Archives-June 2016

Aluminium-3%Magnesium-10% silicon carbide composite is prepared in an induction heating furnace. The physical characteristics of both as-casted sample and corroded samples have been studied. A slice of the composite sample is kept in sea water for 6 weeks (42 days) and the weight loss was measured with the help of an electronic weighing machine in every 7 days to study the corrosion behavior.

Eikenella corrodens (E. corrodens) is one of the main bacteria responsible for halitosis due to its metabolism of amino acids, which produces volatile sulfur compounds (VSCs). High demand for new antibiotic formulations, due to increased resistance to the available types, has triggered attempts to find plants with antibiotic properties. This study aimed to assess the antibacterial effects of Eucalyptus camaldulensis (EC) and Mentha spicata (MS) essential oils on E. corrodens. The antibacterial efficacy of EC and MS against E. corrodens was evaluated using the well diffusion technique. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of EC and MS essential oils against E. corrodens were determined using the broth microdilution method. Data were analyzed using Kruskal-Wallis, Mann-Whitney and Student’s t tests. The mean diameter of the growth inhibition zone was 8.8 ± 0.837 mm for MS and 16 ± 4.637 mm for EC. The MIC values were 0.55 and 0.45 mg/mL for EC and MS, respectively. The MBC values were 1.8 and 2.4 mg/mL for EC and MS, respectively. Based on our findings, MS and EC essential oils possess bacteriostatic properties against E. corrodens. Mouthwashes containing EC and MS essential oils may effectively eliminate bad breath.

Oussudu Lake is an important freshwater body of Puducherry and one of the primary sources of drinking water supply to Puducherry city. This study aims to assess the accumulation of heavy metals as a result of anthropogenic intervention. Heavy metals such as Cu, Zn, Mn, Cd and Pb in the surface water and sediments are determined using Atomic Absorption Spectrophotometer. The mean concentration of Pb was found to be 0.15±0.07mg/l, whereas Cu was found to be within the safe limits for surface water (Central Pollution Control Board). The concentrations of heavy metals in the sediments were: Cd (0.25±0.31µg/g); Pb (1.1±2.32µg/g); Cu (6.6±4.63µg/g); Zn (10.16±8.79 µg/g) and Mn (44.56±21.28 µg/g). The Principal Component Analysis (PCA) resulted in two principal components accounting for a cumulative variance of 94.438%. This study reveals that the water of Oussudu Lake stands exposed to contamination with lead and constant monitoring is essential to maintain water quality.

Soret effect on unsteady MHD flow past an impulsively started inclined oscillating plate with variable temperature and mass diffusion is studied here. The fluid taken is electrically conducting. The Governing equations involved in the present analysis are solved by the Laplace-transform technique. The velocity and concentration profile is discussed with the help of graphs drawn for different parameters like thermal Grashof number, mass Grashof Number, Prandtl number, soret parameter, phase angle, the magnetic field parameter and Schmidt number.

Chemical reaction effect on unsteady MHD flow through porous medium past an impulsively started inclined plate with variable temperature and mass diffusion in the presence of Hall current is studied here. The fluid taken is electrically conducting. The Governing equations involved in the present analysis are solved by the Laplace-transform technique. The velocity profile is discussed with the help of graphs drawn for different parameters like thermal and mass Grashof Number, Prandtl number, chemical parameter, Hall parameter, permeability parameter, magnetic field parameter and Schmidt number, and the numerical values of skin-friction and sherwood number have been tabulated.

The main objective of present investigation is to introduce the magnetohydrodynamic peristaltic transport with porous medium through a coaxial asymmetric vertical tapered channel and Joule heating with radiation. Effects of sundry parameters on the temperature and heat transfer coefficient at the wall y = h1 are studied through graphs. It is noted that the temperature increases when increase in Radiation parameter (N), Prandtl number (Pr), heat source/sink parameter (?), Brinkman number (Br), Hartmann number (M), non-uniform parameter (K1) and non-dimensional amplitude (?) in entire tapered channel. Further, we observe that the heat transfer coefficient decreases when non-uniform parameter (K1) is assigned higher values.

Hydro-geophysical investigations were conducted on a 16-acre piece of land at Kaedabi-Ahwerease in the Akuapem-South Municipality in the Eastern Region of Ghana. The purpose of the study was to determine the groundwater potential at the site and the possibility of drilling a borehole that could yield considerable quantity of groundwater for sustainable potable water for a proposed bottled and sachet water factory. The survey was carried out using the Geonics EM-34 conductivity meter and ABEM Terrameter (model SAS 1000 C) equipment. Electromagnetic (EM) profiling and Vertical electrical sounding (VES) surveys were conducted to determine the vertical variation of the resistivity/conductivity of the sub-surface rock formation with depth with the view to detecting fractures, joints, shear zones and faults, which could serve as conduits for water traps within the underlying bedrock at the project site. The EM profiling data were obtained along three (3) evenly-spaced parallel traverses each of length 300 m with the 20 m inter-coil separation cable. Measurements were taken at 10 m station intervals in the northwest-southeast direction as a means of selecting suitable points for depth-probing (VES investigations). From the EM profiling results, 12 conductivity anomaly points were selected for further investigation using VES methodology. The Schlumberger array was used for the VES survey. The combined interpretation of the EM and VES results indicated the presence of possible aquifer units comprising the weathered, fractured and fresh bedrock within the subsurface of the study area. The results revealed the presence of three geo-electric layers. The resistivity of the top lateritic layer ranged from 78 to 1,895 ?m with thickness between 0.8 and 1.7 m. The resistivity of the regolith (second layer) ranged from 10 to 135 ?m with thickness of 2.1 to 6.4 m; while the bedrock had resistivity values between 303 and 1068 ?m. The combined output from topographic interpretation, paleo-river channel location and resistivity modelling results clearly zoned out areas of high and low groundwater potential in the study area. The estimated groundwater yield for the three test wells drilled within the detected high groundwater potential zone ranged between 50 and 160 lpm, indicating that, the study area has adequate groundwater for the proposed project.

Legendre and Chebyshev collocation methods are presented to solve numerically the voltterra-fredholm integral equations with exponential kernel. We transform the Volterra Fredholm integral equations to a system of Fredholm integral equations of the second kind,a system Fredholm integral equation with exponential kernel is obtained and will be solved using Legendre and Chebyshev polynomials.This lead to a system of algebraic equations with Legendre or Chebychev coeffcients. Thus,by solving the matrix equation,Legendre and Chebychev coeffcients are obtained.A numerical example is included to certify the validity and applicability of the proposed technique.

The main objective of the present work is to conduct the computational study of steady flow through the air intake system of a multicylinder SI engine. The CAD geometry of the air intake system of the multi cylinder in line engine was created. Two modification on the induction side one with circular cross section (Path A) and another with rectangular cross section (Path B) were carried out. All the three models are simulated using ANSYS FLUENT, CFD code for the computational study, steady state flow conduction was assumed and the analysis is carried out assuming the intake air flows steady into the system at mean piston speed of the engine. Flow field is predicted by solving the Navier strokes equation and the turbulence is modelled using k-? RNG model. Good agreement is observed from predicted result.

The most important aspect of organic chemical reactivity is the chemistry of carbonyl group (>C=O) .It directly undergoes nucleophilic attack by different substrates and yields a series of compounds.The prostereogenic carbon gets converted to stereogenic carbon by a nucleophilic attack on either side of the plane of carbonyl group. Different organic compounds containing >C=O group undergo photocyclisation or photoreduction reactions and result a variety of compounds of both chemical and mechanistic interest. ?-diketones an important class of carbonyl compounds afford stable ylides and Aldol adducts when interacted with different reagents under varying conditions.