Mechanics of a functionally graded cylinder subject to static or dynamic axial loading is considered, including a potential application as energy absorber. The mass density and stiffness are power functions of the radial coordinate as may be the case with variable-density open-cell or closed-cell foams. Exact solutions are obtained in the static problem and in the case where the applied load is a periodic function of time. The absorption of energy is analyzed in the static problem that is reduced to an easily implementable nondimensional formulation. It is demonstrated that by using foams with a variable in the radial direction mass density it is possible to achieve higher energy absorption while at the same time saving weight.

关键词：燃料电池；电动汽车；能量梯度

查看摘要 索取原文[18页]

Our overall goal is to increase the capabilities of today s long- rage Unmanned Underwater Vehicles (UUVs) and Unmanned Underwater Gliders (UUGs) by using high-energy-density lithium-seawater batteries. Specific objectives are (1) to test in the laboratory and ocean new lithium-seawater batteries developed and manufactured by the PolyPlus Battery Company, (2) to discover how to mount and operate these cells to minimize adverse impacts of limited mass transfer with the ambient seawater and of bio-fouling, and (3) to develop a long-range underwater UUV or UUG to exploit this energy source. Our target is to double the range/duration of long-range neutrally buoyant underwater vehicles.

关键词：浮力；滑翔机；长距离（距离）；蓄电池

查看摘要 索取原文[6页]

This presentation summarizes NREL's technology validation of stationary fuel cell systems and presents data on number of deployments, system costs, and fuel types.

关键词：燃料电池；燃料；技术评估

查看摘要 索取原文[25页]

Superparamagnetic iron oxide nanoparticle (SPION) has attracted a great deal of attention in the fields of medicine and biology due to its non-toxicity, large specific surface area, amenability to various surface fuctionalization, and unique magnetic properties. For biomedical applications, we synthesized two kinds of SPIONs by co-precipitation and polyol methods, designated as C- and P-SPIONs, respectively. To increase their solubility and stability in an aqueous solution, both of the SPIONs were functionalized with hyperbranched polyglycerol (PG) through ring-opening polymerization of glycidol. Scanning transmission electron microscopy (STEM) and dynamic light scattering (DLS) measurements revealed that the P-SPION provided individual nanoparticles without aggregation after the PG fuctionalization. This P-SPION-PG was highly soluble not only in pure water (＞ 40 mg/mL), but also in a phosphate buffer solution (＞ 25 mg/mL). Such high solubility enabled separation of P-SPION-PG according to their size by size exclusion chromatography (SEC). The size-separated P-SPION-PG shows a gradual increase in transverse relaxivity (r_2) with increasing particle size. The hydroxyl group in PG also serves as a scaffold for further surface functionalization. For targeted cell labeling, we functionalized P-SPION-PG through multi-step organic transformations (-OH → -OTs (tosylate) → -N_3 → -RGD) including click chemistry as a key step to impart targeting specificity by immobilization of cyclic RGD peptide on the surface. The targeting effect was demonstrated by the cell experiments; P-SPION-PG-RGD was taken up by the cells overexpressing α_vP_3-integrin such as U87MG and A549. In addition, near-infrared (NIR) fluorescence dye (IRdye 800CW) was immobilized on the surface of P-SPION-PG through amide linkage. The resulting P-SPION-PG-IRdye showed good solubility in phosphate buffered saline (PBS) and strong fluorescence in NIR region, which may find application in optical/MR bimodal imaging.

关键词：电池磁极；氧化铁材料；电能转换

查看摘要 索取原文[17页]

关键词：燃料电池；物料搬运设备；电动电池

查看摘要 索取原文[37页]

The development of a room temperature (<50 C) fuel cell that would use a generally available fuel such as JP8 would be most valuable. However there are no known catalysts that can selectively activate the CC bonds of such fuels at such temperature. The goal of this project was to investigate whether it is plausible to develop such catalysts. To do this we used validated first-principles (quantum mechanics) based simulations to investigate the barriers for alkyl carbon-carbon cleavage for two prototypical systems: A metal alloy catalyst and an organometallic cluster catalyst. That might serve as an anode for electrochemical power generation. For the metal alloy catalyst we used a top-down approach where we determined the bond energies to the alloy catalyst to various fuel fragments necessary to achieve room temperature decomposition of butane and oxidation to CO2. For organometallic cluster catalyst we used a bottom-up strategy, determining specific metals, ligand compositions, solvents and operating conditions to evaluate which conditions could lead to reasonable rates at room temperature.

关键词：烷烃；碳碳复合材料；电力；低温

查看摘要 索取原文[31页]

Laboratory studies support the potential for jet fuel to promote noise induced hearing loss. Noise alone induces hearing loss due to loss of hair cells in the cochlea, associated with oxidative stress. Jet fuel toxicity in association with noise may be at least partially explained by increased free radical production and oxidative stress at the cellular level, resulting in hair cell dysfunction and loss. This project combines a physiologically-based pharmacokinetic (PBPK) model to describe jet fuel component concentrations in the cochlea with pharmacodynamic (PD) models of free radical formation in the cochlea by both noise and jet fuel components, and mathematical models to predict the combined impact on hair cell functionality and loss. Further development of this preliminary combined PBPK-PD model of JP-8 induced hearing loss with noise will provide the basis for estimating the potential risk to humans exposed to the same chemical and sound scenarios in occupational settings.

关键词：血流量；体重；耳蜗；自由基；毛细胞

查看摘要 索取原文[39页]

Currently, carbon is the preferred support material for platinum catalyst particles used in polymer electrolyte fuel cells (PEFCs). Carbon possesses qualities needed for a fuel cell catalyst: high surface area and conductivity, but is unacceptable as it is prone to oxidization by carbon dioxide in the fuel cell environment. Molybdenum Carbides is known to have the required conductivity. However, making Mo2C with sufficient surface area and with stabilized platinum remains a materials challenge. In this work a novel approach, a variation on the Aerosol-Through-Plasma (ATP) method was employed for making Mo2C with high surface area and stable supported platinum particles. An ammonium molybdate precursor was processed through different ATP conditions to generate the catalyst. These particles were then characterized using X-ray diffraction and SEM techniques in order to produce a support material with the highest concentration of Mo2C. Using the ideal conditions for the ATP, precursor was loaded with platinum and then processed through the ATP. This sample was then characterized using X-ray and SEM techniques to insure that the material was suitable prior to testing the electrochemical properties under PEFC operating conditions. The results were then compared to other leading support catalysis.

关键词：碳化物；燃料电池；钼；铵化合物；碳；二氧化碳

查看摘要 索取原文[89页]

The Dust, Thermal and Radiation Engineering Measurement (DTREM) packages (figure 1) mounted on the central stations of the Apollo 11, 12, 14, and 15 ALSEPs (Apollo Lunar Surface Experiments Packages) measured the outputs of exposed solar cells and thermistors over time. The goal of the experiment, also commonly known as the dust detector, was to study the long-term effects of dust, radiation, and temperature at the lunar surface on solar cells. The monitors returned data for up to almost 8 years from the lunar surface.

关键词：数据处理；数字数据；月球尘埃；辐射效应

查看摘要 索取原文[2页]

Spectral reflectance data through the visible regime was collected at Las Campanas Observatory in Chile using an imaging spectrograph on one of the twin 6.5-m Magellan telescopes. The data were obtained on 1-2 May 2012 on the 'Landon Clay' telescope with the LDSS3 (Low Dispersion Survey Spectrograph 3). Five pieces of Geosynchronous Orbit (GEO) or near-GEO debris were identified and observed with an exposure time of 30 seconds on average. In addition, laboratory spectral reflectance data was collected using an Analytical Spectral Device (ASD) field spectrometer at California Polytechnic State University (Cal Poly) in San Luis Obispo on several typical common spacecraft materials including solar cells, circuit boards, various Kapton materials used for multi-layer insulation, and various paints. The remotely collected data and the laboratory-acquired data were then incorporated in a newly developed model that uses a constrained least squares method to unmix the spectrum in specific material components. The results of this model are compared to the previous method of a human-in-the-loop (considered here the traditional method) that identifies possible material components by varying the materials and percentages until a spectral match is obtained. The traditional model was found to match the remotely collected spectral data after it had been divided by the continuum to remove the space weathering effects, or a reddening of the materials. The constrained least-squares model also used the de-reddened spectra as inputs and the results were consistent with those obtained through the traditional method. For comparison, a first-order examination of including reddening effects into the constrained least-squares model will be explored and comparisons to the remotely collected data will be examined. The identification of each object s suspected material component will be discussed herein.

关键词：空间碎片；光谱反射率；同步轨道；最小二乘法

查看摘要 索取原文[16页]