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Chinese Physics C 2019年第9期43卷 90-100页

作者： Marco Ruggieri Marco Frasca santosh kumar Das School of Nuclear Science and Technology Lanzhou University222 South Tianshui RoadLanzhou 730000China Via Erasmo Gattamelata Rome 00176Italy School of Physical Science Indian Institute of Technology GoaPonda-403401GoaIndia

We consider a simple model for the diffusion of heavy quarks in a hot bath,modeling the latter by an ensemble of oscillators distributed according to either a thermal distribution or to an out-of-equilibrium distribution with a saturation *** this model it is easy to introduce memory effects by changing the distribution of oscillators:we model them by introducing a Gaussian distribution,dN/dω,which can be deformed continuously from aδ?function,giving a Markov dissipation,to a broad kernel with *** the equation of motion of the heavy quark in the bath,we remark how dissipation comes out naturally as an effect of the back-reaction of the oscillators on the ***,the exact solution of this equation allows to define the thermalization time as the time necessary to remove any memory of the initial *** find that the broadening of the dissipative kernel,while keeping the coupling fixed,lowers the thermalization *** also derive the fluctuation-dissipation theorem for the bath,and use it to estimate the kinematic regime in which momentum diffusion of the heavy quark dominates over *** find that diffusion is more important as long as K0/E is small,where K0 and E denote the initial energy of the heavy quark and the average energy of the bath,respectively.

关键词： relativistic heavy ion collisions heavy quarks Brownian motion memory effect quark-gluon plasma

Defect induced room-temperature ferromagnetism and enhanced photocatalytic activity in Ni-doped ZnO synthesized by electrodeposition

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Chinese Physics B 2020年第10期29卷 566-572页

作者： Deepika Raju kumar Ritesh kumar Kamdeo Prasad Yadav Pratyush Vaibhav Seema Sharma Rakesh kumar Singh santosh kumar College o f Commerce Arts and SciencePatna.BiharIndia Jaypee University o f Engineering and Technology GunaMadhya PradeshIndia Anugrah Narayan College PatnaBiharIndia Aryabhatta Knowledge University PatnaBiharIndia

Zn0.90Ni0.10O nanoparticles have been synthesized by single-bath two-electrode electrodeposition at constant voltage. X-ray diffraction, UV vis and photoluminescence studies reveal that a single-phase polycrystalline hcp wurtzite crystal structure of ZnO is evolved. The material consists of a large number of defects such as oxygen vacancy (Ov) and zinc interstitial (Zi). The magnetization study reveals that the sample exhibits room-temperature global ferromagnetism and the ferromagnetic ordering seems to be defect induced via bound magnetic polaron mechanism, and double exchange is also expected to have played role. Interesting optoelectronic properties have been found in the synthesized sample and the material seems to be a potential candidate to be used as a UV sensor. Such a transition metal doped ZnO based dilute magnetic semiconducting system exhibiting room-temperature ferromagnetism is likely to be first of its kind in the sense that such materials have not yet been reported to be synthesized by the simple method of electrodeposition to the best of our knowledge on the basis of ample literature review.

关键词： dilute magnetic semiconductors(DMS) bound magnetic polaron photoluminescence ferromagnetism

Resource potential and planning for exploration of the Hebrus Valles, Mars

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Research in Astronomy and Astrophysics 2019年第8期19卷 99-114页

作者： Ravi Sharma Neeraj Srivastava santosh kumar Yadav J.J.T.University JhunjhunuRajasthan333001India Planetary Science Division Physical Research LaboratoryAhmedabad380009India

Mars is the only extraterrestrial body which could host primitive lifeforms and also has the potential to host a human base in the near future. Towards fulfilling these objectives, several remote sensing missions and rover based missions have been sent to Mars. Still, confirmation of existing or extinct life on this planet in any form has not been achieved and possibly human missions at selected sites in the future are the key to addressing this problem. Here, we have used remote sensing data from Mars Reconnaissance Orbiter(MRO;NASA), Mars Global Surveyor(MGS;NASA), Mars Odyssey(NASA) and Mars Express(MEX;ESA) to devise an exploration strategy for one such area known as Hebrus Valles, which is a potential site for human exploration of the surface of Mars. A geological context map of the Hebrus Valles and Hephaestus Fossae region has been prepared and a candidate landing site has been proposed in the Hebrus Valles region. Suitable rover paths have been worked out from the proposed landing site for harnessing the science and resource potential of the region. The proposed landing site is located in the equatorial region at(20?40′N, 126?23′E) and due to its proximity to the Potential Subsurface Access Candidates(PSACs) in the region, such as sinkholes and skylights and also other resources such as crater ejecta, silicate material and fluvial channels, the site is appropriate for exploration of the region.

关键词： planets and satellites:individual (Mars) planets and satellites:surfaces

Introduction to magnesium alloy processing technology and development of low-cost stir casting process for magnesium alloy and its composites

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Journal of Magnesium and Alloys 2018年第3期6卷 245-254页

作者： Anil kumar santosh kumar N.K.Mukhopadhyay Department of Mechanical Engineering Indian Institute of Technology(BHU)VaranasiIndia Department of Metallurgical Engineering Indian Institute of Technology(BHU)VaranasiIndia

This paper presents the processing of magnesium alloys and its composite through different stir casting *** and devel-opment of stir casting technology that is suitable for processing of magnesium alloys has been done in this *** low-cost stir casting processing of magnesium alloy and its composite with flux and without flux has been *** magnesium alloy and its composite have been fabricated by both the stir casting *** micro structural characterization and mechanical properties of the developed composites has been *** optical emission spectroscopy of the developed alloy and factography of the developed alloy as well as composite was also examined.

关键词： Metal matrix composite Magnesium alloys Stir casting Composite

Artificial neural network-based merging score for Meta search engine

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Journal of Central South University 2016年第10期23卷 2604-2615页

作者： P.Vijaya G.Raju santosh kumar Ray Karpagam University Coimbatore TamilNadu India Faculty of Engineering and Technology Associate Professor Department of Information Technology Kannur University Kannur Kerala-670 567 India Department of Information Technology Al Khawarizmi International College Al Alin UAE

Several users use metasearch engines directly or indirectly to access and gather data from more than one data sources. The effectiveness of a metasearch engine is majorly determined by the quality of the results and it returns and in response to user queries. The rank aggregation methods which have been proposed until now exploits very limited set of parameters such as total number of used resources and the rankings they achieved from each individual resource. In this work, we use the neural network to merge the score computation module effectively. Initially, we give a query to different search engines and the top n list from each search engine is chosen for further processing our technique. We then merge the top n list based on unique links and we do some parameter calculations such as title based calculation, snippet based calculation, content based calculation, domain calculation, position calculation and co-occurrence calculation. We give the solutions of the calculations with user given ranking of links to the neural network to train the system. The system then rank and merge the links we obtain from different search engines for the query we give. Experimentation results reports a retrieval effectiveness of about 80%, precision of about 79% for user queries and about 72% for benchmark queries. The proposed technique also includes a response time of about 76 ms for 50 links and 144 ms for 100 links.

关键词： metasearch engine neural network retrieval of documents ranking list

Mass balance and morphological evolution of the Dokriani Glacier,central Himalaya,India during 1999–2014

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Geoscience Frontiers 2022年第1期13卷 255-267页

作者： Purushottam kumar Garg Jairam Singh Yadav santosh kumar Rai Aparna Shukla Indian Institute of Technology Indore Khandwa RoadSimrolIndore 453552India Wadia Institute of Himalayan Geology 33GMS RoadDehradun 248001India Ministry of Earth Sciences Prithvi BhavanLodhi RoadNew Delhi 110003India

Glaciological mass balance(MB)is considered the most direct,undelayed and unfiltered response of the glaciers to climatic ***,it may inherit errors associated with stake underrepresentation,averaging over the entire glacier and human ***,proper validation of glaciological MB with geodetic MB is highly recommended by the World Glacier Monitoring Service(WGMS).The present study focuses on the Dokriani Glacier,central Himalaya which is one of the bench-mark glaciers in the region and has glaciological MB records from 1993 to 2013 with intermittent *** the present study,firstly the glaciological MB series is extended to 2014 i.e.,field-based MB for one more year is computed and,to compare with it,the geodetic MB is computed for the 1999–2014 period using high resolution Cartosat-1 digital elevation model(DEM)and SRTM ***,the study assesses the regional representation of the Dokriani Glacier in terms of MB and evaluates the influence of the MB regime on its morphological *** show that the average glaciological MB(-0.34±0.2 m water equivalent(w.e.)y-1)is more negative than the geodetic MB(-0.23±0.1 m w.e.y-1)for the 1999–2014 *** is likely because of the partial representation of glacier margins in the glaciological MB,where melting is strikingly low owing to thick debris cover(>30 cm).In contrast,geodetic MB considers all marginal pixels leading to a comparatively low MB.A comparative assessment shows that the MB of Dokriani Glacier is less negative(possibly due to its huge accumulation area)than most other glacier-specific and regional MBs,restricting it to be a representative glacier in the ***,continuous negative MB has brought a peculiar change in the epiglacial morphology in the lower tongue of the glacier as differential debris thickness-induced differential melting has turned the glacier surface into a concave *** concavity has led to development of a large(10–20 m deep)supraglacial ch

关键词： Glacier mass balance Debris cover Epiglacial morphology Supraglacial channel Dokriani Glacier Central Himalaya

Soluble factors secreted by human Wharton’s jelly mesenchymal stromal/stem cells exhibit therapeutic radioprotection: A mechanistic study with integrating network biology

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World Journal of Stem Cells 2022年第5期14卷 347-361页

作者： Dharmendra kumar Maurya Mayuri Bandekar santosh kumar Sandur Radiation Biology and Health Sciences Division Bhabha Atomic Research CentreMumbai 400085MaharashtraIndia Homi Bhabha National Institute AnushaktinagarMumbai 400094India University of Mumbai KalinaMumbai 400098India

BACKGROUND Human Wharton’s jelly-derived mesenchymal stromal/stem cells(hWJ-MSCs)have gained considerable attention in their applications in cell-based therapy due to several advantages offered by ***,we reported that hWJ-MSCs and their conditioned medium have significant therapeutic radioprotective *** finding raised an obvious question to identify unique features of hWJ-MSCs over other sources of stem cells for a better understanding of its radioprotective *** To understand the radioprotective mechanism of soluble factors secreted by hWJMSCs and identification of their unique *** Propidium iodide staining,endogenous spleen colony-forming assay,and survival study were carried out for radioprotection ***-driven proliferation assay was performed for in vivo lymphocyte *** of RNAseq data was performed to find the unique genes of WJ-MSCs by comparing them with bone marrow mesenchymal stem cells,embryonic stem cells,and human *** enrichment analysis and protein-protein interaction network were used for pathway *** Co-culture of irradiated murine splenic lymphocytes with WJ-MSCs offered significant radioprotection to ***-MSC transplantation increased the homeostasis-driven proliferation of the *** of WJ-MSC conditioned medium with granulocyte-colony stimulating factor antibody abolished therapeutic *** analysis showed that WJ-MSCs share several common genes with bone marrow MSCs and embryonic stem cells and express high levels of unique genes such as interleukin(IL)1-α,IL1-β,IL-6,CXCL3,CXCL5,CXCL8,CXCL2,CCL2,FLT-1,and *** was also observed that WJ-MSCs preferentially modulate several cellular pathways and processes that handle the repair and regeneration of damaged tissues compared to stem cells from other ***-based network analysis showed that most of the radiosensitive tissues have a more com

关键词： Radioprotection Mesenchymal stem cells Wharton’s jelly-derived mesenchymal stromal/stem cells Cytokines Granulocyte-colony stimulating factor Network biology

Review of preventive and constructive measures for coal mine explosions:An Indian perspective

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International Journal of Mining Science and Technology 2022年第3期32卷 471-485页

作者： santosh kumar Ray Asfar Mobin Khan Niroj kumar Mohalik Debashish Mishra Somu Mandal Jai Krishna Pandey CSIR-Central Institute of Mining and Fuel Research Barwa RoadDhanbad 826015India Academy of Scientific and Innovative Research(AcSIR) Ghaziabad 201002India

Firedamp and coal dust explosion constitute a lion’s share in mine accidents in a global mining *** paper reports a list of mine explosion disasters since last two decades,a critical review of the different prevention and constructive measures,and its recent development to avoid firedamp and coal dust *** legislation in core coal-producing countries,***,USA,Australia,South Africa,and India related to firedamp and coal dust explosion are critically *** occurred due to explosion after Nationalisation of Coal Mines(1973)in India are *** and constructive measures adopted in India are critically analysed with respect to the global mining *** like methane credit concept,classification of mines/seams with respect to explosion risk zone,deflagration index;installation of automatic fire warning devices,canopy air curtain technology,explosion-prevention measures,such as fire-retardant materials,inhibitors,extinguishing agent,dust suppressor,and active explosion barrier are discussed in detail to avoid explosion and thereby adhering to zero accident policy due to coal mine explosion.

关键词： Firedamp explosion Coal dust explosion Preventive measures Constructive measures Legislation

Electrical conductivity of Gd doped BiFeO3-PbZrO3 composite

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Frontiers of Materials Science 2013年第3期7卷 295-301页

作者： santosh kumar SATPATHY Nilaya kumar MOHANTY Ajay kumar BEHERA Banarji BEHERA Pratibindhya NAYAK Materials Research Laboratory School of Physics Sambalpur University Jyoti Vihar Burla-768019 Odisha India

The composite, 0.5（BiGd0.15Fe0.85O3）-0.5（PbZrO3）, was synthesized using the solid-state reaction technique. The formation of the compound was confirmed by XRD with an orthorhombic structure at room temperature. The impedance parameters were studied using an impedance analyzer in a wide range of frequency （10z-106Hz） at different temperatures. The Nyquist plot suggests the contribution of bulk effect and a slight indication of grain boundary effect and the bulk resistance decreases with a rise in temperature. The presence of temperature-dependent relaxation process occurs in the material. Electrical modulus reveals the presence of the hopping mechanism in the materials. The value of exponent n, pre-factor A and adc were obtained by fitting ac conductivity data with Jonscher＇s universal power law. The activation energies calculated from the ac conductivity were found to be 0.50, 0.46, 0.44, 0.43, 0.42 and 0.38 eV at 1, 10, 50, 100, 500 kHz and I MHz respectively in the temperature region of 110℃-350℃. The dc conductivity was found to increase with the rise in temperature. The activation energy calculated from complex impedance plot and from the fitted Jonscher＇s power law are very close, which results similar type of charge carrier exist in conduction mechanism of the material.

关键词： solid state reaction XRD impedance electrical conductivity

Diagnosis and Detection of Alzheimer’s Disease Using Learning Algorithm

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Big Data Mining and Analytics 2023年第4期6卷 504-512页

作者： Gargi Pant Shukla santosh kumar Saroj kumar Pandey Rohit Agarwal Neeraj Varshney Ankit kumar the Department of Management Doon Business SchoolDehradun 248001India. Jaipuria Institute of Management Jaipur 302033India Department of Computer Engineering and Apllications GLA UniversityMathura 281406India.

In Computer-Aided Detection(CAD)brain disease classification is a vital ***’s Disease(AD)and brain tumors are the primary reasons of *** studies of these diseases are carried out by Magnetic Resonance Imaging(MRI),Positron Emission Tomography(PET),and Computed Tomography(CT)scans which require expertise to understand the *** disease is the most prevalent in the elderly and can be fatal in its later *** result can be determined by calculating the mini-mental state exam score,following which the MRI scan of the brain is *** from that,various classification algorithms,such as machine learning and deep learning,are useful for diagnosing MRI ***,they do have some limitations in terms of *** paper proposes some insightful pre-processing methods that significantly improve the classification performance of these MRI ***,it reduced the time it took to train the model of various pre-existing learning algorithms.A dataset was obtained from Alzheimer’s Disease Neurological Initiative(ADNI)and converted from a 4D format to a 2D *** clipping,grayscale image conversion,and histogram equalization techniques were used to pre-process the *** pre-processing,we proposed three learning algorithms for AD classification,that is random forest,XGBoost,and Convolution Neural Networks(CNN).Results are computed on dataset and show that it outperformed with exiting work in terms of accuracy is 97.57%and sensitivity is 97.60%.

关键词： alzheimer’s disease deep learning random forest XGBoost