National Center for Energy

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National Center for Energy

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Mounkachi O.,Institute for Nanomaterials and Nanotechnology | Salmani E.,Mohammed V University | Boujnah M.,Mohammed V University | Labrim H.,National Center for Energy | And 8 more authors.
Bulletin of Materials Science | Year: 2014

Structural and magnetic properties of Sn0.95Co 0.05O2 nanocrystalline and diluted magnetic semiconductors have been investigated. This sample has been synthesized by co-precipitation route. Study of magnetization hysteresis loop measurements infer that the sample of Sn0.95Co0.05O2 nanoparticle shows a well-defined hysteresis loop at 300 K temperature, which reflects its ferromagnetic behaviour. We confirmed the roomtemperature intrinsic ferromagnetic (FM) semiconductors by ab initio calculation, using the theory of the functional of density (DFT) by employing the method of Korringa-Kohn- Rostoker (KKR) as well as coherent potential approximation (CPA, explain the disorder effect) to systems. The ferromagnetic state energy was calculated and compared with the local-moment-disordered (LMD) state energy for local density approximation (LDA) and LDA-SIC approximation. Mechanism of hybridization and interaction between magnetic ions in Sn0.95Co0.05O 2 is also investigated. To explain the origin of ferromagnetic behaviour, we give information about total and atoms projected density of state functions. © Indian Academy of Sciences.


Bhihi M.,Mohammed V University | Lakhal M.,Mohammed V University | Labrim H.,National Center for Energy | Benyoussef A.,Mohammed V University | And 5 more authors.
Chinese Physics B | Year: 2012

In this work, the hydrogen storage properties of the Mg-based hydrides, i.e., Mg 1-x M x H 2 (M = Ti, V, Fe, 0 ≤ x ≤ 0.1), are studied using the Korringa - Kohn - Rostoker (KKR) calculation with the coherent potential approximation (CPA). In particular, the nature and concentrations of the alloying elements and their effects are studied. Moreover, the material's stability and hydrogen storage thermodynamic properties are discussed. In particular, we find that the stability and the temperature of desorption decrease without significantly affecting the storage capacities. © 2012 Chinese Physical Society and IOP Publishing Ltd.


Boujnah M.,Mohammed V University | Labrim H.,National Center for Energy | Allam K.,Laboratoire Of Chimie Des Materiaux Solides | Belhaj A.,National Center for Energy | And 6 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2013

Using the Korringa-Kohn-Rostoker Coherent Potential Approximation (KKR-CPA) method in connection with the Generalized Gradient Approximation (GGA), we study the magnetic and electronic properties of different point defects in cubic ZrO2. In particular, we discuss the zirconium interstitial (Zr i), zirconium antisite (ZrO), zirconium vacancy (V Zr), oxygen interstitial (Oi), oxygen antisite (O Zr), and oxygen vacancy (VO) defects. It has been shown that oxygen vacancy and zirconium interstitial (VO, Zri) are n-type, while the other point defects are p-type. The magnetic moments are observed only in the oxygen interstitial and antisite (Oi, O Zr) cases. The corresponding ferromagnetic states are more stable than the spin-glass states. It has been found that the mechanism responsible of such stabilities is the double exchange. Based on Mean Field Approximation (MFA), the Curie temperature (TC ) is estimated. Moreover, it has been found that the Oi and OZr defects provide half-metallic properties being the responsible for ferromagnetism. © 2012 Springer Science+Business Media New York.


Lakhal M.,Mohammed V University | Bhihi M.,Mohammed V University | Labrim H.,National Center for Energy | Benyoussef A.,Mohammed V University | And 10 more authors.
International Journal of Hydrogen Energy | Year: 2013

In this work, we propose a model to investigate the hydrogen storage ab/desorption kinetic properties for the pure MgH2 using Kinetic Monte Carlo (KMC) simulations. To do such computations, the activation energies for different elementary processes have been estimated. Moreover, the different thermodynamical quantities of interest are determined by performing the ab-initio calculations. Then, we discuss the hydrogen diffusion in magnesium hydride (such as adsorption, diffusion and desorption). More precisely, we study the effect of each elementary mechanism on the diffusion that we characterize through the density distribution of hydrogen atoms including filling ratios, diffusion time, temperature and pressure. Among others, we show that all elementary mechanisms are needed to reproduce a behavior of ab/desorption which correlates well with the experimental results reported in literature. In particular, at high temperature and pressure, the results of simulations indicate that the studied material involves slow kinetics. © Copyright © 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.


Mounkachi O.,Institute of Nanomaterials and Nanotechnology | Boujnah M.,Mohammed V University | Labrim H.,Institute of Nanomaterials and Nanotechnology | Hamedoun M.,Institute of Nanomaterials and Nanotechnology | And 8 more authors.
Journal of Superconductivity and Novel Magnetism | Year: 2012

Structural and magnetic properties of Zn 0.8(Fe 0.1, Co 0.1)O bulk diluted magnetic semiconductor have been investigated using X-ray diffraction (XRD) and magnetic measurements. TEM (Transmission Electron Microscopy) images confirmed the high crystallinity and grain size of Zn 0.8(Fe 0.1,Co 0.1)O powder, the samples were characterized by energy dispersive spectroscopy (EDS) to confirm the expected stoichiometry. This sample has been synthesized by co-precipitation route. The study of magnetization hysteresis loop measurements infers that the bulk sample of Zn 0.8(Fe 0.1,Co 0.1)O shows a well-defined hysteresis loop at Tc (200 K) temperature, which reflects its ferromagnetic behavior. Hydrogenation treatment was used for the control of phase separation. Based on first-principles spin-density functional calculations, using the Korringa-Kohn-Rostoker method (KKR) combined with the coherent potential approximation (CPA), the ferromagnetic state energy was calculated and compared with the local-moment-disordered (LMD) state energy. The mechanism of hybridization and interaction between magnetic ions in Zn 0.8(Fe 0.1,Co 0.1)O is also investigated. ©Springer Science+Business Media, LLC 2012.


Mounkachi O.,Institute of Nanomaterials and Nanotechnology | Lakhal M.,Mohammed V University | Labrim H.,National Center for Energy | Hamedoun M.,Institute of Nanomaterials and Nanotechnology | And 6 more authors.
Journal of Magnetism and Magnetic Materials | Year: 2012

The crystalline and magnetic properties of 5% Mn and 5% Ni co-doped nanocrystalline ZnO particles, obtained by the co-precipitation method, are performed. X-ray diffraction data revealed that Zn 0.90Mn 0.05Ni 0.05O crystallizes in the monophasic wurtzite structure. DC magnetization measurement showed that the samples are paramagnetic at room temperature. However, a large increase in the magnetization is observed below 50 K. This behavior, along with the negative value of Weiss constant obtained from the linear fit of magnetic susceptibility data below room temperature, indicates ferrimagnetic behavior. The ferrimagnetic properties observed at low temperature are explained and confirmed from ab-initio calculations using the KorringaKohnRostoker method combined with the coherent potential approximation. © 2012 Elsevier B.V. All rights reserved.


Gourai K.,Hassan II University | Allam K.,Hassan II University | El Bouari A.,Hassan II University | Belhorma B.,National Center for Energy | And 2 more authors.
Journal of Materials and Environmental Science | Year: 2015

AquaSolar-Maroc project focuses on brackish water desalination using solar energy. This project is funded by the Institute for Research in Solar Energy and New Energies (IRESEN), and involves both scientists and engineers from CNESTEN, Moulay Ismail and Hassan II Universities, and the "LSA-Industries" and "Tube et Profil" companies, and the Plataforma Solar de Almeria (PSA-Spain).The chosen technologies consist of a combination of reverse osmosis (RO) powered by photovoltaic (PV) panels and membrane distillation (MD) powered by solar thermal panels. This station therefore uses both the heat and the light emitted by the sun to produce on average 5m3 of drinking water per hour. The solar potential of Morocco is among the most higher in the world, with a peak of the global normal irradiance up to 1100W/m2 and an average of 2.8MWh/year. The solar field of the station is composed of 57 flat photovoltaic solar panels and 18 flat thermal solar panels, producing respectively 10kWe and 14kWth necessary to supply autonomously the whole station composed of the RO and MD processes as well as the accessories (air conditioning and lighting). Among the project work packages, we can cite: • Study of hydrological and climatic conditions of the site • Study of the technical performances of RO/PV and MD/thermal processes individually as well as their coupling • Study of perspective material for low cost water treatment This article gives an overview on the AquaSolar-Maroc project, and the main results on the hydrological and climatic conditions of the site.


El Khair M.M.,Hassan II University | El Khair M.M.,National Center for Energy | Ennaji M.M.,Hassan II University | El Kebbaj R.,Hassan II University | And 4 more authors.
Medical Oncology | Year: 2010

Human papillomavirus (HPV) has been implicated in cervical carcinoma and the p53 gene is polymorphic at amino acid 72 of the protein that it encodes. The association between p53 polymorphisms and risk for HPV-associated cervical cancer has been examined, but the results have been conflicting. It has been reported that patients with the arginine form have a higher risk of developing cervical cancer than those with the proline form. The purpose of this study was to examine whether p53 Arg at the polymorphic position 72 could represents a risk factor for women with high-risk HPV-associated malignant cervical lesions. In this study, the polymorphism was examined by both allele-specific PCR and RFLP analysis in 113 patients with cervical cancer and in 100 healthy controls. There was no statistical difference in the subtype distribution between the cervix cancer and the control groups. There was no significant association between genotype distribution of the p53 codon 72 polymorphism and HPV infection. Thus, polymorphism of the p53 itself as well as in combination with HPV infection may not be a genetic risk for cervical cancer and therefore much attention should be paid to other risk factors such as sexual behavior and smoking. © 2009 Humana Press Inc.


Boujnah M.,Mohammed V University | Zaari H.,Mohammed V University | Labrim H.,National Center for Energy | Benyoussef A.,Mohammed V University | And 3 more authors.
Journal of Applied Physics | Year: 2014

The electronic structure, magnetic, and optical properties in cubic crystalline phase of Zr1-xTMxO2 (TM=V, Mn, Fe, and Co) at x=6.25% are studied using density functional theory with the Generalized Gradient Approximation and the modified Becke-Johnson of the exchange-correlation energy and potential. In our calculations, the zirconia is a p-type semiconductor and has a large band gap. We evaluated the possibility of long-range magnetic order for transition metal ions substituting Zr. Our results show that ferromagnetism is the ground state in V, Mn, and Fe-doped ZrO2 and have a high value of energy in Mn-doped ZrO2. However, in Co-doped ZrO2, antiferromagnetic ordering is more stable than the ferromagnetic one. The exchange interaction mechanism has been discussed to explain the responsible of this stability. Moreover, it has been found that the V, Mn, and Fe transition metals provide half-metallic properties considered to be the leading cause, responsible for ferromagnetism. Furthermore, the optical absorption spectra in the TM -doped cubic ZrO2 are investigated. © 2014 AIP Publishing LLC.

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