Pseudo-Schwarzschild Spherical Accretion as a Classical Black Hole Analogue

We demonstrate that a spherical accretion onto astrophysical black holes, under the influence of Newtonian or various post-Newtonian pseudo-Schwarzschild gravitational potentials, may constitute a concrete example of classical analogue gravity naturally found in the Universe. We analytically calculate the corresponding analogue Hawking temperature as a function of the minimum number of physical parameters governing the accretion flow. We study both the polytropic and the isothermal accretion. We show that unlike in a general relativistic spherical accretion, analogue white hole solutions can never be obtained in such post-Newtonian systems. We also show that an isothermal spherical accretion is a remarkably simple example in which the only one information--the temperature of the fluid, is sufficient to completely describe an analogue gravity system. For both types of accretion, the analogue Hawking temperature may become higher than the usual Hawking temperature. However, the analogue Hawking temperature for accreting astrophysical black holes is considerably lower compared with the temperature of the accreting fluid.Comment: Final Version to appear in the journal General Relativity & Gravitation, Volume 27, Issue 11, 2005. 17 pages, Two colour and one black and white figures. Typos corrected. Recent reference on analogue effect in relativistic accretion disc adde

Cultural influences and the mediating role of socio-cultural integration processes on the performance of cross-border mergers and acquisitions

This article has been made available through the Brunel Open Access Publishing Fund.This paper reports findings from a longitudinal case study (2005–2011) of a merger between an Austrian and a German energy provider. I develop a model of socio-cultural integration processes based on an analysis of critical incidents expressed in 71 problem-centred interviews and observations with acquired and acquiring employees at four different points of time: immediately before the takeover and during the first negotiation talks, and one, three and six years after the takeover. The findings suggest that the relationship between national and organizational cultural differences and M&A outcomes is mediated by socio-cultural integration processes defined in terms of the formation of interpersonal relationships, trust and shared identity. Based on these findings I formulate specific propositions and build an evidence-based model of M&A socio-cultural integration processes that guides future research and practice

Community Based Fisheries Management (CBFM) in Sunamganj district of Bangladesh: the nature of cooperation and conflicts

There are altogether 411 haors comprising an area of about 8000 square kilometer, covering 25% of entire region dispersed in the districts of Sunamgonj, Sylhet, Moulvibazar, Hobigonj, Netrokona and Kishoreganj. Sunamganj district is particularly known as a district of haors and baors where a large number of people depend on fishing for their livelihood. Some people are basically fishermen and fish all the year round. Community Based Fisheries Management (CBFM) project has been initiated in this area to develop fishery sector as well as for the development of the inland fishermen of haor area. Healthy cooperation among the beneficiaries of the project is very much present and some NGOs are found working actively there to help the fishermen for the sound implementation of the project. But the influentials of different villages around create troubles and conflicts intentionally in the project area because of which fishermen cannot fish smoothly and the implementation of the project is getting hampered. Therefore, a kind of consensus needs to be reached among the inhabitants of the haor area and a powerful association of the fishermen should be established so that fishing may be undertaken in the beel without having any troubles and conflicts. In this article the conflicts and cooperation that are in existence in the implementation process of CBFM project in the haor areas of Sunamgonj district have been discussed. Some suggestions have been offered in the paper to overcome the existing conflicts impeding the smooth implementation of CBFM project in the fishery sector of haor area under Sunamganj district

Percutaneous coronary intervention in a patient with single coronary artery

AbstractCoronary artery anomalies are found in 1–5% of all coronary angiograms. Single coronary artery is a rare congenital anomaly. The prevalence of the anomaly is 0.024–0.066% of the general population and percutaneous coronary intervention in this anomaly is performed infrequently. The highest incidence of this condition is reported from India. We report a case of a 55 year old patient of anterior wall ST elevation myocardial infarction with L1 group of single coronary artery who underwent successful angioplasty and stenting to left anterior descending artery. The unique features and inherent risks of percutaneous coronary intervention to single coronary artery are discussed

DEVELOPMENT OF ADVANCED SMART AND SECURED SYSTEM

A smart system is designed to control the lighting system, fans and security in the industries. We all know sometimes forget to switch off the lights and fans before leaving the room. This system can control 8 units of lights and 6 units of fans every day. Besides, our highly developed industry consist of lot of appliances which needs security and care. Our project focuses on total security with the help of fire alarm and a message alert of any invader. This project uses the Passive Infrared Sensor (PIR sensor) to detect the body heat and the movements of humans. The PIR sensor will give signal to hardware. The hardware of this project is PIC16F887A and RS232 communication module to interface with GSM Modem

On nearly Hausdorff compactifications

[EN] We introduce and study here the notion of nearly Hausdorffness, a separation axiom, stronger than T1 but weaker than T2. For a space X, from a subfamily of the family of nearly Hausdorff spaces, we construct a compact nearly Hausdorff space rX containing X as a densely C*-embedded subspace. Finally, we discuss when rX is βX.Shah, S.; Das, T. (2006). On nearly Hausdorff compactifications. Applied General Topology. 7(1):125-130. doi:10.4995/agt.2006.1937.SWORD1251307

An Analytical Study on the Multi-critical Behaviour and Related Bifurcation Phenomena for Relativistic Black Hole Accretion

We apply the theory of algebraic polynomials to analytically study the transonic properties of general relativistic hydrodynamic axisymmetric accretion onto non-rotating astrophysical black holes. For such accretion phenomena, the conserved specific energy of the flow, which turns out to be one of the two first integrals of motion in the system studied, can be expressed as a 8$^{th}$ degree polynomial of the critical point of the flow configuration. We then construct the corresponding Sturm's chain algorithm to calculate the number of real roots lying within the astrophysically relevant domain of $\mathbb{R}$. This allows, for the first time in literature, to {\it analytically} find out the maximum number of physically acceptable solution an accretion flow with certain geometric configuration, space-time metric, and equation of state can have, and thus to investigate its multi-critical properties {\it completely analytically}, for accretion flow in which the location of the critical points can not be computed without taking recourse to the numerical scheme. This work can further be generalized to analytically calculate the maximal number of equilibrium points certain autonomous dynamical system can have in general. We also demonstrate how the transition from a mono-critical to multi-critical (or vice versa) flow configuration can be realized through the saddle-centre bifurcation phenomena using certain techniques of the catastrophe theory.Comment: 19 pages, 2 eps figures, to appear in "General Relativity and Gravitation

Supersymmetric isospectral formalism for the calculation of near-zero energy states: application to the very weakly bound 4{^4}He trimer excited state

We propose a novel mathematical approach for the calculation of near-zero energy states by solving potentials which are isospectral with the original one. For any potential, families of strictly isospectral potentials (with very different shape) having desirable and adjustable features are generated by supersymmetric isospectral formalism. The near-zero energy Efimov state in the original potential is effectively trapped in the deep well of the isospectral family and facilitates more accurate calculation of the Efimov state. Application to the first excited state in 4He trimer is presented.Comment: accepte

Community knowledge on malaria among febrile patients in an endemic district of Orissa, India

Background & objectives: Evidence on the community knowledge and perceptions on malaria are crucial todesign appropriate health communication strategies for malaria control. Orissa, an Indian state with a largeproportion of indigenous populations and hilly terrains contributes to the highest malaria burden in India. Astudy was undertaken to assess the knowledge on malaria among community members who had experiencedfever and chills in the endemic district of Boudh in Orissa.Methods: A cross-sectional community-based survey was carried out with respondents (n=300) who had feverwith chills within two weeks prior to data collection through a multi-stage sampling and interviewed themusing a pre-tested, structured interview schedule.Results : About 90% of respondents recognized fever as a common symptom of malaria, 72.3% said mosquitobites cause malaria, 70.3% of respondents reported mosquito control and personal protection to be the methodof malaria prevention, and 24.6% identified chloroquine as the drug used for treatment. Women and scheduledtribe (ST) respondents were found to have lower level of appropriate knowledge of causes, symptoms, andprevention methods of malaria than their counterparts.Interpretation & conclusion: The study population had a fair knowledge of malaria about the causes, symptoms,treatment, modes of prevention and outcomes of non-treatment compared to most of the studies conducted insimilar settings. However, the relatively low awareness among women and tribal population calls for morecontext specific communication strategies. Such strategies should be based on information needs assessment ofdifferent population subgroups, especially of women and members of the ST community, using media that isaccessible and clearly understood by different groups

Non-Newtonian and Gas-non–Newtonian Liquid Flow through Elbows – CFD Analysis

Computational Fluid Dynamics (CFD) analysis for the flow of non-Newtonian and gas-non-Newtonian liquid through elbows is presented. The commercial software Fluent 6.3 has been used for the simulation. Laminar non-Newtonian pseudoplastic power law model has been used for the simulation of non-Newtonian liquid flow through elbows. For twophase flow Elurian-Elurian approach has been used for simulation. The CFD analysis have been tested from our previously published experimental results, Bandyopadhyay and Das (2007), Bandyopadhyay et al. (2000)