Publications Internationales
Permanent URI for this collectionhttps://dspace.univ-boumerdes.dz/handle/123456789/13
Browse
16 results
Search Results
Item Theoretical investigation of the self-association of antitumor drug imexon(Springer, 2020) Guemmour, Hind; Kheffache, DjaffarThe dimers resulting from self-association of oxo-imino, oxo-amino, and hydroxyl-imino tautomers of imexon, that present two hydrogen bonds, were fully optimized with the density functional methods B3LYP, M06-2X in conjunction with 6-311++G(d,p) basis set. Additionally, second-order Møller-Plesset (MP2) level in combination with 6-311++G(d,p) basis set was employed for comparison purpose. The thermodynamic stability of the self assembled structures in gaseous phase has been obtained according to the analyses of total electronic energies and hydrogen bonding interactions. The bulk water environment has been simulated using the universal solvation model based on solute electron density (SMD). Stability and structure of homochiral and heterochiral imexon dimers resulting from the three imexon tautomers have been carried out to investigate the chiral discrimination. The imexon dimer with heterochiral configuration resulting from self-assembling oxo-amino tautomer is found to be thermodynamically most stable in both gas and aqueous phases. The interaction energies for these self assembled structures were further evaluated with the basis set superposition error corrections. The so-called seven-point interaction energy which includes corrections for BSSE and deformation was calculated. The intermolecular interactions of the selected dimers have been analyzed by calculation of electron density (ρ) and Laplacian (∇2ρ) at the bond critical points (BCPs) using atoms-in-molecule (AIM) theory.Item Theoretical Study of Copper Squarate as a Promising Adsorbent for Small Gases Pollutants(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Adjal, Celia; Guechtouli, Nabila; Timón, Vicente; Colmenero, Francisco; Hammoutène, DalilaCopper squarate is a metal–organic framework with an oxo-carbonic anion organic linker and a doubly charged metal mode. Its structure features large channels that facilitate the adsorption of relatively small molecules. This study focuses on exploring the potential of adsorbing small pollutants, primarily greenhouse gases, with additional investigations conducted on larger pollutants. The objective is to comprehend the efficacy of this new material in single and multiple molecular adsorption processes using theoretical methods based on density functional theory. Furthermore, we find that the molecular adsorption energies range from 3.4 KJ∙mol−1 to 63.32 KJ∙mol−1 depending on the size and number of adsorbed molecules. An exception is noted with an unfavorable adsorption energy value of 47.94 KJ∙mol−1 for 4-nitrophenol. More importantly, we demonstrate that water exerts an inhibitory effect on the adsorption of these pollutants, distinguishing copper squarate as a rare MOF with hydrophilic properties. The Connolly surface was estimated to give a more accurate idea of the volume and surface accessibility of copper squarate. Finally, using Monte Carlo simulations, we present a study of adsorption isotherms for individual molecules and molecules mixed with water. Our results point out that copper squarate is an efficient adsorbent for small molecular pollutants and greenhouse gases.Item A systematic DFT study of (Ti3/2RE1/2)AlC alloys: A new database for adjustable mechanical and electronic properties(Elsevier, 2022) Meftah, C.; Iles, N.; Rabahi, L.; Gallouze, M.; Feraoun, H.I.; Drir, M.In this study, ab initio calculations based on Pseudo-Potential Density Functional Theory (PP-DFT) method are carried out in order to highlight the partial substitution effect of Rare Earth (RE) elements in the well-known 211-MAX phase of Ti2AlC. The considered elements are Y, Sc and RE = La, Ce, Pr, Nd, Sm, Eu, Gd leading to (Ti3/2RE1/2)AlC alloys. According to the obtained results, the (Ti3/2RE1/2)AlC alloys are significantly less compressible under uniaxial stress along x and z axes. They exhibit high resistance to shearing along [removed] direction. In addition, the calculated heat capacity for (Ti3/2RE1/2)AlC alloys increases with respect to the temperature, a maximum is found in the temperature range 200–300 K. Localized states occur in (Ti3/2RE1/2)AlC alloys due to the f states filling of the rare earth elements. The magnetic moment of (Ti3/2RE1/2)AlC compounds increases according to 4fn(n=2 for Ce to n=7 for Gd) filling. Our findings provide a theoretical database for new tunable properties of (Ti3/2RE1/2)AlC alloysItem Effects of Electron Correlations on the Magnetic Stability of Rh2TMSn Full Heusler Alloys (TM=Cr, Mn, and Fe)(Springer, 2022) Boulebda, H.; Bourourou, Y.; Bouchenafa, M.; Maabed, S.; Daoudi, Y.; Halit, M.First-principles total energy calculations were performed to study the stability of Rh2TMSn (TM=Cr, Mn and Fe) toward different magnetic ordering, ferromagnetic (FM), antiferromagnetic type I (AFM-I) and antiferromagnetic type II (AFM-II). We studied the effects of electron correlation on the magnetic stability of the compounds in both cubic and tetragonal structures using density functional theory (DFT) within the generalized gradient approximation (GGA) and GGA+U. The results show that the electron correlation has an important role in determining the magnetic stability of the compounds. The magnetic stability obtained from GGA+U agrees well with the available experimental results. The thermodynamic stability of the three compounds shows that all the compounds are stable in both cubic and tetragonal structures. Using the energy difference method, we were able to calculate the exchange interactions and estimate the Curie temperature of the Rh2MnSn compound in the cubic structure. The phonon dispersion curves were investigated for the first time using the linear-response approach in the context of density functional perturbation theory. The results show that all the compounds are dynamically stable in their predicted phasesItem Study of Structural, Elastic, Thermal and Transport Properties of Ternary X(X=Co, Rh and Ir)MnAs Obtained by DFT(V N Karazin Kharkiv National University, 2022) Kadri, Salim; Tourab, Mohamed; Berkani, Mahièddine; Amraoui, Rabie; Bordjiba, ZeynebThe Density Functional Theory (DFT) with an approximation of generalised gradient is used for the study of elastic, thermodynamic and transport properties and for that of structural stability of ternary Half-Heuslers compounds X(X=Co, Rh and Ir)MnAs. This first predictive study of this compounds determines the mechanical properties such that the compression, shearing, Young modulla and Poisson coefficient without omitting the checking parameters of the nature of these compounds such that hardness, Zener anisotropic facto rand Cauchy pressure. The Pugh ratio and Poisson coefficient have allowed the identification of ductile nature of these compounds. The speed of sound and Debye temperature of these compounds has also been estimated from the elastic constants. The thermodynamic properties have been calculated as well for a pressure interval from zero to 25 GPa. The effect of chemical potential variation on Seebeck coefficient, electric, thermal and electronic conductivities, the power and merit factors have also been studied for different temperatures (300, 600, 900°K), so that these alloys can be better potential candidates for thermoelectric applicationsItem Coordination of new palladium (II) complexes with derived furopyran-3,4‑dione ligands: Synthesis, characterization, redox behaviour, DFT, antimicrobial activity, molecular docking and ADMET studies(Elsevier, 2022) Fahima Dechouk, Lamia; Bouchoucha, Afaf; Abdi, Yamina; Si Larbi, Karima; Bouzaheur, Amal; Terrachet-Bouaziz, SouhilaThe synthesis, characterization, theoretical study, electrochemical behaviour and biological activity of new series of Pd (II) complexes were reported with 6-methyl-2-(phenyl(p-tolylamino)methyl)-4H-furo[3,2-c]pyran-3,4(2H)-dione derived ligands. [MLCl2] is the proposed general formula of complexes. The synthesized complexes were prepared and experimentally characterized by elemental analysis, SEM-EDX, FTIR, 1HNMR, UV-Visible spectroscopy, magnetic measurement, conductivity and thermal analysis. FTIR spectroscopy has revealed the coordination mode of complexes through nitrogen and oxygen atoms. The Density Functional Theory calculation was applied to optimize the geometric structure of complexes, whereas Orbital Molecular Frontiers calculations allowed to define their stability. The experimental electronic spectra and magnetic measurement results approved a square planar geometry for all complexes. These results correlate with theoretical calculations. The electrochemical behaviour of ligands and complexes were determined by cyclic voltammetry, which reveal different redox processes of Pd (II) couples for the three complexes. The antimicrobial activity of all compounds was evaluated against different micro-organisms using agar disc-diffusion method. Most of compounds exhibit a remarkable inhibition against standard yeasts and S. aureus Gram positive bacteria. The ADMET study was carried out to predict pharmacokinetic and toxicity of synthesised compounds. Molecular Docking of HL3 and Pd-HL3 against S. aureus was applied in order to study their molecular interactionsItem Oxygen diffusion and migration in clean and defective uranium nitride UN (0 0 1) surfaces(Elsevier, 2018) Zergoug, T.; Abaidia, Seddik-El-Hak; Nedjar, A.This study focuses on the diffusion of atomic and molecular oxygen through the uranium mono-nitride UN (0 0 1) surface. The adsorption of oxygen at the most favorable sites has been checked on different surface states namely: clean surface and surfaces containing defects such as inclusion atoms. Inclusions atoms are positioned at a uranium U atom vacancy or at a nitrogen N atom vacancy location of the UN (0 0 1) surface. Neptunium, plutonium, protactinium, silver and neodymium which are the most probable nuclear reactions (n, U) products have been selected as U atom substitute. Some light elements such as carbon, chromium and silicon were used to replace an N atom. The first principle calculation, based on Density Functional Theory (DFT) was used, taking into account the Generalized Gradient Approximation (GGA) and the Projector-Augmented Wave (PAW) to describe the exchange-correlation functional. The purpose of this work is to verify the oxygen adsorption energy variations performed across all the studied surfaces. The most favorable sites of UN (0 0 1) clean and defective surfaces to oxygen O atom diffusion were preliminary identified. In the second step, atomic dynamical Potential Energy Surface (PES) was used to study the interaction between O atom and UN (0 0 1) surfaces at these sites. Finally, Nudged Elastic Band (NEB) method was used in order to investigate the migration of O atom through the UN (0 0 1) surfaces. The results show that at the bridge site, the adsorption and incorporation energies of oxygen atom on and in the UN (0 0 1) surfaces respectively, do not substantially vary with the type and position of the studied impurities. But, at the N vacancy site, the adsorption energy of the O atom decreases practically when UN (0 0 1) surfaces contain inclusion atoms compared to the clean surface case. Furthermore, the NEB calculations show discrepancies for the Minimum Energy Path (MEP) during the migration of the O atom at the bridge site through the studied UN (0 0 1) surfaces and depending on the type and position of the added impurities. Among the studied MEPs, protactinium is found to be the most suitable barrier to the diffusion of oxygen through the UN surface as an inclusion on UN (0 0 1)Item Experimental and theoretical evaluation of the adsorption process of some polyphenols and their corrosion inhibitory properties on mild steel in acidic media(Elsevier, 2021) Zerroug, Meriem; Ferkous, Hana; Djellali, Souad; Bouzid, Abderrazak; Mohammed A., Amin; Rezki, Leila; Belakhdar, Amina; Jeon, Byong-Hun; Boulechfar, Chérifa; Benguerba, YacinePolyphenols are now widely acknowledged as safe and biodegradable corrosion inhibitors due to their cost-effectiveness. As a result, this research examines how well polyphenols extracted from Artemisia Herba alba (AHA) prevent mild steel corrosion in a 1 M HCl solution. Inhibitory performance is determined using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss tests. The shape and chemical content of the mild steel sample surface are evaluated by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) after contact with AHA secondary metabolites in the acidic solution. According to the results of polarization curves, AHA extract works as a mixed-type inhibitor. For all AHA concentrations tested, the Nyquist plots show a semi-circular capacitive loop. On metal surfaces, the Langmuir isotherm regulates inhibitor adsorption. The effectiveness of inhibition is proportional to the extract concentration, reaching 92.9% at 900 ppm. On metal surfaces, the Langmuir isotherm governs inhibitor adsorption. The effectiveness of inhibition is proportional to the extract concentration, reaching 92.9% at 900 ppm. These findings are supported by metal surface experiments, which show that the deposited inhibitor molecules successfully prevent HCl attacks at steel grain boundaries. Finally, quantum chemistry simulations show that dicaffeoylquinic acids, which were found to be the most prevalent AHA extract components, are effective corrosion inhibitorsItem Theoretical investigation of dicarboxamide mono copper (II) and novel transition metal complexes : structural, chemical reactivity, vibrational and in-silico biological analysis(Elsevier, 2019) Guechtouli, N.; Zaater, S.; Kichou, N.; Bouaziz-Terrachet, Souhila; Meghezzi, H.We are interested to the theoretical investigation of new synthesized dicarboxamide mono copper(II) complex, and other hypothetical one by modifying the transition metal by another one of the same series as (Mn(II), Fe(II), Fe(III), Co(II), Co(III), Cu(II), Ni(II) and Zn(II)). The aim of this study is to predict other stable complexes which can be synthesized and which would have comparable or better biological activity than that obtained experimentally, and predict their synthesis. For this purpose, structural, energetic, spectroscopic (IR, UV–Visible and NMR) properties have been evaluated at the DFT level. The stability of the considered complexes has been studied in the basis of the binding energies. The in-silico biological properties and chemical reactivity descriptors of hypothetical and synthesized compounds have been calculated and discussedItem Out-of-plane ionicity versus in-plane covalency interplay and electron–phonon coupling in MgB 2 superconductor(Elsevier, 2020) Guerfi, T.Using the Density Functional Theory (DFT) within the Generalized Gradient Approximation (GGA) pseudopotential and plane wave basis method along with the frozen-phonon approach that starts from the ab initio evaluation of the total energy Etot of the solid with frozen-in atomic displacements, it is found that a superposition of A2u and the E2gvibrations modes is the key factor in the superconducting mechanism in MgB2 compound. Electron–Phonon coupling to these A2u and E2g phonon modes especially at the zone-boundary A point of the hexagonal Brilliouin zone leads to an interband hole charge transfer (and transfer back) between in-plane σ bond to the out-of-plane π bond along with an interatomic electron charge transfer (and transfer back) between the Magnesium s-states to the Boron out-of-plane pz-state. The direction of the electronic current is opposite to that of hole current so that it reinforces the polarization associated with these currents and may generate a large dynamical charge at a given critical temperature Tc that drives the compound into the superconducting state