ratio channel, using soluble vanadium redox species as fuel and oxidant. The device exhibits a peak

Brolo, Alexandre G.

2007-01-01T23:59:59.000Z

25

Live Cell Chemical Profiling of Temporal Redox Dynamics in a Photoautotrophic Cyanobacterium  

SciTech Connect (OSTI)

Protein reduction-oxidation (redox) modification is an important mechanism that allows microorganisms to sense environmental changes and initiate cellular responses. We have developed a quantitative chemical probe approach for live cell labeling of proteins that are sensitive to redox modifications. We utilize this in vivo strategy to identify 176 proteins undergoing ~5-10 fold dynamic redox change in response to nutrient limitation and subsequent replenishment in the photoautotrophic cyanobacterium, Synechococcus sp. PCC 7002. We detect redox changes in as little as 30 seconds after nutrient perturbation, and oscillations in reduction and oxidation for 60 minutes following the perturbation. Many of the proteins undergoing dynamic redox transformations participate in the major components for the production (photosystems and electron transport chains) or consumption (Calvin-Benson cycle and protein synthesis) of reductant and/or energy in photosynthetic organisms. Thus, our in vivo approach reveals new redox-susceptible proteins, in addition to validating those previously identified in vitro.

Sadler, Natalie C.; Melnicki, Matthew R.; Serres, Margrethe H.; Merkley, Eric D.; Chrisler, William B.; Hill, Eric A.; Romine, Margaret F.; Kim, Sangtae; Zink, Erika M.; Datta, Suchitra; Smith, Richard D.; Beliaev, Alex S.; Konopka, Allan; Wright, Aaron T.

2014-01-01T23:59:59.000Z

26

Short communication All-vanadium redox photoelectrochemical cell: An approach to store  

E-Print Network [OSTI]

24 May 2014 Keywords: Photoelectrochemical reaction Solar energy storage Vanadium redox Solar energy the commercializable value of 30% under light of 600 nm [4]. Alternatively, solar energy storage can be realizedShort communication All-vanadium redox photoelectrochemical cell: An approach to store solar energy

Liu, Fuqiang

27

Resolving Losses at the Negative Electrode in All-Vanadium Redox Flow Batteries Using Electrochemical Impedance Spectroscopy  

SciTech Connect (OSTI)

We present an in situ electrochemical technique for the quantitative measurement and resolution of the ohmic, charge transfer and diffusion overvoltages at the negative electrode of an all-vanadium redox flow battery (VRFB) using electrochemical impedance spectroscopy (EIS). The mathematics describing the complex impedance of the V+2/V+3 redox reaction is derived and matches the experimental data. The voltage losses contributed by each process have been resolved and quantified at various flow rates and electrode thicknesses as a function of current density during anodic and cathodic polarization. The diffusion overvoltage was affected strongly by flow rate while the charge transfer and ohmic losses were invariant. On the other hand, adopting a thicker electrode significantly changed both the charge transfer and diffusion losses due to increased surface area. Furthermore, the Tafel plot obtained from the impedance resolved charge transfer overvoltage yielded the geometric exchange current density, anodic and cathodic Tafel slopes (135 5 and 121 5 mV/decade respectively) and corresponding transfer coefficients = 0.45 0.02 and = 0.50 0.02 in an operating cell.

Sun, Che Nan [ORNL] [ORNL; Delnick, Frank M [ORNL] [ORNL; Aaron, D [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); Mench, Matthew M [ORNL] [ORNL; Zawodzinski, Thomas A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

28

Membrane Separator for Redox Flow Batteries that Utilize Anion Radical Mediators.  

SciTech Connect (OSTI)

A Na + ion conducting polyethylene oxide membrane is developed for an organic electrolyte redox flow battery that utilizes anion radical mediators. To achieve high specific ionic conductivity, tetraethyleneglycol dimethylether (TEGDME) is used as a plasticizer to reduce crystallinity and increase the free volume of the gel film. This membrane is physically and chemically stable in TEGDME electrolyte that contains highly reactive biphenyl anion radical mediators.

Delnick, Frank M.

2014-10-01T23:59:59.000Z

29

Polyvinyl Chloride/Silica Nanoporous Composite Separator for All-Vanadium Redox Flow Battery Applications  

SciTech Connect (OSTI)

Redox flow batteries (RFBs) are capable of reversible conversion between electricity and chemical energy. Potential RFB applications resolve around mitigating the discrepancy between electricity production and consumption to improve the stability and utilization of the power infrastructure and tackling the intermittency of renewables such as photovoltaics or wind turbines to enable their reliable integration [1, 2]. Because the energy is stored in externally contained liquid electrolytes and the energy conversion reactions take place at the electrodes, RFBs hold a unique capability to separate energy and power and thus possess considerable design flexibility to meet either energy management driven or power rating oriented grid applications, which is considered to be a unparalleled advantage over conventional solid-state secondary batteries [3]. Other advantages of RFBs include fast response to load changes, high round-trip efficiency, long calender and cycle lives, safe operations, tolerance to deep discharge, etc. [4]. Among various flow battery chemistries, all-vanadium redox flow battery (VRB) was invented by Maria Skyllas-Kazacos at the University of New South Wales in the 1980s [5, 6] and have attracted substantial attention in both research and industrial communities today [7, 8]. A well-recognized advantage that makes VRB stands out among other redox chemistries is the reduced crossover contamination ascribed to employing four different oxidation states of the same vanadium element as the two redox couples. Recently, great progress has led to remarkably improved energy density of VRB by using sulfuric-chloric mixed acid supporting electrolytes that were stable at 2.5M vanadium and had wider operational temperature window of -5~50oC [9], compared with the traditional sulfuric acid VRB system [10].

Wei, Xiaoliang; Nie, Zimin; Luo, Qingtao; Li, Bin; Sprenkle, Vincent L.; Wang, Wei

2013-04-22T23:59:59.000Z

30

A New Direction in Dye-Sensitized Solar Cells Redox Mediator Development: In Situ Fine-Tuning of the Cobalt(II)/(III) Redox  

E-Print Network [OSTI]

A New Direction in Dye-Sensitized Solar Cells Redox Mediator Development: In Situ Fine 3168, Australia *S Supporting Information ABSTRACT: Dye-sensitized solar cells (DSCs) are an attractive to tackle present and future energy challenges. Dye-sensitized solar cells (DSCs) are considered

31

Concentration Dependence of VO2+ Crossover of Nafion for Vanadium Redox Flow Batteries  

SciTech Connect (OSTI)

The VO2+ crossover, or permeability, through Nafion in a vanadium redox flow battery (VRFB) was monitored as a function of sulfuric acid concentration and VO2+ concentration. A vanadium rich solution was flowed on one side of the membrane through a flow field while symmetrically on the other side a blank or vanadium deficit solution was flowed. The blank solution was flowed through an electron paramagnetic resonance (EPR) cavity and the VO2+ concentration was determined from the intensity of the EPR signal. Concentration values were fit using a solution of Fick s law that allows for the effect of concentration change on the vanadium rich side. The fits resulted in permeability values of VO2+ ions across the membrane. Viscosity measurements of many VO2+ and H2SO4 solutions were made at 30 60 C. These viscosity values were then used to determine the effect of the viscosity of the flowing solution on the permeability of the ion. 2013 The Electrochemical Society. [DOI: 10.1149/2.004306jes] All rights reserved.

Lawton, Jamie [University of Tennessee, Knoxville (UTK); Jones, Amanda [University of Tennessee, Knoxville (UTK); Zawodzinski, Thomas A [ORNL

2013-01-01T23:59:59.000Z

32

In-situ Investigation of Vanadium Ion Transport in Redox Flow Battery  

SciTech Connect (OSTI)

We will show a new method to differentiate the vanadium transport from concentration gradient and that from electric field. Flow batteries with vanadium and iron redox couples as the electro-active species were employed to investigate the transport behavior of vanadium ions in the presence of electric field. It was shown that electric field accelerated the positive-to-negative and reduced the negative-to-positive vanadium ions transport in charge process and affected the vanadium ions transport in an opposite way in discharge process. In addition, a method was designed to differentiate the concentration gradient-driven vanadium ions diffusion and electric field-driven vanadium ions migration. Simplified mathematical model was established to simulate the vanadium ions transport in real charge-discharge operation of flow battery. The concentration gradient diffusion coefficients and electric-migration coefficients of V2+, V3+, VO2+, and VO2+ across Nafion membrane were obtained by fitting the experimental data.

Luo, Qingtao; Li, Liyu; Nie, Zimin; Wang, Wei; Wei, Xiaoliang; Li, Bin; Chen, Baowei; Yang, Zhenguo

2012-06-27T23:59:59.000Z

33

Electrocapturing flow cell  

DOE Patents [OSTI]

A flow cell for electrophoretically-assisted capturing analytes from a flow. The flow cell includes a specimen chamber, a first membrane, a second membrane, a first electrode chamber, and a second electrode chamber. The specimen chamber may have a sample inlet and a sample outlet. A first portion of the first membrane may be coupled to a first portion of the specimen chamber. A first portion of the second membrane may be coupled to a second portion of the specimen chamber. The first electrode chamber may be configured to accept a charge. A portion of the first electrode chamber may be coupled to a second portion of the first membrane. A second electrode chamber may be configured to accept an opposite charge. A portion of the second electrode chamber may be coupled to a second portion of the second membrane.

Morozov, Victor (Manassas, VA)

2011-04-05T23:59:59.000Z

34

E-Print Network 3.0 - all-uranium redox flow Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Redox Poise and Signaling Summary: Chloroplast Redox Poise and Signaling John F. AlIen Lund UnlPerJity, Lllnd, Sweden Chloroplasts... to give carbohydrates. Primary steps in...

35

E-Print Network 3.0 - all-vanadium redox flow Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Redox Poise and Signaling Summary: Chloroplast Redox Poise and Signaling John F. AlIen Lund UnlPerJity, Lllnd, Sweden Chloroplasts... to give carbohydrates. Primary steps in...

36

Paper Offer #: 031CES-216 PlanarArray REDOX Cells and pH Sensors  

E-Print Network [OSTI]

, is below one pM which is needed for water quality measurements. The richness of the detectable speciesPaper Offer #: 031CES-216 PlanarArray REDOX Cells and pH Sensors for ISS Water Quality and Microbe which exposes these elements to steam at 121°C for 30 minutes. INTRODUCTION The goal of this effort

Kounaves, Samuel P.

37

Nanoporous Polytetrafluoroethylene/Silica Composite Separator as a High-Performance All-Vanadium Redox Flow Battery Membrane  

SciTech Connect (OSTI)

Driven by the motivation of searching for low-cost membrane alternatives, a novel nanoporous polytetrafluoroethylene/silica composite separator has been prepared and evaluated for its use in all-vanadium mixed-acid redox flow battery. This separator consisting of silica particles enmeshed in a polytetrafluoroethylene fibril matrix has no ion exchange capacity and is featured with unique nanoporous structures, which function as the ion transport channels in redox flow battery operation, with an average pore size of 38nm and a porosity of 48%. This separator has produced excellent electrochemical performance in the all-vanadium mixed-acid system with energy efficiency delivery comparable to Nafion membrane and superior rate capability and temperature tolerance. The separator also demonstrates an exceptional capacity retention capability over extended cycling, offering additional operational latitude towards conveniently mitigating the capacity decay that is inevitable for Nafion. Because of the inexpensive raw materials and simple preparation protocol, the separator is particularly low-cost, estimated to be at least an order of magnitude more inexpensive than Nafion. Plus the proven chemical stability due to the same backbone material as Nafion, this separator possesses a good combination of critical membrane requirements and shows great potential to promote market penetration of the all-vanadium redox flow battery by enabling significant reduction of capital and cycle costs.

Wei, Xiaoliang; Nie, Zimin; Luo, Qingtao; Li, Bin; Chen, Baowei; Simmons, Kevin L.; Sprenkle, Vincent L.; Wang, Wei

2013-09-02T23:59:59.000Z

38

TEMPO-based Catholyte for High Energy Density Nonaqueous Redox...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow Batteries. Abstract: We will...

39

Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

Ni(III)/(IV) Bis(dicarbollide) as a Fast, Noncorrosive Redox Shuttle for Dye-Sensitized Solar Cells-marks@northwestern.edu; chadnano@northwestern.edu The favorable energetics of dye-sensitized solar cell (DSC) constituents have. Marks,*,, and Joseph T. Hupp*,,,§ Department of Chemistry, Argonne-Northwestern Solar Energy Research

40

Mirrored serpentine flow channels for fuel cell  

DOE Patents [OSTI]

A PEM fuel cell having serpentine flow field channels wherein the input/inlet legs of each channel border the input/inlet legs of the next adjacent channels in the same flow field, and the output/exit legs of each channel border the output/exit legs of the next adjacent channels in the same flow field. The serpentine fuel flow channels may be longer, and may contain more medial legs, than the serpentine oxidant flow channels.

Rock, Jeffrey Allan (Rochester, NY)

2000-08-08T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Fuel cell with internal flow control  

DOE Patents [OSTI]

A fuel cell stack is provided with a plurality of fuel cell cassettes where each fuel cell cassette has a fuel cell with an anode and cathode. The fuel cell stack includes an anode supply chimney for supplying fuel to the anode of each fuel cell cassette, an anode return chimney for removing anode exhaust from the anode of each fuel cell cassette, a cathode supply chimney for supplying oxidant to the cathode of each fuel cell cassette, and a cathode return chimney for removing cathode exhaust from the cathode of each fuel cell cassette. A first fuel cell cassette includes a flow control member disposed between the anode supply chimney and the anode return chimney or between the cathode supply chimney and the cathode return chimney such that the flow control member provides a flow restriction different from at least one other fuel cell cassettes.

Haltiner, Jr., Karl J. (Fairport, NY); Venkiteswaran, Arun (Karnataka, IN)

2012-06-12T23:59:59.000Z

42

Imposed currents in galvanic cells  

E-Print Network [OSTI]

We analyze the steady-state behavior of a general mathematical model for reversible galvanic cells, such as redox flow cells, reversible solid oxide fuel cells, and rechargeable batteries. We consider not only operation ...

Biesheuvel, P. M.

43

Nox2 redox signaling maintains essential cell populations in the Bryan C Dickinson1, Joseph Peltier2, Daniel Stone2, David V Schaffer2, and Christopher J  

E-Print Network [OSTI]

Nox2 redox signaling maintains essential cell populations in the brain Bryan C Dickinson1, Joseph Peltier2, Daniel Stone2, David V Schaffer2, and Christopher J Chang1,3 1Department of Chemistry indicator for hydrogen peroxide (H2O2), we show that adult hippocampal stem/progenitor cells (AHPs) generate

Schaffer, David V.

44

Transitioning from Fuel Cells to Redox Flow Cells | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of EnergyThe EnergyDepartment7 thFuel Processor for

45

Lithium/organosulfur redox cell having protective solid electrolyte barrier formed on anode and method of making same  

DOE Patents [OSTI]

A lithium/organosulfur redox cell is disclosed which comprises a solid lium anode, a liquid organosulfur cathode, and a barrier layer formed adjacent a surface of the solid lithium anode facing the liquid organosulfur cathode consisting of a reaction product of the lithium anode with the organosulfur cathode. The organosulfur cathode comprises a material having the formula (R(S).sub.y).sub.N where y=1 to 6, n=2 to 20 and R is one or more different aliphatic or aromatic organic moieties having 1 to 20 carbon atoms, which may include one or more oxygen, sulfur, nitrogen, or fluorine atoms associated with the chain when R comprises an aliphatic chain, wherein the linear chain may be linear or branched, saturated or unsaturated, and wherein either the aliphatic chain or the aromatic ring may have substituted groups thereon.

De Jonghe, Lutgard C. (Berkeley, CA); Visco, Steven J. (Berkeley, CA); Liu, Meilin (Albany, CA); Mailhe, Catherine C. (Vevey, CH)

1990-01-01T23:59:59.000Z

46

Review of flow battery testing at Sandia  

SciTech Connect (OSTI)

Sandia National Laboratories is evaluating prototype zinc/bromine, Redox, and zinc/ferricyanide flowing electrolyte batteries and cells. This paper will update previous reports of test results of two Exxon zinc/bromine batteries and one NASA Redox iron/chromium battery. Two 60-sq. cm. zinc/ferricyanide cells from Lockheed Missiles and Space Co. are also being evaluated. Performance, life, and operating data will be described for these batteries and cells.

Butler, P.C.; Miller, D.W.; Robinson, C.E.; Rodriguez, G.P.

1984-01-01T23:59:59.000Z

47

Effects of interstitial flow on tumor cell migration  

E-Print Network [OSTI]

Interstitial flow is the convective transport of fluid through tissue extracellular matrix. This creeping fluid flow has been shown to affect the morphology and migration of cells such as fibroblasts, cancer cells, endothelial ...

Polacheck, William J. (William Joseph)

2010-01-01T23:59:59.000Z

48

Co-flow planar SOFC fuel cell stack  

DOE Patents [OSTI]

A co-flow planar solid oxide fuel cell stack with an integral, internal manifold and a casing/holder to separately seal the cell. This construction improves sealing and gas flow, and provides for easy manifolding of cell stacks. In addition, the stack construction has the potential for an improved durability and operation with an additional increase in cell efficiency. The co-flow arrangement can be effectively utilized in other electrochemical systems requiring gas-proof separation of gases.

Chung, Brandon W.; Pham, Ai Quoc; Glass, Robert S.

2004-11-30T23:59:59.000Z

49

A review of flow battery testing at Sandia  

SciTech Connect (OSTI)

Sandia National Laboratories is evaluating prototype zinc/bromine, Redox, and zinc/ferricyanide flowing electrolyte batteries and cells. This paper updates previous reports of test results of two Exxon zinc/bromine batteries and one NASA Redox iron/chromium battery. Two 60sq. cm. zinc/ferricyanide cells from Lockheed Missiles and Space Co. are also being evaluated. Performance, life, and operating data are described for these batteries and cells.

Butler, P.C.; Miller, D.W.; Robinson, C.E.; Rodriguez, G.P.

1984-08-01T23:59:59.000Z

50

Microfabricated Renewable Beads-Trapping/Releasing Flow Cell...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Microfabricated Renewable Beads-TrappingReleasing Flow Cell for Rapid Antigen-Antibody Reaction in Chemiluminescent Immunoassay Microfabricated Renewable Beads-TrappingReleasing...

51

Breakthrough Flow Battery Cell Stack: Transformative Electrochemical Flow Storage System (TEFSS)  

SciTech Connect (OSTI)

GRIDS Project: UTRC is developing a flow battery with a unique design that provides significantly more power than today's flow battery systems. A flow battery is a cross between a traditional battery and a fuel cell. Flow batteries store their energy in external tanks instead of inside the cell itself. Flow batteries have traditionally been expensive because the battery cell stack, where the chemical reaction takes place, is costly. In this project, UTRC is developing a new stack design that achieves 10 times higher power than today’s flow batteries. This high power output means the size of the cell stack can be smaller, reducing the amount of expensive materials that are needed. UTRC’s flow battery will reduce the cost of storing electricity for the electric grid, making widespread use feasible.

None

2010-09-09T23:59:59.000Z

52

Redox Flow Batteries, a Review  

E-Print Network [OSTI]

or novel hydrogen-storage materials are is needed. Althoughof storage tank volume, and thus hydrogen compression

Weber, Adam Z.

2013-01-01T23:59:59.000Z

53

Fuel Cell Assembly Process Flow for High Productivity  

E-Print Network [OSTI]

Fuel Cell Assembly Process Flow for High Productivity Problem Presenter Ram Ramanan Bloom Energy: Introduction Bloom Energy manufactures power modules based on fuel cell technology. These are built up their possible placement within a cell assembly. Currently, these rules for assembling the basic components

Edwards, David A.

54

Piezoelectric Microvalve for Flow Control in Polymer Electrolyte Fuel Cells  

SciTech Connect (OSTI)

Maldistribution of fuel across the cells of a fuel cell stack is an issue that can contribute to poor cell performance and possible cell failure. It has been proposed that an array of microvalves could promote even distribution of fuel across a fuel cell stack. A piezoelectric microvalve has been developed for this purpose. This valve can be tuned to a nominal flow rate (and failure position) from which the actuator would either increase or decrease the flow rate and fuel. The valve can successfully regulate the flow of fuel from 0.7 to 1.1 slpm of hydrogen in the range of temperatures from 80° to 100°C and has been tested over pressure drops from 0.5 to 1 psi. A bank of these valves is currently being tested in a four-cell stack at the U.S. Department of Energy National Energy Technology Laboratory.

Bucci, B.A. (Univ. of Pittsburgh); Vipperman, J.S. (Univ. of Pittsburgh); Clark, W. (Univ. of Pittsburgh); Hensel, J.P.; Thornton, J.D.; Kim. S. (LG Electronics Inc.)

2006-11-01T23:59:59.000Z

55

Renaissance in Flow-Cell Technologies: Recent Advancements and...  

Office of Environmental Management (EM)

Presentation by Mike Perry, United Technologies Research Center, at the Flow Cells for Energy Storage Workshop held March 7-8, 2012, in Washington, DC. flowcells2012perry.pdf...

56

Fuel cell with metal screen flow-field  

DOE Patents [OSTI]

A polymer electrolyte membrane (PEM) fuel cell is provided with electrodes supplied with a reactant on each side of a catalyzed membrane assembly (CMA). The fuel cell includes a metal mesh defining a rectangular flow-field pattern having an inlet at a first corner and an outlet at a second corner located on a diagonal from the first corner, wherein all flow paths from the inlet to the outlet through the square flow field pattern are equivalent to uniformly distribute the reactant over the CMA. In a preferred form of metal mesh, a square weave screen forms the flow-field pattern. In a particular characterization of the present invention, a bipolar plate electrically connects adjacent fuel cells, where the bipolar plate includes a thin metal foil having an anode side and a cathode side; a first metal mesh on the anode side of the thin metal foil; and a second metal mesh on the cathode side of the thin metal foil. In another characterization of the present invention, a cooling plate assembly cools adjacent fuel cells, where the cooling plate assembly includes an anode electrode and a cathode electrode formed of thin conducting foils; and a metal mesh flow field there between for distributing cooling water flow over the electrodes to remove heat generated by the fuel cells. 11 figs.

Wilson, M.S.; Zawodzinski, C.

1998-08-25T23:59:59.000Z

57

Fuel cell with metal screen flow-field  

DOE Patents [OSTI]

A polymer electrolyte membrane (PEM) fuel cell is provided with electrodes supplied with a reactant on each side of a catalyzed membrane assembly (CMA). The fuel cell includes a metal mesh defining a rectangular flow-field pattern having an inlet at a first corner and an outlet at a second corner located on a diagonal from the first corner, wherein all flow paths from the inlet to the outlet through the square flow field pattern are equivalent to uniformly distribute the reactant over the CMA. In a preferred form of metal mesh, a square weave screen forms the flow-field pattern. In a particular characterization of the present invention, a bipolar plate electrically connects adjacent fuel cells, where the bipolar plate includes a thin metal foil having an anode side and a cathode side; a first metal mesh on the anode side of the thin metal foil; and a second metal mesh on the cathode side of the thin metal foil. In another characterization of the present invention, a cooling plate assembly cools adjacent fuel cells, where the cooling plate assembly includes an anode electrode and a cathode electrode formed of thin conducting foils; and a metal mesh flow field therebetween for distributing cooling water flow over the electrodes to remove heat generated by the fuel cells.

Wilson, Mahlon S. (Los Alamos, NM); Zawodzinski, Christine (Los Alamos, NM)

1998-01-01T23:59:59.000Z

58

Fuel cell with metal screen flow-field  

DOE Patents [OSTI]

A polymer electrolyte membrane (PEM) fuel cell is provided with electrodes supplied with a reactant on each side of a catalyzed membrane assembly (CMA). The fuel cell includes a metal mesh defining a rectangular flow-field pattern having an inlet at a first corner and an outlet at a second corner located on a diagonal from the first corner, wherein all flow paths from the inlet to the outlet through the square flow field pattern are equivalent to uniformly distribute the reactant over the CMA. In a preferred form of metal mesh, a square weave screen forms the flow-field pattern. In a particular characterization of the present invention, a bipolar plate electrically connects adjacent fuel cells, where the bipolar plate includes a thin metal foil having an anode side and a cathode side; a first metal mesh on the anode side of the thin metal foil; and a second metal mesh on the cathode side of the thin metal foil. In another characterization of the present invention, a cooling plate assembly cools adjacent fuel cells, where the cooling plate assembly includes an anode electrode and a cathode electrode formed of thin conducting foils; and a metal mesh flow field therebetween for distributing cooling water flow over the electrodes to remove heat generated by the fuel cells.

Wilson, Mahlon S. (Los Alamos, NM); Zawodzinski, Christine (Los Alamos, NM)

2001-01-01T23:59:59.000Z

59

Combustor air flow control method for fuel cell apparatus  

DOE Patents [OSTI]

A method for controlling the heat output of a combustor in a fuel cell apparatus to a fuel processor where the combustor has dual air inlet streams including atmospheric air and fuel cell cathode effluent containing oxygen depleted air. In all operating modes, an enthalpy balance is provided by regulating the quantity of the air flow stream to the combustor to support fuel cell processor heat requirements. A control provides a quick fast forward change in an air valve orifice cross section in response to a calculated predetermined air flow, the molar constituents of the air stream to the combustor, the pressure drop across the air valve, and a look up table of the orifice cross sectional area and valve steps. A feedback loop fine tunes any error between the measured air flow to the combustor and the predetermined air flow.

Clingerman, Bruce J. (Palmyra, NY); Mowery, Kenneth D. (Noblesville, IN); Ripley, Eugene V. (Russiaville, IN)

2001-01-01T23:59:59.000Z

60

Global helioseismic evidence for a deeply penetrating Solar meridional flow consisting of multiple flow cells  

E-Print Network [OSTI]

We use a novel global helioseismic analysis method to infer the meridional flow in the deep Solar interior. The method is based on the perturbation of eigenfunctions of Solar p modes due to meridional flow. We apply this method to time series obtained from Dopplergrams measured by the Michelson Doppler Imager aboard the Solar and Heliospheric Observatory (SOHO) covering the observation period 2004-2010. Our results show evidence that the meridional flow reaches down to the base of the convection zone. The flow profile has a complex spatial structure consisting of multiple flow cells distributed in depth and latitude. Toward the Solar surface, our results are in good agreement with flow measurements from local helioseismology.

Schad, A; Roth, M

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Liquid chromatography/Fourier transform IR spectrometry interface flow cell  

DOE Patents [OSTI]

A zero dead volume (ZDV) microbore high performance liquid chromatography (..mu.. HPLC)/Fourier transform infrared (FTIR) interface flow cell includes an IR transparent crystal having a small diameter bore therein through which a sample liquid is passed. The interface flow cell further includes a metal holder in combination with a pair of inner, compressible seals for directly coupling the thus configured spectrometric flow cell to the outlet of a ..mu.. HPLC column end fitting to minimize the transfer volume of the effluents exiting the ..mu.. HPLC column which exhibit excellent flow characteristics due to the essentially unencumbered, open-flow design. The IR beam passes transverse to the sample flow through the circular bore within the IR transparent crystal, which is preferably comprised of potassium bromide (KBr) or calcium fluoride (CaF/sub 2/), so as to minimize interference patterns and vignetting encountered in conventional parallel-plate IR cells. The long IR beam pathlength and lensing effect of the circular cross-section of the sample volume in combination with the refractive index differences between the solvent and the transparent crystal serve to focus the IR beam in enhancing sample detection sensitivity by an order of magnitude.

Johnson, C.C.; Taylor, L.T.

1985-01-04T23:59:59.000Z

62

Influx - Flow Cytometer Cell Sorter | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickrinformation for planningtoA Journey InsideVorticesInflux - Flow

63

Gradient isolator for flow field of fuel cell assembly  

DOE Patents [OSTI]

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions.

Ernst, William D. (Troy, NY)

1999-01-01T23:59:59.000Z

64

Gradient isolator for flow field of fuel cell assembly  

DOE Patents [OSTI]

Isolator(s) include isolating material and optionally gasketing material strategically positioned within a fuel cell assembly. The isolating material is disposed between a solid electrolyte and a metal flow field plate. Reactant fluid carried by flow field plate channel(s) forms a generally transverse electrochemical gradient. The isolator(s) serve to isolate electrochemically a portion of the flow field plate, for example, transversely outward from the channel(s), from the electrochemical gradient. Further, the isolator(s) serve to protect a portion of the solid electrolyte from metallic ions. 4 figs.

Ernst, W.D.

1999-06-15T23:59:59.000Z

65

Cross-flow electrochemical reactor cells, cross-flow reactors, and use of cross-flow reactors for oxidation reactions  

DOE Patents [OSTI]

This invention discloses cross-flow electrochemical reactor cells containing oxygen permeable materials which have both electron conductivity and oxygen ion conductivity, cross-flow reactors, and electrochemical processes using cross-flow reactor cells having oxygen permeable monolithic cores to control and facilitate transport of oxygen from an oxygen-containing gas stream to oxidation reactions of organic compounds in another gas stream. These cross-flow electrochemical reactors comprise a hollow ceramic blade positioned across a gas stream flow or a stack of crossed hollow ceramic blades containing a channel or channels for flow of gas streams. Each channel has at least one channel wall disposed between a channel and a portion of an outer surface of the ceramic blade, or a common wall with adjacent blades in a stack comprising a gas-impervious mixed metal oxide material of a perovskite structure having electron conductivity and oxygen ion conductivity. The invention includes reactors comprising first and second zones seprated by gas-impervious mixed metal oxide material material having electron conductivity and oxygen ion conductivity. Prefered gas-impervious materials comprise at least one mixed metal oxide having a perovskite structure or perovskite-like structure. The invention includes, also, oxidation processes controlled by using these electrochemical reactors, and these reactions do not require an external source of electrical potential or any external electric circuit for oxidation to proceed.

Balachandran, Uthamalingam (Hinsdale, IL); Poeppel, Roger B. (Glen Ellyn, IL); Kleefisch, Mark S. (Naperville, IL); Kobylinski, Thaddeus P. (Lisle, IL); Udovich, Carl A. (Joliet, IL)

1994-01-01T23:59:59.000Z

66

Long waves in parallel flow in Hele-Shaw cells  

SciTech Connect (OSTI)

During the past several years the flow of immiscible flow in Hele-Shaw cells and porous media has been investigated extensively. Of particular interest to most studies has been frontal displacement, specifically viscous fingering instabilities and finger growth. The practical ramifications regarding oil recovery, as well as many other industrial processes in porous media, have served as the primary driving force for most of these investigations. By contrast, little attention has been paid to the motion of lateral fluid interface, which are parallel to the main flow direction. Parallel flow is an often encountered, although much overlooked regime. The evolution of fluid interfaces in parallel flow in Hele-Shaw cells is studied both theoretically and experimentally in the large capillary number limit. It is shown that such interfaces support wave motion, the amplitude of which for long waves is governed by the KdV equation. Experiments are conducted in a long Hele-Shaw cell that validate the theory in the symmetric case. 35 refs., 16 figs.

Zeybek, M.; Yortsos, Y.C.

1991-04-01T23:59:59.000Z

67

Fuel cell with interdigitated porous flow-field  

DOE Patents [OSTI]

A polymer electrolyte membrane (PEM) fuel cell is formed with an improved system for distributing gaseous reactants to the membrane surface. A PEM fuel cell has an ionic transport membrane with opposed catalytic surfaces formed thereon and separates gaseous reactants that undergo reactions at the catalytic surfaces of the membrane. The fuel cell may also include a thin gas diffusion layer having first and second sides with a first side contacting at least one of the catalytic surfaces. A macroporous flow-field with interdigitated inlet and outlet reactant channels contacts the second side of the thin gas diffusion layer for distributing one of the gaseous reactants over the thin gas diffusion layer for transport to an adjacent one of the catalytic surfaces of the membrane. The porous flow field may be formed from a hydrophilic material and provides uniform support across the backside of the electrode assembly to facilitate the use of thin backing layers. 9 figs.

Wilson, M.S.

1997-06-24T23:59:59.000Z

68

Fuel cell with interdigitated porous flow-field  

DOE Patents [OSTI]

A polymer electrolyte membrane (PEM) fuel cell is formed with an improved system for distributing gaseous reactants to the membrane surface. A PEM fuel cell has an ionic transport membrane with opposed catalytic surfaces formed thereon and separates gaseous reactants that undergo reactions at the catalytic surfaces of the membrane. The fuel cell may also include a thin gas diffusion layer having first and second sides with a first side contacting at least one of the catalytic surfaces. A macroporous flow-field with interdigitated inlet and outlet reactant channels contacts the second side of the thin gas diffusion layer for distributing one of the gaseous reactants over the thin gas diffusion layer for transport to an adjacent one of the catalytic surfaces of the membrane. The porous flow field may be formed from a hydrophilic material and provides uniform support across the backside of the electrode assembly to facilitate the use of thin backing layers.

Wilson, Mahlon S. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

69

MODELING THE EFFECT OF FLOW FIELD DESIGN ON PEM FUEL CELL PERFORMANCE  

E-Print Network [OSTI]

MODELING THE EFFECT OF FLOW FIELD DESIGN ON PEM FUEL CELL PERFORMANCE Jeffrey Glandt, Sirivatch University of South Carolina Columbia, SC 29208 vanzee@engr.sc.edu Key words: PEM fuel cell, flow field or printed in its publications. #12;2 MODELING THE EFFECT OF FLOW FIELD DESIGN ON PEM FUEL CELL PERFORMANCE

Van Zee, John W.

70

Investigation of redox processes at semiconductor electrode liquid junctions  

SciTech Connect (OSTI)

Research in fundamental aspects of photoelectrochemical cells has been in the following areas: chemical probes for hot carrier processes, electrostatic theory for describing electrical interactions at interfaces, and kinetics of electron transfer at ideal semiconductor solution interfaces. Our goal is to achieve a better understanding of dark and photo-induced current flow at the semiconductor electrode/redox electrolyte interface (SEI) so that devices and processes utilizing this interface for solar energy conversion can be developed or improved. Our most important accomplishment has been the development of a redox system capable of detecting hot electrons at the p-InP/acetonitrile interface. Also, we have examined electrostatic theory for the image potential of an ion as a function of distance from the SEI. Finally, our group was one of the first to realize that the 2-dimensional metal chalcogenides (MC) are excellent materials for fundamental studies of electron transfer at the SEI. One of the chief potential advantages for use of MC's is the formation of semiconductor/liquid junctions with nearly ideal electrochemical properties. 27 refs., 1 fig.

Koval, C.A.

1990-08-01T23:59:59.000Z

71

NADPH oxidase and lipid raft-associated redox signaling are required for PCB153-induced upregulation of cell adhesion molecules in human brain endothelial cells  

SciTech Connect (OSTI)

Exposure to persistent organic pollutants, such as polychlorinated biphenyls (PCBs), can lead to chronic inflammation and the development of vascular diseases. Because cell adhesion molecules (CAMs) of the cerebrovascular endothelium regulate infiltration of inflammatory cells into the brain, we have explored the molecular mechanisms by which ortho-substituted polychlorinated biphenyls (PCBs), such as PCB153, can upregulate CAMs in brain endothelial cells. Exposure to PCB153 increased expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), as well as elevated adhesion of leukocytes to brain endothelial cells. These effects were impeded by inhibitors of EGFR, JAKs, or Src activity. In addition, pharmacological inhibition of NADPH oxidase or disruption of lipid rafts by cholesterol depleting agents blocked PCB153-induced phosphorylation of JAK and Src kinases and upregulation of CAMs. In contrast, silencing of caveolin-1 by siRNA interference did not affect upregulation of ICAM-1 and VCAM-1 in brain endothelial cells stimulated by PCB153. Results of the present study indicate that lipid raft-dependent NADPH oxidase/JAK/EGFR signaling mechanisms regulate the expression of CAMs in brain endothelial cells and adhesion of leukocytes to endothelial monolayers. Due to its role in leukocyte infiltration, induction of CAMs may contribute to PCB-induced cerebrovascular disorders and neurotoxic effects in the CNS.

Eum, Sung Yong [Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky, Lexington, KY 40536 (United States)], E-mail: sungyong.eum@uky.edu; Andras, Ibolya [Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky, Lexington, KY 40536 (United States); Hennig, Bernhard [College of Agriculture, University of Kentucky, Lexington, KY 40536 (United States); Toborek, Michal [Molecular Neuroscience and Vascular Biology Laboratory, Department of Neurosurgery, University of Kentucky, Lexington, KY 40536 (United States)

2009-10-15T23:59:59.000Z

72

Liquid Water Dynamics in a Model Polymer Electrolyte Fuel Cell Flow Channel  

E-Print Network [OSTI]

Liquid Water Dynamics in a Model Polymer Electrolyte Fuel Cell Flow Channel by Chris Miller in a Model Polymer Electrolyte Fuel Cell Flow Channel by Chris Miller Bachelors of Engineering, University in a polymer electrolyte fuel cell is a critical issue in ensuring high cell performance. The water production

Victoria, University of

73

Improved Flow-Field Structures for Direct Methanol Fuel Cells  

SciTech Connect (OSTI)

The direct methanol fuel cell (DMFC) is ideal if high energy-density liquid fuels are required. Liquid fuels have advantages over compressed hydrogen including higher energy density and ease of handling. Although state-of-the-art DMFCs exhibit manageable degradation rates, excessive fuel crossover diminishes system energy and power density. Although use of dilute methanol mitigates crossover, the concomitant lowering of the gross fuel energy density (GFED) demands a complex balance-of-plant (BOP) that includes higher flow rates, external exhaust recirculation, etc. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol. NuVant Systems Inc. (NuVant) will maximize the GFED by design and assembly of a DMFC that uses near neat methanol. The approach is to tune the diffusion of highly concentrated methanol (to the anode catalytic layer) to the back-diffusion of water formed at the cathode (i.e. in situ generation of dilute methanol at the anode layer). Crossover will be minimized without compromising the GFED by innovative integration of the anode flow-field and the diffusion layer. The integrated flow-field-diffusion-layers (IFDLs) will widen the current and potential DMFC operating ranges and enable the use of cathodes optimized for hydrogen-air fuel cells.

Gurau, Bogdan

2013-05-31T23:59:59.000Z

74

Flow Cells for Energy Storage Workshop Overview | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecordFederal7.pdfFlash_2010_-24.pdfOverview Flow Cells for Energy Storage

75

Flow Cells for Energy Storage Workshop Summary Report | Department of  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecordFederal7.pdfFlash_2010_-24.pdfOverview Flow Cells for Energy

76

Flow Cells for Energy Storage Workshop | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:Year in3.pdf Flash2006-53.pdf0.pdf Flash2008-50.pdf5.pdfTechnologiesFlow Cells for Energy Storage

77

The flow of red blood cells through a narrow spleen-like slit Jonathan B. Freund  

E-Print Network [OSTI]

The flow of red blood cells through a narrow spleen-like slit Jonathan B. Freund Citation: Phys OF FLUIDS 25, 110807 (2013) The flow of red blood cells through a narrow spleen-like slit Jonathan B are perhaps the smallest blood passages in the body, and red blood cells must deform significantly to pass

Freund, Jonathan B.

78

BIOENERGY AND BIOFUELS A multi-electrode continuous flow microbial fuel cell  

E-Print Network [OSTI]

BIOENERGY AND BIOFUELS A multi-electrode continuous flow microbial fuel cell with separator microbial fuel cells (MFCs) requires the development of compact reactors with multiple electro- des continuous flow treatment using actual wastewaters. Keywords Microbial fuel cell . Scaling up . Separator

79

Electrochimica Acta 50 (2005) 53905398 Membraneless laminar flow-based micro fuel cells operating in alkaline,  

E-Print Network [OSTI]

Electrochimica Acta 50 (2005) 5390­5398 Membraneless laminar flow-based micro fuel cells operating) in membraneless, laminar flow-based micro fuel cells (LF-FCs) eliminates several PEM-related issues such as fuel the anode is in acidic media while the cathode is in alkali, or vice versa. Operating a fuel cell under

Kenis, Paul J. A.

80

A NEW PEMFC FLOW FIELD PLATE OPTIMIZATION COMPARISON - ANSYS FLUENT FUEL-CELL SIMULATION.  

E-Print Network [OSTI]

??The performance of a new cathode flow field plate located on a PEM fuel cell was compared to an industry standard and optimal serpentine design… (more)

Soueidan, Ahmed Yassin

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Solid oxide fuel cell having compound cross flow gas patterns  

DOE Patents [OSTI]

A core construction for a fuel cell is disclosed having both parallel and cross flow passageways for the fuel and the oxidant gases. Each core passageway is defined by electrolyte and interconnect walls. Each electrolyte wall consists of cathode and anode materials sandwiching an electrolyte material. Each interconnect wall is formed as a sheet of inert support material having therein spaced small plugs of interconnect material, where cathode and anode materials are formed as layers on opposite sides of each sheet and are electrically connected together by the interconnect material plugs. Each interconnect wall in a wavy shape is connected along spaced generally parallel line-like contact areas between corresponding spaced pairs of generally parallel electrolyte walls, operable to define one tier of generally parallel flow passageways for the fuel and oxidant gases. Alternate tiers are arranged to have the passageways disposed normal to one another. Solid mechanical connection of the interconnect walls of adjacent tiers to the opposite sides of the common electrolyte wall therebetween is only at spaced point-like contact areas, 90 where the previously mentioned line-like contact areas cross one another.

Fraioli, A.V.

1983-10-12T23:59:59.000Z

82

Redox Shuttles DOI: 10.1002/anie.201002181  

E-Print Network [OSTI]

(dicarbollide) Redox Shuttles in Dye-Sensitized Solar Cells** Alexander M. Spokoyny, Tina C. Li, Omar K. Farha, Charles* Dye-sensitized solar cells (DSCs) are potential next-gener- ation solar electricity sources since molecular dyes to increase light absorption,[3] evaluation of alternative semiconducting photoanodes

83

Original article Normal and sickle red blood cell dynamics under venular flow  

E-Print Network [OSTI]

1 Original article Normal and sickle red blood cell dynamics under venular flow C. Allayousa , A these notions are found in sickle cell disease where sickle red blood cells become more rigid, leading. Thus, normal and sickle red blood cells are classified into different sub-groups, showing

Paris-Sud XI, Université de

84

Redox Flow Batteries - Energy Innovation Portal  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298,NIST 800-53 RevisionDivision andIon Soft Landing.

85

Redox shuttles for lithium ion batteries  

SciTech Connect (OSTI)

Compounds may have general Formula IVA or IVB. ##STR00001## where, R.sup.8, R.sup.9, R.sup.10, and R.sup.11 are each independently selected from H, F, Cl, Br, CN, NO.sub.2, alkyl, haloalkyl, and alkoxy groups; X and Y are each independently O, S, N, or P; and Z' is a linkage between X and Y. Such compounds may be used as redox shuttles in electrolytes for use in electrochemical cells, batteries and electronic devices.

Weng, Wei; Zhang, Zhengcheng; Amine, Khalil

2014-11-04T23:59:59.000Z

86

A Lattice Boltzmann Fictitious Domain Method for Modeling Red Blood Cell Deformation and Multiple-Cell Hydrodynamic Interactions in Flow  

SciTech Connect (OSTI)

To model red blood cell (RBC) deformation in flow, the recently developed LBM-DLM/FD method ([Shi and Lim, 2007)29], derived from the lattice Boltzmann method and the distributed Lagrange multiplier/fictitious domain methodthe fictitious domain method, is extended to employ the mesoscopic network model for simulations of red blood cell deformation. The flow is simulated by the lattice Boltzmann method with an external force, while the network model is used for modeling red blood cell deformation and the fluid-RBC interaction is enforced by the Lagrange multiplier. To validate parameters of the RBC network model, sThe stretching numerical tests on both coarse and fine meshes are performed and compared with the corresponding experimental data to validate the parameters of the RBC network model. In addition, RBC deformation in pipe flow and in shear flow is simulated, revealing the capacity of the current method for modeling RBC deformation in various flows.

Shi, Xing; Lin, Guang; Zou, Jianfeng; Fedosov, Dmitry A.

2013-07-20T23:59:59.000Z

87

Computation of the Redox and Protonation Properties of Quinones...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Computation of the Redox and Protonation Properties of Quinones: Towards the Prediction of Redox Cycling Natural Products. Computation of the Redox and Protonation Properties of...

88

Modeling the influence of optic flow on grid cell firing in the absence of other cues1  

E-Print Network [OSTI]

Modeling the influence of optic flow on grid cell firing in the absence of other cues1 Florian affect the firing of grid cells recorded in entorhinal cortex of rats. Optic flow provides information and superimposed with noise in order to model the optic flow that would be available to the rat. This optic flow

Hasselmo, Michael

89

Characterization of Limiting Factors in Laminar Flow-Based Membraneless Microfuel Cells  

E-Print Network [OSTI]

are underway to develop and optimize microscale fuel cells as high-energy-density power source alternatives, where fuel and oxidant are oxidized and re- duced, respectively, is essential for fuel cell optimization reports the analysis of a microflu- idic fuel cell based on laminar flow using an external reference

Kenis, Paul J. A.

90

Analysis of Pt/C electrode performance in a flowing-electrolyte alkaline fuel cell  

E-Print Network [OSTI]

Analysis of Pt/C electrode performance in a flowing- electrolyte alkaline fuel cell Fikile R 17 October 2011 Accepted 18 October 2011 Available online 12 November 2011 Keywords: Alkaline fuel cell Electrode characterization X-ray micro-computed tomography Microfluidic fuel cell Carbonates a b

Kenis, Paul J. A.

91

Investigation of a U-Shaped Fuel Cell Flow Channel with Particle Image Velocimetry (PIV)  

E-Print Network [OSTI]

Investigation of a U-Shaped Fuel Cell Flow Channel with Particle Image Velocimetry (PIV phenomena that occur within serpentine reactant transport channels of fuel cells. Achieving effective mixing within these channels is crucial for the proper operation of the fuel cell and proper understanding

Victoria, University of

92

Holme et al. Soil Redox Sensor Networks RADIO FREQUENCY ENABLED SOIL REDOX POTENTIAL  

E-Print Network [OSTI]

Holme et al. Soil Redox Sensor Networks RADIO FREQUENCY ENABLED SOIL REDOX POTENTIAL SENSOR technologies that may be combined into a cost effective soil redox sensor network, discuss the merits of each as a component of said network, describe a prototype soil redox sensor network and perform basic laboratory

Rubinstein, Benjamin

93

Constructal flow structure for a PEM fuel cell J.V.C. Vargas a,*, J.C. Ordonez b  

E-Print Network [OSTI]

Constructal flow structure for a PEM fuel cell J.V.C. Vargas a,*, J.C. Ordonez b , A. Bejan c the internal structure (relative sizes, spacings) and external shape (aspect ratios) of a unit PEM fuel cell so) level of a fuel cell stack, i.e., the unit PEM fuel cell, which is modeled as a unidirectional flow

Ordonez, Juan C.

94

Electro-osmotic flow control for living cell analysis in microfluidic Tomasz Glawdel, Carolyn L. Ren *  

E-Print Network [OSTI]

the problems associated with the use of high electric fields required for operating electro-osmotic pumps in living cell analysis. In particular, electroporation of cell mem- branes, Joule heating, electrolysis pressure-driven flow control systems. Futai et al. (2006) developed a recircu- lating perfusion platform

Le Roy, Robert J.

95

Multi-electrode continuous flow microbial electrolysis cell for biogas production from acetate  

E-Print Network [OSTI]

Multi-electrode continuous flow microbial electrolysis cell for biogas production from acetate. For hydrogen production to occur at the cathode, a small voltage must be added to the system to make hydrogen Electrohydrogenesis Hydrogen Methanogenesis Scale-up a b s t r a c t Most microbial electrolysis cells (MECs) contain

96

DETECTION OF EQUATORWARD MERIDIONAL FLOW AND EVIDENCE OF DOUBLE-CELL MERIDIONAL CIRCULATION INSIDE THE SUN  

SciTech Connect (OSTI)

Meridional flow in the solar interior plays an important role in redistributing angular momentum and transporting magnetic flux inside the Sun. Although it has long been recognized that the meridional flow is predominantly poleward at the Sun's surface and in its shallow interior, the location of the equatorward return flow and the meridional flow profile in the deeper interior remain unclear. Using the first 2 yr of continuous helioseismology observations from the Solar Dynamics Observatory/Helioseismic Magnetic Imager, we analyze travel times of acoustic waves that propagate through different depths of the solar interior carrying information about the solar interior dynamics. After removing a systematic center-to-limb effect in the helioseismic measurements and performing inversions for flow speed, we find that the poleward meridional flow of a speed of 15 m s{sup -1} extends in depth from the photosphere to about 0.91 R{sub Sun }. An equatorward flow of a speed of 10 m s{sup -1} is found between 0.82 and 0.91 R{sub Sun} in the middle of the convection zone. Our analysis also shows evidence of that the meridional flow turns poleward again below 0.82 R{sub Sun }, indicating an existence of a second meridional circulation cell below the shallower one. This double-cell meridional circulation profile with an equatorward flow shallower than previously thought suggests a rethinking of how magnetic field is generated and redistributed inside the Sun.

Zhao Junwei; Bogart, R. S.; Kosovichev, A. G.; Hartlep, Thomas [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States); Duvall, T. L. Jr. [Solar Physics Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2013-09-10T23:59:59.000Z

97

Microfluidic Electroporative Flow Cytometry for Studying Single-Cell Biomechanics  

E-Print Network [OSTI]

and metastasis. Screening of cells based on their biome- chanical properties provides rapid tools for label-10A, MCF-7, and 12-O-tetradecanoylphorbol-13-acetate-treated MCF-7) with different malignancy correlation exists between an increase in deformability and progression from a nontumorigenic cell line

Lu, Chang

98

Characterization of protein redox dynamics induced during light-to-dark transitions and nutrient limitation in cyanobacteria  

SciTech Connect (OSTI)

Protein redox chemistry constitutes a major void in knowledge pertaining to photoautotrophic system regulation and signaling processes. We have employed a chemical biology approach to analyze redox sensitive proteins in live Synechococcus sp. PCC 7002 cells in both light and dark periods, and to understand how cellular redox balance is disrupted during nutrient perturbation. The present work identified several novel putative redox-sensitive proteins that are involved in the generation of reductant, macromolecule synthesis, and carbon flux through central metabolic pathways, and may be involved in cell signaling and response mechanisms. Furthermore, our research suggests that dynamic redox changes in response to specific nutrient limitations contribute to the regulatory changes driven by a shift from light to dark. Taken together, these results contribute to the high-level understanding of post-translational mechanisms regulating flux distributions and therefore present potential metabolic engineering targets for redirecting carbon towards biofuel precursors.

Ansong, Charles; Sadler, Natalie C.; Hill, Eric A.; Lewis, Michael P.; Zink, Erika M.; Smith, Richard D.; Beliaev, Alex S.; Konopka, Allan; Wright, Aaron T.

2014-07-03T23:59:59.000Z

99

Development of a cell-based stream flow routing model  

E-Print Network [OSTI]

al. (1994) developed a 2.00x2.50 resolution river routing model for a number of World Rivers, coupled with an atmospheric-ocean model. The GCM of NASA/Goddard Institute for Space Studies (GISS) (Hansen et al., 1983) was used to calculate the runoff... resolution of 2.00 X 2.50 using the coarse river network developed by Miller et al. (1994). Input to each of the grid cell was derived from the improved GISS GCM (Hansen et al., 1983), which improved the model prediction of discharge. Costa and Foley (1997...

Raina, Rajeev

2005-08-29T23:59:59.000Z

100

Cartesian Cut Cell Two-Fluid Solver for Hydraulic Flow Problems  

E-Print Network [OSTI]

Cartesian Cut Cell Two-Fluid Solver for Hydraulic Flow Problems L. Qian1 ; D. M. Causon2 ; D. M. Ingram3 ; and C. G. Mingham4 Abstract: A two-fluid solver which can be applied to a variety of hydraulic with a sloping beach is also calculated to demonstrate the applicability of the method to real hydraulic problems

Ingram, David

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Highly conductive composites for fuel cell flow field plates and bipolar plates  

DOE Patents [OSTI]

This invention provides a fuel cell flow field plate or bipolar plate having flow channels on faces of the plate, comprising an electrically conductive polymer composite. The composite is composed of (A) at least 50% by weight of a conductive filler, comprising at least 5% by weight reinforcement fibers, expanded graphite platelets, graphitic nano-fibers, and/or carbon nano-tubes; (B) polymer matrix material at 1 to 49.9% by weight; and (C) a polymer binder at 0.1 to 10% by weight; wherein the sum of the conductive filler weight %, polymer matrix weight % and polymer binder weight % equals 100% and the bulk electrical conductivity of the flow field or bipolar plate is at least 100 S/cm. The invention also provides a continuous process for cost-effective mass production of the conductive composite-based flow field or bipolar plate.

Jang, Bor Z; Zhamu, Aruna; Song, Lulu

2014-10-21T23:59:59.000Z

102

Novel Redox Shuttles for Overcharge Protection of Lithium-Ion...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Redox Shuttles for Overcharge Protection of Lithium-Ion Batteries Technology available for licensing: Electrolytes containing novel redox shuttles (electron transporters) for...

103

Redox Chemistry in Thin Layers of Organometallic Complexes Prepared...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Redox Chemistry in Thin Layers of Organometallic Complexes Prepared Using Ion Soft Landing. Redox Chemistry in Thin Layers of Organometallic Complexes Prepared Using Ion Soft...

104

Redox reactions of reduced flavin mononucleotide (FMN), riboflavin...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Redox reactions of reduced flavin mononucleotide (FMN), riboflavin (RBF), and anthraquinone-2,6-disulfonate (AQDS) with Redox reactions of reduced flavin mononucleotide (FMN),...

105

Redox polymer electrodes for advanced batteries  

DOE Patents [OSTI]

Advanced batteries having a long cycle lifetime are provided. More specifically, the present invention relates to electrodes made from redox polymer films and batteries in which either the positive electrode, the negative electrode, or both, comprise redox polymers. Suitable redox polymers for this purpose include pyridyl or polypyridyl complexes of transition metals like iron, ruthenium, osmium, chromium, tungsten and nickel; porphyrins (either free base or metallo derivatives); phthalocyanines (either free base or metallo derivatives); metal complexes of cyclams, such as tetraazacyclotetradecane; metal complexes of crown ethers and metallocenes such as ferrocene, cobaltocene and ruthenocene.

Gregg, Brian A. (Golden, CO); Taylor, A. Michael (Golden, CO)

1998-01-01T23:59:59.000Z

106

A microfluidic flow-cell for the study of the ultrafast dynamics of biological systems  

SciTech Connect (OSTI)

The study of biochemical dynamics by ultrafast spectroscopic methods is often restricted by the limited amount of liquid sample available, while the high repetition rate of light sources can induce photodamage. In order to overcome these limitations, we designed a high flux, sub-ml, capillary flow-cell. While the 0.1 mm thin window of the 0.5 mm cross-section capillary ensures an optimal temporal resolution and a steady beam deviation, the cell-pump generates flows up to ?0.35 ml/s that are suitable to pump laser repetition rates up to ?14 kHz, assuming a focal spot-diameter of 100 ?m. In addition, a decantation chamber efficiently removes bubbles and allows, via septum, for the addition of chemicals while preserving the closed atmosphere. The minimal useable amount of sample is ?250 ?l.

Chauvet, Adrien, E-mail: adrien.chauvet@epfl.ch; Chergui, Majed [Ecole Polytechnique Fédérale de Lausanne (EPFL), Laboratoire de Spectroscopie Ultrarapide, ISIC, Faculté des Sciences de Base, Station 6, 1015 Lausanne (Switzerland); Tibiletti, Tania; Caffarri, Stefano [Aix Marseille Université, CNRS, CEA, UMR 7265 Biologie Végétale et Microbiologie Environnementales, 13009 Marseille (France)

2014-10-15T23:59:59.000Z

107

Electrochemical study of multi-electrode microbial fuel cells under fed-batch and continuous flow conditions  

E-Print Network [OSTI]

Electrochemical study of multi-electrode microbial fuel cells under fed-batch and continuous flow November 2013 Available online 18 December 2013 Keywords: Multi-electrode Microbial fuel cells Hydraulic connected microbial fuel cells (MFCs) was compared with the reactors operated using individual electrical

108

Water management studies in PEM fuel cells, Part II: Ex situ investigation of flow maldistribution, pressure drop  

E-Print Network [OSTI]

by externally humidified air and hydrogen gas streams, must be present within the fuel cell to maintain 4 5 6 #12;a fuel cell blocks gas transport pathways in the catalyst layers, gas diffusion layersWater management studies in PEM fuel cells, Part II: Ex situ investigation of flow maldistribution

Kandlikar, Satish

109

An Inertial Cell Model for the Drag Force in Multi-phase Flow  

E-Print Network [OSTI]

A new model for the drag coefficient of a sphere in a concentrated system is described. It is based upon a cell-averaged model for the Stokes regime combined with a physically motivated extrapolation to arbitrary Reynolds number. It can be used as an alternative to the isolated particle drag coefficient in Euler-Lagrange modelling of solid-liquid multi-phase flow.The corresponding drag force also provides a dynamic bed equation for use in Euler-Euler modelling.

Tupper, Gary; Mainza, Aubrey

2015-01-01T23:59:59.000Z

110

Pollution of Natural Waters 1. Redox chemistry  

E-Print Network [OSTI]

. Eutrophication 4. Water treatment 1. Redox chemistry #15; Principle of equilibration of chemical system R Keq;sh and other aquatic life { Shift to anaerobic metabolic mechanisms #15; Eutrophication: agin

Schofield, Jeremy

111

Transient light-induced intracellular oxidation revealed by redox biosensor  

SciTech Connect (OSTI)

Highlights: •Time-resolved live cell imaging revealed light-induced oxidation. •Only the roGFP probe fused with glutaredoxin reveals photooxidation. •The transient oxidation is rapidly reduced by the cytosolic antioxidant system. •Intracellular photooxidation is media-dependent. •Oxidation is triggered exclusively by exposure to short wavelength excitation. -- Abstract: We have implemented a ratiometric, genetically encoded redox-sensitive green fluorescent protein fused to human glutaredoxin (Grx1-roGFP2) to monitor real time intracellular glutathione redox potentials of mammalian cells. This probe enabled detection of media-dependent oxidation of the cytosol triggered by short wavelength excitation. The transient nature of light-induced oxidation was revealed by time-lapse live cell imaging when time intervals of less than 30 s were implemented. In contrast, transient ROS generation was not observed with the parental roGFP2 probe without Grx1, which exhibits slower thiol-disulfide exchange. These data demonstrate that the enhanced sensitivity of the Grx1-roGFP2 fusion protein enables the detection of short-lived ROS in living cells. The superior sensitivity of Grx1-roGFP2, however, also enhances responsiveness to environmental cues introducing a greater likelihood of false positive results during image acquisition.

Kolossov, Vladimir L., E-mail: viadimer@illinois.edu [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Beaudoin, Jessica N. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Hanafin, William P. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States)] [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); DiLiberto, Stephen J. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Kenis, Paul J.A. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL 61801 (United States); Rex Gaskins, H. [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States) [Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Animal Sciences, University of Illinois at Urbana-Champaign, 1207 W. Gregory Drive, Urbana, IL 61801 (United States); Department of Pathobiology, University of Illinois at Urbana-Champaign, 2001 S. Lincoln Avenue, Urbana, IL 61801 (United States); Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, 905 S. Goodwin Avenue, Urbana, IL 61801 (United States)

2013-10-04T23:59:59.000Z

112

The plasma protein fibrinogen stabilizes clusters of red blood cells in microcapillary flows  

E-Print Network [OSTI]

The supply of oxygen and nutrients and the disposal of metabolic waste in the organs depend strongly on how blood, especially red blood cells, flow through the microvascular network. Macromolecular plasma proteins such as fibrinogen cause red blood cells to form large aggregates, called rouleaux, which are usually assumed to be disaggregated in the circulation due to the shear forces present in bulk flow. This leads to the assumption that rouleaux formation is only relevant in the venule network and in arterioles at low shear rates or stasis. Thanks to an excellent agreement between combined experimental and numerical approaches, we show that despite the large shear rates present in microcapillaries, the presence of either fibrinogen or the synthetic polymer dextran leads to an enhanced formation of robust clusters of red blood cells, even at haematocrits as low as 1%. Robust aggregates are shown to exist in microcapillaries even for fibrinogen concentrations within the healthy physiological range. These persistent aggregates should strongly affect cell distribution and blood perfusion in the microvasculature, with putative implications for blood disorders even within apparently asymptomatic subjects.

M. Brust; O. Aouane; M. Thiebaud; D. Flormann; C. Verdier; L. Kaestner; M. W. Laschke; H. Selmi; A. Benyoussef; T. Podgorski; G. Coupier; C. Misbah; C. Wagner

2014-02-25T23:59:59.000Z

113

To be published in IEEE Aerospace Conference Proceedings, 2003, Cat No. 0-7803-7651-X/03/$17.00 2003 IEEE Planar REDOX and Conductivity Sensors  

E-Print Network [OSTI]

/$17.00 © 2003 IEEE Planar REDOX and Conductivity Sensors for ISS Water Quality Measurements1 Martin G. Buehler REDOX and conductivity sensors that are used to detect ionic species in solution by measuring the electrochemical cell current as the voltage is scanned. The simplicity and robustness of these sensors allows

Kounaves, Samuel P.

114

characterization and visualization of two-phase flow properties of gas diffusion layers used in a PEM fuel cell  

E-Print Network [OSTI]

Due to the low-temperature operation of Polymer Electrolyte Membrane fuel cell (PEMFC), liquid water can build up in either flow channels or gas diffusion layers (GDL). Better understanding of the effect of two-phase ...

Gao, Yan

2011-04-26T23:59:59.000Z

115

Fuel Cell Manufacturing Diagnostic Techniques: IR Thermography with Reactive Flow through Excitation  

SciTech Connect (OSTI)

While design and material considerations for PEMFCs have a large impact on cost, it is also necessary to consider a transition to high volume production of fuel cell systems, including MEA components, to enable economies of scale and reduce per unit cost. One of the critical manufacturing tasks is developing and deploying techniques to provide in?process measurement of fuel cell components for quality control. This effort requires a subsidiary task: The study of the effect of manufacturing defects on performance and durability with the objective to establish validated manufacturing tolerances for fuel cell components. This work focuses on the development of a potential quality control method for gas diffusion electrodes (GDEs). The method consists of infrared (IR) thermography combined with reactive flow through (RFT) excitation. Detection of catalyst loading reduction defects in GDE catalyst layers will be presented.

Manak, A. J.; Ulsh, M.; Bender, G.

2012-01-01T23:59:59.000Z

116

NOVEL COMPUTATIONAL SIMULATION OF REDOX REACTIONS WITHIN A METAL ELECTROSPRAY EMITTER  

SciTech Connect (OSTI)

To further both our fundamental understanding implications of the electrolytic nature of the electrospray and our understanding of the analytical ion source, in the context of electrospray mass spectrometry (ES-MS), a computational simulation of the oxidation of chemical species inside a metal emitter has been developed. The analysis code employs a boundary integral method for the solution of the Laplace equation for the electric potential and current, and incorporates standard activation and concentration polarization functions for the redox active species in the system to define the boundary conditions. The specific system modeled consisted of a 100 {mu}m i .d., inert metal capillary CHICN/H2O (90/10 V/V). ES emitter and a spray solution comprised of an analyte dissolved in Variable parameters included the concentration (i.e., 5, 10, 20, and 50 ~M) of the easily oxidized analyte ferrocene (Fe, dicyclopentadienyl iron) in the solution, and solution conductivities of 1.9, 3.8, and 7.6 x 107 Mho/cm. ES currents were on the order of 0.05 {mu}A and the flow rate was 5 @A_nin. Under these defined conditions, the two most prominent reactions at the emitter metakolution interface were assumed to be H20 oxidation (2H20 = 02 + 4H+ + 4e") and Fe oxidation (Fe = Fe' +e-). Using this model it was possible to predict the inter-facial potentials, as well as the current density for each of the reactions, as a function of axial position from the emitter spray tip back upstream, under the various operational conditions. Computational fluid dynamics (CFD) calculations showed that the imposed flow rate through the emitter was adequate to prevent significant back-diffusion of Fe+ into the emitter against the flow direction. The computational simulations predict the same behavior for the ES ion source as has been observed experimentally and is consistent with the controlled-current electrolytic cell analogy of Van Berkel and Zhou (Anal. Chem. 1995, 67,.2916-2923). Furthermore, the simulations demonstrate that the majority of the current involved in the redox reactions originated within a 200- 300 ~m region near the spray tip.

BULLOCK, J.S.IV; GILES, G.E.; GRAY, L.J.; VAN BERKEL, G.J.

1999-01-13T23:59:59.000Z

117

MEMBRANELESS FUEL CELL BASED ON LAMINAR FLOW Eric R. Choban, Piotr Waszczuk, Larry J. Markoski, Andrzej Wieckowski, and Paul J.A. Kenis*  

E-Print Network [OSTI]

MEMBRANELESS FUEL CELL BASED ON LAMINAR FLOW Eric R. Choban, Piotr Waszczuk, Larry J. Markoski in this area focus on downscaling of existing fuel cell technology such as the well-known proton exchange membrane (PEM) fuel cells. Here we study a novel concept for fuel cells: the use of laminar flow instead

Kenis, Paul J. A.

118

MICROSCALE METABOLIC, REDOX AND ABIOTIC REACTIONS IN HANFORD 300 AREA SUBSURFACE SEDIMENTS  

SciTech Connect (OSTI)

The Hanford 300 Area is a unique site due to periodic hydrologic influence of river water resulting in changes in groundwater elevation and flow direction. This area is also highly subject to uranium remobilization, the source of which is currently believed to be the region at the base of the vadose zone that is subject to period saturation due to the changes in the water levels in the Columbia River. We found that microbial processes and redox and abiotic reactions which operate at the microscale were critical to understanding factors controlling the macroscopic fate and transport of contaminants in the subsurface. The combined laboratory and field research showed how microscale conditions control uranium mobility and how biotic, abiotic and redox reactions relate to each other. Our findings extended the current knowledge to examine U(VI) reduction and immobilization using natural 300 Area communities as well as selected model organisms on redox-sensitive and redox-insensitive minerals. Using innovative techniques developed specifically to probe biogeochemical processes at the microscale, our research expanded our current understanding of the roles played by mineral surfaces, bacterial competition, and local biotic, abiotic and redox reaction rates on the reduction and immobilization of uranium.

Beyenal, Haluk [WSU] [WSU; McLEan, Jeff [JCVI] [JCVI; Majors, Paul [PNNL] [PNNL; Fredrickson, Jim [PNNL] [PNNL

2013-11-14T23:59:59.000Z

119

Investigation of Temperature-Driven Water Transport in Polymer Electrolyte Fuel Cell: Phase-Change-Induced Flow  

E-Print Network [OSTI]

Investigation of Temperature-Driven Water Transport in Polymer Electrolyte Fuel Cell: Phase cell membranes, a net flux of water was found to flow from the hot to the cold side of the full, 2008. Published January 8, 2009. Proper water management is critical to achieve high performance

Mench, Matthew M.

120

3D Modeling of One and Two Component Gas Flow in Fibrous Microstructures in Fuel Cells by Using the Lattice-Boltzmann Method  

E-Print Network [OSTI]

In fuel cells, a homogeneous distribution of gas flow is desirable for optimal performance. The gas3D Modeling of One and Two Component Gas Flow in Fibrous Microstructures in Fuel Cells by Using: Fuel Cells, 52425 Jülich, Germany b Institute of Stochastics, Ulm University, 89069 Ulm, Germany

Schmidt, Volker

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Prolonged effect of fluid flow stress on the proliferative activity of mesothelial cells after abrupt discontinuation of fluid streaming  

SciTech Connect (OSTI)

Highlights: Black-Right-Pointing-Pointer Late-onset peritoneal fibrosis leading to EPS remains to be elucidated. Black-Right-Pointing-Pointer Fluid streaming is a potent factor for peritoneal fibrosis in PD. Black-Right-Pointing-Pointer We focused on the prolonged effect of fluid streaming on mesothelial cell kinetics. Black-Right-Pointing-Pointer A history of fluid streaming exposure promoted mesothelial proliferative activity. Black-Right-Pointing-Pointer We have thus identified a potent new factor for late-onset peritoneal fibrosis. -- Abstract: Encapsulating peritoneal sclerosis (EPS) often develops after transfer to hemodialysis and transplantation. Both termination of peritoneal dialysis (PD) and transplantation-related factors are risks implicated in post-PD development of EPS, but the precise mechanism of this late-onset peritoneal fibrosis remains to be elucidated. We previously demonstrated that fluid flow stress induced mesothelial proliferation and epithelial-mesenchymal transition via mitogen-activated protein kinase (MAPK) signaling. Therefore, we speculated that the prolonged bioactive effect of fluid flow stress may affect mesothelial cell kinetics after cessation of fluid streaming. To investigate how long mesothelial cells stay under the bioactive effect brought on by fluid flow stress after removal of the stress, we initially cultured mesothelial cells under fluid flow stress and then cultured the cells under static conditions. Mesothelial cells exposed to fluid flow stress for a certain time showed significantly high proliferative activity compared with static conditions after stoppage of fluid streaming. The expression levels of protein phosphatase 2A, which dephosphorylates MAPK, in mesothelial cells changed with time and showed a biphasic pattern that was dependent on the duration of exposure to fluid flow stress. There were no differences in the fluid flow stress-related bioactive effects on mesothelial cells once a certain time had passed. The present findings show that fluid flow stress exerts a prolonged bioactive effect on mesothelial cells after termination of fluid streaming. These findings support the hypothesis that a history of PD for a certain period could serve as a trigger of EPS after stoppage of PD.

Aoki, Shigehisa, E-mail: aokis@cc.saga-u.ac.jp [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan)] [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan); Ikeda, Satoshi [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan)] [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan); Takezawa, Toshiaki [Transgenic Animal Research Center, National Institute of Agrobiological Sciences, Ibaraki (Japan)] [Transgenic Animal Research Center, National Institute of Agrobiological Sciences, Ibaraki (Japan); Kishi, Tomoya [Department of Internal Medicine, Saga University, Saga (Japan)] [Department of Internal Medicine, Saga University, Saga (Japan); Makino, Junichi [Makino Clinic, Saga (Japan)] [Makino Clinic, Saga (Japan); Uchihashi, Kazuyoshi; Matsunobu, Aki [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan)] [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan); Noguchi, Mitsuru [Department of Urology, Faculty of Medicine, Saga University, Saga (Japan)] [Department of Urology, Faculty of Medicine, Saga University, Saga (Japan); Sugihara, Hajime [Department of Physical Therapy, International University of Health and Welfare, Fukuoka (Japan)] [Department of Physical Therapy, International University of Health and Welfare, Fukuoka (Japan); Toda, Shuji [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan)] [Department of Pathology and Microbiology, Faculty of Medicine, Saga University, Saga (Japan)

2011-12-16T23:59:59.000Z

122

Fact Sheet: Vanadium Redox Flow Batteries (October 2012)  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecord ofESPCofConstructionofFYOxideof EnergyFact Sheet: The

123

Fact Sheet: Vanadium Redox Flow Batteries (October 2012) | Department of  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Office of Inspector General Office of Audit|Department ofof EnergyUnited States- Dataset2012)Fact Sheet:Energy

124

Materials for Use with Aqueous Redox Flow Batteries | Argonne National  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping the Nanoscale LandscapeImports 5.90Materials Porous

125

Electrochemical photovoltaic cells. Project 65021 final technical progress report, April 15, 1979-April 17, 1980  

SciTech Connect (OSTI)

The overall goals of this program have been to experimentally identify semiconductor photoanode/redox couple systems that (a) show promise of meeting acceptable solar efficiencies using polycrystalline materials, and (b) have the potential for use in conjunction with a suitable cathode in which another redox species is available for reduction. Such an overall system allows for the convenient removal, storage, and later discharge of reaction products through the use of porous, flow-through redox electrodes. Increasing solar energy conversion efficiencies and identifying potentially long-life systems were emphasized. Semiconductor/redox couple systems were selected on the basis of the apparent positions of their conduction and valence band energy levels at the interface, together with the semiconductor decomposition potential. Selected redox couples should possess equilibrium potentials that lie negative of the semiconductor decomposition potential and positive of the semiconductor conduction band. Liquid-junction solar cells were characterized using n-MoSe/sub 2/, n-WSe/sub 2/, n-CdSe, and n-GaAs as photoanodes. Results are presented in detail. (WHK)

Ang, P.G.P.; Sammells, A.F.

1980-09-01T23:59:59.000Z

126

Thin graphite bipolar plate with associated gaskets and carbon cloth flow-field for use in an ionomer membrane fuel cell  

DOE Patents [OSTI]

The present invention comprises a thin graphite plate with associated gaskets and pieces of carbon cloth that comprise a flow-field. The plate, gaskets and flow-field comprise a "plate and gasket assembly" for use in an ionomer membrane fuel cell, fuel cell stack or battery.

Marchetti, George A. (Western Springs, IL)

2003-01-03T23:59:59.000Z

127

Redox states of Desulfovibrio vulgaris DsrC, a key protein in dissimilatory sulfite reduction  

SciTech Connect (OSTI)

Highlights: •DsrC is known to interact with the dissimilatory sulfite reductase enzyme (DsrAB). •We show that, however, most cellular DsrC is not associated with DsrAB. •A gel-shift assay was developed that allows monitoring of the DsrC redox state. •The DsrC intramolecularly oxidized state could only be produced by arginine treatment. -- Abstract: Dissimilatory reduction of sulfite is carried out by the siroheme enzyme DsrAB, with the involvement of the protein DsrC, which has two conserved redox-active cysteines. DsrC was initially believed to be a third subunit of DsrAB. Here, we report a study of the distribution of DsrC in cell extracts to show that, in the model sulfate reducer Desulfovibrio vulgaris, the majority of DsrC is not associated with DsrAB and is thus free to interact with other proteins. In addition, we developed a cysteine-labelling gel-shift assay to monitor the DsrC redox state and behaviour, and procedures to produce the different redox forms. The oxidized state of DsrC with an intramolecular disulfide bond, which is proposed to be a key metabolic intermediate, could be successfully produced for the first time by treatment with arginine.

Venceslau, Sofia S. [Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras (Portugal)] [Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras (Portugal); Cort, John R.; Baker, Erin S. [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352 (United States)] [Fundamental and Computational Sciences Directorate, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Chu, Rosalie K.; Robinson, Errol W. [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352 (United States)] [Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Dahl, Christiane [Institut für Mikrobiologie and Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, D-53115 Bonn (Germany)] [Institut für Mikrobiologie and Biotechnologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Meckenheimer Allee 168, D-53115 Bonn (Germany); Saraiva, Lígia M. [Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras (Portugal)] [Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras (Portugal); Pereira, Inês A.C., E-mail: ipereira@itqb.unl.pt [Instituto de Tecnologia Química e Biológica António Xavier, Universidade Nova de Lisboa, Oeiras (Portugal)

2013-11-29T23:59:59.000Z

128

Factors Controlling Redox Speciation of Plutonium and Neptunium in Extraction Separation Processes  

SciTech Connect (OSTI)

The objective of the project was to examine the factors controlling redox speciation of plutonium and neptunium in UREX+ extraction in terms of redox potentials, redox mechanism, kinetics and thermodynamics. Researchers employed redox-speciation extractions schemes in parallel to the spectroscopic experiments. The resulting distribution of redox species w studied uring spectroscopic, electrochemical, and spectro-electrochemical methods. This work reulted in collection of data on redox stability and distribution of redox couples in the nitric acid/nitrate electrolyte and the development of redox buffers to stabilize the desired oxidation state of separated radionuclides. The effects of temperature and concentrations on the redox behavior of neptunium were evaluated.

Paulenova, Alena [Principal Investigator; Vandegrift, III, George F. [Collaborator

2013-09-24T23:59:59.000Z

129

Workshop on electrodes for flowing solution batteries. Summary report  

SciTech Connect (OSTI)

The electrochemical technology of aqueous secondary cells with flowing electrolyte solutions was the subject of a workshop sponsored by EPRI with the cooperation of DOE. The workshop was held in Tampa, Florida, 5-7 November 1979, and was attended by a select group drawn from advanced battery developers, government agencies, universities, and research organizations. The workshop general objectives were to look at the significant parameters believed to govern the performance of the two basic types of electrodes now in use; namely, a porous flow-through electrode (PFTE), and an impervious flow-by electrode. Progress, problems, and prospects were informally discussed. Brief critical reviews were given by session chairmen as a means of introducing each of the key topics (Current Distribution in FTPE, Conversion Efficiency, Segmented FTPE Studies, General Discussion on FTPF Parameters, Surface Activation, Application of FTPE to Waste Recovery, Exxon Zinc-Bromine Flow-By System, FTPE In NASA Redox Energy Storage, and Application of FTPE In Lockheed Zinc/Ferricyanide Redox System). The interaction of this diverse group of engineers and scientists was said by all to be of great benefit in widening understanding of the problems and possible future approaches to new work. The main needs for future work that were identified in the final discussion session among the participants were: (1) engineering analysis, (2) porous structures, (3) materials characteristics, and (4) chemical characteristics. In generally comparing flow-through to flow-by electrodes, there were some surprising differences arising from experimental results that did not fit conventional thinking.

Nanis, L.

1981-02-01T23:59:59.000Z

130

Modulation of ATP/ADP Concentration at the Endothelial Cell Surface by Flow: Effect of Cell Topography  

E-Print Network [OSTI]

Wall shear stress modulation of ATP/ADP concentration at theFlow modulation of agonist (ATP)-response (Ca 2+ ) couplingJ. Ando. Endogenously released ATP mediates shear stress-

Choi, Hyo Won; Barakat, Abdul I.

2009-01-01T23:59:59.000Z

131

Real-Time Redox Measurements during Endoplasmic Reticulum Stress Reveal  

E-Print Network [OSTI]

Real-Time Redox Measurements during Endoplasmic Reticulum Stress Reveal Interlinked Protein Folding.10.011 SUMMARY Disruption of protein folding in the endoplasmic reticulum (ER) causes unfolded proteins to accumu is active. Because ER redox po- tential is optimized for oxidative protein folding, we reasoned

Mullins, Dyche

132

Redox reactions of reduced flavin mononucleotide (FMN), riboflavin (RBF), and anthraquinone-2,6-disulfonate (AQDS) with ferrihydrite and lepidocrocite  

SciTech Connect (OSTI)

Flavins are secreted by the dissimilatory iron-reducing bacterium Shewanella and can function as endogenous electron transfer mediators (ETM). In order to assess the potential importance of flavins in Fe(III) bioreduction, we investigated the redox reaction kinetics of reduced flavins (FMNH2 and RBFH2) with ferrihydrite and lepidocrocite. The organic reductants rapidly reduced and dissolved ferrihydrite and lepidocrocite in the pH range 4-8. The rate constant k for 2-line ferrihydrite reductive dissolution by FMNH2 was 87.5 ? 3.5 M-1?s-1 at pH 7.0 in batch reactors, and the k was similar for RBFH2. For lepidocrocite, the k was 500 ? 61 M-1?s-1 for FMNH2, and 236 ? 22 M-1?s-1 for RBFH2. The surface area normalized initial reaction rates (ra) were between 0.08 and 77 ?moles?m-2?s-1 for various conditions in stopped-flow experiments. Initial rates (ro) were first-order with respect to Fe(III) oxide concentration, and ra increased with decreasing pH. Poorly crystalline 2-line ferrihydrite yielded the highest ra, followed by more crystalline 6-line ferrihydrite, and crystalline lepidocrocite. Compared to a previous whole-cell study with Shewanella oneidensis strain MR-1, our findings suggest that ETM reduction by the Mtr pathway coupled to lactate oxidation are rate limiting, rather than heterogeneous electron transfer to the Fe(III) oxide.

Shi, Zhi; Zachara, John M.; Shi, Liang; Wang, Zheming; Moore, Dean A.; Kennedy, David W.; Fredrickson, Jim K.

2012-11-01T23:59:59.000Z

133

Redox states of Desulfovibrio vulgaris DsrC, a key protein in dissimilatory sulfite reduction  

SciTech Connect (OSTI)

Dissimilatory reduction of sulfite is carried out by the siroheme enzyme DsrAB, with the involvement of the protein DsrC having two conserved cysteine residues. Here, we report a study of the distribution of DsrC in cell extracts, a cysteine-labelling gel-shift assay to monitor its redox state and behaviour, and procedures to produce the different redox forms. We show that, in the model sulfate reducer Desulfovibrio vulgaris, the majority of DsrC is not associated with DsrAB and is thus free to interact with other proteins. In addition, we successfully produced DsrC with an intramolecular disulfide bond (oxidized state) by treatment with arginine.

Venceslau, Sofia S.; Cort, John R.; Baker, Erin Shammel; Chu, Rosalie K.; Robinson, Errol W.; Dahl, Christiane; Saraiva, Ligia M.; Pereira, Ines Ac

2013-11-29T23:59:59.000Z

134

Novel, low-cost separator plates and flow-field elements for use in PEM fuel cells  

SciTech Connect (OSTI)

PEM fuel cells offer promise for a wide range of applications including vehicular (e.g., automotive) and stationary power generation. The performance and cost targets that must be met for PEM technology to be commercially successful varies to some degree with the application. However, in general the cost of PEM fuel cell stacks must be reduced substantially if they are to see widespread use for electrical power generation. A significant contribution to the manufactured cost of PEM fuel cells is the machined carbon plates that traditionally serve as bipolar separator plates and flow-field elements. In addition, carbon separator plates are inherently brittle and suffer from breakage due to shock, vibration, and improper handling. This report describes a bifurcated separator device with low resistivity, low manufacturing cost, compact size and durability.

Edlund, D.J. [Northwest Power Systems, LLC, Bend, OR (United States)

1996-12-31T23:59:59.000Z

135

Transport in a slowly perturbed convective cell flow. A. P. Itin 1 , R. de la Llave 2 , A. I. Neishtadt 1 , and A. A. Vasiliev 1  

E-Print Network [OSTI]

Transport in a slowly perturbed convective cell flow. A. P. Itin 1 , R. de la Llave 2 , A. I in such flows may be very sensitive to initial conditions, making possible chaotic advection [6] of passive­scales (of order # # -3 ln#). In case of a generic perturbation, a drop of passive impurity (e.g. dye) put

136

Anaerobic Redox Cycling of Iron by Freshwater Sediment Microorganisms  

SciTech Connect (OSTI)

The potential for microbially-mediated anaerobic redox cycling of iron (Fe) was examined in a first-generation enrichment culture of freshwater wetland sediment microorganisms. MPN enumerations revealed the presence of significant populations of Fe(III)-reducing (ca. 108 cells mL-1) and Fe(II)-oxidizing, nitrate-reducing organisms (ca. 105 cells mL-1) in the sediment used to inoculate the enrichment cultures. Nitrate reduction commenced immediately following inoculation of acetate-containing (ca. 1 mM) medium with a small quantity (1% vol/vol) of wetland sediment, and resulted in the transient accumulation of NO2- and production of a mixture of end-products including NH4+. Fe(III) oxide (high surface area goethite) reduction took place - after NO3- was depleted and continued until all the acetate was utilized. Addition of NO3 after Fe(III) reduction ceased resulted in the immediate oxidation of Fe(II) coupled to reduction of + NO3-to NH4 . No significant NO2- accumulation was observed during nitrate-dependent Fe(II) oxidation. No Fe(II) oxidation occurred in pasteurized controls. Microbial community structure in the enrichment was monitored by DGGE analysis of PCR amplified 16s rDNA and RT-PCR amplified 16S rRNA, as well as by construction of 16S rDNA clone libraries for four different time points during the experiment. Strong similarities in dominant members of the microbial community were observed in the Fe(III) reduction and nitrate-dependent Fe(II) oxidation phases of the experiment, specifically the common presence of organisms closely related (= 95% sequence similarity) to the genera Geobacter and Dechloromonas. These results indicate that the wetland sediments contained organisms such as Geobacter sp. which are capable of both + dissimilatory Fe(III) reduction and oxidation of Fe(II) with reduction of NO3-reduction to NH4 . Our findings suggest that microbially-catalyzed nitrate-dependent Fe(II) oxidation has the potential to contribute to a dynamic anaerobic Fe redox cycle in freshwater sediments.

Weber, Karrie A.; Urrutia, Matilde M.; Churchill, Perry F.; Kukkadapu, Ravi K.; Roden, Eric E.

2006-01-01T23:59:59.000Z

137

Effect in the KHT sarcoma of CCNU and MISO on cell cycle progression evaluated by flow-cytometry  

SciTech Connect (OSTI)

Previous studies using the KHT sarcoma have shown that misonidazole (MISO) enhances the cytotoxicity of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea (CCNU) by as much as a factor of 2.0. In the present study flow cytometry was used to monitor the changing DNA distributions of cells dissociated from solid tumors at successive times following treatment with CCNU, applied either alone or in combination with 0.5 mg/g MISO. The proportion of cells in late S and the G/sub 2/M phases of the cell cycle increased gradually after CCNU treatment. MISO did not significantly change this block in cell progression, which persisted for at least 48 hr after treatment in all cases. CCNU shows marked carbamoylating activity, which has been associated with inhibition of RNA processing and with the degree of chemopotentiation achieved with MISO. By 24 hr after treatment, CCNU clearly altered the distribution of RNA, but no significant differences could be detected between results obtained from drug and drug plus sensitizer treated groups. These studies demonstrate the effect of CCNU on cell cycle progression in vivo. The addition of MISO did not result in further perturbation of the total tumor population, suggesting that cell cycle redistribution does not play a major role in chemopotentiation by MISO.

Hill, S.A.; Bauer, K.D.; Keng, P.C.; Siemann, D.W.

1984-09-01T23:59:59.000Z

138

Current flow and efficiencies of concentrator InGaP/GaAs/Ge solar cells at temperatures below 300K  

SciTech Connect (OSTI)

The forward dark current density – voltage (J-V) characteristic is one of the most important characteristics of multi-junction solar cells. It indicates that the mechanisms of current flow in the space charge region of photoactive p-n junctions. If one is to idealize the optical and electrical (coupling) elements of the solar cells, it is the J-V characteristic that determines the theoretically possible efficiency of the solar cell. In this paper, using the connection between the dark J-V and photovoltaic (?-J{sub g}) efficiency – generated current density characteristics, the effect of current transport mechanisms in the space charge on the efficiency of multi-junction solar cells was investigated in the temperature range of 300 – 80 K. In the experimental J-V and ?-J{sub g} curves of the multi-junction solar cells, segments corresponding to the dominant current transport mechanisms were identified. The developed method, based on the analysis of forward dark J-V characteristics, makes it possible to identify the parameters affecting the efficiency of the multi-junction solar cells in a wide range of temperatures and solar radiation concentration.

Kalinovsky, Vitaly S., E-mail: vitak.sopt@mail.ioffe.ru; Kontrosh, Evgeny V., E-mail: vitak.sopt@mail.ioffe.ru; Dmitriev, Pavel A., E-mail: vitak.sopt@mail.ioffe.ru; Pokrovsky, Pavel V., E-mail: vitak.sopt@mail.ioffe.ru; Chekalin, Alexander V., E-mail: vitak.sopt@mail.ioffe.ru; Andreev, Viacheslav M., E-mail: vitak.sopt@mail.ioffe.ru [Ioffe Physical-Technical Institute, St. Petersburg, Politekhicheskaya st. 26 (Russian Federation)

2014-09-26T23:59:59.000Z

139

Membranes and separators for flowing electrolyte batteries-a review  

SciTech Connect (OSTI)

Flowing electrolyte batteries are rechargeable electrochemical storage devices in which externally stored electrolytes are circulated through the cell stack during charge or discharge. The potential advantages that flow batteries offer compared to other secondary batteries include: 1) ease of thermal and electrolyte management, 2) simple electrochemistry, 3) deep cycling capability, and 4) minimal loss of capacity with cycling. However, flow batteries are more complex than other secondary batteries and consequently may cost more and may be less reliable. Flow batteries are being developed for utility load leveling, electric vehicles, solar photovoltaic and wind turbine application. The status of flow batteries has recently been reviewed by Clark et al. The flowing electrolyte batteries place rigorous demands on the performance of separators and membranes. The operating characteristics of the iron/chromium redox battery were changed in order to accommodate the limitations in membrane performance. Low cost alternatives to the presently used membrane must be found before the zinc/ferricyanide battery can be economically feasible. The zinc/bromine battery's efficiency could be improved if a suitably selective membrane were available. It is anticipated that better and less costly membranes to meet these needs will be developed as more is learned about their preparation and performance.

Arnold, C.; Assink, R.A.

1983-01-01T23:59:59.000Z

140

Methane oxidation over dual redox catalysts  

SciTech Connect (OSTI)

Catalytic oxidation of methane to partial oxidation products, primarily formaldehyde and C[sub 2] hydrocarbons, was found to be directed by the catalyst used. In this project, it was discovered that a moderate oxidative coupling catalyst for C[sub 2] hydrocarbons, zinc oxide, is modified by addition of small amounts of Cu and Fe dopants to yield fair yields of formaldehyde. A similar effect was observed with Cu/Sn/ZnO catalysts, and the presence of a redox Lewis acid, Fe[sup III] or Sn[sup IV], was found to be essential for the selectivity switch from C[sub 2] coupling products to formaldehyde. The principle of double doping with an oxygen activator (Cu) and the redox Lewis acid (Fe, Sn) was pursued further by synthesizing and testing the CuFe-ZSM-5 zeolite catalyst. The Cu[sup II](ion exchanged) Fe[sup III](framework)-ZSM-5 also displayed activity for formaldehyde synthesis, with space time yields exceeding 100 g/h-kg catalyst. However, the selectivity was low and earlier claims in the literature of selective oxidation of methane to methanol over CuFe-ZSM-5 were not reproduced. A new active and selective catalytic system (M=Sb,Bi,Sn)/SrO/La[sub 2]O[sub 3] has been discovered for potentially commercially attractive process for the conversion of methane to C[sub 2] hydrocarbons, (ii) a new principle has been demonstrated for selectivity switching from C[sub 2] hydrocarbon products to formaldehyde in methane oxidations over Cu,Fe-doped zinc oxide and ZSM-5, and (iii) a new approach has been initiated for using ultrafine metal dispersions for low temperature activation of methane for selective conversions. Item (iii) continues being supported by AMOCO while further developments related to items (i) and (ii) are the objective of our continued effort under the METC-AMOCO proposed joint program.

Klier, K.; Herman, R.G.; Sojka, Z.; DiCosimo, J.I.; DeTavernier, S.

1992-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Development of a novel in vitro model to study the tryptic : endothelial cells, monocytes and flow  

E-Print Network [OSTI]

This thesis describes the development of a novel in vitro model of monocytes transmigration under flow and use in the study of early molecular events of atherogenesis. In this work, we focused on how endothelial dysfunction, ...

Turjman, Alexis S. (Alexis Salomon)

2014-01-01T23:59:59.000Z

142

Anisotropic output-based adaptation with tetrahedral cut cells for compressible flows  

E-Print Network [OSTI]

Anisotropic, adaptive meshing for flows around complex, three-dimensional bodies remains a barrier to increased automation in computational fluid dynamics. Two specific advances are introduced in this thesis. First, a ...

Park, Michael Andrew

2008-01-01T23:59:59.000Z

143

Improving electricity production in tubular microbial fuel cells through optimizing the anolyte flow with spiral spacers  

E-Print Network [OSTI]

Improving electricity production in tubular microbial fuel cells through optimizing the anolyte h l i g h t s " The spiral spacers improve electricity production in tubular microbial fuel cells fuel cells Spiral spacers Energy Wastewater treatment a b s t r a c t The use of spiral spacers

144

Mixing Cell Model: A One-Dimensional Numerical Model for Assessment of Water Flow and Contaminant Transport in the Unsaturated Zone  

SciTech Connect (OSTI)

This report describes the Mixing Cell Model code, a one-dimensional model for water flow and solute transport in the unsaturated zone under steady-state or transient flow conditions. The model is based on the principles and assumptions underlying mixing cell model formulations. The unsaturated zone is discretized into a series of independent mixing cells. Each cell may have unique hydrologic, lithologic, and sorptive properties. Ordinary differential equations describe the material (water and solute) balance within each cell. Water flow equations are derived from the continuity equation assuming that unit-gradient conditions exist at all times in each cell. Pressure gradients are considered implicitly through model discretization. Unsaturated hydraulic conductivity and moisture contents are determined by the material-specific moisture characteristic curves. Solute transport processes include explicit treatment of advective processes, first-order chain decay, and linear sorption reactions. Dispersion is addressed through implicit and explicit dispersion. Implicit dispersion is an inherent feature of all mixing cell models and originates from the formulation of the problem in terms of mass balance around fully mixed volume elements. Expressions are provided that relate implicit dispersion to the physical dispersion of the system. Two FORTRAN codes were developed to solve the water flow and solute transport equations: (1) the Mixing-Cell Model for Flow (MCMF) solves transient water flow problems and (2) the Mixing Cell Model for Transport (MCMT) solves the solute transport problem. The transient water flow problem is typically solved first by estimating the water flux through each cell in the model domain as a function of time using the MCMF code. These data are stored in either ASCII or binary files that are later read by the solute transport code (MCMT). Code output includes solute pore water concentrations, water and solute inventories in each cell and at each specified output time, and water and solute fluxes through each cell and specified output time. Computer run times for coupled transient water flow and solute transport were typically several seconds on a 2 GHz Intel Pentium IV desktop computer. The model was benchmarked against analytical solutions and finite-element approximations to the partial differential equations (PDE) describing unsaturated flow and transport. Differences between the maximum solute flux estimated by the mixing-cell model and the PDE models were typically less than two percent.

A. S. Rood

2010-10-01T23:59:59.000Z

145

Mitigation of biofouling using coatings. Quarterly progress report No. 2. [Coatings for Ge diagnostic plates in flow cells  

SciTech Connect (OSTI)

Progress is reported in research designed to evaluate benefits associated with control of the surface energetic properties of materials used in heat exchangers; and to identify preferred ranges of these surface conditions that minimize deposits of biological fouling known to deteriorate heat exchange efficiencies in seawater, brackish water and freshwater systems. The technical approach employed uses special diagnostic plates in novel flow cells where fluid flow conditions can be well-controlled, modifying the surface chemistry and surface energy of the plates with very thin coatings and examining the earliest events of biofouling caused by macromolecules and microbial organisms. An aquarium system described previously was equilibrated and some initial exposure experiments were carried out. Six silane compounds were used to coat germanium plates for coating viability experiments.

Meyer, A.E.; King, R.W.; Ziegler, R.C.

1981-03-16T23:59:59.000Z

146

Semi-Solid Flowable Battery Electrodes: Semi-Solid Flow Cells for Automotive and Grid-Level Energy Storage  

SciTech Connect (OSTI)

BEEST Project: Scientists at 24M are crossing a Li-Ion battery with a fuel cell to develop a semi-solid flow battery. This system relies on some of the same basic chemistry as a standard Li-Ion battery, but in a flow battery the energy storage material is held in external tanks, so storage capacity is not limited by the size of the battery itself. The design makes it easier to add storage capacity by simply increasing the size of the tanks and adding more paste. In addition, 24M's design also is able to extract more energy from the semi-solid paste than conventional Li-Ion batteries. This creates a cost-effective, energy-dense battery that can improve the driving range of EVs or be used to store energy on the electric grid.

2010-09-01T23:59:59.000Z

147

Study to establish cost projections for production of redox chemicals  

SciTech Connect (OSTI)

A cost study of four proposed manufacturing processes for redox chemicals for the NASA REDOX Energy Storage System yielded favorable selling prices in the range $0.99 to $1.91/kg of chromic chloride, anhydrous basis, including ferrous chloride. The prices corresponded to specific energy storage costs from under $9 to $17/kWh. A refined and expanded cost analysis of the most favored process yielded a price estimate corresponding to a storage cost of $11/kWh. The findings supported the potential economic viability of the NASA REDOX system.

Walther, J.F.; Greco, C.C.; Rusinko, R.N.; Wadsworth, A.L. III

1982-11-01T23:59:59.000Z

148

Experimental and Modeling Studies of Two-Phase Flow in Porous Media and Its Effects on the Performance of a PEM Fuel Cell  

E-Print Network [OSTI]

An experimental investigation was conducted to study the two-phase flow properties of porous media used in proton exchange membrane (PEM) fuel cells. The liquid and gas phase relative permeability of porous media used in PEM fuel cells was measured...

Wang, Xuhai

2010-01-01T23:59:59.000Z

149

Lateral Current Density Variation in PEM Fuel Cells with Interdigitated Flow Fields.  

E-Print Network [OSTI]

??Proton exchange membrane (PEM) fuel cell is regarded as one of the most promising power systems for the future vehicles. When supplied with air and… (more)

Luo, Song

2014-01-01T23:59:59.000Z

150

Redox shuttles for overcharge protection of lithium batteries  

DOE Patents [OSTI]

The present invention is generally related to electrolytes containing novel redox shuttles for overcharge protection of lithium-ion batteries. The redox shuttles are capable of thousands hours of overcharge tolerance and have a redox potential at about 3-5.5 V vs. Li and particularly about 4.4-4.8 V vs. Li. Accordingly, in one aspect the invention provides electrolytes comprising an alkali metal salt; a polar aprotic solvent; and a redox shuttle additive that is an aromatic compound having at least one aromatic ring with four or more electronegative substituents, two or more oxygen atoms bonded to the aromatic ring, and no hydrogen atoms bonded to the aromatic ring; and wherein the electrolyte solution is substantially non-aqueous. Further there are provided electrochemical devices employing the electrolyte and methods of making the electrolyte.

Amine, Khalil (Downers Grove, IL); Chen, Zonghai (Downers Grove, IL); Wang, Qingzheng (San Jose, CA)

2010-12-14T23:59:59.000Z

151

Iron Cycling and Redox Evolution in the Precambrian  

E-Print Network [OSTI]

Green, W.J. , 2002. Rare earth elements in the water columnVangaans, P. , 1988. Rare-Earth Element Distributions inRedox cycling of rare earth elements in the suboxic zone of

Planavsky, Noah John

2012-01-01T23:59:59.000Z

152

Renaissance in Flow-Cell Technologies Recent Advancements and Future Opportunities  

E-Print Network [OSTI]

energy Limited life cycle Continuous self-discharge Conventional battery constraints Low round) Power out Electrode Electrode Energy and power independent Long life cycle Low self-discharge rates been demonstrated in field Technology is proven, but not cost effective · Flow Battery concept

153

Preparation of redox polymer cathodes for thin film rechargeable batteries  

DOE Patents [OSTI]

The present invention relates to the manufacture of thin film solid state electrochemical devices using composite cathodes comprising a redox polymer capable of undergoing oxidation and reduction, a polymer solid electrolyte and conducting carbon. The polymeric cathode material is formed as a composite of radiation crosslinked polymer electrolytes and radiation crosslinked redox polymers based on polysiloxane backbones with attached organosulfur side groups capable of forming sulfur-sulfur bonds during electrochemical oxidation.

Skotheim, T.A.; Lee, H.S.; Okamoto, Yoshiyuki.

1994-11-08T23:59:59.000Z

154

Laminated exfoliated graphite composite-metal compositions for fuel cell flow field plate or bipolar plate applications  

DOE Patents [OSTI]

An electrically conductive laminate composition for fuel cell flow field plate or bipolar plate applications. The laminate composition comprises at least a thin metal sheet having two opposed exterior surfaces and a first exfoliated graphite composite sheet bonded to the first of the two exterior surfaces of the metal sheet wherein the exfoliated graphite composite sheet comprises: (a) expanded or exfoliated graphite and (b) a binder or matrix material to bond the expanded graphite for forming a cohered sheet, wherein the binder or matrix material is between 3% and 60% by weight based on the total weight of the first exfoliated graphite composite sheet. Preferably, the first exfoliated graphite composite sheet further comprises particles of non-expandable graphite or carbon in the amount of between 3% and 60% by weight based on the total weight of the non-expandable particles and the expanded graphite. Further preferably, the laminate comprises a second exfoliated graphite composite sheet bonded to the second surface of the metal sheet to form a three-layer laminate. Surface flow channels and other desired geometric features can be built onto the exterior surfaces of the laminate to form a flow field plate or bipolar plate. The resulting laminate has an exceptionally high thickness-direction conductivity and excellent resistance to gas permeation.

Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

2014-05-20T23:59:59.000Z

155

Microfabricated Renewable Beads-Trapping/Releasing Flow Cell for Rapid Antigen-Antibody Reaction in Chemiluminescent Immunoassay  

SciTech Connect (OSTI)

A filter pillar-array microstructure was coupled with a pneumatic micro-valve to fabricate a reusable miniaturized beads-trapping/releasing flow cell, in which trapping and releasing beads can be conveniently realized by switching the micro-valve. This miniaturized device was suitable to construct automatic fluidic system for “renewable surface analysis”. The renewable surface strategy based on pneumatic micro-valve enabled capture of beads in beads chamber prior to each assay, and release of the used beads after the assay. Chemiluminescent competitive immunoassay of 3,5,6-trichloropyridinol (TCP) was performed as a model to demonstrate the application potential of this reusable miniaturized flow cell. The whole fluidic assay process including beads trapping, immuno-binding, beads washing, beads releasing and signal collection could be completed in 10 min. Immunoassay of TCP using this miniaturized device showed a linear range of 0.20-70 ng/mL with a limit of detection of 0.080 ng/mL. The device had been successfully used for detection of TCP spiked in rat serum with average recovery of 97%. This investigation provides a rapid, sensitive, reusable, low-cost and automatic miniaturized device for solid-phase biochemical analysis for various purposes.

Fu, Zhifeng; Shao, Guocheng; Wang, Jun; Lu, Donglai; Wang, Wanjun; Lin, Yuehe

2011-04-01T23:59:59.000Z

156

Investigating Cell Adhesion via Parallel Disk Rotational Flow: A Biocompatibility Study  

E-Print Network [OSTI]

(methyl methacrylate) (PMMA), polycarbonate (PC), and on gold coated poly(vinylidene fluoride) (Au/PVDF). The critical shear stress for fibroblasts was the lowest for PC with 5.09 dynes/cm2 and highest for PMMA with 21.0 dynes/cm2. This four-fold difference is iv... mainly due to the chemical structure of PMMA which promotes higher cell adhesion when compared to PC. Neurons were cultured on poly-D-lysine coated glass to promote cell adhesion. The critical shear stress of neuron cells varied from 3.94 to 27...

Rocha, Aracely

2011-08-08T23:59:59.000Z

157

Solid oxide fuel cell having monolithic cross flow core and manifolding  

DOE Patents [OSTI]

This invention discloses a monolithic core construction having the flow passageways for the fuel and for the oxidant gases extended transverse to one another, whereby full face core manifolding can be achieved for these gases and their reaction products. The core construction provides that only anode material surround each fuel passageway and only cathode material surround each oxidant passageway, each anode and each cathode further sandwiching at spaced opposing sides electrolyte and interconnect materials to define electrolyte and interconnect walls. Webs of the cathode and anode material hold the electrolyte and interconnect walls spaced apart to define the flow passages. The composite anode and cathode wall structures are further alternately stacked on one another (with the separating electrolyte or interconnect material typically being a single common layer) whereby the fuel passageway and the oxidant passageways are disposed transverse to one another.

Poeppel, Roger B. (Glen Ellyn, IL); Dusek, Joseph T. (Downers Grove, IL)

1984-01-01T23:59:59.000Z

158

Lattice-Boltzmann Simulations of Multiphase Flows in Gas-Diffusion-Layer (GDL) of a PEM Fuel Cell  

SciTech Connect (OSTI)

Improved power density and freeze-thaw durability in automotive applications of Proton Exchange Membrane Fuel Cells (PEMFCs) requires effective water management at the membrane. This is controlled by a porous hydrophobic gas-diffusion-layer (GDL) inserted between the membrane catalyst layer and the gas reactant channels. The GDL distributes the incoming gaseous reactants on the catalyst surface and removes excess water by capillary action. There is, however, limited understanding of the multiphase, multi-component transport of liquid water, vapor and gaseous reactants within these porous materials. This is due primarily to the challenges of in-situ diagnostics for such thin (200 -? 300 {microns}), optically opaque (graphite) materials. Transport is typically analyzed by fitting Darcy's Law type expressions for permeability, in conjunction with capillary pressure relations based on formulations derived for media such as soils. Therefore, there is significant interest in developing predictive models for transport in GDLs and related porous media. Such models could be applied to analyze and optimize systems based on the interactions between cell design, materials, and operating conditions, and could also be applied to evaluating material design concepts. Recently, the Lattice Boltzmann Method (LBM) has emerged as an effective tool in modeling multiphase flows in general, and flows through porous media in particular. This method is based on the solution of a discrete form of the well-known Boltzmann Transport Equation (BTE) for molecular distribution, tailored to recover the continuum Navier-Stokes flow. The kinetic theory basis of the method allows simple implementation of molecular forces responsible for liquid-gas phase separation and capillary effects. The solution advances by a streaming and collision type algorithm that makes it suitable to implement for domains with complex boundaries. We have developed both single and multiphase LB models and applied them to simulate flow through porous GDL materials. We will present an overview of the methods as implemented, verification studies for both microstructure reconstruction and transport simulations, and application to single- and two-phase transport in GDL structures. The applications studies are designed to both improve understanding of transport within a given structure, and to investigate possible routes for improving material properties through microstructure design.

Shiladitya Mukherjeea; J. Vernon Cole; Kunal Jainb; Ashok Gidwania

2008-11-01T23:59:59.000Z

159

Scientists capture 'redox moments' in living cells | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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160

Numerical Analysis of Cell Deformation of Twophase Flow with Discontinuous Viscosity and Nonlinear Surface Tension  

E-Print Network [OSTI]

­linear Surface Tension Zhilin Li and Sharon Lubkin Center For Research in Scientific Computation & Department equations, cell deformation, non­linear surface tension, jump conditions, interface, discontinuous and non boundary separating two fluids that have equal or different viscosity and non­linear surface tension

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Examination of protein degradation in continuous flow, microbial electrolysis cells treating fermentation wastewater  

E-Print Network [OSTI]

16802, USA b Jeju Global Research Center, Korea Institute of Energy Research, 200 Haemajihaean-ro, Gujwa were 0.49 ± 0.05 m3 /m3 -d for the FWW, compared to 0.63 ± 0.02 m3 /m3 -d using a synthetic waste, including dark and light fermentation, and microbial electrolysis cells (MECs). Dark fermentation results

162

In situ characterization of nanoscale catalysts during anodic redox processes  

SciTech Connect (OSTI)

Controlling the structure and composition of the anode is critical to achieving high efficiency and good long-term performance. In addition to being a mixed electronic and ionic conductor, the ideal anode material should act as an efficient catalyst for oxidizing hydrogen, carbon monoxide and dry hydrocarbons without de-activating through either sintering or coking. It is also important to develop novel anode materials that can operate at lower temperatures to reduce costs and minimized materials failure associated with high temperature cycling. We proposed to synthesize and characterize novel anode cermets materials based on ceria doped with Pr and/or Gd together with either a Ni or Cu metallic components. Ceria is a good oxidation catalyst and is an ionic conductor at room temperature. Doping it with trivalent rare earths such as Pr or Gd retards sintering and makes it a mixed ion conductor (ionic and electronic). We have developed a fundamental scientific understanding of the behavior of the cermet material under reaction conditions by following the catalytic oxidation process at the atomic scale using a powerful Environmental Scanning Transmission Electron Microscope (ESTEM). The ESTEM allowed in situ monitoring of structural, chemical and morphological changes occurring at the cermet under conditions approximating that of typical fuel-cell operation. Density functional calculations were employed to determine the underlying mechanisms and reaction pathways during anode oxidation reactions. The dynamic behavior of nanoscale catalytic oxidation of hydrogen and methane were used to determine: ? Fundamental processes during anodic reactions in hydrogen and carbonaceous atmospheres ? Interfacial effects between metal particles and doped ceria ? Kinetics of redox reaction in the anode material

Sharma, Renu [National Institute of Standards and Technology] National Institute of Standards and Technology; Crozier, Peter [Arizona State University] Arizona State University; Adams, James [Arizona State University] Arizona State University

2013-09-19T23:59:59.000Z

163

Redox reactions with empirical potentials: Atomistic battery discharge simulations  

E-Print Network [OSTI]

Batteries are pivotal components in overcoming some of today's greatest technological challenges. Yet to date there is no self-consistent atomistic description of a complete battery. We take first steps toward modeling of a battery as a whole microscopically. Our focus lies on phenomena occurring at the electrode-electrolyte interface which are not easily studied with other methods. We use the redox split-charge equilibration (redoxSQE) method that assigns a discrete ionization state to each atom. Along with exchanging partial charges across bonds, atoms can swap integer charges. With redoxSQE we study the discharge behavior of a nano-battery, and demonstrate that this reproduces the generic properties of a macroscopic battery qualitatively. Examples are the dependence of the battery's capacity on temperature and discharge rate, as well as performance degradation upon recharge.

Dapp, Wolf B

2013-01-01T23:59:59.000Z

164

A model for red blood cells in simulations of large-scale blood flows  

E-Print Network [OSTI]

Red blood cells (RBCs) are an essential component of blood. A method to include the particulate nature of blood is introduced here with the goal of studying circulation in large-scale realistic vessels. The method uses a combination of the Lattice Boltzmann method (LBM) to account for the plasma motion, and a modified Molecular Dynamics scheme for the cellular motion. Numerical results illustrate the quality of the model in reproducing known rheological properties of blood as much as revealing the effect of RBC structuring on the wall shear stress, with consequences on the development of cardiovascular diseases.

Simone Melchionna

2011-07-25T23:59:59.000Z

165

Metal-ligand redox interaction in the multielectron chemistry of porphyrinogen coordination compounds  

E-Print Network [OSTI]

Metal complexes of the macrocycle porphyrinogen (calix[4]pyrrole) are studied with an emphasis on the redox activity ("non-innocence") of the ligand (Chapter I). Porphyrinogen complexes of spherical, redox-inert metal ...

Bachmann, Julien

2006-01-01T23:59:59.000Z

166

Tank Treading of Optically Trapped Red Blood Cells in Shear Flow Himanish Basu, Aditya K. Dharmadhikari, Jayashree A. Dharmadhikari, Shobhona Sharma,* and Deepak Mathur*  

E-Print Network [OSTI]

Tank Treading of Optically Trapped Red Blood Cells in Shear Flow Himanish Basu, Aditya K Research, Mumbai, India ABSTRACT Tank-treading (TT) motion is established in optically trapped, live red while undergoing tank-treading motion (13­17). In an RBC, the cytoskeleton and the plasma membrane form

Sharma, Shobhona

167

A Flow-Through High-Pressure Electrical Conductance Cell for Determining of Ion Association of Aqueous Electrolyte Solutions at High Temperature and Pressure  

SciTech Connect (OSTI)

A flow-through high-pressure electrical conductance cell was designed and constructed to measure limiting molar conductances and ion association constants of dilute aqueous solutions with high precision at high temperatures and pressures. The basic concept of the cell employs the principle developed at the University of Delaware in 1995, but overall targets higher temperatures (to 600 C) and pressures (to 300 MPa). At present the cell has been tested by measuring aqueous NaCl and LiOH solutions (10{sup {minus}3} to 10{sup {minus}5} mol.kg{sup {minus}1}) to 405 C and 33 MPa with good results.

Bianchi, H.; Ho, P.C.; Palmer, D.A.; Wood, R.H.

1999-09-12T23:59:59.000Z

168

DNA binding shifts the redox potential of the transcription factor SoxR  

E-Print Network [OSTI]

DNA binding shifts the redox potential of the transcription factor SoxR Alon A. Gorodetsky , Lars E-modified electrodes are used to probe the effects of binding to DNA on the redox potential of SoxR, a transcription in the absence of DNA. Using Redmond red as a covalently bound redox reporter affixed above the SoxR binding site

Dietrich, Lars

169

Species-specific residues calibrate SoxR sensitivity to redox-active molecules  

E-Print Network [OSTI]

to viologens, which have redox potentials below -350 mV. Using a mutagenic approach, we pin- pointed threeSpecies-specific residues calibrate SoxR sensitivity to redox-active molecules Rebecca Sheplock,1, the transcription factor SoxR triggers a global stress response by sensing a broad spectrum of redox

Dietrich, Lars

170

Method of producing exfoliated graphite composite compositions for fuel cell flow field plates  

DOE Patents [OSTI]

A method of producing an electrically conductive composite composition, which is particularly useful for fuel cell bipolar plate applications. The method comprises: (a) providing a supply of expandable graphite powder; (b) providing a supply of a non-expandable powder component comprising a binder or matrix material; (c) blending the expandable graphite with the non-expandable powder component to form a powder mixture wherein the non-expandable powder component is in the amount of between 3% and 60% by weight based on the total weight of the powder mixture; (d) exposing the powder mixture to a temperature sufficient for exfoliating the expandable graphite to obtain a compressible mixture comprising expanded graphite worms and the non-expandable component; (e) compressing the compressible mixture at a pressure within the range of from about 5 psi to about 50,000 psi in predetermined directions into predetermined forms of cohered graphite composite compact; and (f) treating the so-formed cohered graphite composite to activate the binder or matrix material thereby promoting adhesion within the compact to produce the desired composite composition. Preferably, the non-expandable powder component further comprises an isotropy-promoting agent such as non-expandable graphite particles. Further preferably, step (e) comprises compressing the mixture in at least two directions. The method leads to composite plates with exceptionally high thickness-direction electrical conductivity.

Zhamu, Aruna; Shi, Jinjun; Guo, Jiusheng; Jang, Bor Z

2014-04-08T23:59:59.000Z

171

Adaptive changes in renal mitochondrial redox status in diabetic nephropathy  

SciTech Connect (OSTI)

Nephropathy is a serious and common complication of diabetes. In the streptozotocin (STZ)-treated rat model of diabetes, nephropathy does not typically develop until 30 to 45 days post-injection, although hyperglycemia occurs within 24 h. We tested the hypothesis that chronic hyperglycemia results in a modest degree of oxidative stress that is accompanied by compensatory changes in certain antioxidants and mitochondrial redox status. We propose that as kidneys progress to a state of diabetic nephropathy, further adaptations occur in mitochondrial redox status. Basic parameters of renal function in vivo and several parameters of mitochondrial function and glutathione (GSH) and redox status in isolated renal cortical mitochondria from STZ-treated and age-matched control rats were examined at 30 days and 90 days post-injection. While there was no effect of diabetes on blood urea nitrogen, measurement of other, more sensitive parameters, such as urinary albumin and protein, and histopathology showed significant and progressive worsening in diabetic rats. Thus, renal function is compromised even prior to the onset of frank nephropathy. Changes in mitochondrial respiration and enzyme activities indicated existence of a hypermetabolic state. Higher mitochondrial GSH content and rates of GSH transport into mitochondria in kidneys from diabetic rats were only partially due to changes in expression of mitochondrial GSH carriers and were mostly due to higher substrate supply. Although there are few clear indicators of oxidative stress, there are several redox changes that occur early and change further as nephropathy progresses, highlighting the complexity of the disease. Highlights: ?Adaptive changes in renal mitochondrial and redox status in diabetic rats. ?Modest renal dysfunction even prior to onset of nephropathy. ?Elevated concentrations of mitochondrial GSH in diabetic kidneys. ?Change in GSH due partly to increased protein expression of transporter. ?Oxidatively modified proteins in renal mitochondria from diabetic rats.

Putt, David A.; Zhong, Qing; Lash, Lawrence H., E-mail: l.h.lash@wayne.edu

2012-01-15T23:59:59.000Z

172

Measuring Spatial Variability of Vapor Flux to Characterize Vadose-zone VOC Sources: Flow-cell Experiments  

SciTech Connect (OSTI)

A method termed vapor-phase tomography has recently been proposed to characterize the distribution of volatile organic contaminant mass in vadose-zone source areas, and to measure associated three-dimensional distributions of local contaminant mass discharge. The method is based on measuring the spatial variability of vapor flux, and thus inherent to its effectiveness is the premise that the magnitudes and temporal variability of vapor concentrations measured at different monitoring points within the interrogated area will be a function of the geospatial positions of the points relative to the source location. A series of flow-cell experiments was conducted to evaluate this premise. A well-defined source zone was created by injection and extraction of a non-reactive gas (SF6). Spatial and temporal concentration distributions obtained from the tests were compared to simulations produced with a mathematical model describing advective and diffusive transport. Tests were conducted to characterize both areal and vertical components of the application. Decreases in concentration over time were observed for monitoring points located on the opposite side of the source zone from the local–extraction point, whereas increases were observed for monitoring points located between the local–extraction point and the source zone. The results illustrate that comparison of temporal concentration profiles obtained at various monitoring points gives a general indication of the source location with respect to the extraction and monitoring points.

Mainhagu, Jon; Morrison, C.; Truex, Michael J.; Oostrom, Martinus; Brusseau, Mark

2014-10-20T23:59:59.000Z

173

Parallel flow diffusion battery  

DOE Patents [OSTI]

A parallel flow diffusion battery for determining the mass distribution of an aerosol has a plurality of diffusion cells mounted in parallel to an aerosol stream, each diffusion cell including a stack of mesh wire screens of different density.

Yeh, H.C.; Cheng, Y.S.

1984-01-01T23:59:59.000Z

174

Status of flow-battery research in the United States  

SciTech Connect (OSTI)

Flow batteries are defined as electrochemical energy storage devices in which at least one of the active materials is stored external to the power converting cell-stack, and in which this soluble active material is circulated via the electrolyte, through the cell-stack during system charge or discharge. Although intensive development of some of these systems has been underway for some time, they were only classified as a distinct category in the United States recently. Of the projects on flow batteries which are still being conducted, the work on the zinc/chlorine system (EDA) has been in progress since 1968; programs on zinc/bromine (Exxon, Gould), on iron/chromium Redox (NASA-Lewis Research Center), and on the iron/ferric-ferrous chloride system (NRG/GEL) have all been underway about seven years; research on the zinc/ferro-ferricyanide battery (Lockheed) has been conducted since 1978. The present paper, which reviews the 1982 status of these battery programs, appears timely since, except for the Lockheed system, the developments have all reached the stage where multi-kilowatt-hour batteries are under test.

Clark, R.P.; Chamberlin, J.L.; Saxton, H.J.; Symons, P.C.

1982-01-01T23:59:59.000Z

175

Red blood cells and other non-spherical capsules in shear flow: oscillatory dynamics and the tank-treading-to-tumbling transition  

E-Print Network [OSTI]

We consider the motion of red blood cells and other non-spherical microcapsules dilutely suspended in a simple shear flow. Our analysis indicates that depending on the viscosity, membrane elasticity, geometry and shear rate, the particle exhibits either tumbling, tank-treading of the membrane about the viscous interior with periodic oscillations of the orientation angle, or intermittent behavior in which the two modes occur alternately. For red blood cells, we compute the complete phase diagram and identify a novel tank-treading-to-tumbling transition at low shear rates. Observations of such motions coupled with our theoretical framework may provide a sensitive means of assessing capsule properties.

J. M. Skotheim; T. W. Secomb

2006-05-26T23:59:59.000Z

176

SFTEL: Flow Cell | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar HomePromisingStoriesSANDIA REPORT SANDSDNTM7/31/13 Page 12/01/12NISFTEL:

177

Intermediate Flow Cells | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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178

Application of Flow Battery in Marine Current Turbine System for Daily Power Management  

E-Print Network [OSTI]

focuses on a grid-connected MCT system and proposes using vanadium redox flow battery (VRB) energy storage/energy sizing. In this paper, one grid-connected MCT generation system with battery energy storage system (BESSApplication of Flow Battery in Marine Current Turbine System for Daily Power Management Zhibin Zhou

Brest, Université de

179

E-Print Network 3.0 - auto-protective redox buffering Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

redox processes analogous to those responsible for water oxidation... in the oxygen-evolving complex (OEC) of photosystem II (PSII). DFT B3LYP free energy calculations of...

180

E-Print Network 3.0 - abundant redox proteins Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

real time visual- ization... of such destruc- tive assays is very poor. Redox-sensitive green fluorescent ... Source: Tsien, Roger Y. - Department of Chemistry and Biochemistry,...

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Thermal-fluid and electrochemical modeling and performance study of a planar solid oxide electrolysis cell : analysis on SOEC resistances, size, and inlet flow conditions.  

SciTech Connect (OSTI)

Argonne National Laboratory and Idaho National Laboratory researchers are analyzing the electrochemical and thermal-fluid behavior of solid oxide electrolysis cells (SOECs) for high temperature steam electrolysis using computational fluid dynamics (CFD) techniques. The major challenges facing commercialization of steam electrolysis technology are related to efficiency, cost, and durability of the SOECs. The goal of this effort is to guide the design and optimization of performance for high temperature electrolysis (HTE) systems. An SOEC module developed by FLUENT Inc. as part of their general CFD code was used for the SOEC analysis by INL. ANL has developed an independent SOEC model that combines the governing electrochemical mechanisms based on first principals to the heat transfer and fluid dynamics in the operation of SOECs. The ANL model was embedded into the commercial STAR-CD CFD software, and is being used for the analysis of SOECs by ANL. The FY06 analysis performed by ANL and reported here covered the influence of electrochemical properties, SOEC component resistances and their contributing factors, SOEC size and inlet flow conditions, and SOEC flow configurations on the efficiency and expected durability of these systems. Some of the important findings from the ANL analysis are: (1) Increasing the inlet mass flux while going to larger cells can be a compromise to overcome increasing thermal and current density gradients while increasing the cell size. This approach could be beneficial for the economics of the SOECs; (2) The presence of excess hydrogen at the SOEC inlet to avoid Ni degradation can result in a sizeable decrease in the process efficiency; (3) A parallel-flow geometry for SOEC operation (if such a thing be achieved without sealing problems) yields smaller temperature gradients and current density gradients across the cell, which is favorable for the durability of the cells; (4) Contact resistances can significantly influence the total cell resistance and cell temperatures over a large range of operating potentials. Thus it is important to identify and avoid SOEC stack conditions leading to such high resistances due to poor contacts.

Yildiz, B.; Smith, J.; Sofu, T.; Nuclear Engineering Division

2008-06-25T23:59:59.000Z

182

Neuron, Vol. 36, 11951210, December 19, 2002, Copyright 2002 by Cell Press Sustained Negative BOLD, Blood Flow and Oxygen  

E-Print Network [OSTI]

, Blood Flow and Oxygen Consumption Response and Its Coupling to the Positive Response in the Human Brain Several previous human PET (Shulman et al., 1997;Minneapolis, Minnesota 55455 and others) and f

183

Flow-Through Microfluidic Device for High-Efficiency Transfection of Mammalian Cells through Combined Microelectroporation and Sonoporation  

E-Print Network [OSTI]

In this study we are presenting a proof-of-concept microfluidic device that simultaneously applies the conditions required for microelectroporation and micro-sonoporation in a flow-through fashion that allows for high throughput, high efficiency...

Longsine, Whitney Leigh

2012-07-16T23:59:59.000Z

184

Controlled Chemical Doping of Semiconductor Nanocrystals Using Redox Buffers  

SciTech Connect (OSTI)

Semiconductor nanocrystal solids are attractive materials for active layers in next-generation optoelectronic devices; however, their efficient implementation has been impeded by the lack of precise control over dopant concentrations. Herein we demonstrate a chemical strategy for the controlled doping of nanocrystal solids under equilibrium conditions. Exposing lead selenide nanocrystal thin films to solutions containing varying proportions of decamethylferrocene and decamethylferrocenium incrementally and reversibly increased the carrier concentration in the solid by 2 orders of magnitude from their native values. This application of redox buffers for controlled doping provides a new method for the precise control of the majority carrier concentration in porous semiconductor thin films.

Engel, Jesse H.; Surendranath, Yogesh; Alivisatos, Paul

2013-07-09T23:59:59.000Z

185

Redox-Reactive Membrane Vesicles produced by Shewanella. | EMSL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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186

The Application of Flow Cytometry to Examine Damage Clearance in Stem Cells From Whole-Body Irradiated Mice  

SciTech Connect (OSTI)

The bone marrow contains many types of cells. Approximately 1-2% of these cells are critical for life, these are the so-called ‘bone marrow stem cells’ which divide indefinitely to produce platelets, red blood cells and white blood cells. Death of the bone marrow stem cells results in a diminished ability of the organism to make new blood cell components and can be fatal without medical intervention, such as a bone marrow transplant. Bone marrow stem cells are considered to be particularly sensitive to radiation injury. Therefore, it is important to understand how these cells response to total body radiation exposure and how these cells can be protected from radiation damage. The aim of this project was to determine if these critical cells in the bone marrow are susceptible to short-term and long-term injury after a whole-body exposure to a sub-lethal low dose of ionizing radiation. The overall aims were to determine if the extent of injury produced by the sub-lethal radiation exposure would be cleared from the stem cells and therefore present no long- term genetic risk to the organism, or if the radiation injury persisted and had an adverse long-term consequences for the cell genome. This research question is of interest in order to define the risks to exposed persons after occupational, accidental or terrorism-related sub-lethal low-dose radiation exposures. The novel aspect of this project was the methodology used to obtain the bone marrow stem cell-like cells and examining the outcomes of sub-lethal low-dose radiation in a mammalian animal model. Four radiation treatments were used: single treatments of 0.01Gy, 0.1 Gy, 1 Gy and ten treatments of 0.1 Gy given over 10 days. Bone marrow stem cell-like cells were then harvested 6 hours, 24 hours and 24 days later. The levels of radiation-induced cell death, damage to DNA and permanent changes to cellular DNA were measured in the isolated stem cell-like cells after each radiation treatment and time point and then the results were compared. As expected, the largest radiation dose produced the greatest level of damage but a linear relationship did not exist between cellular effects and radiation dose. The low dose exposures appeared to be more efficient at producing damage than the highest dose when normalized for the initial extent of damage. Additionally, immune stimulation given prior to radiation exposure appeared to protect the critical bone marrow stem cell population from radiation injury. The data suggest that the response of bone marrow stem-cell like cells to radiation injury is dependent on the extent of the initial levels of damage and the effects of total-body low-dose exposures can not be predicted by extrapolating from high dose exposures. This research has provided new information about the radiation sensitivity of bone marrow stem cell-like cells following total-body exposures, and suggests that these critical cells might be more sensitive to radiation than more mature cells in the bone marrow. Further work is need with intermediate radiation doses to confirm this conclusion.

Marples, Brian; Kovalchuk, Olga; McGonagle, Michele; Martinez, Alvaro; Wilson, George, D.

2010-02-26T23:59:59.000Z

187

Photocurrent generation by photosystem 1 integrated in crosslinked redox Adrian Badura,a  

E-Print Network [OSTI]

Photocurrent generation by photosystem 1 integrated in crosslinked redox hydrogels Adrian Badura on a gold electrode surface via an Os complex containing redox polymer hydrogel which simultaneously is used as immobilisation matrix and as electron donor for PS1. On addition of methyl viologen as sacrificial electron

Roegner, Matthias

188

Early diagenesis of carbohydrates and lignin in mangrove sediments subject to variable redox  

E-Print Network [OSTI]

Early diagenesis of carbohydrates and lignin in mangrove sediments subject to variable redox Abstract A comparative study of lignin and neutral carbohydrate compositions, combined with C, N and 13C and lignin in brackish to hypersaline fine-grained mangrove sediments characterized by great changes in redox

Paris-Sud XI, Université de

189

Highly conductive, multi-layer composite precursor composition to fuel cell flow field plate or bipolar plate  

DOE Patents [OSTI]

This invention provides a moldable, multiple-layer composite composition, which is a precursor to an electrically conductive composite flow field plate or bipolar plate. In one preferred embodiment, the composition comprises a plurality of conductive sheets and a plurality of mixture layers of a curable resin and conductive fillers, wherein (A) each conductive sheet is attached to at least one resin-filler mixture layer; (B) at least one of the conductive sheets comprises flexible graphite; and (C) at least one resin-filler mixture layer comprises a thermosetting resin and conductive fillers with the fillers being present in a sufficient quantity to render the resulting flow field plate or bipolar plate electrically conductive with a conductivity no less than 100 S/cm and thickness-direction areal conductivity no less than 200 S/cm.sup.2.

Jang, Bor Z. (Centerville, OH); Zhamu, Aruna (Centerville, OH); Guo, Jiusheng (Centerville, OH)

2011-02-15T23:59:59.000Z

190

Methane oxidation over dual redox catalysts. Final report  

SciTech Connect (OSTI)

Catalytic oxidation of methane to partial oxidation products, primarily formaldehyde and C{sub 2} hydrocarbons, was found to be directed by the catalyst used. In this project, it was discovered that a moderate oxidative coupling catalyst for C{sub 2} hydrocarbons, zinc oxide, is modified by addition of small amounts of Cu and Fe dopants to yield fair yields of formaldehyde. A similar effect was observed with Cu/Sn/ZnO catalysts, and the presence of a redox Lewis acid, Fe{sup III} or Sn{sup IV}, was found to be essential for the selectivity switch from C{sub 2} coupling products to formaldehyde. The principle of double doping with an oxygen activator (Cu) and the redox Lewis acid (Fe, Sn) was pursued further by synthesizing and testing the CuFe-ZSM-5 zeolite catalyst. The Cu{sup II}(ion exchanged) Fe{sup III}(framework)-ZSM-5 also displayed activity for formaldehyde synthesis, with space time yields exceeding 100 g/h-kg catalyst. However, the selectivity was low and earlier claims in the literature of selective oxidation of methane to methanol over CuFe-ZSM-5 were not reproduced. A new active and selective catalytic system (M=Sb,Bi,Sn)/SrO/La{sub 2}O{sub 3} has been discovered for potentially commercially attractive process for the conversion of methane to C{sub 2} hydrocarbons, (ii) a new principle has been demonstrated for selectivity switching from C{sub 2} hydrocarbon products to formaldehyde in methane oxidations over Cu,Fe-doped zinc oxide and ZSM-5, and (iii) a new approach has been initiated for using ultrafine metal dispersions for low temperature activation of methane for selective conversions. Item (iii) continues being supported by AMOCO while further developments related to items (i) and (ii) are the objective of our continued effort under the METC-AMOCO proposed joint program.

Klier, K.; Herman, R.G.; Sojka, Z.; DiCosimo, J.I.; DeTavernier, S.

1992-06-01T23:59:59.000Z

191

Sorption of redox-sensitive elements: critical analysis  

SciTech Connect (OSTI)

The redox-sensitive elements (Tc, U, Np, Pu) discussed in this report are of interest to nuclear waste management due to their long-lived isotopes which have a potential radiotoxic effect on man. In their lower oxidation states these elements have been shown to be highly adsorbed by geologic materials occurring under reducing conditions. Experimental research conducted in recent years, especially through the Waste Isolation Safety Assessment Program (WISAP) and Waste/Rock Interaction Technology (WRIT) program, has provided extensive information on the mechanisms of retardation. In general, ion-exchange probably plays a minor role in the sorption behavior of cations of the above three actinide elements. Formation of anionic complexes of the oxidized states with common ligands (OH/sup -/, CO/sup - -//sub 3/) is expected to reduce adsorption by ion exchange further. Pertechnetate also exhibits little ion-exchange sorption by geologic media. In the reduced (IV) state, all of the elements are highly charged and it appears that they form a very insoluble compound (oxide, hydroxide, etc.) or undergo coprecipitation or are incorporated into minerals. The exact nature of the insoluble compounds and the effect of temperature, pH, pe, other chemical species, and other parameters are currently being investigated. Oxidation states other than Tc (IV,VII), U(IV,VI), Np(IV,V), and Pu(IV,V) are probably not important for the geologic repository environment expected, but should be considered especially when extreme conditions exist (radiation, temperature, etc.). Various experimental techniques such as oxidation-state analysis of tracer-level isotopes, redox potential measurement and control, pH measurement, and solid phase identification have been used to categorize the behavior of the various valence states.

Strickert, R.G.

1980-12-01T23:59:59.000Z

192

Vanadium redox-flow batteries Installation at Ris for characterisation measurements  

E-Print Network [OSTI]

and investigating distributed power systems. SYSLAB consists of two wind turbines, a pv-array, a diesel genset features including independent sizing of power and energy capacity, long lifetime, high efficiency and fast in August 2007. Power systems with high penetration of Wind energy/Renewable energy Renewable energy

193

Nuclear Magnetic Resonance Studies on Vanadium(IV) Electrolyte Solutions for Vanadium Redox Flow Battery  

SciTech Connect (OSTI)

The vanadium (IV) electrolyte solutions with various vanadium concentrations are studied by variable temperature 1H and 17O Nuclear Magnetic Resonance (NMR) spectroscopy. The structure and kinetics of vanadium (IV) species in the electrolyte solutions are explored with respect to vanadium concentration and temperature. It was found that the vanadium (IV) species exist as hydrated vanadyl ion, i.e. [VO(H2O)5]2+ forming an octahedral coordination with vanadyl oxygen in the axial position and the remaining positions occupied by water molecules. This hydrated vanadyl ion structure is stable in vanadium concentrations up to 3M and in the temperature range of 240 to 340 K. The sulfate anions in the electrolyte solutions are found to be weekly bound to this hydrated vanadyl ion and occupies its second coordination sphere. The possible effects of these sulfate anions in proton and water exchange between vanadyl ion and solvent molecules are discussed based on 1H and 17O NMR results.

Vijayakumar, M.; Burton, Sarah D.; Huang, Cheng; Li, Liyu; Yang, Zhenguo; Graff, Gordon L.; Liu, Jun; Hu, Jian Z.; Skyllas-Kazacos, Maria

2010-11-15T23:59:59.000Z

194

Some lessons learned from 20 years in RedOx Flow Battery R&D  

E-Print Network [OSTI]

of many biological processes Closed loop processes Batteries, DSSC, bio-tech Electrochemical balancing pressure (low p) Materials Novel nano-structured non- carbon electrodes Novel low cost discharging Materials that are robust in discharge reactions often fail under charging - e.g carbon Good

195

Vanadium-redox flow and lithium-ion battery modelling and performance in wind energy applications.  

E-Print Network [OSTI]

??As wind energy penetration levels increase, there is a growing interest in using storage devices to aid in managing the fluctuations in wind turbine output… (more)

Chahwan, John A.

2007-01-01T23:59:59.000Z

196

TEMPO-based Catholyte for High Energy Density Nonaqueous Redox Flow  

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197

A Stable Vanadium Redox-Flow Battery with High Energy Density for  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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198

Redox Flow Batteries for Grid-scale Energy Storage - Energy Innovation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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199

Nanorod Niobium Oxide as Powerful Catalysts for an All Vanadium Redox Flow  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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200

Structure and Stability of Hexa-Aqua V(III) Cations in Vanadium Redox Flow  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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201

Flow cytometry apparatus  

DOE Patents [OSTI]

An obstruction across the flow chamber creates a one dimensional convergence of a sheath fluid. A passageway in the construction directs flat cells near to the area of one dimensional convergence in the sheath fluid to provide proper orientation of flat cells at fast rates.

Pinkel, Daniel (Walnut Creek, CA)

1991-01-01T23:59:59.000Z

202

Stable-isotope probe of nano-scale mineral-fluid redox interactions  

SciTech Connect (OSTI)

The project examined how stable isotopes fractionate at an aqueous/solid interface during electrochemical reduction reactions. Measurements in a wide variety of metal deposition systems including Fe, Zn, Li, Mo, and Cu, have led to observations of large isotope fractionations which strongly vary as a function of rate and temperature. For the Fe, Zn, and Li systems, our electrochemical deposition methods provide the largest single-pass fractionation factors that are observed for these systems. Based on these and other experiments and theory showing and predicting significant and rate-dependent fractionations of isotopes at reacting interfaces, we have developed a simple statistical mechanics framework that predicts the kinetic isotope effect accompanying phase transformations in condensed systems. In addition, we have begun to extend our studies of mineral-fluid redox interactions to high pressures and temperatures in the diamond anvil cell. We performed a series of experiments to determine solubilities of Cu and Ni at elevated pressure and temperature conditions relevant to ore-formation.

Kavner, Abby

2014-11-26T23:59:59.000Z

203

Cotton flow  

E-Print Network [OSTI]

Using the conformally invariant Cotton tensor, we define a geometric flow, the "Cotton flow", which is exclusive to three dimensions. This flow tends to evolve the initial metrics into conformally flat ones, and is somewhat orthogonal to the Yamabe flow, the latter being a flow within a conformal class. We define an entropy functional, and study the flow of nine homogeneous spaces both numerically and analytically. In particular, we show that the arbitrarily deformed homogeneous 3-sphere flows into the round 3-sphere. Two of the nine homogeneous geometries, which are degenerated by the Ricci flow, are left intact by the Cotton flow.

Ali Ulas Ozgur Kisisel; Ozgur Sarioglu; Bayram Tekin

2008-06-17T23:59:59.000Z

204

Influence of Iron Redox Transformations on Plutonium Sorption to Sediments  

SciTech Connect (OSTI)

Plutonium subsurface mobility is primarily controlled by its oxidation state, which in turn is loosely coupled to the oxidation state of iron in the system. Experiments were conducted to examine the effect of sediment iron mineral composition and oxidation state on plutonium sorption and oxidation state. A pH 6.3 vadose zone sediment containing iron oxides and iron-containing phyllosilicates was treated with various complexants (ammonium oxalate) and reductants (dithionite-citrate-bicarbonate) to selectively leach and/or reduce iron oxide and phyllosilicate phases. Mössbauer spectroscopy was used to identify initial iron mineral composition of the sediment and monitor dissolution and reduction of iron oxides. Sorption of Pu(V) was monitored over one week for each of six treated sediment fractions. Plutonium oxidation state speciation in the aqueous and solid phases was monitored using solvent extraction, coprecipitation, and XANES. Mössbauer spectroscopy showed that the sediment contained 25-30% hematite, 60-65% Al-goethite, and <10%Fe(III) in phyllosilicate; there was no detectable Fe(II). Upon reduction with a strong chemical reductant (dithionite-citrate buffer, DCB), much of the hematite and goethite disappeared and the Fe in the phyllosilicate reduced to Fe(II). The rate of sorption was found to correlate with the 1 fraction of Fe(II) remaining within each treated sediment phase. Pu(V) was the only oxidation state measured in the aqueous phase, irrespective of treatment, whereas Pu(IV) and much smaller amounts of Pu(V) and Pu(VI) were measured in the solid phase. Surface-mediated reduction of Pu(V) to Pu(IV) occurred in treated and untreated sediment samples; Pu(V) remained on untreated sediment surface for two days before reducing to Pu(IV). Similar to the sorption kinetics, the reduction rate was correlated with sediment Fe(II) concentration. The correlation between Fe(II) concentrations and Pu(V) reduction demonstrates the potential impact of changing iron mineralogy on plutonium subsurface transport through redox transition areas. These findings should influence the conceptual models of long-term stewardship of Pu contaminated sites that have fluctuating redox conditions, such as vadose zones or riparian zones.

Hixon, Amy E.; Hu, Yung-Jin; Kaplan, Daniel I.; Kukkadapu, Ravi K.; Nitsche, Heino; Qafoku, Odeta; Powell, Brian A.

2010-10-01T23:59:59.000Z

205

Molecular cloning and characterization of important stress and redox regulatory genes from Hydra vulgaris  

E-Print Network [OSTI]

In this research, important stress and redox regulatory genes present in Hydra vulgaris were isolated and characterized to facilitate our understanding of the evolution and mechanisms of stress response. H. vulgaris heat shock protein 70 (HvHSP70...

Dash, Bhagirathi

2007-04-25T23:59:59.000Z

206

Hybrid density functional calculations of redox potentials and formation energies of transition metal compounds  

E-Print Network [OSTI]

We compare the accuracy of conventional semilocal density functional theory (DFT), the DFT+U method, and the Heyd-Scuseria-Ernzerhof (HSE06) hybrid functional for structural parameters, redox reaction energies, and formation ...

Ceder, Gerbrand

207

Consequences of redox-active phenazines on the physiology of the opportunistic pathogen Pseudomonas aeruginosa  

E-Print Network [OSTI]

Phenazines are redox-active small molecules produced by bacteria. Although phenazines have been studied extensively for their roles as toxins, how phenazines benefit producing organisms is still being uncovered. Pseudomonas ...

Kern, Suzanne E

2013-01-01T23:59:59.000Z

208

The role of Ncb5or in fatty acid metabolism and redox homeostasis  

E-Print Network [OSTI]

The endoplasmic reticulum (ER)-associated NADH cytochrome b5 oxidoreductase (Ncb5or) is widely distributed in animal tissues. It contains two redox domains that are homologous to microsomal cytochrome b5 (Cyb5A) at the N ...

Xu, Ming

2011-12-31T23:59:59.000Z

209

Redox states of Desulfovibrio vulgaris DsrC, a key protein in...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Venceslau SS, JR Cort, ES Baker, RK Chu, EW Robinson, C Dahl, LM Saraiva, and IA Pereira.2013."Redox states of Desulfovibrio vulgaris DsrC, a key protein in dissimilatory...

210

Redox reaction and foaming in nuclear waste glass melting  

SciTech Connect (OSTI)

This document was prepared by Pacific Northwest Laboratory (PNL) and is an attempt to analyze and estimate the effects of feed composition variables and reducing agent variables on the expected chemistry of reactions occurring in the cold cap and in the glass melt in the nuclear waste glass Slurry-fed, joule-heated melters as they might affect foaming during the glass-making process. Numerous redox reactions of waste glass components and potential feed additives, and the effects of other feed variables on these reactions are reviewed with regard to their potential effect on glass foaming. A major emphasis of this report is to examine the potential positive or negative aspects of adjusting feed with formic acid as opposed to other feed modification techniques including but not limited to use of other reducing agents. Feed modification techniques other than the use of reductants that should influence foaming behavior include control of glass melter feed pH through use of nitric acid. They also include partial replacement of sodium salts by lithium salts. This latter action (b) apparently lowers glass viscosity and raises surface tension. This replacement should decrease foaming by decreasing foam stability.

Ryan, J.L.

1995-08-01T23:59:59.000Z

211

Photocurrent Enhancement by Multilayered Porphyrin Sensitizers in a Photoelectrochemical Cell  

E-Print Network [OSTI]

be useful in dye-sensitized solar cells (DSSCs). We report on the photoelectrochemical responses scheme for use in photoelectrochemical cells. KEYWORDS: porphyrin, light harvesting, dye-sensitized solar nanocrystalline titania and I- / I3 - redox shuttle electrolyte, dye-sensitized solar cells (DSSCs) have become

Dinolfo, Peter H.

212

100-D Area In Situ Redox Treatability Test for Chromate-Contaminated Groundwater  

SciTech Connect (OSTI)

A treatability test was conducted for the In Situ Redox Manipulation (ISRM) technology at the 100 D Area of the U. S. Department of Energy's Hanford Site. The target contaminant was dissolved chromate in groundwater. The ISRM technology creates a permeable subsurface treatment zone to reduce mobile chromate in groundwater to an insoluble form. The ISRM permeable treatment zone is created by reducing ferric iron to ferrous iron within the aquifer sediments, which is accomplished by injecting aqueous sodium dithionite into the aquifer and then withdrawing the reaction products. The goal of the treatability test was to create a linear ISRM barrier by injecting sodium dithionite into five wells. Well installation and site characterization activities began in spring 1997; the first dithionite injection took place in September 1997. The results of this first injection were monitored through the spring of 1998. The remaining four dithionite injections were carried out in May through July of 1998.These five injections created a reduced zone in the Hanford unconfined aquifer approximately 150 feet in length (perpendicular to groundwater flow) and 50 feet wide. The reduced zone extended over the thickness of the unconfined zone. Analysis of post-emplacement groundwater samples showed concentrations of chromate, in the reduced zone decreased from approximately 1.0 mg/L before the tests to below analytical detection limits (<0.007 mg/L). Chromate concentrations also declined in downgradient monitoring wells to as low as 0.020 mg/L. These data, in addition to results from pre-test reducible iron characterization, indicate the barrier should be effective for 20 to 25 years. The 100-D Area ISRM barrier is being expanded to a length of up to 2,300 ft to capture a larger portion of the chromate plume.

Williams, Mark D.; Vermeul, Vincent R.; Szecsody, James E.; Fruchter, Jonathan S.

2000-10-12T23:59:59.000Z

213

Poly(3,4-ethylenedioxypyrrole) Modified Emitter Electrode for Substitution of Homogeneous Redox Buffer Agent Hydroquinone in Electrospray Ionization Mass Spectrometry  

SciTech Connect (OSTI)

The electrolysis inherent to the operation of the electrospray ionization (ESI) source used with mass spectrometry (MS) is a well-known attendant effect of generating unipolar spray droplets and may affect the analysis of the analyte of interest. Undesirable electrolysis of an analyte may be prevented by limiting the emitter electrode current and/or the mass transport characteristics of the system. However, these ways to avoid analyte electrolysis may not be applcable in all ESI-MS experiments. For example, in the case of specific nanospray systems (e.g. the wire-in-a-capillary bulk-loaded or chip-based tip-loaded nanospray configurations), the solution flow rate is fixed in the 50-500 nL/min range and the electrode surface to volume ratio is large presenting a very effcient analyte to electrode mass transport configuration. In these situations, control over the interfacial potential of the working electrode via homogeneous or traditional heterogeneous (sacrificial metal) redox buffering is a possible way to prevent analyte electrolysis. However, byproducts of these redox buffering approaches can appear in the mass spectra and/or they can chemically alter the analyte. For example, the main reason for using hydroquinone as a homogeneous redox buffer, in addition to its relatively low oxidation potential, is that neither the original compound nor its oxidation product benzoquinone can be detected directly by ESI-MS. However, benzoquinone can alter analytes with thiol functional groups by reacting with those groups via a 1,4-Michael addition.

Peintler-Krivan, Emese [ORNL; Van Berkel, Gary J [ORNL; Kertesz, Vilmos [ORNL

2010-01-01T23:59:59.000Z

214

Structural insights into the modulation of the redox properties of two Geobacter sulfurreducens homologous triheme cytochromes.  

SciTech Connect (OSTI)

The redox properties of a periplasmic triheme cytochrome, PpcB from Geobacter sulfurreducens, were studied by NMR and visible spectroscopy. The structure of PpcB was determined by X-ray diffraction. PpcB is homologous to PpcA (77% sequence identity), which mediates cytoplasmic electron transfer to extracellular acceptors and is crucial in the bioenergetic metabolism of Geobacter spp. The heme core structure of PpcB in solution, probed by 2D-NMR, was compared to that of PpcA. The results showed that the heme core structures of PpcB and PpcA in solution are similar, in contrast to their crystal structures where the heme cores of the two proteins differ from each other. NMR redox titrations were carried out for both proteins and the order of oxidation of the heme groups was determined. The microscopic properties of PpcB and PpcA redox centers showed important differences: (1) the order in which hemes become oxidized is III-I-IV for PpcB, as opposed to I-IV-III for PpcA; (2) the redox-Bohr effect is also different in the two proteins. The different redox features observed between PpcB and PpcA suggest that each protein uniquely modulates the properties of their co-factors to assure effectiveness in their respective metabolic pathways. The origins of the observed differences are discussed.

Morgado, L.; Bruix, M.; Orshonsky, V.; Londer, Y. Y.; Duke, N. E. C.; Yang, X.; Pokkuluri, P. R.; Schiffer, M.; Salgueiro, C. A.; Biosciences Division; Univ. Nova de Lisboa; Insti. de Quimica-Fisica

2008-09-01T23:59:59.000Z

215

Insertable fluid flow passage bridgepiece and method  

DOE Patents [OSTI]

A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.

Jones, Daniel O. (Glenville, NV)

2000-01-01T23:59:59.000Z

216

Piezoelectric axial flow microvalve  

SciTech Connect (OSTI)

This invention is directed to a fuel cell operable with a quantity of fuel and a quantity of an oxidizer to produce electrical power, the fuel cell including a fuel cell body including a labyrinth system structured to permit the fuel and the oxidizer to flow therethrough; at least a first catalyst in fluid communication with the labyrinth; and at least a first microvalve operably disposed within at least a portion of the labyrinth. The microvalve utilizes a deflectable member operable upon the application of a voltage from a voltage source. The microvalve includes an elongated flow channel formed therein and extending substantially longitudinally between the first and second ends to permit substantially longitudinal flow of the fluid therethrough and between the first and second ends; and the deflectable member disposed on the valve body, the deflectable member including at least a first piezoelectric portion that is piezoelectrically operable to deflect the deflectable member between an open position and a closed position upon the application of a voltage, the deflectable member in the closed position being operable to resist the flow of the fluid through the flow channel.

Gemmen, Randall; Thornton, Jimmy; Vipperman, Jeffrey S.; Clark, William W.

2007-01-09T23:59:59.000Z

217

An analysis of a back-fed porous electrode for the bromine/bromide redox reaction  

E-Print Network [OSTI]

AN ANALYSIS OF A BACK-FED POROUS ELECTRODE FOR THE BROMINE/BROMIDE REDOX REACTION A Thesis by JOHN WILLIAM VAN ZEE Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1982 Major Subject: Chemical Engineering AN ANALYSIS OF A BACK-FED POROUS ELECTRODE FOR THE BROMINE/BROMIDE REDOX REACTION A Thesis by JOHN WILLIAM VAN ZEE Approved as to style and content by: (Chai man of Committee) (Member...

Van Zee, John William

2012-06-07T23:59:59.000Z

218

The redox nature of copper is utilized in a large number of enzymatic processes, including that catalysed by mitochondrial  

E-Print Network [OSTI]

The redox nature of copper is utilized in a large number of enzymatic processes, including that catalysed by mitochondrial cytochrome c oxidase, which makes copper an essential element for all aerobic organisms (Soloman and Lowery, 1993). However, the redox properties of copper can cause rapid generation

Grosell, Martin

219

Effect of redox potential, sulfide ions and a persulfide forming cysteine residue on carbon monoxide dehydrogenase  

E-Print Network [OSTI]

The Ni-Fe-S C-cluster of carbon monoxide dehydrogenases (CODH), which catalyzes the reversible oxidation of CO to CO2, can be stabilized in four redox states: Cox, Cred1, Cint, and Cred2. The best-supported mechanism of catalysis involves a one...

Feng, Jian

2005-08-29T23:59:59.000Z

220

Antibiotics induce redox-related physiological alterations as part of their lethality  

E-Print Network [OSTI]

and death, thus supporting an evolving, expanded model of antibiotic lethality. reactive oxygen species Center of Synthetic Biology, Boston University, Boston, MA 02215; Departments of d Chemistry and e antibiotics elevate oxygen consumption, indicating significant alterations to bacterial redox physiology. We

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

A Modular Approach to Redox-active Multimetallic Amphiphiles of Discotic Topology  

SciTech Connect (OSTI)

A new modular [Fe{sup II}(Fe{sup III}L{sup 2}){sub 3}](PF{sub 6}){sub 2} species with discoid (disk-like) topology exhibits redox and surfactant properties and points to a new approach for multimetallic Langmuir film precursors.

F Lesh; R Shanmugam; M Allard; M Lanznaster; M Hegg; M Rodgers; J Shearer; C Verani

2011-12-31T23:59:59.000Z

222

J.F. ALLEN, K. ALEXCIEV AND G. HAKANSSON Regulation by redox signalling  

E-Print Network [OSTI]

,5] confirms this suspicion, and shows that redox control over photo- synthesis genes is exerted by two new', phosphorylated on aspar- tate by transfer of a phosphate from its partner, RegB. RegB is a 'sensor kinase; the genes reside in just two operons. It has long been known that the photo- synthetic apparatus

Allen, John F.

223

Mechanical Force Can Fine-Tune Redox Potentials of Disulfide Bonds Ilona B. Baldus  

E-Print Network [OSTI]

Mechanical Force Can Fine-Tune Redox Potentials of Disulfide Bonds Ilona B. Baldus and Frauke Gra, China ABSTRACT Mechanical force applied along a disulfide bond alters its rate of reduction. We here within proteins by point mutations. INTRODUCTION Similar to thermal or light energy, mechanical force can

Gräter, Frauke

224

Redox-linked conformational changes of a multiheme cytochrome from Geobacter sulfurreducens  

SciTech Connect (OSTI)

Multiheme c-type cytochromes from members of the Desulfovibrionacea and Geobactereacea families play crucial roles in the bioenergetics of these microorganisms. Thermodynamic studies using NMR and visible spectroscopic techniques on tetraheme cytochromes c {sub 3} isolated from Desulfovibrio spp. and more recently on a triheme cytochrome from Geobacter sulfurreducens showed that the properties of each redox centre are modulated by the neighbouring redox centres enabling these proteins to perform energy transduction and thus contributing to cellular energy conservation. Electron/proton transfer coupling relies on redox-linked conformational changes that were addressed for some multiheme cytochromes from the comparison of protein structure of fully reduced and fully oxidised forms. In this work, we identify for the first time in a multiheme cytochrome the simultaneous presence of two different conformations in solution. This was achieved by probing the different oxidation stages of a triheme cytochrome isolated from G. sulfurreducens using 2D-NMR techniques. The results presented here will be the foundations to evaluate the modulation of the redox centres properties by conformational changes that occur during the reoxidation of a multiheme protein.

Morgado, Leonor [Requimte - CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Bruix, Marta [Departamento de Espectroscopia y Estructura Molecular, Instituto de Quimica-Fisica 'Rocasolano', CSIC, Serrano 119, 28006 Madrid (Spain); Londer, Yuri Y. [Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Pokkuluri, P. Raj [Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Schiffer, Marianne [Biosciences Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Salgueiro, Carlos A. [Requimte - CQFB, Departamento de Quimica, Faculdade de Ciencias e Tecnologia, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)]. E-mail: csalgueiro@dq.fct.unl.pt

2007-08-17T23:59:59.000Z

225

A mixed-valence copper coordination polymer generated by hydrothermal metal/ligand redox reactions  

E-Print Network [OSTI]

A mixed-valence copper coordination polymer generated by hydrothermal metal/ligand redox reactions A novel coordination polymer of mixed-valence copper(I,II) with 4,4A-bipyridine and in situ oxidized and crystallographically char- acterized to be a laminated structure via weak copper(II)­ oxygen interactions. Extended

Li, Jing

226

Quantification of rapid environmental redox processes with quick-scanning x-ray absorption  

E-Print Network [OSTI]

Quantification of rapid environmental redox processes with quick-scanning x-ray absorption. Here we apply quick-scanning x-ray absorption spectroscopy (Q-XAS), at sub-second time that can be measured using x-ray absorption spectroscopy. arsenic extended x-ray absorption fine structure

Sparks, Donald L.

227

Flow chamber  

DOE Patents [OSTI]

A flow chamber having a vacuum chamber and a specimen chamber. The specimen chamber may have an opening through which a fluid may be introduced and an opening through which the fluid may exit. The vacuum chamber may have an opening through which contents of the vacuum chamber may be evacuated. A portion of the flow chamber may be flexible, and a vacuum may be used to hold the components of the flow chamber together.

Morozov, Victor (Manassas, VA)

2011-01-18T23:59:59.000Z

228

Geological flows  

E-Print Network [OSTI]

In this paper geology and planetology are considered using new conceptual basis of high-speed flow dynamics. Recent photo technics allow to see all details of a flow, 'cause the flow is static during very short time interval. On the other hand, maps and images of many planets are accessible. Identity of geological flows and high-speed gas dynamics is demonstrated. There is another time scale, and no more. All results, as far as the concept, are new and belong to the author. No formulae, pictures only.

Yu. N. Bratkov

2008-11-19T23:59:59.000Z

229

Functionalized Graphene Sheets as a Versatile Replacement for Platinum in Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

) electrodes were tested for catalytic performance in dye-sensitized solar cells (DSSCs). By using ethyl) this residue must not disperse in the electrolyte. KEYWORDS: graphene, dye-sensitized solar cell, cobalt redox mediator, triiodide, sacrificial binder 1. INTRODUCTION Dye-sensitized solar cells (DSSCs

Aksay, Ilhan A.

230

In Situ Redox Manipulation Proof-of-Principle Test at the Fort Lewis Logistics Center: Final Report  

SciTech Connect (OSTI)

Pacific Northwest National Laboratory (PNNL) conducted a proof-of-principle test at the Fort Lewis Logistics Center to determine the feasibility of using the In Situ Redox Manipulation (ISRM) technology for remediating groundwater contaminated with dissolved trichloroethylene (TCE). ISRM creates a permeable treatment zone in the subsurface to remediate redox-sensitive contaminants in groundwater. The permeable treatment zone is formed by injecting a chemical reducing agent (sodium dithionite with pH buffers) into the aquifer through a well to reduce the naturally occurring ferric iron in the sediments to ferrous iron. Once the reducing agent is injected and given sufficient time to react with aquifer sediments, residual chemicals and reaction products are withdrawn from the aquifer through the same well used for the injection. Redox-sensitive contaminants such as TCE, moving through the treatment zone under natural groundwater flow conditions, are destroyed. TCE is degraded via reductive dechlorination within the ISRM treatment zone to benign degradation products (i.e., acetylene, ethylene). Prior to the proof-of-principle field test, the ISRM technology was successfully demonstrated in laboratory experiments for the reductive dechlorination of dissolved TCE using sediments from the Fort Lewis site. The Logistics Center was placed on the National Priorities List in December 1989 because of TCE contamination in groundwater beneath the site. A Federal Facilities Agreement between the Army, the U.S. Environmental Protection Agency, and the Washington State Department of Ecology became effective in January 1990, and a Record of Decision (ROD) was signed in September 1990. The major components of the ROD included installation of two pump-and-treat systems for the upper aquifer and further investigation of the lower aquifer and other potential sources of contamination. The pump-and-treat systems became operational in August 1995. Fort Lewis asked PNNL to provide technical support in accelerating Installation Restoration Program site remediation and significantly reducing site life-cycle costs at the Logistics Center. In support of this program, ISRM was selected as an innovative technology for bench and field-scale demonstration. Emplacement of the ISRM treatment zone was accomplished through a series of four separate dithionite injection tests conducted between November 10, 1998 and March 29,2000. An extensive program of chemical monitoring was also performed before, during, and after each injection to evaluate the performance of ISRM. Prior to emplacement of the ISRM treatment zone, the site was extensively characterized with respect to geologic, hydrologic, and geochemical properties. Sediment core samples collected for the characterization studies were analyzed in bench-scale column tests at PNNL to determine reducible iron content. These site-specific hydrogeologic and geochemical data were used to develop the emplacement design of the pilot-scale (i.e., single injection well) ISRM treatment zone. Performance data obtained from the proof-of-principle test indicate that field-scale reductive dechlorination of TCE using the ISRM technology is feasible. A treatment zone was created in the subsurface that reduced TCE concentrations as much as 92% on the downgradient side of the reduced zone, from a background concentration of approximately 140 ppb to approximately 11 ppb. The appearance of the principal degradation product, acetylene, also confirmed that TCE destruction was occurring. Analysis of sediment samples collected from post-test boreholes showed a high degree of iron reduction, which helped to confirm the effectiveness of the treatment zone emplacement. Another important goal of the testing program was to provide assurances that chemical treatment of the subsurface did not result in undesirable secondary effects, including formation of toxic TCE degradation products, mobilization of trace elements, and degradation of hydraulic performance. Results obtained from the Fort Lewis ISRM proof-of-principle test, which are c

VR Vermeul; MD Williams; JC Evans; JE Szecsody; BN Bjornstad; TL Liikala

2000-10-25T23:59:59.000Z

231

Investigation of Water Droplet Interaction with the Sidewalls of the Gas Channel in a PEM Fuel Cell in the Presence of Gas Flow  

E-Print Network [OSTI]

forms of hydrogen powered technologies exist and have been well-researched, fuel cells is considered efficiently in the fuel cells (4). Inefficient water removal results in flooding of the catalyst layerInvestigation of Water Droplet Interaction with the Sidewalls of the Gas Channel in a PEM Fuel Cell

Kandlikar, Satish

232

Extraordinarily Efficient Conduction in a Redox-Active Ionic Liquid  

E-Print Network [OSTI]

Iodine added to iodide-based ionic liquids leads to extraordinarily efficient charge transport, vastly exceeding that expected for such viscous systems. Using terahertz time-domain spectroscopy, in conjunction with dc conductivity, diffusivity and viscosity measurements we unravel the conductivity pathways in 1-methyl-3-propylimidazolium iodide melts. This study presents evidence of the Grotthuss mechanism as a significant contributor to the conductivity, and provides new insights into ion pairing processes as well as the formation of polyiodides. The terahertz and transport results are reunited in a model providing a quantitative description of the conduction by physical diffusion and the Grotthuss bond-exchange process. These novel results are important for the fundamental understanding of conduction in molten salts and for applications where ionic liquids are used as charge-transporting media such as in batteries and dye-sensitized solar cells.

Verner K. Thorsmølle; Guido Rothenberger; Daniel Topgaard; Jan C. Brauer; Dai-Bin Kuang; Shaik M. Zakeeruddin; Björn Lindman; Michael Grätzel; Jacques-E. Moser

2010-11-09T23:59:59.000Z

233

Cooling Flows or Heating Flows?  

E-Print Network [OSTI]

It is now clear that AGN heat cooling flows, largely by driving winds. The winds may contain a relativistic component that generates powerful synchrotron radiation, but it is not clear that all winds do so. The spatial and temporal stability of the AGN/cooling flow interaction are discussed. Collimation of the winds probably provides spatial stability. Temporal stability may be possible only for black holes with masses above a critical value. Both the failure of cooling flows to have adiabatic cores and the existence of X-ray cavities confirm the importance of collimated outflows. I quantify the scale of the convective flow that the AGN Hydra would need to drive if it balanced radiative inward flow by outward flow parallel to the jets. At least in Virgo any such flow must be confined to r<~20 kpc. Hydrodynamical simulations suggest that AGN outbursts cannot last longer than ~25 Myr. Data for four clusters with well studied X-ray cavities suggests that heating associated with cavity formation approximately balances radiative cooling. The role of cosmic infall and the mechanism of filament formation are briefly touched on.

James Binney

2003-10-08T23:59:59.000Z

234

Redox Shuttle Additive, Wins 2014 R&D 100 Award | Department of Energy  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: AlternativeEnvironment,Institutes and Launches theResidentialRecovery ActInvestmentPolicyRedox

235

Accelerated search kinetics mediated by redox reactions of DNA repair enzymes  

E-Print Network [OSTI]

A Charge Transport (CT) mechanism has been proposed in several papers (e.g., Yavin, et al. PNAS, v102 3546 (2005)) to explain the localization of Base Excision Repair (BER) enzymes to lesions on DNA. The CT mechanism relies on redox reactions of iron-sulfur cofactors that modify the enzyme's binding affinity. These redox reactions are mediated by the DNA strand and involve the exchange of electrons between BER enzymes along DNA. We propose a mathematical model that incorporates enzyme binding/unbinding, electron transport, and enzyme diffusion along DNA. Analysis of our model within a range of parameter values suggests that the redox reactions can increase desorption of BER enzymes not already bound to their targets, allowing the enzymes to be recycled, thus accelerating the overall search process. This acceleration mechanism is most effective when enzyme copy numbers and enzyme diffusivity along the DNA are small. Under such conditions, we find that CT BER enzymes find their targets more quickly than simple "passive" enzymes that simply attach to the DNA without desorbing.

Pak-Wing Fok; Tom Chou

2009-05-20T23:59:59.000Z

236

High-Surface-Area Architectures for Improved Charge Transfer Kinetics at the Dark Electrode in Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

ABSTRACT: Dye-sensitized solar cell (DSC) redox shuttles other than triiodide/iodide have exhibited: dark electrode, inverse opal, dye cell, fill factor INTRODUCTION Dye-sensitized solar cells (DSCsHigh-Surface-Area Architectures for Improved Charge Transfer Kinetics at the Dark Electrode in Dye-Sensitized

237

Differential expressions of cell cycle regulatory proteins and ERK1/2 characterize the proliferative smooth muscle cell phenotype induced by allylamine  

E-Print Network [OSTI]

by redox mechanisms are c-Fos, c-Jun, nrf-2 and AP-1 [61]. Many of these transcription factors are involved in cell growth and differentiation. Not only are ROS implicated in cell growth, differentiation, and survival, ROS can also elicit apoptosis...

Jones, Sarah Anne Louise

2004-09-30T23:59:59.000Z

238

Final Report - Crystal Settling, Redox, and High Temperature Properties of ORP HLW and LAW Glasses, VSL-09R1510-1, Rev. 0, dated 6/18/09  

SciTech Connect (OSTI)

The radioactive tank waste treatment programs at the U. S. Department of Energy (DOE) have featured joule heated ceramic melter technology for the vitrification of high level waste (HLW). The Hanford Tank Waste Treatment and Immobilization Plant (WTP) employs this same basic technology not only for the vitrification of HLW streams but also for the vitrification of Low Activity Waste (LAW) streams. Because of the much greater throughput rates required of the WTP as compared to the vitrification facilities at the West Valley Demonstration Project (WVDP) or the Defense Waste Processing Facility (DWPF), the WTP employs advanced joule heated melters with forced mixing of the glass pool (bubblers) to improve heat and mass transport and increase melting rates. However, for both HLW and LAW treatment, the ability to increase waste loadings offers the potential to significantly reduce the amount of glass that must be produced and disposed and, therefore, the overall project costs. This report presents the results from a study to investigate several glass property issues related to WTP HLW and LAW vitrification: crystal formation and settling in selected HLW glasses; redox behavior of vanadium and chromium in selected LAW glasses; and key high temperature thermal properties of representative HLW and LAW glasses. The work was conducted according to Test Plans that were prepared for the HLW and LAW scope, respectively. One part of this work thus addresses some of the possible detrimental effects due to considerably higher crystal content in waste glass melts and, in particular, the impact of high crystal contents on the flow property of the glass melt and the settling rate of representative crystalline phases in an environment similar to that of an idling glass melter. Characterization of vanadium redox shifts in representative WTP LAW glasses is the second focal point of this work. The third part of this work focused on key high temperature thermal properties of representative WTP HLW and LAW glasses over a wide range of temperatures, from the melter operating temperature to the glass transition.

Kruger, Albert A.; Wang, C.; Gan, H.; Pegg, I. L.; Chaudhuri, M.; Kot, W.; Feng, Z.; Viragh, C.; McKeown, D. A.; Joseph, I.; Muller, I. S.; Cecil, R.; Zhao, W.

2013-11-13T23:59:59.000Z

239

100-D Area In Situ Redox Treatability Test for Chromate-Contaminated Groundwater: FY 1998 Year-End Report  

SciTech Connect (OSTI)

A treatability test was conducted for the In Situ Redox Manipulation (ISRM) technology at the US Department of Energy's Hanford, Washington 100D Area. The target contaminant was dissolved chromate [Cr(VI)] in groundwater. The ISRM technology involves creating a permeable subsurface treatment zone to reduce mobile chromate in groundwater to an insoluble form. The ISRM permeable treatment zone is created by reducing ferric iron [Fe(III)] to ferrous iron [Fe(II)] within the aquifer sediments. This is accomplished by injecting aqueous sodium dithionite into the aquifer and withdrawing the reaction products. The goal of the treatability test was to create a linear ISRM barrier by injecting sodium dithionite into five wells. Well installation and site characterization activities began in the spring of 1997. The first dithionite injection took place in September 1997. The results of this first injection were monitored through the spring of 1998; the remaining four dithionite injections were carried out in May through July of 1998. These five injections created a reduced zone in the Hanford unconfined aquifer 150 feet in length (perpendicular to groundwater flow) by 50 feet wide. The reduced zone extended over the thickness of the unconfined zone, which is approximately 15 feet. Analysis of recent groundwater sampling events shows that the concentrations of chromate [Cr(VI)] in groundwater in the reduced zone have been decreased from starting concentrations of approximately 900 ppb to below analytical detection limits (<7 ppb). Chromate concentrations are also declining in some downgradient monitoring wells. Laboratory analysis of iron in the soil indicates that the barrier should remain in place for approximately 20 to 25 years. These measurements will be confirmed by analysis of sediment cores in FY 1999.

Williams, M.D.; Vermeul, V.R.; Szecsody, J.E.; Fruchter, J.S.; Cole, C.R.

1999-04-15T23:59:59.000Z

240

Control of flow and oxygen in a 3-D perfused micro-environment fosters balanced survival of hepatocyte-non-parenchymal cell co-cultures  

E-Print Network [OSTI]

Creating a physiologically relevant in vitro liver model requires reproducing the cellular heterogeneity of in vivo liver in a functional state. However differentiated sinusoidal endothelial cells (SECs), marked by SE-1 ...

Dash, Ajit

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

A Glucose BioFuel Cell Implanted in Rats Philippe Cinquin1  

E-Print Network [OSTI]

A Glucose BioFuel Cell Implanted in Rats Philippe Cinquin1 *, Chantal Gondran2 , Fabien Giroud2 powerful ones, Glucose BioFuel Cells (GBFCs), are based on enzymes electrically wired by redox mediators applications. Citation: Cinquin P, Gondran C, Giroud F, Mazabrard S, Pellissier A, et al. (2010) A Glucose BioFuel

Paris-Sud XI, Université de

242

Superlattice photoelectrodes for photoelectrochemical cells  

DOE Patents [OSTI]

The application of superlattice semiconductors as photoelectrodes in photoelectrochemical energy conversion processes is described. The invention is comprised of a multiple quantum well, or superlattice, semiconductor positioned on a plate and encapsulated in an insulation material, except the top surface, which is left exposed. An opening in insulation exposes a portion of the plate. When the photoelectrochemical cell is immersed in a liquid electrolyte and exposed to solar radiation, a redox reaction occurs, producing gases such as hydrogen and oxygen from a water electrolyte, which bubble off the cathode and anode portions of the cell. (LEW)

Nozik, A.J.

1985-07-03T23:59:59.000Z

243

Filtration and Leach Testing for PUREX Cladding Sludge and REDOX Cladding Sludge Actual Waste Sample Composites  

SciTech Connect (OSTI)

A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan (Barnes and Voke 2006). The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Hanford Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP RPP WTP 467 (Fiskum et al. 2007), eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan. • Characterizing the homogenized sample groups. • Performing parametric leaching testing on each group for compounds of interest. • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on a filtration/leaching test performed using two of the eight waste composite samples. The sample groups examined in this report were the plutonium-uranium extraction (PUREX) cladding waste sludge (Group 3, or CWP) and reduction-oxidation (REDOX) cladding waste sludge (Group 4, or CWR). Both the Group 3 and 4 waste composites were anticipated to be high in gibbsite, thus requiring caustic leaching. WTP RPT 167 (Snow et al. 2008) describes the homogenization, characterization, and parametric leaching activities before benchtop filtration/leaching testing of these two waste groups. Characterization and initial parametric data in that report were used to plan a single filtration/leaching test using a blend of both wastes. The test focused on filtration testing of the waste and caustic leaching for aluminum, in the form of gibbsite, and its impact on filtration. The initial sample was diluted with a liquid simulant to simulate the receiving concentration of retrieved tank waste into the UFP2 vessel (< 10 wt% undissolved solids). Filtration testing was performed on the dilute waste sample and dewatered to a higher solids concentration. Filtration testing was then performed on the concentrated slurry. Afterwards, the slurry was caustic leached to remove aluminum present in the undissolved solid present in the waste. The leach was planned to simulate leaching conditions in the UFP2 vessel. During the leach, slurry supernate samples were collected to measure the dissolution rate of aluminum in the waste. After the slurry cooled down from the elevated leach temperature, the leach liquor was dewatered from the solids. The remaining slurry was rinsed and dewatered with caustic solutions to remove a majority of the dissolved aluminum from the leached slurry. The concentration of sodium hydroxide in the rinse solutions was high enough to maintain the solubility of the aluminum in the dewatered rinse solutions after dilution of the slurry supernate. Filtration tests were performed on the final slurry to compare to filtration performance before and after caustic leaching.

Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Casella, Amanda J.; Crum, Jarrod V.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Hallen, Richard T.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Swoboda, Robert G.

2009-03-02T23:59:59.000Z

244

Received 11 Jan 2013 | Accepted 29 Apr 2013 | Published 13 Jun 2013 Cyclic electron flow is redox-controlled  

E-Print Network [OSTI]

. Correspondence and requests for materials should be addressed to F.R. (email: Fabrice.Rappaport@ibpc.fr). NATURE Publishers Limited. All rights reserved. #12;T he injection of energy into the biosphere relies-containing stroma lamellae, thereby balancing the excitonic flux between the two photosystems10. In the unicellular

245

Some Lessons Learned from 20 Years in RedOx Flow Battery R&d | Department  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage » SearchEnergyDepartmentScoping Study |4Solid-State TechnologiesEnergyof

246

Flow cytometer  

DOE Patents [OSTI]

A Faraday cage is described which encloses the flow chamber of a cytometer. Ground planes associated with each field deflection plate inhibit electric fields from varying the charge on designated events/droplets and further concentrates. They also increase forces applied to a passing charged event for accurate focus while concomitantly inhibiting a potential shock hazard. 4 figs.

Van den Engh, G.

1995-11-07T23:59:59.000Z

247

Redox buffered hydrofluoric acid etchant for the reduction of galvanic attack during release etching of MEMS devices having noble material films  

DOE Patents [OSTI]

Etchant solutions comprising a redox buffer can be used during the release etch step to reduce damage to the structural layers of a MEMS device that has noble material films. A preferred redox buffer comprises a soluble thiophosphoric acid, ester, or salt that maintains the electrochemical potential of the etchant solution at a level that prevents oxidation of the structural material. Therefore, the redox buffer preferentially oxidizes in place of the structural material. The sacrificial redox buffer thereby protects the exposed structural layers while permitting the dissolution of sacrificial oxide layers during the release etch.

Hankins, Matthew G. (Albuquerque, NM)

2009-10-06T23:59:59.000Z

248

High-energy mechanical synthesis of nanophase fluorite-structured mixed oxide catalysts with a high redox activity  

SciTech Connect (OSTI)

A series of nanostructured, highly defective, ternary solid solutions containing CeO{sub 2}, ZrO{sub 2}, and MnO{sub 2} or CuO were prepared by high-energy mechanical milling of individual components. Morphological and redox properties were studied by XRD, HRTEM and temperature-programmed reduction techniques. It was shown that the introduction of small amounts of copper and manganese strongly promotes the redox behavior of cerium at lower temperatures in comparison with CeO{sub 2} and CeO{sub 2}-ZrO{sub 2}. High temperature treatment of up to 1,400 K was also shown to further promote overall redox capacity without affecting low-temperature redox behavior. Moreover, evidence is provided to show that Cu and Mn are dissolved within the CeO{sub 2} lattice structure. Addition of dopants enhances catalytic redox properties in the oxidation of CO at low temperatures, which is associated with the high concentration of oxygen vacancies that form on the introduction of aliovalent elements into the ceria-zirconia lattice.

Primavera, A.; Trovarelli, A.; Terribile, D.; Leitenburg, C. de; Dolcetti, G. [Univ. di Udine (Italy). Dipt. di Scienze e Tecnologie Chimiche; Llorca, J. [Univ. de Barcelona (Spain). Dept. de Quimica Inorganica

1997-12-31T23:59:59.000Z

249

Effects of Redox Cycling of Iron in Nontronite on Reduction of Technetium.  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed NewcatalystNeutronEnvironmentZIRKLE FRUITYearEffect0/2002catalysts:| EMSL Redox

250

Preserving the Volume of Fluid Using Multi-phase Flow Approach Roman Durikovic  

E-Print Network [OSTI]

complex behaviors. We often see rising bubbles or flow of muddy water, such flows involve sev- eral fluids volume when the fluid passes through a donor cell to an acceptor cell. The VOF method was improved

Durikovic, Roman

251

BIOENERGY AND BIOFUELS Performance of a pilot-scale continuous flow microbial  

E-Print Network [OSTI]

BIOENERGY AND BIOFUELS Performance of a pilot-scale continuous flow microbial electrolysis cell fed performance. Keywords Biohydrogen . Biomethane . Bioelectricity. Microbial electrolysis cell . Bioenergy

252

Micro free-flow isoelectric focusing  

E-Print Network [OSTI]

To unravel the complexity of cellular systems, protein prefractionation tools can be used to reduce cell lysate complexity and increase assay sensitivity. Rapid free flow isoelectric focusing (FF-IEF) is achieved in a ...

Albrecht, Jacob William

2008-01-01T23:59:59.000Z

253

Influence of pH and Redox Conditions on Copper Leaching  

SciTech Connect (OSTI)

The Toxicity Characteristic Leaching Procedure (TCLP) is a regulatory leach test in the RCRA programs. It was developed to determine the leaching potential of landfilled waste in order to assess the hazards associated with the leachates. The test was developed to study concentration of hazardous materials in leachates, under a mismanagement scenario, when they are co-disposed with municipal waste. The test uses leaching of waste at either of two acidic pH values i.e., 2.8 and 4.93. While low pH leachant can extract many metals, some metals soluble at higher pH values are either underestimated or totally unaccounted for. The method also has limitations for application to different waste matrices. The procedure does not take into account the effect of redox conditions on leaching. Leaching studies are, therefore, being conducted to determine the effect of combinations of Eh and pH on the leaching potential of mineral and organic wastes. The goal of this study is to propose alternate methods applicable for a variety of waste matrices. The presentation will discuss the effects of combinations of pH and redox conditions on the leaching behavior of copper from a mineral processing waste.

Kavanaugh, Rathi; Al-Abed, Souhail R.; Purandare, Jaydeep; Allen, Derrick

2004-03-31T23:59:59.000Z

254

A Semiconductor Microlaser for Intracavity Flow Cytometry  

SciTech Connect (OSTI)

Semiconductor microlasers are attractive components for micro-analysis systems because of their ability to emit coherent intense light from a small aperture. By using a surface-emitting semiconductor geometry, we were able to incorporate fluid flow inside a laser microcavity for the first time. This confers significant advantages for high throughput screening of cells, particulates and fluid analytes in a sensitive microdevice. In this paper we discuss the intracavity microfluidics and present preliminary results with flowing blood and brain cells.

Akhil, O.; Copeland, G.C.; Dunne, J.L.; Gourley, P.L.; Hendricks, J.K.; McDonald, A.E.

1999-01-20T23:59:59.000Z

255

Molybdenum in Nuclear Waste Glasses -Incorporation and Redox state R.J. Short, R.J. Hand, N.C. Hyatt,  

E-Print Network [OSTI]

Molybdenum in Nuclear Waste Glasses - Incorporation and Redox state R.J. Short, R.J. Hand, N form in simulated high level nuclear waste (HLW) glass melts have been studied. It was found less attention has been paid to the effects of redox on nuclear waste glasses. One particular element

Sheffield, University of

256

Inner-Sphere Electron-Transfer Single Iodide Mechanism for Dye Regeneration in Dye-Sensitized Solar Cells  

E-Print Network [OSTI]

the regeneration of the oxidized dye in dye-sensitized solar cells, the redox couple of I- /I3 - reduces the photo dye- sensitized solar cell (DSSC) in 1991,1 DSSCs have been considered as promising alternativesInner-Sphere Electron-Transfer Single Iodide Mechanism for Dye Regeneration in Dye-Sensitized Solar

Goddard III, William A.

257

Multiscale Simulations for Polymeric Flow  

E-Print Network [OSTI]

Multiscale simulation methods have been developed based on the local stress sampling strategy and applied to three flow problems with different difficulty levels: (a) general flow problems of simple fluids, (b) parallel (one-dimensional) flow problems of polymeric liquids, and (c) general (two- or three-dimensional) flow problems of polymeric liquids. In our multiscale methods, the local stress of each fluid element is calculated directly by performing microscopic or mesoscopic simulations according to the local flow quantities instead of using any constitutive relations. For simple fluids (a), such as the Lenard-Jones liquid, a multiscale method combining MD and CFD simulations is developed based on the local equilibrium assumption without memories of the flow history. (b), the multiscale method is extended to take into account the memory effects that arise in hydrodynamic stress due to the slow relaxation of polymer-chain conformations. The memory of polymer dynamics on each fluid element is thus resolved by performing MD simulations in which cells are fixed at the mesh nodes of the CFD simulations.For general (two- or three-dimensional) flow problems of polymeric liquids (c), it is necessary to trace the history of microscopic information such as polymer-chain conformation, which carries the memories of past flow history, along the streamline of each fluid element. A Lagrangian-based CFD is thus implemented to correctly advect the polymer-chain conformation consistently with the flow. On each fluid element, coarse-grained polymer simulations are carried out to consider the dynamics of entangled polymer chains that show extremely slow relaxation compared to microscopic time scales.

Takahiro Murashima; Takashi Taniguchi; Ryoichi Yamamoto; Shugo Yasuda

2011-01-06T23:59:59.000Z

258

Mobilisation of arsenic from bauxite residue (red mud) affected soils: Effect of pH and redox conditions  

E-Print Network [OSTI]

). Typically, it comprises residual iron oxides, quartz, sodium aluminosilicates, titanium dioxide, calciumMobilisation of arsenic from bauxite residue (red mud) affected soils: Effect of pH and redox elements, including arsenic. Aerobic and anaer- obic batch experiments were prepared using soils from near

Burke, Ian

259

DOI: 10.1002/ejic.201000555 Flexible and Redox-Active Coordination Polymer: Control of the Network  

E-Print Network [OSTI]

*[a] Keywords: Coordination polymers / Flexible networks / Macrocyles / Palladium / Nickel The coordination[3a] as well as in the fourfold interpenetrating dia- mondoid network[11] by the reaction of organicFULL PAPER DOI: 10.1002/ejic.201000555 Flexible and Redox-Active Coordination Polymer: Control

Paik Suh, Myunghyun

260

Use of Dissolved H2 Concentrations To Determine Distribution of Microbially Catalyzed Redox Reactions in Anoxic Groundwater  

E-Print Network [OSTI]

similartothe HZconcentrationsthat havepreviously been reported for aquatic sedimentswith the same TEAPs. In two aquifers contaminated with petroleum products, it was impossible with standard geochemical analyses actuallyexist (i.e.,there arenofreeelectrons); (2) the redox status of most natural waters cannot be accurately

Lovley, Derek

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Redox Control For Hanford HLW Feeds VSL-12R2530-1, REV 0  

SciTech Connect (OSTI)

The principal objectives of this work were to investigate the effects of processing simulated Hanford HLW at the estimated maximum concentrations of nitrates and oxalates and to identify strategies to mitigate any processing issues resulting from high concentrations of nitrates and oxalates. This report provides results for a series of tests that were performed on the DM10 melter system with simulated C-106/AY-102 HLW. The tests employed simulated HLW feeds containing variable amounts of nitrates and waste organic compounds corresponding to maximum concentrations proj ected for Hanford HLW streams in order to determine their effects on glass production rate, processing characteristics, glass redox conditions, melt pool foaming, and the tendency to form secondary phases. Such melter tests provide information on key process factors such as feed processing behavior, dynamic effects during processing, processing rates, off-gas amounts and compositions, foaming control, etc., that cannot be reliably obtained from crucible melts.

Kruger, A. A. [Department of Energy, Office of River Protection, Richland, Washington (United States); Matlack, Keith S. [The Catholic University of America, Washington, DC (United States); Pegg, Ian L. [The Catholic University of America, Washington, DC (United States); Kot, Wing K. [The Catholic University of America, Washington, DC (United States); Joseph, Innocent [The Catholic University of America, Washington, DC (United States)

2012-12-13T23:59:59.000Z

262

Solar Thermochemical Fuels Production: Solar Fuels via Partial Redox Cycles with Heat Recovery  

SciTech Connect (OSTI)

HEATS Project: The University of Minnesota is developing a solar thermochemical reactor that will efficiently produce fuel from sunlight, using solar energy to produce heat to break chemical bonds. The University of Minnesota is envisioning producing the fuel by using partial redox cycles and ceria-based reactive materials. The team will achieve unprecedented solar-to-fuel conversion efficiencies of more than 10% (where current state-of-the-art efficiency is 1%) by combined efforts and innovations in material development, and reactor design with effective heat recovery mechanisms and demonstration. This new technology will allow for the effective use of vast domestic solar resources to produce precursors to synthetic fuels that could replace gasoline.

None

2011-12-19T23:59:59.000Z

263

Micelle formation and surface activity of functional redox relays: viologens substituted by a long alkyl chain  

SciTech Connect (OSTI)

Viologens are receiving increasing attention from 2 major domains. First, photo- and electroreproductive processes are being developed which exploit the pronounced chromophore effect associated with the one-electron reduction of the viologens: the 2+ state is practically colorless, while the 1+ state has an intense color. However, the most prominent impact in viologen-related research arises from their use as mediators, sometimes referred to as electron relays, in the photionduced generation of hydrogen from water. Photobiologists had discovered earlier that methyl viologen in chloroplast suspensions is suited to act as a Hill reagent which can be coupled with hydrogenase to yield H/sub 2/ under illumination. More recently, in vitro systems have been developed in which synthetic dyes replace the chloroplasts as redox sensitizers. These have been shown to be remarkably effective in H/sub 2/ production. The surfactant and micellar properties of a series of potent candidates, i.e., long-chain-substituted viologens are investigated.

Krieg, M.; Pileni, M.P.; Braun, A.M.; Gratzel, M.

1981-09-01T23:59:59.000Z

264

Electrocatalytic hydrogenation using precious metal microparticles in redox-active polymer films  

SciTech Connect (OSTI)

Glassy carbon felt electrodes have been modified by electrodeposition of poly(pyrrole-viologen) films (derived from N,N{prime}-dialkyl-4,4{prime}-bipyridinium salts), followed by electroprecipitation of precious metal (Pt, Pd, Rh, or Ru) microparticles. The resulting electrodes have been proved to be active for the electrocatalytic hydrogenation of conjugated enones (2-cyclohexen-1-one, cryptone, carvone, isophorone), styrene, and benzonitrile in aqueous media (pH 1). Despite low loadings of metal catalysts, high electric and products yields and a long term stability of these cathodes have been observed. The influence of the metal loading and the polymer structure on the catalytic efficiency as well as the selectivity obtained according to the metal catalyst used have been studied. Comparison with results previously reported for other catalytic cathodes like Pt/Pt, Pd/C, or Raney nickel electrodes proves the high efficiency of these metal microparticles within redox polymer film based electrodes.

Coche, L.; Ehui, B.; Limosin, D.; Moutet, J.C. (Univ. Joseph Fourier, Grenoble (France))

1990-11-09T23:59:59.000Z

265

The complementary redox properties of viologens and pyromellitimides: A new class of organic conductors  

SciTech Connect (OSTI)

Organic charge-transfer (CT) salts have been of interest for some years, especially since the discovery of the metallic conductivity of the TTF-TCNQ salt. The authors have begun an investigation of the charge-transfer chemistry of viologens and pyromellitimides, based on their complementary redox properties, with the intention of proceeding from intermolecular examples to intramolecular CT salts and finally to examples in which the viologens and pyromellitimides are incorporated in a polymer. They report progress in the first two stages of this investigation, including isolation of a new, highly conductive intermolecular CT salt and electrochemical characterization of a covalently linked viologen/pyromellitimide. These studies point to an interesting new class of organic solid-state materials.

Buchwalter, S.L.; Iyengar, R.; Viehbeck, A.; O'Toole, T.R. (Thomas J. Watson Research Center, Yorktown Heights, NY (USA))

1991-01-02T23:59:59.000Z

266

Sampling, preservation, and analytical methods research plan - liquid redox sulfur recovery technologies: Stretford process. Topical report  

SciTech Connect (OSTI)

GRI has developed a sampling, preservation, and analytical (SPandA) methods research plan for developing and validating analytical methodologies for liquid redox sulfur recovery processes (e.g., Stretford process). The document describes the technical approach which will be used to direct research activities to develop SPandA methodologies to analyze gaseous, aqueous, and solid process streams from the Stretford sulfur recovery process. The primary emphasis is on developing and validating methodologies for analyzing vanadium (IV) and vanadium (V), anthraquinone disulphonic acids (ADA), polysulfide-sulfur, sulfide-sulfur, thiosulfate, sulfate, thiocyanate, total soluble sulfur, alkalinity, pH, total dissolved solids, total suspended solids, and dissolved oxygen in aqueous process streams. The document includes descriptions of the process streams and chemical species, selection of candidate analytical methods, and technical approach for methods development and validation.

Trofe, T.W.

1986-11-01T23:59:59.000Z

267

Microfluidic Flow-Flash: Method for Investigating Protein Dynamics  

E-Print Network [OSTI]

Microfluidic Flow-Flash: Method for Investigating Protein Dynamics Michael W. Toepke, Scott H Institute, Troy, New York 12180 We report a new method, microfluidic flow-flash, for measuring protein reaction kinetics. The method couples a microscope imaging detection system with a microfluidic flow cell

Kenis, Paul J. A.

268

Amphiphilic mediated sample preparation for micro-flow cytometry  

DOE Patents [OSTI]

A flow cytometer includes a flow cell for detecting the sample, an oil phase in the flow cell, a water phase in the flow cell, an oil-water interface between the oil phase and the water phase, a detector for detecting the sample at the oil-water interface, and a hydrophobic unit operatively connected to the sample. The hydrophobic unit is attached to the sample. The sample and the hydrophobic unit are placed in an oil and water combination. The sample is detected at the interface between the oil phase and the water phase.

Clague, David S. (Livermore, CA); Wheeler, Elizabeth K. (Livermore, CA); Lee, Abraham P. (Irvine, CA)

2006-07-25T23:59:59.000Z

269

Amphiphilic mediated sample preparation for micro-flow cytometry  

DOE Patents [OSTI]

A flow cytometer includes a flow cell for detecting the sample, an oil phase in the flow cell, a water phase in the flow cell, an oil-water interface between the oil phase and the water phase, a detector for detecting the sample at the oil-water interface, and a hydrophobic unit operatively connected to the sample. The hydrophobic unit is attached to the sample. The sample and the hydrophobic unit are placed in an oil and water combination. The sample is detected at the interface between the oil phase and the water phase.

Clague, David S. (Livermore, CA); Wheeler, Elizabeth K. (Livermore, CA); Lee, Abraham P. (Irvine, CA)

2009-03-17T23:59:59.000Z

270

Low volume flow meter  

DOE Patents [OSTI]

The low flow monitor provides a means for determining if a fluid flow meets a minimum threshold level of flow. The low flow monitor operates with a minimum of intrusion by the flow detection device into the flow. The electrical portion of the monitor is externally located with respect to the fluid stream which allows for repairs to the monitor without disrupting the flow. The electronics provide for the adjustment of the threshold level to meet the required conditions. The apparatus can be modified to provide an upper limit to the flow monitor by providing for a parallel electronic circuit which provides for a bracketing of the desired flow rate.

Meixler, Lewis D. (East Windsor, NJ)

1993-01-01T23:59:59.000Z

271

Miniature fuel-cell system complete with on-demand fuel and oxidant supply  

E-Print Network [OSTI]

scale direct methanol fuel cell development,” Energy, vol.flow-based microfluidic fuel cell," J. Am. Chem. Soc. , vol.electrolyte membrane fuel cell design," J. Power Sources,

Hur, JI; Kim, C-J

2015-01-01T23:59:59.000Z

272

Propeller Flow Meter  

E-Print Network [OSTI]

Propeller flow meters are commonly used to measure water flow rate. They can also be used to estimate irrigation water use. This publication explains how to select, install, read and maintain propeller flow meters....

Enciso, Juan; Santistevan, Dean; Hla, Aung K.

2007-10-01T23:59:59.000Z

273

Dispersed flow film boiling  

E-Print Network [OSTI]

Dispersed flow consists of small liquid droplets entrained in a flowing vapor. This flow regime can occur in cryogenic equipment, in steam generators, and during nuclear reactor loss of coolant accidents. A theoretical ...

Yoder, Graydon L.

1980-01-01T23:59:59.000Z

274

Bacteria in shear flow  

E-Print Network [OSTI]

Bacteria are ubiquitous and play a critical role in many contexts. Their environment is nearly always dynamic due to the prevalence of fluid flow: creeping flow in soil, highly sheared flow in bodily conduits, and turbulent ...

Marcos, Ph.D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

275

Cells having cathodes containing polycarbon disulfide materials  

DOE Patents [OSTI]

The present invention relates to an electric current producing cell which contains an anode, a cathode having as a cathode-active material one or more carbon-sulfur compounds of the formula (CS.sub.x).sub.n, in which x takes values from 1.2 to 2.3 and n is greater or equal to 2, and where the redox process does not involve polymerization and de-polymerization by forming and breaking S--S bonds in the polymer backbone. The cell also contains an electrolyte which is chemically inert with respect to the anode and the cathode.

Okamoto, Yoshi (Fort Lee, NJ); Skotheim, Terje A. (Shoreham, NY); Lee, Hung S. (Rocky Point, NY)

1995-08-15T23:59:59.000Z

276

The effect of scaffold physical properties on endothelial cell function  

E-Print Network [OSTI]

Endothelial cells (EC) are ubiquitous - as vascular epithelial cells they line the inner surface of all vessels and are the contact surface with flowing blood. Macrovascular EC are the first line barrier between flowing ...

Murikipudi, Sylaja

2010-01-01T23:59:59.000Z

277

Multiphase flow calculation software  

DOE Patents [OSTI]

Multiphase flow calculation software and computer-readable media carrying computer executable instructions for calculating liquid and gas phase mass flow rates of high void fraction multiphase flows. The multiphase flow calculation software employs various given, or experimentally determined, parameters in conjunction with a plurality of pressure differentials of a multiphase flow, preferably supplied by a differential pressure flowmeter or the like, to determine liquid and gas phase mass flow rates of the high void fraction multiphase flows. Embodiments of the multiphase flow calculation software are suitable for use in a variety of applications, including real-time management and control of an object system.

Fincke, James R. (Idaho Falls, ID)

2003-04-15T23:59:59.000Z

278

Flow Distances on Open Flow Networks  

E-Print Network [OSTI]

Open flow network is a weighted directed graph with a source and a sink, depicting flux distributions on networks in the steady state of an open flow system. Energetic food webs, economic input-output networks, and international trade networks, are open flow network models of energy flows between species, money or value flows between industrial sectors, and goods flows between countries, respectively. Flow distances (first-passage or total) between any given two nodes $i$ and $j$ are defined as the average number of transition steps of a random walker along the network from $i$ to $j$ under some conditions. They apparently deviate from the conventional random walk distance on a closed directed graph because they consider the openness of the flow network. Flow distances are explicitly expressed by underlying Markov matrix of a flow system in this paper. With this novel theoretical conception, we can visualize open flow networks, calculating centrality of each node, and clustering nodes into groups. We apply fl...

Guo, Liangzhu; Shi, Peiteng; Wang, Jun; Huang, Xiaohan; Zhang, Jiang

2015-01-01T23:59:59.000Z

279

GEOC R Lee Penn Sunday, March 25, 2012 12 -Biogeochemical transformation of Fe-and Mn-along a redox gradient: Implications for carbon sequestration  

E-Print Network [OSTI]

a redox gradient: Implications for carbon sequestration within the Christina River Basin Critical Zone States Organic carbon (C)-mineral complexation mechanism is crucial in C sequestration. It is a function

Sparks, Donald L.

280

Waveguide detection of right-angle-scattered light in flow cytometry  

DOE Patents [OSTI]

A transparent flow cell is used as an index-guided optical waveguide. A detector for the flow cell but not the liquid stream detects the Right-Angle-Scattered (RAS) Light exiting from one end of the flow cell. The detector(s) could view the trapped RAS light from the flow cell either directly or through intermediate optical light guides. If the light exits one end of the flow cell, then the other end of the flow cell can be given a high-reflectivity coating to approximately double the amount of light collected. This system is more robust in its alignment than the traditional flow cytometry systems which use imaging optics, such as microscope objectives.

Mariella, Jr., Raymond P. (Danville, CA)

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Probing Ligand Effects on the Redox Energies of [4Fe-4S] Clusters Using Broken-Symmetry Density Functional Theory  

SciTech Connect (OSTI)

A central issue in understanding redox properties of iron-sulfur proteins is determining the factors that tune the reduction potentials of the Fe-S clusters. Recently, Solomon and coworkers have shown that the Fe-S bond covalency of protein analogs measured by %L, the percent ligand character of the Fe 3d orbitals, from ligand K-edge X-ray absorption spectroscopy (XAS) correlates with the electrochemical redox potentials. Also, Wang and coworkers have measured electron detachment energies for iron-sulfur clusters without environmental perturbations by gas-phase photoelectron spectroscopy (PES). Here the correlations of the ligand character with redox energy and %L character are examined in [Fe?S?L?]2? clusters with different ligands by broken symmetry density functional theory (BS-DFT) calculations using the B3LYP functional together with PES and XAS experimental results. These gas-phase studies assess ligand effects independently of environmental perturbations and thus provide essential information for computational studies of iron-sulfur proteins. The B3LYP oxidation energies agree well with PES data, and the %L character obtained from natural bond orbital analysis correlates with XAS values, although it systematically underestimates them because of basis set effects. The results show that stronger electron-donating terminal ligands increase %Lt, the percent ligand character from terminal ligands, but decrease %Sb, the percent ligand character from the bridging sulfurs. Because the oxidized orbital has significant Fe-Lt antibonding character, the oxidation energy correlates well with %Lt. However, because the reduced orbital has varying contributions of both Fe-Lt and Fe-Sb antibonding character, the reduction energy does not correlate with either %Lt or %Sb. Overall, BSDFT calculations together with XAS and PES experiments can unravel the complex underlying factors in the redox energy and chemical bonding of the [4Fe-4S] clusters in iron-sulfur proteins.

Niu, Shuqiang; Ichiye, Toshiko

2009-05-14T23:59:59.000Z

282

In Situ Redox Manipulation Proof-of-Principle Test at the Fort Lewis Logistics Center: Final Report  

SciTech Connect (OSTI)

Pacific Northwest National Laboratory conducted a proof-of-principle test at the Fort Lewis Logistics Center to determine the feasibility of using the innovative remedial technology In Situ Redox Manipulation (ISRM) to treat groundwater contaminated with dissolved TCE. ISRM creates a permeable treatment zone in the subsurface to remediate redox-sensitive contaminants in groundwater. The permeable treatment zone is created by injecting a chemical reducing agent (sodium dithionite with pH buffers) into the aquifer through a well to chemically reduce the naturally occurring ferric iron in the sediments to ferrous iron. Once the reducing agent has been given sufficient time to react with aquifer sediments, residual chemicals and reaction products are withdrawn through the same well. Redox-sensitive contaminants such as TCE, moving in a dissolved-phase plume through the treatment zone, are destroyed. TCE is degraded via reductive dechlorination within the treatment zone to benign degradation products (acetylene, ehtylene). Analyses of sediment samples collected from post-test boreholes showed a high degree of iron reduction, which confirmed the effectiveness of the treatment zone.

Vermeul, Vincent R.; Williams, Mark D.; Evans, John C.; Szecsody, James E.; Bjornstad, Bruce N.; Liikala, Terry L.

2000-10-25T23:59:59.000Z

283

Portable wastewater flow meter  

DOE Patents [OSTI]

A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under fill pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

1999-02-02T23:59:59.000Z

284

Portable wastewater flow meter  

DOE Patents [OSTI]

A portable wastewater flow meter particularly adapted for temporary use at a single location in measuring the rate of liquid flow in a circular entrance conduit of a sewer manhole both under free flow and submerged, open channel conditions and under full pipe, surcharged conditions, comprising an apparatus having a cylindrical external surface and an inner surface that constricts the flow through the apparatus in such a manner that a relationship exists between (1) the difference between the static pressure head of liquid flowing through the entrance of the apparatus and the static pressure head of liquid flowing through the constriction, and (2) the rate of liquid flow through the apparatus.

Hunter, Robert M. (320 S. Wilson Ave., Bozeman, MT 59715)

1990-01-01T23:59:59.000Z

285

Effects of Protonation State on a Tyrosine?Histidine Bioinspired Redox Mediator  

SciTech Connect (OSTI)

The conversion of tyrosine to the corresponding tyrosyl radical in photosytem II (PSII) is an example of proton-coupled electron transfer. Although the tyrosine moiety (Tyr{sub Z}) is known to function as a redox mediator between the photo-oxidized primary donor (P680{sup •+}) and the Mn-containing oxygen-evolving complex, the protonation states involved in the course of the reaction remain an active area of investigation. Herein, we report on the optical, structural, and electrochemical properties of tyrosine?histidine constructs, which model the function of their naturally occurring counterparts in PSII. Electrochemical studies show that the phenoxyl/phenol couple of the model is chemically reversible and thermodynamically capable of water oxidation. Studies under acidic and basic conditions provide clear evidence that an ionizable proton controls the electrochemical potential of the tyrosine?histidine mimic and that an exogenous base or acid can be used to generate a low-potential or high-potential mediator, respectively. The phenoxyl/phenoxide couple associated with the low-potential mediator is thermodynamically incapable of water oxidation, whereas the relay associated with the high-potential mediator is thermodynamically incapable of reducing an attached photoexcited porphyrin. These studies provide insight regarding the mechanistic role of the tyrosine?histidine complex in water oxidation and strategies for making use of hydrogen bonds to affect the coupling between proton and electron transfer in artificial photosynthetic systems.

Moore, Gary F.; Hambourger, Michael; Kodis, Gerdenis; Michl, Weston; Gust, Devens; Moore, Thomas A.; Moore, Ana L.

2010-01-01T23:59:59.000Z

286

Redox-Dependent Solubility of Technetium in Low Activity Waste Glass  

SciTech Connect (OSTI)

The solubility of technetium was measured in a Hanford low activity waste glass simulant. The simulant glass was melted, quenched and pulverized to make a stock of powdered glass. A series of glass samples were prepared using the powdered glass and varying amounts of solid potassium pertechnetate. Samples were melted at 1000°C in sealed fused quartz ampoules. After cooling, the bulk glass and the salt phase above the glass (when present) were sampled for physical and chemical characterization. Technetium was found in the bulk glass up to 2000 ppm (using the glass as prepared) and 3000 ppm (using slightly reducing conditions). The chemical form of technetium obtained by x-ray absorption near edge spectroscopy can be mainly assigned to isolated Tc(IV), with a minority of Tc(VII) in some glasses and TcO2 in two glasses. The concentration and speciation of technetium depends on glass redox and amount of technetium added. Solid crystals of pertechnetate salts were found in the salt cake layer that formed at the top of some glasses during the melt.

Soderquist, Chuck Z.; Schweiger, Michael J.; Kim, Dong-Sang; Lukens, Wayne W.; Mccloy, John S.

2014-03-01T23:59:59.000Z

287

JUPITER-II Molten Salt Flibe Research: An Update On Tritium, Mobilization and Redox Chemistry Experiments  

SciTech Connect (OSTI)

The second Japan/US Program on Irradiation Tests for Fusion Research (JUPITER-II) began on April 1, 2001. Part of the collaborative research centers on studies of the molten salt 2LiF2–BeF2 (also known as Flibe) for fusion applications. Flibe has been proposed as a self-cooled breeder in both magnetic and inertial fusion power plant designs over the last 25 years. The key feasibility issues associated with the use of Flibe are the corrosion of structural material by the molten salt, tritium behavior and control in the molten salt blanket system, and safe handling practices and releases from Flibe during an accidental spill. These issues are all being addressed under the JUPITER-II program at the Idaho National Laboratory in the Safety and Tritium Applied Research (STAR) facility. In this paper, we review the program to date in the area of tritium/deuterium behavior, Flibe mobilization under accident conditions and testing of Be as a redox agent to control corrosion. Future activities planned through the end of the collaboration are also presented.

D.A. Petti; D. A. Petti; G. R. Smolik; Michael F. Simpson; John P. Sharpe; R. A. Anderl; S. Fukada; Y. Hatano; Masanori Hara; Y. Oya; T. Terai; D.-K. Sze; S. Tanaka

2005-05-01T23:59:59.000Z

288

Macroscopic Properties of Restacked, Redox-Liquid Exfoliated Graphite and Graphite Mimics Produced in Bulk Quantities  

SciTech Connect (OSTI)

The excellent properties exhibited by monolayer graphene have spurred the development of exfoliation techniques using bulk graphite to produce large quantities of pristine monolayer sheets. Development of simple chemistry to exfoliate and intercalate graphite and graphite mimics in large quantities is required for numerous applications. To determine the macroscopic behavior of restacked, exfoliated bulk materials, a systematic approach is presented using a simple, redox-liquid sonication process along to obtain large quantities of 2D and 3D hexagonally layered graphite, molybdenum disulfi de, and boron nitride, which are subsequently characterized to observe chemical and structural changes. For MoS 2 sonicated with the antioxidant sodium bisulfi te, results from Raman spectroscopy, X-ray diffraction, and electron microscopy indicate the presence of distorted phases from different polymorphs, and apparent nanotube structures in the bulk, restacked powder. Furthermore, using thermograviemtric analysis, the antioxidant enhances the resistance to oxidative degradation of MoS 2 , upon thermal treatment up to 900 C. The addition of the ionic antioxidant decreased dispersion stability in non-polar solvent, suggesting decreased compatibility with non-polar systems. Using simple chemical methods, the ability to generate tailored multidimensional layered materials with unique macroscopic properties is critical for numerous applications, including electrical devices, reinforced polymer composites, lithium ion capacitors, and chemical sensing.

Srivastava, Vikram K [ORNL; Quinlan, Ronald [ORNL; Agapov, Alexander L [ORNL; Dunlap, John R [ORNL; Nelson, Kimberly M [ORNL; Duranty, Edward R [ORNL; Sokolov, Alexei P [ORNL; Bhat, Gajanan [ORNL; Mays, Jimmy [ORNL

2014-01-01T23:59:59.000Z

289

Electron Transfer Reactivity Patterns at Chemically Modified Electrodes: Fundamentals and Application to the Optimization of Redox Recycling Amplification Systems  

SciTech Connect (OSTI)

Electroanalytical chemistry is often utilized in chemical analysis and Fundamental studies. Important advances have been made in these areas since the advent of chemically modified electrodes: the coating of an electrode with a chemical film in order to impart desirable, and ideally, predictable properties. These procedures enable the exploitation of unique reactivity patterns. This dissertation presents studies that investigate novel reaction mechanisms at self-assembled monolayers on gold. In particular, a unique electrochemical current amplification scheme is detailed that relies on a selective electrode to enable a reactivity pattern that results in regeneration of the analyte (redox recycling). This regenerating reaction can occur up to 250 times for each analyte molecule, leading to a notable enhancement in the observed current. The requirements of electrode selectivity and the resulting amplification and detection limit improvements are described with respect to the heterogeneous and homogeneous electron transfer rates that characterize the system. These studies revealed that the heterogeneous electrolysis of the analyte should ideally be electrochemically reversible, while that for the regenerating agent should be held to a low level. Moreover, the homogeneous reaction that recycles the analyte should occur at a rapid rate. The physical selectivity mechanism is also detailed with respect to the properties of the electrode and redox probes utilized. It is shown that partitioning of the analyte into/onto the adlayer leads to the extraordinary selectivity of the alkanethiolate monolayer modified electrode. Collectively, these studies enable a thorough understanding of the complex electrode mechanism required for successful redox recycling amplification systems, Finally, in a separate (but related) study, the effect of the akyl chain length on the heterogeneous electron transfer behavior of solution-based redox probes is reported, where an odd-even oscillation (with respect to the number of methylene units in the alkyl chain) was observed. Characterization of the adlayers by infrared reflection spectroscopy, ellipsometry, and wetting revealed odd-even effects in the orientation of the terminal methyl group and hydrophobic character of the adlayers. Using these structural characterizations as a basis, several possible mechanisms that can account for the odd-even effect in the heterogeneous electron transfer rates of solution-based redox couples are discussed.

Adam Johan Bergren

2006-05-01T23:59:59.000Z

290

Corrosion, Passivation, and the Effect of Water Addition on an n-GaAs(100)/Methanol Photoelectrochemical Cell  

E-Print Network [OSTI]

Corrosion, Passivation, and the Effect of Water Addition on an n-GaAs(100)/Methanol of corrosion of the cell on the PL-V profile is examined in detail. It is found that the inclusion of the redox couple gives some protection from corrosion, but the addition of a small amount of water

Richmond, Geraldine L.

291

Soluble Lead Flow Battery: Soluble Lead Flow Battery Technology  

SciTech Connect (OSTI)

GRIDS Project: General Atomics is developing a flow battery technology based on chemistry similar to that used in the traditional lead-acid battery found in nearly every car on the road today. Flow batteries store energy in chemicals that are held in tanks outside the battery. When the energy is needed, the chemicals are pumped through the battery. Using the same basic chemistry as a traditional battery but storing its energy outside of the cell allows for the use of very low cost materials. The goal is to develop a system that is far more durable than today’s lead-acid batteries, can be scaled to deliver megawatts of power, and which lowers the cost of energy storage below $100 per kilowatt hour.

None

2010-09-01T23:59:59.000Z

292

Optimization of channel geometry in a proton exchange membrane (PEM) fuel cell.  

E-Print Network [OSTI]

??Bipolar plates are the important components of the PEM fuel cell. The flow distribution inside the bipolar plate should be uniform. Non-uniform flow distribution inside… (more)

Kasukurthi, Jephanya

2009-01-01T23:59:59.000Z

293

Fuel cell water transport  

DOE Patents [OSTI]

The moisture content and temperature of hydrogen and oxygen gases is regulated throughout traverse of the gases in a fuel cell incorporating a solid polymer membrane. At least one of the gases traverses a first flow field adjacent the solid polymer membrane, where chemical reactions occur to generate an electrical current. A second flow field is located sequential with the first flow field and incorporates a membrane for effective water transport. A control fluid is then circulated adjacent the second membrane on the face opposite the fuel cell gas wherein moisture is either transported from the control fluid to humidify a fuel gas, e.g., hydrogen, or to the control fluid to prevent excess water buildup in the oxidizer gas, e.g., oxygen. Evaporation of water into the control gas and the control gas temperature act to control the fuel cell gas temperatures throughout the traverse of the fuel cell by the gases.

Vanderborgh, Nicholas E. (Los Alamos, NM); Hedstrom, James C. (Los Alamos, NM)

1990-01-01T23:59:59.000Z

294

Redox-active tyrosine residue in the microcin J25 molecule  

SciTech Connect (OSTI)

Research highlights: {yields} Cyclic voltammetry measurements showed irreversible oxidation of MccJ25 and MccJ25 (Y9F). {yields} Infrared spectroscopy studies showed that only Tyr9 could be deprotonated upon chemical oxidation. {yields} Formation of a long-lived tyrosyl radical in the native MccJ25 oxidized by H{sub 2}O{sub 2} was demonstrated. {yields} Tyr9 but not Tyr20 can be easily oxidized and form a tyrosyl radical. -- Abstract: Microcin J25 (MccJ25) is a 21 amino acid lasso-peptide antibiotic produced by Escherichia coli and composed of an 8-residues ring and a terminal 'tail' passing through the ring. We have previously reported two cellular targets for this antibiotic, bacterial RNA polymerase and the membrane respiratory chain, and shown that Tyr9 is essential for the effect on the membrane respiratory chain which leads to superoxide overproduction. In the present paper we investigated the redox behavior of MccJ25 and the mutant MccJ25 (Y9F). Cyclic voltammetry measurements showed irreversible oxidation of both Tyr9 and Tyr20 in MccJ25, but infrared spectroscopy studies demonstrated that only Tyr9 could be deprotonated upon chemical oxidation in solution. Formation of a long-lived tyrosyl radical in the native MccJ25 oxidized by H{sub 2}O{sub 2} was demonstrated by Electron Paramagnetic Resonance Spectroscopy; this radical was not detected when the reaction was carried out with the MccJ25 (Y9F) mutant. These results show that the essential Tyr9, but not Tyr20, can be easily oxidized and form a tyrosyl radical.

Chalon, Miriam C. [Departamento de Bioquimica de la Nutricion, Instituto Superior de Investigaciones Biologicas (Consejo Nacional de Investigaciones Cientificas y Tecnicas-Universidad Nacional de Tucuman) and Instituto de Quimica Biologica 'Dr Bernabe Bloj', Chacabuco 461, 4000 San Miguel de Tucuman, Tucuman (Argentina)] [Departamento de Bioquimica de la Nutricion, Instituto Superior de Investigaciones Biologicas (Consejo Nacional de Investigaciones Cientificas y Tecnicas-Universidad Nacional de Tucuman) and Instituto de Quimica Biologica 'Dr Bernabe Bloj', Chacabuco 461, 4000 San Miguel de Tucuman, Tucuman (Argentina); Wilke, Natalia [CIQUIBIC, Dpto. de Quimica Biologica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Pabellon Argentina, Ciudad Universitaria, X5000HUA, Cordoba (Argentina)] [CIQUIBIC, Dpto. de Quimica Biologica, Facultad de Ciencias Quimicas, Universidad Nacional de Cordoba, Pabellon Argentina, Ciudad Universitaria, X5000HUA, Cordoba (Argentina); Pedersen, Jens; Rufini, Stefano [Department of Biology, University of Rome Tor Vergata 00133, Rome (Italy)] [Department of Biology, University of Rome Tor Vergata 00133, Rome (Italy); Morero, Roberto D.; Cortez, Leonardo; Chehin, Rosana N.; Farias, Ricardo N. [Departamento de Bioquimica de la Nutricion, Instituto Superior de Investigaciones Biologicas (Consejo Nacional de Investigaciones Cientificas y Tecnicas-Universidad Nacional de Tucuman) and Instituto de Quimica Biologica 'Dr Bernabe Bloj', Chacabuco 461, 4000 San Miguel de Tucuman, Tucuman (Argentina)] [Departamento de Bioquimica de la Nutricion, Instituto Superior de Investigaciones Biologicas (Consejo Nacional de Investigaciones Cientificas y Tecnicas-Universidad Nacional de Tucuman) and Instituto de Quimica Biologica 'Dr Bernabe Bloj', Chacabuco 461, 4000 San Miguel de Tucuman, Tucuman (Argentina); Vincent, Paula A., E-mail: pvincent@fbqf.unt.edu.ar [Departamento de Bioquimica de la Nutricion, Instituto Superior de Investigaciones Biologicas (Consejo Nacional de Investigaciones Cientificas y Tecnicas-Universidad Nacional de Tucuman) and Instituto de Quimica Biologica 'Dr Bernabe Bloj', Chacabuco 461, 4000 San Miguel de Tucuman, Tucuman (Argentina)

2011-03-18T23:59:59.000Z

295

Ultrasonic flow metering system  

DOE Patents [OSTI]

A system for determining the density, flow velocity, and mass flow of a fluid comprising at least one sing-around circuit that determines the velocity of a signal in the fluid and that is correlatable to a database for the fluid. A system for determining flow velocity uses two of the inventive circuits with directional transmitters and receivers, one of which is set at an angle to the direction of flow that is different from the others.

Gomm, Tyler J. (Meridian, ID); Kraft, Nancy C. (Idaho Falls, ID); Mauseth, Jason A. (Pocatello, ID); Phelps, Larry D. (Pocatello, ID); Taylor, Steven C. (Idaho Falls, ID)

2002-01-01T23:59:59.000Z

296

Elbow mass flow meter  

DOE Patents [OSTI]

Elbow mass flow meter. The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity.

McFarland, Andrew R. (College Station, TX); Rodgers, John C. (Santa Fe, NM); Ortiz, Carlos A. (Bryan, TX); Nelson, David C. (Santa Fe, NM)

1994-01-01T23:59:59.000Z

297

Structural, Spectroscopic, And Theoretical Elucidation of a Redox-Active Pincer-Type Ancillary Applied in Catalysis  

SciTech Connect (OSTI)

Pincer-type ligands are believed to be very robust scaffolds that can support multifarious functionalities as well as highly reactive metal motifs applied in organometallic chemistry, especially in the realm of catalysis. In this paper, we describe the redox and, therefore, noninnocent behavior of a PNP (PNP{sup -} = N[2-P(CHMe{sub 2}){sub 2}-4-methylphenyl]{sub 2}) pincer ancillary bound to nickel. A combination of structural, spectroscopic, and theoretical techniques suggests that this type of framework can house an electron hole when coordinated to Ni(II).

Adhikari, D.; Mossin, S.; Basuli, F.; Huffman, J.C.; Szilagyi, R.K.; Meyer, K.; Mindiola, D.J.

2009-05-11T23:59:59.000Z

298

Parallel-Flow-Shear Driven Low-Frequency Plasma Instability  

SciTech Connect (OSTI)

Full three dimensional Particle-in-Cell (PIC) simulations are performed in order to investigate effects of field-aligned (parallel) ion flow shears on low-frequency plasma instabilities. It is shown that the parallel ion flow velocity shear can induce the ion-acoustic instability, even when the ion flow velocity is so small that the instability can not take place. Simulation results are consistent with the analysis based on the local theory.

Ishiguro, Seiji [Theory and Computer Simulation Center, National Institute for Fusion Science, Toki-shi, Gifu 509-5292 (Japan); Matsumoto, Noriaki; Kaneko, Toshiro; Hatakeyama, Rikizo [Department of Electronic Engineering, Tohoku University, Sendai 980-8579 (Japan)

2004-12-01T23:59:59.000Z

299

E-Print Network 3.0 - altered blood flow Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

S. Popel, Marcos Intaglietta and Paul C. Johnson of red blood cells flowing... . Armstrong, H. J. Meiselman and O. K. Baskurt Graded alterations of RBC aggregation influence...

300

Pore-Scale Characterization of Biogeochemical Controls on Iron and Uranium Speciation under Flow Conditions  

SciTech Connect (OSTI)

Etched silicon microfluidic pore network models (micromodels) with controlled chemical and redox gradients, mineralogy, and microbiology under continuous flow conditions are used for the incremental development of complex microenvironments that simulate subsurface conditions. We demonstrate the colonization of micromodel pore spaces by an anaerobic Fe(III)-reducing bacterial species (Geobacter sulfurreducens) and the enzymatic reduction of a bioavailable Fe(III) phase within this environment. Using both X-ray Microprobe and X-ray Absorption Spectroscopy, we investigate the combined effects of the precipitated Fe(III) phases and the microbial population on uranium biogeochemistry under flow conditions. Precipitated Fe(III) phases within the micromodel were most effectively reduced in the presence of an electron shuttle (AQDS), and Fe(II) ions adsorbed onto the precipitated mineral surface without inducing any structural change. In the absence of Fe(III), U(VI) was effectively reduced by the microbial population to insoluble U(IV), which was precipitated in discrete regions associated with biomass. In the presence of Fe(III) phases, however, both U(IV) and U(VI) could be detected associated with biomass, suggesting re-oxidation of U(IV) by localized Fe(III) phases. These results demonstrate the importance of the spatial localization of biomass and redox active metals, and illustrate the key effects of pore-scale processes on contaminant fate and reactive transport.

Pearce, Carolyn I.; Wilkins, Michael J.; Zhang, Changyong; Heald, Steve M.; Fredrickson, Jim K.; Zachara, John M.

2012-09-17T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Fuel Cell Technologies Overview: 2012 Flow Cells for Energy Storage  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeatMulti-Dimensional ElectricalEnergy Frozen TelescopeRenewable 0 0 A

302

A New Approach to Computing Max Flows using Electrical Flows  

E-Print Network [OSTI]

A New Approach to Computing Max Flows using Electrical Flows Yin Tat Lee (MIT) Satish Rao (UC-Kelner-Madry-Spielman-Teng'11]: approximate flow in time Uses electrical flows. 7 #12;Electrical Flows 3 1 S t 8 #12;Electrical Flows Identify Graph with Resistor Network R(e)=1/w(e) 1/3 S t 1 9 #12;Electrical Flows Electrical flow

Rajamani, Sriram K.

303

Low flow fume hood  

DOE Patents [OSTI]

A fume hood is provided having an adequate level of safety while reducing the amount of air exhausted from the hood. A displacement flow fume hood works on the principal of a displacement flow which displaces the volume currently present in the hood using a push-pull system. The displacement flow includes a plurality of air supplies which provide fresh air, preferably having laminar flow, to the fume hood. The displacement flow fume hood also includes an air exhaust which pulls air from the work chamber in a minimally turbulent manner. As the displacement flow produces a substantially consistent and minimally turbulent flow in the hood, inconsistent flow patterns associated with contaminant escape from the hood are minimized. The displacement flow fume hood largely reduces the need to exhaust large amounts of air from the hood. It has been shown that exhaust air flow reductions of up to 70% are possible without a decrease in the hood's containment performance. The fume hood also includes a number of structural adaptations which facilitate consistent and minimally turbulent flow within a fume hood.

Bell, Geoffrey C. (Pleasant Hill, CA); Feustel, Helmut E. (Albany, CA); Dickerhoff, Darryl J. (Berkeley, CA)

2002-01-01T23:59:59.000Z

304

LM-MHD free-surface flow experiments in MTOR  

E-Print Network [OSTI]

LM-MHD free-surface flow experiments in MTOR Neil Morley for the APEX Participants VLT Conference concentrators · Free jet · Recirculating cell · Soaker Hose (not discussed here) Slide 5 #12;LM In LM Out #12;LM Jet test for NSTX module simulation · Jet flow is introduced into the high field region between

California at Los Angeles, University of

305

Brief Communications Optic Flow Stimuli Update Anterodorsal Thalamus Head  

E-Print Network [OSTI]

orientation in the yaw plane relative to environmental landmark cues. Head movements provoke optic field flow)istheonlyknownprojectionofheaddirectioninformationtoentorhinalgridcellsandhippocampalplacecells,yawplaneoptic flow signals likely influence representations in this spatial reference coordinate system to the body, independently of the ani- mal's ongoing behavior and of its spatial location. The HD cell system

Arleo, Angelo

306

Coupled modeling of groundwater flow solute transport, chemical reactions and microbial processes in the 'SP' island  

SciTech Connect (OSTI)

The Redox Zone Experiment was carried out at the Aespoe HRL in order to study the redox behavior and the hydrochemistry of an isolated vertical fracture zone disturbed by the excavation of an access tunnel. Overall results and interpretation of the Redox Zone Project were reported by /Banwart et al, 1995/. Later, /Banwart et al, 1999/ presented a summary of the hydrochemistry of the Redox Zone Experiment. Coupled groundwater flow and reactive transport models of this experiment were carried out by /Molinero, 2000/ who proposed a revised conceptual model for the hydrogeology of the Redox Zone Experiment which could explain simultaneously measured drawdown and salinity data. The numerical model was found useful to understand the natural system. Several conclusions were drawn about the redox conditions of recharge waters, cation exchange capacity of the fracture zone and the role of mineral phases such as pyrite, calcite, hematite and goethite. This model could reproduce the measured trends of dissolved species, except for bicarbonate and sulfate which are affected by microbially-mediated processes. In order to explore the role of microbial processes, a coupled numerical model has been constructed which accounts for water flow, reactive transport and microbial processes. The results of this model is presented in this report. This model accounts for groundwater flow and reactive transport in a manner similar to that of /Molinero, 2000/ and extends the preliminary microbial model of /Zhang, 2001/ by accounting for microbially-driven organic matter fermentation and organic matter oxidation. This updated microbial model considers simultaneously the fermentation of particulate organic matter by yeast and the oxidation of dissolved organic matter, a product of fermentation. Dissolved organic matter is produced by yeast and serves also as a substrate for iron-reducing bacteria. Model results reproduce the observed increase in bicarbonate and sulfate concentration, thus adding additional evidence for the possibility of organic matter oxidation as the main source of bicarbonate. Model results indicate that pH and Eh are relatively stable. The dissolution-precipitation trends of hematite, pyrite and calcite also coincide with those indicated by the conceptual model. A thorough sensitivity analysis has been performed for the most relevant microbial parameters as well as for initial and boundary POC and DOC concentrations. The results of such analysis indicate that computed concentrations of bicarbonate, sulfate and DOC are sensitive to most of the microbial parameters, including specific growth rates, half-saturation constants, proportionality coefficients and yield coefficients. Model results, however, are less sensitive to the yield coefficient of DOC to iron-reducer bacteria. The sensitivity analysis indicates that changes in fermentation microbial parameters affect the growth of the iron-reducer, thus confirming the interconnection of both microbial processes. Computed concentrations of bicarbonate and sulfate are found to be sensitive to changes in the initial concentration of POC and the boundary concentration of DOC, but they lack sensitivity to the initial concentration of DOC and the boundary concentration of POC. The explanation for such result is related to the fact that POC has a low mobility due to its large molecular weight. DOC, however, can migrate downwards. Although a coupled hydro-bio-geochemical 1-D model can reproduce the observed ''unexpected'' increase of concentrations of bicarbonate and sulfate at a depth of 70 m, further modeling work is required in order to obtain a similar conclusion under the more realistic two dimensional conditions of the fracture zone.

Samper, Javier; Molinero, Jorg; Changbing, Yang; Zhang, Guoxiang

2003-12-01T23:59:59.000Z

307

Dispersion of swimming algae in laminar and turbulent channel flows: theory and simulations  

E-Print Network [OSTI]

Algal swimming is often biased by environmental cues, e.g. gravitational and viscous torques drive cells towards downwelling fluid (gyrotaxis). In view of biotechnological applications, it is important to understand how such biased swimming affects cell dispersion in a flow. Here, we study the dispersion of gyrotactic swimming algae in laminar and turbulent channel flows. By direct numerical simulation (DNS) of cell motion within upwelling and downwelling channel flows, we evaluate time-dependent measures of dispersion for increasing values of the flow Peclet (Reynolds) numbers, Pe (Re). Furthermore, we derive an analytical `swimming Taylor-Aris dispersion' theory, using flow-dependent transport parameters given by existing microscopic models. In the laminar regime, DNS results and analytical predictions compare very well, providing the first confirmation that cells' response to flow is best described by the generalized-Taylor-dispersion microscopic model. We predict that cells drift along a channel faster th...

Croze, O A; Ahmed, M; Bees, M A; Brandt, L

2012-01-01T23:59:59.000Z

308

Electrochemical DNA biosensor for detection of porcine oligonucleotides using ruthenium(II) complex as intercalator label redox  

SciTech Connect (OSTI)

A DNA biosensor detection of oligonucleotides via the interactions of porcine DNA with redox active complex based on the electrochemical transduction is described. A ruthenium(II) complex, [Ru(bpy){sub 2}(PIP)]{sup 2+}, (bpy = 2,2?bipyridine, PIP = 2-phenylimidazo[4,5-f[[1,10-phenanthroline]) as DNA label has been synthesized and characterized by 1H NMR and mass spectra. The study was carried out by covalent bonding immobilization of porcine aminated DNA probes sequences on screen printed electrode (SPE) modified with succinimide-acrylic microspheres and [Ru(bpy){sub 2}(PIP)]{sup 2+} was used as electrochemical redox intercalator label to detect DNA hybridization event. Electrochemical detection was performed by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) over the potential range where the ruthenium (II) complex was active. The results indicate that the interaction of [Ru(bpy){sub 2}(PIP)]{sup 2+} with hybridization complementary DNA has higher response compared to single-stranded and mismatch complementary DNA.

Halid, Nurul Izni Abdullah; Hasbullah, Siti Aishah; Heng, Lee Yook; Karim, Nurul Huda Abd [School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia); Ahmad, Haslina; Harun, Siti Norain [Chemistry Department, Faculty of Science, Universiti Putra Malaysia, 43400, Serdang, Selangor (Malaysia)

2014-09-03T23:59:59.000Z

309

Membrane-less hydrogen bromine flow battery William A. Braff1  

E-Print Network [OSTI]

refined and optimized over several decades. More recently, a laminar flow fuel cell based on borohydride batteries [23, 27], as well as methanol [25], formic acid [24], and hydrogen fuel cells [29]. However, none

Bazant, Martin Z.

310

Effects of Dioxin on Clock, Melatonin Biosynthetic, and Redox Sensitive Genes on Chick Pinealocytes In Vitro  

E-Print Network [OSTI]

It has been speculated that dioxin treatment can modulate circadian rhythms. Cytochrome P4501A (CYP1A) is strongly induced by the xenobiotic dioxin via activation of arylhydrocarbon receptors within cells. Furthermore, regulation of CYP1A has been...

Hunt, Jayme

2006-07-11T23:59:59.000Z

311

Electrochemical cell method  

DOE Patents [OSTI]

A secondary electrochemical cell is prepared by providing positive and negative electrodes having outer enclosures of rigid perforated electrically conductive material defining an internal compartment containing the electrode material in porous solid form. The electrodes are each immersed in molten electrolyte salt prior to cell assembly to incorporate the cell electrolyte. Following solidification of the electrolyte substantially throughout the porous volume of the electrode material, the electrodes are arranged in an alternating positive-negative array with interelectrode separators of porous frangible electrically insulative material. The completed array is assembled into the cell housing and sealed such that on heating the solidified electrolyte flows into the interelectrode separator.

Kaun, T.D.; Eshman, P.F.

1980-05-09T23:59:59.000Z

312

Turbulent flow in graphene  

E-Print Network [OSTI]

We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.

Kumar S. Gupta; Siddhartha Sen

2010-06-05T23:59:59.000Z

313

Productivity & Energy Flow  

E-Print Network [OSTI]

1 Productivity & Energy Flow Ecosystem approach, focuses: on flow of energy, water, and nutrients (capture) of energy by autotrophs Gross (total) Net (total ­ costs) Secondary productivity- capture of energy by herbivores http://sciencebitz.com/?page_id=204 What Controls the Primary Productivity

Mitchell, Randall J.

314

Elbow mass flow meter  

DOE Patents [OSTI]

The present invention includes a combination of an elbow pressure drop generator and a shunt-type mass flow sensor for providing an output which gives the mass flow rate of a gas that is nearly independent of the density of the gas. For air, the output is also approximately independent of humidity. 3 figs.

McFarland, A.R.; Rodgers, J.C.; Ortiz, C.A.; Nelson, D.C.

1994-08-16T23:59:59.000Z

315

Microelectromechanical flow control apparatus  

DOE Patents [OSTI]

A microelectromechanical (MEM) flow control apparatus is disclosed which includes a fluid channel formed on a substrate from a first layer of a nonconducting material (e.g. silicon nitride). A first electrode is provided on the first layer of the nonconducting material outside the flow channel; and a second electrode is located on a second layer of the nonconducting material above the first layer. A voltage applied between the first and second electrodes deforms the fluid channel to increase its cross-sectional size and thereby increase a flow of a fluid through the channel. In certain embodiments of the present invention, the fluid flow can be decreased or stopped by applying a voltage between the first electrode and the substrate. A peristaltic pumping of the fluid through the channel is also possible when the voltage is applied in turn between a plurality of first electrodes and the substrate. A MEM flow control assembly can also be formed by providing one or more MEM flow control devices on a common substrate together with a submicron filter. The MEM flow control assembly can optionally include a plurality of pressure sensors for monitoring fluid pressure and determining flow rates through the assembly.

Okandan, Murat (NE Albuquerque, NM)

2009-06-02T23:59:59.000Z

316

Precision electron flow measurements in a disk transmission line.  

SciTech Connect (OSTI)

An analytic model for electron flow in a system driving a fixed inductive load is described and evaluated with particle in cell simulations. The simple model allows determining the impedance profile for a magnetically insulated transmission line given the minimum gap desired, and the lumped inductance inside the transition to the minimum gap. The model allows specifying the relative electron flow along the power flow direction, including cases where the fractional electron flow decreases in the power flow direction. The electrons are able to return to the cathode because they gain energy from the temporally rising magnetic field. The simulations were done with small cell size to reduce numerical heating. An experiment to compare electron flow to the simulations was done. The measured electron flow is {approx}33% of the value from the simulations. The discrepancy is assumed to be due to a reversed electric field at the cathode because of the inductive load and falling electron drift velocity in the power flow direction. The simulations constrain the cathode electric field to zero, which gives the highest possible electron flow.

Clark, Waylon T.; Pelock, Michael D.; Martin, Jeremy Paul; Jackson, Daniel Peter Jr.; Savage, Mark Edward; Stoltzfus, Brian Scott; Mendel, Clifford Will, Jr.; Pointon, Timothy David

2008-01-01T23:59:59.000Z

317

Structural basis of inter-domain electron transfer in Ncb5or, a redox enzyme implicated in diabetes and lipid metabolism  

E-Print Network [OSTI]

NADH cytochrome b5 oxidoreductase (Ncb5or) is a multi-domain redox enzyme found in all animal tissues and associated with the endoplasmic reticulum (ER). Ncb5or contains (from N-terminus to C terminus) a novel N-terminal region, the b5 domain (Ncb5...

Deng, Bin

2011-12-31T23:59:59.000Z

318

Computational Biorheology of Human Blood Flow in Health and Disease DMITRY A. FEDOSOV,1  

E-Print Network [OSTI]

with results obtained using this computational framework for blood flow in malaria and sickle cell anemia. Keywords--Hematologic disorders, Dissipative particle dynamics, Coarse-graining, Malaria, Sickle cell in the later stages of the intra-cell parasite development.36 Sickle cell anemia is another blood disorder

Dao, Ming

319

Elliptic flow phenomenon at ATLAS  

E-Print Network [OSTI]

We summarize measurements of elliptic flow and higher order flow harmonics performed by the ATLAS experiment at the LHC. Results on event-averaged flow measurements and event-plane correlations in Pb+Pb collisions are discussed along with the event-by-event flow measurements. Further, we summarize results on flow in p+Pb collisions.

Martin Spousta

2014-06-20T23:59:59.000Z

320

FINAL REPORT INTEGRATED DM1200 MELTER TESTING OF REDOX EFFECTS USING HLW AZ-101 AND C-106/AY-102 SIMULANTS VSL-04R4800-1 REV 0 5/6/  

SciTech Connect (OSTI)

This report documents melter and off-gas performance results obtained on the DM1200 HLW Pilot Melter during processing of AZ-101 and C-106/AY-102 HLW simulants. The tests reported herein are a subset of three tests from a larger series of tests described in the Test Plan for the work; results from the remaining tests will be reported separately. Three nine day tests, one with AZ-101 and two with C-106/AY-102 feeds were conducted with variable amounts of added sugar to address the effects of redox. The test with AZ-101 included ruthenium spikes to also address the effects of redox on ruthenium volatility. One of tests addressed the effects of increased flow-sheet nitrate levels using C-106/AY-102 feeds. With high nitrate/nitrite feeds (such as WTP LAW feeds), reductants are required to prevent melt foaming and deleterious effects on glass production rates. Sugar is the baseline WTP reductant for this purpose. WTP HLW feeds typically have relatively low nitrate/nitrite content in comparison to the organic carbon content and, therefore, have typically not required sugar additions. However, HLW feed variability, particularly with respect to nitrate levels, may necessitate the use of sugar in some instances. The tests reported here investigate the effects of variable sugar additions to the melter feed as well as elevated nitrate levels in the waste. Variables held constant to the extent possible included melt temperature, bubbling rate, plenum temperature, cold cap coverage, the waste simulant composition, and the target glass composition. The principal objectives of the DM1200 melter testing were to determine the achievable glass production rates for simulated HLW feeds with variable amounts of added sugar and increased nitrate levels; characterize melter off-gas emissions; characterize the performance of the prototypical off-gas system components as well as their integrated performance; characterize the feed, glass product, and off-gas effluents; and perform pre- and post test inspections of system components. The specific objectives (including test success criteria) of this testing, along with how each objective was met, are outlined in a table.

KRUGER AA; MATLACK KS; GONG W; BARDAKCI T; D'ANGELO NA; LUTZE W; BIZOT PM; CALLOW RA; BRANDYS M; KOT WK; PEGG IL

2011-12-29T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Redox cycle stability of mixed oxides used for hydrogen generation in the cyclic water gas shift process  

SciTech Connect (OSTI)

Graphical abstract: - Highlights: • Fe{sub 2}O{sub 3} modified with CaO, SiO{sub 2} and Al{sub 2}O{sub 3} was studied in cyclic water gas shift reactor. • For the first time stability of such oxides were tested for 100 redox cycles. • Optimally added oxides significantly improved the activity and the stability of Fe{sub 2}O{sub 3}. • Increased stability was attributed to the impediment of neck formation. - Abstract: Repeated cycles of the reduction of Fe{sub 3}O{sub 4} with reductive gas, e.g. hydrogen and subsequent oxidation of the reduced iron material with water vapor can be harnessed as a process for the production of pure hydrogen. The redox behavior of iron oxide modified with various amounts of SiO{sub 2}, CaO and Al{sub 2}O{sub 3} was investigated in the present study. The total amount of the additional metal oxides was always below 15 wt%. The samples were prepared by co-precipitation using urea hydrolysis method. The influence of various metal oxides on the hydrogen production capacity and the material stability was studied in detail in terms of temperature-programmed reduction (TPR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and BET analysis. Furthermore, the activity and the stability of the samples were tested in repeated reduction with diluted H{sub 2} and re-oxidation cycles with H{sub 2}O. The results indicate that combination of several oxides as promoter increases the stability of the iron oxide material by mitigating the sintering process. The positive influence of the oxides in stabilizing the iron oxide material is attributed to the impediment of neck formation responsible for sintering.

Datta, Pradyot, E-mail: pradyot.datta@gmail.com

2013-10-15T23:59:59.000Z

322

Controlled Assembly of Heterobinuclear Sites on Mesoporous Silica: Visible Light Charge-Transfer Units with Selectable Redox Properties  

SciTech Connect (OSTI)

Mild synthetic methods are demonstrated for the selective assembly of oxo-bridged heterobinuclear units of the type TiOCrIII, TiOCoII, and TiOCeIII on mesoporous silica support MCM-41. One method takes advantage of the higher acidity and, hence, higher reactivity of titanol compared to silanol OH groups towards CeIII or CoII precursor. The procedure avoids the customary use of strong base. The controlled assembly of the TiOCr system exploits the selective redox reactivity of one metal towards another (TiIII precursor reacting with anchored CrVI centers). The observed selectivity for linking a metal precursor to an already anchored partner versus formation of isolated centers ranges from a factor of six (TiOCe) to complete (TiOCr, TiOCo). Evidence for oxo bridges and determination of the coordination environment of each metal centers is based on K-edge EXAFS (TiOCr), L-edge absorption spectroscopy (Ce), and XANES measurements (Co, Cr). EPR, optical, FT-Raman and FT-IR spectroscopy furnish additional details on oxidation state and coordination environment of donor and acceptor metal centers. In the case of TiOCr, the integrity of the anchored group upon calcination (350 oC) and cycling of the Cr oxidation state is demonstrated. The binuclear units possess metal-to-metal charge-transfer transitions that absorb deep in the visible region. The flexible synthetic method for assembling the units opens up the use of visible light charge transfer pumps featuring donor or acceptor metals with selectable redox potential.

Frei, Heinz; Han, Hongxian; Frei, Heinz

2008-06-04T23:59:59.000Z

323

Shroud leakage flow discouragers  

DOE Patents [OSTI]

A turbine assembly includes a plurality of rotor blades comprising a root portion, an airfoil having a pressure sidewall and a suction sidewall, and a top portion having a cap. An outer shroud is concentrically disposed about said rotor blades, said shroud in combination with said tip portions defining a clearance gap. At least one circumferential shroud leakage discourager is disposed within the shroud. The leakage discourager(s) increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the clearance gap to improve overall turbine efficiency.

Bailey, Jeremy Clyde (Middle Grove, NY); Bunker, Ronald Scott (Niskayuna, NY)

2002-01-01T23:59:59.000Z

324

Bypass Flow Study  

SciTech Connect (OSTI)

The purpose of the fluid dynamics experiments in the MIR (Matched Index of-Refraction) flow system at Idaho National Laboratory (INL) is to develop benchmark databases for the assessment of Computational Fluid Dynamics (CFD) solutions of the momentum equations, scalar mixing, and turbulence models for the flow ratios between coolant channels and bypass gaps in the interstitial regions of typical prismatic standard fuel element (SFE) or upper reflector block geometries of typical Modular High-temperature Gas-cooled Reactors (MHTGR) in the limiting case of negligible buoyancy and constant fluid properties. The experiments use Particle Image Velocimetry (PIV) to measure the velocity fields that will populate the bypass flow study database.

Richard Schultz

2011-09-01T23:59:59.000Z

325

Magnetically stimulated fluid flow patterns  

ScienceCinema (OSTI)

Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.

Martin, Jim; Solis, Kyle

2014-08-06T23:59:59.000Z

326

Fuel cell membrane hydration and fluid metering  

DOE Patents [OSTI]

A hydration system includes fuel cell fluid flow plate(s) and injection port(s). Each plate has flow channel(s) with respective inlet(s) for receiving respective portion(s) of a given stream of reactant fluid for a fuel cell. Each injection port injects a portion of liquid water directly into its respective flow channel. This serves to hydrate at least corresponding part(s) of a given membrane of the corresponding fuel cell(s). The hydration system may be augmented by a metering system including flow regulator(s). Each flow regulator meters an injecting at inlet(s) of each plate of respective portions of liquid into respective portion(s) of a given stream of fluid by corresponding injection port(s).

Jones, Daniel O. (Glenville, NY); Walsh, Michael M. (Fairfield, CT)

2003-01-01T23:59:59.000Z

327

Optical flow switching  

E-Print Network [OSTI]

Present-day networks are being challenged by dramatic increases in bandwidth demand of emerging applications. We will explore a new transport, ldquooptical flow switchingrdquo, that will enable significant growth and ...

Chan, Vincent W. S.

328

Olefin Autoxidation in Flow  

E-Print Network [OSTI]

Handling hazardous multiphase reactions in flow brings not only safety advantages but also significantly improved performance, due to better mass transfer characteristics. In this paper, we present a continuous microreactor ...

Neuenschwander, Ulrich

329

Dissipative flows of 2D foams  

E-Print Network [OSTI]

We analyze the flow of a liquid foam between two plates separated by a gap of the order of the bubble size (2D foam). We concentrate on the salient features of the flow that are induced by the presence, in an otherwise monodisperse foam, of a single large bubble whose size is one order of magnitude larger than the average size. We describe a model suited for numerical simulations of flows of 2D foams made up of a large number of bubbles. The numerical results are successfully compared to analytical predictions based on scaling arguments and on continuum medium approximations. When the foam is pushed inside the cell at a controlled rate, two basically different regimes occur: a plug flow is observed at low flux whereas, above a threshold, the large bubble migrates faster than the mean flow. The detailed characterization of the relative velocity of the large bubble is the essential aim of the present paper. The relative velocity values, predicted both from numerical and from analytical calculations that are discussed here in great detail, are found to be in fair agreement with experimental results.

Isabelle Cantat; Renaud Delannay

2005-07-21T23:59:59.000Z

330

Section 13: Flow control 1 Section 13: Flow control  

E-Print Network [OSTI]

Geometries for Energyefficient Flow Around Bodies Abstract 14:30 ­ 14:50: Elfriede Friedmann (Universität

Kohlenbach, Ulrich

331

Characterization of secondary collection system flows beneath synthetic composite liners  

SciTech Connect (OSTI)

Secondary liner systems for landfills are becoming more common. Subtitle D may be construed to require secondary liners to meet monitorability requirements for new units. Michigan requires secondary liners in many situations, most commonly at previously contaminated sites to allow for differential monitoring of the new cell(s). Much work has been done in characterizing the flow of liquids through FML/clay composite liners but less is known about flows through FML/geosynthetic clay liner (GCL) composite liners or through isolated FMLs. Flow and chemical data are examined from two Michigan landfills employing different configurations of all synthetic primary and secondary liners. The data is examined for apparent trends. Conclusions are drawn about the application of generic action flow rates as a regulatory standard to these systems and the chemical characteristics of the liquids in secondary systems. Calculations are presented to achieve a realistic action leakage rate for these systems.

Groenleer, M.E. [Wenck Associates, Inc., Grand Rapids, MI (United States)

1995-12-31T23:59:59.000Z

332

EE580 Solar Cells Todd J. Kaiser  

E-Print Network [OSTI]

7/21/2010 1 EE580 ­ Solar Cells Todd J. Kaiser · Lecture 02 Microfabrication ­ A combination · Photolithograpy · Depostion · Etching 1 Montana State University: Solar Cells Lecture 2: Microfabrication Flow Montana State University: Solar Cells Lecture 2: Microfabrication Questions · What is heat? · Heat

Kaiser, Todd J.

333

Analysis of Fuel Cell Systems Rangan Banerjee  

E-Print Network [OSTI]

Analysis of Fuel Cell Systems Rangan Banerjee Energy Systems Engineering IIT Bombay Lecture in CEP Course on `Fuel Cell' at IIT 14th November 2007 #12;Overview of Talk Energy Crisis ­ Motivation for fuel biological Hydrogen Gasification Fermentation Cracking + Shift Reaction Fuel Cell #12;ENERGY FLOW DIAGRAM

Banerjee, Rangan

334

Multi-processor including data flow accelerator module  

DOE Patents [OSTI]

An accelerator module for a data flow computer includes an intelligent memory. The module is added to a multiprocessor arrangement and uses a shared tagged memory architecture in the data flow computer. The intelligent memory module assigns locations for holding data values in correspondence with arcs leading to a node in a data dependency graph. Each primitive computation is associated with a corresponding memory cell, including a number of slots for operands needed to execute a primitive computation, a primitive identifying pointer, and linking slots for distributing the result of the cell computation to other cells requiring that result as an operand. Circuitry is provided for utilizing tag bits to determine automatically when all operands required by a processor are available and for scheduling the primitive for execution in a queue. Each memory cell of the module may be associated with any of the primitives, and the particular primitive to be executed by the processor associated with the cell is identified by providing an index, such as the cell number for the primitive, to the primitive lookup table of starting addresses. The module thus serves to perform functions previously performed by a number of sections of data flow architectures and coexists with conventional shared memory therein. A multiprocessing system including the module operates in a hybrid mode, wherein the same processing modules are used to perform some processing in a sequential mode, under immediate control of an operating system, while performing other processing in a data flow mode.

Davidson, George S. (Albuquerque, NM); Pierce, Paul E. (Albuquerque, NM)

1990-01-01T23:59:59.000Z

335

Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry  

E-Print Network [OSTI]

Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I.Skillicorn 1 Azimuthal asymmetry using energy flow method Azimuthal angle distribution at Q2 >100 GeV2 Energy flow method.Ukleja on behalf of the ZEUS Collaboration #12; Energy Flow Energy Flow Energy Flow A.Ukleja, T.Tymieniecka, I

336

In situ PEM fuel cell water measurements  

SciTech Connect (OSTI)

Efficient PEM fuel cell performance requires effective water management. The materials used, their durability, and the operating conditions under which fuel cells run, make efficient water management within a practical fuel cell system a primary challenge in developing commercially viable systems. We present experimental measurements of water content within operating fuel cells. in response to operational conditions, including transients and freezing conditions. To help understand the effect of components and operations, we examine water transport in operating fuel cells, measure the fuel cell water in situ and model the water transport within the fuel cell. High Frequency Resistance (HFR), AC Impedance and Neutron imaging (using NIST's facilities) were used to measure water content in operating fuel cells with various conditions, including current density, relative humidity, inlet flows, flow orientation and variable GDL properties. Ice formation in freezing cells was also monitored both during operation and shut-down conditions.

Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Davey, John R [Los Alamos National Laboratory; Spendalow, Jacob S [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

337

Annular feed air breathing fuel cell stack  

DOE Patents [OSTI]

A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

Wilson, Mahlon S. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

338

Evaluation of flow hood measurements for residential register flows  

SciTech Connect (OSTI)

Flow measurement at residential registers using flow hoods is becoming more common. These measurements are used to determine if the HVAC system is providing adequate comfort, appropriate flow over heat exchangers and in estimates of system energy losses. These HVAC system performance metrics are determined by using register measurements to find out if individual rooms are getting the correct airflow, and in estimates of total air handler flow and duct air leakage. The work discussed in this paper shows that commercially available flow hoods are poor at measuring flows in residential systems. There is also evidence in this and other studies that flow hoods can have significant errors even when used on the non-residential systems they were originally developed for. The measurement uncertainties arise from poor calibrations and the sensitivity of exiting flow hoods to non-uniformity of flows entering the device. The errors are usually large--on the order of 20% of measured flow, which is unacceptably high for most applications. Active flow hoods that have flow measurement devices that are insensitive to the entering airflow pattern were found to be clearly superior to commercially available flow hoods. In addition, it is clear that current calibration procedures for flow hoods may not take into account any field application problems and a new flow hood measurement standard should be developed to address this issue.

Walker, I.S.; Wray, C.P.; Dickerhoff, D.J.; Sherman, M.H.

2001-09-01T23:59:59.000Z

339

Electron Transfer Dynamics in Efficient Molecular Solar Cells  

SciTech Connect (OSTI)

This research provided new mechanistic insights into surface mediated photochemical processes relevant to solar energy conversion. In this past three years our research has focused on oxidation photo-redox chemistry and on the role surface electric fields play on basic spectroscopic properties of molecular-semiconductor interfaces. Although this research as purely fundamental science, the results and their interpretation have relevance to applications in dye sensitized and photogalvanic solar cells as well as in the storage of solar energy in the form of chemical bonds.

Meyer, Gerald John

2014-10-01T23:59:59.000Z

340

copyrisht@ree2bythen-""i"",,R3il:'J[$H#"",i*tTy"t"*r1"'J?rt;""mission orthecopyrightowner. Toward Orthogonal Self-Assembly of Redox Active  

E-Print Network [OSTI]

Orthogonal Self-Assembly of Redox Active Molecules on Pt and Au: Selective Reaction of Disulfide with Au.; Uphaus,R. A. Microchem.J.1990,42, 44, and referencestherein on viologen monolayer electrochemistry. (5

Prentiss, Mara

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Workshop on hypersonic flow  

SciTech Connect (OSTI)

An overview is given of research activity on the application of computational fluid dynamics (CDF) for hypersonic propulsion systems. After the initial consideration of the highly integrated nature of air-breathing hypersonic engines and airframe, attention is directed toward computations carried out for the components of the engine. A generic inlet configuration is considered in order to demonstrate the highly three dimensional viscous flow behavior occurring within rectangular inlets. Reacting flow computations for simple jet injection as well as for more complex combustion chambers are then discussed in order to show the capability of viscous finite rate chemical reaction computer simulations. Finally, the nozzle flow fields are demonstrated, showing the existence of complex shear layers and shock structure in the exhaust plume. The general issues associated with code validation as well as the specific issue associated with the use of CFD for design are discussed. A prognosis for the success of CFD in the design of future propulsion systems is offered.

Povinelli, L.A.

1990-01-01T23:59:59.000Z

342

Friction and the oscillatory motion of granular flows  

E-Print Network [OSTI]

This contribution reports on numerical simulations of 2D granular flows on erodible beds. The broad aim is to investigate whether simple flows of model granular matter exhibits spontaneous oscillatory motion in generic flow conditions, and in this case, whether the frictional properties of the contacts between grains may affect the existence or the characteristics of this oscillatory motion. The analysis of different series of simulations show that the flow develops an oscillatory motion with a well-defined frequency which increases like the inverse of the velocity's square root. We show that the oscillation is essentially a surface phenomena. The amplitude of the oscillation is higher for lower volume fractions, and can thus be related to the flow velocity and grains friction properties. The study of the influence of the periodic geometry of the simulation cell shows no significant effect. These results are discussed in relation to sonic sands.

Lydie Staron

2012-11-26T23:59:59.000Z

343

[Unsegmented continuous-flow sample processing and electrochemical detection of gaseous species  

SciTech Connect (OSTI)

Goals were a continuous-flow, unsegmented, all-gas carrier and/or a segmented liquid/gas interface system for sample introduction and transport to detection/determination point; a regenerable electrode probe base on redox reactions of Fe(II) and Fe(III) complexes with 1, 10-phenanthroline and related ligands; and amperometric/coulometric current measurements providing analyte signals. Gases to be detected included NO[sub x] and SO[sub 2]. This report is divided into 3 parts: preparation of new ligands of 1,10-phenanthroline family; glassy carbon surfaces coated with polymeric films prepared from monomeric units of tris[5-amino-1,10-phenanthroline]iron(II); and sulfite oxidase/hexacyanoferrate modified C paste electrode.

Mottola, H.A.

1991-01-01T23:59:59.000Z

344

Liquid-Water Uptake and Removal in PEM Fuel-Cell Components  

E-Print Network [OSTI]

Uptake and Removal in PEM Fuel-Cell Components Prodip K. DasWater management in PEM fuel cells is critical for optimumof droplet dynamics in PEM fuel-cell gas flow channels has

Das, Prodip K.

2013-01-01T23:59:59.000Z

345

Time-resolved fluorescence decay measurements for flowing particles  

DOE Patents [OSTI]

Time-resolved fluorescence decay measurements for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated cw laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes.

Deka, Chiranjit (Miami, FL); Steinkamp, John A. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

346

Time-resolved fluorescence decay measurements for flowing particles  

DOE Patents [OSTI]

Time-resolved fluorescence decay measurements are disclosed for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated CW laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes. 12 figs.

Deka, C.; Steinkamp, J.A.

1999-06-01T23:59:59.000Z

347

Multiphase cooling flows  

E-Print Network [OSTI]

I discuss the multiphase nature of the intracluster medium whose neglect can lead to overestimates of the baryon fraction of clusters by up to a factor of two. The multiphase form of the cooling flow equations are derived and reduced to a simple form for a wide class of self-similar density distributions. It is shown that steady-state cooling flows are \\emph{not} consistent with all possible emissivity profiles which can therefore be used as a test of the theory. In combination, they provide strong constraints on the mass distribution within the cooling radius.

Peter A. Thomas

1996-08-20T23:59:59.000Z

348

Synthesis and charge-transport properties of polymers derived from the oxidation of 1-hydro-1'-(6-(pyrrol-1-yl)hexyl)-4,4'-bipyridium Bis(hexafluorophosphate) and demonstration of pH-sensitive microelectrochemical transistor derived from the redox properties of a conventional redox center  

SciTech Connect (OSTI)

This article describes the synthesis and electrochemical properties of redox polymers, having a polypyrrole backbone and viologen subunits, derived from oxidative electropolymerization of 1-methyl-1'-(6-(pyrrol-1-yl)hexyl)-4,4'-bipyridinium (P-V-Me/sup 2 +/) and 1-hydro-1'-(6-(pyrrol-1-yl)hexyl)-4,4'-bipyridinium (P-V-H/sup 2 +/). Closely spaced (approx. 1.5 ..mu..M) Au microelectrode arrays (approx. 2.5 ..mu..m wide /times/ 50 ..mu..m long /times/ 0.1 ..mu..m high) modified with the polymers can be used to study aspects of the charge-transport behavior of the viologen redox system. Poly(P-V-Me/sup 2 +/) have been used to investigate the characteristics of microelectrochemical transistors based on a viologen redox center and a similar redox center, protonated, monoquaternized bipyridinium, which is pH dependent. The interesting properties from poly(P-V-Me/sup 2 +/) and poly(P-V-H/sup 2 +/) stem from behavior of the pendant viologen redox centers. The device based on poly(P-V-Me/sup 2 +/) has a narrow region (approx. 200 mV) of gate voltage, V/sub G/, where the source-drain current, I/sub D/, is nonzero and has a sharp, pH-independent peak in the I/sub D/-V/sub G/ plot at approx. 0.53 V versus SCE associated with the reversible, one-electron reduction of viologen. This result is consistent with electron self-exchange between redox centers being the mechanism for charge transport. The device based on poly(P-V-H/sup 2 +/) shows a pH-dependent I/sub D/ at fixed V/sub G/, as expected from the electrochemical behavior from reversible protonation of the terminal N of the bipyridinium group of poly(P-V-H/sup 2 +/). The microelectrochemical transistor based on poly(P-V-H/sup 2 +/) illustrates the design of chemically sensitive, molecule-based devices using conventional redox materials.

Shu, C.F.; Wrighton, M.S.

1988-09-08T23:59:59.000Z

349

The role of nanopores on U(VI) sorption and redox behavior in U(VI)-contaminated subsurface sediments  

SciTech Connect (OSTI)

Most reactive surfaces in clay-dominated sediments are present within nanopores (pores of nm dimension). The behavior of geological fluids and minerals in nanopores is significantly different from those in normal non-nanoporous environments. The effect of nanopore surfaces on U(VI) sorption/desorption and reduction is likely to be significant in clay-rich subsurface environments. Our research results from both model nanopore system and natural sediments from both model system (synthetic nanopore alumina) and sediments from the ORNL Field Research Center prove that U(VI) sorption on nanopore surfaces can be greatly enhanced by nanopore confinement environments. The results from the project provide advanced mechanistic, quantitative information on the physiochemical controls on uranium sorption and redox behavior in subsurface sediments. The influence of nanopore surfaces on coupled uranium sorption/desorption and reduction processes is significant in virtually all subsurface environments, because most reactive surfaces are in fact nanopore surfaces. The results will enhance transfer of our laboratory-based research to a major field research initiative where reductive uranium immobilization is being investigated. Our results will also provide the basic science for developing in-situ colloidal barrier of nanoporous alumina in support of environmental remediation and long term stewardship of DOE sites.

Xu, Huifang; Roden, Eric E.; Kemner, Kenneth M.; Jung, Hun-Bok; Konishi, Hiromi; Boyanov, Maxim; Sun, Yubing; Mishra, Bhoopesh

2013-10-16T23:59:59.000Z

350

Electrostatic binding of bicarbonate and formate in viologen-based redox polymers: importance in catalytic reduction of bicarbonate to formate  

SciTech Connect (OSTI)

The relative importance of electrostatic binding of CO3H and HCO2 in a redox polymer derived from an N,N'-dialkyl-4,4'-bipyridinium monomer has been investigated by Fourier transform infrared (FTIR) spectroscopy. At 298 K and a total concentration of C-containing species of 0.1 M the two species are equally firmly bound in a polymer immobilized on a single-crystal Si electrode surface. When the concentration of C-containing species is 1.0 M, the CO3H ion is more firmly bound by about a factor of 2.5, and at a total concentration of 3.0 M the CO3H ion is about 7 times more firmly bound than the HCO2 ion. The HCO2 and Cl anions are equally firmly bound at 1.0 M total anion concentration. On the basis of the lack of change in the cyclic voltammetry response of a derivatized electrode in 1.0 M Na(CO3H) or Na(HCO2) compared to 1.0 M NaCl, the exchange rate of the C-containing anions does not appear to be a factor that would limit the rate of reduction of the CO3H ion at an electrode modified with the polymer and impregnated with Pd(0).

Andre, J.F.; Wrighton, M.S.

1985-12-04T23:59:59.000Z

351

Photoinduced and redox-induced transmembrane processes with vesicle-stabilized colloidal cadmium sulfide and multicharged viologen derivatives  

SciTech Connect (OSTI)

Colloidal cadmium sulfide (CdS) and methylviologen (MV{sup 2+}) or new viologen derivatives carrying more positive charges were placed at specific sites of dihexadecyl phosphate (DHP) vesicles. Benzyl alcohol was used as a sacrificial electron donor to promote reduction of the viologens by photoexcited CdS colloid majority carriers. Transmission electron microscopy, {sup 13}C nuclear magnetic resonance, and differential scanning calorimetry were used for physical characterization. Photochemical events were followed by in situ optical and electrochemical monitoring. Redox-induced transmembrane diffusion, which had been found with MV{sup 2+}, could be reduced by a factor 18 by using a triply charged viologen derivative and by a further factor of 30 in a configuration involving transmembrane electron transfer. In that case the quantum yield was ca. 0.05 at 410 nm, while virtually no reduced viologen leaking could be observed during at least 10 min. Physical evidence was found for a partial penetration of the CdS colloids into the DHP membrane.

Tricot, Y.M.; Porat, Z.; Manassen, J. (Weizmann Inst. of Science, Rehovot (Israel))

1991-04-18T23:59:59.000Z

352

Photoinduced redox reactions in aqueous micelles. Quenching, back-reaction, and competing processes for tetraanionic porphyrins with alkylviologens  

SciTech Connect (OSTI)

Photoinduced redox reactions employing the anionic porphyrins meso-tetrakis(p-sulfonatophenyl)porphyrin (1) and its palladium(II) complex (2) as excited substrates and various alkylviologens as quenchers have been studied in homogeneous aqueous solution and in the presence of the charged detergents sodium dodecyl sulfate (SDS) and cetyltrimethylammonium chloride (CTAC) above the critical micelle concentration (cmc). In homogeneous solution strong ground-state association between the porphyrins and the viologens occurs; even dynamic quenching processes result in no separation of electron transfer product ions. Addition of either SDS or CTAC reduces the quenching rates but allows the detection of product ions surviving up to ca. 100 ms in some cases. The back-reactions are sensitive to a variety of factors including added electrolyte, hydrophobicity of the viologen and its one-electron reduction product, and the charge on the surfactant. The long-lived products can be selectively intercepted by a variety of reagents. In the case of quenching of the palladium porphyrin (2) by methylviologen, the oxidized porphyrin can be reduced by iodide while the reduced viologen can be oxidized via either a colloidal catalyst or reaction with molecular oxygen. These reactions illustrate the possibility for obtaining net chemical conversion in a process whereby both the light-absorbing substrate and the quencher are recycled.

Schmehl, R.H.; Whitten, D.G.

1981-11-12T23:59:59.000Z

353

Filtration and Leach Testing for REDOX Sludge and S-Saltcake Actual Waste Sample Composites  

SciTech Connect (OSTI)

A testing program evaluating actual tank waste was developed in response to Task 4 from the M-12 External Flowsheet Review Team (EFRT) issue response plan.( ) The test program was subdivided into logical increments. The bulk water-insoluble solid wastes that are anticipated to be delivered to the Waste Treatment and Immobilization Plant (WTP) were identified according to type such that the actual waste testing could be targeted to the relevant categories. Under test plan TP-RPP-WTP-467, eight broad waste groupings were defined. Samples available from the 222S archive were identified and obtained for testing. Under this test plan, a waste-testing program was implemented that included: • Homogenizing the archive samples by group as defined in the test plan • Characterizing the homogenized sample groups • Performing parametric leaching testing on each group for compounds of interest • Performing bench-top filtration/leaching tests in the hot cell for each group to simulate filtration and leaching activities if they occurred in the UFP2 vessel of the WTP Pretreatment Facility. This report focuses on filtration/leaching tests performed on two of the eight waste composite samples and follow-on parametric tests to support aluminum leaching results from those tests.

Shimskey, Rick W.; Billing, Justin M.; Buck, Edgar C.; Daniel, Richard C.; Draper, Kathryn E.; Edwards, Matthew K.; Geeting, John GH; Hallen, Richard T.; Jenson, Evan D.; Kozelisky, Anne E.; MacFarlan, Paul J.; Peterson, Reid A.; Snow, Lanee A.; Swoboda, Robert G.

2009-02-20T23:59:59.000Z

354

Fuel cell generator with fuel electrodes that control on-cell fuel reformation  

DOE Patents [OSTI]

A fuel cell for a fuel cell generator including a housing including a gas flow path for receiving a fuel from a fuel source and directing the fuel across the fuel cell. The fuel cell includes an elongate member including opposing first and second ends and defining an interior cathode portion and an exterior anode portion. The interior cathode portion includes an electrode in contact with an oxidant flow path. The exterior anode portion includes an electrode in contact with the fuel in the gas flow path. The anode portion includes a catalyst material for effecting fuel reformation along the fuel cell between the opposing ends. A fuel reformation control layer is applied over the catalyst material for reducing a rate of fuel reformation on the fuel cell. The control layer effects a variable reformation rate along the length of the fuel cell.

Ruka, Roswell J. (Pittsburgh, PA); Basel, Richard A. (Pittsburgh, PA); Zhang, Gong (Murrysville, PA)

2011-10-25T23:59:59.000Z

355

ENERGY FLOWS CLIMATE CHANGE  

E-Print Network [OSTI]

ENERGY FLOWS FORCINGS CLIMATE CHANGE A REALLY TOUGH PROBLEM Stephen E. Schwartz, BNL, 7-20-11 www average temperature 15°C or 59°F #12;ATMOSPHERIC RADIATION Power per area Energy per time per area Unit" temperature to radiative flux. #12;GLOBAL ENERGY BALANCE Global and annual average energy fluxes in watts per

Schwartz, Stephen E.

356

AGN and Cooling Flows  

E-Print Network [OSTI]

For two decades the steady-state cooling-flow model has dominated the literature of cluster and elliptical-galaxy X-ray sources. For ten years this model has been in severe difficulty from a theoretical point of view, and it is now coming under increasing pressure observationally. For two decades the steady-state cooling-flow model has dominated the literature of cluster and elliptical-galaxy X-ray sources. For ten years this model has been in severe difficulty from a theoretical point of view, and it is now coming under increasing pressure observationally. A small number of enthusiasts have argued for a radically different interpretation of the data, but had little impact on prevailing opinion because the unsteady heating picture that they advocate is extremely hard to work out in detail. Here I explain why it is difficult to extract robust observational predictions from the heating picture. Major problems include the variability of the sources, the different ways in which a bi-polar flow can impact on X-ray emission, the weakness of synchrotron emission from sub-relativistic flows, and the sensitivity of synchrotron emission to a magnetic field that is probably highly localized.

James Binney

2001-03-23T23:59:59.000Z

357

Statement of the health problem or issue An inadequate blood flow to the heart muscle (termed cardiac ischemia) often causes  

E-Print Network [OSTI]

of the heart. Severe reductions in blood flow may cause a heart attack (termed myocardial infarction). Following a heart attack, the heart cells can be saved from dying by the restoration of blood flowStatement of the health problem or issue An inadequate blood flow to the heart muscle (termed

MacMillan, Andrew

358

A VLSI Design Flow for Secure Side-Channel Attack Resistant ICs and Ingrid Verbauwhede1,2  

E-Print Network [OSTI]

A VLSI Design Flow for Secure Side-Channel Attack Resistant ICs Kris Tiri1 and Ingrid Verbauwhede1 VLSI design flow to create secure, side-channel attack (SCA) resistant integrated circuits. The design standard cell design flow. We discuss the basis for side-channel attack resistance and adjust the library

Paris-Sud XI, Université de

359

SOFC seal and cell thermal management  

DOE Patents [OSTI]

The solid oxide fuel cell module includes a manifold, a plate, a cathode electrode, a fuel cell and an anode electrode. The manifold includes an air or oxygen inlet in communication with divergent passages above the periphery of the cell which combine to flow the air or oxygen radially or inwardly for reception in the center of the cathode flow field. The latter has interconnects providing circuitous cooling passages in a generally radial outward direction cooling the fuel cell and which interconnects are formed of different thermal conductivity materials for a preferential cooling.

Potnis, Shailesh Vijay (Neenah, WI); Rehg, Timothy Joseph (Huntington Beach, CA)

2011-05-17T23:59:59.000Z

360

Flow-controlled magnetic particle manipulation  

DOE Patents [OSTI]

Inventive methods and apparatus are useful for collecting magnetic materials in one or more magnetic fields and resuspending the particles into a dispersion medium, and optionally repeating collection/resuspension one or more times in the same or a different medium, by controlling the direction and rate of fluid flow through a fluid flow path. The methods provide for contacting derivatized particles with test samples and reagents, removal of excess reagent, washing of magnetic material, and resuspension for analysis, among other uses. The methods are applicable to a wide variety of chemical and biological materials that are susceptible to magnetic labeling, including, for example, cells, viruses, oligonucleotides, proteins, hormones, receptor-ligand complexes, environmental contaminants and the like.

Grate, Jay W [West Richland, WA; Bruckner-Lea, Cynthia J [Richland, WA; Holman, David A [Las Vegas, NV

2011-02-22T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Analysis of flow patterns and flow mechanisms in soils  

E-Print Network [OSTI]

Analysis of flow patterns and flow mechanisms in soils Dissertation Co-directed by the University of paths, varying flow mechanism or changing soil physical properties (stratification). Thus, in stratified-28Jan2010 #12;This doctoral thesis was prepared at the Department of Soil Physics, University

Paris-Sud XI, Université de

362

Fuel cell repeater unit including frame and separator plate  

DOE Patents [OSTI]

An example fuel cell repeater includes a separator plate and a frame establishing at least a portion of a flow path that is operative to communicate fuel to or from at least one fuel cell held by the frame relative to the separator plate. The flow path has a perimeter and any fuel within the perimeter flow across the at least one fuel cell in a first direction. The separator plate, the frame, or both establish at least one conduit positioned outside the flow path perimeter. The conduit is outside of the flow path perimeter and is configured to direct flow in a second, different direction. The conduit is fluidly coupled with the flow path.

Yamanis, Jean; Hawkes, Justin R; Chiapetta, Jr., Louis; Bird, Connie E; Sun, Ellen Y; Croteau, Paul F

2013-11-05T23:59:59.000Z

363

In situ PEM fuel cell water measurements  

SciTech Connect (OSTI)

Efficient PEM (Polymer Electrolyte Membrane) fuel cell performance requires effective water management. To achieve a deeper understanding of water transport and performance issues associated with water management, we have conducted in situ water examinations to help understand the effects of components and operations. High Frequency Resistance (HFR), AC Impedance and Neutron imaging were used to measure water content in operating fuel cells, with various conditions, including current density, relative humidity, inlet flows, flow orientation and variable Gas Diffusion Layer (GDL) properties. High resolution neutron radiography was used to image fuel cells during a variety of conditions. The effect of specific operating conditions, including flow direction (co-flow or counter-flow) was examined. Counter-flow operation was found to result in higher water content than co-flow operation, which correlates to lower membrane resistivity. A variety of cells were used to quantify the membrane water in situ during exposure to saturated gases, during fuel cell operation, and during hydrogen pump operation. The quantitative results show lower membrane water content than previous results suggested.

Borup, Rodney L [Los Alamos National Laboratory; Mukundan, Rangachary [Los Alamos National Laboratory; Davey, John R [Los Alamos National Laboratory; Spendelow, Jacob S [Los Alamos National Laboratory; Hussey, Daniel S [NIST; Jacobson, David L [NIST; Arif, Muhammad [NIST

2009-01-01T23:59:59.000Z

364

Radial flow pulse jet mixer  

DOE Patents [OSTI]

The disclosure provides a pulse jet mixing vessel for mixing a plurality of solid particles. The pulse jet mixing vessel is comprised of a sludge basin, a flow surface surrounding the sludge basin, and a downcoming flow annulus between the flow surface and an inner shroud. The pulse jet mixing vessel is additionally comprised of an upper vessel pressurization volume in fluid communication with the downcoming flow annulus, and an inner shroud surge volume separated from the downcoming flow annulus by the inner shroud. When the solid particles are resting on the sludge basin and a fluid such as water is atop the particles and extending into the downcoming flow annulus and the inner shroud surge volume, mixing occurs by pressurization of the upper vessel pressurization volume, generating an inward radial flow over the flow surface and an upwash jet at the center of the sludge basin.

VanOsdol, John G.

2013-06-25T23:59:59.000Z

365

Corrosion test cell for bipolar plates  

DOE Patents [OSTI]

A corrosion test cell for evaluating corrosion resistance in fuel cell bipolar plates is described. The cell has a transparent or translucent cell body having a pair of identical cell body members that seal against opposite sides of a bipolar plate. The cell includes an anode chamber and an cathode chamber, each on opposite sides of the plate. Each chamber contains a pair of mesh platinum current collectors and a catalyst layer pressed between current collectors and the plate. Each chamber is filled with an electrolyte solution that is replenished with fluid from a much larger electrolyte reservoir. The cell includes gas inlets to each chamber for hydrogen gas and air. As the gases flow into a chamber, they pass along the platinum mesh, through the catalyst layer, and to the bipolar plate. The gas exits the chamber through passageways that provide fluid communication between the anode and cathode chambers and the reservoir, and exits the test cell through an exit port in the reservoir. The flow of gas into the cell produces a constant flow of fresh electrolyte into each chamber. Openings in each cell body is member allow electrodes to enter the cell body and contact the electrolyte in the reservoir therein. During operation, while hydrogen gas is passed into one chamber and air into the other chamber, the cell resistance is measured, which is used to evaluate the corrosion properties of the bipolar plate.

Weisbrod, Kirk R. (Los Alamos, NM)

2002-01-01T23:59:59.000Z

366

The Big Flow  

E-Print Network [OSTI]

The late infall of cold dark matter onto an isolated galaxy, such as our own, produces streams and caustics in its halo. The outer caustics are topological spheres whereas the inner caustics are rings. The self-similar model of galactic halo formation predicts that the caustic ring radii $a_n$ follow the approximate law $a_n \\sim 1/n$. In a study of 32 extended and well-measured external galactic rotation curves evidence was found for this law. In the case of the Milky Way, the locations of eight sharp rises in the rotation curve fit the prediction of the self-similar model at the 3% level. Moreover, a triangular feature in the IRAS map of the galactic plane is consistent with the imprint of a ring caustic upon the baryonic matter. These observations imply that the dark matter in our neighborhood is dominated by a single flow. Estimates of that flow's density and velocity vector are given.

P. Sikivie

2001-12-04T23:59:59.000Z

367

Structural power flow measurement  

SciTech Connect (OSTI)

Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

Falter, K.J.; Keltie, R.F.

1988-12-01T23:59:59.000Z

368

Fuel cell system combustor  

DOE Patents [OSTI]

A fuel cell system including a fuel reformer heated by a catalytic combustor fired by anode and cathode effluents. The combustor includes a turbulator section at its input end for intimately mixing the anode and cathode effluents before they contact the combustors primary catalyst bed. The turbulator comprises at least one porous bed of mixing media that provides a tortuous path therethrough for creating turbulent flow and intimate mixing of the anode and cathode effluents therein.

Pettit, William Henry (Rochester, NY)

2001-01-01T23:59:59.000Z

369

Neutrino Factory Mercury Flow Loop  

E-Print Network [OSTI]

Neutrino Factory Mercury Flow Loop V. GravesV. Graves C. Caldwell IDS-NF Videoconference March 9, 2010 #12;Flow Loop Review · 1 cm dia nozzle, 20 m/s jet requires 1.57 liter/sec mercury flow (94 2 liter/min 24 9 gpm)mercury flow (94.2 liter/min, 24.9 gpm). · MERIT experiment showed that a pump

McDonald, Kirk

370

Orifice flow measurement uncertainty  

SciTech Connect (OSTI)

A computer program is now available from Union Carbide that evaluates the total flow uncertainty of orifice flowmeter systems. Tolerance values for every component in the system and the sensitivity of the measured flowrate to each component can be established using historical data and published hardware specifications. Knowing the tolerance and sensitivity values, a total measurement uncertainty can be estimated with a 95% confidence level. This computer program provides a powerful design tool to ensure correct component matching and total metering system optimization.

Samples, C.R.

1984-04-01T23:59:59.000Z

371

Convective heat flow probe  

DOE Patents [OSTI]

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

Dunn, J.C.; Hardee, H.C.; Striker, R.P.

1984-01-09T23:59:59.000Z

372

Spectroscopic study of a Cu/CeO{sub 2} catalyst subjected to redox treatments in carbon monoxide and oxygen  

SciTech Connect (OSTI)

Redox processes induced by interaction of a calcined Cu/CeO{sub 2} catalyst with CO and reoxidation with O{sub 2} have been investigated by CO-TPR, EPR, FTIR of adsorbed CO, and XPS. The initial calcined samples shows the presence of dispersed Cu{sup 2+} species, which give rise in the EPR spectrum to signals due to isolated entities, a somewhat more aggregated Cu{sup 2+}-containing phase, and copper ionic pairs, in coexistence with an EPR-silent CuO-type phase, revealed by XPS. A significant reduction of copper is produced already by contact with CO at room temperature, EPR results suggesting that reducibility of Cu{sup 2+} species decreases with their aggregation degree. Simultaneously, the ceria surface is also reduced by this interaction, copper acting as a strong promoter of this process. A singular consequence of the synergistic reduction of both components is observed by subjecting the catalyst to CO at T{sub r} {ge} 473 K, at which the CO adsorption capability of copper is apparently suppressed, in view of the absence of copper carbonyls in the FTIR spectrum. This is attributed to the establishment of electronic interactions between reduced ceria and small metallic copper particles generated by the reduction process. Contact of the CO-reduced sample with O{sub 2} at room or higher temperature produces an important reoxidation of both copper and ceria, revealed by FTIR and EPR. The synergetic effects between copper and ceria in the reduction process and the easy reoxidation of deeply reduced ceria are thought to be crucial to explaining the high catalytic activity shown by this system for CO oxidation.

Martinez-Arias, A.; Fernandez-Garcia, M.; Soria, J.; Conesa, J.C. [CSIC, Madrid (Spain). Instituto de Catalisis y Petroleoquimica] [CSIC, Madrid (Spain). Instituto de Catalisis y Petroleoquimica

1999-03-10T23:59:59.000Z

373

Redox Exchange Induced MnO2 Nanoparticle Enrichment in Poly(3,4-ethylenedioxythiophene) Nanowires for Electrochemical Energy Storage  

SciTech Connect (OSTI)

MnO{sub 2} nanoparticle enriched poly(3,4-ethylenedioxythiophene) (PEDOT) nanowires are fabricated by simply soaking the PEDOT nanowires in potassium permanganate (KMnO{sub 4}) solution. The structures of these MnO{sub 2} nanoparticle enriched PEDOT nanowires are characterized by SEM and TEM, which show that the MnO{sub 2} nanoparticles have uniform sizes and are finely dispersed in the PEDOT matrix. The chemical constituents and bonding of these composite nanowires are characterized by energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, and infrared spectroscopy, which indicate that the formation and dispersion of these MnO{sub 2} nanoparticles into the nanoscale pores of the PEDOT nanowires are most likely triggered by the reduction of KMnO{sub 4} via the redox exchange of permanganate ions with the functional group on PEDOT. Varying the concentrations of KMnO{sub 4} and the reaction time controls the loading amount and size of the MnO{sub 2} nanoparticles. Cyclic voltammetry and galvanostatic charge?discharge are used to characterize the electrochemical properties of these MnO{sub 2} nanoparticle loaded PEDOT nanowires. Due to their extremely high exposed surface area with nanosizes, the pristine MnO{sub 2} nanoparticles in these MnO{sub 2} nanoparticle enriched PEDOT nanowires show very high specific capacitance (410 F/g) as the supercapacitor electrode materials as well as high Li+ storage capacity (300 mAh/g) as cathode materials of Li ion battery, which boost the energy storage capacity of PEDOT nanowires to 4 times without causing excessive volume expansion in the polymer. The highly conductive and porous PEDOT matrix facilitates fast charge/discharge of the MnO{sub 2} nanoparticles and prevents them from agglomerating. These synergic properties enable the MnO{sub 2} nanoparticle enriched PEDOT nanowires to be promising electrode materials for supercapacitors and lithium ion batteries.

Liu, R; Duay, Jonathon; Lee, Sang Bok

2010-01-01T23:59:59.000Z

374

Viologen (2+/1+) and viologen(1+/0) electron-self-exchange reactions in a redox polymer  

SciTech Connect (OSTI)

An analysis is given of the electron-self-exchange reactions responsible for the steady-state redox conductivity of thin films of the electropolymerized monomer N,N{prime}-bis(3-pyrrol-1-yl-propyl)-4,4{prime}-bipyridinium tetrafluoroborate, sandwiched between two electrodes. Concentration-gradient-driven electron self-exchange in the liquid-acetonitrile-bathed viologen(2+/1+) mixed-valent state of this polymer, k{sub ex} = 8 {times} 10{sup 3} M{sup {minus}1}s{sup {minus}1}, is much slower than that for the viologen (1+/0) mixed-valent state, k{sub ek} = 1.6 {times} 10{sup 5} M{sup {minus}1} s{sup {minus}1}, which has a smaller activation barrier. Neither self-exchange reaction responds to use of alternative counteranions except that both rates decrease in polymer containing tosylate counterions. The rate constant found for the electrical-gradient-driven viologen (1+/0) electron self-exchange, k{sub ex} = 1.1 {times} 10{sup 5} M{sup {minus}1} s{sup {minus}1}, observed in dry, N{sub 2}-bathed polymer where ClO{sub 4}{sup {minus}} counterion mobility is quenched, is nearly the same as the acetonitrile-bathed value. The rate constants appear to be dominated by characteristics of the polymer phase rather than the bathing environment of the polymer. Estimates are made of the counteranion diffusivity in acetonitrile-bathed films and of how it effects transient electron transport measurements.

Dalton, E.F.; Murray, R.W. (Univ. of North Carolina, Chapel Hill (United States))

1991-08-08T23:59:59.000Z

375

Numerical Investigations of Magnetohydrodynamic Hypersonic Flows.  

E-Print Network [OSTI]

??Numerical simulations of magnetohydrodynamic (MHD) hypersonic flow are presented for both laminar and turbulent flow over a cylinder and flow entering a scramjet inlet. ANSYS… (more)

Guarendi, Andrew N

2013-01-01T23:59:59.000Z

376

Original article Flow and passage rate studies at the ileal level in the  

E-Print Network [OSTI]

based mainly on lucerne meal. Flow and transit measurements were carried out using two particulate markers : ytterbium (Yb) fixed on lucerne meal cell-walls by soaking, and chromium (Cr) fixed

Boyer, Edmond

377

Generator configuration for solid oxide fuel cells  

DOE Patents [OSTI]

Disclosed are improvements in a solid oxide fuel cell generator 1 having a multiplicity of electrically connected solid oxide fuel cells 2, where a fuel gas is passed over one side of said cells and an oxygen-containing gas is passed over the other side of said cells resulting in the generation of heat and electricity. The improvements comprise arranging the cells in the configuration of a circle, a spiral, or folded rows within a cylindrical generator, and modifying the flow rate, oxygen concentration, and/or temperature of the oxygen-containing gases that flow to those cells that are at the periphery of the generator relative to those cells that are at the center of the generator. In these ways, a more uniform temperature is obtained throughout the generator.

Reichner, Philip (Plum Boro, PA)

1989-01-01T23:59:59.000Z

378

UZ Flow Models and Submodels  

SciTech Connect (OSTI)

The purpose of this report is to document the unsaturated zone (UZ) flow models and submodels, as well as the flow fields that have been generated using the UZ flow model(s) of Yucca Mountain, Nevada. In this report, the term ''UZ model'' refers to the UZ flow model and the several submodels, which include tracer transport, temperature or ambient geothermal, pneumatic or gas flow, and geochemistry (chloride, calcite, and strontium) submodels. The term UZ flow model refers to the three-dimensional models used for calibration and simulation of UZ flow fields. This work was planned in the ''Technical Work Plan (TWP) for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Section 1.2.7). The table of included Features, Events, and Processes (FEPs), Table 6.2-11, is different from the list of included FEPs assigned to this report in the ''Technical Work Plan for: Unsaturated Zone Flow Analysis and Model Report Integration'' (BSC 2004 [DIRS 169654], Table 2.1.5-1), as discussed in Section 6.2.6. The UZ model has revised, updated, and enhanced the previous UZ model (BSC 2001 [DIRS 158726]) by incorporating the repository design with new grids, recalibration of property sets, and more comprehensive validation effort. The flow fields describe fracture-fracture, matrix-matrix, and fracture-matrix liquid flow rates, and their spatial distributions as well as moisture conditions in the UZ system. These three-dimensional UZ flow fields are used directly by Total System Performance Assessment (TSPA). The model and submodels evaluate important hydrogeologic processes in the UZ as well as geochemistry and geothermal conditions. These provide the necessary framework to test hypotheses of flow and transport at different scales, and predict flow and transport behavior under a variety of climatic conditions. In addition, the limitations of the UZ model are discussed in Section 8.11.

Y. Wu

2004-11-01T23:59:59.000Z

379

Hematopoietic Stem Cells Differentiate Through A Multipotent Progenitor Before Generating All Mature Hematopoietic Cells  

E-Print Network [OSTI]

FlowJo analysis software (Ashland, OR). Cell populationsJose, CA). Flowjo Software (Ashland, OR) was used for dataJose, CA). Flowjo Software (Ashland, OR) was used for data

Boyer, Scott Wilson

2013-01-01T23:59:59.000Z

380

Detecting multiple cell-secreted cytokines from the same aptamer-functionalized electrode  

E-Print Network [OSTI]

with anthraquinone (AQ) and methylene blue (MB) redox reporters respectively. Random immobilization of two aptamer

Ferrara, Katherine W.

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Similarity of the Surface Reactivity of Hydrous Ferric Oxide and Hematite: Sorption and Redox of U(VI) and Fe(II)  

SciTech Connect (OSTI)

Hydrous Ferric Oxide (HFO) vs. Hematite--Thermodynamically distinctive bulk phases, but the surfaces could be similar due to hydration of the interface. Hypothesis--The surface of HFO is energetically similar to the surface of hematite. Objective--Compare the reactions of HFO and hematite with U(VI) and Fe(II). Experimental--The reactions of interests were (1) preparation of sub-micron hematite, (2) sorption of U(VI), and (3) redox of U(VI) and Fe(II) with HFO or hematite.

Je-Hun Jang; Dempsey, Brian A.; Burgos, William D.; Yeh, George; Roden, Eric

2004-03-17T23:59:59.000Z

382

Aqueous Transition Metal Cations as Impurities in a Wide Gap Oxide: The Cu^2+/Cu^1+ and Ag^2+/Ag^1+ Redox Couples Revisited  

E-Print Network [OSTI]

of 10ps. The longitudinal relaxation is more than a magnitude faster. Results and analysis Gas-phase Table 1 lists the calculated M-O bond lengths in the four gas-phase complexes we have investigated (see fig. 1). One can see that for the same number... containing a fraction of Hartree-Fock exchange. These calculations make use of recent progress in DFTMD technology enabling us to include sp core polarization and Hartree-Fock exchange in condensed phase model systems. Keywords Aqueous redox chemistry...

Liu, Xiandong; Cheng, Jun; Sprik, Michiel

2014-11-11T23:59:59.000Z

383

Fluid flow monitoring device  

DOE Patents [OSTI]

A flow meter and temperature measuring device are described comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips. 7 figures.

McKay, M.D.; Sweeney, C.E.; Spangler, B.S. Jr.

1993-11-30T23:59:59.000Z

384

Fluid flow monitoring device  

DOE Patents [OSTI]

A flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.

McKay, Mark D. (1426 Socastee Dr., North Augusta, SC 29841); Sweeney, Chad E. (3600 Westhampton Dr., Martinez, GA 30907-3036); Spangler, Jr., B. Samuel (2715 Margate Dr., Augusta, GA 30909)

1993-01-01T23:59:59.000Z

385

Radial flow heat exchanger  

DOE Patents [OSTI]

A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

Valenzuela, Javier (Hanover, NH)

2001-01-01T23:59:59.000Z

386

Annular flow diverter valve  

DOE Patents [OSTI]

A valve for diverting flow from the center of two concentric tubes to the annulus between the tubes or, operating in the reverse direction, for mixing fluids from concentric tubes into a common tube and for controlling the volume ratio of said flow consists of a toroidal baffle disposed in sliding engagement with the interior of the inner tube downstream of a plurality of ports in the inner tube, a plurality of gates in sliding engagement with the interior of the inner tube attached to the baffle for movement therewith, a servomotor having a bullet-shaped plug on the downstream end thereof, and drive rods connecting the servomotor to the toroidal baffle, the servomotor thereby being adapted to move the baffle into mating engagement with the bullet-shaped plug and simultaneously move the gates away from the ports in the inner tube and to move the baffle away from the bullet-shaped plug and simultaneously move the gates to cover the ports in the inner tube.

Rider, Robert L. (Walkersville, MD)

1980-01-01T23:59:59.000Z

387

Brazed bipolar plates for PEM fuel cells  

DOE Patents [OSTI]

A liquid-cooled, bipolar plate separating adjacent cells of a PEM fuel cell comprises corrosion-resistant metal sheets brazed together so as to provide a passage between the sheets through which a dielectric coolant flows. The brazement comprises a metal which is substantially insoluble in the coolant. 6 figs.

Neutzler, J.K.

1998-07-07T23:59:59.000Z

388

Brazed bipolar plates for PEM fuel cells  

DOE Patents [OSTI]

A liquid-cooled, bipolar plate separating adjacent cells of a PEM fuel cell comprising corrosion-resistant metal sheets brazed together so as to provide a passage between the sheets through which a dielectric coolant flows. The brazement comprises a metal which is substantially insoluble in the coolant.

Neutzler, Jay Kevin (Rochester, NY)

1998-01-01T23:59:59.000Z

389

Poly(pyridine)ruthenium(II)-photoinduced redox reactions of bipyridinium cations, poly(pyridine)rhodium complexes, and osmium ammines  

SciTech Connect (OSTI)

The quenching of *RuL/sub 3//sup 2 +/ (L is a 2,2'-bipyridine or 1,10-phenanthroline derivative) emissions by three classes of oxidants Q has been examined. The results are discussed in terms of the Marcus electron-transfer model recast in a preequilibrium formalism. Substituted bipyridinium cations (methyl viologen and related compounds) undergo thermodynamically favorable reduction with a driving force ranging from 0.1 to 0.7 eV and rate constants in the range (0.4-2.0) x 10/sup 9/ M/sup -1/s/sup -1/, consistent with a diffusion rate constant of 2.0 x 10/sup 9/ M/sup -1/s/sup -1/ and an exchange rate constant of approx.10/sup 6/ M/sup -1/s/sup -1/ for the Q-Q couples. The yields of the separated redox products RuL/sub 3//sup 3 +/ and Q/sup -/ (typically 0.1 mol einstein/sup -1/ per quenching act) require K/sub 30/, the ''intramolecular'' back-reaction rate constant (to re-form ground-state RuL/sub 3//sup 2 +/ and Q), to be (2-4) x 10/sup 10/ s/sup -1/. Since K/sub 30/ increases weakly with driving force in this series, there is no evidence for inverted behavior despite the fact the ..delta..G/sup 0//sub 30/ is approx.-2 eV. With Q = Rh(4,4'-(CH/sub 3/)/sub 2/bpy)/sub 3//sup 3 +/, the quenching rate constants, k/sub q/ = (0.001-1.0) x 10/sup 9/ M/sup -1/s/sup -1/, exhibit a great sensitivity to the reducing power of *RuL/sub 3//sup 2 +/ and have been fitted to k/sub 11/ approx. = 2 x 10/sup 9/ M/sup -1/s/sup -1/ and E/sup 0//sub Q,Q/sup -// = -0.97 V for the RhL/sub 3//sup 3 +/-RhL/sub 3//sup 2 +/ couple. This E/sup 0/ value is strikingly similar to that (-0.9 V vs. aqueous SCE) obtained via cyclic voltammetry in acetonitrile. The cyclic voltammetry of the RhL/sub 3//sup 3 +/ complexes in water has been reexamined, and it is concluded that the irreversibility observed is due to ligand loss from rhodium(I).

Creutz, C.; Keller, A.D.; Sutin, N.; Zipp, A.P.

1982-06-30T23:59:59.000Z

390

Reduction of a Redox-Active Ligand Drives Switching in a Cu(I) Pseudorotaxane by a Bimolecular Mechanism  

SciTech Connect (OSTI)

The reduction of a redox-active ligand is shown to drive reversible switching of a Cu(I) [2]pseudorotaxane ([2]PR{sup 2+}) into the reduced [3]pseudorotaxane ([3]PR{sup 2+}) by a bimolecular mechanism. The unreduced pseudorotaxanes [2]PR{sup 2+} and [3]PR{sup 2+} are initially self-assembled from the binucleating ligand, 3,6-bis(5-methyl-2-pyridine)-1,2,4,5-tetrazine (Me2BPTZ), and a preformed copper-macrocycle moiety (Cu-M{sup 2+}) based on 1,10-phenanthroline. X-ray crystallography revealed a syn geometry of the [3]PR{sup 2+}. The UV-vis-NIR spectra show low-energy metal-to-ligand charge-transfer transitions that red shift from 808 nm for [2]PR{sup 2+} to 1088 nm for [3]PR{sup 2+}. Quantitative analysis of the UV-vis-NIR titration shows the stepwise formation constants to be K{sub 1} = 8.9 x 10{sup 8} M{sup -1} and K{sub 2} = 3.1 x 10{sup 6} M{sup -1}, indicative of negative cooperativity. The cyclic voltammetry (CV) and coulometry of Me{sub 2}BPTZ, [2]PR{sup 2+}, and [3]PR{sup 2+} shows the one-electron reductions at E{sub 1/2} = -0.96, -0.65, and -0.285 V, respectively, to be stabilized in a stepwise manner by each Cu{sup 2+} ion. CVs of [2]PR{sup 2+} show changes with scan rate consistent with an EC mechanism of supramolecular disproportionation after reduction: [2]PR{sup 0} + [2]PR{sup 2+} = [3]PR{sup 2+} + Me{sub 2}BPTZ{sup 0} (K*{sub D}, k{sub d}). UV-vis-NIR spectroelectrochemistry was used to confirm the 1:1 product stoichiometry for [3]PR{sup 2+}:Me{sub 2}BPTZ. The driving force ({Delta}G*{sub D} = -5.1 kcal mol{sup -1}) for the reaction is based on the enhanced stability of the reduced [3]PR{sup 2+} over reduced [2]PR{sup 0} by 365 mV (8.4 kcal mol{sup -1}). Digital simulations of the CVs are consistent with a bimolecular pathway (k{sub d} = 12,000 s{sup -1} M{sup -1}). Confirmation of the mechanism provides a basis to extend this new switching modality to molecular machines.

McNitt, Kristy A.; Parimal, Kumar; Share, Andrew I.; Fahrenbach, Albert C.; Witlicki, Edward H.; Pink, Maren; Bediako, D. Kwabena; Plaisier, Christina L.; Le, Nga; Heeringa, Lee P.; Vander Griend, Douglas A.; Flood, Amar H.; (Calvin); (Indiana)

2009-04-02T23:59:59.000Z

391

Managed by UT-Battelle for the Department of Energy  

E-Print Network [OSTI]

' Personalized History of PEM Fuel Cells We May Recapitulate This for RFBs Catalysis TestSystem · Small SingleManaged by UT-Battelle for the Department of Energy Transitioning From Fuel Cells to Redox Flow fuel cells ­ Polarization curves, ASR, segmented cells · This is NOT the way battery people test! #12

392

Active combustion flow modulation valve  

DOE Patents [OSTI]

A flow modulation valve has a slidably translating hollow armature with at least one energizable coil wound around and fixably attached to the hollow armature. The energizable coil or coils are influenced by at least one permanent magnet surrounding the hollow armature and supported by an outer casing. Lorentz forces on the energizable coils which are translated to the hollow armature, increase or decrease the flow area to provide flow throttling action. The extent of hollow armature translation depends on the value of current supplied and the direction of translation depends on the direction of current flow. The compact nature of the flow modulation valve combined with the high forces afforded by the actuator design provide a flow modulation valve which is highly responsive to high-rate input control signals.

Hensel, John Peter; Black, Nathaniel; Thorton, Jimmy Dean; Vipperman, Jeffrey Stuart; Lambeth, David N; Clark, William W

2013-09-24T23:59:59.000Z

393

Solid oxide fuel cell generator  

DOE Patents [OSTI]

A solid oxide fuel cell generator has a pair of spaced apart tubesheets in a housing. At least two intermediate barrier walls are between the tubesheets and define a generator chamber between two intermediate buffer chambers. An array of fuel cells have tubes with open ends engaging the tubesheets. Tubular, axially elongated electrochemical cells are supported on the tubes in the generator chamber. Fuel gas and oxidant gas are preheated in the intermediate chambers by the gases flowing on the other side of the tubes. Gas leakage around the tubes through the tubesheets is permitted. The buffer chambers reentrain the leaked fuel gas for reintroduction to the generator chamber.

Draper, R.; George, R.A.; Shockling, L.A.

1993-04-06T23:59:59.000Z

394

[Unsegmented continuous-flow sample processing and electrochemical detection of gaseous species]. Final report, March 1, 1985--February 28, 1991  

SciTech Connect (OSTI)

Goals were a continuous-flow, unsegmented, all-gas carrier and/or a segmented liquid/gas interface system for sample introduction and transport to detection/determination point; a regenerable electrode probe base on redox reactions of Fe(II) and Fe(III) complexes with 1, 10-phenanthroline and related ligands; and amperometric/coulometric current measurements providing analyte signals. Gases to be detected included NO{sub x} and SO{sub 2}. This report is divided into 3 parts: preparation of new ligands of 1,10-phenanthroline family; glassy carbon surfaces coated with polymeric films prepared from monomeric units of tris[5-amino-1,10-phenanthroline]iron(II); and sulfite oxidase/hexacyanoferrate modified C paste electrode.

Mottola, H.A.

1991-12-31T23:59:59.000Z

395

Differential probes aid flow measurement  

SciTech Connect (OSTI)

Nonconstricting differential pressure flow probes which help solve the problems of clogging, wear, and pressure loss at the Seawater Filtration Facility in Saudi Arabia are described. Treated seawater is pumped into oil-bearing formations for secondary recovery. Figures showing principle of operation for probes, installation schematic and long-term accuracy results (flow probes vs. orifice meters) are presented. The new diamond-shaped design flow sensor offers accurate flow measurement with low permanent pressure loss, which translates into cost savings for the operator.

Mesnard, D.R.

1982-07-01T23:59:59.000Z

396

Viscoelastic transient of confined Red Blood Cells  

E-Print Network [OSTI]

The unique ability of a red blood cell to flow through extremely small microcapillaries depends on the viscoelastic properties of its membrane. Here, we study in vitro the response time upon flow startup exhibited by red blood cells confined into microchannels. We show that the characteristic transient time depends on the imposed flow strength, and that such a dependence gives access to both the effective viscosity and the elastic modulus controlling the temporal response of red cells. A simple theoretical analysis of our experimental data, validated by numerical simulations, further allows us to compute an estimate for the two-dimensional membrane viscosity of red blood cells, $\\eta_{mem}^{2D}\\sim 10^{-7}$ N$\\cdot$s$\\cdot$m$^{-1}$. By comparing our results with those from previous studies, we discuss and clarify the origin of the discrepancies found in the literature regarding the determination of $\\eta_{mem}^{2D}$, and reconcile seemingly conflicting conclusions from previous works.

Gaël Prado; Alexander Farutin; Chaouqi Misbah; Lionel Bureau

2014-09-17T23:59:59.000Z

397

Comparative Study on Redox Properties of Nanosized CeO2 and CuO/Ce2 Under CO/O2  

SciTech Connect (OSTI)

Nanosized CeO{sub 2} and CuO/CeO{sub 2} samples, active for CO-PROX or related processes were comparatively examined by O{sub 2} probe electron paramagnetic resonance and in situ Raman and X-ray diffraction techniques. Their behavior toward CO reduction, as well as the oxygen-handling properties of the CO-reduced samples, was explored. An appreciable reduction of the ceria bulk was detected on treatment under CO at 473 K. On the basis of the analysis of the evolution of different oxygen-derived species (superoxide, peroxide, O-) on low-temperature (77-300 K) oxygen chemisorption on the CO-reduced samples, a general picture of the redox properties of the samples is presented. Results demonstrate that the presence of copper promotes completion of the redox cycle under CO/O{sub 2} by favoring both ceria reduction and oxidation. This can be relevant to explaining the remarkable oxidation activity and synergetic effects observed for catalysts combining CuO and CeO{sub 2}.

Martinez-Arias,A.; Gamarra, D.; Fernandez-Garcia, M.; Wang, X.; Hanson, J.; Rodriguez, J.

2006-01-01T23:59:59.000Z

398

E-Print Network 3.0 - adult myogenic cells Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

OF WISCONSIN CURRICULUM VITAE Summary: , California Thesis title: Numerical Simulation of Sickle Cell Blood Flow in the Transverse Arteriole... ,048 (Direct) Invited Lectures and...

399

Section 11: Interfacial flows 1 Section 11: Interfacial flows  

E-Print Network [OSTI]

Abstract 15:10 ­ 15:30: Martin Lübke, Olaf Wünsch (Universität Kassel): Two-Phase Flow in Single- Screw Extruders Abstract S11.4: Capillary Flows Wed, 16:00­18:00 Chair: Dieter Bothe S1|03­123 16:00 ­ 16:20: K

Kohlenbach, Ulrich

400

Analysis of flow patterns and flow mechanisms in soils  

E-Print Network [OSTI]

Analysis of flow patterns and flow mechanisms in soils Dissertation Co-directed by the University mechanism or changing soil physical properties (stratification). Thus, in stratified soil, we restricted was prepared at the Department of Soil Physics, University of Bayreuth, and at the Hydrogeological Laboratory

Avignon et des Pays de Vaucluse, Université de

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

High Average Power Laser Gain Medium With Low Optical Distortion Using A Transverse Flowing Liquid Host  

DOE Patents [OSTI]

A high average power, low optical distortion laser gain media is based on a flowing liquid media. A diode laser pumping device with tailored irradiance excites the laser active atom, ion or molecule within the liquid media. A laser active component of the liquid media exhibits energy storage times longer than or comparable to the thermal optical response time of the liquid. A circulation system that provides a closed loop for mixing and circulating the lasing liquid into and out of the optical cavity includes a pump, a diffuser, and a heat exchanger. A liquid flow gain cell includes flow straighteners and flow channel compression.

Comaskey, Brian J. (Walnut Creek, CA); Ault, Earl R. (Livermore, CA); Kuklo, Thomas C. (Oakdale, CA)

2005-07-05T23:59:59.000Z

402

Effect of flow fluctuations and nonflow on elliptic flow methods  

SciTech Connect (OSTI)

We discuss how the different estimates of elliptic flow are influenced by flow fluctuations and nonflow effects. It is explained why the event-plane method yields estimates between the two-particle correlation methods and the multiparticle correlation methods. It is argued that nonflow effects and fluctuations cannot be disentangled without other assumptions. However, we provide equations where, with reasonable assumptions about fluctuations and nonflow, all measured values of elliptic flow converge to a unique mean v_2,PP elliptic flow in the participant plane and, with a Gaussian assumption on eccentricity fluctuations, can be converted to the mean v_2,RP in the reaction plane. Thus, the 20percent spread in observed elliptic flow measurements from different analysis methods is no longer mysterious.

Ollitrault, Jean-Yves; Poskanzer, Arthur M.; Voloshin, Sergei A.

2009-04-16T23:59:59.000Z

403

Wavelet-based Adaptive Techniques Applied to Turbulent Hypersonic Scramjet Intake Flows  

E-Print Network [OSTI]

The simulation of hypersonic flows is computationally demanding due to large gradients of the flow variables caused by strong shock waves and thick boundary or shear layers. The resolution of those gradients imposes the use of extremely small cells in the respective regions. Taking turbulence into account intensives the variation in scales even more. Furthermore, hypersonic flows have been shown to be extremely grid sensitive. For the simulation of three-dimensional configurations of engineering applications, this results in a huge amount of cells and prohibitive computational time. Therefore, modern adaptive techniques can provide a gain with respect to computational costs and accuracy, allowing the generation of locally highly resolved flow regions where they are needed and retaining an otherwise smooth distribution. An h-adaptive technique based on wavelets is employed for the solution of hypersonic flows. The compressible Reynolds averaged Navier-Stokes equations are solved using a differential Reynolds s...

Frauholz, Sarah; Reinartz, Birgit U; Müller, Siegfried; Behr, Marek

2013-01-01T23:59:59.000Z

404

Advanced Flow Battery Electrodes: Low-cost, High-Performance 50-Year Electrode  

SciTech Connect (OSTI)

GRIDS Project: Primus Power is developing zinc-based, rechargeable liquid flow batteries that could produce substantially more energy at lower cost than conventional batteries. A flow battery is similar to a conventional battery, except instead of storing its energy inside the cell it stores that energy for future use in chemicals that are kept in tanks that sit outside the cell. One of the most costly components in a flow battery is the electrode, where the electrochemical reactions actually occur. Primus Power is investigating and developing mixed-metal materials for their electrodes that could ultimately reduce the lifetime cost of flow batteries because they are more durable and long-lasting than electrodes found in traditional batteries. Using these electrodes, Primus Power’s flow batteries can be grouped together into robust, containerized storage pods for use by utilities, renewable energy developers, businesses, and campuses.

None

2010-09-01T23:59:59.000Z

405

Platinum-CatalyzedOxidations of Organic Compounds by Ferric Sulfate: Use of a Redox Fuel Cell to Mediate Complete Oxidation of  

E-Print Network [OSTI]

and complete oxidation of ethylene glycolto carbon dioxide under mild conditionsusing dioxy- gen operating with ethylene glycol as fuel (5, 10-12). METHODS Materials. Methanol, ethanol, and ethylene catalyst was determined to be 3.3 X mol/g Pt (6.44% dispersion) by alternating titration with hydrogen

Prentiss, Mara

406

Sample handling for kinetics and molecular assembly in flow cytometry  

SciTech Connect (OSTI)

Flow cytometry discriminates particle associated fluorescence from the fluorescence of the surrounding medium. It permits assemblies of macromolecular complexes on beads or cells to be detected in real-time with precision and specificity. The authors have investigated two types of robust sample handling systems which provide sub-second resolution and high throughput: (1) mixers which use stepper-motor driven syringes to initiate chemical reactions in msec time frames; and (2) flow injection controllers with valves and automated syringes used in chemical process control. In the former system, the authors used fast valves to overcome the disparity between mixing 100 {micro}ls of sample in 100 msecs and delivering sample to a flow cytometer at 1 {micro}l/sec. Particles were detected within 100 msec after mixing, but turbulence was created which lasted for 1 sec after injection of the sample into the flow cytometer. They used optical criteria to discriminate particles which were out of alignment due to the turbulent flow. Complex sample handling protocols involving multiple mixing steps and sample dilution have also been achieved. With the latter system they were able to automate sample handling and delivery with intervals of a few seconds. The authors used a fluidic approach to defeat turbulence caused by sample introduction. By controlling both sheath and sample with individual syringes, the period of turbulence was reduced to {approximately} 200 msecs. Automated sample handling and sub-second resolution should permit broad analytical and diagnostic applications of flow cytometry.

Sklar, L.A. [Los Alamos National Lab., NM (United States). National Flow Cytometry Resource]|[Univ. of New Mexico, Albuquerque, NM (United States). School of Medicine; Seamer, L.C.; Kuckuck, F.; Prossnitz, E.; Edwards, B. [Univ. of New Mexico, Albuquerque, NM (United States). School of Medicine; Posner, G. [Northern Arizona Univ., Flagstaff, AZ (United States). Dept. of Chemistry

1998-07-01T23:59:59.000Z

407

DISCONTINUOUS GALERKIN BGK METHOD FOR VISCOUS FLOW EQUATIONS: ONE-DIMENSIONAL SYSTEMS  

E-Print Network [OSTI]

the Riemann solution in the flux construction at a cell interface, the physics of wave propagation that a discontinuous flow distribution is introduced at a cell interface. The artificial kinematic numerical dissi Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (makxu@ust.hk). 1941 #12

Xu, Kun

408

Integrated Adaptive Numerical Methods for Transient Two-phase Flow in Heterogeneous Porous Media  

E-Print Network [OSTI]

remediation, magma flow in the earth crust and water management in porous electrodes of PEM fuel cells in fuel cells. This thesis presents a set of algorithms that are integrated efficiently to achieve the transport equations which elim- inates unnecessary and costly solution of the implicit pressure

Victoria, University of

409

Water Visualization and Flooding in Polymer Electrolyte Membrane Fuel Cells  

E-Print Network [OSTI]

Water Visualization and Flooding in Polymer Electrolyte Membrane Fuel Cells Brian Holsclaw West- 2H2O e- e- e- e- e- H+ H+ H+ Membrane + Schematic of a PEMFC Operation #12;PFR PEM Fuel Cell Plug for membrane Two-phase flow in channels #12;CSTR PEM Fuel Cell Continuous Stirred-Tank Reactor (CSTR) "Perfect

Petta, Jason

410

Direct Methanol Fuel Cell Experimental and Model Validation Study  

E-Print Network [OSTI]

Direct Methanol Fuel Cell Experimental and Model Validation Study M. Mench, J. Scott, S. Thynell boundary Fuel cell performance Current density distribution measurements Conclusions #12;3 Method, flow rate, species inlet and fuel cell temperature, and humidity. Transparent polycarbonate windows

Wang, Chao-Yang

411

Analysis of Real World Fuel Cell Degradation (Presentation)  

SciTech Connect (OSTI)

Presentation about the National Renewable Energy Laboratory's Hydrogen Secure Data Center and its work with fuel cell vehicles, fuel cell early market demonstrations, and fuel cell bus demonstrations. This presentation includes results of composite data products and a summary of the analysis objectives and data flow for the projects.

Kurtz, J.; Wipke, K.; Sprik, S.; Ramsden, T.

2009-12-08T23:59:59.000Z

412

MICROFLUIDIC DEVICE WITH INTEGRATED ANTIBODY ARRAYS FOR CELL SIGNALLING  

E-Print Network [OSTI]

MICROFLUIDIC DEVICE WITH INTEGRATED ANTIBODY ARRAYS FOR CELL SIGNALLING ANALYSIS J. El-Ali1 , S we present the integration of protein arrays with a microfluidic device for analysis of cell a microfluidic segmented flow device that could achieve rapid stimulus and lysis of cells [1][2]. The device had

413

Water Management in Polymer Electrolyte Membrane (PEM) Fuel Cells  

E-Print Network [OSTI]

Water Management in Polymer Electrolyte Membrane (PEM) Fuel Cells Catherine Chan & Lauren Isbell objectives Important variables that lead to results Conclusion #12;Basic Operation of a PEM Fuel Cell fuel cell? A flow channel? The importance of water management Experimental setup and methods Project

Petta, Jason

414

Network Flow Optimization under Uncertainty  

E-Print Network [OSTI]

Network model in words Minimize the cost of satisfying demands for electric energy By: imports, exports and electricity Subject to: conservation of energy flows (net after losses), lower and upper bounds on flows is a reactive approach: how would the optimal solution have changed if I'd only known? · Proactive approaches

Tesfatsion, Leigh

415

Vertical flow chemical detection portal  

DOE Patents [OSTI]

A portal apparatus is described for screening objects or persons for the presence of trace amounts of chemical substances such as illicit drugs or explosives. The apparatus has a test space, in which a person may stand, defined by two generally upright sides spanned by a horizontal transom. One or more fans in the transom generate a downward air flow (uni-directional) within the test space. The air flows downwardly from a high pressure upper zone, past the object or person to be screened. Air moving past the object dislodges from the surface thereof both volatile and nonvolatile particles of the target substance. The particles are entrained into the air flow which continues flowing downward to a lower zone of reduced pressure, where the particle-bearing air stream is directed out of the test space and toward preconcentrator and detection components. The sides of the portal are specially configured to partially contain and maintain the air flow. 3 figs.

Linker, K.L.; Hannum, D.W.; Conrad, F.J.

1999-06-22T23:59:59.000Z

416

Solid oxide fuel cell with monolithic core  

DOE Patents [OSTI]

A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700 C and 1,100 C. 8 figs.

McPheeters, C.C.; Mrazek, F.C.

1988-08-02T23:59:59.000Z

417

Solid oxide fuel cell with monolithic core  

DOE Patents [OSTI]

A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700.degree. C. and 1100.degree. C.

McPheeters, Charles C. (Plainfield, IL); Mrazek, Franklin C. (Hickory Hills, IL)

1988-01-01T23:59:59.000Z

418

Wavy flow cooling concept for turbine airfoils  

DOE Patents [OSTI]

An airfoil including an outer wall and a cooling cavity formed therein. The cooling cavity includes a leading edge flow channel located adjacent a leading edge of the airfoil and a trailing edge flow channel located adjacent a trailing edge of the airfoil. Each of the leading edge and trailing edge flow channels define respective first and second flow axes located between pressure and suction sides of the airfoil. A plurality of rib members are located within each of the flow channels, spaced along the flow axes, and alternately extending from opposing sides of the flow channels to define undulating flow paths through the flow channels.

Liang, George (Palm City, FL)

2010-08-31T23:59:59.000Z

419

Investigation of the performance and water transport of a polymer electrolyte membrane (pem) fuel cell  

E-Print Network [OSTI]

Fuel cell performance was obtained as functions of the humidity at the anode and cathode sites, back pressure, flow rate, temperature, and channel depth. The fuel cell used in this work included a membrane and electrode assembly (MEA) which...

Park, Yong Hun

2009-05-15T23:59:59.000Z

420

Microfluidic Hydrogen Fuel Cell with a Liquid Electrolyte Ranga S. Jayashree, Michael Mitchell, Dilip Natarajan, Larry J. Markoski, and  

E-Print Network [OSTI]

Letters Microfluidic Hydrogen Fuel Cell with a Liquid Electrolyte Ranga S. Jayashree, Michael and characterization of a microfluidic hydrogen fuel cell with a flowing sulfuric acid solution instead of a Nafion membrane as the electrolyte. We studied the effect of cell resistance, hydrogen and oxygen flow rates

Kenis, Paul J. A.

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Pertechnetate (TcO4-) reduction by reactive ferrous iron forms in naturally anoxic, redox transition zone sediments from the Hanford Site, USA  

SciTech Connect (OSTI)

Technetium is an important environmental contaminant introduced by the processing and disposal of irradiated nuclear fuel and atmospheric nuclear tests. Under oxic conditions technetium is soluble and exists as pertechnatate anion (TcO4-), while under anoxic conditions Tc is usually insoluble and exists as precipitated Tc(IV). Here we investigated abiotic Tc(VII) reduction in mineralogically heterogeneous, Fe(II)-containing sediments. The sediments were collected from a 55 m borehole that sampled a semi-confined aquifer at the Hanford Site, USA that contained a dramatic redox transition zone. One oxic facies (18.0-18.3 m) and five anoxic facies (18.3-18.6 m, 30.8-31.1 m, 39.0-39.3 m, 47.2-47.5 m and 51.5-51.8 m) were selected for this study. Chemical extractions, X-ray diffraction, electron microscopy, and Mössbauer spectroscopy were applied to characterize the Fe(II) mineral suite that included: Fe(II)-phyllosilicates, pyrite, magnetite and siderite. The Fe(II) mineral phase distribution differed between the sediments. Sediment suspensions were adjusted to the same 0.5 M HCl extracted Fe(II) concentration (0.6 mM) for Tc(VII) reduction experiments. Aqueous Fe was low in all sediment suspensions (<2 ?M) and below the Fe(II)aq detection limit (10 ?M). Technetium(VII) reduction occurred in all anoxic sediments at depths greater than 18.3 m and reaction time differed significantly between the sediments (8-219 d). Mössbauer analysis of the Tc-reacted, 30.8-31.1 m sediment confirmed that Tc(VII) was reduced by solid-phase Fe(II), with siderite and Fe(II)-containing phyllosilicates implicated as redox reactive phases. Technetium-XAS analysis demonstrated that Tc associated with sediments was in the Tc(IV) valence state and immobilized as clusters of a TcO2·nH2O-like phase. The speciation of redox product Tc(IV) was not affected by reduction rate or Fe(II) mineralogy.

Peretyazhko, Tetyana; Zachara, John M.; Kukkadapu, Ravi K.; Heald, Steve M.; Kutnyakov, Igor V.; Resch, Charles T.; Arey, Bruce W.; Wang, Chong M.; Kovarik, Libor; Phillips, Jerry L.; Moore, Dean A.

2012-09-01T23:59:59.000Z

422

Turbine blade tip flow discouragers  

DOE Patents [OSTI]

A turbine assembly comprises a plurality of rotating blade portions in a spaced relation with a stationery shroud. The rotating blade portions comprise a root section, a tip portion and an airfoil. The tip portion has a pressure side wall and a suction side wall. A number of flow discouragers are disposed on the blade tip portion. In one embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned generally parallel to the direction of rotation. In an alternative embodiment, the flow discouragers extend circumferentially from the pressure side wall to the suction side wall so as to be aligned at an angle in the range between about 0.degree. to about 60.degree. with respect to a reference axis aligned generally parallel to the direction of rotation. The flow discouragers increase the flow resistance and thus reduce the flow of hot gas flow leakage for a given pressure differential across the blade tip portion so as to improve overall turbine efficiency.

Bunker, Ronald Scott (Niskayuna, NY)

2000-01-01T23:59:59.000Z

423

Progress with multigrid schemes for hypersonic flow problems  

SciTech Connect (OSTI)

Several multigrid schemes are considered for the numerical computation of viscous hypersonic flows. For each scheme, the basic solution algorithm employs upwind spatial discretization with explicit multistage time stepping. Two-level versions of the various multigrid algorithms are applied to the two-dimensional advection equation, and Fourier analysis is used to determine their damping properties. The capabilities of the multigrid methods are assessed by solving three different hypersonic flow problems. Some new multigrid schemes based on semicoarsening strategies are shown to be quite effective in relieving the stiffness caused by the high-aspect-ratio cells required to resolve high Reynolds number flows. These schemes exhibit good convergence rates for Reynolds numbers up to 200 X 10{sup 6} and Mach numbers up to 25. 32 refs., 31 figs., 1 tab.

Radespiel, R. [DLR, Braunschweig (Germany)] [DLR, Braunschweig (Germany); Swanson, R.C. [NASA Langley Research Center, Hampton, VA (United States)] [NASA Langley Research Center, Hampton, VA (United States)

1995-01-01T23:59:59.000Z

424

Journal of the Geological Society, London, Vol. 168, 2011, pp. 805815. doi: 10.1144/0016-76492010-132. Hydrothermal origin of elevated iron, manganese and redox-sensitive trace  

E-Print Network [OSTI]

.1144/0016-76492010-132. 805 Hydrothermal origin of elevated iron, manganese and redox-sensitive trace elements in the c. 635 Ma Doushantuo cap carbonate JING HUANG1,2 , XUELEI CHU1,2 *, GANQING JIANG3 , LIANJUN FENG1 & HUAJIN, including REE, concentrations of the Doushantuo cap carbonate (c. 635 Ma) in South China show enrichment

Jiang, Ganqing

425

The transition from two phase bubble flow to slug flow  

E-Print Network [OSTI]

The process of transition from bubble to slug flow in a vertical pipe has been studied analytically and experimentally. An equation is presented which gives the agglomeration time as a function of void fraction, channel ...

Radovcich, Nick A.

1962-01-01T23:59:59.000Z

426

Flow distribution channels to control flow in process channels  

DOE Patents [OSTI]

The invention describes features that can be used to control flow to an array of microchannels. The invention also describes methods in which a process stream is distributed to plural microchannels.

Tonkovich, Anna Lee; Arora, Ravi; Kilanowski, David

2014-10-28T23:59:59.000Z

427

Gas flow characterization of restrictive flow orifice devices  

SciTech Connect (OSTI)

A restrictive flow orifice (RFO) can be used to limit the uncontrolled release of system media upon component or line failure in a gas handling system and can thereby enhance the system safety. This report describes a new RFO product available from the Swagelok Companies and specifies the gas flow characteristics of this device. A family of four different sizes of RFO devices is documented.

Shrouf, R.G. [Sandia National Labs., Albuquerque, NM (United States). Safety Engineering Dept.; Page, S.R. [Albuquerque Valve and Fitting Co., NM (United States)

1997-07-01T23:59:59.000Z

428

Effects of flow cell design on charge percolation and storage...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Hajimolana, F.S. Mjalli, M. Saleem, J. Electrochem. Soc. 158 (2011) R55eR79. 12 E. Agar, C.R. Dennison, K.W. Knehr, E.C. Kumbur, J. Power Sources 225 (2013) 89e94. 13 K.W....

429

Flow cytometry aids basic cell biology research and drug discovery  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

including very deep wells already producing oil and gas and drilling operations for new wells. Wireless technology collects real-time information from oil and gas wells April,...

430

MICRO/MACROSCOPIC FLUID FLOW IN OPEN CELL FIBROUS STRUCTURES  

E-Print Network [OSTI]

, which is a novel approach in Microfluidics. To verify the developed models, several testbeds have been

Bahrami, Majid

431

Electrically Integrated Graphene on Silicon Nitride Liquid Flow Cells for  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: Vegetation Proposed NewcatalystNeutronEnvironmentZIRKLEEFFECTSHigh Resolution TEM - Energy Innovation

432

Flow cytometry aids basic cell biology research and drug discovery  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-SeriesFlickr Flickr Editor's note: Since the Flickr platformFloating

433

Renaissance in Flow-Cell Technologies: Recent Advancements and Future  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l L dDepartmentnews-flashes OfficeTexas |4WebinarAccessOpportunities |

434

Microfabricated Renewable Beads-Trapping/Releasing Flow Cell for Rapid  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth7-1D: VegetationEquipment Surfaces andMapping theEnergyInnovationMichael M.StructuralStartup America

435

An algebraic model for a zinc/bromine flow cell  

E-Print Network [OSTI]

[ ' ' + ? (Cye, Csc;)+Rbc, ] [29] The charge balance equations for the reactor are: *; 0+ ? II;D;(C a )C+ ' IID;C, ], 0[00, ]= I" (d i ? 0. ) A 12 for the difFusion region near the anode, F(pz ? t'ai) s D. t t AT(g P )Q h stl' for the bulk region...] for the difFusion region near the cathode, and finally P. t(. , +. , '. ) = p for the entire reactor. These relationships are derived in Appendices J ? O. [36] The current density is defined as h = Fg . . . , = ? Fg. , r, ' [36] The voltage drop through...

Simpson, Gary Don

1988-01-01T23:59:59.000Z

436

Capillary flows in flexible structures  

E-Print Network [OSTI]

Interactions between capillary and elastic effects are relevant to a variety of applications, from micro- and nano-scale manufacturing to biological systems. In this thesis, we investigate capillary flows in extremely ...

Hoberg, Theresa B. (Theresa Blinn)

2013-01-01T23:59:59.000Z

437

2007 Estimated International Energy Flows  

SciTech Connect (OSTI)

An energy flow chart or 'atlas' for 136 countries has been constructed from data maintained by the International Energy Agency (IEA) and estimates of energy use patterns for the year 2007. Approximately 490 exajoules (460 quadrillion BTU) of primary energy are used in aggregate by these countries each year. While the basic structure of the energy system is consistent from country to country, patterns of resource use and consumption vary. Energy can be visualized as it flows from resources (i.e. coal, petroleum, natural gas) through transformations such as electricity generation to end uses (i.e. residential, commercial, industrial, transportation). These flow patterns are visualized in this atlas of 136 country-level energy flow charts.

Smith, C A; Belles, R D; Simon, A J

2011-03-10T23:59:59.000Z

438

particle flow for nonlinear filters  

E-Print Network [OSTI]

particle flow for nonlinear filters Fred Daum 19 June 2012 Copyright © 2012 Raytheon Company. All rights reserved. Customer Success Is Our Mission is a trademark of Raytheon Company. 1 #12;discrete time

Dobigeon, Nicolas

439

Fluid Flow Modeling in Fractures  

E-Print Network [OSTI]

In this paper we study fluid flow in fractures using numerical simulation and address the challenging issue of hydraulic property characterization in fractures. The methodology is based on Computational Fluid Dynamics, ...

Sarkar, Sudipta

2004-01-01T23:59:59.000Z

440

Mechanical design of flow batteries  

E-Print Network [OSTI]

The purpose of this research is to investigate the design of low-cost, high-efficiency flow batteries. Researchers are searching for next-generation battery materials, and this thesis presents a systems analysis encompassing ...

Hopkins, Brandon J. (Brandon James)

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Field Flows of Dark Energy  

E-Print Network [OSTI]

Field Flows of Dark Energy Robert N. Cahn, Roland de Putter,July 8, 2008) Scalar ?eld dark energy evolving from a longthe key aspects of the dark energy evolution during much of

Cahn, Robert N.

2010-01-01T23:59:59.000Z

442

Longitudinal dispersion in vegetated flow  

E-Print Network [OSTI]

Vegetation is ubiquitous in rivers, estuaries and wetlands, strongly influencing both water conveyance and mass transport. The plant canopy affects both mean and turbulent flow structure, and thus both advection and ...

Murphy, Enda

2006-01-01T23:59:59.000Z

443

Pipe Flow System Holly Guest  

E-Print Network [OSTI]

numbers #12;Pipe Flow System Form #12;Components Form Fitting Loss Coefficient, k Globe valve, fully open 10 Angle valve, fully open 5 Swing check valve, fully open 2.5 Gate valve, fully open .2 Shortradius

Clement, Prabhakar

444

Multiscale modeling in granular flow  

E-Print Network [OSTI]

Granular materials are common in everyday experience, but have long-resisted a complete theoretical description. Here, we consider the regime of slow, dense granular flow, for which there is no general model, representing ...

Rycroft, Christopher Harley

2007-01-01T23:59:59.000Z

445

Subcooled flow boiling of fluorocarbons  

E-Print Network [OSTI]

A study was conducted of heat transfer and hydrodynamic behavior for subcooled flow boiling of Freon-113, one of a group of fluorocarbons suitable for use in cooling of high-power-density electronic components. Problems ...

Murphy, Richard Walter

1971-01-01T23:59:59.000Z

446

Minimum Stream Flow Standards (Connecticut)  

Broader source: Energy.gov [DOE]

These regulations apply to all dams and structures which impound or divert waters on rivers or their tributaries, with some exceptions. The regulations set standards for minimum flow (listed in the...

447

Automation of radiochemical analysis by applying flow  

E-Print Network [OSTI]

of detection systems, including scintillation counting, a-spectrometers, proportional counters, mass spectrometry and spectrophotometry. ª 2010 Published by Elsevier Ltd. Keywords: Flow-analysis technique; Flow

Sánchez, David

448

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER  

E-Print Network [OSTI]

MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts

Lahey, Richard T.

449

Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer, Longer-lasting Batteries Colorado: Isothermal Battery Calorimeter Quantifies Heat Flow, Helps Make Safer,...

450

Equidistribution results for geodesic flows  

E-Print Network [OSTI]

Using the works of Ma\\~n\\'e \\cite{Ma} and Paternain \\cite{Pat} we study the distribution of geodesic arcs with respect to equilibrium states of the geodesic flow on a closed manifold, equipped with a $\\mathcal{C}^{\\infty}$ Riemannian metric. We prove large deviations lower and upper bounds and a contraction principle for the geodesic flow in the space of probability measures of the unit tangent bundle. We deduce a way of approximating equilibrium states for continuous potentials.

Abdelhamid Amroun

2011-09-15T23:59:59.000Z

451

Method for single-cell mass and electrophoretic mobility measurement  

E-Print Network [OSTI]

Analysis of single cells using flow cytometry techniques has created a wealth of knowledge about cellular phenomena that could not be obtained by population average measurements. As these techniques are integrated with ...

Dextras, Philip

2010-01-01T23:59:59.000Z

452

Preliminary Measurements of the Energy Impact of Infiltration in a Test Cell  

E-Print Network [OSTI]

pressure levels ranging from 1-60 Pa. This data was then used to determine the flow constant, k, and the flow expo- nent, n. of the cell according to the equation where Q Is the air flow rate in c frn and AP is the pres- sure difference in Pascal...

Claridge, D. E.; Krarti, M.; Bhattacharyya, S.

1988-01-01T23:59:59.000Z

453

Subcritical dynamos in shear flows  

E-Print Network [OSTI]

Identifying generic physical mechanisms responsible for the generation of magnetic fields and turbulence in differentially rotating flows is fundamental to understand the dynamics of astrophysical objects such as accretion disks and stars. In this paper, we discuss the concept of subcritical dynamo action and its hydrodynamic analogue exemplified by the process of nonlinear transition to turbulence in non-rotating wall-bounded shear flows. To illustrate this idea, we describe some recent results on nonlinear hydrodynamic transition to turbulence and nonlinear dynamo action in rotating shear flows pertaining to the problem of turbulent angular momentum transport in accretion disks. We argue that this concept is very generic and should be applicable to many astrophysical problems involving a shear flow and non-axisymmetric instabilities of shear-induced axisymmetric toroidal velocity or magnetic fields, such as Kelvin-Helmholtz, magnetorotational, Tayler or global magnetoshear instabilities. In the light of several recent numerical results, we finally suggest that, similarly to a standard linear instability, subcritical MHD dynamo processes in high-Reynolds number shear flows could act as a large-scale driving mechanism of turbulent flows that would in turn generate an independent small-scale dynamo.

F. Rincon; G. I. Ogilvie; M. R. E. Proctor; C. Cossu

2008-05-09T23:59:59.000Z

454

Pressure and flow characteristics of restrictive flow orifice devices.  

SciTech Connect (OSTI)

A Restrictive Flow Orifice (RFO) can be used to enhance the safe design of a pressure system in several ways. Pressure systems frequently incorporate a regulator and relief valve to protect the downstream equipment from accidental overpressure caused by regulator failure. Analysis frequently shows that in cases of high-flow regulator failure, the downstream pressure may rise significantly above the set pressure of the relief valve. This is due to limited flow capacity of the relief valve. A different regulator or relief valve may need to be selected. A more economical solution to this problem is to use an RFO to limit the maximum system flow to acceptable limits within the flow capacity of the relief valve, thereby enhancing the overpressure protection of laboratory equipment. An RFO can also be used to limit the uncontrolled release of system fluid (gas or liquid) upon component or line failure. As an example, potential asphyxiation hazards resultant from the release of large volumes of inert gas from a 'house' nitrogen system can be controlled by the use of an RFO. This report describes a versatile new Sandia-designed RFO available from the Swagelok Company and specifies the gas flow characteristics of this device. Two sizes, 0.010 and 0.020 inch diameter RFOs are available. These sizes will allow enhanced safety for many common applications. This new RFO design are now commercially available and provide advantages over existing RFOs: a high pressure rating (6600 psig); flow through the RFO is equal for either forward or reverse directions; they minimize the potential for leakage by incorporating the highest quality threaded connections; and can enhance the safety of pressure systems.

Shrouf, Roger D.

2003-06-01T23:59:59.000Z

455

Regional neurohypophysial and hypothalamic blood flow in rats during hypercapnia  

SciTech Connect (OSTI)

Regional cerebral blood flow (rCBF) was measured in the neurohypophysis and hypothalamus in normocapnic and hypercapnic rats using (/sup 14/C)isopropyliodoamphetamine. Rats were surgically prepared using nitrous oxide and halothane and placed in plaster restraining casts. Hypercapnia was produced by increasing the fractional concentration of inspired CO/sub 2/ (FICO/sub 2/). rCBF in normocapnic rats was higher in the paraventricular nucleus, supraoptic nucleus, median eminence, and neural lobe than rates previously measured by use of diffusible tracers. During hypercapnia blood flow increased linearly with arterial PCO/sub 2/ (PACO/sub 2/) in all regions except the median eminence and neural lobe, which were not affected by hypercapnia. When rats were pretreated with phentolamine (1 mg/kg) to block the alpha-adrenergic receptors, blood flow in the median eminence and neural lobe increased significantly during hypercapnia. We conclude that blood flow in the cell bodies of the paraventricular nucleus and supraoptic nucleus is regulated differently during hypercapnia than blood flow in the nerve terminals in the median eminence and neural lobe. Furthermore, vasodilation produced by increased CO/sub 2/ is offset by alpha-receptor stimulation in the median eminence and neural lobe.

Bryan, R.M. Jr.; Myers, C.L.; Page, R.B.

1988-08-01T23:59:59.000Z

456

Polymer selection and cell design for electric-vehicle supercapacitors  

SciTech Connect (OSTI)

Supercapacitors are devices for applications requiring high operating power levels, such as secondary power sources in electric vehicles (EVs) to provide peak power for acceleration and hill climbing. While electronically conducting polymers yield different redox supercapacitor configurations, devices with the n-doped polymer as the negative electrode and the p-doped polymer as the positive one are the most promising for EV applications. Indeed, this type of supercapacitor has a high operating potential, is able to deliver all the doping charge and, when charged, has both electrodes in the conducting (p- and n-doped) states. This study reports selection criteria for polymer materials and cell design for high performance EV supercapacitors and experimental results of selected polymer materials.

Mastragostino, M.; Arbizzani, C.; Paraventi, R.; Zanelli, A.

2000-02-01T23:59:59.000Z

457

Stochastic models for turbulent reacting flows  

SciTech Connect (OSTI)

The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.

Kerstein, A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

458

Flow Duration Curve Load Duration Curve  

E-Print Network [OSTI]

Flow Duration Curve Load Duration Curve 1. Develop Flow Duration Curve 2. Estimate load given flow and concentration data--select appropriate conversion factors 3. Develop Load Duration Curve 4. Plot observed data with Load Duration Curve What are they? How do you make one? Describes the percent of time a flow rate

459

SHORT-TUBE SUBCRITICAL FLOW Enerag Division  

E-Print Network [OSTI]

#12;SHORT-TUBE SUBCRITICAL FLOW Y. C. Mei Enerag Division Oak Ridge National Laboratory Oak Ridge-tube subcritical flow. For short tubes used as refrigerant expansion devices, the orifice model is found inadequate-TUBE SUBCRITICAL FLOW INTRODUCTION Much theoretical and experimental work regarding short tube fluid flow has

Oak Ridge National Laboratory

460

Mach flow angularity probes for scramjet engine flow path diagnostics  

SciTech Connect (OSTI)

Mach-flow angularity (MFA) probes were developed for use in scramjet flow path probe rakes. Prototype probes were fabricated to demonstrate the assembly processes (numerical control machining, furnace brazing, and electron beam welding). Tests of prototype probes confirmed the thermal durability margins and life cycle. Selected probes were calibrated in air at Mach numbers from 1.75 to 6.0. Acceptance criteria for the production probes stressed thermal durability and pressure (and, consequently, Mach number) measurement quality. This new water-cooled MFA probe has 0.397-cm shaft diameter and is capable of withstanding heat fluxes of 2.724 kW/sq cm.

Jalbert, P.A.; Hiers, R.S. Jr. [Sverdrup Technology, Inc., Arnold AFS, TN (United States)

1993-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Annular feed air breathing fuel cell stack  

DOE Patents [OSTI]

A stack of polymer electrolyte fuel cells is formed from a plurality of unit cells where each unit cell includes fuel cell components defining a periphery and distributed along a common axis, where the fuel cell components include a polymer electrolyte membrane, an anode and a cathode contacting opposite sides of the membrane, and fuel and oxygen flow fields contacting the anode and the cathode, respectively, wherein the components define an annular region therethrough along the axis. A fuel distribution manifold within the annular region is connected to deliver fuel to the fuel flow field in each of the unit cells. The fuel distribution manifold is formed from a hydrophilic-like material to redistribute water produced by fuel and oxygen reacting at the cathode. In a particular embodiment, a single bolt through the annular region clamps the unit cells together. In another embodiment, separator plates between individual unit cells have an extended radial dimension to function as cooling fins for maintaining the operating temperature of the fuel cell stack.

Wilson, Mahlon S. (Los Alamos, NM); Neutzler, Jay K. (Peoria, AZ)

1997-01-01T23:59:59.000Z

462

Pressure compensated flow control valve  

DOE Patents [OSTI]

The invention is an air flow control valve which is capable of maintaining a constant flow at the outlet despite changes in the inlet or outlet pressure. The device consists of a shell assembly with an inlet chamber and outlet chamber separated by a separation plate. The chambers are connected by an orifice. Also located within the inlet chamber is a port controller assembly. The port controller assembly consists of a differential pressure plate and port cap affixed thereon. The cap is able to slide in and out of the orifice separating the inlet and outlet chambers. When the pressure differential is sufficient, the differential pressure plate rises or falls to maintain a constant air flow. Movement of the port controller assembly does not require the use of seals, diaphragms, tight tolerances, bushings, bearings, hinges, guides, or lubricants.

Minteer, Daniel J. (West Richland, WA)

1999-01-01T23:59:59.000Z

463

Multi-stage fuel cell system method and apparatus  

DOE Patents [OSTI]

A high efficiency, multi-stage fuel cell system method and apparatus is provided. The fuel cell system is comprised of multiple fuel cell stages, whereby the temperatures of the fuel and oxidant gas streams and the percentage of fuel consumed in each stage are controlled to optimize fuel cell system efficiency. The stages are connected in a serial, flow-through arrangement such that the oxidant gas and fuel gas flowing through an upstream stage is conducted directly into the next adjacent downstream stage. The fuel cell stages are further arranged such that unspent fuel and oxidant laden gases too hot to continue within an upstream stage because of material constraints are conducted into a subsequent downstream stage which comprises a similar cell configuration, however, which is constructed from materials having a higher heat tolerance and designed to meet higher thermal demands. In addition, fuel is underutilized in each stage, resulting in a higher overall fuel cell system efficiency.

George, Thomas J. (Morgantown, WV); Smith, William C. (Morgantown, WV)

2000-01-01T23:59:59.000Z

464

Flow cytometric measurement of total DNA and incorporated halodeoxyuridine  

DOE Patents [OSTI]

A method for the simultaneous flow cylometric measurement of total cellular DNA content and of the uptake of DNA precursors as a measure of DNA synthesis during various phases of the cell cycle in normal and malignant cells in vitro and in vivo is described. The method comprises reacting cells with labelled halodeoxyuridine (HdU), partially denaturing cellular DNA, adding to the reaction medium monoclonal antibodies (mabs) reactive with HdU, reacting the bound mabs with a second labelled antibody, incubating the mixture with a DNA stain, and measuring simultaneously the intensity of the DNA stain as a measure of the total cellular DNA and the HdU incorporated as a measure of DNA synthesis. (ACR)

Dolbeare, F.A.; Gray, J.W.

1983-10-18T23:59:59.000Z

465

Water injected fuel cell system compressor  

DOE Patents [OSTI]

A fuel cell system including a dry compressor for pressurizing air supplied to the cathode side of the fuel cell. An injector sprays a controlled amount of water on to the compressor's rotor(s) to improve the energy efficiency of the compressor. The amount of water sprayed out the rotor(s) is controlled relative to the mass flow rate of air inputted to the compressor.

Siepierski, James S. (Williamsville, NY); Moore, Barbara S. (Victor, NY); Hoch, Martin Monroe (Webster, NY)

2001-01-01T23:59:59.000Z

466

Connectivity due to preferential flow controls water flow and solute transport at the hillslope scale  

E-Print Network [OSTI]

feedback, flow through the fractured bedrock, kinematic wave routing and flow through discrete preferentialConnectivity due to preferential flow controls water flow and solute transport at the hillslope the major controls on water flow and solute transport at the hillslope scale remains a major topic

Weiler, Markus

467

Rheo-optical determination of flow birefringence and flow dichroism with the pulsed laser method  

E-Print Network [OSTI]

Rheo-optical determination of flow birefringence and flow dichroism with the pulsed laser method online 29 August 2006 Rheo-optical measurements of the flow birefringence, flow dichroism systems under flow. However, the standard setup of an optical train, using phase modulation for the rheo-optical

468

Interfacial flows in corrugated microchannels: flow regimes, transitions and hysteresis  

E-Print Network [OSTI]

, 1266-1276 (2011), doi:10.1016/j.ijmultiphaseflow.2011.08.003 #12;model, microfluidics, porous media 1 of displacing oil by water in enhanced oil recovery (Marle, 1981; Lenormand et al., 1988). More recently on hy- drodynamic principles and concrete flow mechanisms. In fact, conflicting assumptions have been

Feng, James J.

469

Nuclear reactor downcomer flow deflector  

DOE Patents [OSTI]

A nuclear reactor having a coolant flow deflector secured to a reactor core barrel in line with a coolant inlet nozzle. The flow deflector redirects incoming coolant down an annulus between the core barrel and the reactor vessel. The deflector has a main body with a front side facing the fluid inlet nozzle and a rear side facing the core barrel. The rear side of the main body has at least one protrusion secured to the core barrel so that a gap exists between the rear side of the main body adjacent the protrusion and the core barrel. Preferably, the protrusion is a relief that circumscribes the rear side of the main body.

Gilmore, Charles B. (Greensburg, PA); Altman, David A. (Pittsburgh, PA); Singleton, Norman R. (Murrysville, PA)

2011-02-15T23:59:59.000Z

470

High gas flow alpha detector  

DOE Patents [OSTI]

An alpha detector for application in areas of high velocity gas flows, such as smokestacks and air vents. A plurality of spaced apart signal collectors are placed inside an enclosure, which would include smokestacks and air vents, in sufficient numbers to substantially span said enclosure so that gas ions generated within the gas flow are electrostatically captured by the signal collector means. Electrometer means and a voltage source are connected to the signal collectors to generate an electrical field between adjacent signal collectors, and to indicate a current produced through collection of the gas ions by the signal collectors. 4 figs.

Bolton, R.D.; Bounds, J.A.; Rawool-Sullivan, M.W.

1996-05-07T23:59:59.000Z

471

High gas flow alpha detector  

DOE Patents [OSTI]

An alpha detector for application in areas of high velocity gas flows, such as smokestacks and air vents. A plurality of spaced apart signal collectors are placed inside an enclosure, which would include smokestacks and air vents, in sufficient numbers to substantially span said enclosure so that gas ions generated within the gas flow are electrostatically captured by the signal collector means. Electrometer means and a voltage source are connected to the signal collectors to generate an electrical field between adjacent signal collectors, and to indicate a current produced through collection of the gas ions by the signal collectors.

Bolton, Richard D. (Los Alamos, NM); Bounds, John A. (Los Alamos, NM); Rawool-Sullivan, Mohini W. (Los Alamos, NM)

1996-01-01T23:59:59.000Z

472

Non-Newtonian fluid flow  

E-Print Network [OSTI]

zero and unity. The Ostwald- de Waele Equation (4), commonly known as the power law, is sometimes used to describe fluid behavior of this type. The rheological equation is (4) where the parameters "k" and "n" are constant for a particular fluid... be extended to include Reynolds numbers and the type of flow determined to be laminar and/or turbulent. It is assumed that the transition from laminar to turbulent flow occurs at a Reynolds number of 2100, the numeric distribution of Reynolds numbers...

Osinski, Charles Anthony

1963-01-01T23:59:59.000Z

473

Dynamo action in flows with  

E-Print Network [OSTI]

Dynamo action in flows with cat's eyes A l i c e C o u r v o i s i e r A n d r e w G i l b e r t Y of k for R = 500 and the flow (2.4) and (2.5). nts k = 2.5 and k = 5 are highlighted. Magnetic field). In (a) k = 2.5 and we have 0.5 max Bz (with max Bz 0.6 max |B|), and in (b) k = 5 and the levels .65 max

Li, Yi

474

Topological Quantum Computation and Error Correction by Biological Cells  

E-Print Network [OSTI]

A Topological examination of phospholipid dynamics in the Far from Equilibrium state has demonstrated that metabolically active cells use waste heat to generate spatially patterned membrane flows by forced convection and shear. This paper explains the resemblance between this nonlinear membrane model and Witten Kitaev type Topological Quantum Computation systems, and demonstrates how this self-organising membrane enables biological cells to circumvent the decoherence problem, perform error correction procedures, and produce classical level output as shielded current flow through cytoskeletal protein conduit. Cellular outputs are shown to be Turing compatible as they are determined by computable in principle hydromagnetic fluid flows, and importantly, are Adaptive from an Evolutionary perspective.

J T Lofthouse

2005-02-02T23:59:59.000Z

475

RAFT: A simulator for ReActive Flow and Transport of groundwater contaminants  

SciTech Connect (OSTI)

This report documents the use of the simulator RAFT for the ReActive flow and Transport of groundwater contaminants. RAFT can be used as a predictive tool in the design and analysis of laboratory and field experiments or it can be used for the estimation of model/process parameters from experiments. RAFT simulates the reactive transport of groundwater contaminants in one, two-, or three-dimensions and it can model user specified source/link configurations and arbitrary injection strategies. A suite of solvers for transport, reactions and regression are employed so that a combination of numerical methods best suited for a problem can be chosen. User specified coupled equilibrium and kinetic reaction systems can be incorporated into RAFT. RAFT is integrated with a symbolic computational language MAPLE, to automate code generation for arbitrary reaction systems. RAFT is expected to be used as a simulator for engineering design for field experiments in groundwater remediation including bioremediation, reactive barriers and redox manipulation. As an integrated tool with both the predictive ability and the ability to analyze experimental data, RAFT can help in the development of remediation technologies, from laboratory to field.

Chilakapati, A.

1995-07-01T23:59:59.000Z

476

Comparative Study of f-Element Electronic Structure across a Series of Multimetallic Actinide, Lanthanide-Actinide and Lanthanum-Actinide Complexes Possessing Redox-Active Bridging Ligands  

SciTech Connect (OSTI)

A comparative examination of the electronic interactions across a series of trimetallic actinide and mixed lanthanide-actinide and lanthanum-actinide complexes is presented. Using reduced, radical terpyridyl ligands as conduits in a bridging framework to promote intramolecular metal-metal communication, studies containing structural, electrochemical, and X-ray absorption spectroscopy are presented for (C{sub 5}Me{sub 5}){sub 2}An[-N=C(Bn)(tpy-M{l_brace}C{sub 5}Me4R{r_brace}{sub 2})]{sub 2} (where An = Th{sup IV}, U{sup IV}; Bn = CH{sub 2}C{sub 6}H{sub 5}; M = La{sup III}, Sm{sup III}, Yb{sup III}, U{sup III}; R = H, Me, Et) to reveal effects dependent on the identities of the metal ions and R-groups. The electrochemical results show differences in redox energetics at the peripheral 'M' site between complexes and significant wave splitting of the metal- and ligand-based processes indicating substantial electronic interactions between multiple redox sites across the actinide-containing bridge. Most striking is the appearance of strong electronic coupling for the trimetallic Yb{sup III}-U{sup IV}-Yb{sup III}, Sm{sup III}-U{sup IV}-Sm{sup III}, and La{sup III}-U{sup IV}-La{sup III} complexes, [8]{sup -}, [9b]{sup -} and [10b]{sup -}, respectively, whose calculated comproportionation constant K{sub c} is slightly larger than that reported for the benchmark Creutz-Taube ion. X-ray absorption studies for monometallic metallocene complexes of U{sup III}, U{sup IV}, and U{sup V} reveal small but detectable energy differences in the 'white-line' feature of the uranium L{sub III}-edges consistent with these variations in nominal oxidation state. The sum of this data provides evidence of 5f/6d-orbital participation in bonding and electronic delocalization in these multimetallic f-element complexes. An improved, high-yielding synthesis of 4{prime}-cyano-2,2{prime}:6{prime},2{double_prime}-terpyridine is also reported.

Schelter, Eric J.; Wu, Ruilian; Veauthier, Jacqueline M.; Bauer, Eric D.; Booth, Corwin H.; Thomson, Robert K.; Graves, Christopher R.; John, Kevin D.; Scott, Brian L.; Thompson, Joe D.; Morris, David E.; Kiplinger, Jaqueline L.

2010-02-24T23:59:59.000Z

477

Data Flow Testing Neelam Gupta  

E-Print Network [OSTI]

Data Flow Testing Neelam Gupta The University of Arizona, Tucson, Arizona and Rajiv Gupta The University of Arizona, Tucson, Arizona Software testing techniques are designed to execute a program on a set of test cases that provide suÃ?cient coverage under some speci#12;c well-de#12;ned test coverage criterion

Gupta, Rajiv

478

Rinse trough with improved flow  

DOE Patents [OSTI]

Novel rinse troughs accomplish thorough uniform rinsing. The troughs are suitable for one or more essentially planar objects having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs provide uniform rinse fluid flow over the objects` surfaces to accomplish a more thorough rinse than prior art troughs. 5 figs.

O`Hern, T.J.; Grasser, T.W.

1998-08-11T23:59:59.000Z

479

Comments on "Microscale flow visualization"  

E-Print Network [OSTI]

We make comments on the presentation of Sinton's paper (Microfluidics and Nanofluidics {\\bf 1}: 2, 2004) about the microscale flow visualization since the effects of the roughness along the microfabricated wall upon the current macroflow visualization methods could be significant and cannot be neglected in microdomain and even nanodomain.

A. Kwang-Hua Chu

2005-10-22T23:59:59.000Z

480

Superconducting flux flow digital circuits  

DOE Patents [OSTI]

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs) are disclosed. Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics. 8 figs.

Hietala, V.M.; Martens, J.S.; Zipperian, T.E.

1995-02-14T23:59:59.000Z

Note: This page contains sample records for the topic "redox flow cell" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Superconducting flux flow digital circuits  

DOE Patents [OSTI]

A NOR/inverter logic gate circuit and a flip flop circuit implemented with superconducting flux flow transistors (SFFTs). Both circuits comprise two SFFTs with feedback lines. They have extremely low power dissipation, very high switching speeds, and the ability to interface between Josephson junction superconductor circuits and conventional microelectronics.

Hietala, Vincent M. (Placitas, NM); Martens, Jon S. (Sunnyvale, CA); Zipperian, Thomas E. (Albuquerque, NM)

1995-01-01T23:59:59.000Z

482

Flow preconditioner for electrostatic precipitator  

SciTech Connect (OSTI)

A flow preconditioner for an electrostatic precipitator removes particulate matter from a stream of polluted gas immediately after it passes through a tangential inlet at the lower end of a vertical cylindrical housing and straightens and divides the stream into laminations parallel to the axis of the housing. It comprises an annular ledge or choke ring extending inwardly from said housing above the inlet and an assembly of vanes above said ledge extending radially from the axis of the housing and angularly spaced apart. Each of said vanes has a flow receiving edge directed toward said inlet, a curved portion extending upwardly and away from said inlet, and a flat portion extending upwardly from said curved portion in a plane parallel to the housing axis. The curved portion of each vane defines a trough having a camber which gradually decreases along its span from the outer end of the vane towards the axis of the housng, together with means to vary the centrifugal flow distribution relative to the housing to render the preconditioner adjustable for various flow capacities.

Honacker, H.; Drlik, R.J.

1980-01-01T23:59:59.000Z

483

A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow...  

Open Energy Info (EERE)

Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search OpenEI Reference...

484

Of Microenvironments and Mammary Stem Cells  

SciTech Connect (OSTI)

In most adult tissues there reside pools of stem and progenitor cells inside specialized microenvironments referred to as niches. The niche protects the stem cells from inappropriate expansion and directs their critical functions. Thus guided, stem cells are able to maintain tissue homeostasis throughout the ebb and flow of metabolic and physical demands encountered over a lifetime. Indeed, a pool of stem cells maintains mammary gland structure throughout development, and responds to the physiological demands associated with pregnancy. This review discusses how stem cells were identified in both human and mouse mammary glands; each requiring different techniques that were determined by differing biological needs and ethical constraints. These studies together create a robust portrait of mammary gland biology and identify the location of the stem cell niche, elucidate a developmental hierarchy, and suggest how the niche might be manipulated for therapeutic benefit.

LaBarge, Mark A; Petersen, Ole W; Bissell, Mina J

2007-06-01T23:59:59.000Z

485

Local Nusselt number enhancement during gaseliquid Taylor bubble flow in a square mini-channel: An experimental study  

E-Print Network [OSTI]

- scale mass transfer process, fuel cells, etc. The unique and complex flow characteristics require under, Indian Institute of Technology Kanpur, Kanpur 208016, UP, India a r t i c l e i n f o Article history of the unit cell, i.e., the length of adjacent gas bubble and water plug. Ã? 2012 Elsevier Masson SAS. All

Khandekar, Sameer

486

Fuel cell flooding detection and correction  

DOE Patents [OSTI]

Method and apparatus for monitoring an H.sub.2 -O.sub.2 PEM fuel cells to detect and correct flooding. The pressure drop across a given H.sub.2 or O.sub.2 flow field is monitored and compared to predetermined thresholds of unacceptability. If the pressure drop exists a threshold of unacceptability corrective measures are automatically initiated.

DiPierno Bosco, Andrew (Rochester, NY); Fronk, Matthew Howard (Honeoye Falls, NY)

2000-08-15T23:59:59.000Z

487

Liquid metal Flow Meter - Final Report  

SciTech Connect (OSTI)

Measuring the flow of liquid metal presents serious challenges. Current commercially-available flow meters use ultrasonic, electromagnetic, and other technologies to measure flow, but are inadequate for liquid metal flow measurement because of the high temperatures required by most liquid metals. As a result of the reactivity and high temperatures of most liquid metals, corrosion and leakage become very serious safety concerns. The purpose of this project is to develop a flow meter for Lockheed Martin that measures the flow rate of molten metal in a conduit.

Andersen C, Hoogendoom S, Hudson B, Prince J, Teichert K, Wood J, Chase K

2007-01-30T23:59:59.000Z

488

Generation of functional hemangioblasts from human embryonic stem cells  

E-Print Network [OSTI]

(hES) cells using an in vitro differentiation system. Blast cells expressed gene signatures or into mice with ischemia-reperfusion injury of the retina, they localized to the site of injury the mortality rat