for the university in Nouakchott see Lebanese International University for the university in Sana'a see Lebanese International University The Lebanese International University is a private university established by the philanthropist and former Lebanese defense and education minister Abdul Rahim Mourad. The language of instruction is English. Wikipedia.
Assi A.,Lebanese International University |
Al-Amin M.,Technology Group
Procedia Engineering | Year: 2012
Recently, efforts in improving the efficiency of monocrystalline silicon (c-Si) solar cells are focused on optimizing the emitter profile and the metallization which reduces the recombination losses, the contact resistances and improve the collection probability of carriers. The emitter recombination is reduced with decreasing the well passivated emitter thickness and lowering the doping concentration whereas it increases the metal-semiconductor contact resistance and thus reducing the fill factor (FF). In this paper, the metal-semiconductor ohmic contact formation, the emitter optimization, the co-relation with ohmic contact, and the optimum metallization pattern are investigated. The emitter saturation current density (Joe), the carrier life time (τeff), the internal quantum efficiency (IQE), the series resistance (Rs), the short circuit current (I sc), the open circuit voltage (Voc), the fill factor (FF) and the cell efficiency are analyzed for different emitter profiles and compared with the standard process. A batch of 156 pseudo mm square mono c-Si solar cells with average cell efficiency of17.5% is observed at 72-75 Ω/ sheet resistance. © 2012 Elsevier B.V.
Simon E.P.,Lille University of Science and Technology |
Ros L.,CNRS GIPSA Laboratory |
Hijazi H.,Lebanese International University |
Ghogho M.,University of Leeds
IEEE Transactions on Signal Processing | Year: 2012
In this paper, the problem of joint carrier frequency offset (CFO) and channel estimation for OFDM systems over the fast time-varying frequency-selective channel is explored within the framework of the expectation-maximization (EM) algorithm and parametric channel model. Assuming that the path delays are known, a novel iterative pilot-aided algorithm for joint estimation of the multipath Rayleigh channel complex gains (CG) and the carrier frequency offset (CFO) is introduced. Each CG time-variation, within one OFDM symbol, is approximated by a basis expansion model (BEM) representation. An autoregressive (AR) model is built to statistically characterize the variations of the BEM coefficients across the OFDM blocks. In addition to the algorithm, the derivation of the hybrid Cramér-Rao bound (HCRB) for CFO and CGs estimation in our context of very high mobility is provided. We show that the proposed EM has a lower computational complexity than the optimum maximum a posteriori estimator and yet incurs only an insignificant loss in performance. © 2011 IEEE.
Ros L.,CNRS GIPSA Laboratory |
Hijazi H.,Lebanese International University |
Simon E.-P.,Lille University of Science and Technology
Signal Processing | Year: 2014
This paper deals with multipath channel estimation for Orthogonal Frequency-Division Multiplexing systems under slow to moderate fading conditions. Most of the conventional methods exploit only the frequency-domain correlation by estimating the channel at pilot frequencies, and then interpolating the channel frequency response. More advanced algorithms exploit in addition the time-domain correlation, by employing Kalman filters based on the approximation of the time-varying channel. Adopting a parametric approach and assuming a primary acquisition of the path delays, channel estimators have to track the complex amplitudes of the paths. In this perspective, we propose a less complex algorithm than the Kalman methods, inspired by second-order Phase-Locked Loops. An error signal is created from the pilot-aided Least-Squares estimates of the complex amplitudes, and is integrated by the loop to carry out the final estimates. We derive closed-form expressions of the mean squared error of the algorithm and of the optimal loop coefficients versus the channel state, assuming a Rayleigh channel with Jakes' Doppler spectrum. The efficiency of our reduced complexity algorithm is demonstrated, with an asymptotic mean squared error lower than the first-order auto-regressive Kalman filters reported in the literature, and almost the same as a second-order Kalman-based algorithm. © 2013 Elsevier B.V.
Khaled M.,University of Nantes |
Khaled M.,Lebanese International University |
Khaled M.,PSA Peugeot Citroën |
Harambat F.,PSA Peugeot Citroën |
And 2 more authors.
Applied Energy | Year: 2011
The present paper reports a numerical investigation of spatial optimization of heat-exchanger by acting on its positioning in the vehicle's cooling module. This analysis also elucidates how to act on the different parameters influencing heat-exchanger performance in order to optimize their functioning. A two-dimensional computation code permits optimizing the performance of the cooling module by positioning different heat exchangers, in both the driving and stop phases of the vehicle. The ultimate aim is to apply new control approaches to real vehicles so as to reduce pump and compressor energy consumption and thus fuel consumption. Compared to a reference " in-series" configuration of the cooling module HXs (in which the different HXs are superposed in the airflow direction), an " in-parallel" configuration (in which the different HX surfaces are in a row with respect to the air flow direction) increases the thermal power of the HXs by 4.4% and decreases the pressure losses by 0.9%. © 2011 Elsevier Ltd.
Kassem H.,Lebanese International University |
Vigneras V.,Ecole Polytechnique - Palaiseau
2016 3rd International Conference on Advances in Computational Tools for Engineering Applications, ACTEA 2016 | Year: 2016
This paper introduces a new characterization method of measurement for the permittivity of dielectric material in thin films deposited on metallic/semiconductor substrate. The method uses the conformal mapping technique to extract the relative permittivity and loss tangent is a non-destructive way. After measuring the S-parameters of the material when placed on a coplanar transmission line, an inverse problem is applied to extract the dielectric constant. The permittivity measurement is done for thin film of 5 micrometer thickness. The obtained results are satisfying and encouraging and the method is validated using standard FEM simulation software. © 2016 IEEE.
Habchi C.,Lebanese International University |
Antar G.,American University of Beirut
Computers and Fluids | Year: 2015
We present direct numerical simulation results of a conducting fluid subject to the Lorentz force resulting from an external static magnetic field normal to the electric current direction. This research discipline, generally known as electromagnetic forcing flows, is motivated by many engineering and physical applications such as plasma physics, geophysics, weather prediction and solid melting processes. In this paper, a computational fluid dynamics (CFD) code is developed using the open source C++ library OpenFOAM. The solver is based on the electric potential method coupled to the Navier-Stokes equations. The code is then benchmarked to other well-known solvers using different numerical techniques and to the experiment. Excellent agreement is obtained for the forced toroidal channel flow, with three-dimensional dynamics, as well as for the confined vortex-pair in a cylindrical container, with quasi-two-dimensional dynamics. Quasi-two-dimensional forced flow in the presence of non-uniform magnetic field at low Hartmann number is also used for comparison. Furthermore, qualitative comparison with the experiment is made where we are able to successfully simulate the vortex pairs generated by the Lorentz force and the effect of the magnetic field gradient leading to the so-called gradB jets in accordance with the experiment. © 2015 Elsevier Ltd.
Fino A.Z.,Lebanese University |
Fino A.Z.,Lebanese International University |
Ibrahim H.,Lebanese University |
Ibrahim H.,Lebanese International University
Mathematical Methods in the Applied Sciences | Year: 2013
In this paper, we consider a nonhomogeneous space-time fractional telegraph equation defined in a bounded space domain, which is obtained from the standard telegraph equation by replacing the first-order or second-order time derivative by the Caputo fractional derivative Dtα, α > 0 and the Laplacian operator by the fractional Laplacian (- Δ)β2, β ∈ (0,2]. We discuss and derive the analytical solutions under nonhomogeneous Dirichlet and Neumann boundary conditions by using the method of separation of variables. The obtained solutions are expressed through multivariate Mittag-Leffler type functions. Special cases of solutions are also discussed. Copyright © 2013 John Wiley & Sons, Ltd. Copyright © 2013 John Wiley & Sons, Ltd.
Khaled M.,Lebanese International University |
Khaled M.,University Paris Diderot |
Ramadan M.,Lebanese International University |
Hage H.E.,Lebanese International University
Energy Procedia | Year: 2015
The present work considers parametric analyses that examine the attempts of capturing heat from the exhaust gas of 500-kVA power generator. The heat capturing is performed through the use of counter flow concentric tube heat exchanger. The captured heat is utilized to heat water. Therefore, various geometrical configurations of heat exchangers are considered and supplied to heat transfer equations. Two flow-patterns are considered, flow-pattern I where the exhaust gas is streamed in the inner tube while the water is flowing in the annulus, and flow-pattern II where exhaust gas is streamed in the annulus while the water is flowing in the inner tube. The appropriate heat transfer modeling is briefly presented. It was found that the most efficient geometrical configuration is found in flow-pattern II, where water flows in the inner tube with an inner to outer diameter ratio of 0.75. The corresponding captured average heat rate of the aforementioned case is 26 kW. © 2015 The Authors. Published by Elsevier Ltd.
Abood E.A.,Lebanese International University |
Wazaify M.,University of Jordan
Substance Use and Misuse | Year: 2016
Background: The abuse and misuse of prescription and nonprescription or the so-called Over–The–Counter (OTC) drugs is a serious and growing public health problem worldwide. The increased availability of these drugs has contributed to a dramatic rise of inappropriate use. Objectives: The aim of this study was to investigate abuse/misuse of prescription and non-prescription drugs in community pharmacies in Aden city—Yemen and to gather information about suspected drug abusers in the community. Methods: A cross-sectional survey using a structured questionnaire randomly distributed to 200 community pharmacies (June–September 2013). Data were coded and analyzed using SPSS Results: A total of 170 pharmacists completed the questionnaire (85.0% response rate), more than half of which (57.7%) suspected drug abuse/misuse in their pharmacies. The top four suspected medications of abuse were Alprazolam, Ketoprofen, Tramadol, and antibiotics. Most participating pharmacists in this study (83.3%) noticed an increasing pattern of abuse/misuse. The majority of suspects of prescription and non-prescription drug abuse (64.1%) were either chewing Khat or carrying it while buying the drug from the pharmacists. Conclusion: Abuse/misuse of prescription and nonprescription drugs is present in community pharmacies in Aden and it is linked to the recreational use of Khat. Current methods for controlling the problem are ineffective, and better methods should be developed. © 2016, © Taylor & Francis.
Elattar E.E.,Lebanese International University
IEEE PES Innovative Smart Grid Technologies Conference Europe | Year: 2011
Wind power prediction is one of the most critical aspects in wind power integration and operation. This paper presents a new approach to a wind power prediction by combining support vector regression (SVR) with a local prediction framework which employs the correlation dimension and mutual information methods used in time-series analysis for data preprocessing. Local prediction makes use of similar historical data patterns in the reconstructed space to train the regression algorithm. To build an effective local SVR method, the parameters of SVR must be selected carefully. Therefore, a new method is proposed in this paper. The proposed method which known as genetic algorithm (GA)-Local SVR searches for SVR's optimal parameters using real value GA. These optimal parameters are then used to construct the local SVR algorithm. The performance of the proposed method (GA-Local SVR) is evaluated with the real world wind power data from England and is compared with the seasonal auto regressive integrated moving average (SARIMA) method and radial basis function (RBF) network. The results show that the proposed method provides a much better prediction performance in comparison with other methods employing the same data. © 2011 IEEE.