Papers

This paper considers the three dimensional mixed convective MHD flow and heat transfer of a viscous incompressible electrically conducting fluid through a highly porous medium bounded by an infinite vertical porous plate with periodic permeability. The main objective of this study is to analyze the effect of periodic permeability and applied magnetic field on the flow field through a highly porous medium bounded by an infinite vertical porous plate. Assuming the free stream velocity to be uniform, the governing equations are solved and approximate solutions are obtained for the velocity field, the temperature field, the skin friction and the heat flux in terms of Nusselt number (Nu). The effects of the flow parameters characterizing the flow field are studied and discussed with the help of figures and tables.

 

Biosorption of Congo red dye from an aqueous solution was investigated by the Groundnut shell in batch studies at different sorbent dosage (0.2 to 0.6 g per 100 mL), pH (1 to 6) and initial dye concentration (20 to 120 g/L). Langmuir and Freundlich adsorption isotherm models were used to represent the equilibrium data. The Freundlich isotherm model was found to be fitted very well with the experimental data when compared to Langmuir isotherm model. The results showed that the equilibrium uptake capacity was found to be increased with decrease in biomass dosage. The equilibrium uptake capacity was influenced by the initial dye concentration. The sorption results were analysed for pseudo first order and pseudo second order kinetic model. From the result, it was observed that the kinetic data fitted very well with the pseudo second order rate equation when compared to the pseudo first order rate equation.
 

The electromagnetic field in the focal plane of a finite axially-symmetrical paraboloidal reflector illuminated by plane wave of arbitary polarisation incident nearly normally at vertex, has been investigated. This paper describe the investigation, explains the method, and summarizes some of its results. The reflector is assumed to be of a focal length which is large compared with the wave length of the incident wave, and the plane of aperture is assumed to be about halfway between the focus and vertex. The purpose is to view of the diffraction pattern in the focal plane by treating the current induced on the concave surface of the reflector, so that the electromagnetic effect due to them on one part on the surface is taken into account at another by means of waves of current and charges on the paraboloid.
 

Fluoride concentration has been quantitatively determined for ground water samples from Varattupallam and Kumbaravani Pallam watershed of Bhavani Sub-Basin. The results do not indicate large variation. A minimum of 0.2 mg/l to maximum of 2.0mg/l in the post monsoon and a minimum of 0.2 mg/l to a maximum of 11.00 mg/l in pre monsoon samples have been observed in the study area. Most of the samples show <1.5 mg/l except in few locations. The sample near K.T. Ammankoil Pudur (Loc. No. 25) and Kattupalayam (Loc.No.46) have recorded slightly higher concentration >1.5 mg/l during the post monsoon, where as during pre monsoon, the sample near Palliapalam recorded anomalous high concentration of fluoride (11.00 mg/l). The studies of fluoride concentration do not indicate any significance alarming impact except the area near Palliapalayam. The possible source can be attributed to the influence of fluoride bearing minerals in the country rock Fissile Hornblende Biotite Gneiss.
 

The quality of water deteriorating day by day because of increasing population, industrialization and technical advancement. It becomes necessary to know the quality of water before use as water reservoirs are continuously get polluted by wastewater from different industrial discharge. Stone quarrying industries are small scale industries which cause environment pollution. A study was carried out to analysis the water quality in stone quarry area. Many stone quarrying industries are situated in neelbud and ratibad area near Bhopal. Effluent of these industries dumped into kerwa dam. Various physicio chemical parameters temperature, pH, electrical Conductivity, total dissolved Solids, Alkalinity, Sulphate, Nitrate, Phosphate and Chloride were analyzed to assess the quality of water. And it was found that concentration of these parameters were higher than tolerance limits as prescribed by BIS and APHA.

The objective of this investigation was to develop a high performance liquid chromatographic method for the determination of Penicillin G,which is widely used in clinical practice. The quantification was carried out using a RP C-18 column in isocratic mode with mobile phase acetonitrile: water: sodium acetate.Cephalexin was used as internal standard. The detection was carried out at 245 nm which was used for direct evaluation of the chromatograms in reflectance/absorbance mode and the good linear relationship was found. The calibration curves were established as dependence of peak height and peak area versus concentration. Standard deviation obtained from calibration curves was compared. Precision and detection limits was validated and found to be satisfactory. The method was found to be reproducible and convenient for quantitative analysis of penicillin G in their raw materials and their dosage forms.

A detailed analysis of the very low frequency (VLF) wave data obtained during whistler campaigns under All India Coordinated Program of lonosphere Thermosphere Studies (AICPITS) at the low latitude ground station Jammu (geomagnetic latitude = 22° 26^/ N, L = 1.17) has yielded two types of unusual and unique whistler-triggered VLF emissions. These include (1) Whistler-triggered hook VLF emissions and (2) Whistler-triggered long enduring discrete chorus VLF emissions during night time. Such types of whistler-triggered VLF emissions have not been reported earlier from the ground observations at low latitudes. In the present study, the observed characteristics of these emissions are described and interpretated, Dispersion analysis of these emissions show that the whistlers have propagated along a path with L-values lying between L = 2.4 and 3.6, suggesting that these whistlers are to be regarded as mid-latitude whistlers. These waves could have propagated along the geomagnetic field lines earlier in a ducted mode or in a pro-longitudinal mode. It is speculated that these emissions may have been generated through a process of resonant interaction of the whistler waves with energetic electrons.

In present study physico-chemical analysis of waste water which is used for agricultural purpose and chemotoxic analysis of soil have been conducted at Neelbad near Bhopal. The results reveals that chemical pollutants present in soil and irrigated water which are adversely affecting the crops and water reservoirs.

The diester as its monochloridate (C-N-P-linkage) is functionally modified, by the introduction of a p-methoxy substituent in the aryl matrix. The hydrolysis proceeds in the pH region 1.24-10.00 in 20% acetic acid (v/v) at 40^oC. First order rate constants have been estimated in the entire range of study using Allen's modified method of colorimetric measurement. Initial increase in rates is followed by a gradual decrease till a minimum appears at an uncommon pH value, where the percentage of the monoanion is however the maximum. The presence of the neutral form is also decided by knowing their fractions from the pK value at the above pH. Thus neutral form is however, not simple but is rather present as the zwitter ionic form. This is shown by the effect of solvent studies where lowering in rates occurs in spite of an increase in the polarity of the solvent. This is because the zwitterion if present, will form a transition state with the dispersion of charge present, as demanded by the decrease in rates by solvent effect study. The monoanion form, however is expected to form a polar transition state and this is strengthened by a changeover to a solvent of higher polarity leading to higher rates. Arrhenius parameters however require an unstable transition state for the bimolecular hydrolysis to proceed.

In the context of fast depletion of fossil fuels and increase of pollution levels with conventional fuels, the search for alternate fuels has become pertinent. Alcohols and vegetable oils are probable means to replace diesel fuels as they are renewable in nature. However, use of alcohols in internal combustion engines is limited, as the properties of alcohol fuels are not compatible with diesel fuels. Hence much emphasis is given to the non-edible vegetable oils as alternate fuels in internal combustion engines. However, the drawbacks of low volatility and high viscosity associated with non-edible vegetable oils call for hot combustion chamber, provided by low heat rejection diesel engine. The crude vegetable oils are converted into bio-diesel by the process of esterification, to reduce the molecular weight and viscosity of crude oil. The investigations are carried out on low heat rejection diesel engines which consist of different degree of insulations such as i) air gap insulated piston with superni crown, air gap insulated liner with superni insert and ii) air gap insulated piston with superni crown, air gap insulated liner with superni insert and ceramic coated cylinder head with esterified pongamia oil (bio-diesel) with varied injection pressures. Performance is improved with high degree of insulation with vegetable oil in comparison with conventional engine with pure diesel operation