Showing 1 to 10 of 63 matching Articles
Results per page:
Export (CSV)
By
Dasmahapatra, B K
3 Citations
The Kcapture probability (P_{K}) in the decay of^{139}Ce (137.5d) has been determined from the analysis of the K xray gamma ray sumpeak observed with a Ge (Li) xray detector. Furthermore,P_{K} is estimated independently from the measurement of the K xray intensity in the decay, using the known conversion coefficients of the 165.8 keV transition. Using the weighted average ofP_{K} measured as above, the mass difference between^{139}Ce and^{139}La is found to be 273
_{−13}^{+21}
keV.
more …
By
Gai, Pratibha L; Rao, C N R
4 Citations
Lattice imaging technique of high resolution electron microscopy has been employed to examine 4H, 6H and 9R ABO_{3} perovskite polytypes. The lattice images can be correlated with the lattice periodicity and the stacking sequence of AO_{3} layers and BO_{6} octahedra. The study shows the utility and validity of the lattice imaging technique for the study of relatively closepacked systems.
more …
By
Sharma, M L; Bondyopadhyay, D
An approximate method based on Fredholm approximants is used to solve LippmannSchwinger equation forsandpwave Yukawa andswave exponential potential scattering problems. The method is then applied to a problem ofππ scattering i nvolving the use of a well known equivalent potential. The equation for partial wave amplitudes is solved to generate the first threeππ resonances,ρ, f_{0}, andg, in a selfconsistent manner.
more …
By
Mukherjee, D; Moitra, R K; Mukhopadhyay, A
90 Citations
A nonperturbative theory is proposed in this article in which an energy independent effective Hamiltonian is obtained for openshell systems. We have given a diagrammatic version of theory to facilitate the analysis of the problem. The theory has been applied to a model 4π electron problem, for calculating the lowestππ* singlet and triplet energy levels of transbutadiene. Comparison with full Cl calculation indicates the excellent workability of the theory.
more …
By
Amirthalingam, V; Muralidharan, K V
16 Citations
The crystal structure of bis(Lthreonine) copper (II).H_{2}O, Cu (C_{4}H_{8}NO_{3})_{2}.H_{2}O has been determined by heavy atom and Fourier methods and refined by leastsquares using visually estimated threedimensional xray data of 893 reflections. The blue crystals are monoclinic, space groupP2_{1} withα=11·02,b=4·90,c=11·16Å andβ=93·5°,Z=2. The finalR is 0·10. Coordination of copper is distorted square pyramidal with ligands intrans configuration. The conformation of one of the aminoacid ligand is identical with L_{s}Threonine while the other has a conformation with torsional angleχ^{1, 2}=−74(1)°.
more …
By
Abdelaziz, Mohamed E; Eid, Mohamed A; Abdelsalam, Fatma
This work presents the characteristics of a high frequency ion source operating on a low energy, 150 keV accelerator. The latter is to be used as a neutron generator and its design is based on a theoretical analysis which shows that if the axial potential in an electrostatic electrode system is made to increase with four thirds the power of axial distance, inward electric forces will compensate space charge forces tending to blow up the beam. This results in a simplified acceleration tube much shorter and of higher gradient than the conventional acceleration columns. The ion source itself is an ordinary type using axial extraction of the beam, and its main properties investigated are the beam current and beam quality (or emittance). Dependence of the two on different parameters is investigated in a series of tests.
more …
By
Prasanna, A R
1 Citations
In this paper we have extended our earlier studies of solutions of EinsteinCartan equations to the case where a magnetic field coexists with the matter distribution. We have obtained an exact solution of EinsteinCartanMaxwell equations representing a static cylinder of perfect fluid with an axial magnetic fieldH and a nonzero spin densityK, satisfying the equation of stateρ=γ(p_{r}+p_{s}−H^{2}/4π),γ being a constant. We notice that as a consequence of field equations there exists a direct relation between the pressurep, and the spin densityK, indicating that an increase in pressure would enormously increase the spin density.
more …
By
Lord, Eric A
The improvement terms in the generalised energymomentum tensor of Callan, Coleman and Jackiw can be derived from a variational principle if the Lagrangian is generalised to describe coupling between ‘matter’ fields and a spin2 boson field. The required Lorentzinvariant theory is a linearised version of KibbleSciama theory with an additional (generallycovariant) coupling term in the Lagrangian. The improved energymomentum tensor appears as the source of the spin2 field, if terms of second order in the coupling constant are neglected.
more …
By
Bhiday, M R; Rao, Miss S
5 Citations
Absorption of polarization in fluorocarbon foil electrets has been studied under different conditions. The mode of surface charge decay of thermoand radioelectrets has been explained by the mechanism of polarization trapping in electrets.
