Papers

The electrical conductivity (s) and Seebeck Coefficient (S) of the solidified melt of lithium based superionic system Li3BO3 : xLi3PO4 (with x = 0,0.33, 0.50, 0.67, 1.0, 1.5 and 2.0) are presented in the temperature range 450 to the melting point of each solid. The ionic (si) and electronic (se) contribution towards the electrical conductivity (s) have been separated over the entire temperature range with the time dependence study of d.c. electrical conductivity (sdc). In all the studied solids superionic phase have been observed below their melting points and conductivity is purely ionic in that phase. The phase transition temperature (Tp) at which solid undergoes from normal to superionic phase has been obtained. It has been shown that these solids are mixed conductor in normal phase. The variation of both the si and se with the temperature are presented and conduction mechanism have also been discussed.
 

Ultrasonic velocity and density data are utilized to estimate a number of important and useful thermodynamic properties of nine liquids (water, methyl alcohol, ethyl alcohol, n-propyl alconol, n-butyl alcohol, eugenol, carbon tetrachloride, n-hexane & toluene) as a function of pressure at different temperatures. The calculated properties include adiabatic compressibiliy (bs), isothermal compressibility (bT), thermal expansivity (a), heat capacity at constant pressure (Cp) and at constant volume (Cv) pseudo Gruneisen parameter (G), heat capacities ratio (g), energy of vaporization (DEvap), heat of vaporization (DHvap) and molecular radii (r) satisfactory agreement for all the properties has been found.

The measurement of electrical conductivity (s) and Seebeck coefficient (S) of the studied solid of the system (1-x) Li3PO4 : x Li3 VO4 with x = 0, 0.33, 0.55, 0.67 and 1.0 have been reported from 500 K to melting point of the solid. All the studied solids show superionic phase just below their melting point. In superionic phase s value and activation energy decreases but the temperature span of superionic phase increases for the solids with the increase in x. The phase transition temperature (Tp) from normal to superionic phase decreases with decrease in x. All the solids are mixed conductors with dominant ionic conductivity below transition temperature Tp.
 

Apparent molal volume (fv) and apparent molal compressibility (fk) have been evaluated by measuring ultrasonic sound velocities and densities in 20, 30, 40, 50, 60, 70, 80% dioxane-water mixture at 303K. Data obtained is utilised to explain the ion-solvent and ion-ion interaction in solution with increasing percentage of organic solvent.

The present study was undertaken to find out fluoride and trace/toxic elements in ground water sources such as hand pump and borewell. 30Nos of water samples of hand pumps and bore wells were collected from different municipal area of Dabra Covering5sq.Km. area. The primary aim of this study was to find out the concentration of fluoride in the samples of drinking water. These studies revealed that all the chemical parameters of water samples are within the range recommended by ISI and WHO.
 

Taking the role of interaction of return stroke ion beam forming current flow in preionized plasma channel due to stepped leader, a study on the radiated electromagnetic power in the form of ion Whistler Anomalous Doppler Shifted (ADS) mode from lightening return stroke channel is made. As a result of beam particle interaction the return stroke ion beam is retarded by the plasma wave turbulence in the stepped leader. The current thus generated does not vary linearly. Its variation can be approximated to be of the simple harmonic form. In this paper it is estimated that the only one quarter of the total energy of the return stroke is given to electromagnetic waves.

Rare earth elements contents of 30 granitoids from Central Iran have been determind by neutron activation analysis (NAA). Intrusive alkali-granites contain aplitic dikes and enclaves. All of these three rock types are alkali-granite in petrographic study. Similar REE contents and parallel chondrite REE patterns of all samples reveals that they were all produced by a same petrogenesis.