Tsuyama National College of Technology

About: Tsuyama National College of Technology is a education organization based out in Tsuyama, Japan. It is known for research contribution in the topics: Thin film & Electronic circuit. The organization has 203 authors who have published 351 publications receiving 3703 citations. The organization is also known as: Tsuyama Kogyo Koto Senmongakko, Tsuyama Kosen.

Gas Density and X-Ray Surface Brightness Profiles of Clusters of Galaxies from Dark Matter Halo Potentials: Beyond the Isothermal β-Model

Abstract: We describe a theoretical framework to compute the cluster gas distribution in hydrostatic equilibrium embedded in a class of spherical dark matter halo potentials. Unlike the conventional isothermal β-model, the present method provides a physical basis to directly probe the shape of the dark matter halo from the observed X-ray surface brightness and temperature profiles of clusters of galaxies. Specifically, we examine the extent to which the resulting gas density and X-ray surface brightness profiles are sensitive to the inner slope of the dark matter halo density and other more realistic effects, including the self-gravity of the gas and the polytropic equation of state. We also discuss a practical strategy to apply the present methodology to the actual cluster profiles from future X-ray observations.

Gas density and X-ray surface brightness profiles of clusters of galaxies from dark matter halo potentials: beyond the isothermal beta model

Abstract: We describe a theoretical framework to compute the cluster gas distribution in hydrostatic equilibrium embedded in a class of spherical dark matter halo potentials. Unlike the conventional isothermal $\beta$-model, the present method provides a physical basis to directly probe the shape of dark matter halo from the observed X-ray surface brightness and temperature profiles of clusters of galaxies. Specifically, we examine the extent to which the resulting gas density and X-ray surface brightness profiles are sensitive to the inner slope of the dark matter halo density and other more realistic effects including the self-gravity of the gas and the polytropic equation of state. We also discuss a practical strategy to apply the present methodology to the actual cluster profiles from future X-ray observations.

Influence of local flame displacement velocity on turbulent burning velocity

Abstract: In our previous works, the mean local burning velocity turned out to be changed from the originallaminar burning velocity due to the preferential diffusion effect, and it was found to be an important factor dominating the turbulent burning velocity. The present study investigates directly the local flame propagation properties of methane, propane, and hydrogen premixed turbulent flames in the weak turbulence region. A laser tomography technique is used to obtain the temporal local flame configuration and movement in a constant-volume vessel, and quantitative analyses are performed. The local flame-front curvature and the local flame displacement velocity S F are quantitatively obtained as the key parameters of the turbulent combustion. First, the observation of sequential flame tomograms shows that the turbulent flame front seems to be classified into active and inactive parts depending on its geometric configuration. Next, the values of S F are found to be distributed over a wide range and to be dependent on the local curvature of the turbulent flame. In addition, the values of S F for the methane and hydrogen mixtures have a tendency to become larger with decreasing equivalence ratio, whereas those for the propane mixture become smaller. We discuss also the influence of preferential diffusion and Markstein number on the local flame displacement velocity.

Transient Response of a Piezothermoelastic Circular Disk Under Axisymmetric Heating

Abstract: Transient temperature, displacement, stress and electric field intensities in a finite circular piezothermoelastic disk undergoing axisymmetric surface heating are examined. Exact solutions to the equations of equilibrium and electrostatics are obtained using a potential function approach based upon two piezothermoelastic potential functions, three piezoelastic potential functions and a piezoelectric potential function. The disk under consideration is assumed to exhibit hexagonal material symmetry of class 6 mm. The initial temperature of the disk is zero; thereafter one face is subjected to linear heat transfer from an adjacent medium (Newton's law of cooling), while the temperature of the other face remains constant. Both faces are taken to be free of traction. The cylindrical boundary of the disk is thermally insulated, electrically charge-free, and constrained against radial deformation. Numerical results are obtained for the stress and the electric potential distributions in a cadmium selenide disk.