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Your search keyword '"El Ouatib, R."' showing total 9 results
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9 results on '"El Ouatib, R."'

2. Foreword

Author

El Bouari A., El Ouatib R., Hannache H., Krimi S., Lamire M., Mansouri I., Moussa R., and Aboulayt A.

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Published
2013
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3. Development of nano oxide αCoMoO4 by soft chemistry

Author

Lakhlifi H., El Ouatib R., Er-Rakho L., Durand B., and Guillemet-Fritsch S.

Subjects
Engineering (General). Civil engineering (General), TA1-2040
Abstract

Molybdates oxides as AMoO4 (A = Cu, Co), have remarkable properties. These properties depend strongly on the crystallite size. Nanostructured Powders of these molybdates make their applications more usable. The aim of our work is to synthesize oxide CoMoO4 by soft chemistry method, which has the advantage of producing very fine and homogeneous powders, which increases their reactivity. The products obtained were characterized by XRD, SEM and TEM.

Published
2013
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4. Structural and magnetic properties of layered perovskite manganite LaCaBiMn2O7

Author

Oubla, M., Lassri, H., Hlil, E.K., El Bouari, A., El Ouatib, R., Hannache, H., Krimi, S., Lamire, M., Mansouri, I., Moussa, Roger, Aboulayt, A., Magnétisme et Supraconductivité (MagSup), Institut Néel (NEEL), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire de Chimie des Matériaux Solides, Faculté des Sciences Ben M'sik [Casablanca], Université Hassan II [Casablanca] (UH2MC)-Université Hassan II [Casablanca] (UH2MC), Laboratoire d'Ingénierie et Matériaux [Casablanca] (LIMAT), Laboratoire de Physico-Chimie des Matériaux Inorganiques, Faculté des Sciences Aïn Chock [Casablanca] (FSAC), and Laboratoire de Physico-Chimie des Matériaux Inorganiques, Faculté des Sciences Aïn- Chock, Université Hassan II

Subjects
Materials science, Oxide, chemistry.chemical_element, Mineralogy, 02 engineering and technology, Manganese, chemistry.chemical_compound, Tetragonal crystal system, Condensed Matter::Materials Science, Spin wave, Condensed Matter::Superconductivity, ComputingMilieux_MISCELLANEOUS, Valence (chemistry), Condensed matter physics, 020502 materials, Exchange interaction, 021001 nanoscience & nanotechnology, Manganite, 0205 materials engineering, chemistry, Ferromagnetism, lcsh:TA1-2040, [PHYS.COND.CM-MS]Physics [physics]/Condensed Matter [cond-mat]/Materials Science [cond-mat.mtrl-sci], Condensed Matter::Strongly Correlated Electrons, 0210 nano-technology, lcsh:Engineering (General). Civil engineering (General)
Abstract

The layered perovskite oxide, LaCaBiMn 2 O 7 , has been prepared by the conventional aqueous solution precipitation method. The powder X-ray diffraction studies suggest that the phase crystallizes with tetragonal unit cell in the space group I4/mmm. The magnetic properties suggest that the ferromagnetic interactions are dominant and manganese ion in the phase is present in mixed valence states Mn 3+ and Mn 4+ . The thermomagnetization curve is found to obey the Bloch law. Spin wave stiffness constant D and the approximate value for J MnMn exchange interaction were estimated from the experimental results.

Published
2013

5. Multifunctional rare earth or bismuth oxide materials for catalytic or electrical applications

Author

Arab, Madjid, Gavarri, R., Bourja, L., Bakiz, B., Guinneton, F., Villain, Sylvie, Benlhachemi, A., Ezahri, M., El Bouari, A., El Ouatib, R., Hannache, H., Krimi, S., Lamire, M., Mansouri, I., Moussa, Roger, Aboulayt, A., Institut des Matériaux, de Microélectronique et des Nanosciences de Provence (IM2NP), Aix Marseille Université (AMU)-Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Chimie des Matériaux Solides, Faculté des Sciences Ben M'sik [Casablanca], Université Hassan II [Casablanca] (UH2MC)-Université Hassan II [Casablanca] (UH2MC), Laboratoire d'Ingénierie et Matériaux [Casablanca] (LIMAT), Laboratoire de Physico-Chimie des Matériaux Inorganiques, Faculté des Sciences Aïn Chock [Casablanca] (FSAC), Laboratoire de Physico-Chimie des Matériaux Inorganiques, Faculté des Sciences Aïn- Chock, Université Hassan II, Science du Sol - Montpellier, Institut National de la Recherche Agronomique (INRA), U.M.R. Science du Sol, and Université de Toulon (UTLN)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)

Subjects
Materials science, Oxide, chemistry.chemical_element, Nanotechnology, 02 engineering and technology, Conductivity, 7. Clean energy, Catalysis, Bismuth, Tetragonal crystal system, chemistry.chemical_compound, Ionic conductivity, Fourier transform infrared spectroscopy, ComputingMilieux_MISCELLANEOUS, 020502 materials, [CHIM.MATE]Chemical Sciences/Material chemistry, [CHIM.CATA]Chemical Sciences/Catalysis, 021001 nanoscience & nanotechnology, 0205 materials engineering, Chemical engineering, chemistry, 13. Climate action, lcsh:TA1-2040, Crystallite, 0210 nano-technology, lcsh:Engineering (General). Civil engineering (General)
Abstract

We present a review on catalytic or electrical properties of materials based on rare earth (RE) oxides (CeO2 ,L a2O3, Lu2O3) or bismuth based composite systems CeO2-Bi2O3, susceptible to be integrated into catalytic microsystems or gas sensors. The polycrystalline solids can be used as catalysts allowing conversion of CO or CH4 traces in air-gas flows. Fourier Transform infrared spectroscopy is used to determine the conversion rate of CO or CH4 into CO2 through the variations versus time and temperature of vibrational band intensities. The time dependent reactivities are interpreted in terms of an adapted Avrami model. In these catalytic analyses the nature of surfaces of polycrystalline solids seems to play a prominent role in catalytic efficiency. Electrical impedance spectroscopy allows analyzing the variation of conductivity of the system CeO2-Bi2O3. In this system, the specific high ionic conduction of a Bi2O3 tetragonal phase might be linked to the high catalytic activity.

Published
2013

9. Preparation of Cement Clinker from Geopolymer-Based Wastes.

Author

Hattaf R, Benchikhi M, Azzouzi A, El Ouatib R, Gomina M, Samdi A, and Moussa R

Abstract

In order to avoid potential environmental pollution from geopolymer-based material wastes, this work investigated the feasibility of using these materials as alternative raw materials in the preparation of cement clinker. The geopolymer binders and mortars were used as substitutes for natural mineral clays since they are rich in silica and alumina. Simulated geopolymer wastes were prepared by the activation of metakaolin or fly ash by an alkaline silicate solution. The cement-clinkers fired at 1450 °C for 1h were characterized by XRD, XRF, SEM-EDS, and a free lime (CaO f ) content test. The anhydrous clinker mineral phases C 3 S (Ca 3 SiO 5 ), C 2 S (Ca 2 SiO 4 ), C 3 A (Ca 3 Al 2 O 6 ), and C 4 AF (Ca 4 Al 2 Fe 2 O 10 ) were well-crystallized in all investigated formulations. The free lime was lower than 1.3 wt% in all elaborated clinkers, which indicates a high degree of clinkerization. The results demonstrate that geopolymer binder and mortar materials are suitable substitutes for natural mineral clay incement clinker preparation.

Published
2021
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