International Journal of
Physical Sciences

  • Abbreviation: Int. J. Phys. Sci.
  • Language: English
  • ISSN: 1992-1950
  • DOI: 10.5897/IJPS
  • Start Year: 2006
  • Published Articles: 2572

Table of Content: 2 December, 2011; 6(32)

December 2011

Distortion modeling of feedback single stage amplifier

  In this paper, the distortion of feedback single stage amplifier is modeled. The phasor method was exploited to obtain the distortion factor expressions of the feedback amplifier. All the nonlinearities, including intermodulation nonlinearity, are considered in the paper. The derivation is simple and easy to understand. These equations provide deep insights into the distortion modeling of the feedback...

Author(s): Yingwu Miao and Yuxing Zhang

December 2011

Anti-synchronization of chaotic system using adaptive modified function projective method with unknown parameters

  In this paper, a new type of anti-synchronization called adaptive modified function projective anti- synchronization was presented. In this study, state variables of drive system would be anti-synchronized with state variables of response system up to desired scale function matrix. The adaptive control law and the parameter updates were determined to make the states of two Lorenz systems modified function...

Author(s): Mahdieh Adeli, Atefeh Saedian and Hassan Zarabadipour

December 2011

Interaction of DNA and polyethylenimine: Fourier-transform infrared (FTIR) and differential scanning calorimetry (DSC) studies

  Polyplexes, which are formed spontaneously between cationic polymer and negatively charged nucleic acids, are commonly used for gene and oligonucleotide delivery in vitroand in vivo. Many kinds of cationic polymers have been used to condense DNA by electrostatic interaction into small particles (Polyplexes), for protecting the DNA from degradation and enhancing its uptake via...

Author(s): Mohsen M. Mady, Wael A. Mohammed, Nadia M. El-Guendy and Anwar A. Elsayed

December 2011

Measuring radioactivity level in various types of rice using hyper pure germanium (HPGe) detector

  The radioisotopes and nuclear explosions in upper layers of the atmosphere have vigorously polluted the earth. These radionuclides can be transferred to humans through the food chain. Rice is important and a major source of carbohydrates for humans. Soil contains the natural radionuclide such as Uranium, Thorium and Potassium. A study was conducted to determine the radionuclide content and their level of...

Author(s): M. A. Saeed, N. A. A.  Wahab, I. Hossain, R. Ahmed, H.Y. Abdullah, A. T. Ramli and Bashir Ahmed Tahir

December 2011

Leakage power reduction techniques of 45 nm static random access memory (SRAM) cells

  As the technology scales down to 90 nm and below, static random access memory (SRAM) standby leakage power is becoming one of the most critical concerns for low power applications. In this article, we review three major leakage current components of SRAM cells and also discuss some of the leakage current reduction techniques including body biasing, source biasing, dynamic VDD, negative word line, and bit...

Author(s): Manish Dev Singh, Shyam Akashe and Sanjay Sharma

December 2011

Simulation of a transmission system to compensate dispersion in an optical fiber by chirp gratings

  Fiber Bragg Grating (FBG) is one of the applicable and important components in optical communication system, and it first emerged in 1980. In this article, the application of chirped FBG was studied as a dispersion compensator in optical communication systems. By simulating a model of communication system and finding the best amounts of parameters, we investigated the effect of this component in data...

Author(s): S. O. Mohammadi, Saeed Mozaffari and M. Mahdi Shahidi

December 2011

Space-time block-coded systems using numeric variable forgetting factor least squares channel estimator

  In this correspondence, the bit-error-rate (BER) performance evaluation of the space-time block-coded (STBC) communication systems using the numeric-variable-forgetting-factor (NVFF) least-squares (LS) channel estimator is presented. The polynomial channel paradigm is incorporated in LS algorithm in conjunction with NVFF to improve the channel tracking performance under the nonstationary wireless environment....

Author(s): Amit Grover and Amit Kumar Kohli

December 2011

A new operational matrix for Legendre wavelets and its applications for solving fractional order boundary values problems

  In this article, we generalize the Legendre wavelets operational matrix of derivatives to fractional order derivatives in the Caputo sense. Legendre wavelets and their properties are employed for deriving Legendre wavelets operational matrix of fractional derivatives and a general procedure for forming this matrix is introduced. Then truncated Legendre wavelets expansions together with these matrices are used...

Author(s): F. Mohammadi, M. M. Hosseini and Syed Tauseef Mohyud-Din

December 2011

Daily water level forecasting using adaptive neuro-fuzzy interface system with different scenarios: Klang Gate, Malaysia

  Forecasting the level of reservoir has been a significant subject in the management of reservoirs and water resource. For many years, estimation of reservoir water level was primary based on operator’s experience, curves and mathematical models. Recently, Artificial Intelligence (AI) methods are developed in several hydrological aspects, such as classification and forecasting parameters. The major...

Author(s): N. Valizadeh, A. El-Shafie, M. Mukhlisin and A. H. El-Shafie

December 2011

Analysis of hydrological processes of Langat River sub basins at Lui and Dengkil

  Land use changes have seriously impacted the hydrological regimes. This study considered both the upstream and downstream areas of Langat River namely the Lui and Dengkil sub basins, respectively. The important parameters selected for the study were river flowrate, precipitation distribution, and the baseflow (BF) estimation. For the Lui sub basin, the daily flowrate data obtained...

Author(s): Hai Hwee Yang, Othman Jaafar, El-Shafie A. and Sharifah Mastura S. A.

December 2011

Soil organic matter and related soil properties in forest, grassland and cultivated land use types

  The pattern of soil organic carbon storage is influenced by land use and landscape topo-sequence. The variations in soil carbon and land use also impact soil properties, such as bulk density, pH and soil water. The aim of this study was to determine the effects of selected land uses (forest, grassland and cropland) located in Universiti Malaysia Sabah Campus and soil depth on the soil organic matter, soil...

Author(s): Yeoh Chooi Keen, Mohamadu Boyie Jalloh, Osumanu Haruna Ahmed, Mahmud Sudin and Normah Awang Besar