170 research outputs found

    Entropy increase during physical processes for black holes in Lanczos-Lovelock gravity

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    We study quasi-stationary physical process for black holes within the context of Lanczos-Lovelock gravity. We show that the Wald entropy of stationary black holes in Lanczos-Lovelock gravity monotonically increases for quasi-stationary physical processes in which the horizon is perturbed by the accretion of positive energy matter and the black hole ultimately settles down to a stationary state. This result reinforces the physical interpretation of Wald entropy for Lanczos-Lovelock models and takes a step towards proving the analogue of the black hole area increase-theorem in a wider class of gravitational theories.Comment: 5 pages, no figur

    A Research Perspective on Data Management Techniques for Federated Cloud Environment

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    Cloud computing has given a large scope of improvement in processing, storage and retrieval of data that is generated in huge amount from devices and users. Heterogenous devices and users generates the multidisciplinary data that needs to take care for easy and efficient storage and fast retrieval by maintaining quality and service level agreements. By just storing the data in cloud will not full fill the user requirements, the data management techniques has to be applied so that data adaptiveness and proactiveness characteristics are upheld. To manage the effectiveness of entire eco system a middleware must be there in between users and cloud service providers. Middleware has set of events and trigger based policies that will act on generated data to intermediate users and cloud service providers. For cloud service providers to deliver an efficient utilization of resources is one of the major issues and has scope of improvement in the federation of cloud service providers to fulfill user’s dynamic demands. Along with providing adaptiveness of data management in the middleware layer is challenging. In this paper, the policies of middleware for adaptive data management have been reviewed extensively. The main objectives of middleware are also discussed to accomplish high throughput of cloud service providers by means of federation and qualitative data management by means of adaptiveness and proactiveness. The cloud federation techniques have been studied thoroughly along with the pros and cons of it. Also, the strategies to do management of data has been exponentially explored

    Ideal Gas in a strong Gravitational field: Area dependence of Entropy

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    We study the thermodynamic parameters like entropy, energy etc. of a box of gas made up of indistinguishable particles when the box is kept in various static background spacetimes having a horizon. We compute the thermodynamic variables using both statistical mechanics as well as by solving the hydrodynamical equations for the system. When the box is far away from the horizon, the entropy of the gas depends on the volume of the box except for small corrections due to background geometry. As the box is moved closer to the horizon with one (leading) edge of the box at about Planck length (L_p) away from the horizon, the entropy shows an area dependence rather than a volume dependence. More precisely, it depends on a small volume A*L_p/2 of the box, upto an order O(L_p/K)^2 where A is the transverse area of the box and K is the (proper) longitudinal size of the box related to the distance between leading and trailing edge in the vertical direction (i.e in the direction of the gravitational field). Thus the contribution to the entropy comes from only a fraction O(L_p/K) of the matter degrees of freedom and the rest are suppressed when the box approaches the horizon. Near the horizon all the thermodynamical quantities behave as though the box of gas has a volume A*L_p/2 and is kept in a Minkowski spacetime. These effects are: (i) purely kinematic in their origin and are independent of the spacetime curvature (in the sense that Rindler approximation of the metric near the horizon can reproduce the results) and (ii) observer dependent. When the equilibrium temperature of the gas is taken to be equal to the the horizon temperature, we get the familiar A/L_p^2 dependence in the expression for entropy. All these results hold in a D+1 dimensional spherically symmetric spacetime.Comment: 19 pages, added some discussion, matches published versio

    Galilean Gauge Theories from Null Reductions

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    The procedure of null reduction provides a concrete way of constructing field theories with Galilean invariance. We use this to examine Galilean gauge theories, viz. Galilean electrodynamics and Yang-Mills theories in spacetime dimensions 3 and 4. Different non-relativistic conformal symmetries arise in these contexts: Schr{\"o}dinger symmetry in d=3d=3 and Galilean conformal symmetry in d=4d=4. A canonical analysis further reveals that the symmetries enhance to their infinite dimensional versions in phase space and pick up central extensions. In addition, for the Abelian theory, we discuss non-relativistic electro-magnetic duality in d=3d=3 and its difference with the d=4d=4 version. We also mention some quantum aspects for both Abelian and non-Abelian theories

    Study on Morbidity and Mortality Rates in Buffaloes in Pune Division of Maharashtra State in India

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    The present study was carried out to analyse morbidity and mortality rate in buffaloes and its associated factors in Pune division of Maharashtra state in India. Stratified two stages random sampling design was adopted & the data of total 564 buffaloes were collected through pre-tested modified schedule from 157 buffalo owners. The data were analysed statistically by SAS 9.3 software for evaluation of Chi-square and Logistic regression analysis. Overall morbidity (28.01%) and mortality (7.98%) rates were recorded in study area. Digestive diseases and respiratory diseases are major cause of the higher morbidity and mortality in buffaloes, respectively. Statistically, there wasn't significant association of overall disease incidence with age or sex. However, the Chi-square analysis of overall mortality rate showed significance (p<0.01) difference among age and sex. Logistic regression analysis also suggested the same results. Mortality rates were recorded higher in calves and male buffaloes as compared to their respective counterparts. It is suggested that digestive and respiratory problems may be reduced by improving feeding and management practices. This study provides the important tool for determining the health status of buffaloes and has special importance in planning of prevention and control strategies designed to reduce the incidences of diseases in livestock and therefore economic status of farmers

    BACTERIAL DISEASES OF LIVESTOCK ANIMALS AND THEIR IMPACT ON HUMAN HEALTH

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    Recently, whole world is facing the problem of infectious diseases related to animal diseases that pose significant threats to human health. In other words, humans may acquire zoonotic infections through various routes i.e. food, water etc. The transmission of certain bacterial diseases (through food and water) is one of the important cause of illness in both developing and developed countries. Most of the infectious pathogens that are normally reside in the intestinal tract of healthy animals and may transmit the disease through products (meat, milk or eggs) and faecal contamination of the environment. Normally, minute amount of intestinal contents are released and contaminate milk during milking; carcass at slaughter and egg during laying. Generally, risk associated with this type of contamination is somehow minimised where proper food hygiene is normally applied throughout the entire food chain from production, through processing to preparation at home. In this view, we provide some information about bacterial diseases of livestock animals and their effect or impact on human health.Â

    Phase transition and scaling behavior of topological charged black holes in Horava-Lifshitz gravity

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    Gravity can be thought as an emergent phenomenon and it has a nice "thermodynamic" structure. In this context, it is then possible to study the thermodynamics without knowing the details of the underlying microscopic degrees of freedom. Here, based on the ordinary thermodynamics, we investigate the phase transition of the static, spherically symmetric charged black hole solution with arbitrary scalar curvature 2k2k in Ho\v{r}ava-Lifshitz gravity at the Lifshitz point z=3z=3. The analysis is done using the canonical ensemble frame work; i.e. the charge is kept fixed. We find (a) for both k=0k=0 and k=1k=1, there is no phase transition, (b) while k=−1k=-1 case exhibits the second order phase transition within the {\it physical region} of the black hole. The critical point of second order phase transition is obtained by the divergence of the heat capacity at constant charge. Near the critical point, we find the various critical exponents. It is also observed that they satisfy the usual thermodynamic scaling laws.Comment: Minor corrections, refs. added, to appear in Class. Quant. Grav. arXiv admin note: text overlap with arXiv:1111.0973 by other author

    Effect of third component on separation behavior of water+t-butanol+Na2SO3/Na2SO4 system at 298±2 K

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    The liquid-liquid and liquid-liquid-solid equilibria for the ternary t-butanol-water-Na2SO3/Na2SO4 system is reported at ambient pressure and at 298±2 K. The solubility data of solutions of Na2SO3/Na2SO4 in water, t-butanol and solutions of varying compositions of t-butanol in water are reported. The phase diagrams for the studied systems are developed and salting-out effect of salt anion has been described. The structural properties of aqueous t-butanol solutions and the salting-out effect of SO32- and SO42- ions to cause phase separation have been explained. The salting-out ability of Na2SO3 is higher than that of Na2SO4 since the Gibbs free energy of hydration (ΔGhyd) of SO42- (−1080 kJ mol-1) is lower than that of SO32- (−1295 kJ mol-1) ion
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