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Localization of polycyclic aromatic hydrocarbons and heavy metals in surface soil of Asia’s oldest oil and gas drilling site in Assam,northeast India:Implications for the bio-economy

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Emerging Contaminants 2016年第3期2卷 119-127页

作者： Hemen sarma N.F.Islam p.Borgohain A.sarma m.N.V.prasad Department of Botany N N Saikia CollegeTitabarAssamIndia Department of Biotechnology Pandu CollegeGuwahatiAssamIndia Department of plant Science University of HyderabadHyderabadTelanganaIndia

The environmental influx of hazardous contaminants viz pAHs and Hms occurs due to oil and gas drilling,and processing of petroleum products in industrial facilities and *** problem plagues crude oil drilling sites as pAHs are an essential component of and Hms coexist with crude *** analyzed the spatial distribution of 16 pAHs and 8 Hms in 10 contaminated sites of Assam,a state in *** included Digboi,where crude oil was drilled in 1867 and the first oil well in Asia that was ***Ʃ16 pAHs in soil were detected with a minimum of 13.48 and a maximum of 86.3 mgkg1 andƩ8 heavy metal concentrations in the soil ranged between 69.51 and 336.06 mgkg1.A negative correlation was detected between the relative concentrations of pAHs and *** results confirmed that the nonbiodegradable nature of Hms made them stay in the soil for longer periods of *** our study,we found that the levels of lead,copper,nickel,and chromium(total)in soil were 73.62,11.86,58.97 and 158.66 mgkg*** recovery percentage for pAHs and Hms were in the range of 67e97%and 90e95%*** distribution indices for phenanthrene/Anthracene,Naphthalene/Acenapthhylene,Chyrsene/Benzo(g,h,i)perylene and Fluranthene/pyrene)calculated for soil samples indicated that the spatial distribution of pAHs in soil is uneven which might be due to variations in contaminates disseminated in *** regionalized concentration has serious implications on the bio-economy both in terms of health and economy,especially since the proximity of crude oil sites to paddy fields and/or tea plantations uniquely marks the landscape of upper Assam.

关键词： pAH Heavy metals Spatial distribution indices Oil Drilling site

Kadomtsev–petviashvili(Kp) Burgers Equation in Dusty Negative Ion plasmas:Evolution of Dust-Ion Acoustic Shocks

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Communications in Theoretical physics 2014年第12期61卷 875-880页

作者： A.N.Dev J.sarma m.K.Deka A.p.misra N.C.Adhikary Department of Science and Humanities College of Science and Technology RUB Bhutan Department of mathematics R.G.Baruah College Guwahati-781025 Assam India Centre of plasma physics Tepesia Sonapur Kamrup Assam India Department of mathematics Siksha Bhavana Visva-Bharati University Santiniketan-731 235 India physical Sciences Division Institute of Advanced Study in Science and Technology Vigyan Path Paschim BoragaonGarchuk Guwahati – 781035 Assam India

We study the nonlinear propagation of dust-ion acoustic(DIA) shock waves in an un-magnetized dusty plasma which consists of electrons, both positive and negative ions and negatively charged immobile dust grains. Starting from a set of hydrodynamic equations with the ion thermal pressures and ion kinematic viscosities included, and using a standard reductive perturbation method, the Kadomtsev–petviashivili–Burgers(K-p-Burgers) equation is derived, which governs the evolution of DIA shocks. A stationary solution of the K-p-Burgers equation is obtained and its properties are analysed with different plasma number densities, ion temperatures and masses. It is shown that a transition from shocks with negative potential to positive one occurs depending on the negative ion concentration in the plasma and the obliqueness of propagation of DIA waves.

关键词： dusty plasmas Shock wave reductive perturbation technique K-p burgers equation

K-p-Burgers equation in negative ion-rich relativistic dusty plasma including the effect of kinematic viscosity

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Chinese physics B 2016年第10期25卷 215-221页

作者： A N Dev m K Deka J sarma D Saikia N C Adhikary Department of mathematics Siksha ‘O' Anusandhan University Department of Applied Sciences Institute of Science and Technology Gauhati University Department of mathematics R G Baruah College physical Sciences Division Institute of Advanced Study in Science and TechnologyVigyan Path Paschim Boragaon

The stationary solution is obtained for the K–p–Burgers equation that describes the nonlinear propagations of dust ion acoustic waves in a multi-component, collisionless, un-magnetized relativistic dusty plasma consisting of electrons, positive and negative ions in the presence of charged massive dust grains. Here, the Kadomtsev–petviashvili(K–p) equation, threedimensional(3D) Burgers equation, and K–p–Burgers equations are derived by using the reductive perturbation method including the effects of viscosity of plasma fluid, thermal energy, ion density, and ion temperature on the structure of a dust ion acoustic shock wave(DIASW). The K–p equation predictes the existences of stationary small amplitude solitary wave,whereas the K–p–Burgers equation in the weakly relativistic regime describes the evolution of shock-like structures in such a multi-ion dusty plasma.

关键词： K–p–Burgers equation negative ion relativistic plasma reductive perturbation method

Diversity of endophytic fungi associated with Hedychium spicatum Ham ex *** their antifungal activity against the phytopathogen Alternaria solani

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Studies in Fungi 2020年第1期5卷 84-93页

作者： sarma p Dkhar mS Kayang H Kumar m Dubey NK Raghuwanshi R microbial Ecology Laboratory Department of BotanyNorth Eastern Hill UniversityShillong793022 Department of Botany Banaras Hindu UniversityVaranasi221005 Department of Botany Mahila MahavidyalayaBanaras Hindu UniversityVaranasi221005

Twenty eight strains of endophytic fungi including sterile mycelia were isolated from the leaf,rhizome and roots of Hedychium spicatum Ham *** of the endophytic fungi isolated belonged to the phylum Ascomycota which accounted of about 84%.The endophytic assemblage was dominated by the class *** fungal genera such as Fusarium and penicillium were found to be common to all the plant *** of endophytic fungi was found to be highest in the roots(H’=2.43).mucor hiemalis,penicillium sp.,penicillium expansum,***,phoma medicaginis,Trichoderma *** *** showed above 60%inhibition against the phytopathogen Alternaria solani.

关键词： Colonization frequency diversity index percentage inhibition

xF_3(x,Q^2) Structure Function and Gross-Llewellyn Smith Sum Rule with Nuclear Effect and Higher Twist Correction

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Communications in Theoretical physics 2016年第12期65卷 663-670页

作者： N.m.Nath A.mukharjee m.K.Das J.K.sarma Department of physics Rajiv Gandhi University High Energy physics Laboratory Department of Physics Tezpur University

We present an analysis of the xF_3(x,Q^2) structure function and Gross-Llewellyn Smith(GLS) sum rule taking into account the nuclear effects and higher twist correction. This analysis is based on the results presented in[N.m. Nath, et al., Indian J. phys. 90(2016) 117]. The corrections due to nuclear effects predicted in several earlier analysis are incorporated to our results of xF_3(x,Q^2) structure function and GLS sum rule for free nucleon, corrected upto next-next-to-leading order(NNLO) perturbative order and calculate the nuclear structure function as well as sum rule for nuclei. In addition, by means of a simple model we have extracted the higher twist contributions to the nonsinglet structure function xF_3(x,Q^2) and GLS sum rule in NNLO perturbative orders and then incorporated them to our results. Our NNLO results along with nuclear effect and higher twist corrections are observed to be compatible with corresponding experimental data and other phenomenological analysis.

关键词： perturbative QCD Regge theory nuclear effect higher twist effect

Efficacy of natural biocide on control of microbial induced corrosion in oil pipelines mediated by Desulfovibrio vulgaris and Desulfovibrio gigas

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Journal of Environmental Sciences 2011年第8期23卷 1394-1402页

作者： meeta Lavania priyangshu m.sarma Ajoy K.mandal Simrita Cheema Banwari Lal TERI Darbari Seth BlockIndia Habitat CenterLodhi RoadNew Delhi 110003IndiaIndia

We compared the efficacy of a natural biocide with four chemical tetrakishydroxymethyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, and formaldehyde, glutaraldehyde, to control microbial induced corrosion in oil pipelines. The efficacy of biocides were monitored against Desulfovibrio vulgaris and Desulfovibrio gigas in experimental pipes by measuring cell counts, H2S production, Fe（II） production, production of extracellular polymeric substances and structure of biofilm. The treatment with cow urine had minimum planktonic cell counts of 3 x 102 CFU/mL as well as biofilm cell counts of 9 x 101 CFU/mL as compared with tetrakishydroxyl methyl phosphonium sulfonate, benzyl trimethyl ammonium chloride, formaldehyde and glutaraldehyde. Sulfide production was the lowest with cow urine （0.08 mmol]L）, followed by tetrakishydroxymethyl phosphonium sulfonate 0.72 mmol]L. On day 90 of treatment, Fe（II） production was also found to be the lowest with cow urine. The scanning electron microscopic studies indicated that the biofilm bacteria were killed by cow urine. These results demonstrate the cow urine mediated control of microbially induced corrosion, and this is indicative of its potential as a viable substitute of toxic biocides. To the best of our knowledge, this seems to be the first report which screens possible biocidal activity by cow urine as compared to the most common bioeides which oil industry is currently using.

关键词： microbially induced corrosion biocide biofilm extraploymeric substances H2S production Fe(II) production

On Isomorphism Testing of Groups with Normal Hall Subgroups

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Journal of Computer Science & Technology 2012年第4期27卷 687-701页

作者：乔友明 Jayalal sarma m.N 唐邦晟 Institute for Theoretical Computer Science Tsinghua University Department of Computer Science and Engineering Indian Institute of Technology Madras

A normal Hall subgroup N of a group G is a normal subgroup with its order coprime with its index. Schur- Zassenhaus theorem states that every normal Hall subgroup has a complement subgroup, that is a set of coset representatives H which also forms a subgroup of G. In this paper, we present a framework to test isomorphism of groups with at least one normal Hall subgroup, when groups are given as multiplication tables. To establish the framework, we first observe that a proof of Schur-Zassenhaus theorem is constructive, and formulate a necessary and sufficient condition for testing isomorphism in terms of the associated actions of the semidirect products, and isomorphisms of the normal parts and complement parts. We then focus on the case when the normal subgroup is abelian. Utilizing basic facts of representation theory of finite groups and a technique by Le Gall （STACS 2009）, we first get an efficient isomorphism testing algorithm when the complement has bounded number of generators. For the case when the complement subgroup is elementary abelian, which does not necessarily have bounded number of generators, we obtain a polynomial time isomorphism testing algorithm by reducing to generalized code isomorphism problem, which asks whether two linear subspaces are the same up to permutation of coordinates. A solution to the latter can be obtained by a mild extension of the singly exponential （in the number of coordinates） time algorithm for code isomorphism problem developed recently by Babai et al. （SODA 2011）. Enroute to obtaining the above reduction, we study the following computational problem in representation theory of finite groups： given two representations ρandτ- of a group H over Zp^d, a prime, determine if there exists an automorphism ： ФH→ H, such that the induced representation p Ф= ρ o Ф and τ are equivalent, in time poly（｜H｜, p^d）.

关键词： group isomorphism normal Hall subgroup isomorphism testing problem complexity

Influence of Annealing on X-Ray Radiation Sensing properties of TiO2 Thin Film

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photonic Sensors 2018年第1期8卷 70-79页

作者： m. p. sarma J. m. KALITA G. WARY Department of physics Cotton University Guwahati 781001 India Department of physics and Electronics Rhodes University P. O. Box 94 Grahamstown 6140 South Africa

A recent study shows that the titanium dioxide （TiO2） thin film synthesised by a chemical bath deposition technique is a very useful material for the X-ray radiation sensor. In this work, we reported the influence of annealing on the X-ray radiation detection sensitivity of the TiO2 film. The films were annealed at 333 K, 363K, 393K, 473 K, and 573K for 1 hour. Structural analyses showed that the microstrain and dislocation density decreased whereas the average crystallite size increased with annealing. The band gap of the films also decreased from 3.26eV to 3.10eV after annealing. The I-V characteristics record under the dark condition and under the X-ray irradiation showed that the conductivity increased with annealing. The influence of annealing on the detection sensitivity was negligible if the bias voltage applied across the films was low （within 0.2V - 1.0V）. At higher bias voltage （〉1.0V）, the contribution of electrons excited by X-ray became less significant which affected the detection sensitivity.

关键词： Titanium dioxide (TiO2) thin film annealing X-ray sensor

pb–pb baddeleyite ages of mafic dyke swarms from the Dharwar Craton:Implications for paleoproterozoic LIps and diamond potential of mantle keel

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Geoscience Frontiers 2020年第6期11卷 2127-2139页

作者： D.Srinivasa sarma V.parashuramulu m.Santosh E.Nagaraju N.Ramesh Babu CSIR-National Geophysical Research Institute Uppal RoadHyderabad500007India School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing100083China Department of Earth Sciences University of AdelaideAdelaideSA5005Australia

The Dharwar Craton in peninsular India was intruded by a series of mafic dykes during the paleoproterozoic and these mafic magmatic events have important implications on continental rifting and *** we report ten precise pb-pb TE-TImS age determinations on baddeleyite grains separated from seven mafic dykes and three sills,intruding into Archean basement rocks and proterozoic sedimentary formations of the Eastern Dharwar Craton *** crystallization age of the baddeleyite shows 2366.3±1.1 ma,and 2369.2±0.8 ma for the NE-SW trending dykes,2368.1±0.6 ma,2366.4±0.8 ma,2207.2±0.7 ma and 1887.3±1.0 ma for the ENE-WNW to E-W striking dykes,1880.6±1.0 ma,1864.3±0.6 ma and 1863.6±0.9 ma for Cuddapah sills,and 1861.8±1.4 ma for the N-S trending *** results in conjunction with those from previous studies identify eight distinct stages of widespread paleoproterozoic magmatism in the Dharwar *** mantle plume centres of the four radiating dyke swarms with ages of^2367 ma,~2210 ma,~2082 ma,and^1886 ma were traced to establish their proximity to the EDC kimberlite *** the^2367 ma and^1886 ma plume centres are inferred to be located to the west and east of the present day Dharwar craton respectively away from the kimberlite province,location of plume heads of the other two swarms with ages of^2207 ma and^2082 ma are in close *** spite of the ubiquitous occurrence of dyke intrusions of all the seven generations in the kimberlite province,only few of these kimberlites are *** occurrences elsewhere in the vicinity of older Large Igneous provinces(LIps)like the mackenzie,Karoo,parana-Etendeka and Yakutsk-Vilui are also *** has been attributed to the destruction of the lithospheric mantle keel(that hosts the diamonds)by the respective mantle *** diamondiferous nature of the EDC kimberlites therefore suggests that plume activity does not always result in the destruction of the mantle keel.

关键词： paleoproterozoic mafic dykes Baddeleyite geochronology Kimberlite Large igneous province Dharwar craton