Evolution of Primordial Black Holes in Loop Quantum Gravity

In this work, we study the evolution of Primordial Black Holes within the context of Loop Quantum Gravity. First we calculate the scale factor and energy density of the universe for different cosmic era and then taking these as inputs we study evolution of primordial black holes. From our estimation it is found that accretion of radiation does not affect evolution of primordial black holes in loop quantum gravity even though a larger number of primordial black holes may form in early universe in comparison with Einstein's or scalar-tensor theories.Comment: 8 pages, 1 figur

Influence of surface roughness on superhydrophobicity

Superhydrophobic surfaces, with liquid contact angle theta greater than 150 degree, have important practical applications ranging from self-cleaning window glasses, paints, and fabrics to low-friction surfaces. Many biological surfaces, such as the lotus leaf, have hierarchically structured surface roughness which is optimized for superhydrophobicity through natural selection. Here we present a molecular dynamics study of liquid droplets in contact with self-affine fractal surfaces. Our results indicate that the contact angle for nanodroplets depends strongly on the root-mean-square surface roughness amplitude but is nearly independent of the fractal dimension D_f of the surface.Comment: 5 Pages, 6 figures. Minimal changes with respect to the previous versio

Flotation of Low Grade Copper ore from Kallur, Raichur District, Karnataka

Copper, an important non-ferrous metal, is in great demand in India, resulting in a continuous important of large quantities. The total copper ore reserves in India(Raghunandan et. al.1981) have been estimated to be 497 million tons of which an average of 2 million tons are being processed at present. In this c ontext the deve-lopment and exploitation of new reserves assumes impor-tance in order to meet the increasing demand from inter-nal production rather than through imports of the metal. Out of 19.4 million tons of reserves of the ore in Kar-nataka, 4.5 million tons are at present commercially exploited at Ingaldhal and Kalyadi. New ore reserves have been found at Tintini, Kailur, Machanur and Aladahalli and exploratory drilling for copper in these areas have been started by the Department of Mines and Geology. In this paper a detailed account of the beneficiation studies carried out on the low grade copper ore from Kallur, Raichur District, Karnataka are described for possible commercial exploitation in future

An extended Hubbard model with ring exchange: a route to a non-Abelian topological phase

We propose an extended Hubbard model on a 2D Kagome lattice with an additional ring-exchange term. The particles can be either bosons or spinless fermions . At a special filling fraction of 1/6 the model is analyzed in the lowest non-vanishing order of perturbation theory. Such ``undoped'' model is closely related to the Quantum Dimer Model. We show how to arrive at an exactly soluble point whose ground state manifold is the extensively degenerate ``d-isotopy space'', a necessary precondition for for a certain type of non-Abelian topological order. Near the ``special'' values, $d = 2 \cos \pi/(k+2)$, this space is expected to collapse to a stable topological phase with anyonic excitations closely related to SU(2) Chern-Simons theory at level k.Comment: 4 pages, 2 colour figures, submitted to PRL. For an extended treatment of a more general family of models see cond-mat/030912

Titanate-Zircon-Apatite Bearing Diorite-Monzodiorites and their Resource Potentiality

Placer beach sand deposits are considered as the reserve for ilmenite, rutile, zircon, monazite, xenotime. The global reserve for titanium, zirconium and rare earth metals is accounted from the distribution of these miner-als in the beach sand. It is proposed to look into Archean diorites and monzodiorites as the potential resource for these minerals. These rocks contain sphene, ilmenite, zircon and apatite in trace amount but account for about 3 wt% of TiO,, 700 ppm of Zr, and about 500-800 ppm of rare earth in bulk. The mineralogical and geochemical characteristic of such rocks is discussed. The potentia-lity of sphene as a resource for titanium is highlighte

Gamow-Teller transitions and deformation in the proton-neutron random phase approximation

We investigate reliability of Gamow-Teller transition strengths computed in the proton-neutron random phase approximation, comparing with exact results from diagonalization in full $0\hbar\omega$ shell-model spaces. By allowing the Hartree-Fock state to be deformed, we obtain good results for a wide variety of nuclides, even though we do not project onto good angular momentum. We suggest that deformation is as important or more so than pairing for Gamow-Teller transitions.Comment: 8 pages, 5 figures; added references, clarified discussion with regards to stabilit

Studies on Beach Placers of Kerala Coast

In the present paper, studies carried out on beach placer samples of Kerala coast in general and contribut-ions of NML and its current activities in particular on beach sands of Kerala have been discussed. While earlier beneficiation study at NML was on purification of zircon, present study, under network project, consist of charac-terization of samples from different areas to identify prospective area that will be taken up for development of process technology. Characterisation studies involve size and chemical analyses, sink and float studies, optical microscopy and scanning electron microscopy. Samples from four different areas (Valarpattanam Azhikod (VA), Chava-kkad Ponnani (CP), Neendakara Kayamkulam (NK) and Warkala coast) were studied. It has been found that while heavy mineral concentration at NK and Warkala coast is quite high, the same at CP is rather low in comparison and at VA it's not significant

Gyroscopic Precession and Inertial Forces in Axially Symmetric Stationary Spacetimes

We study the phenomenon of gyroscopic precession and the analogues of inertial forces within the framework of general relativity. Covariant connections between the two are established for circular orbits in stationary spacetimes with axial symmetry. Specializing to static spacetimes, we prove that gyroscopic precession and centrifugal force both reverse at the photon orbits. Simultaneous non-reversal of these in the case of stationary spacetimes is discussed. Further insight is gained in the case of static spacetime by considering the phenomena in a spacetime conformal to the original one. Gravi-electric and gravi-magnetic fields are studied and their relation to inertial forces is established.Comment: 21 pages, latex, no figures, http://202.41.67.76/~nayak/gpifass.te