Boughrara K.,University of Khemis Miliana |
Ibtiouen R.,Polytechnic School of Algiers |
Lubin T.,CNRS Research Group in Electrotechnics and Electronics of Nancy
IEEE Transactions on Magnetics | Year: 2012
This paper presents an analytical method based on subdomain method for the computation of open circuit, armature reaction, and on-load magnetic field distribution in integer slot winding parallel double excitation and spoke-type tangential permanent-magnet machines. The proposed model takes into account for stator and rotor slots tooth tips and shape of polar piece. A 2-D exact analytical solution of magnetic field distribution is established. It involves solution of Laplace's and Poisson's equations in semi-closed stator and rotor slots, air-gap, buried permanent magnets into rotor semi-closed slots, and nonmagnetic region under magnets. Obtained exact analytical results of open circuit, armature reaction, and on-load magnetic field distribution are verified with those issued from the finite element method. © 2012 IEEE.
Hemis M.,University of Khemis Miliana |
Raghavan G.S.V.,McGill University
Drying Technology | Year: 2014
The heat and mass transfer that occurred during drying of soybeans by a combined process using microwave (MW) and convective hot air was studied. A coupled mathematical model was developed to simulate this phenomenon. The soybean samples were re-wetted to 20% wet basis, the selected level of initial moisture content (IMC), and then dried in a domestic microwave oven under various MW power levels from 300 to 390 W, using inlet air with relative humidity of 35, 55, 75, and 95%. The simulated moisture loss profiles obtained from the coupled model compared well with those obtained in the experiments. Results showed that the drying rate decreased from 6.235 × 10-5 to 6.192 × 10-5 kg water/(kg wb s) as the inlet air temperature increased from 30 to 60°C. Furthermore, the drying rate was observed to increase from 6.192 × 10-5 to 6.211 × 10-5 kg water/(kg wb s) as the relative humidity (RH) increased from 35 to 95%. © 2014 Taylor & Francis Group, LLC.
Hachama M.,University of Khemis Miliana |
Desolneux A.,Ecole Normale Superieure de Cachan |
Richard F.J.P.,CNRS Laboratory of Analysis, Topology, Probabilities
IEEE Transactions on Image Processing | Year: 2012
In this paper, we address a complex image registration issue arising while the dependencies between intensities of images to be registered are not spatially homogeneous. Such a situation is frequently encountered in medical imaging when a pathology present in one of the images modifies locally intensity dependencies observed on normal tissues. Usual image registration models, which are based on a single global intensity similarity criterion, fail to register such images, as they are blind to local deviations of intensity dependencies. Such a limitation is also encountered in contrast-enhanced images where there exist multiple pixel classes having different properties of contrast agent absorption. In this paper, we propose a new model in which the similarity criterion is adapted locally to images by classification of image intensity dependencies. Defined in a Bayesian framework, the similarity criterion is a mixture of probability distributions describing dependencies on two classes. The model also includes a class map which locates pixels of the two classes and weighs the two mixture components. The registration problem is formulated both as an energy minimization problem and as a maximum a posteriori estimation problem. It is solved using a gradient descent algorithm. In the problem formulation and resolution, the image deformation and the class map are estimated simultaneously, leading to an original combination of registration and classification that we call image classifying registration. Whenever sufficient information about class location is available in applications, the registration can also be performed on its own by fixing a given class map. Finally, we illustrate the interest of our model on two real applications from medical imaging: template-based segmentation of contrast-enhanced images and lesion detection in mammograms. We also conduct an evaluation of our model on simulated medical data and show its ability to take into account spatial variations of intensity dependencies while keeping a good registration accuracy. © 1992-2012 IEEE.
Abderezzak B.,University of Hassiba Ben Bouali Chlef |
Khelidj B.,University of Khemis Miliana |
Tahar Abbes M.,University of Hassiba Ben Bouali Chlef
International Journal of Hydrogen Energy | Year: 2014
Hydrogen is an energy carrier that can be used in industry, residences, transportation, and mobile applications. One of the main attractions for hydrogen is the environmental advantage over fossil fuels. However, Polymer Electrolyte Membrane Fuel Cells, (PEMFC), is an integral part of the future hydrogen economy, they are highly efficient and a low-polluting technology. Numerous applications exist; one of the promising applications is the automotive industry. For this report a comprehensive literature survey is conducted. The findings of the literature survey include hydrogen production and fuel cell models that fit into two broad categories, that is, analytical and empirical. This work is a presentation of our original research and development regarding the production and utilization of a solar hydrogen and its use in a PEM single cell. In order to facilitate the understanding of the charge transfer phenomena in the PEM single cell, a modeling tool with visual basic was developed. All the experiences and results were illustrated in this work. Copyright © 2013, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.
Chetti B.,University of Khemis Miliana
Industrial Lubrication and Tribology | Year: 2016
Purpose: This paper presents an analysis of the static characteristics of two-lobe journal bearings lubricated with couple stress fluids operating in a turbulent regime. The modified Reynolds equation for a couple stress fluids taking into consideration the effect of turbulence is solved using finite difference method. The load-carrying capacity, attitude angle, friction coefficient and side leakage are determined for various values of the couple stress parameter and Reynolds number. It is found that the couple stress fluids affect significantly on the performance of a two-lobe journal bearing in laminar and turbulent regime. Design/methodology/approach: The modified Reynolds equation for a couple stress fluids taking into consideration the effect of turbulence is solved using finite difference method. Findings: It is found that the couple stress fluids affect significantly on the performance of a two-lobe journal bearing in laminar and turbulent regime. Originality/value: A couple stress fluid is used for lubrication of a two-lobe journal bearing in turbulent regime and laminar. © Emerald Group Publishing Limited.
Bouderbala A.,University of Khemis Miliana
Environmental Earth Sciences | Year: 2015
The groundwater of Nador plain has been overexploited during the last two decades. The goal was to meet the demands of intensive agricultural activities and at the same time the supply of drinking water. As a result, the dynamic balance between freshwater and seawater has been disturbed and the quality of the groundwater has deteriorated. The degradation of the groundwater quality is characterized by salinization phenomena. In this project, the analysis of the piezometric map indicates a piezometric water level of 0 m inside the plain. The chemical analysis of major ions in the groundwater was carried out on the water samples of 24 wells: it indicates an electrical conductivity of water exceeding 1,500 µS/cm, and chloride concentrations exceeding 500 mg/L in the downstream of the plain. Presently, the groundwater in this coastal sector is used neither for drinking water nor for irrigation. In this study, 35 vertical electrical soundings (VES) were carried out in the area, with geoelectrical sections and maps of iso-resistivity created to delineate the zones that are affected by saltwater intrusion. The findings suggest that saltwater intrusion has reached a distance of approximately 1,600 m inside the aquifer. © 2014, Springer-Verlag Berlin Heidelberg.
Diaf A.,University of Khemis Miliana
Journal of Physics: Conference Series | Year: 2014
The bound state solutions of the Feynman propagator with the rotating Deng- Fan molecular potential are presented approximately. An approximation of the centrifugal potential is used and nonlinear space-time transformations are applied. A relation between the original path integral and the Green function of a new quantum soluble system is derived. The energy spectrum and the normalized eigenfunctions are both obtained for the application of this technique to the Deng-Fan molecular potential. Our results are in very good agreement with those found by using numerical and other methods. © Published under licence by IOP Publishing Ltd.
Hemis M.,University of Khemis Miliana |
Choudhary R.,Southern Illinois University Carbondale |
Watson D.G.,Southern Illinois University Carbondale
Biosystems Engineering | Year: 2012
Faster drying techniques are preferred to prevent spoilage of harvested wheat seeds. Microwave (MW) drying may be used as an alternate technique for faster drying of crops with efficient utilisation of time and energy. The objective of this study was to develop a mathematical model to simulate the drying condition of wheat seeds during drying in a MW oven. A coupled mathematical model was developed for simultaneous MW and convective drying of wheat seeds in a domestic MW oven, resulting in a system of non-linear equations. Wheat samples with initial moisture levels of 15-25% wet basis were dried under MW power ranging from 245 to 910. W for 3. min. The temperature and the relative humidity of drying air was 23. °C and 27%, respectively. The results revealed that the rate of drying increased with increase in the initial moisture content of wheat seeds. The germination percentage of wheat seeds decreased with the increase of the MW power at each initial moisture content. The predicted temperature of grain during drying with the MW power at 910. W was within the range of 65-70. °C. The experimental results of moisture content of wheat seeds undergoing MW drying were in good agreement with the moisture content of wheat seeds predicted by the coupled mathematical model. © 2012 IAgrE.
Diaf A.,University of Khemis Miliana
Chinese Physics B | Year: 2015
We obtain analytical expressions for the energy eigenvalues of both the Schiöberg and Eckart potentials using an approximation of the centrifugal term. In order to determine the ℓ-states solutions, we use the Feynman path integral approach to quantum mechanics. We show that by performing nonlinear space-time transformations in the radial path integral, we can derive a transformation formula that relates the original path integral to the Green function of a new quantum solvable system. The explicit expression of bound state energy is obtained and the associated eigenfunctions are given in terms of hypergeometric functions. We show that the Eckart potential can be derived from the Schiöberg potential. The obtained results are compared to those produced by other methods and are found to be consistent. © 2015 Chinese Physical Society and IOP Publishing Ltd.
Kali A.,University of Khemis Miliana
Canadian Journal of Forest Research | Year: 2016
In forest firefighting, the longer the fires wait, the larger they grow and the longer they take to control. This study concerns the optimal deployment of single forest suppression processor of initial attack in the case of fires ignited simultaneously. The aim is to minimize the total damage caused by the fires to the burnt areas when all fires are suppressed. In Rachaniotis and Pappis (Can. J. For. Res. 36: 652-658, 2006), they use the concept of start-time dependent job processing times for modelling the time needed for fire suppression. The model is intricate but interesting in the sense that is based on theoretical and empirical research in the field of forest firefighting. As a continuation, a stochastic formulation that includes unpredicted parameters in the proposed model is considered and the “dynamic allocation index” rule is used to solve the problem. The optimality of this rule and its effectiveness are proven. Experimental results depict the framework, and inside it, the forest suppression processor achieves greater efficiency. © 2016 National Research Council of Canada, All rights reserved.