Model study of hot and dense baryonic matter

The properties of baryonic matter have been investigated at finite density and temperature using different models. The variation of baryon masses and fractional number densities with baryon density and temperature obtained from different models have been compared. The quark hadron phase transition have been studied using Chiral Colour Dieletric (CCD) model in the quark sector. No phase transition has been seen for the different variants of the Zimanyi-Moszkowski model. However, a phase transition is observed for the linear and non-linear Walecka model.Comment: Latex, 16 postscript figures available on reques

Reclamation of copper-base scrap and residues

THE importance of secondary metals and alloys in copper and copper alloy industries is recognised when one considers that even in U. S. A., a country fairly rich in copper ores, about half the consumption of copper is accounted for by secondary metals . When such is the case, there is every reason to believe that India can benefit substantially by improving its secondary copper and copper alloy industries as not only is our country relatively poor in copper ore deposits, but also her demand for copper, anticipated as 238 thousand tonnes in 1970-71 would be more than 15 times its estimated licensed capacity- 16.5 thousand tonnes of fire refined blister copper at the end of the Fourth Plan.

Reclamation of Copper Base Scrap and Residues

The Railways' holdings of non-ferrous metals are estimated to exceed RS. 21 crores and a substantial portion of this amount is accounted for by the copper and copper base alloys. The annual outturn of the railway non-ferrous foundries amounts to about 23 thousand tonnes and accumalation of non-ferrous scrap at the end of March 1967 were reported as 11,400 tonnes. The value was esti-mated as Rs. 2.62 crores. The Railways reclaim most of their non-ferrous scrap arisings in their foundries; during the year 1966-67, 19,604 tonnes of non-ferrous scrap, mostly copper base, was utilised by the Railways for their own use and 1469 tonnes was disposed of to the trade

A generalization of Margolus-Levitin bound

The Margolus-Levitin lower bound on minimal time required for a state to be transformed into an orthogonal state is generalized. It is shown that for some initial states new bound is stronger than the Margolus-Levitin one.Comment: 6 pages, no figures; some comments added; final version accepted for publication in Phys. Rev.

Effect of Fibonacci Modulation On Superconductivity

We have studied finite-sized single band models with short range pairing interactions between electrons in presence of diagonal Fibonacci modulation in one dimension. Two models, namely the attractive Hubbard model and the Penson-Kolb model, have been investigated at half-filling at zero temperature by solving the Bogoliubov-de Gennes equations in real space within a mean field approximation. The competition between ``disorder'' and the pairing interaction leads to a suppression of superconductivity (of usual pairs with zero centre-of-mass momenta) in the strong-coupling limit while an enhancement of the pairing correlation is observed in the weak-coupling regime for both the models. However, the dissimilarity of the pairing mechanisms in these two models brings about notable difference in the results. The extent to which the bond ordered wave and the $\eta$-paired (of pairs with centre-of-mass momenta = $\pi$) phases of the Penson-Kolb model are affected by the disorder has also been studied in the present calculation. Some finite size effects are also identified.Comment: 14 pages, 13 figure