42 research outputs found
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Decontamination and reuse of ORGDP aluminum scrap
The Gaseous Diffusion Plants, or GDPs, have significant amounts of a number of metals, including nickel, aluminum, copper, and steel. Aluminum was used extensively throughout the GDPs because of its excellent strength to weight ratios and good resistance to corrosion by UF{sub 6}. This report is concerned with the recycle of aluminum stator and rotor blades from axial compressors. Most of the stator and rotor blades were made from 214-X aluminum casting alloy. Used compressor blades were contaminated with uranium both as a result of surface contamination and as an accumulation held in surface-connected voids inside of the blades. A variety of GDP studies were performed to evaluate the amounts of uranium retained in the blades; the volume, area, and location of voids in the blades; and connections between surface defects and voids. Based on experimental data on deposition, uranium content of the blades is 0.3%, or roughly 200 times the value expected from blade surface area. However, this value does correlate with estimated internal surface area and with lengthy deposition times. Based on a literature search, it appears that gaseous decontamination or melt refining using fluxes specific for uranium removal have the potential for removing internal contamination from aluminum blades. A melt refining process was used to recycle blades during the 1950s and 1960s. The process removed roughly one-third of the uranium from the blades. Blade cast from recycled aluminum appeared to perform as well as blades from virgin material. New melt refining and gaseous decontamination processes have been shown to provide substantially better decontamination of pure aluminum. If these techniques can be successfully adapted to treat aluminum 214-X alloy, internal and, possibly, external reuse of aluminum alloys may be possible
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Contaminated nickel scrap processing
The DOE will soon choose between treating contaminated nickel scrap as a legacy waste and developing high-volume nickel decontamination processes. In addition to reducing the volume of legacy wastes, a decontamination process could make 200,000 tons of this strategic metal available for domestic use. Contaminants in DOE nickel scrap include {sup 234}Th, {sup 234}Pa, {sup 137}Cs, {sup 239}Pu (trace), {sup 60}Co, U, {sup 99}Tc, and {sup 237}Np (trace). This report reviews several industrial-scale processes -- electrorefining, electrowinning, vapormetallurgy, and leaching -- used for the purification of nickel. Conventional nickel electrolysis processes are particularly attractive because they use side-stream purification of process solutions to improve the purity of nickel metal. Additionally, nickel purification by electrolysis is effective in a variety of electrolyte systems, including sulfate, chloride, and nitrate. Conventional electrorefining processes typically use a mixed electrolyte which includes sulfate, chloride, and borate. The use of an electrorefining or electrowinning system for scrap nickel recovery could be combined effectively with a variety of processes, including cementation, solvent extraction, ion exchange, complex-formation, and surface sorption, developed for uranium and transuranic purification. Selected processes were reviewed and evaluated for use in nickel side-stream purification. 80 refs
Susceptibility amplitude ratio for generic competing systems
We calculate the susceptibility amplitude ratio near a generic higher
character Lifshitz point up to one-loop order. We employ a renormalization
group treatment with independent scaling transformations associated to the
various inequivalent subspaces in the anisotropic case in order to compute the
ratio above and below the critical temperature and demonstrate its
universality. Furthermore, the isotropic results with only one type of
competition axes have also been shown to be universal. We describe how the
simpler situations of -axial Lifshitz points as well as ordinary
(noncompeting) systems can be retrieved from the present framework.Comment: 20 pages, no figure
Gender norms and social norms: differences, similarities and why they matter in prevention science.
Two streams of theory and practice on gender equity have begun to elide. The first is work conducted to change social norms, particularly using theory that emerged from studies in social psychology. The second is work done on gender norms, emerging historically from feminist scholars working to counter gender inequality. As these two streams of work intersect, conceptual clarity is needed to understand differences and similarities between these two traditions. Increased clarity will improve efforts to address harmful norms and practices. In this article, we review similarities and differences between social and gender norms, reviewing the history of the concepts and identifying key tension points of contrast. We identified six areas of comparison that might be helpful for practitioners working for the promotion of global health as they make sense of social and gender norms. We then offer a definition of gender norms for practitioners and researchers working at the intersection between these two theories. Our definition draws from the two different streams of thought of how norms influence people's actions, acknowledging the double nature of gender norms: beliefs nested in people's minds and embedded in institutions that profoundly affect health-related behaviours and shape differential access to health services
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Japanese R&D on new cast alloys and materials
On the basis of observations of the JTEC team, it appears that Japanese universities and research institutes are leading long-term R&D thrusts for development of new materials casting technologies. Significant efforts include amorphous metals, intermetallics, application of MHD in continuous casting of steel, and energy efficient furnace technology. Industrial R&D seems focused more on process improvements than on new product technologies, but significant efforts in new cast materials included cast metal matrix composites, materials substitutions for thinner wall products, and advanced ceramic products for foundry industry applications
The Structure And Properties Of Materials Volume III : Mechanical Behavior
viii;p 247;ill.;index;21 c
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Proceedings of the Tungsten Workshop for Hard Target Weapons Program
The purpose of this meeting was to review and exchange information and provide technical input for improving technologies relevant to the Hard Target Weapons Program. This workshop was attended by representatives from 17 organizations, including 4 Department of Defense (DoD) agencies, 8 industrial companies, and 5 laboratories within DOE. Hard targets are defined as reinforced underground structures that house enemy forces, weapon systems, and support equipment. DOE-ORO and Martin Marietta Energy Systems, Inc. (Energy Systems) have been involved in advanced materials research and development (R&D) for several DOE and DoD programs. These programs are conducted in close collaboration with Eglin AFB, Department of the Army`s Picatinny Arsenal, and other DoD agencies. As part of this ongoing collaboration, Eglin AFB and Oak Ridge National Laboratory planned and conducted this workshop to support the Hard Target Weapons Program. The objectives of this workshop were to (1) review and identify the technology base that exists (primarily due to anti-armor applications) and assess the applicability of this technology to the Hard Target Weapons Program requirements; (2) determine future directions to establish the W materials, processing, and manufacturing technologies suitable for use in fixed, hard target penetrators; and (3) identify and prioritize the potential areas for technical collaboration among the participants