Volume 6

ABSTRACT: Nanoparticles (NPs) have been an area of research for the last decade due to their exceptionally small size and expansive surface area, resulting in distinctive physical and chemical transformations compared to bulk materials. The application of nano-biotechnology in health and medicine necessitates a strong coordination among physical scientists, chemists, and biologists. The green method was utilized to synthesize stable silver nanoparticles (Ag-NPs) using Setaria verticillata (SV) and Azadirachta indica (AI) seed exudates as reducing and capping agents. UV-visible and FTIR spectrometry were used to characterize the AgNPs physicochemical properties. In vitro toxicity testing of Ag-NPs produced from SV on adult earthworms (Lumbricina) showed substantial inhibition (P < 0.05). Antimicrobial efficacy of 0.72µg/mL Ag-NPs was tested against gram-positive (Bacillus amyloliquefaciens, Bacillus anthracis, S. warneri, and Staphylococcus aureus) and gram-negative bacteria (E. coli, Acinetobacter baumannii) suppressing pathogen proliferation. In contrast, the Ag-NPs from AI outperformed in killing all tested pathogens. Due to their thick peptidoglycan (PG) covering, Gram-positive bacteria are less vulnerable to Ag-NP penetration, hence their antibacterial activity was tested against several strains. This study examines how nano-catalysts degrade MB and CR. Eco-friendly NaBH₄ usage. Additionally, kinetic models were used to evaluate adsorption kinetics. This research also highlights how the nanocatalyst affects NaBH4’s ecologically sustainable degradation of MB and CR. Additionally, Ag-NPs lowered CR and MB, suggesting their catalytic characteristics might eliminate commercial organic dyes. This research will help formulate eco-friendly bactericides and catalysts for biological applications.

ABSTRACT: We used first-principles density functional theory (DFT) computations to carefully study the structural, electrical, and optical characteristics of pure and Mg-doped CaTiO₃. In contrast to prior studies that concentrated on the dielectric or surface properties of CaTiO₃, the current research investigates the microscopic process by which Mg substitution alters the band structure and optical response pertinent to solar energy conversion. Our findings indicate that the addition of Mg results in a marginal decrease in both lattice parameters and bond lengths, alongside an increase in the electronic band gap from 1.85 to 2.05 eV, signifying a blue shift advantageous for solar cell performance. The movement of the Fermi level into the valence band and the changes in the partial density of states show how strongly Mg affects the electrical structure of CaTiO₃. The optical absorption edge also moves closer to the visible region, which suggests that the optoelectronic response is better. This study offers novel theoretical perspectives on band gap engineering via Mg doping in CaTiO₃ and illustrates its viability as a cost-effective and eco-friendly material for next-generation solar and optoelectronic devices.

ABSTRACT: The effects of laser irradiation in an oxygen gas environment on the exterior and physical properties of aluminum-copper alloy have been studied. Specimens were irradiated by means of an Excimer (KrF) laser (248 nm, 18 ns, 30 Hz) for varied fluences reaching from 3.8 to 5.5 J/cm². A scanning electron microscope (SEM) and an X-ray diffractometer (XRD) were used to analyze the surface and structural changes of the irradiated targets.  Research using scanning electron microscopy (SEM) revealed the formation of multiple LIPSS, or laser induced periodic surface structures. XRD investigation revealed that novel phases (Al₂CuMg, AlCuO₂) have been produced after laser irradiation in the presence of Oxygen gas. The unusual trend in the dislocation density and in crystallite size of Aluminum-copper alloy was noticed. Following laser irradiation of the Aluminum-copper alloy, there is a correlation between the surface and structural property changes.

ABSTRACT: In the present research work, a TBmBJ Exchange-Correlation Functional has been utilized to compute the spin polarized density functional theory. Various properties like structural, electronic as well as magnetic have been computed of Zn_{1 – x} Mn_xS (x= 50%, 25%, 12.5% and 6.25%). The present computed values of bandgap using TBmBJ matched well with the experimental results. Due to strong p-d hybridization, ferromagnetic exchange interactions between Mn -3d atom states are studied via S atom and magnetic moments are measured of these atoms. The exchange splitting parameters N₀α and N₀β are analysed to verify the existence of ferromagnetism. Mn doped ZnS compositions display an n-semiconductor behavior. The presence of d-states at the upper edge of the valence band suggests that the studied materials are very good candidates to fabricate the magneto -optical devices.