%0 Journal Article
%T Studies on Thermophysical Properties of CaO and MgO by -Ray Attenuation
%A A. S. Madhusudhan Rao
%A K. Narender
%J Journal of Thermodynamics
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/123478
%X The study on temperature dependent 污-ray attenuation and thermophysical properties of CaO and MgO has been carried out in the temperature range 300ˋK每1250ˋK using different energies of 污-beam, namely, Am (0.0595ˋMeV), Cs (0.66ˋMeV), and Co (1.173ˋMeV and 1.332ˋMeV) on 污-ray densitometer fabricated in our laboratory. The linear attenuation coefficients (米l) for the pellets of CaO and MgO as a function of temperature have been determined using 污-beam of different energies. The coefficients of temperature dependence of density have been reported. The variation of density and linear thermal expansion of CaO and MgO in the temperature range of 300ˋK每1250ˋK has been studied and compared with the results available in the literature. The temperature dependence of linear attenuation coefficients, density, and thermal expansion has been represented by second degree polynomial. Volume thermal expansion coefficients have been reported. 1. Introduction Density and thermal expansion are fundamental thermophysical properties of solids. The study of temperature dependence of these properties is very important in understanding the temperature variation of other properties like elastic constants, refractive indices, dielectric constants, thermal conductivity, diffusion coefficients, and other heat transfer dimensionless numbers. Thermal expansion of solids is of technical importance as it determines the thermal stability and thermal shock resistance of the material. In general the thermal expansion characteristics decide the choice of material for the construction of metrological instruments and the choice of container material in nuclear fuel technology. A number of methods have evolved for the determination of density and thermal expansion of solids at high temperature like Archimedean method [1每3], pycnometry [4每8], dilatometry [9每12], electromagnetic levitation [13], method of maximal pressure in gas bubble [14每18], method of sessile drop [19], hydrostatic weighing [20, 21], high temperature electrostatic levitation [22], and gamma ray densitometry [23每34]. Using 污-ray attenuation technique Drotning [23] measured thermal expansion of solid materials at high temperatures. He studied thermal expansion of aluminum and type 303 stainless steel at high temperatures and such studies have been extended by him to study the thermal expansion of metals and glasses in the condensed state [24]. The 污-radiation attenuation technique for the determination of thermophysical properties in the condensed state has several advantages over other methods at high temperatures. This is
%U http://www.hindawi.com/journals/jther/2014/123478/