فهرست مطالب

  • Volume:2 Issue:2, 2008
  • تاریخ انتشار: 1387/06/11
  • تعداد عناوین: 10
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  • M. Y. Tanaka, K. Ogiwara, S. Etoh, Sh. Yoshimura, M. Aramaki, J. Vranjes Page 1
    Formation of singular vortices in a magnetized plasma is presented. One is "plasma hole", which is characterized by fast azimuthal rotation and a density hole in its core region. It is found that the charge neutrality condition does break down in the hole region over 1000 times the Debye length. Another example is an anti-E × B vortex, which rotates in the opposite direction to the E × B drift. This result means that there exists a predominant force acting on ions other than the electric field. The interaction between ions and neutral flow and the resultant momentum transfer play an essential role on generation of anti-E x B rotation.
  • S. Vasheghani Farahani, A. A. Masoudi Page 7
    In this article we aim to predict the behavior of a magnetized fluid which is governed by the Magnetohydrodynamic equation in the inviscid limit, which means that the Reynolds number is over 2000 and the system is turbulent. For this we need to have enough knowledge about Magnetohydrodynamics, the conditions governing it, stochastic processes and the methods of solving the KPZ and burgers equations, bearing in mind that this isn’t possible without studying different fields of turbulence and statisticalmechanics. It is shown that there are relations between three nonlinear evolutionary equations named KPZ, Burgers and Magnetohydrodynamics, then from our findings not only the field moments can be calculated but also the time the singularities appear for the magnetohydrodynamics equation could be computed.
  • Nano-Structure and Electrical Properties of Titanium Thin Films as a Function of Substrate Temperature
    K. Khojier, H. Savalonim., Ghoranneviss Page 7
    The transmission and reflection spectra from a right-handed chiral sculptured TiO2 thin film are calculated using the piecewise homogeneity approximation method and the Bruggeman homogenization formalism by considering that the propagation of non-dispersive dielectric function occurs for non-axial states. The results show that the characteristic circular Bragg phenomenon in co-handed circular reflectance is more pronounced and the observed consecutive peaks and troughs in circular remittances are representative of the influence of azimuthal and polar angles on these spectra.
  • Behavior of Amorphous Metal Alloy Mirrors Under Ion Bombardment
    V. S. Voitsenya, A. S. Bakai, A. F. Bardamid, V. G. Konovalov, K. V. Kovtun, D. I. Naidenkova, I. V. Ryzhkov, A. F. Shtan, S. I. Solodovchenko, O. V. Trembach, A. A. Vasilev Page 8
  • F. Babaei, H. Savaloni Page 11
    The transmission and reflection spectra from a right-handed chiral sculptured TiO2 thin film are calculated using the piecewise homogeneity approximation method and the Bruggeman homogenization formalism by considering that the propagation of non-dispersive dielectric function occurs for non-axial states. The results show that the characteristic circular Bragg phenomenon in co-handed circular reflectance is more pronounced and the observed consecutive peaks and troughs in circular remittances are representative of the influence of azimuthal and polar angles on these spectra.
  • M. B. Shiran, D. J. Watmough Page 19
    Sonoluminescence has been attributed by some authors to compression of gas inside collapsing acoustically induced cavities (or even to pulsation violent stable cavities). This adiabatic compression is believed to raise the temperature of the gases by up to 10,000 K which radiate in the visible spectrum. An alternative explanation has been proposed by others as: the changes in charge density on bubble surface during compression leads to electrical discharge (in microscopic scale) and they believe to that this process causes emission of light from the cavity. In this work we report on the measurement of the net charge induced acoustically on the bubble by means of the motion of bubbles in distilled water while an external electric field applied. The motion of the bubbles is recorded on a photographic film during 1 second exposure hence the stationary bubbles appear as points and moving bubbles as lines.The radius of the bubble and hence the bubble charge can be estimated from the velocity of bubble provided by the length of the line.
  • M. Ilkhani, M. R. Abolhassani Page 27
    Electronic structure and hyperfine electric interaction of CeIn3 compound under pressures up to 22 GPa are found.The calculations are done utilizing the density functional simulation through the full-potential (linear) augmented plane-waves method, FP-(L)APW, within the generalized-gradient approximation. The electronic density of states and electric field gradients (EFG’s), at In sites are calculated under pressure. Our result shows that by increasing the pressure, the density of states at Fermi level are decreased and this causes an increase in EFG. At ambient pressure, there is a good agreement between EFG’s and bulk modulus with experimental measurements. Also, the spin magnetic moment of Ce, which is strongly pressure dependent, is computed under pressure. By increasing the pressure, Cerium f states move away from the Fermi level into the conduction band and this suppresses the spin magnetic moment in the vicinity of some quantum critical point, i. e. 14 GPa.
  • M. J. Eshraghi, M. Cho, J. M. Kim, I. Sasada Page 33
    Measurements of the high frequency electromagnetic interference (EMI) of a pulse tube cryocooler are made in a typical laboratory environment using laboratory-made current transformers. The inverter makes high frequency EMI which could cause severe interference with SQUID operation inside the pulse tube cryocooler. By covering thepower lines, including a neutral line, of the valve motor with a copper mesh cover, as a ground line, one order decrease in the magnitude of the EMI noise is successfully obtained. This paper describes an example to show how to observe and reduce conducted high frequency noise currents in a precision experimental system.
  • H. Bayani, Th. Theodoulidis, I. Sasada Page 49
    An axisymmetric cup-cored coil placed above a layered conductive half-space is analyzed by using the truncated region eigenfunction expansion method. Closed-form expressions are presented for the coil impedance as well as the induced eddy current density. The results are in very good agreement with results from 2D-FEM and with experimentalones.