MOHAMED Benhamida

BENHAMIDA Riadh

Etude des propriétés électroniques et magnétiques de Mn2RuGa

SAGHIEUR Messaoud

Propriétés optiques des oxo-borate des terres rares

ZAKAD Khalida

Study of the structural and electronic properties of tungsten nitride (WN), in the NaCl and NbO phase

BOUGUERRA Rima

Ab initio study of the structural and electronic properties of titanium nitride (TiN)

HASNI Faiza

Ab initio study of the structural and electronic properties of tantalum nitride (TaN)

ZELLOUF Moufida

Optical radiation detector

Bio-based composites are outstanding materials to replace many synthetic fiber-based composites due to their biodegradability and sustainable environmental properties. This research aims to characterize and analysis a new cellulosic fibers extracted from Echinops spinosissimus plant stem, to study their integration in the field of various industries such as composites and textiles. Thus, adding and incorporating a new natural fiber to the list of fibers that enter into the production of Bio-based composites materials, and meet the needs of the market that knows a shortage of these materials. In addition, the extracted fibers from Echinops spinosissimus plant, which is abundant and have acceptable properties that can replace the synthetic fibers. The stem anatomy results showed a strong presence of fiber cells, fiber SEM micrographs showed that fiber surface become rough, these fibers have a density of 0.97 ± 0.01 g/cm3, and diameter 280.76 μm. FTIR and XRD showed that these fibers are cellulosic. Thermal analysis revealed that Echinops spinosissimus fiber have a thermal stability of 208°C. Tensile strength, Young modulus and strain at failure were found as 217.54 ± 54.16 MPa, 19.23 ± 0.76 GPa and 3.78 ± 0.36%, respectively. SEM showed that the studied fiber becomes more roughness in the outer surface following the chemical treatments, thus contributing to better adhesion with resin. This work confirmed that Echinops spinosissimus fibers are suitable materials for use in textile and biocomposite applications.

Citation

sidali ZERNADJI , MOHAMED Benhamida , MANSOUR Rokbi , , (2023-10-25), Extraction and characterization of novel natural cellulosic fiber from Echinops spinosissimus plant stem, Journal of Composite Materials, Vol:57, Issue:29, pages:4503-4519, sage journal

Talking about lightweight composite materials reinforced with natural plant cellulosic fibers is a topic of the hour; this is due to the characteristics of these materials such as low cost, non-toxicity and most importantly, their mechanical performances. This is what prompted scientists to search for new materials and include them in various fields such as industry, medicine, and others. In this research paper, a chemical treatment was carried out by pretreated the Coir fibers in a solution of Alkaline (NaOH) with a ratio of 3% for a period of 4 hours, then immersed in permanganate solution with a ratio of 0.066 % for 3 minutes. To use these fibers as a reinforcing material in the Unsatured Venylester (UV) resin, to obtain a composite material, after that the samples are prepared to conduct mechanical tensile tests according to the ASTM D3322-01 Standard applied on 30 samples tests to obtain the average values of tensile properties (Tensile strength, young’s modulus and strain at failure). The results showed an improvement in the mechanical properties that would raise the efficiency and performance of the composite material, and this is due to the improvement of the properties of the Coir fibers after the chemical treatment with Permanganate. Which is largely consistent with the results of previous research.

Citation

sidali ZERNADJI , MOHAMED Benhamida , MANSOUR Rokbi , ,(2023-02-21), Mechanical properties of Unsatured Venylester biocomposites reinforced by Coir fibers chemically treated with permanganate solution,1st International Conference on Frontiers in Academic Research,Konya/Turkey

In the last few years, several techniques for separate determination of adhesion and friction in micromechanical tests have been developed but their experimental realization is rather complicated, because they require an accurate value of the external load at the moment of the crack initiation. So, in this perspective, an effort is done to estimate the interfacial parameters between two kind of thermoset resins and the natural Alfa fiber determined from Microbond tests. As known, the diameter of natural fiber is a crucial factor that participates in the estimation of the interfacial adhesion characteristics. In others words, the measurement of the maximum force required to pull out a fiber from the polymeric resins is investigated by using the micro-droplet test.

Citation

sidali ZERNADJI , MANSOUR Rokbi , MOHAMED Benhamida , , (2022-01-08), Estimation of fiber/polymer bond strength from maximum load values recorded in the micro-bond tests, Materials Today: Proceedings, Vol:53, Issue:2022, pages:247–252, Science Direct, Elsevier

In the last few years, several techniques for separate determination of adhesion and friction in micromechanical tests have been developed but their experimental realization is rather complicated, because they require an accurate value of the external load at the moment of the crack initiation. So, in this perspective, an effort is done to estimate the interfacial parameters between two kind of thermoset resins and the natural Alfa fiber determined from Microbond tests. As known, the diameter of natural fiber is a crucial factor that participates in the estimation of the interfacial adhesion characteristics. In others words, the measurement of the maximum force required to pull out a fiber from the polymeric resins is investigated by using the micro-droplet test.

Citation

MOHAMED Benhamida , MANSOUR Rokbi , , (2022), Estimation of fiber/polymer bond strength from maximum load values recorded in the micro-bond tests, Materials Today: Proceedings, Vol:53, Issue:1, pages:247-252, Materials Today

Based on ab-initio calculations, we have investigated the structural, electronic, and magnetic properties of diluted magnetic semiconductors with (K, Mn) substitution in the parent compounds, BaFZnAs and BaFMnAs. The coexistence of two types of magnetic exchange coupling interactions was detected via the calculation of the distance-resolved and the individual exchange parameters , where runs over the th nearest neighbor atom () of the reference one distanced by . The short-range interactions (SRI), at and , are strongly influenced by hole doping and substitutional disorder of both hole and spin co-doping. The long-range interaction (LRI), at distances beyond the , of a ferromagnetic nature, is less sensitive to hole doping, although these holes are the reason for their appearance. The results analysis showed that the dependence of the LRI on doping ratio, in the co-doping system, is more systematic than on the or doping separately. In (BaK)F(ZnMn)As system, a peak appears in the LRI at around 1.5 of doping ratio. Therefore, an estimation of the optimal hole doping for each spin doping concentration was given, where it is important to obtain the maximal ferromagnetic coupling, therefore the highest ferromagnetic ordering temperature, . Our findings are consistent with experiments, manifested, especially, in the saturation of the ordering temperature at large hole doping, as was obtained for the experimental of system. The results also show a doubling of the when the spin doping is doubled at high hole doping. Finally, we demonstrated via a proposed model that the SRI has the Ruderman–Kittel–Kasuya–Yosida (RKKY) interaction nature.

Citation

MOHAMED Benhamida , , (2022), Competing long-range and short-range interactions in ferromagnetic semiconductors: Evidence from first principle calculations, Journal of Magnetism and Magnetic Materials, Vol:559, Issue:1, pages:169518, Elsevier

During the past years, natural fibers have attracted the thinking and interest of a large number of researchers and scientists in the fields of natural fiber compounds named green compounds due to the nature of the compound’s reinforcing composites, which is what linked the name of compounds to the color of fiber extracted from plants. The researchers considered this research as a major axis and made its development their main concern because composites materials have been widely used in engineering fields like civil, automotive, and aerospace industry, due to their high light weight, strength, and longue life expectancy thanks to the properties of these reinforcing materials In the present study, biocomposites were prepared from thermoset resins named unsatured Polyester (UP) as matrix, and Jute ( Corchorus capsularis ) as natural reinforcing fibers, requires a strong adhesion between fiber and matrix, biocomposites were prepared by putting small drops of synthetic matrix (UP) on the untreated and 3% NaOH alkali treated jute fibers. The mechanical properties of the jute fibers were studied by tensile strength tests, where mechanical properties of biocomposites prepared were characterized in terms of microbond tests, by estimating the values of external loads at moment of crack initiation. The results of mechanical properties showed a significant improvement for tensile strength and young's modulus was observed for treated jute fiber, also a good interfacial adhesion with treated jute fibers and matrix due to the rough fiber surface resulting by chemical treatment.

Citation

sidali ZERNADJI , MANSOUR Rokbi , MOHAMED Benhamida , ,(2022), INVESTIGATION OF THE INTERFACIAL ADHESION BETWEEN JUTE FIBERS AND THE POLYMER MATRIX BY MICRO-BOND TESTS,ICAENS 2022,Konya/Turkey

composites materials have been widely used in engineering fields like civil, automotive, and aerospace industry, due to their high light weight, strength, and longue life expectancy. In the present study, biocomposites were prepared from thermoset resins named unsatured Polyester (UP) as matrix, and sisal ( Agave fourcroydes) as natural reinforcing fibers, requires a strong adhesion between fiber and matrix., biocomposites were prepared by putting small drops of synthetic matrix (UP) on the untreated and 3% NaOH alkali treated sisal fibers. The mechanical properties of the sisal fibers were studied by tensile strength tests, where mechanical properties of biocomposites prepared were characterized in terms of microbond tests, by estimating the values of external loads at moment of crack initiation. The results of mechanical properties showed a significant improvement for tensile strength and young's modulus was observed for treated sisal fiber, also a good interfacial adhesion with treated sisal fibers and matrix.

Citation

sidali ZERNADJI , MANSOUR Rokbi , MOHAMED Benhamida , ,(2022), STUDY OF THE INTERFACIAL ADHESION BETWEEN SISAL FIBERS AND THE POLYMER MATRIX BY MICRO-BOND TESTS,IMMAT' 2022,Sousse, Tunisie

in this work, we made a statistical study that includes the length of a drop of resin of its two types (Polyester /vinyl ester) and the diameter of the raw and alkali-treated Alfa fiber. Each time we change the dimension of the resin drop, and because the natural plant fibers are unequal in diameter, we have an automatic change in the diameters of this latter, which is one of the factors that it intervened in the estimation of the strength of the interfacial adhesion. Where the effect of all these factors on the results of the experiment was discussed, especially for the interfacial shear strength which is one of the most interesting results. Which showed us that the force required to pull out the treated alfa fibers from the resin (Polyester /vinyl ester) is a greater value compared to the raw alfa fibers.

Citation

sidali ZERNADJI , MANSOUR Rokbi , MOHAMED Benhamida , ,(2022), ESTIMATION OF FIBER/ POLYMER BOND STRENGTH FROM MAXIMUM LOAD VALUES RECORDED IN THE MICRO BOND TESTS,PMFIC 2021,Béjaia

The mechanical properties of transition metal carbides Ti x M1–x C (0 ≤ x ≤ 1) alloys, with TM = Nb, V and Zr, were carried out using a first-principles pseudopotential calculation. The Ti substitution by a transition metal TM is assumed to completely random so we can use the virtual crystal approximation (VCA) for the disordered alloys. These calculation shows that the mechanical properties are largely affected by the alloying due to the interplay between ionic and covalent bonding of TM-C. The TiNbC and TiVC show an increase of the hardness with increasing x, while for TiZrC a decrease is observed. The variation of elastic constants is correlated to the electronic structure and the nature of bonding for TMC.

Citation

MOHAMED Benhamida , Nadjib Baadji , Kh. Bouamama, , (2019), Computational Study of Mechanical and Electronic Properties of Transition Metal Carbides Ti x M1–x C with M = Nb, V and Zr, Journal of Nanoelectronics and Optoelectronics, Vol:14, Issue:4, pages:622, American Scientific Publishers

First-principles pseudopotential calculations of the lattice constants and of the single-crystal elastic constants for TixTa1 − xN (0 ≤ x ≤ 1) alloys with B1-rocksalt structure were first carried out. These calculations were performed using density functional perturbation theory (DFPT) within the virtual crystal approximation (VCA) for the disordered alloys and the supercell method (SC) for the ordered alloys, with the ABINIT program. For disordered structures, partial comparisons of the lattice constants and of the bulk modulus are provided with calculations that used the coherent potential approximation (CPA) with the exact muffin-tin orbitals (EMTO). For the exchange-correlation potential we used the generalized gradient methods (GGA). The calculated equilibrium lattice parameters by VCA are in good agreement with the stress-free lattice parameters a0 and exhibit a positive deviation from Vegard's rule corresponding to a positive bowing parameter while the calculated single-crystal stiffness c12 and c44, gradually increase when c11 decreases from TaN to TiN. In a second stage, we have estimated by homogenization methods the averaged stiffnesses , the Young modulus and Poisson ratio of polycrystalline TixTa1 − xN (0 ≤ x ≤ 1) alloys considering a random orientation of crystallites. Finally, comparisons are made with the experimental effective out-of-plane shear elastic modulus C44 and the effective out-of-plane longitudinal elastic constant C33 measured by Brillouin light scattering and picosecond ultrasonics, respectively, on thin films elaborated by magnetron sputtering.

Citation

MOHAMED Benhamida , P. Djemiaa, Kh. Bouamama, L. Belliard, D. Faurie, G. Abadias, , (2013), Structural and elastic properties of ternary metal nitrides TixTa1 − xN alloys: First-principles calculations versus experiments, Surface and Coatings Technology, Vol:215, Issue:1, pages:199, Elsevier

In this paper, the dependence of the optical properties of thin titanium nitride films deposited by reactive DC magnetron sputtering on different nitrogen pressures, as well as the electrical properties and mechanical properties is investigated. The normal reflectivity is measured in a range from 0.5 to 5.5 eV. The results have been fitted using a dielectric function which takes into account the presence of several Lorentz oscillators. Contributions to the absorption due to bound and conduction electrons are separated. This approach allows the computation of the mean free path of conduction electrons, screened plasma energy, and the optical conductivity, which informed about the nature of the defects in TiNx compound.

Citation

MOHAMED Benhamida , A. Meddour, S. Zerkout, S. Achour, , (2006), Calculation of the optical and electronic properties of TiNx thin films on domain IR–VIS–UV, Journal of Molecular Structure, Vol:777, Issue:1, pages:41, Elsevier