Bharata Mata College

The propagation of 1-D nonlinear waves, specifically solitons and shocks, for a three-component highly intense laser-produced plasma is studied. The three components comprise stationary background ions and two groups of electrons (hot and cold electrons). The hot and cold electrons are incorporated with collisional and exchange-correlation effects, respectively. The influence of quantum forces, including the electrostatic force, pressure gradient, Bohm potential, and viscous effects, on wave propagation is systematically analyzed. Quantum hydrodynamic (QHD) modeling, along with the reductive perturbation method, is employed to derive the damped Korteweg-de Vries (KdVs) and Korteweg-de Vries-Burgers (KdVBs) equations governing the nonlinear evolution of the plasma waves such as solitons and shocks, respectively. Results demonstrate that lower hot electron collision frequency and higher electron degeneracy enhance soliton amplitude, while strong shock localization is favored by high cold electron viscosity and low electron degeneracy. Exchange-correlation effects, governed by cold electron parameters, significantly affect both soliton and shock dynamics. These results are thus crucial for interpreting plasma behavior in extreme conditions, predicting wave-mediated processes, and designing laboratory experiments.

We study thermal energy fluctuations of cosmological horizons within the canonical ensemble framework, treating the horizon as a thermodynamic system characterized by temperature and entropy. The analysis is performed for a class of gravitational theories, including (n+1)-dimensional Einstein gravity, Gauss-Bonnet gravity, Lovelock gravity, and models incorporating quantum deformed entropy corrections. We find that horizon energy fluctuations stabilize to a constant value in the asymptotic de Sitter limit, independent of the underlying gravity theory and robust against higher-curvature and quantum corrections. It is worth mentioning that in its final de Sitter state, the universe obeys holographic equipartition condition and in consequence the horizon entropy attains a maximum constant value, just like an ordinary macroscopic system. These findings establish a unified thermodynamic picture in which entropy maximization, holographic equipartition, and the suppression of energy fluctuations collectively characterize the asymptotic de Sitter universe as the equilibrium end state of cosmic evolution.

There is a high chance of accumulating the heavy metals in the edible parts of crops cultivated in contaminated soil. Therefore, heavy metal contamination in arable soils threatens world food security and human health. This study investigated the isolation, characterization, and biosurfactant production capabilities of bacterial strains from contaminated soil collected from the Noyyal River basin in Tirupur and detected their application for heavy metal removal efficiency. Two bacterial strains, such as Bacillus sp. and Rosellomorea sp., were successfully isolated and identified. Biosurfactant production was evaluated using various carbon sources, including sodium citrate, sodium acetate, glycerol, fructose, tryptone, sucrose, lactose, and paraffin in Bushnell-Haas medium supplemented with cooking oil. Among the tested substrates, sodium citrate demonstrated the highest biosurfactant activity, with Rosellomorea sp. showing superior performance (56.25% emulsification index) compared to Bacillus sp. (42.5%). Drop collapse assays, oil displacement tests, and surface tension measurements confirmed strong biosurfactant activity for both strains. TLC revealed lipid-based biosurfactants with average Rf values of 0.72 and 0.75 for Bacillus sp. and Rosellomorea sp., respectively. FTIR analysis confirmed the presence of hydroxyl, carbonyl, and carboxylate functional groups characteristic of biosurfactants, with Rosellomorea sp. showing glycoprotein or lipopeptide structures. GC-MS analysis identified major components, including n-hexadecanoic acid and 9-octadecenoic acid. The biosurfactants demonstrated significant anti-adhesive properties against foodborne pathogens, effectively inhibiting biofilm formation. Finally, Cr (VI) removal from sweet potatoes, elephant yams, carrots and beetroots using both surfactants was analyzed, and the findings highlighted their potential in food safety, biofilm control strategies, and prospects in remediation as well.

East Asia is a biodiversity hotspot shaped by plate collisions, mountain orogeny, and sea-level fluctuations, yet evolutionary and biogeographical processes shaping East Asia's endemic invertebrates remain poorly understood. We investigated these processes using Allochthonius pseudoscorpions, an ancient East Asian lineage serving as a proxy for leaf-litter invertebrates with limited dispersal abilities. Our dataset comprised 61 Allochthonius specimens representing 44 species-level units sampled from China, South Korea, Japan, and the Russian Far East, together with eight outgroup terminals and four molecular markers totalling 2550 bp. Phylogenetic analyses, divergence time estimation, and ancestral range reconstruction were used to examine historical biogeography and dispersal patterns. Allochthonius was recovered as monophyletic, with an estimated Early Cretaceous origin, and is now confined to East Asia, although an Eocene Baltic amber fossil indicates a formerly broader distribution. Divergence patterns reveal historical range shifts among Japan, the Korean Peninsula, and China associated with transient land connections from the Late Cretaceous to the Quaternary. Repeated faunal exchanges between the Korean Peninsula and the Japanese Archipelago indicate a complex history of dispersal and vicariance. Despite limited dispersal capacity, some lineages occur on both continental-shelf and volcanic islands. Collectively, these findings show that Allochthonius diversification reflects dynamic responses to repeated geographic connectivity, isolation, and habitat fragmentation from the Late Cretaceous to the Quaternary, highlighting the interplay of dispersal and vicariance in shaping biogeographical patterns of low-dispersal soil arthropods.

Purpose Drawing on Social Exchange Theory and the Job Demands–Resources (JD-R) model, this study examines how work engagement influences employee well-being in a hybrid IT workplace, with employee voice and innovative work behavior as sequential mediators and co-worker support as a moderator. Design/methodology/approach This quantitative study was conducted among 522 IT professionals employed in a hybrid workplace. Data were collected using standardized self-report questionnaires via purposive sampling. The measurement model was validated using IBM Statistical Package for the Social Sciences (SPSS) Analysis of Moment Structures (AMOS) 24.0, and Hayes’ PROCESS macro (Models 6 and 84) was used to test serial and moderated mediation effects. Findings The results indicate that work engagement has a significant positive effect on employee well-being. Employee voice behavior and innovative work behavior significantly mediate this relationship, both independently and sequentially. Additionally, co-worker support was found to strengthen these relationships, with higher levels of support enhancing the indirect and serial effects. Originality/value This study contributes to the literature by developing and empirically testing an integrated framework explaining how work engagement translates into employee well-being through proactive behaviors in hybrid work environments. It highlights the importance of co-worker support in strengthening these mechanisms and provides practical insights for organizations seeking to foster employee well-being, voice, and innovation in a digitally mediated workplace.