Browsing by Issue Date, starting with "1970"

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Dependence of the phonon conductivity correction term on the relative strength of normal and umklapp processes in undoped and doped Ge in the range from 2 to 80 K
(1970) Y.P. Joshi; M.D. Tiwari; G.S. Verma
Introducing a parameter a which determines the relative strength of normal and umklapp phonon processes, the correction to phonon conductivity of undoped and doped Ge due to normal processes has been estimated in the framework of Callaway's model in the temperature range from 2 to 80 K for various values of a ranging from 0.1 to 10. There is an overall increase in the correction term with the increase in temperature, the maximum being below 10%. © 1970.
New method for the spectrophotometric determination of phosphate as molybdenum blue using ferrous ammonium sulphate as reducing agent
(Springer-Verlag, 1970) T.S.B. Narasaraju; R.P. Singh; V.L.N. Rao
[No abstract available]
Trade Unions' Participation in the Planned Economy of India
(1970) Suresh Chandra Srivastva
[No abstract available]
Kinematical evaluation of force constants: Application to trihalides of phosphorus and arsenic
(1970) S.N. Rai; S.N. Thakur
The F-matrix elements for the two-dimensional symmetry species are dependent on one arbitrary parameter in addition to the vibrational frequencies. This parameter has been chosen as an angle π (0 ≤ π ≤ 2π) and the F-matrix elements for the A1- and the E-species of trihalides of phosphorus and arsenic have been studied as functions of π. It is found that the best values of the force constants obtained from Coriolis 1; constants can be correlated with those values of the angle ξ for which the bending force constant exhibits a minimum. © 1970 Australian Journal of Chemistry. All rights reserved.
Effect of magnetic perturbation on the magneto-active plasma
(1970) R.P. Singh; R.N. Singh
The effect of magnetic perturbation on the magneto-active plasma has been considered. The collisionless Boltzmann transport equation has been solved for an assumed perturbation in the Maxwellian velocity distribution function. An expression for energy transfer has been derived in terms of perturbed distribution function. Using the magnitude of perturbation for certain astrophysical and laboratory conditions, the heating or cooling of the magneto-active plasma has been studied. © 1970 Società Italiana di Fisica.
The evaluation of elastic constants of Mg2Sn and Mg 2Si by an angular force model
(1970) Arunsingh; B. Dayal
The method introduced by Gazis et al (1960) for taking angular forces into account has been used to derive the coupling coefficient of fluorite structure and to compute elastic constants of Mg2Sn and Mg2Si. Very good agreement with experimental results has been obtained. The difference between this type of angular force and that used by de Launay (1956) has been pointed out and the inadequacy of the latter has been discussed.
Influence of ph on cathodic polarization of germanium electrodes
(1970) D. Singh; A.N. Dwivedi
Cathodic polarization of p-Ge electrodes has been studied in solutions (0.02N TEABr + HBr) and (0.02N TEAI + X N H2SO4) where X denotes the normality of acids. The Tafel relation η= a-b log i is not valid over a wide range of current densities. Source of protons in hydrogen evolution in acidic solution is the hydronium ion (H3O+). The parameters: b, α and v support the mechanism: [formula omitted] where Ge denotes the surface of germanium. Hydrogen overpotential decreases with decrease in the pH of the solution. © 1970, Walter de Gruyter. All rights reserved.
On the frequency-magnitude relation log N = a - b M
(Birkhäuser-Verlag, 1970) R.K.S. Chouhan
This paper is an attempt to study the dependence of constants b on a, of the Gutenberg-Richter's frequency-magnitude relation log N = a - b M which seems to be linear. Further it is found that the maximum magnitude observed in a particular region can be approximated by the ratio a/b. © 1970 Birkhäuser Verlag.
Frequency spectra of disordered chains in next-nearest neighbour interaction
(1970) P. Sah; K.P. Srivastava
A study of the frequency spectra of binary, isotopic, one-dimensional lattices in next-nearest-neighbour interaction is reported. The effect of concentration, mass-ratio and force constants is studied for chains of medium length. The apparent contradiction between the results of Martin and Brouers and Deltour has been explained to be due to the role of mass ratio and the relative magnitudes of the force constants in determining the changes in the spectra. © 1970.
Nicotinic activity of choline
(1970) A.K. Sanyal; S.K. Bhattacharya; M.K. Raina
[No abstract available]
Cytological Observations on Two Siphonaceous Marine Algae
(1970) Y.B.K. Chowdary
[No abstract available]
Complexes of pyridine N-oxides with cadmium(II) thiocyanate
(1970) I.S. Ahuja; P. Rastogi
[No abstract available]
On the Connection between the RMS Charge Radii and σbE1for Tri-Nucleons
(1970) V.S. Mathiir; A.V. Lagu
[No abstract available]
PHONON CONDUCTIVITY OF NON-METALLIC CRYSTALS
(1970) G.S. Verma
In doped semiconductors, the resonant scattering of phonons by bound donor electrons at low temperatures in the deformation potential approximation, rigorous theories, both perturbative, and non- perturbative (Green's function), are available. With this aim in view the resonant scattering of phonons in Sb-and As- doped Ge has been examined.
Earthquakes in the Himalayan region
(Birkhäuser-Verlag, 1970) R.K.S. Chouhan
Himalayan earthquakes have been studied following the method of Benioff and then a comparative study of energy relased by the Himalayan and the world shallow earthquakes is made. Frequency-magnitude analysis of these earthquakes gives the frequency-magnitude relation of the form log N =a -bM where a=8.46±0.07 and b=1±0.8. © 1970 Birkhäuser Verlag.
Crystal Vibrations of Silicon by the Use of Valence Force Potentials
(1970) B.D. Singh; B. Dayal
The dispersion curves for silicon in the symmetry directions [ζ, 0, 0], [ζ, ζ, 0] and [ζ, ζ, ζ] are calculated using valence force potentials. Two different models have been used, the one with three valence force constants and the other with six valence force constants. The initial set of three valence force constants have been derived by incorporating Lippincott potential in the general valence force field for silicon. The force constants have been refined using a manual method and further by a least square fitting program with some known neutron scattering frequencies. The results with the six adjusted valence force constants potential model are in good agreement with the experimental results. The Debye characteristic temperatures have been calculated and they are in good agreement with the experimental values. Copyright © 1970 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim
Solidification of aluminium-germanium alloys at high cooling rates
(Kluwer Academic Publishers, 1970) C. Suryanarayana; T.R. Anantharaman
Aluminium-germanium alloys, covering the entire composition range, were subjected to rapid solidification by different techniques ranging from the gun technique of splat cooling to simple quenching of the melt in water. The constitution, microstructure and crystal structure of the alloys thus solidified under cooling rates varying from 103 to 107° C/sec were studied by standard optical, electron- and X-ray metallographic techniques. The solid solubility of Ge in Al could be increased from the equilibrium value of 2.8 at. % to a maximum of 7.2 at. %. In addition, two new non-equilibrium tetragonal phases γ1(a=12.91 to 13.11 Å, c=12.00 to 12.10 Å) and γ2(a=14.98 Å, c= 16.03 Å) could be obtained in alloys containing 15 to 40 and 40 to 80 at. % Ge respectively. In relation to the face-centred cubic α solid solution, these appear to be made up of 30 and 52 unit cells, respectively, with the relations {Mathematical expression}, {Mathematical expression} and {Mathematical expression}, {Mathematical expression}. A new non-equilibrium constitution diagram connecting cooling rate with constitution at room temperature has been proposed and seems to explain all observations satisfactorily. © 1970 Chapman and Hall Ltd.
Seismotectonics of Hindukush
(Birkhäuser-Verlag, 1970) R.K.S. Chouhan
Elastic strain rebound increments for the Hindukush region has been studiedwhich revealed a cyclic pattern of strain release in this area where the rate of strain release decreases with time. The spatial distribution of earthquakes clearly defines the Pamir knot where most of the shocks are concentrated. The dip of the deep seated fault which produces the earthquakes so frequently comes out to be 54° dipping in the northwest direction. This fault is best developed between 70 to 300 kilometers and perhaps both these levels represent tectonic discontinuities. © 1970 Birkhäuser Verlag.
Non existence of spherically symmetric solution representing vacuum electrostatic field
(1970) R. Tiwari; D.N. Pant
Spherically symmetric solution representing the external field of a localized charge does not exist in Einstein's unified field theory. © 1970.
On the connection between the RMS charge radii and σb E1 for tri-nucleons
(1970) V.S. Mathur; A.V. Lagu
[No abstract available]