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991.
992.
In vivo evaluation of garlic (Allium sativum) supplementation to rice straw‐based diet on mitigation of CH4 and CO2 emissions and blood profiles using crossbreed rams 下载免费PDF全文
993.
Electrochemical performance of solid oxide electrolysis cell electrodes under high-temperature coelectrolysis of steam and carbon dioxide 总被引:1,自引:0,他引:1
Pattaraporn Kim-LohsoontornJoongmyeon Bae 《Journal of power sources》2011,196(17):7161-7168
The SOEC electrodes during steam (H2O) electrolysis, carbon dioxide (CO2) electrolysis, and the coelectrolysis of H2O/CO2 are investigated. The electrochemical performance of nickel-yttria stabilised zirconia (Ni-YSZ), Ni-Gd0.1Ce0.9O1.95 (Ni-GDC), and Ni/Ruthenium-GDC (Ni/Ru-GDC) hydrogen electrodes and La0.8Sr0.2MnO3−δ-YSZ (LSM-YSZ), La0.6Sr0.4Co0.8Fe0.2O3−δ (LSCF), and La0.8Sr0.2FeO3−δ (LSF) oxygen electrodes are studied to assess the losses of each electrode relative to a reference electrode. The study is performed over a range of operating conditions, including varying the ratio of H2O/H2 and CO2/CO (50/50 to 90/10), the operating temperature (550-800 °C), and the applied voltage. The activity of Ni-YSZ electrodes during H2O electrolysis is significantly lower than that for H2 oxidation. Comparable activity for operating between the SOEC and solid oxide fuel cell (SOFC) modes is observed for the Ni-GDC and Ni/Ru-GDC. The overpotential of H2 electrodes during CO2 reduction increases as the CO2/CO ratio is increased from 50/50 to 90/10 and further increases when the electrode is exposed to a 100% CO2 (800 °C), corresponding to the increase in the area specific resistance. The electrodes exhibit comparable performance during H2O electrolysis and coelectrolysis, while the electrode performance is lower in the CO2-electrolysis mode. The activity of all the O2 electrodes as an SOFC cathode is higher than that as SOEC anodes. Among these O2 electrodes, LSM-YSZ exhibits the nearest to symmetrical behaviour. 相似文献
994.
Ho-Sik Yoo Hong-Youl RyuSeong-Seock Cho Moon-Hee HanKie-Seo Bae Jong-Hyeon Lee 《International Journal of Hydrogen Energy》2011,36(23):15111-15118
The effect of Si content in Al-Si alloy powder with NaOH on H2 production was investigated. The total amount of H2 produced decreased as Si content increased, which is inconsistent with the results predicted by the chemical reaction. Si caused a delay in the rate of H2 production. Energy dispersive spectrometry showed that a large amount of unreacted Si remained in the matrix, and the unreacted fraction increased as the Si content increased. As the evolution reaction of Al and Al-Si alloys is exothermic, the temperature of all the specimens increased. Si addition reduced the hydroxide removal rate, which decreased the average H2 production rate. The initiation time for H2 evolution depends on the elimination rate of the oxide film formed during production of the powder. On increasing the Si content, SiO2 was formed, which is harder to eliminate than Al2O3; this delayed the initiation. 相似文献
995.
This study investigates the impacts of high international oil prices on the bioethanol and corn markets in the US. Between 2007 and 2008, the prices of major grain crops had increased sharply, reflecting the rise in international oil prices. These dual price shocks had caused substantial harm to the global economy. Employing a structural vector auto-regression model (SVAR), we analyze how increases in international oil prices could impact the prices of and demand for corn, which is used as a major bioethanol feedstock in the US. The results indicate that an increase in the oil price would increase bioethanol demand for corn and corn prices in the short run and that corn prices would stabilize in the long run as corn exports and feedstock demand for corn decline. Consequently, policies supporting biofuels should encourage the use of bioethanol co-products for feed and the development of marginal land to mitigate increases in the feedstock price. 相似文献
996.
Nanocrystalline Al–Si alloy-based composites containing carbon nanotubes (CNTs) were produced by hot rolling ball-milled powders. During the milling process, the grain size was effectively reduced and the Si element was dissolved in the Al matrix. Furthermore, CNTs were gradually dispersed into the aluminum powders, providing an easy consolidation route using a thermo-mechanical process. The composite sheet containing 3 vol.% of CNTs shows ~520 MPa of yield strength with a 5% plastic elongation to failure. 相似文献
997.
Ahn HJ Kim YS Shim HS Park BK Moon WJ Bae Kim W Seong TY 《Journal of nanoscience and nanotechnology》2010,10(12):8199-8203
We have one-pot fabricated Si-based nanocomposite electrodes containing Ag nano-dots for thin-film Li rechargeable batteries by a co-sputtering method. The structural and electrochemical properties of the Si/Ag nanocomposite electrodes are investigated via transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), and cycler. The TEM and XRD results show that crystalline Ag nano-dots (approximately 5-9 in size) are well-dispersed within an amorpohous Si matrix. It is shown that the Si/Ag nanocomposite electrode shows much better structural stability than the Si only sample. It is also shown that the Si/Ag nanocomposite electrode shows superior capacity retention compared to the Si only electrode. The results indicate that the presence of the Ag nano-dots is important minimizing the formation of cracks in the electrode, so leading to the better life-time for thin-film Li rechargeable batteries. 相似文献
998.
With the objective to prepare electrocatalysts with high efficiency, the Pt-Ru@PPy-MWNT catalysts were prepared by different approaches. First, the polypyrrole (PPy) as anchoring materials was coated on the surface of multi walled carbon nanotubes (MWNT) by in situ polymerization. Subsequently, Pt-Ru nanoparticles were deposited onto PPy-MWNT composite by different methods like the reduction of metal ions by gamma-irradiation and chemical reduction using formaldehyde as reducing agent assisted with stirring of magnetic bar, and assisted with microwave irradiation, and assisted with ultrasonic irradiation, in order to prepare electrocatalyst for fuel cell. The catalytic efficiency of Pt-Ru@PPy-MWNT catalyst was examined for CO stripping. 相似文献
999.
Behnam Zamanian Mahdokht Masaeli Jason W. Nichol Masoud Khabiry Matthew J. Hancock Hojae Bae Ali Khademhosseini 《Small (Weinheim an der Bergstrasse, Germany)》2010,6(8):937-944
Cell‐laden hydrogels show great promise for creating engineered tissues. However, a major shortcoming with these systems has been the inability to fabricate structures with controlled micrometer‐scale features on a biologically relevant length scale. In this Full Paper, a rapid method is demonstrated for creating centimeter‐scale, cell‐laden hydrogels through the assembly of shape‐controlled microgels or a liquid–air interface. Cell‐laden microgels of specific shapes are randomly placed on the surface of a high‐density, hydrophobic solution, induced to aggregate and then crosslinked into macroscale tissue‐like structures. The resulting assemblies are cell‐laden hydrogel sheets consisting of tightly packed, ordered microgel units. In addition, a hierarchical approach creates complex multigel building blocks, which are then assembled into tissues with precise spatial control over the cell distribution. The results demonstrate that forces at an air–liquid interface can be used to self‐assemble spatially controllable, cocultured tissue‐like structures. 相似文献
1000.
The rutile TiO2 thin film involving two different top electrodes (Pt and Al) clearly shows the unipolar and bipolar resistive switching transitions which are dependent on the degree of redox properties at TiO2 layer-electrode interfaces. Detailed current level analysis coupled with Auger electron spectroscopy measurements of the Pt/TiO2/Pt and Al/TiO2/Pt structures in the on/off switching states revealed the implication of oxygen ion migration induced chemical reaction at the Al-TiO2 interfaces. Therefore, it is expected that the bipolar transition nature of resistive switching with an Al electrode is the resulting formation of a thin AlOx layer due to redox reaction at Al-TiO2 layer interfaces. 相似文献