Kuvempu University

About: Kuvempu University is a education organization based out in Shimoga, India. It is known for research contribution in the topics: Cyclic voltammetry & Carbon paste electrode. The organization has 1575 authors who have published 2210 publications receiving 39755 citations. The organization is also known as: KU.

Dielectric behavior and ac electrical conductivity in samarium substituted Mg–Ni ferrites

Abstract: Samarium substituted MgNi ferrites with composition Mg1−xNixFe2−ySmyO4 (x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0.0, 0.05, 0.1) have been prepared by ceramic method. Dielectric measurements of the samples have been carried out at room temperature as a function of frequency and composition. X-ray diffraction patterns have confirmed the single-phase spinel cubic structure for all the samples. Dielectric constant (e′) and dielectric loss (tan δ) decrease while ac electrical conductivity (σ ac ) increases with increase in frequency. Dielectric properties have been explained on the basis of Maxwell–Wagner’s two layer model. The conduction mechanism in these ferrites is due to electron hopping between Ni2+ and Ni3+ as well as Fe3+ and Fe2+ ions on octahedral sites. Dielectric constant and ac conductivity increases and decreases respectively with nickel content. A significant reduction in the values of dielectric constant and ac electrical conductivity has been observed in Sm3+ ions substituted samples.

Screening of selected biological activities of artocarpus lakoocha roxb (moraceae) fruit pericarp.

Abstract: Artocarpus lakoocha Roxb (Moraceae) is cultivated in Uttar Pradesh, Bengal, Khasi Hills and Western Ghats. Objectives of the present study were to determine antibacterial, antioxidant, anthelmintic and insecticidal efficacy of methanol extract of A. lakoocha fruit pericarp. Antibacterial activity was tested against by Agar well diffusion method. Antioxidant activity in terms of free radical scavenging ability was determined by DPPH free radical scavenging assay. Anthelmintic efficacy was determined using adult Indian earthworm. Insecticidal activity was tested against second and third instar larvae of Aedes aegypti. The extract has shown dose dependent antibacterial, antioxidant, anthelmintic and insecticidal activity. Among bacteria, S. aureus has shown more susceptibility than K. pneumoniae and P. aeruginosa. The extract exhibited marked antioxidant activity by scavenging DPPH free radical. The IC50 value for extract was found to be 49.42μg/ml. The extract exhibited marked anthelmintic activity by causing paralysis and death of worms and the effect was found to be dose dependent. The extract concentration 100mg/ml has shown marked anthelmintic effect than standard drug. In insecticidal study, the 2(nd) instar larvae were shown to be more susceptible than 3(rd) instar larvae. Phytochemical analysis revealed the presence of tannins and alkaloids. The presence of these phytoconstituents might be responsible for the biological activities of extract tested. The extract could be used to treat free radical damage, bacterial and helmintic infections and to control insect vectors. Further studies on isolation of constituents and their bio-efficacies in vitro and in vivo are under investigation.