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Geochemistry and depositional environment of fuchsite quartzites from Sargur Group,western Dharwar craton,India

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Acta Geochimica 2024年第3期43卷 555-570页

作者： c.S.Sindhuja G.Harshitha c.Manikyamba K.S.v.Subramanyam cSIR(council of Scientific and Industrial Research)-National Geophysical Research Institute(NGRI) Uppal RoadHyderabad 500007India

Meso-Neoarchean fuchsite quartzites are present in different stratigraphic positions of Dharwar craton including the oldest(~3.3 Ga)Sargur Group of western Dharwar *** present study deals with the petro-graphic and geochemical characteristics of the fuchsite quartzites from the Ghattihosahalli belt to evaluate their genesis,depositional setting and the enigma involved in the ancient sedimentation *** major mineral assemblages include quartz,fuchsite,and feldspars along with accessory kyanite and *** geochemical com-positions are characterized by high SiO_(2),Al_(2)O_(3),low MgO,caO,strongly enriched cr(1326–6899 ppm),Ba(1165–3653 ppm),Sr(46–210 ppm),v(107–868 ppm)and Zn(11–158 ppm)contents compared to the upper continental crust(Ucc).The Ucc normalized rare earth element(REE)patterns are characterized by depleted light REE[(La/Sm)Ucc=0.33–0.95]compared to heavy REE[(Gd/Yb)_(Ucc)=0.42–1.65]with conspicuous positive Eu-anomalies(Eu/Eu^(*)=1.35–18.27)characteristic of hydrothermal solutions evidenced through the interlayered *** overall major and trace element systematics reflect a combined mafic-felsic provenance and suggest their deposition at a passive continental margin *** comprehensivefield,petrographic,and geo-chemical studies indicate that these quartzites are infiltrated by cr-richfluids released during high-grade metamorphism of associated ultramafic *** Sargur and the subse-quent Dharwar orogeny amalgamated diverse lithounits from different tectonic settings,possibly leading to the release of cr-richfluids and the formation of fuchsite quartzite during or after the *** sug-gest a pre-existing stable crust prior to the Sargur Group and the link between orogenic events and various mineral deposits in the Dharwar craton.

关键词： Dharwar craton Ghattihosahalli Fuchsite quartzite Provenance Depositional setting

A neutronic experiment to support the design of an Indian TBM shield module for ITER

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Plasma Science and Technology 2019年第6期21卷 147-152页

作者： H L SWAMI M ABHANGI Sanchit SHARMA S TIWARI A N MISTRY v vASAvA v MEHTA S vALA c DANANI v cHAUDHARI P cHAUDHURI Institute for Plasma Research Gandhinagar Gujarat 382428 India Homi Bhabha National Institute(HBNI) Anushaktinagar Mumbai 400094 India Pandit Deendayal Petroleum University Gandhinagar Gujarat 382007 India

A shield module is associated with an Indian Test Blanket Module (TBM) in ITER to limit the radiation doses in port inter-space *** shield module is made of stainless steel plates and water *** is identified as an important component for radiation protection because of its radiation exposure control *** radiation protection classification leads to more assurance of the component *** order to validate and verify the design of the shield module,a neutronic laboratory-scale experiment is designed and *** experiment is planned by considering the irradiation under a neutron source of 14 Mev and yields of 1010 n *** reference neutron spectrum of the ITER TBM shield module has been achieved through optimization of the neutron source spectrum by a combination of steel and lead *** neutron spectrum and flux are measured using a multiple foil activation technique and neutron dose-rate meter LB 6411 (He-3 proton recoil counter with polyethylene),*** neutronic design simulation is assessed using McNP5 and FENDL 2.1 crosssection *** paper covers neutronic design,irradiation and the outcome of the experiment in detail.

关键词： TBM shield module neutronic experiment ITER McNP neutron attenuation

Spectral characterization of Laser Induced Plasma from Titanium Dioxide

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Plasma Science and Technology 2007年第4期9卷 456-459页

作者： v.J.DANN M.v.MATHEW v.P.N.NAMPOORI c.P.G.vALLABHAN v.M.NANDAKUMARAN P.RADHAKRISHNAN International School of Photonics Cochin University of Science and TechnologyCochin 22India Centre of Excellence in Lasers and Optoelectronic SciencesCochin University of Science and TechnologyCochin 22India International School of Photonics Cochin University of Science and TechnologyCochin 22India centre of Excellence in Lasers and Optoelectronic Sciences Cochin University of Science and TechnologyCochin 22India

Optical emission from TiO2 plasma, generated by a nanosecond laser is spectroscopically analysed. The main chemical species are identified and the spatio-temporal distribution of the plasma parameters such as electron temperature and density are characterized based on the study of spectral distribution of the line intensities and their broadening characteristics. The parameters of laser induced plasma vary quickly owing to its expansion at low background pressure and the possible deviations from local thermodynamic equilibrium conditions are tested to show its validity.

关键词： laser induced plasma titanium dioxide optical emission spectroscopy local thermodynamic equilibrium

ETP-AKEP: enhanced three-party authenticated key exchange protocols for data integrity in cloud environments

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Journal of control and Decision 2023年第1期10卷 126-133页

作者： Kalluri Rama Krishna c.v.Guru Rao Faculty of Informatics Osmania UniversityHyderabadIndia School of computer Science&Artificial Intelligence S.R.UniversityWarangalIndia

With key exchange protocols, a secure session key is generated between two remote users, andservers and exchanged between them. It is generally used to prevent unauthorised users fromgaining access to sensitive data. This article presents an enhanced three-party authenticated keyexchange protocols (ETP-AKE) protocol that does not depend on symmetric key encryption andinstead uses asymmetric key encryption. A key component of the proposed ETP-AKE protocol isusing elliptic curve encryption in conjunction with a one-way hash function. Its integrity certificationwas confirmed via the usage of the AvISPA tool package. Our proposed protocol is intendedto protect against various security threats, including the man-in-the-middle assault, the parallelattack, and the key-compromise attack, among others.

关键词： Ecc hash function cloud integrity third party key exchange

Petrology and geochemical characteristics of Precambrian granitic basement complex rocks in the southernmost part of North-central Nigeria

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chinese Journal Of Geochemistry 2009年第4期28卷 377-385页

作者： Obiora S.c. Ukaegbu v.U. National Geophysical Research Institute Geological Studies DivisionUppal Road Hyderabad-500007 India Department of Geology University of NigeriaNsukka Nigeria Department of Geology University of Port HarcourtPort Harcourt Nigeria

The Precambrian basement complex in the southernmost part of North-central Nigeria is underlain by migmatitic banded gneisses, granitic intrusions and dykes of dolerite, rhyolite porphyry and pegmatite. The rocks are generally felsic, containing modal and normative hypersthene, as well as normative corundum. The basement complex has experienced high-grade regional metamorphism as indicated by the presence of hypersthene and plagioclase of andesine composition. Anatectic melting is suggested by the occurrence of ptygmatic folds, folded gneissose foliation, numerous quartzo-feldspathic veins and lenses of dark-colured, micaceous schistose rocks. Geochemically, the rocks have magnesian, calc-alkalic and strongly peraluminous characteristics. Their overall characteristics suggest derivation from progressive (fractional) partial melting of pelitic rocks during high-grade regional metamorphism, possibly associated with intense hydrothermal activities. The magnesian characteristics reflect close affinity to relatively hydrous, oxidizing melts and source regions in settings broadly related to subduction.

关键词：岩石地球化学特征前寒武纪基底尼日利亚花岗岩中央区域变质作用流纹斑岩叶状结构

L-asparaginase production by mangrove derived Bacillus cereus MAB5:optimization by response surface methodology

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Asian Pacific Journal of Tropical Medicine 2011年第6期4卷 486-491页

作者： Thenmozhi c Sankar R Karuppiah v Sampathkumar P centre of Advanced Study in Marine Biology Faculty of Marine Sciences Annamalai University Parangipettai-608 502Tamil NaduIndia

Objective:To isolate marine bacteria,statistically optimize them for maximum asparaginase ***:In the present study,statistically based experimental designs were applied to maximize the production of L-asparaginase from bacterial strain of Bacillus cereus（***） MAB5（HQ675025） isolated and identified by 16S rDNA sequencing from mangroves rhizosphere ***:Plackett-Barman design was used to identify the interactive effect of the eight variables *** extract,soyabean meal,glucose,magnesium sulphate,KH2PO4,wood chips,aspargine and sodium *** the variables are denoted as numerical factors and investigated at two widely spaced intervals designated as -1（low level） and +1（high level）. The effect of individual parameters on L-asparaginase production was *** meal,aspargine,wood chips and sodium chloride were found to be the significant among eight *** maximum amount of L-asparaginase produced（51.54 IU/mL） from the optimized medium containing soyabean meal（6.282 8 g/L）,aspargine（5.5 g/L）,wood chips（1.383 8 g/L） and Nacl（4.535 4 g/L）.conclusions:The study revealed that,it is useful to produce the maximum amount of L-asparaginase from *** MAB5 for the treatment of various infections and diseases.

关键词： L-asparaginase Bacillus cereus Mangroves Plackett-Barman design central composite design

characteristic Study of the Boundary Layer Parameters over the Arabian Sea and the Bay of Bengal Using the QuikScAT Dataset

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Advances in Atmospheric Sciences 2007年第4期24卷 631-643页

作者： v.HAMZA c.A.BABU T.P.SABIN Department of Atmospheric Sciences Cochin University of Science and TechnologyCochin-682 016India

The marine atmospheric boundary layer （MABL） plays a vital role in the transport of momentum and heat from the surface of the ocean into the atmosphere. A detailed study on the MABL characteristics was carried out using high-resolution surface-wind data as measured by the QuikScAT （Quick scatterometer） satellite. Spatial variations in the surface wind, frictional velocity, roughness parameter and drag coefficient for the different seasons were studied. The surface wind was strong during the southwest monsoon season due to the modulation induced by the Low Level Jetstream. The drag coefficient was larger during this season, due to the strong winds and was lower during the winter months. The spatial variations in the frictional velocity over the seas was small during the post-monsoon season （-0.2 m s^-1）. The maximum spatial variation in the frictional velocity was found over the south Arabian Sea （0.3 to 0.5 m s^-1） during the southwest monsoon period, followed by the pre-monsoon over the Bay of Bengal （0.1 to 0.25 m s^-1）. The mean wind-stress curl during the winter was positive over the equatorial region, with a maximum value of 1.5×10^-7 N m^-3, but on either side of the equatorial belt, a negative wind-stress curl dominated. The area average of the frictional velocity and drag coefficient over the Arabian Sea and Bay of Bengal were also studied. The values of frictional velocity shows a variability that is similar to the intraseasonal oscillation （ISO） and this was confirmed via wavelet analysis. In the case of the drag coefficient, the prominent oscillations were ISO and quasi-biweekly mode （QBM）. The interrelationship between the drag coefficient and the frictional velocity with wind speed in both the Arabian Sea and the Bay of Bengal was also studied.

关键词： boundary layer characteristics drag coefficient frictional velocity roughness length QuikScAT wind

Spectroscopy of a Gamma Irradiated Poly(Acrylic Acid)-clotrimazole System

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chinese Physics Letters 2011年第12期28卷 274-277页

作者： M.Todica c.v.Pop Luciana Udrescu Traian Stefan Faculty of Physics Babes-Bolyai University400084 Cluj-NapocaRomania

A poly(acrylic acid)-clotrimazole system,gamma irradiated at different doses,is investigated by Raman *** of the spectrum of the polymeric matrix appear for doses of radiation greater than 333 Gy,whereas the spectrum of clotrimazole remains unaffected at these doses of *** changes correlate with modification of the vibration modes of cOOH and cH_(2) groups of a polymeric matrix after irradiation.

关键词： spectroscopy polymeric matrix

Sea Urchin Spines as a Model-System for Permeable,Light-Weight ceramics with Graceful Failure Behavior. Part I. Mechanical Behavior of Sea Urchin Spines under compression

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Journal of Bionic Engineering 2009年第4期6卷 203-213页

作者： v.Presser S.SchultheiB c.Berthold K.GNickel Institute

The spines of pencil and lance urchins Heterocentrotus mammillatus and Phyllacanthus imperialis were studied as a model of light-weight material with high impact *** complex and variable skeleton construction ('stereom') of body and spines of sea urchins consists of highly porous Mg-bearing calcium *** basically brittle material with pronounced single-crystal cleavage does not fracture by spontaneous catastrophic device failure but by graceful failure over the range of tens of millimeter of bulk compression *** was observed in bulk compression tests and blunt indentation experiments on regular,infiltrated and latex coated sea urchin spine *** characterization was carried out using X-ray computer tomography,optical and scanning electron *** behavior is interpreted to result from the hierarchic structure of sea urchin spines from the rnacroscale down to the *** derived from this study see ceramics with layered porosity as a possible biomimetic construction for appropriate applications.

关键词： sea urchin urchin spines biominmitic mechanical behavior compression calcite

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