National Library of Energy BETA

Sample records for redox flow cell

  1. Performance mapping studies in Redox flow cells

    SciTech Connect (OSTI)

    Hoberecht, M.A.; Thaller, L.H.

    1981-09-01

    Pumping power requirements in any flow battery system constitute a direct parasitic energy loss. It is therefore useful to determine the practical lower limit for reactant flow rates. Through the use of a theoretical framework based on electrochemical first principles, two different experimental flow mapping techniques are developed to evaluate and compare electrodes as a function of flow rate. For the carbon felt electrodes presently used in NASA-Lewis Redox cells, a flow rate 1.5 times greater than the stoichiometric rate seems to be the required minimum.

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

    E-Print Network [OSTI]

    Mayer, Michael

    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

  3. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    of a Vanadium Redox-Flow Battery to Maintain Power Quality,"Fuel System Using Redox Flow Battery," ed: WO Patentand D. B. Hickey, "Redox Flow Battery System for Distributed

  4. Cascade redox flow battery systems

    DOE Patents [OSTI]

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

    2014-07-22

    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.

  5. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    Ltd." . Http://Plurionsystems.Com/Tech_Flow_Advantages.Html.plurionsystems.com/tech_flow_advantages.html [71] P. Leung,High Energy Density Redox Flow Device," ed: WO Patent

  6. Redox Flow Batteries, a Review

    SciTech Connect (OSTI)

    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

    2011-07-15

    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.

  7. A New Hybrid Redox Flow Battery with Multiple Redox Couples

    SciTech Connect (OSTI)

    Wang, Wei; Li, Liyu; Nie, Zimin; Chen, Baowei; Luo, Qingtao; Shao, Yuyan; Wei, Xiaoliang; Chen, Feng; Xia, Guanguang; Yang, Zhenguo

    2012-05-19

    A redox flow battery using V{sup 4+}/V{sup 5+} vs. V{sup 2+}/V{sup 3+} and Fe{sup 2+}/Fe{sup 3+} vs. V{sup 2+}/V{sup 3+} redox couples in chloric/sulphuric mixed acid supporting electrolyte was investigated for potential stationary energy storage applications. The Fe/V hybrid redox flow cell using mixed reactant solutions operated within a voltage window of 0.5-1.7 V demonstrated stable cycling over 100 cycles with energy efficiency {approx}80% and no capacity fading at room temperature. A 66% improvement in the energy density of the Fe/V hybrid cell was achieved compared with the previous reported Fe/V cell using only Fe{sup 2+}/Fe{sup 3+} vs. V{sup 2+}/V{sup 3+} redox couples.

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

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

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

    2014-10-01

    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 energymore »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.« less

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

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

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

    2014-10-01

    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.

  10. Optimization of electrode characteristics for the Br?/H? redox flow cell

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

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

    2014-10-17

    The Br?/H? 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 efficiencymore »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.« less

  11. Optimization of electrode characteristics for the Br?/H? redox flow cell

    SciTech Connect (OSTI)

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

    2015-01-01

    The Br?/H? 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.

  12. Optimization of electrode characteristics for the Br-2/H-2 redox flow cell

    SciTech Connect (OSTI)

    Tucker, MC; Cho, KT; Weber, AZ; Lin, GY; Nguyen, TV

    2014-10-17

    The Br-2/H-2 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.

  13. Rebalancing electrolytes in redox flow battery systems

    DOE Patents [OSTI]

    Chang, On Kok; Pham, Ai Quoc

    2014-12-23

    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.

  14. A New Redox Flow Battery Using Fe/V Redox Couples in Chloride Supporting Electrolyte

    SciTech Connect (OSTI)

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

    2011-08-22

    A new redox flow battery using Fe2+/Fe3+ and V2+/V3+ redox couples in chloride supporting electrolyte was proposed and investigated for potential stationary energy storage applications. The Fe/V redox flow cell using mixed reactant solutions operated within a voltage window of 0.5-1.35 V with a nearly 100% utilization ratio and demonstrated stable cycling with energy efficiency around 80% at room temperature. Compared with Fe/Cr redox flow battery operating at an elevated temperature of 65 C, the necessity of external heat management is eliminated. Similar performance was also achieved using low-cost hydrocarbon-based ion exchange membranes, which allow for further cost reduction. The improved room temperature electrochemical performance makes the Fe/V redox flow battery a promising option as stationary energy storage device to enable renewable integration and stabilization of electrical grid.

  15. Hybrid anodes for redox flow batteries

    DOE Patents [OSTI]

    Wang, Wei; Xiao, Jie; Wei, Xiaoliang; Liu, Jun; Sprenkle, Vincent L.

    2015-12-15

    RFBs having solid hybrid electrodes can address at least the problems of active material consumption, electrode passivation, and metal electrode dendrite growth that can be characteristic of traditional batteries, especially those operating at high current densities. The RFBs each have a first half cell containing a first redox couple dissolved in a solution or contained in a suspension. The solution or suspension can flow from a reservoir to the first half cell. A second half cell contains the solid hybrid electrode, which has a first electrode connected to a second electrode, thereby resulting in an equipotential between the first and second electrodes. The first and second half cells are separated by a separator or membrane.

  16. Hybrid anodes for redox flow batteries

    DOE Patents [OSTI]

    Wang, Wei; Xiao, Jie; Wei, Xiaoliang; Liu, Jun; Sprenkle, Vincent L.

    2015-12-22

    RFBs having solid hybrid electrodes can address at least the problems of active material consumption, electrode passivation, and metal electrode dendrite growth that can be characteristic of traditional batteries, especially those operating at high current densities. The RFBs each have a first half cell containing a first redox couple dissolved in a solution or contained in a suspension. The solution or suspension can flow from a reservoir to the first half cell. A second half cell contains the solid hybrid electrode, which has a first electrode connected to a second electrode, thereby resulting in an equipotential between the first and second electrodes. The first and second half cells are separated by a separator or membrane.

  17. Redox Flow Batteries: An Engineering Perspective

    SciTech Connect (OSTI)

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

    2014-10-01

    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.

  18. High energy density redox flow device

    DOE Patents [OSTI]

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

    2014-05-13

    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.

  19. Carbon fiber electrode for redox flow battery

    SciTech Connect (OSTI)

    Inoue, M.; Tsuzuki, Y.; Iizuka, Y.; Shimada, M.

    1987-03-01

    Advanced secondary batteries have been developed as electrical energy storage systems for use in electrical utility load-levelling and stand-alone photovoltaic installations. Among them, the redox flow system based on aqueous iron and chromium redox couple is one of the most advanced. An important key to its feasibility is electrode fabrication. Woven and non-woven fabrics of carbon fibers have been used as thin but three dimensional electrodes of the redox flow system in view of their electric conductivity, chemical stability, and economy. One of the electrochemical problems of iron-chromium redox battery related to the electrode is the slow reaction rate of reduction and oxidation of chromium complex ion. As the electron transfer rate of chromium complex ion is lower than that of iron ion, the voltaic efficiency of the battery tends to decrease.

  20. High energy density redox flow device

    DOE Patents [OSTI]

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

    2014-05-13

    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.

  1. Numerical modeling of an all vanadium redox flow battery.

    SciTech Connect (OSTI)

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

    2014-01-01

    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.

  2. Membrane Development for Vanadium Redox Flow Batteries

    SciTech Connect (OSTI)

    Schwenzer, Birgit; Zhang, Jianlu; Kim, Soowhan; Li, Liyu; Liu, Jun; Yang, Zhenguo

    2011-10-17

    Large-scale energy storage has become a main bottleneck for increasing the percentage of renewable energy in our electricity grids. Redox flow batteries are considered to be among the best options for electricity storage in the megawatt range, and large demonstration systems have already been installed. Although the full technological potential of these systems has not been reached yet, currently the main problem hindering more widespread commercialization is the high cost of redox flow batteries. Nafion{reg_sign} as the preferred membrane material is responsible for {approx}11% of the overall cost of a 1 MW/8 MWh system. Therefore in recent years two main membrane-related research threads have emerged: (a) chemical and physical modification of Nafion membranes to optimize their properties with regard to vanadium redox flow battery (VRFB) application; and (b) replacement of the Nafion membranes with different, less expensive materials. This review summarizes the underlying basic science issues associated with membrane use in VRFBs and presents an overview of membrane-related research approaches aimed at improving the efficiency of VRFBs and making the technology cost-competitive. Promising research strategies and materials are identified and suggestions are provided on how materials issues could be overcome.

  3. Systems and methods for rebalancing redox flow battery electrolytes

    DOE Patents [OSTI]

    Pham, Ai Quoc; Chang, On Kok

    2015-03-17

    Various methods of rebalancing electrolytes in a redox flow battery system include various systems using a catalyzed hydrogen rebalance cell configured to minimize the risk of dissolved catalyst negatively affecting flow battery performance. Some systems described herein reduce the chance of catalyst contamination of RFB electrolytes by employing a mediator solution to eliminate direct contact between the catalyzed membrane and the RFB electrolyte. Other methods use a rebalance cell chemistry that maintains the catalyzed electrode at a potential low enough to prevent the catalyst from dissolving.

  4. Advanced Redox Flow Batteries for Stationary Electrical Energy Storage

    SciTech Connect (OSTI)

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

    2012-03-19

    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.

  5. Fe-V redox flow batteries

    DOE Patents [OSTI]

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

    2014-07-08

    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.

  6. Microporous Separators for Fe/V Redox Flow Batteries

    SciTech Connect (OSTI)

    Wei, Xiaoliang; Li, Liyu; Luo, Qingtao; Nie, Zimin; Wang, Wei; Li, Bin; Xia, Guanguang; Miller, Eric; Chambers, Jeff; Yang, Zhenguo

    2012-06-28

    The Fe/V redox flow battery has demonstrated promising performance that is advantageous over other redox flow battery systems. The less oxidative nature of the Fe(III) species enables use of hydrocarbon - based ion exchange membranes or separators. Daramic(reg. sign) microporous polyethylene separators were tested on Fe/V flow cells using the sulphuric/chloric mixed acid - supporting electrolytes. Among them, Daramic(reg. sign) C exhibited good flow cell cycling performance with satisfactory repeatability over a broad temperature range of 5 - 50 degrees C. Energy efficiency (EE) of C remains above 67% at current densities of 50 - 80 cm{sup -2} in the temperature range from room temperature to 50 degrees C. The capacity decay problem could be circumvented through hydraulic pressure balancing by applying different pump rates to the positive and negative electrolytes. Stable capacity and energy were obtained over 40 cycles at room temperature and 40 degrees C. These results manifest that the extremely low-cost separators ($10/cm2) are applicable in the Fe/V flow battery system at an acceptable sacrifice of energy efficiency. This stands for a remarkable breakthrough in significant reduction of the capital cost of the Fe/V flow battery system, and is promising to promote its market penetration in grid stabilization and renewable integration.

  7. Fe/V Redox Flow Battery Electrolyte Investigation and Optimization

    SciTech Connect (OSTI)

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

    2013-05-01

    Recently invented Fe/V redox flow battery (IVBs) system has attracted more and more attentions due to its long-term cycling stability. In this paper, the factors (such as compositions, state of charge (SOC) and temperatures) influencing the stability of electrolytes in both positive and negative half-cells were investigated by an extensive matrix study. Thus an optimized electrolyte, which can be operated in the temperature ranges from -5oC to 50oC without any precipitations, was identified. The Fe/V flow cells using the optimized electrolytes and low-cost membranes exhibited satisfactory cycling performances at different temperatures. The efficiencies, capacities and energy densities of flow batteries with varying temperatures were discussed in detail.

  8. Iron-sulfide redox flow batteries

    DOE Patents [OSTI]

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

    2013-12-17

    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.

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

    E-Print Network [OSTI]

    Kounaves, Samuel P.

    in a see- into, flow-through polycarbonate chamber. A water-tight seal is obtained by using O-rings placed], conductivity sensors [3], REDOX cells [3], and pH sensors. This paper focuses on the development of nine REDOX cells, a conductivity sensor, a temperature #12;attached to the polycarbonatechamber

  10. Solution redox couples for electrochemical energy storage and photoelectrochemical cells

    SciTech Connect (OSTI)

    Chen, Y.W.

    1982-01-01

    Some of the properties of solution redox couples in aqueous solution were investigated to obtain guidelines for designing and selecting redox couples for electrochemical energy storage (redox flow battery) or photoelectrochemical cells. Several first row transition metal ions (Fe, Co, Cu, V, Cr) and their complexes were probed. O-phenanthroline and related ligands were employed to complex iron, cobalt, and copper ions. Macrocyclic and noncyclic pentadentate complexes of iron and copper ions were also studied. Some aspects of solution chemistry, such as dissociation rate, complexation rate, air sensitivity, and the stoichiometry of the complex ions were investigated. Measurements of heterogeneous electron transfer rates, mass transfer rates, stability, standard potential and solubility of the complex ions were carried out.

  11. Electrochemical Model of the Fe/V Redox Flow Battery

    SciTech Connect (OSTI)

    Stephenson, David E.; Kim, Soowhan; Chen, Feng; Thomsen, Edwin C.; Viswanathan, Vilayanur V.; Wang, Wei; Sprenkle, Vincent L.

    2012-11-05

    This paper presents a mathematical model for the new Fe/V redox flow battery chemistry. The model is designed to be useful for stack development and cost analysis purposes.

  12. Development of intermittent redox flow battery for PV system

    SciTech Connect (OSTI)

    Tsuda, Izumi; Kurokawa, Kosuke; Nozaki, Ken [Electrotechnical Lab., Tsukuba, Ibaraki (Japan)

    1994-12-31

    Redox flow battery has been developed as a storage device for photovoltaic systems. The pump loss is the greatest problem for redox flow battery under the low current condition. An intermittent flow redox battery has been developed for the reduction of the pump loss. The experimental results of this battery show that the efficiency under the intermittent pump operation increases higher than the continuous pump operation. Moreover, inert gas bubble technology has been introduced to improve the performance under the high current condition. It is clear from the experiments that this technology increases the efficiencies. The simulation results of these technologies are coincident with experimental results. It is shown by the simulation that they can improve the Faradic and energy efficiencies of a number of stacks in series.

  13. Recent Progress in Redox Flow Battery Research and Development

    SciTech Connect (OSTI)

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

    2013-02-20

    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.

  14. A New Fe/V Redox Flow Battery Using Sulfuric/Chloric Mixed Acid Supporting Electrolyte

    SciTech Connect (OSTI)

    Wang, Wei; Nie, Zimin; Chen, Baowei; Chen, Feng; Luo, Qingtao; Wei, Xiaoliang; Xia, Guanguang; Skyllas-Kazacos, Maria; Li, Liyu; Yang, Zhenguo

    2012-04-01

    A redox flow battery using Fe2+/Fe3+ and V2+/V3+ redox couples in chloric/sulphuric mixed acid supporting electrolyte was investigated for potential stationary energy storage applications. The Fe/V redox flow cell using mixed reactant solutions operated within a voltage window of 0.5-1.35 V with a nearly 100% utilization ratio and demonstrated stable cycling over 100 cycles with energy efficiency > 80% and no capacity fading at room temperature. A 25% improvement in the discharge energy density of the Fe/V cell was achieved compared with the previous reported Fe/V cell using pure chloride acid supporting electrolyte. Stable performance was also achieved in the temperature range between 0 C and 50 C as well as using microporous separator as the membrane. The improved electrochemical performance at room temperature makes the Fe/V redox flow battery a promising option as a stationary energy storage device to enable renewable integration and stabilization of the electrical grid.

  15. ORIGINAL PAPER Redox flow batteries: a review

    E-Print Network [OSTI]

    Mench, Matthew M.

    in a mixture (cm2 /s) E0 Standard cell potential (V) Eeq Equilibrium cell potential (V) F Faraday's constant)chemical potential of species i (J/mol) Uk Potential in phase k (V) wi Permeation coefficient of species i (mol/s cm conducting phase O Oxidant R Reductant 1 Introduction Renewable-energy sources, such as solar and wind

  16. Redox flow batteries based on supporting solutions containing chloride

    DOE Patents [OSTI]

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

    2014-01-14

    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.

  17. Development of vanadium redox flow battery for photovoltaic generation system

    SciTech Connect (OSTI)

    Shibata, Akira; Sato, Kanji; Nakajima, Masato

    1994-12-31

    Photovoltaic power generation system (PV) requires a battery for night and rainy day. A redox flow battery has advantage over a lead acid one on this application for the capability of deep discharge and needlessness of equalized charge. The authors have developed the high performance vanadium redox flow battery for this purpose and inexpensive production technology of electrolyte which occupies the majority in the battery cost by chemical reduction from boiler plant by-product. The 2 kW (10 kWh) battery, the minimum unit for practical size battery (50 kW x 50 h), achieved 1.2 kW/cm{sup 2}-electrode area at the 100 mA/cm{sup 2} current density.

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

    SciTech Connect (OSTI)

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

    2012-04-01

    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.

  19. Performance Evaluation of Microporous Separator in Fe/V Redox Flow Battery

    SciTech Connect (OSTI)

    Wei, Xiaoliang; Luo, Qingtao; Li, Bin; Nie, Zimin; Miller, Eric; Chambers, Jeff; Sprenkle, Vincent L.; Wang, Wei

    2013-04-08

    The newly developed Fe/V redox flow battery has demonstrated attractive cell performance. However, the deliverable energy density is relatively inferior due to the low cell voltage. To compensate this disadvantage and compete with other redox flow battery systems, cost reduction of the Fe/V system is necessary. This paper describes evaluation of hydrocarbon-based Daramic® microporous separators for use in the Fe/V system. The separator B having ion exchange capacity demonstrated excellent capacity retention capability. Separator B exhibited energy efficiency above 65% over a broad temperature range of 5-50oC and at current densities up to 80mA/cm2. Plus, separator B is very inexpensive and has exceptional mechanical properties. Therefore, this separator shows great potential to replace the expensive Nafion® membrane. This will drive down the capital cost and make the Fe/V system a promising low-cost energy storage technology.

  20. Nanomaterials for Fuel cells, Batteries, and Supercapacitors Flow Batteries

    E-Print Network [OSTI]

    Dutta, Indranath

    Nanomaterials for Fuel cells, Batteries, and Supercapacitors Flow Batteries 1. Shao Y, X Wang, MH storage in vanadium redox flow batteries." Journal of Power Sources 195(13):4375-4379. 2. Shao Y, MH nanotube electrodes for redox flow batteries." Electrochemistry Communications 11(10):2064-2067. doi:10

  1. Research and development of redox-flow battery in Electrotechnical Laboratory

    SciTech Connect (OSTI)

    Nozaki, K.; Ozawa, T.

    1982-08-01

    Redox-flow batteries for bulk energy storage are under development at Electrotechnical Laboratory. The following results of the research for component technologies related to redox solutions, electrodes and their materials, and cell structures, and testing and scale up of the systems are reported. The effects of hydrochloric acid concentrations to the electrode reaction rate of chromium chloride in catholyte are investigated. Over 40 types of carbon fiber were tested and screened for the cathode, and it has been shown that a type of carbon cloth made by thermal decomposition of polyacrylonitrile cloth gives excellent performance. Single cells with electrode area of 432 cm/sup 2/ (18 x 24 cm) were developed, and 10-cellstacks were constructed and one of those gave power of 119 W at current density of 30 mA/cm/sup 2/. Cation exchange membrane was used in the cells.

  2. Cost and Performance Model for Redox Flow Batteries

    SciTech Connect (OSTI)

    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.

    2014-02-01

    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.

  3. Thermal design requirements of a 50-kW zinc/redox flow battery for solar electrical energy storage

    SciTech Connect (OSTI)

    Selman, J.R.; Wu, H.; Hollandsworth, R.P.

    1985-01-01

    The conceptual engineering design of a large-scale zinc/redox battery for solar electrical energy storage involves the management of considerable heat flows. This is due to the large heat-of-crystallization of sodium ferrocyanide decahydrate produced during discharge, as well as the usual reversible and irreversible cell-reaction heat effects. A discussion of practical design implications is presented.

  4. Thermal design requirements of a 50-kW zinc/redox flow battery for solar electrical energy storage

    SciTech Connect (OSTI)

    Selman, J.R.; Wu, H.; Hollandsworth, R.P.

    1984-09-01

    The conceptual engineering design of a large-scale zinc/redox battery for solar electrical energy storage involves the management of considerable heat flows. This is due to the large heat-of-crystallization of sodium ferrocyanide decahydrate produced during discharge as well as the usual reversible and irreversible cell-reaction heat effects. A discussion of practical design implications is presented.

  5. High performance electrodes in vanadium redox flow batteries through oxygen-enriched thermal activation

    E-Print Network [OSTI]

    Mench, Matthew M.

    National Laboratory, Oak Ridge, TN 37831, USA h i g h l i g h t s Thermal activation of carbon paper: Vanadium redox flow battery Carbon paper Kinetics Surface area Thermal activation Electrode a b s t r a cHigh performance electrodes in vanadium redox flow batteries through oxygen-enriched thermal

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

    SciTech Connect (OSTI)

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

    2012-06-08

    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.

  7. Electrochemical investigation of polyhalide ion oxidation-reduction on carbon nanotube electrodes for redox flow batteries

    SciTech Connect (OSTI)

    Shao, Yuyan; Engelhard, Mark H.; Lin, Yuehe

    2009-10-01

    Polyhalide ions (Br-/BrCl2-) are an important redox couple for redox flow batteries. The oxidation-reduction behavior of polyhalide ions on a carbon nanotube (CNT) electrode has been investigated with cyclic voltammetry and electrochemical impedance spectroscopy. The onset oxidation potential of Br-/BrCl2- is negatively shifted by >100 mV, and the redox current peaks are greatly enhanced on a CNT electrode compared with that on the most widely-used graphite electrode. The reaction resistance of the redox couple (Br-/BrCl2-) is decreased on a CNT electrode. The redox reversibility is increased on a CNT electrode even though it still needs further improvement. CNT is a promising electrode material for redox flow batteries.

  8. Nitrogen-doped mesoporous carbon for energy storage in vanadium redox flow batteries

    SciTech Connect (OSTI)

    Shao, Yuyan; Wang, Xiqing; Engelhard, Mark H.; Wang, Chong M.; Dai, Sheng; Liu, Jun; Yang, Zhenguo; Lin, Yuehe

    2010-03-22

    We demonstrate a novel electrode material?nitrogen-doped mesoporous carbon (NMC)?for vanadium redox flow batteries. Mesoporous carbon (MC) is prepared using a soft-template method and doped with nitrogen by heat-treating MC in NH3. NMC is characterized with X-ray photoelectron spectroscopy and transmission electron microscopy. The redox reaction of VO2+/VO2+ is characterized with cyclic voltammetry and electrochemical impedance spectroscopy. The electrocatalytic kinetics of the redox couple VO2+/VO2+ is significantly enhanced on NMC electrode compared with MC and graphite electrodes. The reversibility of the redox couple VO2+/VO2+ is greatly improved on NMC (0.61 for NMC vs. 0.34 for graphite). Nitrogen doping facilitates the electron transfer on the electrode/electrolyte interface for both oxidation and reduction processes. NMC is a promising electrode material for redox flow batteries.

  9. Towards High-Performance Nonaqueous Redox Flow Electrolyte through Ionic Modification of Active Species

    SciTech Connect (OSTI)

    Wei, Xiaoliang; Cosimbescu, Lelia; Xu, Wu; Hu, Jian Z.; Vijayakumar, M.; Feng, Ju; Hu, Mary Y.; Deng, Xuchu; Xiao, Jie; Liu, Jun; Sprenkle, Vincent L.; Wang, Wei

    2015-01-01

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

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

    SciTech Connect (OSTI)

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

    2014-12-03

    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.

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

    SciTech Connect (OSTI)

    Li, Bin; Gu, Meng; Nie, Zimin; Wei, Xiaoliang; Wang, Chong M.; Sprenkle, Vincent L.; Wang, Wei

    2014-01-01

    Graphite felts (GFs), as typical electrode materials for all vanadium redox flow batteries (VRBs), limit the cell operation to low current density because of their poor kinetic reversibility and electrochemical activity. Here, in order to address this issue we report an electrocatalyst, Nb2O5, decorating the surface of GFs to reduce the activation barrier for redox conversion. Nb2O5 nanofibers with monoclinic phases are synthesized by hydrothermal method and deposited on GFs, which is confirmed to have catalytic effects towards redox couples of V(II)/V(III) at the negative side and V(IV)/V(V) at the positive side, and thus applied in both electrodes of VRB cells. Due to the low conductivity of Nb2O5, the performance of electrodes heavily depends on the nano size and uniform distribution of catalysts on GFs surfaces. The addition of the water-soluble compounds containing W element into the precursor solutions facilitates the precipitation of nanofibers on the GFs. Accordingly, an optimal amount of W-doped Nb2O5 nanofibers with weaker agglomeration and better distribution on GFs surfaces are obtained, leading to significant improvement of the electrochemical performances of VRB cells particularly under the high power operation. The corresponding energy efficiency is enhanced by 10.7 % under the operation of high charge/discharge current density (150 mA•cm-2) owing to faster charge transfer as compared with that without catalysts. These results suggest that Nb2O5 based nanofibers-decorating GFs hold great promise as high-performance electrodes for VRB applications.

  12. Chemical and Mechanical Degradation of Sulfonated Poly(sulfone) Membranes in Vanadium Redox Flow Batteries

    SciTech Connect (OSTI)

    Kim, Soowhan; Tighe, Timothy B.; Schwenzer, Birgit; Yan, Jingling; Zhang, Jianlu; Liu, Jun; Yang, Zhenguo; Hickner, Michael A.

    2011-10-01

    A sulfonated poly(sulfone) (S-Radel{reg_sign}) membrane with high proton conductivity and low vanadium ion diffusion showed high initial performance in a vanadium redox flow battery (VRFB) but suffered damage during charge/discharge cycling. The S-Radel membrane had different degradation behaviors in flow cell cycling and ex-situ vanadium ion immersion tests. The S-Radel membrane immersed in V5+ solution cracked into small pieces, but in the VRFB cell, the membrane underwent internal delamination preferentially on the side of the membrane that faced the positive electrode. A vanadium-rich interface was observed near the membrane surface that experienced delamination and Raman spectroscopic analysis of the surfaces of the membrane indicated a slightly depressed 1026 cm-1 band corresponding to the sulfonate SO2 stretch for the degraded surface. Even though the S-Radel membrane underwent severe mechanical damage during the flow cell cycling, significant chemical degradation was not obvious from the spectroscopic analyses. For the VRFB containing an S-Radel membrane, an increase in membrane resistance caused an abnormal voltage depression during the discharge cycle. The reversible increase in membrane resistance and severe mechanical degradation of the membrane during cycling may be attributed repeated formation and dissolution of particles inside the membrane. The mechanical stresses imposed by the particles coupled with a small amount of chemical degradation of the polymer by V5+, are likely degradation mechanisms of the S-Radel membrane in VRFBs under high state-of-charge conditions.

  13. Vanadium redox-flow batteries Installation at Ris for characterisation measurements

    E-Print Network [OSTI]

    Vanadium redox-flow batteries ­ Installation at Risø for characterisation measurements Henrik-flow batteries hold a great promise for storing electric energy on a large scale. They have many attractive of the project is to characterise a vanadium battery as a system component. The vanadium battery

  14. Composite blend polymer membranes with increased proton selectivity and lifetime for vanadium redox flow batteries

    SciTech Connect (OSTI)

    Chen, Dongyang; Kim, Soowhan; Sprenkle, Vincent L.; Hickner, Michael A.

    2013-06-01

    Composite membranes based on sulfonated fluorinated poly(arylene ether) (SFPAE) and poly(vinylidene fluoride-co-hexafluoropropene) (P(VDF-co-HFP)) were prepared with various contents of P(VDF-co-HFP) for vanadium redox flow battery (VRFB) applications. The compatibility and interaction of SFPAE and P(VDF-co-HFP) were characterized by atomic force microscopy, differential scanning calorimetry, and Fourier transform infrared spectroscopy. The water uptake, mechanical properties, thermal property, proton conductivity, VO2+ permeability and cell performance of the composite membranes were investigated in detail and compared to the pristine SFPAE membrane. It was found that SFPAE had good compatibility with P(VDF-co-HFP) and the incorporation of P(VDF-co-HFP) increased the mechanical properties, thermal property, and proton selectivity of the materials effectively. An SFPAE composite membrane with 10 wt.% P(VDF-co-HFP) exhibited a 44% increase in VRFB cell lifetime as compared to a cell with a pure SFPAE membrane. Therefore, the P(VDF-co-HFP) blending approach is a facile method for producing low-cost, high-performance VRFB membranes.

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

    E-Print Network [OSTI]

    Liu, Fuqiang

    Short communication All-vanadium redox photoelectrochemical cell: An approach to store solar energy Zi Wei, Dong Liu, Chiajen Hsu, Fuqiang Liu Department of Materials Science and Engineering 24 May 2014 Keywords: Photoelectrochemical reaction Solar energy storage Vanadium redox Solar energy

  16. Bismuth Nanoparticle Decorating Graphite Felt as a High-Performance Electrode for an All-Vanadium Redox Flow Battery

    SciTech Connect (OSTI)

    Li, Bin; Gu, Meng; Nie, Zimin; Shao, Yuyan; Luo, Qingtao; Wei, Xiaoliang; Li, Xiaolin; Xiao, Jie; Wang, Chong M.; Sprenkle, Vincent L.; Wang, Wei

    2013-02-04

    The selection of electrode materials plays a great role in improving performances of all vanadium redox flow batteries (VRBs). Low-cost graphite felt (GF) as traditional electrode material has to be modified to address its issue of low electrocatalytic activity. In our paper, low-cost and highly conductive bismuth nanoparticles, as a powerful alternative electrocatalyst to noble metal, are proposed and synchronously electro-deposited onto the surface of GF while running flow cells employing the electrolytes containing suitable Bi3+. Although bismuth is proved to only take effect on the redox reaction of V(II)/V(III) and present at negative half-cell side, the whole cell electrochemical performances are significantly improved. In particular, the energy efficiency is increased by 11% owing to faster charge transfer as compared with one without Bi at high charge/discharge rate of 150 mA/cm2, which is prone to reduce stack size, thus dramatically reducing the cost. The excellent results show great promise of Bi nano-catalysts in the commercialization of VRBs in terms of product cost as well as electrochemical properties.

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

    SciTech Connect (OSTI)

    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

    2014-01-01

    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.

  18. Room Temperature, Hybrid Sodium-Based Flow Batteries with Multi-Electron Transfer Redox Reactions

    SciTech Connect (OSTI)

    Shamie, Jack S.; Liu, Caihong; Shaw, Leon L.; Sprenkle, Vincent L.

    2015-06-11

    We introduce a new concept of hybrid Na-based flow batteries (HNFBs) with a molten Na alloy anode in conjunction with a flowing catholyte separated by a solid Na-ion exchange membrane for grid-scale energy storage. Such HNFBs can operate at ambient temperature, allow catholytes to have multiple electron transfer redox reactions per active ion, offer wide selection of catholyte chemistries with multiple active ions to couple with the highly negative Na alloy anode, and enable the use of both aqueous and non-aqueous catholytes. Further, the molten Na alloy anode permits the decoupled design of power and energy since a large volume of the molten Na alloy can be used with a limited ion-exchange membrane size. In this proof-of-concept study, the feasibility of multielectron transfer redox reactions per active ion and multiple active ions for catholytes has been demonstrated. The critical barriers to mature this new HNFBs have also been explored.

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

    SciTech Connect (OSTI)

    Delnick, Frank M.

    2014-10-01

    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.

  20. Nitrogen-doped mesoporous carbon for energy storage in vanadium redox flow batteries

    SciTech Connect (OSTI)

    Dai, Sheng [ORNL; Shao, Yuyan [Pacific Northwest National Laboratory (PNNL); Wang, Xiqing [ORNL; Engelhard, Mark H [Pacific Northwest National Laboratory (PNNL); Wang, Congmin [ORNL; Liu, Jun [Pacific Northwest National Laboratory (PNNL); YANG, ZHENGUO [Pacific Northwest National Laboratory (PNNL); Lin, Yuehe [ORNL

    2010-01-01

    We demonstrate an excellent performance of nitrogen-doped mesoporous carbon (N-MPC) for energy storage in vanadium redox flow batteries. Mesoporous carbon (MPC) is prepared using a soft-template method and doped with nitrogen by heat-treating MPC in NH{sub 3}. N-MPC is characterized with X-ray photoelectron spectroscopy and transmission electron microscopy. The redox reaction of [VO]{sup 2+}/[VO{sub 2}]{sup +} is characterized with cyclic voltammetry and electrochemical impedance spectroscopy. The electrocatalytic kinetics of the redox couple [VO]{sup 2+}/[VO{sub 2}]{sup +} is significantly enhanced on N-MPC electrode compared with MPC and graphite electrodes. The reversibility of the redox couple [VO]{sup 2+}/[VO{sub 2}]{sup +} is greatly improved on N-MPC (0.61 for N-MPC vs. 0.34 for graphite), which is expected to increase the energystorage efficiency of redoxflowbatteries. Nitrogen doping facilitates the electron transfer on electrode/electrolyte interface for both oxidation and reduction processes. N-MPC is a promising material for redoxflowbatteries. This also opens up new and wider applications of nitrogen-doped carbon.

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

    SciTech Connect (OSTI)

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

    2013-04-22

    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].

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

    E-Print Network [OSTI]

    Brolo, Alexandre G.

    2007-01-01

    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-effective and rapid fabrication, and would be applicable to most microfluidic fuel cell architectures. © 2007 Elsevier

  3. Nickel Phase Wettability and YSZ Redox Fracture Percolation in Solid Oxide Fuel Cell Anodes

    E-Print Network [OSTI]

    Petta, Jason

    Nickel Phase Wettability and YSZ Redox Fracture Percolation in Solid Oxide Fuel Cell Anodes Alex and Aerospace Engineering Background Solid oxide fuel cells lose mechanical stability and functionality when the anode's ceramic structure is damaged [1]. In cases such as interruption of the fuel supply, Ni can

  4. Proton Gradient Regulation 5-Mediated Cyclic Electron Flow under ATP-or Redox-Limited Conditions: A Study of

    E-Print Network [OSTI]

    Proton Gradient Regulation 5-Mediated Cyclic Electron Flow under ATP- or Redox-Limited Conditions.K.N.) The Chlamydomonas reinhardtii proton gradient regulation5 (Crpgr5) mutant shows phenotypic and functional traits discriminate two pathways for CEF and determine their maximum electron flow rates. The PGR5/proton gradient

  5. Room Temperature, Hybrid Sodium-Based Flow Batteries with Multi-Electron Transfer Redox Reactions

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

    Shamie, Jack S.; Liu, Caihong; Shaw, Leon L.; Sprenkle, Vincent L.

    2015-06-11

    We introduce a new concept of hybrid Na-based flow batteries (HNFBs) with a molten Na alloy anode in conjunction with a flowing catholyte separated by a solid Na-ion exchange membrane for grid-scale energy storage. Such HNFBs can operate at ambient temperature, allow catholytes to have multiple electron transfer redox reactions per active ion, offer wide selection of catholyte chemistries with multiple active ions to couple with the highly negative Na alloy anode, and enable the use of both aqueous and non-aqueous catholytes. Further, the molten Na alloy anode permits the decoupled design of power and energy since a large volumemore »of the molten Na alloy can be used with a limited ion-exchange membrane size. In this proof-of-concept study, the feasibility of multielectron transfer redox reactions per active ion and multiple active ions for catholytes has been demonstrated. The critical barriers to mature this new HNFBs have also been explored.« less

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

    SciTech Connect (OSTI)

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

    2013-01-01

    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.

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

    SciTech Connect (OSTI)

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

    2012-06-27

    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.

  8. Effects of additives on the stability of electrolytes for all-vanadium redox flow batteries

    SciTech Connect (OSTI)

    Zhang, Jianlu; Li, Liyu; Nie, Zimin; Chen, Baowei; Vijayakumar, M.; Kim, Soowhan; Wang, Wei; Schwenzer, Birgit; Liu, Jun; Yang, Zhenguo

    2011-10-01

    The stability of the electrolytes for all-vanadium redox flow battery was investigated with ex-situ heating/cooling treatment and in-situ flow-battery testing methods. The effects of inorganic and organic additives have been studied. The additives containing the ions of potassium, phosphate, and polyphosphate are not suitable stabilizing agents because of their reactions with V(V) ions, forming precipitates of KVSO6 or VOPO4. Of the chemicals studied, polyacrylic acid and its mixture with CH3SO3H are the most promising stabilizing candidates which can stabilize all the four vanadium ions (V2+, V3+, VO2+, and VO2+) in electrolyte solutions up to 1.8 M. However, further effort is needed to obtain a stable electrolyte solution with >1.8 M V5+ at temperatures higher than 40 °C.

  9. Cycling performance and efficiency of sulfonated poly(sulfone) membranes in vanadium redox flow batteries

    SciTech Connect (OSTI)

    Kim, Soowhan; Yan, Jingling; Schwenzer, Birgit; Zhang, Jianlu; Li, Liyu; Liu, Jun; Yang, Zhenguo; Hickner, Michael A.

    2010-11-30

    As an alternative to the expensive Nafion® ion exchange membrane, an inexpensive commercially-available Radel® polymer was sulfonated, fabricated into a thin membrane, and evaluated for its performance in a vanadium redox flow battery (VRFB). The sulfonated Radel (S-Radel) membrane showed almost an order of magnitude lower permeability of V (IV) ions (2.07×10-7 cm2/min), compared to Nafion 117 (1.29×10-6 cm2/min), resulting in better coulombic efficiency (~98% vs. 95% at 50 mA/cm2) and lower capacity loss per cycle. Even though the S-Radel membrane had slightly higher membrane resistance, the energy efficiency of the VRFB with the S-Radel membrane was comparable to that of Nafion due to its better coulombic efficiency. The S-Radel membrane exhibited good performance up to 40 cycles, but a decay in performance at later cycles was observed.

  10. Spectroscopic Investigations of the Fouling Process on Nafion Membranes in Vanadium Redox Flow Batteries

    SciTech Connect (OSTI)

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

    2011-01-01

    The Nafion-117 membrane used in vanadium redox flow battery (VRFB) is analyzed by X-ray photoelectron spectroscopy (XPS) and nuclear magnetic resonance (NMR) spectroscopy. The XPS study reveals the chemical identity and environment of vanadium cations accumulated at the surface due to their low diffusivity. On the other hand, the 17O NMR spectrum explores the diffused vanadium cation from the bulk part of Nafion and shows the chemical bonding of cation and the host membrane. The 19F NMR shows the basic Nafion structure is not altered due to the presence of diffused vanadium cation. Based on these spectroscopic studies, the chemical environment of diffused vanadium cation in the Nafion membrane is discussed. This study also shed light into the possible cause for the high diffusivity of certain vanadium cations inside the Nafion membranes.

  11. Electronic Tuning of Nickel-Based Bis(dicarbollide) Redox Shuttles in Dye-Sensitized Solar Cells,

    SciTech Connect (OSTI)

    Spokoyny, Alexander M.; Li, Tina C.; Farha, Omar K.; Machan, C. W.; She, Chunxing; Stern, C. L.; Marks, Tobin J.; Hupp, Joseph T.; Mirkin, Chad

    2010-01-01

    Rational design of a new series of boron-functionalized Ni{sup III}/Ni{sup IV}–bis(dicarbollide) clusters results in a family of robust and tunable redox shuttles. This offers a means to rationally control the redox properties in dye-sensitized solar cells (DSCs), leading to exceptionally high open-circuit voltages.

  12. Mixed-Metal, Structural, and Substitution Effects of Polyoxometalates on Electrochemical Behavior in a Redox Flow Battery

    SciTech Connect (OSTI)

    Pratt, Harry D [Sandia National Laboratories; Pratt, William R [Sandia National Laboratories; Fang, Xikui [Ames Laboratory; Hudak, Nicholas S [Sandia National Laboratories; Anderson, Travis M [Sandia National Laboratories

    2014-08-01

    A pair of redox flow batteries containing polyoxometalates was tested as part of an ongoing program in stationary energy storage. The iron-containing dimer, (SiFe3W9(OH)3O34)2(OH)311?, cycled between (SiFe3W9(OH)3O34)2(OH)311?/(SiFe3W9(OH)3O34)2(OH)314?and (SiFe3W9(OH)3O34)2(OH)317?/(SiFe3W9(OH)3O34)2(OH)314? for the positive and negative electrode, respectively. This compound demonstrated a coulombic efficiency of 83% after 20 cycles with an electrochemical yield (measured discharge capacity as a percentage of theoretical capacity) of 55%. Cyclic voltammetry on the Lindqvist ion, cis-V2W4O194?, showed quasi-reversible vanadium electrochemistry, but tungsten reduction was mostly irreversible. In a flow cell configuration, cis-V2W4O194?had a coulombic efficiency of 45% (for a two-electron process) and an electrochemical yield of 16% after 20 cycles. The poor performance of cis-V2W4O194?was attributed primarily to its higher charge density. Collectively, the results showed that both polyoxometalate size and charge density are both important parameters to consider in battery material performance.

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

    SciTech Connect (OSTI)

    Li, Liyu; Kim, Soowhan; Wang, Wei; Vijayakumar, M.; Nie, Zimin; Chen, Baowei; Zhang, Jianlu; Xia, Guanguang; Hu, Jian Z.; Graff, Gordon L.; Liu, Jun; Yang, Zhenguo

    2011-05-01

    Low cost, high performance redox flow batteries are highly demanded for up to multi-megawatt levels of renewable and grid energy storage. Here, we report a new vanadium redox flow battery with a significant improvement over the current technologies. This new battery utilizes a sulfate-chloride mixed solution, which is capable of dissolving more than 2.5 M vanadium or about a 70% increase in the energy storage capacity over the current vanadium sulfate system. More importantly, the new electrolyte remains stable over a wide temperature range of -5 to 60oC, potentially eliminating the need of active heat management. Its high energy density, broad operational temperature window, and excellent electrochemical performance would lead to a significant reduction in the cost of energy storage, thus accelerating its market penetration.

  14. Vanadium redox flow battery efficiency and durability studies of sulfonated Diels Alder poly(phenylene)s

    SciTech Connect (OSTI)

    Fujimoto, Cy H.; Kim, Soowhan; Stains, Ronald; Wei, Xiaoliang; Li, Liyu; Yang, Zhenguo

    2012-07-01

    Sulfonated Diels Alder poly(phenylene) (SDAPP) was examined for vanadium redox flow battery (VRFB) use. The ion exchange capacity (IEC) was varied from 1.4, 1.6 and 2.0 meq/g in order to tune the proton conductivity and vanadium permeability. Coulombic efficiencies between 92 to 99% were observed, depending on IEC (lower IEC, higher coulombic efficiencies). In all cases the SDAPP displayed comparable energy efficiencies (88 - 90%) to Nafion 117 (88%) at 50mA/cm2. Membrane durability also was dependent on IEC; SDAPP with the highest IEC lasted slightly over 50 cycles while SDAPP with the lowest IEC lasted over 400 cycles and testing was discontinued only due to time constraints. Accelerated vanadium lifetime studies were initialed with SDAPP, by soaking films in a 0.1 M V5+ and 5.0 M total SO4-2 solution. The rate of degradation was also proportional with IEC; the 2 meq/g sample dissolved within 376 hours, the 1.6 meq/g sample dissolved after 860 hours, while the 1.4 meq/g sample broke apart after 1527 hours.

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

    SciTech Connect (OSTI)

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

    2013-09-02

    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.

  16. In situ redox cycle of a nickelYSZ fuel cell anode in an environmental transmission electron microscope

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    In situ redox cycle of a nickel­YSZ fuel cell anode in an environmental transmission electron of a nickel/yttria-stabilized zirconia solid oxide fuel cell anode. The results reveal that the transfer transmission electron microscopy (ETEM); Solid oxide fuel cell (SOFC); Reduction; Oxidation; Density functional

  17. Electronic Tuning of Nickel-Based Bis(dicarbollide) Redox Shuttles in Dye-Sensitized Solar Cells

    SciTech Connect (OSTI)

    Spokoyny, Alexander M. [Northwestern Univ., Evanston, IL (United States); Li, Tina C. [Northwestern Univ., Evanston, IL (United States); Farha, Omar K. [Northwestern Univ., Evanston, IL (United States); Machan, Charles W. [Northwestern Univ., Evanston, IL (United States); She, Chunxing [Northwestern Univ., Evanston, IL (United States); Stern, Charlotte L. [Northwestern Univ., Evanston, IL (United States); Marks, Tobin J. [Northwestern Univ., Evanston, IL (United States); Hupp, Joseph T. [Northwestern Univ., Evanston, IL (United States); Mirkin, Chad A. [Northwestern Univ., Evanston, IL (United States)

    2010-01-01

    Rational design of a new series of boron-functionalized Ni{sup III}/Ni{sup IV}–bis(dicarbollide) clusters results in a family of robust and tunable redox shuttles (see diagram; EDG and EWG denote electron-donating and -withdrawing groups, respectively). This offers a means to rationally control the redox properties in dye-sensitized solar cells (DSCs), leading to exceptionally high open-circuit voltages.

  18. Redox battery including a bromine positive electrode and a chromium ion negative electrode and method

    SciTech Connect (OSTI)

    Giner, J.D.; Stark, H.H.

    1984-09-04

    A redox flow battery with a positive half-cell compartment containing bromide ion, bromine and a complexing organic liquid for bromine, and a negative electrode half-cell compartment containing chromium ion, and including electrolyte fluid communication therebetween.

  19. Platinum-CatalyzedOxidations of Organic Compounds by Ferric Sulfate: Use of a Redox Fuel Cell to Mediate Complete Oxidation of

    E-Print Network [OSTI]

    Prentiss, Mara

    Platinum-CatalyzedOxidations of Organic Compounds by Ferric Sulfate: Use of a Redox Fuel Cell of a redox fuel cell. Figure 1 shows a schematic of the fuel cell. Fe(I1) was electrochemically oxidized consisted of WDF graphite felt (Union Carbide) that was surface oxidized with boiling, concentrated nitric

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

    SciTech Connect (OSTI)

    Li, Tina C.; Spokoyny, Alexander M.; She, Chunxing; Farha, Omar K.; Mirkin, Chad; Marks, Tobin J.; Hupp, Joseph T.

    2010-01-01

    Nickel bis(dicarbollide) is used as a fast, one-electron outer sphere redox couple in dye-sensitized solar cells. Device performances with this anionic shuttle are investigated with different electrolyte concentrations and additives, using only 0.030 M of the Ni(III) bis(dicarbollide) to efficiently regenerate the ruthenium dye. Atomic layer deposition of Al{sub 2}O{sub 3} on the nanoparticulate TiO{sub 2} photoanodes is further used to improve device performances, increasing current densities almost 2-fold and attaining power conversion efficiencies 10× greater than its metallocene analogue, ferrocene/ferrocenium. Open-circuit voltage decay is used to probe the kinetics of the Ni(III)/(IV) bis(dicarbollide) redox couple, and electron interception is found to be 10{sup 3}× slower than ferrocene/ferrocenium, explaining the large discrepancy in open-circuit voltage potentials between these two redox shuttles.

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

    SciTech Connect (OSTI)

    Li, Tina C. [Northwestern Univ., Evanston, IL (United States); Spokoyny, Alexander M. [Northwestern Univ., Evanston, IL (United States); Chunxing, She [Northwestern Univ., Evanston, IL (United States); Farha, Omar K. [Northwestern Univ., Evanston, IL (United States); Mirkin, Chad A. [Northwestern Univ., Evanston, IL (United States); Marks, Tobin J. [Northwestern Univ., Evanston, IL (United States); Hupp, Joseph T. [Northwestern Univ., Evanston, IL (United States)

    2010-01-01

    Nickel bis(dicarbollide) is used as a fast, one-electron outer sphere redox couple in dye-sensitized solar cells. Device performances with this anionic shuttle are investigated with different electrolyte concentrations and additives, using only 0.030 M of the Ni(III) bis(dicarbollide) to efficiently regenerate the ruthenium dye. Atomic layer deposition of Al{sub 2}O{sub 3} on the nanoparticulate TiO{sub 2} photoanodes is further used to improve device performances, increasing current densities almost 2-fold and attaining power conversion efficiencies ?10× greater than its metallocene analogue, ferrocene/ferrocenium. Open-circuit voltage decay is used to probe the kinetics of the Ni(III)/(IV) bis(dicarbollide) redox couple, and electron interception is found to be ?10{sup 3}× slower than ferrocene/ferrocenium, explaining the large discrepancy in open-circuit voltage potentials between these two redox shuttles.

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

    SciTech Connect (OSTI)

    Vijayakumar, M.; Li, Liyu; Nie, Zimin; Yang, Zhenguo; Hu, Jian Z.

    2012-05-09

    The Vanadium (III) cation structure in mixed acid based electrolyte solution from vanadium redox flow batteries were studied by 17O and 35/37Cl Nuclear Magnetic Resonance (NMR) spectroscopy, electronic spectroscopy and density functional theory (DFT) based computational modeling. Both computational and experimental results reveals that the V(III) species can complex with counter anions (sulfate/chlorine) 10 depend on the composition of its solvation sphere. By analyzing the powder precipitate it was found that the formation of sulfate complexed V(III) species is the crucial process in the precipitation reaction. The precipitation occurs through nucleation of neutral species formed through deprotonation and ion-pair formation process. However, the powder precipitate shows a multiphase nature which warrants multiple reaction pathways for precipitation reaction.

  3. A Mathematical model for the iron/chromium redox battery

    SciTech Connect (OSTI)

    Fedkiw, P.S.; Watts, R.W.

    1984-04-01

    A mathematical model has been developed to describe the isothermal operation of a single anode-separator-cathode unit cell in a redox-flow battery and has been applied to the NASA iron/chromium system. The model, based on porous electrode theory, incorporates redox kinetics, mass transfer, and ohmic effects as well as the parasitic hydrogen reaction which occurs in the chromium electrode. A numerical parameter study was carried out to predict cel performance to aid in the rational design, scale-up, and operation of the flow battery. The calculations demonstrate: an optimum electrode thickness and electrolyte flow rate exist; the amount of hydrogen evolved and, hence, cycle faradaic efficiency, can be affected by cell geometry, flow rate, and charging procedure; countercurrent flow results in enhanced cell performance over cocurrent flow; and elevated temperature operation enhances cell performance.

  4. Fuel cell system with coolant flow reversal

    DOE Patents [OSTI]

    Kothmann, Richard E. (Pittsburgh, PA)

    1986-01-01

    Method and apparatus for cooling electrochemical fuel cell system components. Periodic reversal of the direction of flow of cooling fluid through a fuel cell stack provides greater uniformity and cell operational temperatures. Flow direction through a recirculating coolant fluid circuit is reversed through a two position valve, without requiring modulation of the pumping component.

  5. FLOW-THROUGH POROUS ELECTRODES

    E-Print Network [OSTI]

    Trainham, III, James Arthur

    2011-01-01

    configurations for flow redox battery applications: (i) theporous electrodes A flow-redox battery using flow-by poroustrue in battery applications, Flow..through porous

  6. Fuel cell with internal flow control

    DOE Patents [OSTI]

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

    2012-06-12

    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.

  7. Mirrored serpentine flow channels for fuel cell

    DOE Patents [OSTI]

    Rock, Jeffrey Allan (Rochester, NY)

    2000-08-08

    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.

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

    E-Print Network [OSTI]

    industrials, VCs, DOE, DOD and EPA 33,000 ft. facility for laboratory, engineering, rapid prototyping Engineering Chemical Engineering, CFD, Stress, Heat, Current flow Rapid prototyping Pilot plant design membranes and membrane supports Materials testing and establishing QAS's Electrolytes Pumps, pipes

  9. High Performance Vanadium Redox Flow Batteries with Optimized Electrode Configuration and Membrane Selection

    SciTech Connect (OSTI)

    Liu, Q. H. [University of Tennessee, Knoxville (UTK); Grim, G. M. [University of Tennessee, Knoxville (UTK); Papandrew, A [University of Tennessee, Knoxville (UTK); Turhan, A. [University of Tennessee, Knoxville (UTK); Zawodzinski, Thomas A [ORNL; Mench, Matthew M [ORNL

    2012-01-01

    The performance of a vanadium flow battery with no-gap architecture was significantly improved via several techniques. Specifically, gains arising from variation of the overall electrode thickness, membrane thickness, and electrode thermal treatment were studied. There is a trade-off between apparent kinetic losses, mass transfer losses, and ionic resistance as the electrode thickness is varied at the anode and cathode. Oxidative thermal pretreatment of the carbon paper electrode increased the peak power density by 16%. Results of the pretreatment in air showed greater improvement in peak power density compared to that obtained with pretreatment in an argon environment. The highest peak power density in a VRB yet published to the author s knowledge was achieved at a value of 767 mW cm 2 with optimized membrane and electrode engineering. 2012 The Electrochemical Society. [DOI: 10.1149/2.051208jes] All rights reserved.

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

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

    Renaissance in Flow-Cell Technologies: Recent Advancements and Future Opportunities Renaissance in Flow-Cell Technologies: Recent Advancements and Future Opportunities Presentation...

  11. Flow cytometry aids basic cell biology research and drug discovery

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

    Flow cytometry aids basic cell biology research and drug discovery Flow cytometry aids basic cell biology research and drug discovery Life Technologies Corporation and LANL have...

  12. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect (OSTI)

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  13. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

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

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pdmore »deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.« less

  14. Doped Yttrium Chromite-Ceria Composite as a Redox-Stable and Sulfur-Tolerant Anode for Solid Oxide Fuel Cells

    SciTech Connect (OSTI)

    Yoon, Kyung J.; Coyle, Christopher A.; Marina, Olga A.

    2011-12-11

    A Ca- and Co-doped yttrium chromite (YCCC) - samaria-doped ceria (SDC) composite was studied in relation to a potential use as a solid oxide fuel cell (SOFC) anode material. Tests performed using the yttria-stabilized zirconia (YSZ) electrolyte-supported cells revealed that the electrocatalytic activity of the YCCC-SDC anode towards hydrogen oxidation at 800 C was comparable to that of the Ni-YSZ anode. In addition, the YCCC-SDC anode exhibited superior sulfur tolerant characteristics showing less than 10% increase in a polarization resistance, fully reversible, upon exposure to 20 ppm H2S at 800 C. No performance degradation was observed during multiple reduction-oxidation (redox) cycles when the anode was intentionally exposed to the air environment followed by the reduction in hydrogen. The redox tolerance of the YCCC-SDC anode was attributed to the dimensional and chemical stability of the YCCC exhibiting minimal isothermal chemical expansion upon redox cycling.

  15. 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 RankADVANCEDInstallers/ContractorsPhotovoltaicsState ofSavings forTitleJulyAmyDepartment ofMelissa

  16. Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

    E-Print Network [OSTI]

    Marchese, Francis

    Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

  17. High speed flow cytometric separation of viable cells

    DOE Patents [OSTI]

    Sasaki, Dennis T. (Mountain View, CA); Van den Engh, Gerrit J. (Seattle, WA); Buckie, Anne-Marie (Margate, GB)

    1995-01-01

    Hematopoietic cell populations are separated to provide cell sets and subsets as viable cells with high purity and high yields, based on the number of original cells present in the mixture. High-speed flow cytometry is employed using light characteristics of the cells to separate the cells, where high flow speeds are used to reduce the sorting time.

  18. Effects of interstitial flow on tumor cell migration

    E-Print Network [OSTI]

    Polacheck, William J. (William Joseph)

    2010-01-01

    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 ...

  19. Review of flow battery testing at Sandia

    SciTech Connect (OSTI)

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

    1984-01-01

    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.

  20. NASA Redox Storage System Development Project. Final report

    SciTech Connect (OSTI)

    Hagedorn, N.H.

    1984-10-01

    The Redox Storage System Technology Project was jointly supported by the US Department of Energy and NASA. The objectives of the project were to develop the Redox flow battery concept and to prove its technical and economic viability. The iron and chromium redox couples were selected as the reactants. Membranes and electrodes were developed for the original mode of operating at 25/sup 0/C with the reactants separated by an ion-exchange membrane. Analytical capabilities and system-level operating concepts were developed and verified in a 1-kW, 13-kWh pre-prototype system. A subsequent change was made in operating mode, going to 65/sup 0/C and using mixed reactants. New membranes and a new electrode catalyst were developed, resulting in single cell operation as high as 80 mA/cm/sup 2/ with energy efficiencies greater than 80%. Studies indicate a likely system cost of about $75/kWh. Standard Oil of Ohio (Sohio) has undertaken further development of the Redox system. An exclusive patent license was obtained from NASA by Sohio. Transfer of Redox technology to Sohio is supported by the NASA Technology Utilization Office. This report covers the full duration of the project.

  1. Flow-induced mechanotransduction in cell-cell junctions of endothelial cells

    E-Print Network [OSTI]

    Rabodzey, Aleksandr

    2006-01-01

    Endothelial cells show an unexpected behavior shortly after the onset of laminar flow: their crawling speed decreases ~40% within the first 30 min, but only in a confluent monolayer of endothelial cells, not in subconfluent ...

  2. Co-flow planar SOFC fuel cell stack

    DOE Patents [OSTI]

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

    2004-11-30

    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.

  3. An Improved Equilibrium-Kinetics Speciation Algorithm For Redox...

    Open Energy Info (EERE)

    Speciation Algorithm For Redox Reactions In Variably Saturated Subsurface Flow Systems Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

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

    E-Print Network [OSTI]

    multiple redox transformations involving net charges of -2, -1, and 0, with Ni(II), Ni(III) (3), and Ni at the electrolyte interface. Previous DSC Fc/Fc+ couple work showed that dark currents can be suppressed by TiO2/Fc+ vs SCE (translating to a smaller potential difference between the dark electrode and quasi

  5. A review of flow battery testing at Sandia

    SciTech Connect (OSTI)

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

    1984-08-01

    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.

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

    SciTech Connect (OSTI)

    2010-09-09

    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.

  7. Determination of redox reaction rates and –orders by in-situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect (OSTI)

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  8. Determination of redox reaction rates and –orders by in-situ liquid cell electron microscopy of Pd and Au solution growth

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

    Sutter, Eli A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Sutter, Peter W. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-12-03

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e?aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e?aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e?aq]. By comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e?aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  9. Fuel Cell Assembly Process Flow for High Productivity

    E-Print Network [OSTI]

    Edwards, David A.

    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

  10. Affinity Flow Fractionation for label-free cell sorting

    E-Print Network [OSTI]

    Bose, Suman

    2014-01-01

    Capture and isolation of flowing cells from body fluids such as peripheral blood, bone marrow or pleural effusion has enormous implications in diagnosis, disease monitoring, and drug testing. However, in many situations ...

  11. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    streams of aqueous zinc bromide and bromine circulate inzinc reaction does not only involve dissolved species in the aqueous phase. At the positive electrode, bromidebromide and sulphide are 4 ? 10 –5 and 3 ? 10 –6 cm/s, respectively. 5.2.4 Zinc/

  12. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    P. C. Butler, "Advanced Batteries for Electric Vehicles andIntroduction," in Hnadbook of Batteries, 3rd Edition, D.T. B. Reddy, Handbook of Batteries, 2002). [67] R. Zito, US

  13. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    A. Basha, Industrial & Engineering Chemistry Research, 47,N. Bennion, Industrial & Engineering Chemistry Fundamentals,

  14. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    latter issues and energy storage for the grid in general canelectric grid. To date, however, energy storage comprisesgrid- storage technologies and does not require specific geographical siting, as pumped hydroelectric and compressed-air energy storage (

  15. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    Li, and L. T. Thompson, Electrochemistry Communications, 11,A. E. S. Sleightholme, Electrochemistry Communications, 12,Journal of Applied Electrochemistry, 22, 927 (1992). [25] M.

  16. Redox Flow Batteries, a Review

    E-Print Network [OSTI]

    Weber, Adam Z.

    2013-01-01

    is the intimacy of the solid/electrolyte contact [18, 36].a gas phase at the solid/electrolyte interface could be duethrough the electrolyte phase (2) and the solid phase (1) at

  17. Fuel cell with metal screen flow-field

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  18. Fuel cell with metal screen flow-field

    DOE Patents [OSTI]

    Wilson, M.S.; Zawodzinski, C.

    1998-08-25

    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.

  19. Combustor air flow control method for fuel cell apparatus

    DOE Patents [OSTI]

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

    2001-01-01

    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.

  20. Fluid flow plate for decreased density of fuel cell assembly

    SciTech Connect (OSTI)

    Vitale, N.G.

    1999-11-09

    A fluid flow plate includes first and second outward faces. Each of the outward faces has a flow channel thereon for carrying respective fluid. At least one of the fluids serves as reactant fluid for a fuel cell of a fuel cell assembly. One or more pockets are formed between the first and second outward faces for decreasing density of the fluid flow plate. A given flow channel can include one or more end sections and an intermediate section. An interposed member can be positioned between the outward faces at an interface between an intermediate section, of one of the outward faces, and an end section, of that outward face. The interposed member can serve to isolate the reactant fluid from the opposing outward face. The intermediate section(s) of flow channel(s) on an outward face are preferably formed as a folded expanse.

  1. Fluid flow plate for decreased density of fuel cell assembly

    SciTech Connect (OSTI)

    Vitale, Nicholas G.

    1999-01-01

    A fluid flow plate includes first and second outward faces. Each of the outward faces has a flow channel thereon for carrying respective fluid. At least one of the fluids serves as reactant fluid for a fuel cell of a fuel cell assembly. One or more pockets are formed between the first and second outward faces for decreasing density of the fluid flow plate. A given flow channel can include one or more end sections and an intermediate section. An interposed member can be positioned between the outward faces at an interface between an intermediate section, of one of the outward faces, and an end section, of that outward face. The interposed member can serve to isolate the reactant fluid from the opposing outward face. The intermediate section(s) of flow channel(s) on an outward face are preferably formed as a folded expanse.

  2. Liquid chromatography/Fourier transform IR spectrometry interface flow cell

    DOE Patents [OSTI]

    Johnson, Charles C. (Fairfield, OH); Taylor, Larry T. (Blacksburg, VA)

    1986-01-01

    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.

  3. Liquid chromatography/Fourier transform IR spectrometry interface flow cell

    DOE Patents [OSTI]

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

    1985-01-04

    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.

  4. Bistability of Cell Adhesion in Shear Flow

    E-Print Network [OSTI]

    Efremov, Artem K.

    Cell adhesion plays a central role in multicellular organisms helping to maintain their integrity and homeostasis. This complex process involves many different types of adhesion proteins, and synergetic behavior of these ...

  5. Surface deformation and shear flow in ligand mediated cell adhesion

    E-Print Network [OSTI]

    Sircar, Sarthok

    2015-01-01

    We present a single, unified, multi-scale model to study the attachment\\detachment dynamics of two deforming, near spherical cells, coated with binding ligands and subject to a slow, homogeneous shear flow in a viscous fluid medium. The binding ligands on the surface of the cells experience attractive and repulsive forces in an ionic medium and exhibit finite resistance to rotation via bond tilting. The macroscale drag forces and couples describing the fluid flow inside the small separation gap between the cells, are calculated using a combination of methods in lubrication theory and previously published numerical results. For a select range of material and fluid parameters, a hysteretic transition of the sticking probability curves between the adhesion and fragmentation domain is attributed to a nonlinear relation between the total microscale binding forces and the separation gap between the cells. We show that adhesion is favored in highly ionic fluids, increased deformability of the cells, elastic binders ...

  6. Flow Cell Assays with Microtubules: Motility/Dynamics in Fluorescence and VE-DIC

    E-Print Network [OSTI]

    Mitchison, Tim

    Flow Cell Assays with Microtubules: Motility/Dynamics in Fluorescence and VE-DIC Flow cell assays procedures for flow cell assays. I. Solutions & Supplies BRB80 (1X): 80 mM PIPES, 1 mM MgCl2, 1 mM EGTA, pH 6 below) Flow Cells: Flow cells can be constructed in many different ways. The most common way is to place

  7. Gradient isolator for flow field of fuel cell assembly

    DOE Patents [OSTI]

    Ernst, William D. (Troy, NY)

    1999-01-01

    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.

  8. Gradient isolator for flow field of fuel cell assembly

    DOE Patents [OSTI]

    Ernst, W.D.

    1999-06-15

    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.

  9. Efficiency of initiating cell adhesion in hydrodynamic flow

    E-Print Network [OSTI]

    C. Korn; U. S. Schwarz

    2006-09-05

    We theoretically investigate the efficiency of initial binding between a receptor-coated sphere and a ligand-coated wall in linear shear flow. The mean first passage time for binding decreases monotonically with increasing shear rate. Above a saturation threshold of the order of a few 100 receptor patches, the binding efficiency is enhanced only weakly by increasing their number and size, but strongly by increasing their height. This explains why white blood cells in the blood flow adhere through receptor patches localized to the tips of microvilli, and why malaria-infected red blood cells form elevated receptor patches (knobs).

  10. Renaissance in Flow-Cell Technologies Recent Advancements and Future Opportunities

    E-Print Network [OSTI]

    Electrodes Thick = High Energy Thin = High Power 4 #12;uper or s y UTC Proprietary Flow Batteries cells Flow Battery SystemFlow Battery System Electrolyte flow Ion exchange membrane Cell stack (power System Architectures Proton Exchange Membrane Flow Batteries: Energy stored in solutions

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

    DOE Patents [OSTI]

    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)

    1994-01-01

    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.

  12. Fuel cell with interdigitated porous flow-field

    DOE Patents [OSTI]

    Wilson, Mahlon S. (Los Alamos, NM)

    1997-01-01

    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.

  13. Fuel cell with interdigitated porous flow-field

    DOE Patents [OSTI]

    Wilson, M.S.

    1997-06-24

    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.

  14. Laminar flow cells for single-molecule studies of DNA-protein interactions

    E-Print Network [OSTI]

    Cai, Long

    Laminar flow cells for single-molecule studies of DNA-protein interactions Laurence R Brewer1 in which the interactions of proteins with DNA have been studied within the confines of laminar flow cells

  15. Interstitial flow influences direction of tumor cell migration through competing mechanisms

    E-Print Network [OSTI]

    Charest, Joseph L.

    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 ...

  16. 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:FinancingPetroleum12, 2015ExecutiveFluorescentDanKathy LoftusFuel Cell Seminar2015ofFuel

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

    E-Print Network [OSTI]

    Choi, Hyo Won; Barakat, Abdul I.

    2009-01-01

    of the surface topography of living endothelial cells imagedby Flow: Effect of Cell Topography H YO W ON C HOI and AChannel length, L (lm) Cell topography values are based on

  18. A flow field enabling operating direct methanol fuel cells with highly concentrated methanol

    E-Print Network [OSTI]

    Zhao, Tianshou

    the cathode potential, but also leads to a waste of fuel, lowering the overall efficiency of fuel cell [5A flow field enabling operating direct methanol fuel cells with highly concentrated methanol Q. Xu Available online 8 October 2010 Keywords: Fuel cells Direct methanol fuel cells Concentrated methanol Flow

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

    E-Print Network [OSTI]

    Victoria, University of

    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

  20. AIR-BREATHING LAMINAR FLOW BASED MICROFLUIDIC FUEL CELL Ranga S. Jayashree1

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    AIR-BREATHING LAMINAR FLOW BASED MICROFLUIDIC FUEL CELL Ranga S. Jayashree1 , Lajos Gancs2 , Eric R of the laminar flow-based microfluidic fuel cell. A 5-mm thick graphite plate (anode, fuel cell grade graphite bipolar plate purchased from Fuel Cell Stores.com) was cleaned by sonication in large portions of Milli

  1. Improved Flow-Field Structures for Direct Methanol Fuel Cells

    SciTech Connect (OSTI)

    Gurau, Bogdan

    2013-05-31

    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.

  2. An algebraic model for a zinc/bromine flow cell

    SciTech Connect (OSTI)

    Simpson, G.D.; White, R.E. . Dept. of Chemical Engineering)

    1989-08-01

    An algebraic model for a parallel plate, zinc/bromine flow cell is presented and used to predict various performance quantities, which are compared to those predicted by using previously published differential equation models. The results presented compare well with previous work. The model is based on the concept of using well-mixed zones and linear concentration and potential profiles for the diffusion layers and the separator. The Butler-Volmer equation is used for the electro chemical reactions, and the homogeneous reaction between bromine and bromide is included.

  3. Journal of Power Sources 128 (2004) 5460 Microfluidic fuel cell based on laminar flow

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    2004-01-01

    Journal of Power Sources 128 (2004) 54­60 Microfluidic fuel cell based on laminar flow Eric R compartments. While these PEM-type fuel cell designs have great promise to become the power source of choice a novel microfluidic fuel cell concept that utilizes the occurrence of multi-stream laminar flow

  4. Solid oxide fuel cell having compound cross flow gas patterns

    DOE Patents [OSTI]

    Fraioli, Anthony V. (Hawthorn Woods, IL)

    1985-01-01

    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.

  5. Solid oxide fuel cell having compound cross flow gas patterns

    DOE Patents [OSTI]

    Fraioli, A.V.

    1983-10-12

    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.

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

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Analysis of Pt/C electrode performance in a flowing- electrolyte alkaline fuel cell Fikile R cell Electrode characterization X-ray micro-computed tomography Microfluidic fuel cell Carbonates a b a microfluidic H2/O2 fuel cell as an analytical platform. Both anodes and cathodes were investigated

  7. Hybrid energy storage systems utilizing redox active organic compounds

    DOE Patents [OSTI]

    Wang, Wei; Xu, Wu; Li, Liyu; Yang, Zhenguo

    2015-09-08

    Redox flow batteries (RFB) have attracted considerable interest due to their ability to store large amounts of power and energy. Non-aqueous energy storage systems that utilize at least some aspects of RFB systems are attractive because they can offer an expansion of the operating potential window, which can improve on the system energy and power densities. One example of such systems has a separator separating first and second electrodes. The first electrode includes a first current collector and volume containing a first active material. The second electrode includes a second current collector and volume containing a second active material. During operation, the first source provides a flow of first active material to the first volume. The first active material includes a redox active organic compound dissolved in a non-aqueous, liquid electrolyte and the second active material includes a redox active metal.

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

    E-Print Network [OSTI]

    Van Zee, John W.

    and transportation applications. One aspect that is crucial to optimizing the performance of PEM fuel cellsMODELING THE EFFECT OF FLOW FIELD DESIGN ON PEM FUEL CELL PERFORMANCE Jeffrey Glandt, Sirivatch Shimpalee, Woo-kum Lee, and John W. Van Zee Fuel Cell Research Laboratory Department of Chemical Engineering

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

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    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

  10. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impactsand engineersAcquisition and ContractOfficeofHead

  11. Redox shuttles for lithium ion batteries

    DOE Patents [OSTI]

    Weng, Wei; Zhang, Zhengcheng; Amine, Khalil

    2014-11-04

    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.

  12. Grid Applications for Energy Storage Flow Cells for Energy Storage Workshop

    E-Print Network [OSTI]

    Storage #12;Competitive Electric Market Structure Power Generation Distributed Generation Grid Management Power Mkts. & Reliability Micro-Grids Power Quality Grid Reliability Competitive State Regulated FERCGrid Applications for Energy Storage Flow Cells for Energy Storage Workshop Washington DC 7

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

    E-Print Network [OSTI]

    Ordonez, Juan C.

    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

  14. The state diagram for cell adhesion under flow: Leukocyte rolling and firm adhesion

    E-Print Network [OSTI]

    Tees, David F.J.

    The state diagram for cell adhesion under flow: Leukocyte rolling and firm adhesion Kai-Chien Chang, Philadelphia, PA, and approved July 31, 2000 (received for review May 24, 2000) Leukocyte adhesion under flow mediated by selectins) followed by firm adhesion (primarily me- diated by integrins). Using a computational

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

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Electro-osmotic flow control for living cell analysis in microfluidic PDMS chips Tomasz Glawdel April 2008 Received in revised form 20 June 2008 Available online 10 July 2008 Keywords: Electro-osmotic lines each of which consists of an integrated elec- tro-osmotic pump, a cell culture chamber

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

    E-Print Network [OSTI]

    Freund, Jonathan B.

    . [http://dx.doi.org/10.1063/1.4819341] I. INTRODUCTION Flowing red blood cells are well-known to display Since capillary blood vessels are as small as 4 m,3 significant deformations are essential for normal devices of the same scale as blood cells, which offers the possibility of testing or sorting blo

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

    SciTech Connect (OSTI)

    Zhao Junwei; Bogart, R. S.; Kosovichev, A. G.; Hartlep, Thomas; Duvall, T. L. Jr.

    2013-09-10

    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.

  18. Development of a cell-based stream flow routing model 

    E-Print Network [OSTI]

    Raina, Rajeev

    2005-08-29

    This study presents the development of a cell-based routing model. The model developed is a two parameter hydrological routing model that uses a coarse resolution stream network to route runoff from each cell in the watershed to the outlet...

  19. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformation Current HABFES OctoberEvanServices »First ObservationFast(ER1)Flow BatteryFlow

  20. Pollution of Natural Waters 1. Redox chemistry

    E-Print Network [OSTI]

    Schofield, Jeremy

    Pollution of Natural Waters Outline: 1. Redox chemistry 2. Redox potential in aquatic systems 3; Photosynthetic algae limited to euphotic zone where light can penetrate #15; Below euphotic zone, O 2

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

    E-Print Network [OSTI]

    Rubinstein, Benjamin

    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

  2. Enumerating Colorings, Tensions and Flows in Cell Complexes

    E-Print Network [OSTI]

    Beck, Matthias; Breuer, Felix; Godkin, Logan; Martin, Jeremy L.

    2014-02-01

    by Stanley [33]; the best known of these is that |?G(?1)| is the number of acyclic orientations of G. This phenomenon is an instance of combinatorial reciprocity and is closely related to, e.g., Ehrhart’s enumeration of lattice points in polytopes [19... of nowhere-zero K-flows of X, where K is the palette {?k+ 1,?k+ 2, . . . , k? 1} ? Z. When X is a graph, these are all polynomials in k as was shown by Kochol [25, 26]. These can be regarded as Ehrhart functions, enumerating lattice points in inside...

  3. Salt removal using multiple microbial desalination cells under continuous flow conditions

    E-Print Network [OSTI]

    Salt removal using multiple microbial desalination cells under continuous flow conditions Youpeng that inhibit bacterial metabolism. The salt solution also moved through each desalination chamber in series. Increasing the hydraulic retention times (HRTs) of the salt so- lution from 1 to 2 days increased total Na

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

    E-Print Network [OSTI]

    for biohydrogen production based on electrohydro- genesis [1]. In an MEC exoelectrogenic microbes on the anodeMulti-electrode continuous flow microbial electrolysis cell for biogas production from acetate , cathode surface area; 74 A/m3 ) within three days of operation. The maximum hydrogen production (day 3

  5. Hydrogen production from continuous flow, microbial reverse-electrodialysis electrolysis cells treating fermentation

    E-Print Network [OSTI]

    Hydrogen production from continuous flow, microbial reverse-electrodialysis electrolysis cells, USA h i g h l i g h t s Fermentation effluent fed MREC produced hydrogen without grid energy in revised form 23 May 2015 Accepted 25 May 2015 Available online 29 May 2015 Keywords: Microbial reverse

  6. 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 this separator with the cathode. The maximum power density was 975 mW/m2 , with an overall chemical oxygen demand densities, the recovery of elec- trons as current [coulombic efficiency (CE)], and energy recovery while

  7. A three-dimensional numerical model of a micro laminar flow fuel cell with a bridge-shaped microchannel cross-section

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    A three-dimensional numerical model of a micro laminar flow fuel cell with a bridge: Membraneless fuel cell Laminar flow fuel cell Numerical model Convection-diffusion equations Electrode kinetics equations COMSOL a b s t r a c t The operation of a laminar flow fuel cell (LFFC) involves complex interplay

  8. Manufacturing all-polymer laminar flow-based fuel cells A.S. Hollinger, P.J.A. Kenis*

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Manufacturing all-polymer laminar flow-based fuel cells A.S. Hollinger, P.J.A. Kenis* Department, Urbana, IL 61801, USA h i g h l i g h t s Manufactured a lightweight, all-polymer direct methanol April 2013 Keywords: Manufacturing Polymer Laminar flow Microfluidic Fuel cell Stack a b s t r a c

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

    DOE Patents [OSTI]

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

    2014-10-21

    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.

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

    E-Print Network [OSTI]

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

    2014-01-01

    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 pers...

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

    SciTech Connect (OSTI)

    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.

    2014-07-03

    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.

  12. Method for characterization of the redox condition of cementitious materials

    DOE Patents [OSTI]

    Almond, Philip M.; Langton, Christine A.; Stefanko, David B.

    2015-12-22

    Disclosed are methods for determining the redox condition of cementitious materials. The methods are leaching methods that utilize an in situ redox indicator that is present in the cementitious materials as formed. The in situ redox indicator leaches from cementitious material and, when the leaching process is carried out under anaerobic conditions can be utilized to determine the redox condition of the material. The in situ redox indicator can exhibit distinct characteristics in the leachate depending upon the redox condition of the indicator.

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

    E-Print Network [OSTI]

    Mench, Matthew M.

    Investigation of Temperature-Driven Water Transport in Polymer Electrolyte Fuel Cell: Phase and durability for polymer electrolyte fuel cells PEFCs . The most commonly used polymer electrolyte membranes-Change-Induced Flow Soowhan Kim* and M. M. Mench**,z Fuel Cell Dynamics and Diagnostics Laboratory, Department

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

    E-Print Network [OSTI]

    Tupper, Gary; Mainza, Aubrey

    2015-01-01

    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.

  15. 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...

  16. Dynamic states of cells adhering in shear flow: from slipping to rolling

    E-Print Network [OSTI]

    C. B. Korn; U. S. Schwarz

    2008-04-02

    Motivated by rolling adhesion of white blood cells in the vasculature, we study how cells move in linear shear flow above a wall to which they can adhere via specific receptor-ligand bonds. Our computer simulations are based on a Langevin equation accounting for hydrodynamic interactions, thermal fluctuations and adhesive interactions. In contrast to earlier approaches, our model not only includes stochastic rules for the formation and rupture of bonds, but also fully resolves both receptor and ligand positions. We identify five different dynamic states of motion in regard to the translational and angular velocities of the cell. The transitions between the different states are mapped out in a dynamic state diagram as a function of the rates for bond formation and rupture. For example, as the cell starts to adhere under the action of bonds, its translational and angular velocities become synchronized and the dynamic state changes from slipping to rolling. We also investigate the effect of non-molecular parameters. In particular, we find that an increase in viscosity of the medium leads to a characteristic expansion of the region of stable rolling to the expense of the region of firm adhesion, but not to the expense of the regions of free or transient motion. Our results can be used in an inverse approach to determine single bond parameters from flow chamber data on rolling adhesion.

  17. Effect of direct liquid water injection and interdigitated flow field on the performance of proton exchange membrane fuel cells

    E-Print Network [OSTI]

    Wood, D. L.; Yi, Y. S.; Van Nguyen, Trung

    1998-01-01

    Proper water management is vital to ensuring successful performance of proton exchange membrane fuel cells. The effectiveness of the direct liquid water injection scheme and the interdigitated flow field design towards providing adequate gas...

  18. 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]

    Kenis, Paul J. A.

    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

  19. Redox polymer electrodes for advanced batteries

    DOE Patents [OSTI]

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

    1998-01-01

    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.

  20. Eco-friendly Battery and Solar Cell All-in-One | U.S. DOE Office...

    Office of Science (SC) Website

    are in contact with the "catholyte." The Science More efficient, eco-friendly electricity generation with a "solar flow battery" combines a redox flow battery and a...

  1. 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim (1 of 8) 1500271wileyonlinelibrary.com Ionic Liquid Redox Catholyte for High Energy Efficiency,

    E-Print Network [OSTI]

    Angell, C. Austen

    .com Ionic Liquid Redox Catholyte for High Energy Efficiency, Low-Cost Energy Storage Leigang Xue, Telpriore. Although their cell cycled well, the quite high (91%)[3] energy efficiency of the normal ZEBRA battery redox catholyte by combining it with a liquid sodium anode to achieve >96% overall energy efficiency

  2. A new flow field design for polymer electrolyte-based fuel cells C. Xu, T.S. Zhao *

    E-Print Network [OSTI]

    Zhao, Tianshou

    of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, HongA new flow field design for polymer electrolyte-based fuel cells C. Xu, T.S. Zhao * Department (CESFF), for polymer electrolyte-based fuel cells, which was obtained by re-patterning conventional

  3. A simple model for a zinc/bromine flow cell and associated storage tanks

    SciTech Connect (OSTI)

    Simpson, G.D.; White, R.E. . Dept. of Chemical Engineering)

    1990-06-01

    A simple model for a parallel plate, zinc/bromine flow cell and associated storage tanks is presented and used to make time-dependent predictions for various quantities in the system. The model is based on a previously published algebraic model of the cell at steady-state and time-dependent, first-order differential equations for the storage tanks. The Butler--Volmer equation is used for the electrochemical reactions, and the homogeneous reaction between bromine and bromide is included. The model predictions indicate that the charging operation of a zinc/bromine battery can be significantly improved by using a storage tank with a larger residence time for the bromine side of the system.

  4. Automatic analysis of flow cytometric DNA histograms from irradiated mouse male germ cells

    SciTech Connect (OSTI)

    Lampariello, F.; Mauro, F.; Uccelli, R.; Spano, M.

    1989-01-01

    An automatic procedure for recovering the DNA content distribution of mouse irradiated testis cells from flow cytometric histograms is presented. First, a suitable mathematical model is developed, to represent the pattern of DNA content and fluorescence distribution in the sample. Then a parameter estimation procedure, based on the maximum likelihood approach, is constructed by means of an optimization technique. This procedure has been applied to a set of DNA histograms relative to different doses of 0.4-MeV neutrons and to different time intervals after irradiation. In each case, a good agreement between the measured histograms and the corresponding fits has been obtained. The results indicate that the proposed method for the quantitative analysis of germ cell DNA histograms can be usefully applied to the study of the cytotoxic and mutagenic action of agents of toxicological interest such as ionizing radiations.18 references.

  5. Simulations of Blood Flow in Plain Cylindrical and Constricted Vessels with Single Cell Resolution

    E-Print Network [OSTI]

    Florian Janoschek; Federico Toschi; Jens Harting

    2011-05-31

    Understanding the physics of blood is challenging due to its nature as a suspension of soft particles and the fact that typical problems involve different scales. This is valid also for numerical investigations. In fact, many computational studies either neglect the existence of discrete cells or resolve relatively few cells very accurately. The authors recently developed a simple and highly efficient yet still particulate model with the aim to bridge the gap between currently applied methods. The present work focuses on its applicability to confined flows in vessels of diameters up to 100 micrometres. For hematocrit values below 30 percent, a dependence of the apparent viscosity on the vessel diameter in agreement with experimental literature data is found.

  6. Mean encounter times for cell adhesion in hydrodynamic flow: analytical progress by dimensional reduction

    E-Print Network [OSTI]

    C. B. Korn; U. S. Schwarz

    2008-06-27

    For a cell moving in hydrodynamic flow above a wall, translational and rotational degrees of freedom are coupled by the Stokes equation. In addition, there is a close coupling of convection and diffusion due to the position-dependent mobility. These couplings render calculation of the mean encounter time between cell surface receptors and ligands on the substrate very difficult. Here we show for a two-dimensional model system how analytical progress can be achieved by treating motion in the vertical direction by an effective reaction term in the mean first passage time equation for the rotational degree of freedom. The strength of this reaction term can either be estimated from equilibrium considerations or used as a fit parameter. Our analytical results are confirmed by computer simulations and allow to assess the relative roles of convection and diffusion for different scaling regimes of interest.

  7. Progress in Grid Scale Flow Batteries

    E-Print Network [OSTI]

    Progress in Grid Scale Flow Batteries IMRE GYUK, PROGRAM MANAGER ENERGY STORAGE RESEARCH, DOE Flow 2011Year #12;Flow Battery Research at PNNL and Sandia #12; Iron-containing "MetIL" Redox Couples for Flow Batteries, Sandia Sandia has developed

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

    SciTech Connect (OSTI)

    Beyenal, Haluk; McLEan, Jeff; Majors, Paul; Fredrickson, Jim

    2013-11-14

    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.

  9. 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]

    Schmidt, Volker

    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

  10. Practical thermodynamic quantities for aqueous vanadium- and iron-based flow batteries

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

    Hudak, Nicholas S.

    2013-12-31

    A simple method for experimentally determining thermodynamic quantities for flow battery cell reactions is presented. Equilibrium cell potentials, temperature derivatives of cell potential (dE/dT), Gibbs free energies, and entropies are reported here for all-vanadium, iron–vanadium, and iron–chromium flow cells with state-of-the-art solution compositions. Proof is given that formal potentials and formal temperature coefficients can be used with modified forms of the Nernst Equation to quantify the thermodynamics of flow cell reactions as a function of state-of-charge. Such empirical quantities can be used in thermo-electrochemical models of flow batteries at the cell or system level. In most cases, the thermodynamic quantitiesmore »measured here are significantly different from standard values reported and used previously in the literature. The data reported here are also useful in the selection of operating temperatures for flow battery systems. Because higher temperatures correspond to lower equilibrium cell potentials for the battery chemistries studied here, it can be beneficial to charge a cell at higher temperature and discharge at lower temperature. As a result, proof-of-concept of improved voltage efficiency with the use of such non-isothermal cycling is given for the all-vanadium redox flow battery, and the effect is shown to be more pronounced at lower current densities.« less

  11. Practical thermodynamic quantities for aqueous vanadium- and iron-based flow batteries

    SciTech Connect (OSTI)

    Hudak, Nicholas S.

    2013-12-31

    A simple method for experimentally determining thermodynamic quantities for flow battery cell reactions is presented. Equilibrium cell potentials, temperature derivatives of cell potential (dE/dT), Gibbs free energies, and entropies are reported here for all-vanadium, iron–vanadium, and iron–chromium flow cells with state-of-the-art solution compositions. Proof is given that formal potentials and formal temperature coefficients can be used with modified forms of the Nernst Equation to quantify the thermodynamics of flow cell reactions as a function of state-of-charge. Such empirical quantities can be used in thermo-electrochemical models of flow batteries at the cell or system level. In most cases, the thermodynamic quantities measured here are significantly different from standard values reported and used previously in the literature. The data reported here are also useful in the selection of operating temperatures for flow battery systems. Because higher temperatures correspond to lower equilibrium cell potentials for the battery chemistries studied here, it can be beneficial to charge a cell at higher temperature and discharge at lower temperature. As a result, proof-of-concept of improved voltage efficiency with the use of such non-isothermal cycling is given for the all-vanadium redox flow battery, and the effect is shown to be more pronounced at lower current densities.

  12. Co-flow anode/cathode supply heat exchanger for a solid-oxide fuel cell assembly

    DOE Patents [OSTI]

    Haltiner, Jr., Karl J.; Kelly, Sean M.

    2005-11-22

    In a solid-oxide fuel cell assembly, a co-flow heat exchanger is provided in the flow paths of the reformate gas and the cathode air ahead of the fuel cell stack, the reformate gas being on one side of the exchanger and the cathode air being on the other. The reformate gas is at a substantially higher temperature than is desired in the stack, and the cathode gas is substantially cooler than desired. In the co-flow heat exchanger, the temperatures of the reformate and cathode streams converge to nearly the same temperature at the outlet of the exchanger. Preferably, the heat exchanger is formed within an integrated component manifold (ICM) for a solid-oxide fuel cell assembly.

  13. Redox Shuttle Additives | Argonne National Laboratory

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impactsand engineersAcquisition andRedox ShuttleRedox Shuttle

  14. Air-Breathing Laminar Flow-Based Microfluidic Fuel Cell Ranga S. Jayashree, Lajos Gancs, Eric R. Choban,, Alex Primak, Dilip Natarajan,

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Air-Breathing Laminar Flow-Based Microfluidic Fuel Cell Ranga S. Jayashree, Lajos Gancs, Eric R-based microfluidic fuel cell. Micro fuel cells have long been recognized as promising high energy density power sources for portable applications. Many advances in micro fuel cell development have been made, ranging

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

    E-Print Network [OSTI]

    Gao, Yan

    2011-04-26

    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 transport properties on liquid...

  16. FORUM REVIEW ARTICLE Redox Eustress: Roles for Redox-Active Metabolites

    E-Print Network [OSTI]

    Dietrich, Lars

    and Behavior Chinweike Okegbe,1,* Hassan Sakhtah,1,* Matthew D. Sekedat,1,* Alexa Price-Whelan,2 and Lars E and the evolution of complex life forms, respectively (Fig. 1). While the energy provided by redox chemistry

  17. Methods for using redox liposome biosensors

    DOE Patents [OSTI]

    Cheng, Quan (SF, CA); Stevens, Raymond C. (La Jolla, CA)

    2002-01-01

    The present invention provides methods and compositions for detecting the presence of biologically-important analytes by using redox liposome biosensors. In particular, the present invention provides liposome/sol-gel electrodes suitable for the detection of a wide variety of organic molecules, including but not limited to bacterial toxins.

  18. Pipette-friendly laminar flow patterning for cell-based assays Erwin Berthier, Jay Warrick, Ben Casavant and David J. Beebe*

    E-Print Network [OSTI]

    Beebe, David J.

    destination for loaded fluid and balances the pressure applied to each branch for laminar flow patterningPipette-friendly laminar flow patterning for cell-based assays Erwin Berthier, Jay Warrick, Ben Laminar flow patterning (LFP) is a characteristic method of microfluidic systems that allows two (or more

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

    DOE Patents [OSTI]

    Marchetti, George A. (Western Springs, IL)

    2003-01-03

    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.

  20. Microfluidic Microbial Fuel Cells for Microstructure Interrogations

    E-Print Network [OSTI]

    Parra, Erika Andrea

    2010-01-01

    2.2.1 Electrochemistry & Fuel Cells . . . .General Electrochemistry and Redox xiii Thermodynamics &2.2.2 Ultra-micro-electrochemistry (UME) System time

  1. Flow cytometric analysis of expression of interleukin-2 receptor beta chain (p70-75) on various leukemic cells

    SciTech Connect (OSTI)

    Hoshino, S.; Oshimi, K.; Tsudo, M.; Miyasaka, M.; Teramura, M.; Masuda, M.; Motoji, T.; Mizoguchi, H. )

    1990-08-15

    We analyzed the expression of the interleukin-2 receptor (IL-2R) beta chain (p70-75) on various leukemic cells from 44 patients by flow cytometric analysis using the IL-2R beta chain-specific monoclonal antibody, designated Mik-beta 1. Flow cytometric analysis demonstrated the expression of the IL-2R beta chain on granular lymphocytes (GLs) from all eight patients with granular lymphocyte proliferative disorders (GLPDs), on adult T-cell leukemia (ATL) cells from all three patients with ATL, and on T-cell acute lymphoblastic leukemia (T-ALL) cells from one of three patients with T-ALL. Although GLs from all the GLPD patients expressed the IL-2R beta chain alone and not the IL-2R alpha chain (Tac-antigen: p55), ATL and T-ALL cells expressing the beta chain coexpressed the alpha chain. In two of seven patients with common ALL (cALL) and in both patients with B-cell chronic lymphocytic leukemia, the leukemic cells expressed the alpha chain alone. Neither the alpha chain nor the beta chain was expressed on leukemic cells from the remaining 28 patients, including all 18 patients with acute nonlymphocytic leukemia, five of seven patients with cALL, all three patients with multiple myeloma, and two of three patients with T-ALL. These results indicate that three different forms of IL-2R chain expression exist on leukemic cells: the alpha chain alone; the beta chain alone; and both the alpha and beta chains. To examine whether the results obtained by flow cytometric analysis actually reflect functional aspects of the expressed IL-2Rs, we studied the specific binding of 125I-labeled IL-2 (125I-IL-2) to leukemic cells in 18 of the 44 patients. In addition, we performed 125I-IL-2 crosslinking studies in seven patients. The results of IL-2R expression of both 125I-IL-2 binding assay and crosslinking studies were in agreement with those obtained by flow cytometric analysis.

  2. Accepted Manuscript Title: Dramatic Performance Gains in Vanadium Redox Flow

    E-Print Network [OSTI]

    Mench, Matthew M.

    ) are a potentially enabling technology for intermittent, renewable energy sources such as wind and solar power [1 contributors to the installed cost of a VRB are the cost of the vanadium, the membranes used and everything else in similar proportion [10]. The vanadium cost is fixed by the required capacity and the purity

  3. 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:FinancingPetroleum12, 2015Executive Order14, 20111,FYDepartment of Energy United

  4. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on dark matter By Sarah Schlieder *8 Materials Science in11

  5. Comparison of blood flow and cell function in ischemic skin flaps

    SciTech Connect (OSTI)

    Bean, D.; Rees, R.S.; O'Leary, J.P.; Lynch, J.B.

    1984-07-01

    Cellular function and blood flow in acute, steroid-treated, and surgically delayed random skin flaps have been examined. In these studies, the period following flap elevation could be divided into early (0-2 hr), intermediate (4-6 hr), and late (12 hr) periods of ischemia, based on the cutaneous blood flow and cellular function measured by thallium-201 uptake. There was a close correlation between blood flow and cellular function during the early period of ischemia which became worse with time. Blood flow studies demonstrated a significant difference between the early and intermediate periods of ischemia which was abolished by surgical delay. Improvement in cellular function was accomplished by improved blood flow in the surgically delayed flaps, while steroid-treated flaps enhanced cellular metabolism by another mechanism. Cellular function approximated blood flow during the early and immediate period of ischemia. Steroids may augment cellular function without improving blood flow, while surgical delay improves cellular function by improving blood flow.

  6. Downlink User Selection and Resource Allocation for Semi-Elastic Flows in an OFDM Cell

    E-Print Network [OSTI]

    Yang, Chao; Jordan, Scott

    2013-01-01

    Jordan, S. (2004). Two-cell power allocation for downlinkM. (2004). Single-cell forward link power allocation using2005). Utility-based power control for a two-cell CDMA data

  7. Liquid water quantification in the cathode side gas channels of a proton exchange membrane fuel cell through two-phase flow

    E-Print Network [OSTI]

    Kandlikar, Satish

    t s Liquid water in the cathode side channels of PEM fuel cell is quantified. Algorithm developed in MATLABÒ electrolyte membrane fuel cell Two-phase flow visualization Gas channels Area coverage ratio Water quantification a b s t r a c t Water management is crucial to the performance of PEM fuel cells. Water

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

    SciTech Connect (OSTI)

    Paulenova, Alena; Vandegrift, III, George F.

    2013-09-24

    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.

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

    E-Print Network [OSTI]

    Choi, Hyo Won; Barakat, Abdul I.

    2009-01-01

    is the maximum enzyme reaction velocity for ATP hydrolysis,et al. 10 Maximum reaction velocity per area assumes a cell

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

    SciTech Connect (OSTI)

    Kalinovsky, Vitaly S. Kontrosh, Evgeny V. Dmitriev, Pavel A. Pokrovsky, Pavel V. Chekalin, Alexander V. Andreev, Viacheslav M.

    2014-09-26

    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.

  11. Redox Shuttle Additives - 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impactsand engineersAcquisition andRedox Shuttle

  12. 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

  13. Air-Breathing Laminar Flow-Based Direct Methanol Fuel Cell with Alkaline Electrolyte

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    methanol fuel cells DMFCs and polymer electrolyte membrane-based fuel cells PEMFCs, operated with hydrogen/oxygen .1-3 In most fuel cells, a polymer electrolyte membrane such as Nafion allows protons to dif- fuse to fuel cross- over, cathode flooding and anode dry-out water management due to osmotic drag of water

  14. A Combinatorial Approach to Biochemical Space: Description and Application to the Redox Distribution of Metabolism

    E-Print Network [OSTI]

    Bains, William

    Redox chemistry is central to life on Earth. It is well known that life uses redox chemistry to capture energy from environmental chemical energy gradients. Here, we propose that a second use of redox chemistry, related ...

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

    E-Print Network [OSTI]

    Turjman, Alexis S. (Alexis Salomon)

    2014-01-01

    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, ...

  16. Biphasic Electrode Suspensions for Li-Ion Semi-solid Flow Cells...

    Office of Scientific and Technical Information (OSTI)

    and Low-Dissipation Flow Authors: Wei, Teng-Sing ; Fan, Frank Y. ; Helal, Ahmed ; Smith, Kyle C. ; McKinley, Gareth H. ; Chiang, Yet-Ming ; Lewis, Jennifer A. 1 ; MIT) 2...

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

    SciTech Connect (OSTI)

    2010-09-01

    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.

  18. Real-Time Redox Measurements during Endoplasmic Reticulum Stress Reveal

    E-Print Network [OSTI]

    Mullins, Dyche

    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

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

    SciTech Connect (OSTI)

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

    2013-11-29

    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.

  20. 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]

    Wang, Xuhai

    2010-01-01

    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...

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

    E-Print Network [OSTI]

    Rocha, Aracely

    2011-08-08

    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.... Chapter I describes the importance of cell adhesion for biocompatibility. Chapter II describes in more detail the goals of this research and the expected results. Chapter III lists all the materials, equipment, and methods used in this study. The most...

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

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    2005-01-01

    Available online 14 April 2005 Abstract The lack of a polymer electrolyte membrane (PEM, e.g. Nafion crossover, cathode flooding, and anode dry-out, as we reported previously. This paper explores the media: Membraneless micro fuel cells; Polymer electrolyte membrane (PEM); Open cell potential (OCP) 1. Introduction

  3. Parallel flow in Hele-Shaw cells with ferrofluids Jose A. Miranda

    E-Print Network [OSTI]

    Widom, Michael

    are colloidal suspensions of microscopic permanent magnets, respond paramagnetically to applied fields capillary-number limit. For finite capillary number and wavelength, linear stability analysis in- dicates ferrofluids. In this paper we perform the linear stability analysis for parallel flow in which one fluid

  4. Cartesian Cut Cell Two-Fluid Solver for Hydraulic Flow Problems

    E-Print Network [OSTI]

    Ingram, David

    of high velocity air which in turn drives a turbine also involves the flows of both water and air domain encompasses both water and air regions and the interface between the two fluids is treated; Free surface; Air water interaction. Introduction The development of numerical methods which

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

    DOE Patents [OSTI]

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

    2014-05-20

    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.

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

    SciTech Connect (OSTI)

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

    2011-04-01

    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.

  7. A Finite Strain Model of Stress, Diffusion, Plastic Flow and Electrochemical Reactions in a Lithium-ion Half-cell

    E-Print Network [OSTI]

    Bower, Allan F; Sethuraman, Vijay A; 10.1016/j.jmps.2011.01.003

    2011-01-01

    We formulate the continuum field equations and constitutive equations that govern deformation, stress, and electric current flow in a Li-ion half-cell. The model considers mass transport through the system, deformation and stress in the anode and cathode, electrostatic fields, as well as the electrochemical reactions at the electrode/electrolyte interfaces. It extends existing analyses by accounting for the effects of finite strains and plastic flow in the electrodes, and by exploring in detail the role of stress in the electrochemical reactions at the electrode-electrolyte interfaces. In particular, we find that that stress directly influences the rest potential at the interface, so that a term involving stress must be added to the Nernst equation if the stress in the solid is significant. The model is used to predict the variation of stress and electric potential in a model 1-D half-cell, consisting of a thin film of Si on a rigid substrate, a fluid electrolyte layer, and a solid Li cathode. The predicted c...

  8. Rechargeable alkaline zinc/ferricyanide hybrid redox battery

    SciTech Connect (OSTI)

    Adams, G.B.; Hollandsworth, R.P.; Littauer, E.L.

    1981-01-01

    The zinc/ferricyanide battery system is described for utility load leveling and solar photovoltaic/wind applications, with advantages of high cell voltage, near-ambient temperature operation, flowing alkaline electrolyte, low-cost reactant storage, low toxicity, potentially long cycle life and low projected capital costs. 13 refs.

  9. Antibody-Functionalized Fluid-Permeable Surfaces for Rolling Cell Capture at High Flow Rates

    E-Print Network [OSTI]

    Mittal, Sukant

    Adhesion-based cell capture on surfaces in microfluidic devices forms the basis of numerous biomedical diagnostics and in vitro assays. However, the performance of these platforms is partly limited by interfacial phenomena ...

  10. Solid oxide fuel cell having monolithic cross flow core and manifolding

    DOE Patents [OSTI]

    Poeppel, R.B.; Dusek, J.T.

    1983-10-12

    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 passageways and the oxidant passageways are disposed transverse to one another.

  11. Fuel cell assembly fluid flow plate having conductive fibers and rigidizing material therein

    DOE Patents [OSTI]

    Walsh, Michael M. (Fairfield, CT)

    2000-01-01

    A fluid flow plate is preferably formed with three initial sections, for instance, two layers of conductive (e.g., metal) fibers and a barrier material (e.g., metal foil) which is interposed between the two layers. For example, sintering of these three sections can provide electrical path(s) between outer faces of the two layers. Then, the sintered sections can be, for instance, placed in a mold for forming of flow channel(s) into one or more of the outer faces. Next, rigidizing material (e.g., resin) can be injected into the mold, for example, to fill and/or seal space(s) about a conductive matrix of the electrical path(s). Preferably, abrading of surface(s) of the outer face(s) serves to expose electrical contact(s) to the electrical path(s).

  12. Solid oxide fuel cell having monolithic cross flow core and manifolding

    DOE Patents [OSTI]

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

    1984-01-01

    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.

  13. Redox Protein Expression Predicts Radiotherapeutic Response in Early-Stage Invasive Breast Cancer Patients

    SciTech Connect (OSTI)

    Woolston, Caroline M.; Al-Attar, Ahmad; Storr, Sarah J.; Ellis, Ian O.; Morgan, David A.L.; Martin, Stewart G.

    2011-04-01

    Purpose: Early-stage invasive breast cancer patients have commonly undergone breast-conserving surgery and radiotherapy. In a large majority of these patients, the treatment is effective; however, a proportion will develop local recurrence. Deregulated redox systems provide cancer cells protection from increased oxidative stress, such as that induced by ionizing radiation. Therefore, the expression of redox proteins was examined in tumor specimens from this defined cohort to determine whether such expression could predict response. Methods and Materials: The nuclear and cytoplasmic expression of nine redox proteins (glutathione, glutathione reductase, glutaredoxin, glutathione peroxidase 1, 3, and 4, and glutathione S-transferase-{theta}, -{pi}, and -{alpha}) was assessed using conventional immunohistochemistry on a tissue microarray of 224 tumors. Results: A high cytoplasmic expression of glutathione S-transferase-{theta} significantly correlated with a greater risk of local recurrence (p = .008) and, when combined with a low nuclear expression (p = .009), became an independent predictive factor (p = .002) for local recurrence. High cytoplasmic expression of glutathione S-transferase-{theta} also correlated with a worse overall survival (p = .009). Low nuclear and cytoplasmic expression of glutathione peroxidase 3 (p = .002) correlated with a greater risk of local recurrence and was an independent predictive factor (p = .005). These proteins did not correlate with tumor grade, suggesting their function might be specific to the regulation of oxidative stress rather than alterations of tumor phenotype. Only nuclear (p = .005) and cytoplasmic (p = .001) expression of glutathione peroxidase 4 correlated with the tumor grade. Conclusions: Our results support the use of redox protein expression, namely glutathione S-transferase-{theta} and glutathione peroxidase 3, to predict the response to radiotherapy in early-stage breast cancer patients. If incorporated into routine diagnostic tests, they have the potential to aid clinicians in their stratification of patients into more tailored treatment regimens. Future targeted therapies to these systems might improve the efficacy of reactive oxygen species-inducing therapies, such as radiotherapy.

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

    SciTech Connect (OSTI)

    Cape, Jonathan L.; Bowman, Michael K.; Kramer, David M.

    2006-08-01

    Quinone metabolites perform a variety of key functions in plants, including pathogen protection, oxidative phosphorylation, and redox signaling. Many of these structurally diverse compounds have been shown to exhibit potent antimicrobial, anticancer, and anti-inflammatory properties, although the exact mechanisms of action are far from understood. Redox cycling has been proposed as a possible mechanism of action for many quinine species. Experimental determination of the essential thermodynamic data (i.e. electrochemical and pKa values) required to predict the propensity towards redox cycling is often difficult or impossible to obtain due to the experimental limitations. We demonstrate a practical computational approach to obtain reasonable estimates of these parameters.

  15. Redox shuttles for overcharge protection of lithium batteries

    DOE Patents [OSTI]

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

    2010-12-14

    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.

  16. Preparation of redox polymer cathodes for thin film rechargeable batteries

    DOE Patents [OSTI]

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

    1994-11-08

    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.

  17. Versatile plug flow catalytic cell for in situ transmission/fluorescence x-ray absorption fine structure measurements

    SciTech Connect (OSTI)

    Centomo, P.; Zecca, M. [Dipartimento di Scienze Chimiche, via Marzolo 1, Universita degli Studi di Padova, 35131 Padova (Italy); Meneghini, C. [Dipartimento di Scienze, via della Vasca Navale 84, Universita di Roma TRE, 00146 Roma (Italy)

    2013-05-15

    A novel flow-through catalytic cell has been developed for in situ x-ray absorption spectroscopy (XAS) experiments on heterogeneous catalysts under working conditions and in the presence of a liquid and a gas phase. The apparatus allows to carry out XAS measurements in both the transmission and fluorescence modes, at moderate temperature (from RT to 50-80 Degree-Sign C) and low-medium gas pressure (up to 7-8 bars). The materials employed are compatible with several chemicals such as those involved in the direct synthesis of hydrogen peroxide (O{sub 2}, H{sub 2}, H{sub 2}O{sub 2}, methanol). The versatile design of the cell allows to fit it to different experimental setups in synchrotron radiation beamlines. It was used successfully for the first time to test nanostructured Pd catalysts during the direct synthesis of hydrogen peroxide (H{sub 2}O{sub 2}) in methanol solution from dihydrogen and dioxygen.

  18. Design and implementation of a rapid-mixer flow cell for time-resolved infrared microspectroscopy

    SciTech Connect (OSTI)

    Marinkovic, Nebojsa S.; Adzic, Aleksandar R.; Sullivan, Michael; Kovacs, Kevin; Miller, Lisa M.; Rousseau, Denis L.; Yeh, Syun-Ru; Chance, Mark R.

    2000-11-01

    A rapid mixer for the analysis of reactions in the millisecond and submillisecond time domains by Fourier-transform infrared microspectroscopy has been constructed. The cell was tested by examination of cytochrome-c folding kinetics. The device allows collection of full infrared spectral data on millisecond and faster time scales subsequent to chemical jump reaction initiation. The data quality is sufficiently good such that spectral fitting techniques could be applied to analysis of the data. Thus, this method provides an advantage over kinetic measurements at single wavelengths using infrared laser or diode sources, particularly where band overlap exists.

  19. Biphasic Electrode Suspensions for Li-Ion Semi-solid Flow Cells with High

    Office of Scientific and Technical Information (OSTI)

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing Bacteria (Technical Report) | SciTechReport)(Technical Report)cellsEnergy Density, Fast

  20. Fuel Cell with Metal Screen Flow-Field - 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journal Article)Forthcoming UpgradesArea: PADD 1 to PADDFuelFuelFuel Cell

  1. An inner membrane cytochrome required only for reduction of high redox potential extracellular electron acceptors

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

    Levar, Caleb E.; Chan, Chi Ho; Mehta-Kolte, Misha G.; Bond, Daniel R.

    2014-10-28

    Dissimilatory metal-reducing bacteria, such as Geobacter sulfurreducens, transfer electrons beyond their outer membranes to Fe(III) and Mn(IV) oxides, heavy metals, and electrodes in electrochemical devices. In the environment, metal acceptors exist in multiple chelated and insoluble forms that span a range of redox potentials and offer different amounts of available energy. Despite this, metal-reducing bacteria have not been shown to alter their electron transfer strategies to take advantage of these energy differences. Disruption of imcH, encoding an inner membrane c-type cytochrome, eliminated the ability of G. sulfurreducens to reduce Fe(III) citrate, Fe(III)-EDTA, and insoluble Mn(IV) oxides, electron acceptors with potentialsmore »greater than 0.1 V versus the standard hydrogen electrode (SHE), but the imcH mutant retained the ability to reduce Fe(III) oxides with potentials of ?–0.1 V versus SHE. The imcH mutant failed to grow on electrodes poised at +0.24 V versus SHE, but switching electrodes to –0.1 V versus SHE triggered exponential growth. At potentials of ?–0.1 V versus SHE, both the wild type and the imcH mutant doubled 60% slower than at higher potentials. Electrodes poised even 100 mV higher (0.0 V versus SHE) could not trigger imcH mutant growth. These results demonstrate that G. sulfurreducens possesses multiple respiratory pathways, that some of these pathways are in operation only after exposure to low redox potentials, and that electron flow can be coupled to generation of different amounts of energy for growth. Redox potentials that trigger these behaviors mirror those of metal acceptors common in subsurface environments where Geobacter is found.« less

  2. In situ characterization of nanoscale catalysts during anodic redox processes

    SciTech Connect (OSTI)

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

    2013-09-19

    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

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

    DOE Patents [OSTI]

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

    2014-04-08

    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.

  4. Flow Batteries A Historical Perspective

    E-Print Network [OSTI]

    Flow Batteries A Historical Perspective Robert F. Savinell Case Western Reserve University Department of Chemical Engineering DOE Flow Battery Workshop March 2012 #12;2 OUTLINE ·The first flow cell? ·Review articles- documented progress ·Early NASA Work- some learning ·Fuel Cell and Flow Battery

  5. Membrane proteomic analysis of pancreatic cancer cells

    E-Print Network [OSTI]

    Liu, Xiaojun; Zhang, Min; Go, Vay Liang W; Hu, Shen

    2010-01-01

    tricarboxylic acid cycle, gluconeogenesis, metabolism ofredox homeostasis 7.56 Gluconeogenesis 8.3 Glycolysis 4.76matrix protein binding 7.56 Gluconeogenesis 4.76 Cell redox

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

    E-Print Network [OSTI]

    Brest, Université de

    Application of Flow Battery in Marine Current Turbine System for Daily Power Management Zhibin Zhou focuses on a grid-connected MCT system and proposes using vanadium redox flow battery (VRB) energy storage and to guarantee the expected power injection to the local grid. Keywords--Marine current turbine, flow battery

  7. Testing the ancient marine redox record from oxygenic photosynthesis to photic zone euxina

    E-Print Network [OSTI]

    French, Katherine L. (Katherine Louise)

    2015-01-01

    Tracing the evolution of Earth's redox history is one of the great challenges of geobiology and geochemistry. The accumulation of photosynthetically derived oxygen transformed the redox state of Earth's surface environments, ...

  8. A basin redox transect at the dawn of animal life Erik A. Sperling a

    E-Print Network [OSTI]

    that captures the inferred origin and early evolution of animals. Iron-based redox proxies, redox-sensitive trace elements, organic carbon percentages and pyrite sulfur isotopes were analyzed in seven

  9. Parallel flow diffusion battery

    DOE Patents [OSTI]

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

    1984-01-01

    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.

  10. Parallel flow diffusion battery

    DOE Patents [OSTI]

    Yeh, Hsu-Chi (Albuquerque, NM); Cheng, Yung-Sung (Albuquerque, NM)

    1984-08-07

    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.

  11. Detection of human hematopoietic stem cell engraftment in the livers of adult immunodeficient mice by an optimized flow cytometric method

    E-Print Network [OSTI]

    Varga, Nicole L.; Bárcena, Alicia; Fomin, Marina E.; Muench, Marcus O.

    2010-01-01

    CD19 + CD34 + cells, indicating that the full range of humanfull Figure 9. Detection of human B-lymphoid cells in mousefull lymph- oid reconstitution 229 days after FBM trans- plantation are shown in Figure 10. T-cells

  12. REVIEW ARTICLE Redox regulation of intercellular transport

    E-Print Network [OSTI]

    Jackson, David

    # Springer-Verlag 2010 Abstract Plant cells communicate with each other via plasmodesmata (PDs) in order in plant responses to a range of biotic and abiotic stresses. They are also generated during normal metabolism, and mediate signaling path- ways that modulate plant growth and developmental transitions. Recent

  13. Tubular precipitation and redox gradients on a bubbling template

    E-Print Network [OSTI]

    Goldstein, Raymond E.

    Tubular precipitation and redox gradients on a bubbling template David A. Stone* and Raymond E) Tubular structures created by precipitation abound in nature, from chimneys at hydrothermal vents to soda oxides precipitate on the surface of bubbles that linger at the tube rim and then detach, leaving behind

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

    E-Print Network [OSTI]

    J. M. Skotheim; T. W. Secomb

    2006-05-26

    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.

  15. Status of flow-battery research in the United States

    SciTech Connect (OSTI)

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

    1982-01-01

    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.

  16. A flow-­cytometry-­based method to simplify the analysis and quantification of protein association to chromatin in mammalian cells

    E-Print Network [OSTI]

    Forment, Josep V.; Jackson, Stephen P.

    2015-01-01

    ,  human  colon  carcinoma  HCT-­?116  cells,  human  leukaemia   HAP-­?1   cells,   human   immortalised   retinal   RPE-­?1   cells   and   primary   mouse  embryonic  fibroblasts  have  all  yielded  positive...  analysed  cell   is  also  imaged  and  processed   in   a   post-­?acquisition   manner24,25.   Alternatively,   high-­?content  quantitative  microscopy  techniques,  such  as  the  recently  described...

  17. 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 of a a battery of visual and language tasks. Within the occipi-positive BOLD response (PBR). Here, we demonstrate flow and with decreases in oxygen con- of activated and suppressed voxels in the visual cortexsumption

  18. Investigation of photoelectrode redox polymer junctions. Technical report, 16 November-15 January 1984

    SciTech Connect (OSTI)

    Cook, R.L.; Sammells, A.F.

    1985-01-15

    The n-CdS flatband potential in the solid-state cell n-CdS/Nafion 117 + redox species/Au was shifted progressively in a cathode directed upon the introduction of FeCp2, FeCp2 + Ru(bpy)3(2+) into the SPE. This cathodic shift was consistent with that for the oxidation potentials seen for Ru(bpy)3(2+) (E1/2 = 1.25V vs SCE) and FeCp2 (0.285V vs SCE) in acetonitrile. Such perturbations of semiconductor properties can be expected to form the basis of a detector technology when the semiconductor/SPE junction is exposed to selected chemical species.

  19. Paper No. S7_Thu_A_46 6 International Conference on Multiphase Flow,

    E-Print Network [OSTI]

    Hidrovo, Carlos H.

    and flow parameters. Previous polymer electrolyte membrane (PEM) fuel cell flow regime studies have been pattern such as droplet/bubbly flow, annular film flow, and dynamic clogging plug flow in the fuel cell

  20. Flow Battery Solution for Smart Grid Applications

    SciTech Connect (OSTI)

    none,

    2014-11-30

    To address future grid requirements, a U.S. Department of Energy ARRA Storage Demonstration program was launched in 2009 to commercialize promising technologies needed for stronger and more renewables-intensive grids. Raytheon Ktech and EnerVault received a cost-share grant award from the U.S. Department of Energy to develop a grid-scale storage system based on EnerVault’s iron-chromium redox flow battery technology.

  1. The role of nanopores on U(VI) sorption and redox behavior in...

    Office of Scientific and Technical Information (OSTI)

    advanced mechanistic, quantitative information on the physiochemical controls on uranium sorption and redox behavior in subsurface sediments. The influence of nanopore...

  2. Reducing pumping energy by using different flow rates of high and low concentration solutions in reverse electrodialysis cells

    E-Print Network [OSTI]

    Reducing pumping energy by using different flow rates of high and low concentration solutions Keywords: Salinity gradient energy RED Renewable energy production a b s t r a c t Energy use for pumping to reduce the energy needed for pumping, electrical performance and hydrodynamic power losses in a RED stack

  3. Flow-driven transition and associated velocity profiles in a nematic liquid-crystal cell S. A. Jewell,1

    E-Print Network [OSTI]

    Jewell, Sharon

    molding processes. The confinement of a fluid between walls separated on the micron scale can im- pose liquid crystals and the formation of defects when extruding polymeric liquid crys- tals. Thus by the presence of fixed particles and the interaction between flow and topological defects 6 . Experimentally

  4. Lateral flow strip assay

    DOE Patents [OSTI]

    Miles, Robin R. (Danville, CA); Benett, William J. (Livermore, CA); Coleman, Matthew A. (Oakland, CA); Pearson, Francesca S. (Livermore, CA); Nasarabadi, Shanavaz L. (Livermore, CA)

    2011-03-08

    A lateral flow strip assay apparatus comprising a housing; a lateral flow strip in the housing, the lateral flow strip having a receiving portion; a sample collection unit; and a reagent reservoir. Saliva and/or buccal cells are collected from an individual using the sample collection unit. The sample collection unit is immersed in the reagent reservoir. The tip of the lateral flow strip is immersed in the reservoir and the reagent/sample mixture wicks up into the lateral flow strip to perform the assay.

  5. Biogeochemical Redox Processes and their Impact on Contaminant Dynamics

    E-Print Network [OSTI]

    Sparks, Donald L.

    , * , , R U B E N K R E T Z S C H M A R , § A N D R E A S K A P P L E R , | P H I L I P P E V A N C A P P E L L E N , M A T T H E W G I N D E R - V O G E L , # A N D R E A S V O E G E L I N , § , A N D KBiogeochemical Redox Processes and their Impact on Contaminant Dynamics T H O M A S B O R C H

  6. Detection of human hematopoietic stem cell engraftment in the livers of adult immunodeficient mice by an optimized flow cytometric method

    E-Print Network [OSTI]

    Varga, Nicole L.; Bárcena, Alicia; Fomin, Marina E.; Muench, Marcus O.

    2010-01-01

    myeloid cell develop- ment in NOD/ltsz-scid IL2R gamma nullblood and immune systems in NOD/SCID/IL2 receptor {gamma}platelet production assessed in NOD/SCID mice injected with

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

    E-Print Network [OSTI]

    Kandlikar, Satish

    the proton conductivity of the polymer electrolyte membrane; however, excess water must be removed from the cell to avoid flooding. Flooding is a phenomenon in which liquid water accumulation inside

  8. Current flow and potential efficiency of solar cells based on GaAs and GaSb p-n junctions

    SciTech Connect (OSTI)

    Andreev, V. M.; Evstropov, V. V.; Kalinovsky, V. S. Lantratov, V. M.; Khvostikov, V. P.

    2009-05-15

    Dependence of the efficiency of single-junction and multijunction solar cells on the mechanisms of current flow in photoactive p-n junctions, specifically on the form of the dark current-voltage characteristic J-V, has been studied. The resistanceless J-V{sub j} characteristic (with the series resistance disregarded) of a multijunction solar cell has the same shape as the characteristic of a single-junction cell: both feature a set of exponential portions. This made it possible to develop a unified analytical method for calculating the efficiency of singlejunction and multijunction solar cells. The equation relating the efficiency to the photogenerated current at each portion of the J-V{sub j} characteristic is derived. For p-n junctions in GaAs and GaSb, the following characteristics were measured: the dark J-V characteristic, the dependence of the open-circuit voltage on the illumination intensity P-V{sub OC}, and the dependence of the luminescence intensity on the forward current L-J. Calculated dependences of potential efficiency (under idealized condition for equality to unity of external quantum yield) on the photogenerated current for single-junction GaAs and GaSb solar cells and a GaAs/GaSb tandem are plotted. The form of these dependences corresponds to the shape of J-V{sub j} characteristics: there are the diffusion- and recombination-related portions; in some cases, the tunneling-trapping portion is also observed. At low degrees of concentration of solar radiation (C < 10), an appreciable contribution to photogenerated current is made by recombination component. It is an increase in this component in the case of irradiation with 6.78-MeV protons or 1-MeV electrons that brings about a decrease in the efficiency of conversion of unconcentrated solar radiation.

  9. Redox Catalytic Properties of Palladium Nanoparticles: Surfactant and Electron Donor-Acceptor Effects

    E-Print Network [OSTI]

    Wang, Zhong L.

    Redox Catalytic Properties of Palladium Nanoparticles: Surfactant and Electron Donor-0245 Received April 27, 1999. In Final Form: November 10, 1999 Dye reduction catalyzed by palladium catalysts,21-24 and shown that the redox catalytic property of still growing and fully grown palladium

  10. Site-specific incorporation of redox active amino acids into proteins

    DOE Patents [OSTI]

    Alfonta; Lital (San Diego, CA), Schultz; Peter G. (La Jolla, CA), Zhang; Zhiwen (San Diego, CA)

    2010-10-12

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  11. Site-specific incorporation of redox active amino acids into proteins

    DOE Patents [OSTI]

    Alfonta, Lital (San Diego, CA); Schultz, Peter G. (La Jolla, CA); Zhang, Zhiwen (Austin, TX)

    2011-08-30

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  12. Site-specific incorporation of redox active amino acids into proteins

    DOE Patents [OSTI]

    Alfonta, Lital (San Diego, CA); Schultz, Peter G. (La Jolla, CA); Zhang, Zhiwen (San Diego, CA)

    2009-02-24

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  13. Site-specific incorporation of redox active amino acids into proteins

    DOE Patents [OSTI]

    Alfonta, Lital (San Diego, CA); Schultz, Peter G. (La Jolla, CA); Zhang, Zhiwen (San Diego, CA)

    2012-02-14

    Compositions and methods of producing components of protein biosynthetic machinery that include orthogonal tRNAs, orthogonal aminoacyl-tRNA synthetases, and orthogonal pairs of tRNAs/synthetases, which incorporate redox active amino acids into proteins are provided. Methods for identifying these orthogonal pairs are also provided along with methods of producing proteins with redox active amino acids using these orthogonal pairs.

  14. Ultra-high current density water management in polymer electrolyte fuel cell with porous metallic flow field

    E-Print Network [OSTI]

    Mench, Matthew M.

    Ultra-high current density water management in polymer electrolyte fuel cell with porous metallic with the open metallic element architecture and high current density. Flooding is not limiting at high current. Stable operation was demonstrated at 90 C using a polymer electrolyte membrane. Real time NWD

  15. Anisotropic flow

    E-Print Network [OSTI]

    S. A. Voloshin

    2002-11-20

    Recent experimental results on directed and elliptic flow, theoretical developments, and new techniques for anisotropic flow analysis are reviewed.

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

    E-Print Network [OSTI]

    Longsine, Whitney Leigh

    2012-07-16

    , which is a great advantage in vivo as it allows for deep or shallow penetration to specific locations in the human body.23 Acoustic cavitation is believed to be the primary mechanism for cell membrane disruption, and relies on dissolved air and.../or solution impurities for cavitation nuclei.22-23 Cavitation can be enhanced by the introduction of microbubbles, which greatly increase the amount of nuclei and reduce the cavitation threshold.23 Furthermore, microbubbles, otherwise known as ultrasound...

  17. Flow cytometry apparatus

    DOE Patents [OSTI]

    Pinkel, Daniel (Walnut Creek, CA)

    1991-01-01

    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.

  18. Flow cytometry apparatus

    DOE Patents [OSTI]

    Pinkel, D.

    1987-11-30

    An obstruction across the flow chamber creates a one-dimensional convergence of a sheath fluid. A passageway in the obstruction 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. 6 figs.

  19. Sorption of redox-sensitive elements: critical analysis

    SciTech Connect (OSTI)

    Strickert, R.G.

    1980-12-01

    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.

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

    SciTech Connect (OSTI)

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

    2010-11-15

    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.

  1. Elucidating the Higher Stability of Vanadium (V) Cations in Mixed Acid Based Redox Flow Battery Electrolytes

    SciTech Connect (OSTI)

    Vijayakumar, M.; Wang, Wei; Nie, Zimin; Sprenkle, Vincent L.; Hu, Jian Z.

    2013-11-01

    The Vanadium (V) cation structures in mixed acid based electrolyte solution were analysed by density functional theory (DFT) based computational modelling and 51V and 35Cl Nuclear Magnetic Resonance (NMR) spectroscopy. The Vanadium (V) cation exists as di-nuclear [V2O3Cl2.6H2O]2+ compound at higher vanadium concentrations (?1.75M). In particular, at high temperatures (>295K) this di-nuclear compound undergoes ligand exchange process with nearby solvent chlorine molecule and forms chlorine bonded [V2O3Cl2.6H2O]2+ compound. This chlorine bonded [V2O3Cl2.6H2O]2+ compound might be resistant to the de-protonation reaction which is the initial step in the precipitation reaction in Vanadium based electrolyte solutions. The combined theoretical and experimental approach reveals that formation of chlorine bonded [V2O3Cl2.6H2O]2+ compound might be central to the observed higher thermal stability of mixed acid based Vanadium (V) electrolyte solutions.

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

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMassR&D100 Winners * Impactsand engineersAcquisition and

  3. Membranes Optimized for High Conductivity and Low Crossover of Redox Flow

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines light on dark matter By SarahMODELINGMeetingsMembranes - Phosphazene

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

    SciTech Connect (OSTI)

    Kavner, Abby

    2014-11-26

    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.

  5. Transimination of Quinone Imines: A Mechanism for Embedding Exogenous Redox Activity into the Nucleosome

    E-Print Network [OSTI]

    Ye, Wenjie

    Aminophenols can redox cycle through the corresponding quinone imines to generate ROS. The electrophilic quinone imine intermediate can react with protein thiols as a mechanism of immobilization in vivo. Here, we describe ...

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

    E-Print Network [OSTI]

    Dash, Bhagirathi

    2007-04-25

    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 ...

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

    E-Print Network [OSTI]

    Kern, Suzanne E

    2013-01-01

    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 ...

  8. Sandia Energy - EC Publications

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

    with accompanying nonaqueous compatible membranes and flow cell designs for higher energy density redox flow batteries targeted to support increasing demands for stationary...

  9. Gyrokinetic and kinetic particle-in-cell simulations of guide-field reconnection. Part I: macroscopic effects of the electron flows

    E-Print Network [OSTI]

    Muñoz, P A; Kilian, P; Büchner, J; Jenko, F

    2015-01-01

    In this work, we extend a comparison between gyrokinetic (GK) and fully kinetic Particle-in-Cell (PIC) simulations of magnetic reconnection in the limit of strong guide field started by TenBarge et al. [Phys. Plasmas 21, 020708 (2014)]. By using a different set of kinetic PIC and GK simulation codes (ACRONYM and GENE, respectively), we analyze the limits of applicability of the GK approach when comparing to the force free kinetic simulations in the low guide field (bg) regime. Here we report the first part of a much more extended comparison, focusing on the macroscopic effects of the electron flows. For a low beta plasma (beta_i = 0.01), it is shown that magnetic reconnection only displays similar features between both plasma models for higher kinetic PIC guide fields (bg>30) in the secondary magnetic islands than in the region close to the X points or separatrices (bg>5). Kinetic PIC low guide field runs (53) to be negligible due to the reduced reconnection rate and fluctuation level.

  10. A two-photoelectrode solid-state photoelectrochemical cell

    SciTech Connect (OSTI)

    Sammells, A.F.; Schmidt, S.K.

    1985-02-01

    This article describes a two photoelectrode solid-state photoelectrochemical cell which is able to produce photopotentials in excess of one voltage and possesses some inherent storage capacity. The storage capacity is presently limited by the low concentration and thin solid polymer electrolyte (SPE) redox layers used between the photoelectrode and the SPE membrane. The use of solid-electrolyte based photoelectrochemical cells provides a unique approach for the photoelectrochemical conversion and storage of selected redox species incorporated within the proximity of the semiconductor/solid electrolyte interface. It is expected that the described cell will be of potential value as not only a specialized storage device, but for specific detector applications.

  11. Flow dynamics and solute transport in unsaturated rock fractures

    E-Print Network [OSTI]

    Su, G.W.

    2011-01-01

    2.4. Cross-section of flow cell/flange assembly ceramic2.1,2.3 Mariotte bottle Exp.2.2 flow meter o IighttaQt6porous media effecting fluid flow, J. Irrig. Drainage Div.

  12. Review of Methods to Probe Single Cell Metabolism and Bioenergetics...

    Office of Scientific and Technical Information (OSTI)

    recent developments in single cell manipulation, as well as pioneering ones. First, flow-through methods will be discussed, namely methods in which the single cells flow...

  13. Piezoelectric axial flow microvalve

    DOE Patents [OSTI]

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

    2007-01-09

    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.

  14. Insertable fluid flow passage bridgepiece and method

    DOE Patents [OSTI]

    Jones, Daniel O. (Glenville, NV)

    2000-01-01

    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.

  15. Optimization and Analysis of High-Power Hydrogen/Bromine-Flow Batteries for Grid-Scale Energy Storage

    SciTech Connect (OSTI)

    Cho, KT; Albertus, P; Battaglia, V; Kojic, A; Srinivasan, V; Weber, AZ

    2013-10-07

    For storage of grid-scale electrical energy, redox-flow batteries (RFBs) are considered promising technologies. This paper explores the influence of electrolyte composition and ion transport on cell performance by using an integrated approach of experiments and cost modeling. In particular, the impact of the area-specific resistance on system capability is elucidated for the hydrogen/bromine RFB. The experimental data demonstrate very good performance with 1.46 W cm(-2) peak power and 4 A cm(-2) limiting current density at ambient conditions for an optimal cell design and reactant concentrations. The data and cost model results show that higher concentrations of RFB reactants do not necessarily result in lower capital cost as there is a tradeoff between cell performance and storage (tank) requirements. In addition, the discharge time and overall efficiency demonstrate nonlinear effects on system cost, with a 3 to 4 hour minimum discharge time showing a key transition to a plateau in terms of cost for typical RFB systems. The presented results are applicable to many different RFB chemistries and technologies and highlight the importance of ohmic effects and associated area-specific resistance on RFB viability.

  16. Redox-Responsive, Core-Cross-Linked Micelles Capable of On-Demand, Concurrent Drug Release and Structure Disassembly

    E-Print Network [OSTI]

    Cheng, Jianjun

    Redox-Responsive, Core-Cross-Linked Micelles Capable of On- Demand, Concurrent Drug Release- responsive cleavage of the built-in disulfide bonds, resulting in disruption of the micellar structure release of CPT. These redox-responsive CCL micelles showed enhanced cytotoxicity against human breast

  17. Influence of uranyl speciation and iron oxides on uranium biogeochemical redox reactions

    SciTech Connect (OSTI)

    Stewart, B.D.; Amos, R.T.; Nico, P.S.; Fendorf, S.

    2010-03-15

    Uranium is a pollutant of concern to both human and ecosystem health. Uranium's redox state often dictates its partitioning between the aqueous- and solid-phases, and thus controls its dissolved concentration and, coupled with groundwater flow, its migration within the environment. In anaerobic environments, the more oxidized and mobile form of uranium (UO{sub 2}{sup 2+} and associated species) may be reduced, directly or indirectly, by microorganisms to U(IV) with subsequent precipitation of UO{sub 2}. However, various factors within soils and sediments may limit biological reduction of U(VI), inclusive of alterations in U(VI) speciation and competitive electron acceptors. Here we elucidate the impact of U(VI) speciation on the extent and rate of reduction with specific emphasis on speciation changes induced by dissolved Ca, and we examine the impact of Fe(III) (hydr)oxides (ferrihydrite, goethite and hematite) varying in free energies of formation on U reduction. The amount of uranium removed from solution during 100 h of incubation with S. putrefaciens was 77% with no Ca or ferrihydrite present but only 24% (with ferrihydrite) and 14% (no ferrihydrite) were removed for systems with 0.8 mM Ca. Imparting an important criterion on uranium reduction, goethite and hematite decrease the dissolved concentration of calcium through adsorption and thus tend to diminish the effect of calcium on uranium reduction. Dissimilatory reduction of Fe(III) and U(VI) can proceed through different enzyme pathways, even within a single organism, thus providing a potential second means by which Fe(III) bearing minerals may impact U(VI) reduction. We quantify rate coefficients for simultaneous dissimilatory reduction of Fe(III) and U(VI) in systems varying in Ca concentration (0 to 0.8 mM), and using a mathematical construct implemented with the reactive transport code MIN3P, we reveal the predominant influence of uranyl speciation, specifically the formation of uranyl-calcium-carbonato complexes, and ferrihydrite on the rate and extent of uranium reduction in complex geochemical systems.

  18. Transverse flowing liquid Kerr cell for high average power laser Q-switching and for direct modulation of high power laser beams.

    DOE Patents [OSTI]

    Comaskey, Brian J.

    2004-12-07

    A fluid flow concept is applied in an optical apparatus to define a high gain stand-off, fast electro-optical q-switch which is highly impervious to high average power optical loads.

  19. Flow chamber

    DOE Patents [OSTI]

    Morozov, Victor (Manassas, VA)

    2011-01-18

    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.

  20. Geological flows

    E-Print Network [OSTI]

    Yu. N. Bratkov

    2008-11-19

    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.

  1. Flow regimes

    SciTech Connect (OSTI)

    Liles, D.R.

    1982-01-01

    Internal boundaries in multiphase flow greatly complicate fluid-dynamic and heat-transfer descriptions. Different flow regimes or topological configurations can have radically dissimilar interfacial and wall mass, momentum, and energy exchanges. To model the flow dynamics properly requires estimates of these rates. In this paper the common flow regimes for gas-liquid systems are defined and the techniques used to estimate the extent of a particular regime are described. Also, the current computer-code procedures are delineated and introduce a potentially better method is introduced.

  2. Nitric Oxide in Biological Denitrification: Fe/Cu Metalloenzyme and Metal Complex NOx Redox Chemistry

    E-Print Network [OSTI]

    Schroeder, Imke

    Nitric Oxide in Biological Denitrification: Fe/Cu Metalloenzyme and Metal Complex NOx Redox Nitrite Reductase: 1204 2. Copper Nitrite Reductases 1206 B. Nitric Oxide Reductase 1208 1. Structure 1208 Nitric Oxide Sensors, Scavengers, and Delivery Agents 1227 IV. Concluding Remarks 1229 V. Acknowledgments

  3. Arabidopsis Transcriptome Reveals Control Circuits Regulating Redox Homeostasis and the Role of an AP2

    E-Print Network [OSTI]

    Quatrano, Ralph S.

    , etc.], and other secondary metabolites [flavonoids, alkaloids, and carotenoids]; Dietz, 2003 a central role in adjusting plant metabolism and development to changing environmental conditions. We report, as a result, elaborate mechanisms are in place in plants to keep control of redox levels (e.g. by the action

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

    E-Print Network [OSTI]

    Feng, Jian

    2005-08-29

    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...

  5. Mineral formation and redox-sensitive trace elements in a near-surface hydrothermal alteration system

    SciTech Connect (OSTI)

    Gehring, A.U.; Schosseler, P.M.; Weidler, P.G.

    1999-07-01

    A recent hydrothermal mudpool at the southwestern slope of the Rincon de la Vieja volcano in Northwest Costa Rica exhibits an argillic alteration system formed by intense interaction of sulfuric acidic fluids with wall rock materials. Detailed mineralogical analysis revealed an assemblage with kaolinite, alunite, and opal-C as the major mineral phases. Electron paramagnetic resonance spectroscopy (EPR) showed 3 different redox-sensitive cations associated with the mineral phases, Cu{sup +} is structure-bound in opal-C, whereas VO{sup 2+} and Fe{sup 3+} are located in the kaolinite structure. The location of the redox-sensitive cations in different minerals of the assemblage is indicative of different chemical conditions. The formation of the alteration products can be described schematically as a 2-step process. In a first step alunite and opal-C were precipitated in a fluid with slightly reducing conditions and a low chloride availability. The second step is characterized by a decrease in K{sup +} activity and subsequent formation of kaolinite under weakly oxidizing to oxidizing redox conditions as indicated by structure-bound VO{sup 2+} and Fe{sup 3+}. The detection of paramagnetic trace elements structure-bound in mineral phases by EPR provide direct information about the prevailing redox conditions during alteration and can, therefore, be used as additional insight into the genesis of the hydrothermal, near-surface system.

  6. Superlattice photoelectrodes for photoelectrochemical cells

    DOE Patents [OSTI]

    Nozik, A.J.

    1985-07-03

    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)

  7. Metalloprotein and redox protein design are rapidly advancing toward the chemical synthesis of novel proteins that have

    E-Print Network [OSTI]

    Gibney, Brian R.

    485 Metalloprotein and redox protein design are rapidly advancing toward the chemical synthesis of novel proteins that have predictable structures and functions. Current data demonstrate a breadth and combinatorial strategies. These sophisticated synthetic analogs of natural proteins constructively test our

  8. Redox-driven regulation of microbial community morphogenesis Chinweike Okegbe, Alexa Price-Whelan and Lars EP Dietrich

    E-Print Network [OSTI]

    Dietrich, Lars

    Redox-driven regulation of microbial community morphogenesis Chinweike Okegbe, Alexa Price matter, Published by Elsevier Ltd. http://dx.doi.org/10.1016/j.mib.2014.01.006 Introduction The energy

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

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    ) this residue must not disperse in the electrolyte. KEYWORDS: graphene, dye-sensitized solar cell, cobalt redoxFunctionalized Graphene Sheets as a Versatile Replacement for Platinum in Dye-Sensitized Solar) electrodes were tested for catalytic performance in dye-sensitized solar cells (DSSCs). By using ethyl

  10. A Glucose BioFuel Cell Implanted in Rats Philippe Cinquin1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    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

  11. In situ reduction and oxidation of nickel from solid oxide fuel cells in a Titan ETEM

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    In situ reduction and oxidation of nickel from solid oxide fuel cells in a Titan ETEM A. Faes1. C. Singhal, K. Kendall, High Temperature Solid Oxide Fuel Cell - Fundamentals, Design, Denmark antonin.faes@epfl.ch Keywords: In situ ETEM, nickel oxide, reduction, RedOx, SOFC Solid Oxide Fuel

  12. Redox Potentials and Acidity Constants from Density Functional Theory Based Molecular Dynamics

    E-Print Network [OSTI]

    Cheng, Jun; Liu, Xiandong; VandeVondele, Joost; Sulpizi, Marialore; Sprik, Michiel

    2014-11-03

    . Critical error anal- ysis will be carried out to demonstrate how the delocalization error in GGAs affects redox potentials. The improvement by hybrid functionals reinforces this claim. We will end this Account with some conclusions and an outlook. Method... and theoretical (photo-)electrochemistry and catalysis. Xiandong Liu is an associate professor at Nanjing University. He joined the Sprik group at Cambridge in 2012 to work on computational geochemistry of mineral interfaces and transition metal complexes. Joost...

  13. 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: Alternative FuelsofProgram: Report Appendices |ProjectKnowRedox Shuttle Additive, Wins 2014

  14. Radiation-induced non-equilibrium redox chemistry of plutonium: implications for environmental migration

    SciTech Connect (OSTI)

    Haschke, J M; Siekhaus, W J

    2009-02-11

    Static concentrations of plutonium oxidation states in solution and at surfaces in oxide-water systems are identified as non-equilibrium steady states. These kinetically controlled systems are described by redox cycles based on irreversible disproportionation of Pu(IV), Pu(V), and Pu(VI) in OH-bridged intermediate complexes and at OH-covered oxide surfaces. Steady state is fixed by continuous redox cycles driven by radioactivity-promoted electron-transfer and energetically favorable reactions of Pu(III) and Pu(VII) disproportionation products with H2O. A model based on the redox cycles accounts for the high steady-state [Pu] coexisting with Pu(IV) hydrous oxide at pH 0-15 and for predominance of Pu(V) and Pu(VI) in solution. The steady-state [Pu] depends on pH and the surface area of oxide in solution, but not on the initial Pu oxidation state. PuO{sub 2+x} formation is attributed to high Pu(V) concentrations existing at water-exposed oxide surfaces. Results infer that migration of Pu in an aqueous environment is controlled by kinetic factors unique to that site and that the predominant oxidation states in solution are Pu(V) and Pu(VI).

  15. Unveiling Surface Redox Charge Storage of Interacting Two-Dimensional Hetero-Nanosheets in Hierarchical Architectures

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

    Mahmood, Qasim [Department of Chemical Engineering, College of Engineering, Kyung Hee University (Republic of Korea); Bak, Seong-Min [Brookhaven National Laboratory (BNL), Upton, NY (United States); Kim, Min G. [Beamline Research Division, Pohang Accelerator Laboratory, Pohang (Republic of Korea); Yun, Sol [School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon (Republic of Korea); Yang, Xiao-Qing [Brookhaven National Laboratory (BNL), Upton, NY (United States); Shin, Hyeon S. [Department of Energy Engineering, Department of Chemistry, and Low Dimensional Carbon Materials Center, Ulsan National Institute of Science and Technology(UNIST) (Republic of Korea); Kim, Woo S. [Department of Chemical Engineering, College of Engineering, Kyung Hee University (Republic of Korea); Braun, Paul V. [Department of Materials Science and Engineering Materials Research Laboratory and Beckman Institute, University of Illinois at Urbana?Champaign, Urbana, Illinois (United States); Park, Ho S. [School of Chemical Engineering, Sungkyunkwan University (SKKU), Suwon (Republic of Korea)

    2015-04-08

    Two-dimensional (2D) heteronanosheets are currently the focus of intense study due to the unique properties that emerge from the interplay between two low-dimensional nanomaterials with different properties. However, the properties and new phenomena based on the two 2D heteronanosheets interacting in a 3D hierarchical architecture have yet to be explored. Here, we unveil the surface redox charge storage mechanism of surface-exposed WS2 nanosheets assembled in a 3D hierarchical heterostructure using in situ synchrotron X-ray absorption and Raman spectroscopic methods. The surface dominating redox charge storage of WS2 is manifested in a highly reversible and ultrafast capacitive fashion due to the interaction of heteronanosheets and the 3D connectivity of the hierarchical structure. In contrast, compositionally identical 2D WS2 structures fail to provide a fast and high capacitance with different modes of lattice vibration. The distinctive surface capacitive behavior of 3D hierarchically structured heteronanosheets is associated with rapid proton accommodation into the in-plane W–S lattice (with the softening of the E2g bands), the reversible redox transition of the surface-exposed intralayers residing in the electrochemically active 1T phase of WS2 (with the reversible change in the interatomic distance and peak intensity of W–W bonds), and the change in the oxidation state during the proton insertion/deinsertion process. This proposed mechanism agrees with the dramatic improvement in the capacitive performance of the two heteronanosheets coupled in the hierarchical structure.

  16. 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)

    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.

    2013-11-13

    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.

  17. Cell, Vol. 121, 633644, May 20, 2005, Copyright 2005 by Elsevier Inc. DOI 10.1016/j.cell.2005.04.008 Mechanism of Nodal Flow: A Conserved Symmetry

    E-Print Network [OSTI]

    Voigt, Chris

    .04.008 Mechanism of Nodal Flow: A Conserved Symmetry Breaking Event in Left-Right Axis Determination Yasushi Okada gradients as a sub- sequent mechanism of left-right axis determination. Finally, we experimentally oriented according to the preceding A-P and D-V axes. The mechanism that en- ables this coordination

  18. Flow cytometer

    DOE Patents [OSTI]

    Van den Engh, G.

    1995-11-07

    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.

  19. 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 RankADVANCED MANUFACTURINGEnergy BillsNo.Hydrogen4EnergySolid State LightingDepartmentThe Creditof

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

    DOE Patents [OSTI]

    Hankins, Matthew G. (Albuquerque, NM)

    2009-10-06

    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.

  1. Understanding order flow

    E-Print Network [OSTI]

    Evans, MDD; Lyons, Richard K.

    2006-01-01

    Understanding Order Flow October 2005 Martin D. D. Evans 1Rate Fundamentals and Order Flow, typescript, Georgetown2005), Customer Order Flow and Exchange Rate Movements: Is

  2. Unveiling Surface Redox Charge Storage of Interacting Two-Dimensional Hetero-Nanosheets in Hierarchical Architectures

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

    Mahmood, Qasim; Bak, Seong-Min; Kim, Min G.; Yun, Sol; Yang, Xiao-Qing; Shin, Hyeon S.; Kim, Woo S.; Braun, Paul V.; Park, Ho S.

    2015-03-03

    Two-dimensional (2D) heteronanosheets are currently the focus of intense study due to the unique properties that emerge from the interplay between two low-dimensional nanomaterials with different properties. However, the properties and new phenomena based on the two 2D heteronanosheets interacting in a 3D hierarchical architecture have yet to be explored. Here, we unveil the surface redox charge storage mechanism of surface-exposed WS2 nanosheets assembled in a 3D hierarchical heterostructure using in situ synchrotron X-ray absorption and Raman spectroscopic methods. The surface dominating redox charge storage of WS2 is manifested in a highly reversible and ultrafast capacitive fashion due to themore »interaction of heteronanosheets and the 3D connectivity of the hierarchical structure. In contrast, compositionally identical 2D WS2 structures fail to provide a fast and high capacitance with different modes of lattice vibration. The distinctive surface capacitive behavior of 3D hierarchically structured heteronanosheets is associated with rapid proton accommodation into the in-plane W–S lattice (with the softening of the E2g bands), the reversible redox transition of the surface-exposed intralayers residing in the electrochemically active 1T phase of WS2 (with the reversible change in the interatomic distance and peak intensity of W–W bonds), and the change in the oxidation state during the proton insertion/deinsertion process. This proposed mechanism agrees with the dramatic improvement in the capacitive performance of the two heteronanosheets coupled in the hierarchical structure.« less

  3. Miniaturized flow injection analysis system

    DOE Patents [OSTI]

    Folta, J.A.

    1997-07-01

    A chemical analysis technique known as flow injection analysis is described, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38{times}25{times}3 mm, but can be designed for gas analysis and be substantially smaller in construction. 9 figs.

  4. Miniaturized flow injection analysis system

    DOE Patents [OSTI]

    Folta, James A. (Livermore, CA)

    1997-01-01

    A chemical analysis technique known as flow injection analysis, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38.times.25.times.3 mm, but can be designed for gas analysis and be substantially smaller in construction.

  5. Cobalt complexes: correlation of redox potential with effectivity as oxygenation catalysts

    E-Print Network [OSTI]

    Hanzlik, Robert P.; Smith, Dale F.

    1974-01-01

    (I) by Co(acac), (I) was not affected by lOOmM tetra-ethylammonium perchlorate (TEAP) but 50 mM LiC10, completely inhibited the cata- lysis. We propose that in this case the lithium ion becomes chelateds by the ligand donor oxygens of the cobalt... com- plex. By acting as a Lewis acid, the bound lithium ion decreases the availability of electron density on the com- plex thus reducing the likelihood of a cobalt-oxygen inter- action. This is substantiated by the sharp increase in the redox...

  6. Conductance with stochastic resonance in Mn{sub 12} redox network without tuning

    SciTech Connect (OSTI)

    Hirano, Yoshiaki [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan); Graduate School of Engineering, University of Fukui, 3-9-1 Bunkyo, Fukui 910-8507 (Japan); Segawa, Yuji; Kawai, Tomoji [Institute of Scientific and Industrial Research (ISIR), Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Kuroda-Sowa, Takayoshi [Department of Chemistry, Faculty of Science and Engineering, Kinki University, 3-4-1 Kowakae, Higashi-Osaka, Osaka 577-8502 (Japan); Matsumoto, Takuya, E-mail: matsumoto-t@chem.sci.osaka-u.ac.jp [Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama-cho, Toyonaka, Osaka 560-0043 (Japan)

    2014-06-09

    Artificial neuron-based information processing is one of the attractive approaches of molecular-scale electronics, which can exploit the ability of molecular system for self-assembling or self-organization. The self-organized Mn{sub 12}/DNA redox network shows nonlinear current-voltage characteristics that can be described by the Coulomb blockade network model. As a demonstration of the nonlinear network system, we have observed stochastic resonance without tuning for weak periodic input signals and thermal noise, which suggests a route to neural network composed of molecular materials.

  7. Developing Information on Energy Savings and Associated Costs and Benefits of Energy Efficient Emerging Technologies Applicable in California

    E-Print Network [OSTI]

    Xu, Tengfang

    2011-01-01

    of a Vanadium Redox Flow Battery Electricity Storage System.Vanadium Redox Flow Batteries wastewater-8 Using new batterypromising novel battery designs like the vanadium redox flow

  8. Redox Active Layer-by-Layer Structures containing MnO2 Nanoparticles

    SciTech Connect (OSTI)

    Bazito, Fernanda; O'Brien, Robert; Buttry, Daniel A.

    2005-02-01

    Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications. This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathode materials in rechargeable Li batteries. Our recent work has focused on synthesizing MnO2 nanoparticles and using these in layer-by-layer (LbL) structures to probe the redox properties of the nanoparticles. We show that the aqueous colloidal nanoparticles produced by butanol reduction of tetramethylammonium permanganate can be trapped in thin films using a layer-by-layer deposition approach, and that these films are both redox active and exhibit kinetically facile electrochemical responses. We show cyclic voltammetry of MnO2 colloidal nanoparticles entrapped in a LbL thin film at an ITO electrode surface using poly(diallyldimethylammonium chloride) (PDDA). CV experiments demonstrate that Li+ insertion accompanies Mn(IV) reduction in LiClO4 supporting electrolytes, and that reduction is hindered in supporting electrolytes containing only tetrabutylammonium cations. We also show that electron propagation through multilayer films is facile, suggesting that electrons percolate through the films via electron exchange between nanoparticles.

  9. Redox probing study of the potential dependence of charge transport through Li2O2

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

    Knudsen, Kristian B.; Luntz, Alan C.; Jensen, Søren H.; Vegge, Tejs; Hjelm, Johan

    2015-11-20

    In the field of energy storage devices the pursuit for cheap, high energy density, reliable secondary batteries is at the top of the agenda. The Li–O2 battery is one of the possible technologies that, in theory, should be able to close the gap, which exists between the present state-of-the-art Li-ion technologies and the demand placed on batteries by technologies such as electrical vehicles. Here we present a redox probing study of the charge transfer across the main deposition product lithium peroxide, Li2O2, in the Li–O2 battery using outer-sphere redox shuttles. The change in heterogeneous electron transfer exchange rate as amore »function of the potential and the Li2O2 layer thickness (~depth-of-discharge) was determined using electrochemical impedance spectroscopy. In addition, the attenuation of the electron transfer exchange rate with film thickness is dependent on the probing potential, providing evidence that hole transport is the dominant process for charge transfer through Li2O2 and showing that the origin of the sudden death observed upon discharge is due to charge transport limitations.« less

  10. Bioturbating animals control the mobility of redox-sensitive trace elements in organic-rich mudstone

    SciTech Connect (OSTI)

    Harazim, Dario; McIlroy, Duncan; Edwards, Nicholas P.; Wogelius, Roy A.; Manning, Phillip L.; Poduska, Kristin M.; Layne, Graham D.; Sokaras, Dimosthenis; Alonso-Mori, Roberto; Bergmann, Uwe

    2015-10-07

    Bioturbating animals modify the original mineralogy, porosity, organic content, and fabric of mud, thus affecting the burial diagenetic pathways of potential hydrocarbon source, seal, and reservoir rocks. High-sensitivity, synchrotron rapid scanning X-ray fluorescence elemental mapping reveals that producers of phycosiphoniform burrows systematically partition redox-sensitive trace elements (i.e., Fe, V, Cr, Mn, Co, Ni, Cu, and As) in fine-grained siliciclastic rocks. Systematic differences in organic carbon content (total organic carbon >1.5 wt%) and quality (?13Corg~0.6‰) are measured between the burrow core and host sediment. The relative enrichment of redox-sensitive elements in the burrow core does not correlate with significant neo-formation of early diagenetic pyrite (via trace metal pyritization), but is best explained by physical concentration of clay- and silt-sized components. A measured loss (~–15%) of the large-ionic-radius elements Sr and Ba from both burrow halo and core is most likely associated with the release of Sr and Ba to pore waters during biological (in vivo) weathering of silt- to clay-sized lithic components and feldspar. In conclusion, this newly documented effect has significant potential to inform the interpretation of geochemical proxy and rock property data, particularly from shales, where elemental analyses are commonly employed to predict reservoir quality and support paleoenvironmental analysis.

  11. Bioturbating animals control the mobility of redox-sensitive trace elements in organic-rich mudstone

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

    Harazim, Dario; McIlroy, Duncan; Edwards, Nicholas P.; Wogelius, Roy A.; Manning, Phillip L.; Poduska, Kristin M.; Layne, Graham D.; Sokaras, Dimosthenis; Alonso-Mori, Roberto; Bergmann, Uwe

    2015-10-07

    Bioturbating animals modify the original mineralogy, porosity, organic content, and fabric of mud, thus affecting the burial diagenetic pathways of potential hydrocarbon source, seal, and reservoir rocks. High-sensitivity, synchrotron rapid scanning X-ray fluorescence elemental mapping reveals that producers of phycosiphoniform burrows systematically partition redox-sensitive trace elements (i.e., Fe, V, Cr, Mn, Co, Ni, Cu, and As) in fine-grained siliciclastic rocks. Systematic differences in organic carbon content (total organic carbon >1.5 wt%) and quality (?13Corg~0.6‰) are measured between the burrow core and host sediment. The relative enrichment of redox-sensitive elements in the burrow core does not correlate with significant neo-formation ofmore »early diagenetic pyrite (via trace metal pyritization), but is best explained by physical concentration of clay- and silt-sized components. A measured loss (~–15%) of the large-ionic-radius elements Sr and Ba from both burrow halo and core is most likely associated with the release of Sr and Ba to pore waters during biological (in vivo) weathering of silt- to clay-sized lithic components and feldspar. In conclusion, this newly documented effect has significant potential to inform the interpretation of geochemical proxy and rock property data, particularly from shales, where elemental analyses are commonly employed to predict reservoir quality and support paleoenvironmental analysis.« less

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

    E-Print Network [OSTI]

    Hur, JI; Kim, CJ

    2015-01-01

    scale direct methanol fuel cell development,” Energy, vol.flow-based microfluidic fuel cell," J. Am. Chem. Soc. , vol.membraneless microchannel fuel cell system with open circuit

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

    E-Print Network [OSTI]

    Hur, JI; Kim, CJ

    2015-01-01

    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,

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

    E-Print Network [OSTI]

    Sheffield, University of

    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

  15. Theory of Membraneless Electrochemical Cells William A. Braffa

    E-Print Network [OSTI]

    Bazant, Martin Z.

    electrochemical cells, such as flow batteries and electrolyzers, that rely on slow diffusion in laminar flow analytically. The theory is applied to the membrane-less Hydrogen Bromine Laminar Flow Battery and found

  16. Fossil Energy Fuel Cell Wayne Surdoval, SECA Coordinator

    E-Print Network [OSTI]

    #12;IAPG, GPPD-DWC 4/30/03 Solid Oxide Fuel Cell Oxidant Flow Fuel Flow Oxidant Flow End Plate Cathode Powering All Ships Siemens Westinghouse Siemens Westinghouse DelphiDelphi General Electric General Electric

  17. Solar Cell Simulation

    K-12 Energy Lesson Plans and Activities Web site (EERE)

    Students model the flow of energy from the sun as it enters a photovoltaic cell, moves along a wire and powers a load. The game-like atmosphere involves the younger students and helps them understand the continuous nature of the flow of energy. For a related lesson, please see the activity “Solar Powered System” (PDF 430 KB).

  18. Microfluidic Flow-Flash: Method for Investigating Protein Dynamics

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    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

  19. Fuel cell stack with passive air supply

    DOE Patents [OSTI]

    Ren, Xiaoming; Gottesfeld, Shimshon

    2006-01-17

    A fuel cell stack has a plurality of polymer electrolyte fuel cells (PEFCs) where each PEFC includes a rectangular membrane electrode assembly (MEA) having a fuel flow field along a first axis and an air flow field along a second axis perpendicular to the first axis, where the fuel flow field is long relative to the air flow field. A cathode air flow field in each PEFC has air flow channels for air flow parallel to the second axis and that directly open to atmospheric air for air diffusion within the channels into contact with the MEA.

  20. Engineering design factors in flowing electrolyte bipolar batteries

    SciTech Connect (OSTI)

    Grimes, P.; Bellows, R.; Malachesky, P.

    1984-08-01

    Flowing electrolyte bipolar batteries allow a system designer great flexibility in fitting the batteries to applications. A mathematical model has been developed describing flow battery characteristics to aid the designer. This model can be used to compute the interrelationships of power, energy, volume, number of cells, cell area, capacity, weight, etc. Examples from zinc bromine battery systems are given.

  1. Amphiphilic mediated sample preparation for micro-flow cytometry

    DOE Patents [OSTI]

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

    2009-03-17

    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.

  2. Amphiphilic mediated sample preparation for micro-flow cytometry

    DOE Patents [OSTI]

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

    2006-07-25

    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.

  3. Palaeo-redox from calcite REE at Sellafield UK, England GL et al 2005 s.haszeldine@ed.ac.uk Chemical Geology p1 Palaeo-redox conditions of groundwater during glaciation at Sellafield, UK revealed by

    E-Print Network [OSTI]

    Haszeldine, Stuart

    .haszeldine@ed.ac.uk Chemical Geology p1 Palaeo-redox conditions of groundwater during glaciation at Sellafield, UK revealed 668 3184) 2 British Geological Survey, Edinburgh, EH9 3LA, UK 3 British Geological Survey, Keyworth calcite REE at Sellafield UK, England GL et al 2005 s.haszeldine@ed.ac.uk Chemical Geology p2 Abstract

  4. Comparison of planar shear flow and planar elongational flow for systems of small molecules

    E-Print Network [OSTI]

    such as blow-forming, injection molding, and sheet casting. The flows occurring during these processes difficult. Early PEF simulations involved contracting the simulation cell in one of the directions parallel

  5. Mechanisms of G1 cell cycle arrest and apoptosis in myeloma cells...

    Office of Scientific and Technical Information (OSTI)

    Effect of HDAC inhibitors on cell viability was determined by WST-assay and trypan blue assay. Cell cycle was analyzed using flow cytometer. The expression of cell cycle...

  6. Flow induced crystallisation of HDPE (DOW 96001) in cross-slot flow

    E-Print Network [OSTI]

    Scelsi, Lino

    2008-06-30

    Bright-field optical observation of supercooled high density polyethylene (HDPE) flowing in a cross-slot multi-pass rheometer (MPR) cell. The geometry generates a flow field with an extensional component at the centreline. If the no slip condition...

  7. Anal. Chem. 1904, 56,787-792 707 Coulometric Study of the Redox Dynamics of Iron in Seawater

    E-Print Network [OSTI]

    Morel, François M. M.

    [Fe(III)]form with the proportion of the totalsoluble iron present in each oxidation state under intermediate redox couple such as Oz/HzOz), the proportion of soluble iron in the ferrous state will be much)observed the presence and diurnal variation of Fe(I1) species in lake surface waters and attributed

  8. Redox shuttles having an aromatic ring fused to a 1,1,4,4-tetrasubstituted cyclohexane ring

    DOE Patents [OSTI]

    Weng, Wei; Zhang, Zhengcheng; Amine, Khalil

    2015-12-01

    An electrolyte includes an alkali metal salt; an aprotic solvent; and a redox shuttle additive including an aromatic compound having at least one aromatic ring fused with at least one non-aromatic ring, the aromatic ring having two or more oxygen or phosphorus-containing substituents.

  9. Transposing Molecular Fluorescent Switches into the Near-IR: Development of Luminogenic Reporter Substrates for Redox Metabolism

    E-Print Network [OSTI]

    Turro, Nicholas J.

    Transposing Molecular Fluorescent Switches into the Near-IR: Development of Luminogenic Reporter communicate the development of a NIR luminescent redox switch, based on a Nd(III) complex, that serves to afford a good luminescent switch.9 Since the sensitization of lanthanide metals is assumed to occur via

  10. Discovery of agglutinated benthic foraminifera in Devonian black shales and their relevance for the redox state of ancient seas

    E-Print Network [OSTI]

    Polly, David

    Discovery of agglutinated benthic foraminifera in Devonian black shales and their relevance Received in revised form 4 October 2008 Accepted 31 October 2008 Keywords: Black shale Redox Devonian. The discovery that they occur widely in Late Devonian black shales has a bearing on the boundary conditions

  11. Redox-linked protonation state changes in cytochrome bc1 identified by PoissonBoltzmann electrostatics calculations

    E-Print Network [OSTI]

    Ullmann, G. Matthias

    titration calculations have been performed for completely reduced and completely oxidised cytochrome bc1 of CoQ oxidation. The Rieske iron­ sulphur cluster could be shown to undergo redox-linked protonation protein; Cardiolipin; Rieske iron­sulphur cluster; Poisson­Boltzmann electrostatics calculation 1

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

    E-Print Network [OSTI]

    Burke, Ian

    ). 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

  13. The development of a rod-coil redox polymer composed of biphenyl esters and poly (4-vinylpyridine) 

    E-Print Network [OSTI]

    DeCormier, Amy Urbanowicz

    2001-01-01

    A rod-coil polymer was successfully synthesized to provide a backbone structure from which a redox polymer was produced. The rod was composed of biphenyl esters and the coil was composed of poly (4-vinylpyridine). The coil was produced by anionic...

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

    SciTech Connect (OSTI)

    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)

    2012-12-13

    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.

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

    SciTech Connect (OSTI)

    2011-12-19

    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.

  16. A Hybrid Redox-Supercapacitor System with Anionic Catholyte and Cationic Anolyte

    SciTech Connect (OSTI)

    Wang, B; Macia-Agullo, JA; Prendiville, DG; Zheng, X; Liu, D; Zhang, Y; Boettcher, SW; Ji, X; Stucky, GD

    2014-04-11

    A significant challenge for energy storage technologies is to realize battery-level energy density and capacitor-level durability and power density in one device. By introducing an electrolyte composed of an anionic catholyte and a cationic anolyte into a symmetric carbon-based supercapacitor configuration, a hybrid electrochemical battery-supercapacitor system using soluble redox species delivers significantly improved energy density from 20 to 42 W.h/kg (based on the electrode mass) and stable capacities for > 10(4) cycles. The ionic species formed in the electrolyte are studied by UV-Vis, Raman and mass spectroscopy to probe the energy storage mechanism. The strategy is general and may provide a route to critically-needed fast-charging devices with both high energy density and power. (C) 2014 The Electrochemical Society. All rights reserved.

  17. Propeller Flow Meter 

    E-Print Network [OSTI]

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

    2007-10-01

    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....

  18. Bacteria in shear flow

    E-Print Network [OSTI]

    Marcos, Ph.D. Massachusetts Institute of Technology

    2011-01-01

    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 ...

  19. Dispersed flow film boiling

    E-Print Network [OSTI]

    Yoder, Graydon L.

    1980-01-01

    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 ...

  20. Hydrogen Fuel Cell Vehicles

    E-Print Network [OSTI]

    Delucchi, Mark

    1992-01-01

    freezing and about a hundred freeze-thaw cycles, there is no change in fuel cellfuel cell is operating, it generates more than enough heat to prevent water and moisture from freezingfuel cell system, because in the present design the flow fields and manifolds would be damaged by the freezing-

  1. Device for monitoring cell voltage

    SciTech Connect (OSTI)

    Doepke, Matthias; Eisermann, Henning

    2012-08-21

    A device for monitoring a rechargeable battery having a number of electrically connected cells includes at least one current interruption switch for interrupting current flowing through at least one associated cell and a plurality of monitoring units for detecting cell voltage. Each monitoring unit is associated with a single cell and includes a reference voltage unit for producing a defined reference threshold voltage and a voltage comparison unit for comparing the reference threshold voltage with a partial cell voltage of the associated cell. The reference voltage unit is electrically supplied from the cell voltage of the associated cell. The voltage comparison unit is coupled to the at least one current interruption switch for interrupting the current of at least the current flowing through the associated cell, with a defined minimum difference between the reference threshold voltage and the partial cell voltage.

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

    DOE Patents [OSTI]

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

    2000-01-01

    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.

  3. Multiphase flow calculation software

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2003-04-15

    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.

  4. Flow Distances on Open Flow Networks

    E-Print Network [OSTI]

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

    2015-01-01

    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...

  5. Fuel cell water transport

    DOE Patents [OSTI]

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

    1990-01-01

    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.

  6. Electrochemical cell for in-situ x-ray characterization

    SciTech Connect (OSTI)

    Doughty, D.H.; Ingersoll, D.; Rodriguez, M.A.

    1998-08-04

    An electrochemical cell suitable for in-situ XRD analysis is presented. Qualitative information such as phase formation and phase stability can be easily monitored using the in-situ cell design. Quantitative information such as lattice parameters and kinetic behavior is also straightforward. Analysis of the LiMn&sub2;O&sub4; spinel using this cell design shows that the lattice undergoes two major structural shrinkages at approx. 4.0 V and approx. 4.07 V during charging. These shrinkages correlate well with the two electrochemical waves observed and indicate the likelihood of two separate redox processes which charging and discharging.

  7. Photoelectrochemical investigation of a poly(ethylene oxide) cell

    SciTech Connect (OSTI)

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

    1984-03-01

    The photoelectrochemical properties of cells based on the solid polymer electrolyte (SPE) poly(ethylene oxide)/NaSCN with Na2S/S as a redox species are investigated experimentally. The preparation of the SPE is described in detail. Current/voltage curves or voltage/time are shown for cells using p-InP/SPE/conducting-glass, n-GaAs/SPE/conducting-glass, and p-InP/SPE/n-CdS structures. It is concluded that practical cells based on SPE of this type will require increases in the ionic conductivity of poly(ethylene oxide). 13 references.

  8. Microscale gas flow: A comparison of Grad's 13 moment equations and other continuum approaches

    E-Print Network [OSTI]

    Victoria, University of

    and chemical sensors, and fuel cells. The gas and fluid flows in devices of this size exhibit behavior that can) is not negligible compared to the characteristic length scale. The rarefaction of a fluid flow is also seen aircraft. Currently, when one looks to model fluid flow and heat transfer in a rarefied flow there are two

  9. A one-volt p-InP/n-CdSe regenerative photoelectrochemical cell

    SciTech Connect (OSTI)

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

    1983-08-01

    Photoelectrochemical (PEC) cells have the potential utility of being used for either the direct conversion of solar energy to electricity as in regenerative devices or to generate stored redox species which can later be electrochemically discharged in a suitable cell. This latter approach has been particularly intriguing over the last few years. However, although several photoelectrochemical storage cells have been discussed, it has become increasingly desirable to have a high-voltage (approx. =1 V) PEC cell, so that the storage cell with which it is associated has some hope of being competitive with presently available commercial batteries.

  10. 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]

    Sparks, Donald L.

    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

  11. Portable wastewater flow meter

    DOE Patents [OSTI]

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

    1999-02-02

    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.

  12. Portable wastewater flow meter

    DOE Patents [OSTI]

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

    1990-01-01

    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.

  13. A novel redox-based switch: LMW-PTP oxidation enhances Grb2 binding and leads to ERK activation

    SciTech Connect (OSTI)

    Giannoni, Elisa [Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, 50134 Florence (Italy); Raugei, Giovanni [Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, 50134 Florence (Italy); Center of Excellence for Scientific Research DENOTHE, Viale Morgagni 44, 50134 Florence (Italy); Chiarugi, Paola [Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, 50134 Florence (Italy) and Center of Excellence for Scientific Research DENOTHE, Viale Morgagni 44, 50134 Florence (Italy)]. E-mail: paola.chiarugi@unifi.it; Ramponi, Giampietro [Department of Biochemical Sciences, University of Florence, Viale Morgagni 50, 50134 Florence (Italy); Center of Excellence for Scientific Research DENOTHE, Viale Morgagni 44, 50134 Florence (Italy)

    2006-09-22

    Low molecular weight-PTP has been reported as a redox-sensitive protein during both platelet-derived growth factor and integrin signalling. In response to oxidation the phosphatase undergoes a reversible inactivation, which in turn leads to the increase in tyrosine phosphorylation of its substrates and the properly executed anchorage-dependent proliferation program. Here, we report that an exogenous oxidative stress enhances LMW-PTP tyrosine phosphorylation, through oxidation/inactivation of the enzyme, thus preventing its auto-dephosphorylation activity. In particular, we observed a selective hyper-phosphorylation of Tyr132, that acts as a docking site for the adaptor protein Grb2. The redox-dependent enhancement of Grb2 recruitment to LMW-PTP ultimately leads to an improvement of ERK activation, likely triggering a prosurvival signal against the oxidant environment.

  14. Operando X-ray absorption and EPR evidence for a single electron redox process in copper catalysis

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

    Lu, Qingquan; Zhang, Jian; Peng, Pan; Zhang, Guanghui; Huang, Zhiliang; Yi, Hong; Miller, Jeffrey T.; Lei, Aiwen

    2015-05-26

    An unprecedented single electron redox process in copper catalysis is confirmed using operando X-ray absorption and EPR spectroscopies. The oxidation state of the copper species in the interaction between Cu(II) and a sulfinic acid at room temperature, and the accurate characterization of the formed Cu(I) are clearly shown using operando X-ray absorption and EPR evidence. Further investigation of anion effects on Cu(II) discloses that bromine ions can dramatically increase the rate of the redox process. Moreover, it is proven that the sulfinic acids are converted into sulfonyl radicals, which can be trapped by 2-arylacrylic acids and various valuable ?-keto sulfonesmore »are synthesized with good to excellent yields under mild conditions.« less

  15. Simulating Nonuniform Properties in Polymer-Electrolyte Fuel Cells

    E-Print Network [OSTI]

    Weber, A.Z.; Newman, J.

    2006-01-01

    IN POLYMER-ELECTROLYTE FUEL CELLS A. Z. Weber and J. Newmanvapor flow throughout all of the fuel-cell sandwich layers,of the membrane thickness in fuel-cell water management. The

  16. Redox-Dependent Solubility of Technetium in Low Activity Waste Glass

    SciTech Connect (OSTI)

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

    2014-03-01

    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.

  17. Redox linked flavin sites in extracellular decaheme proteins involved in microbe-mineral electron transfer.

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

    Edwards, Marcus J.; White, Gaye F.; Norman, Michael; Tome-Fernandez, Alice; Ainsworth, Emma; Shi, Liang; Fredrickson, Jim K.; Zachara, John M.; Butt, Julea N.; Richardson, David J.; et al

    2015-07-01

    Extracellular microbe-mineral electron transfer is a major driving force for the oxidation of organic carbon in many subsurface environments. Extracellular multi-heme cytochromes of the Shewenella genus play a major role in this process but the mechanism of electron exchange at the interface between cytochrome and acceptor is widely debated. The 1.8 Å x-ray crystal structure of the decaheme MtrC revealed a highly conserved CX?C disulfide that, when substituted for AX?A, severely compromised the ability of S. oneidensis to grow under aerobic conditions. Reductive cleavage of the disulfide in the presence of flavin mononucleotide (FMN) resulted in the reversible formation ofmore »a stable flavocytochrome. Similar results were also observed with other decaheme cytochromes, OmcA, MtrF and UndA. The data suggest that these decaheme cytochromes can transition between highly reactive flavocytochromes or less reactive cytochromes, and that this transition is controlled by a redox active disulfide that responds to the presence of oxygen.« less

  18. Transitions from near-surface to interior redox upon lithiation in conversion electrode materials

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

    He, Kai [Brookhaven National Lab. (BNL), Upton, NY (United States); Xin, Huolin L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhao, Kejie [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Yu, Xiqian [Brookhaven National Lab. (BNL), Upton, NY (United States); Norlund, Dennis [SLAC National Accelerator Lab., Menlo Park, CA (United States); Weng, Tsu-Chien [SLAC National Accelerator Lab., Menlo Park, CA (United States); Li, Jing [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Jiang, Yi [Cornell Univ., Ithaca, NY (United States); Cadigan, Christopher A. [Colorado School of Mines, Golden, CO (United States); Richards, Ryan M. [Colorado School of Mines, Golden, CO (United States); Doeff, Marca M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yang, Xiao-Qing [Brookhaven National Lab. (BNL), Upton, NY (United States); Stach, Eric A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Li, Ju [MIT (Massachusetts Inst. of Technology), Cambridge, MA (United States); Lin, Feng [Colorado School of Mines, Golden, CO (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Su, Dong [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States)

    2015-02-11

    Nanoparticle electrodes in lithium-ion batteries have both near-surface and interior contributions to their redox capacity, each with distinct rate capabilities. Using combined electron microscopy, synchrotron X-ray methods and ab initio calculations, we have investigated the lithiation pathways that occur in NiO electrodes. We find that the near-surface electroactive (Ni²??Ni?) sites saturated very quickly, and then encounter unexpected difficulty in propagating the phase transition into the electrode (referred to as a “shrinking-core” mode). However, the interior capacity for Ni²??Ni? can be accessed efficiently following the nucleation of lithiation “fingers” which propagate into the sample bulk, but only after a certain incubation time. Our microstructural observations of the transition from a slow shrinking-core mode to a faster lithiation finger mode corroborate with synchrotron characterization of large-format batteries, and can be rationalized by stress effects on transport at high-rate discharge. The finite incubation time of the lithiation fingers sets the intrinsic limitation for the rate capability (and thus the power) of NiO for electrochemical energy storage devices. The present work unravels the link between the nanoscale reaction pathways and the C-rate-dependent capacity loss, and provides guidance for the further design of battery materials that favors high C-rate charging.

  19. Transitions from near-surface to interior redox upon lithiation in conversion electrode materials

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

    He, Kai; Xin, Huolin L.; Zhao, Kejie; Yu, Xiqian; Norlund, Dennis; Weng, Tsu-Chien; Li, Jing; Jiang, Yi; Cadigan, Christopher A.; Richards, Ryan M.; et al

    2015-01-29

    Nanoparticle electrodes in lithium-ion batteries have both near-surface and interior contributions to their redox capacity, each with distinct rate capabilities. Using combined electron microscopy, synchrotron X-ray methods and ab initio calculations, we have investigated the lithiation pathways that occur in NiO electrodes. We find that the near-surface electroactive (Ni²??Ni?) sites saturated very quickly, and then encounter unexpected difficulty in propagating the phase transition into the electrode (referred to as a “shrinking-core” mode). However, the interior capacity for Ni²??Ni? can be accessed efficiently following the nucleation of lithiation “fingers” which propagate into the sample bulk, but only after a certain incubationmore »time. Our microstructural observations of the transition from a slow shrinking-core mode to a faster lithiation finger mode corroborate with synchrotron characterization of large-format batteries, and can be rationalized by stress effects on transport at high-rate discharge. The finite incubation time of the lithiation fingers sets the intrinsic limitation for the rate capability (and thus the power) of NiO for electrochemical energy storage devices. The present work unravels the link between the nanoscale reaction pathways and the C-rate-dependent capacity loss, and provides guidance for the further design of battery materials that favors high C-rate charging.« less

  20. Soluble Lead Flow Battery: Soluble Lead Flow Battery Technology

    SciTech Connect (OSTI)

    2010-09-01

    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.

  1. ROLE OF MANGANESE REDUCTION/OXIDATION (REDOX) ON FOAMING AND MELT RATE IN HIGH LEVEL WASTE (HLW) MELTERS (U)

    SciTech Connect (OSTI)

    Jantzen, C; Michael Stone, M

    2007-03-30

    High-level nuclear waste is being immobilized at the Savannah River Site (SRS) by vitrification into borosilicate glass at the Defense Waste Processing Facility (DWPF). Control of the Reduction/Oxidation (REDOX) equilibrium in the DWPF melter is critical for processing high level liquid wastes. Foaming, cold cap roll-overs, and off-gas surges all have an impact on pouring and melt rate during processing of high-level waste (HLW) glass. All of these phenomena can impact waste throughput and attainment in Joule heated melters such as the DWPF. These phenomena are caused by gas-glass disequilibrium when components in the melter feeds convert to glass and liberate gases such as H{sub 2}O vapor (steam), CO{sub 2}, O{sub 2}, H{sub 2}, NO{sub x}, and/or N{sub 2}. During the feed-to-glass conversion in the DWPF melter, multiple types of reactions occur in the cold cap and in the melt pool that release gaseous products. The various gaseous products can cause foaming at the melt pool surface. Foaming should be avoided as much as possible because an insulative layer of foam on the melt surface retards heat transfer to the cold cap and results in low melt rates. Uncontrolled foaming can also result in a blockage of critical melter or melter off-gas components. Foaming can also increase the potential for melter pressure surges, which would then make it difficult to maintain a constant pressure differential between the DWPF melter and the pour spout. Pressure surges can cause erratic pour streams and possible pluggage of the bellows as well. For these reasons, the DWPF uses a REDOX strategy and controls the melt REDOX between 0.09 {le} Fe{sup 2+}/{summation}Fe {le} 0.33. Controlling the DWPF melter at an equilibrium of Fe{sup +2}/{summation}Fe {le} 0.33 prevents metallic and sulfide rich species from forming nodules that can accumulate on the floor of the melter. Control of foaming, due to deoxygenation of manganic species, is achieved by converting oxidized MnO{sub 2} or Mn{sub 2}O{sub 3} species to MnO during melter preprocessing. At the lower redox limit of Fe{sup +2}/{summation}Fe {approx} 0.09 about 99% of the Mn{sup +4}/Mn{sup +3} is converted to Mn{sup +2}. Therefore, the lower REDOX limits eliminates melter foaming from deoxygenation.

  2. Effect of the L499M mutation of the ascomycetous Botrytis aclada laccase on redox potential and catalytic properties

    SciTech Connect (OSTI)

    Osipov, Evgeny [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); Polyakov, Konstantin [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); Engelhardt Institute of Molecular Biology, Vavilova Str. 32, Moscow 119991 (Russian Federation); Kittl, Roman [BOKU – University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien (Austria); Shleev, Sergey [RSC ‘Kurchatov Institute’, Acad. Kurchatov Sq. 1, Moscow 123182 (Russian Federation); Malmö University, 205 06 Malmö (Sweden); Dorovatovsky, Pavel [RSC ‘Kurchatov Institute’, Acad. Kurchatov Sq. 1, Moscow 123182 (Russian Federation); Tikhonova, Tamara, E-mail: ttikhonova@inbi.ras.ru [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); Hann, Stephan; Ludwig, Roland [BOKU – University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Wien (Austria); Popov, Vladimir [A. N. Bach Institute of Biochemistry, Leninsky Prospect 33/2, Moscow 119071 (Russian Federation); RSC ‘Kurchatov Institute’, Acad. Kurchatov Sq. 1, Moscow 123182 (Russian Federation)

    2014-11-01

    The structures of the ascomycetous B. aclada laccase and its L499M T1-site mutant have been solved at 1.7 Å resolution. The mutant enzyme shows a 140 mV lower redox potential of the type 1 copper and altered kinetic behaviour. The wild type and the mutant have very similar structures, which makes it possible to relate the changes in the redox potential to the L499M mutation Laccases are members of a large family of multicopper oxidases that catalyze the oxidation of a wide range of organic and inorganic substrates accompanied by the reduction of dioxygen to water. These enzymes contain four Cu atoms per molecule organized into three sites: T1, T2 and T3. In all laccases, the T1 copper ion is coordinated by two histidines and one cysteine in the equatorial plane and is covered by the side chains of hydrophobic residues in the axial positions. The redox potential of the T1 copper ion influences the enzymatic reaction and is determined by the nature of the axial ligands and the structure of the second coordination sphere. In this work, the laccase from the ascomycete Botrytis aclada was studied, which contains conserved Ile491 and nonconserved Leu499 residues in the axial positions. The three-dimensional structures of the wild-type enzyme and the L499M mutant were determined by X-ray crystallography at 1.7 Å resolution. Crystals suitable for X-ray analysis could only be grown after deglycosylation. Both structures did not contain the T2 copper ion. The catalytic properties of the enzyme were characterized and the redox potentials of both enzyme forms were determined: E{sub 0} = 720 and 580 mV for the wild-type enzyme and the mutant, respectively. Since the structures of the wild-type and mutant forms are very similar, the change in the redox potential can be related to the L499M mutation in the T1 site of the enzyme.

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

    SciTech Connect (OSTI)

    Adam Johan Bergren

    2006-05-01

    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.

  4. Microfluidics is the study of fluid flow at very small scales (micro --one millionth of a meter) and is prevalent in many areas of science and engineering. Typical applications include lab-on-a-chip devices, microfluidic fuel cells, and

    E-Print Network [OSTI]

    , microfluidic fuel cells, and DNA separation technologies. All of these microfluidic devices rely on micron tracking of cells, 3D quantitative fluorescence imaging, and the dynamics of colloidal crystal deposition

  5. Redox signaling via the molecular chaperone BiP protects cells against endoplasmic reticulum-derived oxidative stress

    E-Print Network [OSTI]

    Wang, Jie

    Oxidative protein folding in the endoplasmic reticulum (ER) has emerged as a potentially significant source of cellular reactive oxygen species (ROS). Recent studies suggest that levels of ROS generated as a byproduct of ...

  6. Flow Field Flow Fractionation Method Development for Applied Bioanalysis

    E-Print Network [OSTI]

    Schachermeyer, Samantha Lynn

    2013-01-01

    E. ; Caldwell, K. , Field-Flow Fractionation Handbook. JohnJ. P. , Sedimentation field-flow-fractionation: emergence ofby sedimentation field-flow fractionation. Am. Lab. (

  7. LAMINAR FLOW BASED MICROREACTOR FOR EFFICIENT REGENERATION OF NICOTINAMIDE COFACTORS FOR BIOCATALYIS

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    experiments as well as the microreactor characterization experiments using the ferri/ferrocyanide redox couple

  8. Hydrologic Flow Controls on Biologic Iron(III) Reduction in

    E-Print Network [OSTI]

    Burgos, William

    for energy that likely increased cell synthesis, and decreased the concentration of sorbed Fe(II) that) in a goethite-coated sand was bioreduced by the DMRB Shewanella putrefaciens CN32 in a flow-through column

  9. Numerical simulation of flow separation control by oscillatory fluid injection 

    E-Print Network [OSTI]

    Resendiz Rosas, Celerino

    2005-08-29

    In this work, numerical simulations of flow separation control are performed. The sep-aration control technique studied is called 'synthetic jet actuation'. The developed code employs a cell centered finite volume scheme which handles viscous...

  10. Ultrasonic flow metering system

    DOE Patents [OSTI]

    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)

    2002-01-01

    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.

  11. Redox-active tyrosine residue in the microcin J25 molecule

    SciTech Connect (OSTI)

    Chalon, Miriam C.; Wilke, Natalia; Pedersen, Jens; Rufini, Stefano; Morero, Roberto D.; Cortez, Leonardo; Chehin, Rosana N.; Farias, Ricardo N.; Vincent, Paula A.

    2011-03-18

    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.

  12. Use of Conducting Polymers for Electronic Communication with Redox Active Nanoparticles

    SciTech Connect (OSTI)

    Bazito, Fernanda; O'Brien, Robert; Buttry, Daniel A.

    2004-08-08

    Nanoscale materials provide unique properties that will enable new technologies and enhance older ones. One area of intense activity in which nanoscale materials are being used is in the development of new functional materials for battery applications.1-4 This effort promises superior materials with properties that circumvent many of the problems associated with traditional battery materials. Previously we have worked on several approaches for using nanoscale materials for application as cathode materials in rechargeable Li batteries.5-11 Our recent work has focused on synthesizing MnO2 nanoparticles and using conducting polymers to electronically address these particles in nanoparticle assemblies. This presentation will focus on those efforts. MnO2 nanoparticles that are encapsulated with poly(3,4-ethylenedioxythiophene) (PEDOT) are prepared using 3,4-ethylenedioxythiophene (EDOT) as a chemical reductant for permanganate anion. This non-aqueous preparation is based on a recent report of a similar method for preparation of PEDOT-encapsulated Au nanoparticles.12 We also describe the synthesis of MnO2 colloidal nanoparticles prepared using an aqueous route involving reduction of permanganate anion with butanol using a previously described route.13 We report the synthesis and characterization of the PEDOT material, and the aqueous colloidal material. We show that the aqueous colloidal nanoparticles can be trapped in thin films using a layer-by-layer deposition approach, and that these films are both redox active and exhibit kinetically facile electrochemical responses. This is illustrated in Figure 1 below, which shows cyclic voltammetry of MnO2 colloidal nanoparticles entrapped in a thin film at an ITO electrode surface using poly(diallyldimethylammonium chloride (PDDA). Finally, we report on the use of X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) to characterize the oxidation state and coordination environment around Mn in these materials.

  13. Elbow mass flow meter

    DOE Patents [OSTI]

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

    1994-01-01

    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.

  14. FLOW-THROUGH POROUS ELECTRODES

    E-Print Network [OSTI]

    Trainham, III, James Arthur

    2011-01-01

    Wilhelm. HBoundary conditions of a flow reactor. 1i Chemicala Packed-Bed Electrochemical Flow Reactor." Journal ofRichard, and Brian Gracon. "Flow-Through Porous Electrodes."

  15. Technical Notes Short-Term Physiologic Effects of Mechanical Flow

    E-Print Network [OSTI]

    Jochem, Frank J.

    Technical Notes Short-Term Physiologic Effects of Mechanical Flow Sorting and the Becton to large, high-efficiency cyto- meters, mechanically sorting benchtop instruments pro- vide a feasible photosynthetic rates and esterase activities by mechanical flow sorting and cell concentration

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

    E-Print Network [OSTI]

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

    2012-01-01

    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...

  17. Membrane-less hydrogen bromine flow battery William A. Braff1

    E-Print Network [OSTI]

    Bazant, Martin Z.

    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

  18. Bioinspired design of redox-active ligands for multielectron catalysis: Effects of positioning pyrazine reservoirs on cobalt for electro- and photocatalytic generation of hydrogen from water

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

    Jurss, Jonah W.; Khnayzer, Rony S.; Panetier, Julien A.; El Roz, Karim A.; Nichols, Eva M.; Head-Gordon, Martin; Long, Jeffrey R.; Castellano, Felix N.; Chang, Christopher J.

    2015-06-09

    Mononuclear metalloenzymes in nature can function in cooperation with precisely positioned redox-active organic cofactors in order to carry out multielectron catalysis. Inspired by the finely tuned redox management of these bioinorganic systems, we present the design, synthesis, and experimental and theoretical characterization of a homologous series of cobalt complexes bearing redox-active pyrazines. These donor moieties are locked into key positions within a pentadentate ligand scaffold in order to evaluate the effects of positioning redox non-innocent ligands on hydrogen evolution catalysis. Both metal- and ligand-centered redox features are observed in organic as well as aqueous solutions over a range of pHmore »values, and comparison with analogs bearing redox-inactive zinc(II) allows for assignments of ligand-based redox events. Varying the geometric placement of redox non-innocent pyrazine donors on isostructural pentadentate ligand platforms results in marked effects on observed cobalt-catalyzed proton reduction activity. Electrocatalytic hydrogen evolution from weak acids in acetonitrile solution, under diffusion-limited conditions, reveals that the pyrazine donor of axial isomer 1-Co behaves as an unproductive electron sink, resulting in high overpotentials for proton reduction, whereas the equatorial pyrazine isomer complex 2-Co is significantly more active for hydrogen generation at lower voltages. Addition of a second equatorial pyrazine in complex 3-Co further minimizes overpotentials required for catalysis. The equatorial derivative 2-Co is also superior to its axial 1-Co congener for electrocatalytic and visible-light photocatalytic hydrogen generation in biologically relevant, neutral pH aqueous media. Density functional theory calculations (B3LYP-D2) indicate that the first reduction of catalyst isomers 1-Co, 2-Co, and 3-Co is largely metal-centered while the second reduction occurs at pyrazine. Taken together, the data establish that proper positioning of non-innocent pyrazine ligands on a single cobalt center is indeed critical for promoting efficient hydrogen catalysis in aqueous media, akin to optimally positioned redox-active cofactors in metalloenzymes. In a broader sense, these findings highlight the significance of electronic structure considerations in the design of effective electron–hole reservoirs for multielectron transformations.« less

  19. Low flow fume hood

    DOE Patents [OSTI]

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

    2002-01-01

    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.

  20. Pipe Flow System Holly Guest

    E-Print Network [OSTI]

    Clement, Prabhakar

    Pipe Flow System Design Holly Guest #12;Problem · An engineer is asked to compute the flow rate · Flow type: Turbulent or Laminar flow · Flow rate · Frictional head loss · Optimal diameters if a pump · = - ( . + . ) · f = friction factor · = relative roughness = · = Reynolds Number = · Laminar flow: 2000

  1. Modeling Water Management in Polymer-Electrolyte Fuel Cells

    E-Print Network [OSTI]

    Weber, Adam; Department of Chemical Engineering, University of California, Berkeley

    2008-01-01

    side of the cell in both crossflow and flow-under-the-ribgas flow is probably crossflow. This situation was looked atbalances. They found that crossflow increases the average

  2. Flow patterns in vertical two-phase flow

    SciTech Connect (OSTI)

    McQuillan, K.W.; Whalley, P.B.

    1985-03-01

    This paper is concerned with the flow patterns which occur in upwards gas-liquid two-phase flow in vertical tubes. The basic flow patterns are described and the use of flow patter maps is discussed. The transition between plug flow and churn flow is modelled under the assumption that flooding of the falling liquid film limits the stability of plug flow. The resulting equation is combined with other flow pattern transition equations to produce theoretical flow pattern maps, which are then tested against experimental flow pattern data. Encouraging agreement is obtained.

  3. Electrolytic cell. [For separating anolyte and catholyte

    DOE Patents [OSTI]

    Bullock, J.S.; Hale, B.D.

    1984-09-14

    An apparatus is described for the separation of the anolyte and the catholyte during electrolysis. The electrolyte flows through an electrolytic cell between the oppositely charged electrodes. The cell is equipped with a wedge-shaped device, the tapered end being located between the electrodes on the effluent side of the cell. The wedge diverts the flow of the electrolyte to either side of the wedge, substantially separating the anolyte and the catholyte.

  4. Site-specific and redox-controlled S-nitrosation of thioredoxin

    E-Print Network [OSTI]

    Barglow, Katherine T.

    Protein S-nitrosation on cysteine residues has emerged as an important posttranslational modification in mammalian cells. Previous studies have suggested a primary role for thioredoxin (Trx) in controlling protein S-nitrosation ...

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

    E-Print Network [OSTI]

    Hunt, Jayme

    2006-07-11

    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...

  6. The role of Ncb5or in fatty acid metabolism and redox homeostasis

    E-Print Network [OSTI]

    Xu, Ming

    2011-12-31

    response gene expression, oxidized glutathione content and cell death. These phenotypes could be alleviated by co-incubation with oleic acid via TAG channeling. Taken together, these findings suggest that increased FFA accumulation and catabolism...

  7. AN EXPLORATION INTO BATTERY CHEMISTRY IONIC FLOW, INTERCALATION AND

    E-Print Network [OSTI]

    Petta, Jason

    AN EXPLORATION INTO BATTERY CHEMISTRY IONIC FLOW, INTERCALATION AND CRYSTAL LATTICES JAKE GARCIA ALLA ZAMARAYEVA ADVISOR: DAN STEINGART #12;A PROBLEM IN SOCIETY! · The energy problem · Batteries-cost and environmentally friendly battery? #12;BACKGROUND · Different Common Battery types: Galvanic "Wet" Cell Dry Cell

  8. Forced Granular Orifice Flow

    E-Print Network [OSTI]

    Zheng Peng; Hepeng Zheng; Yimin Jiang

    2009-09-06

    The flow of granular material through an orifice is studied experimentally as a function of force $F$ pushing the flow. It is found that the flow rate increases linearly with $F$ -- a new, unexpected result that is in contrast to the usual view that $F$, completely screened by an arch formed around the orifice, has no way of altering the rate. Employing energy balance, we show that this behavior results mainly from dissipation in the granular material.

  9. Turbulent flow in graphene

    E-Print Network [OSTI]

    Kumar S. Gupta; Siddhartha Sen

    2010-06-05

    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.

  10. Solids mass flow determination

    DOE Patents [OSTI]

    Macko, Joseph E. (Hempfield Township, Westmoreland County, PA)

    1981-01-01

    Method and apparatus for determining the mass flow rate of solids mixed with a transport fluid to form a flowing mixture. A temperature differential is established between the solids and fluid. The temperature of the transport fluid prior to mixing, the temperature of the solids prior to mixing, and the equilibrium temperature of the mixture are monitored and correlated in a heat balance with the heat capacities of the solids and fluid to determine the solids mass flow rate.

  11. On the redox origin of surface trapping in AlGaN/GaN high electron mobility transistors

    SciTech Connect (OSTI)

    Gao, Feng; Chen, Di; Tuller, Harry L.; Thompson, Carl V.; Palacios, Tomás

    2014-03-28

    Water-related redox couples in ambient air are identified as an important source of the surface trapping states, dynamic on-resistance, and drain current collapse in AlGaN/GaN high electron mobility transistors (HEMTs). Through in-situ X-ray photoelectron spectroscopy (XPS), direct signature of the water-related species—hydroxyl groups (OH) was found at the AlGaN surface at room temperature. It was also found that these species, as well as the current collapse, can be thermally removed above 200?°C in vacuum conditions. An electron trapping mechanism based on the H{sub 2}O/H{sub 2} and H{sub 2}O/O{sub 2} redox couples is proposed to explain the 0.5?eV energy level commonly attributed to the surface trapping states. Finally, the role of silicon nitride passivation in successfully removing current collapse in these devices is explained by blocking the water molecules away from the AlGaN surface.

  12. Real-Time Maps of Fluid Flow Fields in Porous Biomaterials

    E-Print Network [OSTI]

    Julia J. Mack; Khalid Youssef; Onika D. V. Noel; Michael Lake; Ashley Wu; M. Luisa Iruela-Arispe; Louis-S. Bouchard

    2013-01-13

    Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.

  13. Real-Time Maps of Fluid Flow Fields in Porous Biomaterials

    E-Print Network [OSTI]

    Mack, Julia J; Noel, Onika D V; Lake, Michael; Wu, Ashley; Iruela-Arispe, M Luisa; Bouchard, Louis-S; 10.1016/j.biomaterials.2012.11.030

    2013-01-01

    Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.

  14. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

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

    2003-01-01

    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).

  15. Fuel cell membrane hydration and fluid metering

    DOE Patents [OSTI]

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

    1999-01-01

    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 in order to mix its respective portion of liquid water with the corresponding portion of the stream. 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).

  16. Oscillatory concentration pulses of some divalent metal ions induced by a redox oscillator

    E-Print Network [OSTI]

    Epstein, Irving R.

    + and Ni2+ are induced by adding these species to the BrO3 À ­SO3 2À chemical oscillator in a flow reactor. In the systems examined here, the oscillatory reductant SO3 2À binds the free metal ion in a MSO3 precipitate, reducing its level to a minimal value when [SO3 2À ] is high, followed by release of the metal ion when

  17. Balanced Flow Geostrophic, Inertial, Gradient, and Cyclostrophic Flow

    E-Print Network [OSTI]

    Hennon, Christopher C.

    Balanced Flow Geostrophic, Inertial, Gradient, and Cyclostrophic Flow The types of atmospheric flows describe here have the following characteristics: 1) Steady state (meaning that the flows do surfaces) These are "idealized" flows, created by balances of horizontal forces. They provide a qualitative

  18. Productivity & Energy Flow

    E-Print Network [OSTI]

    Mitchell, Randall J.

    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

  19. Elbow mass flow meter

    DOE Patents [OSTI]

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

    1994-08-16

    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.

  20. Microelectromechanical flow control apparatus

    SciTech Connect (OSTI)

    Okandan, Murat (NE Albuquerque, NM)

    2009-06-02

    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.

  1. Flow cytometric measurement of total DNA and incorporated halodeoxyuridine

    DOE Patents [OSTI]

    Dolbeare, Frank A. (Livermore, CA); Gray, Joe W. (Livermore, CA)

    1986-01-01

    A method for the simultaneous flow cytometric measurement of the total DNA content and the level of DNA synthesis in normal and malignant cells is disclosed. The sensitivity of the method allows a study of cell cycle traverse rates for large scale cell populations as well as single cell measurements. A DNA stain such as propidium iodide is used as the probe for the measurement of total DNA content and a monoclonal antibody reactive with a DNA precursor such as bromodeoxyuridine (BrdU) is used as a probe for the measurement of BrdU uptake by the cells as a measure of DNA synthesis.

  2. Analysis of Fuel Cell Systems Rangan Banerjee

    E-Print Network [OSTI]

    Banerjee, Rangan

    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

  3. EE580 Solar Cells Todd J. Kaiser

    E-Print Network [OSTI]

    Kaiser, Todd J.

    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

  4. Conceptual engineering design of a 50-kW rechargeable alkaline zinc/redox battery

    SciTech Connect (OSTI)

    Selman, J.R.; Hollansworth, R.P.

    1984-08-01

    The zinc/ferro-ferricyanide battery has been advanced over the past 6 years from a concept to a working unit of demonstrated high energy efficiency. A conceptual engineering design for a 50-kW solar storage battery system has been formulated, based upon performance data of 60, 200, and 1000 cm/sup 2/ cells and physical property data collected from the literature or determined earlier. Starting with a cell performance model and a crystallizer model, mass and energy balances are analyzed using a modular design. Isothermal and adiabatic operations are considered, and thermal storage requirements estimated

  5. Apparatus and method for transforming living cells

    DOE Patents [OSTI]

    Okandan, Murat; Galambos, Paul C.

    2003-11-11

    An apparatus and method are disclosed for in vitro transformation of living cells. The apparatus, which is formed as a microelectromechanical device by surface micromachining, can be used to temporarily disrupt the cell walls or membrane of host cells one at a time so that a particular substance (e.g. a molecular tag, nucleic acid, bacteria, virus etc.) can be introduced into the cell. Disruption of the integrity of the host cells (i.e. poration) can be performed mechanically or electrically, or by both while the host cells are contained within a flow channel. Mechanical poration is possible using a moveable member which has a pointed or serrated edge and which is driven by an electrostatic actuator to abrade, impact or penetrate the host cell. Electroporation is produced by generating a relatively high electric field across the host cell when the host cell is located in the flow channel between a pair of electrodes having a voltage applied therebetween.

  6. In situ PEM fuel cell water measurements

    SciTech Connect (OSTI)

    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

    2008-01-01

    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.

  7. Effect of flow fluctuations and nonflow on elliptic flow methods

    E-Print Network [OSTI]

    Ollitrault, Jean-Yves

    2009-01-01

    24.10.Nz I. INTRODUCTION II. FLOW METHODS Elliptic ?ow hasin the participant plane. Flow methods involve variousow e?ects are negligible. Flow ?uctuations modify both the

  8. Regulation of Bone Morphogenetic Protein 9 by Redox-Dependent Proteolysis

    E-Print Network [OSTI]

    Wei, Zhenquan; Salmon, Richard M.; Upton, Paul D.; Morrell, Nicholas W.; Li, Wei

    2014-09-18

    of the orphan activin receptor-like kinase 1 (ALK1) in endothelial cells. Blood 109, 1953-1961 3. Johnson, D. W., Berg, J. N., Baldwin, M. A., Gallione, C. J., Marondel, I., Yoon, S. J., Stenzel, T. T., Speer, M., Pericak-Vance, M. A., Diamond, A., Guttmacher, A...

  9. Structural and Functional Characterization of Redox Mn and Co Sites in AlPO Materials and Their Role in Alkane Oxidation Catalysis

    E-Print Network [OSTI]

    Iglesia, Enrique

    and at similar rates, indicating excellent agreement between these techniques. No H2O or CO2 were detected during could be accurately described by Arrhenius-type behavior, and H2/Me ratios showed that only a fraction of all Me cations undergo reversible redox cycles. This fraction was 0.86 for MnAPO-18 (atomic Mn/P ) 0

  10. THERMAL ANALYSIS OF AIR-COOLED FUEL CELLS Setareh Shahsavari

    E-Print Network [OSTI]

    Bahrami, Majid

    - cooled proton exchange membrane fuel cells (PEMFC). In the modeled fuel cell stack, forced air flow for thermal analysis of air-cooled PEMFC stacks, where temperature non-uniformity is high and thermal

  11. 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)

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

    2011-12-29

    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.

  12. Bedrock Erosion by Granular Flow

    E-Print Network [OSTI]

    Hsu, Leslie

    2010-01-01

    of boulders later in the flow when the matrix has thickenedMaximum height of the flow is 3.3 m. Appendix A true storyThe physics of debris flows, Reviews of Geophysics 35(3),

  13. Magnetically stimulated fluid flow patterns

    SciTech Connect (OSTI)

    Martin, Jim; Solis, Kyle

    2014-03-06

    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.

  14. Magnetically stimulated fluid flow patterns

    ScienceCinema (OSTI)

    Martin, Jim; Solis, Kyle

    2014-08-06

    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.

  15. Microfluidic Hydrogen Fuel Cell with a Liquid Electrolyte Ranga S. Jayashree, Michael Mitchell, Dilip Natarajan, Larry J. Markoski, and

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    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, and electrolyte flow rate on fuel cell performance to obtain a maximum power density of 191 mW/cm2. This flowing

  16. Stackable Miniature Fuel Cells with On-Demand Fuel and Oxygen Supply

    E-Print Network [OSTI]

    Hur, Janet

    2013-01-01

    formic acid microfabricated fuel cells," J. Power Sources,flow-based microfluidic fuel cell," J. Am. Chem. Soc. , vol.in a direct formic acid fuel cell (DFAFC): Use of array

  17. Stackable Miniature Fuel Cells with On-Demand Fuel and Oxygen Supply

    E-Print Network [OSTI]

    Hur, Janet

    2013-01-01

    acid microfabricated fuel cells," J. Power Sources, vol.flow-based microfluidic fuel cell," J. Am. Chem. Soc. , vol.in a direct formic acid fuel cell (DFAFC): Use of array

  18. Enviro Hurdles: Instream Flow | Department of Energy

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

    Hurdles: Instream Flow Enviro Hurdles: Instream Flow Enviro Hurdles: Instream Flow 76enviornlbevelhimer4.pptx More Documents & Publications Instream Flow Project Development and...

  19. Flow Map Manager 

    E-Print Network [OSTI]

    Moya, Maria J

    2011-11-24

    Long-distance bus companies, operate services along routes which have a flow of passengers. Along a route some passengers will leave the bus while others join. To monitor demand sufficiently well a tool is required which can help estimate...

  20. Complex Flow Workshop Report

    SciTech Connect (OSTI)

    none,

    2012-05-01

    This report documents findings from a workshop on the impacts of complex wind flows in and out of wind turbine environments, the research needs, and the challenges of meteorological and engineering modeling at regional, wind plant, and wind turbine scales.

  1. Optical flow switching

    E-Print Network [OSTI]

    Chan, Vincent W. S.

    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 ...

  2. Electron Transfer Dynamics in Efficient Molecular Solar Cells

    SciTech Connect (OSTI)

    Meyer, Gerald John

    2014-10-01

    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.

  3. Electrochemical flow capacitors

    DOE Patents [OSTI]

    Gogotsi, Yury; Presser, Volker; Kumbar, Emin Caglan

    2015-11-05

    The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).

  4. Electrochemical flow capacitors

    DOE Patents [OSTI]

    Gogotsi, Yury; Presser, Volker; Kumbur, Emin Caglan

    2015-10-27

    The present invention generally relates to devices for energy storage technologies, and more particularly to electrochemical flow capacitor systems and applications. In some aspects, these flow capacitors have at least one electrode comprising a non-stationary solid or semi-solid composition comprising supercapacitive particles and an electrolytic solvent in electrical communication with at least one current collector, and energy is stored and/or released by charging and/or discharging the electrode(s).

  5. Conjugate flow action functionals

    E-Print Network [OSTI]

    Daniele Venturi

    2013-10-15

    We present a new general method to construct an action functional for a non-potential field theory. The key idea relies on representing the governing equations of the theory relative to a diffeomorphic flow of curvilinear coordinates which is assumed to be functionally dependent on the solution field. Such flow, which will be called the conjugate flow of the theory, evolves in space and time similarly to a physical fluid flow of classical mechanics and it can be selected in order to symmetrize the Gateaux derivative of the field equations with respect to suitable local bilinear forms. This is equivalent to requiring that the governing equations of the field theory can be derived from a principle of stationary action on a Lie group manifold. By using a general operator framework, we obtain the determining equations of such manifold and the corresponding conjugate flow action functional. In particular, we study scalar and vector field theories governed by second-order nonlinear partial differential equations. The identification of transformation groups leaving the conjugate flow action functional invariant could lead to the discovery of new conservation laws in fluid dynamics and other disciplines.

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

    DOE Patents [OSTI]

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

    2011-10-25

    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.

  7. Fluid Flow Estimation Through Integration of Physical Flow Configurations

    E-Print Network [OSTI]

    Garbe, Christoph S.

    Fluid Flow Estimation Through Integration of Physical Flow Configurations Christoph S. Garbe IWR, University of Heidelberg Christoph.Garbe@iwr.uni-heidelberg.de Abstract. The measurement of fluid flows is an emerging field for op- tical flow computation. In a number of such applications, a tracer is visualized

  8. Boundary Layer Analysis of Membraneless Electrochemical Cells

    E-Print Network [OSTI]

    Braff, William

    A mathematical theory is presented for the charging and discharging behavior of membraneless electrochemical cells that rely on slow diffusion in laminar flow to separate the half reactions. Ion transport is described by ...

  9. Electrochemical Cells with Intermediate Capacitor Elements

    E-Print Network [OSTI]

    Grebel, Haim

    2015-01-01

    Our goal is to electronically regulate electrochemical cells. For this, we introduced a third element, called the gate, which was placed between the cathode and the anode electrodes of the cell. Voltage applied to this element controlled the local potential of the electrolyte, thus impacting the flow of ions within the cell. The flow of ions was monitored by the electronic current in the external cell's circuit. We provide simulations and experimental data as proof to the validity of this concept. This is but the first step towards a demonstration of a two-dimensional, bi-carrier ion transistors.

  10. SOFC seal and cell thermal management

    DOE Patents [OSTI]

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

    2011-05-17

    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.

  11. 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

  12. Water management studies in PEM fuel cells, Part I: Fuel cell design and in situ water distributions

    E-Print Network [OSTI]

    Kandlikar, Satish

    Water management studies in PEM fuel cells, Part I: Fuel cell design and in situ water. Trabolda, * a General Motors Fuel Cell Laboratory, 10 Carriage Street, Honeoye Falls, New York, USA b Accepted 23 December 2008 Available online 23 February 2009 Keywords: PEM fuel cell Two-phase flow Neutron

  13. Fuel cell stack arrangements

    DOE Patents [OSTI]

    Kothmann, Richard E. (Churchill Boro, PA); Somers, Edward V. (Murrysville, PA)

    1982-01-01

    Arrangements of stacks of fuel cells and ducts, for fuel cells operating with separate fuel, oxidant and coolant streams. An even number of stacks are arranged generally end-to-end in a loop. Ducts located at the juncture of consecutive stacks of the loop feed oxidant or fuel to or from the two consecutive stacks, each individual duct communicating with two stacks. A coolant fluid flows from outside the loop, into and through cooling channels of the stack, and is discharged into an enclosure duct formed within the loop by the stacks and seals at the junctures at the stacks.

  14. Two-phase flow studies

    SciTech Connect (OSTI)

    Hanold, R.J.

    1983-12-01

    The two-phase flow program is directed at understanding the hydrodynamics of two-phase flows. The two-phase flow regime is characterized by a series of flow patterns that are designated as bubble, slug, churn, and annular flow. Churn flow has received very little scientific attention. This lack of attention cannot be justified because calculations predict that the churn flow pattern will exist over a substantial portion of the two-phase flow zone in producing geothermal wells. The University of Houston is experimentally investigating the dynamics of churn flow and is measuring the holdup over the full range of flow space for which churn flow exists. These experiments are being conducted in an air/water vertical two-phase flow loop. Brown University has constructed and is operating a unique two-phase flow research facility specifically designed to address flow problems of relevance to the geothermal industry. An important feature of the facility is that it is dedicated to two-phase flow of a single substance (including evaporation and condensation) as opposed to the case of a two-component two-phase flow. This facility can be operated with horizontal or vertical test sections of constant diameter or with step changes in diameter to simulate a geothermal well profile.

  15. Sequestration of terrigenous organic carbon on the northern California shelf : role of hyperpycnal flows

    E-Print Network [OSTI]

    Moeremans, Raphaële E.

    2011-01-01

    cores have not experienced diagenesis from deep burial andwith redox-related diagenesis. Maxima in Fe/Ti ratio could

  16. Corrosion test cell for bipolar plates

    DOE Patents [OSTI]

    Weisbrod, Kirk R. (Los Alamos, NM)

    2002-01-01

    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.

  17. Time-resolved fluorescence decay measurements for flowing particles

    DOE Patents [OSTI]

    Deka, C.; Steinkamp, J.A.

    1999-06-01

    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.

  18. In situ PEM fuel cell water measurements

    SciTech Connect (OSTI)

    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

    2009-01-01

    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.

  19. Fuel cell current collector

    DOE Patents [OSTI]

    Katz, Murray (Newington, CT); Bonk, Stanley P. (West Willington, CT); Maricle, Donald L. (Glastonbury, CT); Abrams, Martin (Glastonbury, CT)

    1991-01-01

    A fuel cell has a current collector plate (22) located between an electrode (20) and a separate plate (25). The collector plate has a plurality of arches (26, 28) deformed from a single flat plate in a checkerboard pattern. The arches are of sufficient height (30) to provide sufficient reactant flow area. Each arch is formed with sufficient stiffness to accept compressive load and sufficient resiliently to distribute the load and maintain electrical contact.

  20. Fuel cell system combustor

    DOE Patents [OSTI]

    Pettit, William Henry (Rochester, NY)

    2001-01-01

    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.

  1. Fuel cell repeater unit including frame and separator plate

    SciTech Connect (OSTI)

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

    2013-11-05

    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.

  2. Multiphase cooling flows

    E-Print Network [OSTI]

    Peter A. Thomas

    1996-08-20

    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.

  3. Variable Refrigerant Flow HVAC 

    E-Print Network [OSTI]

    Jones, S.

    2013-01-01

    Variable refrigerant flow technology HVAC CATEE 2013 San Antonio, TX ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency Conference, San Antonio, Texas Dec. 16-18 What is the acronym VRF? ? Variable Refrigerant Flow Operates like a... heat pump utilizing VFD Inverter Compressors and LEV’s Unlike conventional commercial and residential HVAC systems in the USA The predominate method of cooling and heating in the world ESL-KT-13-12-33 CATEE 2013: Clean Air Through Energy Efficiency...

  4. Progresses in Ab Initio QM/MM Free Energy Simulations of Electrostatic Energies in Proteins: Accelerated QM/MM Studies of pKa, Redox Reactions and Solvation Free Energies

    E-Print Network [OSTI]

    Kamerlin, Shina C. L.

    2009-01-01

    J. ; Glennon, T. ; Warshel, A. QM/MM approaches for studyingProgresses in Ab Initio QM/MM Free Energy Simulations ofin Proteins: Accelerated QM/MM Studies of pK a , Redox

  5. Generator configuration for solid oxide fuel cells

    DOE Patents [OSTI]

    Reichner, Philip (Plum Boro, PA)

    1989-01-01

    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.

  6. Variable area fuel cell cooling

    DOE Patents [OSTI]

    Kothmann, Richard E. (Churchill Borough, PA)

    1982-01-01

    A fuel cell arrangement having cooling fluid flow passages which vary in surface area from the inlet to the outlet of the passages. A smaller surface area is provided at the passage inlet, which increases toward the passage outlet, so as to provide more uniform cooling of the entire fuel cell. The cooling passages can also be spaced from one another in an uneven fashion.

  7. EXPERIMENTAL INVESTIGATION OF Ti and Fe VALENCE IN CHONDRULE-LIKE MELTS DURING COOLING UNDER CHANGING REDOX CONDITIONS AT LOW PARTIAL PRESSURES. S. B. Simon1

    E-Print Network [OSTI]

    Grossman, Lawrence

    . This idea is being tested experimentally. Initial results were re- ported by [3]; here we report results CHANGING REDOX CONDITIONS AT LOW PARTIAL PRESSURES. S. B. Simon1 , J. R. Beckett2 , S. R. Sutton1,3 and L melted on Fe loops. Three runs are reported here: an isothermal run (I6) at 1400°C for 66 h at 2.75 log

  8. BaCe1-xPdxO3-(0 e x e 0.1): Redox Controlled Ingress and Egress of Palladium in a Perovskite

    E-Print Network [OSTI]

    Rappe, Andrew M.

    BaCe1-xPdxO3- (0 e x e 0.1): Redox Controlled Ingress and Egress of Palladium in a Perovskite Jun-ray photoelectron spectroscopy that Pd2+ ions can be substituted for Ce in perovskite BaCeO3 and that, under description of the structure. The Pd2+-containing perovskite phases extrude elemental face-centered cubic

  9. US energy flow, 1991

    SciTech Connect (OSTI)

    Borg, I.Y.; Briggs, C.K.

    1992-06-01

    Trends in energy consumption and assessment of energy sources are discussed. Specific topics discussed include: energy flow charts; comparison of energy use with 1990 and earlier years; supply and demand of fossil fuels (oils, natural gas, coal); electrical supply and demand; and nuclear power.

  10. ENERGY FLOWS CLIMATE CHANGE

    E-Print Network [OSTI]

    Schwartz, Stephen E.

    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

  11. Flow-controlled magnetic particle manipulation

    DOE Patents [OSTI]

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

    2011-02-22

    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.

  12. Subsurface microbial community structure correlates with uranium redox phases during in situ field manipulation in a contaminated aquifer

    SciTech Connect (OSTI)

    Kostka, Joel [Florida State University; Green, Stefan [Florida State University, Tallahassee; Wu, Wei-min [Stanford University; Criddle, Craig [Stanford University; Watson, David B [ORNL; Jardine, Philip M [ORNL

    2009-07-01

    Long-term field manipulation experiments investigating the effects of subsurface redox conditions on the fate and transport of soluble uranium(VI) were conducted over a 3 year period at the Oak Ridge Integrated Field Research Center (OR-IFRC) in Oak Ridge, TN. In the highly contaminated source zone, introduction of ethanol to the subsurface stimulated native denitrifying, sulfate-reducing, iron-reducing and fermentative microorganisms and reduced U to below 0.03 mg/L. Subsequently, oxygen and nitrate were experimentally re-introduced into the subsurface to examine the potential for re-oxidation and re-mobilization of U(IV). Introduction of oxygen or nitrate caused changes in subsurface geochemistry and re-oxidation of U. After reoxidation, the subsurface experienced several months of starvation conditions before ethanol injection was restored to reduce the treatment zone. Subsurface microorganisms were characterized by community fingerprinting, targeted population analyses, and quantitative PCR of key functional groups in 50 samples taken during multiple phases of field manipulation. Statistical analysis confirmed the hypothesis that the microbial community would co-vary with the shifts in the subsurface geochemistry. The level of hydraulic connectivity of sampling wells to the injection well was readily tracked by microbial community analysis. We demonstrate quantitatively that specific populations, especially Desulfosporosinus, are heavily influenced by geochemical conditions and positively correlate with the immobilization of uranium. Following nitrate reoxidation, populations of Fe(II)-oxidizing, nitrate reducing organisms (Thiobacillus) showed an increase in relative abundance.

  13. Brazed bipolar plates for PEM fuel cells

    DOE Patents [OSTI]

    Neutzler, J.K.

    1998-07-07

    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.

  14. Brazed bipolar plates for PEM fuel cells

    DOE Patents [OSTI]

    Neutzler, Jay Kevin (Rochester, NY)

    1998-01-01

    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.

  15. Cell division: a source of active stress in cellular monolayers

    E-Print Network [OSTI]

    Doostmohammadi, Amin; Saw, Thuan B; Lim, Chwee T; Ladoux, Benoit; Yeomans, Julia M

    2015-01-01

    We introduce the notion of cell division-induced activity and show that the cell division generates extensile forces and drives dynamical patterns in cell assemblies. Extending the hydrodynamic models of lyotropic active nematics we describe turbulent-like velocity fields that are generated by the cell division in a confluent monolayer of cells. We show that the experimentally measured flow field of dividing Madin-Darby Canine Kidney (MDCK) cells is reproduced by our modeling approach. Division-induced activity acts together with intrinsic activity of the cells in extensile and contractile cell assemblies to change the flow and director patterns and the density of topological defects. Finally we model the evolution of the boundary of a cellular colony and compare the fingering instabilities induced by cell division to experimental observations on the expansion of MDCK cell cultures.

  16. Supercritical flow in rectangular expansions 

    E-Print Network [OSTI]

    Walsh, Peter.

    1968-01-01

    In recent years the occasions for design of channels to contain supercritical flow has increased considerably. Consequently there has developed a need for a method of predicting the physical characteristics of such flow based on theory...

  17. Radial flow pulse jet mixer

    DOE Patents [OSTI]

    VanOsdol, John G.

    2013-06-25

    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.

  18. HYDROLYZED WOOD SLURRY FLOW MODELING

    E-Print Network [OSTI]

    Wrathall, Jim

    2012-01-01

    LBL-10090 UC-61 HYDROLYZED WOOD SLURRY FLOW MODELING JimLBL-10090 HYDROLYZED WOOD SLURRY FLOW MODELING Jim Wrathallconversion of hydrolyzed wood slurry to fuel oil, Based on

  19. Flammable gas interlock spoolpiece flow response test plan and procedure

    SciTech Connect (OSTI)

    Schneider, T.C., Fluor Daniel Hanford

    1997-02-13

    The purpose of this test plan and procedure is to test the Whittaker electrochemical cell and the Sierra Monitor Corp. flammable gas monitors in a simulated field flow configuration. The sensors are used on the Rotary Mode Core Sampling (RMCS) Flammable Gas Interlock (FGI), to detect flammable gases, including hydrogen and teminate the core sampling activity at a predetermined concentration level.

  20. Structural power flow measurement

    SciTech Connect (OSTI)

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

    1988-12-01

    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.

  1. Ricci flow and quantum theory

    E-Print Network [OSTI]

    Robert Carroll

    2007-11-05

    We show some relations between Ricci flow and quantum theory via Fisher information and the quantum potential.

  2. Flow dynamics of the Moon

    E-Print Network [OSTI]

    Yu. N. Bratkov

    2010-04-03

    Flow analysis of big basins is given. Internal structure of flows is considered. Correlations between flows are calculated. For example, Mare Orientale is a moving basin. Orientale and Imbrium continental basins are introduced and are considered. Olbers ray crater is a result of precise interaction of the two basins. Flows of the Tycho type are studied. Two Antarctidae, an Indian Ocean, and an America are demonstrated.

  3. TEP process flow diagram

    SciTech Connect (OSTI)

    Wilms, R Scott; Carlson, Bryan; Coons, James; Kubic, William

    2008-01-01

    This presentation describes the development of the proposed Process Flow Diagram (PFD) for the Tokamak Exhaust Processing System (TEP) of ITER. A brief review of design efforts leading up to the PFD is followed by a description of the hydrogen-like, air-like, and waterlike processes. Two new design values are described; the mostcommon and most-demanding design values. The proposed PFD is shown to meet specifications under the most-common and mostdemanding design values.

  4. Convective heat flow probe

    DOE Patents [OSTI]

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

    1984-01-09

    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.

  5. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Draper, R.; George, R.A.; Shockling, L.A.

    1993-04-06

    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.

  6. Solid oxide fuel cell generator

    DOE Patents [OSTI]

    Draper, Robert (Churchill Boro, PA); George, Raymond A. (Pittsburgh, PA); Shockling, Larry A. (Plum Borough, PA)

    1993-01-01

    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.

  7. Microgravity Flow Regime Transition Modeling 

    E-Print Network [OSTI]

    Shephard, Adam M.

    2010-07-14

    Flow regime transitions and the modeling thereof underlie the design of microgravity two-phase systems. Through the use of the zero-g laboratory, microgravity two-phase flows can be studied. Because microgravity two-phase flows exhibit essentially...

  8. Effect of Flow Field Design and Voltage Change Range on the Dynamic Behavior of PEMFCs

    E-Print Network [OSTI]

    Van Zee, John W.

    Effect of Flow Field Design and Voltage Change Range on the Dynamic Behavior of PEMFCs Sunhoe Kim exchange membrane fuel cell PEMFC subjected to rapid changes in the voltage depends on the type of flow that these peak heights are limited primarily by oxygen mass transfer, even though the PEMFC is operating at close

  9. Modeling shrouded stator cavity flows in axial-flow compressors

    SciTech Connect (OSTI)

    Wellborn, S.R.; Tolchinsky, I.; Okiishi, T.H.

    2000-01-01

    Experiments and computational analyses were completed to understand the nature of shrouded stator cavity flows. From this understanding, a one-dimensional model of the flow through shrouded stator cavities was developed. This model estimates the leakage mass flow, temperature rise, and angular momentum increase through the cavity, given geometry parameters and the flow conditions at the interface between the cavity and primary flow path. This cavity model consists of two components, one that estimates the flow characteristics through the labyrinth seals and the other that predicts the transfer of momentum due to windage. A description of the one-dimensional model is given. The incorporation and use of the one-dimensional model in a multistage compressor primary flow analysis tool is described. The combination of this model and the primary flow solver was used to reliably simulate the significant impact on performance of the increase of hub seal leakage in a twelve-stage axial-flow compressor. Observed higher temperatures of the hub region fluid, different stage matching, and lower overall efficiencies and core flow than expected could be correctly linked to increased hub seal clearance with this new technique. The importance of including these leakage flows in compressor simulations is shown.

  10. Cell Stem Cell Stem Cell States, Fates,

    E-Print Network [OSTI]

    Peterson, Carsten

    Cell Stem Cell Review Stem Cell States, Fates, and the Rules of Attraction Tariq Enver,1 Martin Pera,2 Carsten Peterson,3,4 and Peter W. Andrews5,* 1The Molecular Haematology Unit, The Weatherall and their relationship to commitment to differ- entiate and lineage selection can be elucidated in terms of a landscape

  11. Viscoelastic transient of confined Red Blood Cells

    E-Print Network [OSTI]

    Gaël Prado; Alexander Farutin; Chaouqi Misbah; Lionel Bureau

    2014-09-17

    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.

  12. Characterization of flow-through electrode processes by AC impedance

    SciTech Connect (OSTI)

    Yuh, C.Y. (Energy Research Corp., Danbury, CT (United States)); Selman, J.R. (Illinois Inst. of Tech., Chicago (United States))

    1993-04-01

    Flow-through porous electrodes, such as packed-bed and fluidized-bed electrodes, are attractive for electrowinning, electro-organic synthesis and flow-battery applications. The extensive surface area of the porous electrodes makes high volumetric reaction rate more possible than in a cell with smooth electrodes. Forced convection also enhances mass-transfer rate and hence reduces concentration polarization. AC-impedance method has been used successfully in characterizing a packed-bed flow-through electrode system. A macrohomogeneous model was developed to simulate the effect of structural, physical and flow parameters. The relative importance of kinetics and mass transfer can be inferred from the AC-impedance analysis. Kinetic information about copper deposition in supported cupric sulfate solution has been obtained successfully using this technique.

  13. Characterization of illuminated semiconductor/solid-electrolyte junctions. photoelectrochemical investigation of a poly(ethylene oxide) cell. Interim technical report 1 Mar-30 Apr 83

    SciTech Connect (OSTI)

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

    1983-05-01

    Photoelectrochemical effects have been observed with solid-state cells using a poly(ethylene oxide) .NaSCN solid polymer electrolyte containing a Na2S/S redox couple. Photoeffects were observed at the interface of this electrolyte with p-InP, n-GaAs, and in a two-photoelectrode cell of configuration p-InP/PEO-NaSCN, Na2S,S/n-CdS. In this latter cell, photopotentials of 540 mV were generated using 100 mW/cm2 quartz iodine illumination.

  14. Tuning redox potentials of bis(imino)pyridine cobalt complexes: an experimental and theoretical study involving solvent and ligand effects

    SciTech Connect (OSTI)

    Moyses Araujo, C.; Doherty, Mark D.; Konezny, Steven J.; Luca, Oana R.; Usyatinsky, Alex; Grade, Hans; Lobkovsky, Emil; Soloveichik, Grigorii L.; Crabtree, Robert H.; Batista, Victor S.

    2012-01-01

    The structure and electrochemical properties of a series of bis(imino)pyridine CoII complexes (NNN)CoX? and [(NNN)?Co][PF?]? (NNN = 2,6-bis[1-(4-R-phenylimino)ethyl]pyridine, with R = CN, CF?, H, CH?, OCH?, N(CH?)?; NNN = 2,6-bis[1-(2,6-(iPr)?-phenylimino)ethyl]pyridine and X = Cl, Br) were studied using a combination of electrochemical and theoretical methods. Cyclic voltammetry measurements and DFT/B3LYP calculations suggest that in solution (NNN)CoCl? complexes exist in equilibrium with disproportionation products [(NNN)?Co]²? [CoCl?]²? with the position of the equilibrium heavily influenced by both the solvent polarity and the steric and electronic properties of the bis(imino)pyridine ligands. In strong polar solvents (e.g., CH?CN or H?O) or with electron donating substituents (R = OCH? or N(CH?)?) the equilibrium is shifted and only oxidation of the charged products [(NNN)?Co]²? and [CoCl?]²? is observed. Conversely, in nonpolar organic solvents such as CH?Cl? or with electron withdrawing substituents (R = CN or CF?), disproportionation is suppressed and oxidation of the (NNN)CoCl? complexes leads to 18e? CoIII complexes stabilized by coordination of a solvent moiety. In addition, the [(NNN)?Co][PF?]? complexes exhibit reversible CoII/III oxidation potentials that are strongly dependent on the electron withdrawing/donating nature of the N-aryl substituents, spanning nearly 750 mV in acetonitrile. The resulting insight on the regulation of redox properties of a series of bis(imino)pyridine cobalt(II) complexes should be particularly valuable to tune suitable conditions for reactivity.

  15. Low hydrostatic head electrolyte addition to fuel cell stacks

    DOE Patents [OSTI]

    Kothmann, Richard E. (Churchill Boro, PA)

    1983-01-01

    A fuel cell and system for supply electrolyte, as well as fuel and an oxidant to a fuel cell stack having at least two fuel cells, each of the cells having a pair of spaced electrodes and a matrix sandwiched therebetween, fuel and oxidant paths associated with a bipolar plate separating each pair of adjacent fuel cells and an electrolyte fill path for adding electrolyte to the cells and wetting said matrices. Electrolyte is flowed through the fuel cell stack in a back and forth fashion in a path in each cell substantially parallel to one face of opposite faces of the bipolar plate exposed to one of the electrodes and the matrices to produce an overall head uniformly between cells due to frictional pressure drop in the path for each cell free of a large hydrostatic head to thereby avoid flooding of the electrodes. The bipolar plate is provided with channels forming paths for the flow of the fuel and oxidant on opposite faces thereof, and the fuel and the oxidant are flowed along a first side of the bipolar plate and a second side of the bipolar plate through channels formed into the opposite faces of the bipolar plate, the fuel flowing through channels formed into one of the opposite faces and the oxidant flowing through channels formed into the other of the opposite faces.

  16. Hydrogen and Fuel Cells Merit Review May 22, 2003

    E-Print Network [OSTI]

    MANAGEMENT CONSIDERATIONS: · FLOW RATE: AFFECTS THE FUEL CELL STACK EFFICIENCY AND THE PARASITIC POWER REQUIRED FOR THE AIR MANAGEMENT · PRESSURE: AFFECTS THE FUEL CELL STACK EFFICIENCY AND THE PARASITIC POWERHydrogen and Fuel Cells Merit Review May 22, 2003 C:\\mkg\\doefc4\\030522H2fuelcelllsmeritreview

  17. Direct Methanol Fuel Cell Experimental and Model Validation Study

    E-Print Network [OSTI]

    Wang, Chao-Yang

    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

  18. 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

  19. Water Visualization and Flooding in Polymer Electrolyte Membrane Fuel Cells

    E-Print Network [OSTI]

    Petta, Jason

    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

  20. Relation between photospheric flow fields and the magnetic field distribution on the solar surface

    SciTech Connect (OSTI)

    Simon, G.W.; Title, A.M.; Topka, K.P.; Tarbell, T.D.; Shine, R.A.

    1988-04-01

    Using the technique of local correlation tracking on a 28 minute time sequence of white-light images of solar granulation, the horizontal flow field on the solar surface is measured. The time series was obtained by the Solar Optical Universal Polarimeter (SOUP) on Spacelab 2 (Space Shuttle flight 51-F) and is free from atmospheric blurring and distortion. The SOUP flow fields have been compared with carefully aligned magnetograms taken over a nine hour period at the Big Bear Solar Observatory before, during, and after the SOUP images. The flow field and the magnetic field agree in considerable detail: vectors which define the flow of the white-light intensity pattern (granulation) point toward magnetic field regions, magnetic fields surround flow cells, and magnetic features move along the flow arrows. The projected locations of free particles (corks) in the measured flow field congregate at the same locations where the magnetic field is observed. 31 references.