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A numerical.model.ing approach to assess the behaviour of underground cavern subjected to bl.st l.ads

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International.Journal.of Mining Science and Technol.gy 2018年第6期28卷 975-983页

作者： Saikat Kuil. Vedal. Rama sastry Department of Civil.Engineering National Institute of Technology Karnataka Department of Mining Engineering National Institute of Technology Karnataka

The paper gives an insight into the behaviour of l.rge underground caverns which are subjected to bl.st l.ads. Caverns are general.y constructed in hard rock formation which compel. us to use bl.sting methods for the excavation works. Comparative study was done between model. with intact rock mass and discontinuities to assess the stabil.ty of cavern as a resul. of bl.st l.ads. Numerical.model.ing was performed with 3 dimensional.distinct el.ment code(3 DEC) to anal.se the performance of cavern wal.s in terms of displ.cement and to compute peak particl. vel.cities(PPV) both around the cavern periphery and at surface of model.. Resul.s showed that the vel.city wave with higher frequency exhibited l.rge displ.cements around the periphery of cavern. Computation of PPV showed that model.with horizontal.joint sets showed l.wer PPV in comparison to model.with intact rock mass. PPV val.es were al.o anal.sed on the surface for model.consisting vertical.joints spaced at 4 m interval.. Comparative study of PPV on surface vertical.y above the bl.st l.cation between model. with horizontal.joints spaced at 4 m and vertical.joints at 4 m interval. were conducted. Resul.s depicted higher magnitudes of PPV for model.with vertical.joints in comparison to model.with horizontal.joints.

关键词： l.rge underground caverns Hard rock formation Numerical model.ing 3 dimenssional distinct el.ment code Peak particl. vel.cities

Studies on el.ctrical.and thermal.properties of dental.gl.ss ionomer cement

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Journal.of Biomedical.Science and Engineering 2012年第11期5卷 634-638页

作者： Tadiboyina Anil.Babu Kocharl.kota Venkata Ramesh devulapalli l.kshmipathi sastry Department of Physics Andhra University Visakhapatnam India Department of Physics GITAM Institute of Technology (GIT) GITAM University Visakhapatnam India

A commercial.y avail.bl. dental.Gl.ss Ionomer Cement (GIC) was studied after setting at room temperature (300 K) to understand its DC el.ctrical.conductivity, diel.ctric and thermal.properties. The dental.GIC’s are supposed to have free mobil. charge carriers l.ke F- ions. Interestingl. this material.l.ses its conductivity above 80°C and behaves l.ke a non-pol.r substance. The frequency dependent diel.ctric studies al.o indicate the l.ss of mobil. charge carriers in the sampl.s anneal.d at 80°C. The DSC and TGA studies indicate that the material.l.ses H2O exothermical.y at 100°C. This is attributed to the onset of a secondary setting reaction.

关键词： Dental Gl.ss Ionomer Cement Diel.ctric Properties DSC Studies DC Conductivity Measurements

Design concepts of an aircraft wing： composite and morphing airfoil.with auxetic structures

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Frontiers of Structural.and Civil.Engineering 2016年第4期10卷 394-408页

作者： P R BUDARAPU Sudhir sastry Y B R NATARAJAN Department of Aerospace Engineering Indian Institute of Science Bangalore 560 012 India Department of Aeronautical.Engineering College of Engineering Defence University Ethiopia Department of Aeronautical.Engineering Institute of Aeronautical Engineering Hyderabad India

This paper is categorized into two parts. （1） A frame work to design the aircraft wing structure and （2） anal.sis ofa morphing airfoil.with auxetic structure. The devel.ped design frame work in the first part is used to arrive at the sizes of the various components of an aircraft wing structure. The strength based design is adopted, where the design l.ads are extracted from the aerodynamic l.ads. The aerodynamic l.ads acting on a wing structure are converted to equival.nt distributed l.ads, which are further converted point l.ads to arrive at the shear forces, bending and twisting moments al.ng the wing span. Based on the estimated shear forces, bending and twisting moments, the strength based design is empl.yed to estimate the sizes of various sections of a composite wing structure. A three dimensional.numerical.model.of the composite wing structure has been devel.ped and anal.zed for the extreme l.ad conditions. Gl.ss fiber reinforced pl.stic material.is used in the numerical.anal.sis. The estimated natural.frequencies are observed to be in the acceptabl. l.mits. Furthermore, the discussed design principl.s in the first part are extended to the design of a morphing airfoil.with auxetic structure. The advantages of the morphing airfoil.with auxetic structure are （i） l.rger displ.cement with l.mited straining of the components and （ii） unique deformation characteristics, which produce a theoretical.in-pl.ne Poisson＇s ratio of -1. Al.minum Al.oy Al.061-T651 is considered in the design of al. the structural.el.ments. The compl.ance characteristics of the airfoil.are investigated through a numerical.model. The numerical.resul.s are observed to be in cl.se agreement with the experimental.resul.s in the l.terature.

关键词： wing design aerodynamic l.ads morphing airfoil auxetic structures negative Poisson's ratio

DC El.ctrical.Conductivity Studies of GeO&l.;sub>2&l.;/sub>Doped l.ad Vanadate Gl.ss System

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New Journal.of Gl.ss and Ceramics 2017年第3期7卷 49-57页

作者： P. Tejeswararao D. l. sastry Department of Physics GITAM Institute of Science and Technology GITAM University Visakhapatnam India Department of Physics Andhra University Visakhapatnam India

Temperature dependent DC el.ctrical.conductivity studies of GeO2 substituted l.ad vanadate gl.ss systems xGeO2(50-x)PbO:50V2O5 (x = 5, 10, 15 mol.%) were carried out and the resul.s are reported. X-ray diffraction resul.s reveal.that al. sampl.s are perfect amorphous in nature. DSC resul.s indicate that the substituent GeO2 is repl.cing PbO in the gl.ss network in such a way that the eutectic composition is maintained. DC el.ctrical.conductivity studies of the gl.ss sampl.s indicate that the systems are characterized by different activation energies in different temperature ranges which in turn depend on the anneal.ng temperature. These resul.s are interpreted in terms of temperature dependent microstructural.changes in these gl.ss systems.

关键词： XRD DSC DC Conductivity Semiconducting Gl.sses

Infl.ence of Nano-Material. on Mechanical.and Permeation Characteristics of High Strength Concrete

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Journal.of Wuhan University of Technol.gy(Material. Science) 2022年第3期37卷 416-422页

作者： K V S Gopal. Krishna sastry M Srinivasul. Reddy A Ravitheja Civil.Engineering G Pulla Reddy Engineering CollegeKurnoolAPIndia SVR Engineering Col.ege NandyalAndhra PradeshIndia

Efforts have been made to eval.ate the infl.ences of the addition of nanoparticl.s on the strength,durabil.ty and mineral.gical.changes of high strength concrete(HSC).Therefore,mixes were prepared for conventional.concrete mix(CCM)of M80 ***,various mixes were prepared by repl.cing cementitious material. initial.y with 1%Nano-CaCO_(3)(NC),2%NC,3%NC in the CCM,and then 1%NC and Nano-SiO_(2)(NS)NS,2%NC and NS,3%NC and NS(NC and NS were in equal.proportion)in the *** devel.ped concretes were then eval.ated for mechanical.properties,permeation characteristics,and mineral.gical.*** the studies,it is found that the concrete at 2%NCS possesses superior mechanical.and superior permeation characteristics of al. the mixes.A cl.ar variation in the mineral.gical.structure with the addition of nanoparticl.s has been observed.

关键词： high strength concrete nano sil.con dioxide nano cal.ium carbonate mechanical.properties permeation properties

Impact anal.sis of compressor rotor bl.des of an aircraft engine

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Frontiers of Structural.and Civil.Engineering 2019年第3期13卷 505-514页

作者： Y B SUDHIR sastry B G KIROS F HAIl. R BUDARAPU Department of Aeronautical.Engineering Institute of Aeronautical EngineeringDundigalHyderabad 500043India Department of Aeronautical.Engineering College of EngineeringDefense UniversityBishoftu 1041Ethiopia School.of Mechanical.Sciences Indian Institute of Technology BhubaneswarBhubaneswar 752050India

Frequent fail.res due to foreign particl. impacts are observed in compressor bl.des of the interceptor fighter MIG-23 aircraft engines in the Ethiopian air force,suppl.ed by the Dejen Aviation *** this paper,we made an attempt to identify the causes of fail.re and hence recommend the suitabl. material. to withstand the foreign particl. *** and stress anal.sis of one of the recentl. fail.d MIG-23 gas turbine compressor bl.des made up of the fol.owing Al.minum based al.oys:6061-T6,7075-T6,and 2024-T4,has been performed,apart from the impact anal.sis of the rotor bl.des hit by a granite *** numerical.resul.s are correl.ted to the practical.*** on the modal.stress and impact anal.sis and the material.properties of the three considered al.oys,al.oy 7075-T6 has been recommended as the bl.de material.

关键词： axial fl.w compressor rotor and stator bl.des aircraft engine stress and impact anal.sis al.minum al.oys

Preparation and Characterization of Hydroxyapatite-Coated Sel.nium Nanoparticl.s and their Interaction with Osteosarcoma(SaOS-2) Cel.s

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Acta Metal.urgica Sinica(Engl.sh l.tters) 2014年第6期27卷 1152-1158页

作者： Thiagarajan Hemal.tha Gunasekaran Krithiga Baskar Santhosh Kumar Thotapal.i P. sastry Bioproducts l.boratory Central Leather Research Institute

Nanotechnol.gy has taken a firm step to revol.tionize the fiel. of orthopedic impl.nts. Current research on bone impl.nts focuses to devel.p impl.nts with mul.ifaceted functions viz., osteoinduction, chemoprevention, antimicrobial.action etc., especial.y for cancerous bone resection. The objective of the present study was to synthesize a novel.composite for bone impl.nts, possessing the above properties. Sel.nium was sel.cted owing to its chemopreventive and chemotherapeutic properties. Hydroxyapatite was sel.cted owing to its bioactivity and simil.rity in composition to bone mineral.properties. Sel.nium nanoparticl.s were prepared by chemical.reduction method and coated with ***-coated sel.nium nanoparticl.（HASnp） was characterized physico-chemical.y using fourier transform infrared spectroscopy, X-ray diffractometry, scanning el.ctron microscope, and energy-dispersive X-ray *** was anal.sed in vitro using SaOS-2 cel. l.ne. Enhanced cel. prol.feration and al.al.ne phosphatase activity were observed in HASnp-treated cel.s. The resul.s indicate that HASnp is highl. suitabl. for the use in orthopedic appl.cations.

关键词： Osteogenesis Biocompatibil.ty Bone tissue engineering Biomaterial. Biomedical.appl.cations

Effect of grain structure on the mechanical.properties of a Monel.al.oy fabricated by l.ser-based directed energy deposition

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Journal.of Material. Science & Technol.gy 2023年第33期164卷 129-139页

作者： Ze Chen Wei Fan Shubo Gao Yang Qi sastry Yagnanna Kandukuri Kun Zhou Singapore Centre for 3D Printing School of Mechanical and Aerospace EngineeringNanyang Technological University50 Nanyang AvenueSingapore 639798Singapore DNV AS HøvikOslo 1363Norway

Monel.K-500 is a Ni–Cu al.oy widel. used in the marine and offshore industry due to their superior resistance to corrosion in seawater and hence easil. *** address this probl.m,l.ser-based directed energy deposition(l.ED)is used to repair or refabricate these high-val.e worn *** optimize the mechanical.properties of repaired parts,the commonl. appl.ed sol.tion and aging is not ideal.because it al.o changes the properties of the base ***,in situ control.of the grain structures during the l.ED process becomes an effective approach for high-performance *** this study,we fabricated a dupl.x grain structure with smal. grain size and l.w texture intensity using l.w l.ser power and scanning *** dupl.x microstructure consists of short col.mnar grains and zigzag-distributed fine equiaxed *** formation of this grain structure is dependent on both the sol.dification and recrystal.ization *** strength of this grain structure is improved to 523.5 MPa without the sacrifice of ductil.ty,which is instead 20%higher than that of the counterpart consisting of typical.col.mnar grains due to the grain refinement and crack *** mechanical.properties of the al.oy with the dupl.x grain structure are even comparabl. to heat-treated Monel.K-500 fabricated by wire arc additive *** work provides val.abl. insights into the in situ optimization of the microstructure and mechanical.properties of l.ED-fabricated parts.

关键词： Additive manufacturing Directed energy deposition Monel.al.oy Grain structure Mechanical.properties

G-protein coupl.d receptors and synaptic pl.sticity in sl.ep deprivation

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Worl. Journal.of Psychiatry 2021年第11期11卷 954-980页

作者： Shweta Parmar Ramakrishna Tadavarty Bhagavatul. R sastry Department of Anesthesiol.gy Pharmacology and TherapeuticsThe University of British ColumbiaVancouver V6T 1Z3British ColumbiaCanada

Insufficient sl.ep has been correl.ted to many physiol.gical.and psychoneurol.gical.*** the years,our understanding of the state of sl.ep has transcended from an inactive period of rest to a more active state invol.ing important cel.ul.r and mol.cul.r *** addition,during sl.ep,el.ctrophysiol.gical.changes al.o occur in pathways in specific regions of the mammal.an central.nervous system(CNS).Activity mediated synaptic pl.sticity in the CNS can l.ad to l.ng-term and sometimes permanent strengthening and/or weakening synaptic strength affecting neuronal.network *** consol.dation and l.arning that take pl.ce during sl.ep cycl.s,can be affected by changes in synaptic pl.sticity during sl.ep disturbances.G-protein coupl.d receptors(GPCRs),with their versatil. structural.and functional.attributes,can regul.te synaptic pl.sticity in CNS and hence,may be potential.y affected in sl.ep deprived *** this review,we aim to discuss important functional.changes that can take pl.ce in the CNS during sl.ep and sl.ep deprivation and how changes in GPCRs can l.ad to potential.probl.ms with therapeutics with pharmacol.gical.interventions.

关键词： G-protein coupl.d receptors Metabotropic gl.tamate receptors Gammaamino butyric acid-B receptor Synaptic pl.sticity Sl.ep deprivation Memory consol.dation