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Geoscience Frontiers 2019年第3期10卷 793-809页

作者： sandeep singh Department of Earth Sciences Indian Institute of Technology Roorkee

The Higher Himalayan Crystallines(HHC), in western Garhwal, Uttarakhand are located in a regionalscale intracontinental ductile shear zone(15-20 km wide) bounded by the Main Central Thrust at the base, and the South Tibetan Detachment System at the top. The migmatite zone in the centre has the highest grade of metamorphism in the NW Himalayas and show evidence of flowage. Zircons extracted from samples of metasediment, migmatite, biotite granite and in situ partial melt(tourmaline-bearing leucogranite) along the Bhagirathi Valley, preserve U-Pb isotopic evidence of magmatic history, magma source and effects of the Himalayan orogeny in the region. Three distinct periods of zircon growth in the leucogranite record the episodic influx of magma between 46 Ma and 20 Ma indicating a time span of more than 25 Ma between the onset of fluid-fluxed partial melting in the mid-crustal intracontinental shear zone and the emplacement of the magma into the upper crust in a post-collisional extensional setting. Metamorphic zircon growth was initiated about 46 Ma, when the partial melts were generated as the migmatite zone was exhumed.

关键词： Himalayas Crustal anatexis Zircon SHRIMP U-Pb dating Migmatites Granites

Geochronological and genetic characterization of basaltic basement from western offshore basins in India

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Geoscience Frontiers 2024年第5期15卷 372-398页

作者： Piyush Gupta Shakti singh Rathore sandeep singh Geochronology Laboratory KDMIPEOil and Natural Gas Corporation Ltd.9Kaulagarh RoadDehradun 248195India Department of Earth Sciences Indian Institute of TechnologyRoorkee 247667India

^(40)Ar-^(39)Ar geochronology,geochemistry,and Sr-Nd isotopic compositions of 30 core samples from 24 offshore drill wells in the Western offshore basins have been used to characterize the genetics of the volcanic basement from the Kutch,Mumbai,and Kerala-Konkan offshore *** from the volcanic basement rocks demonstrate extremely varied isotopic and geochemical fingerprints,which are suggestive of significantly diverse parent magma compositions and emplacement *** tholeiitic basement from Kutch Offshore basin has Ar-Ar ages that range between 60 Ma and 62 *** basement is characterised by a within-plate basalt signature,with depleted isotopic signatures similar to least contaminated Deccan Traps basalts,and a component of subducted crustal *** basement from Mumbai Offshore Basin has eruption ages between 63 Ma and 65 Ma and show a strong within-plate OIB *** and isotopic signatures are consistent with Renuion lavas and an enriched-end member of Deccan Traps ***,Kerala-Konkan Offshore Basin shows significant E-MORB affinity and is characterized by primitive-mantle signatures and least contamination from the upper continental crust,with ages of eruption between 60 Ma and 61 Ma based on obtained^(40)Ar-^(39)Ar *** study suggests that the Mumbai Offshore Basalts’mode of the eruption was comparable with onshore Deccan volcanism,whereas the basaltic basement in Kutch Offshore was formed after the main phase of Deccan eruption and may have been an offshoot of a"tail"of the main Deccan *** parent magma for the volcanic E-MORB basement in the Kerala-Konkan Offshore Basin is thought to have come from mixing along the Carlsberg Mid-Oceanic Ridge and the material from the Réunion plume with the northward movement of the Indian Plate during the Early *** is thought to have occurred concurrently with the formation of the Chagos-Laccadive Ridge.

关键词： ^(40)Ar-^(39)Ar geochronology Western offshore basins Kutch offshore basin Mumbai offshore basin Kerala-Konkan offshore basin

Evaluation of phenolic composition, antioxidant, anti-inflammatory and anticancer activities of Polygonatum verticillatum(L.)

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Journal of Integrative Medicine 2018年第4期16卷 273-282页

作者： sandeep Kumar singh Arjun Patra Institute of Pharmacy Guru Ghasidas University

Objective： Polygonaturn verticillatum （L） All. （Ruscaceae）, one of the Ashtawarga plants, is widely used for treatment of various ailments. The present study was undertaken to determine the phenolic composition, antioxidant, anti-inflammatory and anticancer activities of several extracts （petroleum ether, dichloro- methane, chloroform, ethanol, and aqueous） from the rhizomes of the plant. Methods： Coarsely powdered dry rhizome was successively extracted with different solvents of increas- ing polarity （petroleum ether, dichloromethane, chloroform, ethanol and water）. The phenolic composi- tions, in terms of total phenolic content （TPC）, total flavonoid content （TFC） and total condensed tannin content （JTC）, were evaluated with the Folin-Ciocalteu assay, aluminum chloride colorimetric assay and vanillin spectrophotometric assay, respectively. Total antioxidant capacity, 1,1-diphenyl-2- picrylhydrazyl and 2,2＇-azino-his（3-ethylbenzothiazoline-6-sulfonic acid） assays were used to assess the antioxidant potential of each extract. A protein denaturation model and 3-（4,5-dimethylthiazol-2- yl）-2,5-diphenyltetrazolium bromide assay were used to evaluate in vitro anti-inflammatory and anti- cancer activities, respectively. Gas chromatography-mass spectrometry （GC/MS） analysis was carried out to demonstrate various phytoconstituents in each extract. Correlation studies were also performed between phenolic composition （TPC, TFC and TFC） and different biological activities. Results： Ethanol extract showed maximum TPC （0.126 mg/g, gallic acid equivalent in dry sample）, TFC （0.094 mg/g, rutin equivalent in dry sample） and TTC （29.32 mg/g, catechin equivalent in dry sample）, as well as antioxidant and anti-inflammatory properties. Chloroform extract exhibited the strongest cyto- toxicity against the human breast cancer cell line, MCF-7. GC/MS analysis revealed the presence of 90 different phytoconstituents among the extracts. Antioxidant and anti-inflammatory activities had a pos

关键词： Polygonatum verticillatum Gas chromatography-mass spectrometry Phenolic profile MCF-7 cells

Early Paleozoic basement diorite of arc-magmatism from Kutch basin, Western India

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Acta Geochimica 2024年第2期43卷 296-307页

作者： Piyush Gupta sandeep singh Shakti singh Rathore Argha Narayan Sarkar Geochronology Laboratory KDMIPEOil and Natural Gas Corporation Ltd.9Kaulagarh RoadDehradun 248195India Department of Earth Sciences Indian Institute of TechnologyRoorkee 247667India

In this study,we report for theﬁrst time an Early Palaeozoic basement diorite from the drilled well Nirona-A in the Banni Half-Graben of the Kutch basin,western *** 40Ar–39Ar dates provided a plateau age of 441.84±2.66 Ma and another pseudo plateau of 441.28±5.82 to 388.08±16.65 Ma for the basement *** ages constrain the basement formation age to the Late Ordovician-Early Silurian *** obtained basement ages are correlatable with the later part of Cambro-Ordovician alkaline magmatism that has been reported from the Huqf area in Central Oman,whereas their lithological and petrographic correlativity with base-ment diorites occurring in the Dinsi Body of Nagar Parkar igneous complex in Pakistan can also be *** geochemical studies characterized the diorite with enrich-ment of LILE(Rb,Ba,and K)and LREE(La,Ce,Nd),strong depletion of HFSE(Nb,Sr,P,and Ti),along with weakly negative Eu *** geochemical signatures indicate their petrogenetic afﬁliation with mantle-derived magmas,as well as their tectonic setting to be arc-related,having post-collisional continental-arc type afﬁ****440 Ma basement of Kutch,therefore,appears to rep-resent the later thermal event associated with the reworked Neoproterozoic subduction-related suite from Greater India’s northwest edge,which has implications for Gond-wana assembly in the northwest Indian subcontinent.

关键词： Kutch basin 40Ar–39Ar ages Early palaeozoic basement Continental-arc magmatism Calc-alkaline magmatism

Optimization of CMOS Repeater Driven Interconnect RC Line Using Genetic Algorithm

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Journal of Shanghai Jiaotong university(Science) 2017年第2期22卷 167-172页

作者： KAUR Jasmeet GILL sandeep singh KAUR Navneet Department of Electronics and Communication Engineering Guru Nanak Dev Engineering CollegeLudhiana 141006India

In this work, optimization of complementary metal oxide semiconductor (CMOS) repeater driven interconnect resistive-capacitive (RC) line is carried out using genetic algorithm (GA). This work is aimed at powerdelay- product (PDP) minimization of RC interconnect at 180 nm technology node. The algorithm simultaneously optimizes the values of supply voltage, number of repeaters and repeater width for delay and PDP minimization. The accuracy of results obtained is verified by simulations from Cadence virtuoso tool. For delay minimization, comparison of GA results with previous results of the literature shows an improvement of 44.4% in the value of the optimal number of repeaters required. This improvement is obtained by increasing the repeater size, which also increases power dissipation, so a tradeoff has also been achieved in terms of PDP minimization. The comparison of PDP results obtained in this work, with the results at 70, 100, and 130 nm technologies from literature shows improvement in optimal number of repeaters required. The results of algorithm and simulations are in good agreement and demonstrate the validity of proposed algorithm. © 2017, Shanghai Jiaotong University and Springer-Verlag Berlin Heidelberg.

关键词： complementary metal oxide semiconductor(CMOS) genetic algorithm interconnects optimal power-delay-product repeater

Efficient Clustering and Simulated Annealing Approach for Circuit Partitioning

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Journal of Shanghai Jiaotong university(Science) 2011年第6期16卷 708-712页

作者： sandeep singh Gill RAJEEVAN Chandel ASHWANI Kumar Chandel Department of Electronics and Communication Engineering Guru Nanak Dev Engineering College National Institute of Technology

Circuit net list bipartitioning using simulated annealing technique has been proposed in the *** method converges asymptotically and probabilistically to global *** circuit net list is partitioned into two partitions such that the number of interconnections between the partitions is *** proposed method begins with an innovative clustering technique to obtain a good initial *** obtained show the versatility of the proposed method in solving non polynomial hard problems of circuit net list partitioning and show an improvement over those available in literature.

关键词： cut size non polynomial hard partitioning simulated annealing interconnections very large scale integration(VLSI) design

Rapid accessibility evaluation for ballistic lunar capture via manifolds: A Gaussian process regression application

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Astrodynamics 2022年第4期6卷 375-397页

作者： sandeep K.singh John L.Junkins Manoranjan Majji Ehsan Taheri Department of Aerospace Engineering Texas A&M UniversityCollege StationTX 77843USA Department of Aerospace Engineering Auburn UniversityAuburnAL 36849USA

In this study,a supervised machine learning approach called Gaussian process regression(GPR)was applied to approximate optimal bi-impulse rendezvous maneuvers in the cis-lunar *** demonstrate the use of the GPR approximation of the optimal bi-impulse transfer to patch points associated with various invariant manifolds in the cis-lunar *** proposed method advances preliminary mission design operations by avoiding the computational costs associated with repeated solutions of the optimal bi-impulsive Lambert transfer because the learned map is computationally *** approach promises to be useful for aiding in preliminary mission *** use of invariant manifolds as part of the transfer trajectory design offers unique features for reducing propellant consumption while facilitating the solution of trajectory optimization *** ballistic capture coasts are also very attractive for mission guidance,navigation,and control robustness.A multi-input single-output GPR model is presented to represent the fuel costs(in terms of theΔV magnitude)associated with the class of orbital transfers of interest *** developed model is also proven to provide efficient *** multi-resolution use of local GPRs over smaller sub-domains and their use for constructing a global GPR model are also *** of the unique features of GPRs is that they provide an estimate of the quality of approximations in the form of covariance,which is proven to provide statistical consistency with the optimal trajectories generated through the approximation *** numerical results demonstrate our basis for optimism for the utility of the proposed method.

关键词： Gaussian process regression supervised learning invariant manifolds ballistic transfers Bayesian inference

Empirical study of gum ghatti as an alternative thickening agent in hydraulic fracturing

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Petroleum 2022年第4期8卷 567-576页

作者： Prathamesh Sapale Vishesh Bhadariya sandeep singh Rana Tondepu Subbaiah Mohammad Vaseem Chavhan Parinder Kaur Vignan's Foundation for Science Technology&ResearchAndhra PradeshIndia Lovely Professional University PunjabIndia

Gum ghatti(anogeissus latifolia)is being widely used as an emulsifier,thickener,stabilizer in food,pharmaceutical,and allied industries due to its shelf life,tolerance of heat,and pH *** the oil&gas industry application,it is ideal for a hydraulic fracturing fluid additive as a direct replacement for guar ***,unlike guar gum,it contains less residual hull and it is suitable for low permeability unconventional reservoir;mainly shale gas reservoir,where permeability counts trivial in *** polymer of ghatti aid exceptional rheological properties and help to produce higher molecular weight polymer;which has excellent proppant carrying capacity and fracture *** this paper,the experimental study has been carried out in two different *** was achieved through optimization and characterization of hydraulic fracturing fluid which was embedded with gum *** Phase-I,the study was carried out by using response surface methodology(RSM).Wherein,the relation between several explanatory and response variables have been *** Phase-II,the characterization was done by using a scanning electron microscope(SEM),differential scanning calorimeter(DSC),thermo-gravimetric analysis(TGA)and also,Fourier-transform infrared spectroscopy(FTIR).This experimental study will potentially benefit for development of a new hydraulic fracturing *** gum ghatti observed as a satisfactory alternative agent for guar gum.

关键词： Hydraulic fracturing fluid Gum ghatti Rheological properties Polymer science Unconventional reservoir

Design of a Low Loss RF Mixer in Ku-Band (12 - 18 GHz)

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Wireless Engineering and Technology 2012年第1期3卷 46-50页

作者： Sanjeev Kumar Shah Rudra Pratap singh Chauhan Sanjay singh Lalit Pandey sandeep singh Uttaranchal Institute of Technology

The goal of this paper is to design and develop low conversion loss mixers at Ku Band (12 - 18 GHz) in microstrip line configuration. The Ku-band (Kurtz-under band) is primarily used for satellite Communications, particularly for editing and broadcasting satellite television. CAD tools (Agilent’s Advance Design System software) have been used for simulation and optimization of the circuits. 180 degree balanced mixer configuration has been adopted due to better RF to LO isolation requirement. The circuit is designed on microstrip line using RT Duroid (Dielectric Constant = 2.22). Initially a rat race coupler (180 degree hybrid) was designed and simulated and optimized for required performance successfully.

关键词： Single Balanced Mixer Double Balanced Mixer

Optimizing the transplanting window for higher productivity of short and medium duration rice cultivars in Punjab,India using CERES-Rice model

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Circular Agricultural Systems

Circular Agricultural Systems 2024年第1期4卷 85-95页

作者： Anupama Aryal Prabhjyot-Kaur sandeep singh Sandhu Shivani Kothiyal Department of Climate Change and Agricultural Meteorology Punjab Agricultural UniversityLudhiana-141004India

The CERES-Rice(V4.7.5)model was used to identify the optimum transplanting window for higher productivity of rice in Indian *** model was first sensitized for 11 genetic coefficients and then these values were used for calibrating and validating the model for rice *** Normalized Root Mean Square Error was in excellent range(<10%)for all the parameters—the coefficient of determination(R2)for ***126 and PR127 for days taken to anthesis and maturity were 0.94 and 0.89−0.96,respectively while grain yield and LAI(leaf area index)were 0.89−0.98 and 0.87−0.89,*** optimum transplanting window of 24−30 June for PR126 and 20−26 June for PR127 simulated the grain yield/LAI ranging from 8,425−8,473 kg·ha^(−1)/4.23−4.24 for PR126 and 8,298−8,356 kg·ha^(−1)/4.20−4.21 for *** early transplantation of rice cultivars on 7th June resulted in the lowest yield/LAI of 6,702 kg·ha^(−1)/3.8 for PR126 and 6,865 kg·ha^(−1)/3.9 for *** deviation for the grain yield and HI(harvest index)of PR126 was between−14.2%to+8.2%and−15.1%to+10.5%,respectively,and of PR127 varied between−11.2%to+8.1%and−14.2%to+10.6%,*** decline in the yield/HI from the average was observed during early transplantation in 2^(nd)week of June(before the 15^(th)of June for PR126 and the 13^(th)of June for PR127)as well as late transplantation in the 1st week of July(after 11^(th)July for PR126 and 6^(th)July for PR127)for rice *** negative effect on yield and HI of both varieties during early and late transplantation could be due to unfavorable climatic conditions.

关键词： cultivar Punjab optimum