Government College

About: Government College is a based out in . It is known for research contribution in the topics: Population & Ring (chemistry). The organization has 4481 authors who have published 5986 publications receiving 57398 citations.

Enhancing the performance of electrochemical machining of 20MnCr5 alloy steel and optimization of process parameters by PSO-DF optimizer

Abstract: Electrochemical machining (ECM) of metals, particularly steels, plays an important role in numerous industrial applications. The alloy steels especially 20MnCr5 are used as good wear resistant in the applications of boxes, piston bolts, spindles, camshafts, gears, shafts and other mechanical controlling parts. Machining of above complicated shapes with conventional machine tools is cumbersome task. Hence, investigation was made to study the electrochemical machining characteristics of 20MnCr5 alloy steel. Hydrogen peroxide (H2O2) mixed aqueous NaCl was used as electrolyte in order to enhance the machining performance of ECM. The predominant ECM process parameters such as applied voltage (V), inter-electrode gap (IEG) and electrolyte concentration (EC) were considered to study its influence on the material removal rate (MRR) and surface roughness (R a). Microstructure of surface of the 20MnCr5 steel specimen machined with ECM was studied to understand the effect of electrolyte during the machining. The contour plots were generated to study the effect of process parameters as well as their interactions. The optimized machined conditions found with particle swarm optimization (PSO)-desirability function (DF) optimizer were quite close with experimental results. Additional advantage of H2O2 presence was noted that scales formed on flow path of electrolyte were completely removed.

Propagation of the Rayleigh Wave in an Initially Stressed Transversely Isotropic Dual-Phase-Lag Magnetothermoelastic Half-Space

Abstract: The basic equations for the wave on the surface of an initially stressed transversely isotropic dual-phase-lag thermoelastic body subjected to the action of a magnetic field were solved. Particular solutions were applied to the thermally insulated free surface of a half-space to obtain the frequency equation for the Rayleigh wave. This equation was approximated for calculating the numerical values of the dimensionless velocity of the Rayleigh wave. The Rayleigh-wave velocity was represented graphically for the cases of coupled, Lord–Shulman, and dual-phaselag thermoelasticities. The influence of the dual-phase-lag and the initial stress of a body, the value of the magnetic field, and the frequency of the Rayleigh wave on the velocity of this wave were determined.

Antioxidant and Hepatoprotective Effects of Methanolic Extracts of Zilla spinosa and Hammada elegans Against Carbon Tetrachlorideinduced Hepatotoxicity in Rats

Abstract: Abstract The detoxification, metabolism, and excretion of various endogenous and exogenous materials occur mainly in the liver. Liver diseases are a global concern, and classified as chronic hepatitis, cirrhosis, and hepatosis. The development of safe hepatoprotective agents remains an unmet need. Therefore, we investigated the antioxidant effects of methanolic and n-hexane fractions of Zilla spinosa (ZSM and ZSH, respectively) and Hammada elegans (HEM and HEH, respectively) against carbon tetrachloride (CCl4)-induced liver toxicity in rats. Antioxidant activity was studied by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The rats were divided into 11 groups (n=6)–group, 1 (control), group 2 (CCl4 only), group 3 (CCl4+silymarin 10 mg/kg), group 4 (CCl4+HEM 250 mg/kg), group 5 (CC14+HEM 500 mg/kg), group 6 (CCl4+HEH 250 mg/kg), group, 7 (CCl4+HEH 500 mg/kg), group, 8 (CCl4+ZSM 250 mg/kg), group 9 (CCl4+ZSM 500 mg/kg), group 10 (CCl4+ZSH 250 mg/kg), and group 11 (CCl4+ZSH 500 mg/kg). Serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma glutamyl transferase, and total bilirubin were measured. The extent of hepatic injury was histopathologically assessed. Treatment with ZSM and ZSH at 250 and 500 mg/kg did not significantly affect biochemical results compared with the CCl4 only group. However, treatment with both HEM and HEH at 250 and 500 mg/kg provided significant (p<0.001) results compared with the CCl4 only group. These results were consistent with histological findings. HEM and HEH at 250 μg/mL significantly inhibited DPPH radical formation by 38.E6 and 35.65%, rerpectively. However antioxidant effects of ZSM and ZSH were insignificant.