Variation of the total ozone column during tropical cyclones over the Bay of Bengal and the Arabian Sea   总被引：1，自引：0，他引：1  

S. K. Midya  S. S. Dey  B. Chakraborty 《Meteorology and Atmospheric Physics》2012,117(1-2):63-71

The variation of the total ozone column (TOC) before, during, and after tropical cyclones occurring in the pre-monsoon and post-monsoon periods over the Bay of Bengal and the Arabian Sea for the period 1997–2009 is presented. From the analysis, it is concluded that TOC decreases steadily before and during the formation of a cyclone, followed by a more or less increasing trend after dissipation of the cyclone. It is also observed that, when the cyclone reaches its peak intensity indicated by its maximum wind speed, there is a sudden fall in TOC over those regions where the cyclone has intensified. The observed variation of TOC is consistent with existing chemical and dynamical theories.  相似文献   

The orientation of elliptical galaxies     

D. K. Chakraborty  A. K. Diwakar 《Astrophysics and Space Science》2011,331(2):419-428

We determine the orientations of the light distribution of individual elliptical galaxies by combining the profiles of photometric data from the literature with triaxial models. The orientation is given by a Bayesian probability distribution. The likelihood of obtaining the data from a model is a function of the parameters describing the intrinsic shape and the orientation. Integrating the likelihood over the shape parameters, we obtain the estimates of the orientation. We find that the position angle difference between the two suitably chosen points from the profiles of the photometric data plays a key role in constraining the orientation of the galaxy. We apply the methodology to a sample of ten galaxies. The alignment of the intrinsic principle axes of the NGC 3379, 4486 and NGC 5638 are studied.  相似文献   

Range of applicability of real mode superposition approximation method for seismic response calculation of non-classically damped industrial buildings     

Li Xiaodong  Sun Hongyang  Ji Xiaodong  Sanjukta Chakraborty  Wang Lijun 《地震工程与工程振动(英文版)》2022,(2):475-488

An industrial building is a non-classically damped system due to the different damping properties of the primary structure and equipment.The objective of this p...  相似文献   

Inflationary solution in higher dimensions     

Ashok KR. Chakraborty 《Astrophysics and Space Science》1992,192(2):321-324

In this Letter the five-dimensional Kaluza-Klein cosmological model is studied in the presence of a massless scalar field, whose potential has a flat part. By use of the polynomial relation between the two scale factors, inflationary solutions are obtained. The results show that the scale factor corresponding to the extra dimension is either constant or varies inversely as some power of the usual scale factor.  相似文献   

A study on Bianchi-IX cosmological model     

Subenoy Chakraborty 《Astrophysics and Space Science》1991,180(2):293-303

In this paper the inflationary solutions are studied for the Bianchi-IX space-time in presence of a massless scalar field with a flat potential. Also a class of cosmological solutions of massive strings are obtained following the techniques used by Letelier and Stachel. Some solutions are calculated for pure massive strings following the Takabayashi equation of state =(1+w).  相似文献   

Duration of Eo-Alpine metamorphic events obtained from multicomponent diffusion modeling of garnet: a case study from the Eastern Alps   总被引：2，自引：2，他引：0  

Shah?Wali?FaryadEmail author  Sumit?Chakraborty 《Contributions to Mineralogy and Petrology》2005,150(3):306-318

Rocks from the Micaschist–Marble Complex of the Wölz Tauern, which are part of the middle Austroalpine unit, contain large (up to 2 cm) garnet crystals that show clear evidence of multistage growth. Isotopic dating indicates that a Variscan (～270 Ma) garnet core was overgrown by new garnet formed during Eo-Alpine metamorphism at Cretaceous times. P-T paths for the Eo-Alpine metamorphism were obtained using the method of pseudosections (Powell and Holland in Metam Geol 16:309–343, 1998) and are consistent with earlier results from independent thermobarometry. Due to the large size of the garnets, growth zoning was preserved during amphibolite facies metamorphism at both Variscan and Alpine times. Full multicomponent diffusion modeling of compositional zoning at the interface of the Alpine and Pre-Alpine garnets in conjunction with the retrieved P-T paths allow average subduction/exhumation as well as heating/cooling rates to be retrieved. The modeling suggests that a minimum subduction/exhumation rate of ～4 cm/a and heating/cooling rates on the order of 100–260°C/Ma for a 60°C subduction angle are required to preserve the observed compositional zoning overall while modifying the zoning at the interface between two garnets to the extent observed. Such rapid rates of burial/exhumation are consistent with the results of direct GPS measurements of convergence rates at several orogenic belts as well as with inferred rates from modeling in the Alps and other areas. In combination, this indicates that such rapid rates are commonplace during metamorphism in collisional orogens and places important constraints on the rheological behavior of crustal blocks in such orogens.  相似文献   

Disturbances in a viscoelastic medium due to impulsive forces on a spherical cavity     

Sakti Kanta Chakraborty 《Pure and Applied Geophysics》1961,48(1):23-26

Summary The disturbances produced in a visco-elastic medium by impulsive forces on the surface of a spherical cavity inside the medium have been studied.  相似文献   

Dynamic Analysis of Tunnel in Weathered Rock Subjected to Internal Blast Loading     

Rohit Tiwari  Tanusree Chakraborty  Vasant Matsagar 《Rock Mechanics and Rock Engineering》2016,49(11):4441-4458

  相似文献   

Assessing crop water stress during late kharif season using Normalized Diurnal Difference Vegetation Water Content (nddVWC) of Advanced Microwave Scanning Radiometer–Earth Observing System (AMSR-E)     

Abhishek Chakraborty  M. V. R. Seshasai  V. K. Dadhwal 《Natural Hazards》2016,84(1):533-549

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Determination of Free Nickel Ion Concentrations Using the Ion Exchange Technique: Application to Aqueous Mining and Municipal Effluents     

Yamini Gopalapillai  Ismail I. Fasfous  John D. Murimboh  Tahir Yapici  Parthasarathi Chakraborty  Chuni L. Chakrabarti 《Aquatic Geochemistry》2008,14(2):99-116

Free metal ion concentration is generally considered a useful indicator of a metal’s bioavailability and ecotoxicity to aquatic biota. This article reports the speciation of nickel in mining and municipal effluents from Sudbury (Ontario, Canada), and also in model solutions containing a fully characterized laurentian fulvic acid (LFA) at environmentally relevant concentrations. A column ion exchange technique (IET) using a cation exchange resin (Dowex 50W-X8) was applied to determine free nickel ion concentrations. In model solutions, reasonable correlation was found between the predictions of an equilibrium-based computer speciation code, Windermere Humic Aqueous Model (WHAM) VI, and the results obtained by IET at low nickel-to-fulvic acid ratios. However at higher mole ratios, the WHAM VI predicted higher free nickel ion concentrations than IET. Only three out of six effluent samples showed reasonable agreement between the IET and the WHAM VI results, indicating the need for further development of IET for application to effluent waters.  相似文献