American Journal of Physics and Applications

Volume 1, Issue 1, July 2013

  • Nonlinear and Negative Resistance in Loose Electrical Contacts Dark Bridge

    Hiromichi Kubota, Shunsuke Sasaki, Hiroyuki Ishida, Tasuku Takagi

    Issue: Volume 1, Issue 1, July 2013
    Pages: 1-4
    Received: 2 May 2013
    Published: 10 June 2013
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    Abstract: The dark bridge in loose electrical contacts was investigated, which grew up when the contact gap was increased a little with micron by micron. The dark bridge was watched by microscopic camera along with measurement of voltage-current (V-I) relationship. At very small gap (less than 19μm for iron (Fe) contacts but different from materials), the V-... Show More
  • A plasma Formation in Pulsed Coaxial Gun at Continuously Filling Regime

    A. M Zhukeshov, A. U Amrenova, A. T Gabdullina, B. M Ibraev

    Issue: Volume 1, Issue 1, July 2013
    Pages: 5-9
    Received: 14 May 2013
    Published: 10 June 2013
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    Abstract: In work presented the results of researches of plasma flow formation and propagate in the electrodynamics pulsed gun. Experimental researches carried out on the basis of pulse plasma accelerator CPU-30 with a coaxial symmetric geometry electrodes. It was shown, that structure of the flow significantly depends on initial operating pressure of worki... Show More
  • Statistical tuning of walfisch-bertoni pathloss prediction model based on building and street geometry sensitivity parameters in built-up terrains

    Isabona Joseph, Babalola Michael

    Issue: Volume 1, Issue 1, July 2013
    Pages: 10-17
    Received: 25 May 2013
    Published: 30 June 2013
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    Abstract: One of the underlying difficulties with the application of a prediction pathloss model for any environment is that no two areas are identical in the composition of the buildings and terrain. A pathloss model developed by Walfisch-Bertoni considers the impact of rooftops and building heights by using diffraction to predict average signal strength lo... Show More
  • Experimental and Theoretical Study of Parasitic Effects in InAlAs/InGaAs/InP HEMT’s

    S. Bouzgarrou, M. M. Ben Salem, A. Kalboussi, A. Souifi

    Issue: Volume 1, Issue 1, July 2013
    Pages: 18-24
    Received: 21 May 2013
    Published: 30 June 2013
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    Abstract: A detailed study of electrically active defects present in InAlAs/InP heterostructure and InAlAs/InGaAs/InP High Electron Mobility Transistors (HEMTs) grown by metal organic chemical vapor deposition (MOCVD) is presented. Current and capacitance Deep Level Transient Spectroscopy (I-DLTS and C-DLTS) techniques are used for the identification of acti... Show More
  • Study of Radiation in Spherical Media Using Moment Method

    T. Sghaier

    Issue: Volume 1, Issue 1, July 2013
    Pages: 25-32
    Received: 3 June 2013
    Published: 10 July 2013
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    Abstract: A moment technique is presented to improve the performance of the discrete ordinates method when solving the radiation problems in spherical media. In this approach the angular derivative term of the discretized 1-D radiative transfer equation is derived from an expansion of the radiative intensity on the basis of angular moments. The set of result... Show More