The Experts below are selected from a list of 309 Experts worldwide ranked by ideXlab platform

Zhen-yan Deng - One of the best experts on this subject based on the ideXlab platform.

  • Effect of Initial Gas pressure on the reaction of Al with water
    International Journal of Hydrogen Energy, 2014
    Co-Authors: Wei-zhuo Gai, Zhen-yan Deng
    Abstract:

    Abstract The effect of Initial Gas pressure on Al–water reaction was investigated systematically. It was found that there is a non-monotonic relationship between the Initial pressure and the induction time for the beginning of Al–water reaction. The induction time decreases with decreasing the Initial pressure at the first stage from atmospheric pressure, then reaches a minimum, and finally increases with further decreasing the Initial pressure. The mechanism analyses revealed that the special vacuum pressure corresponding to the minimum induction time is close to the saturated vapor pressure, below which probably there are some vapor bubbles passing or adsorbing on Al particle surfaces due to boiling, retarding the hydration process of Al surface oxide film and increasing the reaction induction time. The present results imply that a suitable Initial Gas pressure should be chosen for Al–water reaction to generate hydrogen.

Takahiro Hosokawa - One of the best experts on this subject based on the ideXlab platform.

  • In-Situ Capillary Trapping of CO2 by Co-Injection
    Transport in Porous Media, 2011
    Co-Authors: Tetsuya Suekane, Takahiro Hosokawa, Sadamu Inaoka, Qiuwang Wang
    Abstract:

    Co-injection of water with CO2 is an effective scheme to control Initial Gas saturation in porous media. A fractional flow rate of water of approximately 5–10% is sufficient to reduce Initial Gas saturations. After water injection following the co-injection, most of the Gas injected in the porous media is trapped by capillarity with a low fractional volume of migrating Gas. In this study, we first derive an analytical model to predict the Gas saturation levels for co-injection with water. The Initial Gas saturation is controlled by the fractional flow ratio in the co-injection process. Next, we experimentally investigate the effect of Initial Gas saturation on residual Gas saturation at capillary trapping by co-injecting Gas and water followed by pure water injection, using a water and nitrogen system at room temperature. Depending on relative permeability, Initial Gas saturation is reduced by co-injection of water. If the Initial saturation in the Berea sandstone core is controlled at 20–40%, most of the Gas is trapped by capillarity, and less than 20% of the Gas with respect to the injected Gas volume is migrated by water injection. In the packed bed of Toyoura standard sand, the Initial Gas saturation is approximately 20% for a wide range of Gas with a fractional flow rate from 0.50 to 0.95. The residual Gas saturation for these conditions is approximately 15%. Less than approximately 25% of the Gas migrates by water injection. The amount of water required for co-injection systems is estimated on the basis of the analytical model and experimental results.

  • Maximization of capillary trapping ratio to injected CO2 by means of co-injection
    Energy Procedia, 2011
    Co-Authors: Tetsuya Suekane, Na Zhou, Takahiro Hosokawa
    Abstract:

    Abstract Co-injection of water with CO2 is an effective scheme to control the Initial Gas saturation in porous media. The fractional flow rate of water about 5 to 10% is enough to reduce the Initial Gas saturations, and after water injection, most of Gas injected in porous media is trapped by capillarity with low fractional volume of migrating Gas. In this paper, first we derive an analytical model to predict the Gas saturations for the co-injection with water. Next, the effect of the Initial Gas saturation, which is controlled by the fractional flow ratio in co-injection process, on the residual Gas saturation at capillary trapping is investigated experimentally for the water and nitrogen system at room condition. Depending on the relative permeabilities, the Initial Gas saturation is reduced by the co-injection of water. In case of the Berea sandstone core, if the Initial saturation is controlled to be in the range between 20% and 40%, most of the Gas is trapped by capillarity and less than 20% of Gas with respect to the injected Gas volume is migrate by water injection. In case of the packed bed of Toyoura standard sand, the Initial Gas saturation is about 20% for a wide range of Gas fractional flow rate from 0.50 to 0.95. The residual Gas saturation for these conditions is about 15%. Approximately less than 25% of Gas migrates by water injection. Based on the analytical model and the experimental results, advantages and disadvantages of co-injection systems are discussed.

Christine Anne Coverdale - One of the best experts on this subject based on the ideXlab platform.

  • 2D rad-MHD model assessment of designs for multiple-shell Gas nozzles for Z.
    Bulletin of the American Physical Society, 2010
    Co-Authors: J.w. Thornhill, John Giuliani, A. L. Velikovich, John P. Apruzese, Y. K. Chong, Jean-paul Davis, Arati Dasgupta, Robert E. Clark, Brent Manley Jones, Christine Anne Coverdale
    Abstract:

    AASC is designing multiple-shell Gas puff loads for Z. Here we assess the influence of the loads Initial Gas distribution on its K-shell yield performance. Emphasis is placed on designing an optimal central jet Initial Gas distribution, since it is believed to have a controlling effect on pinch stability, pinch conditions, and radiation physics. We are looking at distributions that optimize total Ar K-shell emission and high energy (>10 KeV) continuum radiation. This investigation is performed with the Mach2 MHD code with non-LTE kinetics and ray trace based radiation transport.

Nasser Darabiha - One of the best experts on this subject based on the ideXlab platform.

  • classical and dynamic analysis of Gas phase reactivity influence of carbon precursor in the cvd of sic
    Journal of The Electrochemical Society, 2004
    Co-Authors: Stephanie De Persis, Francis Teyssandier, Dominique Thevenin, Nasser Darabiha
    Abstract:

    The intrinsic low dimensional manifold method (ILDM), which is a reduction method of large Gaseous chemical systems, is applied to the Gas-phase chemistry used to deposit 4H or 6H silicon carbide (SiC). The 1-dimensional (1-D) manifold corresponding to the relaxation of all the fast reaction modes of the complex Gaseous chemical system is calculated and represented according to different projections in the state space. The ILDM method is also used to compare trajectories corresponding to various Initial Gas-phase compositions. These Initial Gas-phase mixtures, which include different carbon precursors, all converge towards the same thermodynamic equilibrium. Long before thermodynamic equilibrium is reached, the trajectories are attracted by the 1-D manifold.

N. I. Fainer - One of the best experts on this subject based on the ideXlab platform.

  • Study of chemical bonds and element composition of silicon oxycarbonitride films by the methods of XP-, IR-, and energy-dispersive spectroscopy
    Glass Physics and Chemistry, 2017
    Co-Authors: N. I. Fainer, A. G. Plekhanov, I. P. Asanov
    Abstract:

    The element composition and chemical bonds of nanocomposite films of hydrogenated silicon oxycarbonitride fabricated through high-frequency plasma-chemical deposition from Initial Gas mixtures of 1,1,3,3-tetramethyldisilazane with nitrogen and oxygen in the temperature range 373–973 K depending on the synthesis conditions is studied. The effect of changes in the temperature and chemical composition of the Initial Gas mixtures on the element composition and types of chemical bonds in SiC x N y O z :H films is investigated.

  • Structure and elemental composition of transparent nanocomposite silicon oxycarbonitride films
    Journal of Structural Chemistry, 2017
    Co-Authors: N. I. Fainer, A. G. Plekhanov, A. N. Golubenko, Yu. M. Rumyantsev, E. A. Maksimovskii, V. R. Shayapov
    Abstract:

    Based on thermodynamic simulation on the deposition of condensed phases with the complex composition in the Si–C–N–O–H system in a wide temperature range, using Initial Gas mixtures of 1,1,3,3-tetramethyldisilazane (HSi(CH3)2)2NH (TMDS), TMDS with a variable mixture of oxygen and nitrogen (O2+xN2), a method is developed to obtain SiC x N y O z :H nanocomposite films by the plasma chemical decomposition of this Gas mixture in the temperature range of 373-973 K. By FTIR and energy dispersive X-ray spectroscopy the structure of chemical bonds and the elemental composition of the obtained silicon oxycarbonitride films are studied. The in situ composition of the Initial Gas phase in PECVD processes is examined by optical emission spectroscopy.