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Porous carbon catalysis in sustainable synthesis of functional heterocycles:An overview

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Chinese Chemical Letters 2024年第8期35卷 170-186页

作者： uttam Pandurang Patil Department of Chemistry ACS CollegeShivaji UniversityPalus 416310MSIndia

Heterogeneous porous carbon(PC)materials have gained unique importance in the catalysis community due to their captivating properties,including high specific surface area,tunable porosity,and *** can play a prominent role in the sustainable synthesis of functional heterocycles,as they are a low-cost alternative while being an efficient and user-friendly *** review examines the prepa-ration and applicability of these carbonaceous materials used as catalysts or support for biologically active heterocycles synthesis,including hydrogenation,oxidation,oxidative dehydrogenation,cross-coupling,and other organic ***,the challenges,potential future development directions,and opportuni-ties in the synthesis of potent bioactive heterocycles over PC materials have been *** review will inspire further research to explore novel PC materials and their implications in heterocyclization.

关键词： Sustainable chemistry Heterogeneous catalysts Porous carbons Heterocycles synthesis

COVID-19 therapeutics:Clinical application of repurposed drugs and futuristic strategies for target-based drug discovery

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Genes & Diseases 2023年第4期10卷 1402-1428页

作者： Sunny kumar Malini Basu Pratyasha Ghosh uttam Pal Mrinal k.Ghosh Cancer Biology and Inflammatory Disorder Division Council of Scientific and Industrial Research-Indian Institute of Chemical Biology(CSIR-IICB)TRUE CampusCN-6SectoreVSalt LakeKolkata-700091&4Raja S.C.Mullick RoadJadavpurKolkata 700032India Department of Microbiology Dhruba Chand Halder CollegeDakshin BarasatWest Bengal 743372India Department of Economics Bethune CollegeUniversity of CalcuttaKolkata 700006India

Severe acute respiratory syndrome coronavirus-2(SARS-CoV-2)causes the compli-cated disease *** are continuously facing huge problems in the treatment of patients,as COVID-19-specific drugs are not available,hence the principle of drug repurpos-ing serves as a one-and-only ***,the repurposing of many drugs is underway;few of them are already approved by the regulatory bodies for their clinical use and most of them are in different phases of clinical *** in this review,our main aim is to discuss in detail the up-to-date information on the target-based pharmacological classification of repurposed drugs,the potential mechanism of actions,and the current clinical trial status of various drugs which are under repurposing since early *** last,we briefly proposed the probable phar-macological and therapeutic drug targets that may be preferred as a futuristic drug discovery approach in the development of effective medicines.

关键词： Clinical trials COVID-19 Drug discovery Pharmacology Repurposing of drugs SARS-CoV-2

Impact of anthropogenic disturbance on species diversity and vegetation structure of a lowland tropical rainforest of eastern Himalaya, India

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Journal of Mountain Science 2018年第11期15卷 2453-2465页

作者： Anudip GOGOI uttam kumar SAHOO Department of Forestry Mizoram University

Impact of anthropogenic disturbance on species diversity and vegetation structure of a lowland tropical rainforest was studied in the foothills of Eastern Himalaya, India. Tree species richness,density, basal area and the diversity indices were found significantly(P100 cm dbh class in all three sites. Density of the matured trees decreased with increasing DBH whereas, tree basal area tended to increase with increasing DBH in all three sites. Tree species richness was highest in the lower DBH classes.62.07% of the total tree species regenerated in the largely undisturbed site followed by 50% in the mildly disturbed and 26.32% in the highly disturbed *** overall regeneration condition was found to be good in the largely undisturbed site. Mildly disturbed site exhibited fair regeneration and so was in the highly disturbed site. Discernable variations in species composition, diversity, regeneration and tree population structure revealed the impact of anthropogenic disturbances on rainforest vegetation dynamics. Higher degree of disturbance was furtherly found not only affecting species diversity but also promoting the growth of invasive weed *** of Hydnocarpus kurzii and Crypteronia paniculata in the highly disturbed site also indicated that these les

关键词： Biodiversity Deforestation Abundance Vegetation Dynamics Conservation Management

Thermal inertia at the MSL and InSight mission sites on Mars

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Earth and Planetary Physics 2022年第1期6卷 18-27页

作者： D.Singh S.uttam Centre of Studies in Resources Engineering Indian Institute of Technology BombayMumbaiIndia Physical Research Laboratory AhmedabadIndia

For planetary surface materials,thermal inertia is the critical property that governs the surface’s daily thermal response and controls diurnal and seasonal surface temperature *** we use the ground measurements made by the MSL Curiosity rover and the InSight lander to determine the thermal inertia of two sites on *** study compares the variation of thermal inertia during and after the Large Dust Storm(LDS)of Martian Year(MY)*** determine surface thermal inertia,we derive a simple approximation(using energy balance),which utilizes surface albedo,surface energy flux,and diurnal change in the surface *** average thermal inertia in MY34 is about 39.2%,3.7%,and 3.4%higher than MY35 average thermal inertia for the MSL,InSight(FOV1),and InSight(FOV2),***,the thermal inertia at the InSight(FOV1)is consistently lower by about 20 J·m^(-2)·s^(-1/2)·k^(-1) than the InSight(FOV2)site for all scenarios,indicating variation in the region’s surface *** best-fit surface albedo in MY34(determined using the kRC model)are about 0.08,0.05,and 0.03 higher than MY35 surface albedo for the MSL,InSight(FOV1),and InSight(FOV2),*** increase in both surface albedo and thermal inertia during the LDS indicates that the underlying surface is both more thermally resistant and more reflective than the overlying loose dust.

关键词： Mars Mars surface thermal inertia dust storm Mars climate

Ultra-small amorphous MoS2 decorated reduced graphene oxide for supercapacitor application

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Journal of Materials Science & Technology 2020年第5期40卷 196-203页

作者： Poulami Hota Milon Miah Saptasree Bose Diptiman Dinda uttam k.Ghorai Yan-kuin Su Shyamal k.Saha Department of Materials Science Indian Association for the Cultivation of ScienceJadavpurKolkata700032India Department of Materials Science and Engineering Seoul National UniversitySeoul151-744Republic of Korea Department of Industrial Chemistry and Applied Chemistry Ramakrishna Mission Vidyamandira and Swami Vivekananda Research CenterBelur MathHowrah711202India Green Energy Technology Research Center Kun Shan UniversityTainanTaiwanChina

Amorphous materials have recently gained much attention as electrode materials in supercapacitor application due to the presence of larger amount active sites which can efficiently increase the storage capacity of the *** engineering is an elegant approach to fully utilize the advantages of the amorphous ***,large surface area and high conductivity of reduced graphene oxide(RGO)can efficiently increase the storage capacity of the *** this idea,in the present work,we have successfully synthesized amorphous MoS2 of two different sizes on reduced graphene oxide and thoroughly investigated the supercapacitor behavior of the *** specific capacitance of the composite structures has been found to be largely increased with decreasing size of the amorphous nano *** specific capacitance of amorphous MoS2-RGO composite containing nearly 50 nm of MoS2 found to be 270 F/g whereas when the particle size is reduced to 5–7 nm,value of specific capacitance increases to 460 F/*** large increase in specific capacitance with the tuning of the size of amorphous nano particle has been explained by the presence of a large number of active sulfur edges of ultra-small MoS2 nano structure along with the better charge transport which can effectively increase the storage capacity of the overall *** retention in the capacitance of the material has been found to be 90%after 5000 cycles.

关键词： Supercapacitor Ultrasmall amorphous MoS2 nanoparticles Sulfur edge sites Reduced graphene oxide(RGO) Specific capacitance

Effect of tool rotational speed on the particle distribution in friction stir welding of AA6092/17.5 SiCp-T6 composite plates and its consequences on the mechanical property of the joint

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Defence Technology（防务技术） 2020年第2期16卷 381-391页

作者： uttam Acharya Barnik Saha Roy Subhash Chandra Saha Department of Mechanical Engineering National Institute of Technology AgartalaBarjalaJiraniaWest Tripura799046India

This study investigates the effect of tool rotational speed(TRS)on particle distribution in nugget zone(NZ)through quantitative approach and its consequences on the mechanical property of friction stir welded joints of AA6092/17.5 SiCp-T6 composite.6 mm thick plates are welded at a constant tool tilt angle of 2°and tool traverse speed of 1 mm/s by varying the TRS at 1000 rpm,1500 rpm and 2000 rpm with a taper pin profiled *** analysis shows large quantity of uniformly shaped smaller size SiC particle with lower average particle area which are homogeneously distributed in the *** fragmentation of bigger size particles has been observed because of abrading action of the hard tool and resulting shearing effect and severe stress generation due to the rotation of *** particles occupy maximum area in the matrix compared to that of the base material(BM)due to the redistribution of broken particles as an effect of *** migration of particles towards the TMAZ-NZ transition zone has been also encountered at higher TRS(2000 rpm).The microhardness analysis depicts variation in average hardness from top to bottom of the NZ,minimum for 1500 rpm and maximum for 2000 *** impact strength at 1000 rpm and 1500 rpm remains close to that of BM(21.6 J)while 2000 rpm shows the accountable *** maximum joint efficiency has been achieved at 1500 rpm(84%)and minimum at 1000 rpm(68%)under tensile *** analysis shows mixed mode of failure for BM,1000 rpm and 1500 rpm,whereas 2000 rpm shows the brittle mode of failure.

关键词： Friction stir welding Aluminium matrix composite Tool rotational speed Particle distribution Mechanical property

First-principles study on the mechanical and thermodynamic properties of MoNbTaTiW

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International Journal of Minerals,Metallurgy and Materials 2020年第10期27卷 1398-1404页

作者： uttam Bhandari Congyan Zhang Shengmin Guo Shizhong Yang Department of Computer Science Southern University and Agricultural&Mechanical CollegeBaton RougeLouisiana 70813USA Department of Mechanical and Industrial Engineering Louisiana State UniversityBaton RougeLouisiana 70803USA

Refractory high-entropy alloys(RHEAs)are emerging as new materials for high temperature structural applications because of their stable mechanical and thermal properties at temperatures higher than 2273 *** this study,the mechanical properties of MoNbTaTiW RHEA are examined by applying calculations based on first-principles density functional theory(DFT)and using a large unit cell with 100 randomized *** phase calculation of MoNbTaTiW with CALPHAD method shows the existence of a stable body-centered cubic structure at a high temperature and a hexagonal closely packed phase at a low *** predicted phase,shear modulus,Young’s modulus,Poisson’s ratio,and hardness values are consistent with available experimental *** linear thermal expansion coefficient,vibrational entropy,and vibrational heat capacity of MoNbTaTiW RHEA are investigated in accordance with Debye-Grüneisen *** results may provide a basis for future research related to the application of RHEAs.

关键词： high-entropy alloy MoNbTaTiW mechanical properties thermodynamic properties density functional theory

Vegetation and ecosystem carbon recovery following shifting cultivation in MizoramManipur-kachin rainforest eco-region,Southern Asia

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Ecological Processes 2020年第1期9卷 236-248页

作者： Anudip Gogoi uttam kumar Sahoo Hemanta Saikia Department of Forestry Mizoram UniversityAizawl 796004India College of Sericulture Assam Agricultural UniversityJorhat 785013India

Background:Shifting cultivation(locally known as“jhum”)is a major driver of deforestation and loss of ecosystem services in *** developing any effective conservation of biodiversity and carbon service program,an indepth understanding to the recovery of vegetation and carbon after abandonment of jhum is *** estimated species richness,abundance and composition of trees,shrubs and herbs,carbon distribution in aboveground and belowground components along a chronosequence of jhum fallow in northeast India,and elucidated the factors affecting the recovery processes of jhum ***:Species composition and other plant community attributes,carbon storage in different pools were studied in 5 jhum fallows(kage“nlme”for identifying the important factors contributing to the recovery of vegetation and ***:Species composition varied significantly(Pk in the oldest jhum fallow was 33%and 62%of those in the old-growth forest,*** fallow age was found to be the most important explanatory factor in the recovery process of vegetation and carbon stock in re-growing ***:The shifting cultivation fallows gradually recovered both vegetation and carbon and are potential repository sites for biodiversity conservation,which may take much longer time to reach up to old-growth forest in northeast India.

关键词： Biodiversity conservation Regrowth forest Vegetation succession Carbon storage Restoration of degraded land

Applicability of unique scarf joint configuration in friction stir welding of AA6061-T6:Analysis of torque,force,microstructure and mechanical properties

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Defence Technology（防务技术） 2022年第4期18卷 567-582页

作者： Durjyodhan Sethi uttam Acharya Shashank Shekhar Barnik Saha Roy Department of Mechanical Engineering National Institute of Technology AgartalaBarjalaJiraniaWest TripuraPin-799046India Department of Materials Science and Engineering Indian Institute of Technology KanpurKanpur208016India

The present research introduces a unique concept of scarf joint technique in friction stir welding(FSW) of aluminum alloy AA 6061-T6 plates and an investigation on weld quality.A new joint configuration with two distinct scarf angles(75°and 60°) was considered in this *** various aspects of welding were compared with contemporary simple square butt(SSB) joint *** was carried out at a constant tool rotation speed(TRS),tool traverse speed(TTS) and tool tilt angle of 1100 rpm,2 mm/s and2°,*** results are analyzed in terms of force and torque distribution,microstructure,macrostructure,and mechanical property perspective for different joint *** study reveals the minimum amount of force and torque at 60°scarf angle joint configuration compared to that of square butt joint *** study shows that all the joints were defect-free,and a prominent onion ring was present in the lower portion of the weld nugget(WN).Fine equiaxed grains with a minimum average grain size diameter of 6.82 μm were obtained in the WN of scarf joint configuration(SJC).The maximum ultimate tensile strength(UTS) and maximum average NZ hardness of 267 MPa and83.82 HV0.1were obtained in SJC3 at a scarf angle of 60°.It has been observed from the investigation that the joint efficiency increases from 72.5%(SSB) to 86%(SJC3) at a 60° scarf *** unique characteristic may lay an impetus on probable joint strength enhancement technique without increasing the production cost.

关键词： Friction stir welding Joint configuration Al alloys Force and torque Microstructure Mechanical property