Gasoline is a complex contamination agent, which may be originated from a variety of contamination sources. Sources may include, among others, leakage of underground fuel storage tanks in gas stations and large farms. Identifying and quantifying the soil and groundwater contaminations due to leakage from the underground gasoline tanks are of primary importance in providing better regulations to protect the environment. This subject has not received much of researchers' attention in the Gulf area which is recognized by its huge oil production industry.

Six-phase induction motor “IM” has advantages over three phase“3-”IM like lower harmonics, lower losses, improved reliability, higher torque per ampere, and higher power rating drive. However the control of such motors is more complex than that of the 3- ◻motors. The principles of direct torque control “DTC”, which is a well-known control method for 3-◻motors, can be utilized to overcome this complexity. This paper introduces the application of the DTC principles to 6-◻◻IMs drives. The whole 6-◻IM drive system is modeled and simulated in the stationary reference frame. However, it is noted from circuit analysis and Matlab simulations that the use of the conventional 6-◻inverter gives poor performance drive. This is due to the fact that with the conventional inverter only six switching states can give balanced output voltages instead of 64 switching states. This results in lower capability of control, less utilization of the DC supply, and more harmonic distortion as well. However to avoid this demerits, the authors have inferred that the use of a dual 3- inverter is the solution to be adapted. Simulation results of a DTC 6-◻IM drive show improved performance compared with the performance of the field orientation trials in the literature.

This paper presents a complete analysis of an induction generator linked to the power network through an ac voltage controller aiming to control the generated active and reactive power at different speeds. The ac voltage controller uses the extinction angle strategy to control the generator terminal voltage. The generator performance characteristics regarding the harmonic distortion factors, active power, reactive power, power factor, torque ripples and efficiency have been computed at different speeds. These characteristics have been determined with the help of a novel equivalent circuit in the frequency domain.

In this article, hard and soft digital cores have been developed for refining, shaping, counting and multi-channel analysing (MCA) of scintillation detector signals. These cores are implemented to apply the forward wavelet transform for signal decomposition and the back interpolation technique for the reconstruction phase. We aim to de-noise, compress and reconstruct these signals by which the processing speed and storage will be optimized. Moreover, the presented technique deliver all important features of the scintillation signals such as; counting, shaping, pulse height. Also, it performs multichannel analysing from the single channel analyzing results. The new contribution of our framework arises from employing the interpolation techniques to reconstruct the signal where the mother wavelet and details are neglected. Moreover, soft techniques have been applied to evaluate the performance of the nonlinear mother wavelets and interpolation methods. The hardware design is implemented using hardware description language (HDL) and is implemented practically on the FPGA. The performance of the design has been tested in simulation mode on Model Sim benchmark and in real time mode on XC2S 50 Spartan-II FPGA. The soft processing included in this article employs a special purpose digital filter to refine the nuclear pulses and to extract their important features.

A new method for obtaining a compact parametric general solution of a system of Boolean equations is presented. The method relies on the use of the variable-entered Karnaugh map (VEKM) to implement various steps of the solution procedure and to ensure minimization of the expressions obtained. It is highly efficient as it requires the construction of natural maps that are significantly smaller than those required by classical methods. Moreover, the method is applicable to general Boolean equations and is not restricted to the two- valued case. As an offshoot, the paper contributes some pictorial insight on the representation of “big” Boolean algebras and functions. It also predicts the correct number of particular solutions of a Boolean equation, and produces a comprehensive list of particular solutions, if desired. Details of the method are carefully explained and further demonstrated via an illustrative example.