Preparation and Properties of Tricyclopentadienyl Cerium (IV) Chloride and Bisindenyl Cerium (IV) Dichloride

The reactions of dipyridinium cerium (IV) hexachloride with tetracyclopentadienyl cerium or sodium cyclopentadienide and tetraindenyl cerium or sodium indenide in tetrahydrofuran yield tricyclopentadienyl cerium (IV) chloride and bisindenyl cerium (IV) dichloride. Infrared spectra, thermal stabilities and other characteristics of the compounds have been studied.     

Theory of photo induced open circuit voltage decay in a solar cell

Experimental results of photo induced open circuit voltage decay in a solar cell are now available [1]. Theoretical expressions for the decay of the voltage are derived and used to interpret these experiments.     

Phosphorus diffusion in gallium arsenide

The formation of monocrystalline GaAs_1?xP_x by the solid state diffusion of phosphorus into monocrystalline GaAs at a phosphorus pressure of 35 atm has been confirmed by X-rays and reflectivity measurements. Phosphorus distribution in GaAs specimens diffused in the temperature range 800–1100°C has been determined by reflectance studies. The diffusion coefficient and the activation energy computed from the known phosphorus distributions in the diffused specimens are found to depend on the content of phosphorus in the diffused region. The variation of the depth of GaAs_1?xP_x-GaAs junction with time (at a fixed temperature, 1000°C) and temperature (for a fixed time, 24.5 hr) has been studied.     

Consideration of viscosity variation in determining the performance characteristics of circular bearings in the laminar and turbulent regimes

The effect of viscosity variation with hydrodynamic pressure on the performance characteristics of hydrodynamic circular journal bearings was studied. Weibull's exponential relation for the pressure-dependent viscosity and the linearized turbulence theory of Ng and Pan were used to obtain the static and dynamic performance characteristics of journal bearings for a wide range of operating eccentricity ratios. The results are compared for the different values of the normalized pressure-viscosity coefficients.     

Coupled-mode model of dispersion in microstrip

A coupled-mode model for dispersion in microstrip is developed which predicts dispersion for a wide range of microstrip configurations (2 ? ?r ? 104, 0.025 in ? h ? 0.125 in and 0.9 ? w/h ? 6). The expression for the coupling coefficient is derived using qualitative arguments and experimental results, and is convenient for design purposes of microstrip components.     

On some transport properties of strontium-doped lanthanum chromite ceramics

D.C. Electrical conductivity, Hall mobility and magnetic susceptibility measurements on La_1?x Sr _x CrO₃ (0?x?0.25) perovskite ceramic system, and their temperature dependence, have been carried out to understand the nature of the transport mechanism in them. The electrical conductivity and Hall mobility displayed thermally activated temperature dependence with activation energies that varied from 0.13 to 0.23 ev. The variation of the d.c. conductivity of the polycrystalline La_1?x Sr _x CrO₃ with strontium content (X) has been found to be strongly affected by the changes in microstructure. Magnetic susceptibility data indicate that the electronic transport is due to the presence of Cr⁴⁺ ions in the lattice, and that the localized level of hopping is associated with the chromium 3d band.