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Sample records for breached fuel plate

  1. A model for release of fission products from a breached fuel plate under wet storage

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, L.A.A.; Seerban, R.S.; Zeituni, C.A.; Silva, J.E.R. da; Silva, A.T. e; Castanheira, M.; Lucki, G.; Damy, M. de A.; Teodoro, C.A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)]. E-mail: laaterre@ipen.br

    2007-07-01

    MTR fuel elements burned-up inside the core of nuclear research reactors are stored worldwide mainly under the water of storage pools. When cladding breach is present in one or more fuel plates of such elements, radioactive fission products are released into the storage pool water. This work proposes a model to describe the release mechanism considering the diffusion of nuclides of a radioactive fission product either through a postulated small cylindrical breach or directly from a large circular hole in the cladding. In each case, an analytical expression is obtained for the activity released into the water as a function of the total storage time of a breached fuel plate. Regarding sipping tests already performed at the IEA-R1 research reactor on breached MTR fuel elements, the proposed model correlates successfully the specific activity of {sup 137}Cs, measured as a function of time, with the evaluated size of the cladding breach. (author)

  2. Development of breached pin performance analysis code SAFFRON (System of Analyzing Failed Fuel under Reactor Operation by Numerical method)

    Energy Technology Data Exchange (ETDEWEB)

    Ukai, Shigeharu [Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center

    1995-03-01

    On the assumption of fuel pin failure, the breached pin performance analysis code SAFFRON was developed to evaluate the fuel pin behavior in relation to the delayed neutron signal response during operational mode beyond the cladding failure. Following characteristic behavior in breached fuel pin is modeled in 3-dimensional finite element method : pellet swelling by fuel-sodium reaction, fuel temperature change, and resultant cladding breach extension and delayed neutron precursors release into coolant. Particularly, practical algorithm of numerical procedure in finite element method was originally developed in order to solve the 3-dimensional non-linear contact problem between the swollen pellet due to fuel-sodium reaction and breached cladding. (author).

  3. Dual fuel gradients in uranium silicide plates

    Energy Technology Data Exchange (ETDEWEB)

    Pace, B.W. [Babock and Wilcox, Lynchburg, VA (United States)

    1997-08-01

    Babcock & Wilcox has been able to achieve dual gradient plates with good repeatability in small lots of U{sub 3}Si{sub 2} plates. Improvements in homogeneity and other processing parameters and techniques have allowed the development of contoured fuel within the cladding. The most difficult obstacles to overcome have been the ability to evaluate the bidirectional fuel loadings in comparison to the perfect loading model and the different methods of instilling the gradients in the early compact stage. The overriding conclusion is that to control the contour of the fuel, a known relationship between the compact, the frames and final core gradient must exist. Therefore, further development in the creation and control of dual gradients in fuel plates will involve arriving at a plausible gradient requirement and building the correct model between the compact configuration and the final contoured loading requirements.

  4. PEM fuel cell bipolar plate material requirements for transportation applications

    Energy Technology Data Exchange (ETDEWEB)

    Borup, R.L.; Stroh, K.R.; Vanderborgh, N.E. [Los Alamos National Lab., NM (United States)] [and others

    1996-04-01

    Cost effective bipolar plates are currently under development to help make proton exchange membrane (PEM) fuel cells commercially viable. Bipolar plates separate individual cells of the fuel cell stack, and thus must supply strength, be electrically conductive, provide for thermal control of the fuel stack, be a non-porous materials separating hydrogen and oxygen feed streams, be corrosion resistant, provide gas distribution for the feed streams and meet fuel stack cost targets. Candidate materials include conductive polymers and metal plates with corrosion resistant coatings. Possible metals include aluminium, titanium, iron/stainless steel and nickel.

  5. Evolution of fuel plate parameters during deformation in rolling

    Science.gov (United States)

    Durazzo, M.; Vieira, E.; Urano de Carvalho, E. F.; Riella, H. G.

    2017-07-01

    The Nuclear and Energy Research Institute - IPEN/CNEN-SP routinely produces the nuclear fuel necessary for operating its research reactor, IEA-R1. This fuel consists of fuel plates containing U3Si2-Al composites as the meat, which are fabricated by rolling. The rolling process currently deployed was developed based on information obtained from literature, which was used as a premise for defining the current manufacturing procedures, according to a methodology with an essentially empirical character. Despite the current rolling process being perfectly stable and highly reproducible, it is not well characterized and is therefore not fully known. The objective of this work is to characterize the rolling process for producing dispersion fuel plates. Results regarding the evolution of the main parameters of technological interest, after each rolling pass, are presented. Some defects that originated along the fuel plate deformation during the rolling process were characterized and discussed. The fabrication procedures for manufacturing the fuel plates are also presented.

  6. Laser-based characterization of nuclear fuel plates

    Science.gov (United States)

    Smith, James A.; Cottle, Dave L.; Rabin, Barry H.

    2014-02-01

    Ensuring the integrity of fuel-clad and clad-clad bonding in nuclear fuels is important for safe reactor operation and assessment of fuel performance, yet the measurement of bond strengths in actual fuels has proved challenging. The laser shockwave technique (LST) originally developed to characterize structural adhesion in composites is being employed to characterize interface strength in a new type of plate fuel being developed at Idaho National Laboratory (INL). LST is a non-contact method that uses lasers for the generation and detection of large-amplitude acoustic waves and is well suited for application to both fresh and irradiated nuclear-fuel plates. This paper will report on initial characterization results obtained from fresh fuel plates manufactured by different processes, including hot isostatic pressing, friction stir welding, and hot rolling.

  7. Laser-Based Characterization of Nuclear Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    James A. Smith; David L. Cottle; Barry H. Rabin

    2013-07-01

    Ensuring the integrity of fuel-clad and clad-clad bonding in nuclear fuels is important for safe reactor operation and assessment of fuel performance, yet the measurement of bond strengths in actual fuels has proved challenging. The laser shockwave technique (LST) originally developed to characterize structural adhesion in composites is being employed to characterize interface strength in a new type of plate fuel being developed at Idaho National Laboratory (INL). LST is a non-contact method that uses lasers for the generation and detection of large-amplitude acoustic waves and is well suited for application to both fresh and irradiated nuclear-fuel plates. This paper will report on initial characterization results obtained from fresh fuel plates manufactured by different processes, including hot isostatic pressing, friction stir welding, and hot rolling.

  8. Composite Bipolar Plate for Unitized Fuel Cell/Electrolyzer Systems

    Science.gov (United States)

    Mittelsteadt, Cortney K.; Braff, William

    2009-01-01

    In a substantial improvement over present alkaline systems, an advanced hybrid bipolar plate for a unitized fuel cell/electrolyzer has been developed. This design, which operates on pure feed streams (H2/O2 and water, respectively) consists of a porous metallic foil filled with a polymer that has very high water transport properties. Combined with a second metallic plate, the pore-filled metallic plates form a bipolar plate with an empty cavity in the center.

  9. Fuel cell repeater unit including frame and separator plate

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. Microfabrication of Microchannels for Fuel Cell Plates

    OpenAIRE

    Ho Su Jang; Dong Sam Park

    2009-01-01

    Portable electronic devices such as notebook computers, PDAs, cellular phones, etc., are being widely used, and they increasingly need cheap, efficient, and lightweight power sources. Fuel cells have been proposed as possible power sources to address issues that involve energy production and the environment. In particular, a small type of fuel-cell system is known to be suitable for portable electronic devices. The development of micro fuel cell systems can be achieved by the application of m...

  11. Laser shockwave technique for characterization of nuclear fuel plate interfaces

    Science.gov (United States)

    Perton, M.; Lévesque, D.; Monchalin, J.-P.; Lord, M.; Smith, J. A.; Rabin, B. H.

    2013-01-01

    The US National Nuclear Security Agency is tasked with minimizing the worldwide use of high-enriched uranium. One aspect of that effort is the conversion of research reactors to monolithic fuel plates of low-enriched uranium. The manufacturing process includes hot isostatic press bonding of an aluminum cladding to the fuel foil. The Laser Shockwave Technique (LST) is here evaluated for characterizing the interface strength of fuel plates using depleted Uranium/Mo foils. LST is a non-contact method that uses lasers for the generation and detection of large amplitude acoustic waves and is therefore well adapted to the quality assurance of this process. Preliminary results show a clear signature of well-bonded and debonded interfaces and the method is able to classify/rank the bond strength of fuel plates prepared under different HIP conditions.

  12. Low Cost PEM Fuel Cell Metal Bipolar Plates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Conghua [TreadStone Technologies, Inc.

    2013-05-30

    Bipolar plate is an important component in fuel cell stacks and accounts for more than 75% of stack weight and volume. The technology development of metal bipolar plates can effectively reduce the fuel cells stack weight and volume over 50%. The challenge is the metal plate corrosion protection at low cost for the broad commercial applications. This project is aimed to develop innovative technological solutions to overcome the corrosion barrier of low cost metal plates. The feasibility of has been demonstrated and patented (US Patent 7,309,540). The plan is to further reduce the cost, and scale up the technology. The project is built on three pillars: 1) robust experimental evidence demonstrating the feasibility of our technology, 2) a team that consists of industrial leaders in fuel cell stack application, design, and manufactures; 3) a low-risk, significant-milestone driven program that proves the feasibility of meeting program objectives The implementation of this project will reduce the fuel cell stack metal bipolar separator plate cost which accounts 15-21% of the overall stack cost. It will contribute to the market adoption of fuel cell technologies. In addition, this corrosion protection technology can be used similar energy devices, such as batteries and electrolyzers. Therefore, the success of the project will be benefit in broad markets.

  13. Microfabrication of microchannels for fuel cell plates.

    Science.gov (United States)

    Jang, Ho Su; Park, Dong Sam

    2010-01-01

    Portable electronic devices such as notebook computers, PDAs, cellular phones, etc., are being widely used, and they increasingly need cheap, efficient, and lightweight power sources. Fuel cells have been proposed as possible power sources to address issues that involve energy production and the environment. In particular, a small type of fuel-cell system is known to be suitable for portable electronic devices. The development of micro fuel cell systems can be achieved by the application of microchannel technology. In this study, the conventional method of chemical etching and the mechanical machining method of micro end milling were used for the microfabrication of microchannel for fuel cell separators. The two methods were compared in terms of their performance in the fabrication with regards to dimensional errors, flatness, straightness, and surface roughness. Following microchannel fabrication, the powder blasting technique is introduced to improve the coating performance of the catalyst on the surface of the microchannel. Experimental results show that end milling can remarkably increase the fabrication performance and that surface treatment by powder blasting can improve the performance of catalyst coating.

  14. Microfabrication of Microchannels for Fuel Cell Plates

    Directory of Open Access Journals (Sweden)

    Ho Su Jang

    2009-12-01

    Full Text Available Portable electronic devices such as notebook computers, PDAs, cellular phones, etc., are being widely used, and they increasingly need cheap, efficient, and lightweight power sources. Fuel cells have been proposed as possible power sources to address issues that involve energy production and the environment. In particular, a small type of fuel-cell system is known to be suitable for portable electronic devices. The development of micro fuel cell systems can be achieved by the application of microchannel technology. In this study, the conventional method of chemical etching and the mechanical machining method of micro end milling were used for the microfabrication of microchannel for fuel cell separators. The two methods were compared in terms of their performance in the fabrication with regards to dimensional errors, flatness, straightness, and surface roughness. Following microchannel fabrication, the powder blasting technique is introduced to improve the coating performance of the catalyst on the surface of the microchannel. Experimental results show that end milling can remarkably increase the fabrication performance and that surface treatment by powder blasting can improve the performance of catalyst coating.

  15. UPDATE ON MECHANICAL ANALYSIS OF MONOLITHIC FUEL PLATES

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Burkes; F. J. Rice; J.-F. Jue; N. P. Hallinan

    2008-03-01

    Results on the relative bond strength of the fuel-clad interface in monolithic fuel plates have been presented at previous RRFM conferences. An understanding of mechanical properties of the fuel, cladding, and fuel / cladding interface has been identified as an important area of investigation and quantification for qualification of monolithic fuel forms. Significant progress has been made in the area of mechanical analysis of the monolithic fuel plates, including mechanical property determination of fuel foils, cladding processed by both hot isostatic pressing and friction bonding, and the fuel-clad composite. In addition, mechanical analysis of fabrication induced residual stress has been initiated, along with a study to address how such stress can be relieved prior to irradiation. Results of destructive examinations and mechanical tests are presented along with analysis and supporting conclusions. A brief discussion of alternative non-destructive evaluation techniques to quantify not only bond quality, but also bond integrity and strength, will also be provided. These are all necessary steps to link out-of-pile observations as a function of fabrication with in-pile behaviours.

  16. Fuel Cell Thermal Management Through Conductive Cooling Plates

    Science.gov (United States)

    Colozza, Anthony J.; Burke, Kenneth A.

    2008-01-01

    An analysis was performed to evaluate the concept of utilizing conductive cooling plates to remove heat from a fuel cell stack, as opposed to a conventional internal cooling loop. The potential advantages of this type of cooling system are reduced stack complexity and weight and increased reliability through the reduction of the number of internal fluid seals. The conductive cooling plates would extract heat from the stack transferring it to an external coolant loop. The analysis was performed to determine the required thickness of these plates. The analysis was based on an energy balance between the thermal energy produced within the stack and the heat removal from the cooling plates. To accomplish the energy balance, the heat flow into and along the plates to the cooling fluid was modeled. Results were generated for various numbers of cells being cooled by a single cooling plate. The results provided cooling plate thickness, mass, and operating temperature of the plates. It was determined that utilizing high-conductivity pyrolitic graphite cooling plates can provide a specific cooling capacity (W/kg) equivalent to or potentially greater than a conventional internal cooling loop system.

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

    Science.gov (United States)

    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.

  18. Plate-Based Fuel Processing System Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Faz; Helen Liu; Jacques Nicole; David Yee

    2005-12-22

    On-board reforming of liquid fuels into hydrogen is an enabling technology that could accelerate consumer usage of fuel cell powered vehicles. The technology would leverage the convenience of the existing gasoline fueling infrastructure while taking advantage of the fuel cell efficiency and low emissions. Commercial acceptance of on-board reforming faces several obstacles that include: (1) startup time, (2) transient response, and (3) system complexity (size, weight and cost). These obstacles are being addressed in a variety of projects through development, integration and optimization of existing fuel processing system designs. In this project, CESI investigated steam reforming (SR), water-gas-shift (WGS) and preferential oxidation (PrOx) catalysts while developing plate reactor designs and hardware where the catalytic function is integrated into a primary surface heat exchanger. The plate reactor approach has several advantages. The separation of the reforming and combustion streams permits the reforming reaction to be conducted at a higher pressure than the combustion reaction, thereby avoiding costly gas compression for combustion. The separation of the two streams also prevents the dilution of the reformate stream by the combustion air. The advantages of the plate reactor are not limited to steam reforming applications. In a WGS or PrOx reaction, the non-catalytic side of the plate would act as a heat exchanger to remove the heat generated by the exothermic WGS or PrOx reactions. This would maintain the catalyst under nearly isothermal conditions whereby the catalyst would operate at its optimal temperature. Furthermore, the plate design approach results in a low pressure drop, rapid transient capable and attrition-resistant reactor. These qualities are valued in any application, be it on-board or stationary fuel processing, since they reduce parasitic losses, increase over-all system efficiency and help perpetuate catalyst durability. In this program, CESI

  19. Plate-Based Fuel Processing System Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Faz; Helen Liu; Jacques Nicole; David Yee

    2005-12-22

    On-board reforming of liquid fuels into hydrogen is an enabling technology that could accelerate consumer usage of fuel cell powered vehicles. The technology would leverage the convenience of the existing gasoline fueling infrastructure while taking advantage of the fuel cell efficiency and low emissions. Commercial acceptance of on-board reforming faces several obstacles that include: (1) startup time, (2) transient response, and (3) system complexity (size, weight and cost). These obstacles are being addressed in a variety of projects through development, integration and optimization of existing fuel processing system designs. In this project, CESI investigated steam reforming (SR), water-gas-shift (WGS) and preferential oxidation (PrOx) catalysts while developing plate reactor designs and hardware where the catalytic function is integrated into a primary surface heat exchanger. The plate reactor approach has several advantages. The separation of the reforming and combustion streams permits the reforming reaction to be conducted at a higher pressure than the combustion reaction, thereby avoiding costly gas compression for combustion. The separation of the two streams also prevents the dilution of the reformate stream by the combustion air. The advantages of the plate reactor are not limited to steam reforming applications. In a WGS or PrOx reaction, the non-catalytic side of the plate would act as a heat exchanger to remove the heat generated by the exothermic WGS or PrOx reactions. This would maintain the catalyst under nearly isothermal conditions whereby the catalyst would operate at its optimal temperature. Furthermore, the plate design approach results in a low pressure drop, rapid transient capable and attrition-resistant reactor. These qualities are valued in any application, be it on-board or stationary fuel processing, since they reduce parasitic losses, increase over-all system efficiency and help perpetuate catalyst durability. In this program, CESI

  20. Endurance test for mini-plate fuel rig

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Heung June; Yang, Sun Kyu; Park, Jong Man; Kim, Chang Kyu; Ryu, Jeong Soo

    1999-07-01

    This report presents the pressure drop, vibration and endurance test results for mini-plate fuel rig which were designed by KAERI and fabricated by Daewoo Precision Co. From the pressure drop test results, it is noted that the flow velocity across the fuel rig corresponding to the pressure drop of 200 kPa is measured to be about 6.78 kg/sec. Vibration frequency for the fuel rig ranges from 14 to 19 Hz. RMZ (Root Mean Square) displacement for the fuel rig is less than 7 {mu}m, and the maximum displacement is less than 20 {mu}m. Based on the endurance rest results, the appreciable fretting wear for the fuel rig is not observed but the small amount of wear was observed at the interface region between the mini-plates and upper housing cap as well as at the slot regions of a bottom endplate interfacing with the bottom guide arms. (author). 4 refs., 10 tabs., 33 figs.

  1. Uranium density reduction on fuel element side plates assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Ilka A. [Centro Tecnologico da Marinha em Sao Paulo (CTMSP), Sao Paulo, SP (Brazil); Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Andrade, Delvonei A.; Domingos, Douglas B.; Umbehaun, Pedro E. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    During operation of IEA-R1 research reactor, located at Instituto de Pesquisas Energeticas e Nucleares, IPEN - CNEN/SP, an abnormal oxidation on some fuel elements was noted. It was also verified, among the possible causes of the problem, that the most likely one was insufficient cooling of the elements in the core. One of the propositions to solve or minimize the problem is to reduce uranium density on fuel elements side plates. In this paper, the influence of this change on neutronic and thermal hydraulic parameters for IEA-R1 reactor is verified by simulations with the codes HAMMER and CITATION. Results are presented and discussed. (author)

  2. Next Generation Bipolar Plates for Automotive PEM Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Adrianowycz, Orest; Norley, Julian; Stuart, David J; Flaherty, David; Wayne, Ryan; ; Williams, Warren; Tietze, Roger; Nguyen, Yen-Loan H; Zawodzinski, Tom; Pietrasz, Patrick

    2010-04-15

    The results of a successful U.S. Department of Energy (DoE) funded two-year $2.9 MM program lead by GrafTech International Inc. (GrafTech) are reported and summarized. The program goal was to develop the next generation of high temperature proton exchange membrane (PEM) fuel cell bipolar plates for use in transportation fuel cell applications operating at temperatures up to 120 °C. The bipolar plate composite developed during the program is based on GrafTech’s GRAFCELL resin impregnated flexible graphite technology and makes use of a high temperature Huntsman Advanced Materials resin system which extends the upper use temperature of the composite to the DoE target. High temperature performance of the new composite is achieved with the added benefit of improvements in strength, modulus, and dimensional stability over the incumbent resin systems. Other physical properties, including thermal and electrical conductivity of the new composite are identical to or not adversely affected by the new resin system. Using the new bipolar plate composite system, machined plates were fabricated and tested in high temperature single-cell fuel cells operating at 120 °C for over 1100 hours by Case Western Reserve University. Final verification of performance was done on embossed full-size plates which were fabricated and glued into bipolar plates by GrafTech. Stack testing was done on a 10-cell full-sized stack under a simulated drive cycle protocol by Ballard Power Systems. Freeze-thaw performance was conducted by Ballard on a separate 5-cell stack and shown to be within specification. A third stack was assembled and shipped to Argonne National Laboratory for independent performance verification. Manufacturing cost estimate for the production of the new bipolar plate composite at current and high volume production scenarios was performed by Directed Technologies Inc. (DTI). The production cost estimates were consistent with previous DoE cost estimates performed by DTI for the

  3. Cr plating technology for preventing Fuel Cladding Chemical Interaction

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jun Hwan; Ryu, Ho Jin; Jee, Seung Hyun; Cheon, Jin Sik; Lee, Byoung Oon; Lee, Chan Bock; Yang, Seong Woo [KAERI, Daejeon (Korea, Republic of)

    2010-11-15

    The objectives of the report are to analyze chrome electroplating technology in order to apply in the field of diffusion barrier to suppress Fuel-Cladding Chemical Interaction (FCCI). This report consists of the principle of the chrome electroplating, plating parameter and possibility of the barrier application. Chrome plating has been considered as one of the probable candidates in the field of barrier tube because of its simpleness, superior FCCI resistance, and effective coating performance at relatively low cost. However, cracks can be generate at the surface of the coating surface which reduces the coating performance. To minimize such a crack, controlling plating parameter like bath composition and bath temperature, current profile, and post-heat treatment has been reviewed. Concept for the application at the inner surface of the cladding has been also described. Based on the technology that suggested at the present report, optimizing plating parameter will be carried out. After the performance test like diffusion couple test of the metallic fuel, final barrier condition will be concluded and the fabrication of the prototype barrier tube will be conducted in the near future

  4. Fuel burnup calculation of a research reactor plate element

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Nadia Rodrigues dos; Lima, Zelmo Rodrigues de; Moreira, Maria de Lourdes, E-mail: nadiasam@gmail.com, E-mail: zrlima@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2013-07-01

    This work consists in simulating the burnup of two different plate type fuel elements, where one is the benchmark MTR of the IAEA, which is made of an alloy of uranium and aluminum, while the other belonging to a typical multipurpose reactor is composed of an alloy of uranium and silicon. The simulation is performed using the WIMSD-5B computer code, which makes use of deterministic methods for solving neutron transport. In developing this task, fuel element equivalent cells were calculated representing each of the reactors to obtain the initial concentrations of each isotope constituent element of the fuel cell and the thicknesses corresponding to each region of the cell, since this information is part of the input data. The compared values of the k∞ showed a similar behavior for the case of the MTR calculated with the WIMSD-5B and EPRI-CELL codes. Relating the graphs of the concentrations in the burnup of both reactors, there are aspects very similar to each isotope selected. The application WIMSD-5B code to calculate isotopic concentrations and burnup of the fuel element, proved to be satisfactory for the fulfillment of the objective of this work. (author)

  5. Evaluation of Five Jet Fuels in the Salmonella-Escherichia coli / Microsome Plate Incorporation Assay

    Science.gov (United States)

    2010-09-01

    AFRL-RH-WP-TR-2010-0138 Evaluation of Five Jet Fuels in the Salmonella-Escherichia coli / Microsome Plate Incorporation Assay Edward S...31 Jul 2010 4. TITLE AND SUBTITLE Evaluation of Five Jet Fuels in the Salmonella-Escherichia coli / Microsome Plate Incorporation Assay 5a...the Salmonella typhimurium-Escherichia coli/ microsome plate incorporation assay. The assay was performed using the plate incorporation procedure

  6. 10 MW research reactor simulation using fuel plate type

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa, M. El Sayed, E-mail: memmm67@yahoo.com [Reactors Department, Nuclear Researches Center, Inshas (Egypt); Shaat, M. [Reactors Department, Nuclear Researches Center, Inshas (Egypt); Kady, M. El [Mechanical Power Engineering Department, Faculty of Engineering, Al Azhar University, Cairo (Egypt)

    2016-04-15

    A computer code was established named ET-RR-1-10 to investigate the thermal hydraulic behavior of the ETRR1 (first Egyptian research reactor) research reactor when its power upgraded to 10 MW using the new fuel plate elements type. The work done include both normal and flow reduction conditions. The code modeled primary loop, secondary lop, and reactor kinetics. All code models used finite difference technique. The code results were tested against the available corresponding experimental data taken from a similar research reactor MITR (Massachusetts Institute of Technology research reactor) for the sake of code validation. The results showed good agreement, and the code can be used for thermal hydraulic calculations.

  7. Surface modified stainless steels for PEM fuel cell bipolar plates

    Science.gov (United States)

    Brady, Michael P [Oak Ridge, TN; Wang, Heli [Littleton, CO; Turner, John A [Littleton, CO

    2007-07-24

    A nitridation treated stainless steel article (such as a bipolar plate for a proton exchange membrane fuel cell) having lower interfacial contact electrical resistance and better corrosion resistance than an untreated stainless steel article is disclosed. The treated stainless steel article has a surface layer including nitrogen-modified chromium-base oxide and precipitates of chromium nitride formed during nitridation wherein oxygen is present in the surface layer at a greater concentration than nitrogen. The surface layer may further include precipitates of titanium nitride and/or aluminum oxide. The surface layer in the treated article is chemically heterogeneous surface rather than a uniform or semi-uniform surface layer exclusively rich in chromium, titanium or aluminum. The precipitates of titanium nitride and/or aluminum oxide are formed by the nitriding treatment wherein titanium and/or aluminum in the stainless steel are segregated to the surface layer in forms that exhibit a low contact resistance and good corrosion resistance.

  8. An examination of the elastic structural response of the Advanced Neutron Source fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Swinson, W.F.; Luttrell, C.R.; Yahr, G.T.

    1994-09-01

    Procedures for evaluating the elastic structural response of the Advanced Neutron Source (ANS) fuel plates to coolant flow and to temperature variations are presented in this report. Calculations are made that predict the maximum deflection and the maximum stress for a representative plate from the upper and from the lower fuel elements.

  9. Microstructural Analysis of Irradiated U-Mo Fuel Plates: Recent Results

    Energy Technology Data Exchange (ETDEWEB)

    D. D. Keiser, Jr.; J. Jue; B. D. Miller; J. Gan; A. B. Robinson; P. V. Medvedev

    2012-03-01

    Microstructural characterization of irradiated dispersion and monolithic RERTR fuel plates using scanning electron microscopy (SEM) is being performed in the Electron Microscopy Laboratory at the Idaho National Laboratory. The SEM analysis of samples from U-Mo dispersion fuel plates focuses primarily on the behavior of the Si that has been added to the Al matrix to improve the irradiation performance of the fuel plate and on the overall behavior of fission gases (e.g., Xe and Kr) that develop as bubbles in the fuel microstructure. For monolithic fuel plates, microstructural features of interest, include those found in the U-Mo foil and at the U-Mo/Zr and Zr/6061 Al cladding interfaces. For both dispersion and monolithic fuel plates, samples have been produced using an SEM equipped with a Focused Ion Beam (FIB). These samples are of very high quality and can be used to uncover some very unique microstructural features that are typically not observed when characterizing samples produced using more conventional techniques. Overall, for the dispersion fuel plates with matrices that contained Si, narrower fuel/matrix interaction layers are typically observed compared to the fuel plates with pure Al matrix, and for the monolithic fuel plates microstructural features have been observed in the U-10Mo foil that are similar to what have been observed in the fuel particles found in U-Mo dispersion fuels. Most recently, more prototypic monolithic fuel samples have been characterized and this paper describes the microstructures that have been observed in these samples.

  10. Swelling of U-7Mo/Al-Si dispersion fuel plates under irradiation - Non-destructive analysis of the AFIP-1 fuel plates

    Science.gov (United States)

    Wachs, D. M.; Robinson, A. B.; Rice, F. J.; Kraft, N. C.; Taylor, S. C.; Lillo, M.; Woolstenhulme, N.; Roth, G. A.

    2016-08-01

    Extensive fuel-matrix interactions leading to plate pillowing have proven to be a significant impediment to the development of a suitable high density low-enriched uranium molybdenum alloy (U-Mo) based dispersion fuel for high power applications in research reactors. The addition of silicon to the aluminum matrix was previously demonstrated to reduce interaction layer growth in mini-plate experiments. The AFIP-1 project involved the irradiation, in-canal examination, and post-irradiation examination of two fuel plates. The irradiation of two distinct full size, flat fuel plates (one using an Al-2wt%Si matrix and the other an Al-4043 (∼4.8 wt% Si) matrix) was performed in the INL ATR reactor in 2008-2009. The irradiation conditions were: ∼250 W/cm2 peak Beginning Of Life (BOL) power, with a ∼3.5e21 f/cm3 peak burnup. The plates were successfully irradiated and did not show any pillowing at the end of the irradiation. This paper reports the results and interpretation of the in-canal and post-irradiation non-destructive examinations that were performed on these fuel plates. It further compares additional PIE results obtained on fuel plates irradiated in contemporary campaigns in order to allow a complete comparison with all results obtained under similar conditions. Except for a brief indication of accelerated swelling early in the irradiation of the Al-2Si plate, the fuel swelling is shown to evolve linearly with the fission density through the maximum burnup.

  11. Microstructural analysis of MTR fuel plates damaged by a coolant flow blockage

    Science.gov (United States)

    Leenaers, A.; Joppen, F.; Van den Berghe, S.

    2009-10-01

    In 1975, as a result of a blockage of the coolant inlet flow, two plates of a fuel element of the BR2 reactor of the Belgian Nuclear Research Centre (SCK•CEN) were partially melted. The fuel element consisted of Al-clad plates with 90% 235U enriched UAl x fuel dispersed in an Al matrix. The element had accumulated a burn up of 21% 235U before it was removed from the reactor. Recently, the damaged fuel plates were sent to the hot laboratory for detailed PIE. Microstructural changes and associated temperature markers were used to identify several stages in the progression to fuel melting. It was found that the temperature in the center of the fuel plate had increased above 900-950 °C before the reactor was scrammed. In view of the limited availability of such datasets, the results of this microstructural analysis provide valuable input in the analysis of accident scenarios for research reactors.

  12. Preliminary Analysis for Flow Blockage of Plate Fuel using a Commercial CFD Code

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jong-Pil; Park, Suki [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    A plate-type fuel assembly is widely used in the research reactors in order to enhance power density. This type fuel assembly consists of a number of fuel plates, supporting plates, and narrow rectangular cooling channels between the fuel plates. Due to the narrow rectangular channels consisting of parallel plate fuels and side plates, the cooling channels are isolated from each other so that the cross flow between the channels are completely restricted. When blockage at the inlet of the channel occurs, therefore, the coolant flow through the blocked channel will be greatly reduced or completely interrupted. Accordingly, the blocked channel loses its own cooling capability. This event may cause initiation of nucleate boiling and two phase flow instability (FI) in the blocked channel. In recent years, CFD analyses of flow blockage of a research reactor have been performed by many researchers. The present study reports a 3-dimensional CFD simulation using two-phase model for flow blockage of two channels of a plate-type fuel assembly. The present result shows limited information since the simulation is working at the moment. However, the present study indicates that it is possible to predict a damage propagation of a plate-type fuel assembly due to the flow instability caused by flow blockage using a commercial CFD code.

  13. 78 FR 33132 - Quality Verification for Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test...

    Science.gov (United States)

    2013-06-03

    ... COMMISSION Quality Verification for Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test... Verification for Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test Reactors.'' This guide... plate-type uranium-aluminum fuel elements used in research and test reactors (RTRs). ADDRESSES: Please...

  14. U-Mo Foil/Cladding Interactions in Friction Stir Welded Monolithic RERTR Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    D.D. Keiser; J.F. Jue; C.R. Clark

    2006-10-01

    Interaction between U-Mo fuel and Al has proven to dramatically impact the overall irradiation performance of RERTR dispersion fuels. It is of interest to better understand how similar interactions may affect the performance of monolithic fuel plates, where a uranium alloy fuel is sandwiched between aluminum alloy cladding. The monolithic fuel plate removes the fuel matrix entirely, which reduces the total surface area of the fuel that is available to react with the aluminum and moves the interface between the fuel and cladding to a colder region of the fuel plate. One of the major fabrication techniques for producing monolithic fuel plates is friction stir welding. This paper will discuss the interactions that can occur between the U-Mo foil and 6061 Al cladding when applying this fabrication technique. It has been determined that the time at high temperatures should be limited as much as is possible during fabrication or any post-fabrication treatment to reduce as much as possible the interactions between the foil and cladding. Without careful control of the fabrication process, significant interaction between the U-Mo foil and Al alloy cladding can result. The reaction layers produced from such interactions can exhibit notably different morphologies vis-à-vis those typically observed for dispersion fuels.

  15. Flow hydrodynamics in embankment breach

    Institute of Scientific and Technical Information of China (English)

    ZHAO Gensheng; VISSER Paul J; REN Yankai; UIJTTEWAAL Wim S J

    2015-01-01

    Breaching flow occurs during the breach development of the embankment, dike, earthen dam, landslide barrier, etc. and plays an import role in the breaching erosion as the driving force. According to the previous research, the breaching process can be classified into initiation phase, breach widening phase and breach deepening phase. Based on the breaching development classifications, the breaching flow can be seen as a special compound weir flow when the breach channel is in the relatively equilibrium condition. There were five physical flow models were designed in the hypothesis of rectangular shape and trapezoidal shape for the breach channel cross sections to study the breaching flow characteristics. The distributions of water level and velocity were measured and analysed in the breaching flows in overtopping condition and emerged condition. There were two helicoidal flows above the breach channel slopes and triangular hydraulic jump in the downstream of the breach channel in the overtopping condition and emerged condition. The hydraulic energy loss was calculated according to the breaching velocity and water level distribution in the upstream and downstream of the model. It is found that the test results of the breach flow physical model can be valuable to bring insight of the breaching process of embankment and make contributions to the validations and verifications of breach numerical models.

  16. An Expert System to Analyze Homogeneity in Fuel Element Plates for Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Tolosa, S.C.; Marajofsky, A.

    2004-10-06

    In the manufacturing control of Fuel Element Plates for Research Reactors, one of the problems to be addressed is how to determine the U-density homogeneity in a fuel plate and how to obtain qualitative and quantitative information in order to establish acceptance or rejection criteria for such, as well as carrying out the quality follow-up. This paper is aimed at developing computing software which implements an Unsupervised Competitive Learning Neural Network for the acknowledgment of regions belonging to a digitalized gray scale image. This program is applied to x-ray images. These images are generated when the x-ray beams go through a fuel plate of approximately 60 cm x 8 cm x 0.1 cm thick. A Nuclear Fuel Element for Research Reactors usually consists of 18 to 22 of these plates, positioned in parallel, in an arrangement of 8 x 7 cm. Carrying out the inspection of the digitalized x-ray image, the neural network detects regions with different luminous densities corresponding to U-densities in the fuel plate. This is used in quality control to detect failures and verify acceptance criteria depending on the homogeneity of the plate. This modality of inspection is important as it allows the performance of non-destructive measurements and the automatic generation of the map of U-relative densities of the fuel plate.

  17. Medical data breaches

    DEFF Research Database (Denmark)

    Kierkegaard, Patrick

    2012-01-01

    notification law in the US to be characterized by less government intrusions, while the revised EU Privacy Directive, 2009/136/EC calls for tougher privacy protection for data held by electronic communication providers. While the EU law sets a global de facto standard, the law remains toothless without strong......The EU and the United States have implemented data breach notification rules that cover the health sectors. Nevertheless, data breach incidents involving medical data continue to rise, especially in the US and the UK. The HITECH Act, Pub. L. 111-5 Title XIII is the first federal health breach...

  18. Modification of Neutron Kinetic Code for Plate Type Fuel Nuclear Reactor

    Directory of Open Access Journals (Sweden)

    Salah Ud-Din Khan

    2013-01-01

    Full Text Available The research is conducted on the modification of neutron kinetic code for the plate type fuel nuclear reactor. REMARK is a neutron kinetic code that works only for the cylindrical type fuel nuclear reactor. In this research, our main emphasis is on the modification of this code in order to be applicable for the plate type fuel nuclear reactor. For this purpose, detailed mathematical studies have been performed and are subjected to write the program in Fortran language. Since REMARK code is written in Fortran language, so we have developed the program in Fortran and then inserted it into the source library of the code. The main emphasis is on the modification of subroutine in the source library of the code for hexagonal fuel assemblies with plate type fuel elements in it. The number of steps involved in the modification of the code has been included in the paper. The verification studies were performed by considering the small modular reactor with hexagonal assemblies and plate type fuel in it to find out the power distribution of the reactor core. The purpose of the research is to make the code work for the hexagonal fuel assemblies with plate type fuel element.

  19. Advanced Composite Bipolar Plate for Unitized Regenerative Fuel Cell/Electrolyzer Systems Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Development of an advanced composite bipolar plate is proposed for a unitized regenerative fuel cell and electrolyzer system that operates on pure feed streams...

  20. Data breaches. Final rule.

    Science.gov (United States)

    2008-04-11

    This document adopts, without change, the interim final rule that was published in the Federal Register on June 22, 2007, addressing data breaches of sensitive personal information that is processed or maintained by the Department of Veterans Affairs (VA). This final rule implements certain provisions of the Veterans Benefits, Health Care, and Information Technology Act of 2006. The regulations prescribe the mechanisms for taking action in response to a data breach of sensitive personal information.

  1. Data Breach Preparation

    Energy Technology Data Exchange (ETDEWEB)

    Belangia, David Warren [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-13

    The Home Depot Data Breach is the second largest data breach on record. It has or will affect up to 56 million debit or credit cards. A trusted vendor account, coupled with the use of a previously unknown variant of malware that allowed the establishment of a foothold, was the entry point into the Home Depot network. Once inside the perimeter, privilege escalation provided an avenue to obtain the desired information. Home Depot did, however, learn some lessons from Target. Home Depot certainly communicated better than Target, procured insurance, and instituted as secure an environment as possible. There are specific measures an institution should undertake to prepare for a data breach, and everyone can learn from this breach. Publicly available information about the Home Depot Data Breach provides insight into the attack, an old malware variant with a new twist.While the malware was modified as to be unrecognizable with tools, it probably should have been detected. There are also concerns with Home Depot’s insurance and the insurance provider’s apparent lack of fully reimbursing Home Depot for their losses. The effect on shareholders and Home Depot’s stock price was short lived. This story is still evolving but provides interesting lessons learned concerning how an organization should prepare for it inevitable breach.

  2. Corrosion-resistant, electrically-conductive plate for use in a fuel cell stack

    Science.gov (United States)

    Carter, J David [Bolingbrook, IL; Mawdsley, Jennifer R [Woodridge, IL; Niyogi, Suhas [Woodridge, IL; Wang, Xiaoping [Naperville, IL; Cruse, Terry [Lisle, IL; Santos, Lilia [Lombard, IL

    2010-04-20

    A corrosion resistant, electrically-conductive, durable plate at least partially coated with an anchor coating and a corrosion resistant coating. The corrosion resistant coating made of at least a polymer and a plurality of corrosion resistant particles each having a surface area between about 1-20 m.sup.2/g and a diameter less than about 10 microns. Preferably, the plate is used as a bipolar plate in a proton exchange membrane (PEMFC) fuel cell stack.

  3. Applying Mechanistic Dam Breach Models to Historic Levee Breaches

    Directory of Open Access Journals (Sweden)

    Risher Paul

    2016-01-01

    Full Text Available Hurricane Katrina elevated levee risk in the US national consciousness, motivating agencies to assess and improve their levee risk assessment methodology. Accurate computation of the flood flow magnitude and timing associated with a levee breach remains one of the most difficult and uncertain components of levee risk analysis. Contemporary methods are largely empirical and approximate, introducing substantial uncertainty to the damage and life loss models. Levee breach progressions are often extrapolated to the final width and breach formation time based on limited experience with past breaches or using regression equations developed from a limited data base of dam failures. Physically based embankment erosion models could improve levee breach modeling. However, while several mechanistic embankment breach models are available, they were developed for dams. Several aspects of the levee breach problem are distinct, departing from dam breach assumptions. This study applies three embankments models developed for dam breach analysis (DL Breach, HR BREACH, and WinDAM C to historic levee breaches with observed (or inferred breach rates, assessing the limitations, and applicability of each model to the levee breach problem.

  4. EVALUATION OF U10MO FUEL PLATE IRRADIATION BEHAVIOR VIA NUMERICAL AND EXPERIMENTAL BENCHMARKING

    Energy Technology Data Exchange (ETDEWEB)

    Samuel J. Miller; Hakan Ozaltun

    2012-11-01

    This article analyzes dimensional changes due to irradiation of monolithic plate-type nuclear fuel and compares results with finite element analysis of the plates during fabrication and irradiation. Monolithic fuel plates tested in the Advanced Test Reactor (ATR) at Idaho National Lab (INL) are being used to benchmark proposed fuel performance for several high power research reactors. Post-irradiation metallographic images of plates sectioned at the midpoint were analyzed to determine dimensional changes of the fuel and the cladding response. A constitutive model of the fabrication process and irradiation behavior of the tested plates was developed using the general purpose commercial finite element analysis package, Abaqus. Using calculated burn-up profiles of irradiated plates to model the power distribution and including irradiation behaviors such as swelling and irradiation enhanced creep, model simulations allow analysis of plate parameters that are either impossible or infeasible in an experimental setting. The development and progression of fabrication induced stress concentrations at the plate edges was of primary interest, as these locations have a unique stress profile during irradiation. Additionally, comparison between 2D and 3D models was performed to optimize analysis methodology. In particular, the ability of 2D and 3D models account for out of plane stresses which result in 3-dimensional creep behavior that is a product of these components. Results show that assumptions made in 2D models for the out-of-plane stresses and strains cannot capture the 3-dimensional physics accurately and thus 2D approximations are not computationally accurate. Stress-strain fields are dependent on plate geometry and irradiation conditions, thus, if stress based criteria is used to predict plate behavior (as opposed to material impurities, fine micro-structural defects, or sharp power gradients), unique 3D finite element formulation for each plate is required.

  5. Development of bipolar plates with different flow channel configurations for fuel cells

    Science.gov (United States)

    Boddu, Rajesh; Marupakula, Uday Kumar; Summers, Benjamin; Majumdar, Pradip

    Bipolar plates include separate gas flow channels for anode and cathode electrodes of a fuel cell. These gases flow channels supply reactant gasses as well as remove products from the cathode side of the fuel cell. Fluid flow, heat and mass transport processes in these channels have significant effect on fuel cell performance, particularly to the mass transport losses. The design of the bipolar plates should minimize plate thickness for low volume and mass. Additionally, contact faces should provide a high degree of surface uniformity for low thermal and electrical contact resistances. Finally, the flow fields should provide for efficient heat and mass transport processes with reduced pressure drops. In this study, bipolar plates with different serpentine flow channel configurations are analyzed using computational fluid dynamics modeling. Flow characteristics including variation of pressure in the flow channel across the bipolar plate are presented. Pressure drop characteristics for different flow channel designs are compared. Results show that with increased number of parallel channels and smaller sizes, a more effective contact surface area along with decreased pressured drop can be achieved. Correlations of such entrance region coefficients will be useful for the PEM fuel cell simulation model to evaluate the affects of the bipolar plate design on mass transfer loss and hence on the total current and power density of the fuel cell.

  6. Dimensional metrology of bipolar fuel cell plates using laser spot triangulation probes

    Science.gov (United States)

    Muralikrishnan, Bala; Ren, Wei; Everett, Dennis; Stanfield, Eric; Doiron, Ted

    2011-07-01

    As in any engineering component, manufacturing a bipolar fuel cell plate for a polymer electrolyte membrane (PEM) hydrogen fuel cell power stack to within its stated design tolerances is critical in achieving the intended function. In a bipolar fuel cell plate, the dimensional features of interest include channel width, channel height, channel parallelism, side wall taper, straightness of the bottom or side walls, plate parallelism, etc. Such measurements can be performed on coordinate measuring machines (CMMs) with micro-probes that can access the narrow channels. While CMM measurements provide high accuracy (less than 1 µm), they are often very slow (taking several hours to measure a single plate) and unsuitable for the manufacturing environment. In this context, we describe a system for rapid dimensional measurement of bipolar fuel cell plates using two laser spot triangulation probes that can achieve comparable accuracies to those of a touch probe CMM, while offering manufacturers the possibility for 100% part inspection. We discuss the design of the system, present our approach to calibrating system parameters, present validation data, compare bipolar fuel cell plate measurement results with those obtained using a Mitutoyo UMAP (see footnote 1) fiber probe CMM, and finally describe the uncertainty in channel height and width measurements.

  7. Verification of 235U mass content in nuclear fuel plates by an absolute method

    Science.gov (United States)

    El-Gammal, W.

    2007-01-01

    Nuclear Safeguards is referred to a verification System by which a State can control all nuclear materials (NM) and nuclear activities under its authority. An effective and efficient Safeguards System must include a system of measurements with capabilities sufficient to verify such NM. Measurements of NM using absolute methods could eliminate the dependency on NM Standards, which are necessary for other relative or semi-absolute methods. In this work, an absolute method has been investigated to verify the 235U mass content in nuclear fuel plates of Material Testing Reactor (MTR) type. The most intense gamma-ray signature at 185.7 keV emitted after α-decay of the 235U nuclei was employed in the method. The measuring system (an HPGe-spectrometer) was mathematically calibrated for efficiency using the general Monte Carlo transport code MCNP-4B. The calibration results and the measured net count rate were used to estimate the 235U mass content in fuel plates at different detector-to-fuel plate distances. Two sets of fuel plates, containing natural and low enriched uranium, were measured at the Fuel Fabrication Facility. Average accuracies for the estimated 235U masses of about 2.62% and 0.3% are obtained for the fuel plates containing natural and low enriched uranium; respectively, with a precision of about 3%.

  8. 77 FR 16868 - Quality Verification for Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test...

    Science.gov (United States)

    2012-03-22

    ... COMMISSION Quality Verification for Plate-Type Uranium-Aluminum Fuel Elements for Use in Research and Test...-Type Uranium-Aluminum Fuel Elements for Use in Research and Test Reactors,'' is temporarily identified... verifying the quality of plate-type uranium-aluminum fuel elements used in research and test reactors (RTRs...

  9. Irradiated microstructure of U-10Mo monolithic fuel plate at very high fission density

    Energy Technology Data Exchange (ETDEWEB)

    Gan, J.; Miller, B. D.; Keiser, D. D.; Jue, J. F.; Madden, J. W.; Robinson, A. B.; Ozaltun, H.; Moore, G.; Meyer, M. K.

    2017-08-01

    Monolithic U-10Mo alloy fuel plates with Al-6061 cladding are being developed for use in research and test reactors as low enrichment fuel (< 20% U-235 enrichment) as a result of its high uranium loading capacity compared to that of U-7Mo dispersion fuel. These fuel plates contain a Zr diffusion barrier between the U-10Mo fuel and Al-6061 cladding that suppresses the interaction between the U-Mo fuel foil and Al alloy cladding that is known to be problematic under irradiation. This paper discusses the TEM results of the U-10Mo/Zr/Al6061 monolithic fuel plate (Plate ID: L1P09T, ~ 59% U-235 enrichment) irradiated in Advanced Test Reactor at Idaho National Laboratory as part of RERTR-9B irradiation campaign with an unprecedented high local fission density of 9.8E+21 fissions/cm3. The calculated fuel foil centerline temperature at the beginning of life and the end of life is 141 and 194 C, respectively. A total of 5 TEM lamellas were prepared using focus ion beam lift-out technique. The estimated U-Mo fuel swelling, based on the fuel foil thickness change from SEM, is approximately 76%. Large bubbles (> 1 µm) are distributed evenly in U-Mo and interlink of these bubbles is evident. The average size of subdivided grains at this fission density appears similar to that at 5.2E+21 fissions/cm3. The measured average Mo and Zr content in the fuel matrix is ~ 30 at% and ~ 7 at%, respectively, in general agreement with the calculated Mo and Zr from fission density.

  10. Development of computer code SAFFRON for evaluating breached pin performance in FBR's

    Energy Technology Data Exchange (ETDEWEB)

    Ukai, Shigeharu; Shikakura, Sakae (Power Reactor and Nuclear Fuel Development Corp., Oarai, Ibaraki (Japan). Oarai Engineering Center); Sano, Yuji; Takita, Masami

    1994-07-01

    In order to evaluate the breached pin behavior in FBR, the breached pin performance analysis code SAFFRON was developed. Based on the results of run-beyond-cladding-breach test in FBR-II as a collaborative program between PNC and U.S.DOE, the following behaviors were taken into consideration; fuel sodium reaction product (FSRP) formation, resultant fuel expansion, breach extension of cladding and release of delayed neutron precursors into the coolant. Using 3-dimensional elastic analyses by finite element method, breached pin diameter increase is adequately predicted with the reduced Young's modulus of the breached fuel. The delayed neutron signal response in on-line diagnosis was evaluated in relation to the growth of FSRP and breached area enlargement. (author).

  11. Modeling of the heat transfer performance of plate-type dispersion nuclear fuel elements

    Science.gov (United States)

    Ding, Shurong; Huo, Yongzhong; Yan, XiaoQing

    2009-08-01

    Considering the mutual actions between fuel particles and the metal matrix, the three-dimensional finite element models are developed to simulate the heat transfer behaviors of dispersion nuclear fuel plates. The research results indicate that the temperatures of the fuel plate might rise more distinctly with considering the particle swelling and the degraded surface heat transfer coefficients with increasing burnup; the local heating phenomenon within the particles appears when their thermal conductivities are too low. With rise of the surface heat transfer coefficients, the temperatures within the fuel plate decrease; the temperatures of the fuel plate are sensitive to the variations of the heat transfer coefficients whose values are lower, but their effects are weakened and slight when the heat transfer coefficients increase and reach a certain extent. Increasing the heat generation rate leads to elevating the internal temperatures. The temperatures and the maximum temperature differences within the plate increase along with the particle volume fractions. The surface thermal flux goes up along with particle volume fractions and heat generation rates, but the effects of surface heat transfer coefficients are not evident.

  12. Breach to Nowhere

    Science.gov (United States)

    Schaffhauser, Dian

    2009-01-01

    Will that data breach be the end of a chief security officer (CSO)? Managing information security in higher education requires more than just technical expertise, especially when the heat is cranked up. This article takes a look at how two CSOs deal with hack attacks at their universities. When Purdue University Chief Information Security Officer…

  13. Breach to Nowhere

    Science.gov (United States)

    Schaffhauser, Dian

    2009-01-01

    Will that data breach be the end of a chief security officer (CSO)? Managing information security in higher education requires more than just technical expertise, especially when the heat is cranked up. This article takes a look at how two CSOs deal with hack attacks at their universities. When Purdue University Chief Information Security Officer…

  14. Development of Noncontact Imaging Technology for the Detection of Internal Defects of a Nuclear Fuel Plate

    Energy Technology Data Exchange (ETDEWEB)

    Park, S. K.; Baik, S. H.; Lee, Y. S.; Cheong, Y. M.

    2012-01-15

    The object of the research is to develop a new imaging inspection technology for the quality testing of plate-type nuclear fuel whose demanding is currently increasing in nuclear research reactors. A new noncontact imaging inspection technique is developed for the detection of internal defects in plate-type nuclear fuel. To develop the imaging inspection technique, a hardware system based on active optical interference is configured. An operating software for the developed nondestructive inspection system is developed after designing an advanced signal processing algorithm to improve the detection capability of the system. The developed system is optimized through experiments and optimal heating condition is studied. The performance of a lock-in thermography is also evaluated to see the possibility of the plate-type nuclear fuel application.

  15. A graphite-coated carbon fiber epoxy composite bipolar plate for polymer electrolyte membrane fuel cell

    Science.gov (United States)

    Yu, Ha Na; Lim, Jun Woo; Suh, Jung Do; Lee, Dai Gil

    A PEMFC (polymer electrolyte membrane fuel cell or proton exchange membrane fuel cell) stack is composed of GDLs (gas diffusion layers), MEAs (membrane electrode assemblies), and bipolar plates. One of the important functions of bipolar plates is to collect and conduct the current from cell to cell, which requires low electrical bulk and interfacial resistances. For a carbon fiber epoxy composite bipolar plate, the interfacial resistance is usually much larger than the bulk resistance due to the resin-rich layer on the composite surface. In this study, a thin graphite layer is coated on the carbon/epoxy composite bipolar plate to decrease the interfacial contact resistance between the bipolar plate and the GDL. The total electrical resistance in the through-thickness direction of the bipolar plate is measured with respect to the thickness of the graphite coating layer, and the ratio of the bulk resistance to the interfacial contact resistance is estimated using the measured data. From the experiment, it is found that the graphite coating on the carbon/epoxy composite bipolar plate has 10% and 4% of the total electrical and interfacial contact resistances of the conventional carbon/epoxy composite bipolar plate, respectively, when the graphite coating thickness is 50 μm.

  16. Highly conductive thermoplastic composites for rapid production of fuel cell bipolar plates

    Science.gov (United States)

    Huang, Jianhua [Blacksburg, VA; Baird, Donald G [Blacksburg, VA; McGrath, James E [Blacksburg, VA

    2008-04-29

    A low cost method of fabricating bipolar plates for use in fuel cells utilizes a wet lay process for combining graphite particles, thermoplastic fibers, and reinforcing fibers to produce a plurality of formable sheets. The formable sheets are then molded into a bipolar plates with features impressed therein via the molding process. The bipolar plates formed by the process have conductivity in excess of 150 S/cm and have sufficient mechanical strength to be used in fuel cells. The bipolar plates can be formed as a skin/core laminate where a second polymer material is used on the skin surface which provides for enhanced conductivity, chemical resistance, and resistance to gas permeation.

  17. Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates. Part 2: Single-cell fuel cell evaluation of stamped plates

    Science.gov (United States)

    Toops, Todd J.; Brady, Michael P.; Tortorelli, Peter F.; Pihl, Josh A.; Estevez, Francisco; Connors, Daniel; Garzon, Fernando; Rockward, Tommy; Gervasio, Don; Mylan, William; Kosaraju, Sree Harsha

    Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr 2N, CrN, TiN, V 2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of proton exchange membrane (PEM) single-cell fuel cell studies of stamped and pre-oxidized/nitrided developmental Fe-20Cr-4V weight percent (wt.%) and commercial type 2205 stainless steel alloy foils. The single-cell fuel cell behavior of the stamped and pre-oxidized/nitrided material was compared to as-stamped (no surface treatment) 904L, 2205, and Fe-20Cr-4V stainless steel alloy foils and machined graphite of similar flow field design. The best fuel cell behavior among the alloys was exhibited by the pre-oxidized/nitrided Fe-20Cr-4V, which exhibited ∼5-20% better peak power output than untreated Fe-20Cr-4V, 2205, and 904L metal stampings. Durability was assessed for pre-oxidized/nitrided Fe-20Cr-4V, 904L metal, and graphite plates by 1000+ h of cyclic single-cell fuel cell testing. All three materials showed good durability with no significant degradation in cell power output. Post-test analysis indicated no metal ion contamination of the membrane electrode assemblies (MEAs) occurred with the pre-oxidized and nitrided Fe-20Cr-4V or graphite plates, and only a minor amount of contamination with the 904L plates.

  18. Microstructure of U 3Si 2 fuel plates submitted to a high heat flux

    Science.gov (United States)

    Leenaers, A.; Van den Berghe, S.; Koonen, E.; Jacquet, P.; Jarousse, C.; Guigon, B.; Ballagny, A.; Sannen, L.

    2004-05-01

    In order to gain insight on the performance limits of U 3Si 2 fuel with Al cladding, fuel plates with a fissile material density of 5.1 and 6.1 g U/cm 3 were irradiated in the BR2 reactor of SCK • CEN in Mol. The plates were intended to be subjected to severe conditions leading to a cladding surface temperature of 180-200 °C and fuel temperatures of 220-240 °C. The irradiation program was stopped after the second cycle based on the visual inspection and wet sipping tests of the elements, correspondingly showing degradations on the outer Al surfaces of the U 3Si 2 plates and the release of fission products. The maximum fuel burn-up was 29% and 25% 235U, respectively. In a PIE program the microstructural causes for this degradation are analysed. It is found that the failure of the plates is entirely related to the corrosion of the Al cladding, which has caused temperatures to rise well beyond the calculated values. In all stages, the fuel grains have retained their integrity and, apart from the formation of an interaction phase with the Al matrix, they do not demonstrate deleterious changes in their physical properties.

  19. Conversion from film to image plates for transfer method neutron radiography of nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Craft, Aaron E.; Papaioannou, Glen C.; Chichester, David L.; Williams, Walter J.

    2017-02-01

    This paper summarizes efforts to characterize and qualify a computed radiography (CR) system for neutron radiography of irradiated nuclear fuel at Idaho National Laboratory (INL). INL has multiple programs that are actively developing, testing, and evaluating new nuclear fuels. Irradiated fuel experiments are subjected to a number of sequential post-irradiation examination techniques that provide insight into the overall behavior and performance of the fuel. One of the first and most important of these exams is neutron radiography, which provides more comprehensive information about the internal condition of irradiated nuclear fuel than any other non-destructive technique to date. Results from neutron radiography are often the driver for subsequent examinations of the PIE program. Features of interest that can be evaluated using neutron radiography include irradiation-induced swelling, isotopic and fuel-fragment redistribution, plate deformations, and fuel fracturing. The NRAD currently uses the foil-film transfer technique with film for imaging fuel. INL is pursuing multiple efforts to advance its neutron imaging capabilities for evaluating irradiated fuel and other applications, including conversion from film to CR image plates. Neutron CR is the current state-of-the-art for neutron imaging of highly-radioactive objects. Initial neutron radiographs of various types of nuclear fuel indicate that radiographs can be obtained of comparable image quality currently obtained using film. This paper provides neutron radiographs of representative irradiated fuel pins along with neutron radiographs of standards that informed the qualification of the neutron CR system for routine use. Additionally, this paper includes evaluations of some of the CR scanner parameters and their effects on image quality.

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

    Science.gov (United States)

    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.

  1. Microstructural Characterization of Burnable Absorber Materials Being Evaluated for Application in LEU U-Mo Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    J. F. Jue; B. Miller; B. Yao; E. Perez; Y. H. Sohn

    2011-03-01

    The starting microstructure of a fuel plate will impact how it performs during irradiation. As a result, microstructural characterization has been performed on as-fabricated monolithic fuel plates to determine the changes in fuel plate microstructure that may result from changes in fabrication parameters. Particular focus has been given to the fuel plate U-10Mo/Zr and Zr/AA6061 cladding interfaces, since the integrity of these interfaces will play a big role in determining the overall performance of the fuel plate during irradiation. In addition, burnable absorber materials for potential incorporation into monolithic fuel plates have been characterized to identify their as-fabricated microstructures. This information will be important when trying to understand the PIE data from fuel plates with burnable absorbers that are irradiated in future irradiation experiments. This paper will focus on the microstructures observed using optical metallography, X-ray diffraction, and scanning and transmission electron microscopy for monolithic fuel plates exposed to different fabrication parameters and for as-fabricated burnable absorber materials.

  2. Fabrication and testing of U-7Mo monolithic plate fuel with Zircaloy cladding

    Science.gov (United States)

    Pasqualini, E. E.; Robinson, A. B.; Porter, D. L.; Wachs, D. M.; Finlay, M. R.

    2016-10-01

    Nuclear fuel designs are being developed to replace highly enriched fuel used in research and test reactors with fuels of low enrichment. In the most challenging cases, U-(7-10 wt%)Mo monolithic plate fuels are proposed. One of the considered designs includes aluminum-alloy cladding, which provides some challenges in fabrication and fuel/cladding interaction during service. Zircaloy cladding, specifically Zry-4, was investigated as an alternative cladding, and development of a fabrication method was performed by researchers with the Comisión Nacionalde Energia Atómica (CNEA) in Argentina, resulting in test fuel plates (Zry-4 clad U-7Mo) which were subsequently tested in the Advanced Test Reactor in Idaho. Because Zry-4 and U-(7-10)Mo have similar high-temperature mechanical properties, fabrication was simplified in that the fuel foil and cladding could be co-rolled and bonded. The challenge was to prevent a thermal-expansion mismatch, which could destroy the fuel/cladding bond before complete bonding was achieved; the solution was to prevent the composites from cooling significantly during or between roll passes. The final product performed very well in-reactor, showing good bonding, very little fuel/cladding interaction-either from fabrication or in-reactor testing-and little swelling, especially no detectable heterogeneous bubble formation at the fuel/cladding interface tested to a fission density of up to 2.7E+21 (average) fissions/cm3, 3.8E+21 (peak).

  3. Fabrication of simulated plate fuel elements: Defining role of out-of-plane residual shear stress

    Science.gov (United States)

    Rakesh, R.; Kohli, D.; Sinha, V. P.; Prasad, G. J.; Samajdar, I.

    2014-02-01

    Bond strength and microstructural developments were investigated during fabrication of simulated plate fuel elements. The study involved roll bonding of aluminum-aluminum (case A) and aluminum-aluminum + yttria (Y2O3) dispersion (case B). Case B approximated aluminum-uranium silicide (U3Si2) 'fuel-meat' in an actual plate fuel. Samples after different stages of fabrication, hot and cold rolling, were investigated through peel and pull tests, micro-hardness, residual stresses, electron and micro-focus X-ray diffraction. Measurements revealed a clear drop in bond strength during cold rolling: an observation unique to case B. This was related to significant increase in 'out-of-plane' residual shear stresses near the clad/dispersion interface, and not from visible signatures of microstructural heterogeneities.

  4. AFIP-6 Breach Assessment Report

    Energy Technology Data Exchange (ETDEWEB)

    Dan Wachs; Adam Robinson; Pavel Medvedev

    2011-02-01

    Analysis of the AFIP-6 experiment is summarized in this report in order to determine the cause of gaseous fission product release observed during irradiation. During the irradiation, a series of small fission product releases were observed. In order to limit the potential for primary coolant contamination, the operating cycle was terminated and the AFIP-6 experiment was removed for examination. Both in-canal and post-irradiation examination revealed the presence of an unusually thick oxide layer and discrete surface blisters on the fuel plates. These blisters were the likely cause of fission product release. Subsequent detailed thermal hydraulic analysis of the experiment indicated that the combination of the high operating power and test vehicle configuration led to high nominal operating temperatures for the fuel plates. This elevated temperature led to accelerated surface corrosion and eventually spallation of the fuel plate cladding. The thermal insulating nature of this corrosion layer led to significantly elevated fuel meat temperatures that induced blistering. Analysis was performed to validate a corrosion rate model and criteria for onset of spallation type surface corrosion were determined. The corrosion rate model will be used to estimate the oxide thickness anticipated for experiments in the future. The margin to the spallation threshold will then be used to project the experiment performance.

  5. Al slurry coatings for molten carbonate fuel cells separator plates

    Energy Technology Data Exchange (ETDEWEB)

    Agueero, A.; Garcia, M.C.; Muelas, R.; Sanchez, A. [Instituto Nacional de Tecnica Aerospacial, Madrid (Spain); Perez, F.J.; Duday, D.; Hierro, M.P.; Gomez, C. [Universidad Complutense de Madrid (Spain). Dept. de Ciencia de los Materiales

    2001-07-01

    The corrosion behaviour of Al slurry coated AISI 310 stainless steel, with and without diffusion heat treatment, was investigated as a wet seal material for molten carbonate fuel cell (MCFC) at 650 C. The results were compared with IVD Al coated AISI 310. Characterization of the samples before and after exposure to the eutectic 62 mol% Li{sub 2}CO{sub 3}-38 mol% K{sub 2}CO{sub 3} mixture at 650 C for 1000 h by SEM-EDS and XRD was carried out. The presence of LiAlO{sub 2} on the coated samples was confirmed by XRD. The slurry Al-coated stainless steels performed at least as well as the IVD Al coating. (orig.)

  6. A Development of Technical Specification of a Research Reactor with Plate Fuels Cooled by Upward Flow

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sujin; Kim, Jeongeun; Kim, Hyeonil [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2016-10-15

    The contents of the TS(Technical Specifications) are definitions, safety limits, limiting safety system settings, limiting conditions for operation, surveillance requirements, design features, and administrative controls. TS for Nuclear Power Plants (NPPs) have been developed since many years until now. On the other hands, there are no applicable modernized references of TS for research reactors with many differences from NPPs in purpose and characteristics. Fuel temperature and Departure from Nuclear Boiling Ratio (DNBR) are being used as references from the thermal-hydraulic analysis point of view for determining whether the design of research reactors satisfies acceptance criteria for the nuclear safety or not. Especially for research reactors using plate-type fuels, fuel temperature and critical heat flux, however, are very difficult to measure during the reactor operation. This paper described the outline of main contents of a TS for open-pool research reactor with plate-type fuels using core cooling through passive systems, where acceptance criteria for nuclear safety such as CHF and fuel temperature cannot be directly measured, different from circumstances in NPPs. Thus, three independent variables instead of non-measurable acceptance criteria: fuel temperature and CHF are considered as safety limits, i.e., power, flow, and flow temperature.

  7. Computational simulation of fuel burnup estimation for research reactors plate type

    Energy Technology Data Exchange (ETDEWEB)

    Santos, Nadia Rodrigues dos, E-mail: nadiasam@gmail.com [Instituto Federal de Educacao, Ciencia e Tecnologia do Rio de Janeiro (IFRJ), Paracambi, RJ (Brazil); Lima, Zelmo Rodrigues de; Moreira, Maria de Lourdes, E-mail: zrlima@ien.gov.br, E-mail: malu@ien.gov.br [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2015-07-01

    The aim of this study is to estimate the spatial fuel burnup, through computational simulation, in two research reactors plate type, loaded with dispersion fuel: the benchmark Material Test Research - International Atomic Energy Agency (MTR-IAEA) and a typical multipurpose reactor (MR). The first composed of plates with uranium oxide dispersed in aluminum (UAlx-Al) and a second composed with uranium silicide (U{sub 3}Si{sub 2}) dispersed in aluminum. To develop this work we used the deterministic code, WIMSD-5B, which performs the cell calculation solving the neutron transport equation, and the DF3DQ code, written in FORTRAN, which solves the three-dimensional neutron diffusion equation using the finite difference method. The methodology used was adequate to estimate the spatial fuel burnup , as the results was in accordance with chosen benchmark, given satisfactorily to the proposal presented in this work, even showing the possibility to be applied to other research reactors. For future work are suggested simulations with other WIMS libraries, other settings core and fuel types. Comparisons the WIMSD-5B results with programs often employed in fuel burnup calculations and also others commercial programs, are suggested too. Another proposal is to estimate the fuel burnup, taking into account the thermohydraulics parameters and the Xenon production. (author)

  8. Performance evaluation and characterization of metallic bipolar plates in a proton exchange membrane (PEM) fuel cell

    Science.gov (United States)

    Hung, Yue

    Bipolar plate and membrane electrode assembly (MEA) are the two most repeated components of a proton exchange membrane (PEM) fuel cell stack. Bipolar plates comprise more than 60% of the weight and account for 30% of the total cost of a fuel cell stack. The bipolar plates perform as current conductors between cells, provide conduits for reactant gases, facilitate water and thermal management through the cell, and constitute the backbone of a power stack. In addition, bipolar plates must have excellent corrosion resistance to withstand the highly corrosive environment inside the fuel cell, and they must maintain low interfacial contact resistance throughout the operation to achieve optimum power density output. Currently, commercial bipolar plates are made of graphite composites because of their relatively low interfacial contact resistance (ICR) and high corrosion resistance. However, graphite composite's manufacturability, permeability, and durability for shock and vibration are unfavorable in comparison to metals. Therefore, metals have been considered as a replacement material for graphite composite bipolar plates. Since bipolar plates must possess the combined advantages of both metals and graphite composites in the fuel cell technology, various methods and techniques are being developed to combat metallic corrosion and eliminate the passive layer formed on the metal surface that causes unacceptable power reduction and possible fouling of the catalyst and the electrolyte. The main objective of this study was to explore the possibility of producing efficient, cost-effective and durable metallic bipolar plates that were capable of functioning in the highly corrosive fuel cell environment. Bulk materials such as Poco graphite, graphite composite, SS310, SS316, incoloy 800, titanium carbide and zirconium carbide were investigated as potential bipolar plate materials. In this work, different alloys and compositions of chromium carbide coatings on aluminum and SS316

  9. Carbon composite bipolar plate for high-temperature proton exchange membrane fuel cells (HT-PEMFCs)

    Science.gov (United States)

    Lee, Dongyoung; Lee, Dai Gil

    2016-09-01

    A carbon/epoxy composite bipolar plate is an ideal substitute for the brittle graphite bipolar plate for lightweight proton exchange membrane fuel cells (PEMFCs) because of its high specific strength and stiffness. However, conventional carbon/epoxy composite bipolar plates are not applicable for high-temperature PEMFCs (HT-PEMFCs) because these systems are operated at higher temperatures than the glass transition temperatures of conventional epoxies. Therefore, in this study, a cyanate ester-modified epoxy is adopted for the development of a carbon composite bipolar plate for HT-PEMFCs. The composite bipolar plate with exposed surface carbon fibers is produced without any surface treatments or coatings to increase the productivity and is integrated with a silicone gasket to reduce the assembly cost. The developed carbon composite bipolar plate exhibits not only superior electrical properties but also high thermo-mechanical properties. In addition, a unit cell test is performed, and the results are compared with those of the conventional graphite bipolar plate.

  10. Characterization of commercially pure aluminum powder for research reactor fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Downs, V.D. [Babcock and Wilcox Co., Lynchburg, VA (United States); Wiencek, T.C. [Argonne National Lab., IL (United States)

    1992-11-01

    Aluminum powder is used as the matrix material in the production of uranium aluminide, oxide, and silicide dispersion fuel plates for research and test reactors. variability in the characteristics of the aluminum powder, such as moisture content and particle-size distribution, influences blending and compacting of the aluminum/fuel powder. A detailed study was performed to characterize the physical properties of three aluminum powder lots. An angle-of-shear test was devised to characterize the cohesiveness of the aluminum powder. Flow-rate measurements, apparent density determination, subsieve analysis, surface area measurements, and scanning electron microscopy were also used in the study. It was found that because of the various types of commercially available powders, proper specification of powder variables will ensure the receipt of consistent raw materials. Improved control of the initial powder will reduce the variability of fuel-plate production and will improve overall plate reproducibility. It is recommended that a standard specification be written for the aluminum powder and silicide fuel.

  11. Characterization of commercially pure aluminum powder for research reactor fuel plates

    Energy Technology Data Exchange (ETDEWEB)

    Downs, V.D. (Babcock and Wilcox Co., Lynchburg, VA (United States)); Wiencek, T.C. (Argonne National Lab., IL (United States))

    1992-01-01

    Aluminum powder is used as the matrix material in the production of uranium aluminide, oxide, and silicide dispersion fuel plates for research and test reactors. variability in the characteristics of the aluminum powder, such as moisture content and particle-size distribution, influences blending and compacting of the aluminum/fuel powder. A detailed study was performed to characterize the physical properties of three aluminum powder lots. An angle-of-shear test was devised to characterize the cohesiveness of the aluminum powder. Flow-rate measurements, apparent density determination, subsieve analysis, surface area measurements, and scanning electron microscopy were also used in the study. It was found that because of the various types of commercially available powders, proper specification of powder variables will ensure the receipt of consistent raw materials. Improved control of the initial powder will reduce the variability of fuel-plate production and will improve overall plate reproducibility. It is recommended that a standard specification be written for the aluminum powder and silicide fuel.

  12. Experimental fuel cell performance analysis under different operating conditions and bipolar plate designs

    Energy Technology Data Exchange (ETDEWEB)

    Iranzo, Alfredo; Pino, Javier; Rosa, Felipe [Energy Engineering Department, School of Engineering, University of Seville, Camino de los Descubrimientos s/n, 41092 Seville (Spain); Munoz, Miguel; Lopez, Eduardo [INTA - National Institute for Aerospace Technology, Ctra. San Juan del Puerto-Matalascanas km 33, 21130 Mazagon (Huelva) (Spain)

    2010-10-15

    This work presents experimental performance results for a 50 cm{sup 2} Polymer Electrolyte Membrane (PEM) Fuel Cell, including polarization curves and Electrochemical Impedance Spectroscopy (EIS) analysis of the Fuel Cell. EIS results were used for the determination of the cell ohmic resistance as well as charge transfer resistances under different operating conditions. Different combinations of operating conditions and bipolar plate designs were analysed. In particular, the effect of the cathode oxygen concentration, reactant gases humidification, and bipolar plate (BP) design were assessed. Butler-Volmer (BV) kinetic parameters such as the charge transfer coefficient were also determined from Tafel plots. The electronic contact resistances were measured for both Bipolar Plate designs, and the membrane protonic resistances were calculated. Its dependence on the BP flow field design and operating conditions is addressed. The results obtained in this work are aimed both at gaining insight into the fundamental processes determining the fuel cell performance, and at determining parameters needed for Computational Fuel Cell Dynamics (CFCD) numerical simulations. (author)

  13. 38 CFR 75.113 - Data breach.

    Science.gov (United States)

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Data breach. 75.113...) INFORMATION SECURITY MATTERS Data Breaches § 75.113 Data breach. Consistent with the definition of data breach in § 75.112 of this subpart, a data breach occurs under this subpart if there is a loss or theft...

  14. An experimental study on the effects of the thermal barrier plating over engine fuel consumption exhaust temperature and emissions

    Directory of Open Access Journals (Sweden)

    Hüseyin Gürbüz

    2014-01-01

    Full Text Available The aim of this study, the combustion chamber elements of a one-cylinder diesel engine which is air-cooled, single-cylinder, direct injection, 4-stroke and starter motor were plated with thermal barrier plating and tested with diesel fuel between the speeds of 1600 1/min to 3200 1/min and determined the effects of the thermal barrier plating on the engine exhaust gas temperature, emissions and fuel consumption. Increase in the temperature of the exhaust gas, decrease in HC and CO emissions that are harmful to the environment and living things and improvement in fuel consumption were observed.

  15. Micro direct methanol fuel cell with perforated silicon-plate integrated ionomer membrane

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent; Dalslet, Bjarke Thomas; Johansson, Anne-Charlotte Elisabeth Birgitta

    2014-01-01

    This article describes the fabrication and characterization of a silicon based micro direct methanol fuel cell using a Nafion ionomer membrane integrated into a perforated silicon plate. The focus of this work is to provide a platform for micro- and nanostructuring of a combined current collector...... at a perforation ratio of 40.3%. The presented fuel cells also show a high volumetric peak power density of 2 mW cm−3 in light of the small system volume of 480 μL, while being fully self contained and passively feed....... and catalytic electrode. AC impedance spectroscopy is utilized alongside IV characterization to determine the influence of the plate perforation geometries on the cell performance. It is found that higher ratios of perforation increases peak power density, with the highest achieved being 2.5 mW cm−2...

  16. Fabrication of simulated plate fuel elements: Defining role of stress relief annealing

    Science.gov (United States)

    Kohli, D.; Rakesh, R.; Sinha, V. P.; Prasad, G. J.; Samajdar, I.

    2014-04-01

    This study involved fabrication of simulated plate fuel elements. Uranium silicide of actual fuel elements was replaced with yttria. The fabrication stages were otherwise identical. The final cold rolled and/or straightened plates, without stress relief, showed an inverse relationship between bond strength and out of plane residual shear stress (τ13). Stress relief of τ13 was conducted over a range of temperatures/times (200-500 °C and 15-240 min) and led to corresponding improvements in bond strength. Fastest τ13 relief was obtained through 300 °C annealing. Elimination of microscopic shear bands, through recovery and partial recrystallization, was clearly the most effective mechanism of relieving τ13.

  17. Thermal Hydraulic Characteristics of Fuel Defects in Plate Type Nuclear Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bodey, Isaac T [ORNL

    2014-05-01

    Turbulent flow coupled with heat transfer is investigated for a High Flux Isotope Reactor (HFIR) fuel plate. The Reynolds Averaged Navier-Stokes Models are used for fluid dynamics and the transfer of heat from a thermal nuclear fuel plate using the Multi-physics code COMSOL. Simulation outcomes are compared with experimental data from the Advanced Neutron Source Reactor Thermal Hydraulic Test Loop. The computational results for the High Flux Isotope Reactor core system provide a more physically accurate simulation of this system by modeling the turbulent flow field in conjunction with the diffusion of thermal energy within the solid and fluid phases of the model domain. Recommendations are made regarding Nusselt number correlations and material properties for future thermal hydraulic modeling efforts

  18. Seasonal breaching of coastal barriers

    NARCIS (Netherlands)

    Tuan, Thieu Quang

    2007-01-01

    Natural or unintended breaching can be catastrophic, causing loss of human lives and damage to infrastructures, buildings and natural habitats. Quantitative understand-ing of coastal barrier breaching is therefore of great importance to vulnerability as-sessment of protection works as well as to

  19. Cost and performance prospects for composite bipolar plates in fuel cells and redox flow batteries

    Science.gov (United States)

    Minke, Christine; Hickmann, Thorsten; dos Santos, Antonio R.; Kunz, Ulrich; Turek, Thomas

    2016-02-01

    Carbon-polymer-composite bipolar plates (BPP) are suitable for fuel cell and flow battery applications. The advantages of both components are combined in a product with high electrical conductivity and good processability in convenient polymer forming processes. In a comprehensive techno-economic analysis of materials and production processes cost factors are quantified. For the first time a technical cost model for BPP is set up with tight integration of material characterization measurements.

  20. Design and performance of tubular flat-plate solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, T.; Ikeda, D.; Kanagawa, H. [NTT Integrated Information & Energy Systems Labs., Tokyo (Japan)] [and others

    1996-12-31

    With the growing interest in conserving the environmental conditions, much attention is being paid to Solid Oxide Fuel Cell (SOFC), which has high energy-conversion efficiency. Many organizations have conducted studies on tubular and flat type SOFCs. Nippon Telegraph and Telephone Corporation (NTT) has studied a combined tubular flat-plate SOFC, and already presented the I-V characteristics of a single cell. Here, we report the construction of a stack of this SOFC cell and successful generation tests results.

  1. Mechanical behaviors of the dispersion nuclear fuel plates induced by fuel particle swelling and thermal effect II: Effects of variations of the fuel particle diameters

    Science.gov (United States)

    Ding, Shurong; Wang, Qiming; Huo, Yongzhong

    2010-02-01

    In order to predict the irradiation mechanical behaviors of plate-type dispersion nuclear fuel elements, the total burnup is divided into two stages: the initial stage and the increasing stage. At the initial stage, the thermal effects induced by the high temperature differences between the operation temperatures and the room temperature are mainly considered; and at the increasing stage, the intense mechanical interactions between the fuel particles and the matrix due to the irradiation swelling of fuel particles are focused on. The large-deformation thermo-elasto-plasticity finite element analysis is performed to evaluate the effects of particle diameters on the in-pile mechanical behaviors of fuel elements. The research results indicate that: (1) the maximum Mises stresses and equivalent plastic strains at the matrix increase with the fuel particle diameters; the effects of particle diameters on the maximum first principal stresses vary with burnup, and the considered case with the largest particle diameter holds the maximum values all along; (2) at the cladding near the interface between the fuel meat and the cladding, the Mises stresses and the first principal stresses undergo major changes with increasing burnup, and different variations exist for different particle diameter cases; (3) the maximum Mises stresses at the fuel particles rise with the particle diameters.

  2. A Review of Metallic Bipolar Plates for Proton Exchange Membrane Fuel Cells: Materials and Fabrication Methods

    Directory of Open Access Journals (Sweden)

    Shahram Karimi

    2012-01-01

    Full Text Available The proton exchange membrane fuel cell offers an exceptional potential for a clean, efficient, and reliable power source. The bipolar plate is a key component in this device, as it connects each cell electrically, supplies reactant gases to both anode and cathode, and removes reaction products from the cell. Bipolar plates have been fabricated primarily from high-density graphite, but in recent years, much attention has been paid to developing cost-effective and feasible alternative materials. Two different classes of materials have attracted attention: metals and composites. This paper offers a comprehensive review of the current research being carried out on metallic bipolar plates, covering materials and fabrication methods.

  3. Structural analysis of plate-type fuel assemblies and development of a non-destructive method to assess their integrity

    Energy Technology Data Exchange (ETDEWEB)

    Caresta, Mauro, E-mail: mcaresta@yahoo.it [School of Mechanical and Manufacturing Engineering, The University of New South Wales, Sydney 2052, NSW (Australia); Wassink, David [Australian Nuclear Science and Technology Organisation (ANSTO), Lucas Heights 2234, NSW (Australia)

    2013-09-15

    Highlights: • A plate-type fuel assembly is made of thin plates mounted in a box-like structure. • Drag force from the coolant can shift the plates. • A non invasive method is proposed to test the strength of the plate connections. • The natural frequencies’ shift is used to assess the fuel integrity. -- Abstract: This work is concerned with the structural behaviour and the integrity of parallel plate-type nuclear fuel assemblies. A plate-type assembly consists of several thin plates mounted in a box-like structure and is subjected to a coolant flow that can result in a considerable drag force. A finite element model of an assembly is presented to study the sensitivity of the natural frequencies to the stiffness of the plates’ junctions. It is shown that the shift in the natural frequencies of the torsional modes can be used to check the global integrity of the fuel assembly while the local natural frequencies of the inner plates can be used to estimate the maximum drag force they can resist. Finally a non-destructive method is developed to assess the resistance of the inner plates to bear an applied load. Extensive computational and experimental results are presented to prove the applicability of the method presented.

  4. End plate for e.g. solid oxide fuel cell stack, sets thermal expansion coefficient of material to predetermined value

    DEFF Research Database (Denmark)

    2011-01-01

    .05-0.3 mm. USE - End plate for solid oxide fuel cell stack (claimed). Can also be used in polymer electrolyte fuel cell stack and direct methanol fuel cell stack. ADVANTAGE - The robustness of the end plate is improved. The structure of the end plate is simplified. The risk of delamination of the stack......NOVELTY - The end plate is made of material whose thermal expansion coefficient is corresponding to that of material of a cell (103). The thermal expansion coefficient of material is 9asterisk10-6 K-1 to 14asterisk10-6 K11. The thickness of the end plate is within the range of 0.001-1 mm and 0...

  5. Miniaturized polymer electrolyte fuel cell (PEFC) stack using micro structured bipolar plate

    Energy Technology Data Exchange (ETDEWEB)

    Veziridis, Z.; Scherer, G.G.; Marmy, Ch.; Glaus, F. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    In Polymer Electrolyte Fuel Cell (PEFC) technology the reducing of volume and mass of the fuel cell stack and the improvement of catalyst utilization are of great interest. These parameters affect applicability and system cost. In this work we present an alternative way for reducing the stack volume by combining gas distribution and catalytic active area in one plate. Micro machined glassy carbon electrodes serve as support material for the platinum catalyst, as well as gas distributor at the same time. A comparison of these electrodes with conventional platinum-black gas diffusion electrodes under fuel cell conditions shows that the new system is a promising electrode type for enhanced power density and catalyst utilization. (author) 3 figs., 5 refs.

  6. Irradiation Performance of U-Mo Alloy Based ‘Monolithic’ Plate-Type Fuel – Design Selection

    Energy Technology Data Exchange (ETDEWEB)

    A. B. Robinson; G. S. Chang; D. D. Keiser, Jr.; D. M. Wachs; D. L. Porter

    2009-08-01

    A down-selection process has been applied to the U-Mo fuel alloy based monolithic plate fuel design, supported by irradiation testing of small fuel plates containing various design parameters. The irradiation testing provided data on fuel performance issues such as swelling, fuel-cladding interaction (interdiffusion), blister formation at elevated temperatures, and fuel/cladding bond quality and effectiveness. U-10Mo (wt%) was selected as the fuel alloy of choice, accepting a somewhat lower uranium density for the benefits of phase stability. U-7Mo could be used, with a barrier, where the trade-off for uranium density is critical to nuclear performance. A zirconium foil barrier between fuel and cladding was chosen to provide a predictable, well-bonded, fuel-cladding interface, allowing little or no fuel-cladding interaction. The fuel plate testing conducted to inform this selection was based on the use of U-10Mo foils fabricated by hot co-rolling with a Zr foil. The foils were subsequently bonded to Al-6061 cladding by hot isostatic pressing or friction stir bonding.

  7. Characterization of Thermal and Mechanical Properties of Polypropylene-Based Composites for Fuel Cell Bipolar Plates and Development of Educational Tools in Hydrogen and Fuel Cell Technologies

    Science.gov (United States)

    Lopez Gaxiola, Daniel

    2011-01-01

    In this project we developed conductive thermoplastic resins by adding varying amounts of three different carbon fillers: carbon black (CB), synthetic graphite (SG) and multi-walled carbon nanotubes (CNT) to a polypropylene matrix for application as fuel cell bipolar plates. This component of fuel cells provides mechanical support to the stack,…

  8. Characterization of Thermal and Mechanical Properties of Polypropylene-Based Composites for Fuel Cell Bipolar Plates and Development of Educational Tools in Hydrogen and Fuel Cell Technologies

    Science.gov (United States)

    Lopez Gaxiola, Daniel

    2011-01-01

    In this project we developed conductive thermoplastic resins by adding varying amounts of three different carbon fillers: carbon black (CB), synthetic graphite (SG) and multi-walled carbon nanotubes (CNT) to a polypropylene matrix for application as fuel cell bipolar plates. This component of fuel cells provides mechanical support to the stack,…

  9. Parametric study of the deformation of dispersion fuel plates; Estudo parametrico da deformacao de placas combustiveis com nucleos de dispersao

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, E.; Durazzo, M., E-mail: evieira@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2010-07-01

    The Nuclear and Energy Research Institute - IPEN-CNEN/SP produces routinely the nuclear fuel necessary for operating its research reactor, IEA-R1. This fuel consists of fuel plates containing U{sub 3}Si{sub 2}-Al composites as the meat, which are fabricated by rolling. The rolling process currently deployed was developed with base on information obtained from literature, which were used as premises for defining the current manufacturing procedures, according to a methodology with essentially empirical character. Despite the current rolling process to be perfectly stable and highly reproducible, it is not well characterized and therefore is not fully known. The objective of this work is to characterize the rolling process for producing fuel plates, presenting results of the evolution of all parameters of technological interest, after each rolling pass, obtaining information along the fuel plate deformation during the rolling process. (author)

  10. Research on Precaution and Detection Technology for Flow Blockage of Plate-type Fuel Element in Research Reactors

    Institute of Scientific and Technical Information of China (English)

    DING; Li; QIAO; Ya-xin; ZHANG; Nian-peng; LUO; Bei-bei; HUA; Xiao; JIA; Shu-jie; YAN; Hui-yang

    2013-01-01

    The main aim of this study is to offer the technical support for safety operation and management of research reactors using plate-type fuel assemblies in China,which is performed from analysis of precaution measures for flow blockage and detection methods of accidents.Study shows that most accidents were induced by in-core foreign objects and the swelling of fuel

  11. Applications of profile filtering in the dimensional metrology of fuel cell plates

    Science.gov (United States)

    Muralikrishnan, Bala; Ren, Wei; Stanfield, Eric; Everett, Dennis; Zheng, Alan; Doiron, Ted

    2013-06-01

    We describe the application of several surface profile filters as an enabling tool in the dimensional measurements of an engineering artifact, namely, a fuel cell plate. We recently reported work on the development of a non-contact system for dimensional metrology of bipolar fuel cell plates. That system comprises two laser spot triangulation probes that acquire profile data across a plate. While the non-contact system provides rapid measurements (measurement speed of 100 mm s-1 to 500 mm s-1), the data are noisy and cannot be used directly to obtain features of interest such as channel depth and width. In this paper, we show how different surface profile filters such as the spline, morphological, and robust filters, can be employed to identify and suppress outliers and to produce a mean line that serves as a substitute geometry from which we can determine features of interest. Further, we compare the non-contact probe data against contact probe measurements made using a coordinate measuring machine. Surface profile filters are again useful in correcting the reference data for tip size and also in removing any free form deformation in both data sets prior to parameter evaluation and comparison.

  12. Design and simulation of novel flow field plate geometry for proton exchange membrane fuel cells

    Science.gov (United States)

    Ruan, Hanxia; Wu, Chaoqun; Liu, Shuliang; Chen, Tao

    2016-10-01

    Bipolar plate is one of the many important components of proton exchange membrane fuel cell (PEMFC) stacks as it supplies fuel and oxidant to the membrane-electrode assembly (MEA), removes water, collects produced current and provides mechanical support for the single cells in the stack. The flow field design of a bipolar plate greatly affects the performance of a PEMFC. It must uniformly distribute the reactant gases over the MEA and prevent product water flooding. This paper aims at improving the fuel cell performance by optimizing flow field designs and flow channel configurations. To achieve this, a novel biomimetic flow channel for flow field designs is proposed based on Murray's Law. Computational fluid dynamics based simulations were performed to compare three different designs (parallel, serpentine and biomimetic channel, respectively) in terms of current density distribution, power density distribution, pressure distribution, temperature distribution, and hydrogen mass fraction distribution. It was found that flow field designs with biomimetic flow channel perform better than that with convectional flow channel under the same operating conditions.

  13. Mathematical model of a plate fin heat exchanger operating under solid oxide fuel cell working conditions

    Science.gov (United States)

    Kaniowski, Robert; Poniewski, Mieczysław

    2013-12-01

    Heat exchangers of different types find application in power systems based on solid oxide fuel cells (SOFC). Compact plate fin heat exchangers are typically found to perfectly fit systems with power output under 5 kWel. Micro-combined heat and power (micro-CHP) units with solid oxide fuel cells can exhibit high electrical and overall efficiencies, exceeding 85%, respectively. These values can be achieved only when high thermal integration of a system is assured. Selection and sizing of heat exchangers play a crucial role and should be done with caution. Moreover, performance of heat exchangers under variable operating conditions can strongly influence efficiency of the complete system. For that reason, it becomes important to develop high fidelity mathematical models allowing evaluation of heat exchangers under modified operating conditions, in high temperature regimes. Prediction of pressure and temperatures drops at the exit of cold and hot sides are important for system-level studies. Paper presents dedicated mathematical model used for evaluation of a plate fin heat exchanger, operating as a part of micro-CHP unit with solid oxide fuel cells.

  14. Intermittent ephemeral river-breaching

    Science.gov (United States)

    Reniers, A. J.; MacMahan, J. H.; Gallagher, E. L.; Shanks, A.; Morgan, S.; Jarvis, M.; Thornton, E. B.; Brown, J.; Fujimura, A.

    2012-12-01

    In the summer of 2011 we performed a field experiment in Carmel River State Beach, CA, at a time when the intermittent natural breaching of the ephemeral Carmel River occurred due to an unusually rainy period prior to the experiment associated with El Nino. At this time the river would fill the lagoon over the period of a number of days after which a breach would occur. This allowed us to document a number of breaches with unique pre- and post-breach topographic surveys, accompanying ocean and lagoon water elevations as well as extremely high flow (4m/s) velocities in the river mouth during the breaching event. The topographic surveys were obtained with a GPS-equipped backpack mounted on a walking human and show the evolution of the river breaching with a gradually widening and deepening river channel that cuts through the pre-existing beach and berm. The beach face is qualified as a steep with an average beach slope of 1:10 with significant reflection of the incident waves (MacMahan et al., 2012). The wave directions are generally shore normal as the waves refract over the deep canyon that is located offshore of the beach. The tide is mixed semi-diurnal with a range on the order of one meter. Breaching typically occurred during the low-low tide. Grain size is highly variable along the beach with layers of alternating fine and coarse material that could clearly be observed as the river exit channel was cutting through the beach. Large rocky outcroppings buried under the beach sand are also present along certain stretches of the beach controlling the depth of the breaching channel. The changes in the water level measured within the lagoon and the ocean side allows for an estimate of the volume flux associated with the breach as function of morphology, tidal elevation and wave conditions as well as an assessment of the conditions and mechanisms of breach closure, which occurred on the time scale of O(0.5 days). Exploratory model simulations will be presented at the

  15. The Fabrication of Flow Field Plates for Direct Methanol Fuel Cell Using Lithography and Radio Frequency Sputtering.

    Science.gov (United States)

    Chang, Ho; Kao, Mu-Jung; Chen, Chih-Hao; Cho, Kun-Ching; Hsu, Chun-Yao; Chen, Zhi-Lun

    2015-08-01

    This study uses lithography to etch flow fields on a single side of a printed circuit board (PCB) and combines a flow field plate with a collector plate to make innovative anode flow field plates and cathode flow field plates for a direct methanol fuel cell (DMFC). TiO2 thin film is also sputtered on the anode flow field plate using radio frequency (RF) sputtering. The experimental results show that the prepared DMFC has a better maximum power density of 11.928 mW/cm2. Furthermore, when a TiO2 thin film is sputtered on the flow field plate of the assembled DMFC, the maximum power density is 14.426 mW/cm2, which is actually 21% more than that for a DMFC with no TiO2 thin film coated on the flow field plate.

  16. An Investigation on Monolithic U-Mo Plate Type Fuel by a Pressure-Sintering Method

    Energy Technology Data Exchange (ETDEWEB)

    Kim, C. K.; Oh, J. M.; Jang, S. J. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Choi, G. H.; Chun, B. S. [Chungnam National University, Daejeon (Korea, Republic of)

    2009-05-15

    Previously the average particle diameter of U-Mo powder used for developing U-Mo dispersion fuel was about 50 {mu}m. U-Mo/Al dispersion fuels were shown that an extensive interaction between the UMo particle and the Al matrix occurred in high power- density of dispersion fuel. Because the interaction product has a low thermal conductivity and density, which have harmful effects for fuel performance, several attempts to avoid the above problems have been made such as (1) the decrease of the contacting area between the fuel and Al matrix, (2) the increase of the alloy stability of the interaction phase through the addition of an additional alloying element, such as Si, Ti and Zr, into the Al matrix. In KAERI U-Mo powder with very large particle size of more than 500 {mu}m could be produced by rotating disk centrifugal atomization process through adjusting the operating parameters in 2006. A consideration was taken for an application of a large particle to plate type fuel with a layer array. When the particles of spherical shape arrayed in a closed packing way the equivalent U-density of fuel meat would approach to more than 8 g-U/cc. The interface temperature between the U-Mo particle and the Al matrix is expected to be low because aluminum with good thermal conductivity is connected from the interface to the cooling water without any thermal diffusion interruption. The temperature at the center of the large U-Mo particle is calculated to be not too high. When the heat flux and the particle diameter are supposed to be 560 W/cm{sup 2} and 700 {mu}m, the temperature difference was about 36 .deg. C. In addition, the U-Mo particles are surrounded with an aluminum matrix so that a little of the constraint force will act on the fuel particles from the aluminum matrix. A problem like debonding between U-Mo foil and Al cladding in monolithic U-Mo fuel under development can be avoided. Some experiments related to the fabrication of large particle array fuel were carried out

  17. Investigations into the failure of fuel bundle end plates in a Darlington reactor

    Energy Technology Data Exchange (ETDEWEB)

    Price, E.G. [Atomic Energy of Canada Ltd., Montreal, PQ (Canada). CANDU Operations; Ho, E.T.C.; Shek, G.; Ramasubramanian, N. [Canadian Fusion Fuels Technology Project, Toronto, ON (Canada); Maguire, M.; Hosbons, R. [Atomic Energy of Canada Ltd., Kanata, ON (Canada). Radiochemical Co.

    1994-12-31

    After about 90 channels had been refueled in the 480 channel Darlington reactor, a failed fuel bundle at the outlet of channel N12 prevented refuelling of that channel. Subsequent inspection of the outlet ends of a number of channels, showed that several high power channels in the central columns of the reactor had cracks in the end plates of the outlet bundles. This discovery precipitated a multi-discipline investigation, involving a large number of Canadian organizations, to determine the cause and develop a solution. A metallurgical team was set up and given the nominal mandate of determining: - the mode of failure of the end plates; - when failure had occurred and thus by inference the heat transport conditions at the time of failure; - the type of stressing or the metallurgical conditions that had caused failure. (authors). 6 figs., 4 refs.

  18. Characterization of Bond Strength of U-Mo Fuel Plates Using the Laser Shockwave Technique: Capabilities and Preliminary Results

    Energy Technology Data Exchange (ETDEWEB)

    J. A. Smith; D. L. Cottle; B. H. Rabin

    2013-09-01

    This report summarizes work conducted to-date on the implementation of new laser-based capabilities for characterization of bond strength in nuclear fuel plates, and presents preliminary results obtained from fresh fuel studies on as-fabricated monolithic fuel consisting of uranium-10 wt.% molybdenum alloys clad in 6061 aluminum by hot isostatic pressing. Characterization involves application of two complementary experimental methods, laser-shock testing and laser-ultrasonic imaging, collectively referred to as the Laser Shockwave Technique (LST), that allows the integrity, physical properties and interfacial bond strength in fuel plates to be evaluated. Example characterization results are provided, including measurement of layer thicknesses, elastic properties of the constituents, and the location and nature of generated debonds (including kissing bonds). LST provides spatially localized, non-contacting measurements with minimum specimen preparation, and is ideally suited for applications involving radioactive materials, including irradiated materials. The theoretical principles and experimental approaches employed in characterizing nuclear fuel plates are described, and preliminary bond strength measurement results are discussed, with emphasis on demonstrating the capabilities and limitations of these methods. These preliminary results demonstrate the ability to distinguish bond strength variations between different fuel plates. Although additional development work is necessary to validate and qualify the test methods, these results suggest LST is viable as a method to meet fuel qualification requirements to demonstrate acceptable bonding integrity.

  19. Effects of cooling channel blockage on fuel plate temperature in Tehran Research Reactor

    Institute of Scientific and Technical Information of China (English)

    TABBAKH Farshid

    2009-01-01

    In this study, the variation of the temperature distribution of the fuel plate in Tehran Research Reactor core was studied in case of coolant channels blockage. While the experimental method is not possible, both the analytical and simulation methods were used to obtain the more reliable data. The results show that one channel blockage will increase the fuel temperature to about 100%, but it does not lead to clad melt down still. With further calculation and simulation it is understood that if the coolant velocity drops to 90% of its nominal value, it may causes the clad melt-ing down. At least two channels with complete blockage even at the positions far from the core center can also melt down the clad.

  20. Bipolar plate materials in molten carbonate fuel cells. Final CRADA report.

    Energy Technology Data Exchange (ETDEWEB)

    Krumpelt, M.

    2004-06-01

    Advantages of implementation of power plants based on electrochemical reactions are successfully demonstrated in the USA and Japan. One of the msot promising types of fuel cells (FC) is a type of high temperature fuel cells. At present, thanks to the efforts of the leading countries that develop fuel cell technologies power plants on the basis of molten carbonate fuel cells (MCFC) and solid oxide fuel cells (SOFC) are really close to commercialization. One of the problems that are to be solved for practical implementation of MCFC and SOFC is a problem of corrosion of metal components of stacks that are assembled of a number of fuel cells. One of the major components of MCFC and SOFC stacks is a bipolar separator plate (BSP) that performs several functions - it is separation of reactant gas flows sealing of the joints between fuel cells, and current collection from the surface of electrodes. The goal of Task 1 of the project is to develop new cost-effective nickel coatings for the Russian 20X23H18 steel for an MCFC bipolar separator plate using technological processes usually implemented to apply corrosion stable coatings onto the metal parts for products in the defense. There was planned the research on production of nickel coatings using different methods, first of all the galvanic one and the explosion cladding one. As a result of the works, 0.4 x 712 x 1296 mm plates coated with nickel on one side were to be made and passed to ANL. A line of 4 galvanic baths 600 liters was to be built for the galvanic coating applications. The goal of Task 2 of the project is the development of a new material of an MCFC bipolar separator plate with an upgraded corrosion stability, and development of a technology to produce cold roll sheets of this material the sizes of which will be 0.8 x 712x 1296 mm. As a result of these works, a pilot batch of the rolled material in sheets 0.8 x 712 x 1296 mm in size is to be made (in accordance with the norms and standards of the Russian

  1. Management of Classes with Breaches of Discipline

    Institute of Scientific and Technical Information of China (English)

    陈海军

    2009-01-01

    As an only child is pampered and spoiled by parents, the contemporary student easily breaches class discipline. Class management appears more concerned than ever because breaches of class discipline have great impact on teaching. The author clarifies the necessity to study the management of classes with breaches of class discipline, numerates the phenomena of breaches of class discipline, precisely analyzes the causes from teachers and students and especially submits several measures to effectively prevent breaches of class discipline.

  2. High Frequency Transducer Dedicated to the High-resolution in Situ Measurement of the Distance between Two Nuclear Fuel Plates

    Science.gov (United States)

    Zaz, G.; Dekkious, A.; Meignen, P. A.; Calzavara, Y.; Le Clézio, E.; Despaux, G.

    Most high flux reactors for research purposes have fuel elements composed of plates and not pencils. The measure of inter-plate distance of a fuel element is tricky since a resolution of a micron is searched to measure plate swellings of about ten microns while the dimension between the plates is close to the millimeter. This measure should provide information about the fuel and particularly its history of irradiation. That is the reason why a solution has been considered: a robust device based upon high frequency ultrasonic probes adapted to the high radiation environment and thinned to 1 mm to be inserted into a 1.8 mm width water channel between two fuel plates. To achieve the expected resolution, the system is excited with frequencies up to 150 MHz. Thanks to a specific signal processing, this device allows the distance measurement through an ultrasonic wave's time of flight. The feasibility of such challenging distance measurement has already been proved with success on a full size irradiated fuel element of the RHF.

  3. Evaluation of materials for bipolar plates in simulated PEM fuel-cell cathodic environments

    Energy Technology Data Exchange (ETDEWEB)

    Rivas, S.V.; Belmonte, M.R.; Moron, L.E.; Torres, J.; Orozco, G. [Centro de Investigacion y Desarrollo Technologico en Electroquimica S.C. Parcque Sanfandila, Queretaro (Mexico); Perez-Quiroz, J.T. [Mexican Transport Inst., Queretaro (Mexico); Cortes, M. A. [Mexican Petroleum Inst., Mexico City (Mexico)

    2008-04-15

    The bipolar plates in proton exchange membrane fuel cells (PEMFC) are exposed to an oxidizing environment on the cathodic side, and therefore are susceptible to corrosion. Corrosion resistant materials are needed for the bipolar plates in order to improve the lifespan of fuel cells. This article described a study in which a molybdenum (Mo) coating was deposited over austenitic stainless steel 316 and carbon steel as substrates in order to evaluate the resulting surfaces with respect to their corrosion resistance in simulated anodic and cathodic PEMFC environments. The molybdenum oxide films were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. The article presented the experiment and discussed the results of the corrosion behaviour of coated stainless steel. In general, the electrochemical characterization of bare materials and coated steel consisted of slow potentiodynamic polarization curves followed by a constant potential polarization test. The test medium was 0.5M sulfuric acid with additional introduction of oxygen to simulate the cathodic environment. All tests were performed at ambient temperature and at 50 degrees Celsius. The potentiostat used was a Gamry instrument. It was concluded that it is possible to deposit Mo-oxides on steel without using another alloying metal. The preferred substrate for corrosion prevention was found to be an alloy with high chromium content. 24 refs., 4 figs.

  4. Development of alternative low-cost and durable metallic bipolar plates for polymer electrolyte membrane (PEM) fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Okafor, A.C.; Kilicay, O. [Missouri Univ. of Science and Technology, Rolla (United States). Dept. of Mechanical and Aerospace Engineering

    2009-07-01

    Bipolar plates account for significant portion of the cost of proton exchange membrane fuel cells (PEMFCs). This study discussed the design of a high corrosion-resistance metallic bipolar plate as an alternative to the porous graphite bipolar plates currently used in PEMFCs. A literature review of bipolar plate materials and flow field design configurations was conducted. Metallic candidate materials and flow field configurations were identified. Computer-aided design (CAD) models were then development in order to design the software programs used to machine the bipolar plates in 3 different materials. The machined bipolar plates are now being integrated with state-of-the-art membrane electrode assemblies (MEAs) and sealants into single- and 3-cell stacks. The results of some performance, durability, and degradation mechanism analyses were presented.

  5. Post-irradiation examination of AlFeNi cladded U 3Si 2 fuel plates irradiated under severe conditions

    Science.gov (United States)

    Leenaers, A.; Koonen, E.; Parthoens, Y.; Lemoine, P.; Van den Berghe, S.

    2008-04-01

    Three full size AlFeNi cladded U 3Si 2 fuel plates were irradiated in the BR2 reactor of the Belgian Nuclear Research Centre (SCK·CEN) under relatively severe, but well defined conditions. The irradiation was part of the qualification campaign for the fuel to be used in the future Jules Horowitz reactor in Cadarache, France. After the irradiation, the fuel plates were submitted to an extensive post-irradiation campaign in the hot cell laboratory of SCK·CEN. The PIE shows that the fuel plates withstood the irradiation successfully, as no detrimental defects have been found. At the cladding surface, a multilayered corrosion oxide film has formed. The U-Al-Si layer resulting from the interaction between the U 3Si 2 fuel and the Al matrix, has been quantified as U(Al,Si) 4.6. It is found that the composition of the fuel particles is not homogenous; zones of USi and U 3Si 2 are observed and measured. The fission gas-related bubbles generated in both phases show a different morphology. In the USi fuel, the bubbles are small and numerous while in U 3Si 2 the bubbles are larger but there are fewer.

  6. 3D COMSOL Simulations for Thermal Deflection of HFIR Fuel Plate in the "Cheverton-Kelley" Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Prashant K [ORNL; Freels, James D [ORNL; Cook, David Howard [ORNL

    2012-08-01

    Three dimensional simulation capabilities are currently being developed at Oak Ridge National Laboratory using COMSOL Multiphysics, a finite element modeling software, to investigate thermal expansion of High Flux Isotope Reactor (HFIR) s low enriched uranium fuel plates. To validate simulations, 3D models have also been developed for the experimental setup used by Cheverton and Kelley in 1968 to investigate the buckling and thermal deflections of HFIR s highly enriched uranium fuel plates. Results for several simulations are presented in this report, and comparisons with the experimental data are provided when data are available. A close agreement between the simulation results and experimental findings demonstrates that the COMSOL simulations are able to capture the thermal expansion physics accurately and that COMSOL could be deployed as a predictive tool for more advanced computations at realistic HFIR conditions to study temperature-induced fuel plate deflection behavior.

  7. Monopolar fuel cell stack coupled together without use of top or bottom cover plates or tie rods

    Science.gov (United States)

    Narayanan, Sekharipuram R. (Inventor); Valdez, Thomas I. (Inventor)

    2009-01-01

    A monopolar fuel cell stack comprises a plurality of sealed unit cells coupled together. Each unit cell comprises two outer cathodes adjacent to corresponding membrane electrode assemblies and a center anode plate. An inlet and outlet manifold are coupled to the anode plate and communicate with a channel therein. Fuel flows from the inlet manifold through the channel in contact with the anode plate and flows out through the outlet manifold. The inlet and outlet manifolds are arranged to couple to the inlet and outlet manifolds respectively of an adjacent one of the plurality of unit cells to permit fuel flow in common into all of the inlet manifolds of the plurality of the unit cells when coupled together in a stack and out of all of the outlet manifolds of the plurality of unit cells when coupled together in a stack.

  8. Evaluation of plate type fuel elements by eddy current test method; Avaliacao de combustiveis nucleares tipo placa pelo metodo de correntes parasitas

    Energy Technology Data Exchange (ETDEWEB)

    Frade, Rangel Teixeira

    2015-07-01

    Plate type fuel elements are used in MTR research nuclear reactors. The fuel plates are manufactured by assembling a briquette containing the fissile material inserted in a frame, with metal plates in both sides of the set, to act as a cladding. This set is rolled under controlled conditions in order to obtain the fuel plate. In Brazil, this type of fuel is manufactured by IPEN and used in the IEA-R1 reactor. After fabrication of three batches of fuel plates, 24 plates, one of them is taken, in order to verify the thickness of the cladding. For this purpose, the plate is sectioned and the thickness measurements are carried out by using optical microscopy. This procedure implies in damage of the plate, with the consequent cost. Besides, the process of sample preparation for optical microscopy analysis is time consuming, it is necessary an infrastructure for handling radioactive materials and there is a generation of radioactive residues during the process. The objective of this study was verify the applicability of eddy current test method for nondestructive measurement of cladding thickness in plate type nuclear fuels, enabling the inspection of all manufactured fuel plates. For this purpose, reference standards, representative of the cladding of the fuel plates, were manufactured using thermomechanical processing conditions similar to those used for plates manufacturing. Due to no availability of fuel plates for performing the experiments, the presence of the plate’s core was simulated using materials with different electrical conductivities, fixed to the thickness reference standards. Probes of eddy current testing were designed and manufactured. They showed high sensitivity to thickness variations, being able to separate small thickness changes. The sensitivity was higher in tests performed on the reference standards and samples without the presence of the materials simulating the core. For examination of the cladding with influence of materials simulating the

  9. AlSi matrices for U(Mo) dispersion fuel plates

    Science.gov (United States)

    Leenaers, A.; Van den Berghe, S.; Detavernier, C.

    2013-08-01

    Several irradiation experiments of U(Mo) dispersion fuel performed with aluminum as matrix resulted in unacceptable swelling of the fuel plate due to the formation of an interaction layer between Al and U(Mo). It was found that an improvement in fuel behavior can be achieved by adding Si to the Al matrix and creating a Si rich preformed layer which delays the formation of the interaction layer. Such Al-Si matrices can be formed either by mixing silicon powder with aluminum or using an AlSi alloy. AlSi alloy powders have very different mechanical properties which complicate fuel plate fabrication. Aging experiments on AlSi alloys reveal that giving the alloy the correct heat treatment results in a homogenous dispersion of fine Si precipitates in a soft and strain free Al matrix. The diffusion of such small precipitates towards the U(Mo) particles will be more effective than the transportation of Si from the larger Si particles used in a mixture matrix. Out of pile experiments are performed to show the difference between using a mixture or an alloy for the interaction with U(Mo). It was found that the U(Mo) particles dispersed in an AlSi alloy matrix have a more uniform Si rich preformed layer after heat treatment. the thermal component of the in-pile diffusion (340 °C); the fabrication behavior (450 °C); the enhanced diffusion due to fission product recoils (550 °C). At the same time, they have been chosen at values where literature data exists for comparison [26]. Although only the true in-reactor behavior can provide final conclusions, the results of these out-of-pile tests provide some good indications on the expected relative behavior. Table 3 provides an overview of the experiment.After the thermal treatment, the pellets are removed from the capsules and cut in their longitudinal direction. One half of the pellet is embedded in epoxy resin and polished on successively finer grid finishing on cloth using 1 μm diamond paste.The samples have been investigated

  10. Douglas County Dam Breach Inundation Areas

    Data.gov (United States)

    Kansas Data Access and Support Center — Dam breach analysis provides a prediction of the extent and timing of flooding from a catastrophic breach of the dams. These results are sufficient for developing...

  11. An Information Theory of Willful Breach

    National Research Council Canada - National Science Library

    Oren Bar-Gill; Omri Ben-Shahar

    2009-01-01

    Should willful breach be sanctioned more severely than inadvertent breach? Strikingly, there is sharp disagreement on this matter within American legal doctrine, in legal theory, and in comparative law...

  12. Iron-based alloy and nitridation treatment for PEM fuel cell bipolar plates

    Science.gov (United States)

    Brady, Michael P [Oak Ridge, TN; Yang, Bing [Oak Ridge, TN; Maziasz, Philip J [Oak Ridge, TN

    2010-11-09

    A corrosion resistant electrically conductive component that can be used as a bipolar plate in a PEM fuel cell application is composed of an alloy substrate which has 10-30 wt. % Cr, 0.5 to 7 wt. % V, and base metal being Fe, and a continuous surface layer of chromium nitride and vanadium nitride essentially free of base metal. A oxide layer of chromium vanadium oxide can be disposed between the alloy substrate and the continuous surface nitride layer. A method to prepare the corrosion resistant electrically conductive component involves a two-step nitridization sequence by exposing the alloy to a oxygen containing gas at an elevated temperature, and subsequently exposing the alloy to an oxygen free nitrogen containing gas at an elevated temperature to yield a component where a continuous chromium nitride layer free of iron has formed at the surface.

  13. Nondestructive Image Detection of Cracks for a Nuclear Fuel Plate by Using Active Thermal Phase

    Energy Technology Data Exchange (ETDEWEB)

    Park, Nak Kyu; Park, Seung Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cha, Byung Heon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Kang, Young June [Chonbuk National University, Jeonju (Korea, Republic of)

    2012-05-15

    Nondestructive crack detection is a key process for the safety insurance of the nuclear fuel plates which are widely used in a nuclear research reactor. Among nondestructive detection techniques, X-ray inspection technique and ultrasonic inspection technique using high frequency are widely used to detect internal cracks of a nuclear fuel plate at present. Though X-ray inspection is fast and efficient technique by providing a crack image for whole specimen area, this technique hardly provides the delaminated crack information which should be detected. Ultrasonic inspection is also an efficient tool to detect internal cracks of materials. High frequency ultrasound based on the piezoelectric transducers is usually used to detect cracks of a nuclear fuel plate. Though it is useful technique, the inspection should be carried out by an immersion test in a water-tank and its signal is complex and it is time consuming technique because the inspection is scanned point by point in sequence for whole inspection area. A commercial scanning ultrasonic system using high frequency is usually adopted to detect cracks. An alternative inspection technique to overcome the disadvantages of the high frequency ultrasonic inspection technique is needed. Especially, nondestructive imaging techniques of the internal cracks will be useful because it can be easily used in the field. One of efficient nondestructive testing techniques is infrared thermo-graphic technique. Infrared thermographic is a contactless optical imaging technique by detecting the invisible infrared radiation. Pulsed and lock-in thermography are commonly used in thermo-graphic nondestructive evaluation techniques. The two techniques are distinctly different but are deployed in the inspection of similar components. In general, these techniques are suitable for the detection of shallow planer defects, e.g. delamination in composites or adhesion defect in surface coatings. The surface of a specimen is instantaneously heated

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Science.gov (United States)

    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.

  16. Photothermally induced bromination of carbon/polymer bipolar plate materials for fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Schade, Martin; Franzka, Steffen [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Cappuccio, Franco; Peinecke, Volker; Heinzel, Angelika [Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany); Zentrum für BrennstoffzellenTechnik (ZBT), Carl-Benz-Straße 201, 47057 Duisburg (Germany); Hartmann, Nils, E-mail: nils.hartmann@uni-due.de [Fakultät für Chemie, Universität Duisburg-Essen, 45117 Essen (Germany); Center for Nanointegration Duisburg-Essen (CENIDE), University of Duisburg-Essen, Carl-Benz-Straße 199, 47057 Duisburg (Germany)

    2015-05-01

    Graphical abstract: - Highlights: • Photothermal laser bromination of carbon/polymer materials is demonstrated. • Using a microfocused laser functionalized domains with diameters of 5 μm and 100 μm and more can be fabricated. • Bromine groups can be transformed in a variety of other chemical functionalities, i.e. amine groups. • Depending on the chemical functionality, the local chemical affinity and wettability is changed. • The routine can be applied to standard bipolar plate materials used for fuel cell applications. - Abstract: A facile photothermal procedure for direct functionalization of carbon/polymer bipolar plate materials is demonstrated. Through irradiation with a microfocused beam of an Ar{sup +}-laser at λ = 514 nm in gaseous bromine and distinct laser powers and pulse lengths local bromination of the carbon/polymer material takes place. At a 1/e spot diameter of 2.1 μm, functionalized surface areas with diameters down to 5 μm are fabricated. In complementary experiments large-area bromination is investigated using an ordinary tungsten lamp. For characterization contact angle goniometry, X-ray photoelectron spectroscopy and electron microscopy in conjunction with labeling techniques are employed. After irradiation bromine groups can easily be substituted by other chemical functionalities, e.g. azide and amine groups. This provides a facile approach in order to fabricate surface patterns and gradient structures with varying wetting characteristics. Mechanistic aspects and prospects of photothermal routines in micropatterning of carbon/polymer materials are discussed.

  17. 13 CFR 115.69 - Imminent Breach.

    Science.gov (United States)

    2010-01-01

    ... 13 Business Credit and Assistance 1 2010-01-01 2010-01-01 false Imminent Breach. 115.69 Section... Surety Bond (PSB) Guarantees § 115.69 Imminent Breach. (a) No prior approval requirement. SBA will... an Imminent Breach of the terms of a Contract covered by an SBA guaranteed bond. The PSB Surety...

  18. Simulation of irradiation hardening of Zircaloy within plate-type dispersion nuclear fuel elements

    Science.gov (United States)

    Jiang, Yijie; Wang, Qiming; Cui, Yi; Huo, Yongzhong; Ding, Shurong

    2011-06-01

    Within plate-type dispersion nuclear fuel elements, the metal matrix and cladding attacked continuously by fast neutrons undergo irradiation hardening, which might have remarkable effects upon the mechanical behaviors within fuel elements. In this paper, with the irradiation hardening effect of metal materials mainly considered together with irradiation growth effect of the cladding, the three-dimensional large-deformation constitutive relations for the metal matrix and cladding are developed. The method of virtual temperature increase in the previous studies is further developed to model the irradiation swelling of fuel particles; the method of anisotropic thermal expansion is introduced to model irradiation growth of the cladding; and a method of multi-step-temperature loading is proposed to simulate the coupling features of irradiation-induced swelling of the fuel particles together with irradiation growth of the cladding. Above all, based on the developed relationship between irradiation growth at certain burnup and the loaded virtual temperatures, with considering that certain burnup corresponds to certain fast neutron fluence, the time-dependent constitutive relation due to irradiation hardening effect is replaced by the virtual-temperature-dependent one which is introduced into the commercial software to simulate the irradiation hardening effects of the matrix and cladding. Numerical simulations of the irradiation-induced mechanical behaviors are implemented with the finite element method in consideration of the micro-structure of the fuel meat. The obtained results indicate that when the irradiation hardening effects are introduced into the constitutive relations of the metal matrix and cladding: (1) higher maximum Mises stresses for certain burnup at the matrix exist with the equivalent plastic strains remaining almost the same at lower burnups; (2) the maximum Mises stresses for certain burnup at the cladding are enhanced while the maximum equivalent

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

    Science.gov (United States)

    Jang, Bor Z.; Zhamu, Aruna; Guo, Jiusheng

    2011-02-15

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

  20. The preparation technique optimization of epoxy/compressed expanded graphite composite bipolar plates for proton exchange membrane fuel cells

    Science.gov (United States)

    Du, Chao; Ming, Pingwen; Hou, Ming; Fu, Jie; Fu, Yunfeng; Luo, Xiaokuan; Shen, Qiang; Shao, Zhigang; Yi, Baolian

    Vacuum resin impregnation method has been used to prepare polymer/compressed expanded graphite (CEG) composite bipolar plates for proton exchange membrane fuel cells (PEMFCs). In this research, three different preparation techniques of the epoxy/CEG composite bipolar plate (Compression-Impregnation method, Impregnation-Compression method and Compression-Impregnation-Compression method) are optimized by the physical properties of the composite bipolar plates. The optimum conditions and the advantages/disadvantages of the different techniques are discussed respectively. Although having different characteristics, bipolar plates obtained by these three techniques can all meet the demands of PEMFC bipolar plates as long as the optimum conditions are selected. The Compression-Impregnation-Compression method is shown to be the optimum method because of the outstanding properties of the bipolar plates. Besides, the cell assembled with these optimum composite bipolar plates shows excellent stability after 200 h durability testing. Therefore the composite prepared by vacuum resin impregnation method is a promising candidate for bipolar plate materials in PEMFCs.

  1. Prediction of the micro-thermo-mechanical behaviors in dispersion nuclear fuel plates with heterogeneous particle distributions

    Science.gov (United States)

    Jiang, Yijie; Wang, Qiming; Cui, Yi; Huo, Yongzhong; Ding, Shurong; Zhang, Lin; Li, Yuanming

    2011-11-01

    Dispersion nuclear fuel elements have promising prospects to be used in advanced nuclear reactors and disposal of nuclear wastes. They consist of fuel meat and cladding, and the fuel meat is a kind of composite fuel in which the fuel particles are embedded in the non-fissile matrix. Prediction of the micro-thermo-mechanical behaviors in dispersion nuclear plates is of importance to their irradiation safety and optimal design. In this study, the heterogeneity of the fuel particles along the thickness direction in the fuel meat is considered. The 3D finite element models have been developed respectively for two cases: (1) variation of fuel particle-particle (PP) distances for the particles near the mid-plane of the fuel meat; (2) variation of the particle-cladding (PC) distances for the fuel particles near the interface between the fuel meat and the cladding. The respective finite strain constitutive relations are developed for the fuel particle, metal matrix and cladding. The developed virtual temperature method is used to simulate irradiation swelling of the fuel particles and irradiation growth of the metal cladding. Effects of the heterogeneous distributions of the fuel particles on the micro temperature fields and the micro stress-strain fields are investigated. The obtained results indicate that: (1) as a whole, the maximum Mises stress, equivalent plastic strain and first principal stress at the matrix between the two closest particles increase with decreasing the particle-particle (PP) distance; existence of large first principal stresses there may be the main factor that induces the matrix failure; (2) variation of the particle-cladding (PC) distance has remarkable effects on the interfacial normal stress and shear stress at the interface between the fuel meat and the cladding; the first principal stress at the cladding near the interface increases dramatically when the fuel particle is closer and closer to the cladding. Thus, the proper distance between the

  2. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    ’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through......Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  3. PLATE

    DEFF Research Database (Denmark)

    Kling, Joyce; Hjulmand, Lise-Lotte

    2008-01-01

    Copenhagen Business School (CBS) finds itself needing to address the issue of English-medium instruction for its increasing number of foreign exchange and full degree students. With internationalisation as a main pillar of the institution’s agenda, there are concerns whether the teaching faculty......’s level of English is sufficient for the increasing number of courses offered in English each semester. This paper addresses these concerns and describes a pilot project initiated in 2003 at CBS to gauge the overall English language proficiency of those teaching content courses in English. Through...... the Project in Language Assessment for Teaching in English (PLATE) language professionals from CBS’s Language Center observe teachers and provide feedback using evaluation criteria from the Common European Framework for Reference (CEFR) supplemented by some additional criteria which take the LSP nature...

  4. SCANNING ELECTRON MICROSCOPY ANALYSIS OF FUEL/MATRIX INTERACTION LAYERS IN HIGHLY-IRRADIATED U-Mo DISPERSION FUEL PLATES WITH Al AND Al–Si ALLOY MATRICES

    Directory of Open Access Journals (Sweden)

    DENNIS D. KEISER, JR.

    2014-04-01

    Full Text Available In order to investigate how the microstructure of fuel/matrix-interaction (FMI layers change during irradiation, different U–7Mo dispersion fuel plates have been irradiated to high fission density and then characterized using scanning electron microscopy (SEM. Specifially, samples from irradiated U–7Mo dispersion fuel elements with pure Al, Al-2Si and AA4043 (∼4.5 wt.%Si matrices were SEM characterized using polished samples and samples that were prepared with a focused ion beam (FIB. Features not observable for the polished samples could be captured in SEM images taken of the FIB samples. For the Al matrix sample, a relatively large FMI layer develops, with enrichment of Xe at the FMI layer/Al matrix interface and evidence of debonding. Overall, a significant penetration of Si from the FMI layer into the U–7Mo fuel was observed for samples with Si in the Al matrix, which resulted in a change of the size (larger and shape (round of the fission gas bubbles. Additionally, solid fission product phases were observed to nucleate and grow within these bubbles. These changes in the localized regions of the microstructure of the U–7Mo may contribute to changes observed in the macroscopic swelling of fuel plates with Al-Si matrices.

  5. Requirements and testing methods for surfaces of metallic bipolar plates for low-temperature PEM fuel cells

    Science.gov (United States)

    Jendras, P.; Lötsch, K.; von Unwerth, T.

    2017-03-01

    To reduce emissions and to substitute combustion engines automotive manufacturers, legislature and first users aspire hydrogen fuel cell vehicles. Up to now the focus of research was set on ensuring functionality and increasing durability of fuel cell components. Therefore, expensive materials were used. Contemporary research and development try to substitute these substances by more cost-effective material combinations. The bipolar plate is a key component with the greatest influence on volume and mass of a fuel cell stack and they have to meet complex requirements. They support bending sensitive components of stack, spread reactants over active cell area and form the electrical contact to another cell. Furthermore, bipolar plates dissipate heat of reaction and separate one cell gastight from the other. Consequently, they need a low interfacial contact resistance (ICR) to the gas diffusion layer, high flexural strength, good thermal conductivity and a high durability. To reduce costs stainless steel is a favoured material for bipolar plates in automotive applications. Steel is characterized by good electrical and thermal conductivity but the acid environment requires a high chemical durability against corrosion as well. On the one hand formation of a passivating oxide layer increasing ICR should be inhibited. On the other hand pitting corrosion leading to increased permeation rate may not occur. Therefore, a suitable substrate lamination combination is wanted. In this study material testing methods for bipolar plates are considered.

  6. In Vitro Dissolution Tests of Plutonium and Americium Containing Contamination Originating From ZPPR Fuel Plates

    Energy Technology Data Exchange (ETDEWEB)

    William F. Bauer; Brian K. Schuetz; Gary M. Huestis; Thomas B. Lints; Brian K. Harris; R. Duane Ball; Gracy Elias

    2012-09-01

    Assessing the extent of internal dose is of concern whenever workers are exposed to airborne radionuclides or other contaminants. Internal dose determinations depend upon a reasonable estimate of the expected biological half-life of the contaminants in the respiratory tract. One issue with refractory elements is determining the dissolution rate of the element. Actinides such as plutonium (Pu) and Americium (Am) tend to be very refractory and can have biological half-lives of tens of years. In the event of an exposure, the dissolution rates of the radionuclides of interest needs to be assessed in order to assign the proper internal dose estimates. During the November 2011 incident at the Idaho National Laboratory (INL) involving a ZPPR fuel plate, air filters in a constant air monitor (CAM) and a giraffe filter apparatus captured airborne particulate matter. These filters were used in dissolution rate experiments to determine the apparent dissolution half-life of Pu and Am in simulated biological fluids. This report describes these experiments and the results. The dissolution rates were found to follow a three term exponential decay equation. Differences were noted depending upon the nature of the biological fluid simulant. Overall, greater than 95% of the Pu and 93% of the Am were in a very slow dissolving component with dissolution half-lives of over 10 years.

  7. Non-destructive evaluation of the cladding thickness in LEU fuel plates by accurate ultrasonic scanning technique

    Energy Technology Data Exchange (ETDEWEB)

    Borring, J.; Gundtoft, H.E.; Borum, K.K.; Toft, P. [Riso National Lab. (Denmark)

    1997-08-01

    In an effort to improve their ultrasonic scanning technique for accurate determination of the cladding thickness in LEU fuel plates, new equipment and modifications to the existing hardware and software have been tested and evaluated. The authors are now able to measure an aluminium thickness down to 0.25 mm instead of the previous 0.35 mm. Furthermore, they have shown how the measuring sensitivity can be improved from 0.03 mm to 0.01 mm. It has now become possible to check their standard fuel plates for DR3 against the minimum cladding thickness requirements non-destructively. Such measurements open the possibility for the acceptance of a thinner nominal cladding than normally used today.

  8. Improving 6061-Al Grain Growth and Penetration across HIP-Bonded Clad Interfaces in Monolithic Fuel Plates: Initial Studies

    Energy Technology Data Exchange (ETDEWEB)

    Hackenberg, Robert E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); McCabe, Rodney J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clarke, Kester D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Edwards, Randall L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crapps, Justin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trujillo, R. Ralph [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aikin, Beverly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vargas, Victor D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hollis, Kendall J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lienert, Thomas J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Forsyth, Robert T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Harada, Kiichi L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-05-06

    Grain penetration across aluminum-aluminum cladding interfaces in research reactor fuel plates is desirable and was obtained by a legacy roll-bonding process, which attained 20-80% grain penetration. Significant grain penetration in monolithic fuel plates produced by Hot Isostatic Press (HIP) fabrication processing is equally desirable but has yet to be attained. The goal of this study was to modify the 6061-Al in such a way as to promote a much greater extent of crossinterface grain penetration in monolithic fuel plates fabricated by the HIP process. This study documents the outcomes of several strategies attempted to attain this goal. The grain response was characterized using light optical microscopy (LOM) electron backscatter diffraction (EBSD) as a function of these prospective process modifications done to the aluminum prior to the HIP cycle. The strategies included (1) adding macroscopic gaps in the sandwiches to enhance Al flow, (2) adding engineering asperities to enhance Al flow, (3) adding stored energy (cold work), and (4) alternative cleaning and coating. Additionally, two aqueous cleaning methods were compared as baseline control conditions. The results of the preliminary scoping studies in all the categories are presented. In general, none of these approaches were able to obtain >10% grain penetration. Recommended future work includes further development of macroscopic grooving, transferred-arc cleaning, and combinations of these with one another and with other processes.

  9. FINITE ELEMENT SIMULATION FOR STRUCTURAL RESPONSE OF U7MO DISPERSION FUEL PLATES VIA FLUID-THERMAL-STRUCTURAL INTERACTION

    Energy Technology Data Exchange (ETDEWEB)

    Hakan Ozaltun; Herman Shen; Pavel Madvedev

    2010-11-01

    This article presents numerical simulation of dispersion fuel mini plates via fluid–thermal–structural interaction performed by commercial finite element solver COMSOL Multiphysics to identify initial mechanical response under actual operating conditions. Since fuel particles are dispersed in Aluminum matrix, and temperatures during the fabrication process reach to the melting temperature of the Aluminum matrix, stress/strain characteristics of the domain cannot be reproduced by using simplified models and assumptions. Therefore, fabrication induced stresses were considered and simulated via image based modeling techniques with the consideration of the high temperature material data. In order to identify the residuals over the U7Mo particles and the Aluminum matrix, a representative SEM image was employed to construct a microstructure based thermo-elasto-plastic FE model. Once residuals and plastic strains were identified in micro-scale, solution was used as initial condition for subsequent multiphysics simulations at the continuum level. Furthermore, since solid, thermal and fluid properties are temperature dependent and temperature field is a function of the velocity field of the coolant, coupled multiphysics simulations were considered. First, velocity and pressure fields of the coolant were computed via fluidstructural interaction. Computed solution for velocity fields were used to identify the temperature distribution on the coolant and on the fuel plate via fluid-thermal interaction. Finally, temperature fields and residual stresses were used to obtain the stress field of the plates via fluid-thermal-structural interaction.

  10. Continuous electricity generation from domestic wastewater and organic substrates in a flat plate microbial fuel cell.

    Science.gov (United States)

    Min, Booki; Logan, Bruce E

    2004-11-01

    A microbial fuel cell (MFC) is a device that converts organic matter to electricity using microorganisms as the biocatalyst. Most MFCs contain two electrodes separated into one or two chambers that are operated as a completely mixed reactor. In this study, a flat plate MFC (FPMFC) was designed to operate as a plug flow reactor (no mixing) using a combined electrode/proton exchange membrane (PEM) system. The reactor consisted of a single channel formed between two nonconductive plates that were separated into two halves by the electrode/PEM assembly. Each electrode was placed on an opposite side of the PEM, with the anode facing the chamber containing the liquid phase and the cathode facing a chamber containing only air. Electricity generation using the FPMFC was examined by continuously feeding a solution containing wastewater, or a specific substrate, into the anode chamber. The system was initially acclimated for 1 month using domestic wastewater orwastewater enriched with a specific substrate such as acetate. Average power density using only domestic wastewater was 72+/-1 mW/m2 at a liquid flow rate of 0.39 mL/min [42% COD (chemical oxygen demand) removal, 1.1 h HRT (hydraulic retention time)]. At a longer HRT = 4.0 h, there was 79% COD removal and an average power density of 43+/-1 mW/m2. Power output was found to be a function of wastewater strength according to a Monod-type relationship, with a half-saturation constant of Ks = 461 or 719 mg COD/L. Power generation was sustained at high rates with several organic substrates (all at approximately 1000 mg COD/L), including glucose (212+/-2 mW/ m2), acetate (286+/-3 mW/m2), butyrate (220+/-1 mW/ m2), dextran (150+/-1 mW/m2), and starch (242+/-3 mW/ m2). These results demonstrate the versatility of power generation in a MFC with a variety of organic substrates and show that power can be generated at a high rate in a continuous flow reactor system.

  11. Preparation and properties of carbon nanotube/polypropylene nanocomposite bipolar plates for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Liao, Shu-Hang; Yen, Chuan-Yu; Weng, Cheng-Chih; Lin, Yu-Feng; Ma, Chen-Chi M.; Yang, Ching-Hung; Tsai, Ming-Chi; Yen, Ming-Yu; Hsiao, Min-Chien; Lee, Shuo-Jen; Xie, Xiao-Feng; Hsiao, Yi-Hsiu

    This study aims at the fabrication of lightweight and high performance nanocomposite bipolar plates for the application in polymer electrode membrane fuel cells (PEMFCs). The thin nanocomposite bipolar plates (the thickness polypropylene (PP) with different crystallinities including high crystallinity PP (HC-PP), medium crystallinity PP (MC-PP), low crystallinity PP (LC-PP) were prepared to investigate the influence of crystallinity on the dispersion of MWCNTs in PP matrix. The optimum composition of original composite bipolar plates was determined at 80 wt.% graphite content and 20 wt.% PP content based on the measurements of electrical and mechanical properties with various graphite contents. Results also indicate that MWCNTs was dispersed better in LC-PP than other PP owing to enough dispersed regions in nanocomposite bipolar plates. This good MWCNT dispersion of LC-PP would cause better bulk electrical conductivity, mechanical properties and thermal stability of MWCNTs/PP nanocomposite bipolar plates. In the MWCNTs/LC-PP system, the bulk electrical conductivities with various MWCNT contents all exceed 100 S cm -1. The flexural strength of the MWCNTs/LC-PP nanocomposite bipolar plate with 8 phr of MWCNTs was approximately 37% higher than that of the original nanocomposite bipolar plate and the unnotched Izod impact strength of MWCNTs/LC-PP nanocomposite bipolar plates was also increased from 68.32 J m -1 (0 phr) to 81.40 J m -1 (8 phr), increasing 19%. In addition, the coefficient of thermal expansion of MWCNTs/LC-PP nanocomposite bipolar plate was decreased from 32.91 μm m -1 °C -1 (0 phr) to 25.79 μm m -1 °C -1 (8 phr) with the increasing of MWCNT content. The polarization curve of MWCNTs/LC-PP nanocomposite bipolar plate compared with graphite bipolar plate was also evaluated. These results confirm that the addition of MWCNTs in LC-PP leads to a significant improvement on the cell performance of the nanocomposite bipolar plate.

  12. Thermal-hydraulic analysis under partial loss of flow accident hypothesis of a plate-type fuel surrounded by two water channels using RELAP5 code

    Directory of Open Access Journals (Sweden)

    Itamar Iliuk

    2016-01-01

    Full Text Available Thermal-hydraulic analysis of plate-type fuel has great importance to the establishment of safety criteria, also to the licensing of the future nuclear reactor with the objective of propelling the Brazilian nuclear submarine. In this work, an analysis of a single plate-type fuel surrounding by two water channels was performed using the RELAP5 thermal-hydraulic code. To realize the simulations, a plate-type fuel with the meat of uranium dioxide sandwiched between two Zircaloy-4 plates was proposed. A partial loss of flow accident was simulated to show the behavior of the model under this type of accident. The results show that the critical heat flux was detected in the central region along the axial direction of the plate when the right water channel was blocked.

  13. Evaluation of CoBlast Coated Titanium Alloy as Proton Exchange Membrane Fuel Cell Bipolar Plates

    Directory of Open Access Journals (Sweden)

    Atinuke M. Oladoye

    2014-01-01

    Full Text Available We investigated the potential of graphite based coatings deposited on titanium V alloy by a low-cost powder based process for bipolar plate application. The coatings which were deposited from a mixture of graphite and alumina powders at ambient temperature, pressure of 90 psi, and speed of 20 mm were characterised and electrochemically polarised in 0.5 M H2SO4 + 2 ppm HF bubbled with air and hydrogen gas to depict the cathode and anode PEM fuel cell environment, respectively. Surface conductivity and water contact angles were also evaluated. Corrosion current in the 1 μA/cm2 range in both cathodic and anodic environment at room temperature and showed negligible influence on the electrochemical behaviour of the bare alloy. Similar performance, which was attributed to the discontinuities in the coatings, was also observed when polarised at 0.6 V and −0.1 V with air and hydrogen bubbling at 70∘C respectively. At 140 N/cm2, the coated alloy exhibited contact resistance of 45.70 mΩ·cm2 which was lower than that of the bare alloy (66.50 mΩ·cm2 but twice that of graphite (21.29 mΩ·cm2. Similarly, the wettability test indicated that the coated layer exhibited higher contact angle of 99.63° than that of the bare alloy (66.32°. Over all, these results indicated need for improvement in the coating process to achieve a continuous layer.

  14. PEM fuel cells with injection moulded bipolar plates of highly filled graphite compounds; PEM-Brennstoffzellen mit spritzgegossenen Bipolarplatten aus hochgefuelltem Graphit-Compound

    Energy Technology Data Exchange (ETDEWEB)

    Kreuz, Can

    2008-04-11

    This work concerns with the injection moulding of highly filled graphite compounds to bipolar plates for PEM fuel cells in a power output range between 100 - 500 Watts. A particular focus is laid on the combination of the three multidisciplinary scopes like material development, production technology and component development / design. The results of the work are specified by the process-oriented characterisation of the developed and manufactured bipolar plates as well as their application in a functioning fuel cell. (orig.)

  15. Improvement of visualization efficiency for the nondestructive inspection image of internal defects in plate type nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Kyu; Park, Nak Kyu; Baik, Sung Hoon; Lee, Yoon Sang; Cheong, Yong Moo [KAERI, Daejeon (Korea, Republic of); Kang, Young June [Chonbuk National Univ., Chonju (Korea, Republic of)

    2012-10-15

    Plate type nuclear fuel has been adopted in most research reactors. The production quality of the fuel is a key part for an efficient and stable generation of thermal energy in research reactors. Thus, a nondestructive quality inspection for the internal defects of plate type nuclear fuel is a key process during the production of nuclear fuel for safety insurance. Nondestructive quality inspections based on X rays and ultrasounds have been widely used for the defect detection of plate type nuclear fuel. X ray testing is a simple and fast inspection method, and provides an image in real time as the inspection results. Thus, the testing can be carried out by a non expert field worker. However, it is hard to detect closed type defects that should be detected during the production of plate type nuclear fuel. Ultrasonic testing is a powerful tool to detect internal defects including open type and closed type defects in plate type nuclear fuel. However, the inspection process is complicated because an immersion test should be carried out in a water tank. It is also a time consuming inspection method because area testing to acquire image is based on the scanning of the point by point inspections. Among nondestructive inspection techniques, the techniques based on laser interferometry and infrared thermography have been widely used in the detection of internal defects of plate type composite materials, such as aircraft, automotive etc. While infrared thermography technique (IRT) analyses the thermal behavior of the specimen surface, laser interferometry technique (LIT) analyses the deformation field. Both techniques are useful tools for detection and evaluation of internal defects in composite materials. Especially, the laser interferometry technique can provide the depth information of internal defects. Laser interferometry technique (LIT) is a non contact inspection method faster than thermography. Also, this technique requires less energy than thermography and the

  16. Microstructural Characterization of a Mg Matrix U-Mo Dispersion Fuel Plate Irradiated in the Advanced Test Reactor to High Fission Density: SEM Results

    Science.gov (United States)

    Keiser, Dennis D.; Jue, Jan-Fong; Miller, Brandon D.; Gan, Jian; Robinson, Adam B.; Medvedev, Pavel G.; Madden, James W.; Moore, Glenn A.

    2016-06-01

    Low-enriched (U-235 reactors. In most cases, fuel plates with Al or Al-Si alloy matrices have been tested in the Advanced Test Reactor to support this development. In addition, fuel plates with Mg as the matrix have also been tested. The benefit of using Mg as the matrix is that it potentially will not chemically interact with the U-Mo fuel particles during fabrication or irradiation, whereas with Al and Al-Si alloys such interactions will occur. Fuel plate R9R010 is a Mg matrix fuel plate that was aggressively irradiated in ATR. This fuel plate was irradiated as part of the RERTR-8 experiment at high temperature, high fission rate, and high power, up to high fission density. This paper describes the results of the scanning electron microscopy (SEM) analysis of an irradiated fuel plate using polished samples and those produced with a focused ion beam. A follow-up paper will discuss the results of transmission electron microscopy (TEM) analysis. Using SEM, it was observed that even at very aggressive irradiation conditions, negligible chemical interaction occurred between the irradiated U-7Mo fuel particles and Mg matrix; no interconnection of fission gas bubbles from fuel particle to fuel particle was observed; the interconnected fission gas bubbles that were observed in the irradiated U-7Mo particles resulted in some transport of solid fission products to the U-7Mo/Mg interface; the presence of microstructural pathways in some U-9.1 Mo particles that could allow for transport of fission gases did not result in the apparent presence of large porosity at the U-7Mo/Mg interface; and, the Mg-Al interaction layers that were present at the Mg matrix/Al 6061 cladding interface exhibited good radiation stability, i.e. no large pores.

  17. The STAT7 Code for Statistical Propagation of Uncertainties In Steady-State Thermal Hydraulics Analysis of Plate-Fueled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Floyd E. [Argonne National Lab. (ANL), Argonne, IL (United States); Hu, Lin-wen [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Nuclear Reactor Lab.; Wilson, Erik [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-12-01

    The STAT code was written to automate many of the steady-state thermal hydraulic safety calculations for the MIT research reactor, both for conversion of the reactor from high enrichment uranium fuel to low enrichment uranium fuel and for future fuel re-loads after the conversion. A Monte-Carlo statistical propagation approach is used to treat uncertainties in important parameters in the analysis. These safety calculations are ultimately intended to protect against high fuel plate temperatures due to critical heat flux or departure from nucleate boiling or onset of flow instability; but additional margin is obtained by basing the limiting safety settings on avoiding onset of nucleate boiling. STAT7 can simultaneously analyze all of the axial nodes of all of the fuel plates and all of the coolant channels for one stripe of a fuel element. The stripes run the length of the fuel, from the bottom to the top. Power splits are calculated for each axial node of each plate to determine how much of the power goes out each face of the plate. By running STAT7 multiple times, full core analysis has been performed by analyzing the margin to ONB for each axial node of each stripe of each plate of each element in the core.

  18. Evaluation of plate type fuel options for small power reactors; Avaliacao de alternativas de combustivel tipo placa para reatores de pequeno porte

    Energy Technology Data Exchange (ETDEWEB)

    Andrzejewski, Claudio de Sa

    2005-07-01

    Plate type fuels are generally used in research reactor. The utilization of this kind of configuration improves significantly the overall performance fuel. The conception of new fuels for small power reactors based in plate-type configuration needs a complete review of the safety criteria originally used to conduce power and research reactor projects. In this work, a group of safety criteria is established for the utilization of plate-type fuels in small power reactors taking into consideration the characteristics of power and research reactors. The performance characteristics of fuel elements are strongly supported by its materials properties and the adopted configuration for its fissile particles. The present work makes an orientated bibliographic investigation searching the best material properties (structural materials and fuel compounds) related to the performance fuel. Looking for good parafermionic characteristics and manufacturing exequibility associated to existing facilities in national research centres, this work proposes several alternatives of plate type fuels, considering its utilization in small power reactors: dispersions of UO{sub 2} in stainless steel, of UO{sub 2} in zircaloy, and of U-Mo alloy in zircaloy, and monolithic plates of U-Mo cladded with zircaloy. Given the strong dependency of radiation damage with temperature increase, the safety criteria related to heat transfer were verified for all the alternatives, namely the DNBR; coolant temperature lower than saturation temperature; peak meat temperature to avoid swelling; peak fuel temperature to avoid meat-matrix reaction. It was found that all alternatives meet the safety criteria including the 0.5 mm monolithic U-Mo plate cladded with zircaloy. (author)

  19. Two-Dimensional Mapping of the Calculated Fission Power for the Full-Size Fuel Plate Experiment Irradiated in the Advanced Test Reactor

    Science.gov (United States)

    Chang, G. S.; Lillo, M. A.

    2009-08-01

    The National Nuclear Security Administrations (NNSA) Reduced Enrichment for Research and Test Reactors (RERTR) program assigned to the Idaho National Laboratory (INL) the responsibility of developing and demonstrating high uranium density research reactor fuel forms to enable the use of low enriched uranium (LEU) in research and test reactors around the world. A series of full-size fuel plate experiments have been proposed for irradiation testing in the center flux trap (CFT) position of the Advanced Test Reactor (ATR). These full-size fuel plate tests are designated as the AFIP tests. The AFIP nominal fuel zone is rectangular in shape having a designed length of 21.5-in (54.61-cm), width of 1.6-in (4.064-cm), and uniform thickness of 0.014-in (0.03556-cm). This gives a nominal fuel zone volume of 0.482 in3 (7.89 cm3) per fuel plate. The AFIP test assembly has two test positions. Each test position is designed to hold 2 full-size plates, for a total of 4 full-size plates per test assembly. The AFIP test plates will be irradiated at a peak surface heat flux of about 350 W/cm2 and discharged at a peak U-235 burn-up of about 70 at.%. Based on limited irradiation testing of the monolithic (U-10Mo) fuel form, it is desirable to keep the peak fuel temperature below 250°C to achieve this, it will be necessary to keep plate heat fluxes below 500 W/cm2. Due to the heavy U-235 loading and a plate width of 1.6-in (4.064-cm), the neutron self-shielding will increase the local-to-average-ratio (L2AR) fission power near the sides of the fuel plates. To demonstrate that the AFIP experiment will meet the ATR safety requirements, a very detailed 2-dimensional (2D) Y-Z fission power profile was evaluated in order to best predict the fuel plate temperature distribution. The ability to accurately predict fuel plate power and burnup are essential to both the design of the AFIP tests as well as evaluation of the irradiated fuel performance. To support this need, a detailed MCNP Y

  20. What caused the breach? An examination of use of information technology and health data breaches.

    Science.gov (United States)

    Wikina, Suanu Bliss

    2014-01-01

    Data breaches arising from theft, loss, unauthorized access/disclosure, improper disclosure, or hacking incidents involving personal health information continue to increase every year. As of September 2013, reported breaches affecting individuals reached close to 27 million since 2009, when compilation of records on breaches began. These breaches, which involved 674 covered entities and 153 business associates, involved computer systems and networks, desktop computers, laptops, paper, e-mail, electronic health records, and removable/portable devices (CDs, USBs, x-ray films, backup tapes, etc.). Even with the increased use of health information technology by health institutions and allied businesses, theft and loss (not hacking) constitute the major types of data breaches encountered. Removable/portable devices, desktop computers, and laptops were the top sources or locations of the breached information, while the top six states-Virginia, Illinois, California, Florida, New York, and Tennessee-in terms of the number of reported breaches accounted for nearly 75 percent of the total individual breaches, 33 percent of breaches in covered entities, and about 30 percent of the total breaches involving business associates.

  1. Neutron diffraction measurement of residual stresses, dislocation density and texture in Zr-bonded U-10Mo "mini" fuel foils and plates

    Science.gov (United States)

    Brown, D. W.; Okuniewski, M. A.; Sisneros, T. A.; Clausen, B.; Moore, G. A.; Balogh, L.

    2016-12-01

    Al clad U-10Mo fuel plates are being considered for conversion of several research reactors from high-enriched to low-enriched U fuel. Neutron diffraction measurements of the textures, residual phase stresses, and dislocation densities in the individual phases of the mini-foils throughout several processing steps and following hot-isostatic pressing to the Al cladding, have been completed. Recovery and recrystallization of the bare U-10Mo fuel foil, as indicated by the dislocation density and texture, are observed depending on the state of the material prior to annealing and the duration and temperature of the annealing process. In general, the cladding procedure significantly reduces the dislocation density, but the final state of the clad plate, both texture and dislocation density, depends strongly on the final processing step of the fuel foil. In contrast, the residual stress state of the final plate is dominated by the thermal expansion mismatch of the constituent materials.

  2. Multilayer graphene for long-term corrosion protection of stainless steel bipolar plates for polymer electrolyte membrane fuel cell

    DEFF Research Database (Denmark)

    Stoot, Adam Carsten; Camilli, Luca; Spiegelhauer, Susie Ann

    2015-01-01

    /SS, both samples exhibiting a similar trend, thus questioning the short-term positive effect of graphene coatings. However, partial immersion in boiling seawater for three weeks reveals a clear superiority of the graphene coating with respect to steel just protected by Ni. After the test, the graphene film......Abstract Motivated by similar investigations recently published (Pu et al., 2015), we report a comparative corrosion study of three sets of samples relevant as bipolar plates for polymer electrolyte fuel cells: stainless steel, stainless steel with a nickel seed layer (Ni/SS) and stainless steel...

  3. Data security breaches and privacy in Europe

    CERN Document Server

    Wong, Rebecca

    2013-01-01

    Data Security Breaches and Privacy in Europe aims to consider data protection and cybersecurity issues; more specifically, it aims to provide a fruitful discussion on data security breaches. A detailed analysis of the European Data Protection framework will be examined. In particular, the Data Protection Directive 95/45/EC, the Directive on Privacy and Electronic Communications and the proposed changes under the Data Protection Regulation (data breach notifications) and its implications are considered. This is followed by an examination of the Directive on Attacks against information systems a

  4. Fabrication of CNT Dispersion Fluid by Wet-Jet Milling Method for Coating on Bipolar Plate of Fuel Cell

    Directory of Open Access Journals (Sweden)

    Anas Almowarai

    2015-01-01

    Full Text Available Water based carbon nanotube (CNT dispersion was produced by wet-jet milling method. Commercial CNT was originally agglomerated at the particle size of less than 1 mm. The wet-jet milling process exfoliated CNTs from the agglomerates and dispersed them into water. Sedimentation of the CNTs in the dispersion fluid was not observed for more than a month. The produced CNT dispersion was characterized by the SEM and the viscometer. CNT/PTFE composite film was formed with the CNT dispersion in this study. The electrical conductivity of the composite film increased to 10 times when the CNT dispersion, which was produced by the wet-jet milling method, was used as a constituent of the film. Moreover, the composite film was applied to bipolar plate of fuel cell and increased the output power of the fuel cell to 1.3 times.

  5. Hot Isostatic Press Can Optimization for Aluminum Cladding of U-10Mo Reactor Fuel Plates: FY12 Final Report and FY13 Update

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, Kester D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Crapps, Justin M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Scott, Jeffrey E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Aikin, Beverly [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Vargas, Victor D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dvornak, Matthew J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Duffield, Andrew N. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Weinberg, Richard Y. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Alexander, David J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Montalvo, Joel D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Hudson, Richard W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Mihaila, Bogdan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Liu, Cheng [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lovato, Manuel L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dombrowski, David E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-08-26

    Currently, the proposed processing path for low enriched uranium – 10 wt. pct. molybdenum alloy (LEU-10Mo) monolithic fuel plates for high power research and test reactors includes hot isostatic pressing (HIP) to bond the aluminum cladding that encapsulates the fuel foil. Initial HIP experiments were performed at Idaho National Laboratory (INL) on approximately ¼ scale “mini” fuel plate samples using a HIP can design intended for these smaller experimental trials. These experiments showed that, with the addition of a co-rolled zirconium diffusion barrier on the LEU-10Mo alloy fuel foil, the HIP bonding process is a viable method for producing monolithic fuel plates. Further experimental trials at Los Alamos National Laboratory (LANL) effectively scaled-up the “mini” can design to produce full-size fuel prototypic plates. This report summarizes current efforts at LANL to produce a HIP can design that is further optimized for higher volume production runs. The production-optimized HIP can design goals were determined by LANL and Babcock & Wilcox (B&W) to include maintaining or improving the quality of the fuel plates produced with the baseline scaled-up mini can design, while minimizing material usage, improving dimensional stability, easing assembly and disassembly, eliminating machining, and significantly reducing welding. The initial small-scale experiments described in this report show that a formed-can approach can achieve the goals described above. Future work includes scaling the formed-can approach to full-size fuel plates, and current progress toward this goal is also summarized here.

  6. Investigation of bio-inspired flow channel designs for bipolar plates in proton exchange membrane fuel cells

    Science.gov (United States)

    Kloess, Jason P.; Wang, Xia; Liu, Joan; Shi, Zhongying; Guessous, Laila

    Proton exchange membrane (PEM) fuel cell performance is directly related to the flow channel design on bipolar plates. Power gains can be found by varying the type, size, or arrangement of channels. The objective of this paper is to present two new flow channel patterns: a leaf design and a lung design. These bio-inspired designs combine the advantages of the existing serpentine and interdigitated patterns with inspiration from patterns found in nature. Both numerical simulation and experimental testing have been conducted to investigate the effects of two new flow channel patterns on fuel cell performance. From the numerical simulation, it was found that there is a lower pressure drop from the inlet to outlet in the leaf or lung design than the existing serpentine or interdigitated flow patterns. The flow diffusion to the gas diffusion layer was found be to more uniform for the new flow channel patterns. A 25 cm 2 fuel cell was assembled and tested for four different flow channels: leaf, lung, serpentine and interdigitated. The polarization curve has been obtained under different operating conditions. It was found that the fuel cell with either leaf or lung design performs better than the convectional flow channel design under the same operating conditions. Both the leaf and lung design show improvements over previous designs by up to 30% in peak power density.

  7. Investigation of bio-inspired flow channel designs for bipolar plates in proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kloess, Jason P. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI (United States); Wang, Xia; Shi, Zhongying; Guessous, Laila [Department of Mechanical Engineering, Oakland University, Rochester, MI 48309 (United States); Liu, Joan [Department of Mechanical Engineering, Olin College of Engineering, MA (United States)

    2009-03-01

    Proton exchange membrane (PEM) fuel cell performance is directly related to the flow channel design on bipolar plates. Power gains can be found by varying the type, size, or arrangement of channels. The objective of this paper is to present two new flow channel patterns: a leaf design and a lung design. These bio-inspired designs combine the advantages of the existing serpentine and interdigitated patterns with inspiration from patterns found in nature. Both numerical simulation and experimental testing have been conducted to investigate the effects of two new flow channel patterns on fuel cell performance. From the numerical simulation, it was found that there is a lower pressure drop from the inlet to outlet in the leaf or lung design than the existing serpentine or interdigitated flow patterns. The flow diffusion to the gas diffusion layer was found be to more uniform for the new flow channel patterns. A 25 cm{sup 2} fuel cell was assembled and tested for four different flow channels: leaf, lung, serpentine and interdigitated. The polarization curve has been obtained under different operating conditions. It was found that the fuel cell with either leaf or lung design performs better than the convectional flow channel design under the same operating conditions. Both the leaf and lung design show improvements over previous designs by up to 30% in peak power density. (author)

  8. A Novel Heat Pipe Plate for Passive Thermal Control of Fuel Cells Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR project aims to develop a lightweight, highly thermally and electrically conductive heat pipe plate for passive removal of the heat from the individual...

  9. Corporate governance: remedying and ratifying directors' breaches

    OpenAIRE

    Worthington, Sarah

    2000-01-01

    Extent to which company may relax scope and content of directors' duties, whether it can exonerate directors who default on their duties and whether it can ratify actions of defaulting directors and determine remedy for breach of duty.

  10. How to Survive a Data Breach

    CERN Document Server

    Mitchell, Stewart

    2009-01-01

    This is the downloadable version of this new pocket guide which provides essential support for organisations who would like to have a tried and tested procedure in place for dealing with data breaches.

  11. Characterisation of micro direct methanol fuel cells with silicon plate supported integrated ionomer membranes

    DEFF Research Database (Denmark)

    Larsen, Jackie Vincent; Dalslet, Bjarke Thomas; Kallesee, C.

    2013-01-01

    This work deals with the investigation and fabrication of Micro Direct Methanol Fuel Cells (μDMFC). They are investigated as a possible alternative for zinc-air batteries in small size consumer devices such as hearing aids. In such devices the conventional rechargeable batteries such as lithium......-ion batteries have insufficiently low energy density in the range 240 Wh/L to 300 Wh/L Methanol is a promising fuel for such devices due to the high energy density, with pure methanol having an energy density of 4400 Wh/L. Using a liquid fuel also allows refueling, which can be achieved much faster than battery...

  12. On the Importance of Default Breach Remedies

    OpenAIRE

    Sloof, Randolph; Oosterbeek, Hessel; Sonnemans, Joep

    2006-01-01

    Theory predicts that default breach remedies are immaterial whenever contracting costs are negligible. Some experimental studies, however, suggest that in practice default rules do matter, as they may affect parties' preferences over contract terms. This paper presents results from an experiment designed to address the importance of default breach remedies for actual contract outcomes. We find that default rules do have an influence. The reason for this is not that contract proposals and/or r...

  13. SWOT analysis of breach models for common dike failure mechanisms

    NARCIS (Netherlands)

    Peeters, P.; Van Hoestenberghe, T.; Vincke, L.; Visser, P.J.

    2011-01-01

    The use of breach models includes two tasks: predicting breach characteristics and estimating flow through the breach. Strengths and weaknesses as well as opportunities and threats of different simplified and detailed physically-based breach models are listed following theoretical and practical crit

  14. 16 CFR 318.3 - Breach notification requirement.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Breach notification requirement. 318.3... HEALTH BREACH NOTIFICATION RULE § 318.3 Breach notification requirement. (a) In general. In accordance... breach of security of unsecured PHR identifiable health information that is in a personal health...

  15. SWOT analysis of breach models for common dike failure mechanisms

    NARCIS (Netherlands)

    Peeters, P.; Van Hoestenberghe, T.; Vincke, L.; Visser, P.J.

    2011-01-01

    The use of breach models includes two tasks: predicting breach characteristics and estimating flow through the breach. Strengths and weaknesses as well as opportunities and threats of different simplified and detailed physically-based breach models are listed following theoretical and practical

  16. Neutron Diffraction Measurement of Residual Stresses, Dislocation Density and Texture in Zr-bonded U-10Mo ''Mini'' Fuel Foils and Plates

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Donald W. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Okuniewski, M. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Sisneros, Thomas A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Clausen, Bjorn [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Moore, G. A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Balogh, L [Queen' s Univ., Kingston, ON (Canada)

    2014-08-07

    Aluminum clad monolithic uranium 10 weight percent molybdenum (U-10Mo) fuel plates are being considered for conversion of several research and test nuclear reactors from high-enriched to low-enriched uranium fuel due to the inherently high density of fissile material. Comprehensive neutron diffraction measurements of the evolution of the textures, residual phase stresses, and dislocation densities in the individual phases of the mini-foils throughout several processing steps and following hot-isostatic pressing to the Al cladding, have been completed. Recovery and recrystallization of the bare U-10Mo fuel foil, as indicated by the dislocation density and texture, are observed depending on the state of the material prior to annealing and the duration and temperature of the annealing process. In general, the HIP procedure significantly reduces the dislocation density, but the final state of the clad plate, both texture and dislocation density, depends strongly on the final processing step of the fuel foil. In contrast, the residual stresses in the clad fuel plate do not depend strongly on the final processing step of the bare foil prior to HIP bonding. Rather, the residual stresses are dominated by the thermal expansion mismatch of the constituent materials of the fuel plate.

  17. Heat Transfer Calculation on Plate-Type Fuel Assembly of High Flux Research Reactor

    Directory of Open Access Journals (Sweden)

    Daxin Gong

    2015-01-01

    Full Text Available Heat transfer characteristics of fuel assemblies for a high flux research reactor with a neutron trap are numerically investigated in this study. Single-phase turbulence flow is calculated by a commercial code, FLUENT, where the computational objective covers standard and control fuel assemblies. The simulation is carried out with an inlet coolant velocity varying from 4.5 m/s to 7.5 m/s in hot assemblies. The results indicate that the cladding temperature is always lower than the saturation temperature in the calculated ranges. The temperature rise in the control fuel assembly is smaller than that of the standard fuel assembly. Additionally, the assembly with a hot spot is specially studied, and the safety of the research reactor is also approved.

  18. Electroless Ni-Cu-P/nano-graphite composite coatings for bipolar plates of proton exchange membrane fuel cells

    Science.gov (United States)

    Lee, Cheng-Kuo

    2012-12-01

    This study evaluates the effects of an electroless Ni-Cu-P/nano-graphite composite coating on the surface characteristics of anodized 5083 aluminum alloy, including electrical resistivity, corrosion resistance of the alloy in a simulated solution of 0.5 M H2SO4 + 2 ppm NaF in polymer electrolyte membrane fuel cells (PEMFCs). The co-deposition and adhesion of the composite coatings on a 5083 substrate are enhanced by an anodizing process. The electroless Ni-Cu-P plating solution is prepared by adding different CuSO4·5H2O concentrations into the electroless Ni-P plating solution and adding nano-graphite (15-40 nm) particles to form the Ni-Cu-P/nano-graphite composite coatings. Experimental results indicate that the electroless Ni-Cu-P/nano-graphite composite coating enhances the hardness, conductivity, corrosion resistance of the 5083 substrate in the corrosive solution. The anodizing treatment enhances the electroless composite coatings by providing better uniformity, density, and adhesion compared to substrate without anodizing treatment. The electroless Ni-Cu-P/nano-graphite composite coating deposited on the optimal anodized 5083 substrate at a low CuSO4·5H2O concentration of 0.25 g l-1 with 20 g l-1 nano-graphite added have the best surface structure, highest hardness, electrical conductivity and corrosion resistance. Therefore, this novel electroless Ni-Cu-P/nano-graphite composite-coated 5083 aluminum alloy has potential applications in bipolar plates of PEM fuel cells.

  19. Synergy effects of hybrid carbon system on properties of composite bipolar plates for fuel cells

    Science.gov (United States)

    Kim, Jong Wan; Kim, Nam Hoon; Kuilla, Tapas; Kim, Tae Jin; Rhee, Kyong Yop; Lee, Joong Hee

    A hybrid carbon system of graphite powder (GP) and continuous carbon fibre fabric (CFF) is used for an epoxy composite to improve the electrical conductivity, mechanical properties and mouldability of a composite bipolar plate. These improvements are achieved simultaneously by inserting several layers of CFF into the GP/epoxy composite to enhance the mechanical properties and in-plane conductivity. The electrical properties, flexural strength and mouldability of the composite plates are measured as a function of conducting filler content and number of CFF layers. The composites show improved electrical conductivity, flexural properties and mouldability. Composites with 70-75 vol.% carbon fillers have the highest electrical conductivity with reasonable flexural properties. These results suggest that the poor mouldability and low through-plane electrical conductivity of the continuous fibre composite bipolar plate, as well as the weak flexural properties of GP composites, can be overcome by incorporating a GP/CFF hybrid system.

  20. A review of composite and metallic bipolar plates in proton exchange membrane fuel cell: Materials, fabrication, and material selection

    Science.gov (United States)

    Taherian, Reza

    2014-11-01

    Proton exchange membrane (PEM) fuel cells offer exceptional potential for a clean, efficient, and reliable power source. The bipolar plate (BP) is a key component in this device, as it connects each cell electrically, supplies reactant gases to both anode and cathode, and removes reaction products from the cell. BPs have primarily been fabricated from high-density graphite, but in recent years, much attention has been paid to develop the cost-effective and feasible alternative materials. Recently, two different classes of materials have been attracted attention: metals and composite materials. This paper offers a comprehensive review of the current researches being carried out on the metallic and composite BPs, covering materials and fabrication methods. In this research, the phenomenon of ionic contamination due to the release of the corrosion products of metallic BP and relative impact on the durability as well as performance of PEM fuel cells is extensively investigated. Furthermore, in this paper, upon several effective parameters on commercialization of PEM fuel cells, such as stack cost, weight, volume, durability, strength, ohmic resistance, and ionic contamination, a material selection is performed among the most common BPs currently being used. This material selection is conducted by using Simple Additive Weighting Method (SAWM).

  1. Thermal-hydraulic behavior of physical quantities at critical velocities in a nuclear research reactor core channel using plate type fuel

    Directory of Open Access Journals (Sweden)

    Sidi Ali Kamel

    2012-01-01

    Full Text Available The thermal-hydraulic study presented here relates to a channel of a nuclear reactor core. This channel is defined as being the space between two fuel plates where a coolant fluid flows. The flow velocity of this coolant should not generate vibrations in fuel plates. The aim of this study is to know the distribution of the temperature in the fuel plates, in the cladding and in the coolant fluid at the critical velocities of Miller, of Wambsganss, and of Cekirge and Ural. The velocity expressions given by these authors are function of the geometry of the fuel plate, the mechanical characteristics of the fuel plate’s material and the thermal characteristics of the coolant fluid. The thermal-hydraulic study is made under steady-state; the equation set-up of the thermal problem is made according to El Wakil and to Delhaye. Once the equation set-up is validated, the three critical velocities are calculated and then used in the calculations of the different temperature profiles. The average heat flux and the critical heat flux are evaluated for each critical velocity and their ratio reported. The recommended critical velocity to be used in nuclear channel calculations is that of Wambsganss. The mathematical model used is more precise and all the physical quantities, when using this critical velocity, stay in safe margins.

  2. Mechanical behaviors of the dispersion nuclear fuel plates induced by fuel particle swelling and thermal effect I: Effects of variations of the fuel particle volume fractions

    Science.gov (United States)

    Wang, Qiming; Yan, Xiaoqing; Ding, Shurong; Huo, Yongzhong

    2010-05-01

    A new method of modeling the in-pile mechanical behaviors of dispersion nuclear fuel elements is proposed. Considering the irradiation swelling together with the thermal effect, numerical simulations of the in-pile mechanical behaviors are performed with the developed finite element models for different fuel particle volume fractions of the fuel meat. The effects of the particle volume fractions on the mechanical performances of the fuel element are studied. The research results indicate that: (1) the maximum Mises stresses and equivalent plastic strains at the matrix increase with the particle volume fractions at each burnup; the locations of the maximum first principal stresses shift with increasing burnup; at low burnups, the maximum first principal stresses increase with the particle volume fractions; while at high burnups, the 20% volume fraction case holds the lowest value; (2) at the cladding, the maximum equivalent plastic strains and the tensile principal stresses increase with the particle volume fractions; while the maximum Mises stresses do not follow this order at high burnups; (3) the maximum Mises stresses at the fuel particles increase with the particle volume fractions, and the particles will engender plastic strains until the particle volume fraction reaches high enough.

  3. Research on the interfacial behaviors of plate-type dispersion nuclear fuel elements

    Science.gov (United States)

    Wang, Qiming; Yan, Xiaoqing; Ding, Shurong; Huo, Yongzhong

    2010-04-01

    The three-dimensional constitutive relations are constructed, respectively, for the fuel particles, the metal matrix and the cladding of dispersion nuclear fuel elements, allowing for the effects of large deformation and thermal-elastoplasticity. According to the constitutive relations, the method of modeling their irradiation behaviors in ABAQUS is developed and validated. Numerical simulations of the interfacial performances between the fuel meat and the cladding are implemented with the developed finite element models for different micro-structures of the fuel meat. The research results indicate that: (1) the interfacial tensile stresses and shear stresses for some cases will increase with burnup, but the relative stresses will decrease with burnup for some micro-structures; (2) at the lower burnups, the interfacial stresses increase with the particle sizes and the particle volume fractions; however, it is not the case at the higher burnups; (3) the particle distribution characteristics distinctly affect the interfacial stresses, and the face-centered cubic case has the best interfacial performance of the three considered cases.

  4. Gamma spectrometry of irradiated fuel plates; Espectrometria gama em elementos combustiveis tipo placa irradiados

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis A.A.; Zeituni, Carlos A.; Perrotta, Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Engenharia do Nucleo

    1997-10-01

    This work describes the fundamental aspects of a method which uses gamma-ray spectroscopy in order to perform non-destructive burnup measurements in irradiated MTR fuel elements. Experiments based on such method will be conducted at the storage pool area of the IEA-R1 research reactor. Some preliminary results are presented. (author). 10 refs., 5 figs., 1 tab.

  5. Surface composition effect of nitriding Ni-free stainless steel as bipolar plate of polymer electrolyte fuel cell

    Science.gov (United States)

    Yu, Yang; Shironita, Sayoko; Nakatsuyama, Kunio; Souma, Kenichi; Umeda, Minoru

    2016-12-01

    In order to increase the corrosion resistance of low cost Ni-free SUS445 stainless steel as the bipolar plate of a polymer electrolyte fuel cell, a nitriding surface treatment experiment was carried out in a nitrogen atmosphere under vacuum conditions, while an Ar atmosphere was used for comparison. The electrochemical performance, microstructure, surface chemical composition and morphology of the sample before and after the electrochemical measurements were investigated using linear sweep voltammetry (LSV), X-ray diffraction (XRD), glow discharge optical emission spectroscopy (GDS) and laser scanning microscopy (LSM) measurements. The results confirmed that the nitriding heat treatment not only increased the corrosion resistance, but also improved the surface conductivity of the Ni-free SUS445 stainless steel. In contrast, the corrosion resistance of the SUS445 stainless steel decreased after heat treatment in an Ar atmosphere. These results could be explained by the different surface compositions between these samples.

  6. Ex situ evaluation of nanometer range gold coating on stainless steel substrate for automotive polymer electrolyte membrane fuel cell bipolar plate

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, A.; Ricketts, M.; Hirano, S. [Ford Motor Company, 2101 Village Road, Dearborn, MI 48121 (United States)

    2010-03-01

    The bipolar plate in polymer electrolyte membrane (PEM) fuel cell helps to feed reactant gases to the membrane electrode assembly (MEA) and collect current from the MEA. To facilitate these functions, the bipolar plate material should exhibit excellent electrical conductivity and corrosion resistance under fuel cell operating conditions, and simultaneously be of low-cost to meet commercialization enabling targets for automotive fuel cells. In the present work, we focus on the benchmarking of 10 nm gold coated SS316L (a.k.a. Au Nanoclad {sup registered}) bipolar plate material through ex situ tests, which is provided by Daido Steel (Japan). The use of nanometer range Au coatings help to retain the noble properties of gold while significantly reducing the cost of the bipolar plate. The area specific resistance of the flat sample is 0.9 m{omega} cm{sup 2} while that for the formed bipolar plate is 6.3 m{omega} cm{sup 2} at compaction force of 60 N cm{sup -2}. The corrosion current density was less than 1 {mu}A cm{sup -2} at 0.8 V/NHE with air sparge simulating cathodic conditions. Additionally, gold coated SS316L showed anodic passivation of SS316L, thereby exhibiting robustness towards coating defects including surface scratches that may originate during the manufacturing of the bipolar plate. These series of ex situ tests indicate that 10 nm gold coated SS316L has good potential to be considered for commercial bipolar plates in automotive fuel cell stack. (author)

  7. Mechanical Interactions between Gas Diffusion Layers and Bipolar Plates in low Temperature Fuel Cells

    OpenAIRE

    Knöri, Torsten; Schulze, Mathias; Gülzow, Erich

    2007-01-01

    In contrast to stiff backing materials (e.g. carbon paper) softer ones like carbon cloth are compressed over the ribs of the gas distributors or impressed into the channels when the PEFC is assembled. During fuel cell optimisation the interactions between the gas diffusion layer and the flow field are frequently neglected; hence flow fields as well as gas diffusion layers are commonly optimized independently. The DLR has investigated these interactions with a two-stage approach: At firs...

  8. Alumina-carbon nanofibers nanocomposites obtained by spark plasma sintering for proton exchange membrane fuel cell bipolar plates

    Energy Technology Data Exchange (ETDEWEB)

    Borrell, A.; Torrecillas, R. [Centro de Investigacion en Nanomateriales y Nanotecnologia (CINN) Consejo Superior de Investigaciones Cientificas, Universidad de Oviedo, Principado de Asturias, Parque Tecnologico de Asturias, Llanera Asturias (Spain); Rocha, V.G.; Fernandez, A. [ITMA Materials Technology, Parque Tecnologico de Asturias, Llanera Asturias (Spain)

    2012-08-15

    There is an increasing demand of multifunctional materials for a wide variety of technological developments. Bipolar plates for proton exchange membrane fuel cells are an example of complex functionality components that must show among other properties high mechanical strength, electrical, and thermal conductivity. The present research explored the possibility of using alumina-carbon nanofibers (CNFs) nanocomposites for this purpose. In this study, it was studied for the first time the whole range of powder compositions in this system. Homogeneous powders mixtures were prepared and subsequently sintered by spark plasma sintering. The materials obtained were thoroughly characterized and compared in terms of properties required to be used as bipolar plates. The control on material microstructure and composition allows designing materials where mechanical or electrical performances are enhanced. A 50/50 vol.% alumina-CNFs composite appears to be a very promising material for this kind of application. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Optimization of the polypyrrole-coating parameters for proton exchange membrane fuel cell bipolar plates using the Taguchi method

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yan; Northwood, Derek O. [Department of Mechanical, Automotive, and Materials Engineering, University of Windsor, 401 Sunset Avenue, Windsor, Ontario (Canada)

    2008-10-15

    In order to overcome the high price, weight and volume of non-porous graphite bipolar plates, metallic bipolar plates are being investigated as a substitute material. However, metallic materials can corrode under proton exchange membrane fuel cell (PEMFC) working conditions, leading to a degradation in the performance of the membrane. Previous work had shown that a polypyrrole coating on SS316L can significantly increase the corrosion resistance of the base material. In this study, a Taguchi design of experiment method was used to optimize the process parameters for the polypyrrole coating so as to produce the maximum corrosion resistance. Potentiodynamic and potentiostatic tests were used to determine the corrosion resistance of the polypyrrole-coated SS316L. Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) was used to characterize the coating thickness and coating appearance. Inductively coupled plasma optical emission spectroscopy (ICP-OES) was used to determine the metal ion concentration in the solution after corrosion. The interfacial contact resistance of SS316L with carbon paper was measured both before and after coating with polypyrrole. (author)

  10. Thermal-hydraulic Fortran program for steady-state calculations of plate-type fuel research reactors

    Directory of Open Access Journals (Sweden)

    Khedr Ahmed

    2008-01-01

    Full Text Available The safety assessment of research and power reactors is a continuous process covering their lifespan and requiring verified and validated codes. Power reactor codes all over the world are well established and qualified against real measuring data and qualified experimental facilities. These codes are usually sophisticated, require special skills and consume a lot of running time. On the other hand, most research reactor codes still require much more data for validation and qualification. It is, therefore, of benefit to any regulatory body to develop its own codes for the review and assessment of research reactors. The present paper introduces a simple, one-dimensional Fortran program called THDSN for steady-state thermal-hydraulic calculations of plate-type fuel research reactors. Besides calculating the fuel and coolant temperature distributions and pressure gradients in an average and hot channel, the program calculates the safety limits and margins against the critical phenomena encountered in research reactors, such as the onset of nucleate boiling, critical heat flux and flow instability. Well known thermal-hydraulic correlations for calculating the safety parameters and several formulas for the heat transfer coefficient have been used. The THDSN program was verified by comparing its results for 2 and 10 MW benchmark reactors with those published in IAEA publications and a good agreement was found. Also, the results of the program are compared with those published for other programs, such as the PARET and TERMIC.

  11. The upgrade and conversion of the ET-RR-1 research reactor using plate type fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Ashoub, N. [Reactor Physics Dept., Nuclear Research Center, Atomic Energy Authority, Cairo (Egypt); Saleh, H.G. [Faculty of Girls for Arts and Education, Ain-Shams Univ., Cairo (Egypt)

    2001-11-01

    The ET-RR-1 research reactor has been operated at 2 MW since 1961 using EK-10 fuel elements with 10% enriched uranium. The reactor has been used for nuclear applied research and isotope production. In order to upgrade the reactor power to a reasonable limit facing up-to-date uses, core conversion by a new type of fuel element available is necessary. Two fuel elements in plate type are suggested in this study to be used in the ET-RR-1 reactor core rather than the utilized ones. The first element has a dimension of 8 x 8 x 50 cm and consists of 19.7% enriched uranium, which is typical for that utilized in the ET-RR-2 reactor, but with a different length. The other element is proposed with a dimension of 7 x 7 x 50 cm and has the same uranium enrichment. To accomplish safety requirements for these fuel elements, thermal-hydraulic evaluation has been carried out using the PARET code. To reach a core conversion of the ET-RR-1 reactor with the above two types of fuel elements, neutronic calculations have been performed using WIMSD4, DIXY2 and EREBUS codes. Some important nuclear parameters needed in the physical design of the reactor were calculated and included in this study. (orig.) [German] Der ET-RR-1 Forschungsreaktor wird seit 1961 unter Verwendung von EK-10 Brennelementen mit einer Leistung von 2 MW betrieben. Der Reaktor wird in der angewandten Forschung und zur Isotopenherstellung eingesetzt. Um die Reaktorleistung im Hinblick auf eine zeitgemaesse Nutzung der Anlage in einem vernuenftigen Mass zu erhoehen, ist eine Umwandlung des Kerns durch Verwendung neuartiger Brennelemente noetig. In der vorliegenden Untersuchung wird vorgeschlagen, anstelle der z. Z. verwendeten Elemente zwei neue, plattenfoermige Brennelemente zu verwenden. Das erste Element hat eine Groesse von 8 x 8 x 50 cm und besteht aus 19,7% angereichertem Uran, was den im ET-RR-2 Reaktor verwendeten Elementen entspricht, allerdings mit einer anderen Groesse. Das zweite Element hat die gleiche

  12. Anticorrosion Coating of Carbon Nanotube/Polytetrafluoroethylene Composite Film on the Stainless Steel Bipolar Plate for Proton Exchange Membrane Fuel Cells

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Show

    2013-01-01

    Full Text Available Composite film of carbon nanotube (CNT and polytetrafluoroethylene (PTFE was formed from dispersion fluids of CNT and PTFE. The composite film showed high electrical conductivity in the range of 0.1–13 S/cm and hydrophobic nature. This composite film was applied to stainless steel (SS bipolar plates of the proton exchange membrane fuel cell (PEMFC as anticorrosion film. This coating decreased the contact resistance between the surface of the bipolar plate and the membrane electrode assembly (MEA of the PEMFC. The output power of the fuel cell is increased by 1.6 times because the decrease in the contact resistance decreases the series resistance of the PEMFC. Moreover, the coating of this composite film protects the bipolar plate from the surface corrosion.

  13. Effect of filler content on the properties of expanded- graphite-based composite bipolar plates for application in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Masand, Aakash; Borah, Munu; Pathak, Abhishek K.; Dhakate, Sanjay R.

    2017-09-01

    Minimization of the weight and volume of a hydrogen-based PEM fuel cell stack is an essential area of research for the development and commercialization of PEMFCs for various applications. Graphite-based composite bipolar plates have significant advantages over conventional metallic bipolar plates due to their corrosion resistivity and low cost. On the other hand, expanded graphite is seen to be a potential candidate for facilitating the required electrical, thermal and mechanical properties of bipolar plates with a low density. Therefore, in the present study, the focus is on minimization of the high loading of graphite and optimizes its composition to meet the target properties of bipolar plates as per the USDOE target. Three types of expanded graphite (EG)-phenolic-resin-based composite bipolar plates were developed by partially replacing the expanded graphite content with natural graphite (NG) and carbon black as an additional filler. The three types of composite plate with the reinforcing constituent ratio EG:NG:R (25:25:50) give a bending strength of 49 MPa, a modulus of ~6 GPa, electrical conductivity  >100 S cm‑1, a shore hardness of 55 and a bulk density of 1.55 g/cc. The 50 wt% loading of resin is sufficient to wet the 50 wt% filler content in the composite plate. This study gives an insight into using hybrid reinforcements in order to achieve the desired properties of bipolar plates.

  14. Development of a brazing process for the production of water- cooled bipolar plates made of chromium-coated metal foils for PEM fuel cells

    Science.gov (United States)

    Mueller, M.; Hoehlich, D.; Scharf, I.; Lampke, T.; Hollaender, U.; Maier, H. J.

    2016-03-01

    Beside lithium batteries, PEM fuel cells are the most promising strategy as a power source to achieve the targets for introducing and increasing the usage of electric vehicles. Due to limited space and weight problems, water cooled, metallic bipolar plates in a fuel cell metal stack are preferred in motor vehicles. These plates are stamped metal sheets with a complex structure, interconnected media-tight. To meet the multiple tasks and requirements in use, complex and expensive combinations of materials are currently in use (carbon fiber composites, graphite, gold-plated nickel, stainless and acid resistant steel). The production of such plates is expensive as it is connected with considerable effort or the usage of precious metals. As an alternative, metalloid nitrides (CrN, VN, W2N, etc.) show a high chemical resistance, hardness and a good conductivity. So this material category meets the basic requirements of a top layer. However, the standard methods for their production (PVD, CVD) are expensive and have a slow deposition rate and a lower layer thicknesses. Because of these limitations, a full functionality over the life cycle of a bipolar plate is not guaranteed. The contribution shows the development and quantification of an alternative production process for bipolar plates. The expectation is to get significant advantages from the combination of chromium electrodeposition and thermochemical treatment to form chromium nitrides. Both processes are well researched and suitable for series production. The thermochemical treatment of the chromium layer also enables a process-integrated brazing.

  15. On the importance of default breach remedies

    NARCIS (Netherlands)

    Sloof, R.; Oosterbeek, H.; Sonnemans, J.

    2007-01-01

    Theory predicts that default breach remedies are immaterial whenever contracting costs are negligible. Some experimental studies, however, suggest that in practice default rules do matter, as they may affect parties' preferences over contract terms. This paper presents results from an experiment

  16. 7 CFR 3431.21 - Breach.

    Science.gov (United States)

    2010-01-01

    ... Regulations of the Department of Agriculture (Continued) COOPERATIVE STATE RESEARCH, EDUCATION, AND EXTENSION SERVICE, DEPARTMENT OF AGRICULTURE VETERINARY MEDICINE LOAN REPAYMENT PROGRAM Administration of the Veterinary Medicine Loan Repayment Program § 3431.21 Breach. (a) General. If a program participant fails to...

  17. On the importance of default breach remedies

    NARCIS (Netherlands)

    Sloof, R.; Oosterbeek, H.; Sonnemans, J.

    2007-01-01

    Theory predicts that default breach remedies are immaterial whenever contracting costs are negligible. Some experimental studies, however, suggest that in practice default rules do matter, as they may affect parties' preferences over contract terms. This paper presents results from an experiment des

  18. Mass Transfer Model for a Breached Waste Package

    Energy Technology Data Exchange (ETDEWEB)

    C. Hsu; J. McClure

    2004-07-26

    The degradation of waste packages, which are used for the disposal of spent nuclear fuel in the repository, can result in configurations that may increase the probability of criticality. A mass transfer model is developed for a breached waste package to account for the entrainment of insoluble particles. In combination with radionuclide decay, soluble advection, and colloidal transport, a complete mass balance of nuclides in the waste package becomes available. The entrainment equations are derived from dimensionless parameters such as drag coefficient and Reynolds number and based on the assumption that insoluble particles are subjected to buoyant force, gravitational force, and drag force only. Particle size distributions are utilized to calculate entrainment concentration along with geochemistry model abstraction to calculate soluble concentration, and colloid model abstraction to calculate colloid concentration and radionuclide sorption. Results are compared with base case geochemistry model, which only considers soluble advection loss.

  19. Verification of nuclear fuel plates by a developed non-destructive assay method

    Science.gov (United States)

    El-Gammal, W.; El-Nagdy, M.; Rizk, M.; Shawky, S.; Samei, M. A.

    2005-11-01

    Nuclear material (NM) verification is a main target for NM accounting and control. In this work a new relative non-destructive assay technique has been developed to verify the uranium mass content in nuclear fuel. The technique uses a planar high-resolution germanium gamma ray spectrometer in combination with the MCNP-4B Monte Carlo transport code. A standard NM sample was used to simulate the assayed NM and to determine the average intrinsic full energy peak efficiency of the detector for assayed configuration. The developed technique was found to be capable of verifying the operator declarations with an average accuracy of about 2.8% within a precision of better than 4%.

  20. Swelling of U(Mo)-Al(Si) dispersion fuel under irradiation - Non-destructive analyses of the LEONIDAS E-FUTURE plates

    Science.gov (United States)

    Van den Berghe, S.; Parthoens, Y.; Charollais, F.; Kim, Y. S.; Leenaers, A.; Koonen, E.; Kuzminov, V.; Lemoine, P.; Jarousse, C.; Guyon, H.; Wachs, D.; Keiser, D., Jr.; Robinson, A.; Stevens, J.; Hofman, G.

    2012-11-01

    In the framework of the elimination of High-Enriched Uranium (HEU) from the civil circuit, the search for an appropriate fuel to replace the high-enriched research reactor fuel in those reactors that currently still require it for their operation has led to the development of a U-7 wt.%Mo alloy based dispersion fuel with an Al-Si matrix. The European LEONIDAS program, joining SCK•CEN, ILL, CEA and AREVA-CERCA, is aimed at the qualification of such a fuel for the use in high power conditions. The first experiment of the program, designated E-FUTURE, was performed to select the appropriate matrix Si concentration and fuel plate post-production heat treatment parameters for further qualification. It consisted of the irradiation of four distinct (4% and 6% Si, 3 different heat treatments) full size, flat fuel plates in the BR2 reactor. The irradiation conditions were relatively severe: 470 W/cm2 peak BOL power, with a ˜70% 235U peak burnup.

  1. 14 CFR 1274.936 - Breach of safety or security.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Breach of safety or security. 1274.936... AGREEMENTS WITH COMMERCIAL FIRMS Other Provisions and Special Conditions § 1274.936 Breach of safety or security. Breach of Safety or Security July 2002 Safety is the freedom from those conditions that can...

  2. 24 CFR 982.453 - Owner breach of contract.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 4 2010-04-01 2010-04-01 false Owner breach of contract. 982.453... Contract and Owner Responsibility § 982.453 Owner breach of contract. (a) Any of the following actions by the owner (including a principal or other interested party) is a breach of the HAP contract by...

  3. Elastomer based composite materials for bipolar plates in polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Petrach, Elaine M.

    2011-07-01

    In most investigations, polymer conductive composite bipolar plates have failed to achieve the low resistivity required for PEMFCs. The goal of this dissertation is to investigate whether a composite of conductive fillers and a two-phase polymeric matrix will achieve low resistivity through preferred distribution of the fillers at the interface of the two phases. The use of an elastomer as one component of the blend will impart fracture resistance. Three types of matrices were investigated, a single phase polyvinyl ester plastic matrix, a compatible one-phase blend of polyvinyl ester (VER) and polyurethane (PU) elastomer, and a two-phase system of polyvinyl ester and ethylene propylene diene monomer (EPDM) elastomer. The different phases were determined by the theory of mixing. When solubility parameters are closer together it is likely that the system will be one phase. The one and two-phase systems were analyzed within the composition containing natural Cytec DKD graphite fibers, Asbury synthetic graphite 4012 flakes and ultra high surface area synthetic graphite TC 307. Phase systems affect the mechanical, electrical, and thermal properties. The percolation theory analysis was applied to determine the optimal percentage of conductive fillers and polymer blends. The optimal composition for composite materials consisted of 35vo1% of conductive fillers and 65vo1% of a two-phase blend matrix. The conductive filler included 3vol% of synthetic graphite TC307, 25.5vol% of Cytec DKD graphite fibers and 6.5vol% of Asbury synthetic graphite 4012 flakes. The two-phase blend matrix included 40vol% of EPDM to 60vol% of VER. This resulted in an electrical resistivity of 0.009O-cm and a thermal conductivity of 11.6W/m-K. The two-phase blend matrix added more ductility to the composition with the ability to withstand a stress of 10MPa with over 1% strain applied to the overall composite bipolar plates. The composition also absorbed 60% more mechanical energy than that

  4. Characterization of thermal and mechanical properties of polypropylene-based composites for fuel cell bipolar plates and development of educational tools in hydrogen and fuel cell technologies

    Science.gov (United States)

    Lopez Gaxiola, Daniel

    In this project we developed conductive thermoplastic resins by adding varying amounts of three different carbon fillers: carbon black (CB), synthetic graphite (SG) and multi-walled carbon nanotubes (CNT) to a polypropylene matrix for application as fuel cell bipolar plates. This component of fuel cells provides mechanical support to the stack, circulates the gases that participate in the electrochemical reaction within the fuel cell and allows for removal of the excess heat from the system. The materials fabricated in this work were tested to determine their mechanical and thermal properties. These materials were produced by adding varying amounts of single carbon fillers to a polypropylene matrix (2.5 to 15 wt.% Ketjenblack EC-600 JD carbon black, 10 to 80 wt.% Asbury Carbons' Thermocarb TC-300 synthetic graphite, and 2.5 to 15 wt.% of Hyperion Catalysis International's FIBRIL(TM) multi-walled carbon nanotubes) In addition, composite materials containing combinations of these three fillers were produced. The thermal conductivity results showed an increase in both through-plane and in-plane thermal conductivities, with the largest increase observed for synthetic graphite. The Department of Energy (DOE) had previously set a thermal conductivity goal of 20 W/m·K, which was surpassed by formulations containing 75 wt.% and 80 wt.% SG, yielding in-plane thermal conductivity values of 24.4 W/m·K and 33.6 W/m·K, respectively. In addition, composites containing 2.5 wt.% CB, 65 wt.% SG, and 6 wt.% CNT in PP had an in-plane thermal conductivity of 37 W/m·K. Flexural and tensile tests were conducted. All composite formulations exceeded the flexural strength target of 25 MPa set by DOE. The tensile and flexural modulus of the composites increased with higher concentration of carbon fillers. Carbon black and synthetic graphite caused a decrease in the tensile and flexural strengths of the composites. However, carbon nanotubes increased the composite tensile and flexural

  5. SnO2:F Coated Duplex Stainless Steel for PEM Fuel Cell Bipolar Plates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Turner, J. A.

    2008-01-01

    Duplex 2205 stainless steel was deposited with 0.6 {micro}m thick SnO2:F coating; coated steel was characterized for PEMFC bipolar plate application. Compared with bare alloy, interfacial contact resistance (ICR) values of the coated 2205 steel are higher. SnO2:F coating adds its own resistance to the air-formed film on the steel. In a PEMFC anode environment, a current peak of ca. 25 {micro}A/cm2 registered at ca. 30 min for coated 2205 steel. It stabilized at ca. 2.0 {approx} -1.0 {micro}A/cm2. This peak is related to the complicated process of coating dissolution and oxide-layer formation. Anodic-cathodic current transfer occurred at ca. 200 min polarization. In a PEMFC cathode environment, current was stable immediately after polarization. The stable current was ca. 0.5 {approx} 2.0 {micro}A/cm2 during the entire polarization period. AES depth profiles with tested samples and ICP analysis with the tested solutions confirmed the excellent corrosion resistance of the SnO2:F coated 2205 alloy in simulated PEMFC environments.

  6. Evaluation of Annealing Treatments for Producing Si-Rich Fuel/Matrix Interaction Layers in Low-Enriched U-Mo Dispersion Fuel Plates Rolled at a Low Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Dennis D. Keiser, Jr.; Jan-Fong Jue; Nicolas E. Woolstenhulme

    2010-06-01

    During fabrication of U-7Mo dispersion fuels, exposure to relatively high temperatures affects the final microstructure of a fuel plate before it is inserted into a reactor. One impact of this high temperature exposure is a chemical interaction that can occur between dissimilar materials. For U-7Mo dispersion fuels, the U-7Mo particles will interact to some extent with the Al or Al alloy matrix to produce interaction products. It has been observed that the final irradiation behavior of a fuel plate can depend on the amount of interaction that occurs at the U-7Mo/matrix interface during fabrication, along with the type of phases that develop at this interface. For the case where a U-7Mo dispersion fuel has a Si-containing Al alloy matrix and is rolled at around 500°C, a Si-rich interaction product has been observed to form that can potentially have a positive impact on fuel performance during irradiation. This interaction product can exhibit stable irradiation behavior and it can act as a diffusion barrier to additional U-Mo/matrix interaction during irradiation. However, for U-7Mo dispersion fuels with softer claddings that are rolled at lower temperatures (e.g., near 425°C), a significant interaction layer has not been observed to form. As a result, the bulk of any interaction layer that develops in these fuels happens during irradiation, and the layer that forms may not exhibit as stable a behavior as one that is formed during fabrication. Therefore, it may be beneficial to add a heat treatment step during the fabrication of dispersion fuel plates with softer cladding alloys that will result in the formation of a uniform, Si-rich interaction layer that is a few microns thick around the U-Mo fuel particles. This type of layer would have characteristics like the one that has been observed in dispersion fuel plates with AA6061 cladding that are fabricated at 500°C, which may exhibit increased stability during irradiation. This report discusses the result of

  7. The flat-plate plant-microbial fuel cell: the effect of a new design on internal resistances

    Directory of Open Access Journals (Sweden)

    Helder Marjolein

    2012-09-01

    Full Text Available Abstract Due to a growing world population and increasing welfare, energy demand worldwide is increasing. To meet the increasing energy demand in a sustainable way, new technologies are needed. The Plant-Microbial Fuel Cell (P-MFC is a technology that could produce sustainable bio-electricity and help meeting the increasing energy demand. Power output of the P-MFC, however, needs to be increased to make it attractive as a renewable and sustainable energy source. To increase power output of the P-MFC internal resistances need to be reduced. With a flat-plate P-MFC design we tried to minimize internal resistances compared to the previously used tubular P-MFC design. With the flat-plate design current and power density per geometric planting area were increased (from 0.15 A/m2 to 1.6 A/m2 and from 0.22 W/m2 to and 0.44 W/m2as were current and power output per volume (from 7.5 A/m3 to 122 A/m3 and from 1.3 W/m3 to 5.8 W/m3. Internal resistances times volume were decreased, even though internal resistances times membrane surface area were not. Since the membrane in the flat-plate design is placed vertically, membrane surface area per geometric planting area is increased, which allows for lower internal resistances times volume while not decreasing internal resistances times membrane surface area. Anode was split into three different sections on different depths of the system, allowing to calculate internal resistances on different depths. Most electricity was produced where internal resistances were lowest and where most roots were present; in the top section of the system. By measuring electricity production on different depths in the system, electricity production could be linked to root growth. This link offers opportunities for material-reduction in new designs. Concurrent reduction in material use and increase in power output brings the P-MFC a step closer to usable energy density and economic feasibility.

  8. Electrical conductivity modeling of multiple carbon fillers in liquid crystal polymer composites for fuel cell bipolar plate applications

    Energy Technology Data Exchange (ETDEWEB)

    Barton, R.L.; Keith, J.M.; King, J.A. [Michigan Technological Univ., Houghton, MI (United States). Dept. of Chemical Engineering

    2008-08-15

    This study modelled the electrical conductivity of a single filler composite system using a general effective media (GEM) equation. The aim of the study was to investigate the use of synthetic graphite and carbon fiber in liquid crystal polymers for fuel cell bipolar plate applications. The polymer consisted of 73 mole per cent hydroxybenzoic acid and 27 mole per cent hydroxynaphthoic acid. Composites of various concentrations of single and multiple filler combinations were tested. A volumetric in-plane electrical conductivity test was conducted on all samples in order to measure voltage drop. A through-plane conductivity test was conducted to measure resistivity. The GEM equation was then used to model the conductivity data obtained during the tests. Results of the study showed that at 45 vol per cent, the electrical conductivity of the multiple filler composite was comparable to data obtained from single filler electrical conductivities. The electrical conductivity of the multiple filler composite at 60 per cent graphite and 10 per cent carbon fiber was comparable to the single filler carbon fiber composite, but lower than the single filler synthetic graphite composite. Results also showed that the GEM equation provided excellent agreement with results obtained during the experiments. It was concluded that the percolation threshold of the multiple filler composite was almost identical to the single carbon fiber filler, but lower than the single synthetic graphite composite. 35 refs., 3 tabs., 2 figs.

  9. Electrical properties of carbon-based polypropylene composites for bipolar plates in polymer electrolyte membrane fuel cell (PEMFC)

    Science.gov (United States)

    Dweiri, Radwan; Sahari, Jaafar

    An investigation is made of the electrical properties of polypropylene/graphite (PP/G) composites as prospective replacements for the traditional graphite bipolar plate in proton-exchange membrane fuel cells. The composites have relatively low electrical conductivities, i.e., up to 28 S cm -1 at 90 wt.% G. Combination of G with carbon black (CB) is an effective way to develop higher conductivity composites. The conductivity reaches 35 S cm -1 by combination of 25 wt.% CB and 55 wt.% G to 20 wt.% PP. This is five times the value at 80 wt.% G and 20 wt.% PP (7 S cm -1). Two methods are mainly adopted for the preparation of composites, namely, melt compounding and solution blending. Solution blending of PP with conductive fillers followed by moulding of the dried powder leads to higher conductivities compared with those of melt-compounded composites. The combination of conjugated conducting polymers such as polyaniline (PANi) with the PP, G, and CB is also investigated. It is found that composites containing PANi have lower conductivities than those of the neat composites. This decrease in conductivity is attributed to the poor thermal stability of PANi.

  10. Breaching barriers to collaboration in public spaces

    DEFF Research Database (Denmark)

    Heinemann, Trine; Mitchell, Robb

    2014-01-01

    Technology provoking disparate individuals to collaborate or share experiences in the public space faces a difficult barrier, namely the ordinary social order of urban places. We employed the notion of the breaching experiment to explore how this barrier might be overcome. We analyse responses to...... of life in public spaces. Arising from this, we argue for the importance of qualities such as availability, facilitation, perspicuous settings, and perspicuous participants to encourage and support co-located strangers to collaborate and share experiences.......Technology provoking disparate individuals to collaborate or share experiences in the public space faces a difficult barrier, namely the ordinary social order of urban places. We employed the notion of the breaching experiment to explore how this barrier might be overcome. We analyse responses...

  11. New process for fuel cell fabrication. 3D screen printing of metal bipolar plates; Neues Verfahren zur Brennstoffzellenfertigung. 3D-Siebdruck von metallischen Bipolarplatten

    Energy Technology Data Exchange (ETDEWEB)

    Studnitzky, Thomas [Fraunhofer-Institut fuer Fertigungstechnik und Angewandte Materialforschung (IFAM), Dresden (Germany); Helm, Peter; Heinzel, Angelika [Zentrum fuer BrennstoffzellenTechnik GmbH (ZBT), Duisburg (Germany)

    2011-01-15

    Minimization of space requirements, weight, and production cost is one of the key preconditions for successful launching of the polymer electrolyte membrane fuel cell (PEM). In the stacks constructed from single PEM cells, the bipolar plate is a central component. It determines the weight and volume of the stack and accounts for more than 30 percent of the overall cost, depending on the fabrication process. It is therefore important for producers of fuel cells to develop a process that combines free design, high functionality and low cost in serial production.

  12. Combat Simulation Using Breach Computer Language

    Science.gov (United States)

    1979-09-01

    Armament Division, FC5SCWSL; and Mr. John Tobak, Scientific and Engineering Application Division, Management Information Systems Directorate. The...what was then the US Army Electonic Command, Fort Monmouth. At this point, BREACH became known as BREWS, which stands for Battlefield Related...November 1976 Goldberg, S. et al, "ASARS Battle Model," Book 1, Volume 1, Executive Summary, SA Group Technical Report TR 9073, Fort

  13. Development of a plate-type fuel model for the neutronics and thermal-hydraulics coupled code - SIMMER-III - and its application to the analyses of SPERT

    Energy Technology Data Exchange (ETDEWEB)

    Liu Ping, E-mail: ping.liu@areva.co [Karlsruhe Institute of Technology (KIT), Institute for Nuclear and Energy Technologies (IKET), P.O. Box 3640, D-76021 Karlsruhe (Germany); Gabrielli, Fabrizio; Rineiski, Andrei; Maschek, Werner [Karlsruhe Institute of Technology (KIT), Institute for Nuclear and Energy Technologies (IKET), P.O. Box 3640, D-76021 Karlsruhe (Germany); Bruna, Giovanni B. [Reactor Safety Division, French Institute for Radioprotection and Nuclear Safety (IRSN), B.P. 17, 92262 Fontenay aux Roses Cedex (France)

    2010-10-15

    SIMMER-III, a neutronics and thermal-hydraulics coupled code, was originally developed for core disruptive accident analyses of liquid metal cooled fast reactors. Due to its versatility in investigating scenarios of core disruption, the code has also been extended to the simulation of transients in thermal neutron systems such as the criticality accident at the JCO fuel fabrication plant, and, in recent years, applied to water-moderated thermal research reactor transient studies, too. Originally, SIMMER considered only cylindrical fuel pin geometry. Therefore, implementation of a plate-type fuel model to the SIMMER-III code is of importance for the analysis of research reactors adopting this kind of fuel. Furthermore, validation of the SIMMER-III modeling of light water-cooled thermal reactor reactivity initiated transients is of necessity. This paper presents the work carried out on the SIMMER-III code in the framework of a KIT and IRSN joint activity aimed at providing the code with experimental reactor transient study capabilities. The first step of the job was the implementation of a new fuel model in SIMMER-III. Verification on this new model indicates that it can well simulate the steady-state temperature profile in the fuel. Secondly, three cases with the shortest reactor periods of 5.0 ms, 4.6 ms and 3.2 ms among the Special Power Excursion Reactor Tests (SPERT) performed in the SPERT I D-12/25 facility have been simulated. Comparison of the results between the SIMMER-III simulation and the reported SPERT results indicates that although there is space for further improvement on the modeling of negative feedback mechanisms, with this plate-type fuel model SIMMER-III can well represent the transient phenomena of reactivity driven power excursion.

  14. Comparing overflow and wave-overtopping induced breach initiation mechanisms in an embankment breach experiment

    Directory of Open Access Journals (Sweden)

    van Damme Myron

    2016-01-01

    Full Text Available As part of the SAFElevee project Delft University of Technology collabored with Flanders Hydraulics Research, and Infram B.V. in the preperation and execution of a full scale embankment breach experiment in November 2015. This breach experiment was performed on an 3.5m high embankment with a sand core and clay outer layer situated along the tidal river Scheldt in Belgium near Schellebelle. During the experiment a wave overtopping simulator and overflow simulator were used to initiate a breach. Both simulators were placed near the top of the waterside slope. The use of the simulators facilitated comparison between the effects of continueous overflow and the effects of intermittent wave overtopping. This paper presents the data collected during the experiment, describe the development of hypotheses on the failure processes using the latest insights, and comment on the failure initiation process of a grass covered flood embankment with a clay outer layer and a sandy core.

  15. Thermal-hydraulic analysis of the outermost fuel plates of a MTR5 fuel element used in the IEA-R1 research reactor; Analise termo-hidraulica das placas externas de um elemento combustivel tipo placa utilizado no reator de pesquisas IEA-R1

    Energy Technology Data Exchange (ETDEWEB)

    Umbehaun, Pedro Ernesto; Torres, Walmir Maximo; Andrade, Delvonei Alves de [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil)]. E-mail: umbehaun@ipen.br; wmtorres@ipen.br; delvonei@ipen.br

    2004-07-01

    This work presents the thermal-hydraulic analysis for the outermost fuel plates for 5 MW reactor operation power, considering internal flow distribution experimentally measured, and by using the flow through the channels between two fuel elements, external flow. Results showed the necessity of changing the fuel element design, which was taken into account through the reduction of uranium concentration for external plates in order to guarantee its suitable cooling.

  16. High energy X-ray diffraction measurement of residual stresses in a monolithic aluminum clad uranium-10 wt% molybdenum fuel plate assembly

    Science.gov (United States)

    Brown, D. W.; Okuniewski, M. A.; Almer, J. D.; Balogh, L.; Clausen, B.; Okasinski, J. S.; Rabin, B. H.

    2013-10-01

    Residual stresses are expected in monolithic, aluminum clad uranium 10 wt% molybdenum (U-10Mo) nuclear fuel plates because of the large mismatch in thermal expansion between the two bonded materials. The full residual stress tensor of the U-10Mo foil in a fuel plate assembly was mapped with 0.1 mm resolution using high-energy (86 keV) X-ray diffraction. The in-plane stresses in the U-10Mo foil are strongly compressive, roughly -250 MPa in the longitudinal direction and -140 MPa in the transverse direction near the center of the fuel foil. The normal component of the stress is weakly compressive near the center of the foil and tensile near the corner. The disparity in the residual stress between the two in-plane directions far from the edges and the tensile normal stress suggest that plastic deformation in the aluminum cladding during fabrication by hot isostatic pressing also contributes to the residual stress field. A tensile in-plane residual stress is presumed to be present in the aluminum cladding to balance the large in-plane compressive stresses in the U-10Mo fuel foil, but cannot be directly measured with the current technique due to large grain size.

  17. An investigation of the typical corrosion parameters used to test polymer electrolyte fuel cell bipolar plate coatings, with titanium nitride coated stainless steel as a case study

    Science.gov (United States)

    Orsi, A.; Kongstein, O. E.; Hamilton, P. J.; Oedegaard, A.; Svenum, I. H.; Cooke, K.

    2015-07-01

    Stainless steel bipolar plates (BPP) for polymer electrolyte membrane fuel cells (PEMFCs) have good manufacturability, durability and low costs, but inadequate corrosion resistance and elevated interfacial contact resistance (ICR) in the fuel cell environment. Thin film coatings of titanium nitride (TiN) of 1 μm in thickness, were deposited by means of physical vapour deposition (PVD) process on to stainless steel (SS) 316L substrates and were evaluated, in a series of tests, for their level of corrosion protection and ICR. In the ex-situ corrosion tests, variables such as applied potential, experimental duration and pH of the sulphate electrolyte at 80 °C were altered. The ICR values were found to increase after exposure to greater applied potentials and electrolytes of a higher pH. In terms of experimental duration, the ICR increased most rapidly at the beginning of each experiment. It was also found that the oxidation of TiN was accelerated after exposure to electrolytes of a higher pH. When coated BPPs were incorporated into an accelerated fuel cell test, the degradation of the fuel cell cathode resembled the plates that were tested at the highest anodic potential (1.4 VSHE).

  18. Evaluation of Corrosion of the Dummy “EE” Plate 19 in YA Type ATR Fuel Element During Reactor PALM Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Brower, Jeffrey Owen [Idaho National Lab. (INL), Idaho Falls, ID (United States); Glazoff, Michael Vasily [Idaho National Lab. (INL), Idaho Falls, ID (United States); Eiden, Thomas John [Idaho National Lab. (INL), Idaho Falls, ID (United States); Rezvoi, Aleksey Victor [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-08-01

    Advanced Test Reactor (ATR) Cycle 153B-1 was a 14-day, high-power, powered axial locator mechanism (PALM) operating cycle that completed on April 12, 2013. Cycle 153B-1 was a typical operating cycle for the ATR and did not result in any unusual plant transients. ATR was started up and shut down as scheduled. The PALM drive physically moves the selected experiments into and out of the core to simulate reactor startup and heat up, and shutdown and cooldown transients, while the reactor remains in steady state conditions. However, after the cycle was over, several thousand of the flow-assisted corrosion pits and “horseshoeing” defects were readily observable on the surface of the several YA-type fuel elements (these are “dummy” plates that contain no fuel). In order understand these corrosion phenomena a thermal-hydraulic model of coolant channel 20 on a YA-M fuel element was generated. The boundaries of the model were the aluminum EE plate of a YA-M fuel element and a beryllium reflector block with 13 horizontal saw cuts which represented regions of zero flow. The heat generated in fuel plates 1 through 18 was modeled to be passing through the aluminum EE plate. The coolant channel 20 width was set at 0.058 in. (58 mils). It was established that the horizontal saw cuts had a significant effect on the temperature of the coolant. The flow, which was expected to vary linearly with gradual heating of the coolant as it passed through the channel, was extremely turbulent. The temperature rise, which was expected to be a smooth “S” curve, was represented by a series temperature rise “humps,” which occurred at each horizontal saw cut in the beryllium reflector block. Each of the 13 saw cuts had a chamfered edge which resulted in the coolant flow being re-directed as a jet across the coolant channel into the surface of the EE plate, which explained the temperature rise and the observed sscalloping and possibly pitting degradation on the YA-M fuel elements. In

  19. Breached cylinder incident at the Portsmouth gaseous diffusion plant

    Energy Technology Data Exchange (ETDEWEB)

    Boelens, R.A. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

    1991-12-31

    On June 16, 1990, during an inspection of valves on partially depleted product storage cylinders, a 14-ton partially depleted product cylinder was discovered breached. The cylinder had been placed in long-term storage in 1977 on the top row of Portsmouth`s (two rows high) storage area. The breach was observed when an inspector noticed a pile of green material along side of the cylinder. The breach was estimated to be approximately 8- inches wide and 16-inches long, and ran under the first stiffening ring of the cylinder. During the continuing inspection of the storage area, a second 14-ton product cylinder was discovered breached. This cylinder was stacked on the bottom row in the storage area in 1986. This breach was also located adjacent to a stiffening ring. This paper will discuss the contributing factors of the breaching of the cylinders, the immediate response, subsequent actions in support of the investigation, and corrective actions.

  20. Overtopping breaching of river levees constructed with cohesive sediments

    Science.gov (United States)

    Wei, Hongyan; Yu, Minghui; Wang, Dangwei; Li, Yitian

    2016-07-01

    Experiments were conducted in a bend flume to study the overtopping breaching process and the corresponding overflow rates of river levees constructed with cohesive sediments. The river and land regions were separated by the constructed levee in the bend flume. Results showed that the levee breaching process can be subdivided into a slope erosion stage, a headcut retreat stage and a breach widening stage. Mechanisms such as flow shear erosion, impinging jet erosion, side slope erosion and cantilever collapse were discovered in the breaching process. The erosion characteristics were determined by both flow and soil properties. Finally, a depth-averaged 2-D flow model was used to simulate the levee breaching flow rates, which is well expressed by the broad-crested weir flow formula. The deduced discharge coefficient was smaller than that of common broad-crested rectangular weirs because of the shape and roughness of the breach.

  1. Evaluation of Erosion of the Dummy “EE” Plate 19 in YA Type ATR Fuel Element During Reactor PALM Cycles

    Energy Technology Data Exchange (ETDEWEB)

    Brower, Jeffrey O. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Advanced Test Reactor; Glazoff, Michael V. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Advanced Test Reactor; Eiden, Thomas J. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Advanced Test Reactor; Rezvoi, Aleksey V. [Idaho National Lab. (INL), Idaho Falls, ID (United States). Advanced Test Reactor

    2016-08-01

    Advanced Test Reactor (ATR) Cycle 153B-1 was a 14-day, high-power, powered axial locator mechanism (PALM) operating cycle that completed on April 12, 2013. Cycle 153B-1 was a typical operating cycle for the ATR and did not result in any unusual plant transients. ATR was started up and shut down as scheduled. The PALM drive physically moves the selected experiments into and out of the core to simulate reactor startup and heat up, and shutdown and cooldown transients, while the reactor remains in steady state conditions. However, after the cycle was over, when the fuel elements were removed from the core and inspected, several thousand flow-assisted erosion pits and “horseshoeing” defects were readily observed on the surface of the several YA-type fuel elements (these are aluminum “dummy” plates that contain no fuel). In order to understand these erosion phenomena a thermal-hydraulic model of coolant channel 20 on a YA-M fuel element was generated. The boundaries of the model were the aluminum EE plate of a YA-M fuel element and a beryllium reflector block with 13 horizontal saw cuts which represented regions of zero flow. The heat generated in fuel plates 1 through 18 was modeled to be passing through the aluminum EE plate. The coolant channel 20 width was set at 0.058 in. (58 mils). It was established that the horizontal saw cuts had a significant effect on the temperature of the coolant. The flow, which was expected to vary linearly with gradual heating of the coolant as it passed through the channel, was extremely turbulent. The temperature rise, which was expected to be a smooth “S” curve, was represented by a series temperature rise “humps,” which occurred at each horizontal saw cut in the beryllium reflector block. Each of the 13 saw cuts had a chamfered edge which resulted in the coolant flow being re-directed as a jet across the coolant channel into the surface of the EE plate, which explained the temperature rise and the observed scalloping

  2. Differences in physico-mechanical behaviors of resol(e) and novolac type phenolic resin based composite bipolar plate for proton exchange membrane (PEM) fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Kakati, Biraj Kumar [Department of Chemical Engineering, Indian Institute of Technology Guwahati, North Guwahati, PIN 781 039, Dist. Kamrup (Assam) (India); Deka, Dhanapati [Department of Energy, Tezpur University, Tezpur 784 028, Dist. Sonitpur (Assam) (India)

    2007-09-15

    Composite bipolar plates for Proton Exchange Membrane Fuel Cell (PEMFC) are prepared by compression molding technique using polymer as binder and graphite as electric filler material with some other reinforcements. Study on the effect of resole and novolac type phenolic resin on the properties of composite bipolar plate, such as bulk density, porosity, bulk conductivity, hardness, flexural strength, etc. shows that both of the resin shows different physico-mechanical properties. Moreover, single cell performance analysis also shows variation for resole and novolac based composites. A novel concept of triple continuous structure to provide graphite polymer blends with high electrical conductivity, high shore hardness, high flexural strength, less porosity and low density has been proposed and study on the effect of different types of phenolic resin on the properties and performance of bipolar plate reveals that novolac type powdered phenolic resin gives better mechanical properties than resole type phenolic resin. However, resole type phenolic resin compound has slightly higher electrical conductivity due to more number of polar -OH group presents on its cured form. But due to the less porosity and higher mechanical strength, bipolar plates with novolac type phenolic resin gives better performance in I-V analysis than bipolar plates with resole type phenolic resin. (author)

  3. Estimation of Discharge from Breached Earthfill Levee with Elapsed Time

    Science.gov (United States)

    Kim, Sooyoung; Yang, Jiro; Song, Chang Geun; Lee, Seung Oh

    2014-05-01

    Lack of the freeboard of levee has been occurred due to abnormally peaked flood events. Thus, the risk from overtopping of earthfill levee has been remarkably increased. When overflow on levee starts to occur, the breaching gap suddenly grows up at initial stage. As the breach width is extended, the discharge from breached section is also nonlinearly increased. Moreover, if the levee is located through multiple cities, the related damage cannot be predictable. However, researches about the breach mechanism have been focused on the breached shape of levee on the equilibrium state and the study on the development of levee breach is not enough to utilize the prediction of damage itself and select its countermeasure. In this study, the formula for breach discharge was presented to be able to predict that based on hydraulic experimental results. All experiments have been conducted with the movable levee which was the crown width of 0.3 m, the height of 0.3 m, the landside slope of 2:1 (H:V). Breach was induced by the lateral overflow for Froude numbers in main channel from 0.15 to 0.35 with the increment of 0.05. Based on the dimensional analysis with significant parameters such as main channel depth, breach width and discharge coefficient, temporal variation of each parameter was estimated with 25 experimental cases. Finally, the formula for prediction of breach flow due to overtopping failure of levee was presented considering the elapsed time for each Froude number after combing all significant parameters. When Froude number was less than 0.3, the breach discharge occurred to increase with Froude number while it became decreased with Froude number exceeding 0.3, which means the maximum breach discharge was occurred at Froude number = 0.3. It would be explained with the flow diversion caused by the collision of breach flow on the breached section downstream, which decreased the breach discharge into landside for higher Froude number of 0.3. As a future works, when the

  4. Influence of the silicon content on the core corrosion properties of dispersion type fuel plates; Influencia del Contenido en silicio sobre la corrosion acuosa de los nucleos de placas combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, C.; Saenz de Tejada, L. M.; Diaz Diaz, J.

    1969-07-01

    A new process to produce aluminium base dispersion type fuel plates has been developed at the Spanish JEN (Junta de Energia Nuclear). The dispersed fuel material is obtained by an aluminothermic process to render a stoichiometric cermet of UAI{sub 3} and AI{sub 2}O{sub 3} according to the reaction. (Author)

  5. Pre-oxidized and nitrided stainless steel alloy foil for proton exchange membrane fuel cell bipolar plates: Part 1. Corrosion, interfacial contact resistance, and surface structure

    Science.gov (United States)

    Brady, M. P.; Wang, H.; Turner, J. A.; Meyer, H. M.; More, K. L.; Tortorelli, P. F.; McCarthy, B. D.

    Thermal (gas) nitridation of stainless steel alloys can yield low interfacial contact resistance (ICR), electrically conductive and corrosion-resistant nitride containing surface layers (Cr 2N, CrN, TiN, V 2N, VN, etc.) of interest for fuel cells, batteries, and sensors. This paper presents results of scale-up studies to determine the feasibility of extending the nitridation approach to thin 0.1 mm stainless steel alloy foils for proton exchange membrane fuel cell (PEMFC) bipolar plates. Developmental Fe-20Cr-4V alloy and type 2205 stainless steel foils were treated by pre-oxidation and nitridation to form low-ICR, corrosion-resistant surfaces. As-treated Fe-20Cr-4V foil exhibited target (low) ICR values, whereas 2205 foil suffered from run-to-run variation in ICR values, ranging up to 2× the target value. Pre-oxidized and nitrided surface structure examination revealed surface-through-layer-thickness V-nitride particles for the treated Fe-20Cr-4V, but near continuous chromia for treated 2205 stainless steel, which was linked to the variation in ICR values. Promising corrosion resistance was observed under simulated aggressive PEMFC anode- and cathode-side bipolar plate conditions for both materials, although ICR values were observed to increase. The implications of these findings for stamped bipolar plate foils are discussed.

  6. Numerical model of a thermoelectric generator with compact plate-fin heat exchanger for high temperature PEM fuel cell exhaust heat recovery

    DEFF Research Database (Denmark)

    Xin, Gao; Andreasen, Søren Juhl; Chen, Min

    2012-01-01

    This paper presents a numerical model of an exhaust heat recovery system for a high temperature polymer electrolyte membrane fuel cell (HTPEMFC) stack. The system is designed as thermoelectric generators (TEGs) sandwiched in the walls of a compact plate-fin heat exchanger. Its model is based...... plate-fin heat exchangers is adopted. Then the model is validated against experimental data and the main variables are identified by means of a sensitivity analysis. Finally, the system configuration is optimized for recovering heat from the exhaust gas. The results exhibit the crucial importance...... on a finite-element approach. On each discretized segment, fluid properties, heat transfer process and TEG performance are locally calculated for higher model precision. To benefit both the system design and fabrication, the way to model TEG modules is herein reconsidered; a database of commercialized compact...

  7. An experimental comparison of reliance levels under alternative breach remedies

    NARCIS (Netherlands)

    Leuven, E.; Oosterbeek, H.; Sloof, R.; Sonnemans, J.H.

    2003-01-01

    Breach remedies serve an important role in protecting relationship-specific investments. Theory predicts that some common remedies protect too well and induce overinvestment because of complete insurance against potential separation, and the possibility to prevent breach by increasing the damage

  8. Just in Time Research: Data Breaches in Higher Education

    Science.gov (United States)

    Grama, Joanna

    2014-01-01

    This "Just in Time" research is in response to recent discussions on the EDUCAUSE Higher Education Information Security Council (HEISC) discussion list about data breaches in higher education. Using data from the Privacy Rights Clearinghouse, this research analyzes data breaches attributed to higher education. The results from this…

  9. Do Data Breach Disclosure Laws Reduce Identity Theft?

    Science.gov (United States)

    Romanosky, Sasha; Telang, Rahul; Acquisti, Alessandro

    2011-01-01

    In the United States, identity theft resulted in corporate and consumer losses of $56 billion dollars in 2005, with up to 35 percent of known identity thefts caused by corporate data breaches. Many states have responded by adopting data breach disclosure laws that require firms to notify consumers if their personal information has been lost or…

  10. Do Data Breach Disclosure Laws Reduce Identity Theft?

    Science.gov (United States)

    Romanosky, Sasha; Telang, Rahul; Acquisti, Alessandro

    2011-01-01

    In the United States, identity theft resulted in corporate and consumer losses of $56 billion dollars in 2005, with up to 35 percent of known identity thefts caused by corporate data breaches. Many states have responded by adopting data breach disclosure laws that require firms to notify consumers if their personal information has been lost or…

  11. Flow distribution measurements at the exit of bipolar plates in a PEM fuel cell stack; Messung der Stroemungsverteilung am Austritt der Bipolarplatten eines Brennstoffzellen-Stacks

    Energy Technology Data Exchange (ETDEWEB)

    Klinner, Joachim; Willert, Christian [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Koeln (Germany). Abt. Triebwerksmesstechnik; Schneider, Armin; Mack-Gardner, Andre [Adam Opel GmbH, Ruesselsheim (Germany). Alternative Propulsion Center Europe

    2011-07-01

    This paper presents two different experimental approaches which concentrate on capturing the flow distribution close to the anode exit header of a prototype 8-12 KW fuel cell stack operated with air at realistic flow rates. The first approach intends to visualize the penetration depth of millimeter-sized jets towards the exit manifold. The second one is focused on obtaining the exit jet velocity field downstream of the bipolar plate exit header across the entire stack height by repeated 2C-PIV measurements on densely spaced adjacent light sheet planes. An overview of the experimental setup and the data evaluation is given. (orig.)

  12. Growth kinetics and microstructural evolution during hot isostatic pressing of U-10 wt.% Mo monolithic fuel plate in AA6061 cladding with Zr diffusion barrier

    Science.gov (United States)

    Park, Y.; Yoo, J.; Huang, K.; Keiser, D. D.; Jue, J. F.; Rabin, B.; Moore, G.; Sohn, Y. H.

    2014-04-01

    Phase constituents and microstructure changes in RERTR fuel plate assemblies as functions of temperature and duration of hot-isostatic pressing (HIP) during fabrication were examined. The HIP process was carried out as functions of temperature (520, 540, 560 and 580 °C for 90 min) and time (45-345 min at 560 °C) to bond 6061 Al-alloy to the Zr diffusion barrier that had been co-rolled with U-10 wt.% Mo (U10Mo) fuel monolith prior to the HIP process. Scanning and transmission electron microscopies were employed to examine the phase constituents, microstructure and layer thickness of interaction products from interdiffusion. At the interface between the U10Mo and Zr, following the co-rolling, the UZr2 phase was observed to develop adjacent to Zr, and the α-U phase was found between the UZr2 and U10Mo, while the Mo2Zr was found as precipitates mostly within the α-U phase. The phase constituents and thickness of the interaction layer at the U10Mo-Zr interface remained unchanged regardless of HIP processing variation. Observable growth due to HIP was only observed for the (Al,Si)3Zr phase found at the Zr/AA6061 interface, however, with a large activation energy of 457 ± 28 kJ/mole. Thus, HIP can be carried to improve the adhesion quality of fuel plate without concern for the excessive growth of the interaction layer, particularly at the U10Mo-Zr interface with the α-U, Mo2Zr, and UZr2 phases.

  13. Fission product release model for failed plate-type fuel element and storage under water; Modelo para liberacao de produtos de fissao por placa combustivel falhada e armazenada sob agua

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, L.A.A.; Zeituni, C.A.; Silva, J.E.R. da; Castanheira, M.; Lucki, G.; Silva, A.T. e; Teodoro, C.A.; Damy, M. de A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear]. E-mail: laaterre@ipen.br

    2005-07-01

    Plate-type fuel elements burned-up inside the core of nuclear research reactors are stored mainly under deionized water of storage pools. When cladding failure occurs in such elements, radioactive fission products are released into the storage pool water. This work proposes a model to describe the release mechanism considering the diffusion through a postulated small cylindrical failure. As a consequence, an analytical expression is obtained for the activity released into the water as a function of the total storage time of a failed fuel plate. The proposed model reproduces the linear increasing of {sup 137}Cs specific activity observed in sipping tests already performed on failed plate-type fuel elements. (author)

  14. Effect of assembly error of bipolar plate on the contact pressure distribution and stress failure of membrane electrode assembly in proton exchange membrane fuel cell

    Science.gov (United States)

    Liu, Dong'an; Peng, Linfa; Lai, Xinmin

    In practice, the assembly error of the bipolar plate (BPP) in a PEM fuel cell stack is unavoidable based on the current assembly process. However its effect on the performance of the PEM fuel cell stack is not reported yet. In this study, a methodology based on FEA model, "least squares-support vector machine (LS-SVM)" simulation and statistical analysis is developed to investigate the effect of the assembly error of the BPP on the pressure distribution and stress failure of membrane electrode assembly (MEA). At first, a parameterized FEA model of a metallic BPP/MEA assembly is established. Then, the LS-SVM simulation process is conducted based on the FEA model, and datasets for the pressure distribution and Von Mises stress of MEA are obtained, respectively for each assembly error. At last, the effect of the assembly error is obtained by applying the statistical analysis to the LS-SVM results. A regression equation between the stress failure and the assembly error is also built, and the allowed maximum assembly error is calculated based on the equation. The methodology in this study is beneficial to understand the mechanism of the assembly error and can be applied to guide the assembly process for the PEM fuel cell stack.

  15. Preparation and properties of functionalized multiwalled carbon nanotubes/polypropylene nanocomposite bipolar plates for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Liao, Shu-Hang; Weng, Cheng-Chih; Yen, Chuan-Yu; Hsiao, Min-Chien; Ma, Chen-Chi M.; Tsai, Ming-Chi; Su, Ay; Yen, Ming-Yu; Lin, Yu-Feng; Liu, Po-Lan

    Multiwalled carbon nanotubes (MWCNTs) are covalently modified with different molecular weights 400 and 2000 poly(oxyalkylene)-amine bearing the diglycidyl ether of bisphenol A (DGEBA) epoxy (POA400-DGEBA and POA2000-DGEBA) oligomers. The oxidized MWCNTs (MWCNTs-COOH) are converted to the acid chloride-functionalized MWCNTs, followed by the reaction with POA-DGEBAs to prepare the MWCNTs/POA400-DGEBA and MWCNTs/POA2000-DGEBA. FTIR, thermogravimetric analysis (TGA) and high resolution X-ray photoelectron spectra (XPS) reveal that the POA-DGEBAs are covalently attached to the surface of MWCNTs. The morphology of MWCNTs/POA-DGEBA is observed by TEM. The POA400-DGEBA coated on the MWCNTs is thicker and more uniform. However, the coating of POA2000-DGEBA on the MWCNTs shows a worm-like bulk substance and the MWCNT surface is bare. In addition, the flexural strength and the bulk electrical conductivity of the MWCNTs/polypropylene nanocomposite bipolar plates are measured 59% and 505% higher than those of the original composite bipolar plates by adding 8 phr of MWCNTs/POA400-DGEBA. The maximum current density and power density of the single cell test for the nanocomposite bipolar plate with 4 phr MWCNTs/POA400-DGEBA are 1.32 A cm -2 and 0.533 W cm -2, respectively. The overall performance confirms the functionalized MWCNTs/polypropylene nanocomposite bipolar plates prepared in this study are suitable for PEMFC application.

  16. Preparation and properties of functionalized multiwalled carbon nanotubes/polypropylene nanocomposite bipolar plates for polymer electrolyte membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Shu-Hang; Weng, Cheng-Chih; Yen, Chuan-Yu.; Hsiao, Min-Chien; Ma, Chen-Chi M.; Yen, Ming-Yu.; Liu, Po-Lan [Department of Chemical Engineering, National Tsing Hua University, Hsin-Chu 30043 (China); Tsai, Ming-Chi [Department of Engineering and System Science, National Tsing Hua University, Hsin-Chu 30043 (China); Su, Ay [Fuel Cell Center, Yuan Ze University, Tao-Yuan 32003 (China); Lin, Yu-Feng [Plastics Industry Development Center, Tai-Chung 40768 (China)

    2010-01-01

    Multiwalled carbon nanotubes (MWCNTs) are covalently modified with different molecular weights 400 and 2000 poly(oxyalkylene)-amine bearing the diglycidyl ether of bisphenol A (DGEBA) epoxy (POA400-DGEBA and POA2000-DGEBA) oligomers. The oxidized MWCNTs (MWCNTs-COOH) are converted to the acid chloride-functionalized MWCNTs, followed by the reaction with POA-DGEBAs to prepare the MWCNTs/POA400-DGEBA and MWCNTs/POA2000-DGEBA. FTIR, thermogravimetric analysis (TGA) and high resolution X-ray photoelectron spectra (XPS) reveal that the POA-DGEBAs are covalently attached to the surface of MWCNTs. The morphology of MWCNTs/POA-DGEBA is observed by TEM. The POA400-DGEBA coated on the MWCNTs is thicker and more uniform. However, the coating of POA2000-DGEBA on the MWCNTs shows a worm-like bulk substance and the MWCNT surface is bare. In addition, the flexural strength and the bulk electrical conductivity of the MWCNTs/polypropylene nanocomposite bipolar plates are measured 59% and 505% higher than those of the original composite bipolar plates by adding 8 phr of MWCNTs/POA400-DGEBA. The maximum current density and power density of the single cell test for the nanocomposite bipolar plate with 4 phr MWCNTs/POA400-DGEBA are 1.32 A cm{sup -2} and 0.533 W cm{sup -2}, respectively. The overall performance confirms the functionalized MWCNTs/polypropylene nanocomposite bipolar plates prepared in this study are suitable for PEMFC application. (author)

  17. An extreme breaching of a barrier spit: insights on large breach formation and its impact on barrier dynamics

    Science.gov (United States)

    Iulian Zăinescu, Florin; Vespremeanu-Stroe, Alfred; Tătui, Florin

    2017-04-01

    In this study, we document a case of exceptionally large natural breaching of a sandy spit (Sacalin barrier, Danube delta) using Lidar data and satellite imagery, annual (and seasonal) surveys of topography and bathymetry on successive cross-barrier profiles, and hourly datasets of wind and waves. The breach morphology and dynamics was monitored and described from its inception to closure, together with its impact on the adjoining features (upper shoreface, back-barrier lagoon, downdrift coast) and on the local sediment budgets. Breaching is first observed to occur on a beach-length of 0.5 km in April 2012 and two years later reached 3.5 km (May 2014). The barrier translates to a recovery stage dominated by continuous back-barrier deposition through subaqueous cross-breach sediment transport. Soon, the barrier widening triggers a negative feedback which limits the back-barrier sediment transfer. As a result, back-barrier deposition decreases whilst the barrier aggradation through overwash becomes more frequent. The event was found to be a natural experiment which switched the barrier's decadal evolution from low cross-shore transport to high cross-shore transport over the barrier. Although previously considered as constant, the cross-shore transport recorded during the large breach lifespan is an order of magnitude larger than in the non-breach period. 3 x 106 m3 of sediment were deposited in three years which is equivalent to the modelled longshore transport in the region. Nevertheless, the sediment circuits are more complex involving exchanges with the upper shoreface, as indicated by the extensive erosion down to -4m. In the absence of tides, the Sacalin breach closed naturally in 3 years and brings a valuable contribution on how breaches may evolve, as only limited data has been internationally reported until now. The very high deposition rate of sediment in the breach is a testimony of the high sediment volumes supplied by the longshore transport and the high

  18. Uranium-molybdenum nuclear fuel plates behaviour under heavy ion irradiation: An X-ray diffraction analysis

    Science.gov (United States)

    Palancher, H.; Wieschalla, N.; Martin, P.; Tucoulou, R.; Sabathier, C.; Petry, W.; Berar, J.-F.; Valot, C.; Dubois, S.

    2009-03-01

    Heavy ion irradiation has been proposed for discriminating UMo/Al specimens which are good candidates for research reactor fuels. Two UMo/Al dispersed fuels (U-7 wt%Mo/Al and U-10 wt%Mo/Al) have been irradiated with a 80 MeV 127I beam up to an ion fluence of 2 × 1017 cm-2. Microscopy and mainly X-ray diffraction using large and micrometer sized beams have enabled to characterize the grown interaction layer: UAl3 appears to be the only produced crystallized phase. The presence of an amorphous additional phase can however not be excluded. These results are in good agreement with characterizations performed on in-pile irradiated fuels and encourage new studies with heavy ion irradiation.

  19. The A to Z of healthcare data breaches.

    Science.gov (United States)

    Kobus, Theodore J

    2012-01-01

    There currently exists a myriad of privacy laws that impact a healthcare entity, including more than 47 notification laws that require notification when a data breach occurs, as well as the breach notification requirements of the Health Information Technology for Economic and Clinical Health Act. Given the plethora of issues a healthcare entity faces, there are certain principles that can be built into an organization's philosophy that will comply with the law and help protect it from reputational harm.

  20. 48 CFR 1852.223-75 - Major breach of safety or security.

    Science.gov (United States)

    2010-10-01

    ... major breach of safety may constitute a breach of contract that entitles the Government to exercise any of its rights and remedies applicable to material parts of this contract, including termination for default. A major breach of safety must be related directly to the work on the contract. A major breach...

  1. Values underlying perceptions of breach of the psychological contract

    Directory of Open Access Journals (Sweden)

    Leon Botha

    2010-03-01

    Full Text Available Orientation: This study identifies the most prominent breaches of the psychological contract and the values underlying the perceptions that violations have occurred.Research purpose: The study identifies the most important breaches and investigates which values underlie employee perceptions of breach of the psychological contract. It also addresses values that lead to employees interpreting incidents as breaches.Motivation for the study: The study calls on the fact that employees make inconsequential contributions to the terms of many formal employment contracts may imply that such contracts cannot be viewed as documents between equals.Research design, approach and method: The study identifies the most prominent breaches of the psychological contract and the values underlying the perceptions that violations have occurred.Main findings: The data revealed lack of promotion, poor interpersonal relations between colleagues and bad treatment by seniors as three main breaches of the contract, and social recognition, world of peace and sense of accomplishment as three dominant values that underlie perceptions of contract violation.Practical/managerial implications: The competent and intelligent manner in which lack of promotion is handled and communicated to employees is vital because it has implications for their willingness to contribute, their career prospects and their intention to stay in the organisation.Contribution/value-add: This research can serve as the basis for the development of survey or research instruments that are appropriate and relevant to the population.

  2. Large earthquakes create vertical permeability by breaching aquitards

    Science.gov (United States)

    Wang, Chi-Yuen; Liao, Xin; Wang, Lee-Ping; Wang, Chung-Ho; Manga, Michael

    2016-08-01

    Hydrologic responses to earthquakes and their mechanisms have been widely studied. Some responses have been attributed to increases in the vertical permeability. However, basic questions remain: How do increases in the vertical permeability occur? How frequently do they occur? Is there a quantitative measure for detecting the occurrence of aquitard breaching? We try to answer these questions by examining data from a dense network of ˜50 monitoring stations of clustered wells in a sedimentary basin near the epicenter of the 1999 M7.6 Chi-Chi earthquake in western Taiwan. While most stations show evidence that confined aquifers remained confined after the earthquake, about 10% of the stations show evidence of coseismic breaching of aquitards, creating vertical permeability as high as that of aquifers. The water levels in wells without evidence of coseismic breaching of aquitards show tidal responses similar to that of a confined aquifer before and after the earthquake. Those wells with evidence of coseismic breaching of aquitards, on the other hand, show distinctly different postseismic tidal response. Furthermore, the postseismic tidal response of different aquifers became strikingly similar, suggesting that the aquifers became hydraulically connected and the connection was maintained many months thereafter. Breaching of aquitards by large earthquakes has significant implications for a number of societal issues such as the safety of water resources, the security of underground waste repositories, and the production of oil and gas. The method demonstrated here may be used for detecting the occurrence of aquitard breaching by large earthquakes in other seismically active areas.

  3. Development and Validation of Capabilities to Measure Thermal Properties of Layered Monolithic U-Mo Alloy Plate-Type Fuel

    Science.gov (United States)

    Burkes, Douglas E.; Casella, Andrew M.; Buck, Edgar C.; Casella, Amanda J.; Edwards, Matthew K.; MacFarlan, Paul J.; Pool, Karl N.; Smith, Frances N.; Steen, Franciska H.

    2014-07-01

    The uranium-molybdenum (U-Mo) alloy in a monolithic form has been proposed as one fuel design capable of converting some of the world's highest power research reactors from the use of high enriched uranium to low enriched uranium. One aspect of the fuel development and qualification process is to demonstrate appropriate understanding of the thermal-conductivity behavior of the fuel system as a function of temperature and expected irradiation conditions. The purpose of this paper is to verify functionality of equipment installed in hot cells for eventual measurements on irradiated uranium-molybdenum (U-Mo) monolithic fuel specimens, refine procedures to operate the equipment, and validate models to extract the desired thermal properties. The results presented here demonstrate the adequacy of the equipment, procedures, and models that have been developed for this purpose based on measurements conducted on surrogate depleted uranium-molybdenum (DU-Mo) alloy samples containing a Zr diffusion barrier and clad in aluminum alloy 6061 (AA6061). The results are in excellent agreement with thermal property data reported in the literature for similar U-Mo alloys as a function of temperature.

  4. Preparation and properties of thin epoxy/compressed expanded graphite composite bipolar plates for proton exchange membrane fuel cells

    Science.gov (United States)

    Du, Chao; Ming, Pingwen; Hou, Ming; Fu, Jie; Shen, Qiang; Liang, Dong; Fu, Yunfeng; Luo, Xiaokuan; Shao, Zhigang; Yi, Baolian

    Although the composite bipolar plates prepared by the method of the vacuum resin impregnation in compressed expanded graphite (CEG) sheets have been applied in the KW-class stacks, there have been few investigations of the preparation and properties of them so far. In this research, the influences of the microstructure on the physical properties of the thin epoxy/CEG composites (the thickness is 1 mm) are investigated for the first time and the optimum preparation conditions are obtained. Results demonstrated that the mechanical property and the impermeability of the composites increases evidently with the resin content changing from 4% to 30%, while the electrical properties keep nearly constant. It can be attributed to the continuous expanded graphite (EG) conductive network of the raw CEG sheet. The epoxy (30 wt.%)/CEG composite is shown to be the optimum composite, displaying in-plane conductivity of 119.8 S cm -1, through-plane resistance of 17.13 mΩ cm 2, density of 1.95 g cm -3, gas permeability of 1.94 × 10 -6 cm 3 cm -2 s -1 and flexural strength of 45.8 MPa. The alcohol scrubbing is the optimum method of surface post-processing. The performance of a single cell with the optimum composite bipolar plates is tested and demonstrated to be outstanding. Above all, the composite prepared by resin vacuum impregnation in the CEG sheet is a promising candidate for bipolar plate materials in PEMFCs.

  5. Multifunctional polymeric nanocomposites fabricated by incorporation of exfoliated graphene nanoplatelets and their application in bipolar plates for polymer electrolyte membrane fuel cells

    Science.gov (United States)

    Jiang, Xian

    The focus of this research is to investigate the potential of using exfoliated graphene nanoplatelets, GNP, as the multifunctional nano-reinforcement in fabricating polymer/GNP nanocomposites and then explore their prospective applications in bipolar plates for polymer electrolyte membrane (PEM) fuel cells. Firstly, HDPE (high density polyethylene)/GNP nanocomposites were fabricated using the conventional compounding method of melt-extrusion followed by injection molding. The mechanical properties, crystallization behaviors, thermal stability, thermal conductivity, and electrical conductivity of the resulting HDPE/GNP nanocomposites were evaluated as a function of GNP concentration. Results showed that HDPE/GNP nanocomposites exhibit equivalent flexural modulus and strength to HDPE composites filled with other commercial reinforcements but they have superior impact strength. By investigating the crystallization behavior of HDPE/GNP nanocomposites, it was found that GNP is a good nucleating agent at low loading levels and as a result can significantly increase crystallization temperature and crystallinity of HDPE. At high GNP loadings, however, the close proximity of GNP particles retards the crystallization process. The thermal stability and thermal conductivity of HDPE/GNP nanocomposites were significantly enhanced due to the excellent thermal properties of GNP. Meanwhile, results indicated that the percolation threshold of these nanocomposites prepared by the conventional melt-extrusion and injection molding is relatively high at around 10--15 vol% GNP loading. To enhance the electrical conductivity of HDPE/GNP nanocomposites, two special processing methods named solid state ball milling (SSBM) and solid state shear pulverization (SSSP) were studied. The mechanism by which SSBM and SSSP are capable of producing lower percolation or higher electrical conductivity is to coat the polymer surface by GNP platelets which facilitate the formation of conductive networks

  6. Optimization of the preform shape in the three-stage forming process of the shielded slot plate in fuel cell manufacturing

    Science.gov (United States)

    Yang, Dong-Yol; Lee, Chang-Whan; Kang, Dong-Woo; Chang, In-Gab; Lee, Tae-Won

    2013-05-01

    The shielded slot plate, a repeated structure of high sheared protrusions, is a major component of metallic bipolar plates for the molten carbonate fuel cell (MCFC). In order to increase the efficiency of the MCFC and long-term operation capability, the sheared protrusion should have a relatively large flat contact area. In addition, defects from the forming process such as local thinning should be minimized. In this work, the preform shape in the three-stage forming process that integrates the slitting process, the preforming process, and the final forming process was optimized to minimize the effective plastic strain. In the simulation of the forming process, the ductile fracture criterion was employed to the user material subroutine VUMAT in ABAQUS/Explicit. Steepest descent method was utilized in the design of the forming process to minimize equivalent plastic strain. High sheared protrusions were manufactured without defects from the three-stage forming process using the optimized preform shape. The minimum thickness of one sheared protrusion was increased by 25% over that of the two-stage forming process. The three-stage forming process using the optimized preform shape enables more uniformly distributed deformation and reduces localized deformation.

  7. Electrochemical behavior of nanocrystalline Ta/TaN multilayer on 316L stainless steel: Novel bipolar plates for proton exchange membrane fuel-cells

    Science.gov (United States)

    Alishahi, M.; Mahboubi, F.; Mousavi Khoie, S. M.; Aparicio, M.; Hübner, R.; Soldera, F.; Gago, R.

    2016-08-01

    Insufficient corrosion resistance and surface conductivity are two main issues that plague large-scale application of stainless steel (SS) bipolar plates in proton exchange membrane fuel cells (PEMFCs). This study explores the use of nanocrystalline Ta/TaN multilayer coatings to improve the electrical and electrochemical performance of polished 316L SS bipolar plates. The multilayer coatings have been deposited by (reactive) magnetron sputtering and characterized by X-ray diffraction, field-emission scanning electron microscopy and transmission electron microscopy. The electrochemical behavior of bare and coated substrates has been evaluated in simulated PEMFC working environments by potentiodynamic and potentiostatic polarization tests at ambient temperature and 80 °C. The results show that the Ta/TaN multilayer coating increases the polarization resistance of 316L SS by about 30 and 104 times at ambient and elevated temperatures, respectively. The interfacial contact resistance (ICR) shows a low value of 12 mΩ × cm2 before the potentiostatic test. This ICR is significantly lower than for the bare substrate and remains mostly unchanged after potentiostatic polarization for 14 h. In addition, the high contact angle (92°) with water for coated substrates indicates a hydrophobic character, which can improve the water management within the cell in PEMFC stacks.

  8. Multilayered Zr-C/a-C film on stainless steel 316L as bipolar plates for proton exchange membrane fuel cells

    Science.gov (United States)

    Bi, Feifei; Peng, Linfa; Yi, Peiyun; Lai, Xinmin

    2016-05-01

    A multilayered zirconium-carbon/amorphous carbon (Zr-C/a-C) coating is synthesized by magnetron sputtering in order to improve the corrosion resistance and interfacial conductivity of stainless steel 316L (SS316L) as bipolar plates for proton exchange membrane fuel cells (PEMFCs). Zr-C/a-C film contains an outmost pure amorphous carbon layer and a sub zirconium containing carbon layer. Interfacial contact resistance (ICR) between carbon paper and coated SS316L decreases to 3.63 mΩ cm2 at 1.4 MPa. Potentiodynamic polarization results reveal that the corrosion potential of Zr-C/a-C coated sample is more positive than pure a-C coated sample and the current density is only 0.49 μA cm-2 at the cathode applied potential 0.6 V. Electrochemical impendence spectroscopy also indicates that multilayered Zr-C/a-C film coated SS316L has much higher charge transfer resistance than the bare sample. After potentiostatic polarization, ICR values are 3.92 mΩ cm2 and 3.82 mΩ cm2 in the simulated PEMFCs cathode and anode environment, respectively. Moreover, XPS analysis of the coated samples before and after potential holding tests shows little difference, which disclose the chemical stability of multilayered Zr-C/a-C film. Therefore, the multilayered Zr-C/a-C coating exhibits excellent performance in various aspects and is preferred for the application of stainless steel bipolar plates.

  9. Experiences of using UAVs for monitoring levee breaches

    Science.gov (United States)

    Brauneck, J.; Pohl, R.; Juepner, R.

    2016-11-01

    During floods technical protection facilities are subjected to high loads and might fail as several examples have shown in the past. During the major 2002 and 2013 floods in the catchment area of the Elbe River (Germany), some breaching levees caused large inundations in the hinterland. In such situations the emergency forces need comprehensive and reliable realtime information about the situation, especially the breach enlargement and discharge, the spatial and temporal development of the inundation and the damages. After an impressive progress meanwhile unmanned aerial vehicles (UAV) also called remotely piloted aircraft systems (RPAS) are highly capable to collect and transmit precise information from not accessible areas to the task force very quickly. Using the example of the Breitenhagen levee failure near the Saale-Elbe junction in Germany in June 2013 the processing steps will be explained that are needed to come from the visual UAV-flight information to a hydronumeric model. Modelling of the breach was implemented using photogrammetric ranging methods, such as structure from motion and dense image matching. These methods utilize conventional digital multiple view images or videos recorded by either a moving aerial platform or terrestrial photography and allow the construction of 3D point clouds, digital surface models and orthophotos. At Breitenhagen, a UAV recorded the beginning of the levee failure. Due to the dynamic character of the breach and the moving areal platform, 4 different surface models show valid data with extrapolated breach widths of 9 to 40 meters. By means of these calculations the flow rate through the breach has been determined. In addition the procedure has been tested in a physical model, whose results will be presented too.

  10. Managing breaches of containment and eradication of invasive plant populations.

    Science.gov (United States)

    Fletcher, Cameron S; Westcott, David A; Murphy, Helen T; Grice, Anthony C; Clarkson, John R

    2015-02-01

    Containment can be a viable strategy for managing invasive plants, but it is not always cheaper than eradication. In many cases, converting a failed eradication programme to a containment programme is not economically justified. Despite this, many contemporary invasive plant management strategies invoke containment as a fallback for failed eradication, often without detailing how containment would be implemented.We demonstrate a generalized analysis of the costs of eradication and containment, applicable to any plant invasion for which infestation size, dispersal distance, seed bank lifetime and the economic discount rate are specified. We estimate the costs of adapting eradication and containment in response to six types of breach and calculate under what conditions containment may provide a valid fallback to a breached eradication programme.We provide simple, general formulae and plots that can be applied to any invasion and show that containment will be cheaper than eradication only when the size of the occupied zone exceeds a multiple of the dispersal distance determined by seed bank longevity and the discount rate. Containment becomes proportionally cheaper than eradication for invaders with smaller dispersal distances, longer lived seed banks, or for larger discount rates.Both containment and eradication programmes are at risk of breach. Containment is less exposed to risk from reproduction in the 'occupied zone' and three types of breach that lead to a larger 'occupied zone', but more exposed to one type of breach that leads to a larger 'buffer zone'.For a well-specified eradication programme, only the three types of breach leading to reproduction in or just outside the buffer zone can justify falling back to containment, and only if the expected costs of eradication and containment were comparable before the breach.Synthesis and applications. Weed management plans must apply a consistent definition of containment and provide sufficient implementation detail

  11. Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 2: Numerical Modeling

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available The separator plays a key role on the performance of passive air-breathing flat-plate MFCs (FPMFC as it isolates the anaerobic anode from the air-breathing cathode. The goal of the present work was to study the separator characteristics and its effect on the performance of passive air-breathing FPMFCs. This was performed partially through characterization of structure, properties, and performance correlations of eight separators presented in Part 1. Current work (Part 2 presents a numerical model developed based on the mixed potential theory to investigate the sensitivity of the electrode potentials and the power output to the separator characteristics. According to this numerical model, the decreased peak power results from an increase in the mass transfer coefficients of oxygen and ethanol, but mainly increasing mixed potentials at the anode by oxygen crossover. The model also indicates that the peak power is affected by the proton transport number of the separator, which affects the cathode pH. Anode pH, on the other hand, remains constant due to application of phosphate buffer solution as the electrolyte. Also according to this model, the peak power is not sensitive to the resistivity of the separator because of the overshadowing effect of the oxygen crossover.

  12. Microstructural characterization of an irradiated RERTR-6 U-7Mo/AA4043 alloy dispersion fuel plate specimen blister-tested to a final temperature of 500 °C

    Science.gov (United States)

    Keiser, Dennis D.; Jue, Jan-Fong; Gan, Jian; Miller, Brandon D.; Robinson, Adam B.; Madden, James W.; Ross Finlay, M.; Moore, Glenn; Medvedev, Pavel; Meyer, Mitch

    2017-05-01

    The Material Management and Minimization (M3) Reactor Conversion Program, in the past called the Reduced Enrichment for Research and Test Reactor (RERTR) Program, is developing low-enriched uranium (LEU) fuels for application in research and test reactors. U-Mo alloy dispersion fuel is one type being developed. Blister testing has been performed on different fuel plate samples to determine the margin to failure for fuel plates irradiated to different fission densities. Microstructural characterization was performed using scanning electron microscopy and transmission electron microscopy on a sample taken from a U-7Mo/AA4043 matrix dispersion fuel plate irradiated in the RERTR-6 experiment that was blister-tested up to a final temperature of 500 °C. The results indicated that two types of grain/cell boundaries were observed in the U-7Mo fuel particles, one with a relatively low Mo content and fission gas bubbles and a second type enriched in Si, due to interdiffusion from the Si-containing matrix, with little evidence of fission gas bubbles. With respect to the behavior of the major fission gas Xe, a significant amount of the Xe was still observed within the U-7Mo fuel particle, along with microns into the AA4043 matrix. For the fuel/matrix interaction layers that form during fabrication and then grow during irradiation, they change from the as-irradiated amorphous structure to one that is crystalline after blister testing. In the AA4043 matrix, the original Si-rich precipitates, which are typically observed in as-irradiated U-Mo dispersion fuel, get consumed due to interdiffusion with the U-7Mo fuel particles during the blister test. Finally, the fission gas bubbles that were originally around 3 nm in diameter and resided on a fission gas superlattice (FGS) in the intragranular regions of as-irradiated U-7Mo fuel grew in size (up to ∼20 nm diameter) during blister testing and, in many areas, are no longer organized as a superlattice.

  13. Numerical and Experimental Investigation of a Supersonic Flow Field around Solid Fuel on an Inclined Flat Plate

    Directory of Open Access Journals (Sweden)

    Uzu-Kuei Hsu

    2009-01-01

    Full Text Available This research adopts a shock tube 16 meters long and with a 9 cm bore to create a supersonic, high-temperature, and high-pressure flowfield to observe the gasification and ignition of HTPB solid fuel under different environments. Also, full-scale 3D numerical simulation is executed to enhance the comprehension of this complex phenomenon. The CFD (Computational Fluid Dynamics code is based on the control volume method and the pre-conditioning method for solving the Navier-Stokes equations to simulate the compressible and incompressible coupling problem. In the tests, a HTPB slab is placed in the windowed-test section. Various test conditions generate different supersonic Mach numbers and environmental temperatures. In addition, the incident angles of the HTPB slab were changed relative to the incoming shock wave. Results show that as the Mach number around the slab section exceeded 1.25, the flowfield temperature achieved 1100 K, which is higher than the HTPB gasification temperature (930 K ~ 1090 K. Then, gasification occurred and a short-period ignition could be observed. In particular, when the slab angle was 7∘, the phenomenon became more visible. This is due to the flow field temperature increase when the slab angle was at 7∘.

  14. Decrease the Number of Glovebox Glove Breaches and Failures

    Energy Technology Data Exchange (ETDEWEB)

    Hurtle, Jackie C. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2013-12-24

    Los Alamos National Laboratory (LANL) is committed to the protection of the workers, public, and environment while performing work and uses gloveboxes as engineered controls to protect workers from exposure to hazardous materials while performing plutonium operations. Glovebox gloves are a weak link in the engineered controls and are a major cause of radiation contamination events which can result in potential worker exposure and localized contamination making operational areas off-limits and putting programmatic work on hold. Each day of lost opportunity at Technical Area (TA) 55, Plutonium Facility (PF) 4 is estimated at $1.36 million. Between July 2011 and June 2013, TA-55-PF-4 had 65 glovebox glove breaches and failures with an average of 2.7 per month. The glovebox work follows the five step safety process promoted at LANL with a decision diamond interjected for whether or not a glove breach or failure event occurred in the course of performing glovebox work. In the event that no glove breach or failure is detected, there is an additional decision for whether or not contamination is detected. In the event that contamination is detected, the possibility for a glove breach or failure event is revisited.

  15. 50 CFR 38.9 - Breach of the peace.

    Science.gov (United States)

    2010-10-01

    ... NATIONAL WILDLIFE REFUGE SYSTEM MIDWAY ATOLL NATIONAL WILDLIFE REFUGE Prohibitions § 38.9 Breach of the peace. No person on Midway Atoll National Wildlife Refuge will: (a) With intent to cause public... one's conduct is likely to cause affront or alarm. ...

  16. 75 FR 13138 - Grand Ditch Breach Restoration Environmental Impact Statement, Rocky Mountain National Park, CO

    Science.gov (United States)

    2010-03-18

    ... National Park Service Grand Ditch Breach Restoration Environmental Impact Statement, Rocky Mountain... prepare an Environmental Impact Statement for the Grand Ditch Breach Restoration, Rocky Mountain National...), the National Park Service is preparing an Environmental Impact Statement for the Grand Ditch...

  17. Characterization and performance of UNS S63019 (21-4N) as bipolar plate material in a simulated polymer electrolyte membrane fuel cell environment

    Science.gov (United States)

    Howell, Andrew G.; Wang, Heli; Cowley, Scott W.; Turner, John A.

    The austenitic stainless steel UNS S63019 was evaluated regarding its potential as bipolar plate material in a polymer electrolyte membrane fuel cell (PEMFC) environment. Segregated grains of niobium carbide (NbC x) were identified in polished cross-sections of the alloy, offering a possible pathway for enhanced electrical conductivity through the passive surface oxide. Additionally, the alloy was tested for corrosion resistance in a simulated PEMFC environment. It was considered that perhaps the elevated nitrogen concentration in the alloy would provide some benefit for corrosion resistance. Results for interfacial contact resistance (ICR) testing of the air-formed surface film on UNS S63019 showed decreased electrical conductivity as compared to UNS S30400. Niobium carbide particles did not improve film conductivity due to a non-conductive niobium oxide layer that formed on the surface. Corrosion resistance of the alloy was also poor as compared with UNS S30400, demonstrating that elevated nitrogen concentration in the alloy was not adequate in itself to enhance corrosion resistance. Poor corrosion resistance was attributed primarily to high carbon content in the alloy which combined with a significant amount of chromium to form carbides.

  18. A Systematic Study of Separators in Air-Breathing Flat-Plate Microbial Fuel Cells—Part 1: Structure, Properties, and Performance Correlations

    Directory of Open Access Journals (Sweden)

    Sona Kazemi

    2016-01-01

    Full Text Available Passive air-breathing microbial fuel cells (MFCs are a promising technology for energy recovery from wastewater and their performance is highly dependent on characteristics of the separator that isolates the anaerobic anode from the air-breathing cathode. The goal of the present work is to systematically study the separator characteristics and its effect on the performance of passive air-breathing flat-plate MFCs (FPMFCs. This was performed through characterization of structure, properties, and performance correlations of eight separators in Part 1 of this work. Eight commercial separators were characterized, in non-inoculated and inoculated setups, and were examined in passive air-breathing FPMFCs with different electrode spacing. The results showed a decrease in the peak power density as the oxygen and ethanol mass transfer coefficients in the separators increased, due to the increase of mixed potentials especially at smaller electrode spacing. Increasing the electrode spacing was therefore desirable for the application of diaphragms. The highest peak power density was measured using Nafion®117 with minimal electrode spacing, whereas using Nafion®117 or Celgard® with larger electrode spacing resulted in similar peak powers. Part 2 of this work focuses on numerical modelling of the FPMFCs based on mixed potential theory, implementing the experimental data from Part 1.

  19. Thermally Nitrided Stainless Steels for Polymer Electrolyte Membrane Fuel Cell Bipolar Plates: Part 2: Beneficial Modification of Passive Layer on AISI446

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Heli [National Renewable Energy Laboratory (NREL); Brady, Michael P [ORNL; More, Karren Leslie [ORNL; Meyer III, Harry M [ORNL; Turner, John [National Renewable Energy Laboratory (NREL)

    2004-01-01

    Thermal nitridation of AISI446 mod-1 superferritic stainless steel for 24 h at 1100 C resulted in an adherent, inward growing surface layer based on (Cr, Fe){sub 2}N{sub 1-x} (x = 0--0.5). The layer was not continuous, and although it resulted in low interfacial contact resistance (ICR) and good corrosion resistance under simulated polymer electrolyte membrane fuel cell (PEMFC) cathodic conditions; poor corrosion resistance was observed under simulated anodic conditions. Nitridation for 2 h at 1100 C resulted in little nitrogen uptake and a tinted surface. Analysis by SEM, XPS, and AES suggested a complex heterogeneous modification of the native passive oxide film by nitrogen rather than the desired microns-thick exclusive Cr-rich nitride layer. Surprisingly, this modification resulted in both good corrosion resistance under simulated cathodic and anodic conditions and low ICR, well over an order of magnitude lower than the untreated alloy. Further, little increase in ICR was observed under passivating polarization conditions. The potential of this phenomenon for PEMFC bipolar plates is discussed.

  20. The Treatment of PPCP-Containing Sewage in an Anoxic/Aerobic Reactor Coupled with a Novel Design of Solid Plain Graphite-Plates Microbial Fuel Cell

    Directory of Open Access Journals (Sweden)

    Yi-Tang Chang

    2014-01-01

    Full Text Available Synthetic sewage containing high concentrations of pharmaceuticals and personal care products (PPCPs, mg/L level was treated using an anoxic/aerobic (A/O reactor coupled with a microbial fuel cell (MFC at hydraulic retention time (HRT of 8 h. A novel design of solid plain graphite plates (SPGRPs was used for the high surface area biodegradation of the PPCP-containing sewage and for the generation of electricity. The average CODCr and total nitrogen removal efficiencies achieved were 97.20% and 83.75%, respectively. High removal efficiencies of pharmaceuticals, including acetaminophen, ibuprofen, and sulfamethoxazole, were also obtained and ranged from 98.21% to 99.89%. A maximum power density of 532.61 mW/cm2 and a maximum coulombic efficiency of 25.20% were measured for the SPGRP MFC at the anode. Distinct differences in the bacterial community were presented at various locations including the mixed liquor suspended solids and biofilms. The bacterial groups involved in PPCP biodegradation were identified as Dechloromonas spp., Sphingomonas sp., and Pseudomonas aeruginosa. This design, which couples an A/O reactor with a novel design of SPGRP MFC, allows the simultaneous removal of PPCPs and successful electricity production.

  1. Surface characteristic of chemically converted graphene coated low carbon steel by electro spray coating method for polymer electrolyte membrane fuel cell bipolar plate.

    Science.gov (United States)

    Kim, Jungsoo; Kim, Yang Do; Nam, Dae Geun

    2013-05-01

    Graphene was coated on low carbon steel (SS400) by electro spray coating method to improve its properties of corrosion resistance and contact resistance. Exfoliated graphite was made of the graphite by chemical treatment (Chemically Converted Graphene, CCG). CCG is distributed using dispersing agent, and low carbon steel was coated with diffuse graphene solution by electro spray coating method. The structure of the CCG was analyzed using XRD and the coating layer of surface was analyzed using SEM. Analysis showed that multi-layered graphite structure was destroyed and it was transformed in to fine layers graphene structure. And the result of SEM analysis on the surface and the cross section, graphene layer was uniformly formed with 3-5 microm thickness on the surface of substrate. Corrosion resistance test was applied in the corrosive solution which is similar to the polymer electrolyte membrane fuel cell (PEMFC) stack inside. And interfacial contact resistance (ICR) test was measured to simulate the internal operating conditions of PEMFC stack. As a result of measuring corrosion resistance and contact resistance, it could be confirmed that low carbon steel coated with CCG was revealed to be more effective in terms of its applicability as PEMFC bipolar plate.

  2. Antecedents of Psychological Contract Breach: The Role of Job Demands, Job Resources, and Affect

    OpenAIRE

    Tim Vantilborgh; Jemima Bidee; Roland Pepermans; Yannick Griep; Joeri Hofmans

    2016-01-01

    While it has been shown that psychological contract breach leads to detrimental outcomes, relatively little is known about factors leading to perceptions of breach. We examine if job demands and resources predict breach perceptions. We argue that perceiving high demands elicits negative affect, while perceiving high resources stimulates positive affect. Positive and negative affect, in turn, influence the likelihood that psychological contract breaches are perceived. We conducted two experien...

  3. Battling Data Breaches: For Higher Education Institutions, Data Breach Prevention is More Complex than for Industry and Business

    Science.gov (United States)

    Patton, Madeline

    2015-01-01

    Data breach prevention is a battle, rarely plain and never simple. For higher education institutions, the Sisyphean aspects of the task are more complex than for industry and business. Two-year colleges have payrolls and vendor contracts like those enterprises. They also have public record and student confidentiality requirements. Colleges must…

  4. Application of sediment transport formulae to sand-dike breach erosion

    NARCIS (Netherlands)

    Visser, P.J.

    1994-01-01

    The Technical Advisory Committee on Water Defences in the Netherlands has decided to develop a mathematical model for breach erosion in dunes and dikes, with which it will be possible to predict the growth of the breach and the discharge rate through the breach in case of a dike-burst. An essential

  5. Overtopping breaching of cohesive homogeneous earth dam with different cohesive strength

    Institute of Scientific and Technical Information of China (English)

    ZHANG JianYun; LI Yun; XUAN GuoXiang; WANG XiaoGang; LI Jun

    2009-01-01

    dumping collapse.When the cohesive strength is smaller,the breach process becomes faster,and the peak outflow,the final width and depth of breach become bigger.The main character of the breach formation is single level head cutting and shearing collapse.

  6. Experimental study of breach process of landslide dams by overtopping and its initiation mechanisms

    Institute of Scientific and Technical Information of China (English)

    杨阳; 曹叔尤; 杨克君; 李文萍

    2015-01-01

    The present paper studies the physics of the breach erosion process, particularly, the breach initiation process in over- topped landslide dams. Due to great complexities involved, only homogeneous landslide dams are considered. The flume experime- nts of dam overtopping are conducted to study the breach growth process. And in order to reveal the effects of the seepage during the breach development, the permeability characteristics of the dam materials are also taken into consideration. With the experimental observation, the details of the breach growth are examined, and the whole breach process could be distinguished into five stages, i.e., Stage I, the seepage erosion, Stage II, the formation of the initial breach, Stage III, the erosion toward the head, Stage IV, the expan- sion and incision of the breach, and Stage V, the re-equilibration of the river channel through the breach. It is shown that once trigge- red the entire breach process goes continually without stop, which highlights the significant impact of the early stages on the later deformation of the dam. Evidence shows that the initial breach of the dam is most likely to take place in the downstream slope of the dam, near the upper edge of the seepage face. The experimental results show a “headcut” mechanism of the breach initiation.

  7. 25 CFR 163.42 - Obligated service and breach of contract.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Obligated service and breach of contract. 163.42 Section... breach of contract. (a) Obligated service. (1) Individuals completing forestry education programs with an... request for waiver. (b) Breach of contract. Any individual who has participated in and accepted...

  8. 15 CFR 971.405 - Breach of international peace and security involving armed conflict.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Breach of international peace and..., Modification/revision; Suspension/revocation § 971.405 Breach of international peace and security involving... expected to lead to a breach of international peace and security involving armed conflict....

  9. 78 FR 32441 - Grand Ditch Breach Restoration, Final Environmental Impact Statement, Rocky Mountain National...

    Science.gov (United States)

    2013-05-30

    ... National Park Service Grand Ditch Breach Restoration, Final Environmental Impact Statement, Rocky Mountain... Availability of the Final Environmental Impact Statement for the Grand Ditch Breach Restoration, Rocky Mountain... Grand Ditch Breach Restoration, Rocky Mountain National Park, Colorado. DATES: The National Park...

  10. 31 CFR 355.6 - What happens if the presenting bank breaches its warranty?

    Science.gov (United States)

    2010-07-01

    ... breaches its warranty? 355.6 Section 355.6 Money and Finance: Treasury Regulations Relating to Money and... GOVERNING FISCAL AGENCY CHECKS § 355.6 What happens if the presenting bank breaches its warranty? If the presenting bank breaches its warranty, the payor Reserve Bank may either return the check to the...

  11. 41 CFR 50-203.1 - Reports of breach or violation.

    Science.gov (United States)

    2010-07-01

    ... 41 Public Contracts and Property Management 1 2010-07-01 2010-07-01 true Reports of breach or... of the Walsh-Healey Public Contracts Act § 50-203.1 Reports of breach or violation. (a) Any employer, employee, labor or trade organization or other interested person or organization may report a breach...

  12. 15 CFR 970.505 - Breach of international peace and security involving armed conflict.

    Science.gov (United States)

    2010-01-01

    ... 15 Commerce and Foreign Trade 3 2010-01-01 2010-01-01 false Breach of international peace and.../revision; Suspension/revocation § 970.505 Breach of international peace and security involving armed... to a breach of international peace and security involving armed conflict....

  13. 32 CFR 507.18 - Processing complaints of alleged breach of policies.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Processing complaints of alleged breach of... Program § 507.18 Processing complaints of alleged breach of policies. The Institute of Heraldry may revoke or suspend the certificate of authority to manufacture if there are breaches of quality...

  14. Analysis of Blistering Mechanism for Dispersion-Type Fuel Plates During Irradiation%弥散型燃料板的辐照起泡机理分析

    Institute of Scientific and Technical Information of China (English)

    高利军; 陈炳德; 姜胜耀; 肖忠; 俞冀阳; 张林; 李垣明

    2012-01-01

    弥散型燃料在研究堆和动力堆中有着广泛的应用.起泡是弥散型燃料特有的失效模式,起泡的发生将导致堆芯传热性能恶化,威胁反应堆的运行安全.在分析总结国内外弥散型燃料板的辐照后起泡退火试验结果的基础上,从微观尺度到宏观尺度分析了起泡发生的机理,重点研究了弥散型燃料板的一种重要起泡模式——孔洞连通模式,剖析了孔洞连通发生的3个基本过程.同时应用孔洞连通机理,在估算裂变气体压力的前提下,通过力学计算给出了可引起起泡的孔洞连通的圆形区域尺度约为1.8 mm,这与实验观察结果相符.本文分析表明,燃料板的孔洞连通起泡机理涉及到高燃耗效应、燃料相的肿胀和开裂、裂变碎片损伤和应力腐蚀开裂等过程,建立起泡模型需做弹塑性力学和断裂力学的数值计算.%Dispersion fuels are widely used in research reactors and power reactors. Blistering is a special failure mode for dispersion fuels, which can reduce the efficiency of thermal removal in the core and threaten the nuclear reactor safety. Based on the results of blistering of dispersion-type fuel plates during post-irradiation annealing experiments worldwide, the mechanism of blistering was studied both at the microscopic scale and at the macroscopic scale and the important blistering mode known as void interconnection, which consisted of three separate processes, was emphasized and elaborated. Using the proposed mechanism and assuming the estimation of the pressure caused by fission gas, the dimension of the round region which could induce blistering was calculated using mechanics method and the value of 1. 8 mm was gained, showing good consistency with the experimental observation. This work shows that the proposed void interconnection mechanism of blistering is closely related to the high burnup structure, swelling and cracking of fuel phase, fission fragment damage and stress

  15. Study on mould pressing composite bipolar plates made of expanded graphite/resin for fuel cells%燃料电池模压膨胀石墨/树脂复合双极板研究

    Institute of Scientific and Technical Information of China (English)

    史惟澄; 杨代军; 刘金玲; 钱铮; 马建新

    2013-01-01

    The resin and expanded graphite used to prepare the mould pressing composite bipolar plates of fuel cells were discussed: the influence of ratio of resin on bipolar plates, the resin would not only ensure the high mechanical strength and gas permeability of bipolar plates, but also would be beneficial to reduce the manufacture. It could help to develop the fuel cells and marketization. In order to make up the decline of electrical conductivity when adding resin to bipolar plates, some auxiliary conductive filler should be added, such as carbon fiber, carbon nano tube to bipolar plates. Furthermore, the technological parameter of mould pressing would influence on the property of bipolar plates.%综述了用于质子交换膜燃料电池的模压膨胀石墨/树脂复合双极板的树脂选型以及膨胀石墨:树脂的配比对双极板性能的影响,所选树脂除了要能保证双极板的较高机械强度和气密性外,还要有利于低成本化的模压生产,才能有效地促进燃料电池的发展,推动其商业化.为了弥补双极板加入树脂后带来的电导率下降的问题,还需加入碳纤维、碳纳米管等辅助导电填料.此外,模压工艺及参数的选择与确定对双极板的性能也有直接影响.

  16. Tapping Transaction Costs to Forecast Acquisition Cost Breaches

    Science.gov (United States)

    2016-01-01

    management , survival analysis  lead image by Diane Fleischer 58 Controlling cost growth for a major defense acquisition program (MDAP) has been...directing and controlling a totally integrated engineering effort of a system or program.” Program management is defined as “the business and...56 Defense ARJ, January 2016, Vol. 23 No. 1 : 56–76 TAPPING Transaction Costs to Forecast Acquisition COST BREACHES Laura E. Armey and Diana I

  17. Implications of Transaction Costs for Acquisition Program Cost Breaches

    Science.gov (United States)

    2013-06-01

    Government. IRB Protocol number ____N/A____. 12a. DISTRIBUTION / AVAILABILITY STATEMENT Approved for public release; distribution is unlimited 12b...purchasing price for the home (bargaining and decision costs). Last, if the home was purchased using money that was borrowed from a mortgage lender , the...not significantly affect the ability of an MDAP to operate within its approved financial constraints as measured by cost breaches. B. DATA The cost

  18. Transaction Costs and Cost Breaches in Major Defense Acquisition Programs

    Science.gov (United States)

    2014-02-04

    ADDRESS(ES) 10. SPONSOR/MONITOR’S ACRONYM(S) 11. SPONSOR/MONITOR’S REPORT NUMBER(S) 12. DISTRIBUTION/AVAILABILITY STATEMENT Approved for public release...price for the home (bargaining and decision costs). Last, if the home was purchased using money that was borrowed from a mortgage lender , the...operate within its approved financial constraints as measured by cost breaches. Data Sources This study used two major data sources to develop the

  19. Standard breach remedies, quality thresholds, and cooperative investments

    OpenAIRE

    Stremitzer, Alexander

    2008-01-01

    When investments are non-verifiable, inducing cooperative investments with simple contracts may not be as difficult as previously thought. Indeed, modeling 'expectation damages' close to legal practice, we show that the default remedy of contract law induces the first best. Yet, in order to lower informational requirements of courts, parties may opt for a 'specific performance' regime which grants the breached-against buyer an option to choose 'restitution' if the tender's value falls below s...

  20. Temporally remote destabilization of prediction after rare breaches of expectancy.

    Science.gov (United States)

    Kühn, Anne B; Schubotz, Ricarda I

    2012-08-01

    While neural signatures of breaches of expectancy and their immediate effects have been investigated, thus far, temporally more remote effects have been neglected. The present fMRI study explored neural correlates of temporally remote destabilization of prediction following rare breaches of expectancy with a mean delay of 14 s. We hypothesized temporally remote destabilization to be reflected either in an attenuation of areas related to long-term memory or in an increase of lateral fronto-parietal loops related to the encoding of new stimuli. Monitoring a deterministic 24-digit sequence, subjects were asked to indicate occasional sequential omissions by key press. Temporally remote destabilization of prediction was expected to be revealed by contrasting sequential events whose equivalent was omitted in the preceding sequential run n-1 (destabilized events) with sequential events without such history (nondestabilized events). Temporally remote destabilization of prediction was reflected in an attenuation of activity in the dorsal frontomedian cortex (Brodmann Area (BA) 9) bilaterally. Moreover, activation of the left medial BA 9 was enhanced by contrasting nondestabilized events with breaches. The decrease of dorsal frontomedian activation in the case of destabilized events might be interpreted as a top-down modulation on perception causing a less expectation-restricted encoding of the current stimulus and hence enabling the adaptation of expectation and prediction in the long run.

  1. Mainstream body-character breach films and subjectivization.

    Science.gov (United States)

    Meiri, Sandra; Kohen-Raz, Odeya

    2017-02-01

    The authors analyze a unique cinematic corpus - 'body-character breach films' (one character, initially played by a certain actor, occupies the body of another character) - demonstrating Lacan's notion of traversing the fantasy, both on the level of the films' diegesis and that of spectatorship. Breaching the alliance between actors and their characters perturbs the viewer's fantasy of wholeness enabled by this very alliance. Consequently, a change in subject/spectatorial position in relation to the lack in the Other is induced, enhanced through the visualization of various scenarios of unconscious fantasies (mostly incest). These are meant to unsettle the spectator into an awareness of how a conscious fantasy conceals another unconscious fundamental fantasy, thereby encouraging a change in spectatorial position (from 'perverse'/fetishistic to 'neurotic'). Conflating this change with Lacan's notion of traversing the fantasy, the authors contend that mainstream cinema has the capacity to induce a process of subjectivization (assuming responsibility for one's own desire). This process is contingent on four conditions: identification with the protagonist's fantasy to conceal the lack in the Other; dissolution of this fantasy, initiated by the body-character breach; rhetorical strategies (the coding of unconscious scenarios cinematically); and an ethical dimension (encouraging the subject/spectator to follow her/his desire). Copyright © 2016 Institute of Psychoanalysis.

  2. Fuel nozzle tube retention

    Energy Technology Data Exchange (ETDEWEB)

    Cihlar, David William; Melton, Patrick Benedict

    2017-02-28

    A system for retaining a fuel nozzle premix tube includes a retention plate and a premix tube which extends downstream from an outlet of a premix passage defined along an aft side of a fuel plenum body. The premix tube includes an inlet end and a spring support feature which is disposed proximate to the inlet end. The premix tube extends through the retention plate. The spring retention feature is disposed between an aft side of the fuel plenum and the retention plate. The system further includes a spring which extends between the spring retention feature and the retention plate.

  3. Overtopping breaching of cohesive homogeneous earth dam with different cohesive strength

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    In consideration of the range of clay content of Chinese earth dams, the world’s highest prototype tests have been made to research on the effects of cohesive strength of filling of cohesive homogeneous earth dam on breach formation. Three breach mechanisms were presented, they were the source-tracing erosion of dam body with the form of "multilevel headcut", "two-helix flow" erosion of dam crest and collapse of breach sidewalls due to instability. It can be concluded that the cohesive strength of filling of earth dam has great effect on breach formation. When the cohesive strength is bigger, the breach process becomes slower, and the peak outflow and the final width and depth of breach become smaller. The main character of the breach formation is head cutting and dumping collapse. When the cohesive strength is smaller, the breach process becomes faster, and the peak outflow, the final width and depth of breach become bigger. The main character of the breach formation is single level head cutting and shearing collapse.

  4. Development of a portable PEM fuel cell system with bipolar plates consisting an electronically conductive thermoplastic Compound material; Entwicklung eines portablen PEM-Brennstoffzellensystems mit Bipolarplatten aus einem elektronisch leitfaehigen thermoplastischen Compound-Material

    Energy Technology Data Exchange (ETDEWEB)

    Niemzig, O.C.

    2005-07-18

    In order to meet the cost targets of PEM fuel cells for commercialization significant cost reductions of cell stack components like membrane/electrode assemblies and bipolar plates have become key aspects of research and development. Central topics of his work are the bipolar plates and humidification for portable applications. Best results concerning conductivity of an extensive screening of a variety of carbon polymer compounds with polypropylene as matrix could be achieved with the carbon black/graphite/polypropylene-base system. Successful tests of this material in a fuel cell stack could be performed as well as the proof of suitability concerning material- and manufacturing costs. Dependent on application a decrease of material cost to 2 Euro/kg to 1,8 Euro/kW seems to be possible. Finally bipolar plates consisting of a selected carbon polymer compound were successfully integrated and tested in a 20-cell stack which was implemented in a portable PEFC-demonstrator unit with a power output between 50 and 150 W. (orig.)

  5. INL HIP Plate Fabrication

    Energy Technology Data Exchange (ETDEWEB)

    B. H. Park; C. R. Clark; J. F. Jue

    2010-02-01

    This document outlines the process used to bond monolithic fuel plates by Hot Isostatic Pressing (HIP). This method was developed at Idaho National Laboratory (INL) for the Reduced Enrichment for Research and Test Reactors (RERTR) program. These foils have been used in a number of irradiation experiments in support of the United States Global Threat Reduction Initiative (GTRI) program.

  6. Analysis on the `Thermite` reaction consequences in accidents involving research reactors using plate-type fuel; Analisis sobre las concequencias de la reaccion `Termita` en caso de accidentes en reactores de investigacion que utilizan combustible tipo placa

    Energy Technology Data Exchange (ETDEWEB)

    Boero, Norma L.; Bruno, Hernan R.; Camacho, Esteban F.; Cincotta, Daniel O.; Yorio, Daniel [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Constituyentes

    1999-11-01

    The mixture of Al-U{sub 3} O{sub 8} is not in a state of chemical equilibrium, and at temperatures of between 850 deg C and 1000 deg C, it reacts exo thermally. This is known, in corresponding bibliography as a `Thermite reaction. This mixture is used in the manufacturing of the plate-type fuel used in research reactors. It has been pointed out that the release of energy caused by this type of reactions might represent a risk in case of accidents in this type of reactor. Conclusions, in general, tend to indicate that no such risk exists, although no concrete assurance is given that this is the case, and this fact, therefore, leaves room for doubt. The objective of this paper is to provide an in-depth study of what happens to a fuel plate when it is subjected to thermite reaction. We will, furthermore, analyze the consequences of the release of energy generated by this type of reaction within the core of the reactor, clearly defining the problem for this type of fuel and this kind of reactor. (author) 3 refs., 9 figs., 1 tab.

  7. Impact of uranium concentration reduction in side plates of the fuel elements of IEA-R1 reactor on neutronic and thermal hydraulic analyses; Impacto da reducao na concentracao de uranio nas placas laterais dos elementos combustiveis do reator IEA-R1 nas analises neutronica e termo-hidraulica

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Ilka Antonia

    2013-09-01

    This master thesis presents a study to verify the impact of the uranium concentration reduction in the side plates of the reactor IEA-R1 fuel elements on the neutronic and thermal-hydraulic analyses. To develop such study, a previous IPEN-CNEN/SP research was reproduced by simulating the fuel elements burn-up, with side plate uranium density reduced to 50, 60 and 70% of the standard fuel element plates. This research begins with the neutronic analysis using the computer code HAMMER and the first step consists in the calculation of the cross section of all materials presented at the reactor core, with their initial concentration; the second step consists in the calculation of the fast and thermal neutron group fluxes and power densities for fuel elements using the computer code CITATION. HAMMER output data is used as input data. Once the neutronic analysis is finished and the most critical fuel elements with highest power density have been defined, the thermal-hydraulics analysis begins. This analysis uses MCTR-IEA-R1 thermal-hydraulics model, which equations are solved by commercial code EES. Thermalhydraulics analysis input is the power density data calculated by CITATION: it is considered the highest power density on each fuel element, where there is a higher energy release and, consequently, higher temperatures. This data is used on energy balance equations to calculate temperatures on critical fuel element regions. Reactor operation comparison for three different uranium densities on fuel side plates is presented. Uranium density reduction contributes to the cladding surface temperature to remain below the established limit, as reactor operation safety requirement and it does not affect significantly fuel element final burn-up nor reactor reactivity. The reduction of uranium in the side plates of the fuel elements of the IEA-R1 showed to be a viable option to avoid corrosion problems due to high temperatures. (author)

  8. Psychological contract breaches, organizational commitment, and innovation-related behaviors: a latent growth modeling approach.

    Science.gov (United States)

    Ng, Thomas W H; Feldman, Daniel C; Lam, Simon S K

    2010-07-01

    This study examined the relationships among psychological contract breaches, organizational commitment, and innovation-related behaviors (generating, spreading, implementing innovative ideas at work) over a 6-month period. Results indicate that the effects of psychological contract breaches on employees are not static. Specifically, perceptions of psychological contract breaches strengthened over time and were associated with decreased levels of affective commitment over time. Further, increased perceptions of psychological contract breaches were associated with decreases in innovation-related behaviors. We also found evidence that organizational commitment mediates the relationship between psychological contract breaches and innovation-related behaviors. These results highlight the importance of examining the nomological network of psychological contract breaches from a change perspective.

  9. HIV-1 Nef breaches placental barrier in rat model.

    Science.gov (United States)

    Singh, Poonam; Agnihotri, Saurabh Kumar; Tewari, Mahesh Chandra; Kumar, Sadan; Sachdev, Monika; Tripathi, Raj Kamal

    2012-01-01

    The vertical transmission of HIV-1 from the mother to fetus is known, but the molecular mechanism regulating this transmission is not fully characterized. The fetus is highly protected by the placenta, which does not permit microbial pathogens to cross the placental barrier. In the present study, a rat model was established to observe the effect of HIV-1 protein Nef on placental barrier. Evans blue dye was used to assay permeability of placental barrier and fourteen day pregnant Sprague Dawley rats were injected intravenously with 2% Evans blue dye along with various concentrations of recombinant Nef. After an hour, animals were sacrificed and dye migration was observed through the assimilation of peripheral blood into fetus. Interestingly, traces of recombinant Nef protein were detected in the embryo as well as amniotic fluid and amniotic membrane along with placenta and uterus. Our study indicates that recombinant HIV-1-Nef protein breaches the placental barrier and allows the migration of Evans blue dye to the growing fetus. Further the concentration of Nef protein in blood is directly proportional to the intensity of dye migration and to the amount of Nef protein detected in uterus, placenta, amniotic membrane, amniotic fluid and embryo. Based on this study, it can be concluded that the HIV-1 Nef protein has a direct effect on breaching of the placental barrier in the model we have established in this study. Our observations will be helpful to understand the molecular mechanisms related to this breach of placental barrier by Nef in humans and may be helpful to identify specific Nef inhibitors.

  10. Security breaches: tips for assessing and limiting your risks.

    Science.gov (United States)

    Coons, Leeanne R

    2011-01-01

    As part of their compliance planning, medical practices should undergo a risk assessment to determine any vulnerability within the practice relative to security breaches. Practices should also implement safeguards to limit their risks. Such safeguards include facility access controls, information and electronic media management, use of business associate agreements, and education and enforcement. Implementation of specific policies and procedures to address security incidents is another critical step that medical practices should take as part of their security incident prevention plan. Medical practices should not only develop policies and procedures to prevent, detect, contain, and correct security violations, but should make sure that such policies and procedures are actually implemented in their everyday operations.

  11. 单片式核燃料板轧制过程的数值模拟研究%Numerical Simulation Research on Rolling Process of Monolithic Nuclear Fuel Plate

    Institute of Scientific and Technical Information of China (English)

    万继波; 孔祥喆; 丁淑蓉; 徐宏彬; 霍永忠

    2015-01-01

    针对UMo合金单片式核燃料板锆合金包壳材料应变率相关的力学本构关系,推导出其三维应力更新算法,相应地编写了定义其本构关系的VUMAT子程序并验证了程序的正确性;建立了对UMo合金单片式板元件的框架轧制过程进行计算模拟的有限元模型;利用显式动力有限元法,计算分析了复合坯内部的变形以及接触压强在轧制过程中的演化规律。研究结果表明,利用VUMAT 用户材料子程序能方便正确地定义材料应变率相关的本构关系;燃料芯体与盖板之间的轧制接触压力随时间而演化,在靠近宽度方向的对称面处具有最大的接触压力。本研究为优化UMo合金单片式核燃料板的制造工艺参数提供了理论基础和计算手段。%For the strain‐rate‐dependent constitutive relation of zircaloy cladding in UMo monolithic nuclear fuel plates , the three‐dimensional stress updating algorithm was derived out , and the corresponding VUMAT subroutine to define its constitutive relation was developed and validated ;the finite element model was built to simulate the frame rolling process of UMo monolithic nuclear fuel plates ;with the explicit dynamic finite element method , the evolution rules of the deformation and contact pressure during the rolling process within the composite slab were obtained and analyzed .The research results indicate that it is convenient and efficient to define the strain‐rate‐dependent constitutive relations of materials with the user‐defined material subroutine VUMAT ;the rolling‐induced contact pressure between the fuel meat and the covers varies with time ,and the maximum pressure exits at the symmetric plane along the plate width direction .This study supplies a foundation and a computation method for optimi‐zing the processing parameters to manufacture UMo monolithic nuclear fuel plates .

  12. Barrier island breach evolution: Alongshore transport and bay-ocean pressure gradient interactions

    Science.gov (United States)

    Safak, Ilgar; Warner, John C.; List, Jeffrey H.

    2016-12-01

    Physical processes controlling repeated openings and closures of a barrier island breach between a bay and the open ocean are studied using aerial photographs and atmospheric and hydrodynamic observations. The breach site is located on Pea Island along the Outer Banks, separating Pamlico Sound from the Atlantic Ocean. Wind direction was a major control on the pressure gradients between the bay and the ocean to drive flows that initiate or maintain the breach opening. Alongshore sediment flux was found to be a major contributor to breach closure. During the analysis period from 2011 to 2016, three hurricanes had major impacts on the breach. First, Hurricane Irene opened the breach with wind-driven flow from bay to ocean in August 2011. Hurricane Sandy in October 2012 quadrupled the channel width from pressure gradient flows due to water levels that were first higher on the ocean side and then higher on the bay side. The breach closed sometime in Spring 2013, most likely due to an event associated with strong alongshore sediment flux but minimal ocean-bay pressure gradients. Then, in July 2014, Hurricane Arthur briefly opened the breach again from the bay side, in a similar fashion to Irene. In summary, opening and closure of breaches are shown to follow a dynamic and episodic balance between along-channel pressure gradient driven flows and alongshore sediment fluxes.

  13. SECURITY BREACH IN TRADING SYSTEM-COUNTERMEASURE USING IPTRACEBACK

    Directory of Open Access Journals (Sweden)

    M. P. Rajakumar

    2014-01-01

    Full Text Available Recently, economic scenario is often facing security breach that has heavy impact on the financial soundness of a company particularly, stock prices on firms. The utmost consequence being the whole business comes to a standstill. From the estimates attributed by the financial sector, it has been inferred that the loss incurred on virus and worms attack is said to have the greatest impact that hampers the prosperity of a business entity. Thus, security strategies attempt on revolving around the act of security breach, thereby targeting to curb the financial losses of a company totally or at least minimize the losses. If the operating system of the stock market or financial sector gets corrupted the whole system need to be formatted, a new operating system has to be reinstalled and the antivirus software tends to be useless in such cases. In this study, virus and worms are encountered using IPTraceback technique and network security is ensured. The effective integration of spectral analysis, worm detection and IPTraceback, alerts the user dynamically and kills the source which distributes the virus. Real time traffic data are used for evaluating the performance.

  14. The anterior insular cortex represents breaches of taste identity expectation.

    Science.gov (United States)

    Veldhuizen, Maria G; Douglas, Danielle; Aschenbrenner, Katja; Gitelman, Darren R; Small, Dana M

    2011-10-12

    Despite the importance of breaches of taste identity expectation for survival, its neural correlate is unknown. We used fMRI in 16 women to examine brain response to expected and unexpected receipt of sweet taste and tasteless/odorless solutions. During expected trials (70%), subjects heard "sweet" or "tasteless" and received the liquid indicated by the cue. During unexpected trials (30%), subjects heard sweet but received tasteless or they heard tasteless but received sweet. After delivery, subjects indicated stimulus identity by pressing a button. Reaction time was faster and more accurate after valid cuing, indicating that the cues altered expectancy as intended. Tasting unexpected versus expected stimuli resulted in greater deactivation in fusiform gyri, possibly reflecting greater suppression of visual object regions when orienting to, and identifying, an unexpected taste. Significantly greater activation to unexpected versus expected stimuli occurred in areas related to taste (thalamus, anterior insula), reward [ventral striatum (VS), orbitofrontal cortex], and attention [anterior cingulate cortex, inferior frontal gyrus, intraparietal sulcus (IPS)]. We also observed an interaction between stimulus and expectation in the anterior insula (primary taste cortex). Here response was greater for unexpected versus expected sweet compared with unexpected versus expected tasteless, indicating that this region is preferentially sensitive to breaches of taste expectation. Connectivity analyses confirmed that expectation enhanced network interactions, with IPS and VS influencing insular responses. We conclude that unexpected oral stimulation results in suppression of visual cortex and upregulation of sensory, attention, and reward regions to support orientation, identification, and learning about salient stimuli.

  15. Modeling of molecular and particulate transport in dry spent nuclear fuel canisters

    Science.gov (United States)

    Casella, Andrew M.

    2007-09-01

    The transportation and storage of spent nuclear fuel is one of the prominent issues facing the commercial nuclear industry today, as there is still no general consensus regarding the near- and long-term strategy for managing the back-end of the nuclear fuel cycle. The debate continues over whether the fuel cycle should remain open, in which case spent fuel will be stored at on-site reactor facilities, interim facilities, or a geologic repository; or if the fuel cycle should be closed, in which case spent fuel will be recycled. Currently, commercial spent nuclear fuel is stored at on-site reactor facilities either in pools or in dry storage containers. Increasingly, spent fuel is being moved to dry storage containers due to decreased costs relative to pools. As the number of dry spent fuel containers increases and the roles they play in the nuclear fuel cycle increase, more regulations will be enacted to ensure that they function properly. Accordingly, they will have to be carefully analyzed for normal conditions, as well as any off-normal conditions of concern. This thesis addresses the phenomena associated with one such concern; the formation of a microscopic through-wall breach in a dry storage container. Particular emphasis is placed on the depressurization of the canister, release of radioactivity, and plugging of the breach due to deposition of suspended particulates. The depressurization of a dry storage container upon the formation of a breach depends on the temperature and quantity of the fill gas, the pressure differential across the breach, and the size of the breach. The first model constructed in this thesis is capable of determining the depressurization time for a breached container as long as the associated parameters just identified allow for laminar flow through the breach. The parameters can be manipulated to quantitatively determine their effect on depressurization. This model is expanded to account for the presence of suspended particles. If

  16. Evaluation of a hydrological model based on Bidirectional Reach (BReach)

    Science.gov (United States)

    Van Eerdenbrugh, Katrien; Van Hoey, Stijn; Verhoest, Niko E. C.

    2016-04-01

    Evaluation and discrimination of model structures is crucial to ensure an appropriate use of hydrological models. When evaluating model results by aggregating their quality in (a subset of) individual observations, overall results of this analysis sometimes conceal important detailed information about model structural deficiencies. Analyzing model results within their local (time) context can uncover this detailed information. In this research, a methodology called Bidirectional Reach (BReach) is proposed to evaluate and analyze results of a hydrological model by assessing the maximum left and right reach in each observation point that is used for model evaluation. These maximum reaches express the capability of the model to describe a subset of the evaluation data both in the direction of the previous (left) and of the following data (right). This capability is evaluated on two levels. First, on the level of individual observations, the combination of a parameter set and an observation is classified as non-acceptable if the deviation between the accompanying model result and the measurement exceeds observational uncertainty. Second, the behavior in a sequence of observations is evaluated by means of a tolerance degree. This tolerance degree expresses the condition for satisfactory model behavior in a data series and is defined by the percentage of observations within this series that can have non-acceptable model results. Based on both criteria, the maximum left and right reaches of a model in an observation represent the data points in the direction of the previous respectively the following observations beyond which none of the sampled parameter sets both are satisfactory and result in an acceptable deviation. After assessing these reaches for a variety of tolerance degrees, results can be plotted in a combined BReach plot that show temporal changes in the behavior of model results. The methodology is applied on a Probability Distributed Model (PDM) of the river

  17. Modelling dune erosion, overwash and breaching at Fire Island (NY) during hurricane Sandy

    NARCIS (Netherlands)

    De Vet, P.L.M.; McCall, R.T.; Den Bieman, J.P.; Stive, M.J.F.; Van Ormondt, M.

    2015-01-01

    In 2012, Hurricane Sandy caused a breach at Fire Island (NY, USA), near Pelican Island. This paper aims at modelling dune erosion, overwash and breaching processes that occured during the hurricane event at this stretch of coast with the numerical model XBeach. By using the default settings, the ero

  18. a longitudinal study of age-related differences in reactions to phsycological contract breach

    NARCIS (Netherlands)

    Bal, Matthijs; Lange, Annet de; Jansen, Paul; Velde, Mandy van der

    2013-01-01

    The current paper investigated age‐related differences in the relations of psychological contract breach with work outcomes over time. Based on affective events theory, we expected job satisfaction to mediate the longitudinal relationship of contract breach with changes in job performance. Moreover,

  19. 48 CFR 52.233-4 - Applicable Law for Breach of Contract Claim.

    Science.gov (United States)

    2010-10-01

    ... Provisions and Clauses 52.233-4 Applicable Law for Breach of Contract Claim. As prescribed in 33.215(b), insert the following clause: Applicable Law for Breach of Contract Claim (OCT 2004) United States law... 48 Federal Acquisition Regulations System 2 2010-10-01 2010-10-01 false Applicable Law for...

  20. Psychological Contract Breach and Job Attitudes: A Meta-Analysis of Age as a Moderator

    Science.gov (United States)

    Bal, P. Matthijs; De Lange, Annet H.; Jansen, Paul G. W.; Van Der Velde, Mandy E. G.

    2008-01-01

    The aim of this study was to examine the influence of age in the relation between psychological contract breach and the development of job attitudes. Based on affective events, social exchange, and lifespan theory, we hypothesized that (1) psychological contract breach would be related negatively to job attitudes, and (2) that age would moderate…

  1. Psychological contract breach and job attitudes: A meta-analysis of age as a moderator

    NARCIS (Netherlands)

    Bal, P.M.; Lange, A.H. de; Jansen, P.G.W.; Velde, M.E.G. van der

    2008-01-01

    The aim of this study was to examine the influence of age in the relation between psychological contract breach and the development of job attitudes. Based on affective events, social exchange, and lifespan theory, we hypothesized that (1) psychological contract breach would be related negatively to

  2. Breaches of health information: are electronic records different from paper records?

    Science.gov (United States)

    Sade, Robert M

    2010-01-01

    Breaches of electronic medical records constitute a type of healthcare error, but should be considered separately from other types of errors because the national focus on the security of electronic data justifies special treatment of medical information breaches. Guidelines for protecting electronic medical records should be applied equally to paper medical records.

  3. 5 CFR 2634.702 - Breaches by trust fiduciaries and interested parties.

    Science.gov (United States)

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Breaches by trust fiduciaries and interested parties. 2634.702 Section 2634.702 Administrative Personnel OFFICE OF GOVERNMENT ETHICS GOVERNMENT... § 2634.702 Breaches by trust fiduciaries and interested parties. (a) The Attorney General may bring...

  4. An Examination of the Explicit Costs of Sensitive Information Security Breaches

    Science.gov (United States)

    Toe, Cleophas Adeodat

    2013-01-01

    Data security breaches are categorized as loss of information that is entrusted in an organization by its customers, partners, shareholders, and stakeholders. Data breaches are significant risk factors for companies that store, process, and transmit sensitive personal information. Sensitive information is defined as confidential or proprietary…

  5. Inversion Method for Early Detection of ARES-1 Case Breach Failure

    Science.gov (United States)

    Mackey, Ryan M.; Kulikov, Igor K.; Bajwa, Anupa; Berg, Peter; Smelyanskiy, Vadim

    2010-01-01

    A document describes research into the problem of detecting a case breach formation at an early stage of a rocket flight. An inversion algorithm for case breach allocation is proposed and analyzed. It is shown how the case breach can be allocated at an early stage of its development by using the rocket sensor data and the output data from the control block of the rocket navigation system. The results are simulated with MATLAB/Simulink software. The efficiency of an inversion algorithm for a case breach location is discussed. The research was devoted to the analysis of the ARES-l flight during the first 120 seconds after the launch and early prediction of case breach failure. During this time, the rocket is propelled by its first-stage Solid Rocket Booster (SRB). If a breach appears in SRB case, the gases escaping through it will produce the (side) thrust directed perpendicular to the rocket axis. The side thrust creates torque influencing the rocket attitude. The ARES-l control system will compensate for the side thrust until it reaches some critical value, after which the flight will be uncontrollable. The objective of this work was to obtain the start time of case breach development and its location using the rocket inertial navigation sensors and GNC data. The algorithm was effective for the detection and location of a breach in an SRB field joint at an early stage of its development.

  6. Pro-active data breach detection: examining accuracy and applicability on personal information detected

    CSIR Research Space (South Africa)

    Botha, J

    2016-03-01

    Full Text Available breaches but does not provide a clear indication of the level of personal information available on the internet since only reported incidents are taken into account. The possibility of pro-active automated breach detection has previously been discussed as a...

  7. Psychological contract breach and job attitudes : A meta-analysis of age as a moderator

    NARCIS (Netherlands)

    Bal, P. Matthijs; De lange, Annet H.; Jansen, Paul G. W.; Van der Velde, Mandy E. G.

    2008-01-01

    The aim of this study was to examine the influence of age in the relation between psychological contract breach and the development of job attitudes. Based on affective events, social exchange, and lifespan theory, we hypothesized that (1) psychological contract breach would be related negatively to

  8. The extreme risk of personal data breaches and the erosion of privacy

    Science.gov (United States)

    Wheatley, Spencer; Maillart, Thomas; Sornette, Didier

    2016-01-01

    Personal data breaches from organisations, enabling mass identity fraud, constitute an extreme risk. This risk worsens daily as an ever-growing amount of personal data are stored by organisations and on-line, and the attack surface surrounding this data becomes larger and harder to secure. Further, breached information is distributed and accumulates in the hands of cyber criminals, thus driving a cumulative erosion of privacy. Statistical modeling of breach data from 2000 through 2015 provides insights into this risk: A current maximum breach size of about 200 million is detected, and is expected to grow by fifty percent over the next five years. The breach sizes are found to be well modeled by an extremely heavy tailed truncated Pareto distribution, with tail exponent parameter decreasing linearly from 0.57 in 2007 to 0.37 in 2015. With this current model, given a breach contains above fifty thousand items, there is a ten percent probability of exceeding ten million. A size effect is unearthed where both the frequency and severity of breaches scale with organisation size like s0.6. Projections indicate that the total amount of breached information is expected to double from two to four billion items within the next five years, eclipsing the population of users of the Internet. This massive and uncontrolled dissemination of personal identities raises fundamental concerns about privacy.

  9. Modelling dune erosion, overwash and breaching at Fire Island (NY) during hurricane Sandy

    NARCIS (Netherlands)

    De Vet, P.L.M.; McCall, R.T.; Den Bieman, J.P.; Stive, M.J.F.; Van Ormondt, M.

    2015-01-01

    In 2012, Hurricane Sandy caused a breach at Fire Island (NY, USA), near Pelican Island. This paper aims at modelling dune erosion, overwash and breaching processes that occured during the hurricane event at this stretch of coast with the numerical model XBeach. By using the default settings, the

  10. Advances in one-dimensional numerical breach modeling of sand barriers

    NARCIS (Netherlands)

    Tuan, T.Q.; Verhagen, H.J.; Visser, P.J.

    2006-01-01

    A hydrodynamic numerical model is formulated to describe the breach erosion process of sandy barriers. The breach flow is based on the system of unsteady shallow water equations, which is solved using a robust upwind numerical approach in conjunction with the Finite Volume Method (FVM). The hydrauli

  11. Disappearance of breach rhythm heralding recurrent tumor progression in a patient with astrocytoma.

    Science.gov (United States)

    Kampf, Christina; Grossmann, Annette; Benecke, Reiner; Rösche, Johannes

    2013-07-01

    The breach rhythm is sometimes considered the consequence of reduced resistance between the cortex and the scalp electrode in the region of a skull defect. On the other hand, the electroencephalographic (EEG) changes after craniotomy were attributed to an activation of EEG activity by meningocortical adhesions with admixed gliosis. We report changes of the breach rhythm in a patient with astrocytoma, which give further evidence that the breach rhythm is not merely the result of physical changes in the area of a skull defect. In our patient, the breach rhythm was no longer detectable before a new tumor progression took place, showed up again, and at the end changed into localized slowing before the deterioration of the patient's general medical condition. This case suggests that in patients with brain tumors, the loss or attenuation in frequency of an established breach rhythm might be considered as an indication of a new tumor progression.

  12. On Breaching Enterprise Data Privacy Through Adversarial Information Fusion

    CERN Document Server

    Ganta, Srivatsava Ranjit

    2008-01-01

    Data privacy is one of the key challenges faced by enterprises today. Anonymization techniques address this problem by sanitizing sensitive data such that individual privacy is preserved while allowing enterprises to maintain and share sensitive data. However, existing work on this problem make inherent assumptions about the data that are impractical in day-to-day enterprise data management scenarios. Further, application of existing anonymization schemes on enterprise data could lead to adversarial attacks in which an intruder could use information fusion techniques to inflict a privacy breach. In this paper, we shed light on the shortcomings of current anonymization schemes in the context of enterprise data. We define and experimentally demonstrate Web-based Information- Fusion Attack on anonymized enterprise data. We formulate the problem of Fusion Resilient Enterprise Data Anonymization and propose a prototype solution to address this problem.

  13. Investigation of breached depleted UF sub 6 cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Barber, E.J.; Butler, T.R.; DeVan, J.H.; Googin, J.M.; Taylor, M.S.; Dyer, R.H.; Russell, J.R.

    1991-09-01

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton steel cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. Both holes, concealed by UF{sub 4} reaction products identical in color to the cylinder coating, were similarly located near the front stiffening ring. The UF{sub 4} appeared to have self-sealed the holes, thus containing nearly all of the uranium contents. Martin Marietta Energy Systems, Inc., Vice President K.W. Sommerfeld immediately formed an investigation team to: (1) identify the most likely cause of failure for the two breached cylinders, (2) determine the impact of these incidents on the three-site inventory, and (3) provide recommendations and preventive measures. This document discusses the results of this investigation.

  14. Investigation of breached depleted UF{sub 6} cylinders

    Energy Technology Data Exchange (ETDEWEB)

    Barber, E.J.; Butler, T.R.; DeVan, J.H.; Googin, J.M.; Taylor, M.S.; Dyer, R.H.; Russell, J.R.

    1991-09-01

    In June 1990, during a three-site inspection of cylinders being used for long-term storage of solid depleted UF{sub 6}, two 14-ton steel cylinders at Portsmouth, Ohio, were discovered with holes in the barrel section of the cylinders. Both holes, concealed by UF{sub 4} reaction products identical in color to the cylinder coating, were similarly located near the front stiffening ring. The UF{sub 4} appeared to have self-sealed the holes, thus containing nearly all of the uranium contents. Martin Marietta Energy Systems, Inc., Vice President K.W. Sommerfeld immediately formed an investigation team to: (1) identify the most likely cause of failure for the two breached cylinders, (2) determine the impact of these incidents on the three-site inventory, and (3) provide recommendations and preventive measures. This document discusses the results of this investigation.

  15. Triple Plate Mold Final Report: Optimization of the Mold Design and Casting Parameters for a Thin U-10mo Fuel Casting

    Energy Technology Data Exchange (ETDEWEB)

    Aikin, Jr., Robert M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-01-04

    This work describes the experiments and modeling that have been performed to improve and try to optimize the simultaneous casting of three plates of U-10wt%Mo in a single coil vacuum induction melting (VIM) furnace. The plates of interest are 280 mm wide by 203 mm tall by 5 mm thick (11" x 8" x 0.2"). The initial mold design and processing parameters were supplied by Y-12. The mold and casting cavity were instrumented with a number of thermocouples, and the casting performed to determine the thermal history of the mold and casting. The resulting cast plates were radiographed and numerous defects identified. Metallography was performed to help identify the nature of the radiographically observed defects. This information was then used to validate a mold filling and solidification model of that casting. Based on the initial casting, good casting design practice, and process simulation of several design alternatives, a revised design was developed with the goal of minimizing casting defects such as porosity. The redesigned mold had a larger hot-top and had its long axis along the horizontal direction. These changes were to try to develop a strong thermal gradient conducive to good feeding and minimization of micro- and macroporosity in the cast plates. An instrumented casting was then performed with the revised mold design and a linear distributor. This design yielded cast plates with significantly less radiographically identified defects. Unfortunately, there was significant variation in plate weight and metal content in their hot-tops. Fluid flow simulations were then performed on this mold/distributor design. This helped identify the issue with this linear distributor design. Additional simulations were then performed on candidate distributor redesigns and a preferred distributor annular design was identified. This improved annular design was used to produce a third instrumented casting with favorable results. These refined designs and their radiographic

  16. MINIMIZING GLOVEBOX GLOVE BREACHES, PART IV: CONTROL CHARTS

    Energy Technology Data Exchange (ETDEWEB)

    COURNOYER, MICHAEL E. [Los Alamos National Laboratory; LEE, MICHELLE B. [Los Alamos National Laboratory; SCHREIBER, STEPHEN B. [Los Alamos National Laboratory

    2007-02-05

    At the Los Alamos National Laboratory (LANL) Plutonium Facility, plutonium. isotopes and other actinides are handled in a glovebox environment. The spread of radiological contamination, and excursions of contaminants into the worker's breathing zone, are minimized and/or prevented through the use of glovebox technology. Evaluating the glovebox configuration, the glovebo gloves are the most vulnerable part of this engineering control. Recognizing this vulnerability, the Glovebox Glove Integrity Program (GGIP) was developed to minimize and/or prevent unplanned openings in the glovebox environment, i.e., glove failures and breaches. In addition, LANL implement the 'Lean Six Sigma (LSS)' program that incorporates the practices of Lean Manufacturing and Six Sigma technologies and tools to effectively improve administrative and engineering controls and work processes. One tool used in LSS is the use of control charts, which is an effective way to characterize data collected from unplanned openings in the glovebox environment. The benefit management receives from using this tool is two-fold. First, control charts signal the absence or presence of systematic variations that result in process instability, in relation to glovebox glove breaches and failures. Second, these graphical representations of process variation detennine whether an improved process is under control. Further, control charts are used to identify statistically significant variations (trends) that can be used in decision making to improve processes. This paper discusses performance indicators assessed by the use control charts, provides examples of control charts, and shows how managers use the results to make decisions. This effort contributes to LANL Continuous Improvement Program by improving the efficiency, cost effectiveness, and formality of glovebox operations.

  17. Identification of consistency in rating curve data: Bidirectional Reach (BReach)

    Science.gov (United States)

    Van Eerdenbrugh, Katrien; Van Hoey, Stijn; Verhoest, Niko E. C.

    2016-04-01

    Before calculating rating curve discharges, it is crucial to identify possible interruptions in data consistency. In this research, a methodology to perform this preliminary analysis is developed and validated. This methodology, called Bidirectional Reach (BReach), evaluates in each data point results of a rating curve model with randomly sampled parameter sets. The combination of a parameter set and a data point is classified as non-acceptable if the deviation between the accompanying model result and the measurement exceeds observational uncertainty. Moreover, a tolerance degree that defines satisfactory behavior of a sequence of model results is chosen. This tolerance degree equals the percentage of observations that are allowed to have non-acceptable model results. Subsequently, the results of the classification is used to assess the maximum left and right reach for each data point of a chronologically sorted time series. This maximum left and right reach in a gauging point represent the data points in the direction of the previous respectively the following observations beyond which none of the sampled parameter sets both are satisfactory and result in an acceptable deviation. This analysis is repeated for a variety of tolerance degrees. Plotting results of this analysis for all data points and all tolerance degrees in a combined BReach plot enables the detection of changes in data consistency. Moreover, if consistent periods are detected, limits of these periods can be derived. The methodology is validated with various synthetic stage-discharge data sets and proves to be a robust technique to investigate temporal consistency of rating curve data. It provides satisfying results despite of low data availability, large errors in the estimated observational uncertainty, and a rating curve model that is known to cover only a limited part of the observations.

  18. 25 CFR 224.87 - What are the obligations of a tribe if it discovers a violation or breach?

    Science.gov (United States)

    2010-04-01

    ... violation or breach? 224.87 Section 224.87 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR... DETERMINATION ACT Implementation of Tribal Energy Resource Agreements Violation Or Breach § 224.87 What are the obligations of a tribe if it discovers a violation or breach? As soon as practicable after discovering...

  19. 29 CFR 37.102 - What happens if a grant applicant or recipient breaches a Conciliation Agreement?

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true What happens if a grant applicant or recipient breaches a... Procedures § 37.102 What happens if a grant applicant or recipient breaches a Conciliation Agreement? When it... Notification of Breach of Conciliation Agreement....

  20. Feasibility investigations on a novel micro-manufacturing process for fabrication of fuel cell bipolar plates: Internal pressure-assisted embossing of micro-channels with in-die mechanical bonding

    Energy Technology Data Exchange (ETDEWEB)

    Koc, Muammer [NSF I/UCR Center for Precision Forming (CPF), Department of Mechanical Engineering, Virginia Commonwealth University (VCU), Richmond, VA (United States); Mahabunphachai, Sasawat [NSF I/UCR Center for Precision Forming (CPF), Department of Mechanical Engineering, Virginia Commonwealth University (VCU), Richmond, VA (United States); Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI (United States)

    2007-10-25

    In this paper, we present the results of our studies on conceptual design and feasibility experiments towards development of a novel hybrid manufacturing process to fabricate fuel cell bipolar plates that consists of multi-array micro-channels on a large surface area. The premises of this hybrid micro-manufacturing process stem from the use of an internal pressure-assisted embossing process (cold or warm) combined with mechanical bonding of double bipolar plates in a single-die and single-step operation. Such combined use of hydraulic and mechanical forming forces and in-process bonding will (a) enable integrated forming of micro-channels on both surfaces (as anode and cathode flow fields) and at the middle (as cooling channels), (b) reduce the process steps, (c) reduce variation in dimensional tolerances and surface finish, (d) increase the product quality, (e) increase the performance of fuel cell by optimizing flow-field designs and ensuring consistent contact resistance, and (f) reduce the overall stack cost. This paper explains two experimental investigations that were performed to characterize and evaluate the feasibility of the conceptualized manufacturing process. The first investigation involved hydroforming of micro-channels using thin sheet metals of SS304 with a thickness of 51 {mu}m. The width of the channels ranged from 0.46 to 1.33 mm and the height range was between 0.15 and 0.98 mm. Our feasibility experiments resulted in that different aspect ratios of micro-channels could be fabricated using internal pressure in a controllable manner although there is a limit to very sharp channel shapes (i.e., high aspect ratios with narrow channels). The second investigation was on the feasibility of mechanical bonding of thin sheet metal blanks. The effects of different process and material variables on the bond quality were studied. Successful bonding of various metal blanks (Ni201, Al3003, and SS304) was obtained. The experimental results from both

  1. Study of transient flow in fuel element of tubular plates. Accident: Shaft locking of primary cooling pump without opening the emergency gate; Estudio del regimen transitorio en el elemento combustible de placas tubulares. Accidente: Agarrotamiento de la bomba. No se abre la compuerta

    Energy Technology Data Exchange (ETDEWEB)

    Aguilas, F.; Moneva, M. A.; Garcia Ramirez, L.; Lopez Jimenez, J.; Diaz Diaz, J.

    1971-07-01

    It is analysed the thermal distribution of a fuel element of tubular plates irradiated in the JEN-1 reactor in the case of shaft locking of the primary cooling pump without opening the emergency gate. The fuel element hottest channel is studied in the position of maximum neutronic flux for three reactor power levels: 3 Hw (maximum reactor power), 2 Mw and 1 Hw. (Author) 8 refs.

  2. Acute Dermal Irritation Study and Salmonella-Escherichia coli/Microsome Plate Incorporation Assay of Hydroprocessed Esters and Fatty Acids (HEFA) Bio-Based Jet Fuels

    Science.gov (United States)

    2013-01-01

    and certified for use in the U.S. Air Force fleet. The second class of alternative fuels was initially called hydrotreated renewable jet (HRJ...Medicine HRJ hydrotreated renewable jet kg kilogram M molar MA metabolic activation mg milligram min minutes mL milliliter mm millimiter NCIMB

  3. Levee Breach Experiment by Overflow at the Full Scale Experimental Channel

    Science.gov (United States)

    Shimada, T.; Yokoyama, H.

    2010-12-01

    The increased occurrence of storm disasters caused by typhoons and local downpours in recent years has given rise to concerns over the possibility of large-scale floods resulting from river overflow. Levee breaches cause particularly severe damage, and in Japan, more than 80% of such accidents in the past have been attributed to overflow. Studies on levee breach by overflow have been conducted from various viewpoints using diverse methods. However, the mechanism of three-dimensional levee breach by overflow has not been clarified in past studies. Elucidation of this mechanism is very important for disaster prevention as well as for the future progress of studies on levee breach by overflow. Levees (levee crown width; 3m, levee height; 3m, levee length; 80m) were built in the Chiyoda Experimental Channel (full-scale experimental channel; width is 30m, length is 1,300m, maximum discharge is 170t/s) in Hokkaido Japan in 2010, and a three-dimensional experiment on levee breach by overflow. The findings of the experiment are as follows: After the beginning of overflow, levee breach widening did not begin until after most of the levee section had collapsed. It was also considered that, even if overflow occurred, extremely serious damage (e.g., sudden increase in levee breach width and overflow discharge) was unlikely unless the majority of the levee section collapsed.

  4. Numerical modelling of Glacial Lake Outburst Floods using physically based dam-breach models

    Science.gov (United States)

    Westoby, M. J.; Brasington, J.; Glasser, N. F.; Hambrey, M. J.; Reynolds, J. M.; Hassan, M. A. A. M.

    2014-06-01

    The rapid development and instability of moraine-dammed proglacial lakes is increasing the potential for the occurrence of catastrophic Glacial Lake Outburst Floods (GLOFs) in high-mountain regions. Advanced, physically-based numerical dam-breach models represent an improvement over existing methods for the derivation of breach outflow hydrographs. However, significant uncertainty surrounds the initial parameterisation of such models, and remains largely unexplored. We use a unique combination of numerical dam-breach and two-dimensional hydrodynamic modelling, employed with a Generalised Likelihood Uncertainty Estimation (GLUE) framework to quantify the degree of equifinality in dam-breach model output for the reconstruction of the failure of Dig Tsho, Nepal. Monte Carlo analysis was used to sample the model parameter space, and morphological descriptors of the moraine breach were used to evaluate model performance. Equifinal breach morphologies were produced by parameter ensembles associated with differing breach initiation mechanisms, including overtopping waves and mechanical failure of the dam face. The material roughness coefficient was discovered to exert a dominant influence over model performance. Percentile breach hydrographs derived from cumulative distribution function hydrograph data under- or overestimated total hydrograph volume and were deemed to be inappropriate for input to hydrodynamic modelling. Our results support the use of a Total Variation Diminishing solver for outburst flood modelling, which was found to be largely free of numerical instability and flow oscillation. Routing of scenario-specific optimal breach hydrographs revealed prominent differences in the timing and extent of inundation. A GLUE-based method for constructing likelihood-weighted maps of GLOF inundation extent, flow depth, and hazard is presented, and represents an effective tool for communicating uncertainty and equifinality in GLOF hazard assessment. However, future

  5. Determination of burnup grade of fuel plates by gamma spectrometry; Determinacao do grau de queima em elementos combustiveis tipo placa por meio de espectrometria gama

    Energy Technology Data Exchange (ETDEWEB)

    Terremoto, Luis A.A.; Zeituni, Carlos A.; Perrotta, Jose A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN), Sao Paulo, SP (Brazil). Div. de Engenharia do Nucleo

    1999-11-01

    This work describes absolute burnup measurements on spent MTR fuel elements by means of non-destructive gamma-ray spectroscopy which correlates activities of radioactive fission products with the fissioned mass of {sup 235} U. Experiments based on such method were performed at the storage pool area of the IEA-R1 research reactor. The obtained results were compared with calculational ones based on neutronics. (author) 7 refs., 6 figs., 1 tab.; e-mail: laaterre at net.ipen.br

  6. A guide to California's breaches. First year of state reporting requirement reveals common privacy violations.

    Science.gov (United States)

    Dimick, Chris

    2010-04-01

    Effective January 1, 2009, California healthcare providers were required to report every breach of patient information to the state. They have sent a flood of mishaps and a steady stream of malicious acts.

  7. BREACHING THE SEXUAL BOUNDARIES IN THE DOCTOR–PATIENT RELATIONSHIP: SHOULD ENGLISH LAW RECOGNISE FIDUCIARY DUTIES?

    Science.gov (United States)

    Ost, Suzanne

    2016-01-01

    In this article, I argue that sexual exploitation in the doctor–patient relationship would be dealt with more appropriately by the law in England and Wales on the basis of a breach of fiduciary duty. Three different types of sexual boundary breaches are discussed, and the particular focus is on breaches where the patient's consent is obtained through inducement. I contend that current avenues of redress do not clearly catch this behaviour and, moreover, they fail to capture the essence of the wrong committed by the doctor—the knowing breach of trust for self-gain—and the calculated way in which consent is induced. Finally, I demonstrate that the fiduciary approach is compatible with the contemporary pro-patient autonomy model of the doctor–patient relationship. PMID:26846652

  8. BREACHING THE SEXUAL BOUNDARIES IN THE DOCTOR-PATIENT RELATIONSHIP: SHOULD ENGLISH LAW RECOGNISE FIDUCIARY DUTIES?

    Science.gov (United States)

    Ost, Suzanne

    2016-01-01

    In this article, I argue that sexual exploitation in the doctor-patient relationship would be dealt with more appropriately by the law in England and Wales on the basis of a breach of fiduciary duty. Three different types of sexual boundary breaches are discussed, and the particular focus is on breaches where the patient's consent is obtained through inducement. I contend that current avenues of redress do not clearly catch this behaviour and, moreover, they fail to capture the essence of the wrong committed by the doctor-the knowing breach of trust for self-gain-and the calculated way in which consent is induced. Finally, I demonstrate that the fiduciary approach is compatible with the contemporary pro-patient autonomy model of the doctor-patient relationship. © The Author 2016. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.

  9. Direct and Indirect Effects of Psychological Contract Breach on Academicians’ Turnover Intention in Turkey

    OpenAIRE

    Ozan BUYUKYILMAZ; Cakmak, Ahmet F.

    2013-01-01

    This study aims to investigate the assumed direct and indirect relationships between psychological contract breach and turnover intention through psychological contract violation and perceived organizational support. Data for the sample was collected from 570 academicians from a variety of universities in Turkey. Hierarchical regression analyses were conducted to test the hypotheses. The results show that psychological contract breach was positively related to turnover intention and psycholog...

  10. The older the better?: age-related differences in emotion regulation after psychological contract breach

    OpenAIRE

    Bal, P. Matthijs; Smit, Priscilla

    2012-01-01

    Purpose: The aim of this paper was to investigate the role of emotion regulation and age in reactions to psychological contract breach towards positive and negative affect. We expected that in the context of contract breach, reappraisal emotion regulation mitigate the negative relation with affect. Moreover, based on lifespan theory, suppression emotion regulation was expected to be important for younger workers, because older workers have learned how to express themselves appropriately at th...

  11. Fuel Tank Technology

    Science.gov (United States)

    1989-11-01

    structures b) - Equal thermic inertia c) - Equal fluid volume d) - Equal pressure variation on both wings at the change of the room temperature - This...individual fuel sections. Each fuel section is further ccmpartmentated by metall tank shear walls and tank floors into three individual fuel cells to...plate Dy a stretch forming process, and the metallic tank floors . The air intake segments extend from one bulkhead to the other, thus reducing assembly

  12. Fuel flexible fuel injector

    Science.gov (United States)

    Tuthill, Richard S; Davis, Dustin W; Dai, Zhongtao

    2015-02-03

    A disclosed fuel injector provides mixing of fuel with airflow by surrounding a swirled fuel flow with first and second swirled airflows that ensures mixing prior to or upon entering the combustion chamber. Fuel tubes produce a central fuel flow along with a central airflow through a plurality of openings to generate the high velocity fuel/air mixture along the axis of the fuel injector in addition to the swirled fuel/air mixture.

  13. Effect of different surface treatments on the stability of stainless steels for use as bipolar plates in low and high temperature proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Richards, J.; Schmidt, K. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Wolfsburg (Germany); Tuebke, J.; Cremers, C. [Fraunhofer-Institut fuer Chemische Technologie (ICT), Pfinztal (Germany)

    2010-07-01

    The stability of different stainless steels against corrosion under simulated low and high temperature proton exchange membrane fuel cell (PEMFC) operating conditions was studied. These investigations showed a moderate corrosion resistance for a couple of steels under LT-PEMFC conditions. However, for the HT-PEMFC conditions all specimens except one exhibit visible corrosion traces. With regards to their corrosion resistance after different surface treatments results show a minor improvement in corrosion resistance after the electro polishing process for most of the tested stainless steel samples. (orig.)

  14. Antecedents of Psychological Contract Breach: The Role of Job Demands, Job Resources, and Affect.

    Directory of Open Access Journals (Sweden)

    Tim Vantilborgh

    Full Text Available While it has been shown that psychological contract breach leads to detrimental outcomes, relatively little is known about factors leading to perceptions of breach. We examine if job demands and resources predict breach perceptions. We argue that perceiving high demands elicits negative affect, while perceiving high resources stimulates positive affect. Positive and negative affect, in turn, influence the likelihood that psychological contract breaches are perceived. We conducted two experience sampling studies to test our hypotheses: the first using daily surveys in a sample of volunteers, the second using weekly surveys in samples of volunteers and paid employees. Our results confirm that job demands and resources are associated with negative and positive affect respectively. Mediation analyses revealed that people who experienced high job resources were less likely to report psychological contract breach, because they experienced high levels of positive affect. The mediating role of negative affect was more complex, as it increased the likelihood to perceive psychological contract breach, but only in the short-term.

  15. Antecedents of Psychological Contract Breach: The Role of Job Demands, Job Resources, and Affect.

    Science.gov (United States)

    Vantilborgh, Tim; Bidee, Jemima; Pepermans, Roland; Griep, Yannick; Hofmans, Joeri

    2016-01-01

    While it has been shown that psychological contract breach leads to detrimental outcomes, relatively little is known about factors leading to perceptions of breach. We examine if job demands and resources predict breach perceptions. We argue that perceiving high demands elicits negative affect, while perceiving high resources stimulates positive affect. Positive and negative affect, in turn, influence the likelihood that psychological contract breaches are perceived. We conducted two experience sampling studies to test our hypotheses: the first using daily surveys in a sample of volunteers, the second using weekly surveys in samples of volunteers and paid employees. Our results confirm that job demands and resources are associated with negative and positive affect respectively. Mediation analyses revealed that people who experienced high job resources were less likely to report psychological contract breach, because they experienced high levels of positive affect. The mediating role of negative affect was more complex, as it increased the likelihood to perceive psychological contract breach, but only in the short-term.

  16. Legal Effect of Breach of Warranty in Construction Insurance in Malaysia

    Directory of Open Access Journals (Sweden)

    Arazi Idrus

    2011-12-01

    Full Text Available This study is aimed at analyzing the legal effect of breach of warranty in construction insurance contracts in Malaysia in light of the current developments in The English insurance law. The required data and information were collected from Malaysian and English court decisions dealing with breach of warranties in English marine insurance law from the online Malayan Law Journal published on the LexisNexis online database and from published textbooks related to insurance warranties. This study would help to offer judicial guidance to courts in Peninsular Malaysia on how to resolve the legal dilemma associated with breach of warranty in Malaysian insurance law. It was found out that the effect of breach of a continuing warranty will result in the contract of insurance remaining in existence and the risk is being treated as having incepted at the outset but automatically coming to an end as of the date of the breach. More so, the insurer is being discharged from any future liability, although any liabilities of the insurer before the date of the breach are unaffected.

  17. Neutronics Benchmarks for the Utilization of Mixed-Oxide Fuel: Joint U.S./ Russian Progress Report for Fiscal Year 1997, Volume 4, Part 8 - Neutron Poison Plates in Assemblies Containing Homogeneous Mixtures of Polystyrene-Moderated Plutonium and Uranium Oxides

    Energy Technology Data Exchange (ETDEWEB)

    Yavuz, M.

    1999-05-01

    In the 1970s at the Battelle Pacific Northwest Laboratory (PNL), a series of critical experiments using a remotely operated Split-Table Machine was performed with homogeneous mixtures of (Pu-U)O{sub 2}-polystyrene fuels in the form of square compacts having different heights. The experiments determined the critical geometric configurations of MOX fuel assemblies with and without neutron poison plates. With respect to PuO{sub 2} content and moderation [H/(Pu+U)atomic] ratio (MR), two different homogeneous (Pu-U) O{sub 2}-polystyrene mixtures were considered: Mixture (1) 14.62 wt% PuO{sub 2} with 30.6 MR, and Mixture (2) 30.3 wt% PuO{sub 2} with 2.8 MR. In all mixtures, the uranium was depleted to about O.151 wt% U{sup 235}. Assemblies contained copper, copper-cadmium or aluminum neutron poison plates having thicknesses up to {approximately}2.5 cm. This evaluation contains 22 experiments for Mixture 1, and 10 for Mixture 2 compacts. For Mixture 1, there are 10 configurations with copper plates, 6 with aluminum, and 5 with copper-cadmium. One experiment contained no poison plate. For Mixture 2 compacts, there are 3 configurations with copper, 3 with aluminum, and 3 with copper-cadmium poison plates. One experiment contained no poison plate.

  18. Epithelial cell extrusion leads to breaches in the intestinal epithelium.

    Science.gov (United States)

    Liu, Julia J; Davis, Elisabeth M; Wine, Eytan; Lou, Yuefei; Rudzinski, Jan K; Alipour, Misagh; Boulanger, Pierre; Thiesen, Aducio L; Sergi, Consolato; Fedorak, Richard N; Muruve, Daniel; Madsen, Karen L; Irvin, Randall T

    2013-04-01

    Two distinct forms of intestinal epithelial cell (IEC) extrusion are described: 1 with preserved epithelial integrity and 1 that introduced breaches in the epithelial lining. In this study, we sought to determine the mechanism underlying the IEC extrusion that alters the permeability of the gut epithelium. IEC extrusions in polarized T84 monolayer were induced with nigericin. Epithelial permeability was assessed with transepithelial electrical resistance and movements of latex microspheres and green fluorescent protein-transfected Escherichia coli across the monolayer. In vivo IEC extrusion was modulated in wild-type and a colitic (interleukin-10 knock-out) mouse model with caspase-1 activation and inhibition. Luminal aspirates and mucosal biopsies from control patients and patients with inflammatory bowel disease were analyzed for caspase-1 and caspase-3&7 activation. Caspase-1-induced IEC extrusion in T84 monolayers resulted in dose-dependent and time-dependent barrier dysfunction, reversible with caspase-1 inhibition. Moreover, the movements of microspheres and microbes across the treated epithelial monolayers were observed. Increased caspase-1-mediated IEC extrusion in interleukin-10 knock-out mice corresponded to enhanced permeation of dextran, microspheres, and translocation of E. coli compared with wild type. Caspase-1 inhibition in interleukin-10 knock-out mice resulted in a time-dependent reduction in cell extrusion and normalization of permeability to microspheres. Increased IEC extrusion in wild-type mice was induced with caspase-1 activation. In human luminal aspirates, the ratio of positively stained caspase-1 to caspase-3&7 cells were 1:1 and 2:1 in control patients and patients with inflammatory bowel disease, respectively; these observations were confirmed by cytochemical analysis of mucosal biopsies. IEC extrusion mediated by caspase-1 activation contributes to altered intestinal permeability in vitro and in vivo.

  19. Update On Monolithic Fuel Fabrication Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R Clark; J. M. Wight; G. C. Knighton; G. A. Moore; J. F. Jue

    2005-11-01

    Efforts to develop a viable monolithic research reactor fuel plate have continued at Idaho National Laboratory. These efforts have concentrated on both fabrication process refinement and scale-up to produce full sized fuel plates. Advancements have been made in the production of U-Mo foil including full sized foils. Progress has also been made in the friction stir welding and transient liquid phase bonding fabrication processes resulting in better bonding, more stable processes and the ability to fabricate larger fuel plates.

  20. Corrosion resistant metallic bipolar plate

    Science.gov (United States)

    Brady, Michael P.; Schneibel, Joachim H.; Pint, Bruce A.; Maziasz, Philip J.

    2007-05-01

    A corrosion resistant, electrically conductive component such as a bipolar plate for a PEM fuel cell includes 20 55% Cr, balance base metal such as Ni, Fe, or Co, the component having thereon a substantially external, continuous layer of chromium nitride.

  1. Fuel cell assembly with electrolyte transport

    Science.gov (United States)

    Chi, Chang V.

    1983-01-01

    A fuel cell assembly wherein electrolyte for filling the fuel cell matrix is carried via a transport system comprising a first passage means for conveying electrolyte through a first plate and communicating with a groove in a second plate at a first point, the first and second plates together sandwiching the matrix, and second passage means acting to carry electrolyte exclusively through the second plate and communicating with the groove at a second point exclusive of the first point.

  2. Experimental study on buoyancy-driven exchange flows through breaches of a tokamak vacuum vessel in a fusion reactor under the loss-of-vacuum-event conditions

    Energy Technology Data Exchange (ETDEWEB)

    Takase, Kazuyuki; Tomoaki, Kunugi; Ogawa, Masurou; Seki, Yasushi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan)

    1997-02-01

    As one of thermofluid safety studies in the International Thermonuclear Experimental Reactor, buoyancy-driven exchange flow behavior through breaches of a vacuum vessel (VV) has been investigated quantitatively by using a preliminary loss-of-vacuum-event (LOVA) apparatus that simulated the tokamak VV of a fusion reactor with a small-scaled model. To carry out the present experiments under the atmospheric pressure condition, helium gas and air were provided as the working fluids. The inside of the VV was initially filled with helium gas and the outside was atmosphere. The breaches on the VV under the LOVA condition were simulated by opening six simulated breaches to which were set the different positions on the VV. When the buoyancy-driven exchange flow through the breach occurred, helium gas went out from the inside of the VV through the breach to the outside and air flowed into the inside of the VV through the breach from the outside. The exchange rate in the VV between helium gas and air was calculated from the measured weight change of the VV with time since the experiment has started. experimental parameters were breach position, breach number, breach length, breach size, and breach combination. The present study clarifies that the relation between the exchange rate and the breach position of the VV depended on the magnitude of the potential energy from the ground level to the breach position, and then, the exchange rate decreased as the breach length increased and as the breach size decreased.

  3. Out-of-pile Verifying Test for the Hydraulic Stability of the CARR Standard Fuel Assembly

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The CARR standard fuel element is a flat-plate-type assembly. A fuel plate consists of 0.6 mmthickness layer of uranium- silicon - aluminum fuel (U3Si2-Al) and 0.38 mm thickness of aluminumcladding. The fuel plates are attached to aluminum alloy side plates by a "roll swaging" technique. Thistype of fuel assembly is first used in China. The testing simulates the in-pile thermal-hydraulic operating conditions except for neutron

  4. Numerical modelling of glacial lake outburst floods using physically based dam-breach models

    Science.gov (United States)

    Westoby, M. J.; Brasington, J.; Glasser, N. F.; Hambrey, M. J.; Reynolds, J. M.; Hassan, M. A. A. M.; Lowe, A.

    2015-03-01

    The instability of moraine-dammed proglacial lakes creates the potential for catastrophic glacial lake outburst floods (GLOFs) in high-mountain regions. In this research, we use a unique combination of numerical dam-breach and two-dimensional hydrodynamic modelling, employed within a generalised likelihood uncertainty estimation (GLUE) framework, to quantify predictive uncertainty in model outputs associated with a reconstruction of the Dig Tsho failure in Nepal. Monte Carlo analysis was used to sample the model parameter space, and morphological descriptors of the moraine breach were used to evaluate model performance. Multiple breach scenarios were produced by differing parameter ensembles associated with a range of breach initiation mechanisms, including overtopping waves and mechanical failure of the dam face. The material roughness coefficient was found to exert a dominant influence over model performance. The downstream routing of scenario-specific breach hydrographs revealed significant differences in the timing and extent of inundation. A GLUE-based methodology for constructing probabilistic maps of inundation extent, flow depth, and hazard is presented and provides a useful tool for communicating uncertainty in GLOF hazard assessment.

  5. Caudate nucleus signals for breaches of expectation in a movement observation paradigm.

    Science.gov (United States)

    Schiffer, Anne-Marike; Schubotz, Ricarda I

    2011-01-01

    The striatum has been established as a carrier of reward-related prediction errors. This prediction error signal concerns the difference between how much reward was predicted and how much reward is gained. However, it remains to be established whether general breaches of expectation, i.e., perceptual prediction errors, are also implemented in the striatum. The current study used functional magnetic resonance imaging (fMRI) to investigate the role of caudate nucleus in breaches of expectation. Importantly, breaches were not related to the occurrence or absence of reward. Preceding the fMRI study, participants were trained to produce a sequence of whole-body movements according to auditory cues. In the fMRI session, they watched movies of a dancer producing the same sequences either according to the cue (88%) or not (12%). Caudate nucleus was activated for the prediction-violating movements. This activation was flanked by activity in posterior superior temporal sulcus, the temporo-parietal junction and adjacent angular gyrus, a network that may convey the deviating movement to caudate nucleus, while frontal areas may reflect adaptive adjustments of the current prediction. Alternative interpretations of caudate activity relating either to the saliency of breaches of expectation or to behavioral adaptation could be excluded by two control contrasts. The results foster the notion that neurons in the caudate nucleus code for a breach in expectation, and point toward a distributed network involved in detecting, signaling and adjusting behavior and expectations toward violated prediction.

  6. Whip Rule Breaches in a Major Australian Racing Jurisdiction: Welfare and Regulatory Implications

    Science.gov (United States)

    Hood, Jennifer; McDonald, Carolyn; Wilson, Bethany; McManus, Phil; McGreevy, Paul

    2017-01-01

    Simple Summary An evidence-based analysis of whip rule breaches in horse racing is needed to address community expectations that racehorses are treated humanely. The study provides the first peer-reviewed characterisation of whip rule breaches and their regulatory outcomes in horseracing, and considers the relationship between rules affecting racing integrity and the welfare of racehorses in a major Australian racing jurisdiction. Abstract Whip use in horseracing is increasingly being questioned on ethical, animal welfare, social sustainability, and legal grounds. Despite this, there is weak evidence for whip use and its regulation by Stewards in Australia. To help address this, we characterised whip rule breaches recorded by Stewards using Stewards Reports and Race Diaries from 2013 and 2016 in New South Wales (NSW) and the Australian Capital Territory (ACT). There were more recorded breaches at Metropolitan (M) than Country (C) or Provincial (P) locations, and by riders of horses that finished first, second, or third than by riders of horses that finished in other positions. The most commonly recorded breaches were forehand whip use on more than five occasions before the 100-metre (m) mark (44%), and whip use that raises the jockey’s arm above shoulder height (24%). It is recommended that racing compliance data be analysed annually to inform the evidence-base for policy, education, and regulatory change, and ensure the welfare of racehorses and racing integrity.

  7. Controls on the breach geometry and flood hydrograph during overtopping of non-cohesive earthen dams

    Science.gov (United States)

    Walder, Joseph S.; Iverson, Richard M.; Godt, Jonathan W.; Logan, Matthew; Solovitz, Stephen A.

    2015-01-01

    Overtopping failure of non-cohesive earthen dams was investigated in 13 large-scale experiments with dams built of compacted, damp, fine-grained sand. Breaching was initiated by cutting a notch across the dam crest and allowing water escaping from a finite upstream reservoir to form its own channel. The channel developed a stepped profile, and upstream migration of the steps, which coalesced into a headcut, led to the establishment of hydraulic control (critical flow) at the channel head, or breach crest, an arcuate erosional feature that functions hydraulically as a weir. Novel photogrammetric methods, along with underwater videography, revealed that the retreating headcut maintained a slope near the angle of friction of the sand, while the cross section at the breach crest maintained a geometrically similar shape through time. That cross-sectional shape was nearly unaffected by slope failures, contrary to the assumption in many models of dam breaching. Flood hydrographs were quite reproducible--for sets of dams ranging in height from 0.55 m to 0.98 m--when the time datum was chosen as the time that the migrating headcut intersected the breach crest. Peak discharge increased almost linearly as a function of initial dam height. Early-time variability between flood hydrographs for nominally identical dams is probably a reflection of subtle experiment-to-experiment differences in groundwater hydrology and the interaction between surface water and groundwater.

  8. Flood hydrology and dam-breach hydraulic analyses of five reservoirs in Colorado

    Science.gov (United States)

    Stevens, Michael R.; Hoogestraat, Galen K.

    2013-01-01

    The U.S. Department of Agriculture Forest Service has identified hazard concerns for areas downstream from five Colorado dams on Forest Service land. In 2009, the U.S. Geological Survey, in cooperation with the Forest Service, initiated a flood hydrology analysis to estimate the areal extent of potential downstream flood inundation and hazard to downstream life, property, and infrastructure if dam breach occurs. Readily available information was used for dam-breach assessments of five small Colorado reservoirs (Balman Reservoir, Crystal Lake, Manitou Park Lake, McGinnis Lake, and Million Reservoir) that are impounded by an earthen dam, and no new data were collected for hydraulic modeling. For each reservoir, two dam-breach scenarios were modeled: (1) the dam is overtopped but does not fail (break), and (2) the dam is overtopped and dam-break occurs. The dam-breach scenarios were modeled in response to the 100-year recurrence, 500-year recurrence, and the probable maximum precipitation, 24-hour duration rainstorms to predict downstream flooding. For each dam-breach and storm scenario, a flood inundation map was constructed to estimate the extent of flooding in areas of concern downstream from each dam. Simulation results of the dam-break scenarios were used to determine the hazard classification of the dam structure (high, significant, or low), which is primarily based on the potential for loss of life and property damage resulting from the predicted downstream flooding.

  9. Effects of passive films on corrosion resistance of uncoated SS316L bipolar plates for proton exchange membrane fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ying, E-mail: yingyang@nwu.edu.cn [Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Institute of Analytical Science, Northwest University, Xi’an, Shaanxi 710069 (China); International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Ning, Xiaohui; Tang, Hongsheng [Shaanxi Provincial Key Laboratory of Electroanalytical Chemistry, Institute of Analytical Science, Northwest University, Xi’an, Shaanxi 710069 (China); Guo, Liejin [International Research Center for Renewable Energy, State Key Laboratory of Multiphase Flow in Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049 (China); Liu, Hongtan [Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, FL 33124 (United States)

    2014-11-30

    Highlights: • The passive film formed at PEMFC anode side shows a single layer structure. • The passive film formed at PEMFC cathode side shows a bi-layer structure. • The Cr/Fe atomic ratios in passive films formed at different side are different. • The passive films behave as n-type semiconductor at both anode and cathode sides. • The anode/cathode potential is positive than the flatband potential of passive film. - Abstract: The effects of passive films on the corrosion behaviors of uncoated SS316L in anode and cathode environments of proton exchange membrane fuel cells (PEMFCs) are studied. Potentiodynamic and potentiostatic polarizations are employed to study the corrosion behavior; Mott-Schottky measurements are used to characterize the semiconductor properties of passive films; X-ray photoelectron spectroscopy (XPS) analyses are used to identify the compositions and the depth profiles of passive films. The passive films formed in the PEMFC anode and cathode environments under corresponding conditions both behave as n-type semiconductor. The passive film formed in the anode environment has a single-layer structure, Cr is the major element (Cr/Fe atomic ratio > 1), and the Cr/Fe atomic ratio decreases from the surface to the bulk; while the passive film formed in the PEMFC cathode environment has a bi-layer structure, Fe is the major element (Cr/Fe atomic ratio < 0.5), and in the external layer of the bi-layer structure Fe content increases rapidly and gradually in the internal layer. SS316L shows better corrosion resistance owing to both the high content of Cr oxide in the passive film and low band bending in normal PEMFC anode environments.

  10. Proton exchange membrane fuel cells

    CERN Document Server

    Qi, Zhigang

    2013-01-01

    Preface Proton Exchange Membrane Fuel CellsFuel CellsTypes of Fuel CellsAdvantages of Fuel CellsProton Exchange Membrane Fuel CellsMembraneCatalystCatalyst LayerGas Diffusion MediumMicroporous LayerMembrane Electrode AssemblyPlateSingle CellStackSystemCell Voltage Monitoring Module (CVM)Fuel Supply Module (FSM)Air Supply Module (ASM)Exhaust Management Module (EMM)Heat Management Module (HMM)Water Management Module (WMM)Internal Power Supply Module (IPM)Power Conditioning Module (PCM)Communications Module (COM)Controls Module (CM)SummaryThermodynamics and KineticsTheoretical EfficiencyVoltagePo

  11. Psychological contract types as moderator in the breach-violation and violation-burnout relationships.

    Science.gov (United States)

    Jamil, Amber; Raja, Usman; Darr, Wendy

    2013-01-01

    This research examined the relationships between perceived psychological contract breach, felt violation, and burnout in a sample (n = 361) of employees from various organizations in Pakistan. The moderating role of contract types in these relationships was also tested. Findings supported a positive association between perceived psychological contract breach and felt violation and both were positively related to burnout. Transactional and relational contracts moderated the felt violation-burnout relationship. Scores on relational contract type tended to be higher than for transactional contract type showing some contextual influence.

  12. Cheating in OSCEs: The Impact of Simulated Security Breaches on OSCE Performance.

    Science.gov (United States)

    Gotzmann, Andrea; De Champlain, André; Homayra, Fahmida; Fotheringham, Alexa; de Vries, Ingrid; Forgie, Melissa; Pugh, Debra

    2017-01-01

    Construct: Valid score interpretation is important for constructs in performance assessments such as objective structured clinical examinations (OSCEs). An OSCE is a type of performance assessment in which a series of standardized patients interact with the student or candidate who is scored by either the standardized patient or a physician examiner. In high-stakes examinations, test security is an important issue. Students accessing unauthorized test materials can create an unfair advantage and lead to examination scores that do not reflect students' true ability level. The purpose of this study was to assess the impact of various simulated security breaches on OSCE scores. Seventy-six 3rd-year medical students participated in an 8-station OSCE and were randomized to either a control group or to 1 of 2 experimental conditions simulating test security breaches: station topic (i.e., providing a list of station topics prior to the examination) or egregious security breach (i.e., providing detailed content information prior to the examination). Overall total scores were compared for the 3 groups using both a one-way between-subjects analysis of variance and a repeated measure analysis of variance to compare the checklist, rating scales, and oral question subscores across the three conditions. Overall total scores were highest for the egregious security breach condition (81.8%), followed by the station topic condition (73.6%), and they were lowest for the control group (67.4%). This trend was also found with checklist subscores only (79.1%, 64.9%, and 60.3%, respectively for the security breach, station topic, and control conditions). Rating scale subscores were higher for both the station topic and egregious security breach conditions compared to the control group (82.6%, 83.1%, and 77.6%, respectively). Oral question subscores were significantly higher for the egregious security breach condition (88.8%) followed by the station topic condition (64.3%), and they were

  13. Retrospective Analysis of Allegations About the Breach of Discipline in Ankara Chamber of Dentist Between 2005-2009

    Directory of Open Access Journals (Sweden)

    Zehtiye Füsun Yaşar

    2014-04-01

    Full Text Available PURPOSE: The allegations about the breach of disciplinary code in the Ankara Chamber of Dentists, the topic of the allegation and the specifications of the people whom allegedly breached the code are examined. METHOD: 198 files charging 116 dentists have been examined in this study. The nature of the allegation, the age, sex, professional position of the doctor, and the sanctions held against the dentists when the allegations of breaching were true are studied. FINDINGS: 45 (%38,8 of the dentists who were subject to questioning were women and 71 (%61,2 were men. It was observed that 76 of the dentists (%65,5 worked at polyclinics, and the 63 (%54,3 dentists who worked at polyclinics were responsible managers. Out of 198 breaching allegations 163 (%82,3 were proven to be true and various sanctions were implied to dentists. When the distribution of the breaches were examined it was found out that mostly the dentists didn’t comply with the prohibition of advertising (%42,9 and worked under the minimum wage (%22,7. CONCLUSION: It was observed that the majority of the dentists, who were questioned under the allegations of breach, did not have enough information about the law, code and regulations concerning their profession and also some dentists breached the same regulation again. With all the obtained data, it is suggested that the dentists should be educated about the rules and regulations by people from professional associations. Key Words: Dentist; law; regulation; breach

  14. The Relationship between Psychological Contract Breach and Organizational Commitment: Exchange Imbalance as a Moderator of the Mediating Role of Violation

    Science.gov (United States)

    Cassar, Vincent; Briner, Rob B.

    2011-01-01

    This study tested the mediating role of violation in the relationship between breach and both affective and continuance commitment and the extent to which this mediating role is moderated by exchange imbalance amongst a sample of 103 sales personnel. Results suggest that violation mediated the relationship between breach and commitment. Also,…

  15. 29 CFR 37.105 - Whom must the Director notify if enforcement action under a Notification of Breach of...

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Whom must the Director notify if enforcement action under a Notification of Breach of Conciliation Agreement is commenced? 37.105 Section 37.105 Labor Office of the... action under a Notification of Breach of Conciliation Agreement is commenced? In such circumstances,...

  16. Case Study of the Chaq-Chaq Dam Failure: Parameter Estimation and Evaluation of Dam Breach Prediction Models

    Directory of Open Access Journals (Sweden)

    Dr. KawaZedanAbdulrahman

    2014-05-01

    Full Text Available On 4th of February, 2006 at about 10:00 pm.Chaq-Chaq dam failed due to overtopping. The fall of 131.2 mm of rain over a 24-hour period was recorded at Sulaimani metrological gage station, which is located about 7.5Kmsouth-east of the dam. As a result, the reservoir level rose, the dam has been overtopped and finally breached near the spillway at the right abutment. Fortunately no human lives loss nor important structure destruction were reporteddue to the dam failure. The aim of this paper is to estimate the flood hydrograph passing through Chaq-Chaq dam breach using measured breach geometry as input to unsteady option of HEC RAS 4.1.0 and calibrating the breach formation time to obtain the measured maximum water surface at Chaq-Chaq Bridge (1.36 km downstream of dam axis. In addition the recent breach prediction models were evaluated to check their accuracy in predicting the breach geometry, breach formation time and peak breach discharge.

  17. Psychological contract breach in the anticipatory stage of change : Employee responses and the moderating role of supervisory informational justice

    NARCIS (Netherlands)

    de Ruiter, M.; Schalk, R.; Schaveling, Jaap; van Gelder, Daniel

    This study examined the impact of two types of psychological contract breach (organizational policies and social atmosphere breach) on resistance to change and engagement in the anticipatory phase of change and assessed whether supervisory informational justice mitigated the negative effects of

  18. Psychological contract breach in the anticipatory stage of change : Employee responses and the moderating role of supervisory informational justice

    NARCIS (Netherlands)

    De Ruiter, M.; Schaveling, J.; Schalk, R.; Gelder, van D.

    2016-01-01

    This study examined the impact of two types of psychological contract breach (organizational policies and social atmosphere breach) on resistance to change and engagement in the anticipatory phase of change and assessed whether supervisory informational justice mitigated the negative effects of

  19. Corrosion Minimization for Research Reactor Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Eric Shaber; Gerard Hofman

    2005-06-01

    Existing university research reactors are being converted to use low-enriched uranium fue to eliminate the use of highly-enriched uranium. These conversions require increases in fuel loading that will result in the use of elements with more fuel plates, resulting in a net decrease in the water annulus between fuel plates. The proposed decrease in the water annulus raises questions about the requirements and stability of the surface hydroxide on the aluminum fuel cladding and the potential for runaway corrosion resulting in fuel over-temperature incidents. The Nuclear Regulatory Commission (NRC), as regulator for these university reactors, must ensure that proposed fuel modifications will not result in any increased risk or hazard to the reactor operators or the public. This document reviews the characteristics and behavior of aluminum hydroxides, analyzes the drivers for fuel plate corrosion, reviews relevant historical incidents, and provides recommendations on fuel design, surface treatment, and reactor operational practices to avoid corrosion issues.

  20. TARDEC Assured Fuels Initiative

    Science.gov (United States)

    2008-05-07

    Objectives • Develop and build two microchannel reactors − FT reactor : convert CO + H2 to long-chain hydrocarbons − Hydrocracker: upgrade FT wax to...present depending on the FT reactor conditions and catalyst used and subsequent upgrade-to-finished fuel processing • Lack of aromatics impacts fuel... Microchannel Processing Technology (MPT) The Technology • Stacks of closely spaced thin plates form microchannels • Process fluids pass through

  1. UMo/Al弥散型燃料元件溶解回收工艺研究%Recovery of UMo Alloy from UMo/Al Dispersion Fuel Plates by Dissolution

    Institute of Scientific and Technical Information of China (English)

    任萌; 李佳; 刘锦洪; 朱常桂

    2011-01-01

    Methods for dissolving Umo/Al dispersion fuel plates in the compounded mixed basic aqueous (NaOH and NaNO3) are studied on laboratory scale. After removing the clad and the matrix of the substandard Umo/Al dispersion fuel elements, the U loss ratios are calculated and the granularity distributions of the recovered Umo alloy powder are analyzed by the metallurgical microscope. Besides, the phase structure and the composition of the recovered Umo alloy powder are analyzed by the XRD. The results indicate that as the concentration of NaOH increases, uranium loss ratio increases; but as the concentration of NaNO3 increases, U loss ration increases firstly and then decreases subsequently; generally, the U recovery ratios are more than 99.3%. The granularity of recovered Umo powders are very small and most parts of γ-U have been oxidated to UO2. Therefore, further study is required to determined whether the recovered Umo alloy could be returned to the product line.%以配制好的混合碱(NaOH和NaNO3)为UMo/Al弥散型燃料元件样品铝包壳和铝基体的溶解液,将不合格的UMo弥散型燃料元件的包壳和弥散基去除,并计算铀损失率;采用金相显微镜分析UMo合金粉末的粒度分布,并用X射线衍射分析其相结构与成分.初步实验结果表明:随着NaOH浓度增大,铀损失率增大;随着NaNO3浓度的增大,铀损失率呈现先增大后减小的趋势;NaNO3浓度对铀的损失率影响不大,铀的回收率高于99.3%;铝溶解后的UMo合金粉末粒度较小,部分铀已经被氧化成了UO2,需要进一步研究才能确定回收得到的UMo合金粉末能否重新用于燃料元件的生产.

  2. A laser profilometry technique for monitoring fluvial dike breaching in laboratory experiments

    Science.gov (United States)

    Dewals, Benjamin; Rifai, Ismail; Erpicum, Sébastien; Archambeau, Pierre; Violeau, Damien; Pirotton, Michel; El kadi Abderrezzak, Kamal

    2017-04-01

    A challenging aspect for experimental modelling of fluvial dike breaching is the continuous monitoring of the transient breach geometry. In dam breaching cases induced by flow overtopping over the whole breach crest (plane erosion), a side view through a glass wall is sufficient to monitor the breach formation. This approach can be extended for 3D dam breach tests (spatial erosion) if the glass wall is located along the breach centreline. In contrast, using a side view does not apply for monitoring fluvial dike breaching, because the breach is not symmetric in this case. We present a non-intrusive, high resolution technique to record the breach development in experimental models of fluvial dikes by means of a laser profilometry (Rifai et al. 2016). Most methods used for monitoring dam and dike breaching involve the projection of a pattern (fringes, grid) on the dam or dike body and the analysis of its deformation on images recorded during the breaching (e.g., Pickert et al. 2011, Frank and Hager 2014). A major limitation of these methods stems from reflection on the water surface, particularly in the vicinity of the breach where the free surface is irregular and rippled. This issue was addressed by Spinewine et al. (2004), who used a single laser sheet so that reflections on the water surface were strongly limited and did not hamper the accurate processing of each image. We have developed a similar laser profilometry technique tailored for laboratory experiments on fluvial dike breaching. The setup is simple and relatively low cost. It consists of a digital video camera (resolution of 1920 × 1080 pixels at 60 frames per second) and a swiping red diode 30 mW laser that enables the projection of a laser sheet over the dike body. The 2D image coordinates of each deformed laser profile incident on the dike are transformed into 3D object coordinates using the Direct Linear Transformation (DLT) algorithm. All 3D object coordinates computed over a swiping cycle of the

  3. Breach modelling by overflow with TELEMAC 2D: Comparison with large-scale experiments

    Science.gov (United States)

    An erosion law has been implemented in TELEMAC 2D to represent the surface erosion process to model the breach formation of a levee. We focus on homogeneous and earth fill levee to simplify this first implementation. The first part of this study reveals the ability of this method to represent simu...

  4. Disclosure of past crimes: an analysis of mental health professionals' attitudes towards breaching confidentiality.

    Science.gov (United States)

    Wangmo, Tenzin; Handtke, Violet; Elger, Bernice Simone

    2014-09-01

    Ensuring confidentiality is the cornerstone of trust within the doctor-patient relationship. However, health care providers have an obligation to serve not only their patient's interests but also those of potential victims and society, resulting in circumstances where confidentiality must be breached. This article describes the attitudes of mental health professionals (MHPs) when patients disclose past crimes unknown to the justice system. Twenty-four MHPs working in Swiss prisons were interviewed. They shared their experiences concerning confidentiality practices and attitudes towards breaching confidentiality in prison. Qualitative analysis revealed that MHPs study different factors before deciding whether a past crime should be disclosed, including: (1) the type of therapy the prisoner-patient was seeking (i.e., whether it was court-ordered or voluntary), (2) the type of crime that is revealed (e.g., a serious crime, a crime of a similar nature to the original crime, or a minor crime), and (3) the danger posed by the prisoner-patient. Based on this study's findings, risk assessment of dangerousness was one of the most important factors determining disclosures of past crimes, taking into consideration both the type of therapy and the crime involved. Attitudes of MHPs varied with regard to confidentiality rules and when to breach confidentiality, and there was thus a lack of consensus as to when and whether past crimes should be reported. Hence, legal and ethical requirements concerning confidentiality breaches must be made clear and known to physicians in order to guide them with difficult cases.

  5. Remedies for Breach Under the United Nations Convention on Contracts for International Sale of Goods (CISG)

    DEFF Research Database (Denmark)

    Lookofsky, Joseph

    2011-01-01

    For every breach of a binding contract, there must be some remedy. The gap-filling remedial structure of the 1980 Vienna Sales Convention (CISG) reflects the fact that all significant forms of remedial relief may be said to fall within three basic courses of action which modern legal systems make...

  6. Morphologic evolution of the wilderness area breach at Fire Island, New York—2012–15

    Science.gov (United States)

    Hapke, Cheryl J.; Nelson, Timothy R.; Henderson, Rachel E.; Brenner, Owen T.; Miselis, Jennifer L.

    2017-09-18

    IntroductionHurricane Sandy, which made landfall on October 29, 2012, near Atlantic City, New Jersey, had a significant impact on the coastal system along the south shore of Long Island, New York. A record significant wave height of 9.6 meters (m) was measured at wave buoy 44025, approximately 48 kilometers offshore of Fire Island, New York. Surge and runup during the storm resulted in extensive beach and dune erosion and breaching of the Fire Island barrier island system at two locations, including a breach that formed within the Otis Pike Fire Island High Dune Wilderness area on the eastern side of Fire Island.The U.S. Geological Survey (USGS) has a long history of conducting morphologic change and processes research at Fire Island. One of the primary objectives of the current research effort is to understand the morphologic evolution of the barrier system on a variety of time scales (from storm scale to decade(s) to century). A number of studies that support the project objectives have been published. Prior to Hurricane Sandy, however, little information was available on specific storm-driven change in this region. The USGS received Hurricane Sandy supplemental funding (project GS2–2B: Linking Coastal Processes and Vulnerability, Fire Island, New York, Regional Study) to enhance existing research efforts at Fire Island. The existing research was greatly expanded to include inner continental shelf mapping and investigations of processes of inner shelf sediment transport; beach and dune response and recovery; and observation, analysis, and modeling of the newly formed breach in the Otis Pike High Dune Wilderness area, herein referred to as the wilderness breach. The breach formed at the site of Old Inlet, which was open from 1763 to 1825. The location of the initial island breaching does not directly correspond with topographic lows of the dunes, but instead the breach formed in the location of a cross-island boardwalk that was destroyed during Hurricane Sandy

  7. Developing a broader approach to management of infection control breaches in health care settings.

    Science.gov (United States)

    Patel, Priti R; Srinivasan, Arjun; Perz, Joseph F

    2008-12-01

    Our experiences with health departments and health care facilities suggest that questions surrounding instrument reprocessing errors and other infection control breaches are becoming increasingly common. We describe an approach to management of these incidents that focuses on risk of bloodborne pathogen transmission and the role of public health and other stakeholders to inform patient notification and testing decisions.

  8. Simulation of dam breach development for emergency treatment of the Tangjiashan Quake Lake in China

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Tangjiashan Quake Lake is the largest quake lake triggered by the 5.12 Wenchuan Earthquake that happened on May 12,2008 in China,posing high risk of catastrophic flash flood hazards to downstream human life and properties.A physics-based numerical simulation approach is proposed for real-time prediction of dam breach development of the Tangjiashan Quake Lake in the case of emergency treatment.Bed erosion and lateral development of the dam breach are represented through accounting for the underlying physics including selective sediment transport and gravitational collapse.Conceptualized breach erosion model that involves few parameters enables quick calibration based on the monitored hydrological data in emergency analysis where fully geotechnical information about the barrier dam is not available.The process of dam breach development is found to be nonlinear in cascades due to the combined effects of headcutting and bank collapse.The agreement between the simulation results and the observed data shows the applicability of the present approach for emergency analysis of quake lakes.Limitations will arise in the situation where the soil composition of barrier dam is significantly inhomogeneous.Incorporation of circular arc failure for cohesive soil and lateral seepage in bank slope will also enhance its applicability to complex situations.

  9. Consequence analysis of a liner breach due to steam under the liner

    Energy Technology Data Exchange (ETDEWEB)

    HIMES, D.A.

    1999-06-01

    Radiological and toxicological consequences are estimated for a steam release from tank C-106 associated with a breach of the tank liner due to formation of steam under the liner after dry-out of the sludge layer in the tank. The consequences are shown to be well below the most restrictive risk guidelines.

  10. 47 CFR 64.2011 - Notification of customer proprietary network information security breaches.

    Science.gov (United States)

    2010-10-01

    ... Proprietary Network Information § 64.2011 Notification of customer proprietary network information security... 47 Telecommunication 3 2010-10-01 2010-10-01 false Notification of customer proprietary network information security breaches. 64.2011 Section 64.2011 Telecommunication FEDERAL COMMUNICATIONS...

  11. Liability to disgorge profits upon breach of contract or a delict

    NARCIS (Netherlands)

    Schrage, E.J.H.

    2013-01-01

    Remedies regarding contract and tort are, generally speaking, concerned with the incidence of liability for loss or damage suffered, whereas the claim in unjust enrichment is said to require that the enrichment has occurred at the expense of the creditor. Consequently claims for breach of contract a

  12. Create Your Plate

    Medline Plus

    Full Text Available ... A A A Listen En Español Create Your Plate Create Your Plate is a simple and effective ... and that your options are endless. Create Your Plate! Click on the plate sections below to add ...

  13. High performance fuel electrodes fabricated by electroless plating of copper on BaZr0.8Ce0.1Y0.1O3-δ proton-conducting ceramic

    Science.gov (United States)

    Patki, Neil S.; Way, J. Douglas; Ricote, Sandrine

    2017-10-01

    The stability of copper at high temperatures in reducing and hydrocarbon-containing atmospheres makes it a good candidate for fabricating fuel electrodes on proton-conducting ceramics, such as BaZr0.9-xCexY0.1O3-δ (BZCY). In this work, the electrochemical performance of Cu-based electrodes fabricated by electroless plating (ELP) on BaZr0.8Ce0.1Y0.1O3-δ is studied with impedance spectroscopy. Three activation catalysts (Pd, Ru, and Cu) are investigated and ELP is compared to a commercial Cu paste (ESL 2312-G) for electrode fabrication. The area specific resistances (ASR) for Pd, Ru, and Cu activations at 700 °C in moist 5% H2 in Ar are 2.1, 3.2, and 13.4 Ω cm2, respectively. That is a 1-2 orders of magnitude improvement over the commercial Cu paste (192 Ω cm2). Furthermore, the ASR has contributions from electrode processes and charge transfer at the electrode/electrolyte interface. Additionally, the morphology of the as-fabricated electrode is unaffected by the activation catalyst. However, heat treatment at 750 °C in H2 for 24 h leads to sintering and large reorganization of the electrode fabricated with Cu activation (micron sized pores seen in the tested sample), while Pd and Ru activations are immune to such reorganization. Thus, Pd and Ru are identified as candidates for future work with improvements to charge transfer required for the former, and better electrode processes required for the latter.

  14. Process of Levee Breach by Overflow at the Full Scale Chiyoda Experimental Channel

    Science.gov (United States)

    Shimada, T.; Yokoyama, H.

    2011-12-01

    The increased occurrence of storm disasters caused by typhoons and local downpours in recent years has given rise to concerns over the possibility of large-scale floods resulting from river overflow. Levee breaches cause particularly severe damage, and in Japan, more than 80% of such accidents in the past have been attributed to overflow. Previous studies on overflow-induced levee breaches have not revealed the mechanisms of these issues on a full-scale 3D basis (i.e., side-overflow taking river flow on the riverside land into consideration). It is important to clarify these mechanisms in terms of disaster prevention and for the purpose of bringing progress in future studies on overflow-induced failure. Levees (levee crown width is 3m in 2010 and 6m in 2011, levee height is 3m, levee length is 80m) were built in the Chiyoda Experimental Channel (full-scale experimental channel; width is 30m, length is 1,300m, maximum discharge is 170t/s) in Hokkaido Japan, and a three-dimensional experiment on levee breach by overflow. The findings of the experiment are as follows: After the beginning of overflow, levee breach widening did not begin until after most of the levee section had collapsed. And in case of 6m of the levee crown width, that time in becomes long. It was also considered that, even if overflow occurred, extremely serious damage (e.g., sudden increase in levee breach width and overflow discharge) was unlikely unless the majority of the levee section collapsed.

  15. Modeling of Breaching Due to Overtopping Flow and Waves Based on Coupled Flow and Sediment Transport

    Directory of Open Access Journals (Sweden)

    Zhiguo He

    2015-08-01

    Full Text Available Breaching of earthen or sandy dams/dunes by overtopping flow and waves is a complicated process with strong, unsteady flow, high sediment transport, and rapid bed changes in which the interactions between flow and morphology should not be ignored. This study presents a depth-averaged two-dimensional (2D coupled flow and sediment transport model to investigate the flow and breaching processes with and without waves. Bed change and variable flow density are included in the flow continuity and momentum equations to consider the impacts of sediment transport. The model adopts the non-equilibrium approach for total-load sediment transport and specifies different repose angles to handle non-cohesive embankment slope avalanching. The equations are solved using an explicit finite volume method on a rectangular grid with the improved Godunov-type central upwind scheme and the nonnegative reconstruction of the water depth method to handle mixed-regime flows near the breach. The model has been tested against two sets of experimental data which show that it well simulates the flow characteristics, bed changes, and sediment transport. It is then applied to analyze flow and morphologic changes by overtopping flow with and without waves. The simulated bed change and breach cross-section shape show a significant difference if waves are considered. Erosion by flow without waves mainly occurs at the breach and is dominated by vertical erosion at the initial stage followed by the lateral erosion. With waves, the flow overtops the entire length of the dune to cause faster erosion along the entire length. Erosion mainly takes place at the upper layer at the initial stage and gradually accelerates as the height of the dune reduces and flow discharge increases, which indicates the simulated results with waves shall be further verified by physical experimental evidence.

  16. 25 CFR 224.88 - What must the Director do after receiving notice of a violation or breach from the tribe?

    Science.gov (United States)

    2010-04-01

    ... violation or breach from the tribe? 224.88 Section 224.88 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF... DEVELOPMENT AND SELF DETERMINATION ACT Implementation of Tribal Energy Resource Agreements Violation Or Breach § 224.88 What must the Director do after receiving notice of a violation or breach from the tribe?...

  17. Monolithic Fuel Fabrication Process Development

    Energy Technology Data Exchange (ETDEWEB)

    C. R. Clark; N. P. Hallinan; J. F. Jue; D. D. Keiser; J. M. Wight

    2006-05-01

    The pursuit of a high uranium density research reactor fuel plate has led to monolithic fuel, which possesses the greatest possible uranium density in the fuel region. Process developments in fabrication development include friction stir welding tool geometry and cooling improvements and a reduction in the length of time required to complete the transient liquid phase bonding process. Annealing effects on the microstructures of the U-10Mo foil and friction stir welded aluminum 6061 cladding are also examined.

  18. Simulating dam-breach flood scenarios of the Tangjiashan landslide dam induced by the Wenchuan Earthquake

    Directory of Open Access Journals (Sweden)

    X. Fan

    2012-10-01

    Full Text Available Floods from failures of landslide dams can pose a hazard to people and property downstream, which have to be rapidly assessed and mitigated in order to reduce the potential risk. The Tangjiashan landslide dam induced by the Mw = 7.9 2008 Wenchuan earthquake had impounded the largest lake in the earthquake affected area with an estimated volume of 3 × 108 m3, and the potential catastrophic dam breach posed a serious threat to more than 2.5 million people in downstream towns and Mianyang city, located 85 km downstream. Chinese authorities had to evacuate parts of the city until the Tangjiashan landslide dam was artificially breached by a spillway, and the lake was drained. We propose an integrated approach to simulate the dam-breach floods for a number of possible scenarios, to evaluate the severity of the threat to Mianyang city. Firstly, the physically-based BREACH model was applied to predict the flood hydrographs at the dam location, which were calibrated with observational data of the flood resulting from the artificial breaching. The output hydrographs from this model were inputted into the 1-D–2-D SOBEK hydrodynamic model to simulate the spatial variations in flood parameters. The simulated flood hydrograph, peak discharge and peak arrival time at the downstream towns fit the observations. Thus this approach is capable of providing reliable predictions for the decision makers to determine the mitigation plans. The sensitivity analysis of the BREACH model input parameters reveals that the average grain size, the unit weight and porosity of the dam materials are the most sensitive parameters. The variability of the dam material properties causes a large uncertainty in the estimation of the peak flood discharge and peak arrival time, but has little influence on the flood inundation area and flood depth downstream. The effect of cascading breaches of smaller dams downstream of the Tangjiashan dam was

  19. Air-cooled, hydrogen-air fuel cell

    Science.gov (United States)

    Shelekhin, Alexander B. (Inventor); Bushnell, Calvin L. (Inventor); Pien, Michael S. (Inventor)

    1999-01-01

    An air-cooled, hydrogen-air solid polymer electrolyte (SPE) fuel cell with a membrane electrode assembly operatively associated with a fluid flow plate having at least one plate cooling channel extending through the plate and at least one air distribution hole extending from a surface of the cathode flow field into the plate cooling channel.

  20. Effects of breach formation parameter uncertainty on inundation risk area and consequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Skousen, Benjamin Don [Los Alamos National Laboratory; David, Judi [Los Alamos National Laboratory; Mc Pherson, Timothy [Los Alamos National Laboratory; Burian, Steve [UNIV OF UTAH

    2010-01-01

    According to the national inventory of dams (NID), there are approximately 79,500 dams in the United States, with 11,800 of these dams being classified as high-hazard. It has been recommended that each high-hazard dam in the United States have an emergency action plan (EAP), but it has been found that only about 60% of the high-hazard dams have a complete EAP. A major aspect of these plans is inundation risk area identification and associated impacts in the event of dam failure. In order to determine the inundation risk area an estimation of breach discharge must be completed. Most methods used to determine breach discharge, including the NWS-DAMBRK model, require modelers to select size, shape, and time of breach formation. Federal agencies (e.g. Bureau of Reclamation, Federal Energy Regulatory Commission) with oversight of U.S. dams have recommended ranges of values for each of these parameters based on dam type. However, variations in these parameters even within the recommended range have the potential to impose significant transformation on the discharge hydrograph relative to both timing and magnitude of the peak discharge. Therefore, it has also been recommended that sensitivity of these parameters be investigated when performing breach inundation analyses. This paper presents a sensitivity analysis of three breach parameters (average breach width, side slope, and time to failure) on a case study dam located in the United States. The sensitivity analysis employed was based on the 3{sup 3} factorial design, in which three levels (e.g. low, medium, and high) were selected for each of the three parameters, resulting in twenty-seven combinations. The three levels remained within the recommended range of values for each parameter type. With each combination of input parameters, a discharge hydrograph was generated and used as a source condition for inundation analysis using a two-dimensional shallow water equation model. The resulting simulations were compared to

  1. Effects of breach formation parameter uncertainty on inundation risk area and consequence analysis

    Energy Technology Data Exchange (ETDEWEB)

    Skousen, Benjamin Don [Los Alamos National Laboratory; David, Judi [Los Alamos National Laboratory; Mc Pherson, Timothy [Los Alamos National Laboratory; Burian, Steve [UNIV OF UTAH

    2010-01-01

    According to the national inventory of dams (NID), there are approximately 79,500 dams in the United States, with 11,800 of these dams being classified as high-hazard. It has been recommended that each high-hazard dam in the United States have an emergency action plan (EAP), but it has been found that only about 60% of the high-hazard dams have a complete EAP. A major aspect of these plans is inundation risk area identification and associated impacts in the event of dam failure. In order to determine the inundation risk area an estimation of breach discharge must be completed. Most methods used to determine breach discharge, including the NWS-DAMBRK model, require modelers to select size, shape, and time of breach formation. Federal agencies (e.g. Bureau of Reclamation, Federal Energy Regulatory Commission) with oversight of U.S. dams have recommended ranges of values for each of these parameters based on dam type. However, variations in these parameters even within the recommended range have the potential to impose significant transformation on the discharge hydrograph relative to both timing and magnitude of the peak discharge. Therefore, it has also been recommended that sensitivity of these parameters be investigated when performing breach inundation analyses. This paper presents a sensitivity analysis of three breach parameters (average breach width, side slope, and time to failure) on a case study dam located in the United States. The sensitivity analysis employed was based on the 3{sup 3} factorial design, in which three levels (e.g. low, medium, and high) were selected for each of the three parameters, resulting in twenty-seven combinations. The three levels remained within the recommended range of values for each parameter type. With each combination of input parameters, a discharge hydrograph was generated and used as a source condition for inundation analysis using a two-dimensional shallow water equation model. The resulting simulations were compared to

  2. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    Science.gov (United States)

    Carmack, W. J.; Chichester, H. M.; Porter, D. L.; Wootan, D. W.

    2016-05-01

    The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The MFF fuel operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This places the peak fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in EBR-II experiments. Data from the MFF-3 and MFF-5 assemblies are most comparable to the data obtained from the EBR-II X447 experiment. The two X447 pin breaches were strongly influenced by fuel/cladding chemical interaction (FCCI) at the top of the fuel column. Post irradiation examination data from MFF-3 and MFF-5 are presented and compared to historical EBR-II data.

  3. MONOLITHIC FUEL FABRICATION PROCESS DEVELOPMENT AT THE IDAHO NATIONAL LABORATORY_

    Energy Technology Data Exchange (ETDEWEB)

    G. A. Moore; F. J. Rice; N. E. Woolstenhulme; J-F. Jue; B. H. Park; S. E. Steffler; N. P. Hallinan; M. D. Chapple; M. C. Marshall; B. L. Mackowiak; C. R. Clark; B. H. Rabin

    2009-11-01

    Full-size/prototypic U10Mo monolithic fuel-foils and aluminum clad fuel plates are being developed at the Idaho National Laboratory’s (INL) Materials and Fuels Complex (MFC). These efforts are focused on realizing Low Enriched Uranium (LEU) high density monolithic fuel plates for use in High Performance Research and Test Reactors. The U10Mo fuel foils under development afford a fuel meat density of ~16 gU/cc and thus have the potential to facilitate LEU conversions without any significant reactor-performance penalty. An overview is provided of the ongoing monolithic UMo fuel development effort, including application of a zirconium barrier layer on fuel foils, fabrication scale-up efforts, and development of complex/graded fuel foils. Fuel plate clad bonding processes to be discussed include: Hot Isostatic Pressing (HIP) and Friction Bonding (FB).

  4. An unusual case of coccidiosis in laboratory-reared pheasants resulting from a breach in biosecurity.

    Science.gov (United States)

    Gerhold, R W; Williams, S M; Fuller, A L; McDougald, L R

    2010-09-01

    An outbreak of coccidiosis in laboratory-reared Chinese ring-necked pheasants (Phasianus colchicus) resulted in high morbidity and moderate mortality. The outbreak was associated with a breach in biosecurity caused by the cleaning of a sewer line with a mechanical device, resulting in extensive splattering of fecal material throughout the "clean room" where birds were held prior to use in coccidiosis experiments. Mortality and morbidity in the affected birds were seen exactly 5 days after the incident, after birds had been moved to another room for experimental use, corresponding closely with the known prepatent or preclinical period of Eimeria phasiani and Eimeria colchici. Gross lesions in the affected birds varied from dehydration to intestinal and ventricular hemorrhage. Microscopic examination confirmed a diagnosis of severe intestinal coccidiosis. This report underscores the ease of contamination of experimental birds leading to coccidiosis outbreaks during breaches of management and biosecurity.

  5. Mass transport in a PEMFC fuel battery using combinations of monopolar plates and reaction-diffusion medium; Transporte de masa en una pila a combustible tipo PEMFC utilizando combinaciones de platos monopolares y medios de difusion de reactivos

    Energy Technology Data Exchange (ETDEWEB)

    Rosas Paleta, M. G. Araceli [Benemerita Universidad Autonoma de Puebla, Puebla, Puebla (Mexico); Bautista Rodriguez, C. Moises [Alter-Energias Puebla, Puebla (Mexico)] email: celso.bautista@thyssenkrupp.com; Rivera Marquez, J. Antonio; Tepale Ochoa, Nancy [Benemerita Universidad Autonoma de Puebla, Puebla, Puebla (Mexico)

    2009-09-15

    The efficiency of a PEMFC fuel battery is limited due to a variety of mass transport-related phenomena that take place while it is operating. The electromotive force of the PEM fuel battery is related to the generation of concentration gradients resulting from the distribution of the reactants on the active sites of the electrode. The reactant gases supplied to the PEMFC are distributed over the diffusion layer of the electrodes through the channels of the polar plates. They then spread toward the active layer where the semi-reactions take place. Another important aspect is the presence of water molecules, a product of the reaction. When they accumulate, they cover the porosity of the electrodes, involving the reduction in the flow of reactants, even at high current density values and, combined with the diffusion phenomena involved, cause the PEMFC to complete cease functioning. The critical parameters for the transport phenomena are porosity, the diameter of the pore in the diffusion layer and the characteristics of the distribution of the reactants. The present works includes an experimental design of two distribution media and two diffusion media of the reactant gases in a PEMFC, involving three case studies. The results show significantly notable interactions between the diameter of the pore, the type of diffusion layer applied and the type of distributor applied. The combination in the second case significantly reduces the ohmic resistance and moderately reduces the diffusion resistances. While the combination in case three notably increases the ohmic resistance, diffusion resistance is significantly reduced. [Spanish] La eficiencia de una pila a combustible tipo PEMFC es limitada por diversos fenomenos de transporte de masa presentes durante su funcionamiento. La fuerza electromotriz de la pila a combustible tipo PEM esta relacionada con la generacion de gradientes de concentracion los cuales se dan como resultado de la distribucion de los reactivos sobre los

  6. Evidence of a role for Th17 cells in the breach of immune tolerance in arthritis

    OpenAIRE

    Yu, Xinhua; Ibrahim, Saleh M.

    2011-01-01

    Th17 cells are thought to play a pathogenic role in various autoimmune diseases. Cytokines secreted by Th17 cells like IL-17, IL-17F and IL-22 have the capacity to mediate a massive inflammatory response. These proinflammatroy cytokines are likely to mediate the pathogenic potential of Th17 cells. Recent evidence suggests a role for Th17 cells in the breach of immune tolerance. This might shed some new light on the pathogenic role of Th17 cells in autoimmunity.

  7. A Model for Understanding the Relationship Between Transaction Costs and Acquisition Cost Breaches

    Science.gov (United States)

    2014-04-30

    become a research sponsor, or to print additional copies of reports, please contact any of the staff listed on the Acquisition Research Program...the Root Cause: Nunn-McCurdy Breaches in Major Defense Acquisition Programs Bill Shelton, RAND Corporation Irv Blickstein, RAND Corporation Jerry...and Wolter J. Fabrycky. 2010. Systems Engineering and Analysis. 5th ed. Upper Saddle River, NJ: Prentice Hall. Blickstein, Irv , Michael Boito

  8. Digging Out the Root Cause: Nunn-McCurdy Breaches in Major Defense Acquisition Programs

    Science.gov (United States)

    2014-04-30

    Acquisition Programs Bill Shelton, RAND Corporation Irv Blickstein, RAND Corporation Jerry Sollinger, RAND Corporation Charles Nemfakos, RAND...to become a research sponsor, or to print additional copies of reports, please contact any of the staff listed on the Acquisition Research Program...Out the Root Cause: Nunn-McCurdy Breaches in Major Defense Acquisition Programs Bill Shelton, RAND Corporation Irv Blickstein, RAND Corporation

  9. Comparative Remedies for Breach of Contract, hrsg. von Nili Cohen und Ewan McKendrick

    OpenAIRE

    Müller-Chen, Markus

    2007-01-01

    Nili Cohen, Professorin an der Tel-Aviv Universität und Ewan McKendrick, Professor in Oxford, haben die verdienstvolle Aufgabe unternommen, einen rechtsvergleichenden Sammelband zu einer der Kernmaterien des Schuldrechts, den Folgen einer Vertragsverletzung, herauszugeben. Die Beiträge sind das Ergebnis einer im Jahre 2002 an der Universität Tel-Aviv durchgeführten Konferenz zum Thema "Remedies for Breach of Contract". Die vertraglichen Rechtsbehelfe werden aus der Perspektive des Common Law,...

  10. Once more unto the breach managing information security in an uncertain world

    CERN Document Server

    Simmons, Andrea C

    2012-01-01

    In Once more unto the Breach, Andrea C Simmons speaks directly to information security managers and provides an insider's view of the role, offering priceless gems from her extensive experience and knowledge. Based on a typical year in the life of an information security manager, the book examines how the general principles can be applied to all situations and discusses the lessons learnt from a real project.

  11. Better than Fuller:a two interests model of remedies for breach of contract

    OpenAIRE

    Campbell, David

    2015-01-01

    The attempt to combine the contractual interests properly so-called with the restitution interest in the Fuller and Purdue three interests model of remedies for breach of contract is ineradicably incoherent. Stimulated by reflection on contemporary restitution doctrine’s understanding of the quasi-contractual remedies of recovery and quantum meruit, this paper argues that the complete elimination from the law of contract of the restitution interest, which incorporates those remedies into the ...

  12. Comparative Remedies for Breach of Contract, hrsg. von Nili Cohen und Ewan McKendrick

    OpenAIRE

    Müller-Chen, Markus

    2007-01-01

    Nili Cohen, Professorin an der Tel-Aviv Universität und Ewan McKendrick, Professor in Oxford, haben die verdienstvolle Aufgabe unternommen, einen rechtsvergleichenden Sammelband zu einer der Kernmaterien des Schuldrechts, den Folgen einer Vertragsverletzung, herauszugeben. Die Beiträge sind das Ergebnis einer im Jahre 2002 an der Universität Tel-Aviv durchgeführten Konferenz zum Thema "Remedies for Breach of Contract". Die vertraglichen Rechtsbehelfe werden aus der Perspektive des Common Law,...

  13. High specific power, direct methanol fuel cell stack

    Science.gov (United States)

    Ramsey, John C.; Wilson, Mahlon S.

    2007-05-08

    The present invention is a fuel cell stack including at least one direct methanol fuel cell. A cathode manifold is used to convey ambient air to each fuel cell, and an anode manifold is used to convey liquid methanol fuel to each fuel cell. Tie-bolt penetrations and tie-bolts are spaced evenly around the perimeter to hold the fuel cell stack together. Each fuel cell uses two graphite-based plates. One plate includes a cathode active area that is defined by serpentine channels connecting the inlet manifold with an integral flow restrictor to the outlet manifold. The other plate includes an anode active area defined by serpentine channels connecting the inlet and outlet of the anode manifold. Located between the two plates is the fuel cell active region.

  14. Modeling of Breaching Due to Overtopping Flow and Waves Based on Coupled Flow and Sediment Transport

    CERN Document Server

    He, Zhiguo; Zhao, Liang; Wu, Ganfeng; Pähtz, Thomas

    2015-01-01

    Breaching of earthen or sandy dams/dunes by overtopping flow and waves is a complicated process with strong, unsteady flow, high sediment transport, and rapid bed changes in which the interactions between flow and morphology should not be ignored. This study presents a depth-averaged two-dimensional (2D) coupled flow and sediment transport model to investigate the flow and breaching processes with and without waves. Bed change and variable flow density are included in the flow continuity and momentum equations to consider the impacts of sediment transport. The model adopts the non-equilibrium approach for total-load sediment transport and specifies different repose angles to handle non-cohesive embankment slope avalanching. The equations are solved using an explicit finite volume method on a rectangular grid with the improved Godunov-type central upwind scheme and the nonnegative reconstruction of the water depth method to handle mixed-regime flows near the breach. The model has been tested against two sets o...

  15. Whip Rule Breaches in a Major Australian Racing Jurisdiction: Welfare and Regulatory Implications.

    Science.gov (United States)

    Hood, Jennifer; McDonald, Carolyn; Wilson, Bethany; McManus, Phil; McGreevy, Paul

    2017-01-16

    Whip use in horseracing is increasingly being questioned on ethical, animal welfare, social sustainability, and legal grounds. Despite this, there is weak evidence for whip use and its regulation by Stewards in Australia. To help address this, we characterised whip rule breaches recorded by Stewards using Stewards Reports and Race Diaries from 2013 and 2016 in New SouthWales (NSW) and the Australian Capital Territory (ACT). There were more recorded breaches at Metropolitan (M) than Country (C) or Provincial (P) locations, and by riders of horses that finished first, second, or third than by riders of horses that finished in other positions. The most commonly recorded breaches were forehand whip use on more than five occasions before the 100-metre (m) mark (44%), and whip use that raises the jockey's arm above shoulder height (24%). It is recommended that racing compliance data be analysed annually to inform the evidence-base for policy, education, and regulatory change, and ensure the welfare of racehorses and racing integrity.

  16. After the data breach: Managing the crisis and mitigating the impact.

    Science.gov (United States)

    Brown, Hart S

    2016-01-01

    Historically, the unauthorised access and theft of information was a tactic used between countries as part of espionage campaigns, during times of conflict as well as for personal and criminal purposes. The consumers of the information were relatively isolated and specific. As information became stored and digitised in larger quantities in the 1980s the ability to access mass amounts of records at one time became possible. The expertise needed to remotely access and exfiltrate the data was not readily available and the number of markets to monetise the data was limited. Over the past ten years, shadow networks have been used by criminals to collaborate on hacking techniques, exchange hacking advice anonymously and commercialise data on the black market. The intersection of these networks along with the unintentional losses of information have resulted in 5,810 data breaches made public since 2005 (comprising some 847,807,830 records) and the velocity of these events is increasing. Organisations must be prepared for a potential breach event to maintain cyber resiliency. Proper management of a breach response can reduce response costs and can serve to mitigate potential reputational losses.

  17. Breaching the skin barrier--insights from molecular simulation of model membranes.

    Science.gov (United States)

    Notman, Rebecca; Anwar, Jamshed

    2013-02-01

    Breaching the skin's barrier function by design is an important strategy for delivering drugs and vaccines to the body. However, while there are many proposed approaches for reversibly breaching the skin barrier, our understanding of the molecular processes involved is still rudimentary. Molecular simulation offers an unprecedented molecular-level resolution with an ability to reproduce molecular and bulk level properties. We review the basis of the molecular simulation methodology and give applications of relevance to the skin lipid barrier, focusing on permeation of molecules and chemical approaches for breaching the lipid barrier by design. The bulk kinetic model based on Fick's Law describing absorption of a drug through skin has been reconciled with statistical mechanical quantities such as the local excess chemical potential and local diffusion coefficient within the membrane structure. Applications of molecular simulation reviewed include investigations of the structure and dynamics of simple models of skin lipids, calculation of the permeability of molecules in simple model membranes, and mechanisms of action of the penetration enhancers, DMSO, ethanol and oleic acid. The studies reviewed illustrate the power and potential of molecular simulation to yield important physical insights, inform and rationalize experimental studies, and to predict structural changes, and kinetic and thermodynamic quantities. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Single-Beam Bathymetry Point Data Shapefile of the Hurricane Sandy Breach at Fire Island, New York, June 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset, 20130626_bathy_points.zip, consists of single-beam point data collected in June 2013 during a bathymetry survey of the Wilderness Breach and adjacent...

  19. Single-Beam XYZ Point Bathymetry Data of the Hurricane Sandy Breach at Fire Island, New York, June 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset, 20130626_bathy_xyz.zip, consists of single-beam point data collected in June 2013 during a bathymetry survey of the Wilderness Breach and adjacent...

  20. Single-Beam XYZ Point Bathymetry Data of the Hurricane Sandy Breach at Fire Island, New York, June 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset, 20130626_bathy_xyz.zip, consists of single-beam point data collected in June 2013 during a bathymetry survey of the Wilderness Breach and adjacent...

  1. Coastal bathymetry data collected in June 2014 from Fire Island, New York—The wilderness breach and shoreface

    Science.gov (United States)

    Nelson, Timothy R.; Miselis, Jennifer L.; Hapke, Cheryl J.; Wilson, Kathleen E.; Henderson, Rachel E.; Brenner, Owen T.; Reynolds, Billy J.; Hansen, Mark E.

    2016-08-02

    Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, collected bathymetric data along the upper shoreface and within the wilderness breach at Fire Island, New York, in June 2014. The U.S. Geological Survey is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the shoreface along Fire Island and model the evolution of the wilderness breach as a part of the Hurricane Sandy Supplemental Project GS2-2B. During this study, bathymetry was collected with single-beam echo sounders and global positioning systems, mounted to personal watercraft, along the Fire Island shoreface and within the wilderness breach. Additional bathymetry was collected using backpack global positioning systems along the flood shoals and shallow channels within the wilderness breach.

  2. Followup to Columbia Investigation: Reinforced Carbon/Carbon From the Breach Location in the Wing Leading Edge Studied

    Science.gov (United States)

    Jacobson, Nathan S.; Opila, Elizabeth J.; Tallant, David

    2005-01-01

    Initial estimates on the temperature and conditions of the breach in the Space Shuttle Columbia's wing focused on analyses of the slag deposits. These deposits are complex mixtures of the reinforced carbon/carbon (RCC) constituents, insulation material, and wing structural materials. Identification of melted/solidified Cerachrome insulation (Thermal Ceramics, Inc., Augusta, GA) indicated that the temperatures at the breach had exceeded 1760 C.

  3. A method for determining the spent-fuel contribution to transport cask containment requirements

    Energy Technology Data Exchange (ETDEWEB)

    Sanders, T.L.; Seager, K.D. [Sandia National Labs., Albuquerque, NM (United States); Rashid, Y.R.; Barrett, P.R. [ANATECH Research Corp., La Jolla, CA (United States); Malinauskas, A.P. [Oak Ridge National Lab., TN (United States); Einziger, R.E. [Pacific Northwest Lab., Richland, WA (United States); Jordan, H. [EG and G Rocky Flats, Inc., Golden, CO (United States). Rocky Flats Plant; Duffey, T.A.; Sutherland, S.H. [APTEK, Inc., Colorado Springs, CO (United States); Reardon, P.C. [GRAM, Inc., Albuquerque, NM (United States)

    1992-11-01

    This report examines containment requirements for spent-fuel transport containers that are transported under normal and hypothetical accident conditions. A methodology is described that estimates the probability of rod failure and the quantity of radioactive material released from breached rods. This methodology characterizes the dynamic environment of the cask and its contents and deterministically models the peak stresses that are induced in spent-fuel cladding by the mechanical and thermal dynamic environments. The peak stresses are evaluated in relation to probabilistic failure criteria for generated or preexisting ductile tearing and material fractures at cracks partially through the wall in fuel rods. Activity concentrations in the cask cavity are predicted from estimates of the fraction of gases, volatiles, and fuel fines that are released when the rod cladding is breached. Containment requirements based on the source term are calculated in terms of maximum permissible volumetric leak rates from the cask. Calculations are included for representative cask designs.

  4. Characterization of gold and nickel coating on AISI 304 stainless steel for use in the fabrication of current collector plates for fuel cells; Caracterizacion de recubrimientos de oro y niquel realizados sobre acero inoxidable AISI 304 para su empleo en la fabricacion de placas colectoras de corriente para celdas de combustible

    Energy Technology Data Exchange (ETDEWEB)

    Flores Hernandez, J. Roberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)] e-mail: jrflores@iie.org.mx; Aguilar Gama, M. Tulio [UNAM. Facultad de Quimica, Mexico D.F. (Mexico); Cano Castillo, Ulises; Albarran, Lorena [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Olvera, J. Carlos; Orozco, German [CIDETEQ, Pedro Escobedo, Queretaro (Mexico)

    2009-09-15

    Among the different components that compose fuel cell technology (MEA, bipolar plates, seals, etc.) current collector plates play an important role in the good performance of fuel cells, since they collect all of the current generated and distribute it to the external circuit. Therefore, the most important properties that the current collector plates should have are excellent conductivity and good resistance to the corrosive conditions present in the fuel cell. This document presents results obtained during the nickel and gold electrodeposition process on AISI 304 stainless steel and the morphology and thickness of each coating, their adhesion, hardness and conductivity values. Finally, results obtained during some of the electrochemical tests performed on the coatings are shown. [Spanish] De los diferentes componentes que integran la tecnologia de celdas de combustible (MEA's, placas bipolares, sellos, etc.), las placas colectoras de corriente tienen un importante rol en el buen desempeno de la celdas de combustibles, ya que en estas placas se colecta toda la corriente generada y se distribuye al circuito externo. Debido a esto, las propiedades mas importantes que deben tener las placas colectaras de corriente son: excelente conductividad y buena resistencia a las condiciones corrosivas presentes en la celda de combustible. En este documento se presentan los resultados obtenidos en el proceso de electrodeposicion de niquel y oro sobre acero inoxidable AISI 304, asi como la morfologia y el espesor de cada recubrimiento, sus valores de adherencia, dureza y conductividad. Finalmente se muestran tambien los resultados obtenidos de algunas pruebas electroquimicas a los que fueron sometidos los recubrimientos.

  5. EVALUATING DAMAGE ASSESSMENT OF BREACHES ALONG THE EMBANKMENTS OF INDUS RIVER DURING FLOOD 2010 USING REMOTE SENSING TECHNIQUES

    Directory of Open Access Journals (Sweden)

    R. Ahmad

    2013-09-01

    Full Text Available Natural disasters cause human sufferings and property loss, if not managed properly. It cannot be prevented but their adverse impacts can be reduced through proper planning and disaster mitigation measures. The floods triggered by heavy rains during July 2010 in Pakistan caused swallowing of rivers causing human, agriculture, livestock and property losses in almost all over the country. The heavy rains in upper part of country were attributed to El-Nina effect. Accumulated water in the rivers floodplain overtopped and breached flood protective infrastructure. Flood damage particularly in Sindh province was caused by breaches in the embankments and even after months of flood recession in rivers, flood water affected settled areas in the province. This study evaluates the role of satellite remote sensing particularly in assessment of breaches and consequential damages as well as measures leading to minimize the effects of floods caused by breaches in flood protective infrastructure. More than 50 SPOT-5 imageries had been used for this purpose and breached areas were delineated using pre and post flood imageries, later on rehabilitation work were also monitored. A total 136 breaches were delineated out of which 60 were in the Punjab and 76 in Sindh province. The study demonstrates the potentials of satellite remote sensing for mapping and monitoring natural disasters and devising mitigation strategies.

  6. Hollow electrode loose plate SOFC design

    Energy Technology Data Exchange (ETDEWEB)

    Jaspers, B.C.; Dongen, B.A.M. van; Monaster, G.A. [Seed Capital Investments B.V., Utrecht (Netherlands); Roosmalen, J.A.M. van; Plaisier, K.H.; Schoonman, J. [Delft Univ. of Technology (Netherlands). Lab. for Applied Inorganic Chemistry

    1995-12-31

    A novel planar SOFC design is presented, based on the loose stacking of hollow electrode elements, conventional plate type electrolytes and interconnectors. This facilitates free thermal expansion during operation, and thermal cycling, thereby significantly improving prospects for reliable SOFC operation in power generation practice. Each individual element only consists of one material, eliminating the need for sealing and for matching thermal expansion coefficients of fuel cell components. Application of hollow electrodes results in an inherent manifolding of the gas streams eliminating the need for seals at the fuel cell stack itself. The design has been tested at laboratory scale and a small working prototype fuel cell has been successfully tested.

  7. Cap assembly for a bundled tube fuel injector

    Energy Technology Data Exchange (ETDEWEB)

    LeBegue, Jeffrey Scott; Melton, Patrick Benedict; Westmoreland, III, James Harold; Flanagan, James Scott

    2016-04-26

    A cap assembly for a bundled tube fuel injector includes an impingement plate and an aft plate that is disposed downstream from the impingement plate. The aft plate includes a forward side that is axially separated from an aft side. A tube passage extends through the impingement plate and the aft plate. A tube sleeve extends through the impingement plate within the tube passage towards the aft plate. The tube sleeve includes a flange at a forward end and an aft end that is axially separated from the forward end. A retention plate is positioned upstream from the impingement plate. A spring is disposed between the retention plate and the flange. The spring provides a force so as to maintain contact between at least a portion of the aft end of the tube sleeve and the forward side of the aft plate.

  8. Optimization of electrical conduction and passivity properties of stainless steels used for PEM fuel cell bipolar plates; Opmisation des proprietes de conduction electrique et de passivite d'aciers inoxydables pour la realisation de plaques bipolaires de pile a combustible de type PEMFC

    Energy Technology Data Exchange (ETDEWEB)

    Andre, J

    2007-10-15

    Among the new technologies for energy for sustainable development, PEMFC (proton exchange membrane fuel cells) offer seducing aspects. However, in order to make this technology fit large scale application requirements, it has to comply with stringent cost, performance, and durability criteria. In such a frame, the goal of this work was to optimize electrical conduction properties and passivity of stainless steels for the conception of PEMFC bipolar plates, used instead of graphite, the reference material. This work presents the possible ways of performance loss when using stainless steels and some methods to solve this problem. Passive film properties were studied, as well as their modifications by low cost industrial surface treatments, without deposition. Ex situ characterizations of corrosion resistance and electrical conduction were performed. Electrochemical impedance spectroscopy, water analysis, surface analysis by microscopy and photoelectron spectroscopy allowed to study the impact of ageing on two alloys in different states, and several conditions representative of an exposure to PEMFC media. Correlations between semi-conductivity properties, composition, and structure of passive layers were considered, but not leading to clear identification of all parameters responsible for electrical conduction and passivity. The plate industrial state is not convenient for direct use in fuel cell to comply with durability and performance requirements. A surface modification studied improves widely electrical conduction at initial state. The performance is degraded with ageing, but maintaining a level higher than the initial industrial state. This treatment increases also corrosion resistance, particularly on the anode side. (author)

  9. Processless offset printing plates

    Directory of Open Access Journals (Sweden)

    Sanja Mahović Poljaček

    2015-06-01

    Full Text Available With the implementation of platesetters in the offset printing plate making process, imaging of the printing plate became more stable and ensured increase of the printing plate quality. But as the chemical processing of the printing plates still highly influences the plate making process and the graphic reproduction workflow, development of printing plates that do not require chemical processing for offset printing technique has been one of the top interests in graphic technology in the last few years. The main reason for that came from the user experience, where majority of the problems with plate making process could be connected with the chemical processing of the printing plate. Furthermore, increased environmental standards lead to reducing of the chemicals used in the industrial processes. Considering these facts, different types of offset printing plates have been introduced to the market today. This paper presents some of the processless printing plates.

  10. Temperature and burnup correlated fuel-cladding chemical interaction in U-10ZR metallic fuel

    Science.gov (United States)

    Carmack, William J.

    Metallic fuels are proposed for use in advanced sodium cooled fast reactors and provide a number of advantages over other fuel types considering their fabricability, performance, recyclability, and safety. Resistance to cladding "breach" and subsequent release of fission products and fuel constituents to the nuclear power plant primary coolant system is a key performance parameter for a nuclear fuel system. In metallic fuel, FCCI weakens the cladding, especially at high power-high temperature operation, contributing to fuel pin breach. Empirical relationships for FCCI have been developed from a large body of data collected from in-pile (EBR-II) and out-of-pile experiments [1]. However, these relationships are unreliable in predicting FCCI outside the range of EBR-II experimental data. This dissertation examines new FCCI data extracted from the MFF-series of prototypic length metallic fuel irradiations performed in the Fast Flux Test Facility (FFTF). The fuel in these assemblies operated a temperature and burnup conditions similar to that in EBR-II but with axial fuel height three times longer than EBR-II experiments. Comparing FCCI formation data from FFTF and EBR-II provides new insight into FCCI formation kinetics. A model is developed combining both production and diffusion of lanthanides to the fuel-cladding interface and subsequent reaction with the cladding. The model allows these phenomena to be influenced by fuel burnup (lanthanide concentrations) and operating temperature. Parameters in the model are adjusted to reproduce measured FCCI layer thicknesses from EBR-II and FFTF. The model predicts that, under appropriate conditions, rate of FCCI formation can be controlled by either fission product transport or by the reaction rate of the interaction species at the fuel-cladding interface. This dissertation will help forward the design of metallic fuel systems for advanced sodium cooled fast reactors by allowing the prediction of FCCI layer formation in full

  11. Electroconvulsive therapy, hypertensive surge, blood-brain barrier breach, and amnesia

    DEFF Research Database (Denmark)

    Andrade, Chittaranjan; Bolwig, Tom G

    2014-01-01

    Preclinical and clinical evidence show that electroconvulsive therapy (ECT)-induced intraictal surge in blood pressure may result in a small, transient breach in the blood-brain barrier, leading to mild cerebral edema and a possible leach of noxious substances from blood into brain tissues...... of blood pressure during electroconvulsive shocks attenuate electroconvulsive shock-induced amnestic changes; however, the evidence suggests that antihypertensive mechanisms may not necessarily be involved. Clinical studies involving pre-ECT administration of antihypertensive medications do not provide...

  12. Responding to moderate breaches in professionalism: an intervention for medical students.

    Science.gov (United States)

    Gill, Anne C; Nelson, Elizabeth A; Mian, Ayesha I; Raphael, Jean L; Rowley, David R; Mcguire, Amy L

    2015-02-01

    Much has been written about how we understand, teach and evaluate professionalism in medical training. Less often described are explicit responses to mild or moderate professionalism concerns in medical students. To address this need, Baylor College of Medicine created a mechanism to assess professionalism competency for medical students and policies to address breaches in professional behavior. This article describes the development of an intervention using a guided reflection model, student responses to the intervention, and how the program evolved into a credible resource for deans and other educational leaders.

  13. Breach of information duties in the B2C e-commerce: adequacy of available remedies

    Directory of Open Access Journals (Sweden)

    Zofia Bednarz

    2016-07-01

    Full Text Available

    B2C e-commerce is characterised by the information asymmetry between the contracting parties. Various information duties are imposed on traders, both at the European and national level to correct this asymmetry and to ensure proper market functioning. The mandated disclosure is based on the assumption of consumers' rationality. However, developments of behavioural economics challenge this assumption. The utility of mandated disclosure in consumer contracts depends also on the remedies available to consumers in a case of breach of information duties. Those remedies are often heavily influenced by the national general private law applicable to the contractual relationship between the parties. Nevertheless, since the economics of general contract law differ importantly from principles of consumer e-commerce, various problems can be associated with the application of general law remedies to the breach of information duties in B2C contracts. The limited value of the majority of the online B2C transactions is incompatible with costly and lengthy court proceedings. Moreover, breach of information duties will often not produce enough material damage on the side of the consumer to make the remedies available. Different solutions are explored, from ADR, to the duty to advise, to non-legal mechanisms making the information easier to use for consumers throughlimiting disclosure. Finally, the right of withdrawal is analysed as an example of a specific remedy, adapted to the economics of the B2C electronic transactions, where the aims parties pursue through contracts are different than in commercial contracts, and their relationship is marked with the inequality of economic power and information asymmetry. However, the legally established cooling-off period is not free from limitations, and only a combination of various measures, including effective

  14. Motive Matters! An exploration of the notion ‘deliberate breach of contract’ and its consequences for the application of remedies

    OpenAIRE

    Kogelenberg, Martijn

    2012-01-01

    textabstractThis thesis explores the notion of deliberate breach of contract and its potential remedial consequences. In the major jurisdictions in Europe and in the United States the notion of deliberate breach of contract is generally not coherently and officially defined and acknowledged as an independent legal phenomenon. The ultimate added value of this thesis intends to be a first coherent comparative research on deliberate breach of contract and its potential consequences for the core ...

  15. Gas only nozzle fuel tip

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel, William Theodore (Scotia, NY); Fitts, David Orus (Ballston Spa, NY); DeLeonardo, Guy Wayne (Glenville, NY)

    2002-01-01

    A diffusion flame nozzle gas tip is provided to convert a dual fuel nozzle to a gas only nozzle. The nozzle tip diverts compressor discharge air from the passage feeding the diffusion nozzle air swirl vanes to a region vacated by removal of the dual fuel components, so that the diverted compressor discharge air can flow to and through effusion holes in the end cap plate of the nozzle tip. In a preferred embodiment, the nozzle gas tip defines a cavity for receiving the compressor discharge air from a peripheral passage of the nozzle for flow through the effusion openings defined in the end cap plate.

  16. Breaches of the pial basement membrane and disappearance of the glia limitans during development underlie the cortical lamination defect in the mouse model of muscle-eye-brain disease.

    Science.gov (United States)

    Hu, Huaiyu; Yang, Yuan; Eade, Amber; Xiong, Yufang; Qi, Yue

    2007-05-10

    Neuronal overmigration is the underlying cellular mechanism of cerebral cortical malformations in syndromes of congenital muscular dystrophies caused by defects in O-mannosyl glycosylation. Overmigration involves multiple developmental abnormalities in the brain surface basement membrane, Cajal-Retzius cells, and radial glia. We tested the hypothesis that breaches in basement membrane and the underlying glia limitans are the key initial events of the cellular pathomechanisms by carrying out a detailed developmental study with a mouse model of muscle-eye-brain disease, mice deficient in O-mannose beta1,2-N-acetylglucosaminyltransferase 1 (POMGnT1). The pial basement membrane was normal in the knockout mouse at E11.5. It was breached during rapid cerebral cortical expansion at E13.5. Radial glial endfeet, which comprise glia limitans, grew out of the neural boundary. Neurons moved out of the neural boundary through these breaches. The overgrown radial glia and emigrated neurons disrupted the overlying pia mater. The overmigrated neurons did not participate in cortical plate (CP) development; rather they formed a diffuse cell zone (DCZ) outside the original cortical boundary. Together, the DCZ and the CP formed the knockout cerebral cortex, with disappearance of the basement membrane and the glia limitans. These results suggest that disappearance of the basement membrane and the glia limitans at the cerebral cortical surface during development underlies cortical lamination defects in congenital muscular dystrophies and a cellular mechanism of cortical malformation distinct from that of the reeler mouse, double cortex syndrome, and periventricular heterotopia.

  17. Metrology for Fuel Cell Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Stocker, Michael [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Stanfield, Eric [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

    2015-02-04

    The project was divided into three subprojects. The first subproject is Fuel Cell Manufacturing Variability and Its Impact on Performance. The objective was to determine if flow field channel dimensional variability has an impact on fuel cell performance. The second subproject is Non-contact Sensor Evaluation for Bipolar Plate Manufacturing Process Control and Smart Assembly of Fuel Cell Stacks. The objective was to enable cost reduction in the manufacture of fuel cell plates by providing a rapid non-contact measurement system for in-line process control. The third subproject is Optical Scatterfield Metrology for Online Catalyst Coating Inspection of PEM Soft Goods. The objective was to evaluate the suitability of Optical Scatterfield Microscopy as a viable measurement tool for in situ process control of catalyst coatings.

  18. Highest average burnups achieved by MTR fuel elements of the IEA-R1 research reactor

    Energy Technology Data Exchange (ETDEWEB)

    Damy, Margaret A.; Terremoto, Luis A.A.; Silva, Jose E.R.; Silva, Antonio Teixeira e; Castanheira, Myrthes; Teodoro, Celso A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Engenharia Nuclear (CEN)]. E-mail: madamy@ipen.br

    2007-07-01

    Different nuclear fuels were employed in the manufacture of plate type at IPEN , usually designated as Material Testing Reactor (MTR) fuel elements. These fuel elements were used at the IEA-R1 research reactor. This work describes the main characteristics of these nuclear fuels, emphasizing the highest average burn up achieved by these fuel elements. (author)

  19. The breach between academic studies and professional intervention in health field

    Directory of Open Access Journals (Sweden)

    Graciela H. Tonón

    2015-08-01

    Full Text Available The main objective of this project was the definition of the breach between academic studies and professional exercise of professional that work in Health field. The project was developed in the Psychology Research Center of the Faculty of Social Sciences of the Universidad de Palermo (Argentina, which was a training space for students of the Psychology Doctoral Program of this university. It is a qualitative descriptive study in which we applied semi-structured interviews to professionals that work in Health field in private and public health institutions of the Ciudad Autónoma de Buenos Aires. People interviewed said that in their university studies the role of the theory was more important than the role of practice; even we can observe differences between the decades of graduation and type of university institution (public or private. At the same time, they recognized a breach between academic studies and professional exercise which characterized by the lack of spaces for the practice before the graduation and the knowledge about labor market, and at the same time the increase of the number of students in the universities. They recommended give a protagonist role to the practice in the university studies and regain the recognition for health professionals from the population and the governments. 

  20. Breaching the security of the Kaiser Permanente Internet patient portal: the organizational foundations of information security.

    Science.gov (United States)

    Collmann, Jeff; Cooper, Ted

    2007-01-01

    This case study describes and analyzes a breach of the confidentiality and integrity of personally identified health information (e.g. appointment details, answers to patients' questions, medical advice) for over 800 Kaiser Permanente (KP) members through KP Online, a web-enabled health care portal. The authors obtained and analyzed multiple types of qualitative data about this incident including interviews with KP staff, incident reports, root cause analyses, and media reports. Reasons at multiple levels account for the breach, including the architecture of the information system, the motivations of individual staff members, and differences among the subcultures of individual groups within as well as technical and social relations across the Kaiser IT program. None of these reasons could be classified, strictly speaking, as "security violations." This case study, thus, suggests that, to protect sensitive patient information, health care organizations should build safe organizational contexts for complex health information systems in addition to complying with good information security practice and regulations such as the Health Insurance Portability and Accountability Act (HIPAA) of 1996.

  1. Coastal bathymetry data collected in May 2015 from Fire Island, New York—Wilderness breach and shoreface

    Science.gov (United States)

    Nelson, Timothy R.; Miselis, Jennifer L.; Hapke, Cheryl J.; Brenner, Owen T.; Henderson, Rachel E.; Reynolds, Billy J.; Wilson, Kathleen E.

    2017-05-12

    Scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, conducted a bathymetric survey of Fire Island from May 6-20, 2015. The USGS is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the wilderness breach as a part of the Hurricane Sandy Supplemental Project GS2-2B. During this study, bathymetry data were collected with single-beam echo sounders and Global Positioning Systems, which were mounted to personal watercraft, along the Fire Island shoreface and within the wilderness breach. Additional bathymetry and elevation data were collected using backpack Global Positioning Systems on flood shoals and in shallow channels within the wilderness breach.

  2. Bathymetry data collected in October 2014 from Fire Island, New York—The wilderness breach, shoreface, and bay

    Science.gov (United States)

    Nelson, Timothy R.; Miselis, Jennifer L.; Hapke, Cheryl J.; Brenner, Owen T.; Henderson, Rachel E.; Reynolds, Billy J.; Wilson, Kathleen E.

    2017-03-24

    Scientists from the U.S. Geological Survey St. Petersburg Coastal and Marine Science Center in St. Petersburg, Florida, conducted a bathymetric survey of Fire Island, New York, from October 5 to 10, 2014. The U.S. Geological Survey is involved in a post-Hurricane Sandy effort to map and monitor the morphologic evolution of the wilderness breach, which formed in October 2012 during Hurricane Sandy, as part of the Hurricane Sandy Supplemental Project GS2-2B. During this study, bathymetry data were collected, using single-beam echo sounders and global positioning systems mounted to personal watercraft, along the Fire Island shoreface and within the wilderness breach, Fire Island Inlet, Narrow Bay, and Great South Bay east of Nicoll Bay. Additional bathymetry and elevation data were collected using backpack and wheel-mounted global positioning systems along the subaerial beach (foreshore and backshore), flood shoals, and shallow channels within the wilderness breach and adjacent shoreface.

  3. Dam-breach analysis and flood-inundation mapping for selected dams in Oklahoma City, Oklahoma, and near Atoka, Oklahoma

    Science.gov (United States)

    Shivers, Molly J.; Smith, S. Jerrod; Grout, Trevor S.; Lewis, Jason M.

    2015-01-01

    Dams provide beneficial functions such as flood control, recreation, and storage of water supplies, but they also entail risk; dam breaches and resultant floods can cause substantial property damage and loss of life. The State of Oklahoma requires each owner of a high-hazard dam, which the Federal Emergency Management Agency defines as dams for which failure or improper operation probably will cause loss of human life, to develop an emergency action plan specific to that dam. Components of an emergency action plan are to simulate a flood resulting from a possible dam breach and map the resulting downstream flood-inundation areas. The resulting flood-inundation maps can provide valuable information to city officials, emergency managers, and local residents for planning an emergency response if a dam breach occurs.

  4. FY04 Inspection Results for Wet Uruguay Fuel in L-Basin

    Energy Technology Data Exchange (ETDEWEB)

    VORMELKER, PHILIP

    2005-09-01

    The 2004 visual inspection of four Uruguay nuclear fuel assemblies stored in L-Basin was completed. This was the third inspection of this wet stored fuel since its arrival in the summer of 1998. Visual inspection photographs of the fuel from the previous and the recent inspections were compared and no evidence of significant corrosion was found on the individual fuel plate photographs. Fuel plates that showed areas of pitting in the cladding during the original receipt inspection were also identified during the 2004 inspection. However, a few pits were found on the non-fuel aluminum clamping plates that were not visible during the original and 2001 inspections.

  5. Results of Recent Microstructural Characterization of Irradiated U-Mo Dispersion Fuels with Al Alloy Matrices that Contain Si

    Energy Technology Data Exchange (ETDEWEB)

    Keiser, Jr, D D; Robinson, A B; Janney, D E; Jue, J F

    2008-03-01

    RERTR U-Mo dispersion fuel plates are being developed for application in research reactors throughout the world. Of particular interest is the irradiation performance of U-Mo dispersion fuels with Si added to the Al matrix. Si is added to improve the performance of U-Mo dispersion fuels. Microstructural examinations have been performed on fuel plates with either Al-0.2Si or 4043 Al (~4.8% Si) alloy matrix in the as-fabricated and/or as-irradiated condition using optical metallography and/or scanning electron microscopy. Fuel plates with either matrix can have Si-rich layers around the U-7Mo particles after fabrication, and during irradiation these layers were observed to grow in thickness and to become Si-deficient in some areas of the fuel plates. For the fuel plates with 4043 Al, this was observed in fuel plate areas that were exposed to very aggressive irradiation conditions.

  6. Create Your Plate

    Medline Plus

    Full Text Available ... steps to get started: Using your dinner plate, put a line down the middle of the plate. ... vegetables . Now in one of the small sections, put grains and starchy foods. See this list of ...

  7. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... 2016 Articles from Diabetes Forecast® magazine: wcie-meal-planning, In this section Food Planning Meals Diabetes Meal ...

  8. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal ... Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook ...

  9. Food guide plate

    Science.gov (United States)

    ... chips or cookies. VEGETABLES: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Vegetables can be raw, fresh, ... as a snack. FRUITS: MAKE HALF OF YOUR PLATE FRUITS AND VEGETABLES Fruits can be fresh, canned, ...

  10. Growth Plate Fractures

    Science.gov (United States)

    ... the most widely used by doctors is the Salter-Harris system, described below. Type I Fractures These ... incidence of growth plate fractures peaks in adolescence. Salter-Harris classification of growth plate fractures. AAOS does ...

  11. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  12. Create Your Plate

    Medline Plus

    Full Text Available ... Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook ... Create Your Plate Meal Planning for Vegetarian Diets Gluten Free Diets Holiday Meal Planning Cook with Heart- ...

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets you still choose the foods you want, but changes the portion sizes so you are getting larger ...

  14. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate It's simple and effective for both managing diabetes and losing weight. Creating your plate lets ... Sleeve Custom jerseys for your Tour de Cure team benefits the cause. Ask the Experts: Learn to ...

  15. Accelerated plate tectonics.

    Science.gov (United States)

    Anderson, D L

    1975-03-21

    The concept of a stressed elastic lithospheric plate riding on a viscous asthenosphere is used to calculate the recurrence interval of great earthquakes at convergent plate boundaries, the separation of decoupling and lithospheric earthquakes, and the migration pattern of large earthquakes along an arc. It is proposed that plate motions accelerate after great decoupling earthquakes and that most of the observed plate motions occur during short periods of time, separated by periods of relative quiescence.

  16. Fabrication procedures for manufacturing High Flux Isotope Reactor fuel elements - 2

    Energy Technology Data Exchange (ETDEWEB)

    Knight, R.W.; Morin, R.A.

    1999-12-01

    The original fabrication procedures written in 1968 delineated the manufacturing procedures at that time. Since 1968, there have been a number of procedural changes. This rewrite of the fabrication procedures incorporates these changes. The entire fuel core of this reactor is made up of two fuel elements. Each element consists of one annular array of fuel plates. These annuli are identified as the inner and outer fuel elements, since one fits inside the other. The inner element consists of 171 identical fuel plates, and the outer element contains 369 identical fuel plates differing slightly from those in the inner element. Both sets of fuel plates contain U{sub 3}O{sub 8} powder as the fuel, dispersed in an aluminum powder matrix and clad with aluminum. Procedures for manufacturing and inspection of the fuel elements are described and illustrated.

  17. Create Your Plate

    Medline Plus

    Full Text Available ... Reset Plate Share Create Your Plate ! Share: Seven Simple Steps to Create Your Plate It's simple and effective for both managing diabetes and losing ... en.html Have Type 2 Diabetes? Our free program will help you live well. More from diabetes. ...

  18. Obliquity along plate boundaries

    Science.gov (United States)

    Philippon, Mélody; Corti, Giacomo

    2016-12-01

    Most of the plate boundaries are activated obliquely with respect to the direction of far field stresses, as roughly only 8% of the plate boundaries total length shows a very low obliquity (ranging from 0 to 10°, sub-orthogonal to the plate displacement). The obliquity along plate boundaries is controlled by (i) lateral rheological variations within the lithosphere and (ii) consistency with the global plate circuit. Indeed, plate tectonics and magmatism drive rheological changes within the lithosphere and consequently influence strain localization. Geodynamical evolution controls large-scale mantle convection and plate formation, consumption, and re-organization, thus triggering plate kinematics variations, and the adjustment and re-orientation of far field stresses. These geological processes may thus result in plate boundaries that are not perpendicular but oblique to the direction of far field stresses. This paper reviews the global patterns of obliquity along plate boundaries. Using GPlate, we provide a statistical analysis of present-day obliquity along plate boundaries. Within this framework, by comparing natural examples and geological models, we discuss deformation patterns and kinematics recorded along oblique plate boundaries.

  19. Categorization of failed and damaged spent LWR (light-water reactor) fuel currently in storage

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, W.J.

    1987-11-01

    The results of a study that was jointly sponsored by the US Department of Energy and the Electric Power Research Institute are described in this report. The purpose of the study was to (1) estimate the number of failed fuel assemblies and damaged fuel assemblies (i.e., ones that have sustained mechanical or chemical damage but with fuel rod cladding that is not breached) in storage, (2) categorize those fuel assemblies, and (3) prepare this report as an authoritative, illustrated source of information on such fuel. Among the more than 45,975 spent light-water reactor fuel assemblies currently in storage in the United States, it appears that there are nearly 5000 failed or damaged fuel assemblies. 78 refs., 23 figs., 19 tabs.

  20. Hazards Induced by Breach of Liquid Rocket Fuel Tanks: Conditions and Risks of Cryogenic Liquid Hydrogen-Oxygen Mixture Explosions

    Science.gov (United States)

    Osipov, Viatcheslav; Muratov, Cyrill; Hafiychuk, Halyna; Ponizovskya-Devine, Ekaterina; Smelyanskiy, Vadim; Mathias, Donovan; Lawrence, Scott; Werkheiser, Mary

    2011-01-01

    We analyze the data of purposeful rupture experiments with LOx and LH2 tanks, the Hydrogen-Oxygen Vertical Impact (HOVI) tests that were performed to clarify the ignition mechanisms, the explosive power of cryogenic H2/Ox mixtures under different conditions, and to elucidate the puzzling source of the initial formation of flames near the intertank section during the Challenger disaster. We carry out a physics-based analysis of general explosions scenarios for cryogenic gaseous H2/Ox mixtures and determine their realizability conditions, using the well-established simplified models from the detonation and deflagration theory. We study the features of aerosol H2/Ox mixture combustion and show, in particular, that aerosols intensify the deflagration flames and can induce detonation for any ignition mechanism. We propose a cavitation-induced mechanism of self-ignition of cryogenic H2/Ox mixtures that may be realized when gaseous H2 and Ox flows are mixed with a liquid Ox turbulent stream, as occurred in all HOVI tests. We present an overview of the HOVI tests to make conclusion on the risk of strong explosions in possible liquid rocket incidents and provide a semi-quantitative interpretation of the HOVI data based on aerosol combustion. We uncover the most dangerous situations and discuss the foreseeable risks which can arise in space missions and lead to tragic outcomes. Our analysis relates to only unconfined mixtures that are likely to arise as a result of liquid propellant space vehicle incidents.

  1. Hazards Induced by Breach of Liquid Rocket Fuel Tanks: Conditions and Risks of Cryogenic Liquid Hydrogen-Oxygen Mixture Explosions

    CERN Document Server

    Osipov, Viatcheslav; Hafiychuk, Halyna; Ponizovskaya-Devine, Ekaterina; Smelyanskiy, Vadim; Mathias, Donovan; Lawrence, Scott; Werkheiser, Mary

    2010-01-01

    We analyze the data of purposeful rupture experiments with LOx and LH2 tanks, the Hydrogen-Oxygen Vertical Impact (HOVI) tests that were performed to clarify the ignition mechanisms, the explosive power of cryogenic H2/Ox mixtures under different conditions, and to elucidate the puzzling source of the initial formation of flames near the intertank section during the Challenger disaster. We carry out a physics-based analysis of general explosions scenarios for cryogenic gaseous H2/Ox mixtures and determine their realizability conditions, using the well-established simplified models from the detonation and deflagration theory. We study the features of aerosol H2/Ox mixture combustion and show, in particular, that aerosols intensify the deflagration flames and can induce detonation for any ignition mechanism. We propose a cavitation-induced mechanism of self-ignition of cryogenic H2/Ox mixtures that may be realized when gaseous H2 and Ox flows are mixed with a liquid Ox turbulent stream, as occurred in all HOVI ...

  2. Fuel cell commercialization issues for light-duty vehicle applications

    Science.gov (United States)

    Borroni-Bird, Christopher E.

    The major challenges facing fuel cells in light-duty vehicle applications relate to the high cost of the fuel cell stack components (membrane, electro-catalyst and bipolar plate) which dictate that new manufacturing processes and materials must be developed. Initially, the best fuel for a mass market light-duty vehicle will probably not be the best fuel for the fuel cell (hydrogen); refueling infrastructure and energy density concerns may demand the use of an on-board fuel processor for petroleum-based fuels since this will increase customer acceptance. The use of fuel processors does, however, reduce the fuel cell system's efficiency. Moreover, if such fuels are used then the emissions benefit associated with fuel cells may come with a significant penalty in terms of added complexity, weight, size and cost. However, ultimately, fuel cells powered by hydrogen do promise to be the most efficient and cleanest of automotive powertrains.

  3. Phosphoric Acid Fuel Cell Technology Status

    Science.gov (United States)

    Simons, S. N.; King, R. B.; Prokopius, P. R.

    1981-01-01

    A review of the current phosphoric acid fuel cell system technology development efforts is presented both for multimegawatt systems for electric utility applications and for multikilowatt systems for on-site integrated energy system applications. Improving fuel cell performance, reducing cost, and increasing durability are the technology drivers at this time. Electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, and fuel selection are discussed.

  4. State Security Breach Response Laws: State-by-State Summary Table. Using Data to Improve Education: A Legal Reference Guide to Protecting Student Privacy and Data Security

    Science.gov (United States)

    Data Quality Campaign, 2011

    2011-01-01

    Under security breach response laws, businesses--and sometimes state and governmental agencies--are required to inform individuals when the security, confidentiality or integrity of their personal information has been compromised. This resource provides a state-by-state analysis of security breach response laws. [The Data Quality Campaign has…

  5. The Effect of Perceived Privacy Breaches on Continued Technology Use and Individual Psychology: The Construct, Instrument Development, and an Application Using Internet Search Engines

    Science.gov (United States)

    Ahmad, Altaf

    2010-01-01

    This dissertation involved the development of a new construct, perceived privacy breach (PPB), to evaluate how a person perceives breaches of privacy in terms of whether they perceive any exchange of information was fair or not and how they believe it will impact people whose information has been shared. . This instrument assists researchers to…

  6. Market Reactions to Publicly Announced Privacy and Security Breaches Suffered by Companies Listed on the United States Stock Exchanges: A Comparative Empirical Investigation

    Science.gov (United States)

    Coronado, Adolfo S.

    2012-01-01

    Using a sample of security and privacy breaches the present research examines the comparative announcement impact between the two types of events. The first part of the dissertation analyzes the impact of publicly announced security and privacy breaches on abnormal stock returns, the change in firm risk, and abnormal trading volume are measured.…

  7. Motive Matters! An exploration of the notion ‘deliberate breach of contract’ and its consequences for the application of remedies

    NARCIS (Netherlands)

    M. van Kogelenberg (Martijn)

    2012-01-01

    textabstractThis thesis explores the notion of deliberate breach of contract and its potential remedial consequences. In the major jurisdictions in Europe and in the United States the notion of deliberate breach of contract is generally not coherently and officially defined and acknowledged as an in

  8. Enhanced methanol utilization in direct methanol fuel cell

    Science.gov (United States)

    Ren, Xiaoming; Gottesfeld, Shimshon

    2001-10-02

    The fuel utilization of a direct methanol fuel cell is enhanced for improved cell efficiency. Distribution plates at the anode and cathode of the fuel cell are configured to distribute reactants vertically and laterally uniformly over a catalyzed membrane surface of the fuel cell. A conductive sheet between the anode distribution plate and the anodic membrane surface forms a mass transport barrier to the methanol fuel that is large relative to a mass transport barrier for a gaseous hydrogen fuel cell. In a preferred embodiment, the distribution plate is a perforated corrugated sheet. The mass transport barrier may be conveniently increased by increasing the thickness of an anode conductive sheet adjacent the membrane surface of the fuel cell.

  9. Angular shear plate

    Science.gov (United States)

    Ruda, Mitchell C [Tucson, AZ; Greynolds, Alan W [Tucson, AZ; Stuhlinger, Tilman W [Tucson, AZ

    2009-07-14

    One or more disc-shaped angular shear plates each include a region thereon having a thickness that varies with a nonlinear function. For the case of two such shear plates, they are positioned in a facing relationship and rotated relative to each other. Light passing through the variable thickness regions in the angular plates is refracted. By properly timing the relative rotation of the plates and by the use of an appropriate polynomial function for the thickness of the shear plate, light passing therethrough can be focused at variable positions.

  10. The OSU Hydro-Mechanical Fuel Test Facility: Standard Fuel Element Testing

    Energy Technology Data Exchange (ETDEWEB)

    Wade R. Marcum; Brian G. Woods; Ann Marie Phillips; Richard G. Ambrosek; James D. Wiest; Daniel M. Wachs

    2001-10-01

    Oregon State University (OSU) and the Idaho National Laboratory (INL) are currently collaborating on a test program which entails hydro-mechanical testing of a generic plate type fuel element, or standard fuel element (SFE), for the purpose of qualitatively demonstrating mechanical integrity of uranium-molybdenum monolithic plates as compared to that of uranium aluminum dispersion, and aluminum fuel plates due to hydraulic forces. This test program supports ongoing work conducted for/by the fuel development program and will take place at OSU in the Hydro-Mechanical Fuel Test Facility (HMFTF). Discussion of a preliminary test matrix, SFE design, measurement and instrumentation techniques, and facility description are detailed in this paper.

  11. Computational Complexities and Breaches in Authentication Frameworks of Broadband Wireless Access

    CERN Document Server

    Hashmi, Raheel Maqsood; Jabeen, Memoona; Alimgeer, Khurram S; Khan, Shahid A

    2009-01-01

    Secure access of communication networks has become an increasingly important area of consideration for the communication service providers of present day. Broadband Wireless Access (BWA) networks are proving to be an efficient and cost effective solution for the provisioning of high rate wireless traffic links in static and mobile domains. The secure access of these networks is necessary to ensure their superior operation and revenue efficacy. Although authentication process is a key to secure access in BWA networks, the breaches present in them limit the networks performance. In this paper, the vulnerabilities in the authentication frameworks of BWA networks have been unveiled. Moreover, this paper also describes the limitations of these protocols and of the solutions proposed to them due to the involved computational complexities and overheads. The possible attacks on privacy and performance of BWA networks have been discussed and explained in detail.

  12. LMX, Breach Perceptions, Work-Family Conflict, and Well-Being: A Mediational Model.

    Science.gov (United States)

    Hill, Rachel T; Morganson, Valerie J; Matthews, Russell A; Atkinson, Theresa P

    2016-01-01

    Despite research advances, work-family scholars still lack an understanding of how leadership constructs relate to an employee's ability to effectively manage the work-family interface. In addition, there remains a need to examine the process through which leadership and work-family conflict influence well-being outcomes. Using a sample of 312 workers, a mediated process model grounded in social exchange theory is tested wherein the authors seek to explain how leaders shape employee perceptions, which, in turn, impact organizational fulfillment of expectations (i.e., psychological contract breach), work-family conflict, and well-being. A fully latent structural equation model was used to test study hypotheses, all of which were supported. Building on existing theory, findings suggest that the supervisor plays a critical role as a frontline representative for the organization and that work-family conflict is reduced and well-being enhanced through a process of social exchange between the supervisor and worker.

  13. Human experimentation: historical perspective of breaches of ethics in US health care.

    Science.gov (United States)

    Layman, Elizabeth J

    2009-01-01

    Health care supervisors and managers may participate in ethical discussions and serve on ethics committees in their health care organizations. To aid them in their participation and service, this article expands upon the knowledge of ethics that they obtained in their academic training. The article provides readers with a common language based on frequently cited cases and key documents. The article traces a brief history of human experimentation, describes ethical breaches in the United States, and summarizes key documents guiding current thought on informed and voluntary consent. The article concludes with 3 common misconceptions that health care supervisors and managers will want to avoid in ethical discussions and ethical decision making. Health care supervisors and managers will be prepared to meaningfully contribute to the discussion of ethical issues and to the resolution of ethical problems in their health care organizations.

  14. Ground Penetrating Radar Profiles of Breached Anticlinal Ridges in the Northern Piedmont of the San Bernardino Mountains in Southern California

    Science.gov (United States)

    Bobyarchick, A. R.; Eppes, M. C.; Diemer, J. A.; Cathey, R. B.; Cottingham, M. A.; Eckardt, I. J.; Shiflet, J. E.; Waldron, A. J.

    2006-12-01

    The northern piedmont of the San Bernardino Mountains contains kinematic elements characteristic of the Mojave block dextral plate boundary zone between the North American and Pacific plates and the complex convergent Transverse Ranges partition of that motion here represented by the North Frontal thrust system. Predominantly lateral slip in the central Mojave block is carried by the Helendale fault through Lucerne Valley and southward to intersect the North Frontal thrust system in the San Bernardino Mountains. Active anticlinal flexures and partially emergent north-verging thrust faults have deformed Pleistocene alluvial fans and older rocks into east-trending ridges in the piedmont on both sides of the Helendale fault. The Cougar Buttes anticline underlies such a ridge east of the fault and is breached by contemporaneous orthogonal washes in several places along strike of the anticline. Greater relief occurs where the alluvial fans comprise carbonate- cemented soils and particularly resistant, prominent petrocalcic horizons. It is within these incised valleys that the sequence of Tertiary through Pleistocene deposits show that the asymmetric anticline is cored by a thrust fault. In order to examine more closely the fold-fault association in the Cougar Buttes anticline and suggest possible kinematic models, we conducted several ground penetrating radar (GPR) profiles at different levels across the ridge. Relatively superior relief in some washes allowed us to conduct profiles along the present topographic ridge crests (and thus along the crestal zone of the fold) and also along wash bottoms to provide profiles at the level of the fold's core. We used a GSSI SIR-3000 GPR system equipped with a monostatic 100 MHz antennae set to continuous recording mode; traverses over very irregular ground were done in point data mode. The system was set up with nominal high and low cutoff filters and automatic gain control, but we found that AGC overly amplified multiples or

  15. Breach of autoreactive B cell tolerance by post-translationally modified proteins.

    Science.gov (United States)

    Dekkers, Jacqueline S; Verheul, Marije K; Stoop, Jeroen N; Liu, Bisheng; Ioan-Facsinay, Andreea; van Veelen, Peter A; de Ru, Arnoud H; Janssen, George M C; Hegen, Martin; Rapecki, Steve; Huizinga, Tom W J; Trouw, Leendert A; Toes, René E M

    2017-08-01

    Over 50% of patients with rheumatoid arthritis (RA) harbour a variety of anti-modified protein antibodies (AMPA) against different post-translationally modified (PTM) proteins, including anti-carbamylated protein (anti-CarP) antibodies. At present, it is unknown how AMPA are generated and how autoreactive B cell responses against PTM proteins are induced. Here we studied whether PTM foreign antigens can breach B cell tolerance towards PTM self-proteins. Serum reactivity towards five carbamylated proteins was determined for 160 patients with RA and 40 healthy individuals. Antibody cross-reactivity was studied by inhibition experiments. Mass spectrometry was performed to identify carbamylated self-proteins in human rheumatic joint tissue. Mice were immunised with carbamylated or non-modified (auto)antigens and analysed for autoantibody responses. We show that anti-CarP antibodies in RA are highly cross-reactive towards multiple carbamylated proteins, including modified self-proteins and modified non-self-proteins. Studies in mice show that anti-CarP antibody responses recognising carbamylated self-proteins are induced by immunisation with carbamylated self-proteins and by immunisation with carbamylated proteins of non-self-origin. Similar to the data observed with sera from patients with RA, the murine anti-CarP antibody response was, both at the monoclonal level and the polyclonal level, highly cross-reactive towards multiple carbamylated proteins, including carbamylated self-proteins. Self-reactive AMPA responses can be induced by exposure to foreign proteins containing PTM. These data show how autoreactive B cell responses against PTM self-proteins can be induced by exposure to PTM foreign proteins and provide new insights on the breach of autoreactive B cell tolerance. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  16. Consistency assessment of rating curve data in various locations using Bidirectional Reach (BReach)

    Science.gov (United States)

    Van Eerdenbrugh, Katrien; Van Hoey, Stijn; Coxon, Gemma; Freer, Jim; Verhoest, Niko E. C.

    2017-04-01

    When estimating discharges through rating curves, temporal data consistency is a critical issue. In this research, consistency in stage-discharge data is investigated using a methodology called Bidirectional Reach (BReach). This methodology considers a period to be consistent if no consecutive and systematic deviations from a current situation occur that exceed observational uncertainty. Therefore, the capability of a rating curve model to describe a subset of the (chronologically sorted) data is assessed in each observation by indicating the outermost data points for which the model behaves satisfactory. These points are called the maximum left or right reach, depending on the direction of the investigation. This temporal reach should not be confused with a spatial reach (indicating a part of a river). Changes in these reaches throughout the data series indicate possible changes in data consistency and if not resolved could introduce additional errors and biases. In this research, various measurement stations in the UK, New Zealand and Belgium are selected based on their significant historical ratings information and their specific characteristics related to data consistency. For each station, a BReach analysis is performed and subsequently, results are validated against available knowledge about the history and behavior of the site. For all investigated cases, the methodology provides results that appear consistent with this knowledge of historical changes and facilitates thus a reliable assessment of (in)consistent periods in stage-discharge measurements. This assessment is not only useful for the analysis and determination of discharge time series, but also to enhance applications based on these data (e.g., by informing hydrological and hydraulic model evaluation design about consistent time periods to analyze).

  17. Corrosion test cell for bipolar plates

    Science.gov (United States)

    Weisbrod, Kirk R.

    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.

  18. Breaching vulnerability of coastal barriers under effects of tropical cyclones: a model study on the Hue lagoon - Vietnam

    NARCIS (Netherlands)

    Tuan, T.Q.; Stive, M.J.F.; Verhagen, H.J.

    2006-01-01

    Under effects of tropical cyclones, the coast is subjected to attack both by surge and wave from the sea and by flooding from the bay. These forces pose a serious breaching threat to natural sea-defence works such as barrier spits, barrier islands, lagoon barriers, etc. on the coast. Unintended

  19. Pupils' Visual Representations in Standard and Problematic Problem Solving in Mathematics: Their Role in the Breach of the Didactical Contract

    Science.gov (United States)

    Deliyianni, Eleni; Monoyiou, Annita; Elia, Iliada; Georgiou, Chryso; Zannettou, Eleni

    2009-01-01

    This study investigated the modes of representations generated by kindergarteners and first graders while solving standard and problematic problems in mathematics. Furthermore, it examined the influence of pupils' visual representations on the breach of the didactical contract rules in problem solving. The sample of the study consisted of 38…

  20. Breaching vulnerability of coastal barriers under effects of tropical cyclones: a model study on the Hue lagoon - Vietnam

    NARCIS (Netherlands)

    Tuan, T.Q.; Stive, M.J.F.; Verhagen, H.J.

    2006-01-01

    Under effects of tropical cyclones, the coast is subjected to attack both by surge and wave from the sea and by flooding from the bay. These forces pose a serious breaching threat to natural sea-defence works such as barrier spits, barrier islands, lagoon barriers, etc. on the coast. Unintended brea

  1. Technical difficulties. Recent health IT security breaches are unlikely to improve the public's perception about the safety of personal data.

    Science.gov (United States)

    Becker, Cinda

    2006-02-20

    Consumers who claimed in recent surveys that they were "more afraid of cyber crimes than physical crimes" may have had reason for caution. A spate of well-publicized information thefts and security breaches at healthcare organizations have eroded trust in technology, says Carol Diamond, left, of the Markle Foundation, and that could have an adverse effect on acceptance of electronic medical records.

  2. Pupils' Visual Representations in Standard and Problematic Problem Solving in Mathematics: Their Role in the Breach of the Didactical Contract

    Science.gov (United States)

    Deliyianni, Eleni; Monoyiou, Annita; Elia, Iliada; Georgiou, Chryso; Zannettou, Eleni

    2009-01-01

    This study investigated the modes of representations generated by kindergarteners and first graders while solving standard and problematic problems in mathematics. Furthermore, it examined the influence of pupils' visual representations on the breach of the didactical contract rules in problem solving. The sample of the study consisted of 38…

  3. "Microscopic evidences of heavy metals distribution and anatomic alterations in breaching-leaves of Cupressus lindleyi growing around mining wastes".

    Science.gov (United States)

    Juan Miguel, Gómez-Bernal; Ofelia, Morton-Bermea; Esther Aurora, Ruiz-Huerta; Maria Aurora, Armienta-Hernández; Dávila Osiel, González

    2014-09-01

    In this article a study of the distribution of heavy metals in Cupressus lindleyi breaching-leaves was done in Taxco, Guerrero. At the same, heavy metals micro-localization was conducted in the breaching-leaves to understand the structural changes provoked by mining waste on plants. The most abundant contaminants in soils, tailings and different plant organs (roots, stems, and leaves) were Zn, Mn, and Pb. Nevertheless, As was more accumulated in the stem and breaching-leaves. The translocation factor and the bio-concentration factor were less than 1. The structural changes observed were the great accumulation of starch grains and phenolic compounds in the palisade parenchyma, changes in the hypodermis cell wall and necrotic zones in the palisade parenchyma. The distribution of heavy metals in breaching-leaves tissues was homogeneous in most of the elements. These results showed that C. lindleyi is a species that can be employed in phytostabilization of contaminated zones with mining waste because it is a native plant that does not require a lot of conditions for its development.

  4. Dam-breach analysis and flood-inundation mapping for Lakes Ellsworth and Lawtonka near Lawton, Oklahoma

    Science.gov (United States)

    Rendon, Samuel H.; Ashworth, Chad E.; Smith, S. Jerrod

    2012-01-01

    Dams provide beneficial functions such as flood control, recreation, and reliable water supplies, but they also entail risk: dam breaches and resultant floods can cause substantial property damage and loss of life. The State of Oklahoma requires each owner of a high-hazard dam, which the Federal Emergency Management Agency defines as dams for which failure or misoperation probably will cause loss of human life, to develop an emergency action plan specific to that dam. Components of an emergency action plan are to simulate a flood resulting from a possible dam breach and map the resulting downstream flood-inundation areas. The resulting flood-inundation maps can provide valuable information to city officials, emergency managers, and local residents for planning the emergency response if a dam breach occurs. Accurate topographic data are vital for developing flood-inundation maps. This report presents results of a cooperative study by the city of Lawton, Oklahoma, and the U.S. Geological Survey (USGS) to model dam-breach scenarios at Lakes Ellsworth and Lawtonka near Lawton and to map the potential flood-inundation areas of such dam breaches. To assist the city of Lawton with completion of the emergency action plans for Lakes Ellsworth and Lawtonka Dams, the USGS collected light detection and ranging (lidar) data that were used to develop a high-resolution digital elevation model and a 1-foot contour elevation map for the flood plains downstream from Lakes Ellsworth and Lawtonka. This digital elevation model and field measurements, streamflow-gaging station data (USGS streamflow-gaging station 07311000, East Cache Creek near Walters, Okla.), and hydraulic values were used as inputs for the dynamic (unsteady-flow) model, Hydrologic Engineering Center's River Analysis System (HEC-RAS). The modeled flood elevations were exported to a geographic information system to produce flood-inundation maps. Water-surface profiles were developed for a 75-percent probable maximum

  5. Fuel cell and membrane therefore

    Energy Technology Data Exchange (ETDEWEB)

    Aindow, Tai-Tsui

    2016-08-09

    A fuel cell includes first and second flow field plates, and an anode electrode and a cathode electrode between the flow field plates. A polymer electrolyte membrane (PEM) is arranged between the electrodes. At least one of the flow field plates influences, at least in part, an in-plane anisotropic physical condition of the PEM that varies in magnitude between a high value direction and a low value direction. The PEM has an in-plane physical property that varies in magnitude between a high value direction and a low value direction. The PEM is oriented with its high value direction substantially aligned with the high value direction of the flow field plate.

  6. Scale-up of Carbon/Carbon Bipolar Plates

    Energy Technology Data Exchange (ETDEWEB)

    David P. Haack

    2009-04-08

    This project was focused upon developing a unique material technology for use in PEM fuel cell bipolar plates. The carbon/carbon composite material developed in this program is uniquely suited for use in fuel cell systems, as it is lightweight, highly conductive and corrosion resistant. The project further focused upon developing the manufacturing methodology to cost-effectively produce this material for use in commercial fuel cell systems. United Technology Fuel Cells Corp., a leading fuel cell developer was a subcontractor to the project was interested in the performance and low-cost potential of the material. The accomplishments of the program included the development and testing of a low-cost, fully molded, net-shape carbon-carbon bipolar plate. The process to cost-effectively manufacture these carbon-carbon bipolar plates was focused on extensively in this program. Key areas for cost-reduction that received attention in this program was net-shape molding of the detailed flow structures according to end-user design. Correlations between feature detail and process parameters were formed so that mold tooling could be accurately designed to meet a variety of flow field dimensions. A cost model was developed that predicted the cost of manufacture for the product in near-term volumes and long-term volumes (10+ million units per year). Because the roduct uses lowcost raw materials in quantities that are less than competitive tech, it was found that the cost of the product in high volume can be less than with other plate echnologies, and can meet the DOE goal of $4/kW for transportation applications. The excellent performance of the all-carbon plate in net shape was verified in fuel cell testing. Performance equivalent to much higher cost, fully machined graphite plates was found.

  7. Electrometallurgical treatment of degraded N-reactor fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gourishankar, K. V.; Karell, E. J.; Everhart, R. E.; Indacochea, E.

    2000-03-03

    N-Reactor fuel constitutes almost 80% of the entire mass of the US Department of Energy's (DOE's) spent fuel inventory. The current plan for disposition of this fuel calls for interim dry storage, followed by direct repository disposal. However, this approach may not be viable for the entire inventory of N-Reactor fuel. The physical condition and chemical composition of much of the fuel have changed during the period that it has been in storage. The cladding of many of the fuel elements has been breached, allowing the metallic uranium fuel to react with water in the storage pools producing uranium oxides (U{sub x}O{sub y}) and uranium hydride (UH{sub 3}). Even if the breached fuel is placed in dry storage, it may continue to undergo significant changes caused by the reaction of exposed uranium with any remaining water in the container. Uranium oxides, uranium hydride, and hydrogen gas are expected to form as a result of this reaction. The presence of potentially explosive hydrogen and uranium hydride, which under certain conditions is pyrophoric, raises technical concerns that will need to be addressed. The electrometallurgical treatment process developed by Argonne National Laboratory (ANL) has potential for conditioning degraded N-Reactor fuel for long-term storage or disposal. The first step in evaluating the applicability of this process is the preparation of degraded fuel that is similar to the actual degraded N-Reactor fuel. Subsequently, the simulated degraded fuel can be introduced into an electrorefiner to examine the effect of corrosion products on the electrorefining process. Some of the technical issues to be resolved include the viability of direct electrorefining without a head-end reduction step, the effect of adherent corrosion products on the electrorefining kinetics, and the recovery and treatment of loose corrosion products that pull away from the degraded fuel. This paper presents results from an experimental study of the preparation

  8. Generalized Fibonacci zone plates

    CERN Document Server

    Ke, Jie; Zhu, Jianqiang

    2015-01-01

    We propose a family of zone plates which are produced by the generalized Fibonacci sequences and their axial focusing properties are analyzed in detail. Compared with traditional Fresnel zone plates, the generalized Fibonacci zone plates present two axial foci with equal intensity. Besides, we propose an approach to adjust the axial locations of the two foci by means of different optical path difference, and further give the deterministic ratio of the two focal distances which attributes to their own generalized Fibonacci sequences. The generalized Fibonacci zone plates may allow for new applications in micro and nanophotonics.

  9. Direct Investigations of the Immobilization of Radionuclides in the Alteration Products of Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Peter C. Burns; Robert J. Finch; David J. Wronkiewicz

    2004-12-27

    Safe disposal of the nation's nuclear waste in a geological repository involves unique scientific and engineering challenges owing to the very long-lived radioactivity of the waste. The repository must retain a variety of radionuclides that have vastly different chemical characters for several thousand years. Most of the radioactivity that will be housed in the proposed repository at Yucca Mountain will be associated with spent nuclear fuel, much of which is derived from commercial reactors. DOE is custodian of approximately 8000 tons of spent nuclear fuel that is also intended for eventual disposal in a geological repository. Unlike the spent fuel from commercial reactors, the DOE fuel is diverse in composition with more than 250 varieties. Safe disposal of spent fuel requires a detailed knowledge of its long-term behavior under repository conditions, as well as the fate of radionuclides released from the spent fuel as waste containers are breached.

  10. Direct Investigations of the Immobilization of Radionuclides in the Alteration Products of Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Peter C. Burns; Robert J. Finch; David J. Wronkiewicz

    2004-12-27

    Safe disposal of the nation's nuclear waste in a geological repository involves unique scientific and engineering challenges owing to the very long-lived radioactivity of the waste. The repository must retain a variety of radionuclides that have vastly different chemical characters for several thousand years. Most of the radioactivity that will be housed in the proposed repository at Yucca Mountain will be associated with spent nuclear fuel, much of which is derived from commercial reactors. DOE is custodian of approximately 8000 tons of spent nuclear fuel that is also intended for eventual disposal in a geological repository. Unlike the spent fuel from commercial reactors, the DOE fuel is diverse in composition with more than 250 varieties. Safe disposal of spent fuel requires a detailed knowledge of its long-term behavior under repository conditions, as well as the fate of radionuclides released from the spent fuel as waste containers are breached.

  11. Response of a direct methanol fuel cell to fuel change

    Energy Technology Data Exchange (ETDEWEB)

    Leo, T.J. [Dpto de Sistemas Oceanicos y Navales- ETSI Navales, Univ. Politecnica de Madrid, Avda Arco de la Victoria s/n, 28040 Madrid (Spain); Raso, M.A.; de la Blanca, E. Sanchez [Dpto de Quimica Fisica I- Fac. CC. Quimicas, Univ. Complutense de Madrid, Avda Complutense s/n, 28040 Madrid (Spain); Navarro, E.; Villanueva, M. [Dpto de Motopropulsion y Termofluidodinamica, ETSI Aeronauticos, Univ. Politecnica de Madrid, Pza Cardenal Cisneros 3, 28040 Madrid (Spain); Moreno, B. [Instituto de Ceramica y Vidrio, Consejo Superior de Investigaciones Cientificas, C/Kelsen 5, Campus de la UAM, 28049 Cantoblanco, Madrid (Spain)

    2010-10-15

    Methanol and ethanol have recently received much attention as liquid fuels particularly as alternative 'energy-vectors' for the future. In this sense, to find a direct alcohol fuel cell that able to interchange the fuel without losing performances in an appreciable way would represent an evident advantage in the field of portable applications. In this work, the response of a in-house direct methanol fuel cell (DMFC) to the change of fuel from methanol to ethanol and its behaviour at different ambient temperature values have been investigated. A corrosion study on materials suitable to fabricate the bipolar plates has been carried out and either 316- or 2205-duplex stainless steels have proved to be adequate for using in direct alcohol fuel cells. Polarization curves have been measured at different ambient temperature values, controlled by an experimental setup devised for this purpose. Data have been fitted to a model taking into account the temperature effect. For both fuels, methanol and ethanol, a linear dependence of adjustable parameters with temperature is obtained. Fuel cell performance comparison in terms of open circuit voltage, kinetic and resistance is established. (author)

  12. Fossil Fuels.

    Science.gov (United States)

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  13. Fossil Fuels.

    Science.gov (United States)

    Crank, Ron

    This instructional unit is one of 10 developed by students on various energy-related areas that deals specifically with fossil fuels. Some topics covered are historic facts, development of fuels, history of oil production, current and future trends of the oil industry, refining fossil fuels, and environmental problems. Material in each unit may…

  14. Hydrology and Sedimentology of a Series of Dam-Breach Paleolakes at Idaeus Fossae, Mars

    Science.gov (United States)

    Salese, F.; Di Achille, G.; Ori, G. G.

    2014-12-01

    We report on the identification and geological study of a nearly 300-km-long valley system located westward of Idaeus Fossae, in Tempe Terra, Mars. The valley apparently originates from a subsided area surrounding the ejecta of a relatively fresh crater and after about 25 km from its source area enters a series of dam-breach paleolakes. The lake chain consists of six open basins (with associated fan-shaped sedimentary deposits) and covers an area of about 2500 sq. km over a E-W stretch of about 100 km. The latter lakes are interconnected and were likely coeval and drain eastward into a main 20-km-diameter crater-lake forming a complex and multilobate deltaic deposit whose front lies at about 1800-1820 m below the martian datum. The deltaic deposit is about 8-km-long and morphologically resembles the Jezero delta, showing a well-developed distributary pattern with evidence of channel switching on the delta plain. The floor of the crater-lake is not incised by the main valley, however a breach area is present along the eastern crater rim and consists of two spillover channels at about the same elevation of the crater inlet (-1820 m). These latter channels connect the crater lake to the eastward portion of the valley continuing towards Idaeus Fossae with a more than 180-km-long complex pattern of anabranching channels . We used high-resolution imagery and topography (HRSC, and CTX and HiRISE stereo pairs) to derive a geological-geomorphological map of the area and to understand its evolution. The extension and morphology of the observed fluvio-lacustrine features suggest relatively long-term (>103 yrs) formation timescales as also supported by the presence of the main fan delta in the central open basin. The overall water source for the 300-km-long fluvial system is unclear, though the occurrence of many rampart craters and the relationships between their ejecta and the channels suggest that subsurface volatiles might have also played an important role.

  15. Fuel distribution

    Energy Technology Data Exchange (ETDEWEB)

    Tison, R.R.; Baker, N.R.; Blazek, C.F.

    1979-07-01

    Distribution of fuel is considered from a supply point to the secondary conversion sites and ultimate end users. All distribution is intracity with the maximum distance between the supply point and end-use site generally considered to be 15 mi. The fuels discussed are: coal or coal-like solids, methanol, No. 2 fuel oil, No. 6 fuel oil, high-Btu gas, medium-Btu gas, and low-Btu gas. Although the fuel state, i.e., gas, liquid, etc., can have a major impact on the distribution system, the source of these fuels (e.g., naturally-occurring or coal-derived) does not. Single-source, single-termination point and single-source, multi-termination point systems for liquid, gaseous, and solid fuel distribution are considered. Transport modes and the fuels associated with each mode are: by truck - coal, methanol, No. 2 fuel oil, and No. 6 fuel oil; and by pipeline - coal, methane, No. 2 fuel oil, No. 6 oil, high-Btu gas, medium-Btu gas, and low-Btu gas. Data provided for each distribution system include component makeup and initial costs.

  16. Blue Willow Story Plates

    Science.gov (United States)

    Fontes, Kris

    2009-01-01

    In the December 1997 issue of "SchoolArts" is a lesson titled "Blue Willow Story Plates" by Susan Striker. In this article, the author shares how she used this lesson with her middle-school students many times over the years. Here, she describes a Blue Willow plate painting project that her students made.

  17. Create Your Plate

    Medline Plus

    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Create Your Plate Create Your Plate is a ...

  18. Create Your Plate

    Medline Plus

    Full Text Available ... Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning ... Planning Meals Diabetes Meal Plans and a Healthy Diet Create Your Plate Meal Planning for Vegetarian Diets ...

  19. Rapid Prototyping Bipolar Plate of PEMFC by Gelcasting

    Institute of Scientific and Technical Information of China (English)

    LUO Bing; CHEN Shang-wei; HUANG Ming-yu; WANG Lian-jun

    2006-01-01

    Bipolar plate is one key component of proton exchange membrane fuel cell (PEMFC). According to this paper, mesocarbon microbeads were used as raw materials for forming the green bodies of bipolar plates with complex flow channels by gelcasting technique. Then, the final bipolar plates would be gained after the green parts were died, burned out and sintered. Meanwhile, its properties are researched and evaluated by the test of flexible strength and electric resistivity. The resultant flexural strength of sintered sample is 67 Mpa and the electric resistivity is 52 μΩ·m.

  20. Modelling of HTR Confinement Behaviour during Accidents Involving Breach of the Helium Pressure Boundary

    Directory of Open Access Journals (Sweden)

    Joan Fontanet

    2009-01-01

    Full Text Available Development of HTRs requires the performance of a thorough safety study, which includes accident analyses. Confinement building performance is a key element of the system since the behaviour of aerosol and attached fission products within the building is of an utmost relevance in terms of the potential source term to the environment. This paper explores the available simulation capabilities (ASTEC and CONTAIN codes and illustrates the performance of a postulated HTR vented confinement under prototypical accident conditions by a scoping study based on two accident sequences characterized by Helium Pressure Boundary breaches, a small and a large break. The results obtained indicate that both codes predict very similar thermal-hydraulic responses of the confinement both in magnitude and timing. As for the aerosol behaviour, both codes predict that most of the inventory coming into the confinement is eventually depleted on the walls and only about 1% of the aerosol dust is released to the environment. The crosscomparison of codes states that largest differences are in the intercompartmental flows and the in-compartment gas composition.

  1. The moderating role of overcommitment in the relationship between psychological contract breach and employee mental health.

    Science.gov (United States)

    Reimann, Mareike

    2016-09-30

    This study investigated whether the association between perceived psychological contract breach (PCB) and employee mental health is moderated by the cognitive-motivational pattern of overcommitment (OC). Linking the psychological contract approach to the effort-reward imbalance model, this study examines PCB as an imbalance in employment relationships that acts as a psychosocial stressor in the work environment and is associated with stress reactions that in turn negatively affect mental health. The analyses were based on a sample of 3,667 employees who participated in a longitudinal linked employer-employee survey representative of large organizations (with at least 500 employees who are subject so social security contributions) in Germany. Fixed-effects regression models, including PCB and OC, were estimated for employee mental health, and interaction effects between PCB and OC were assessed. The multivariate fixed-effects regression analyses showed a significant negative association between PCB and employee mental health. The results also confirmed that OC does indeed significantly increase the negative effect of PCB on mental health and that OC itself has a significant and negative effect on mental health. The results suggest that employees characterized by the cognitive-motivational pattern of OC are at an increased risk of developing poor mental health if they experience PCB compared with employees who are not overly committed to their work. The results of this study support the assumption that psychosocial work stressors play an important role in employee mental health.

  2. 'I knew before I was told': Breaches, cues and clues in the diagnostic assemblage.

    Science.gov (United States)

    Locock, Louise; Nettleton, Sarah; Kirkpatrick, Susan; Ryan, Sara; Ziebland, Sue

    2016-04-01

    Diagnosis can be both a 'diagnostic moment', but also a process over time. This paper uses secondary analysis of narrative interviews on ovarian cancer, antenatal screening and motor neurone disease to explore how people relate assembling procedural, spatial and interactional evidence before the formal diagnostic moment. We offer the idea of a diagnostic assemblage to capture the ways in which individuals connect to and re-order signs and events that come to be associated with their bodies. Building on the empirical work of Poole and Lyne (2000) in the field of breast cancer diagnosis, we identify how patients describe being alerted to their diagnosis, either through 'clues' they report picking up (often inadvertently) or through 'cues', perceived as a more intentional prompt given by a health professional, or an organisational process. For patients, these clues frequently represent a breach in the expected order of their encounter with healthcare. Even seemingly mundane episodes or behaviours take on meanings which health professionals may not themselves anticipate. Our findings speak to an emergent body of work demonstrating that experiences of formal healthcare during the lead-up to diagnosis shape patients' expectations, degree of trust in professionals, and even health outcomes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Identification of temporal consistency in rating curve data: Bidirectional Reach (BReach)

    Science.gov (United States)

    Van Eerdenbrugh, Katrien; Van Hoey, Stijn; Verhoest, Niko E. C.

    2016-08-01

    In this paper, a methodology is developed to identify consistency of rating curve data based on a quality analysis of model results. This methodology, called Bidirectional Reach (BReach), evaluates results of a rating curve model with randomly sampled parameter sets in each observation. The combination of a parameter set and an observation is classified as nonacceptable if the deviation between the accompanying model result and the measurement exceeds observational uncertainty. Based on this classification, conditions for satisfactory behavior of a model in a sequence of observations are defined. Subsequently, a parameter set is evaluated in a data point by assessing the span for which it behaves satisfactory in the direction of the previous (or following) chronologically sorted observations. This is repeated for all sampled parameter sets and results are aggregated by indicating the endpoint of the largest span, called the maximum left (right) reach. This temporal reach should not be confused with a spatial reach (indicating a part of a river). The same procedure is followed for each data point and for different definitions of satisfactory behavior. Results of this analysis enable the detection of changes in data consistency. The methodology is validated with observed data and various synthetic stage-discharge data sets and proves to be a robust technique to investigate temporal consistency of rating curve data. It provides satisfying results despite of low data availability, errors in the estimated observational uncertainty, and a rating curve model that is known to cover only a limited part of the observations.

  4. Breaching Biological Barriers: Protein Translocation Domains as Tools for Molecular Imaging and Therapy

    Directory of Open Access Journals (Sweden)

    Benjamin L. Franc

    2003-10-01

    Full Text Available The lipid bilayer of a cell presents a significant barrier for the delivery of many molecular imaging reagents into cells at target sites in the body. Protein translocation domains (PTDs are peptides that breach this barrier. Conjugation of PTDs to imaging agents can be utilized to facilitate the delivery of these agents through the cell wall, and in some cases, into the cell nucleus, and have potential for in vitro and in vivo applications. PTD imaging conjugates have included small molecules, peptides, proteins, DNA, metal chelates, and magnetic nanoparticles. The full potential of the use of PTDs in novel in vivo molecular probes is currently under investigation. Cells have been labeled in culture using magnetic nanoparticles derivatized with a PTD and monitored in vivo to assess trafficking patterns relative to cells expressing a target antigen. In vivo imaging of PTD-mediated gene transfer to cells of the skin has been demonstrated in living animals. Here we review several natural and synthetic PTDs that have evolved in the quest for easier translocation across biological barriers and the application of these peptide domains to in vivo delivery of imaging agents.

  5. What do Islamic institutional fatwas say about medical and research confidentiality and breach of confidentiality?

    Science.gov (United States)

    Alahmad, Ghiath; Dierickx, Kris

    2012-08-01

    Protecting confidentiality is an essential value in all human relationships, no less in medical practice and research.(1) Doctor-patient and researcher-participant relationships are built on trust and on the understanding those patients' secrets will not be disclosed.(2) However, this confidentiality can be breached in some situations where it is necessary to meet a strong conflicting duty.(3) Confidentiality, in a general sense, has received much interest in Islamic resources including the Qur'an, Sunnah and juristic writings. However, medical and research confidentiality have not been explored deeply. There are few fatwas about the issue, despite an increased effort by both individuals and Islamic medical organizations to use these institutional fatwas in their research. Infringements on confidentiality make up a significant portion of institutional fatwas, yet they have never been thoroughly investigated. Moreover, the efforts of organizations and authors in this regard still require further exploration, especially on the issue of research confidentiality. In this article, we explore medical and research confidentiality and potential conflicts with this practice as a result of fatwas released by international, regional, and national Islamic Sunni juristic councils. We discuss how these fatwas affect research and publication by Muslim doctors, researchers, and Islamic medical organizations. We argue that more specialized fatwas are needed to clarify Islamic juristic views about medical and research confidentiality, especially the circumstances in which infringements on this confidentiality are justified. © 2012 Blackwell Publishing Ltd.

  6. Vertical deformation of lacustrine shorelines along breached relay ramps, Catlow Valley fault, southeastern Oregon, USA

    Science.gov (United States)

    Hopkins, Michael C.; Dawers, Nancye H.

    2016-04-01

    Vertical deformation of pluvial lacustrine shorelines is attributed to slip along the Catlow Valley fault, a segmented Basin and Range style normal fault in southeastern Oregon, USA. The inner edges of shorelines are mapped along three breached relay ramps along the fault to examine the effect of fault linkage on the distribution of slip. Shoreline inner edges act as paleohorizontal datums so deviations in elevation from horizontal, outside of a 2 m error window, are taken to be indications of fault slip. The sites chosen represent a spectrum of linkage scenarios in that the throw on the linking fault compared to that on the main fault adjacent to the linking fault varies from site to site. Results show that the maturity of the linkage between segments (i.e. larger throw on the linking fault with respect to the main fault) does not control the spatial distribution of shoreline deformation. Patterns of shoreline deformation indicate that the outboard, linking, and/or smaller ramp faults have slipped since the shorelines formed. Observations indicate that displacement has not fully localized on the linking faults following complete linkage between segments.

  7. [Anthropozoonoses and other inter-specific infections: breaches in the "species barrier"].

    Science.gov (United States)

    Parodi, A L

    2008-06-01

    Infectious outbreaks in human populations frequently occurred during the last decades. Most of these epidemics were emerging or re-emerging diseases and about 75% of them were caused by animal pathogens mainly from wild animal species. Thus the "species barrier" dogma seems to be frequently in the wrong. Many factors are probably involved in this failure. Among them, genetic mutations mainly in viruses which are more and more frequently discovered. On the other hand, anthropic factors are the major causes of this species barrier breaches. Closer contacts with domestic and/or wild animals, dramatic growth of human populations, poverty, numerous immunodepressed people, international travels and trading are facilitating or determining factors of the inter-specific transmission of pathogens. International mobilization is mandatory to efficiently anticipate and control the emergence of such zoonoses. According to their unpredictable emergence and their rapid potential worldwide spreading, their control requires an international cooperation both in a permanent epidemiological surveillance and a rapid efficient riposte. Human and veterinary medical institutions have to closely cooperate in this issue.

  8. Breach of belongingness: Newcomer relationship conflict, information, and task-related outcomes during organizational socialization.

    Science.gov (United States)

    Nifadkar, Sushil S; Bauer, Talya N

    2016-01-01

    Previous studies of newcomer socialization have underlined the importance of newcomers' information seeking for their adjustment to the organization, and the conflict literature has consistently reported negative effects of relationship conflict with coworkers. However, to date, no study has examined the consequences of relationship conflict on newcomers' information seeking. In this study, we examined newcomers' reactions when they have relationship conflict with their coworkers, and hence cannot obtain necessary information from them. Drawing upon belongingness theory, we propose a model that moves from breach of belongingness to its proximal and distal consequences, to newcomer information seeking, and then to task-related outcomes. In particular, we propose that second paths exist-first coworker-centric and the other supervisor-centric-that may have simultaneous yet contrasting influence on newcomer adjustment. To test our model, we employ a 3-wave data collection research design with egocentric and Likert-type multisource surveys among a sample of new software engineers and their supervisors working in India. This study contributes to the field by linking the literatures on relationship conflict and newcomer information seeking and suggesting that despite conflict with coworkers, newcomers may succeed in organizations by building relationships with and obtaining information from supervisors.

  9. Breaches of the pial basement membrane are associated with defective dentate gyrus development in mouse models of congenital muscular dystrophies.

    Science.gov (United States)

    Li, Jing; Yu, Miao; Feng, Gang; Hu, Huaiyu; Li, Xiaofeng

    2011-11-07

    A subset of congenital muscular dystrophies (CMDs) has central nervous system manifestations. There are good mouse models for these CMDs that include POMGnT1 knockout, POMT2 knockout and Large(myd) mice with all exhibiting defects in dentate gyrus. It is not known how the abnormal dentate gyrus is formed during the development. In this study, we conducted a detailed morphological examination of the dentate gyrus in adult and newborn POMGnT1 knockout, POMT2 knockout, and Large(myd) mice by immunofluorescence staining and electron microscopic analyses. We observed that the pial basement membrane overlying the dentate gyrus was disrupted and there was ectopia of granule cell precursors through the breached pial basement membrane. Besides these, the knockout dentate gyrus exhibited reactive gliosis in these mouse models. Thus, breaches in the pial basement membrane are associated with defective dentate gyrus development in mouse models of congenital muscular dystrophies.

  10. Can Cross-Listing Mitigate the Impact of an Information Security Breach Announcement on a Firm's Values?

    Science.gov (United States)

    Chen, Yong; Dong, Feng; Chen, Hong; Xu, Li

    2016-08-01

    The increase in globalization in the markets has driven firms to adopt online technologies and to cross-list their stocks. Recent studies have consistently found that the announcements of information security breaches (ISBs) are negatively associated with the market values of the announcing firms during the days surrounding the breach announcements. Given the improvement in firms’ information environments and the better protection for investors generated by cross-listing, does cross-listing help firms to reduce the negative impacts caused by their announcements of ISBs? This paper conducts an event study of 120 publicly traded firms (among which 25 cross-list and 95 do not), in order to explore the answer. The results indicate that the impact of ISB announcements on a firm's stock prices shows no difference between cross-listing firms and non-cross-listing firms. Cross-listing does not mitigate the impact of ISBs announcement on a firm's market value.

  11. Quasi 2D hydrodynamic modelling of the flooded hinterland due to dyke breaching on the Elbe River

    Directory of Open Access Journals (Sweden)

    S. Huang

    2007-01-01

    Full Text Available In flood modeling, many 1D and 2D combination and 2D models are used to simulate diversion of water from rivers through dyke breaches into the hinterland for extreme flood events. However, these models are too demanding in data requirements and computational resources which is an important consideration when uncertainty analysis using Monte Carlo techniques is used to complement the modeling exercise. The goal of this paper is to show the development of a quasi-2D modeling approach, which still calculates the dynamic wave in 1D but the discretisation of the computational units are in 2D, allowing a better spatial representation of the flow in the hinterland due to dyke breaching without a large additional expenditure on data pre-processing and computational time. A 2D representation of the flow and velocity fields is required to model sediment and micro-pollutant transport. The model DYNHYD (1D hydrodynamics from the WASP5 modeling package was used as a basis for the simulations. The model was extended to incorporate the quasi-2D approach and a Monte-Carlo Analysis was used to conduct a flood sensitivity analysis to determine the sensitivity of parameters and boundary conditions to the resulting water flow. An extreme flood event on the Elbe River, Germany, with a possible dyke breach area was used as a test case. The results show a good similarity with those obtained from another 1D/2D modeling study.

  12. Review of Phenomenological Models for the Initial Phase HCDA Analysis in a Metal-Fueled Sodium-Cooled Fast Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Young Min; Lee, Ki Rim; Ha, Kwi Seok; Chang, Won Pyo; Suk, Soo Dong

    2009-03-15

    The safety aspects of the KALIMER design results from the advanced safety performance characteristics of its ternary alloy metallic fuel. The superior thermal, mechanical, and neutronic performance of the metal-fueled core assures inherent safety response to unprotected and multiple fault accidents which are HCDA initiating events. HCDA has received great attentions because of its significant consequence, leading to substantial core disruption, although its probability of occurrence is very low. The SAS4A code provides an integrated quantitative framework for examining the phenomenological behaviors under HCDA conditions. Various phenomenological models such as prefailure characterization, transient pin response, margins to cladding failure, axial in-pin fuel relocation prior to cladding breach, and molten fuel relocation after cladding breach are required for the HCDA analysis. The important mechanisms which introduce negative reactivity during HCDA are fuel extrusion and in-pin fuel relocation, and structural feedback through thermal-mechanical neutronic effects. This report describes the safety performance characteristics of the metal fuel as observed in ex-pile and in-pile tests, and describes associated theoretical models employed into the SAS4A HCDA analysis code. Most of such tests and experiments, and development of theoretical models have been performed for the IFR program by ANL. This report provides a phenomenological basis for gaining an understanding of the metal fuel performance characteristics that obtained from expile experiments and in-pile tests. This report will provide insight and direction for planning HCDA experiments and developing theoretical models in Korea later.

  13. Single-Beam Bathymetry of the Hurricane Sandy Breach at Fire Island, New York, June 2013 (1-Meter Digital Elevation Model)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This dataset, 20130626_bathy_DEM.zip, contains a 1-meter (m) grid of June 2013 bathymetry of the breach channel, ebb shoal, and adjacent coast of the Fire Island...

  14. Pixelated neutron image plates

    Science.gov (United States)

    Schlapp, M.; Conrad, H.; von Seggern, H.

    2004-09-01

    Neutron image plates (NIPs) have found widespread application as neutron detectors for single-crystal and powder diffraction, small-angle scattering and tomography. After neutron exposure, the image plate can be read out by scanning with a laser. Commercially available NIPs consist of a powder mixture of BaFBr : Eu2+ and Gd2O3 dispersed in a polymer matrix and supported by a flexible polymer sheet. Since BaFBr : Eu2+ is an excellent x-ray storage phosphor, these NIPs are particularly sensitive to ggr-radiation, which is always present as a background radiation in neutron experiments. In this work we present results on NIPs consisting of KCl : Eu2+ and LiF that were fabricated into ceramic image plates in which the alkali halides act as a self-supporting matrix without the necessity for using a polymeric binder. An advantage of this type of NIP is the significantly reduced ggr-sensitivity. However, the much lower neutron absorption cross section of LiF compared with Gd2O3 demands a thicker image plate for obtaining comparable neutron absorption. The greater thickness of the NIP inevitably leads to a loss in spatial resolution of the image plate. However, this reduction in resolution can be restricted by a novel image plate concept in which a ceramic structure with square cells (referred to as a 'honeycomb') is embedded in the NIP, resulting in a pixelated image plate. In such a NIP the read-out light is confined to the particular illuminated pixel, decoupling the spatial resolution from the optical properties of the image plate material and morphology. In this work, a comparison of experimentally determined and simulated spatial resolutions of pixelated and unstructured image plates for a fixed read-out laser intensity is presented, as well as simulations of the properties of these NIPs at higher laser powers.

  15. Plate removal following orthognathic surgery.

    Science.gov (United States)

    Little, Mhairi; Langford, Richard Julian; Bhanji, Adam; Farr, David

    2015-11-01

    The objectives of this study are to determine the removal rates of orthognathic plates used during orthognathic surgery at James Cook University Hospital and describe the reasons for plate removal. 202 consecutive orthognathic cases were identified between July 2004 and July 2012. Demographics and procedure details were collected for these patients. Patients from this group who returned to theatre for plate removal between July 2004 and November 2012 were identified and their notes were analysed for data including reason for plate removal, age, smoking status, sex and time to plate removal. 3.2% of plates were removed with proportionally more plates removed from the mandible than the maxilla. 10.4% of patients required removal of one or more plate. Most plates were removed within the first post-operative year. The commonest reasons for plate removal were plate exposure and infection. The plate removal rates in our study are comparable to those seen in the literature.

  16. Anisotropic elastic plates

    CERN Document Server

    Hwu, Chyanbin

    2010-01-01

    As structural elements, anisotropic elastic plates find wide applications in modern technology. The plates here are considered to be subjected to not only in plane load but also transverse load. In other words, both plane and plate bending problems as well as the stretching-bending coupling problems are all explained in this book. In addition to the introduction of the theory of anisotropic elasticity, several important subjects have are discussed in this book such as interfaces, cracks, holes, inclusions, contact problems, piezoelectric materials, thermoelastic problems and boundary element a

  17. Plating in Top Agar

    OpenAIRE

    sprotocols

    2014-01-01

    1. Warm plates to room temperature before use. Cold plates causes the top agar to solidify irregularly. DO not warm plates to 37° as the top agar will take forever to solidify. - Prepare top agar as the appropriate liquid medium with 0.7% agar. Keeping 100 mL bottles is convenient. For phages, use λ top agar, which is less rich and yields bigger plaques. - Melt top agar in the microwave completely. Allow the agar to boil after liquification; incompletely melted agar looks liquid, but is...

  18. Fuel Cells

    DEFF Research Database (Denmark)

    Smith, Anders; Pedersen, Allan Schrøder

    2014-01-01

    Fuel cells have been the subject of intense research and development efforts for the past decades. Even so, the technology has not had its commercial breakthrough yet. This entry gives an overview of the technological challenges and status of fuel cells and discusses the most promising applications...... of the different types of fuel cells. Finally, their role in a future energy supply with a large share of fluctuating sustainable power sources, e.g., solar or wind, is surveyed....

  19. Dynamic response of nuclear fuel assembly excited by pressure pulsations

    Directory of Open Access Journals (Sweden)

    Zeman V.

    2012-12-01

    Full Text Available The paper deals with dynamic load calculation of the hexagonal type nuclear fuel assembly caused by spatial motion of the support plates in the reactor core. The support plate motion is excited by pressure pulsations generated by main circulation pumps in the coolant loops of the primary circuit of the nuclear power plant. Slightly different pumps revolutions generate the beat vibrations which causes an amplification of fuel assembly component dynamic deformations and fuel rods coating abrasion. The cyclic and central symmetry of the fuel assembly makes it possible the system decomposition into six identical revolved fuel rod segments which are linked with central tube and skeleton by several spacer grids in horizontal planes.The modal synthesis method with condensation of the fuel rod segments is used for calculation of the normal and friction forces transmitted between fuel rods and spacer grids cells.

  20. Fabrication of Monolithic RERTR Fuels by Hot Isostatic Pressing

    Energy Technology Data Exchange (ETDEWEB)

    Jan-Fong Jue; Blair H. Park; Curtis R. Clark; Glenn A. Moore; Dennis D. Keiser, Jr.

    2010-11-01

    The RERTR (Reduced Enrichment for Research and Test Reactors) Program is developing advanced nuclear fuels for high-power test reactors. Monolithic fuel design provides higher uranium loading than that of the traditional dispersion fuel design. Hot isostatic pressing is a promising process for low-cost batch fabrication of monolithic RERTR fuel plates for these high-power reactors. Bonding U Mo fuel foil and 6061 Al cladding by hot isostatic press bonding was successfully developed at Idaho National Laboratory. Due to the relatively high processing temperature, the interaction between fuel meat and aluminum cladding is a concern. Two different methods were employed to mitigate this effect: (1) a diffusion barrier and (2) a doping addition to the interface. Both types of fuel plates have been fabricated by hot isostatic press bonding. Preliminary results show that the direct fuel/cladding interaction during the bonding process was eliminated by introducing a thin zirconium diffusion barrier layer between the fuel and the cladding. Fuel plates were also produced and characterized with a silicon-rich interlayer between fuel and cladding. This paper reports the recent progress of this developmental effort and identifies the areas that need further attention.

  1. Metallography and fuel cladding chemical interaction in fast flux test facility irradiated metallic U-10Zr MFF-3 and MFF-5 fuel pins

    Energy Technology Data Exchange (ETDEWEB)

    Carmack, W. J.; Chichester, H. M.; Porter, D. L.; Wootan, D. W.

    2016-05-01

    Abstract The Mechanistic Fuel Failure (MFF) series of metal fuel irradiations conducted in the Fast Flux Test Facility (FFTF) provides an important potential comparison between data generated in the Experimental Breeder Reactor (EBR-II) and that expected in a larger-scale fast reactor. The irradiations were the beginning tests to qualify U-10wt%Zr as a driver fuel for FFTF. The FFTF core, with a 91.4 cm tall fuel column and a chopped cosine neutron flux profile, operated with a peak cladding temperature at the top of the fuel column, but developed peak burnup at the centerline of the core. This places the peak fuel temperature midway between the core center and the top of fuel, lower in the fuel column than in previous EBR-II experiments that had a 32-cm height core. The MFF-3 and MFF-5 qualification assemblies operated in FFTF to >10 at% burnup, and performed very well with no cladding breaches. The MFF-3 assembly operated to 13.8 at% burnup with a peak inner cladding temperature of 643°C, and the MFF-5 assembly operated to 10.1 at% burnup with a peak inner cladding temperature of 651°C. Because of the very high operating temperatures for both the fuel and the cladding, data from the MFF assemblies are most comparable to the data obtained from the EBR-II X447 experiment, which experienced two pin breaches. The X447 breaches were strongly influenced by a large amount of fuel/cladding chemical interaction (FCCI). The MFF pins benefitted from different axial locations of high burnup and peak cladding temperature, which helped to reduce interdiffusion between rare earth fission products and stainless steel cladding. Post-irradiation examination evidence illustrates this advantage. Comparing other performance data of the long MFF pins to prior EBR-II test data, the MFF fuel inside the cladding grew less axially, and the gas release data did not reveal a definitive difference.

  2. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... but changes the portion sizes so you are getting larger portions of non-starchy vegetables and a ...

  3. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... 4/Box) Taking the guesswork out of portion control has never been easier. It can be a ...

  4. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  5. MyPlate

    Science.gov (United States)

    ... our stage of life, situations, preferences, access to food, culture, traditions, and the personal decisions we make over time. All your food and beverage choices count. MyPlate offers ideas and ...

  6. Create Your Plate

    Medline Plus

    Full Text Available ... blood glucose levels and lose weight. With this method, you fill your plate with more non-starchy ... you have an easy portion control solution that works. Last Reviewed: October 8, 2015 Last Edited: September ...

  7. Designing Assemblies Of Plates

    Science.gov (United States)

    Williams, F. W.; Kennedy, D.; Butler, R.; Aston, G.; Anderson, M. S.

    1992-01-01

    VICONOPT calculates vibrations and instabilities of assemblies of prismatic plates. Designed for efficient, accurate analysis of buckling and vibration, and for optimum design of panels of composite materials. Written in FORTRAN 77.

  8. Create Your Plate

    Medline Plus

    Full Text Available ... Your Plate Gluten Free Diets Meal Planning for Vegetarian Diets Cook with Heart-Healthy Foods Holiday Meal Planning What Can I Eat? Making Healthy Food Choices Diabetes Superfoods Non-starchy Vegetables Grains and Starchy Vegetables ...

  9. Create Your Plate

    Medline Plus

    Full Text Available ... Recipes Association Cookbook Recipes Planning Meals Diabetes Meal Plans Create Your Plate Gluten Free Diets Meal Planning ... serving of dairy or both as your meal plan allows. Choose healthy fats in small amounts. For ...

  10. Create Your Plate

    Medline Plus

    Full Text Available ... 1 Diabetes Get Started Safely Get And Stay Fit Types of Activity Weight Loss Assess Your Lifestyle ... manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  11. Create Your Plate

    Medline Plus

    Full Text Available ... Plate is a simple and effective way to manage your blood glucose levels and lose weight. With ... been easier. It can be a challenge to manage portion control wherever you are. Now, our best- ...

  12. Tectonic Plate Movement.

    Science.gov (United States)

    Landalf, Helen

    1998-01-01

    Presents an activity that employs movement to enable students to understand concepts related to plate tectonics. Argues that movement brings topics to life in a concrete way and helps children retain knowledge. (DDR)

  13. Create Your Plate

    Medline Plus

    Full Text Available ... Carbohydrates Carbohydrate Counting Make Your Carbs Count Glycemic ... to manage portion control wherever you are. Now, our best-selling, sectioned to-go plate with easy-sealing ...

  14. Carbon fuel cells with carbon corrosion suppression

    Science.gov (United States)

    Cooper, John F [Oakland, CA

    2012-04-10

    An electrochemical cell apparatus that can operate as either a fuel cell or a battery includes a cathode compartment, an anode compartment operatively connected to the cathode compartment, and a carbon fuel cell section connected to the anode compartment and the cathode compartment. An effusion plate is operatively positioned adjacent the anode compartment or the cathode compartment. The effusion plate allows passage of carbon dioxide. Carbon dioxide exhaust channels are operatively positioned in the electrochemical cell to direct the carbon dioxide from the electrochemical cell.

  15. Origami - Folded Plate Structures

    OpenAIRE

    Buri, Hans Ulrich

    2010-01-01

    This research investigates new methods of designing folded plate structures that can be built with cross-laminated timber panels. Folded plate structures are attractive to both architects and engineers for their structural, spatial, and plastic qualities. Thin surfaces can be stiffened by a series of folds, and thus not only cover space, but also act as load bearing elements. The variation of light and shadow along the folded faces emphasizes the plas...

  16. Fractal multifiber microchannel plates

    Science.gov (United States)

    Cook, Lee M.; Feller, W. B.; Kenter, Almus T.; Chappell, Jon H.

    1992-01-01

    The construction and performance of microchannel plates (MCPs) made using fractal tiling mehtods are reviewed. MCPs with 40 mm active areas having near-perfect channel ordering were produced. These plates demonstrated electrical performance characteristics equivalent to conventionally constructed MCPs. These apparently are the first MCPs which have a sufficiently high degree of order to permit single channel addressability. Potential applications for these devices and the prospects for further development are discussed.

  17. Composite nozzle design for reactor fuel assembly

    Energy Technology Data Exchange (ETDEWEB)

    Marlatt, G.R.; Allison, D.K.

    1984-01-24

    A composite nozzle is described for a fuel assembly adapted for installation on the upper or lower end thereof and which is constructed from two components. The first component includes a casting weldment or forging designed to carry handling loads, support fuel assembly weight and flow loads, and interface with structural members of both the fuel assembly and reactor internal structures. The second component of the nozzle consists of a thin stamped bore machine flow plate adapted for attachment to the casting body. The plate is designed to prevent fuel rods from being ejected from the core and provide orifices for coolant flow to a predetermined value and pressure drop which is consistent with the flow at other locations in the core.

  18. Finding an optimization of the plate element of Egyptian research reactor using genetic algorithm

    Institute of Scientific and Technical Information of China (English)

    WAHED Mohamed; IBRAHIM Wesam; EFFAT Ahmed

    2008-01-01

    The second Egyptian research reactor ET-RR-2 went critical on the 27th of November 1997. The National Center of Nuclear Safety and Radiation Control (NCNSRC) has the responsibility of the evaluation and assessment of the safety of this reactor. The purpose of this paper is to present an approach to optimization of the fuel element plate.For an efficient search through the solution space we use a multi objective genetic algorithm which allows us to identify a set of Pareto optimal solutions providing the decision maker with the complete spectrum of optimal solutions with respect to the various targets. The aim of this paper is to propose a new approach for optimizing the fuel element plate in the reactor. The fuel element plate is designed with a view to improve reliability and lifetime and it is one of the most important elements during the shut down. In this present paper, we present a conceptual design approach for fuel element plate, in conjunction with a genetic algorithm to obtain a fuel plate that maximizes a fitness value to optimize the safety design of the fuel plate.

  19. A study to assess and measure the breaches in the child rights

    Directory of Open Access Journals (Sweden)

    Pooja Chaudhary

    2014-10-01

    Full Text Available Background: Children signify eternal optimism in the human being and provide potential for the development. Every nation whether developed or developing, links its future with the status of child. An understanding of the physical, social and behavioral factors is conducive to assess the current situation and vulnerability of any child. To ensure the utmost level of health and safety of a child, we need to have an insight of the violation of child rights. We conducted this study to assess and measure the breaches in child rights. Materials and Methods: A cross-sectional study was carried out among 200 children between 10 to 18 years of age in one of the field practice areas of Community Medicine department, B. J. Medical College, Ahmedabad. Results: More than 90% of the children were born in the hospital settings, fully vaccinated and living with their parents. Of these, 60% of the children reported to have some kind of illness in the past one year, and majority of them approached healthcare facility for that the treatment. Of these, 26% of them had low birth weight (LBW and 68% had body mass index (BMI <18.5. About 93% of the children were enrolled in either government or private school and out of them, 54% complained of the burden of either homework or tuition. Of these, 6.5% children were school dropouts and all of them were girls; 4% of them were child labors. Conclusion: The study indicated positive findings in the areas of child survival, development and to some extent, in the domain of right to participation, though there were poor environmental conditions and recreational activities. Prevalence of malnutrition and child labor was also high. Study results highlighted the need for adequate services in these areas.

  20. Early degassing of lunar urKREEP by crust-breaching impact(s)

    Science.gov (United States)

    Barnes, Jessica J.; Tartèse, Romain; Anand, Mahesh; McCubbin, Francis M.; Neal, Clive R.; Franchi, Ian A.

    2016-08-01

    Current models for the Moon's formation have yet to fully account for the thermal evolution of the Moon in the presence of H2O and other volatiles. Of particular importance is chlorine, since most lunar samples are characterised by unique heavy δ37Cl values, significantly deviating from those of other planetary materials, including Earth, for which δ37Cl values cluster around ∼0‰. In order to unravel the cause(s) of the Moon's unique chlorine isotope signature, we performed a comprehensive study of high-precision in situ Cl isotope measurements of apatite from a suite of Apollo samples with a range of geochemical characteristics and petrologic types. The Cl-isotopic compositions measured in lunar apatite in the studied samples display a wide range of δ37Cl values (reaching a maximum value of +36‰), which are positively correlated with the amount of potassium (K), Rare Earth Element (REE) and phosphorous (P) (KREEP) component in each sample. Using these new data, integrated with existing H-isotope data obtained for the same samples, we are able to place these findings in the context of the canonical lunar magma ocean (LMO) model. The results are consistent with the urKREEP reservoir being characterised by a δ37Cl ∼+30‰. Such a heavy Cl isotope signature requires metal-chloride degassing from a Cl-enriched urKREEP LMO residue, a process likely to have been triggered by at least one large crust-breaching impact event that facilitated the transport and exposure of urKREEP liquid to the lunar surface.