Universal criterion for black hole stability

It is shown that a non-rotating macroscopic black hole with very large horizon area can remain in stable thermal equilibrium with Hawking radiation provided {\it its mass, as a function of horizon area, exceeds its microcanonical entropy, i.e., its entropy when isolated, without thermal radiation or accretion, and having a constant horizon area} (in appropriate units). The analysis does not use properties of specific classical spacetimes, but depends only on the plausible assumption that the mass is a function of the horizon area for large areas.Comment: 6 pages Latex, no figures; an equation adde

Universal canonical black hole entropy

Non-rotating black holes in three and four dimensions are shown to possess a canonical entropy obeying the Bekenstein-Hawking area law together with a leading correction (for large horizon areas) given by the logarithm of the area with a {\it universal} finite negative coefficient, provided one assumes that the quantum black hole mass spectrum has a power law relation with the quantum area spectrum found in Non-perturbative Canonical Quantum General Relativity. The thermal instability associated with asymptotically flat black holes appears in the appropriate domain for the index characterising this power law relation, where the canonical entropy (free energy) is seen to turn complex.Comment: Revtex, 5 pages, no figures. Typos corrected and a footnote and some references adde

Mass and charge fluctuations and black hole entropy

The effects of thermal fluctuations of the mass (horizon area) and electric charge, on the entropy of non-rotating charged {\it macroscopic} black holes, are analyzed using a grand canonical ensemble. Restricting to Gaussian fluctuations around equilibrium, and assuming a power law type of relation between the black hole mass, charge and horizon area, characterized by two real positive indices, the grand canonical entropy is shown to acquire a logarithmic correction with a positive coefficient proportional to the sum of the indices. However, the root mean squared fluctuations of mass and charge relative to the mean values of these quantities turn out to be independent of the details of the assumed mass-area relation. We also comment on possible cancellation between log (area) corrections arising due to {\it fixed area} quantum spacetime fluctuations and that due to thermal fluctuations of the area and other quantities.Comment: 8 pages revtex, no figure

Cosmic optical activity from an inhomogeneous Kalb-Ramond field

The effects of introducing a harmonic spatial inhomogeneity into the Kalb-Ramond field, interacting with the Maxwell field according to a `string-inspired' proposal made in earlier work are investigated. We examine in particular the effects on the polarization of synchrotron radiation from cosmologically distant (i.e. of redshift greater than 2) galaxies, as well as the relation between the electric and magnetic components of the radiation field. The rotation of the polarization plane of linearly polarized radiation is seen to acquire an additional contribution proportional to the square of the frequency of the dual Kalb-Ramond axion wave, assuming that it is far smaller compared to the frequency of the radiation field.Comment: 9 pages, Revtex, no figure

Reflection coefficient for superresonant scattering

We investigate superresonant scattering of acoustic disturbances from a rotating acoustic black hole in the low frequency range. We derive an expression for the reflection coefficient, exhibiting its frequency dependence in this regime.Comment: 7 page

Multiple stab incision technique to prevent postoperative acute compartment syndrome of leg in proximal and segmental fracture tibia and fibula: a prospective study

The objective is to study the effectiveness of Multiple stab incision technique in preventing acute compartment syndrome (ACS) in proximal and segmental fractures of both bones (Tibia and fibula) in leg. This study is prospective done at K. S. Hospital Koppal, Karnataka spanning for a period of one year (April 2020 to April 2021). A total of 20 patients of both genders aged 20-60 years were included in the study. Multiple stab incision technique was performed in patients after fixation of Tibia by either closed nailing or MIPPO plating. This procedure was done under spinal anesthesia. Multiple stab incision technique significantly decreased the chances of post-op ACS in proximal and segmental fractures of both bones (tibia and fibula) in leg. Multiple stab incision technique is help full in preventing developing compartment syndrome. 

Current-driven orbital order-disorder transition in LaMnO3

We report significant influence of electric current on the orbital order-disorder transition in LaMnO3. The transition temperature T_OO, thermal hysteresis in the resistivity (rho) versus temperature (T) plot around T_OO, and latent heat L associated with the transition decrease with the increase in current density. Eventually, at a critical current density, L reaches zero. The transition zone, on the other hand, broadens with the increase in current density. The states at ordered, disordered, and transition zone are all found to be stable within the time window from ~10^-3 to ~10^4 seconds.Comment: 7 pages including 5 figures; resolution of Fig.1 is better here than the published versio

Design and Development of Sports Intimate Apparel - A Review

It is necessary to evaluate and analyze the brassiere design problems to alleviate theproblems in terms of fit, support, elastics and fastening. With an aim to achieve a perfectbrassiere, designers have a strong drive to develop a super quality brassiere with highperformance and proper usage of components and materials. The encapsulation brassiere wasmore effective than compression brassiere in controlling breast displacement. The mainproblems were shoulder straps digging into the shoulder and shoulder straps slipping off theshoulder. There are several design flaws associated with these sports brassiere which lead todiscomfort, pain and swelling of the breasts. Tightness around the chest may also cause beastsoreness. The straps are often very thin and cut into the shoulders of women. The mosteffective brassiere had a unique inverted-u shape bounded seam over the upper and sideboundaries of the cups with a wide cross-back design. Wicking materials are used in this typeof brassieres to give comfort and breast supporting pads having pad components to giveadequate support. The inner layer consists of silicone material which can increase theadherence capacity due to its high coefficient of friction. This review paper contains detailsabout the design and development of sports brassiere

Generalized Hawking-Page Phase Transition

The issue of radiant spherical black holes being in stable thermal equilibrium with their radiation bath is reconsidered. Using a simple equilibrium statistical mechanical analysis incorporating Gaussian thermal fluctuations in a canonical ensemble of isolated horizons, the heat capacity is shown to diverge at a critical value of the classical mass of the isolated horizon, given (in Planckian units) by the {\it microcanonical} entropy calculated using Loop Quantum Gravity. The analysis reproduces the Hawking-Page phase transition discerned for anti-de Sitter black holes and generalizes it in the sense that nowhere is any classical metric made use of.Comment: 9 Pages, Latex with 2 eps figure