1,272 research outputs found

    Asymptotic analysis and spectrum of three anyons

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    The spectrum of anyons confined in harmonic oscillator potential shows both linear and nonlinear dependence on the statistical parameter. While the existence of exact linear solutions have been shown analytically, the nonlinear dependence has been arrived at by numerical and/or perturbative methods. We develop a method which shows the possibility of nonlinearly interpolating spectrum. To be specific we analyse the eigenvalue equation in various asymptotic regions for the three anyon problem.Comment: 28 pages, LaTeX, 2 Figure

    Radiation and Chemical Reaction Effects on Unsteady MHD Free Convective Periodic Heat Transport Modeling In a Saturated Porous Medium for Arotating System

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    A rotating model is extended for a two-dimensional, unsteady, incompressible electrically conducting, laminar immediate convection boundary layer flow of light and mass communicate in a saturated porous crystal ball gazer, among an overall vertical porous surface in the perseverance of radiation and vicious circle effects was considered. The fundamental equations governing the flow are in the art an element of partial differential equations and have been reduced to a inhere of non-linear ordinary differential equations by applying suitable similarity transformations. The problem is tackled analytically using classical two term perturbation technique. Pertinent results with respect to embedded parameters are displayed through graphically for the velocity, Temperature, concentration, skin friction, Sherwood number, Nusselt number are discussed qualitatively

    CHARACTERIZATION OF ALPHA-AMYLASE FROM THE SEEDS OF Mucuna pruriens

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    Amylases are hydrolytic enzymes which are widely distributed in nature, animals, plants and microorganisms. Amylases are of great significance in present-day biotechnology. In present study, amylases are isolated from the soaked seeds of Mucuna pruriens under extreme acidic conditions. Conventional protein purification techniques such as salt fractionation, ion exchange chromatography on CM-cellulose and sephadex G-75 was employed for the purification of amylase from the seeds of Mucuna pruriens. The amylase activity was eluted in one peak. The specific activity and yield of the purified amylase was 6.25 and 29.99, respectively. Native PAGE, SDS-PAGE and gel electrofocussing were employed to establish homogeneity of the purified amylase. SDS-PAGE and gel-filtration chromatography on sephadex G-75 was used to determine the molecular weight of the purified amylase. The purified amylase was nearly homogenous and its molecular weight was found to be 78.4 kDa. The optimum pH and temperature of the purified amylase were 7.0 and 50oC, respectively. The isolectric pH of the purified amylase was 7.2 and the activity was linear up to 60 minutes

    Magnetic anomalies of offshore Krishna-Godavari basin, eastern continental margin of India

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    The marine magnetic data acquired from offshore Krishna-Godavari (K-G) basin, eastern continental margin of India (ECMI), brought out a prominent NE-SW trending feature, which could be explained by a buried structural high formed by volcanic activity. The magnetic anomaly feature is also associated with a distinct negative gravity anomaly similar to the one associated with 85°E Ridge. The gravity low could be attributed to a flexure at the Moho boundary, which could in turn be filled with the volcanic material. Inversion of the magnetic and gravity anomalies was also carried out to establish the similarity of anomalies of the two geological features (structural high on the margin and the 85°E Ridge) and their interpretations. In both cases, the magnetic anomalies were caused dominantly by the magnetization contrast between the volcanic material and the surrounding oceanic crust, whereas the low gravity anomalies are by the flexures of the order of 3-4 km at Moho boundary beneath them. The analysis suggests that both structural high present in offshore Krishna-Godavari basin and the 85°E Ridge have been emplaced on relatively older oceanic crust by a common volcanic process, but at discrete times, and that several of the gravity lows in the Bay of Bengal can be attributed to flexures on the Moho, each created due to the load of volcanic material

    To Provide A Privacy Preserving Auditing Protocol In Cloud Computing Using Tpa

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    To completely make sure the data honesty and save the cloud users’ calculation possessions as well as online burden it is of significant importance to facilitate public auditing service for cloud data storage so that users may alternative to an independent third-party auditor (TPA) to review the outsourced data when needed. The TPA who has know-how and potential that users do not can episodically check the integrity of all the data stored in the cloud on behalf of the users which provides a much more easier and reasonable way for the users to make sure their storage correctness in the cloud. Furthermore in addition to help users to evaluate the hazard of their subscribed cloud data services the audit results from TPA would also be advantageous for the cloud service providers to recover their cloud-based service platform and even serve up for independent negotiation purposes. In a word facilitate public auditing services will participate an important role for this promising cloud economy to become fully established where users will need ways to measure risk and gain trust in the cloud

    Critical Crossover Between Yosida-Kondo Dominant Regime and Magnetic Frustration Dominant Regime in the System of a Magnetic Trimer on a Metal Surface

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    Quantum Monte Carlo simulations were carried out for the system of a magnetic trimer on a metal surface. The magnetic trimer is arranged in two geometric configurations, viz., isosceles and equilateral triangles. The calculated spectral density and magnetic susceptibility show the existence of two phases: Yosida-Kondo dominant phase and magnetic frustration dominant phase. Furthermore, a critical transition between these two phases can be induced by changing the configuration of the magnetic trimers from isosceles to equilateral triangle.Comment: 8 pages, 4 figures; accepted for publication in J. Phys. Soc. Jp

    Assessment of GPS radiosonde descent data

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    Radiosondes are widely used to obtain basic meteorological parameters such as pressure (<i>P</i>), temperature (<i>T</i>), relative humidity (RH) and horizontal winds during the balloon ascent up to the altitude of balloon burst, usually ~ 32–35 km. Data from the radiosondes released from Gadanki (13.5° N, 79.2° E), a tropical station in India, have been collected during the ascent and during the descent as well without attaching any parachute or its equivalent since the year 2008. In the present study an attempt has been made to characterize the radiosonde descent data with the main objective of exploring its usefulness and reliability for scientific purposes. We compared the data obtained during ascent and descent phases of the same sounding. The mean differences in <i>T</i>, RH and horizontal winds between ascent and descent data are found to be small and are sometimes even within the uncertainty of the measurements and/or expected diurnal variation itself. The very good consistency observed between the ascent and the descent data shows that one more profile of the meteorological parameters can be constructed within 3 h of time of balloon launch practically at no additional cost. Further checks are done by utilizing the 3-hourly radiosonde observations collected during the Tropical Tropopause Dynamics campaigns conducted at Gadanki. In the process of checking the consistency between the radiosonde ascent and descent data, several new findings are arrived at and are reported in this study. In general, it has taken more than half an hour for the balloon to reach the ground from the burst altitude. It is also observed that the fall velocity is close to 10 m s<sup>−1</sup> near the surface. Finally, it is suggested to record the observations also when the balloon is descending as this information is useful for scientific purposes

    Exactly solvable toy models of unconventional magnetic alloys: Bethe Ansatz versus Renormalization Group method

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    We propose toy models of unconventional magnetic alloys, in which the density of band states, ρ(ϵ)\rho(\epsilon), and hybridization, t(ϵ)t(\epsilon), are energy dependent; it is assumed, however, that t2(ϵ)ρ1(ϵ)t^2(\epsilon)\propto\rho^{-1}(\epsilon), and hence an effective electron-impurity coupling Γ(ϵ)=ρ(ϵ)t2(ϵ)\Gamma(\epsilon)=\rho(\epsilon)t^2(\epsilon) is energy independent. In the renormalization group approach, the physics of the system is assumed to be governed by Γ(ϵ)\Gamma(\epsilon) only rather than by separate forms of ρ(ϵ)\rho(\epsilon) and t(ϵ)t(\epsilon). However, an exact Bethe Ansatz solution of the toy Anderson model demonstrates a crucial role of a form of inverse band dispersion k(ϵ)k(\epsilon).Comment: A final version. A previous one has been sent to Archive because of my technical mistake. Sorr

    Validation of the COSMIC Radio Occultation Data over Gadanki (13.48°N, 79.2°E): A Tropical Region

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    Constellation Observing System for Meteorology Ionosphere and Climate (COSMIC), consisting of six Low Earth Orbit (LEO) Global Position System (GPS) receivers, on board the Formosat Satellite 3 (FORMOSAT-3) is providing dense observations of density, refractivity, temperature and water vapor profiles of the neutral atmosphere since middle of July 2006. Special radiosonde (Väisälä) campaign was conducted at Gadanki (13.48°N, 79.18°E), a tropical site in India, during July 2006 to March 2007 to validate these meteorological parameters. Co-located Nd: YAG Rayleigh lidar was also operated during the overpass of COSMIC and is utilized to validate the temperatures in the height range of 30 to 40 km. Atotal of 142 overpasses occurred during the above mentioned period within 300 km distance from Gadanki out of which 41 overpasses occurred within a time difference of ±4 hours of radiosonde launch. In addition, 18 overpasses occurred within the time difference of ±4 hours of lidar operation. A detailed comparison has been made with all these overpasses for the refractivity, temperature and water vapor obtained from COSMIC. The water vapor comparison has shown generally a good agreement with a mean difference of 5 - 10% below 6 - 7 km. Although there is a colder bias between COSMIC and radiosonde, a very good comparison in temperature is also found between 10 and 27 km with a mean difference of less than 1 K (RMS difference is only 0.64 K). There exists a large difference in temperature of about 8 K between 30 and 40 km (between COSMIC and lidar). Possible reasons for these large differences are given. There was one event that occurred just over Gadanki for which a detailed comparison has been made with special emphasis on water vapor retrievals. Sensitivity test is also done on the fractional difference in N for the event that occurred on 24 July 2006 between COSMIC (1D-var) and radiosonde and found that pressure plays a key role than temperature in determining the refractivity

    Studies on biosorption of nickel using immobilized fungus, Rhizomucor tauricus

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    Rhizomucor tauricus, an industrial fungus, was immobilized in sodium alginate and used as adsorbent for the removal of nickel from aqueous solutions. The biosorption capacity of Ni(II) was found to be 394 mg/g of immobilized biomass. It was observed that an increase in pH from 3 to 6 increased the percent adsorption, and an increase in liquid-to-solid ratio from 2 to 10 increased the metal uptake. The percent adsorption was increased when increasing the initial metal concentration from 25 to 100 mg/L. The equilibrium biosorption data was evaluated by Langmuir, Freundlich, and Langmuir-Freundlich (L-R) isotherm models, and was best described by the Langmuir and Freundlich isotherms. FTIR analysis revealed that –NH (bending), C–H (stretching), C=O (stretching), and –OH functional groups were mainly responsible for Ni(II) biosorption. Thus, this study demonstrated that the immobilized Rhizomucor tauricus biomass could be used as an adsorbent for the treatment of Ni(II) from aqueous solution
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