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Journal of Modern Physics 2011年第11期2卷 1354-1365页

作者： Goutam Sau Aparajita Bhattacharya subrata bhattacharyya 不详

With the help of a phenomenological approach outlined in the text in some detail, we have dealt here with the description of the plots on rapidity and pseudorapidity spectra of some hadron-secondaries produced in various nucleus-nucleus interactions at high energies. The agreement between the measured data and the attempted fits are, on the whole, modestly satisfactory excepting a very narrow central region in the vicinity of y = η = 0. At last, hints to how the steps suggested in the main body of the text to proceed with the description of the measured data given in the plots could lead finally to a somewhat systematic methodology have also been made.

关键词： Relativistic Heavy Ion Collisions Inclusive Cross-Section Inclusive Production with Identified Hadrons Quarks Gluons and QCD in Nuclear Reactions

On the Nature of the Average Transverse Momenta of the Low-<i>pT</i>Secondaries in Some High Energy Nuclear Collisions

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Journal of Modern Physics 2012年第8期3卷 831-838页

作者： Amar Chandra Das Ghosh Goutam Sau Pradeepta Guptaroy subrata bhattacharyya Beramara RamChandrapur High School SouthIndia Department of Microbiology Surendranath College Kolkata India Department of Physics Raghunathpur College Raghunathpur Purulia India Physics and Applied Mathematics Unit(PAMU) Indian Statistical Institute Kolkata India

That the values of average transverse momenta ( ) of the secondaries produced in high energy collisions rise very slowly with energy is modestly well-known and accepted. We would like to probe into this aspect of the problem for production of the main variety of the 'soft' secondaries in two high energy symmetric nuclear collisions with the help of two non-QCD models. Our model-based results are found to be quite consistent with the anticipated behaviours and also with the observations.

关键词： Relativistic Heavy ion Collision Inclusive Production with Identified hadrons Inclusive Cross-Section Meson Production

Characteristics of Strange Hadron Production in Some High Energy Collisions and the Role of Power Laws

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Open Journal of Microphysics 2012年第1期2卷 1-11页

作者： Sunil Kumar Biswas Goutam Sau Amar Chandra Das Ghosh subrata bhattacharyya Beramara RamChandrapur High School Kolkata India Department of Microbiology Surendranath College Kolkata India Physics and Applied Mathematics Unit (PAMU) Indian Statistical Institute Kolkata India West Kodalia Adarsha Siksha Sadan New Barrackpore Kolkata India

Studies on “strange” particle production have always occupied a very important space in the domain of Particle Physics. This was and is so, just because of some conjectures about specially abundant or excess production of “strange” particles, at certain stages and under certain conditions arising out of what goes by the name of “Standard” model in Particle Physics. With the help of Hagedornian power laws we have attempted to understand and interpret here the nature of the pT-spectra for the strange particle production in a few high energy nuclear collisions, some interesting ratio-behaviors and the characteristics of the nuclear modification factors that are measured in laboratory experiments. After obtaining and analysing the final results we do not confront any peculiarities or oddities or extraneous excesses in the properties of the relevant observables with no left-over problems or puzzles. The model(s) used by us work(s) quite well for explaining the measured data.

关键词： Hadron-Nucleus Collisions Inclusive Production Scaling Phenomena Power Laws

Seismic fragility analysis of bridges by relevance vector machine based demand prediction model

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Earthquake Engineering and Engineering Vibration 2022年第1期21卷 253-268页

作者： Swarup Ghosh subrata Chakraborty Department of Civil Engineering Indian Institute of Engineering Science and TechnologyShibpurHowrah 711103India

A relevance vector machine(RVM)based demand prediction model is explored for efficient seismic fragility analysis(SFA)of a bridge *** proposed RVM model integrates both record-to-record variations of ground motions and uncertainties of parameters characterizing the bridge *** efficient fragility computation,ground motion intensity is included as an added dimension to the demand prediction *** incorporate different sources of uncertainty,random realizations of different structural parameters are generated using Latin hypercube sampling *** fragility,along with its dispersions,is estimated based on the log-normal fragility model for different critical components of a *** effectiveness of the proposed RVM model-based SFA of a bridge structure is elucidated numerically by comparing it with fragility results obtained by the commonly used SFA approaches,while considering the most accurate direct Monte Carlo simulation-based fragility estimates as the *** proposed RVM model provides a more accurate estimate of fragility than conventional approaches,with significantly less computational *** addition,the proposed model provides a measure of uncertainty in fragility estimates by constructing confidence intervals for the fragility curves.

关键词： bridge structure seismic fragility analysis seismic demand model relevance vector machine

Heat transfer in boundary layer stagnation-point flow towards a shrinking sheet with non-uniform heat flux

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Chinese Physics B 2013年第7期22卷 328-333页

作者： Krishnendu bhattacharyya Department of Mathematics The University of Burdwan

In this paper, the effect of non-uniform heat flux on heat transfer in boundary layer stagnation-point flow over a shrinking sheet is studied. The variable boundary heat fluxes are considered of two types： direct power-law variation with the distance along the sheet and inverse power-law variation with the distance. The governing partial differential equations （PDEs） are transformed into non linear self-similar ordinary differential equations （ODEs） by similarity transformations, and then those are solved using very efficient shooting method. The direct variation and inverse variation of heat flux along the sheet have completely different effects on the temperature distribution. Moreover, the heat transfer characteristics in the presence of non-uniform heat flux for several values of physical parameters are also found to be interesting.

关键词： non-uniform heat flux heat transfer stagnation-point flow shrinking sheet

Boundary Layer Flow and Heat Transfer over an Exponentially Shrinking Sheet

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Chinese Physics Letters 2011年第7期28卷 198-201页

作者： Krishnendu bhattacharyya Department of Mathematics the University of BurdwanBurdwan-713104West BengalIndia

An analysis is made to study boundary layer flow and heat transfer over an exponentially shrinking *** similarity transformations in exponential form,the governing boundary layer equations are transformed into self-similar nonlinear ordinary differential equations,which are then solved numerically using a very efficient shooting *** analysis reveals the conditions for the existence of steady boundary layer flow due to exponential shrinking of the sheet and it is found that when the mass suction parameter exceeds a certain critical value,steady flow is *** dual solutions for velocity and temperature distributions are *** increasing values of the mass suction parameter,the skin friction coefficient increases for the first solution and decreases for the second solution.

关键词： solution method exponential

Dual Solutions in Unsteady Stagnation-Point Flow over a Shrinking Sheet

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Chinese Physics Letters 2011年第8期28卷 165-168页

作者： Krishnendu bhattacharyya Department of Mathematics The University of BurdwanBurdwan-713104West BengalIndia

An analysis is made to study the dual nature of solution of unsteady stagnation-point flow due to a shrinking *** similarity transformations,the governing boundary layer equations are transformed into the self-similar nonlinear ordinary differential *** transformed equations are solved numerically using a very efficient shooting *** study reveals the conditions of existence,uniqueness and non-existence of unsteady similarity *** dual solutions for velocity distribution exist for certain values of velocity ratio parameter(c/a),and the increment in the unsteadiness parameter A increases the range of c/a where solution ***,with increasing A,the skin friction coefficient increases for the first solution and decreases for the second.

关键词： solution method unsteady

Simultaneous observations of a pair of kilohertz QPOs and a plausible 1860Hz QPO from an accreting neutron star system

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Research in Astronomy and Astrophysics 2010年第3期10卷 227-234页

作者： Sudip bhattacharyya Department of Astronomy and Astrophysics Tata Institute of Fundamental Research

We report an indication （3.22 or） of ≈ 1860 Hz quasi-periodic oscillations from a neutron star low-mass X-ray binary 4U 1636-536. If confirmed, this will be by far the highest frequency feature observed from an accreting neutron star system, and hence could be very useful in understanding such systems. This plausible timing feature was observed simultaneously with lower （≈ 585 Hz） and upper （≈ 904 Hz） kilohertz quasi-periodic oscillations. The two kilohertz quasi-periodic oscillation frequencies had a ratio of ≈ 1.5, and the frequency of the alleged ≈ 1860 Hz feature was close to the triple and the double values of these frequencies. This can be useful for constraining the models of all the three features. In particular, the ≈ 1860Hz feature could be （1） from a new and heretofore unknown class of quasi-periodic oscillations, or （2） the first observed overtone of lower or upper kilohertz quasi-periodic oscillations. Finally, we note that, although the relatively low significance of the ≈ 1860 Hz feature argues for caution, even a 3.22 σ feature at such a uniquely high frequency should be interesting enough to spur a systematic search in the archival data, as well as to scientifically motivate sufficiently large timing instruments for the next generation X-ray missions.

关键词： accretion accretion disks -- methods: data analysis -- relativity -- stars: neutron -- X-rays: binaries -- X-rays: individual (4U 1636-536)

Analytics of an Imperfect Four-Layer Production Inventory Model Under Two-Level Credit Period Using Branch-and-Bound Technique

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Journal of the Operations Research Society of China 2022年第4期10卷 725-748页

作者： subrata Panja Shyamal Kumar Mondal Department of Applied Mathematics with Oceanology and Computer Programming Vidyasagar UniversityMidnaporeW.B.721102India

This paper explains an integrated production inventory supply chain model,which consists of a supplier,a manufacturer and a retailer under two-level credit *** is manufacturer’s credit period offered by the supplier,and other is retailer’s credit period offered by the ***,the manufacturer replenishes raw materials from the supplier and produces non-deteriorating products in some cycles of equal *** is noted that here four inventory structures have been considered to show the flow of the materials as either raw materials or finished products from supplier to retailer via *** in this model,manufacturer’s imperfect production has been *** imperfect items are not *** retailer receives good finished products from the manufacturer and sells these to his/her customers during some cycles of equal length in total time *** main objective is to find the optimal number of production and business cycles of the manufacturer such that the integrated system can get the maximum *** above discussed model is elaborated with the help of a numerical example,and a sensitivity analysis is done with respect to some parameters used in this model.

关键词： Supply chain Integrated production inventory Four-layer inventory system Imperfect production Two-level credit period

Heat transfer for boundary layers with cross flow

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Chinese Physics B 2014年第2期23卷 327-332页

作者： Krishnendu bhattacharyya Ioan Pop Department of Mathematics The University of Burdwan Faculty of Mathematics Babes-Bolyai University

An analysis is presented to study the dual nature of solutions for the forced convective boundary layer flow and heat transfer in a cross flow with viscous dissipation terms in the energy equation. The governing equations are transformed into a set of three self-similar ordinary differential equations by similarity transformations. These equations are solved numerically using the very efficient shooting method. This study reveals that the dual solutions of the transformed similarity equations for velocity and temperature distributions exist for certain values of the moving parameter, Prandtl number, and Eckert numbers. The reverse heat flux is observed for larger Eckert numbers; that is, heat absorption at the wall occurs.

关键词： heat transfer boundary layer cross flow viscous dissipation dual solutions