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Laser-Heated Diamond-Anvil Cell (LHDAC) in Materials Science Research 被引量:1
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作者 N.V.Chandra Shekar P.Ch.Sahu K.Govinda Rajan 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第6期518-525,共8页
Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperatur... Laser-heated diamond-anvil cell (LHDAC) is emerging as the most suitable, economical and versatile tool for the measurement of a large spectrum of physical properties of materials under extreme pressure and temperature conditions. In this review, the recent developments in the instrumentation, pressure and temperature measurement techniques, results of experimental investigations from the literature were discussed. Also, the future scope of the technique in various avenues of science was explored. 展开更多
关键词 Laser heating Diamond-anvil cell High pressure-high temperature Materials synthesis Melting phenomena Phase equilibria
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Hybrid Intelligent Modeling for Optimizing Welding Process Parameters for Reduced Activation Ferritic-Martensitic (RAFM) Steel 被引量:2
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作者 Chandrasekhar Neelamegam Vishnuvardhan Sapineni +1 位作者 Vasudevan Muthukumaran Jayakumar Tamanna 《Journal of Intelligent Learning Systems and Applications》 2013年第1期39-47,共9页
Reduced-activated ferritic-martensitic steels are being considered for use in fusion energy reactor and subsequent fusion power reactor applications. Typically, those reduced activated steels can loose their radioacti... Reduced-activated ferritic-martensitic steels are being considered for use in fusion energy reactor and subsequent fusion power reactor applications. Typically, those reduced activated steels can loose their radioactivity in approximately 100 years, compared to thousands of years for the non-reduced-activated steels. The commonly used welding process for fabricating this steel are electron-beam welding, and tungsten inert gas (TIG) welding. Therefore, Activated-flux tungsten inert gas (A-TIG) welding, a variant of TIG welding has been developed in-house to increase the depth of penetration in single pass welding. In structural materials produced by A-TIG welding process, weld bead width, depth of penetration and heat affected zone (HAZ) width play an important role in determining in mechanical properties and also the performance of the weld joints during service. To obtain the desired weld bead geometry, HAZ width and make a good weld joint, it becomes important to set up the welding process parameters. The current work attempts to develop independent models correlating the welding process parameters like current, voltage and torch speed with weld bead shape will bead shape parameters like depth of penetration, bead width, HAZ width using ANFIS. These models will be used to evaluate the objective function in the genetic algorithm. Then genetic algorithm is employed to determine the optimum A-TIG welding process parameters to obtain the desired weld bead shape parameters and HAZ width. 展开更多
关键词 ANFIS GENETIC Algorithm RAFM STEEL A-TIG WELDING
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Application of Electron Energy Loss Spectroscopy and Energy Filtering Transmission Electron Microscopy for Microchemical Studies in 2.25Cr-1Mo Steel
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作者 P.Parameswaran Ilse Papst +2 位作者 F.Hofer W.Grogger V.S.Raghunathan 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2005年第3期361-366,共6页
Electron enregy loss spectroscopy (EELS) and energy filtering transmission electron microscopy (EFTEM) investigation on 2.25Cr-lMo steel was carried out to understand the nature of evolution of secondary carbides. The... Electron enregy loss spectroscopy (EELS) and energy filtering transmission electron microscopy (EFTEM) investigation on 2.25Cr-lMo steel was carried out to understand the nature of evolution of secondary carbides. The filtered images obtained from two different ageing treatments indicate that the steel evolves to a more stable carbide namely M23C6 in comparison to M2C. Microchemical information was generated from EELS spectra. Suitable choice for estimating the microchemical state was discussed. To evaluate the behaviour of ageing an elemental ratio of Fe to Cr is employed. 展开更多
关键词 Ferritic steels 2.25Cr-lMo steel EFTEM EELS Ageing
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Development of Multilevel Meteorological Data Acquisition System for Radiation Emergency Decision Support
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作者 D.N. Krishnakumar A. Bagavath Singh Anjukumari R. Baskaran M.T. Jose B. Venkatraman 《Journal of Earth Science and Engineering》 2013年第8期545-553,共9页
This paper describes a development of multilevel meteorological data acquisition system implemented at Kalpakkam coastal site for atmospheric dispersion and model validation studies. Meteorological data are one of the... This paper describes a development of multilevel meteorological data acquisition system implemented at Kalpakkam coastal site for atmospheric dispersion and model validation studies. Meteorological data are one of the most important inputs into any air dispersion model. As a part of atmospheric dispersion modeling studies and developing a methodology to forecast the site-specific dispersion characteristics, the real time monitoring of meteorological parameters assumes significance. This is achieved by erecting met towers instrumented at multilevel and single level at different locations with sensors for measuring various meteorological parameters. Real-world data logging applications involve not only just acquiring and recording signals, but also combination of offline analysis, display, report generation and data sharing. This paper covers development of low cost compact MMDAS (modular meteorological data acquisition system), its performance evaluation, field deployment test and data comparison analysis with fast response and high accuracy internationally acclaimed sonic anemometer. The system is based on embedded modules from Advantech and is designed to acquire analogue and digital signals from a multilevel instrumented met tower. The collected data are transferred from remote base station to central server for storage and further processing using wireless interface. MMDAS has many advantages like cost effectiveness, less complex signal conditioning electronics and easy maintenance. This system has good application during radiation emergency as well as site specific meteorological data collection and model validation studies. 展开更多
关键词 Radiation emergency meteorological data acquisition MMDAS dispersion modeling sonic anemometer.
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Skewness Based Elman Recurrent Neural Network Model for Classification of Cavitation Signals from Pressure Drop Devices of Prototype Fast Breeder Reactor
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作者 Ramadevi Rathinasabapathy Sheela Rani Balasubramaniam +1 位作者 Prakash Vasudevan Kalyasundaram Perumal 《通讯和计算机(中英文版)》 2011年第7期517-522,共6页
关键词 神经网络模型 回归神经网络 信号分类 快中子增殖反应堆 偏度 空化 压力降 ELMAN网络
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Developed New Procedure for Low Concentrations of Hydrazine Determination by Spectrophotometry: Hydrazine-Potassium Permanganate System
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作者 S. Ganesh Fahmida Khan +3 位作者 M. K. Ahmed P. Velavendan N. K. Pandey U. Kamachi Mudali 《Journal of Analytical Sciences, Methods and Instrumentation》 2012年第2期98-102,共5页
An indirect, sensitive and accurate method for the determination of trace amounts of hydrazine is described. In this proposed the spectrophotometric method is based on its reduction properties of hydrazine with a know... An indirect, sensitive and accurate method for the determination of trace amounts of hydrazine is described. In this proposed the spectrophotometric method is based on its reduction properties of hydrazine with a known concentration of potassium permanganate to reduce the colour. The absorbance of unreduced permanganate is measured the colour difference at different wavelengths 546 and 526 nm which show an absorption spectrum with hydrazine. Hydrazine can be determined in the range of 100 - 700 μg/ml with correlation coefficient of 0.999 and relative standard deviation 1%. The method is successfully applied for the determination of hydrazine in water streams in nuclear reactors/purex process/boiler water and polluted water samples. 展开更多
关键词 Hydrazine/Potassium PERMANGANATE UV-VIS SPECTROPHOTOMETRY Reducing Property Water STREAMS Nuclear Reactors
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Structural,phonon,elastic,thermodynamic and electronic properties of Mg-X(X=La,Nd,Sm)intermetallics:The first principles study 被引量:6
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作者 S.Rameshkumar G.Jaiganesh V.Jayalakshmi 《Journal of Magnesium and Alloys》 SCIE EI CAS 2019年第1期166-185,共20页
We show the results of first-principles calculations of structural,phonon,elastic,thermal and electronic properties of the Mg-X inter-metallics in their respective ground state phase and meta-stable phases at equilibr... We show the results of first-principles calculations of structural,phonon,elastic,thermal and electronic properties of the Mg-X inter-metallics in their respective ground state phase and meta-stable phases at equilibrium geometry and the studied pressure range.Phonon dispersion spectra for these compounds were investigated by using the linear response technique.The phonon spectra do not show any abnormality in their respective ground state phase.The respective ground states phases of the studied system remain stable within the studied pressure range.Electronic and thermodynamic properties were derived by analysis of the electronic structures and quasi-harmonic approximation.The mixed bonding character of the Mg-X intermetallics is revealed by Mg-X bonds,and it leads the metallic nature.Most of the contribution originated from X ions d like states at Fermi level compared to that of Mg ion in these intermetallics.In this work,we also predicted the melting temperature of these intermetallics and evaluated the Debye temperature by using elastic constants. 展开更多
关键词 Mg-X intermetallics First principle calculation Heat of formation Elastic constants Electronic and phonon properties Thermodynamic property
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Instrumental neutron activation analysis of beachrock samples of South East Coast of Tamilnadu,India 被引量:5
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作者 R.RAVISANKAR P.ESWARAN +1 位作者 N.P.SESHADERSSAN Bramaji RAO 《Nuclear Science and Techniques》 SCIE CAS CSCD 2007年第4期204-211,共8页
Element profiles of some beach rock samples collected from South East Coast of Tamilnadu, India have been determined using single comparator method of INAA. The geo-chemical behavior of the elements in the region is d... Element profiles of some beach rock samples collected from South East Coast of Tamilnadu, India have been determined using single comparator method of INAA. The geo-chemical behavior of the elements in the region is discussed. The irradiations were done at thermal neutron flux of ~ 1011 cm-2·s-1 at 20kW power using Kalpakkam Mini Reactor (KAMINI), IGCAR, Kalpakkam, Tamilnadu, India. Around 19 elements have been determined from 15 samples by high-resolution gamma spectrometry. The accuracy and precision were evaluated by assaying the irradiated Standard Reference Material (SRM 1646a Estuarine sediment) and were found to be in good agreement with certified values. 展开更多
关键词 中子 激活分析 KAMANI反应器 岩石
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Study on hydrogen assisted cracking susceptibility of HSLA steel by implant test 被引量:2
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作者 Gopa CHAKRABORTY R. REJEESH S.K. ALBERT 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2016年第6期490-495,共6页
DMR-249 A is an indigenously developed high strength low alloy steel for Indian ship building industry for making ship-hull and is extensively used in the construction of war ships and submarines. Welding electrodes c... DMR-249 A is an indigenously developed high strength low alloy steel for Indian ship building industry for making ship-hull and is extensively used in the construction of war ships and submarines. Welding electrodes conforming to SFA 5.5 AWS E8018 C1 has been indigenously developed for welding of this steel using shielded metal arc welding process. In the present study, susceptibility to hydrogen assisted cracking of DMR-249 A steel welds made using this electrode has been assessed using implant test. Implant tests were conducted using this electrode at two different levels of diffusible hydrogen, measured using gas chromatography technique. It is observed that both the steel and the welding consumable are not susceptible to hydrogen assisted cracking even with a high diffusible hydrogen level of 9 m L/100 g of weld metal. In implant tests, specimen did not fracture even after loading to stress levels higher than the yield strength of the base metal. The good resistance of this steel and the welding consumable, even with high levels of diffusible hydrogen, is attributed to absence of a susceptible microstructure in both the weld metal and heat affected zone. Hence, this study shows that, in the absence of a susceptible microstructure, hydrogen assisted cracking is unlikely to occur even if hydrogen level is high. It also confirms that in welding of DMR-249 A with indigenously developed E8018 C1 electrode, hydrogen assisted cracking is not a concern and no preheating is required to avoid it during welding. 展开更多
关键词 HSLA steel HYDROGEN ASSISTED CRACKING Diffusible HYDROGEN IMPLANT test Lower critical stress
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Investigation of enhancement in planar fast neutron detector efficiency with stacked structure using Geant4 被引量:2
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作者 Shivang Tripathi Chandrakant Upadhyay +3 位作者 C. P. Nagaraj K. Devan A. Venkatesan K. Madhusoodanan 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第11期154-163,共10页
Geant4 based Monte Carlo study has been carried out to assess the improvement in efficiency of the planar structure of Silicon Carbide(SiC)-based semiconductor fast neutron detector with the stacked structure. A proto... Geant4 based Monte Carlo study has been carried out to assess the improvement in efficiency of the planar structure of Silicon Carbide(SiC)-based semiconductor fast neutron detector with the stacked structure. A proton recoil detector was simulated, which consists of hydrogenous converter, i.e., high-density polyethylene(HDPE) for generating recoil protons by means of neutron elastic scattering(n, p) reaction and semiconductor material SiC, for generating a detectable electrical signal upon transport of recoil protons through it. SiC is considered in order to overcome the various factors associated with conventional Si-based devices such as operability in a harsh radiation environment, as often encountered in nuclear facilities. Converter layer thickness is optimized by considering 10~9 neutron events of different monoenergetic neutron sources as well as ^(241)Am-Be neutron spectrum. It is found that the optimized thickness for neutron energy range of 1–10 MeV is ~400 μm. However, the efficiency of fast neutron detection is estimated to be only 0.112%,which is considered very low for meaningful and reliable detection of neutrons. To overcome this problem, a stacked juxtaposition of converter layer between SiC layers has been analyzed in order to achieve high efficiency. It is noted that a tenfold efficiency improvement has been obtained—1.04% for 10 layers stacked configuration vis-à-vis 0.112% of single converter layer detector. Further simulation of the stacked detector with respect to variable converter thickness has been performed to achieve the efficiency as high as ~3.85% with up to 50 stacks. 展开更多
关键词 GEANT4 Fast NEUTRON DETECTOR Silicon CARBIDE RECOIL PROTON Stacked DETECTOR
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Radioactivity levels in soil of salt field area,Kelambakkam,Tamilnadu,India 被引量:2
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作者 R.RAVISANKAR A.RAJALAKSHMI +2 位作者 P.ESWARAN V GAJENDIRAN V.MEENAKSHISUNDRAM 《Nuclear Science and Techniques》 SCIE CAS CSCD 2007年第6期372-375,共4页
Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ^(232)Th,^(238)U and ^(40)K are ranged from 27.88 to 45... Soil samples in and around salt field area have been analyzed for natural radioactivity concentration using gamma ray spectrometer.The activity concentration for ^(232)Th,^(238)U and ^(40)K are ranged from 27.88 to 45.27 Bq/kg, from BDL to 13.30 Bq/kg,and from 135.54 to 381.28 Bq/kg,respectively.The measured activity concentrations for these radionuclides were compared with world average activity of soil.The average activity concentration of ^(232)Th in the present study is 1.19 times higher than world median value while the activity of ^(238)U and ^(40)K is found to be lower. The absorbed dose rates due to these radionuclides were calculated.The average absorbed gamma dose rate due to the presence of ^(232)Th,^(238)U and ^(40)K in soil samples is 36.99 nGy·h^(-1).These results indicate no radiological anomaly. The data presented in this study will serve as a base line survey for primordial radionuclides concentration in the study area. 展开更多
关键词 自然反射性 土壤样品 盐碱地 环境反射学
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Burn-Up Measurements on Dissolver Solution of Mixed Oxide Fuel Using HPLC-Mass Spectrometric Method 被引量:2
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作者 S. Bera R. Balasubramanian +7 位作者 Arpita Datta R. Sajimol S. Nalini T. S. Lakshmi Narasimhan M. P. Antony N. Sivaraman K. Nagarajan P. R. Vasudeva Rao 《International Journal of Analytical Mass Spectrometry and Chromatography》 2013年第1期55-60,共6页
Burn-up measurement on an irradiated mixed oxide (MOX) test fuel pellet was carried out through measurements on the dissolver solution by HPLC-Thermal Ionization Mass Spectrometric (TIMS) technique. The studies carrie... Burn-up measurement on an irradiated mixed oxide (MOX) test fuel pellet was carried out through measurements on the dissolver solution by HPLC-Thermal Ionization Mass Spectrometric (TIMS) technique. The studies carried out using HPLC as well as TIMS for quantification of burn-up value are described. While in one case, both the separation and determination of elements of interest (U, Pu and Nd) were carried out by HPLC;in another case, TIMS technique was used to quantify them from the HPLC separated fractions.The rapid separation procedures developed in our laboratory earlier were employed to isolate pure fractions of the desired elements. The individual lanthanide fission products (La to Eu) were separated from each other using dynamic ion-exchange chromatographic technique whereas uranium and plutonium were separated from each other using reversed phase chromatographic technique. The pure fractions of U, Pu and Nd obtained after HPLC separation procedure for “spiked” and “unspiked” dissolver solutions were used in TIMS measurements for the first time in our laboratory. In TIMS analysis, isotopic abundances of uranium, plutonium and neodymium fractions obtained from HPLC separation procedure on an “unspiked” fuel sample were measured. For the determination of U, Pu and Nd by isotopic dilution mass spectrometric technique (IDMS), known quantities of tracers enriched in 238U, 240Pu and 142Nd were added to the pre-weighed dissolver solution and subjected to HPLC separation procedures. The isotope ratios viz. 142Nd/(145Nd +146Nd), 238U/233U and 240Pu/239Pu in the pertinent “spiked” fractions were subsequently measured by TIMS. The spikes were pre-standardized in our laboratory employing reverse isotopic dilution technique against the standard solutions available in our laboratory (for 238U, 239Pu and 142Nd, standard solutions of 233U, 239Pu (of higher abundance than in the sample) and 150Nd were employed as spikes). The burn-up values from duplicate spiking experiments were computed based on the summation of 145Nd + 146Nd. The concentrations of neodymium, uranium and plutonium were also measured using HPLC with post-column derivatisation technique using aresenazo(III) as the post-column reagent. The atom % burn-up computed from HPLC and TIMS techniques were in good agreement. 展开更多
关键词 MOX Dissolver SOLUTION HPLC TIMS Uranium PLUTONIUM NEODYMIUM
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Pitting and stress corrosion cracking studies on AISI type 316N stainless steel weldments 被引量:1
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作者 Anita Toppo M.G.Pujar +1 位作者 N.Sreevidya John Philip 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2018年第3期226-237,共12页
Pitting and stress corrosion cracking(SCC) studies on the 316 N stainless steel(SS) weldments in aswelded(AW) and thermally aged(solution annealing(SA), 550C/4 h and 750C/1 h) conditions were carried out in acidic and... Pitting and stress corrosion cracking(SCC) studies on the 316 N stainless steel(SS) weldments in aswelded(AW) and thermally aged(solution annealing(SA), 550C/4 h and 750C/1 h) conditions were carried out in acidic and acidic chloride media. Pitting corrosion and SCC resistance was the highest for SA weldment, which was attributed to homogenization of microstructural and microchemical heterogeneities during solution annealing. SA specimen showed the most stable passive film as compared to AW weldment because of higher amount of delta-ferrite in AW weld metal, which resulted in an increased heterogeneity and inferior SCC resistance in AW. Stability of passive film was found to be adversely affected due to heat treatments(at 550C/4 h and 750C/1 h) because of the precipitation of carbide and sigma phases. 展开更多
关键词 压力腐蚀 不锈钢 AISI 焊接金属 SCC 稳定性 氯化物 微结构
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EDXRF analysis of beach rock samples of Andaman Island 被引量:1
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作者 Ravisankar R Eswaran P +5 位作者 Vijay Anand K Rajalakshmi A Prasad MVR Satpathy K K Rajashekhar C Alok Athavale 《Nuclear Science and Techniques》 SCIE CAS CSCD 2009年第2期93-98,共6页
B Elemental contents of beach rock samples were analyzed using EDXRF.The samples were collected from three locations of Andaman Island.The Al,Ca,K,Fe,Ti,Si,V,Co,Cu,Ba,Zn,Pb,Cd and Mn contents were determined.The geoch... B Elemental contents of beach rock samples were analyzed using EDXRF.The samples were collected from three locations of Andaman Island.The Al,Ca,K,Fe,Ti,Si,V,Co,Cu,Ba,Zn,Pb,Cd and Mn contents were determined.The geochemical behavior of elements in the region is discussed.The elemental contents of beach rock samples from Andaman Island are much below the values of both earth crust and that of Tamilnadu region.However,content of the biogenic element Ca was the highest of all elements.This is due to the typical beach rock formation. 展开更多
关键词 能量色散X射线荧光分析 岩石样本 海滩 地球化学行为 元素含量 生物元素 锰含量 样品
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Characteristics of friction welded AZ31B magnesium-commercial pure titanium dissimilar joints 被引量:1
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作者 A.K.Lakshminarayanan R.Saranarayanan +1 位作者 V.Karthik Srinivas B.Venkatraman 《Journal of Magnesium and Alloys》 SCIE EI CAS 2015年第4期315-321,共7页
It is essential to understand the weld interface characteristics and mechanical properties of dissimilar joints to improve its quality.This study is aimed at exploring the properties of friction welded magnesium-titan... It is essential to understand the weld interface characteristics and mechanical properties of dissimilar joints to improve its quality.This study is aimed at exploring the properties of friction welded magnesium-titanium dissimilar joint using tensile testing coupled with digital image correlation,optical and scanning electron microscopy,x-ray diffraction and microhardness measurements.Microstructurally different regions such as contact zone,dynamic recrystallized zone,thermo-mechanically affected zone,and partially deformed zone in the magnesium side were observed.No discernible regions were observed in the titanium side,as it had not undergone any significant plastic deformation.Phase analysis indicated that the aluminium from the magnesium side diffused toward the weld interface and formed a thin continuous intermetallic layer by reacting with the titanium.Microhardness mapping showed a steep hardness gradient from the titanium to magnesium side.Critical analysis is done on the tensile characteristics of the specimen and the response of the local regions to the deformation process is mapped. 展开更多
关键词 Friction welding Dissimilar joints MICROSTRUCTURE Digital image correlation
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Influence of Co-Solvent on the Extraction Behaviour of Uranium and Thorium Nitrates with Organophosphorous Compounds 被引量:1
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作者 K. C. Pitchaiah K. Sujatha +4 位作者 C. V. S. Brahmmananda Rao N. Sivaraman T. G. Srinivasan K. Nagarajan P. R. Vasudeva Rao 《International Journal of Analytical Mass Spectrometry and Chromatography》 2014年第2期33-42,共10页
Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical car... Supercritical Fluid Extraction (SFE) is emerging as a powerful technique in the extraction of metal ions. In the present study, the extraction of nitrates of uranium and thorium was carried out using supercritical carbon dioxide (Sc-CO2) modified with various organophosphorous compounds such as dialkylalkyl phosphonates, trialkyl phosphates and trialkyl phosphine oxides in the presence of co-solvents such as methanol, dichlormethane and n-hexane. The influence of ligand and co-solvent on the extraction of the metal nitrates was studied in detail. These studies have established that co-solvent plays an important role in the extraction as well as fractionation of uranium and thorium nitrates. Polar co-solvent, methanol provided faster extraction without fractionation whereas the non-polar solvent, e.g. n-hexane provided some fractionation of metal nitrates though the extraction kinetics was slower. 展开更多
关键词 CO-SOLVENT URANIUM and THORIUM ORGANOPHOSPHOROUS COMPOUNDS
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A study of PFBR auxiliary neutron source strength activation and its variability with respect to the neutron spectrum and 123Sb capture cross section
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作者 G.Pandikumar D.Sunil Kumar +4 位作者 M.M.Shanthi Bagchi Subhrojit A.John Arul D.Venkata Subramanian Rajeev Ranjan Prasad 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第8期114-122,共9页
In fast reactors, the inherent neutron source strength is often insufficient for monitoring the reactor start-up operation with ex-core detectors. To increase the subcritical neutron flux, an auxiliary neutron source ... In fast reactors, the inherent neutron source strength is often insufficient for monitoring the reactor start-up operation with ex-core detectors. To increase the subcritical neutron flux, an auxiliary neutron source subassembly(SSA) is generally used to overcome this problem. In this study, the estimated neutron source strength and detector count rate of an antimony-beryllium-based SSA are obtained using the deterministic transport code DORT and Monte Carlo calculations. Because the antimony activation rate is a critical parameter, its sensitivity to the capture cross section and neutron flux spectrum is studied. The reaction cross section sensitivity is studied by considering data from different evaluated nuclear data files.It is observed that, because of the variation in the cross sections from different evaluated nuclear data files, the values of the saturation gamma(> 1.67 MeV) activity and neutron strength predicted by ORIGEN2 lie within ±2%.The obtained antimony activation rate and sensitivity to the neutron flux are partially validated by irradiating samples of antimony in the KAMINI reactor. The average onegroup capture cross sections of bare and cadmium-covered 123Sb samples obtained by the ratio method are 4.0 and 1.78 b, respectively. The results of the calculation predicting the activated neutron source strength as a function of operating time and sensitivity to the neutron spectrum in the irradiation region are also presented. 展开更多
关键词 Fast reactors NEUTRON source Coremonitoring NEUTRON and GAMMA transport Antimonyactivation Material depletion
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Stress corrosion cracking behaviour of gas tungsten arc welded super austenitic stainless steel joints
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作者 M.VINOTH KUMAR V.BALASUBRAMANIAN +1 位作者 S.RAJAKUMAR SHAJU K.ALBERT 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2015年第3期282-291,共10页
Super 304 H austenitic stainless steel with 3% of copper posses excellent creep strength and corrosion resistance, which is mainly used in heat exchanger tubing of the boiler. Heat exchangers are used in nuclear power... Super 304 H austenitic stainless steel with 3% of copper posses excellent creep strength and corrosion resistance, which is mainly used in heat exchanger tubing of the boiler. Heat exchangers are used in nuclear power plants and marine vehicles which are intended to operate in chloride rich offshore environment. Chloride stress corrosion cracking is the most likely life limiting failure with austenitic stainless steel tubing. Welding may worsen the stress corrosion cracking susceptibility of the material. Stress corrosion cracking susceptibility of Super 304 H parent metal and gas tungsten arc(GTA) welded joints were studied by constant load tests in 45% boiling Mg Cl2 solution. Stress corrosion cracking resistance of Super 304 H stainless steel was deteriorated by GTA welding due to the formation of susceptible microstructure in the HAZ of the weld joint and the residual stresses. The mechanism of cracking was found to be anodic path cracking, with transgranular nature of crack propagation. Linear relationships were derived to predict the time to failure by extrapolating the rate of steady state elongation. 展开更多
关键词 奥氏体不锈钢管 应力腐蚀裂纹 钨极氩弧焊 开裂行为 钢接头 开裂敏感性 焊接接头 应力腐蚀开裂
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Influence of flash trap profiles on joint properties of friction welded CP-Ti tube to 304L stainless steel tube plate using external tool
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作者 C.MAXWELL REJIL C.SHARAN +1 位作者 S.MUTHUKUMARAN M.VASUDEVAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第8期2067-2078,共12页
Titanium tube and stainless steel tube plate were welded by an innovative friction welding of tube to tube plate using an external tool (FWTPET). Copper was used as an interlayer for joining the dissimilar materials a... Titanium tube and stainless steel tube plate were welded by an innovative friction welding of tube to tube plate using an external tool (FWTPET). Copper was used as an interlayer for joining the dissimilar materials and also to minimize the effect of intermetallics formed at the joint interface. The process parameters that govern FWTPET process are plunge rate, rotational speed, plunge depth, axial load and flash trap profile. Among them, the flash trap profile of the tube has a significant influence on the joint integrity. Various flash trap profiles like vertical slots, holes, zig-zag holes, and petals were made on the titanium tube welded to the stainless steel tube plate. Macroscopic and microscopic studies reveal defect-free joints. The presence of copper interlayer and intermetallics was evident from X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) studies. The microhardness survey was presented across and along the interface. A novel test procedure called “plunge shear test” was developed to evaluate the joint properties of the welded joints. The highest shear fracture load of 31.58 kN was observed on the sample having petals as flash trap profile. The sheared surfaces were further characterized using SEM for fractography. 展开更多
关键词 304L stainless steel tube plate CP-Ti tube friction welding joint properties flash trap external tool
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Measurement of natural radionuclides in bricks and brick-making clays from Cuddalore district,Tamilnadu,India
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作者 G.Viruthagiri R.Ravisankar +3 位作者 B.Rajamannan K.Thillaivelavan A.Chandrasekaran V.Meenkshisundram 《Nuclear Science and Techniques》 SCIE CAS CSCD 2010年第4期218-220,共3页
In India,bricks as building materials are mainly prepared by clay using the deposited sediments of rivers,and the radionuclide contents in bricks and brick-making clays should vary with origin and geological condition... In India,bricks as building materials are mainly prepared by clay using the deposited sediments of rivers,and the radionuclide contents in bricks and brick-making clays should vary with origin and geological condition.In this paper,the radionuclide contents of these materials from river bank areas of Cuddalore district,Tamilnadu India are measured by gamma ray spectrometer using NaI(Tl) detector,and compared with those of other countries.The radiation hazard indices,which are evaluated by radium-equivalent(Raeq) activity,are lower than that of NEA-OECD. 展开更多
关键词 射线测量 天然放射性核素 制砖 粘土 印度 放射性核素含量 河流沉积物 建筑材料
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