Parnasree Pally, India
Parnasree Pally, India

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Dutta S.,Behala College | Dutta S.,National University of Singapore
Journal of Statistical Mechanics: Theory and Experiment | Year: 2010

The multifractal properties of two-channel ECG patterns of patients suffering from severe congestive heart failure (New York Heart Association (NYHA) classes III-IV) are studied and are compared with those for normal healthy people using the multifractal detrended fluctuation analysis methodology. Ivanov et al (1999 Nature 399 461) have studied the multifractality of human heart rate dynamics using the wavelet transformation modulus maxima (WTMM) methodology. But it has been observed by several scientists that multifractal detrended fluctuation analysis (MFDFA) works better than the WTMM method in the detection of monofractal and multifractal characteristics of the data. Galaska et al (2008 Ann. Noninvasive Electrocardiol. 13 155) have observed that MFDFA is more sensitive compared to the WTMM method in the differentiation between multifractal properties of the heart rate in healthy subjects and patients with left ventricular systolic dysfunction. In the present work the variation of two parameters of the multifractal spectrum-its width W (related to the degree of multifractality) and the value of the Hölder exponent α0-for the healthy and congestive heart failure patients is studied. α0 is a measure of the degree of correlation. The degree of multifractality varies appreciably (85-90% C.L.) for the normal and the CHF sets for channel I. For channel II no significant change in the values is observed. The degree of correlation is found to be comparatively high for the normal healthy people compared to those suffering from CHF. © 2010 IOP Publishing Ltd and SISSA.

Rahaman F.,Jadavpur University | Kuhfittig P.K.F.,Milwaukee School of Engineering | Bhui B.C.,Meghnad Saha Institute of Technology | Rahaman M.,Meghnad Saha Institute of Technology | Mondal U.F.,Behala College
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2013

In this paper, a Bañados-Teitelboim-Zanelli (BTZ) black hole is constructed from an exact solution of the Einstein field equations in a (2+1) - dimensional anti - de Sitter spacetime in the context of noncommutative geometry. The BTZ black hole turns out to have either two horizons, no horizon, or a single horizon corresponding to a minimal mass. Certain thermodynamical properties are investigated, including Hawking temperature, entropy, and heat capacity. Also discussed is the geodesic structure of BTZ black holes for both massless and massive particles. In particular, it is shown that bound orbits for test particles are possible. © 2013 American Physical Society.

Dutta S.,Behala College | Ghosh D.,Jadavpur University | Samanta S.,Seacom Engineering College | Dey S.,Tata Institute of Fundamental Research
Physica A: Statistical Mechanics and its Applications | Year: 2014

This paper presents a study on multifractal parameters of EEG patterns on the human brain. Multifractal detrended fluctuation analysis was applied to human EEG for normal and epileptic patients in different states. The results show that the degree of multifractality of EEG for patients in an epileptic seizure are much higher compared to normal healthy people. The degree of multifractality for normal humans with eyes open and closed was also significantly different. Thus the multifractal parameters can be used to distinguish between different physiological and pathological states of the human brain. The results are discussed in detail. © 2013 Elsevier B.V. All rights reserved.

Seth S.K.,Indian Association for The Cultivation of Science | Sarkar D.,A B N Seal College | Jana A.D.,Behala College | Kar T.,Indian Association for The Cultivation of Science
Crystal Growth and Design | Year: 2011

Four organic compounds based on substituted coumarin derivatives (1 - 4) have been synthesized and characterized by X-ray structural studies with a detailed analysis of Hirshfeld surface and fingerprint plots facilitating a comparison of intermolecular interactions in building different supramole-cular architectures. The X-ray study reveals that in the molecular packing C - H · · ·O, π · · · π, and carbonyl (lone pair) · · · π interactions cooperatively take part. The recurring feature of the self-assembly in all the compounds is the appearance of the molecular ribbon through weak hydrogen bonding. These hydrogen bonded ribbons further stacked into molecular layers by π · · · π forces. The mode of cooperativity of the weak C - H · · · O and π · · · π forces is such that they operate in mutuallyperpen-dicular directions - hydrogen bonding in the plane of the molecule at their edges and π-stacking perpendicular to the molecular plane. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analyses reveals that more than two-thirds of the close contacts are associated with weak interactions. Hirshfeld surface and breakdown of the corresponding fingerprint plots of four coumarin structures clearly quantify the interactions within the crystal structures, revealing significant similarities in the interactions experienced by each compound. The binding energies associated with the weak interactions have been estimated using density functional theory calculations. © 2011 American Chemical Society.

Saha R.,Jadavpur University | Dey S.K.,Jadavpur University | Biswas S.,Jadavpur University | Jana A.D.,Behala College | Kumar S.,Jadavpur University
Crystal Growth and Design | Year: 2013

The nonlinear optical active chiral complex 1 [{Co(2,5-pdc)(H 2O)2}H2O]n (2,5-pdc = 2,5-pyridine dicarboxylate) has been synthesized via a solvothermal technique using the achiral 2,5-pdc ligand. Complex 1 (phase 1), a two-dimensional coordination polymer, undergoes crystalline to amorphous (phase 2) transformation upon deaquation, which under reaquation generates a new microcrystalline phase (phase 3). The crystal structure of phase 3 has been determined by powder X-ray diffraction analysis (PXRD), which reveals that the resultant microcrystalline phase 3 is an achiral complex consisting of one-dimensional coordination chains. Phase 3 undergoes reversible structural transformation via amorphous phase (phase 2) upon dehydration and subsequent rehydration. This amorphous phase shows selective adsorption of water from a water-DMF mixture and water-CCl 4 mixture. Phase 1 to phase 3 structural transformation proceeds through selective bond breaking. The magnetic studies of the two crystalline and the amorphous phase reveal that phase 1 behaves as a canted antiferromagnet, while both amorphous phase 2 and phase 3 show antiferromagnetism. © 2013 American Chemical Society.

Sarkar A.,APC College | Sarkar A.,Jadavpur University | Middya T.R.,Jadavpur University | Jana A.D.,Behala College
Journal of Molecular Modeling | Year: 2012

In a pursuit of electronic level understanding of the antioxidant activity of a series of flavonoids, quantitative structure-activity relationship (QSAR) studies have been carried out using density functional theory (DFT) based quantum chemical descriptors. The best QSAR model have been selected for which the computed square correlation coefficient r2=0.937 and cross-validated squared correlation coefficient q2 =0.916. The QSAR model indicates that hardness (η), group electrophilic frontier electron density (FE A) and group philicity (ω + B) of individual molecules are responsible for in vitro biological activity. To the best our knowledge, the group electrophilic frontier electron density (FE A) has been used for the first time to explain the radical scavenging activity (RSA) of flavonoids. The excellent correlation between the RSA and the above mentioned DFT based descriptors lead us to predict new antioxidants having very good antioxidant activity. © Springer-Verlag 2011.

Ghosh D.,Jadavpur University | Dutta S.,Behala College | Samanta S.,Seacom Engineering College
Acta Physica Polonica B | Year: 2012

The time series for gold price has been investigated in past and it was observed that the time series has multifractal properties. The gold price data from 1973 to the present time has been divided into sets of five years each and the variation of degree of multifractality with time is investigated. An attempt has been made to physically interpret the results and to make future predictions of variation in price.

Dutta S.,Behala College | Ghosh D.,Jadavpur University | Samanta S.,Seacom Engineering College
Physica A: Statistical Mechanics and its Applications | Year: 2014

This paper studies the variation of autocorrelation and cross correlation coefficients of gold price and SENSEX fluctuations with time. The paper uses MFDFA and MFDXA methodologies. SENSEX plays a more dominant role in the variation of cross correlations. It is observed that the cross correlation coefficients can be linked with the stability of the market. The market is most stable when the two series are most correlated. © 2014 Elsevier B.V. All rights reserved.

Pani R.,Sundarban Hazi Desarat College | Mukhopadhyay U.,Behala College
Energy | Year: 2011

In the context of the present worldwide concern and desperate search for policies to curtail carbon dioxide emission, the paper aims to determine the roles of major driving forces in aggravating emission and examine the possibility of emission cut without compromising economic growth. Variance analysis method, in the line of management accounting, is used to decompose the changes in emission of 156 sample countries over the period 1993-2007. The major findings suggest that in aggregate, rising per capita GDP has been about seven times more responsible than that of population in accentuating emission; decline in energy intensity has been instrumental in offsetting nearly half of their potential effects, while inter-fuel substitution and change in emission intensities have meager roles. However, wide disparities in structural composition of energy intensity and emission intensity of fuels among countries over the period, point towards the crucial role of proper energy management in lowering emission concomitant with high economic growth. Management accounting control, particularly variance analysis, at the national level can be an effective tool in identifying the weaknesses and exploring the areas where emission reduction can be possible. © 2010 Elsevier Ltd.

Pani R.,Sundarban Hazi Desarat College | Mukhopadhyay U.,Behala College
Environmentalist | Year: 2010

The paper using data on 114 countries during 1992-2004 identifies the major perpetrators of escalating global emissions. Using the LMDI decomposition technique, we examine the contribution of the major factors in changing the level of emissions. The effect of GDP on emission is found to be substantially more than that of population. However, the income effect shows high fluctuation over time, while the population effect has been roughly constant. The upper middle-income countries, particularly of Europe and Central Asia, despite high economic growth have reduced their emissions substantially, while in the countries of North America, East Asia Pacific and South Asia increase in income have been significantly accompanied by increase in emission. Apart from few low emitting countries, almost all others have been successful in increasing emission efficiency, but their energy efficiencies have not been remarkable. Although emission efficiency has been more instrumental in curtailing emission, in some cases the path of change in emission follows that of change in energy intensity. Thus, both energy and emission intensity have crucial roles in determining the level of emissions. It may be suggested that emphasis should be given on policies oriented towards sufficient counteractive energy and emission efficiencies before embarking on a path towards economic growth. © Springer Science+Business Media, LLC 2010.

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