Vol. 2 & Issue 2 ; Section C : Physical Sciences

Date : Feb. to Apr.2012

 

Numerical Accuracy of Runge-Kutta Fourth Order Method

R. B. Srivastava and Vikas Kant Pandey

  • Abstract

    Set of ordinary differential equations with boundary conditions has been solved by using Runge-Kutta fourth order method by developing a computer program. Values of y at the points of the interval [0, 1] have been calculated by adopting the stepwise of 0.01 and have been compared with the exact values of y at these points. Minimum, maximum and percentage errors have been calculated for each differentia equation. It has been observed that Runge-Kutta fourth order method is accurate up to seven digits after the decimal point in some cases. In the worst case, it is accurate up to two digits after the decimal point.

Numerical Accuracy of Runge-Kutta Fehlberg’s Method

R. B. Srivastava and Vikas Kant Pandey

  • Abstract

    Fifteen ordinary equations with boundary conditions have been solved with the help of Runge-Kutta Fehlberg’s method and compared with the exact values. It has been observed that the Runge-Kutta Fehlberg’s method is accurate up to 10 digits after the decimal point at some points. Average of maximum errors indicates that Runge-Kutta Fehlberg’s method is at least accurate up to two digits after the decimal point. Average of maximum percentage errors at each point has been found to be 0.07261551465131.

Estimation of solar power generation in some Nigerian cities using artificial neural network

Ashigwuike .C. Evans

  • Abstract

    This study introduces neural network technique for estimating solar (photovoltaic) power generation. It dealt with the construction and training of an Artificial Neural Network to estimate the solar power generated from photovoltaic systems based on latitude of PV site, day of the year, cell efficiency and area of solar array. It describes in some detail the important attribute that this technique has which makes it particularly well suited for solving problems where conventional methods have limitations. The major goal of this project therefore was to assess the suitability or otherwise of the feed forward neural network for the estimation of solar generated power of a small isolated water pumping and street lighting power systems using data obtained from field of operation of PV power systems. The neural network was simulated using Artificial Neural Network module in MATLAB

Dielectric constant and emissivity of dry and wet black soils at C-band microwave frequency<

Vidya D. Ahire , D. V. Ahire and P. R. Chaudhari

  • Abstract

    This study provides the experimental measurements of dielectric constant and dielectric loss of black soils having various percentages gravimetric Moisture Content (MC) at C-band microwave frequency, 5 GHz. Black soil samples were collected from the three different places located in north Maharashtra region (India). Measurements of complex dielectric constants of these soils have been carried out by using Waveguide cell method. We have used an automated C-band microwave set-up with PC-based slotted line control and data acquisition system. The dielectric constants and dielectric losses of these black soil samples are found increased with the corresponding increase in MC. Emissivity values are estimated by using emissivity model for vertical and horizontal polarizations show decrease with increase in MC / dielectric constant. Further, the data on the physical and chemical properties of these soils are also prov

Dielectric and emissive properties of tree leaves at X- Band microwave frequencies

D. V. Ahire, P. R. Chaudhari and Vidya D. Ahire

  • Abstract

    This study presents the experimental data of the measurements on complex dielectric constant of leaves from two tree species at X- band microwave frequencies (10.5 and 11.5 GHz). Leaves from two different tree species viz., Eucalyptus (Nilgiri) and Teak (Sag), have been used in these measurements. These measurements have been carried out by using Waveguide Cell Method. Initially, dielectric constants of freshly plucked leaves are measured. Then the gravimetric moisture content (wet basis) of the leaf sample was gradually reduced by drying it in a hot air oven at 50o to 60oC. Our results show that dielectric constant (ε') for the leaves of Eucalyptus lie over a range 1.25 to 6.0 when their gravimetric MC (%) (wet basis) changed from 0 % (oven dry) to around 70 % and for the leaves of Teak (Sag) lie over a range 1.29 to 5.4 when their gravimetric moisture content (wet basis) changed from 0 % to around 50

Influence of slip and jump boundary conditions on MHD oscillato

Rakesh Kumar

  • Abstract

    In the present paper, the effects of slip and jump boundary conditions on hydromagnetic oscillatory flow of an incompressible viscous fluid between two vertical parallel porous plates are investigated under the following conditions: (i) The fluid is electrically conducting (ii) Both the plates are subjected to the same constant injection and suction velocities respectively (iii) A magnetic field of uniform strength is applied in the direction normal to the plane of the plates (iv)The plates are kept at different temperatures which is high enough to induce the radiative heat transfer. By considering the fluid slip and temperature jump at the right plate of the channel, a closed form solution is obtained for the velocity and temperature profiles. The effects of the various parameters entering into the problem, on the velocity and the temperature are depicted graphically and on the skin friction is depicted in tabular

The characteristics, dielectric properties and surface morpholo

M.Abdul salim

  • Abstract

    Pure single crystals of calcium oxalate monohydrate were grown by gel technique using silica gel. Double diffusion technique is used for the growth of crystals. The powder X-ray diffraction pattern, FTIR spectrum and thermograms of grown crystals were recorded and analyzed. The crystal further subjected for the study of dielectric properties and surface morphology.

Effects of thickness on the structural and optical properties of thermally evaporated CdTe thin films

S.S.Patil   and P.H.Pawar

  • Abstract

    CdTe thin films of different thicknesses on glass substrates have been prepared by thermal evaporation technique at room temperature in vacuum (≈10-5Torr). The selected samples were annealed at 573 K for 30 min. in vacuum (≈10-5Torr).The X-ray diffraction (XRD) patterns of the annealed CdTe samples with five different thicknesses were recorded by X-ray diffractometer. The XRD patterns exhibits polycrystalline nature which suggests that these CdTe films are of zinc blende structure with a preferential orientation along the (111) plane of cubic phase. The degree of such a preferred orientation was found to increase with film thickness. The crystallite size (D), dislocation density (δ) and strain (ε) were calculated. The lattice parameter values obtained are a ≈ 6.47 Å and a ≈ 6.50 Å. The reflectance and transmittance spectra of these samples were recorded using double beam spectrophotometer in the spectral

Estimation of Errors in Newton’s Divided Difference Formu

V. P. Singh , Satish Kumar , R. B. Srivastava

  • Abstract

    We have taken three continuous functions sin-1 x, cos-1 x and tan-1 x defined in the interval [-1, 1] for polynomial interpolation and then obtained the polynomials equivalent to these functions with the help of Newton’s divided difference formula. We have also calculated the exact values of the functions and the values obtained by interpolating polynomials at equally spaced points of the interval. Errors from exact values have also been reported. Minimum percentage error in the interpolation of tan-1 x has been observed. The order of percentage errors in the interpolation of sin-1 x, cos-1 x and tan-1 x using Newton’s interpolation formula is tan-1 x < sin-1 x < cos-1 x.

Variation of dielectric constant of dry soils with their physic

P. R. Chaudhari, D. V. Ahire and Vidya D. Ahire

  • Abstract

    The objective of this paper was to study the variability of the dielectric constant of dry soils with their physical constituents and available nutrients. The soil samples were collected from 10 different locations of North Maharashtra region at the depth of 0 – 15 cm. The soils were found to be slightly alkaline, non-saline and moderately calcareous in nature. Soil samples were analyzed for physicochemical properties and for the status of available nutrients. The dielectric constant of dry soil samples was measured at C- band microwave frequency 4.5 GHz and its variations with physical constituents and nutrients of soil samples were presented. The results were analyzed statistically, which showed the strong significant correlation between dielectric constant and texture of the soil. Similarly significant correlation was observed between dielectric constant and available nutrients in the soil except nitrogen,

Magnetized bianchi type III anisotropic bulk viscous cosmological models with time dependent Λ and variable magnetic permeability

Gajendra Pal Singh, Atul Tyagi and Barkha Rani Tripathi

 

  • Abstract

    We have investigated bulk viscous Bianchi type-III cosmological models with time dependent cosmological term and variable magnetic permeability. To get deterministic model, we have assumed that F23 is the only non- vanishing component of electromagnetic field tensor. The coefficient of bulk viscosity is assume to be a simple power function of mass density (ζ=ζ0ρm). The physical and geometrical implications of models are also discussed.

Heat and Mass Transfer by Laminar Mixed Convection Flow from a Vertical Surface with Induced Magnetic Field and Convective Boundary

Anil Sharma and Komal Choudhary

  • Abstract

    The present paper deal with the heat and mass transfer by steady mixed convective flow from a vertical plate with induced magnetic field. The govering equation of motion and energy are solved analytically. The result in the form of graphs for velocity, temperature and concentration have been shown.