Effect of Viscous Dissipation, Soret and Dufour Effect on Free Convection Heat and Mass Transfer from Vertical Surface in a Porous Medium

AbstractIn the present approach, a two dimensional steady free convection flow of heat and mass transfer from a vertical surface in porous media with viscous dissipation has been analyzed numerically considering Soret and Dufour effects. The governing non linear partial differential equations have been transformed by a similar transformation in to a system of ordinary differential equations, which are solved numerically by using implicit finite difference scheme. The dimensionless velocity, temperature and concentration profiles are displayed graphically showing the effects for the different values of the Lewis number, soret number and viscous dissipation parameter

Preliminary Results of Radiological Impact Studies on the Usage of Granites in Hyderabad, Telangana State, India

Abstract Natural background gamma radiation levels were measured using a NaI crystal based survey meter in different type's granite slab environs. These levels are found to vary between 2015 µGy y -1 and 2716 µGy y -1 with an average of 2270 µGy y -1 . This study establishes that usage of the granites as a flooring material in the building construction industry in the city like Hyderabad may not pose any additional radiation burden on the population

Determination of Phase Composition of Cobalt Nanoparticles Using 59Co Internal Field Nuclear Magnetic Resonance

It is well known that cobalt exhibits polymorphism, i.e., the co-existence of both the hcp and fcc phases. In particular, the method of synthesis and other thermodynamic conditions is known to play a crucial role in determining the particular phase of cobalt. In this work, we have compared the phase composition of the cobalt nanoparticles synthesized using two different solvents (water) and ethanol (Co@C). XRD measurements confirm the existence of fcc phase in commercial cobalt nanoparticles (Co@A), co-existence of fcc and hcp phases in Co@B, while the existence of the hcp phase in Co@C. We have studied these cobalt nanoparticles using 59Co internal field nuclear magnetic resonance (IFNMR) for verification of phase composition. Our studies reveal that the Co@A has fcc as a major phase with minor quantity hcp phase. Co@B exhibits approximately equal amount of fcc and hcp phase while Co@C exhibits hcp as a major phase with minor fcc phase. Our SEM micrograph studies confirm that the cobalt particles have spherical shape in the fcc phase. The cobalt particles exhibit both spherical and dendrite morphology confirming the co-existence of fcc and hcp phases, while the sample with pure hcp phase exhibits the dendrite morphology. Our studies also throw light on understanding the effect of solvent in the phase formation of the cobalt nanoparticles

Determination of Phase Composition of Cobalt Nanoparticles Using 59Co Internal Field Nuclear Magnetic Resonance

It is well known that cobalt exhibits polymorphism, i.e., the co-existence of both the hcp and fcc phases. In particular, the method of synthesis and other thermodynamic conditions is known to play a crucial role in determining the particular phase of cobalt. In this work, we have compared the phase composition of the cobalt nanoparticles synthesized using two different solvents (water) and ethanol (Co@C). XRD measurements confirm the existence of fcc phase in commercial cobalt nanoparticles (Co@A), co-existence of fcc and hcp phases in Co@B, while the existence of the hcp phase in Co@C. We have studied these cobalt nanoparticles using 59Co internal field nuclear magnetic resonance (IFNMR) for verification of phase composition. Our studies reveal that the Co@A has fcc as a major phase with minor quantity hcp phase. Co@B exhibits approximately equal amount of fcc and hcp phase while Co@C exhibits hcp as a major phase with minor fcc phase. Our SEM micrograph studies confirm that the cobalt particles have spherical shape in the fcc phase. The cobalt particles exhibit both spherical and dendrite morphology confirming the co-existence of fcc and hcp phases, while the sample with pure hcp phase exhibits the dendrite morphology. Our studies also throw light on understanding the effect of solvent in the phase formation of the cobalt nanoparticles

DEVELOPMENT OF STABILITY INDICATING RP-HPLC METHOD FOR THE SIMULTANEOUS ESTIMATION OF AMBROXOL HYDROCHLORIDE AND LEVOCETIRIZINE DIHYDROCHLORIDE

A simple, precise and accurate method has been developed for simultaneous estimation of Ambroxol hydrochloride and Levocetirizine dihydrochloride. The proposed RP-HPLC method utilises Enable C18 G column (250 x 4.6mm, 5m), mobile phase consisting of Phosphate buffer pH 3.0: Methanol in the ratio of 20:80 (v/v) and UV detection at 236nm using a photodiode array detector. ambroxol hydrochloride and levocetirizine dihydrochloride were exposed to acidic, alkali, oxidative, thermal and photolytic stress conditions and the stressed samples were analysed by the proposed method. Peak homogeneity data of ambroxol hydrochloride and levocetirizine dihydrochloride in the stressed samples demonstrated the specificity of the method for their estimation in presence of degradants. The described method was linear over a range of 15 45 g/mL for ambroxol hydrochloride and 1 3 g/mL for levocetirizine dihydrochloride respectively. The method validation data showed excellent results for accuracy, precision, linearity, specificity, limit of detection, limit of quantification and robustness. The present method can be successfully used for routine quality control and stability studies

Evaluation of Neonatal Streptozotocin Induced Diabetic Rat Model for the Development of Cataract

Type 2 diabetes (T2D) generally follows prediabetes (PD) conditions such as impaired fasting glucose (IFG) and/or impaired glucose tolerance (IGT). Although studies reported an association of IGT or IFG with cataract, the experimental basis for PD associated cataract is not known. Hence, we evaluated neonatal streptozotocin (nSTZ) induced rat model to study PD associated cataractogenesis by injecting STZ to two-day old rats. While majority (70%) of nSTZ injected pups developed IGT (nSTZ-PD) by two months but not cataract even after seven months, remaining (30%) nSTZ rats developed hyperglycemia (nSTZ-D) by two months and mature cataract by seven months. Lens biochemical analysis indicated increased oxidative stress as indicated by increased SOD activity, lipid peroxidation, and protein carbonyl levels in nSTZ-D cataractous lens. There was also increased polyol pathway as assessed by aldose reductase activity and sorbitol levels. Though nSTZ-PD animals have not shown any signs of lenticular opacity, insolubilization of proteins along with enhanced polyol pathway was observed in the lens. Further there was increased oxidative stress in lens of IGT animals. These results suggest that oxidative stress along with increased polyol pathway might play a role in IGT-associated lens abnormalities. In conclusion, nSTZ-PD rat model could aid to investigate IGT-associated lens abnormalities

Three Dimensional Casson nanofluid Flow with Convective Boundary Layer via Stretching Sheet

The present work examined Casson nanofluid in a three-dimensional boundary layer motion via stretching sheet. The study focuses on analyzing the behavior of a Casson nanofluid, which is one type of non-Newtonian fluid. The study appears to involve solving partial differential equations related to fluid flow, heat transfer, and mass transfer. These PDEs are transformed into ordinary differential equations using standard similarity variables. To solve the ODEs, the researchers employ the Runge-Kutta-Fehlberg (R-K-F) 4th order iterative scheme. It appears that higher values of the Biot number can significantly affect the temperature and concentration profiles in the Casson liquid flow

Ensuring biological safety of drinking water at International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh, India

Potability of drinking water from various sources at the campus of International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Andhra Pradesh, India had been assessed for 17 years (1994 to 2010). All four sources of drinking water at ICRISAT, including Manjeera water (Municipal corporation supplied drinking water), borewell 1, borewell 2 and ICRISAT water (mixture of both Manjeera as well as borewells after treatment), were tested for their potability once in two months by most probable number (MPN) method. The results indicated that water from borewells were not safe to drink without treatment as Escherichia coli was found in 10 and 12 years out of 17 tested years for bore wells 1 and 2, respectively. Manjeera water samples were also found unsafe in two out of the 17 years, whereas ICRISAT water was found safe to drink throughout the study period. This study indicated that even deep borewells (of about 135 ft) can get contaminated, and its water is not safe to drink without treatment, and an additional treatment of municipal water supply is required in order to have safe drinking water.Keywords: Potability, drinking water, Escherichia coli, borewell water, municipal wate

EXPERIMENTAL INVESTIGATION ON PERFORMANCE AND EMISSION ANALYSIS OF CI ENGINE FUELLED WITH TAMANU BIO-DIESEL AND DIESEL USING ADDITIVE

In the current energy scene of fossil fuel, renewable energy sources such as biodiesel, bio-ethanol, bio-methane, and biomass from waste and hydrogen have become the subjects of great interest. These fuels contribute to the reduction of dependence on fossil fuels. In addition, energy sources such as these could partially replace the use of those fuels which are responsible for environmental pollution and may be scarce in the future. Vegetable oil cannot be directly used in the diesel engine for its high viscosity, high density, high flash point and lower calorific value. So it needs to be converted into biodiesel to make it consistent with fuel properties of diesel. A large variety of plants that produce non-edible oils can be considered for biodiesel production such as Tamanu (Calophyllum Inophyllum), Jatropha Curcas (Ratan Jyot), Pongamia Pinnata (Karanja) and Melia Azadirachta (Neem) etc., are easily available in developing countries and are very economical comparable to edible oils. Transport vehicles greatly pollute the environment through emissions such as CO, CO2, NOx, un-burnt or partially burnt HC and particulate emissions. Fossil fuels are the chief contributors to urban air pollution and major source of Green House Gases (GHG) and considered to be the prime cause behind the global climate change. Though diesel fuelled Compression Ignition Engine can operate at high thermal efficiency creates more emission of HC and CO, the high level of NOx poses problems. The high combustion temperature and lean mixtures used are the reasons. This work presents the results of performance and emission analysis carried out in a non-modified diesel engine fuelled with Tamanu Bio- Diesel, Di-ethyl Ether (DEE) its blends with diesel. Engine tests have been conducted to get the comparative measures of Brake Specific Fuel Consumption (BSFC), Indicated Brake Thermal Efficiency (IBTE), Mechanical Efficiency (ME), Brake Thermal Efficiency (BTE), Volumetric Efficiency and Emissions such as HC, CO, NOx and Exhaust gas temperature