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A Comparative Study on the Corrosion Behaviour of Hard Anodic Coatings on AA 6061 Obtained Using DC and Pulsed DC Power Sources

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Acta Metallurgica Sinica(English Letters) 2013年第6期26卷 647-656页

作者： Franco M. Hari krishna t. Anju M.Pillai A.Rajendra A.k.Sharma thermal Systems Group ISRO Satellite Centre

the corrosion behaviour of the hard anodic coatings prepared by three different methods viz., conventional hard anodizing （C-HA）, pulse hard anodizing （P-HA） and low voltage room temperature pulse hard anodizing （LVP- HA） on AA 6061 was compared using electrochemical impedance spectroscopy （EIS） and linear polarisation. Scanning electron microscope （SEM） was used to study the surface morphology before and after corrosion. EIS data revealed that no significant difference in corrosion resistance was observed among three types. Rp, Icorr and Ecorr were found to be highly stable over the exposure period up to 72 h which confirms the excellent corrosion resistance. the studies indicate that the corrosion resistance of LVP-HA and P-HA, which are processed at lower voltage and at relatively higher temperatures, are comparable to that of C-HA which is processed at sub-zero temperatures and high operating voltages. the corrosion resistance of all coatings was found to be improved after hydrothermal sealing.

关键词： Aluminium Anodic films EIS Polarisation SEM

Nonlinear thermal Buoyancy on Ferromagnetic Liquid Stream Over a Radiated Elastic Surface with Non Fourier Heat Flux

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Computer Modeling in Engineering & Sciences 2021年第2期126卷 599-616页

作者： t.k.Sreelakshmi Abraham Annamma A.S.Chethan M.krishna Murthy C.S.k.Raju Department of Mathematics BMS Institute of Technology and ManagementBengaluru560064India Department of Mathematics School of Applied SciencesREVA UniversityBengaluru560064India Department of Mathematics GITAM School of ScienceGITAM Deemed to be UniversityBengaluru562163India

the current article discusses the heat transfer characteristics of ferromagnetic liquid over an elastic surface with the thermal radiation and non-Fourier heat *** most of the existing studies,the heat flux is considered as constant,but whereas we incorporated the non-Fourier flux to get the exact performance of the ***,we excluded the PWt and PHF cases to control the boundary layer of the *** governing equations related to our contemplate are changed into non-linear ordinary differential equations(ODE’s)by utilizing appropriate similarity changes,which are at the point enlightened by Runge–k.t.a based shooting *** equations are broken down concerning boundary conditions and to be explained prescribed wall temperature(PWt)and prescribed heat flux(PHF)*** impacts of diverse non-dimensional physical parameters on velocity and temperature profiles are laid out ***,the assortment of skin friction and local Nusselt number for both PWt and PHF cases for various assessments of non-dimensional parameters have been sorted *** the wrap-up of the examination,we suspect that the friction factor coefficient is higher in the PWt case compared to the PHF *** result helps to conclude that the flux conditions are useful for cooling applications.

关键词： Ferromagnetic liquid nonlinear thermal buoyancy non-Fourier heat flux radiated elastic surface

Improvement in hot corrosion resistance of dissimilar alloy 825 and AISI 321 CO2-laser weldment by HVOF coating in aggressive salt environment at 900℃

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International Journal of Minerals,Metallurgy and Materials 2020年第11期27卷 1536-1550页

作者： S.M.Muthu M.Arivarasu t.Hari krishna Supriyo Ganguly k.V.Phani Prabhakar Saurav Mohanty School of Mechanical Engineering Vellore Institute of TechnologyVelloreTamil Nadu 632014India Center for Innovative Manufacture Research Vellore Institute of TechnologyVelloreTamil Nadu 632014India Welding Engineering and Laser Processing Centre Cranfield UniversityBedfordUnited Kingdom CLPM International Advanced Research Centre for Powder Metallurgy&New Materials(ARCI)HyderabadIndia Department of Mechanical Engineering North Carolina State UniversityRaleighUSA

this study investigated the hot corrosion performance of a dissimilar weldment of Ni-based superalloy and stainless steel joined by CO2-laser welding and improved by high-velocity oxy-fuel(HVOF)coating in a Na2SO4-60wt%V2O5 environment at 900℃.A dissimilar butt joint of AISI 321 and alloy 825 was fabricated by CO2-laser welding with low heat input after obtaining the optimum welding parameters by bead-on-plate *** metallurgical and mechanical properties of the laser weldment were *** tensile test results indicated the occurrence of fracture in the base metal AISI 321 *** HVOF process was employed to coat Ni-20wt%Cr on the *** evaluate the surface morphology of the corrosion products formed on the uncoated and Ni-20wt%Cr-coated weldments,scanning electron microscopy(SEM)analysis was ***-dispersive spectroscopy(EDS)was used to determine the different elements present on the surface *** existence of oxide phases on the weldments was determined by X-ray diffraction(XRD).the cross sections of the weldments were characterized by SEM with EDS line mapping *** results indicated that the Ni-20wt%Cr-coated weldment exhibited superior hot corrosion resistance due to the development of Cr2O3 and NiCr2O4 protective oxide scales.

关键词： nickel-based superalloy dissimilar welding weldment corrosion high-velocity oxy-fuel coating corrosion kinetics

Stakeholder Perspectives on Use,trade,and Conservation of Medicinal Plants in the Rasuwa District of Central Nepal

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Journal of Mountain Science 2011年第1期8卷 75-86页

作者： Yadav UPREtY Ram C.POUDEL Hugo ASSELIN Emmanuel k.BOON krishna k.SHREStHA Human Ecology Department Vrije Universiteit BrusselLaarbeeklaan 109B-1090 BrusselsBelgium Canada Research Chair in Aboriginal Forestry Université du Québec en Abitibi-Témiscamingue445Boulevard de l'UniversitéRouyn-NorandaQuébecJ9X 5E4Canada kunming Institute of Botany Chinese Academy of Sciences Central Department of Botany Tribhuvan University

People's livelihood in several Himalayan regions largely depends on collection,use,and trade of medicinal *** use is generally not a problem,but commercial gathering of selected species to meet increasing national and international demand can result in *** management of medicinal plants requires a clear understanding of the respective roles,responsibilities and viewpoints of the various stakeholders *** personal interviews and group discussions,this study aimed at investigating the views of two stakeholder groups on use,trade and conservation of medicinal plants in the Rasuwa district of *** people and district and national organizations agreed that medicinal plants are collected for a combination of commercial and personal *** on mark.t.availability differed significantly:100 % of the respondents from district and national organizations saw mark.t. as easily available,against only 36 % for local *** could explain why medicinal plants were perceived by local people to contribute less to income generation than to livelihood *** viewpoints were also expressed concerning the status of medicinal plants in the district:81 % of the respondents from district and national organizationsconsidered that medicinal plants were threatened,compared to only 28 % for local *** this disparity,both stakeholder groups agreed upon potential threats to medicinal plants:over-harvesting;habitat loss due to land-use change and deforestation;and over-grazing by *** challenges were identified regarding sustainable management of medicinal plants,such as ambiguous policies;lack of resources,information and infrastructures;habitat degradation;and *** these challenges,respondents agreed that the medicinal plants sector offers huge opportunities in the Rasuwa district,given resource availability,community awareness and motivation,and the priority given

关键词： Medicinal plants Livelihood improvement Income generation Himalaya Local people Conservation Policy

MicroRNAs in hepatocellular carcinoma treatment:Charting the path forward

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World Journal of Gastroenterology 2024年第11期30卷 1470-1474页

作者： Hong t Lin Antonio F Alvarez Castaneda Somashekar G krishna khalid Mumtaz Division of Gastroenterology Hepatology and NutritionDepartment of MedicineThe Ohio State University Wexner Medical CenterColumbusOH 43210United States

MicroRNAs(miRNAs)are recognized for their involvement in the regulation of gene expression and exhibit significant potential in both the prognostic assessment and treatment of hepatocellular carcinoma(HCC).HCC,like other tumors,seldom occurs in isolation;instead,it evolves within a microenvironment featuring oncogenic and tumor-suppressive *** combined with suitable delivery vehicles,miRNA technology provides the capability to directly engage with these elements,thereby hindering tumor formation and *** research in this domain holds the promise of enabling a more efficacious and multi-modal treatment approach for HCC in the near future.

关键词： Hepatocellular carcinoma tumor microenvironment MicroRNA Mesenchymal stem cell Exosome

Orchestration between ILC2s and th2 cells in shaping type 2 immune responses

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Cellular & Molecular Immunology 2019年第3期16卷 225-235页

作者： Rama krishna Gurram Jinfang Zhu Molecular and Cellular Immunoregulation Section Laboratory of Immune System BiologyNational Institute of Allergy and Infectious DiseasesNational Institutes of HealthBethesdaMD 20892USA

the type 2 immune response is critical for host defense against large parasites such as *** the other hand,dysregulation of the type 2 immune response may cause immunopathological conditions,including asthma,atopic dermatitis,rhinitis,and ***,a balanced type 2 immune response must be achieved to mount effective protection against invading pathogens while avoiding *** classical model of type 2 immunity mainly involves the differentiation of type 2 t helper(th2)cells and the production of distinct type 2 cytokines,including interleukin-4(IL-4),IL-5,and *** 2 innate lymphoid cells(ILC2s)were recently recognized as another important source of type 2 *** eosinophils,mast cells,and basophils can also express type 2 cytokines and participate in type 2 immune responses to various degrees,the production of type 2 cytokines by the lymphoid lineages,th2 cells,and ILC2s in particular is the central event during the type 2 immune *** this review,we discuss recent advances in our understanding of how ILC2s and th2 cells orchestrate type 2 immune responses through direct and indirect interactions.

关键词： type 2 immune response type 2 t helper cell(th2) Group 2 innate lymphoid cell(ILC2) Allergy and asthma

Non-Fullerene-Based Inverted Organic Photovoltaic Device with Long-term Stability

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Energy & Environmental Materials 2023年第3期6卷 214-221页

作者： Do Hui kim Febrian t.A.Wibowo Dongchan Lee Narra V.krishna Sujung Park Shinuk Cho Sung-Yeon Jang Department of Physics and Energy Harvest Storage Research Center University of UlsanUlsan 44610Republic of Korea School of Energy and Chemical Engineering Ulsan National Institute of Science and Technology(UNIST)50 UNIST-gilUlsan 44919Republic of Korea

In this work,we developed the PM6:Y6-based inverted structure organic photovoltaic(i-OPV)with improved power conversion efficiency(PCE)and long-term stability by resolving the origins of the performance *** deep defects between the metal oxide-based electron transport layer and bulk-heterojunction photoactive layer interface were responsible for suboptimal PCE and facilitated degradation of *** the density of deep traps is increased during the storage of i-OPV,the penetrative oxygen-containing defects additionally generated shallow traps below the band-edge of Y6,causing an additional loss in the open-circuit *** suppression of interfacial defects by chemical modification effectively improved the PCE and long-term stability of *** modified i-OPV(mi-OPV)achieved a PCE of 17.42%,which is the highest value among the reported PM6:Y6-based i-OPV ***,long-term stability was significantly improved:~90%and~80%retention of its initial PCE after 1200 h of air storage and illumination,respectively.

关键词： deep trap inverted structure long-term stability organic photovoltaic power conversion efficiency

kOH activated carbon derived from biomass-banana fibers as an efficient negative electrode in high performance asymmetric supercapacitor

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Journal of Energy Chemistry 2017年第1期26卷 56-62页

作者： Chaitrak Vinny R t Sivaraman P Narendra Reddy Chunyan Hu krishna Venk.t.sh Vivek C S Nagaraju N k.t.yayini N Department of Nanobiosciences Centre for Emerging TechnologiesJain Global CampusJain UniversityJakkasandra postKanakapura TalukRamanagara DistrictBangalore Rural 562112 KarnatakaIndia Naval Materials Research Laboratory DRDOAmbernathThane 421506India Department of Chemistry St.Joseph’s College P.G.Centre.46Langford RoadShanthinagarBangaloreKarnataka 560027India Research Resource Centre Visveswaraya Technological UniversityBelagaviIndia College of Chemistry Chemical Engineering and BiotechnologyDonghua UniversityShanghai 201620China National Engineering Research Center for Dyeing and Finishing of textiles Donghua UniversityShanghai 201620China

Here we demonstrate the fabrication, electrochemical performance and application of an asymmetric supercapacitor (AS) device constructed with ss-Ni(OH)(2)/MWCNts as positive electrode and kOH activated honeycomb-like porous carbon (k-PC) derived from banana fibers as negative electrode. Initially, the electrochemical performance of hydrothermally synthesized ss-Ni(OH)(2)/MWCNts nanocomposite and k-PC was studied in a three-electrode system using 1 M kOH. these materials exhibited a specific capacitance (Cs) of 1327 Fig and 324 F/g respectively at a scan rate of 10 mV/s. Further, the AS device i.e., ss-Ni(OH)(2)/MWCNts// k-PC in 1 M kOH solution, demonstrated a Cs of 156 F/g at scan rate of 10 mV/s in a broad cell voltage of 0-2.2 V. the device demonstrated a good rate capability by maintaining a Cs of 59 F/g even at high current density (25 A/g). the device also offered high energy density of 63 Wh/kg with maximum power density of 5.2 kW/kg. the AS device exhibited excellent cycle life with 100% capacitance retention at 5000th cycle at a high current density of 25 A/g. two AS devices connected in series were employed for powering a pair of LEDs of different colors and also a mini fan. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

关键词： Asymmetric supercapacitor device Activated porous carbon High energy density Cyclability Power source

A silver-catalyzed[3+3]-annulation cascade of alkynyl alcohols andα,β-unsaturated k.t.nes for the regioselective assembly of chromanes

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Organic Chemistry Frontiers 2022年第3期9卷 802-809页

作者： Ashwini k.Nak.t. Sagar S.thorat Shailja Jain Gamidi Rama krishna kumar Vanka Ravindar kontham Organic Chemistry Division CSIR-National Chemical LaboratoryDr Homi Bhabha RoadPune-411008India Academy of Scientific and Innovative Research(AcSIR) Ghaziabad-201002India Centre for Materials Characterization CSIR-National Chemical LaboratoryDr Homi Bhabha RoadPune-411008India Physical and Materials Chemistry Division CSIR-National Chemical LaboratoryDr Homi Bhabha RoadPune-411008India

An unprecedented Ag(I)-catalyzed[3+3]-annulation of alkynyl alcohols(5-hexyn-1-ols)andα,β-unsaturated k.t.nes is reported to construct simple to complex *** transformation begins with hydroalkoxylation of alkynol through C-C triple bond activation to give cyclic-enol ether,followed by intermolecular 1,4-addition and intramolecular 1,2-addition of enol ethers onto the enone and oxidative aromatization or Grob-type elimination steps.

关键词： alcohols unsaturated catalyzed