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Strength and dilatancy behaviors of deep sands in Shanghai with a focus on grain size and shape effect

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第6期12卷 1214-1225页

作者： Bandana Tiwaria Guanlin Ye Mingguang Li Usama Khalid santosh kumar yadav Department of Civil Engineering and State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai200240China Department of Civil Engineering IOEPulchowk CampusTribhuvan UniversityLalitpur44700Nepal

With rapid development of infrastructures like tunnels and open excavations in Shanghai,investigations on deeper soils have become critically *** of the existing laboratory works were focused on the clayey strata up to Layer 6 in Shanghai,*** depth of up to 40 *** this paper,Layers 7,9,and 11,which were mostly formed of sandy soils at depth of up to 150 m,were experimentally investigated with respect to physico-mechanical *** stressestrain behaviors were analyzed by the consolidated drained/undrained(CD/CU)triaxial tests under monotonic ***-dimensional(1D)oedometer tests were performed to investigate the consolidation properties of the sandy *** were prepared at three different relative densities for each ***,the micro-images and particle size analyzers were used to analyze the shape and size of the sand *** influences of grain size,density,and angularity on the stressestrain behaviors and compressibility were also *** to the other layers,Layer 11 had the smallest mean grain size(D50),highest compressibility,and lowest shear *** contrast,Layer 9 had the largest mean grain size,lowest compressibility,and highest shear *** 7 was of intermediate mean grain size,exhibiting more compressibility and less shear strength than that of Layer ***,the critical state parameters and maximum dilatancy rate of different layers were discussed.

关键词： Deep sands in Shanghai Laboratory tests Shear strength Dilatancy Relative density

Intrusion detection systems for wireless sensor networks using computational intelligence techniques

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Cybersecurity 2024年第2期7卷 81-95页

作者： Vaishnavi Sivagaminathan Manmohan Sharma santosh kumar Henge Lovely Professional University PhagwaraIndia

Network Intrusion Detection Systems(NIDS)are utilized to find hostile network *** can be accom-plished by looking at traffic network activity,but it takes a lot of *** NIDS heavily utilizes approaches for data extraction and machine learning to find *** terms of feature selection,NIDS is far more *** is accurate since anomaly identification uses a number of time-consuming *** of this,the feature selec-tion method influences how long it takes to analyze movement patterns and how clear it *** goal of the study is to provide NIDS with an attribute selection *** has been used for that *** Network Intrusion Detection System that is being developed will be able to identify any malicious activity in the network or any unusual behavior in the network,allowing the identification of the illegal activities and safeguarding the enormous amounts of confidential data belonging to the customers from being *** the research,datasets were produced utilising both a network infrastructure and a simulation *** is used to gather data packets whereas Cisco Packet Tracer is used to build a network in a simulated ***,a physical network consisting of six node MCUs connected to a laptop and a mobile hotspot,has been built and communication packets are being recorded using the Wireshark *** train several machine learning models,all the datasets that were gatheredcre-ated datasets from our own studies as well as some common datasets like NSDL and UNSW acquired from Kaggle-were ***,PsO,which is an optimization method,has been used with these ML algorithms for feature *** the research,KNN,decision trees,and ANN have all been combined with PSO for a specific case *** it was found demonstrated the classification methods PSO+ANN outperformed PSO+KNN and PSO+DT in this case study.

关键词： Network intrusion detection systems(NIDS) Cisco packet tracer Wireshark tool Machine learning PSO Cybersecurity Optimization

New Convenient Synthesis of 8-C-Methylated Homoisoflavones and Analysis of Their Structure by NMR and Tandem Mass Spectrometry

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International Journal of Organic Chemistry 2021年第1期11卷 46-54页

作者： santosh kumar yadav Department of Organic Chemistry & FDW Andhra University Visakhapatnam India DMPK Sai Life Sciences Ltd. Pune Maharashtra India

Homoisoflavonoids are in the subclass of the larger family of flavonoids having one more alkyl carbon than flavonoids. Among them, 8-C-Methylated homoisoflavones have not been extensively studied for synthesis and biological evaluation. Author’s current objective is to synthesize 8-C-Methylated homoisoflavones by the reaction of 3-C-methylated dihydrochalcones with N,N’-dimethyl (chloromethylene) ammonium chloride generated in situ from DMF and PCl5 for one carbon extension at about room temperature. The 3-C-methylated dihydrochalcones were synthesized by the reduction of 3-C-methylated chalcones, which were prepared from 3-C-methylated acetophenones and aromatic aldehydes in the presence of base. All the synthesized novel homoisoflavones’s structures were characterized by NMR and Tandem Mass Spectrometry.

关键词： 8-C-Methylated Homoisoflavones 3-C-Methylated Dihydrochalcones 3-C-Methylated Chalcones 3-C-Methylated Acetophenones Dimethylformamide BF3·Et2O PCl5

Process for the Preparation of Chromones, Isoflavones and Homoisoflavones Using Vilsmeier Reagent Generated from Phthaloyl Dichloride and DMF

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International Journal of Organic Chemistry 2014年第4期4卷 236-246页

作者： santosh kumar yadav Department of Organic Chemistry & FDW Andhra University Visakhapatnam India

Vilsmeier reagent formed from phthaloyl dichloride and DMF was found to be very effective for converting 2-hydroxyacetophenones, deoxybenzoins and dihydrochalcones into corresponding chromones, isoflavones and homoisoflavones with excellent yield. This method offers significant advantages such as efficiency and mild reaction conditions with shorter reaction time.

关键词： Phthaloyl Dichloride Dimethylformamide Chromones Isoflavones Homoisoflavones BF3·Et2O Vilsmeier Reagent

Study of Structural, Optical, Electrical and Dielectric Properties of Gd-Doped ZnO Composites Synthesized by Solid State Reaction Method

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Open Journal of Composite Materials 2024年第2期14卷 91-108页

作者： santosh kumar Kundara Kanhaiya Chawla Dinesh kumar yadav Chhagan Lal Balram Tripathi Narendra Jakhar Department of Physics University of Rajasthan Jaipur India Sw. P.N.K.S. Government PG College Dausa India Government PG College Pratapgarh India S.S. Jain Subodh PG (Autonomous) College Jaipur India

In this manuscript, we are reporting structural, bonding, optical, dielectric, and electrical properties of Gd-doped ZnO composite samples (Zn1−xGdxO, x = 0, 0.05, 0.10) prepared by solid-state reaction method. XRD spectra confirm the wurtzite hexagonal phase with a grain size distribution of 42 - 47 nm. The FT-IR spectra confirm bonding behavior like Zn-O, O=C=O, and O-H stretching modes. FESEM micrographs show that the grains of crystallites possess nearly spherical morphology. Optical absorption spectra confirm that the optical band gap decreases systematically from 3.19 eV to 3.15 eV for x = 0.0 to x = 0.10 samples. For all samples, PL spectra exhibited near-band emission, blue emission, and green emission peaks. The dielectric constant decreases as the applied frequency increases. Hall effect results show that with increasing doping concentration of Gd, mobility and resistivity increase while bulk concentration decreases. Current-Voltage study shows that current increases when temperature is increased. Rare earth-doped ZnO is potential material used for optoelectronics and spintronics device applications. Properties of Gd-doped ZnO are studied by various research groups, but dielectric studies are limitedly reported. Therefore, the present research work aims to study the change of electrical, optical, and dielectric properties of Gd-doped ZnO for device applications.

关键词： ZnO:Gd Composites Optical Band Gap Green Emission Dielectric Constant

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

Pleistocene glaciation advances the cryptic speciation of Stellera chamaejasme *** a major biodiversity hotspot

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Journal of Integrative Plant Biology 2024年第6期66卷 1192-1205页

作者： santosh kumar Rana Hum Kala Rana Jacob BLandis Tianhui Kuang Juntong Chen Hengchang Wang Tao Deng Charles C.Davis Hang Sun CAS Key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming 650201China Arkansas Biosciences Institute Arkansas State UniversityJonesboroArkansas 72401USA School of Integrative Plant Science Section of Plant Biology and the L.H.Bailey HortoriumCornell UniversityIthacaNew York 14853USA BTI Computational Biology Center Boyce Thompson InstituteIthacaNew York 14853USA CAS Key Laboratory of Plant Germplasm Enhancement and Specialty Agriculture Chinese Academy of SciencesWuhan Botanical GardenWuhan 430074China Department of Organismic and Evolutionary Biology HerbariaHarvard UniversityCambridgeMassachusetts 02138USA

The mountains of Southwest China comprise a significant large mountain range and biodiversity hotspot imperiled by global climate *** high species diversity in this mountain system has long been attributed to a complex set of factors,and recent large-scale macroevolutionary investigations have placed a broad timeline on plant diversification that stretches from 10 million years ago(Mya)to the *** our increasing understanding of the temporal mode of speciation,finer-scale populationlevel investigations are lacking to better refine these temporal trends and illuminate the abiotic and biotic influences of cryptic *** is largely due to the dearth of organismal sampling among closely related species and populations,spanning the incredible size and topological heterogeneity of this *** study dives into these evolutionary dynamics of speciation using genomic and ecomorphological data of Stellera chamaejasme *** identified four previously unrecognized cryptic species having indistinct morphological traits and large metapopulation of evolving lineages,suggesting a more recent diversification(~2.67-0.90 Mya),largely influenced by Pleistocene glaciation and biotic *** factors likely influenced allopatric speciation and advocated cyclical warming–cooling episodes along elevational gradients during the *** study refines the evolutionary timeline to be much younger than previously implicated and raises the concern that projected future warming may influence the alpine species diversity,necessitating increased conservation efforts.

关键词： cryptic speciation glacial-interglacial Hengduan Mountains north-south migration Stellera chamaejasme

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

Peraluminous A-type granites formed through synchronous fractionation,magma mixing,mingling,and undercooling:evidence from microgranular enclaves and host Mesoproterozoic Kanigiri granite pluton,Nellore Schist Belt,southeast India

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Acta Geochimica 2023年第4期42卷 603-636页

作者： Ch.Narshimha santosh kumar Department of Geology Centre of Advanced StudyKumaun UniversityNainital 263001India

The field and microstructural features coupled with mineral chemical data from microgranular enclave(ME)and host Mesoproterozoic Kanigiri granite(KG)pluton of Nellore Schist Belt(NSB),Southeastern India,have been documented in order to infer the likely processes responsible for the origin and evolution of ME and host KG *** ME and host KG bear the same mineral assemblages barring the KG which does not contain amphibole;however,they are modally *** ME in KG is originated due to multiple intrusions of ME magmas into the crystallizing host KG magma *** and textural features indicate the dynamic magma flow,mingling,and undercooling of the ME against a relatively cooler surface of host KG *** presence of NSB country rock xenoliths and its diffuse boundaries suggest the intrusive relation and marginal assimilation by the intruding KG *** occasional cumulate texture in the ME appears to have formed by the accumulation of early-formed minerals that crystallized rapidly in the ME magma *** ME shows the magmatically deform features developed due to the flowage and erosion by the subsequent intrusions of ME magma pulses into the crystallizing host KG magma *** ME amphiboles show unusual composition as ferro-edenitic hornblende to potassian-hastingsitic hornblende,that crystallized in the subalkaline-alkaline transition,low fO_(2)(reducing to mildly oxidizing)*** unusual extremely low Mg/Mg+Fe^(t)=0.015(avg.)of ME amphiboles may be related to the changing physico-chemical(P,T,fO_(2),and H_(2)O)condition of the ME magma or they might have crystallized in equilibrium with more evolved KG *** KG(FeOt/MgO=37.04,avg.)and ME(FeO~t/MgO=77.72,avg.)biotites are siderophyllite,and buffered between QFM and NNO syn-crystallizing in the water undersaturated(H_(2O)≈3.58 wt.%in KG;≈3.53wt.%in ME),alkaline anorogenic(A-type)host magmas that were emplaced at mid-crustal(4–5 kbar;17 km)***,microtextural and mineral

关键词： Enclave Kanigiri granite Magma mixing-fractionation Nellore schist belt SE India