Yogi Vemana University is a newly established university in the Kadapa district with its West Campus at Idupulapaya. Earlier, it was a part of Sri Venkateswara University. It is named after a great thinker, philosopher, and social reformer Yogi Vemana, the most celebrated Telugu poet and sage of all time.It is located at Mittamedipalli village and Panchayat about 15 km from the Kadapa on the Kadapa-Pulivendla road. The campus is spread over 450 acres (1.8 km2) of land.
Cobalt-zinc spinel ferrites are promising multifunctional materials due to their tunable magnetic, dielectric, and electrical properties governed by cation distribution and lattice defects. In this work, Co1-xZnxFe2O4 (x = 0.1-0.9) nanocrystalline spinel ferrites were synthesized via a hydrothermal method to investigate the relationship between microstructural strain and functional properties. X-ray diffraction confirmed the formation of a single-phase cubic spinel structure with lattice parameters increasing from 8.329 to 8.401 & Aring; with Zn2 + substitution. Microstructural analysis using Scherrer, Williamson-Hall, Halder-Wagner, and size-strain plot models revealed crystallite sizes of 2-7 nm along with notable variations in lattice microstrain and defect density. Scanning electron microscopy showed agglomerated particle clusters with sizes between 167 and 311 nm, while energy dispersive x-ray spectroscopy confirmed the presence of Fe, Co, Zn, and O without detectable impurities. Vibrating sample magnetometry measurements indicated soft magnetic behavior with saturation magnetization values ranging from 10.76 to 15.33 emu g- 1, influenced by Zn-induced cation redistribution and surface spin disorder. Dielectric analysis revealed strong low-frequency permittivity and Maxwell-Wagner polarization behavior. The composition x = 0.5 exhibited optimal magnetic ordering and dielectric response, indicating potential for high-frequency electronics and electromagnetic interference shielding applications.
The annealing effect on the structural, surface topology, optical and electrical possessions of the Au/ZnPc/un-InP metal/polymer/semiconductor (MPS) diodes was investigated before and after annealing at 100 ℃, 200 ℃, 300 ℃ and 400 ℃. The structural behaviour of ZnPc films was examined by X-ray diffraction (XRD), which indicated that a phase transition occurred after annealing at 300 ℃. Furthermore, the surface topology of ZnPc films was analyzed using atomic force microscopy (AFM) and field emission scanning electron microscope (FESEM) with energy dispersive X-ray spectroscopy (EDAX) approaches before and after annealing. AFM analysis revealed that the surface roughness (root-mean-square value) increased with annealing up to 200 ℃ (6.76 nm), slightly decreased at 300 ℃ (6.70 nm), and increased again at 400 ℃ (7.60 nm). Optical studies revealed temperature-dependent shifts in Q-band absorption and enhanced Davydov splitting, while the optical band gap remained nearly unchanged. The electronic parameters of the MPS diode were evaluated before and after annealing through the current-voltage (I–V) process. The results demonstrated that the MPS diode exhibited a rectifying behavior regardless of the annealing temperature. A statistical distribution study was employed to determine the mean Φb and ‘n’ for the 20 MPS diodes before and after annealing. These outcomes point out that the Φb rises for the diode annealed at 300 ℃ (0.87 eV) and subsequently drops for annealing temperatures of 400 ℃ (0.79 eV). Further, homogeneous Φb was estimated from the relationship between experimental Φb and n for the MPS diodes before and after annealing. The interface state density (NSS) of the MPS diodes, estimated from the I-V, exhibited a decreasing trend with increasing annealing temperature up to 300 ℃ (4.59 × 109 eV−1 cm−2), followed by an increase for the diode annealed at 400 ℃ (3.50 × 1011 eV−1 cm−2). Under forward-bias conditions, ohmic conduction dominated at lower-bias regions, while space charge limited current (SCLC) predominated at higher-bias regions for the as-deposited and annealed MPS diodes at various temperatures. These findings emphasized the potential of MPS diodes to enhance the performance and reliability of organic–inorganic hybrid semiconductor devices utilized for electronic and optoelectronic applications.
Environmental exposure to redox-active metal oxides, such as CdO, Hg₂O, NiO, and PbO, presents a significant toxicological concern due to their environmental persistence and systemic bioaccumulation via inhalation, ingestion, and dermal routes. These metal oxides promote the excessive production of reactive oxygen species (ROS), disrupt antioxidant defense systems, and induce lipid peroxidation, mitochondrial dysfunction, and apoptosis within biological systems. Prolonged exposure contributes to cellular senescence and dysregulation of protective signaling pathways, ultimately leading to neurodegenerative, hepatic, renal, and cardiovascular diseases. Therefore, elucidating the molecular mechanisms underlying metal oxide–induced oxidative stress is essential for developing effective therapeutic strategies. Morin, a polyhydroxylated flavonol, exhibits potent antioxidant and metal-chelating properties due to its 4-keto and hydroxyl functional groups, making it a promising candidate for mitigating metal oxide toxicity. Density functional theory (DFT) calculations were conducted in the gas phase using ORCA 6.0 at the B3LYP/def2-TZVPP level of theory, with the def2/J auxiliary basis and RI-J approximation. Geometry optimizations were performed using tight SCF convergence criteria with a maximum of 900 iterations, employing DIIS and SOSCF convergence schemes. Frequency calculations confirmed the absence of imaginary frequencies, indicating the presence of true minima. Chemcraft 1.8 was utilized to visualize and analyze the structural, electronic, and vibrational properties.
A numerical investigation is carried out to examine magnetohydrodynamic natural convection of a TiO2-Cu/water hybrid nanofluid inside a square enclosure partially filled with a porous medium. The model incorporates the effects of thermal radiation, internal heat generation/absorption, and nonlinear temperature-buoyancy coupling. The governing dimensionless conservation equations are solved using an improved Marker-and-Cell (MAC) algorithm with second-order finite difference discretization. The influences of key parameters including the Hartmann number (0 <= Ha <= 30), heat generation parameter (-3 <= Q <= 3), Darcy number (10(-4) <= Da <= 10(-1)), Rayleigh number (10(3) <= Ra <= 10(6)), radiation parameter (0 <= Rd <= 4), and nonlinear temperature parameter (0 <= lambda <= 3) are systematically examined. The results show that increasing Ra from 10(3) to 10(6) enhances the average Nusselt number by approximately 165%, indicating strong buoyancy-driven convection. The results reveal that thermal radiation substantially enhances heat-transfer performance; the average Nusselt number increases by approximately 246% as Rd rises from 0 to 4. In contrast, the application of a magnetic field suppresses convective flow, leading to a 35-40% reduction in the Nusselt number when Ha increases from 0 to 30. Increasing porous permeability (Da: 10(-4)-10(-1)) strengthens circulation and improves heat transfer by nearly 30%, while internal heat generation significantly alters thermal stratification near the active boundaries. Overall, the study establishes that porous permeability, magnetic damping, nonlinear thermal buoyancy, and radiative heat flux strongly regulate convection strength and heat transfer performance in hybrid nanofluid-filled enclosures.
A total of 100 groundwater samples collected during the pre-monsoon (PRM) and post-monsoon (POM) seasons of 2019 were analyzed to evaluate hydrogeochemistry and groundwater quality in the southwestern part of Y.S.R. Kadapa District, Andhra Pradesh, India. Groundwater is predominantly alkaline and hard in nature. Nitrate concentrations exceeded the drinking water limit (45 mg/L) in 42
