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91.
92.
R.N. Acharya K. Sudarshan A.G.C. Nair Y.M. Scindia A. Goswami A.V.R. Reddy S.B. Manohar 《Journal of Radioanalytical and Nuclear Chemistry》2001,250(2):303-307
The guided thermal neutron beam at 100 MW Dhruva research reactor facility of Bhabha Atomic Research Centre (BARC) was used to carry out prompt gamma-ray neutron activation analysis (PGNAA). The prompt k
0-factors have been determined for the isotopes of the elements H, B, K, Co, Cu, Ca, Ti, Cr, Cd, Ba, Hg and Gd with respect to 1951 keV gamma-line of 36Cl. The prompt k
0-factors for H, Cl and Cu were also measured with respect to the 1381 keV gamma-line of 49Ti. Different samples like NH4Cl, Ti metal, cobalt chloride and other stoichiometric compounds and pure metals were used for this purpose. Prompt gamma-rays were accumulated using a 22% HPGe detector connected to a PC based 8k MCA in single mode counting. The energy calibration in the range of 100–8500 keV was carried out using gamma-rays from 152Eu and 60Co, and the prompt gamma-rays from 36Cl whereas the absolute detection efficiency for this energy range was determined using 152Eu and prompt gamma-rays from 36Cl and 49Ti. 相似文献
93.
The response of a rigid rectangular block resting on a rigid foundation and acted upon simultaneously by a horizontal and a vertical random white-noise excitation is considered. In the equation of motion, the energy dissipation is modeled through a viscous damping term. Under the assumption that the body does not topple, the steady-state joint probability density function of the rotation and the rotational velocity is obtained using the Fokker-Planck equation approach. Closed form solution is obtained for a specific combination of system parameters. A more general but approximate solution to the joint probability density function based on the method of equivalent non-linearization is also presented. Further, the problem of overturning of the block is approached in the framework of the diffusion methods for first passage failure studies. The overturning of the block is deemed incipient when the response trajectories in the phase plane cross the separatrix of the conservative unforced system. Expressions for the moments of first passage time are obtained via a series solution to the governing generalized Pontriagin-Vitt equations. Numerical results illustra- tive of the theoretical solutions are presented and their validity is examined through limited amount of digital simulations. 相似文献
94.
95.
M. C. Goromonzi S. K. Raman B. D. Padalia A. Manohar P. N. Koul 《Reaction Kinetics and Catalysis Letters》1980,15(1):131-136
The cause for a fall in the conversion of NH3 to NO within 73 hours from 97% to 78% with a cobalt oxide catalyst was investigated. Results show that sintering, change in valence and cation distribution in Co3O4 contribute to the decrease in activity. Incorporation of ThO2 and K2O improves the performance of the catalyst.
NH3 NO 73 97% 78%. , , Co3O4. ThO2 K2O NH3 NO.相似文献
96.
97.
Nanofibers of doped polyaniline.HCSA having diameters 1-2 nm are observed in TEM images of bath sonicated aqueous dispersions of larger nanofibers (30-50 nm diameter) synthesized by surfactant-assisted chemical oxidative polymerization of aniline in dilute aqueous organic acids. 相似文献
98.
99.
A. Goswami S. B. Manohar S. K. Das A. V. R. Reddy B. S. Tomar S. Prakash 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(3):299-301
Mass resolved fission fragment angular distribution was measured in the 28.5 MeV alpha induced fission of233U using recoil catcher technique and direct gamma spectrometry. The angular distribution of 8 fission products were obtained. The angular anisotropies of asymmetric fission products were found to be higher than those of symmetric products indicating a correlation between the fragment angular distribution and the mass distribution.The authors are grateful to Dr. S.K. Kataria and Dr. T. Datta for fruitful discussions. We thank the operation crew of the variable energy cyclotron, Calcutta for their help in carrying out the irradiations. Thanks are due to Dr. P.R. Natarajan, Head of the Radiochemistry Division for his keen interest in the work. 相似文献
100.
B. S. Tomar A. Goswami A. V. R. Reddy S. K. Das P. P. Burte S. B. Manohar Satya Prakash 《Zeitschrift für Physik A Hadrons and Nuclei》1992,342(2):223-227
Excitation functions for the evaporation residues for the reactions12C+93Nb and16O+89Y in the projectile energy range of 4 to 6.5 MeV/amu have been measured using off-line gamma spectrometry. The excitation functions for neutron(xn), proton(pxn) and one alpha(xn) emission channels are practically similar for both the reactions. However the products formed by two alpha(2xn) emission show much higher cross sections in the12C+93Nb than the16O+89Y system. This has been explained in terms of the incomplete fusion process involving transfer of an alpha particle from the projectile to the target in the former case.Authors thank Shri D.C. Ephraim for making the rolled metal foils and the operation crew of PELLETRON facility for their help in carrying out the irradiations. Authors are grateful to Dr. P.R. Natarajan, Head Radiochemistry Division for his keen interest in this work. 相似文献