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报告分类:外文技术报告

  • 351.PFSA膜的形态和电导率的压缩影响

    [电力、热力、燃气及水生产和供应业,电气机械和器材制造业] [2015-08-31]

    Polymer-Electrolyte-Fuel-Cells (PEFCs) are promising candidates for powering vehicles and portable devices using renewable-energy sources. The core of a PEFC is the solid electrolyte membrane that conducts protons from anode to cathode, where water is generated. The conductivity of the membrane, however, depends on the water content of the membrane, which is strongly related to the cell operating conditions. The membrane and other cell components are typically compressed to minimize various contact resistances. Moreover, the swelling of a somewhat constrained membrane in the cell due to the humidity changes generates additional compressive stresses in the membrane. These external stresses are balanced by the internal swelling pressure of the membrane and change the swelling equilibrium. It was shown using a fuel-cell setup that compression could reduce the water content of the membrane or alter the cell resistance. Nevertheless, the effect of compression on the membranes transport properties is yet to be understood, as well as its implications in the structure-functions relationships of the membrane. We previously studied, both experimentally and theoretically, how compression affects the water content of the membrane. However, more information is required the gain a fundamental understanding of the compression effects. In this talk, we present the results of our investigation on the in-situ conductivity of the membrane as a function of humidity and cell compression pressure. Moreover, to better understand the morphology of compressed membrane, small-angle X-ray-scattering (SAXS) experiments were performed. The conductivity data is then analyzed by investigating the size of the water domains of the compressed membrane determined from the SAXS measurements.
    关键词:燃料电池;固体电解质;聚合物;阳极
  • 352.发动机测试设备声学评估

    [电气机械和器材制造业,电力、热力、燃气及水生产和供应业] [2015-08-31]

    An acoustical evaluation of the engine test cell facilities at Misawa AB, Japan, was performed in December 2012. This assessment was accomplished to help determine overall sound pressure levels during multiple power settings of aircraft engine run-up procedures. It was determined that personnel performing these duties are exposed to hazardous noise levels. Therefore, it was recommended that engine test cell facilities should remain labeled as hazardous noise areas, personnel should be enrolled in the hearing conservation program and receive audiograms, and noise dosimetry should be performed to better characterize the cumulative noise exposures.
    关键词:声学;飞机发动机的噪音;发动机试验
  • 353.沼气和燃料电池研讨会综述

    [电力、热力、燃气及水生产和供应业,化学原料和化学制品制造业] [2015-08-31]

    The National Renewable Energy Laboratory (NREL), in association with the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE), held a Biogas and Fuel Cells Workshop on June 11-13, 2012, in Golden, Colorado, to discuss biogas and waste-to-energy technologies for fuel cell applications. The meeting was spearheaded by the Fuel Cell Technologies Program in coordination with the Biomass Program. The overall objective was to identify opportunities for coupling renewable biomethane with highly efficient fuel cells to produce electricity; heat; combined heat and power (CHP); or combined heat, hydrogen and power (referred to as CHHP or trigeneration) for stationary or motive applications. The workshop focused on biogas sourced from wastewater treatment plants (WWTPs), landfills, and industrial facilities that generate or process large amounts of organic waste, including large biofuel production facilities (biorefineries).
    关键词:生物质燃料;燃料电池;厌氧消化;沼气
  • 354.美国国防部低成本可充电锂离子电池的先进制造工艺

    [计算机、通信和其他电子设备制造业] [2015-08-31]

    LithChem Energy (LCE) successfully designed and built a partially automated lithium-ion bi-cell production machine to produce lower cost prismatic lithium-ion batteries for the DOD. This machine was completed and started up to produce a short run of lithium-ion bi-cells with lithium cobaltate as the cathode material. This system included the design and successful fabrication of two dip coaters, a brush tabber for the coated electrodes to form the weldable electrodes, and a coater for priming the electrode metal grids prior to dip coating. Work stations were constructed for quantitative cell filling, resistance welding of the cell pack electrodes, and for cell pack formation. The prismatic cell packs were designed to be 6 Ah with eight of these to fit into the space of a BB2590 to achieve 12 V and 24 V circuits. In a parallel effort, a new high energy capacity cathode material was optimized based on a lithium nickel cobaltate which achieved an energy density of 230 mAh/g in the voltage range of 2.6 V to 3.9 V at C/10. This cathode material also exhibited high power density up to 40 C discharge rates. This advanced manufacturing System and new cathode material have been designed to lower the cost of All-American made rechargeable lithium-ion cells and batteries for the DOD.
    关键词:阴极;涂料;成本;;浸渍涂布;能量密度高
  • 355.高温高压下蓝宝石细胞中子的散射实验

    [科学研究和技术服务业] [2015-08-31]

    The high pressure, high temperature sapphire cell was designed to provide users at the Spallation Neutron Source the ability to do in-situ supercritical bulk water studies.
    关键词:蓝宝石;中子源;散射;约束
  • 356.直接甲醇燃料电池(DMFC)电池更换计划

    [化学原料和化学制品制造业,计算机、通信和其他电子设备制造业] [2015-08-31]

    Active DMFCs require complicated balance of plant to ensure recirculation of unreacted methanol and internally produced water as well as venting of exhaust gases. An alternative approach is redesign of the fuel delivery system to accommodate concentrated methanol that is consumed entirely within the fuel cell, thus removing the need for recirculation. A specialized anodic porous structure was designed which the dual role of flowfield and diffusion medium for concentrated methanol. In addition, a highly hydrophobic gas diffusion media were used at the DMFC cathode to prevent water loss by promoting water back-diffusion to the anode. This internally dilutes the methanol and enables use of highly concentrated methanol. The anodic porous structure used in concert with the hydrophobic cathode diffusion medium led to gross fuel energy densities of the operating cell of ca. 845 W*hr/Lfuel and fuel utilization in excess of 70%. A small 2 cell stack was built and successfully operated to verify that the concept is scalable. The hydrophobicity of the cathode diffusion layer is of vital importance for this concept and research for improved materials that will reduce water loss even more is still ongoing using internal funds. The project also funded student research at Northeastern University and at Inter American University in Puerto Rico. This hardware based program complemented an IFDL modeling program sponsored by the DOE.
    关键词:阴极;甲醇燃料电池;电动电池;电化学
  • 357.液体氢仓库推进剂管理装置的性能绩效

    [电力、热力、燃气及水生产和供应业,电气机械和器材制造业] [2015-08-30]

    This paper presents background, experimental design, and preliminary experimental results for the liquid hydrogen bubble point tests conducted at the Cryogenic Components Cell 7 facility at the NASA Glenn Research Center in Cleveland, Ohio. The purpose of the test series was to investigate the parameters that affect liquid acquisition device (LAD) performance in a liquid hydrogen (LH2) propellant tank, to mitigate risk in the final design of the LAD for the Cryogenic Propellant Storage and Transfer Technology Demonstration Mission, and to provide insight into optimal LAD operation for future LH2 depots. Preliminary test results show an increase in performance and screen retention over the low reference LH2 bubble point value for a 325 2300 screen in three separate ways, thus improving fundamental LH2 LAD performance. By using a finer mesh screen, operating at a colder liquid temperature, and pressurizing with a noncondensible pressurant gas, a significant increase in margin is achieved in bubble point pressure for LH2 screen channel LADs.
    关键词:液态电池;电能利用;电能存储
  • 358.热光硅微环式器械马赫-曾德调制器和开关

    [汽车制造业] [2015-08-30]

    Low-power consumption thermo-optically controlled silicon microring resonator loaded Mach-Zehnder modulators and switches (MRR-loaded MZMs/MZ switches) are demonstrated. We experimentally characterized single microring and cascaded-multiple-MRR resonators coupled to one arm of a Mach-Zehnder interferometer (MZI). The anving power consumption of the proposed MZM is significantly reduced owing to the enhanced phase shift in the MRR. The device was fabricated on a silicon-on-insulator (SOI) waveguide structure and each microring is equipped with TiN microheater for thermo-optic tuning. The coupling efficiency between a microring and a busline waveguide was regulated by varying the gap between two waveguides at a directional coupler. Power consumption of a single microring MZI and cascaded MRR-loaded MZMs were approximately 0.4 mW and1mW, respectively. The phase-shift enhancement factor of up to19 with a maximum extinction ratio of18 dB was obtained experimentally. Multiple-wavelength operation was also demonstrated in the cascaded MRR-loaded MZM.
    关键词:微环谐振器;热光效应;硅;马赫-曾德干涉仪
  • 359.大功率锂离子二次电池III的碳涂层集电极

    [计算机、通信和其他电子设备制造业,电气机械和器材制造业] [2015-08-30]

    The ultimate goal of this project is to develop a viable C-coating process of the current collector in order to improve the overall power performance of the electrode of Li-ion batteries. During this third-year period, the performance of different thickness of carbon coating on Al foil is compared. The result shows that only the samples with sufficient thickness to form conductive channel on the surface would give a positive effect on the performance. Scale up of this coating process is further developed to make 1.5 m long C-coated tape by a contentious process followed with a special batch thermal process called roll-calcination. The same positive effects seen on small samples have been reproduced.
    关键词:电池;电极涂层;锂离子电池
  • 360.先进氧化过程中紫外线发光二极管的使用

    [计算机、通信和其他电子设备制造业] [2015-08-30]

    Cleanup from a hazardous chemical release can result in large volumes of water containing hazardous materials, such as organophosphates. Unfortunately, this water cannot be treated in a municipal wastewater treatment plant without adversely affecting the performance of the plant. A known method for pretreating this water to prepare it for processing in a traditional treatment plant includes the addition of hydrogen peroxide, followed by ultraviolet (UV) light exposure to form reactive hydroxyl radicals which oxidize the chemical. Light emitting diodes (LEDs) are explored as a UV source as they are durable; compact; can be powered by low voltage, direct current from solar cells or batteries; and do not contain other hazardous materials, making them useful in a tactical environment. This research evaluated the operating mode (continuous or pulsed current) of 240 nanometer UV LEDs for application in such an advanced oxidation process. The experimental results demonstrated the production of hydroxyl radicals from hydrogen peroxide from both continuously driven and pulsed UV LEDs. However, continuously driven UV LEDs were shown to be more effective than pulsed in this application.
    关键词:电池;紫外线发光二极管;电能
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