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Genetic and morphological variation in natural teak(Tectona grandis) populations of the Western Ghats in Southern India

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Journal of Forestry Research 2014年第4期25卷 805-812页

作者： p.m.Sreekanth m.Balasundaran p.A.Nazeem Biotechnology and Applied Genetics Bangalore City College New Campus Kalyan Nagar Banaswadi Outer Ring Road Bangalore 560043 India Environmental Biotechnology Tropical Institute of Ecological Sciences Velloor P.O Kottayam – 686501 Kerala India Centre for plant Biotechnology and molecular Biology Kerala Agricultural University KAU Campus P.O Thrissur 680656 Kerala India

Teak （Tectona grandis L.f.） is a popular hardwood species native to South and South-East Asia. The possible association of ampli- fied fragment length polymorphism （AFLp） marker with morphological variables of eleven important characters viz. girth at breast height （GBH）, height of tree, bole height, branch knots, presence of fluting, spiral stem, leaf hair, leaf length/breadth ratio, branching pattern, bark colour and petiole shape for nine natural populations comprising 180 genotypes of teak （9 populations x 20 trees）. The phenogram constructed using Euclidean distances for the eleven morphological characters showed that the populations were not grouped according to their geographical origin. The mantel＇s test for pairwise correlation between Euclidean distances of different morphological variables and genetic distances from AFLp data revealed that only petiole character （r =0.269; p =0.046） and height of tree （r =0,200; p =0.001） were significantly correlated with that of AFLp data matrix. The nine populations in this study covered a geographic area of about 1000 km stretch along the Western Ghat of South India. A test of correlation between genetic and geographic distance matrices revealed a significant positive correlation （r =0.475; p =0.009）. The lack of perfect congruence between morphological and molecular data except for geo-graphic distance, tree height and petiole character suggested that the morphological system might be useful for the morphotypes management but not appropriate to study the genetic structure of the teak populations.

关键词： AFLp genetic teak morphology Tectona grandis

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An autoregressive integrated moving average model for short-term prediction of hepatitis C virus seropositivity among male volunteer blood donors in Karachi,pakistan

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World Journal of Gastroenterology 2009年第13期15卷 1607-1612页

作者： Saeed akhtar Shafquat Rozi Department of Community medicine and Behavioral Sciences Faculty of MedicineKuwait University Department of Community Health Sciences Medical CollegeAga Khan University

AIm： To identify the stochastic autoregressive integrated moving average （ARImA） model for short term forecasting of hepatitis C virus （HCV） seropositivity among volunteer blood donors in Karachi, pakistan.mETHODS： Ninety-six months （1998-2005） data on HCV seropositive cases （1000-1 x month1） among male volunteer blood donors tested at four major blood banks in Karachi, pakistan were subjected to ARImA modeling. Subsequently, a fitted ARImA model was used to forecast HCV seropositive donors for 91-96 mo to contrast with observed series of the same months. To assess the forecast accuracy, the mean absolute error rate （%） between the observed and predicted HCV seroprevalence was calculated. Finally, a fitted ARImA model was used for short-term forecasts beyond the observed series.RESULTS： The goodness-of-fit test of the optimum ARImA （2,1,7） model showed non-significant autocorrelations in the residuals of the model. The forecasts by ARImA for 91-96 mo closely followed the pattern of observed series for the same months, with mean monthly absolute forecast errors （%） over 6 mo of 6.5%. The short-term forecasts beyond the observed series adequately captured the pattern in the data and showed increasing tendency of HCV seropositivity with a mean ± SD HCV seroprevalence （1000^-1× month^-1） of 24.3 ±1.4 over the forecast interval.CONCLUSION： To curtail HCV spread, public health authorities need to educate communities and health care providers about HCV transmission routes based on known HCV epidemiology in pakistan and its neighboring countries. Future research may focus on factors associated with hyperendemic levels of HCV infection.

关键词： Hepatitis C virus Blood donor Ecologicalanalysis Autoregressive integrated moving averagemodel pakistan

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A new global raster water mask at 250 m resolution

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International Journal of Digital Earth 2009年第4期2卷 291-308页

作者： m.L.Carroll J.R.Townshend C.m.Dimiceli p.Noojipady R.A.Sohlberg Department of Geography University of MarylandCollege Park MDUSA

Accurate depiction of the land and water is critical for the production of land surface parameters from remote sensing data *** parameters,including the land surface temperature,active fires and surface reflectance,can be processed differently when the underlying surface is water as compared with *** errors in the underlying water mask can then pervade into these products and any products created from *** many global databases have been created to depict global surface *** databases still fall short of the current needs of the terrestrial remote sensing community working at 250 m spatial *** most recent attempt to address the problem uses the Shuttle Radar Topography mission(SRTm)data set to create the SRTm Water Body Data set(SWBD 2005).The SWBD represents a good first step but still requires additional work to expand the spatial coverage to include the whole globe and to address some erroneous discontinuities in major river *** address this issue a new water mask product has been created using the SWBD in combination with mODIS 250 m data to create a complete global map of surface water at 250 m spatial *** effort is automated and intended to produce a dataset for use in processing of raster data(mODIS and future instruments)and for masking out water in final terrestrial raster data *** new global dataset is produced from remotely sensed data and provided to the public in digital format,free of *** data set can be found on the Global Land Cover Facility(GLCF)website at http://*** dataset is expected to be a base set of information to describe the surface of Earth as either land or water which is a fundamental distinction upon which other descriptions can be made.

关键词： digital earth land cover remote sensing mODIS water

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Carbon capture for decarbonisation of energy-intensive industries:a comparative review of techno-economic feasibility of solid looping cycles

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Frontiers of Chemical Science and Engineering 2022年第9期16卷 1291-1317页

作者： mónica p.S.Santos Dawid p.Hanak Energy and power School of WaterEnergy and EnvironmentCranfield UniversityBedfordshire MK430ALUK

Carbon capture and storage will play a crucial role in industrial ***,the current literature presents a large variability in the techno-economic feasibility of CO_(2)capture ***,reliable pathways for carbon capture deployment in energyintensive industries are still *** work provides a comprehensive review of the state-of-the-art CO_(2)capture technologies for decarbonisation of the iron and steel,cement,petroleum refining,and pulp and paper *** scrubbing was shown to be the least feasible option,resulting in the average avoided CO_(2)cost of between 62.7∈t_(CO_(2))^(-1)for the pulp and paper and 104.6∈t_(CO_(2))^(-1)for the iron and steel *** average equivalent energy requirement varied between 2.7(iron and steel)and 5.1mJ_(th)·kg_(CO_(2))^(-1)(cement).Retrofits of emerging calcium looping were shown to improve the overall viability of CO_(2)capture for industrial *** looping was shown to result in the average avoided CO_(2)cost of between 32.7(iron and steel)and 42.9(cement).Its average equivalent energy requirement varied between 2.0(iron and steel)and 3.7(pulp and paper).Such performance demonstrated the superiority of calcium looping for industrial *** work should focus on standardising the techno-economic assessment of technologies for industrial decarbonisation.

关键词： industrial CO_(2)emissions CCS deployment carbonate looping net-zero industry carbon capture benchmarks

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prediction and analysis of process failures by ANN classification during wire-EDm of Inconel 718

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Advances in manufacturing 2020年第4期8卷 519-536页

作者： Abhilash p.m. Chakradhar D. Department of mechanical Engineering Indian Institute of Technology PalakkadPalakkadKeralaIndia

Wire breakages and spark absence are two typical machining failures that occur during wire electric discharge machining(wire-EDm),if appropriate parameter settings are not *** after several attempts to optimize the process,machining failures cannot be eliminated completely.A n offline classification model is presented herein to predict machining *** aim of the current study is to develop a multiclass classification model using an artificial neural network(ANN).The training dataset comprises 81 full factorial experiments with three levels of pulse-on time,pulse-off time,servo voltage,and wire feed rate as input *** classes are labeled as normal machining,spark absence,and wire *** model accuracy is tested by conducting 20 confirmation experiments,and the model is discovered to be 95%accurate in classifying the machining *** effects of process parameters on the process failures are discussed and analyzed.A microstructural analysis of the machined surface and worn wire surface is *** developed model proved to be an easy and fast solution for verifying and eliminating process failures.

关键词： Wire electric discharge machining(wire-EDm) process failure Spark absence Wire breakage Artificial neural network(ANN)classification Failure prediction

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Development of gas tungsten arc welding using current pulsing technique to preclude chromium carbide precipitation in aerospace-grade alloy 80A

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International Journal of minerals,metallurgy and materials 2019年第2期26卷 210-221页

作者： p.Subramani m.manikandan School of mechanical Engineering Vellore Institute of Technology

Weldments were produced using gas tungsten arc welding(GTAW) and pulsed current gas tungsten arc welding(pCGTAW) techniques with ERNiCr-3 filler wire. macro examination revealed that the resultant weldments were free from defects. A refined microstructure was observed in the weldment fabricated through pCGTAW. Scanning electron microscopy(SEm) analysis revealed secondary phases in the grain boundaries. Energy-dispersive X-ray spectroscopy(EDS) analysis revealed that microsegregation of Cr carbide precipitates was completely eradicated through pCGTAW. The microsegregation of Nb precipitates was observed in the GTA and pCGTA weldments. X-ray diffraction(XRD) analysis revealed the existence of m_(23)C?_6 Cr-rich carbide and Ni_8Nb phases in the GTA weldments. By contrast, in the pCGTA weldments, the Ni_8Nb phase was observed. The Cr_2Ti phase was observed in both the GTA and the pCGTA weldments. Tensile tests showed that the strength and ductility of the pCGTA weldments were slightly higher than those of the GTA weldments.

关键词： Ni-based superalloy welding pulse current microsegregation chromium carbide

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Stochastic asymptotical synchronization of chaotic markovian jumping fuzzy cellular neural networks with mixed delays and the Wiener process based on sampled-data control

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Chinese physics B 2013年第7期22卷 564-573页

作者： m. Kalpana p. Balasubramaniam Department of mathematics Gandhigram Rural InstituteDeemed University

We investigate the stochastic asymptotical synchronization of chaotic markovian jumping fuzzy cellular neural networks （mJFCNNs） with discrete, unbounded distributed delays, and the Wiener process based on sampled-data control using the linear matrix inequality （LmI） approach. The Lyapunov–Krasovskii functional combined with the input delay approach as well as the free-weighting matrix approach is employed to derive several sufficient criteria in terms of LmIs to ensure that the delayed mJFCNNs with the Wiener process is stochastic asymptotical synchronous. Restrictions （e.g., time derivative is smaller than one） are removed to obtain a proposed sampled-data controller. Finally, a numerical example is provided to demonstrate the reliability of the derived results.

关键词： stochastic asymptotical synchronization fuzzy cellular neural networks chaotic markovian jumping parameters sampled-data control

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Review on the effect of different processing techniques on the microstructure and mechanical behaviour of AZ31 magnesium alloy

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Journal of magnesium and Alloys 2021年第5期9卷 1709-1732页

作者： Rakshith m. Seenuvasaperumal p. School of mechanical Engineering Vellore Institute of TechnologyVellore632014India

magnesium(mg)alloys despite being the ideal candidate for structural applications,owing to their high specific strength and low density,are not widely used due to lack of active slip systems at room temperature in their hexagonal close-packed crystal structure,eliciting poor ductility and *** the various series of mg alloys,the AZ and ZK series alloys have been standouts,as they inherit better room temperature strength and flow characteristics through their solute *** refinement,as well as eliminating casting defects through metal processing techniques are vital for the commercial viability of these alloys since they play a key role in controlling the mechanical *** such,this review highlights the effect of different Bulk-deformation and Severe plastic Deformation techniques on the crystal orientation and the corresponding mechanical behaviours of the AZ31 ***,every process parameter surrounding these techniques must be well thought of,as they require specially designed *** the advent of finite element analysis,these processes could be computationally realized for different parameters and optimized in an economically viable ***,this article also covers the developments made in finite element methods towards these techniques.

关键词： AZ31 magnesium alloy Severe plastic deformation process Rolling Extrusion Finite element simulation

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Effects of heat treatment on the properties of powder injection molded AlN ceramics

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Rare metals 2008年第1期27卷 70-73页

作者： DU Xueli QIN mingli akhtar Farid FENG peizhong QU Xuanhui Institute of powder metallurgy University of Science and Technology Beijing Beijing 100083 China School of materials Science andEngineering Tianjin University of Technology Tianjin 300191 China

The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride（AlN） ceramics were *** AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis（SHS） and compacts were fabricated by employing powder injection molding *** polymer-wax binder consisted of 60 wt.% paraffin wax（pW）,35 wt.% polypropylene（pp）,and 5 wt.% stearic acid（SA）.After the removal of binder,specimens were sintered at 1850°С in nitrogen atmosphere under atmospheric *** improve the thermal conductivity,sintered samples were *** result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN *** thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m^-1·K^-1 and 3.28 g·cm^-3 and the secondary phase is yttrium *** the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W·m^-1·K^-1 and 3.23 g·cm^-3,respectively,and the secondary phase is YN.

关键词： powder injection molding AIN ceramics heat treatment thermal conductivity

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mechanical characterization of the role of defects in sintered FeCrAIY foams

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Acta mechanica Sinica 2007年第4期23卷 383-398页

作者： m.Kepets A.p.Dowling Engineering Department Cambridge UniversityCambridge CB2 1PZUK

Open celled metal foams fabricated through metal sintering are a new class of material that offers novel mechanical and acoustic properties. previously, polymer foams have been widely used as a means of absorbing acoustic energy. However, the structural applications of these foams are limited. The metal sintering approach offers a costeffective means for the mass-production of open-cell foams from a range of materials, including high-temperature steel alloys. In this first part of two-paper series, the mechanical properties of open-celled steel alloy （FeCrA1Y） foams were characterized under uniaxial compression and shear loading. Compared to predictions from established models, a significant knockdown in material properties was observed. This knockdown was attributed to the presence of defects throu- ghout the microstructure that result from the unique fabrication process. Further in situ tests were carried out in a SEm （scanning electronic microscope） in order to investigate the effects of defects on the properties of the foams. Typically, the onset of plastic yielding was observed to occur at defect locations within the microstructure. At lower relative densities, ligament bending dominates, with the deformation initializing at defects. At higher relative densities, an additional deformation mechanism associated with membrane elements was observed. In the follow-up of this paper, a finite element model will be constructed to quantify the effects of defects on the mechanical performance of the opencell foam.

关键词： metal foam Defect mechanical characterization SEm

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