Search

In this investigation, we employ density functional theory with the generalized gradient approximation of Wu–Cohen and the modified Beck–Johnson approach. Our focus is on examining the structural, electronic and thermodynamic properties of ternary chalcopyrite CdXP2 (X: Si and Sn) compounds. Our computed results of ternary structures for structural properties, for instance, tetragonal distortion, equilibrium lattice constants and bond lengths, show good agreement with the available results of the experimental and theoretical calculations. Our calculated positive results of cohesive energy and negative values of the formation energies of the title materials show their thermodynamic stability as well as highlight their possible experimental fabrication at these concentrations. From band structure calculations, it is found that the energy bandgap is of direct nature at Γ–Γ symmetry points for both ternary and quaternary alloys; however, the width of the bandgap is found to be decreased with increasing Sn concentration in the CdSi1–xSnxP2 alloys. Moreover, thermodynamic properties using the quasi-harmonic Debye model are also computed. Our study provides a platform for further experimental and theoretical investigations to expose the potential of these materials for their applications. [ABSTRACT FROM AUTHOR]

In the present work, we present a theoretical study of the physical properties of ternary CdXP2 (X: Si, Ge, and Sn) chalcopyrite materials through the full-potential linearized augmented plane wave method. The generalized gradient approximations of Perdew, Burke, and Ernzerhof have been used to handle the exchange–correlation potential. Moreover, the electronic structure calculations are further improved through the modified Becke Johnson potential. Our calculations for the structural parameters of the studied compounds are found well-matching with the literature. Investigations of the electronic properties of the considered compounds have been executed through the calculation of the band structure. We observe that our compounds are semiconductors characterized by a direct energy gap between the Γ-Γ symmetry points. The optical constants, including the dielectric functions, were calculated for energy up to 30 eV. Using the GIBBS program, which is based on the quasi-harmonic model of Debye, we have investigated the thermodynamic behavior of the considered chalcopyrite under pressure and temperature effects. The variation of the volume, bulk modulus, and temperature-dependent Debye temperature and heat capacities for different pressures are estimated. [ABSTRACT FROM AUTHOR]

Algeria is one of the wealthiest countries in terms of hydrothermal sources, with more than two hundred hot springs. However, diverse and little-described microbial communities colonize these habitats, making them an intriguing research subject. This work reports the isolation of bacteria from two hot springs water samples in northeastern Algeria, evaluating their enzymatic activities and effect on plant pathogens. Out of the obtained 72 bacterial isolates and based on the 16S rRNA gene sequence analysis, the strain HGR5 belonging to Bacillus halotolerans had the most interesting activity profile. Interestingly, HGR5 was substantially active against Fusarium graminearum, Phytophthora infestans, and Alternaria alternata. Furthermore, this strain presented a high ability to degrade casein, Tween 80, starch, chitin, cellulose, and xylan. The genome sequence of HGR5 allowed taxonomic validation and screening of specific genetic traits, determining its antagonistic and enzymatic activities. Genome mining revealed that strain HGR5 encloses several secondary metabolite biosynthetic gene clusters (SM-BGCs) involved in metabolite production with antimicrobial properties. Thus, antimicrobial metabolites included bacillaene, fengycin, laterocidine, bacilysin, subtilosin, bacillibactin, surfactin, myxovirescin, dumulmycin, and elansolid A1. HGR5 strain genome was also mined for CAZymes associated with antifungal activity. Finally, the HGR5 strain exhibited the capacity to degrade polycaprolactone (PCL), a model substrate for polyester biodegradation. Overall, these results suggest that this strain may be a promising novel biocontrol agent with interesting plastic-degradation capability, opening the possibilities of its use in various biotechnological applications.