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International Journal of Minerals,Metallurgy and Materials 2020年第7期27卷 954-961页

作者： p.Nithin Raj p.k.Navaneethkrishnan k.Sekar M.A.Joseph Department of Mechanical Engineering National Institute of TechnologyCalicutIndia

Duplex stainless steels(DSSs)used in subsea structures and desalination industries require high corrosion and erosion resistance as well as excellent mechanical *** newly introduced cast duplex grade ASTM A8907 A has a unique composition and is expected to have a much better resistance to corrosion and erosion compared with the super-duplex grades 5 A and 6 *** work is a comparative study of the mechanical properties,corrosion,and erosion-corrosion resistance of super-duplex grades 5 A and 6 A and the hyper-duplex grade 7 *** three DSSs exhibited equiaxial austenite islands in the ferrite matrix and balanced phase *** hardness of the grade 7 A was nearly 15%higher than those of the super-duplex grades,which is attributed to the effect of the higher contents of W and Mn in 7 *** impact toughness of grade 7 A was found to be lower than those of the super-duplex grades due to the carbide precipitation resulting from the partial substitution of Mo with *** oxide layer strengthening effect of rare earth elements and the higher pitting resistance equivalent number(pREN)of grade7 A resulted in higher corrosion *** harder and more passive grade 7 A showed a 35%lower material loss during erosion-corrosion.

关键词： hyper-duplex stainless steels erosion−corrosion electrochemical corrosion marine environment super-duplex stainless steels

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Communications in Theoretical physics 2018年第8期69卷 197-208页

作者： p.k.Sahu Department of Mathematics Government Shyama Prasad Mukharjee College Sitapur-497111 Sarguja University

Similarity solution for a spherical shock wave with or without gravitational field in a dusty gas is studied under the action of monochromatic radiation. It is supposed that dusty gas be a mixture of perfect gas and micro solid particles. Equilibrium flow condition is supposed to be maintained and energy is varying which is continuously supplied by inner expanding surface. It is found that similarity solution exists under the constant initial density. The comparison between the solutions obtained in gravitating and non-gravitating medium is done. It is found that the shock strength increases with an increase in gravitational parameter or ratio of the density of solid particles to the initial density of the gas, whereas an increase in the radiation parameter has decaying effect on the shock waves.

关键词： spherical shock wave dusty gas similarity solution gravitational medium Roche model monochromatic radiation

Contrasting REE Signatures on Manganese Ores of Iron Ore Group in North Orissa, India

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Journal of Rare Earths 2007年第6期25卷 749-758页

作者： p.p.Mishra B.k.Mohapatra p.p.Singh Institute of Minerals and Materials Technology Bhubaneswar 751013 India post Graduate Department of Geology Utkal University Bhubaneswar 751004 India

The distribution pattern of Rare Earth Elements （REE） in three categories of manganese ores viz. stratiform, stratabound-replacement, and detrital of precambrian Iron Ore Group from north Orissa, India was reported. These categories of Mn-ore differed in their major and trace chemistry and exhibited contrasting REE signature. The stratiform ores were relatively enriched in ∑REE content （697 μg·g^-1） and their normalized pattern showed both positive Ce and Eu anomalies, whereas the stratabound-replacement types were comparatively depleted in ∑REE content （211 μg·g^-1） and showed negative Ce and flat Eu signatures. The detrital categories showed mixed REE pattern. The data plotted in different discrimination diagrams revealed a mixed volcaniclastic and chemogenic source of material for stratiform categories, and LREE （Light Rare Earth Elements） and HREE （Heavy Rare Earth Elements） are contributed by such sources, respectively. In contrast, the stratabound ore bodies were developed during the remobilization of stratiform ores, and associated Mncontaining rocks under supergene condition followed by the redeposition of circulating mineralized colloidal solutions in structurally favorable zones. During this process, some of the constituents were found only in very low concentration within stratabound ores, and this is attributed to their poor leachability/mobility. The detrital ores did not exhibit any significant characteristic in respect of REE as their development was via a complex combination of processes involving weathering, fragmentation, recementation, and burial under soil cover.

关键词： manganese ore REE normalization geochemistry Bonai-keonjhar belt Orissa rare earths

Effect of Cold Deformation on phase Evolution and Mechanical properties in an Austenitic Stainless Steel for Structural and Safety Applications

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Journal of Iron and Steel Research International 2012年第4期19卷 63-68页

作者： S k Ghosh p Mallick p p Chattopadhyay Department of Metallurgy and Materials Engineering Bengal Engineering and Science UniversityShibpurHowrah 711 103India

The effects of cold deformation on the formation of strain induced α’ martensite and mechanical properties of an austenitic stainless steel have been examined.X-ray diffraction analysis has revealed that 30% and 40% cold rolling have resulted in the formation of 24% and 31.5% martensite *** investigation has demonstrated that the formation of martensite is enhanced with increase in the percent deformation at 0 ℃.Investigation of mechanical properties reveals that hardness,yield strength and tensile strength values increase where as percent elongation drops with increasing *** fractographic observation corroborates the tensile *** of sub-surface at the fractured end of the tensile sample manifests that void/microcrack nucleation occurs in the interfacial regions of the martensite phase as well as at the austenite-martensite interface

关键词： austenitic stainless steel cold deformation martensite mechanical property

production of pig iron from red mud waste fines using thermal plasma technology

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International Journal of Minerals,Metallurgy and Materials 2012年第8期19卷 679-684页

作者： k. Jayasankar p.k. Ray A.k. Chaubey A. padhi B.k. Satapathy p.S. Mukherjee CSIR-Institute of Minerals & Materials Technology Bhubaneswar India National Aluminum Company Ltd. Bhubaneswar India

Red mud, an insoluble residue produced during alkali leaching of bauxite, is considered as a low-grade iron ore containing 30% to 50% iron. The present paper deals with the use of thermal plasma technology for producing pig iron from red mud waste fines. The smelting reduction of red mud was carried out in a 35 kW DC extended arc thermal plasma reactor. Red mud was properly mixed with fluxes and graphite （fixed carbon, 99%） as a reductant as per stoichiometric requirement. The effect of various process parameters like a reductant, fluxes and smelting time on iron recovery was studied and optimized. An optimum condition for the maximum recovery of iron was obtained. A new thermal plasma process applicable to direct iron making from red mud waste fines that would achieve significant utilization of red mud was proposed.

关键词： pig iron waste utilization red mud smelting dolomite limestone thermal plasma

Impacts of pI3k/protein kinase B pathway activation in reactive astrocytes: from detrimental effects to protective functions

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Neural Regeneration Research 2025年第4期20卷 1031-1041页

作者： Ramón pérez-Núñez María Fernanda González Ana María Avalos Lisette Leyton Cellular Communication Laboratory Programa de Biología Celular y MolecularCenter for Studies on ExerciseMetabolism and Cancer(CEMC)Instituto de Ciencias Biomédicas(ICBM)Facultad de MedicinaUniversidad de ChileSantiagoChile Advanced Center for Chronic Diseases(ACCDiS) Faculty of Chemical and Pharmaceutical Sciences&Faculty of MedicineUniversidad de ChileSantiagoChile Instituto de Ciencias Biomédicas Facultad de Ciencias de la SaludUniversidad Autónoma de ChileSantiagoChile

Astrocytes are the most abundant type of glial cell in the central nervous *** injury and inflammation,astrocytes become reactive and undergo morphological and functional *** on their phenotypic classification as A1 or A2,reactive astrocytes contribute to both neurotoxic and neuroprotective responses,***,this binary classification does not fully capture the diversity of astrocyte responses observed across different diseases and *** analysis has revealed that reactive astrocytes have a complex landscape of gene expression profiles,which emphasizes the heterogeneous nature of their *** actively participate in regulating central nervous system inflammation by interacting with microglia and other cell types,releasing cytokines,and influencing the immune *** phosphoinositide 3-kinase(pI3k)/protein kinase B(AkT)signaling pathway is a central player in astrocyte reactivity and impacts various aspects of astrocyte behavior,as evidenced by in silico,in vitro,and in vivo *** astrocytes,inflammatory cues trigger a cascade of molecular events,where nuclear factor-κB serves as a central mediator of the pro-inflammatory ***,we review the heterogeneity of reactive astrocytes and the molecular mechanisms underlying their *** highlight the involvement of various signaling pathways that regulate astrocyte reactivity,including the pI3k/AkT/mammalian target of rapamycin(mTOR),αvβ3 integrin/pI3k/AkT/connexin 43,and Notch/pI3k/AkT *** targeting the inactivation of the pI3k/AkT cellular signaling pathway to control reactive astrocytes and prevent central nervous system damage,evidence suggests that activating this pathway could also yield beneficial *** dual function of the pI3k/AkT pathway underscores its complexity in astrocyte reactivity and brain function *** review emphasizes the importance of employing astrocyte-exclusive models to underst

关键词： inflammation integrins neuroprotective neurotoxic phosphatidylinositol 3-kinase reactive astrocytes signal transduction Thy-1(CD90)

Characterization of Vacuum Ultraviolet (VUV) Radiation for the Development of a Fluorescent Lamp

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plasma Science and Technology 2011年第4期13卷 480-485页

作者： Hasina kHATUN A.k.SHARMA p.k.BARHAI Microwave Tubes Area Central Electronics Engineering Research Institute Applied physic Department Birla Institute of Technology

A negative unipolar pulsed voltage is applied to study internal electrical parameters of the xenon filled dielectric barrier discharge （DBD） sources. The VUV radiation emitted from these sources is characterized by means of the photoluminescence intensity of the red phosphor pellet. The red phosphor converts the VUV radiation into visible radiation and the emission spectra include a peak at 619.56 nm. The emission characteristics of the red phosphor are analyzed in terms of the pressure-distance （pd）, rise time and frequency of the pulsed voltage waveform. The emission intensity measured at different operational conditions confirms that the formation and decay of the xenon excimer, Xe2^＊, increase with the increase in reduced electric field, E/N. After exceeding certain limits of E/N, the intensity of Xe2^＊ decreases rapidly.

关键词： dielectric barrier discharge vacuum ultraviolet photoluminescence RGB

Solitary kinetic Alfven waves in dense plasmas with relativistic degenerate electrons and positrons

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plasma Science and Technology 2019年第4期21卷 85-93页

作者： Monzurul k AHMED Om p SAH Department of physics Biijhora MahavidyalayaBongaigaon-783380AssamIndia

propagation of solitary kinetic Alfven waves(kAWs)is investigated in small but finite/3(particle-to-magnetic pressure ratio)collisionless dense plasma whose constituents are non degenerate wann ions,and relativistic degenerate electrons and *** the use of reductive perturbation technique,kortweg-de Vries equation is derived to obtain small amplitude localized wave solution of *** effects of plasma 0,positron concentration,electron relativistic degeneracy parameter,ion thermal temperature and obliqueness parameter on solitary kAWs are *** results of this theoretical investigation are aimed at elucidating characteristics of kinetic Alfven solitary waves in relativistic degenerate e-p-i plasmas found in dense astrophysical objects specifically neutron stars and white dwarfs.

关键词： solitary kinetic Alfven waves dense plasmas electron-positron-ion plasma,relativistic degenerate plasma reductive perturbation technique

Systematic study on heavy-particle radioactivity of superheavy nuclei ^(297–300)119

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Nuclear Science and Techniques 2024年第11期35卷 108-123页

作者： Megha Chandran V.k.Anjali k.p.Santhosh Department of physics University of CalicutThenhipalamKerala 673635India School of pure and Applied physics Kannur UniversitySwami Anandatheertha CampusPayyanurKerala 670327India

In the current study,we examined every possible cluster-daughter combination in the heavy-particle decay of isotopes ^(297-300)119 and computed the decay half-lives using the modified generalized liquid drop model(MGLDM)with the preformation factor depending on the disintegration *** predicted half-life of every heavy cluster(Z_(C)≥32)was within the experimentally observable *** results aligned with the predictions of poenaru et al.[***.107,062503(2011)]that superheavy nuclei(SHN)with Z>110 will release heavy particles with a penetrability comparable to or greater than theα-*** half-lives predicted using the MGLDM for clusters^(89)Rb,^(91)Rb,and^(92)Rb from parents^(297)119,^(299)119,and^(300)119,respectively,agreed with the predictions of poenaru et al.[***.J.A 54,14(2018)].It was found that the isotopes of heavy clusters kr,Rb,Sr,pa,In,and Cd had half-lives comparable to theαhalf-life;and isotopes of clusters I,Xe,and Cs had the minimum half-life(10^(-14)s).These observations revealed the role of the shell closure(Z=82,N=82,and N=126)of the cluster and daughter nuclei in heavy-cluster *** predicted that isotope ^(297,299)119 decayed by 4αdecay chains and isotope^(300)119 decayed by 6αdecay chains,while^(298)119 decayed by continuousαdecay *** predicted half-lives and modes of decay of the nuclei in the decay chains of^(297-300)119 agreed with the experimental data,proving the reliability of our *** present study determined the most favorable heavy-cluster emissions from these nuclei and provided suitable projectile-target combinations for their synthesis.

关键词： Cluster radioactivity Alpha radioactivity Superheavy nuclei

Three-Dimensional Numerical Modeling of an Ar-N_2 plasma Arc Inside a Non-Transferred Torch

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plasma Science and Technology 2009年第6期11卷 679-687页

作者： B.SELVAN k.RAMACHANDRAN k.p.SREEkUMAR T.k.THIYAGARAJAN p.V.ANANTHApADMANABHAN School of Mechanical and Building Sciences Vellore Institute of Technology UniversityVellore 632014India Laser and plasma Technology Division Bhabha Atomic Research CentreMumbai 400085India

A three-dimensional numerical model is developed to study the behaviour of an argon-nitrogen plasma arc inside a non-transferred torch. In this model, both the entire cathode and anode nozzle are considered to simulate the plasma arc. The argon-nitrogen plasma arc is simulated for different arc currents and gas flow rates of argon. Various combinations of arc core radius and arc length, which correspond to a given torch power, are predicted. A most feasible combination of the same, which corresponds to an actual physical situation of the arc inside the torch, is identified using the thermodynamic principle of minimum entropy production for a particular torch power. The effect of the arc current and gas flow rate on the plasma arc characteristics and torch efficiency is explained. The effect of the nitrogen content in the plasma gas on the torch power and efficiency is clearly detected. predicted torch efficiencies are comparable to the measured ones and the effect of the arc current and gas flow rate on predicted and measured efficiencies is almost similar. The efficiency of the torch, cathode and anode losses and core temperature and velocity at the nozzle exit are reported for five different cases.

关键词： plasma arc numerical modeling plasma torch minimum entropy production electro-thermal efficiency