The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform
Gary P Halada - One of the best experts on this subject based on the ideXlab platform.
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development of an environmentally friendly protective coating for the depleted Uranium 0 75 wt titanium Alloy part i surface morphology and electrochemistry
Electrochimica Acta, 2005Co-Authors: Donald F Roeper, Devicharan Chidambaram, C R Clayton, Gary P HaladaAbstract:Abstract The surface of the depleted Uranium (DU)-0.75 wt.% titanium Alloy has been studied using scanning electron microscopy, energy dispersive spectroscopy and optical microscopy. The samples were examined after mechanical polishing and again after nitric acid cleaning. The acicular martensitic microstructure is revealed after chemical etching. Several of the impurities have been identified and their prevalence has been found to change depending on the surface treatments. The impurities have also been found to vary from sample to sample and within the same sample. The electrochemistry and corrosion characteristics of the Alloy were studied using open circuit potential measurements and potentiodynamic polarization techniques. This study has been directed towards developing environmentally friendly protective coatings for this Alloy. In this paper, we discuss our efforts in finding suitable chemical species to act as inhibitors and activators during coating formation. The effect of various oxyanions, MoO42−, PO43−, VO43−, MnO4−, SiO44− and WO42−, on the electrochemical behavior of the depleted Uranium Alloy in quiescent nitric acid has been explored including their ability to inhibit corrosion. Results indicate that chemical or electrochemical activation of the DU Alloy in 0.1 M HNO3 + 0.025 M MoO42− can lead to the formation of a rudimentary coating. The effect of several fluorine compounds was also examined and their electrochemical response indicates that several of them may have a potential use as a surface activator.
Donald F Roeper - One of the best experts on this subject based on the ideXlab platform.
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development of an environmentally friendly protective coating for the depleted Uranium 0 75 wt titanium Alloy part i surface morphology and electrochemistry
Electrochimica Acta, 2005Co-Authors: Donald F Roeper, Devicharan Chidambaram, C R Clayton, Gary P HaladaAbstract:Abstract The surface of the depleted Uranium (DU)-0.75 wt.% titanium Alloy has been studied using scanning electron microscopy, energy dispersive spectroscopy and optical microscopy. The samples were examined after mechanical polishing and again after nitric acid cleaning. The acicular martensitic microstructure is revealed after chemical etching. Several of the impurities have been identified and their prevalence has been found to change depending on the surface treatments. The impurities have also been found to vary from sample to sample and within the same sample. The electrochemistry and corrosion characteristics of the Alloy were studied using open circuit potential measurements and potentiodynamic polarization techniques. This study has been directed towards developing environmentally friendly protective coatings for this Alloy. In this paper, we discuss our efforts in finding suitable chemical species to act as inhibitors and activators during coating formation. The effect of various oxyanions, MoO42−, PO43−, VO43−, MnO4−, SiO44− and WO42−, on the electrochemical behavior of the depleted Uranium Alloy in quiescent nitric acid has been explored including their ability to inhibit corrosion. Results indicate that chemical or electrochemical activation of the DU Alloy in 0.1 M HNO3 + 0.025 M MoO42− can lead to the formation of a rudimentary coating. The effect of several fluorine compounds was also examined and their electrochemical response indicates that several of them may have a potential use as a surface activator.
G P Mishra - One of the best experts on this subject based on the ideXlab platform.
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development preparation and characterization of Uranium molybdenum Alloys for dispersion fuel application
Journal of Alloys and Compounds, 2009Co-Authors: V P Sinha, P V Hegde, G J Prasad, R Keswani, C B Basak, G P MishraAbstract:Abstract Most of the research and test reactors worldwide have undergone core conversion from high enriched Uranium base fuel to low enriched Uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) program, which was launched in the late 1970s to reduce the risk of nuclear proliferation. To realize this goal, high density Uranium compounds and γ-stabilized Uranium Alloy powder were identified. In Metallic Fuels Division of BARC, R&D efforts are on to develop these high density Uranium base Alloys. This paper describes the preparation flow sheet for different compositions of Uranium and molybdenum Alloys by an innovative powder processing route with Uranium and molybdenum metal powders as starting materials. The same composition of U–Mo Alloys were also fabricated by conventional method i.e. ingot metallurgy route. The U–Mo Alloys prepared by both the methods were then characterized by XRD for phase analysis. The photomicrographs of Alloys with different compositions prepared by powder metallurgy and ingot metallurgy routes are also included in the paper. The paper also covers the comparison of properties of the Alloys prepared by powder metallurgy and ingot metallurgy routes.
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development of high density Uranium compounds and Alloys as dispersion fuel for research and test reactors
Transactions of The Indian Institute of Metals, 2008Co-Authors: V P Sinha, P V Hegde, G J Prasad, G P Mishra, S PalAbstract:Most of the research and test reactors worldwide have undergone core conversion from high enriched Uranium base fuel to low enriched Uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) programme, which was launched in the late 70’s to reduce the threat of nuclear proliferation. Various compounds of Uranium were considered and studied for the purpose but the best fuel compound identified for the development of low enriched Uranium base fuel was Uranium silicide (U3Si2). The fabrication method qualified for making U3Si2-Al dispersion fuel was giving a maximum heavy atom density in the range of 4.8 g/cm3 to 6.0 g/cm3. Under the RERTR programme an ambitious goal of achieving heavy metal density of 8.0 to 9.0 g/cm3 in aluminium based dispersion fuel was set and to realize this high density γ - stabilized Uranium Alloy (e.g. U-Mo, U-Zr etc.) powder in conjunction with advanced fabrication techniques.
V P Sinha - One of the best experts on this subject based on the ideXlab platform.
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development preparation and characterization of Uranium molybdenum Alloys for dispersion fuel application
Journal of Alloys and Compounds, 2009Co-Authors: V P Sinha, P V Hegde, G J Prasad, R Keswani, C B Basak, G P MishraAbstract:Abstract Most of the research and test reactors worldwide have undergone core conversion from high enriched Uranium base fuel to low enriched Uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) program, which was launched in the late 1970s to reduce the risk of nuclear proliferation. To realize this goal, high density Uranium compounds and γ-stabilized Uranium Alloy powder were identified. In Metallic Fuels Division of BARC, R&D efforts are on to develop these high density Uranium base Alloys. This paper describes the preparation flow sheet for different compositions of Uranium and molybdenum Alloys by an innovative powder processing route with Uranium and molybdenum metal powders as starting materials. The same composition of U–Mo Alloys were also fabricated by conventional method i.e. ingot metallurgy route. The U–Mo Alloys prepared by both the methods were then characterized by XRD for phase analysis. The photomicrographs of Alloys with different compositions prepared by powder metallurgy and ingot metallurgy routes are also included in the paper. The paper also covers the comparison of properties of the Alloys prepared by powder metallurgy and ingot metallurgy routes.
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development of high density Uranium compounds and Alloys as dispersion fuel for research and test reactors
Transactions of The Indian Institute of Metals, 2008Co-Authors: V P Sinha, P V Hegde, G J Prasad, G P Mishra, S PalAbstract:Most of the research and test reactors worldwide have undergone core conversion from high enriched Uranium base fuel to low enriched Uranium base fuel under the Reduced Enrichment for Research and Test Reactor (RERTR) programme, which was launched in the late 70’s to reduce the threat of nuclear proliferation. Various compounds of Uranium were considered and studied for the purpose but the best fuel compound identified for the development of low enriched Uranium base fuel was Uranium silicide (U3Si2). The fabrication method qualified for making U3Si2-Al dispersion fuel was giving a maximum heavy atom density in the range of 4.8 g/cm3 to 6.0 g/cm3. Under the RERTR programme an ambitious goal of achieving heavy metal density of 8.0 to 9.0 g/cm3 in aluminium based dispersion fuel was set and to realize this high density γ - stabilized Uranium Alloy (e.g. U-Mo, U-Zr etc.) powder in conjunction with advanced fabrication techniques.
C R Clayton - One of the best experts on this subject based on the ideXlab platform.
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development of an environmentally friendly protective coating for the depleted Uranium 0 75 wt titanium Alloy part i surface morphology and electrochemistry
Electrochimica Acta, 2005Co-Authors: Donald F Roeper, Devicharan Chidambaram, C R Clayton, Gary P HaladaAbstract:Abstract The surface of the depleted Uranium (DU)-0.75 wt.% titanium Alloy has been studied using scanning electron microscopy, energy dispersive spectroscopy and optical microscopy. The samples were examined after mechanical polishing and again after nitric acid cleaning. The acicular martensitic microstructure is revealed after chemical etching. Several of the impurities have been identified and their prevalence has been found to change depending on the surface treatments. The impurities have also been found to vary from sample to sample and within the same sample. The electrochemistry and corrosion characteristics of the Alloy were studied using open circuit potential measurements and potentiodynamic polarization techniques. This study has been directed towards developing environmentally friendly protective coatings for this Alloy. In this paper, we discuss our efforts in finding suitable chemical species to act as inhibitors and activators during coating formation. The effect of various oxyanions, MoO42−, PO43−, VO43−, MnO4−, SiO44− and WO42−, on the electrochemical behavior of the depleted Uranium Alloy in quiescent nitric acid has been explored including their ability to inhibit corrosion. Results indicate that chemical or electrochemical activation of the DU Alloy in 0.1 M HNO3 + 0.025 M MoO42− can lead to the formation of a rudimentary coating. The effect of several fluorine compounds was also examined and their electrochemical response indicates that several of them may have a potential use as a surface activator.
