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Hydrogen Absorption (hydrogen + absorption)
Selected AbstractsChemInform Abstract: Hydrogen Absorption in Transition Metal Silicides: La3Pd5Si-Hydrogen System.CHEMINFORM, Issue 44 2008Yaroslav O. Tokaychuk Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Hydrogen degradation of structural steels in technical hydrocarbon liquidsMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 4 2008B. Swieczko-Zurek Abstract Hydrogen absorption, mechanical testing under different loading mode and electrochemical measurement were done for 0.3C low alloy steels used in the ship engine parts at immersion in the boiler fuel and in the used engine mineral oil at elevated temperatures corresponding to the operating conditions. The hydrogen charging of steels has been found to reach a level causing their plasticity loss. No effect, a plasticity loss and a significant decrease in the number of cycles have been stated in constant load, slow strain rate and fatigue tests, respectively. The results showed the local active plastic deformation proceeded close to the surface of hydrogen ingress to provide the highest possibility for hydrogen induced metal degradation in hydrocarbon environments. Although the source of hydrogen evolved in the case of technical hydrocarbons has been discussed, the promoting effect of formed H2S should be recognized as the important factor influencing the hydrogen charging from those environments. Some variation in the steel microstructure, chemical composition and hardness of steels, even allowed by the standard may affect their susceptibility to hydrogen degradation in hydrocarbons. [source] Combustion-type hydrogenation of nanostructured Mg-based composites for hydrogen storageINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 13 2009M. V. Lototsky Abstract In this study Reactive Ball Milling in hydrogen gas was used to synthesize nanostructured hydrogenated composites of Mg and V-based alloy. After hydrogen desorption, the nanocomposites exhibited a dramatic facilitation of the rate of H absorption by Mg and reduction of the temperature of onset of hydrogenation. These favourable changes were caused by a synergy of catalytic effect of the V-based alloy on hydrogen absorption by Mg and heat release caused by exothermic hydrogen absorption by the V-based alloy. When the initial interaction temperature exceeded a threshold, rather low, value of 20,125°C, depending on the H2 pressure, composition of the sample and its total amount, a combustion-type hydrogenation took place. With optimal interaction parameters applied, H absorption was completed in just 5,70,s and was accompanied by a significant heat release. The observed features can be utilized to reach fast recharge of the Mg-based H stores and to develop efficient heat management systems. Copyright © 2009 John Wiley & Sons, Ltd. [source] The angular correlation function of the ROSAT All-Sky Survey Bright Source CatalogueMONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2000A. Akylas We have derived the angular correlation function of a sample of 2096 sources detected in the ROSAT All-Sky Survey (RASS) Bright Source Catalogue, in order to investigate the clustering properties of active galactic nuclei (AGN) in the local Universe. Our sample is constructed by rejecting all known stars, as well as extended X-ray sources. Areas with |b|<30° and declination ,<,30° are also rejected owing to the high or uncertain neutral hydrogen absorption. Cross-correlation of our sample with the Hamburg/RASS optical identification catalogue suggests that the vast majority of our sources are indeed AGN. A 4.1, correlation signal between 0° and 8° was detected with w(,<8°)=2.5±0.6×10,2. Assuming a two-point correlation function of the form w(,)=(,,0),0.8, we find ,0=0062. Deprojection on three dimensions, using Limber's equation, yields a spatial correlation length of r0,6.0±1.6 h,1 Mpc. This is consistent with the AGN clustering results derived at higher redshifts in optical surveys and suggests a comoving model for the clustering evolution. [source] Dynamic simulation of kinetics, heat and mass transfer during hydrogen sorption by LaNi5ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2010Dr Tarek Moustafa Abstract A two-dimensional transient heat and mass transfer models have been developed to investigate the dynamic phenomena of hydrogen absorption and desorption in metal hydride bed. LaNi5 has been chosen as the alloy used for hydrogen storage. The numerical simulation has been conducted to simulate the time,space evolution of temperature, fractional conversion, hydrogen pressure and velocity, in addition to metal density. A correlation for the volumetric reaction rate has been deduced. Also, comparisons have been done between various bed geometries and their influence on the average hydrogen desorbed mass. The simulation results showed that heat transfer controls the overall rate of absorption and desorption processes, and because the driving force for the hydrogen flow is the axial pressure difference; the challenge to get optimum bed geometry is in compromising between heat transfer and pressure drop limitations. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd. [source] | ||||||||||