Santiniketan, India
Santiniketan, India

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Visva Bharati and Council Of Scientific & Industrial Research | Date: 2012-09-05

The present invention relates to a synergistic pharmaceutical composition comprising Compound C2 (Neo-isopulegol), C3 (Iso-pulegol) and C4 (Citronellol) derived from herbal seed extract of Litsea cubeba useful for the treatment of lung cancer. The present invention also relates to the activity of compounds C2 or C3 or C4 either alone or in combination in killing of A549 lung cancer cells.

Ghosh S.,Visva Bharati
Journal of the Optical Society of America B: Optical Physics | Year: 2013

The group index and its lineshape parameters of a relatively weak double-resonance probe pulse (signal) propagating through an open doubly driven M-type five-level atomic system are analytically formulated. It is shown for the first time, to our knowledge, that the group velocity status of the signal can be altered (between superluminal and subluminal propagation) by the combined effect of atomic coherence and linear AC Stark shift through coherent coupling. The distinct feature in this scheme is that, although it does not rely on electromagnetically induced transparency, a double-switching effect (i.e., from superluminal to subluminal and vice versa) is observed with negligible absorption/gain at two different frequency regimes. © 2013 Optical Society of America.

Mondal B.,Visva Bharati | Raha S.,Visva Bharati
IEEE Transactions on Fuzzy Systems | Year: 2011

This paper investigates the inverse problem of approximate reasoning [to conclude A′ from B′ and A→ B)] from different angles. We develop a method to find a solution to the inverse problem by the use of the law of contrapositive symmetry. In the process, generalized modus ponens, generalized modus tollens, and their generating functions are studied extensively. An attempt is made here to establish that the concept of similarity plays an important role in inverse approximate reasoning. We apply the concept of similarity to model inverse approximate reasoning and develop a new methodology that is named similarity-based inverse approximate reasoning for a solution to the problem. Algorithms are presented and illustrated with simple yet concrete examples. We then use Zadehs compositional rule of inference (CRI) as a combination of cylindrical extension and projection and, thereby, model generalized modus tollens in a different way. We, thus, develop a third way to find a solution to the inverse problem of approximate reasoning. A comparison between the result of application of our technique and the real static characteristic of a dc shunt motor is presented. © 2011 IEEE.

Kar R.K.,Visva Bharati
Plant Signaling and Behavior | Year: 2011

Responses of plants to water stress may be assigned as either injurious change or tolerance index. One of the primary and cardinal changes in response to drought stress is the generation of reactive oxygen species (ROS), which is being considered as the cause of cellular damage. However, recently a signaling role of such ROS in triggering the ROS scavenging system that may confer protection or tolerance against stress is emerging. Such scavenging system consists of antioxidant enzymes like SOD, catalase and peroxidases, and antioxidant compounds like ascorbate, reduced glutathione; a balance between ROS generation and scavenging ultimately determines the oxidative load. As revealed in case of defense against pathogen, signaling via ROS is initiated by NADPH oxidase-catalyzed super oxide generation in the apoplastic space (cell wall) followed by conversion to hydrogen peroxide by the activity of cell wall-localized SOD. Wall peroxidase may also play role in ROS generation for signaling. Hydrogen peroxide may use Ca 2+ and MAPK pathway as downstream signaling cascade. Plant hormones associated with stress responses like ABA and ethylene play their role possibly via a cross talk with ROS toward stress tolerance, thus projecting a dual role of ROS under drought stress. © 2011 Landes Bioscience.

Nechab M.,Aix - Marseille University | Mondal S.,Visva Bharati | Bertrand M.P.,Aix - Marseille University
Chemistry - A European Journal | Year: 2014

Hydrogen-atom transfer (HAT) counts amongst the most widely investigated routes to carbon-centered radicals. Intramolecular processes involving 1,5-HAT are widespread to promote regioselective radical "C-H activation". The aim of this review is to draw up a comprehensive inventory of the less commonly encountered 1,n-radical translocations (n†5) with the aim to update this topic with the most recent relevant data. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Majumdar P.,Muc Womens College | Samanta S.K.,Visva Bharati
Computers and Mathematics with Applications | Year: 2010

In this paper, we define generalised fuzzy soft sets and study some of their properties. Application of generalised fuzzy soft sets in decision making problem and medical diagnosis problem has been shown. © 2009 Elsevier Ltd. All rights reserved.

This paper deals with capitalist agricultural development in West Bengal, India. Based on a field study of two regions at different ends of the development spectrum, it shows the class-specific nature of agrarian development. Farms based on hired labour adopt more capital-intensive techniques, operate on a much larger scale and have higher yields in comparison to farms based on family labour, regardless of their size. Differentiation of the peasantry is intense where the adoption of capital-intensive technology is high. The paper concludes that the arguments of A.V. Chayanov and A.K. Sen, which seek to explain the inverse relation between farm size and productivity in terms of the superior efficiency of farms based on family labour compared to capitalist farms, are not borne out by our findings. Moreover, in the advanced region of Bardhaman, farmers of all economic classes are found to be subject to a form of compulsive exchange or stressed commerce brought about by traders external to the region. © 2011 Blackwell Publishing Ltd.

Ghosh S.,Visva Bharati
Journal of the Optical Society of America B: Optical Physics | Year: 2012

A detailed analytical description of a Doppler-free probe response (absorption and dispersion) is presented for a coherently prepared four-level atomic tripod driven by two coupling fields. Under the density matrix formalism the field-dependent and field-independent coherence are introduced through the off-diagonal matrix elements. Field-dependent coherence appears due to the interference between the probability amplitudes of finding the atom in energy levels associated with the allowed transition, while field-independent phases measure the atomic coherence for a coherently prepared lower state triplet. The double-control coherent effects on the probe response are investigated by controlling the relative driving contribution (coherence) of the two coupling fields, whereas the driving contribution can be controlled by the use of field-independent coherence, along with two coupling parameters like Rabi frequency and detuning of the respective coupling field. We report on the possibility of modifying the Rabi splitting into a perfect electromagnetically induced transparent window at probe resonance by a coherent double-control mechanism in an on-resonance coupling situation. Moreover, for off-resonance coupling, we exhibit the enhancement of multiphoton (two- or three-photon) absorption via coherent control of multiresonance processes. © 2012 Optical Society of America.

Nandy S.K.,A.K.P.C Mahavidyalaya | Mahapatra T.R.,Visva Bharati
International Journal of Heat and Mass Transfer | Year: 2013

The objective of the present study is to analyze the effects of velocity slip and heat generation/absorption on magnetohydrodynamic (MHD) stagnation-point flow and heat transfer over a stretching/shrinking surface, with convective boundary conditions, in the presence of nanoparticle fractions. The effects of Brownian motion and thermophoresis are also considered. The velocity, temperature and nanoparticle concentration profiles are analyzed with respect to the involved parameters, namely, slip parameter (δ), magnetic parameter (M), source/sink parameter (λ), Brownian motion parameter (Nb), thermophoresis parameter (Nt), Prandtl number (Pr), Lewis number (Le), Biot number (γ) and ratio of the rate constants of stretching/shrinking velocity to the free stream velocity (α). The numerical results indicate that for the stretching sheet, the velocity at a point decreases with the increase in the values of δ and M; whereas both temperature and nanoparticle concentration increase with the increase in δ and M. It is also observed that the temperature of the fluid increases with the increase in heat source parameter (i.e. λ > 0). Different from a stretching sheet, it is found that for a shrinking sheet the solutions are non-unique. A comparative study between the previously published results and the present results for a special case is found to be in good agreement. © 2013 Elsevier Ltd. All rights reserved.

Asif Ikbal M.,Visva Bharati
International Journal of Non-Linear Mechanics | Year: 2012

Current theoretical investigation deals with mathematical model of unsteady non-Newtonian flow of blood through a stenosed artery. The flowing blood is considered as a viscoelastic fluid having shear-thinning rheology and characterized by generalised Oldroyd-B model. The arterial wall is considered to be rigid having cosine shaped stenosis in its lumen. The governing equations of motion accompanied by appropriate choice of the initial and boundary conditions are solved numerically by MAC (Marker and Cell) method and the results are checked for numerical stability with desired degree of accuracy. The quantitative analysis has been carried out finally which includes the respective profiles of the flow-field. The key factors like the wall shear stress and flow separation are also examined for further qualitative insight into the flow through arterial stenosis. The present results show quite consistency with several existing results in the literature which substantiate sufficiently to validate the applicability of the model under consideration. © 2012 Elsevier Ltd.

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