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Search Results: 1 - 10 of 14 matches for " BenSaid "
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Maio de 68: uma página na história mundial de lutas
Daniel Bensaid
Em Pauta : Teoria Social e Realidade Contemporanea , 2009,
Abstract:
First Determination of Source Parameters of Moderate Earthquakes (4.1 ≤ M ≤ 5.1) in Morocco from Spectral Analysis  [PDF]
Ihsane Bensaid, Lahcen Bahi, Fida Medina
Open Journal of Earthquake Research (OJER) , 2014, DOI: 10.4236/ojer.2014.32007
Abstract:

Recent installation of an array of broad band seismological stations in Morocco allowed us to study the records of five recent (2005-2008) moderate earthquakes (4.1 ≤ M ≤ 5.1) in order to determine their source parameters (seismic moment, fault slip, rupture area and stress drop) from P-wave spectra. We also studied the older Rissani events of 1992 using teleseismic data. Values of Mo, r, Δu and Δσ are, respectively, 1.1 × 1013 - 6 × 1016 Nm; 0.50 - 3.9 km; 0.8 - 5.8 cm and 0.3 - 1.49 MPa. The results are in accordance with the seismotectonic and geodynamic setting of Morocco as, for instance, the amount of slip along the faults with respect to the relative displacement of Nubia to Iberia (~4 mm·yr-1) determined from GPS data, taking into account the period of stress accumulation. However, some events show very variable corner frequency and low-frequency amplitude values which lead to considerably higher stress drop and fault slip values, especially at the nearest stations, which may reflect some site effects or uncertainties on depth and take-off angles.

First Principles Investigation of Ferromagnetism for Zn1-xMnxY(Y = S, Se, Te)
N. BenkhettouD. Bensaid
The Open Condensed Matter Physics Journal , 2008, DOI: 10.2174/1874186X00801010029]
Abstract: Through first-principles full-potential linear muffin-tin orbital (FP-LMTO) method within the local density approximation, we investigate the structural and electronic properties of Zn1-xMnx Y (VIa) where Y represent an element of the VIa column(S, Se and Te) compounds-based diluted magnetic semiconductors (DMS) in the Zinc-blend structure. We have investigated the lattice parameters and band gap energies. The lattice constants a are found to change linearly for the Zn1-xMnxTe and Zn1-xMnxS alloy.
Structural and Electronic Properties of Bixo3 (X = Mn, Fe, Cr)  [PDF]
Djillali Bensaid, Nour-Eddine Benkhettou, Ali Kourdassi
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.27075
Abstract: The candidate multiferroic BiCrO3 and its chemical neighbors BiMnO3 and BiFeO3 are known to be ferromagnetic and ferroelectric respectively. With structural distortions driven by the strongly polarizable Bi ions, we present results of the first-principles density functional calculations using the (FP-LMTO) method with the spin-orbit coupling for those materials in the pseudo-cubic perovskite phase. The results showed that the valence bands in these compounds are formed by the 6p orbitals of bismuth and 3d orbital’s of the transition metals. Our results indicate that these materials have metallic behavior for spin-up polarization but being a clear tandance for semiconductor spin-down BiMnO3.
On the evaluation of linear and non-linear models using DNS data of turbulent channel flows
BenSaid, Hasna;Mompean, Gilmar;Naji, Hassane;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2012, DOI: 10.1590/S1678-58782012000400007
Abstract: in this paper, a priori and a posteriori analyses of algebraic linear and non-linear models are carried out in order to compare their ability to predict near wall turbulent flows. tests were done using data from a direct numerical simulation (dns) of a plane channel flow for three reynolds numbers, based on the friction velocity, reτ = 180, reτ = 395 and reτ = 590 . these models include the linear standard k - ε model, the linear v2- f (manceau et al., 2002) and the non-linear model of shih (shih et al., 1995). the results obtained are then compared with the dns data of moser et al. (1999). the comparisons are shown for the mean velocity profile, components of the reynolds stress tensor, the turbulent kinetic energy (k), and the dissipation rate (ε). the results suggest that the v2 - f is an efficient model to capture the turbulent shear stress component of the reynolds stress near wall flows. however, it is unable to predict correctly the level of anisotropy between normal components of the reynolds stress tensor. furthermore, it is shown that the presence of non-linear terms in a turbulent model improves the ability to predict the anisotropy
Contribution a la modelisation et simulation numerique de l ecoulement du sang dans l artere
H . Alla,M. S. Gueblaoui,M. H. Bensaid
Physics , 2009,
Abstract: Numerous are the questionings raised by medicine interventionnelle, concerning the hold in charge of the pathologies of the arterial partition (aneurysm, dissection, coarctation, atherosclerosis).for it we made the modeling and the numeric simulation of the blood flow in the renal artery taken by the Medical imagery. Geometry has been rebuilt from the medical pictures of angiography, angioscanner and IRM. While considering that blood like a fluid Newtonian and stationary flow. The results gotten in terms of the physical parameters as the velocity, the dynamic pressure is shown that the simplest case was enough to collect relevant data for the development of stenos or thrombosis in the arteries.
Elimination of Active Trachoma after Two Topical Mass Treatments with Azithromycin 1.5% Eye Drops
Abdou Amza,Pablo Goldschmidt,Ellen Einterz,Pierre Huguet ,Celine Olmiere,Philippe Bensaid,Lucienne Bella-Assumpta
PLOS Neglected Tropical Diseases , 2010, DOI: 10.1371/journal.pntd.0000895
Abstract: Background Following an epidemiological study carried out in 2006 showing a high prevalence of blinding trachoma in the Far North Region of Cameroon, a trachoma elimination programme using the SAFE strategy was initiated: three yearly trachoma mass treatments were to be performed. Methodology/Principal Findings The entire district population (120,000 persons) was treated with azithromycin 1.5% eye drops in February 2008 and January 2009. To assess the effect of treatment on the prevalence of active trachoma, three epidemiological studies were conducted on a representative sample of children aged between 1 and 10 years. The first study was performed just prior to the first treatment, the second just prior to the 2nd treatment and the third one, one year later. The prevalence of active forms of trachoma (TF + TI) dropped from 31.5% (95%CI 26.4–37.5) before treatment to 6.3% (95%CI 4.1–9.6) one year after first treatment; a reduction of nearly 80%. One year after the second treatment, the prevalence decreased to 3.1% (95%CI 2.0–4.9), a total reduction of 90%. Furthermore, there were no more TI cases (only TF). There was no report of serious or systemic side effects. Tolerance was excellent. Conclusions/Significance Active trachoma mass treatment with azithromycin 1.5% eye drops is feasible, well tolerated, and effective.
Giant aneurysm of the right intra thoracic sub-clavian artery presenting as a dysphonia
A Mechchat, MM El Hammoumi, A EL Mesnaoui, B Lekehal, Y Bensaid
Pan African Medical Journal , 2011,
Abstract: Aneurysms of the intra-thoracic subclavian artery (SCA) are rare. They are often revealed by complications. Surgical treatment is always indicated. Endovascular treatment is a less invasive alternative. We report a case of a 60 years-old woman admitted for right chest pain and dysphonia. Laryngoscopy noted a right vocal cord palsy. Chest computed tomography and angiography showed a giant aneurysm of the intra-thoracic right SCA. A resection-ligation of the aneurysm was performed by a supra-clavicular approach. Postoperative course was uneventful. The histology defined an atherosclerotic aneurysm. The patient underwent voice reeducation with partial improvement after six months.
Band Gap Engineering of Alloys
Djillali Bensaid,Mohammed Ameri,Nadia Benseddik,Ali Mir,Nour Eddine Bouzouira,Fethi Benzoudji
International Journal of Metals , 2014, DOI: 10.1155/2014/286393
Abstract: The structural and electronic properties of the ternary alloys have been calculated using the full-potential linear muffin-tin-orbital (FP-LMTO) method based on density functional theory within local density approximation (LDA). The calculated equilibrium lattice constants and bulk moduli are compared with previous results. The concentration dependence of the electronic band structure and the direct and indirect band gaps are investigated. Moreover, the refractive index and the optical dielectric constant for are studied. The thermodynamic stability of the alloys of interest is investigated by means of the miscibility. This is the first quantitative theoretical prediction to investigate the effective masses, optical and thermodynamic properties for alloy, and still awaits experimental. 1. Introduction In recent years, the wide-gap II–VI compounds are widely investigated because of the attractive applications in fabricating blue-green and blue optoelectronic devices, such as light-emitting diodes and laser diodes [1–4]. The applications include the use of II–VI compound based materials as light sources, in full colour displays, and for increasing the information density in optical recording [5, 6]. The beryllium containing II–VI compounds had been found to possess an enhanced ability to significantly reduce the defect propagation due to a greater prevalence of strong covalent bonding and lattice hardening in the materials [7, 8]. The strong covalent bonding in beryllium-based II–VI compounds achieves a considerable lattice hardening, which avoids multiplication of defects during the operation of II–VI semiconductor laser devices [9, 10] alloys have attracted great attention because they are promising for the fabrication of full-colour visible optical devices due to a large difference in the energy gaps of the binary constituents (CdSe, ?eV; BeSe, ?eV) [11]. In the present theoretical work, band gap of zinc-blende CdSe is varied systematically by alloying with Be. In order to investigate the optoelectronic nature of these alloys, their structural, electronic, and optical properties are calculated. All calculations are based on density functional full-potential linear muffin-tin orbital (FP-LMTO) method with perdew-wang local density approximation (LDA). 2. Method of Calculations The calculations reported here were carried out using the ab initio full-potential linear muffin-tin orbital (FP-LMTO) method [12–15] as implemented in the Lmtart code [16]. The exchange and correlation potential was calculated using the local density approximation (LDA) [17]. The
A Vectorial modeling for the pentaphase Permanent Magnet Synchronous Machine based on multimachine approach
Abdelkrim Sellam,Boubakeur Dehiba,Mohamed B. Benabdallah,Mohamed Abid,Nacéra Bachir Bouiadjra,Boubakeur Bensaid,Mustapha Djouhri
International Journal of Advanced Computer Research , 2012,
Abstract: The polyphase [1] machines are developed mainly inthe field of variable speed drives of high powerbecause increasing the number of phases on the onehand allows to reduce the dimensions of thecomponents in power modulators energy and secondlyto improve the operating safety. By a vector approach(vector space), it is possible to find a set of singlephasemachine and / or two-phase fictitious equivalentto polyphase synchronous machine.These fictitiousmachines are coupled electrically and mechanicallybut decoupled magnetically. This approach leads tointroduce the concept of the equivalent machine(multimachine multiconverter system MMS) whichaims to analyze systems composed of mul tiplemachines (or multiple converters) in electric drives. Afirst classification multimachine multiconvertersystem follows naturally from MMS formalism. Wepresent an example of a synchronous machine pent
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