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Investigations on luminescence of rare earths doped CaTiO_3:Pr^(3+) phosphor

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Journal of Rare Earths 2010年第4期28卷 488-492页

作者： N. suriyamurthy b.s. Panigrahi Radiological safety Division Technical services Division Indira Gandhi Centre for Atomic Research Kalpakkam-603 102 India

Calcium titanate doped with praseodymium was prepared through solid state reaction and it exhibited intense red emission at 612 nm. Phosphors were characterized for photoluminescence, thermo-luminescence and afterglow emissions. study of effects of rare earths on photoluminescence as well as afterglow intensity was reported. Presence of gadolinium enhanced luminescence. Presence of some monovalent ions enhanced both afterglow and photoluminescence emission. Thermo-luminescence glow curves were analyzed and ...

关键词： perovskites calcium titanates red afterglow rare earths

Utilization of low quality water of mountain reservoirs: a case study from Al Jabal Al Akhdar, Oman

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Journal of Mountain science 2016年第8期13卷 1423-1430页

作者： Mushtaque AHMED Reginald VICTOR Mohammed JAsHOUL b.s. CHOUDRI Department of soils Water and Agricultural Engineering College of Agricultural and Marine SciencesSultan Qaboos University Department of biology College of ScienceSultan Qaboos University salalah Free Zone Sultanate of Oman Center for Environmental studies and Research Sultan Qaboos University

Al Jabal al Akhdar(Green Mountain) in arid northern Oman has freshwater resources that had supported small communities for hundreds of years. Jabal Akhdar receives more rainfall(300-400 mm) when compared to the desert plains. In the last few years, this region had undergone enormous changes due to rapid development. The resident and transient populations have increased and their activities exert severe stress on the water resources. There are 24 retention reservoirs in the area, but most are eutrophic and the nutrient loading is due to input of animal fecal matter via surface run-off. As expected, these waters contaminated with coliform bacteria and some have pathogenic Escherichia coli. Drinking water needs of all the villages met by groundwater extraction. because of poor quality, the surface water in the reservoirs is under-utilized. A low-cost lowmaintenance treatment system designed, constructed and operated in one village to clean the reservoir water for non-drinking human use. The treatment unit improved the water quality parameters. A survey among the adult male population of the village showed their eagerness to adopt this system and use the treated reservoir water for uses other than agriculture. Establishment of these treatment units in other villages should reduce the pressures on groundwater extraction.

关键词： Jabal Akhdar Oman Reservoir Eutrophication Treatment society

A MODIFIED PROJECTION AND CONTRACTION METHOD FOR A CLAss OF LINEAR COMPLEMENTARITY PRObLEMs

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Journal of Computational Mathematics 1996年第1期14卷 54-63页

作者： b.s. He(Department of Mathematics, Nanjing University, Nanjing, China) NANJING UNIV DEPT MATHNANJING 210008PEOPLES R CHINA

Recently, we have proposed an iterative projection and contraction (PC) method for a class of linear complementarity problems (LCP)([4]). The method was showed to be globally convergent, but no statement could be made about the rate of convergence. In this paper, we develop a modified globally linearly convergent PC method for linear complementarity problems. both the method and the convergence proofs are very simple. The method can also be used to solve some linear variational inequalities. several computational experiments are presented to indicate that the method is surprising good for solving some known difficult problems.

关键词： Th Pn A MODIFIED PROJECTION AND CONTRACTION METHOD FOR A CLAss OF LINEAR COMPLEMENTARITY PRObLEMs II

surface radioactive anomalies at srisailam sub b.s.n,Cuddapah b.s.n,India

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Chinese Journal Of Geochemistry 2015年第2期34卷 265-271页

作者： Vishnu bhoopathi s.Niranjan Kumar R.s.N.sastry b.s.inivas Department of Applied Geochemistry Osmania University Atomic Mineral Directorate for Exploration and Research

surface radioactive survey has been carried with portable gamma ray spectrometer(PGRs) about the 45 km2 around the srisailam sub b.s.n,the surface radioactive anomalies were found at Chennakesavula gutta in the srisailam sub b.s.n of Cuddapah b.s.n in the age of meso-neo proterozoic,*** integrated geochemical and radiometric surveys were conducted as part of research work in the srisailam b.s.n,it has resulted the locating of surface radioactive anomalies near the Chennakesavula *** uranium minerals are observed along with the fracture planes in the Archean b.s.ment granite in the proximity of unconformity contact of srisailam *** granite underlies the srisailam formation and forms the source for possible unconformity related uranium mineralisation in the srisailam sub-b.s.n evidence by the significant radioactive *** radioactivity recorded by PGRs reflected uraniferous nature of the radioactivity(Average total counts =195 ppm;U = 202 ppm;Th =22ppm;%K = 4.1,n = 15).

关键词：放射性异常表面印度分盆 γ射线谱仪放射性调查 m盆地地球化学

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） analysis ofa morphing airfoil with auxetic structure. The developed 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 b.s.d design is adopted, where the design loads are extracted from the aerodynamic loads. The aerodynamic loads acting on a wing structure are converted to equivalent distributed loads, which are further converted point loads to arrive at the shear forces, bending and twisting moments along the wing span. b.s.d on the estimated shear forces, bending and twisting moments, the strength b.s.d design is employed to estimate the sizes of various sections of a composite wing structure. A three dimensional numerical model of the composite wing structure has been developed and analyzed for the extreme load conditions. Glass fiber reinforced plastic material is used in the numerical analysis. The estimated natural frequencies are observed to be in the acceptable limits. Furthermore, the discussed design principles 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） larger displacement with limited straining of the components and （ii） unique deformation characteristics, which produce a theoretical in-plane Poisson＇s ratio of -1. Aluminum Alloy AL6061-T651 is considered in the design of all the structural elements. The compliance characteristics of the airfoil are investigated through a numerical model. The numerical results are observed to be in close agreement with the experimental results in the literature.

关键词： wing design aerodynamic loads morphing airfoil auxetic structures negative Poisson's ratio

Impact analysis of compressor rotor blades 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.s.DHIR sastry b G KIROs F HAILU 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 failures due to foreign particle impacts are observed in compressor blades of the interceptor fighter MIG-23 aircraft engines in the Ethiopian air force,supplied by the Dejen Aviation *** this paper,we made an attempt to identify the causes of failure and hence recommend the suitable materials to withstand the foreign particle *** and stress analysis of one of the recently failed MIG-23 gas turbine compressor blades made up of the following Aluminum b.s.d alloys:6061-T6,7075-T6,and 2024-T4,has been performed,apart from the impact analysis of the rotor blades hit by a granite *** numerical results are correlated to the practical *** on the modal,stress and impact analysis and the material properties of the three considered alloys,alloy 7075-T6 has been recommended as the blade material.

关键词： axial flow compressor rotor and stator blades aircraft engine stress and impact analysis aluminum alloys

sIMULATION OF LARGE TURbINE ROTOR's HEAT TREATMENT PROCEss

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Acta Metallurgica sinica(English Letters) 2005年第6期18卷 768-772页

作者： C. Jiang Y.b. Chen b.s. Wu Q.L. Jin beijing Research Institute of Mechanical and Electrical Technology Beijing 100083 China

Temperature field numerical simulation about he heat treatment process curve of large turbine rotor is presented. With simulation software Deform3D in according to the heat treatment processing of China First Heavy Machinery, the details of temperature change at the different location of the rotor is to be found. Once knowing the temperature field change, the duplex grain defect long time existed in large forgings can be solved with a quantitative analysis instead of only the qualitative one. Precondition for small metal samples is brought to simulate microstructare and grain size change of large rotor according to the numerical simulation result. Also, consistent feature with real manufacture is showed from the physical experiment, so that the simulation can be used to not only improve the products process but also prevent wasting unnecessary energy and shorten process periods. The rotor quality is controlled thoroughly with plenty of experiments data.

关键词： temperature field numerical simulation grain size

MICROsTRUCTURAL CHARACTERIsTICs AssOCIATED WITH HIGH- sTRAIN-RATE PLAsTIC DEFORMATION IN THE ELECTROFORMED COPPER LINER OF sHAPED CHARGEs

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Acta Metallurgica sinica(English Letters) 2005年第5期18卷 620-626页

作者： A.L. Fan W.H. Tian Q. suns b.s. Wang Department of Materials Physics and Chemistry University of Science and Technology Beijing Beijing 100083 China Taiyuan University of science and Technology Taiyuan 030024 China 210 Institute The Chinese Ordnance Industry Institute Beijing 100081 China

The microstructures of electroformed copper liners of shaped charges that had undergone high-strain-rate deformation were observed by optical microscopy （OM） and scanning electron microscopy （sEM）. Meanwhile, the orientation distribution of the grains in the recovered jet was examined by electron backscattering Kikuchi pattern （EbsP） technique. EbsP analysis reveals that the fibrous texture observed in the as-electroformed copper liners disappeared after explosive detonation deformation. OM observation shows that the microstructure evolves system- atically from the jet center to its perimeter during cooling from high temperatures after explosive detonation deformation. This microstructural characteristic is similar to that of solidification, i.e. there exist equiaxed grains in the center of the jet and significant columnar grains around the equiaxed grains. The result reveals that there is melting-related phenomenon in the jet center. Corresponding microhardness variations from the jet center to its perimeter is also determined. All the phenomena can be explained by a strong gradient of temperature across the section of the jet during plastic deformation at high-strain-rate.

关键词： jetting electroformation microstructure hardness,ultra-high strain rate deformation

Influence of Nano-Materials on Mechanical and Permeation Characteristics of High strength Concrete

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Journal of Wuhan University of Technology(Materials science) 2022年第3期37卷 416-422页

作者： K V s Gopala Krishna sastry M srinivasula Reddy A Ravitheja Civil Engineering G Pulla Reddy Engineering CollegeKurnoolAPIndia sVR Engineering College NandyalAndhra PradeshIndia

Efforts have been made to evaluate the influences of the addition of nanoparticles on the strength,durability and mineralogical changes of high strength concrete(HsC).Therefore,mixes were prepared for conventional concrete mix(CCM)of M80 ***,various mixes were prepared by replacing cementitious materials initially 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 *** developed concretes were then evaluated for mechanical properties,permeation characteristics,and mineralogical *** the studies,it is found that the concrete at 2%NCs possesses superior mechanical and superior permeation characteristics of all the mixes.A clear variation in the mineralogical structure with the addition of nanoparticles has been observed.

关键词： high strength concrete nano silicon dioxide nano calcium carbonate mechanical properties permeation properties