Bishop Heber College

About: Bishop Heber College is a based out in . It is known for research contribution in the topics: Thin film & Band gap. The organization has 548 authors who have published 692 publications receiving 7144 citations.

Novel VOPO4/g-C3N4-PMS system for organic pollutant degradation: Assessment of toxicity by Danio rerio

Abstract: The hydrothermally synthesized Vanadyl phosphate (VP) was doped with graphitic carbon nitride (g-C3N4) which has low band gap energy and high nitrogen content to form VP/g-C3N4 (VP/GCN) composite. These synthesized materials were aided by PMS activation, and then these materials were evaluated for the photocatalytic degradation of organic Azure B (Az B) dye. The structure and surface morphology of the synthesized materials were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS), transmission electron microscopy techniques (TEM), UV− Vis-DRS spectroscopy and Fourier transform-infra red spectroscopy (FT-IR) analysis. The photocatalytic degradation of the organic dye was carried out in a photocatalytic chamber under visible light. The PMS activation enhances the catalytic efficiency of the synthesized material. The degradation efficiency of the PMS activated VP/GCN composite was found to be nearly 93% for Az B dye effluent in a time duration of 120 min. The treated effluent water was investigated for the animal survival to understand its toxic nature. VP/GCN composite catalyst treated dye effluent exhibited better survival for zebra fish (Danio rerio) when compared with the untreated dye effluent which clearly proves the VP/GCN catalyst to be an excellent material for water purification.

Synthesis and characterization in vitro antimicrobial and cytotoxicity testing of oxalic acid-derived cadmium chelating agents

Abstract: Objective : The aim of this study is to investigate the growth, structure, spectral, solubility and biological activity of sodium cadmium oxalate dehydrate (NaCdOx) and cadmium oxalate trihydrate (CdOx) crystals prepared by a single diffusion method in the silica gel medium. Methods: The present crystals were grown using single diffusion methods and tested for XRD, UV absorption (190 to 1100 mm) and solubility (distilled water at 20-29 °C) studies. The antimicrobial efficacy of the grown samples at various concentrations (25, 50, 75 and 100 μg/ml) was studied against Streptococcus , (G+Ve) , Pseudomonas aeruginosa (G-Ve) and Candida albicans (antifungal). The cytotoxicity evolution was carried out against human cervical cancer cell line (HeLa) using MTT assays. Results : The existing single crystals were successfully grown by silica gel technique. The solubility of sodium cadmium oxalate dehydrate (NaCdOx) was moderately good in deionized warm water. The FTIR spectral studies confirmed the chelating bands of the present samples and UV spectra showed the better the optical conductivity of as-grown crystals. The complexes showed good antimicrobial activity against all tested microbial strains and they exhibited a decrease in cytotoxicity activity. Conclusion : The gel method was suitable to grow metal complexes of legend crystals. The modification of structural properties of cadmium oxalate trihydrate (CdOx) by sodium doping was much improved the solubility, anticancer, antimicrobial activity and polarization by the high optical conductivity of sodium cadmium oxalate dehydrate (NaCdOx) compound. Hence sodium cadmium oxalate dehydrate (NaCdOx) might be a candidate for biomedical applications.

Insights on photocatalytic dye inactivation and antimicrobial activity of pH-dependent facile synthesised copper oxide nanoparticles

Abstract: Photocatalytic efficacy of copper oxide nanoparticles (CuO Nps) synthesised by a simple wet chemical route at different pH values ranging from 4 to 10 was investigated. The synthesised nanoparticles were characterised by analytical tools such as X-ray diffraction (XRD), diffuse reflectance spectroscopy, photoluminescence, scanning electron microscope and Raman spectroscopy. The XRD pattern endorses the formation of monoclinic CuO with an average particle size of 26 nm at higher pH (pH 8), whereas at lower pH levels (pH 4 & 6) copper oxide complexes with monoclinic structure were observed. The diffuse reflectance spectrum of the CuO Nps showed band gap energy of ~ 1.4 eV. The SEM images displayed diverse morphologies while altering the pH during the synthesis process of CuO Nps. The degradation efficiency of CuO Nps towards rhodamine B was recorded as 88% after 6 h and could be reused. The extent of mineralisation of the dyes was evaluated by chemical oxygen demand. Owing to the application of remediation of contaminated water, the samples were also treated with different gram-positive and gram-negative bacteria and showed efficient against the microbes harmful to human lungs.

A stochastic model on the mean time to recruitment for a two graded manpower system associated with a univariate policy of recruitment involving combined thresholds using same geometric process for inter-decesion times

Abstract: In this paper, an organization with two grades subjected to loss of manpower due to the policy decisions taken by the organization is considered. A mathematical model is constructed and an appropriate univariate recruitment policy, based on shock model approach involving combined optional thresholds and combined mandatory thresholds for the loss of manpower in the organization is suggested. The expected time for recruitment is obtained for different cases on the distribution of the thresholds when (i) the loss of manpower forms a sequence of independent and identically distributed exponential random variables and (ii) the inter-decision times for the two grades form the same geometric process. The analytical results are substantiated by numerical illustrations and relevant conclusions are presented.

A Parameter-Uniform First Order Convergent Numerical Method for a System of Singularly Perturbed Second Order Delay Differential Equations

Abstract: In this paper, a boundary value problem for a system of two singularly perturbed second order delay differential equations is considered on the interval [0, 2]. The components of the solution of this system exhibit boundary layers at x = 0 and x = 2 and interior layers at x = 1. A numerical method composed of a classical finite difference scheme applied on a piecewise uniform Shishkin mesh is suggested to solve the problem. The method is proved to be first order convergent in the maximum norm uniformly in the perturbation parameters. Numerical illustration provided support the theory.