NOPR Community:

Heat and mass transfer over a three-dimensional inclined non-linear stretching sheet with convective boundary conditions

2017-12-01T00:00:00Z

Title: Heat and mass transfer over a three-dimensional inclined non-linear stretching sheet with convective boundary conditions Authors: Jain, Shalini; Bohra, Shweta Abstract: This investigation has been made to study of heat and mass on three-dimensional boundary layer flow of an incompressible fluid due to inclined non-linear stretching sheet with convective boundary conditions. The effect of thermophoresis and chemical reaction has been taken into account. Numerical solution has been obtained for the set of non-linear coupled ordinary equations which are reduced by using similarity transformations from non-linear partial differential equations. Transforms system of equations has been solved using Runge–Kutta–Fehlberg fourth–fifth order method along with shooting technique. Effects of various parameters on velocity, temperature and concentration profiles have been obtained. These results have been presented through graphs and also our analysis explores the physical quantities of interest through the tables. Page(s): 847-856

Investigation of fixed point of copper in the metal-in-graphite blackbody cavity using standard photoelectric linear pyrometer

2017-12-01T00:00:00Z

Title: Investigation of fixed point of copper in the metal-in-graphite blackbody cavity using standard photoelectric linear pyrometer Authors: Rani, Arti; Singh, Y P Abstract: The phase transition temperature of high purity copper has been used as fixed point temperature to calibrate standard thermometers of both contact as well as non-contact type. In the present work the freezing point of copper has been measured by a spectral radiation pyrometer using copper-in-graphite black body crucible fabricated in the form of a cavity with an aperture of 10 mm. A recently procured detector based photoelectric pyrometer, LP4 has been used as transfer standard in the measurement process. The output signal of photocurrent due to radiation from the source of copper blackbody cavity at wavelength of 650 nm in vacuum has been measured during the period when metal changes its phase from solid to liquid and liquid to solid. The stability of fixed point has been determined from the melting and freezing curves plotted between the photocurrent or corresponding temperature and the time period of the whole cycle. The uncertainty in the measurement of copper point has been evaluated to be ± 0.530 ºC and thus the copper freezing point has been determined to be 1083.41 ºC (± 0.53 ºC, at k =2) differing from the assigned value in the international temperature scale of 1990 (ITS-90) by 1.21 ºC lower while the melting point of copper has been determined to be 1084.23 °C differing by 0.39 °C lower respectively than the defined value of ITS-90. Page(s): 857-863

Viscous dissipation and Joule heating effects on an unsteady magnetohydrodynamic flow over a linearly stretching permeable surface with uniform wall temperature

2017-12-01T00:00:00Z

Title: Viscous dissipation and Joule heating effects on an unsteady magnetohydrodynamic flow over a linearly stretching permeable surface with uniform wall temperature Authors: Chaudhary, Santosh; Choudhary, Mohan Kumar Abstract: An analysis has been presented to describe the effects of viscous dissipation and Joule heating on an unsteady laminar two-dimensional flow of a viscous incompressible electrically conducting fluid over a stretching permeable surface in the presence of a uniform transverse magnetic field. Similarity solutions for the problem have been formulated and reduced nonlinear ordinary differential equations have been solved numerically using fourth order Runge-Kutta method with shooting technique. Influences of various parameters, namely, mass transfer parameter, unsteadiness parameter, magnetic parameter, Prandtl numberand Eckert number on velocity and temperature distributions have been plotted graphically while skin-friction coefficient and Nusselt number have been shown numerically. A comparison of the obtained numerical results has been made with previously published results for non-magnetic case. Page(s): 864-872

Physico chemical study on extraction of uranium

2017-12-01T00:00:00Z

Title: Physico chemical study on extraction of uranium Authors: Giri, R; Nath, G Abstract: In extraction technology, the sample pretreatment and particle disruption is an important aspects for analysis of extraction efficiency of any blended chemicals. This analytical study can be performed with the propagation of high energy ultrasound due to its characteristic property like high frequency and high wavelength comparable to atomic and subatomic dimension. This paper describes the effect of ultrasonic wave and sonication effect for extraction of uranyl nitrate with optimum blended solvent methyl iso-butyl ketone (MIBK). The result of physico-chemical properties well establishes the supporting environment for extraction of uranium (IV) from uranyl nitrate using 40% of MIBK at room temperature and for the low frequency ultrasonic wave. Page(s): 873-880