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Journal of Minerals and Materials Characterization and Engineering 2012年第8期11卷 790-799页

作者： Kondapalli Siva prasad Chalamalasetti Srinivasa rao Damera Nageswara rao Centurion University of Technology & Management Odissa INDIA Department of Mechanical Engineering Andhra University Visakhapatnam INDIA Department of Mechanical Engineering Anil Neerukonda Institute of Technology & Sciences Visakhapatnam INDIA

Pulsed current Micro Plasma Arc Welding is used to joint thin sheets of AISI 304L sheets, which are used in manufacturing of metallic bellows and diaphragms. In this article the effects of pulsing current parameters on weld pool geometry namely front width, back width, front height and back height of pulsed current micro plasma arc welded AISI 304L stainless steel sheets was analyzed. Four factors, five levels, central composite design was used to develop mathematical models, incorporating pulsed current parameters and weld pool geometry. The mathematical models have been developed by response Surface Method. The adequacy of the models was checked by ANOVA technique. Variation of output responses with input process variables are discussed. By using the developed mathematical models, weld pool geometry parameters can be predicted.

关键词： Pulsed Current Micro Plasma Arc Welding Mathematical Model Aisi 304l Stainless Steel Weld Pool Geometry ANOVA

Hot forging of Mg-4Al-2Ba-2Ca(ABa X422) alloy and validation of processing map

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Transactions of Nonferrous Metals Society of China 2018年第8期28卷 1495-1503页

作者： K.SUrESH K.P.rao Y.V.r.K.prasad N.HOrT H.DIErINGA Department of mechanical and Biomedical Engineering City Uiliversity of Hong Kong Tat Chee Avenue Kowloon Hoilg Koilg China *** No. 2/B vinayaka Nagar Hebbal Bengalum 560024 India Helmholtz-zentrum Geesthacht institute of Materials ResearchMagnesium innovation Centre Max-Planck-StraBe 1 Geesthacht 21502 Germany

A cup-shaped component of Mg-4 Al-2 Ba-2 Ca（ABa X422） alloy was forged in the temperature range of 300-500 °C and at speeds in the range of 0.01-10 mm/s with a view to validate the processing map and study the microstructural development. The process was simulated through finite-element method to estimate the local and average strain rate ranges in the forging envelope. The processing map exhibited two domains in the following ranges：（1） 300-390 °C and 0.0003-0.001 s^-1, and（2） 400-500 °C and 0.0003-0.3 s^-1 and both represented dynamic recrystallization（DrX）. The map revealed a wide flow instability regime at higher strain rates and temperatures lower than 400 °C, in which flow localization occurred. Forgings produced under conditions of the above two domains were sound and symmetrical, and had finer grain sizes when being forged in the first domain. However, when being forged in the flow instability regimes, the alloy fractured before the final shape was reached. The experimental load-stroke curves for the conditions within the domains correlated well with the simulated ones, whereas the curves obtained in the instability regime were uneven.

关键词： magnesium alloy, processing map hot forging dynamic recrystallization

Microstructure and mechanical properties of as-cast Mg-Sn-Ca alloys and effect of alloying elements

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Transactions of Nonferrous Metals Society of China 2013年第12期23卷 3604-3610页

作者： K.SUrESH K.P.rao Y.V.r.K.prasad N.HOrT K.U.KAINEr Department of Mechanical and Biomedical Engineering City University of Hong Kong Consultant *** No. 2/B Vinayaka Nagar Helmholtz-Zentrum Geesthacht Institute of Materials Research Magnesium Innovation Centre

The effect of Sn, Ca, Al, Si and Zn addition on the compressive strength of cast Mg-Sn-Ca （TX） alloys was studied in the temperature range of 25-250 °C and correlated with the microstructure. The Sn to Ca mass ratio up to 2.5 contributes to the formation of Mg2Ca phase at the grain boundaries and CaMgSn in the matrix, while a ratio of 3 gives only CaMgSn phase mostly in the matrix. While the compressive strength decreases with the increase in temperature, for Sn/Ca up to 2.5, a plateau occurs in 100-175 °C, which is attributed to the strengthening by Mg2Ca. However, for ratio of 3, the strength is lower and decreases more gradually. Mg-3Sn-2Ca （TX32） has the highest strength and the addition of 0.4%Al increases its strength but simultaneous addition of Si lowers the strength. Likewise, the addition of Zn improves its strength but simultaneous addition of Al slightly decreases the strength. The results are correlated with the types of intermetallic phases that form in various alloys.

关键词： Sn/Ca ratio Mg-Sn-Ca alloys alloying additions microstructure compressive strength

Spectral matching techniques (SMTs) and automated cropland classification algorithms (ACCAs) for mapping croplands of Australia using MODIS 250-m time-series (2000–2015) data

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International Journal of Digital Earth 2017年第9期10卷 944-977页

作者： Pardhasaradhi Teluguntla prasad S.Thenkabail Jun Xiong Murali Krishna Gumma russell G.Congalton Adam Oliphant Justin Poehnelt Kamini Yadav Mahesh rao richard Massey U.S.Geological Survey(USGS) Western Geographic Science CenterFlagstaffAZUSA Bay Area Environmental research Institute(BAErI) PetalumaCAUSA International Crops research Institute for the Semi-Arid Tropics(ICrISAT) PatancheruHyderabadIndia Department of Natural resources and the Environment University of New HampshireDurhamNHUSA Department of Forestry and Wildland resources Humboldt State UniversityArcataCAUSA School of Earth Science and Environmental Sustainability Northern Arizona UniversityFlagstaffAZUSA

Mapping croplands,including fallow areas,are an important measure to determine the quantity of food that is produced,where they are produced,and when they are produced(***).Furthermore,croplands are known as water guzzlers by consuming anywhere between 70%and 90%of all human water use *** these facts and the increase in global population to nearly 10 billion by the year 2050,the need for routine,rapid,and automated cropland mapping year-after-year and/or season-after-season is of great *** overarching goal of this study was to generate standard and routine cropland products,year-after-year,over very large areas through the use of two novel methods:(a)quantitative spectral matching techniques(QSMTs)applied at continental level and(b)rule-based Automated Cropland Classification Algorithm(ACCA)with the ability to hind-cast,now-cast,and *** was chosen for the study given its extensive croplands,rich history of agriculture,and yet nonexistent routine yearly generated cropland products using multi-temporal remote *** research produced three distinct cropland products using Moderate resolution Imaging Spectroradiometer(MODIS)250-m normalized difference vegetation index 16-day composite time-series data for 16 years:2000 through *** products consisted of:(1)cropland extent/areas versus cropland fallow areas,(2)irrigated versus rainfed croplands,and(3)cropping intensities:single,double,and continuous *** accurate reference cropland product(rCP)for the year 2014(rCP2014)produced using QSMT was used as a knowledge base to train and develop the ACCA algorithm that was then applied to the MODIS time-series data for the years 2000–2015.A comparison between the ACCA-derived cropland products(ACPs)for the year 2014(ACP2014)versus rCP2014 provided an overall agreement of 89.4%(kappa=0.814)with six classes:(a)producer’s accuracies varying between 72%and 90%and(b)user’s accuracies varying between 79%and 90%.ACPs

关键词： Croplands food security automated cropland classification algorithms machine learning algorithms quantitative spectral matching techniques Australia

Physiological and biochemical characteristics associated with leaf retention in mulberry (<i>Morus</i>spp.)

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Open Journal of Genetics 2011年第3期1卷 27-33页

作者： Subramaniam Gandhi Doss shyama prasad Chakraborti Soumen Chattopadhyay Nirvan Kumar Das Partha Dev Ghosh Kunjupillai Vijayan 不详

Mulberry leaf production plays a key role in the sustainability of silk industry as the silkworm Bom-byx mori can not survive on any other leaf. In fact, silkworm merely acts as an instrument to convert mulberry leaf proteins into the silk proteins. In India, West Bengal is the second highest silk producing state but with varied climatic conditions and suffers to a great extent from non-availability of adequate quantity of quality leaf during the colder months. Delayed sprouting, slow growth rate and higher leaf fall are the major factors contributing this leaf scarcity. To overcome these problems, nine mulberry genotypes, developed through systematic breeding, were tested against the current popular variety for 3 consecutive years taking into account of their performance during the colder months. Annual leaf yield was highest in CT-44 (48 mt/ha/ year) followed by CT-11 (44 mt/ha/year). Leaf senescence was least in CT-44 (9.8%) followed by CT-11 (16.8%) while the check variety showed 20% leaf senescence. Significantly higher values were observed for net photosynthetic rate (Pn) (14.83 μ mol. m-2·s-1);physiological water use efficiency (pWUE) (1.16 8 mol CO2, mol–1 H2O);total soluble protein (TSP) (27.87 mg·g–1·fw);total soluble sugar (TSS) (39.74 mg·g–1 fw);nitrate reductase activity (NrA) (17.78 8 mol. NO2·g–1·fw·h–1) in CT-44. Correlations of these physiological and biochemical characters with leaf yield and leaf senescence (%) revealed highly significant positive correlations of leaf yield with Pn (0.536), TSP (0.674), NrA (0.610), pWUE (0.433), LAI (0.776) and negative correlations with leaf senescence (–0.239). TSS (0.292) and TSP (0.780) had positive association with NrA. Leaf senescence (%) had significant negative association with Pn (–0.755), TSP (–0.462), NrA (–0.438) and pWUE (–0.359). Path coefficient analysis revealed the direct effect of Pn (0.218), TSP (0.449) and LAI (0.730) on leaf yield. The study, therefore, indicated the possibility of using Pn,

关键词： Cold Tolerance Leaf Senescence Mulberry Photosynthetic rate LAI

Effect of ramp-cavity on hydrogen fueled scramjet combustor

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Propulsion and Power research 2014年第1期3卷 22-28页

作者： J.V.S.Moorthy B.rajinikanth B.V.N.Charyulu G.Amba prasad rao Scientist Defence Research and Development LaboratoryHyderabadAndhra Pradesh 500058India Professor in Mechanical Engineering National Institute of TechnologyWarangalAndhra Pradesh 506004India

Sustained combustion and optimization of combustor are the two challenges being faced by combustion scientists working in the area of supersonic *** mixing,lower stagnation pressure losses,positive thrust and sustained combustion are the key issues in the field of supersonic *** fluid mechanism is required to achieve good *** induce such mechanisms in supersonic inflows,the fuel injectors should be critically shaped incurring less flow *** investigations are focused on the effect of fuel injection scheme on a model scramjet combustor *** at supersonic flow generate axial vortices that help in macro-mixing of fuel with *** of shocks generated by ramps with the fuel stream generates boro-clinic torque at the air&liquid fuel interface,enhancing *** zones present in cavities increase the residence time of the combustible *** use of the advantageous features of both,a ramp-cavity combustor is *** combustor has two ***,constant height section consists of a backward facing step followed by ramps and cavities on both the top and bottom *** ramps are located alternately on top and bottom *** complete combustor width is utilized for the *** second section of the combustor is diverging area *** is provided to avoid thermal *** the present work gaseous hydrogen is considered as *** study was mainly focused on the mixing different fuel injection *** was found that injecting fuel upstream of the ramp was beneficial from fuel spread point of view.

关键词： Supersonic combustion Combustion instabilities ramps Cavities Mixing

Flux blended synthesis of novel Y2O3：Eu^3＋ sensing arrays for highly sensitive dual mode detection of LFPs on versatile surfaces

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Journal of rare Earths 2018年第9期36卷 954-964页

作者： K.N. Venkatachalaiah H. Nagabhushana r.B. Basavaj G.r Darshan B. Daruka prasad S.C. Sharma Department of Physics Amrito School of Engineering Amrito Vishwa Vidyapeethom Amrita University Bengoluru 560035 India research and Development Center Bharathiar University Coimbatore 641046 India Prof. C.N.r. rao Centre for Advanced Material Science Tumakuru University Tumakuru 572103 India Department of Physics Acharya Institute of Graduate Studies Bangalore 560107 India Department of Physics B.M.S. Institute of Technology and Management Visveswaraya Technological University affiliated Bangalore 560064 India Honorary Professor Department of Mechanical Engineering Jain University Advisor Jain Croup of Institutions Bangalore 560069 India

In the present communication,various fluxes blended Y2 O3：Eu3＋（5 mol%） nanopowders（NPs） were successfully fabricated by solution combustion *** pattern confirms body-centered cubic structure of the prepared *** band gap（Eg） of the fabricated products was estimated and is found to be in the range of 3.13-3.32 ***（PL） emission spectra exhibit sharp and intense peaks at ～579,592,614,657,704 nm corresponding to 5 D0→7 FJ（J = 0,1,2,3 and 4） transitions of Eu3＋ *** of fluxes for enhancing the PL emissions was extensively *** studies of the prepared samples are located in pure red *** NPs were explored as a novel sensing agent for visualization of latent fingerprints（LFPs） on various surfaces including porous,semiporous and non-porous surfaces followed by powder dusting *** experiments including aging,temperature,scratching and aquatic fresh water treatment tests were performed to evaluate applicability of the fabricated *** LFPs exhibit well defined ridge details including most authenticated sweat pores are also revealed with high sensitivity,selectivity,little background hindrance and less *** results evidence that the method and fabricated NPs can be considered to be simple,rapid and economical and provide novel sensing platform for LFPs visualization in prospective forensic applications.

关键词： Fluxes Photoluminescence Latent fingerprint Sweat pores Forensic applications rare earths

Study on Weld Quality Characteristics of Pulsed Current Micro Plasma Arc Welding of Inconel625 Sheets

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Journal of Minerals and Materials Characterization and Engineering 2012年第2期11卷 133-141页

作者： K. Siva prasad Ch.Srinivasa rao D.Nageswara rao Department of Mechanical Engineering Andhra University Visakhapatnam INDIA Department of Mechanical Engineering Anil Neerukonda Institute of Technology & Sciences Visakhapatnam INDIA Vice Chancellor Centurion University Orissa INDIA

Nickel alloys had gathered wide acceptance in the fabrication of components which require high temperature resistance and corrosion resistance, such as metallic bellows used in expansion joints used in aircraft, aerospace and petroleum industry. In the present paper an attempt is made to study various weld quality characteristics like weld bead geometry dimensions, micro hardness, microstructure, grain size and tensile properties of Pulsed Current Micro Plasma Welding of Inconel625sheets. Weld joint was prepared by fusing the two parent metals of Inconel625 sheets. Square butt joint is used and welding was carried out using Pulsed DCEN, without filler wire. Peak current, back current, pulse and pulse width are considered as the main influential input variables during the welding.

关键词： pulsed current micro plasma arc welding Inconel625 weld bead geometry hardness microstructure grain size.

Prediction of Weld Bead Geometry in Plasma Arc Welding using Factorial Design Approach

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Journal of Minerals and Materials Characterization and Engineering 2011年第10期10卷 875-886页

作者： K. Siva prasad Ch.Srinivasa rao D.Nageswara rao Department of Mechanical Engineering Andhra University Visakhapatnam India Department of Mechanical Engineering Anil Neeerukonda Institute of Technology & Sciences Visakhapatnam India.

The effect of various process parameters like welding current, torch height, welding speed and plasma gas flow rate on front melting width, back melting width and weld reinforcement of plasma arc welding on aluminum alloy is investigated by using factorial design approach. Variable polarity plasma arc welding is used for welding aluminum alloy. Trail experiments are conducted and the limits of the input process parameters are decided. Two levels and four input process parameters are chosen and experiments are conducted as per typical design matrix considering full factorial design. Total sixteen experiments are conducted and output responses are measured. The coefficients are calculated by using regression analysis and the mathematical models are constructed. By using the mathematical models the main and interaction effect of various process parameters on weld quality is studied.

关键词： Plasma Arc Welding Factorial Design regression Analysis Welding current Welding speed Torch height Plasma gas flow rate Front Melting Width Back MeltingWidth Weld reinforcement.

rapid visualization of latent fingerprints using novel CaSiO_3:Sm^(3+) nanophosphors fabricated via ultrasound route

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Journal of rare Earths 2019年第1期37卷 32-44,M0003页

作者： r.B.Basavaraj G.P.Darshan B.Daruka prasad S.C.Sharma H.Nagabhushana Prof.C.N.r.rao Centre for Advanced Materials Tumkur University Department of Physics Acharya Institute of Graduate Studies Department of Physics B M S Institute of Technology and ManagementVTU Affiliated Department of Mechanical Engineering Jain UniversityAdvisor Jain Group of Institutions

Latent fingerprints (LFPs) were the most significant identification method for individualization. Most commonly available fingerprints (FPs) in crime spot investigation were latent and patent types. Generally,LFPs were invisible and thus the effective visualization technique necessitates for the analysis of such FPs. In the past years, many traditional visualization techniques have been employed, but suffered with low resolution, sensitivity, contrast and high background noise. To overcome such limitations, we synthesized Sm^(3+) doped CaSiO_3 nanophosphors (NPs) via an ultrasound irradiation route using mimosa pudica (m. p.)leaves extract as a bio-surfactant. The morphological behavior of the prepared samples was extensively studied by varying the concentration of the m. p. extract, ultrasound irradiation duration, pH level of the precursor solution and sonication power. The photoluminescence (PL) emission spectra exhibit characteristic peaks at～561,601 and 647 nm, which were attributed to^5G_(5/2)→~6H_J(J=5/2,7/2 and 9/2) transitions of Sm^(3+) *** Judd-Ofelt(J-O) intensity parameters and other radiative properties were estimated using PL data. The Commission International de I'Eclairage (CIE) color coordinates were positioned in orange-red region shows average correlated color temperature (CCT) value of～3576 K. The optimized samples can be used as a labeling agent for the visualization of LFPs on various porous and non-porous surfaces under normal light irradiation. The visualized FPs reveals well defined ridge characteristics, namely whorl, loop,arch, bifurcation, eye, island, bridge, sweat pores, etc, with high sensitivity, selectivity, low contrast and background hindrance. Aforementioned results evidence that the prepared CaSiO_3:Sm^(3+) NPs were promising luminescent materials for solid state lighting and forensic applications.

关键词： Ultrasonication,synthesis Photoluminescence Fingerprint Photometric properties Judd-Ofelt analysis rare earths