In this work, we systematically investigate the mechanical properties of tungsten-rhenium (W-Re) alloys using molecular dynamics simulations. Our approach involves employing the embedded atomic method (EAM) potential and conducting a tensile test within the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) framework. Through these simulations, we aim to gain insights into the mechanical behavior of W-Re alloys. The effect of temperature and concentration of Rhenium (Re) on the mechanical behaviors of tungsten (W) are discussed. To show the impact of these factors, a box (15.7 Å*5.7 Å*94.2 Å) of about 1500 atoms with an atomic structure of a Cubic Body Center single crystal was created by LAMMPS code. The obtained results showed that the young modulus, the yield stress and the tensile strength of W and W-Re alloys decreases with increasing temperature. In addition, these mechanical parameters were decreased with increasing Re concentrations; it was observed as well that addition of Re contributed to increased ductility of W. These findings may provide important information for further experimental and simulations studies of W-Re alloys materials.

In this work, we present experimental and simulation study of damaged, failure and cracking of concrete beam in the absence and in the presence of reinforced honeycomb sandwich panel structures. The experimental program included three beam specimens. Two of the beams were reinforced with different thicknesses of honeycomb panel structures. Flexural test was performed. The material model was simulated in Abaqus finite element package and is capable of developing the stress-strain curves, stress max principal versus tensile damage and load displacement. The beam was loaded in three-points. The mechanical properties of the used materials in our simulation are obtained from the data of the literature. The results obtained are discussed. By this study, we intend to contribute to a better understanding tensile damage-strain by using reinforcement in concrete beam. The main goal is to predict what extent a reinforced concrete structure can resist.

Energy harvesting have a variety of application areas such as aircraft,automotive, medical this energy provides a route for the realization of autonomous and self-powered low power electronic devices, for wireless sensor networks, it eliminates the need for wireless or replacement batteries. The purpose of this paper is to develop and improve the capacity of energy harvesting. In this study, an MFC harvesting elements were laid up with the Natural fiber/epoxy composites that will be fabricated prapag at the fabrication stage, and co-within an autoclave that can convert mechanical vibrations to electrical energy will study to supply power a wireless impedance sensor node. Finally, a series of experimental tests will be verified.

In this work, the results of an experimental investigation on reinforced concrete by fiberglass honeycomb sandwich panel structures are presented. The experimental program included three beam specimens. Two of the beams were reinforced with different thicknesses of honeycomb structures. Flexural and uniaxial compression tests were performed. The tensile strength remains to be increases by a factor of 2.40 for compression and by 1.60 for flexion. The results obtained in terms of reinforcement are discussed. The changes are likely attributed to a modification of the adhesion forces at the honeycomb structures/concrete interface.

The purpose of this work is to present the results of a simulation investigation on reinforced concrete by fiberglass honeycomb panel structures. The numerical study program included three beam specimens. Flexural compression test were simulated and compared to previous work conducted in our laboratory. The experiment was combined with simulations using finite element analysis (FEA) code Abaqus and revealed that both of them were in a fairly good agreement.

Tensile uniaxial test and simulation dynamic molecular have been used to evaluate the effect of gold (Au) addition and the temperature on the elastic behaviors and structure of Si-Au alloy single crystal. By the following, the interactions are described via a modified embedded-atom model. It has been found that, the yield stress and young modulus decrease when the fraction of atoms Au increases. An increase in the yield stress with temperatures has also been noted. On the other hand, we analyzed the structure of the alloys for high stress. We have shown a dependency of the structure as a function of temperatures.

In this work we performed a series of nanoindentation test on nanocrystalline (nc) tungsten (W) specimens, using Molecular Dynamics (MD) simulations and Embedded Atom Method (EAM). We studied the grain size effect in the range of 6 to 15 nm, with a penetration rate of 5 Å/ps and at room temperature 300 K. We found an increase in reduced elastic modulus Er and the Young elastic modulus E with the increase in grain size. On the other hand, we investigated the effect of the penetration velocity ranging from 3 Å/ps to 5 Å/ps. We found that the elastic modulus increases when the rate of penetration increases. The found results are in good agreement with the literature

The elastic moduli of nancrystalline tungsten have been calculated from elastic constants by molecular dynamic simulation using embedded atom model. The nanocrystal containing 16 grains with average diameters ranging from 4, 2 to 8, 9 is made using the Voronoi construction. We have been interested in the investigation of both temperature and grain size effects on elastic moduli. A softening of material was observed with the temperature increase and the grain size decrease. The anisotropy calculations have shown that the material becomes more isotropic in high temperature. The found results are in good agreement with the literature.

Zinc selenide (ZnSe), copper, nickel, and cobalt doped ZnSe (Cu, Ni, Co-ZnSe) nanoparticles were effectively synthesized through solvothermal method. The as-synthesized ZnSe nanoparticles were described to their optical, structural, elemental composition, morphological properties and electrochemical studies. X-ray diffraction pattern supports hexagonal, wurtzite structure and the crystallite sizes were justified as 13.7, 13.1, 10.6 and 7.9 nm for ZnSe, Cu, Ni and Co-ZnSe nanoparticles respectively, which are further confirmed by TEM analysis. Band-gap energy was computed as 2.5, 2.7, 3.2 and 3.5 eV for ZnSe, Cu, Ni, Co-ZnSe nanoparticles. Scanning electron microscopic images showed the formation of rod shaped nanoparticles, and the effective doping was further confirmed by EDX spectral analysis. The kinetics of electron transport properties were studied by electrochemical analysis and it was found that Co-ZnSe has more electrocatalytic activity compared to Cu, Ni- ZnSe nanoparticles. DSSCs were fabricated with ruthenium dye immobilized semiconductor photo anode (TiO2), redox electrolyte (I-/I3 -), ZnSe, Cu, Ni and Co-ZnSe nanoparticles as counter electrodes (CE). The maximum power conversion efficiency of solar cells was found to be 1.20%, 1.99%, 2.51% and 3.21% for ZnSe, Cu, Ni and Co- ZnSe nanoparticles, and it was found that the dopant with more number of unpaired electron influences the solar cell effectively.

In this study, we present a static finite element study of reinforced concrete beam reinforced by steel fibers and by fiber reinforced–polymer composites subjected to a load of 500 kN. Preliminary results in term of simulation using a codeprogram (Abaqus) are presented. The material model was simulated in Abaqus finite element package and is capable of developing the stress-strain curves. The beam was loaded in three-points. The mechanical properties of carbon fiber reinforced polymer (CFRP), steel and the concrete used in our simulation are obtained from the data of the literature. The results obtained in terms of constraints and displacements are discussed. By this work, we contribute to more understanding the comportment of stress and strain law using numerical study. The main goal is to predict what extent a reinforced concrete structure can resist in the elastic mode.

Nanomaterials are the building blocks of today’s nanoscience and nanotechnology. Due to the distinct features of the nanomaterials, their utilization in the application sectors has increased. The field of metal nanocluster has been studied with increasing interest in the past few years. In this context, we study the influence of mechanical deformation on the optical transmittance of gold nanoclusters deposited on polymer substrate the polyurethane Clear Flex® 50 during in situ tensile test.

This study is devoted to characterize the microstructural and mechanical state of polycrystalline 304 L stain-less steel (SS), deposited on Si substrate by the ion beam sputtering technique using the ion beam assisted deposition (IBAD) processes, by using X-ray diffraction method. The conventional Sin(2) Psi method shows that both stress and stress-free lattice parameters are found to be decrease under the IBAD processes. The size of coherently diffracting domains D and microdistortions (1/2) in thick films are obtained using the integral width (IW) methods. The measurements show that D increases and (1/2) decreases. The texture analysis confirm the < 110 > texture that increases with assistance rate.

In this study we tried a series of nanoindentation test on nanocrystalline (nc) tungsten (W) specimens, using Molecular Dynamics (MD) simulations and Embedded Atom Method (EAM). We studied the grain size effect in the range of 6 to 15 nm, with a penetration rate of 5 Å /ps and at room temperature 300 K. We found the reduced elastic modulus Er and the Young elastic modulus E dependent of grain size. On the other hand, we investigated the effect of the penetration velocity ranging from 3 Å/ps to 5 Å/ps. We found that the elastic modulus increases when the rate of penetration increases. The found results are in good agreement with data experiment and the literature.

L’optimisation des politiques de maintenance preventive est devenue un sujet d’interet qui a fait l’objet de nombreux travaux. Cette contribution propose une nouvelle politique optimisee de la maintenance preventive pour le systeme axe du galet. Elle est divisee en deux grandes parties. La premiere propose une nouvelle conception de l’axe ou l’effet de la maintenance preventive est integre, et la deuxieme elabore une nouvelle technique de controle adapte a la nouvelle conception. A ce propos, nous nous sommes interesses aux axes des galets des fours rotatifs de cimenterie. Nous avons note les contraintes imposees a l'axe «complet» du rouleau. Ces contraintes qui ont provenu de contact entre le bandage et ses rouleaux de soutien. Actuellement, la methode de controle par ultrasons de l’axe plein dans cette situation pose des inconvenients, par exemple, l’obligation de l’arret de l’installation ou encore la difficulte de detecter et de dimensionner les defauts (fissures) engendres par le champ de contraintes. Nous proposons dans cette etude, une autre approche, nous preconisons d’opter pour un axe creux au lieu d’un cylindre plein, avec un diametre minimal qui permet au systeme de controle de penetrer axe creux afin de faire un controle par ultrasons. Ceci permettra un controle preventif, en fonctionnement par la technique non destructive des ultrasons. L’analyse donne les differents resultats de comparaison entre l’axe de cylindres plein et creux, ayant les memes dimensions et le meme materiau et finalement le plus interessant c’est le meme fonctionnement.

The blow bar and cone of crusher used in mineral processing are made of Hadfield steel typically containing over 12% manganese. This steel is characterized by a structural change in service caused by hardening. According to the microstructure formed after annealing, the transformation of austenite during the hardening into martensite determines its operating life. Premature failure of these components is a cause of concern because of the down times and replacement costs. In this paper, we present the results of the metallographic studies and the analysis of the chemical composition of the various studied samples. We highlight that the haste of carbides in the joints of grains can be considered as a phenomenon favorable to the progress of pre-existent cracks in these areas. This study allowed to develop steel grade manganese can be integrated into the production of blow bar and cone with improved cycle life.

The mobile communication is based on the use of electromagnetic fields with frequencies between 300 MHz and 300 GHz. Many studies on humans and animals have suggested that these microwaves could interfere with cognitive functions. In the present study, we examined the effects of chronic exposure of 3 months to a mobile phone radiation of 930 MHz, produced by a wave generator bound to a communication system, on Wistar rats memory, in using several tests including the radial maze and the hole board. 60 rats were divided into 6 groups according to sex (males and females) and duration of exposure (controls, exposed 1h and 2h). The statistical analysis of results was performed by repeated measures of ANOVA test and Newman- Keuls test, which allows comparison of the means in pairs. The Results were considered statistically significant when the probability p is less than 0.05. We observed that females are more affected by the action of the electromagnetic waves compared to males. The mean of errors made by rats during the radial maze test increases significantly (p<0,05) for both sexes in the exposed rats compared to the controls. When testing the hole board, the mean number of holes explored by animals decreases significantly while the mean number of stumbling increases significantly in both sexes in the exposed rats compared to controls. In conclusion, the electromagnetic waves emitted by mobile phones may induce deficits at the working memory and reference, as well as the level of the exploratory and psychomotor capacities of Wistar rats.

The nucleation of an edge dislocation from the free surface of a multilayer composed of a buried layer embedded in an infinite- size matrix has been investigated from a theoretical point of view when a misfit stress is present in the layer. From an energy variation calculation, the metastable and stable equilibrium positions of the dislocation have been determined as a function of the misfit stress.

IJAR - Indian Journal of Applied Research (IJAR) IJAR is a double reviewed monthly print journal that accepts research works from scholars, academicians, professors, doctorates, lecturers, and corporate in their respective expertise of studies.