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University of Technology of Compiègne, France

Tawati D.M.,Universiti Sains Malaysia | Tawati D.M.,University of Malaya | Tawati D.M.,Garyounis University | Jamel Basha Adlan M.,Universiti Sains Malaysia | Abdullah M.J.,Universiti Sains Malaysia
Journal of Non-Crystalline Solids | Year: 2011

The dc conductivity of semiconducting cobalt-phosphate glasses has been measured at temperatures ranging from 213 to 530 K. Four bulk samples of CoO-P 2O 5 glasses of different compositions were produced by melting dry mixtures of analytical reagent grades of CoO and P 2O 5 at temperatures between 1200-1250 °C for 2 h using a press-quenching method from glass melt. Samples were annealed at 400 °C for 1 h. The dc conductivity was found to be dependent on the CoO content in the glass. At temperatures from 213 to 444 K, however, both Mott's variable-range hopping (VRH) and the Greaves' intermediate range hopping models are found to be applicable. VRH at this range of temperatures is attributed to large values of the disorder energy of these glasses. © 2011 Elsevier B.V. All rights reserved. Source


Jaeger J.,CNRS Institute of Paleoprimatology, Human Paleontoly: Evolution and Paleoenvironments | Marivaux L.,CNRS Institute of Paleoprimatology, Human Paleontoly: Evolution and Paleoenvironments | Salem M.,University of Tripoli | Bilal A.,Garyounis University | And 8 more authors.
Zoological Journal of the Linnean Society | Year: 2010

In this paper, we describe four fossil rodent taxa from two new localities situated in the Idam Unit ('Bioturbated Unit') of the Dur At-Talah escarpment in central Libya. These rodents belong to the family Phiomyidae (Hystricognathi) and are distributed amongst three genera (Phiomys, Protophiomys, and Talahphiomys gen. nov.) that include three new species (Phiomys hammudai sp. nov., Protophiomys durattalahensis sp. nov., and Talahphiomys libycus sp. nov.). Although some of these new species are morphologically close to certain phiomyids from the latest Eocene and Oligocene of the Jebel el-Qatrani Formation of the Fayum in Egypt, the Idam rodent faunas lack the abundant and somewhat morphologically derived Fayum phiomyids (such as: Metaphiomys, Gaudeamus, Paraphiomys, Phiocricetomys), thereby excluding a similar age for the Dur At-Talah rodent assemblages. More resemblance is shared with the phiomyid (Protophiomys algeriensis) of the Nementcha locality in Algeria, for which a late middle Eocene age is presently admitted. Protophiomys is a primitive representative of the phiomyid African radiation and it is represented at Dur At-Talah by a slightly more derived species (Pr. durattalahensis) than that of Nementcha, thereby suggesting a younger age for Dur At-Talah. As a result, the new rodent assemblages suggest a late middle Eocene age for the Idam ('Bioturbated') deposits of the Dur At-Talah escarpment. This age hypothesis is substantiated by other mammals (especially Proboscidea), which occur in the same sedimentological unit. Interestingly, the dental pattern of Protophiomys and that of Talahphiomys have somewhat stronger affinities with South Asian hystricognath baluchimyines than with Fayum phiomyids. It is clear that baluchimyines and phiomyids have a common ancestry, and that dispersal occurred between Asia and Africa during the middle of the Palaeogene. However, it is not clear if both groups can be strictly separated in two distinct natural groups inasmuch as some baluchimyines (e.g. Lophibaluchia, Bugtimys, Hodsahibia) appear to be phiomyid-like, and some early members of phiomyids (e.g. Protophiomys, Talahphiomys) are baluchimyine-like. South Asia and North Africa represent two centres of adaptive radiation of early hystricognathous rodents. The strong dental resemblances between early Asian and African forms are perhaps the result of subsequent convergent evolution after an initial dispersal from Asia. Otherwise, the systematics of these rodents has to be entirely revised, or we must consider that their historical biogeography is much more complex. © 2010 The Linnean Society of London. Source


Sharif S.A.I.,Garyounis University | El-Tajoury A.N.,Omar Al-Mukhtar University | Elamari A.A.,University of Benghazi
E-Journal of Chemistry | Year: 2011

The mixed ligand complexes of Co(II), Ni(II), Cu(II) and Cd(II) have been synthesized by using 1-phenylazo-2-naphthol as primary ligand and salicylaldehyde as secondary ligand. All the prepared complexes were identified and confirmed by elemental analyses (C, H and N), molar conductance measurements, infrared, electronic absorption and electron paramagnetic resonance. The elemental analysis data suggest that the stoichiometry of the complexes to be 1:1:1[M: L 1: L 2] ratio. The molar conductance measurements of the complexes indicate their non-electrolytic nature. The infrared spectral data showed the coordination sites of the free ligand with the central metal ion. The electronic absorption spectral data revealed the existence of an octahedral geometry for Co(II) and Cd(II) complexes and a square planar geometry for Ni(II) and Cu(II) complexes. The electron paramagnetic resonance spectra of the Co(II) and Cu(II) complexes showed the existence a paramagnetic phenomenon and supported their geometrical structures which confirmed by the electronic absorption spectra. The ligands and mixed ligand complexes have been tested on antibacterial activity against three strains of pathogenic bacteria such as Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa. Source


Elammari M.,Garyounis University | Issa Z.,Garyounis University
International Arab Journal of Information Technology | Year: 2013

In recent years, Multi-Agent Systems (MAS) had started gaining widespread acceptance in the field of information technology. This prompted many researchers to attempt to find ways to facilitate their development process, which typically includes building different models. The transformation of system specifications into models and their subsequent translation into code is often performed by relying on unstandardized methods, hindering adaptation to rapid changes in technology. Furhtermore, there is a big gap between the analysis, the design and the implementation in the methodologies of multi-agent systems development. On the other hand, we have seen that the top-down Model Driven Architecture (MDA) approach can be used to provide an efficient way to write specifications, develop applications and separation of business functions and application from the technical platform to be used. In this work, we propose using the MDA architecture for developing MAS. We demonstrate several different approaches, resulting in a variety of methods for developing MAS. This, in turn, increases the flexibility and ease of the development of MAS, and avoids any previously imposed restrictions. Source

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