Gauhati University is the first public university of North-East India, located in Guwahati, Assam, India. It was established on 26 January 1948. The University is situated to the west of Guwahati City and has 239 affiliated colleges. Wikipedia.
News Article | March 2, 2017
This research article by Dr. Rita Mahanta et al has been published in Cardiovascular & Hematological Agents in Medicinal Chemistry Investigations by researchers of Zoology Department of Cotton College, Guwahati, and Gauhati University, Guwahati, Assam, India, have revealed that long term exposure to elevated doses of Anabolic Androgenic Steroids (AAS) can significantly affect aldosterone concentration and serum sodium/ potassium levels in albino mice. The research led by Dr. Rita Mahanta, Associate Professor (Retd.) in the Department of Zoology, Cotton College, Guwahati and Ph.D. student, Parmita Chowdhury from Gauhati University, Zoology Department, have discovered that prolonged administration of Nandrolone Decanoate, an AAS, upon a group of male albino mice significantly increased serum aldosterone and sodium ion levels when compared with a group of albino mice that did not receive such treatment. Post treatment alterations were also revealed through measuring the level of potassium ion but this change was reported to be insignificant. This study, published in the journal Cardiovascular and Hematological Agents in Medicinal Chemistry (Bentham Science), volume 14, issue 3, further emphasizes that a change of this kind where a marked increase in aldosterone levels occurred upon chronic exposure to Nandrolone Decanoate could be a possible indication of steroid related cardiovascular disorders as a number of literatures are available that support the correlation between aldosterone concentration and cardiovascular diseases. For more information about this article, please visit http://benthamscience.
Sen Gupta S.,B N College |
Bhattacharyya K.G.,Gauhati University
Advances in Colloid and Interface Science | Year: 2011
It is necessary to establish the rate law of adsorbate-adsorbent interactions to understand the mechanism by which the solute accumulates on the surface of a solid and gets adsorbed to the surface. A number of theoretical models and equations are available for the purpose and the best fit of the experimental data to any of these models is interpreted as giving the appropriate kinetics for the adsorption process. There is a spate of publications during the last few years on adsorption of various metals and other contaminants on conventional and non-conventional adsorbents, and many have tried to work out the kinetics. This has resulted from the wide interest generated on using adsorption as a practical method for treating contaminated water. In this review, an attempt has been made to discuss the kinetics of adsorption of metal ions on inorganic solids on the basis of published reports. A variety of materials like clays and clay minerals, zeolites, silica gel, soil, activated alumina, inorganic polymer, inorganic oxides, fly ash, etc. have been considered as the adsorbents and cations and anions of As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn as adsorbate have been covered in this review. The majority of the interactions have been divided into either pseudo first order or second order kinetics on the basis of the best fit obtained by various groups of workers, although second order kinetics has been found to be the most predominant one. The discussion under each category is carried out with respect to each type of metal ion separately. Application of models as given by the Elovich equation, intra-particle diffusion and liquid film diffusion has also been shown by many authors and these have also been reviewed. The time taken for attaining equilibrium in each case has been considered as a significant parameter and is discussed almost in all the cases. The values of the kinetic rate coefficients indicate the speed at which the metal ions adsorb on the materials and these are discussed in all available cases. The review aims to give a comprehensive picture on the studies of kinetics of adsorption during the last few years. © 2011 Elsevier B.V.
Sen Gupta S.,B N College |
Bhattacharyya K.G.,Gauhati University
RSC Advances | Year: 2014
This review deals with adsorption of metal ions, particularly those considered as hazardous, on clays and some inorganic solids and covers the publication years 2000-2013 describing and quantifying the use of isotherms to obtain the adsorption capacities of the solids. The inorganic solids in the review include clays and clay minerals, their modified forms (obtained by treatment with acids and alkalis, organic functionalization, etc.), zeolites, silica gel, soil, river sediment, activated alumina, inorganic polymers, red mud, inorganic oxides, fly ash, etc. The use of two parameter and three parameter linear isotherms are only discussed with a view to obtain quantitative description of adsorptive accumulation and separation of metal ions from aqueous solution on the solids. The extensively used isotherms are those of Freundlich, Langmuir, Dubinin-Radushkevich and Redlich-Peterson. How these isotherms are being used to obtain the adsorption capacities along with their interpretations form the bulk of the review. The review is divided into sections, each describing the use of a particular isotherm. The metal cations receiving immense importance in adsorption studies are As(iii)/As(v), Cd(ii), Cr(iii)/Cr(vi), Cu(ii), Co(ii), Pb(ii), Ni(ii), Hg(ii), and Zn(ii), and the review covers both the cationic and the anionic metal ions. A few other cations such as Mn(ii), Fe(iii), Se(v), which have not received much attention, are also covered. © 2014 the Partner Organisations.
Sen Gupta S.,B N College |
Bhattacharyya K.G.,Gauhati University
Physical Chemistry Chemical Physics | Year: 2012
The process of adsorption is considered to be one of the best water treatment technologies around the world. Different heavy metals, due to their toxic and hazardous nature, are possibly the most widespread groundwater contaminants imposing a serious threat to human health. In this review, an attempt has been made to discuss the use of two common clay materials, namely kaolinite and montmorillonite, along with their modified forms for heavy metal removal on the basis of published reports (2008 onwards). The modifications of clays have been attempted by the process of pillaring, intercalation, acid/base activation, functionalization, etc. The adsorption of toxic metals, viz., As, Cd, Cr, Co, Cu, Fe, Pb, Mn, Ni, Zn, etc., has been studied predominantly. Montmorillonite and its modified forms have much higher metal adsorption capacity compared to that of kaolinite as well as modified-kaolinite. The modification often boosted the adsorption capacities of the clays, however, reverse trends are also reported in some cases. © 2012 the Owner Societies.
Dutta H.,Gauhati University
Journal of the Franklin Institute | Year: 2011
The main aim of this article is to extend the notion of strongly Cesàro summable and strongly lacunary summable real sequences to n-normed linear space valued (n-nls valued) difference sequences. Consequently we introduce the spaces |σ1|(X,∇) and Nθ(X, ∇), respectively, where X is an n-normed space and ∇ is a difference operator. We investigate these spaces for completeness as well as for the relationship between these spaces. © 2011 The Franklin Institute © 2011 Published by Elsevier Ltd. on behalf of The Franklin Institute. All rights reserved.
Bhattacharyya P.N.,Gauhati University |
Jha D.K.,Gauhati University
World Journal of Microbiology and Biotechnology | Year: 2012
Plant growth-promoting rhizobacteria (PGPR) are the rhizosphere bacteria that can enhance plant growth by a wide variety of mechanisms like phosphate solubilization, siderophore production, biological nitrogen fixation, rhizosphere engineering, production of 1-Aminocyclopropane-1-carboxylate deaminase (ACC), quorum sensing (QS) signal interference and inhibition of biofilm formation, phytohormone production, exhibiting antifungal activity, production of volatile organic compounds (VOCs), induction of systemic resistance, promoting beneficial plant-microbe symbioses, interference with pathogen toxin production etc. The potentiality of PGPR in agriculture is steadily increased as it offers an attractive way to replace the use of chemical fertilizers, pesticides and other supplements. Growth promoting substances are likely to be produced in large quantities by these rhizosphere microorganisms that influence indirectly on the overall morphology of the plants. Recent progress in our understanding on the diversity of PGPR in the rhizosphere along with their colonization ability and mechanism of action should facilitate their application as a reliable component in the management of sustainable agricultural system. The progress to date in using the rhizosphere bacteria in a variety of applications related to agricultural improvement along with their mechanism of action with special reference to plant growth-promoting traits are summarized and discussed in this review. © 2011 Springer Science+Business Media B.V.
Kalita K.,Gauhati University
Journal of Physics G: Nuclear and Particle Physics | Year: 2011
The complete, incomplete and fission cross sections are being measured for 12,13C + 208,207Pb systems to investigate the influence of breakup at above-barrier energies which form the same compound nucleus at the same excitation energies. The α-active heavy reaction products are measured for most dominant reaction xn-channels along with fission cross sections which originate almost exclusively from the complete fusion (CF). The results from the present systems show substantial components from the incomplete fusion in addition to CF. The CF cross section is suppressed by 12 2% for 12C and 3 2% for 13C compared with the single-barrier penetration model calculations. A systematic variation of the suppression of CF for reactions of weakly bound nuclei 6,7Li, 9Be, 10,11 B and 12,13C on targets of 207,208Pb and 209Bi is being found as a function of the breakup threshold energy. © 2011 IOP Publishing Ltd.
Ahmed N.,Gauhati University
Journal of Heat Transfer | Year: 2012
An exact solution to the problem of MHD transient free convection and mass transfer flow of a viscous, incompressible, and electrically conducting fluid past a suddenly started infinite vertical plate taking into account the thermal diffusion as well as the thermal radiation is presented. Assuming the medium to be nonscattered and the fluid to be nongray, emitting-absorbing, and optically thin radiation limit properties, the equations governing the flow and heat and mass transfer are solved by Laplace transform technique. The expressions for the velocity field, the concentration field, the skin friction at the plate in the direction of the flow, and the coefficient of heat transfer and mass transfer from the plate to the fluid have been obtained, and their numerical values for different values of the physical parameters involved in the problem have been demonstrated in graphs and tables, and these are physically interpreted. It is found that the thermal radiation retards the fluid flow whereas the Soret effect accelerates the flow. The viscous drag on the plate is increased under the Soret and magnetic field effects whereas the thermal radiation reduces the skin friction. Further, the rate of heat transfer at the plate increases under thermal radiation effect. Also, in the presence of radiation, the Soret effect results in a steady increase in the mass flux from the fluid to the plate. © 2012 American Society of Mechanical Engineers.
Bhagawati N.,Gauhati University
Acta Physica Polonica B | Year: 2014
We apply a simple transformation method to construct a set of new exactly solvable potentials (ESP) which gives rise to bound state solution of the D-dimensional Schrödinger equation. The important property of such exactly solvable quantum systems is that their normalized eigenfunctions can be written in terms of recently introduced exceptional orthogonal polynomials (EOP).
Borah A.J.,Gauhati University |
Phukan P.,Gauhati University
Chemical Communications | Year: 2012
A catalyst-free protocol has been developed for amidation of alkyl aromatics and aldehydes using TsNBr 2via a nitrene transfer process in the presence of a base in excellent yield within a short time. The reaction was found to be selective for secondary and tertiary benzylic C-H bonds and C-H bonds of aldehydic groups. © 2012 The Royal Society of Chemistry.