Browse Articles

    Volume 1, Issue 1, Dec 2015

    Biological population model and its solution by reduced differential transform method
    H.S. Shukla, Gufran Malik
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      • Abstract: In this paper, an approximate solution of the generalized biological population model (BPM) is proposed by means of a recent semi-analytical method: “reduced differential transformation method”. The method is very reliable, effective and efficient powerful technique for solving wide range of problems arising in natural sciences. Using the method, it is possible to find an exact solution or a closed approximate solution of any differential equation. The scheme is very easy to implement since it takes very small size of computation contrary to the other methods. Four numerical examples are carried out in order to validate and illustrate the efficiency of the method considering the scenario of both linear and nonlinear biological population model.

    A cylindrical shadow eclipse prediction model for LEO satellites with application to IRS satellites
    Prakash Shiggavi, Hemalata M.G
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      • Abstract: Most of the Low Earth-Orbiting (LEO) spacecraft experience eclipse when the spacecraft passes through the shadow side of the Earth. As the spacecraft is eclipsed, space scientists and engineers express their interest in various objectives such as the shadow entrance and exit timings, the Sun-satellite geometry etc. The shadow information of a satellite is very useful for various utilizations, e.g., spacecraft thermal control, solar panel power, attitude control, and celestial viewing conditions. This paper describes an Earth cylindrical shadow model for the LEO spacecraft. The model is simulated to arbitrarily chosen three Indian remote sensing (IRS) satellites; Cartosat-2A, Resourcesat-2, Oceansat-2 and is compared well with the real time data. The accuracy of the developed model is also carried out in terms of 3 sigma estimation.

    Numerical study of natural convection in horizontal concentric cylinders with porous material
    Seetu Rana
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      • Abstract: In this paper, the main goal is to study of the effect of porous material in the annulus between two horizontal isothermal concentric cylinders. Higher order semi compact scheme is used to solve the governing equations. The Darcy-Brinkman model is considered to study the effect of porous material.

    An approximate analytic solution description of time-fractional order Fokker-Planck equation by using FRDTM
    Dhiman, A. Chauhan
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      • Abstract: The fractional Fokker-Plank equation paid much more attention by researchers due to its wide range of applications in several areas of sciences and engineering. In this article, our main motto is to present a new approximate solution of time-fractional FPE by means of a new semi-analytical approach called fractional reduced differential transform method (FRDTM), with appropriate initial condition. In FRDTM, fractional derivative is considered in the Caputo sense. The validity and efficiency of FRDTM is illustrated by considering three numeric experiments. The solutions behavior and the effects of different values of fractional order are depicted graphically.

    Flattening effects of the Moon and the Earth on predicting shadow events of a lunar orbiting spacecraft
    Shivali Kulshrestha
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      • Abstract: In this paper, we describe the line of intersection model for predicting shadow eclipses due to the Moon and the Earth for any lunar orbiting spacecraft. Both spherical and non-spherical shapes of the Moon and the Earth are accounted in the model in order to show the effect of oblateness of both celestial bodies on predicting shadow eclipses. On a lunar orbiting spacecraft, shadow eclipses due to the Moon occurs frequently whereas eclipses due to the Earth is not regular and number of its occurrence per orbital location varies with an average of two per year. These Earth shadow eclipses on a lunar orbiter mission can cause severe operational problems. This study provides significant insights beneficial to a mission designer, planner and operation.

    Design of 2.4 GHz rectangular micro strip patch antenna used in wireless communication systems
    R.K. Chaurasia, V. Mathur, M. Madhukar, G. Giri
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      • Abstract: The aim of this short communication is to design and fabricate rectangular micro strip antenna and analyze the effect of antenna dimensions length (L), width (W) band width, substrate parameters relative dielectric constant (€r), substrate thickness. Low dielectric constants are generally preferred for maximum radiation. The conducting patch can take any shape but rectangular and circular configurations are the most commonly used configurations. Other configurations are complex to analyzed and required heavy numerical computation. In this communication, partial swarm optimization method based on IE3D is used to design and inset feed rectangular 2.4 GHz micro strip patch antenna. Using this method bandwidth and VSWR of the micro strip antenna is obtained.