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Sample records for pu availability option

  1. What Treatment Options Are Available for Male Infertility?

    MedlinePlus

    ... Publications What treatment options are available for male infertility? Skip sharing on social media links Share this: ... deliver a live-born infant, in most cases, infertility has no other outward symptoms. The evaluation of ...

  2. Expert opinion on available options treating pulmonary arterial hypertension.

    PubMed

    Naeije, Robert; Huez, Sandrine

    2007-10-01

    Until in the early nineties, pulmonary arterial hypertension (PAH) was a uniformly fatal disease, with a median life expectancy of approximately 2.5 years. Uncontrolled studies showed that a small proportion of patients responded to high-dose calcium channel blockers, retrospective studies supported the use of anticoagulant therapy and heart-lung or lung transplantation remained the only option. In 1996, a 3-month randomised, placebo-controlled trial showed that chronic intravenous epoprostenol (synthetic prostacyclin) improved functional state, exercise capacity, haemodynamics, and even survival in patients with idiopathic PAH. Similar benefits were subsequently reported and extended to all PAH categories, and confirmed with more stable prostacyclin analogues administered subcutaneously (treprostinil), by inhalation (iloprost), or even orally (beraprost). In the early 2000s, two randomised controlled trials showed efficacy of the oral intake of the dual endothelin A/B receptor antagonist bosentan. Two selective endothelin-A receptor antagonists, sitaxsentan and ambrisentan, are being developed. Finally, a randomised controlled trial has established the therapeutic efficacy of phosphodiesterase-5 inhibition with sildenafil, introducing a third signalling pathway to be targeted by the pharmacological treatment of PAH. Another phosphodiesterase-5 inhibitor, tadalafil, is already being evaluated. While all these treatments have markedly improved the lives of PAH patients, they have not offered yet a cure of the disease. Multi-drug approaches are now under evaluation, with more ambitious therapeutic goals. Alternative approaches with stem cells, RhoA-Rho-kinase inhibitors, platelet derived growth factor inhibitors and vasoactive intestinal peptides are being considered. PMID:17927481

  3. Best available control technology (BACT) of VOC for PU (polyurethane) synthetic leather surface coating industry in Taiwan

    SciTech Connect

    Shen, K.P.; Lai, C.C.; Lin, S.S.; Wu, H.H.; Huang, J.J.; Wang, Y.M.; Chen, H.W.

    1999-07-01

    In Taiwan, the polyurethane (PU) synthetic leather surface coating industry produced about 61,400 tons of volatile organic compound (VOC) emissions, accounting for 11 % of total stationary emissions of VOC. The industry is the largest VOC emission source in Taiwan. Major pollutants are dimethyl formamide (DMF), toluene, and methyl ethyl ketone (MEK). To obtain the best available control technology (BACT) of VOC emissions for the PU synthetic leather surface coating industry, this study followed the BACT guidelines of US EPA. For DMF, the BACT was the wet scrubbing technology for exhaust gas treatment, followed by a solvent recovery system. The change of coating methods or solvents, e.g., the use of water-base instead of organic-base solvents, was found to be the BACT for toluene and MEK. Through computer simulation, a wet scrubber with three in-series packing towers was found to be the most effective and economic for DMF. Based on the simulation, a full scale of plant was built and the test results were presented in this study. Results showed that 99% removal efficiency of DMF was achieved and the annual operation cost could be retrieved through the recovery of DMF solvent. The regulation for the industry established based on the BACT was also described in this study.

  4. 40 CFR 80.1342 - What compliance options are available to small refiners under this subpart?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Benzene Small Refiner Provisions § 80.1342 What compliance options are available to small refiners under... this section must comply with the applicable benzene standards at § 80.1230 beginning with the...

  5. 40 CFR 80.1342 - What compliance options are available to small refiners under this subpart?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Benzene Small Refiner Provisions § 80.1342 What compliance options are available to small refiners under... this section must comply with the applicable benzene standards at § 80.1230 beginning with the...

  6. 40 CFR 80.1342 - What compliance options are available to small refiners under this subpart?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Benzene Small Refiner Provisions § 80.1342 What compliance options are available to small refiners under... this section must comply with the applicable benzene standards at § 80.1230 beginning with the...

  7. Evaluating options for balancing the water-electricity nexus in California: part 1--securing water availability.

    PubMed

    Tarroja, Brian; AghaKouchak, Amir; Sobhani, Reza; Feldman, David; Jiang, Sunny; Samuelsen, Scott

    2014-11-01

    The technical potential and effectiveness of different water supply options for securing water availability in a large-scale, interconnected water supply system under historical and climate-change augmented inflow and demand conditions were compared. Part 1 of the study focused on determining the scale of the options required to secure water availability and compared the effectiveness of different options. A spatially and temporally resolved model of California's major surface reservoirs was developed, and its sensitivity to urban water conservation, desalination, and water reuse was examined. Potential capacities of the different options were determined. Under historical (baseline) hydrology conditions, many individual options were found to be capable of securing water availability alone. Under climate change augment conditions, a portfolio approach was necessary. The water savings from many individual options other than desalination were insufficient in the latter, however, relying on seawater desalination alone requires extreme capacity installations which have energy, brine disposal, management, and cost implications. The importance of identifying and utilizing points of leverage in the system for choosing where to deploy different options is also demonstrated. PMID:25022721

  8. Availability and accessibility of healthier options and nutrition information at New Zealand fast food restaurants.

    PubMed

    Chand, Ashmita; Eyles, Helen; Ni Mhurchu, Cliona

    2012-02-01

    The aim of this study was to assess the availability of healthier options and nutrition information at major New Zealand fast food chains. A cross-sectional survey was undertaken at 24 fast food stores (two from each of 12 major chains) using on-site visits, telephone calls, and website searches. Of available products, only 234/1126 (21%) were healthier options. Healthier options were generally cheaper and lower in energy, total fat, saturated fat, sugar, and sodium per serve than their regular counterparts. Regular options were commonly high in sugar or sodium per serve (mean sugar content of beverages=56 g (11 teaspoons) and sodium content of burgers and pasta=1095 mg and 1172 mg, respectively). Nutrition information was available at 11/12 (92%) restaurant chains (range=0% at Tank Juice to 99% at Domino's Pizza). However, <1% of this information was available at the point-of-purchase. Therefore, there is huge potential for improving nutrition in the New Zealand fast food restaurant setting. Implications of these findings for policy and food industry include: consideration of mandatory menu labelling, increasing the percentage of healthier options available, and improving the nutrient content of regular options at New Zealand fast food restaurants. PMID:22019449

  9. The need and options available for permanent CO{sub 2} disposal

    SciTech Connect

    Ziock, H.J.; Butt, D.P.; Lackner, K.S.; Wendt, C.H.

    1999-04-01

    Inexpensive, readily available energy is the cornerstone of modern society and the basis of a decent standard of living. The high probability of future restrictions on CO{sub 2} emissions has put in question the use of fossil fuels, the largest, most convenient, and most cost-effective energy resource available. The rapidly growing world population, the need for an improved standard of living worldwide, and the nearly linear dependence of the standard of living on energy consumption, all coupled with the magnitude of today`s CO{sub 2} emissions point to an impending crisis. The authors briefly review the problem and look at the available options. They conclude that for the foreseeable future, fossil fuels will continue to dominate the world energy market, but that CO{sub 2} disposal will be required. Of the possible disposal options, mineral sequestration of CO{sub 2} appears as an extremely promising, permanent, and environmentally benign disposal option.

  10. Availability of healthier options in traditional and nontraditional rural fast-food outlets

    PubMed Central

    Creel, Jennifer S; Sharkey, Joseph R; McIntosh, Alex; Anding, Jenna; Huber, J Charles

    2008-01-01

    Background Food prepared away from home has become increasingly popular to U.S. families, and may contribute to obesity. Sales have been dominated by fast food outlets, where meals are purchased for dining away from home or in the home. Although national chain affiliated fast-food outlets are considered the main source for fast food, fast foods are increasingly available in convenience stores and supermarkets/grocery stores. In rural areas, these nontraditional fast-food outlets may provide most of the opportunities for procurement of fast foods. Methods Using all traditional and nontraditio nal fast-food outlets identified in six counties in rural Texas, the type and number of regular and healthiermenu options were surveyed using on-site observation in all food venues that were primarily fast food, supermarket/grocery store, and convenience store and compared with 2005 Dietary Guidelines. Results Traditional fast-food outlets represented 84 (41%) of the 205 opportunities for procurement of fast food; 109 (53.2%) were convenience stores and 12 (5.8%) supermarkets/grocery stores. Although a s imilar variety of regular breakfast and lunch/dinner entrées were available in traditional fast-food outlets and convenience stores, the variety of healthier breakfast and lunch/dinner entrées was significantly greater in fast food outlets. Compared with convenience stores, supermarkets/grocery stores provided a greater variety of regular and healthier entrées and lunch/dinner side dishes. Conclusion Convenience stores and supermarkets/grocery stores more than double the potential access to fast foods in this rural area than traditional fast-food outlets alone; however, traditional fast food outlets offer greater opportunity for healthier fast food options than convenience stores. A complete picture of fast food environment and the availability of healthier fast food options are essential to understand environmental influences on diet and health outcomes, and identify

  11. TEMPERATURE MONITORING OPTIONS AVAILABLE AT THE IDAHO NATIONAL LABORATORY ADVANCED TEST REACTOR

    SciTech Connect

    J.E. Daw; J.L. Rempe; D.L. Knudson; T. Unruh; B.M. Chase; K.L Davis

    2012-03-01

    As part of the Advanced Test Reactor National Scientific User Facility (ATR NSUF) program, the Idaho National Laboratory (INL) has developed in-house capabilities to fabricate, test, and qualify new and enhanced sensors for irradiation testing. To meet recent customer requests, an array of temperature monitoring options is now available to ATR users. The method selected is determined by test requirements and budget. Melt wires are the simplest and least expensive option for monitoring temperature. INL has recently verified the melting temperature of a collection of materials with melt temperatures ranging from 100 to 1000 C with a differential scanning calorimeter installed at INL’s High Temperature Test Laboratory (HTTL). INL encapsulates these melt wires in quartz or metal tubes. In the case of quartz tubes, multiple wires can be encapsulated in a single 1.6 mm diameter tube. The second option available to ATR users is a silicon carbide temperature monitor. The benefit of this option is that a single small monitor (typically 1 mm x 1 mm x 10 mm or 1 mm diameter x 10 mm length) can be used to detect peak irradiation temperatures ranging from 200 to 800 C. Equipment has been installed at INL’s HTTL to complete post-irradiation resistivity measurements on SiC monitors, a technique that has been found to yield the most accurate temperatures from these monitors. For instrumented tests, thermocouples may be used. In addition to Type-K and Type-N thermocouples, a High Temperature Irradiation Resistant ThermoCouple (HTIR-TC) was developed at the HTTL that contains commercially-available doped molybdenum paired with a niobium alloy thermoelements. Long duration high temperature tests, in furnaces and in the ATR and other MTRs, demonstrate that the HTIR-TC is accurate up to 1800 C and insensitive to thermal neutron interactions. Thus, degradation observed at temperatures above 1100 C with Type K and N thermocouples and decalibration due to transmutation with tungsten

  12. 41 CFR 102-194.40 - For what Standard or Optional forms should an electronic version not be made available?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Optional forms should an electronic version not be made available? 102-194.40 Section 102-194.40 Public... For what Standard or Optional forms should an electronic version not be made available? All forms should include an electronic version unless it is not practicable to do so. Areas where it may not...

  13. Temperature monitoring options available at the Idaho national laboratory advanced test reactor

    NASA Astrophysics Data System (ADS)

    Daw, J. E.; Rempe, J. L.; Knudson, D. L.; Unruh, T. C.; Chase, B. M.; Davis, K. L.; Palmer, A. J.

    2013-09-01

    As part of the Advanced Test Reactor National Scientific User Facility (ATR-NSUF) program, the Idaho National Laboratory (INL) has developed in-house capabilities to fabricate, test, and qualify new and enhanced temperature sensors for irradiation testing. Clearly, temperature sensor selection for irradiation tests will be determined based on the irradiation environment and budget. However, temperature sensors now offered by INL include a wide array of melt wires in small capsules, silicon carbide monitors, commercially available thermocouples, and specialized high temperature irradiation resistant thermocouples containing doped molybdenum and niobium alloy thermoelements. In addition, efforts have been initiated to develop and evaluate ultrasonic thermometers for irradiation testing. This array of temperature monitoring options now available to ATR and other Material and Test Reactor (MTR) users fulfills recent customer requests.

  14. Pu-239 and Pu-240 inventories and Pu-240/ Pu-239 atom ratios in the water column off Sanriku, Japan.

    NASA Astrophysics Data System (ADS)

    Yamada, Masatoshi; Zheng, Jian; Aono, Tatsuo

    2013-04-01

    A magnitude 9.0 earthquake and subsequent tsunami occurred in the Pacific Ocean off northern Honshu, Japan, on 11 March 2011 which caused severe damage to the Fukushima Dai-ichi Nuclear Power Plant. This accident has resulted in a substantial release of radioactive materials to the atmosphere and ocean, and has caused extensive contamination of the environment. However, no information is available on the amounts of radionuclides such as Pu isotopes released into the ocean at this time. Investigating the background baseline concentration and atom ratio of Pu isotopes in seawater is important for assessment of the possible contamination in the marine environment. Pu-239 (half-life: 24,100 years), Pu-240 (half-life: 6,560 years) and Pu-241 (half-life: 14.325 years) mainly have been released into the environment as the result of atmospheric nuclear weapons testing. The atom ratio of Pu-240/Pu-239 is a powerful fingerprint to identify the sources of Pu in the ocean. The Pu-239 and Pu-240 inventories and Pu-240/Pu-239 atom ratios in seawater samples collected in the western North Pacific off Sanriku before the accident at Fukushima Dai-ichi Nuclear Power Plant will provide useful background baseline data for understanding the process controlling Pu transport and for distinguishing additional Pu sources. Seawater samples were collected with acoustically triggered quadruple PVC sampling bottles during the KH-98-3 cruise of the R/V Hakuho-Maru. The Pu-240/Pu-239 atom ratios were measured with a double-focusing SF-ICP-MS, which was equipped with a guard electrode to eliminate secondary discharge in the plasma and to enhance overall sensitivity. The Pu-239 and Pu-240 concentrations were 2.07 and 1.67 mBq/m3 in the surface water, respectively, and increased with depth; a subsurface maximum was identified at 750 m depth, and the concentrations decreased with depth, then increased at the bottom layer. The total Pu-239+240 inventory in the entire water column (depth interval 0

  15. Pain management following spinal surgeries: An appraisal of the available options

    PubMed Central

    Bajwa, Sukhminder Jit Singh; Haldar, Rudrashish

    2015-01-01

    Spinal procedures are generally associated with intense pain in the postoperative period, especially for the initial few days. Adequate pain management in this period has been seen to correlate well with improved functional outcome, early ambulation, early discharge, and preventing the development of chronic pain. A diverse array of pharmacological options exists for the effective amelioration of post spinal surgery pain. Each of these drugs possesses inherent advantages and disadvantages which restricts their universal applicability. Therefore, combination therapy or multimodal analgesia for proper control of pain appears as the best approach in this regard. The current manuscript discussed the pathophysiology of postsurgical pain including its nature, the various tools for assessment, and the various pharmacological agents (both conventional and upcoming) available at our disposal to respond to post spinal surgery pain. PMID:26288544

  16. Achieving Resource Conservation in Electronic Waste Management: A Review of Options Available to Developing Countries

    NASA Astrophysics Data System (ADS)

    Chidi Nnorom, Innocent; Osibanjo, Oladele; Onyedikachi Nnorom, Stanley

    Large quantities of waste electronic devices (e-waste) at their end-of-life, generated internally or imported illegally from developed countries, are currently being managed in the developing countries, through low-end means such as crude backyard recycling and disposal at unlined landfills or open dumps. The extension of the lifespan of electronic devices through reuse options such as repair, reconditioning and remanufacturing should be a priority in the management of electronic waste in developing countries considering the near absence of state-of-the-art recycling facilities in these countries. Life extension through product and component reuse is especially critical to electronic products because in recent years, electronics have increased in technological complexity, with new product innovations and ever shortening product life expectancy. For many products, environmentalists assume that reuse is environmentally beneficial because it replaces the manufacturing and purchase of new goods. However, on the contrary, manufacturers may oppose this type of reuse for the same reason. There is an urgent need to control the trans-boundary movement of electronic scrap especially to countries without established recycling facilities. Importations of secondhand electronics make such devices available to those who cannot afford new products. However, an international method of testing and certification is needed to ensure that exported secondhand devices are functional. Establishment of formal recycling facilities for e-waste in the developing countries will ensure resource reutilization with both economical and ecological gains. This study reviews options available in working towards eco-efficient management of e-waste in developing countries in the light of the present low-end management practices.

  17. Current aproach to cancer pain management: Availability and implications of different treatment options

    PubMed Central

    Nersesyan, Hrachya; Slavin, Konstantin V

    2007-01-01

    Despite tremendous progress in medicine during last couple of decades, cancer still remains the most horrifying diagnosis for anybody due to its almost inevitable futility. According to American Cancer Society Statistics, it is estimated that only in the United States more than half a million people will die from cancer in 2006. For those who survive, probably the most fearsome symptom regardless of cancer type will be the pain. Although most pain specialists and oncologists worldwide are well aware of the importance to adequately treat the pain, it was yet established that more than half of cancer patients have insufficient pain control, and about quarter of them actually die in pain. Therefore, in this review article we attempted to provide the comprehensive information about different options available nowadays for treating cancer pain focusing on most widely used pharmacologic agents, surgical modalities for intractable pain control, their potential for adverse effects, and ways to increase the effectiveness of treatment maximally optimizing analgesic regimen and improving compliance. PMID:18488078

  18. Unique mission options available with a megawatt-class nuclear electric propulsion system

    SciTech Connect

    Coomes, E.P.; McCauley, L.A.; Christian, J.L.; Gomez, M.A.; Wong, W.A.

    1988-10-01

    The advantages of using electric propulsion systems are well-known in the aerospace community with the most common being its high specific impulse, lower propellant requirements, and lower system mass. But these advantages may not be as important as the overall unique mission options electric propulsion makes possible, especially if the system is powered by a megawatt-class nuclear electric power source. Although the lack of suitable electric power systems has been a major drawback to electric propulsion, recent efforts have shown megawatt-class nuclear electric power systems are feasible and could be available by the turn of the century. Coupling this with the resurgence in interest in free-space electromagnetic transmission of energy and technology developments in this area provide a whole new aspect to the view of electric propulsion. The propulsion system now has a second mission function that may be of more value than the well understood benefits of electric propulsion; that is providing large quantities of prime power in support of a broad spectrum of mission tasks. 30 refs., 9 figs.

  19. No Child Left Behind Educational Options: Availability Expands, But Participation Remains Low. Research Brief

    ERIC Educational Resources Information Center

    Neumann, Michael J.

    2009-01-01

    As required by the No Child Left Behind Act of 2001 (NCLB), most school districts with low-performing schools offer public school choice and supplemental educational services. However, researchers found that, although the total number of students participating in both options has increased substantially since NCLB began, only a small proportion…

  20. 20 CFR 404.1094 - Options available for figuring net earnings from self-employment.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... from self-employment. 404.1094 Section 404.1094 Employees' Benefits SOCIAL SECURITY ADMINISTRATION...-employment. (a) General. If you have income from a trade or business in certain situations, you have options... you have income from an agricultural trade or business or a non-agricultural trade or business. For...

  1. 45 CFR 310.5 - What options are available for Computerized Tribal IV-D Systems and office automation?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... IV-D Systems and office automation? 310.5 Section 310.5 Public Welfare Regulations Relating to Public... AUTOMATION Requirements for Computerized Tribal IV-D Systems and Office Automation § 310.5 What options are available for Computerized Tribal IV-D Systems and office automation? (a) Allowable computerized...

  2. 45 CFR 310.5 - What options are available for Computerized Tribal IV-D Systems and office automation?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... IV-D Systems and office automation? 310.5 Section 310.5 Public Welfare Regulations Relating to Public... AUTOMATION Requirements for Computerized Tribal IV-D Systems and Office Automation § 310.5 What options are available for Computerized Tribal IV-D Systems and office automation? (a) Allowable computerized...

  3. Moving Elite Athletes Forward: Examining the Status of Secondary School Elite Athlete Programmes and Available Post-School Options

    ERIC Educational Resources Information Center

    Brown, Seth

    2015-01-01

    Purpose: The purpose of this study focused specifically on examining the status of and the promotion of two elite athlete programmes (EAPs), the students/elite athlete selection process and available post-school options. The research was guided by Michel Foucault's work in understanding the relationship between power and knowledge. Participants,…

  4. Primary Intracranial Melanoma with Early Leptomeningeal Spread: A Case Report and Treatment Options Available

    PubMed Central

    Balakrishnan, Rajesh; Porag, Rokeya; Asif, Dewan Shamsul; Satter, A. M. Rejaus; Taufiq, Md.; Gaddam, Samson S. K.

    2015-01-01

    Primary CNS melanomas are rare and they constitute about 1% of all cases of melanomas and 0.07% of all brain tumors. These tumors are aggressive in nature and may metastasise to other organs. Till date less than 25 cases have been reported in the literature. The primary treatment for local intraparenchymal tumours is complete resection and/or radiotherapy and it is associated with good survival. However once there is disease spread to leptomeninges the overall median survival is around 10 weeks. In this case report we describe a primary intracranial melanoma without any dural attachment in 16-year-old boy who had radical excision of the tumor followed by radiotherapy who eventually had rapidly developed leptomeningeal disease and review the literature with a focus on the clinic pathological, radiological, and treatment options. PMID:26294993

  5. A risk-based framework for water resource management under changing water availability, policy options, and irrigation expansion

    NASA Astrophysics Data System (ADS)

    Hassanzadeh, Elmira; Elshorbagy, Amin; Wheater, Howard; Gober, Patricia

    2016-08-01

    Long-term water resource management requires the capacity to evaluate alternative management options in the face of various sources of uncertainty in the future conditions of water resource systems. This study proposes a generic framework for determining the relative change in probabilistic characteristics of system performance as a result of changing water availability, policy options and irrigation expansion. These probabilistic characteristics can be considered to represent the risk of failure in the system performance due to the uncertainty in future conditions. Quantifying the relative change in the performance risk can provide a basis for understanding the effects of multiple changing conditions on the system behavior. This framework was applied to the water resource system of the Saskatchewan River Basin (SaskRB) in Saskatchewan, Canada. A "bottom-up" flow reconstruction algorithm was used to generate multiple realizations for water availability within a feasible range of change in streamflow characteristics. Consistent with observed data and projected change in streamflow characteristics, the historical streamflow was perturbed to stochastically generate feasible future flow sequences, based on various combinations of changing annual flow volume and timing of the annual peak. In addition, five alternative policy options, with and without potential irrigation expansion, were considered. All configurations of water availability, policy decisions and irrigation expansion options were fed into a hydro-economic water resource system model to obtain empirical probability distributions for system performance - here overall and sectorial net benefits - under the considered changes. Results show that no one specific policy can provide the optimal option for water resource management under all flow conditions. In addition, it was found that the joint impacts of changing water availability, policy, and irrigation expansion on system performance are complex and

  6. Offsite commercial disposal of oil and gas exploration and production waste :availability, options, and cost.

    SciTech Connect

    Puder, M. G.; Veil, J. A.

    2006-09-05

    A survey conducted in 1995 by the American Petroleum Institute (API) found that the U.S. exploration and production (E&P) segment of the oil and gas industry generated more than 149 million bbl of drilling wastes, almost 18 billion bbl of produced water, and 21 million bbl of associated wastes. The results of that survey, published in 2000, suggested that 3% of drilling wastes, less than 0.5% of produced water, and 15% of associated wastes are sent to offsite commercial facilities for disposal. Argonne National Laboratory (Argonne) collected information on commercial E&P waste disposal companies in different states in 1997. While the information is nearly a decade old, the report has proved useful. In 2005, Argonne began collecting current information to update and expand the data. This report describes the new 2005-2006 database and focuses on the availability of offsite commercial disposal companies, the prevailing disposal methods, and estimated disposal costs. The data were collected in two phases. In the first phase, state oil and gas regulatory officials in 31 states were contacted to determine whether their agency maintained a list of permitted commercial disposal companies dedicated to oil. In the second stage, individual commercial disposal companies were interviewed to determine disposal methods and costs. The availability of offsite commercial disposal companies and facilities falls into three categories. The states with high oil and gas production typically have a dedicated network of offsite commercial disposal companies and facilities in place. In other states, such an infrastructure does not exist and very often, commercial disposal companies focus on produced water services. About half of the states do not have any industry-specific offsite commercial disposal infrastructure. In those states, operators take their wastes to local municipal landfills if permitted or haul the wastes to other states. This report provides state-by-state summaries of the

  7. An analysis of options available for developing a common laser ray tracing package for Ares and Kull code frameworks

    SciTech Connect

    Weeratunga, S K

    2008-11-06

    Ares and Kull are mature code frameworks that support ALE hydrodynamics for a variety of HEDP applications at LLNL, using two widely different meshing approaches. While Ares is based on a 2-D/3-D block-structured mesh data base, Kull is designed to support unstructured, arbitrary polygonal/polyhedral meshes. In addition, both frameworks are capable of running applications on large, distributed-memory parallel machines. Currently, both these frameworks separately support assorted collections of physics packages related to HEDP, including one for the energy deposition by laser/ion-beam ray tracing. This study analyzes the options available for developing a common laser/ion-beam ray tracing package that can be easily shared between these two code frameworks and concludes with a set of recommendations for its development.

  8. 5 CFR 892.211 - What options are available to me if I go on a period of leave without pay (LWOP) or other types...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false What options are available to me if I go on a period of leave without pay (LWOP) or other types of non-pay status? 892.211 Section 892.211... What options are available to me if I go on a period of leave without pay (LWOP) or other types of...

  9. 26 CFR 1.1402(a)-15 - Options available to farmers in computing net earnings from self-employment for taxable years...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 26 Internal Revenue 12 2014-04-01 2014-04-01 false Options available to farmers in computing net... available to farmers in computing net earnings from self-employment for taxable years ending on or after... by the two partners. A is an experienced farmer and for his services as manager of the...

  10. Room-temperature electron spectroscopy of 239Pu and 240Pu

    NASA Astrophysics Data System (ADS)

    Ahmad, I.; Kondev, F. G.; Greene, J. P.; Zhu, S.

    2015-06-01

    Passivated, implanted, planar silicon (PIPS) detectors have been used for the measurement of electron spectra. The commercially available PIPS detectors, available in thicknesses of 100 μm, 300 μm, and 500 μm, have an energy resolution (FWHM) of ~ 2.2 keV, which is essentially the same as that of PIN diodes. Alpha and electron spectra of mass-separated 239Pu and 240Pu sources have been measured with a 300-μm thick PIPS detector and the electron to alpha ratios for the conversion lines of the 51.62- and 45.24-keV transitions have been determined. A procedure has been developed to determine the amount of 239Pu and 240Pu in a mixed source. The α-particle emission rate of the mixed source is measured, which is the sum of individual rates. From the electron spectrum of the mixed source, measured with the same setup as the alpha spectrum, the rates of 239Pu electron lines are determined. Using the electron rate of the 239Pu line and the electron to alpha ratio measured for the pure source, the α-particle emission rate of 239Pu is determined. The difference from the total α-particle emission rate gives the α-particle emission rate of 240Pu. In addition, electron intensities and conversion coefficients of the 239Pu and 240Pu transitions have been measured.

  11. Seromuscular Colonic Flap for Intrapelvic Soft-Tissue Coverage: A Reconstructive Option for Plastic Surgeons When Traditionally Used Flaps Are Not Available

    PubMed Central

    Aho, Johnathon; Winocour, Sebastian; Hammoudeh, Ziyad S.; Nelson, Heidi; Rose, Peter; Tran, Nho V.

    2015-01-01

    Background. Reconstruction of intrapelvic defects can be a challenging problem in patients with limited regional muscle flap options and previously resected omentum. In such situations, alternative methods of mobilizing vascularized tissue may be required. Methods. A case of a patient that underwent pelvic extirpation for recurrent rectal cancer who had limited donor sites for flap reconstruction is presented. The mucosa was removed from a blind loop of colon, and a pedicled seromuscular flap based on the colonic mesentery was placed into the pelvis for vascularized soft-tissue coverage and elimination of dead space. Results. The postoperative course was only complicated by a small subcutaneous fluid collection beneath the sacrectomy skin incision, which was drained with radiological assistance. The patient recovered without any major postoperative complications. Conclusion. Seromuscular colonic flap is a useful option for soft-tissue coverage after pelvic extirpation and should be considered by plastic surgeons when other reconstruction options are not available. PMID:26688771

  12. Pu Workshop Letter

    SciTech Connect

    Tobin, J G; Schwartz, A J; Fluss, M

    2006-03-06

    In preparation for the upcoming Pu Workshop in Livermore, CA, USA, during July 14 and 15, 2006, we have begun to give some thought as to how the meeting will be structured and what will be discussed. Below, you will find our first proposal as to the agenda and contents of the meeting. From you, we need your feedback and suggestions concerning the desirability of each aspect of our proposal. Hopefully, we will be able to converge to a format that is acceptable to all parties. First, it now appears that we will be limited to three main sessions, Friday morning (July 14), Friday afternoon (July 14) and Saturday morning (July 15). The Pu Futures Meeting will conclude on Thursday, July 13. Following a social excursion, the Russian participants will be transported from Monterey Bay to their hotel in Livermore. We anticipate that the hotel will be the Residence Inn at 1000 Airway Blvd in Livermore. However, the hotel arrangements still need to be confirmed. We expect that many of our participants will begin their travels homeward in the afternoon of Saturday, July 15 and the morning of Sunday, July 16. Associated with the three main sessions, we propose that there be three main topics. Each session will have an individual focus. Because of the limited time available, we will need to make some judicious choices concerning the focus and the speakers for each session. We will also have a poster session associated with each session, to facilitate discussions, and a rotating set of Lab Tours, to maximize participation in the tour and minimize the disruption of the speaking schedule. Presently, we are planning a tour of the Dynamical Transmission Electron Microscope (DTEM) facilities, but this is still in a preliminary stage. We estimate that for each session and topic, there will be time for five (5) speakers. We propose that, typically, there be three (3) Russian and two (2) American speakers per session. We also propose that each session have a chair (or two chairs), who

  13. Economical Production of Pu-238

    SciTech Connect

    Steven D. Howe; Douglas Crawford; Jorge Navarro; Terry Ring

    2013-02-01

    All space exploration missions traveling beyond Jupiter must use radioisotopic power sources for electrical power. The best isotope to power these sources is plutonium-238. The US supply of Pu-238 is almost exhausted and will be gone within the next decade. The Department of Energy has initiated a production program with a $10M allocation from NASA but the cost is estimated at over $100 M to get to production levels. The Center for Space Nuclear Research has conceived of a potentially better process to produce Pu-238 earlier and for significantly less cost. The new process will also produce dramatically less waste. Potentially, the front end costs could be provided by private industry such that the government only had to pay for the product produced. Under a NASA Phase I NIAC grant, the CSNR has evaluated the feasibility of using a low power, commercially available nuclear reactor to produce at least 1.5 kg of Pu-238 per year. The impact on the neutronics of the reactor have been assessed, the amount of Neptunium target material estimated, and the production rates calculated. In addition, the size of the post-irradiation processing facility has been established. In addition, a new method for fabricating the Pu-238 product into the form used for power sources has been identified to reduce the cost of the final product. In short, the concept appears to be viable, can produce the amount of Pu-238 needed to support the NASA missions, can be available within a few years, and will cost significantly less than the current DOE program.

  14. The Available Options for Wavelength Group Selection and Transceiver Design for Next Generation PON Stage 2 (NG-PON2)

    NASA Astrophysics Data System (ADS)

    Niazi, Shahab Ahmad; Zhang, Xiaoguang; Xi, Lixia; Chen, Yong Li; Idress, Muhammad

    2013-09-01

    The full service access network (FSAN) task group meeting was held in April 2012, where they agreed to adopt time and wavelength division multiplexed passive optical network (TWDM-PON) as a primary solution to NG-PON2. Major requirements includes at least 40 Gbit/s aggregate rate in downstream, 1:64 split ratio, 40 km differential reach, and at least 1 Gb/s access rate per optical network unit (ONU). In this paper, a performance analysis will be carried out for downstream 4-wavelengths group selection from S-band, L-band, and C-band. A comparison for optimal transmitter design is also investigated among probable options of chirp managed laser diode, Lithium Niobate (LiNbo3) Mach Zehnder modulator, besides examining tunable transceivers in contrary to remotely fed colorless ONUs.

  15. Hepatitis C virus genotype 3: Meta-analysis on sustained virologic response rates with currently available treatment options

    PubMed Central

    Ampuero, Javier; Reddy, K Rajender; Romero-Gomez, Manuel

    2016-01-01

    AIM: To address the therapeutic efficacy of various treatment regimens in genotype 3 selecting randomized clinical trials and prospective National Cohort Studies. METHODS: (1) PEG-INF-based therapy including sofosbuvir (SOF) + RBV for 12 wk vs SOF + RBV 24 wk; (2) SOF + RBV therapy 12 wk/16 wk vs 24 wk; and (3) the role of RBV in SOF + daclatasvir (DCV) and SOF + ledipasvir (LDV) combinations. This meta-analysis provides robust information with the intention of addressing treatment strategy for hepatitis C virus genotype 3. RESULTS: A combination treatment including SOF + RBV + PEG-IFN for 12 wk notes better SVR than with only SOF + RBV for 12 wk, although its association with more frequent adverse effects may be a limiting factor. Longer duration therapy with SOF + RBV (24 wk) has achieved higher SVR rates than shorter durations (12 or 16 wk). SOF + LDV are not an ideal treatment for genotype 3. CONCLUSION: Lastly, SOF + DCV combination is probably the best oral therapy option and the addition of RBV does not appear to be needed to increase SVR rates substantially. PMID:27298572

  16. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    SciTech Connect

    Bolton, H., Jr.; Bailey, V.L.; Plymale, A.E.; Rai, D.; Xun, L.

    2006-04-05

    The complexation of radionuclides (e.g., plutonium (Pu) and {sup 60}Co) by co-disposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Pu(IV)-EDTA is not stable in the presence of relatively soluble Fe(III) compounds. Since most DOE sites have Fe(III) containing sediments, Pu(IV) is likely not the mobile form of Pu-EDTA. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions and the anaerobic biodegradation of Pu-EDTA. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV), the redox conditions required for this reduction, the strength of the Pu(III)-EDTA, how the Pu(III)-EDTA competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, soluble Pu(III)-EDTA under anaerobic conditions would require anaerobic degradation of the EDTA to limit Pu(III) transport. Anaerobic EDTA degrading microorganisms have never been isolated. Recent results have shown that Shewanella oneidensis MR-1, a dissimilatory metal reducing bacterium, can reduce Pu(IV) to Pu(III). The Pu(IV) was provided as insoluble PuO2. The highest rate of Pu(IV) reduction was with the addition of AQDS, an electron shuttle. Of the total amount of Pu solubilized (i.e., soluble through a 0.36 nm filter), approximately 70% was Pu(III). The amount of soluble Pu was between 4.8 and 3.2 micromolar at day 1 and 6, respectively, indicating rapid reduction. The micromolar Pu is significant since the drinking water limit for Pu is 10{sup -12} M. On-going experiments are investigating the influence of EDTA on the rate of Pu reduction and the stability of the formed Pu(III). We have also

  17. Reproductive rights and options available to women infected with HIV in Ghana: perspectives of service providers from three Ghanaian health facilities

    PubMed Central

    2013-01-01

    Background Owing to improved management of HIV and its associated opportunistic infections, many HIV-positive persons of reproductive age are choosing to exercise their right of parenthood. This study explored the knowledge of health workers from two Ghanaian districts on the reproductive rights and options available to HIV-positive women who wish to conceive. Methods Facility-based cross-sectional in design, the study involved the entire population of nurse counselors (32) and medical officers (3) who provide counseling and testing services to clients infected with HIV. Both structured and in-depth interviews were conducted after informed consent. Results Two main perspectives were revealed. There was an overwhelmingly high level of approbation by the providers on HIV-positive women’s right to reproduction (94.3%). At the same time, the providers demonstrated a lack of knowledge regarding the various reproductive options available to women infected with HIV. Site of facility, and being younger were associated with practices that violated client’s right to contraceptive counseling (p < 0.05) in each case. Some of the providers openly expressed their inability to give qualified guidance to HIV-positive women on the various reproductive options. Conclusions Taken together, these findings suggest that many HIV-positive clients do not receive comprehensive information about their reproductive options. These findings highlight some of the problems that service providers face as HIV counselors. Both service providers and policy makers need to recognize these realities and incorporate reproductive health issues of HIV-persons into the existing guidelines. PMID:23496943

  18. Optical properties of PuO2 and α-Pu2O3 by GGA + U + QA studies

    NASA Astrophysics Data System (ADS)

    Yang, Yu; Lu, Yong; Zhang, Ping

    2014-09-01

    By performing first-principles calculations plus quasi-annealing simulations, we systematically study the ground-state electronic and optical properties for PuO2 and α-Pu2O3. We find that α-Pu2O3 has an energy band gap of 1.38 eV. Our obtained atomic and electronic structures for the two plutonium oxides are in agreement with available experimental as well as other theoretical results. Based on the ground-state electronic structures, we systematically calculate the frequency dependent dielectric functions, as well as the optical spectra for α-Pu2O3 and PuO2. It is found that at the visible light frequency range, the adsorption coefficient of α-Pu2O3 and PuO2 are similar, but their refractive indexes differ much. This difference can be used to detect or trace the oxidation products of the plutonium surfaces.

  19. Anaerobic Biotransformation and Mobility of Pu and Pu-EDTA

    SciTech Connect

    Bolton, H., Jr.; Rai, D.; Xun, L.

    2005-04-18

    The complexation of radionuclides (e.g., plutonium (Pu) and {sup 60}Co) by codisposed ethylenediaminetetraacetate (EDTA) has enhanced their transport in sediments at DOE sites. Our previous NABIR research investigated the aerobic biodegradation and biogeochemistry of Pu(IV)-EDTA. Plutonium(IV) forms stable complexes with EDTA under aerobic conditions and an aerobic EDTA degrading bacterium can degrade EDTA in the presence of Pu and decrease Pu mobility. However, our recent studies indicate that while Pu(IV)-EDTA is stable in simple aqueous systems, it is not stable in the presence of relatively soluble Fe(III) compounds (i.e., Fe(OH){sub 3}(s)--2-line ferrihydrite). Since most DOE sites have Fe(III) containing sediments, Pu(IV) in likely not the mobile form of Pu-EDTA in groundwater. The only other Pu-EDTA complex stable in groundwater relevant to DOE sites would be Pu(III)-EDTA, which only forms under anaerobic conditions. Research is therefore needed in this brand new project to investigate the biotransformation of Pu and Pu-EDTA under anaerobic conditions. The biotransformation of Pu and Pu-EDTA under various anaerobic regimes is poorly understood including the reduction kinetics of Pu(IV) to Pu(III) from soluble (Pu(IV)-EDTA) and insoluble Pu(IV) as PuO2(am) by metal reducing bacteria, the redox conditions required for this reduction, the strength of the Pu(III)-EDTA complex, how the Pu(III)-EDTA complex competes with other dominant anoxic soluble metals (e.g., Fe(II)), and the oxidation kinetics of Pu(III)-EDTA. Finally, the formation of a stable soluble Pu(III)-EDTA complex under anaerobic conditions would require degradation of the EDTA complex to limit Pu(III) transport in geologic environments. Anaerobic EDTA degrading microorganisms have not been isolated. These knowledge gaps preclude the development of a mechanistic understanding of how anaerobic conditions will influence Pu and Pu-EDTA fate and transport to assess, model, and design approaches to stop

  20. Pu(V) and Pu(IV) sorption to montmorillonite.

    PubMed

    Begg, James D; Zavarin, Mavrik; Zhao, Pihong; Tumey, Scott J; Powell, Brian; Kersting, Annie B

    2013-05-21

    Plutonium (Pu) adsorption to and desorption from mineral phases plays a key role in controlling the environmental mobility of Pu. Here we assess whether the adsorption behavior of Pu at concentrations used in typical laboratory studies (≥10(-10) [Pu] ≤ 10(-6) M) are representative of adsorption behavior at concentrations measured in natural subsurface waters (generally <10(-12) M). Pu(V) sorption to Na-montmorillonite was examined over a wide range of initial Pu concentrations (10(-6)-10(-16) M). Pu(V) adsorption after 30 days was linear over the wide range of concentrations studied, indicating that Pu sorption behavior from laboratory studies at higher concentrations can be extrapolated to sorption behavior at low, environmentally relevant concentrations. Pu(IV) sorption to montmorillonite was studied at initial concentrations of 10(-6)-10(-11) M and was much faster than Pu(V) sorption over the 30 day equilibration period. However, after one year of equilibration, the extent of Pu(V) adsorption was similar to that observed for Pu(IV) after 30 days. The continued uptake of Pu(V) is attributed to a slow, surface-mediated reduction of Pu(V) to Pu(IV). Comparison between rates of adsorption of Pu(V) to montmorillonite and a range of other minerals (hematite, goethite, magnetite, groutite, corundum, diaspore, and quartz) found that minerals containing significant Fe and Mn (hematite, goethite, magnetite, and groutite) adsorbed Pu(V) faster than those which did not, highlighting the potential importance of minerals with redox couples in increasing the rate of Pu(V) removal from solution. PMID:23614502

  1. Preventing smoking during pregnancy: the importance of maternal knowledge of the health hazards and of the treatment options available*

    PubMed Central

    Bertani, André Luís; Garcia, Thais; Tanni, Suzana Erico; Godoy, Irma

    2015-01-01

    OBJECTIVE: To examine the pattern of tobacco use and knowledge about tobacco-related diseases, as well as to identify popular types of electronic media, in pregnant women, in order to improve strategies for the prevention or cessation of smoking among such women. METHODS: A cross-sectional study involving 61 pregnant women, seen at primary care clinics and at a university hospital, in the city of Botucatu, Brazil. For all subjects, we applied the Hospital Anxiety and Depression Scale. For subjects with a history of smoking, we also applied the Fagerström Test for Nicotine Dependence, and we evaluated the level of motivation to quit smoking among the current smokers. RESULTS: Of the 61 pregnant women evaluated, 25 (40.9%) were smokers (mean age, 26.4 ± 7.4 years), 24 (39.3%) were former smokers (26.4 ± 8.3 years), and 12 (19.8%) were never-smokers (25.1 ± 7.2 years). Thirty-nine women (63.9%) reported exposure to passive smoking. Of the 49 smokers/former smokers, 13 (26.5%) were aware of the pulmonary consequences of smoking; only 2 (4.1%) were aware of the cardiovascular risks; 23 (46.9%) believed that smoking does not harm the fetus or newborn infant; 21 (42.9%) drank alcohol during pregnancy; 18 (36.7%) reported increased cigarette consumption when drinking; 25 (51.0%) had smoked flavored cigarettes; and 12 (24.5%) had smoked a narghile. Among the 61 pregnant women evaluated, television was the most widely available and favorite form of electronic media (in 85.2%), as well as being the form most preferred (by 49.2%). CONCLUSIONS: Among pregnant women, active smoking, passive smoking, and alternative forms of tobacco consumption appear to be highly prevalent, and such women seem to possess little knowledge about the consequences of tobacco use. Educational programs that include information about the consequences of all forms of tobacco use, employing new and effective formats tailored to this particular population, should be developed, in order to promote

  2. Biotransformation of PuEDTA: Implications to Pu Immobilization

    SciTech Connect

    Bolton, Harvey, Jr.

    2006-06-01

    This project integrates three distinct goals to develop a fundamental understanding of the potential fate and disposition of plutonium in sediments that are co-contaminated with EDTA. The three objectives are: (1) Develop thermodynamic data for Pu-EDTA species and determine the dominant mobile form of Pu under anaerobic conditions. (2) Elucidate the mechanism and rates of Pu(IV) and Pu(IV)-EDTA reduction by metal-reducing bacteria and determine where the Pu is located (in solution, biosorbed, bioaccumulated). (3) Enrich and isolate anaerobic EDTA-degrading microorganisms to investigate the anaerobic biodegradation of Pu-EDTA.

  3. Electronic and thermodynamic properties of α-Pu2O3

    NASA Astrophysics Data System (ADS)

    Lu, Yong; Yang, Yu; Zheng, Fawei; Zhang, Ping

    2014-08-01

    Based on density functional theory+U calculations and the quasi-annealing simulation method, we obtain the ground electronic state for α-Pu2O3 and present its phonon dispersion curves as well as various thermodynamic properties, which have seldom been theoretically studied because of the huge unit cell. We find that the Pu-O chemical bonding is weaker in α-Pu2O3 than in fluorite PuO2, and subsequently a frequency gap appears between oxygen and plutonium vibration density of states. Based on the calculated Helmholtz free energies at different temperatures, we further study the reaction energies for Pu oxidation, PuO2 reduction, and transformation between PuO2 and α-Pu2O3. Our reaction energy results are in agreements with available experiment. And it is revealed that high temperature and insufficient oxygen environment are in favor of the formation of α-Pu2O3.

  4. Pu-238 production at the Savannah River Plant

    SciTech Connect

    Roggenkamp, P.L.

    1987-11-01

    Pu-238 production capability at SRP is dependent on the availability of Np-237 feed material. With continuing operation of three production reactors at SRP, production of 46 kg Pu-238 per year can be sustained. Capacity of auxiliary facilities is adequate to support the production rates.

  5. LA-ICP-MS for Pu source identification at Mayak PA, the Urals, Russia.

    PubMed

    Cagno, S; Hellemans, K; Lind, O C; Skipperud, L; Janssens, K; Salbu, B

    2014-02-01

    Information on Pu in environmental samples is traditionally based on the determination of the (240+239)Pu activity via Alpha Spectrometry (AS). A large number of alpha spectrometry sources (planchettes) containing radiochemically separated Pu are therefore stored worldwide and are available for further analyses. These archive samples represent a resource from which valuable information on isotopic composition of alpha emitters including Pu can be obtained. The relative abundances of Pu isotopes can be used to trace specific Pu sources and characterize the relative contributions of different Pu sources in a sample. Thus, in addition to the total (239+240)Pu activity, determination of the (240)Pu/(239)Pu ratio can provide valuable information on the nature of the Pu emitting sources. The Pu isotopic ratios can be determined by mass spectrometry techniques such as Sector Field Inductively Coupled Plasma Mass Spectrometry (SF-ICPMS) or Accelerator Mass Spectrometry (AMS) that require dissolution and complete destruction of the material deposited on the planchettes. In this study Laser Ablation (LA)-quadrupole-ICP-MS has been employed for the analysis of (239)Pu/(240)Pu ratios from alpha-planchettes prepared from samples originating from the Mayak PA nuclear facility, Russia. The results are compared with data from AMS and show that the (240)Pu/(239)Pu ratios obtained by LA-ICP-MS can be utilized to distinguish weapons-grade Pu from civil reprocessing sources. Moreover, isotope ratio mapping can also be performed across the planchettes, allowing e.g. the visualization of possible inhomogeneities in the Pu-isotope distribution on their surface. Thus, this solid sample technique can be applied to extract additional information from existing archives of samples. PMID:24424783

  6. Formation of Pu amorphous alloys or metastable structures in Pu-Fe, Pu-Ta, and Pu-Si alloys

    SciTech Connect

    Rizzo, H.F.; Echeverria, A.W.

    1985-08-20

    Sputter deposition technique was used to study the possible formation of amorphous structures in Pu-Fe, Pu-Ta, and Pu-Si systems. A triode sputtering system was used to prepare sputtered coatings: 13 to 59 at. % (a/o) Fe, 10 to 50 a/o Si, and 15 to 65 a/o Ta. Structure of the coatings was determined by x-ray diffraction techniques. The temperature stability of the obtained structures was determined by Differential Scanning Calorimetry (DSC) measurements. The Pu-Fe and Pu-Si binary systems showed strong evidence for the formation of amorphous phases in the sputtered coatings. X-ray analyses indicated the presence of Pu6Fe in the 13 to 20 a/o Fe range of Pu-Fe alloys and no apparent crystalline phases over the entire 10 to 50 a/o Si range of Pu-Si alloys. In the Pu-Ta system, the DSC data obtained for compositions below 50 a/o Ta did not show typical crystallization exotherms. At compositions above 50 a/o Ta, a metastable bcc alpha Ta structure was observed with an expanded lattice parameter. The calculated volume expansion (2.9%) corresponds to 29 a/o of Pu in solid solution if the lattice parameter is assumed to follow Vegards Law. After storage in a nitrogen glovebox atmosphere for over two years, the Pu-Si and Pu-Ta coatings have maintained a metallic luster and have shown no visible evidence of surface oxidation.

  7. Preliminary studies of Pu measurement by AMS using PuF4-

    NASA Astrophysics Data System (ADS)

    Zhao, X.-L.; Kieser, W. E.; Dai, X.; Priest, N. D.; Kramer-Tremblay, S.; Eliades, J.; Litherland, A. E.

    2013-01-01

    Using targets made with PbF2 matrices, Cs+ sputter sources have been found to yield element-specific patterns of molecular fluoride anions that may be used to enhance the mass spectrometry of certain elements. While the patterns are found similar for all lanthanides and the heavier actinides, substantial differences are found for the lighter actinides. In the case of Pu and U, of all their fluoride anions, PuF4- and UF5- are produced with the highest yield. Mass spectrometry of Pu using PuF4- can provide a partial chemical separation in the ion source, as the yield of UF4- is two orders of magnitude lower than that of the UF5-. This, in turn, reduces scattering of U ions when measuring Pu in the high-energy components of the AMS system. This instrumental reduction of U is advantageous in cases that require rapid Pu analyses as it simplifies the chemistry of Pu/U separation and other steps in the sample processing. In this procedure, Pu can be co-precipitated with another element as a fluoride, which is then mixed with a sufficient amount of PbF2 powder to form a sputter target. A series of tests were carried out and NdF3 was identified as one such suitable carrier. Measurements of Pu+3 at ∼0.85 MV terminal voltage showed that the 239,240,241,242Pu isotopes can be detected with a manageably low background, high efficiency and a 1 fg detection limit. Preliminary tests were carried out using the existing IsoTrace AMS system, modified only by the addition of electronic controls to automatically adjust the terminal voltage and all high-energy electric analyzers, along with the injection magnet bouncer. However, both the injection and detection systems were not designed for this task, so considerable room is available for reducing the detection limit into the ag range with modern AMS systems - such as the one being commissioned at University of Ottawa.

  8. Katimavik Options.

    ERIC Educational Resources Information Center

    Crelinsten, Michael; And Others

    Designed for students who are just about to complete Katimavik (a nine-month volunteer community service and experiential learning program for 17 to 21-year-old Canadian youth), the bilingual information guide presents facts and considerations about options in lifestyle, academic attainment, and career goals available as a result of Katimavik…

  9. Elastic properties of Pu metal and Pu-Ga alloys

    SciTech Connect

    Soderlind, P; Landa, A; Klepeis, J E; Suzuki, Y; Migliori, A

    2010-01-05

    We present elastic properties, theoretical and experimental, of Pu metal and Pu-Ga ({delta}) alloys together with ab initio equilibrium equation-of-state for these systems. For the theoretical treatment we employ density-functional theory in conjunction with spin-orbit coupling and orbital polarization for the metal and coherent-potential approximation for the alloys. Pu and Pu-Ga alloys are also investigated experimentally using resonant ultrasound spectroscopy. We show that orbital correlations become more important proceeding from {alpha} {yields} {beta} {yields} {gamma} plutonium, thus suggesting increasing f-electron correlation (localization). For the {delta}-Pu-Ga alloys we find a softening with larger Ga content, i.e., atomic volume, bulk modulus, and elastic constants, suggest a weakened chemical bonding with addition of Ga. Our measurements confirm qualitatively the theory but uncertainties remain when comparing the model with experiments.

  10. Designing Pu600 for Authentication

    SciTech Connect

    White, G

    2008-07-10

    Many recent Non-proliferation and Arms Control software projects include an authentication component. Demonstrating assurance that software and hardware performs as expected without hidden 'back-doors' is crucial to a project's success. In this context, 'authentication' is defined as determining that the system performs only its intended purpose and performs that purpose correctly and reliably over many years. Pu600 is a mature software solution for determining the presence of Pu and the ratio of Pu240 to Pu239 by analyzing the gamma ray spectra in the 600 KeV region. The project's goals are to explore hardware and software technologies which can by applied to Pu600 which ease the authentication of a complete, end-to-end solution. We will discuss alternatives and give the current status of our work.

  11. Magnetic Properties of Radiation Damage in Pu and Pu Alloys

    SciTech Connect

    McCall, S; Fluss, M J; Chung, B; Chapline, G; McElfresh, M; Jackson, D; Baclet, N; Jolly, L; Dormeval, M

    2005-03-31

    Among the many exceptional properties of Pu is its apparent lack of either local moments or cooperative magnetism. Lashley et al., have recently noted that little experimental evidence for the existence of local moments or collective magnetism has been found in over 50 years. Nevertheless the search for local moments in Pu and Pu-alloys continues, why? Plutonium's physical properties: resistance, magnetic susceptibility, and heat capacity, all support a system with an enhanced electron density of states. Pu sits on the edge of both magnetism and superconductivity and possesses one of the highest elemental Pauli susceptibilities, consistent with a highly correlated electron system. The low-density {delta}-Pu has eluded full first principles description and is both a challenge and an area of active investigation for theorists. The complex changes associated with the transition between the light and heavy actinides happen within the phase diagram of Pu, thus making Pu an intriguing and challenging solid-state system for continuing experimental and theoretical investigation. Recently, Griveau et al., observed the variations in the resistance and superconducting properties of Am metal as a function of pressure to 27GPa and T>0.4K. They postulate that the interesting features in the superconducting critical temperature, T{sub c}, vs. pressure, indicate a Mott-like, f-electron localization-delocalization transition as pressure drives Am towards a Pu and then a U-like structure. Hence, we posit that it would be reasonable to expect that dilating the Pu lattice will bring one to a similar transition. Experimental evidence supporting this point of view is given here.

  12. Evaluation Report of the Presidential/Secretarial Objective -- School Management Options Available to Indian People. Research and Evaluation Report Series No. 29.08.

    ERIC Educational Resources Information Center

    National Indian Training and Research Center, Tempe, AZ.

    Presenting evaluations of the Bureau of Indian Affairs' (BIA) implementation of the School Management Option Project, a project designed to further American Indian control of schools and elevated to the status of Presidential/Secretarial Objective (P/SO) in 1974, this report includes separate evaluations by the National Indian Training and…

  13. Pu Anion Exchange Process Intensification

    SciTech Connect

    Taylor-Pashow, K.

    2015-10-08

    This project seeks to improve the efficiency of the plutonium anion-exchange process for purifying Pu through the development of alternate ion-exchange media. The objective of the project in FY15 was to develop and test a porous foam monolith material that could serve as a replacement for the current anion-exchange resin, Reillex® HPQ, used at the Savannah River Site (SRS) for purifying Pu. The new material provides advantages in efficiency over the current resin by the elimination of diffusive mass transport through large granular resin beads. By replacing the large resin beads with a porous foam there is much more efficient contact between the Pu solution and the anion-exchange sites present on the material. Several samples of a polystyrene based foam grafted with poly(4-vinylpyridine) were prepared and the Pu sorption was tested in batch contact tests.

  14. You Want Me to Learn How?: Today's Teachers Have a Range of Personalized Learning Options Available to Them, Often for Free. Which Will You Choose in Your Quest to Be a Better Teacher?

    ERIC Educational Resources Information Center

    Dill, Dennis

    2015-01-01

    Today's teachers have many personalized learning options available to them, and several are free. The author discusses how to use social media for professional learning, describes edcamps where much of the focus is on teaching best practices, technology usage, and connecting and collaborating with other education professionals, and the advantages…

  15. Program Pu Futures 2006

    SciTech Connect

    Fluss, M

    2006-06-12

    The coordination chemistry of plutonium remains relatively unexplored. Thus, the fundamental coordination chemistry of plutonium is being studied using simple multi-dentate ligands with the intention that the information gleaned from these studies may be used in the future to develop plutonium-specific sequestering agents. Towards this goal, hard Lewis-base donors are used as model ligands. Maltol, an inexpensive natural product used in the commercial food industry, is an ideal ligand because it is an all-oxygen bidentate donor, has a rigid structure, and is of small enough size to impose little steric strain, allowing the coordination preferences of plutonium to be the deciding geometric factor. Additionally, maltol is the synthetic precursor of 3,4-HOPO, a siderophore-inspired bidentate moiety tested by us previously as a possible sequestering agent for plutonium under acidic conditions. As comparisons to the plutonium structure, Ce(IV) complexes of the same and related ligands were examined as well. Cerium(IV) complexes serve as good models for plutonium(IV) structures because Ce(IV) has the same ionic radius as Pu(IV) (0.94 {angstrom}). Plutonium(IV) maltol crystals were grown out of a methanol/water solution by slow evaporation to afford red crystals that were evaluated at the Advanced Light Source at Lawrence Berkeley National Laboratory using single crystal X-ray diffraction. Cerium(IV) complexes with maltol and bromomaltol were crystallized via slow evaporation of the mother liquor to afford tetragonal, black crystals. All three complexes crystallize in space group I4{sub 1}/a. The Ce(IV) complex is isostructural with the Pu(IV) complex, in which donating oxygens adopt a trigonal dodecahedral geometry around the metal with the maltol rings parallel to the crystallographic S{sub 4} axis and lying in a non-crystallographic mirror plane of D{sub 2d} molecular symmetry (Fig 1). The metal-oxygen bonds in both maltol complexes are equal to within 0.04 {angstrom

  16. Eleven-year field study of Pu migration from Pu III, IV, and VI sources.

    PubMed

    Kaplan, Daniel I; Demirkanli, Deniz I; Gumapas, Leo; Powell, Brian A; Fjeld, Robert A; Molz, Fred J; Serkiz, Steven M

    2006-01-15

    Understanding the processes controlling Pu mobility in the subsurface environment is important for estimating the amount of Pu waste that can be safely disposed in vadose zone burial sites. To study long-term Pu mobility, four 52-L lysimeters filled with sediment collected from the Savannah River Site near Aiken, South Carolina were amended with well-characterized solid Pu sources (PuIIICl3, PuIV(NO3)4, PuIV(C2O4)2, and PuVIO2(NO3)2) and left exposed to natural precipitation for 2-11 years. Pu oxidation state distribution in the Pu(III) and Pu(IV) lysimeters sediments (a red clayey sediment, pH = 6.3) were similar, consisting of 0% Pu(III), >92% Pu(IV), 1% Pu(V), 1% Pu(VI), and the remainder was a Pu polymer. These three lysimeters also had near identical sediment Pu concentration profiles, where >95% of the Pu remained within 1.25 cm of the source after 11 years; the other 5% of Pu moved at an overall rate of 0.9 cm yr(-1). As expected, Pu moved more rapidly through the Pu(VI) lysimeter, at an overall rate of 12.5 cm yr(-1). Solute transport modeling of the sediment Pu concentration profile data in the Pu(VI) lysimeter indicated that some transformation of Pu into a much less mobile form, presumably Pu(IV), had occurred during the course of the two-year study. This modeling also supported previous laboratory measurements showing that Pu(V) or Pu(VI) reduction was 5 orders of magnitude faster than corresponding Pu(III) or Pu(IV) oxidation. The slow oxidation rate (1 x 10(-8) hr(-1); t1/2 = 8000 yr) was not discernible from the Pu(VI) lysimeter data that reflected only two years of transport butwas readily discernible from the Pu(III) and Pu(IV) lysimeter data that reflected 11 years of transport. PMID:16468387

  17. Determination of plutonium isotopes (238Pu, 239Pu, 240Pu, 241Pu) in environmental samples using radiochemical separation combined with radiometric and mass spectrometric measurements.

    PubMed

    Xu, Yihong; Qiao, Jixin; Hou, Xiaolin; Pan, Shaoming; Roos, Per

    2014-02-01

    This paper reports an analytical method for the determination of plutonium isotopes ((238)Pu, (239)Pu, (240)Pu, (241)Pu) in environmental samples using anion exchange chromatography in combination with extraction chromatography for chemical separation of Pu. Both radiometric methods (liquid scintillation counting and alpha spectrometry) and inductively coupled plasma mass spectrometry (ICP-MS) were applied for the measurement of plutonium isotopes. The decontamination factors for uranium were significantly improved up to 7.5 × 10(5) for 20 g soil compared to the level reported in the literature, this is critical for the measurement of plutonium isotopes using mass spectrometric technique. Although the chemical yield of Pu in the entire procedure is about 55%, the analytical results of IAEA soil 6 and IAEA-367 in this work are in a good agreement with the values reported in the literature or reference values, revealing that the developed method for plutonium determination in environmental samples is reliable. The measurement results of (239+240)Pu by alpha spectrometry agreed very well with the sum of (239)Pu and (240)Pu measured by ICP-MS. ICP-MS can not only measure (239)Pu and (240)Pu separately but also (241)Pu. However, it is impossible to measure (238)Pu using ICP-MS in environmental samples even a decontamination factor as high as 10(6) for uranium was obtained by chemical separation. PMID:24401459

  18. Rehabilitation Options

    MedlinePlus

    ... Speech Pathology Occupational Therapy Art Therapy Recreational therapy Neuropsychology Home Care Options Advanced Care Planning Palliative Care ... Speech Pathology Occupational Therapy Art Therapy Recreational therapy Neuropsychology Home Care Options Advanced Care Planning Palliative Care ...

  19. Great Careers in Two Years: The Associate Degree Option. High Skill and High Wage Jobs Available through Two-Year Programs.

    ERIC Educational Resources Information Center

    Phifer, Paul

    This book explores high-skill and high-wage jobs available through two-year programs. It identifies 100 high-need occupational areas, and discusses "hot" programs and starting salaries for graduates of dental hygiene, manufacturing, process technology, telecommunications, physical therapy assisting, and registered nursing. Each career article…

  20. Global plutonium management: A security option

    SciTech Connect

    Sylvester, K.W.B.

    1998-12-31

    The US surplus plutonium disposition program was created to reduce the proliferation risk posed by the fissile material from thousands of retired nuclear weapons. The Department of Energy has decided to process its Put into a form as secure as Pu in civilian spent fuel. While implementation issues have been considered, a major one (Russian reciprocity) remains unresolved. Russia has made disposition action conditional on extracting the fuel value of its Pu but lacks the infrastructure to do so. Assistance in the construction of the required facilities would conflict with official US policy opposing the development of a Pu fuel cycle. The resulting stagnation provides impetus for a reevaluation of US nonproliferation objectives and Pu disposition options. A strategy for satisfying Russian fuel value concerns and reducing the proliferation risk posed by surplus weapons-grade plutonium (WGPu) is proposed. The effectiveness of material alteration (e.g., isotopic, chemical, etc.{hor_ellipsis}) at reducing the desire, ability and opportunity for proliferation is assessed. Virtually all the security benefits attainable by material processing can be obtained by immobilizing Pu in large unit size/mass monoliths without a radiation barrier. Russia would be allowed to extract the Pu at a future date for use as fuel in a verifiable manner. Remote tracking capability, if proven feasible, would further improve safeguarding capability. As an alternate approach, the US could compensate Russia for its Pu, allowing it to be disposed of or processed elsewhere. A market based method for pricing Pu is proposed. Surplus Pu could represent access to nuclear fuel at a fixed price at a future date. This position can be replicated in the uranium market and priced using derivative theory. The proposed strategy attempts to meet nonproliferation objectives by recognizing technical limitations and satisfying political constraints.

  1. Study of Pu consumption in light water reactors: Evaluation of GE advanced boiling water reactor plants, compilation of Phase 1C task reports

    SciTech Connect

    Not Available

    1994-01-15

    This report summarizes the evaluations conducted during Phase 1C of the Pu Disposition Study have provided further results which reinforce the conclusions reached during Phase 1A & 1B: These conclusions clearly establish the benefits of the fission option and the use of the ABWR as a reliable, proven, well-defined and cost-effective means available to disposition the weapons Pu. This project could be implemented in the near-term at a cost and on a schedule being validated by reactor plants currently under construction in Japan and by cost and schedule history and validated plans for MOX plants in Europe. Evaluations conducted during this phase have established that (1) the MOX fuel is licensable based on existing criteria for new fuel with limited lead fuel rod testing, (2) that the applicable requirements for transport, handling and repository storage can be met, and (3) that all the applicable safeguards criteria can be met.

  2. Pricing Options.

    ERIC Educational Resources Information Center

    Tenopir, Carol

    1998-01-01

    Presents results of a recent survey of over 100 public and academic libraries about pricing options from online companies. Most options fall into three categories: pay-as-you-go, fixed-rate, and user-based. Results are discussed separately for public and academic libraries and for consortial discounts. Trends in pricing options preferred by…

  3. Controls on soluble Pu concentrations in PuO2/magnetite suspensions.

    PubMed

    Felmy, Andrew R; Moore, Dean A; Pearce, Carolyn I; Conradson, Steven D; Qafoku, Odeta; Buck, Edgar C; Rosso, Kevin M; Ilton, Eugene S

    2012-11-01

    Time-dependent reduction of PuO(2)(am) was studied over a range of pH values in the presence of aqueous Fe(II) and magnetite (Fe(3)O(4)) nanoparticles. At early time frames (up to 56 days) very little aqueous Pu was mobilized from PuO(2)(am), even though measured pH and redox potentials, coupled to equilibrium thermodynamic modeling, indicated the potential for significant reduction of PuO(2)(am) to relatively soluble Pu(III). Introduction of Eu(III) or Nd(III) to the suspensions as competitive cations to displace possible sorbed Pu(III) resulted in the release of significant concentrations of aqueous Pu. However, the similarity of aqueous Pu concentrations that resulted from the introduction of Eu(III)/Nd(III) to suspensions with and without magnetite indicated that the Pu was solubilized from PuO(2)(am), not from magnetite. PMID:23016948

  4. Distinguishing Pu Metal From Pu Oxide Using Fast Neutron Counting

    SciTech Connect

    Verbeke, J M; Chapline, G F; Nakae, L; Wurtz, R; Sheets, S

    2012-05-29

    We describe a method for simultaneously determining the {alpha}-ratio and k{sub eff} for fissile materials using fast neutrons. Our method is a generalization of the Hage-Cifarrelli method for determining k{sub eff} for fissile assemblies which utilizes the shape of the fast neutron spectrum. In this talk we illustrate the method using Monte Carlo simulations of the fast neutrons generated in PuO{sub 2} to calculate the fast neutron spectrum and Feynman correlations.

  5. Activity ratios of 137Cs, 90Sr and 239+240Pu in environmental samples.

    PubMed

    Bossew, P; Lettner, H; Hubmer, A; Erlinger, C; Gastberger, M

    2007-01-01

    Both global and Chernobyl fallout have resulted in environmental contamination with radionuclides such as 137Cs, 90Sr and 239+240Pu. In environmental samples, 137Cs and 239+240Pu can be divided into the contributions of either source, if also the isotopes 134Cs and 238Pu are measurable, based on the known isotopic ratios in global and Chernobyl fallout. No analogous method is available for 90Sr. The activity ratios of Sr to Cs and Pu, respectively, are known for the actual fallout mainly from air filter measurements; but due to the high mobility of Sr in the environment, compared to Cs and Pu, these ratios generally do not hold for the inventory many years after deposition. In this paper we suggest a method to identify the mean contributions of global and Chernobyl fallout to total Sr in soil, sediment and cryoconite samples from Alpine and pre-Alpine regions of Austria, based on a statistical evaluation of Sr/Cs/Pu radionuclide activity ratios. Results are given for Sr:Cs, Sr:Pu and Cs:Pu ratios. Comparison with fallout data shows a strong depletion of Sr against Cs and Pu. PMID:17407799

  6. EnEnvironmental Mobility of Pu(IV) in the Presence of Ethylenediaminetetraacetic Acid: Myth or Reality

    SciTech Connect

    Rai, Dhanpat; Moore, Dean A.; Rosso, Kevin M.; Felmy, Andrew R.; Bolton, Harvey

    2008-07-01

    Ethylenediaminetetracetic acid (EDTA), which was co-disposed with Pu at several U. S. Department of Energy sites, has been reported to enhance the solubility and transport of Pu. It is generally assumed that this enhanced transport of Pu in geologic environments is a result of complexation of Pu(IV) with EDTA. However, the fundamental bases for this assumption have never been fully explored. Whether EDTA can mobilize Pu(IV) in geologic environments is dependent on many factors, chief among them are not only the complexation constants of Pu with EDTA and dominant oxidation state and the nature of Pu solids, but also 1) the complexation constants of environmentally important metal ions (e.g. Fe, Al, Ca, Mg) that compete with Pu for EDTA and 2) EDTA interactions with geomedia (e.g., adsorption, biodegradation) that reduce effective EDTA concentrations available for complexation. Extensive studies over a large range of pH values (1 to 14) and EDTA concentrations (0.0001 to 0.01 M) as a function of time were conducted on the solubility of 2-line ferrihydrite (Fe(OH)3(s)), PuO2(am) in the presence of different concentrations of Ca ions, and mixtures of PuO2(am) and Fe(OH)3(s). The solubility data were interpreted using Pitzer’s ion-interaction approach to determine/validate the solubility product of Fe(OH)3(s), the complexation constants of Pu(IV)-EDTA and Fe(III)-EDTA, and to determine the affect of EDTA in solubilizing Pu(IV) from PuO2(am) in the presence of Fe(III) compounds and aqueous Ca concentrations. Predictions based on these extensive fundamental data show that environmental mobility of Pu as a result of Pu(IV)-EDTA complexation as reported/implied in the literature is a myth rather than the reality.

  7. Oxidation of Pu-bearing solids: A process for Pu recovery from Rocky Flats incinerator ash

    SciTech Connect

    Karraker, D.G.

    1997-07-18

    High-fired PuO{sub 2}, RFP ash heels, and synthetic RFP incinerator ash were easily soluble after oxidation of Pu(IV) to Pu(VI) by heating with Na{sub 2}O{sub 2} or KO{sub 2} to 450{degrees} for two hours. This offers a route to the recovery of Pu from these and similar PuO{sub 2}-bearing solids that can be carried out in present equipment. Evidence for new compounds K{sub 2}PuO{sub 4}, K{sub 4}PuO{sub 5} and K{sub 6}PuO{sub 6} is presented. A process for recovery of Pu from RFP incinerator ash is presented.

  8. Economical Production of Pu-238: NIAC Phase I Final Report

    NASA Technical Reports Server (NTRS)

    Howe, Steven D.; Crawford, Douglas; Navarro, Jorge; O'Brien, Robert C.; Katalenich, Jeff; Ring, Terry

    2016-01-01

    All space exploration missions traveling beyond Jupiter must use radioisotopic power sources for electrical power. The best isotope to power these sources is plutonium-238 (Pu-238). The US supply of Pu-238 is almost exhausted and will be gone within the next decade. The Department of Energy has initiated a production program with a $10M allocation from NASA but the cost is estimated at over $100M to get to production levels. The Center for Space Nuclear Research (CSNR) has conceived of a potentially better process to produce Pu-238 earlier and for significantly less cost. Potentially, the front end capital costs could be provided by private industry such that the government only had to pay for the product produced. In the Phase I NIAC (NASA Innovative Advanced Concepts) grant, the CSNR has evaluated the feasibility of using a low power, commercially available nuclear reactor to produce 1.5 kg of Pu-238 per year. The impact on the neutronics of the reactor have been assessed, the amount of Neptunium target material estimated, and the production rates calculated. In addition, the size of the post-irradiation processing facility has been established. Finally, as the study progressed, a new method for fabricating the Pu-238 product into the form used for power sources has been identified to reduce the cost of the final product. In short, the concept appears to be viable, can produce the amount of Pu-238 needed to support the NASA missions, can be available within a few years, and will cost significantly less than the current DOE program.

  9. Controls on Soluble Pu Concentrations in PuO2/Magnetite Suspensions

    SciTech Connect

    Felmy, Andrew R.; Moore, Dean A.; Pearce, Carolyn I.; Conradson, Steven D.; Qafoku, Odeta; Buck, Edgar C.; Rosso, Kevin M.; Ilton, Eugene S.

    2012-11-06

    Time-dependent reduction of PuO2(am) was studied over a range of pH values in the presence of aqueous Fe(II) and magnetite (Fe3O4) nanoparticles. At early time frames (up to 56 days) very little aqueous Pu was mobilized from PuO2(am), even though measured pH and redox potentials, coupled to equilibrium thermodynamic modeling indicated the potential for significant reduction of PuO2(am) to relatively soluble Pu(III). Introduction of Eu(III) or Nd(III) to the suspensions as competitive cations to displace possible sorbed Pu(III) resulted in the release of significant concentrations of aqueous Pu. However, the similarity of aqueous Pu concentrations that resulted from the introduction of Eu(III)/Nd(III) to suspensions with and without magnetite indicated that the Pu was displaced from the PuO2(am), not from magnetite. The fact that soluble forms of Pu can be displaced from the surface of PuO2(am) represents a potential, but previously unidentified, source of Pu to aqueous solution or subsurface groundwaters.

  10. Pu electronic structure and photoelectron spectroscopy

    SciTech Connect

    Joyce, John J; Durakiewicz, Tomasz; Graham, Kevin S; Bauer, Eric D; Moore, David P; Mitchell, Jeremy N; Kennison, John A; Martin, Richard L; Roy, Lindsay E; Scuseria, G. E.

    2010-01-01

    The electronic structure of PuCoGa{sub 5}, Pu metal, and PuO{sub 2} is explored using photoelectron spectroscopy. Ground state electronic properties are inferred from temperature dependent photoemission near the Fermi energy for Pu metal. Angle-resolved photoemission details the energy vs. crystaJ momentum landscape near the Fermi energy for PuCoGa{sub 5} which shows significant dispersion in the quasiparticle peak near the Fermi energy. For the Mott insulators AnO{sub 2}(An = U, Pu) the photoemission results are compared against hybrid functional calculations and the model prediction of a cross over from ionic to covalent bonding is found to be reasonable.

  11. Adsorption of Atmospheric Gases on Pu Surfaces

    SciTech Connect

    Nelson, A J; Holliday, K S; Stanford, J A; Grant, W K; Erler, R G; Allen, P G; McLean, W; Roussel, P

    2012-03-29

    Surface adsorption represents a competition between collision and scattering processes that depend on surface energy, surface structure and temperature. The surface reactivity of the actinides can add additional complexity due to radiological dissociation of the gas and electronic structure. Here we elucidate the chemical bonding of gas molecules adsorbed on Pu metal and oxide surfaces. Atmospheric gas reactions were studied at 190 and 300 K using x-ray photoelectron spectroscopy. Evolution of the Pu 4f and O 1s core-level states were studied as a function of gas dose rates to generate a set of Langmuir isotherms. Results show that the initial gas dose forms Pu{sub 2}O{sub 3} on the Pu metal surface followed by the formation of PuO{sub 2} resulting in a layered oxide structure. This work represents the first steps in determining the activation energy for adsorption of various atmospheric gases on Pu.

  12. Comparative skeletal distribution of Am and Pu in man, monkey, and baboon

    SciTech Connect

    Lynch, T.P.; Kathren, R.L.; Dagle, G.E.; McInroy, J.F. )

    1989-01-01

    The skeletal distribution of Am and Pu in four human cases was compared with the skeletal distributions of these radioelements in baboons and monkeys. Excellent agreement was noted among the four human cases; data were available for Am in all four and Pu in three. A statistically significant correlation was found between the {sup 241}Am and {sup 239}Pu + {sup 240}Pu skeletal distributions in the humans and those in nonhuman primates. Trabecular bone had the highest concentrations of {sup 241}Am and {sup 239+240}Pu in humans, baboons, and monkeys. Scaling factors are proposed to convert the percentages of skeletal activity in animal bones to the corresponding percentages in the bones of the human skeleton.

  13. Highly accurate measurements of the spontaneous fission half-life of 240,242Pu

    NASA Astrophysics Data System (ADS)

    Salvador-Castiñeira, P.; Bryś, T.; Eykens, R.; Hambsch, F.-J.; Moens, A.; Oberstedt, S.; Sibbens, G.; Vanleeuw, D.; Vidali, M.; Pretel, C.

    2013-12-01

    Fast spectrum neutron-induced fission cross-section data for transuranic isotopes are of special demand from the nuclear data community. In particular highly accurate data are needed for the new generation IV nuclear applications. The aim is to obtain precise neutron-induced fission cross sections for 240Pu and 242Pu. To do so, accurate data on spontaneous fission half-lives must be available. Also, minimizing uncertainties in the detector efficiency is a key point. We studied both isotopes by means of a twin Frisch-grid ionization chamber with the goal of improving the present data on the neutron-induced fission cross section. For the two plutonium isotopes the high α-particle decay rates pose a particular problem to experiments due to piling-up events in the counting gas. Argon methane and methane were employed as counting gases, the latter showed considerable improvement in signal generation due to its higher drift velocity. The detection efficiency for both samples was determined, and improved spontaneous fission half-lives were obtained with very low statistical uncertainty (0.13% for 240Pu and 0.04% for 242Pu): for 240Pu, T1/2,SF=1.165×1011 yr (1.1%), and for 242Pu, T1/2,SF=6.74×1010 yr (1.3%). Systematic uncertainties are due to sample mass (0.4% for 240Pu and 0.9% for 242Pu) and efficiency (1%).

  14. The Origins of Options

    PubMed Central

    Smaldino, Paul E.; Richerson, Peter J.

    2012-01-01

    Most research on decision making has focused on how human or animal decision makers choose between two or more options, posed in advance by the researchers. The mechanisms by which options are generated for most decisions, however, are not well understood. Models of sequential search have examined the trade-off between continued exploration and choosing one’s current best option, but still cannot explain the processes by which new options are generated. We argue that understanding the origins of options is a crucial but untapped area for decision making research. We explore a number of factors which influence the generation of options, which fall broadly into two categories: psycho-biological and socio-cultural. The former category includes factors such as perceptual biases and associative memory networks. The latter category relies on the incredible human capacity for culture and social learning, which doubtless shape not only our choices but the options available for choice. Our intention is to start a discussion that brings us closer toward understanding the origins of options. PMID:22514515

  15. Use of plutonium isotope activity ratios in dating recent sediments. [/sup 238/Pu//sup 239/Pu + /sup 240/Pu

    SciTech Connect

    Beasley, T. M.

    1982-01-01

    The majority of plutonium presently in the biosphere has come from the testing of nuclear devices. In the early 1950s, the Pu-238/239+240 activity ratio of fallout debris was > 0.04; in the more extensive test series of 1961 to 1962, the Pu-238/239+240 activity ratios were quite consistent at 0.02 to 0.03 and maximum fallout delivery occurred in mid-1963. A significant perturbation in Pu isotope activity ratios occurred in mid-1966 with the deposition of Pu-238 from the SNAP-9A reentry and burn-up. Recently deposited sediments have recorded these events and where accumulation rates are rapid (> 1 cm/y), changes in Pu isotope activity ratios can be used as a geochronological tool.

  16. Code System to Determine Pu Isotope Abundances from Multichannel Analyzer Gamma Spectra.

    Energy Science and Technology Software Center (ESTSC)

    2008-09-26

    Version 00 The MGA (Multiple Group Analysis) program determines the relative abundances of plutonium and other actinide isotopes in different materials. The program analyzes spectra taken of such samples using a 4096-channel germanium (Ge) gamma-ray spectrometer. The code can be run in a one or two detector mode. The first spectrum, which is required and must be taken at a gain of 0.075 Kev/channel with a high resolution planar detector, contains the 0-300Kev energy region.more » The second spectrum, which is optional, must be taken at a gain of 0.25 Kev/channel; it becomes important when analyzing high burnup samples (concentration of Pu241 greater than one percent). Isotopic analysis precisions of one percent or better can be obtained, and no calibrations are required. The system also measures the abundances of U235, U238, Np237, and Am241. A special calibration option is available to perform a one-time peak-shape characterization when first using a new detector system.« less

  17. Fractionation of (137)Cs and Pu in natural peatland.

    PubMed

    Mihalík, Ján; Bartusková, Miluše; Hölgye, Zoltán; Ježková, Tereza; Henych, Ondřej

    2014-08-01

    High Cs-137 concentrations in plants growing on peatland inspired us to investigate the quantity of its bioavailable fraction in natural peat. Our investigation aims to: a) estimate the quantity of bioavailable Cs-137 and Pu present in peat, b) verify the similarity of Cs-137 and K-40 behaviours, and c) perform a quantification of Cs-137 and Pu transfer from peat to plants. We analysed the vertical distribution of Cs-137 and Pu isotopes in the peat and their concentrations in plants growing on these places. Bioavailability of radionuclides was investigated by sequential extraction. Sequential analyses revealed that it was the upper layer which contained the majority of Cs-137 in an available form while deeper layers retained Cs-137 in immobile fractions. We can conclude that 18% of all Cs-137 in the peat is still bioavailable. Despite of the low quantity of bioavailable fraction of Cs-137 its transfer factor reached extremely high values. In the case of Pu, 64% of its total amount was associated with fulvic/humic acids which resulted in the high transfer factor from peat to plants. 27 years after the Chernobyl nuclear accident, the significant part of radionuclides deposited in peatland is still bioavailable. PMID:24631917

  18. Probing the Pu4 + magnetic moment in PuF4 with 19F NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Capan, Cigdem; Dempsey, Richard J.; Sinkov, Sergey; McNamara, Bruce K.; Cho, Herman

    2016-06-01

    The magnetic fields produced by Pu4 + centers have been measured by 19F NMR spectroscopy to elucidate the Pu-F electronic interactions in polycrystalline PuF4. Spectra acquired at applied fields of 2.35 and 7.05 T reveal a linear scaling of the 19F line shape. A model is presented that treats the line broadening and shifts as due to dipolar fields produced by Pu valence electrons in localized noninteracting orbitals. Alternative explanations for the observed line shape involving covalent Pu-F bonding, superexchange interactions, and electronic configurations with enhanced magnetic moments are considered.

  19. MGA Analysis on Elevated 238 Pu Samples

    NASA Astrophysics Data System (ADS)

    Wang, T. F.; Moody, K. J.; Raschke, K. E.; Ruhter, W. D.

    2002-10-01

    Plutonium gamma-ray data analysis, in the 100-keV region, using MGA has been improved to overcome the original maximum limit of 2% 238Pu relative plutonium content in a sample in order to perform an analysis. MGA analysis results of elevated 238Pu samples are compared to the results from mass spectrometry.

  20. Traits of bulk Pu phases in Pb-Pu superlattice phases from first principles

    NASA Astrophysics Data System (ADS)

    Rudin, Sven P.

    2007-11-01

    Density functional theory calculations allowing spin polarization predict two phases in Pb-Pu superlattices. One phase exhibits bond lengths similar to bulk α-Pu and a degree of localization of 5f electron states corresponding to bulk β-Pu , while for the other phase, these take on values like those found in bulk δ-Pu . The superlattice geometry localizes the 5f electron states mainly in planes perpendicular to the stacking direction. The disparate volumes between phases found in bulk Pu also emerge in Pb-Pu superlattices. The structures of the two phases differ in the presence of pairing between neighboring Pu planes. The paired and unpaired phases can coexist in special cases. The simple geometry of the pairing allows for detailed calculations to explore the transition along the complete path connecting the two phases; to date, the bulk phases have evaded such an examination. In Pb-Pu superlattices, the localization of 5f electron states smoothly parallels changes in geometry, in accordance with tendencies that emerge in bulk Pu calculations. Changing the layer thicknesses affects the ordering of the energies of the two phases for stacking along the (001) and (111) directions. For stacking in the (011) direction, only one phase appears with very weakly paired Pu planes. Compared to bulk Pb and Pu, the superlattices with single-monolayer thicknesses appear energetically favorable; pilot calculations suggest that thicker layers become energetically favorable with interface alloying.

  1. Optimization of burnable poison design for Pu incineration in fully fertile free PWR core

    SciTech Connect

    Fridman, E.; Shwageraus, E.; Galperin, A.

    2006-07-01

    The design challenges of the fertile-free based fuel (FFF) can be addressed by careful and elaborate use of burnable poisons (BP). Practical fully FFF core design for PWR reactor has been reported in the past [1]. However, the burnable poison option used in the design resulted in significant end of cycle reactivity penalty due to incomplete BP depletion. Consequently, excessive Pu loading were required to maintain the target fuel cycle length, which in turn decreased the Pu burning efficiency. A systematic evaluation of commercially available BP materials in all configurations currently used in PWRs is the main objective of this work. The BP materials considered are Boron, Gd, Er, and Hf. The BP geometries were based on Wet Annular Burnable Absorber (WABA), Integral Fuel Burnable Absorber (IFBA), and Homogeneous poison/fuel mixtures. Several most promising combinations of BP designs were selected for the full core 3D simulation. All major core performance parameters for the analyzed cases are very close to those of a standard PWR with conventional UO{sub 2} fuel including possibility of reactivity control, power peaking factors, and cycle length. The MTC of all FFF cores was found at the full power conditions at all times and very close to that of the UO{sub 2} core. The Doppler coefficient of the FFF cores is also negative but somewhat lower in magnitude compared to UO{sub 2} core. The soluble boron worth of the FFF cores was calculated to be lower than that of the UO{sub 2} core by about a factor of two, which still allows the core reactivity control with acceptable soluble boron concentrations. The main conclusion of this work is that judicial application of burnable poisons for fertile free fuel has a potential to produce a core design with performance characteristics close to those of the reference PWR core with conventional UO{sub 2} fuel. (authors)

  2. Exercising options

    NASA Astrophysics Data System (ADS)

    Carlowicz, Michael

    In a recent speech to graduates of the College of Computer, Mathematical, and Physical Sciences at the University of Maryland, Anne Petersen, deputy director of the National Science Foundation, encouraged a new generation of scientists to embrace opportunity and choice, and to use their scientific training as an employment credential, not a limit. In her May 23 commencement address, Petersen exhorted students to view their freshly minted diplomas as tickets to a broad and diverse job market, not just one-way trips to the laboratory.“Looking for the options and alternatives open to us—and creating options for ourselves where they are not apparent—can give us a sense of direction and volition that enriches our lives immensely…

  3. Thermal test options

    SciTech Connect

    Koski, J.A.; Keltner, N.R.; Sobolik, K.B.

    1993-02-01

    Shipping containers for radioactive materials must be qualified to meet a thermal accident environment specified in regulations, such at Title 10, Code of Federal Regulations, Part 71. Aimed primarily at the shipping container design, this report discusses the thermal testing options available for meeting the regulatory requirements, and states the advantages and disadvantages of each approach. The principal options considered are testing with radiant heat, furnaces, and open pool fires. The report also identifies some of the facilities available and current contacts. Finally, the report makes some recommendations on the appropriate use of these different testing methods.

  4. Assessment of Startup Fuel Options for the GNEP Advanced Burner Reactor (ABR)

    SciTech Connect

    Jon Carmack; Kemal O. Pasamehmetoglu; David Alberstein

    2008-02-01

    The Global Nuclear Energy Program (GNEP) includes a program element for the development and construction of an advanced sodium cooled fast reactor to demonstrate the burning (transmutation) of significant quantities of minor actinides obtained from a separations process and fabricated into a transuranic bearing fuel assembly. To demonstrate and qualify transuranic (TRU) fuel in a fast reactor, an Advanced Burner Reactor (ABR) prototype is needed. The ABR would necessarily be started up using conventional metal alloy or oxide (U or U, Pu) fuel. Startup fuel is needed for the ABR for the first 2 to 4 core loads of fuel in the ABR. Following start up, a series of advanced TRU bearing fuel assemblies will be irradiated in qualification lead test assemblies in the ABR. There are multiple options for this startup fuel. This report provides a description of the possible startup fuel options as well as possible fabrication alternatives available to the program in the current domestic and international facilities and infrastructure.

  5. [Pu(IV) behavior in the serum].

    PubMed

    Surova, Z I

    1984-01-01

    This paper presents the results of studies of the hydrolysis and polymerization of Pu(IV) in blood serum. With nitrite Pu(IV) solutions incubated with blood serum 20-34% of the nuclide were precipitated as hydroxide and 11-36% converted into polymeric forms bound by high molecular weight proteins. For citrate solutions, these values were 3.8 and 3.0%, respectively. PMID:6505160

  6. Resonant Photoemission in f Electron Systems: Pu& Gd

    SciTech Connect

    Tobin, J G; Chung, B W; Schulze, R K; Terry, J; Farr, J D; Shuh, D K; Heinzelman, K; Rotenberg, E; Waddill, G D; van der Laan, G

    2003-03-07

    Resonant photoemission in the Pu5f and Pu6p states is compared to that in the Gd4f and Gd5p states. Spectral simulations, based upon and atomic model with angular momentum coupling, are compared to the Gd and Pu results. Additional spectroscopic measurements of Pu, including core level photoemission and x-ray absorption are also presented.

  7. Synthesis of Pu-Doped Ceramic

    SciTech Connect

    Anderson, E. B

    1998-09-02

    Plutonium-doped zircon containing about 10 wt% Pu was synthesized in this cooperative project between Russia and the United States conducted at the V. G. Khlopin Radium Institute. The sol-gel method was used for starting precursor preparation to provide complete mixing of initial components and to avoid dust formation inside the glove-box. The sol-gel process also gives interim Pu stabilization in the form of amorphous zirconium hydrosilicate (AZHS), which is a result of gel solidification. AZHS is a solid and relatively durable material that can be easy converted into crystalline zircon by pressureless sintering, thus avoiding significant radioactive contamination of laboratory equipment. A methanol-aqueous solution of tetraethoxysilane Si(OC2H5)4, Pu-nitrate, and zirconil oxynitrate was prepared in final stoichiometry of zircon (Zr,Pu)SiO4 80 wt% + zirconia (Zr,Pu)O2 20 wt%. Gelation occurred after 90 hours at room temperature. AZHS with excess of zirconia 20 wt% was obtained as an interim calcine product and then it was converted into zircon/zirconia ceramic by sintering at 1490 to 1500°C in air for different time periods. The samples obtained were studied by SRD and ESEM methods. It was found that both zircon yield and zircon cell parameters that are correlated with Pu incorporation depend on sintering time.

  8. [Not Available].

    PubMed

    Forstner, Christina; Pletz, Mathias W

    2016-02-01

    Infections with multi-drug resistant bacteria are increasing worldwide. Glycopeptides, linezolid, daptomycin and 5th generation cephalosporins ("MRSA-cephalsoporins") are used against severe infections with MRSA, combination partners are rifampin and fosfomycin. Treatment options against VRE-infections are limited to linezolid, daptomycin and tigecyclin. New agents with activity against MRSA and VRE are tedizolid, dalbvancin and oritavancin. For monotherapy of severe infections due to 3MRGN carbapenems are available. Ceftolozane/tazobactam has been licensed by the European Medical Agency and shows good activity against a relevant proportion of ESBL-pathogens. Oral agents such as nitrofurantoin or fosfomycin are used for treatment of uncomplicated cystitis. Colistin shows best in vitro susceptibility against carbapenem-resistant Enterobacteriaceae, followed by fosfomycin and tigecycline. For serious infections with 4MRGN a colistin-based combination treatment with two to three agents is recommended. In such cases a carbapenem as combination partner may be useful. PMID:26949908

  9. Nevada Transportatoion Options Study

    SciTech Connect

    P. GEHNER; E.M. WEAVER; L. FOSSUM

    2006-05-25

    This study performs a cost and schedule analysis of three Nevada Transportation options that support waste receipt at the repository. Based on the U.S. Department of Energy preference for rail transportation in Nevada (given in the Final Environmental Impact Statement), it has been assumed that a branch rail line would be constructed to support waste receipt at the repository. However, due to potential funding constraints, it is uncertain when rail will be available. The three Nevada Transportation options have been developed to meet a varying degree of requirements for transportation and to provide cost variations used in meeting the funding constraints given in the Technical Direction Letter guidelines for this study. The options include combinations of legal-weight truck, heavy-haul truck, and rail. Option 1 uses a branch rail line that would support initial waste receipt at the repository in 2010. Rail transportation would be the primary mode, supplemented by legal weight trucks. This option provides the highest level of confidence in cost and schedule, lowest public visibility, greatest public acceptability, lowest public dose, and is the recommended option for support of waste receipt. The completion of rail by 2010 will require spending approximately $800 million prior to 2010. Option 2 uses a phased rail approach to address a constrained funding scenario. To meet funding constraints, Option 2 uses a phased approach to delay high cost activities (final design and construction) until after initial waste receipt in 2010. By doing this, approximately 95 percent of the cost associated with completion of a branch rail line is deferred until after 2010. To support waste receipt until a branch rail line is constructed in Nevada, additional legal-weight truck shipments and heavy-haul truck shipments (on a limited basis for naval spent nuclear fuel) would be used to meet the same initial waste receipt rates as in Option 1. Use of heavy-haul shipments in the absence

  10. Options Study - Phase II

    SciTech Connect

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2010-09-01

    The Options Study has been conducted for the purpose of evaluating the potential of alternative integrated nuclear fuel cycle options to favorably address the issues associated with a continuing or expanding use of nuclear power in the United States. The study produced information that can be used to inform decisions identifying potential directions for research and development on such fuel cycle options. An integrated nuclear fuel cycle option is defined in this study as including all aspects of the entire nuclear fuel cycle, from obtaining natural resources for fuel to the ultimate disposal of used nuclear fuel (UNF) or radioactive wastes. Issues such as nuclear waste management, especially the increasing inventory of used nuclear fuel, the current uncertainty about used fuel disposal, and the risk of nuclear weapons proliferation have contributed to the reluctance to expand the use of nuclear power, even though it is recognized that nuclear power is a safe and reliable method of producing electricity. In this Options Study, current, evolutionary, and revolutionary nuclear energy options were all considered, including the use of uranium and thorium, and both once-through and recycle approaches. Available information has been collected and reviewed in order to evaluate the ability of an option to clearly address the challenges associated with the current implementation and potential expansion of commercial nuclear power in the United States. This Options Study is a comprehensive consideration and review of fuel cycle and technology options, including those for disposal, and is not constrained by any limitations that may be imposed by economics, technical maturity, past policy, or speculated future conditions. This Phase II report is intended to be used in conjunction with the Phase I report, and much information in that report is not repeated here, although some information has been updated to reflect recent developments. The focus in this Options Study was to

  11. Thermophysical properties of α-Pu2O3: A new potential model

    NASA Astrophysics Data System (ADS)

    Günay, S. D.; Akgenç, B.; Akdere, Ü.; Taşseven, ć.

    2013-12-01

    α-Pu2O3 is an important material among plutonium based materials in nuclear industry. Pure plutonium surfaces quickly oxidizes into α-Pu2O3 and PuO2 which are in the form of layers one on another [1]. Here we have investigated thermal properties of α-Pu2O3 by molecular dynamics simulation by using a partially ionic semi-empirical rigid ion potential. Mechanical properties, thermal expansion, and heat capacity are calculated. Results were compared with available experimental data and quantum calculation [2]. Due to the experimental limitations such as toxicity and radiation effects, studying the physical properties of such materials from molecular dynamics simulations have vital importance.

  12. The Spectroscopic Signature of Aging in (delta)-Pu(Ga)

    SciTech Connect

    Tobin, J G; Yu, S; Chung, B W

    2009-04-29

    The electronic structure of Pu is briefly discussed, with emphasis upon Aging effects. Photoelectron Spectroscopy and X-ray Absorption Spectroscopy have contributed greatly to our improved understanding of Pu electronic structure. (See Figure 1.) From these and related measurements, the following has been determined: (1) The Pu 5f spin-orbit splitting is large; (2) The number of Pu5f electrons is 5; and (3) The Pu 5f spin-orbit splitting effect dominates 5f itineracy.

  13. Alternative Education Options.

    ERIC Educational Resources Information Center

    Little (Arthur D.), Inc., Washington, DC.

    This guide deals with various areas of alternative education programs, including current practices and different options available to school and community personnel. Steps are outlined to assess present educational settings, design new programs, select the participants, and implement and evaluate the new program. The first appendix contains…

  14. Our Energy Options.

    ERIC Educational Resources Information Center

    Meyers, Paul A.; Witt, Frank C.

    Presented is an analysis of alternatives available to the United States in dealing with energy problems. Options explained and evaluated include coal, solar, hydroelectric, nuclear, geothermal, wind, biomass, and energy conservation. The booklet is part of Project APEC (America's Possible Energy Choices), a nationally validated Title IVc project…

  15. Np and Pu Sorption to Manganese Oxide Minerals

    SciTech Connect

    Zhao, P; Johnson, M R; Roberts, S K; Zavarin, M

    2005-08-30

    Manganese oxide minerals are a significant component of the fracture lining mineralogy at Yucca Mountain (Carlos et al., 1993) and within the tuff-confining unit at Yucca Flat (Prothro, 1998), Pahute Mesa (Drellack et al., 1997), and other locations at the Nevada Test Site (NTS). Radionuclide sorption to manganese oxide minerals was not included in recent Lawrence Livermore National Laboratory (LLNL) hydrologic source term (HST) models which attempt to predict the migration behavior of radionuclides away from underground nuclear tests. However, experiments performed for the Yucca Mountain Program suggest that these minerals may control much of the retardation of certain radionuclides, particularly Np and Pu (Triay et al., 1991; Duff et al., 1999). As a result, recent HST model results may significantly overpredict radionuclide transport away from underground nuclear tests. The sorption model used in HST calculations performed at LLNL includes sorption to iron oxide, calcite, zeolite, smectite, and mica minerals (Zavarin and Bruton 2004a; 2004b). For the majority of radiologic source term (RST) radionuclides, we believe that this accounts for the dominant sorption processes controlling transport. However, for the case of Np, sorption is rather weak to all but the iron and manganese oxides (Figure 1). Thus, we can expect to significantly reduce predicted Np transport by accounting for Np sorption to manganese oxides. Similarly, Pu has been shown to be predominantly associated with manganese oxides in Yucca Mountain fractured tuffs (Duff et al., 1999). Recent results on colloid-facilitated Pu transport (Kersting and Reimus, 2003) also suggest that manganese oxide coatings on fracture surfaces may compete with colloids for Pu, thus reducing the effects of colloid-facilitated Pu transport (Figure 1b). The available data suggest that it is important to incorporate Np and Pu sorption to manganese oxides in reactive transport models. However, few data are available for

  16. Neutron-diffraction study of PuAs and PuSb

    NASA Astrophysics Data System (ADS)

    Burlet, P.; Quezel, S.; Rossat-Mignod, J.; Spirlet, J. C.; Rebizant, J.; Müller, W.; Vogt, O.

    1984-12-01

    The first neutron scattering experiments on PuAs and PuSb single crystals are reported. PuAs is found to be a ferromagnet below Tc=123+/-1 K. PuSb develops below TN=85+/-1 K an incommensurate ordering and undergoes, at TIC=67 K, a first-order transition to a commensurate phase, ferromagnetic in nature. In both compounds, moments are perpendicular to the ferromagnetic (001) planes, their low-temperature value is μ=(0.75+/-0.1)μB, indicating a Γ8-type ground state within the Russell-Saunders level scheme. The magnetic phase diagram of PuSb has been determined. The incommensurate phase is suppressed by a small field of 8.5 kOe.

  17. Chemical potential of oxygen in (U, Pu) mixed oxide with Pu/(U+Pu) = 0.46

    NASA Astrophysics Data System (ADS)

    Dawar, Rimpi; Chandramouli, V.; Anthonysamy, S.

    2016-05-01

    Chemical potential of oxygen in (U,Pu) mixed oxide with Pu/(U + Pu) = 0.46 was measured for the first time using H2/H2O gas equilibration combined with solid electrolyte EMF technique at 1073, 1273 and 1473 K covering an oxygen potential range of -525 to -325 kJ mol-1. The effect of oxygen potential on the oxygen to metal ratio was determined. Increase in oxygen potential increases the O/M. In this study the minimum O/M obtained was 1.985 below which reduction was not possible. Partial molar enthalpy ΔHbar O2 and entropy ΔSbar O2 of oxygen were calculated from the oxygen potential data. The values of -752.36 kJ mol-1 and 0.25 kJ mol-1 were obtained for ΔHbar O2 and ΔSbar O2 respectively.

  18. Prompt fission γ -ray spectrum characteristics from 240Pu(sf ) and 242Pu(sf )

    NASA Astrophysics Data System (ADS)

    Oberstedt, S.; Oberstedt, A.; Gatera, A.; Göök, A.; Hambsch, F.-J.; Moens, A.; Sibbens, G.; Vanleeuw, D.; Vidali, M.

    2016-05-01

    In this paper we present first results for prompt fission γ -ray spectra (PFGS) characteristics from the spontaneous fission (sf) of 240Pu and 242Pu. For 242Pu(sf ) we obtained, after proper unfolding of the detector response, an average energy per photon ɛ¯γ=(0.843 ±0.012 ) MeV, an average multiplicity M¯γ=(6.72 ±0.07 ) , and an average total γ -ray energy release per fission E¯γ ,tot = (5.66 ± 0.06) MeV. The 240Pu(sf ) emission spectrum was obtained by applying a so-called detector-response transformation function determined from the 242Pu spectrum measured in exactly the same geometry. The results are an average energy per photon ɛ¯γ=(0.80 ±0.07 ) MeV, the average multiplicity M¯γ = (8.2 ± 0.4), and an average total γ -ray energy release per fission E¯γ ,tot = (6.6 ± 0.5) MeV. The PFGS characteristics for 242Pu(sf ) are in very good agreement with those from thermal-neutron-induced fission on 241Pu and scales well with the corresponding prompt neutron multiplicity. Our results in the case of 240Pu(sf ), although drawn from a limited number of events, show a significantly enhanced average multiplicity and average total energy, but may be understood from a different fragment yield distribution in 240Pu(sf ) compared to that of 242Pu(sf ).

  19. MCSNA: Experimental Benchmarking of Pu Electronic Structure

    SciTech Connect

    Tobin, J G

    2007-01-29

    The objective of this work is to develop and/or apply advanced diagnostics to the understanding of aging of Pu. Advanced characterization techniques such as photoelectron and x-ray absorption spectroscopy will provide fundamental data on the electronic structure of Pu phases. These data are crucial for the validation of the electronic structure methods. The fundamental goal of this project is to narrow the parameter space for the theoretical modeling of Pu aging. The short-term goal is to perform experiments to validate electronic structure calculations of Pu. The long-term goal is to determine the effects of aging upon the electronic structure of Pu. Many of the input parameters for aging models are not directly measurable. These parameters will need to be calculated or estimated. Thus a First Principles-Approach Theory is needed, but it is unclear what terms are important in the Hamiltonian. (H{Psi} = E{Psi}) Therefore, experimental data concerning the 5f electronic structure are needed, to determine which terms in the Hamiltonian are important. The data obtained in this task are crucial for reducing the uncertainty of Task LL-01-developed models and predictions. The data impact the validation of electronic structure methods, the calculation of defect properties, the evaluation of helium diffusion, and the validation of void nucleation models. The importance of these activities increases if difficulties develop with the accelerating aging alloy approach.

  20. Peak load management: Potential options

    SciTech Connect

    Englin, J.E.; De Steese, J.G.; Schultz, R.W.; Kellogg, M.A.

    1989-10-01

    This report reviews options that may be alternatives to transmission construction (ATT) applicable both generally and at specific locations in the service area of the Bonneville Power Administration (BPA). Some of these options have potential as specific alternatives to the Shelton-Fairmount 230-kV Reinforcement Project, which is the focus of this study. A listing of 31 peak load management (PLM) options is included. Estimated costs and normalized hourly load shapes, corresponding to the respective base load and controlled load cases, are considered for 15 of the above options. A summary page is presented for each of these options, grouped with respect to its applicability in the residential, commercial, industrial, and agricultural sectors. The report contains comments on PLM measures for which load shape management characteristics are not yet available. These comments address the potential relevance of the options and the possible difficulty that may be encountered in characterizing their value should be of interest in this investigation. The report also identifies options that could improve the efficiency of the three customer utility distribution systems supplied by the Shelton-Fairmount Reinforcement Project. Potential cogeneration options in the Olympic Peninsula are also discussed. These discussions focus on the options that appear to be most promising on the Olympic Peninsula. Finally, a short list of options is recommended for investigation in the next phase of this study. 9 refs., 24 tabs.

  1. Possible differences in biological availability of isotopes of plutonium: Report of a workshop

    SciTech Connect

    Kercher, J.R.; Gallegos, G.M.

    1993-09-01

    This paper presents the results of a workshop conducted on the apparent different bioavailability of isotopes {sup 238}Pu and {sup 239}Pu. There is a substantial body of evidence that {sup 238}Pu as commonly found in the environment is more biologically available than {sup 239}Pu. Studies of the Trinity Site, Nevada Test Site from nonnuclear and nuclear events, Rocky Flats, Enewetak and Bikini, and the arctic tundra support this conclusion and indicate that the bioavailability of {sup 238}Pu is more than an order of magnitude greater than that of {sup 239}Pu. Plant and soil studies from controlled environments and from Savannah River indicate no isotopic difference in availability of Pu to plants; whereas studies at the Trinity Site do suggest a difference. While it is possible that these observations can be explained by problems in the experimental procedure and analytical techniques, this possibility is remote given the ubiquitous nature of the observations. Studies of solubility of Pu in the stomach contents of cattle grazing at the Nevada Test Site and from fish from Bikini Atoll both found that {sup 238}Pu was more soluble than {sup 239}Pu. Studies of the Los Alamos effluent stream indicate that as particle size decreases, the content of {sup 238}Pu relative to {sup 239}Pu increases.

  2. Spectroscopy of Neutron-rich Pu Nuclei

    SciTech Connect

    Chowdhury, P.; Hota, S.; Lakshmi, S.; Tandel, S. K.; Harrington, T.; Jackson, E.; Moran, K.; Shirwadkar, U.; Ahmad, I.; Carpenter, M. P.; Greene, J.; Hoffman, C. R.; Janssens, R. V. F.; Khoo, T. L.; Kondev, F. G.; Lauritsen, T.; Lister, C. J.; McCutchan, E. A.; Seweryniak, D.; Stefanescu, I.

    2011-10-28

    Spectroscopic studies of nuclei in the A{approx}250, Z{approx}100 region provide critical input to theoretical models that attempt to describe the structure and stability of the heaviest elements. We report here on new spectroscopic studies in the N = 150,151 nuclei {sup 244,245}Pu. (Z = 94). Excitations in these nuclei on the neutron-rich side of the valley of stability, accessed via inelastic and transfer reactions, complement fusion-evaporation studies of Z{>=}100 nuclei. States in {sup 244,245}Pu were populated using {sup 47}Ti and {sup 208}Pb beams incident on a {sup 244}Pu target, with delayed and prompt gamma rays detected by the Gammasphere array. The new results are discussed in the context of emerging systematics of one- and two-quasiparticle excitations in N{>=}150 nuclei.

  3. Presence of plutonium isotopes, 239Pu and 240Pu, in soils from Chile

    NASA Astrophysics Data System (ADS)

    Chamizo, E.; García-León, M.; Peruchena, J. I.; Cereceda, F.; Vidal, V.; Pinilla, E.; Miró, C.

    2011-12-01

    Plutonium is present in every environmental compartment, due to a variety of nuclear activities. The Southern Hemisphere has received about 20% of the global 239Pu and 240Pu environmental inventory, with an important contribution of the so-called tropospheric fallout from both the atmospheric nuclear tests performed in the French Polynesia and in Australia by France and United Kingdom, respectively. In this work we provide new data on the impact of these tests to South America through the study of 239Pu and 240Pu in soils from different areas of Northern, Central and Southern Chile. The obtained results point out to the presence of debris from the French tests in the 20-40° Southern latitude range, with 240Pu/ 239Pu atomic ratios quite heterogeneous and ranging from 0.02 to 0.23. They are significantly different from the expected one for the global fallout in the Southern Hemisphere for the 30-53°S latitude range (0.185 ± 0.047), but they follow the same trend as the reported values by the Department of Energy of United States for other points with similar latitudes. The 239 + 240Pu activity inventories show as well a wider variability range in that latitude range, in agreement with the expected heterogeneity of the contamination.

  4. Neutron Capture Cross Section of 239Pu

    NASA Astrophysics Data System (ADS)

    Mosby, S.; Arnold, C.; Bredeweg, T. A.; Couture, A.; Jandel, M.; O'Donnell, J. M.; Rusev, G.; Ullmann, J. L.; Chyzh, A.; Henderson, R.; Kwan, E.; Wu, C. Y.

    2014-09-01

    The 239Pu(n,γ) cross section has been measured over the energy range 10 eV - 10 keV using the Detector for Advanced Neutron Capture Experiments (DANCE) as part of a campaign to produce precision (n,γ) measurements on 239Pu in the keV region. Fission coincidences were measured with a PPAC and used to characterize the prompt fission γ-ray spectrum in this region. The resulting spectra will be used to better characterize the fission component of another experiment with a thicker target to extend the (n,γ) cross section measurement well into the keV region.

  5. System evaluations of laser power beaming options

    NASA Technical Reports Server (NTRS)

    Montgomery, Edward E., IV

    1992-01-01

    The major technology options for high-energy FELs and adaptive optics available to the Space Laser Energy (SELENE) program are reviewed. Initial system evaluations of these options are described. A feasibility assessment of laser power beaming is given.

  6. [Not Available].

    PubMed

    Goffinet, L; Breton, A; Gavillot, C; Barbary, S; Journeau, P; Lascombes, P; Dautel, G

    2015-09-30

    The early management of pediatric hand burns includes surgical treatment, medical follow up and prevention of abnormal scarring by splits and/or pressure garment therapy. The aim of this review was to find the best available evidence in the literature on the surgical part of this management. This review started with a search in the PubMed database for the keywords, hand AND/OR child AND/OR burn. Only the articles published between January 1(st), 2005 and January 1(st), 2011 were selected. The data were compared to French and American textbooks. Contradictory findings were reported on the timing of the excision and graft, with only two comparative studies reported, with a lot of biases. The state of the art on the initial management of hand burns in children is not totally conclusive due to the lack of statistic power in these studies, but many expert opinions help to define options for good therapeutic paradigms. It is important to include these patients in prospective protocols with both early and long-term follow-up in order to increase the amount of evidence at our disposal. PMID:27279807

  7. [Not Available].

    PubMed

    Chaibdraa, A; Medjelekh, M S; Saouli, A; Bentakouk, M C

    2015-09-30

    Use of local/regional anesthesia in burn patients is limited by many factors. It is considered as marginal in the multimodal treatment of nociceptive pain. We conducted a retrospective study on regional anesthesia used for analgesia over a period of three years. Given the lack of available literature on this subject, the results obtained from this study will enable suggestions to be made for possible uses of this technique. We identified 634 uses of regional anesthesia of which 96% were in adults. Most cases involved the lower limbs (76%). Spinal anesthesia was performed on 32 patients, including four children. Incidents were infrequent (3%) and had no morbid consequence. Regional anesthesia may be a useful option in a multimodal strategy of analgesia, allowing early passive rehabilitation and recovery after surgical skin grafts. It should be assessed in outpatients, since 95% of burns patients are not hospitalized. Use of regional anesthesia in burn patients should generate more interest to allow the establishment of protocols in multidisciplinary reflection. PMID:27279806

  8. Nitrate anion exchange in 238Pu aqueous scrap recovery operations

    NASA Astrophysics Data System (ADS)

    Pansoy-Hjelvik, M. E.; Silver, G. L.; Reimus, M. A. H.; Ramsey, K. B.

    1999-01-01

    Strong base, nitrate anion exchange (IX) is crucial to the purification of 238Pu solution feedstocks with gross levels of impurities. This paper discusses the work involved in bench scale experiments to optimize the nitrate anion exchange process. In particular, results are presented of experiments conducted to a) demonstrate that high levels of impurities can be separated from 238Pu solutions via nitrate anion exchange and, b) work out chemical pretreatment methodology to adjust and maintain 238Pu in the IV oxidation state to optimize the Pu(IV)-hexanitrato anionic complex sorption to Reillex-HPQ resin. Additional experiments performed to determine the best chemical treatment methodology to enhance recovery of sorbed Pu from the resin and VIS-NIR absorption studies to determine the steady state equilibrium of Pu(IV), Pu(III), and Pu(VI) in nitric acid are discussed.

  9. Experimental Benchmarking of Pu Electronic Structure

    SciTech Connect

    Tobin, J G; Moore, K T; Chung, B W; Wall, M A; Schwartz, A J; Ebbinghaus, B B; Butterfield, M T; Teslich, Jr., N E; Bliss, R A; Morton, S A; Yu, S W; Komesu, T; Waddill, G D; der Laan, G v; Kutepov, A L

    2005-10-13

    The standard method to determine the band structure of a condensed phase material is to (1) obtain a single crystal with a well defined surface and (2) map the bands with angle resolved photoelectron spectroscopy (occupied or valence bands) and inverse photoelectron spectroscopy (unoccupied or conduction bands). Unfortunately, in the case of Pu, the single crystals of Pu are either nonexistent, very small and/or having poorly defined surfaces. Furthermore, effects such as electron correlation and a large spin-orbit splitting in the 5f states have further complicated the situation. Thus, we have embarked upon the utilization of unorthodox electron spectroscopies, to circumvent the problems caused by the absence of large single crystals of Pu with well-defined surfaces. Our approach includes the techniques of resonant photoelectron spectroscopy [1], x-ray absorption spectroscopy [1,2,3,4], electron energy loss spectroscopy [2,3,4], Fano Effect measurements [5], and Bremstrahlung Isochromat Spectroscopy [6], including the utilization of micro-focused beams to probe single-crystallite regions of polycrystalline Pu samples. [2,3,6

  10. New options for developing of nuclear energy using an accelerator-driven reactor

    SciTech Connect

    Takahashi, Hiroshi

    1997-09-01

    Fissile fuel can be produced at a high rate using an accelerator-driven Pu-fueled subcritical fast reactor. Thus, the necessity of early introduction of the fast reactor can be moderated. High reliability of the proton accelerator, which is essential to implementing an accelerator-driven reactor in the nuclear energy field can be achieved by a slight extension of the accelerator`s length, with only a small economical penalty. Subcritical operation provides flexible nuclear energy options including high neutron economy producing the fuel, transmuting high-level wastes, such as minor actinides, and of converting efficiently the excess Pu and military Pu into proliferation-resistant fuel.

  11. Statistical properties of 243Pu, and 242Pu(n ,γ ) cross section calculation

    NASA Astrophysics Data System (ADS)

    Laplace, T. A.; Zeiser, F.; Guttormsen, M.; Larsen, A. C.; Bleuel, D. L.; Bernstein, L. A.; Goldblum, B. L.; Siem, S.; Garotte, F. L. Bello; Brown, J. A.; Campo, L. Crespo; Eriksen, T. K.; Giacoppo, F.; Görgen, A.; Hadyńska-KlÈ©k, K.; Henderson, R. A.; Klintefjord, M.; Lebois, M.; Renstrøm, T.; Rose, S. J.; Sahin, E.; Tornyi, T. G.; Tveten, G. M.; Voinov, A.; Wiedeking, M.; Wilson, J. N.; Younes, W.

    2016-01-01

    The level density and γ -ray strength function (γ SF ) of 243Pu have been measured in the quasicontinuum using the Oslo method. Excited states in 243Pu were populated using the 242Pu(d ,p ) reaction. The level density closely follows the constant-temperature level density formula for excitation energies above the pairing gap. The γ SF displays a double-humped resonance at low energy as also seen in previous investigations of actinide isotopes. The structure is interpreted as the scissors resonance and has a centroid of ωSR=2.42 (5 ) MeV and a total strength of BSR=10.1 (15 ) μN2 , which is in excellent agreement with sum-rule estimates. The measured level density and γ SF were used to calculate the 242Pu(n ,γ ) cross section in a neutron energy range for which there were previously no measured data.

  12. Investigation of single crystal zircon, (Zr,Pu)SiO4 doped with Pu

    NASA Astrophysics Data System (ADS)

    Hanchar, J. M.; Burakov, B. E.; Anderson, E. B.; Zamoryanskaya, M. V.

    2003-04-01

    Zircon-based ceramics are under consideration as durable waste forms for immobilization of weapons grade plutonium and other actinide elements. Samples of polycrystalline zircon doped with 238Pu and 239Pu have been obtained in previous studies. These materials, however, are difficult to use for precise measurement of the leach-rate of Pu, and to accurately determine the level of Pu doping that can be attained in zircon, (Zr,Pu)SiO_4. Single crystals of 238Pu doped zircon (ranging from 0.3 to 3.5 mm in size) were successfully grown for the first time ever using a Li-Mo flux synthesis method. The incorporation of Pu ranged from 1.9 to 4.7 wt. % el. (with approximately 81 wt.% of 238Pu isotope) based on electron microprobe analysis. The zircon crystals were pinkish-brown when they were crystallized, and then over a period of five months changed to a brown color. After fourteen months the crystals turned to a brown-gray color. The zircon crystals glow in the dark probably from alpha particle induced luminescence. The intensity of the cathodoluminescence (CL) emission in the Pu doped crystals is correlated with the Pu content, and the CL emission showed no change 141 days after the initial CL measurements were made. Single crystal X-ray diffraction results obtained 141 days after synthesis indicate unit cell parameters (in angstroms): a = 6.6267(15), c = 5.9992(10) and a cell volume of 263.41(10). When the zircon crystals were grown, they were free of cracks. Over the course of five months cracks appeared throughout the crystals, and after fourteen months the cracks became much more abundant. The zircon crystals were transparent upon crystallization, and even with numerous cracks throughout the crystals remain transparent. Radiation damage calculations indicate that after only a short period of time, six months, these zircon crystals had already accumulated significant alpha-induced radiation damage (˜2.5 x1014 alpha-decay events per milligram). After five years they

  13. Spectroscopic Signature of Aging in (delta)-Pu(Ga)

    SciTech Connect

    Chung, B W; Schwartz, A J; Ebbinghaus, B B; Fluss, M J; Haslam, J J; Blobaum, K M; Tobin, J G

    2005-04-15

    Resonant Photoemission, a variant of Photoelectron Spectroscopy, has been demonstrated to have sensitivity to aging of Pu samples. The spectroscopic results are correlated with resistivity measurements and are shown to be the fingerprint of mesoscopic or nanoscale internal damage in the Pu physical structure. This means that a spectroscopic signature of internal damage due to aging in Pu has been established.

  14. Prediction of thermodynamic property of Pu-zircon and Pu-pyrochlore

    NASA Astrophysics Data System (ADS)

    Xu, Hulfang; Wang, Yifeng

    2000-07-01

    Due to its high durability, zircon is often present as a heavy mineral in natural environments and is the oldest mineral that has been dated on the earth. There are four zircon structure phases of M4+SiO4 occurring in nature: zircon (ZrSiO4), hafnon (HfSiO4), thorite (ThSiO4), and coffinite (USiO4). These phases may form solid solution. Recent interest in zircon minerals stems from the study of highly durable radioactive waste forms. Crystalline phases of M4+SiO4 with zircon structure have been proposed as a durable ceramic waste form for immobilizing actinides such as Pu, Np, and U. To predict the behavior of zircon-based waste forms in a geologic repository environment as well as to optimize the fabrication of those waste forms, the thermodynamic and kinetic properties for zircon mineral phases have to be determined. In this paper, we use a linear free energy relationship to predict the Gibbs free energies of formation of Pu-bearing phases (Xu et al., 1999). The calculated results show that the PuSiO4 phase with zircon structure is unstable with respect to oxides of PuO2 and quartz. However, the PuSiO4 phase will be stable with respect to oxides of PuO2 and silica glass at low temperature.

  15. Pu speciation in actual and simulated aged wastes

    SciTech Connect

    Lezama-pacheco, Juan S; Conradson, Steven D

    2008-01-01

    X-ray Absorption Fine Structure Spectroscopy (XAFS) at the Pu L{sub II/III} edge was used to determine the speciation of this element in (1) Hanford Z-9 Pu crib samples, (2) deteriorated waste resins from a chloride process ion-exchange purification line, and (3) the sediments from two Waste Isolation Pilot Plant Liter Scale simulant brine systems. The Pu speciation in all of these samples except one is within the range previously displayed by PuO{sub 2+x-2y}(OH){sub y}{center_dot}zH{sub 2}O compounds, which is expected based on the putative thermodynamic stability of this system for Pu equilibrated with excess H{sub 2}O and O{sub 2} under environmental conditions. The primary exception was a near neutral brine experiment that displayed evidence for partial substitution of the normal O-based ligands with Cl{sup -} and a concomitant expansion of the Pu-Pu distance relative to the much more highly ordered Pu near neighbor shell in PuO{sub 2}. However, although the Pu speciation was not necessarily unusual, the Pu chemistry identified via the history of these samples did exhibit unexpected patterns, the most significant of which may be that the presence of the Pu(V)-oxo species may decrease rather than increase the overall solubility of these compounds. Several additional aspects of the Pu speciation have also not been previously observed in laboratory-based samples. The molecular environmental chemistry of Pu is therefore likely to be more complicated than would be predicted based solely on the behavior of PuO{sub 2} under laboratory conditions.

  16. Biokinetics of sup 237 Pu citrate and nitrate in the rat: Implications for Pu studies in man

    SciTech Connect

    Talbot, R.J.; Knight, D.A.; Morgan, A. )

    1990-08-01

    Plutonium-237 decays mainly by electron capture with a half-life of 45 d. Alpha particles are emitted in only 5 x 10(-3)% of its disintegrations. This nuclide can now be produced with relatively small amounts of alpha-emitting contaminants so that, in principle, {sup 237}Pu can be used for studies of Pu biokinetics in man. However, because of its high specific activity, there was some doubt that its metabolism would be the same as that of the alpha- and beta-emitting isotopes of Pu normally encountered in the nuclear industry. In this study, the biokinetics of nearly pure, high specific activity {sup 237}Pu are compared with those of lower specific activity, impure {sup 237}Pu containing significant amounts of alpha-emitting Pu, following administration to rats by intravenous injection as the citrate. Both the distribution and excretion of the pure and impure {sup 237}Pu used in the two studies were similar and also in good agreement with the results of previously reported studies using {sup 239}Pu and {sup 241}Pu citrate, thus validating the use of {sup 237}Pu for studies of Pu metabolism in man. Data on the biokinetics of {sup 237}Pu nitrate are also included.

  17. Electrochemical behaviors of PuN and (U, Pu)N in LiCl KCl eutectic melts

    NASA Astrophysics Data System (ADS)

    Shirai, O.; Kato, T.; Iwai, T.; Arai, Y.; Yamashita, T.

    2005-02-01

    Electrochemical behaviors of PuN and (U, Pu)N in the LiCl KCl eutectic melts at 773 K were investigated by cyclic voltammetry. The electrochemical dissolution of PuN and (U, Pu)N began nearly at -0.90±0.05 and -0.95±0.05 V (vs. Ag+/Ag), respectively. The rest potentials of PuN and (U, Pu)N were observed at about 0.15 V more negative potential than that of UN, in the present experimental condition. The observed rest potentials of (U, Pu)N depended on the equilibrium potential of the Pu3+/PuN. In the cyclic voltammogram measured by use of (U, Pu)N as the working electrode, a steep rise of the positive current was observed at potentials more positive than -0.45 V in analogy with the cyclic voltammogram measured by use of UN as the working electrode. These indicate that UN and PuN in (U, Pu)N would be dissolved independently irrespective of forming the solid solution.

  18. Redox reactions of Pu(IV) and Pu(III) in the presence of acetohydroxamic acid in HNO(3) solutions.

    PubMed

    Tkac, Peter; Precek, Martin; Paulenova, Alena

    2009-12-21

    The reduction of Pu(IV) in the presence of acetohydroxamic acid (HAHA) was monitored by vis-NIR spectroscopy. All experiments were performed under low HAHA/Pu(IV) ratios, where only the Pu(IV)-monoacetohydroxamate complex and Pu uncomplexed with HAHA were present in relevant concentrations. Time dependent concentrations of all absorbing species were resolved using molar extinction coefficients for Pu(IV), Pu(III), and the Pu(AHA)(3+) complex by deconvolution of spectra. From fitting of the experimental data by rate equations integrated by a numeric method three reactions were proposed to describe a mechanism responsible for the reduction and oxidation of plutonium in the presence of HAHA and HNO(3). Decomposition of Pu(AHA)(3+) follows a second order reaction mechanism with respect to its own concentration and leads to the formation of Pu(III). At low HAHA concentrations, a two-electron reduction of uncomplexed Pu(IV) with HAHA also occurs. Formed Pu(III) is unstable and slowly reoxidizes back to Pu(IV), which, at the point when all HAHA is decomposed, can be catalyzed by the presence of nitrous acid. PMID:19904974

  19. Novel operative treatment options.

    PubMed

    Ricketts, D N J; Pitts, N B

    2009-01-01

    There are an increasing number of more novel options available for operative intervention. This chapter outlines a series of operative treatment options which are available to the modern clinician to select from once a decision has been made to treat a carious lesion operatively. A series of novel methods of caries removal have been described; including chemomechanical caries removal, air abrasion, sono-abrasion, polymer rotary burs and lasers. There are also novel approaches to ensure complete caries removal and novel approaches for the management of deep caries. A novel question increasingly asked by clinicians is: does all the caries need to be removed? Operative management options here include: therapeutic fissure sealants, ultraconservative caries removal, stepwise excavation and the Hall technique. In conclusion, there is now a growing wealth of evidence that questions the traditional methods of caries removal and restoring the tooth. In parallel, there is a growing movement exploring the merits of therapeutically sealing caries into the tooth. This philosophy is alien to many of today's dentists and, until further randomized controlled trials are carried out in primary care, prudent caution must be exercised with this promising approach. Research is required into techniques which will allow monitoring of sealed caries to detect any rare, but insidious, failures. These novel techniques are an alternative way of managing the later stages of the caries process from a sounder biological basis and have marked potential benefits to patients from treatment, pain and outcome perspectives. PMID:19494685

  20. Self-irradiation of Pu, its alloys and compounds

    NASA Astrophysics Data System (ADS)

    Timofeeva, L. F.

    2000-07-01

    Self-irradiation of Pu, its alloys and compounds by products of known α-decomposition is a continuous complicated process, which includes numerous different phenomena. The accumulation of Pu decomposition products causes material structure and properties change. This problem is the subject of many works, most of them concerned with the behavior of Pu and its alloys at low (liquid He and N) temperatures. The survey is given of the results of our experiments connected with radiogenic helium behavior, crystal structure and properties of Pu metallic compounds and Pu oxide ceramics in a self-irradiation process at room temperature under isochronal heat treatments.

  1. Flexible Work Options within the Organisational System

    ERIC Educational Resources Information Center

    Albion, Majella J.; Chee, Munli

    2006-01-01

    The availability of flexible work options provides an opportunity for individuals to shape their careers in order to optimise their work and life goals. This study takes a systems theory approach to examine how the use of flexible work options influences relationships and interactions in the workplace. The "Flexible Work Options Questionnaire"…

  2. Osteoporosis: Therapeutic Options.

    PubMed

    Ivanova, Stefka; Vasileva, Liliya; Ivanova, Stanislava; Peikova, Lily; Obreshkova, Danka

    2016-01-01

    The definition of osteoporosis was originally formulated at a conference of the World Health Organization (WHO) in 1993 as 'a systemic skeletal disease characterized by decreased bone mass and altered micro-architecture of bone tissue, leading to enhanced bone fragility and risk of fractures'. Osteoporosis is characterized by low bone mineral density (BMD) and loss of the structural and bio-mechanical properties that are required to maintain bone homeostasis. This review aims to address the currently available options in prevention and treatment of osteoporosis. Management of osteoporosis includes non-pharmacological treatment - diet rich of calcium and vitamin D, healthy lifestyle, proper exercise plan, and pharmacological therapy. Combination of non-pharmacological and pharmacological treatment options have to be considered for prevention of osteoporosis and minimization of the risk of fractures. Given the heterogeneity of osteoporosis syndrome and lack of significant number of comparative studies, the choice of a pharmacological agents should be individualized. PMID:27180344

  3. Formation and stability of metastable structures and amorphous phases in PU-V, PU-TA, and PU-YB systems with positive heats of mixing

    NASA Astrophysics Data System (ADS)

    Rizzo, H. F.; Zocco, T.; Massalski, T. B.; Nastasi, M.; Echeverria, A.

    1994-08-01

    The triode sputtering technique with a “split-target” arrangement was used to obtain metastable crystalline and amorphous phases in the Pu-V, Pu-Ta, and Pu-Yb systems. The proposed phase diagrams for these systems all exhibit liquid immiscibility. The heats of mixing are estimated to be highly positive, and the atomic radii of the component atoms differ by at least 10 pct. Extended amorphous and body-centered cubic (bcc) solid-solution regions were observed in the Pu-V and Pu-Ta systems. The corresponding lattice parameters appear to follow in each case an assumed Vegard’s Law extension. In the Pu-Yb system, no amorphous phase was obtained, but an extended face-centered cubic (fcc) solid-solution region (24 to 78 at. pct Yb) was observed with a large positive deviation of the lattice parameter (˜9 pct at 40 at. pct Yb) from a linear Vegard’s Law between the pure fcc components. The observed ranges of amorphous and metastable solid-solution phases have been interpreted in terms of predicated heats of formation for these phases using Miedema’s thermodynamic approximations that include chemical, elastic, and structural contributions. The effect of the high deposition rates on the formation of amorphous and metastable phases has also been considered. Thermal annealing of Pu-Ta amorphous alloys brings about a rapid diffusion of Pu to the free surface of the amorphous phase without crystallization of the remaining Ta-rich amorphous phase. Microhardness measurements indicate that amorphous Pu-V and Pu-Ta alloys are softer than the crystalline bcc solid-solution alloys in the same composition range. Several similarities in the formation of mixed phase regions (amorphous and solid solutions), microhardness, and resistance to decomposition on heating were noted between the Pu-Ta and Pu-V systems and the Cu-W system studied previously.

  4. Search for higher oxides of Pu: A photoemission study

    NASA Astrophysics Data System (ADS)

    Gouder, T.; Seibert, A.; Havela, L.; Rebizant, J.

    2007-07-01

    After decades of believing in a very stable PuO 2, suitable for final storage of nuclear waste, the existence of a higher oxide, PuO 2+ x, was recently claimed. This would have far reaching consequences on the strategies of storage of Pu-based waste. Its formation therefore has been discussed controversially for several years. In this work, existence and stability of the higher oxide, PuO 2+ x, has been probed by photoelectron spectroscopy study of PuO 2 exposed to atomic oxygen. The validity of this approach is first tested on UO 2, which oxidizes readily to UO 3. Under the same reaction conditions, PuO 2 is only covered by a chemisorbed layer of oxygen, which desorbs at elevated temperature. The study excludes the stability of any higher binary Pu oxide as a bulk species.

  5. PuReMD-GPU: A reactive molecular dynamics simulation package for GPUs

    SciTech Connect

    Kylasa, S.B.; Aktulga, H.M.; Grama, A.Y.

    2014-09-01

    We present an efficient and highly accurate GP-GPU implementation of our community code, PuReMD, for reactive molecular dynamics simulations using the ReaxFF force field. PuReMD and its incorporation into LAMMPS (Reax/C) is used by a large number of research groups worldwide for simulating diverse systems ranging from biomembranes to explosives (RDX) at atomistic level of detail. The sub-femtosecond time-steps associated with ReaxFF strongly motivate significant improvements to per-timestep simulation time through effective use of GPUs. This paper presents, in detail, the design and implementation of PuReMD-GPU, which enables ReaxFF simulations on GPUs, as well as various performance optimization techniques we developed to obtain high performance on state-of-the-art hardware. Comprehensive experiments on model systems (bulk water and amorphous silica) are presented to quantify the performance improvements achieved by PuReMD-GPU and to verify its accuracy. In particular, our experiments show up to 16× improvement in runtime compared to our highly optimized CPU-only single-core ReaxFF implementation. PuReMD-GPU is a unique production code, and is currently available on request from the authors.

  6. Saccular Aneurysms of the Transverse Aortic Arch: Treatment Options Available in the Endovascular EraBased on a Presentation at the 2013 VEITH Symposium, November 19-23, 2013 (New York, NY, USA).

    PubMed

    Preventza, Ourania; Coselli, Joseph S

    2015-04-01

    Saccular aneurysms of the aortic arch, whether single or multiple, are uncommon. The choice of repair technique is influenced by patients' comorbidities and age. Repairing saccular aneurysms with traditional open techniques can be technically demanding; therefore, endovascular technology and a variety of hybrid approaches have been developed to facilitate such repairs and, potentially, to improve clinical outcomes, especially in high-risk patients. There have been no large, randomized studies to compare the outcomes of these different treatment options in patients with single or multiple saccular aneurysms of the arch. In this review, we outline the etiology and common locations of these aneurysms, the different open, completely endovascular, and hybrid techniques used to treat them, and the treatment selection process. PMID:26798759

  7. Fabrication of a 238Pu target

    SciTech Connect

    Wu, C Y; Chyzh, A; Kwan, E; Henderson, R; Gostic, J; Carter, D

    2010-11-16

    Precision neutron-induced reaction data are important for modeling the network of isotope production and destruction within a given diagnostic chain. This network modeling has many applications such as the design of advanced fuel cycle for reactors and the interpretation of radiochemical data related to the stockpile stewardship and nuclear forensics projects. Our current funded effort is to improve the neutron-induced reaction data on the short-lived actinides and the specific goal is to improve the neutron capture data on {sup 238}Pu with a half-life of 87.7 years. In this report, the fabrication of a {sup 238}Pu target for the proposed measurement using the DANCE array at LANL is described. The {sup 238}Pu target was fabricated from a sample enriched to 99.35%, acquired from ORNL. A total of 395 {micro}g was electroplated onto both sides of a 3 {micro}m thick Ti foil using a custom-made plating cell, shown in Fig 1. The target-material loaded Ti foil is sandwiched between two double-side aluminized mylar foils with a thickness of 1.4 {micro}m. The mylar foil is glued to a polyimide ring. This arrangement is shown partially in Fig. 2. The assembled target is then inserted into an aluminum container with a wall thickness of 0.76 mm, shown in Fig. 3. A derlin ring is used to keep the target assembly in place. The ends of this cylindrical container are vacuum-sealed by two covers with thin Kapton foils as windows for the beam entrance and exit. Shown in Fig. 4 is details of the arrangement. This target is used for phase I of the proposed measurement on {sup 238}Pu scheduled for Nov 2010 together with the DANCE array to address the safety issues raised by LANL. Shown in Fig. 5 is the preliminary results on the yield spectrum as a function of neutron incident energy with a gate on the total {gamma}-ray energy of equivalent Q value. Since no fission PPAC is employed, the distinction between the capture and fission events cannot be made, which is important for the

  8. PuPO4(cr, hyd.) Solubility Product and Pu3+ Complexes With Phosphate and Ethylenediaminetetraacetic Acid

    SciTech Connect

    Rai, Dhanpat; Moore, Dean A.; Felmy, Andrew R.; Rosso, Kevin M.; Bolton, Harvey

    2010-06-15

    To determine the solubility product of PuPO4(cr, hyd.) and the complexation constants of Pu(III) with phosphate and EDTA, the solubility of PuPO4(cr, hyd.) was investigated as a function of: 1) time and pH varying from 1.0 to 12.0 and at a fixed 0.00032 M phosphate concentration; 2) NaH2PO4 concentrations varying from 0.0001 M to 1.0 M and at a fixed pH value of 2.5; 3) time and pH varying from 1.3 to 13.0 at fixed concentrations of 0.00032 M phosphate and 0.0004 M or 0.002 M Na2H2EDTA; and 4) Na2H2EDTA concentrations varying from 0.00005 M to 0.0256 M at a fixed 0.00032 M phosphate concentration and at pH values of approximately 3.5, 10.6, and 12.6. A combination of solvent extraction and spectrophotometric techniques confirmed that the use of hydroquinone and Na2S2O4 helped maintain Pu as Pu(III). The solubility data were interpreted using Pitzer and SIT models, and both provided similar values for the solubility product of PuPO4(cr, hyd.) and for the formation constant of PuEDTA-. The log10 of the solubility product of PuPO4(cr, hyd.) (PuPO4(cr, hyd.) = Pu3+ + PO4 ) was determined to be –(24.42 ± 0.38). Pitzer modeling showed that phosphate interactions with Pu3+ were extremely weak and did not require any phosphate complexes (e.g., PuPO4(aq), PuH2PO42+, Pu(H2PO4)2+, Pu(H2PO4)3(aq), and Pu(H2PO4)4-), as proposed in existing literature, to explain the experimental data. SIT modeling, however, required the inclusion of PuH2PO42+ to explain the data in high NaH2PO4 concentrations; this illustrates the differences one can expect when using these two chemical models to interpret the data. As the Pu(III)-EDTA species, only PuEDTA- was needed to interpret the experimental data in a large range in pH values (1.3–12.9) and EDTA concentrations (0.00005–0.256 M). Calculations based on density functional theory support the existence of PuEDTA- (with prospective stoichiometry as Pu(OH2)3EDTA-) as the chemically and structurally stable species. The log10 of the

  9. Pu(VI) hydrolysis: further evidence for a dimeric plutonyl hydroxide and contrasts with U(VI) chemistry.

    PubMed

    Reilly, Sean D; Neu, Mary P

    2006-02-20

    A significant fraction of plutonium that is soluble in environmental waters and other aqueous solutions can be present as complexes of plutonyl, PuO2(2+). Few thermodynamic data are available for this ion, representing a problematic gap in plutonium chemistry and in the forecasting of radionuclide behavior under contamination and nuclear repository conditions. To address this need and more accurately determine the stoichiometry and stability of the basic hydrolytic products, we completed complimentary potentiometric and spectrophotometric studies of plutonium(VI) hydrolysis over the concentration range of 10(-2) to 10(-5) M Pu(VI). Dinuclear hydroxide species (PuO2)2(OH)2(2+) and (PuO2)2(OH)4(0)(aq) with hydrolysis constants log beta(2,2) = -7.79 +/- 0.20 and log beta(4,2) = -19.3 +/- 0.5 are indicated in all experiments of millimolar Pu(VI), 0.10 M NaNO3 solutions at 25 degrees C. At lower Pu(VI) concentrations, at and below 10(-4) M, the monomeric species PuO2OH+ and PuO2(OH)2(0)(aq) form with hydrolysis constants of log beta(1,1) = -5.76 +/- 0.07 and log beta(2,1) = -11.69 +/- 0.05, respectively. Distinct optical absorbance bands at 842 and 845 nm are reported for the mononuclear and dinuclear first hydrolysis species. Standard hydrolysis constants at zero ionic strength were calculated from the experimentally determined constants using the specific ion interaction theory. The Pu(VI) hydrolysis species and constants are compared with results from previous studies for plutonium and uranium. Major differences between uranyl and plutonyl hydrolysis are described. PMID:16472001

  10. Nevada test site fallout atom ratios: /sup 240/Pu//sup 239/Pu and /sup 241/Pu//sup 239/Pu

    SciTech Connect

    Hicks, H.G.; Barr, D.W.

    1984-02-01

    The exposure of the population in Utah to external gamma radiation from the fallout from nuclear weapons tests carried out between 1951 and 1958 at the Nevada Test Site (NTS) has been reconstructed from recent measurements of /sup 137/Cs and plutonium in soil. The fraction of /sup 137/Cs in the fallout from NTS events was calculated from the total plutonium and the /sup 240/Pu//sup 239/Pu ratios measured in the soil, using the values of 0.180 +- 0.006 and 0.032 +- 0.003 for that ratio in global fallout and NTS fallout, respectively. The total population exposure from NTS events was then calculated on the basis of exposure rates resulting from short-lived radionuclides associated with the /sup 137/Cs at the time of deposition. While the /sup 240/Pu//sup 239/Pu ratio is constant in global fallout, this ratio varies greatly in the fallout from individual events. While the composition of fallout on Utah from NTS events is rather uniform, the Off-Site Radiation Exposure Review Project is currently reconstructing radiation exposures for locations close to NTS where the fallout may be predominantly from one event. Therefore, the authors compiled the pertinent ratios in order to provide information concerning the exposure resulting from any individual event. The plutonium ratios measured at 30 days postshot were compiled from unpublished values in the archives of the Nuclear Chemistry Division of LLNL and INC-11 of LANL. These ratios are pertinent to fallout data. Dates for each event were taken from a publication by the Nevada Operations Office of the Department of Energy. 3 references.

  11. Calculated k-effectives for light water reactor typical, U + Pu nitrate solution critical experiments

    SciTech Connect

    Primm, R.T. III; Mincey, J.F.

    1982-01-01

    The Department of Energy's Consolidated Fuel Reprocessing Program has as a goal the design of nuclear fuel reprocessing equipment. In order to validate computer codes used for criticality analyses in the design of such equipment, k-effectives have been calculated for several U + Pu nitrate solution critical experiments. As of January 1981, descriptions of 45 unpoisoned, U + Pu solution experiments were available in the open literature. Twelve of these experiments were performed with solutions which have physical characteristics typical of dissolved, light water reactor fuel. This paper contains a discussion of these twelve experiments, a review of the calculational procedure used to determine k-effectives, and the results of the calculations.

  12. The early solar system abundance of /sup 244/Pu as inferred from the St. Severin chondrite

    SciTech Connect

    Hudson, G.B.; Kennedy, B.M.; Podosek, F.A.; Hohenberg, C.M.

    1987-03-01

    We describe the analysis of Xe released in stepwise heating of neutron-irradiated samples of the St. Severin chondrite. This analysis indicates that at the time of formation of most chondritic meteorites, approximately 4.56 x 10/sup 9/ years ago, the atomic ratio of /sup 244/Pu//sup 238/U was 0.0068 +- 0.0010 in chondritic meteorites. We believe that this value is more reliable than that inferred from earlier analyses of St. Severin. We feel that this value is currently the best available estimate for the early solar system abundance of /sup 244/Pu. 42 refs., 2 tabs.

  13. Sensitivities of five alpha continuous air monitors for detection of airborne sup 239 Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  14. Sensitivities of five alpha continuous air monitors for detection of airborne {sup 239}Pu

    SciTech Connect

    McIsaac, C.V.; Amaro, C.R.

    1992-07-01

    Results of measurements of the sensitivities of five alpha continuous air monitors (CAMs) for detection of airborne {sup 239}Pu are presented. Four commercially available alpha CAMs (Kurz model 8311, Merlin Gerin Edgar, RADeCO model 452, and Victoreen model 758) and a prototype alpha CAM currently in use at Argonne National Laboratory- West (ANL-W) were tested sampling natural ambient air and laboratory-generated atmospheres laden with either blank dust or dust containing nCi/g concentrations of {sup 239}Pu. Cumulative alpha spectra were stored at 30 or 60 minute intervals during each sampling and were subsequently analyzed using three different commonly used alpha spectrum analysis algorithms. The effect of airborne dust concentration and sample filter porosity on detector resolution and sensitivity for airborne {sup 239}Pu are described.

  15. Transfer of aged Pu to cattle grazing on a contaminated environment

    SciTech Connect

    Gilbert, R.O.; Engel, D.W.; Smith, D.D.; Shinn, J.H.; Anspaugh, L.R.; Eisele, G.R.

    1988-03-01

    Estimates are obtained of the fraction of ingested or inhaled 239+240Pu transferred to blood and tissues of a reproducing herd of beef cattle, individuals of which grazed within fenced enclosures for up to 1064 d under natural conditions with no supplemental feeding at an arid site contaminated 16 y previously with Pu oxide. The estimated (geometric mean (GM)) fraction of Pu transferred from the gastrointestinal tract to blood serum was about 5 x 10(-6) (geometric standard error (GSE) = 1.4) with an approximate upper bound of about 2 x 10(-5). These results are in reasonable agreement with the value of 1 x 10(-5) recommended for human radiation protection purposes by the International Commission on Radiological Protection (ICRP) for insoluble Pu oxides that are free of very small particles. Also, results from a laboratory study by Stanley (St75), in which large doses of /sup 238/Pu were orally administered daily to dairy cattle for 19 consecutive days, suggest that aged 239+240Pu at this arid grazing site may not be more biologically available to blood serum than fresh 239+240Pu oxide. The estimated fractions of 239+240Pu transferred from blood serum to tissues of adult grazing cattle were: femur (3.2 X 10(-2), 1.8; GM, GSE), vertebra (1.4 X 10(-1), 1.6), liver (2.3 X 10(-1), 2.0), muscle (1.3 X 10(-1), 1.9), female gonads (7.9 X 10(-5), 1.5), and kidney (1.4 X 10(-3), 1.7). The blood-to-tissue fractional transfers for cattle initially exposed in utero were greater than those exposed only as adults by a factor of about 4 for femur (statistically significant) and of about 2 for other tissues (not significant). The estimated (GM) fraction of inhaled Pu initially deposited in the pulmonary lung was 0.34 (GSE = 1.3) for adults and 0.15 (GSE = 1.3) for cattle initially exposed in utero (a statistically significant difference).

  16. Transfer of aged Pu to cattle grazing on a contaminated environment.

    PubMed

    Gilbert, R O; Engel, D W; Smith, D D; Shinn, J H; Anspaugh, L R; Eisele, G R

    1988-03-01

    Estimates are obtained of the fraction of ingested or inhaled 239+240Pu transferred to blood and tissues of a reproducing herd of beef cattle, individuals of which grazed within fenced enclosures for up to 1064 d under natural conditions with no supplemental feeding at an arid site contaminated 16 y previously with Pu oxide. The estimated (geometric mean [GM]) fraction of Pu transferred from the gastrointestinal tract to blood serum was about 5 x 10(-6) (geometric standard error [GSE] = 1.4) with an approximate upper bound of about 2 x 10(-5). These results are in reasonable agreement with the value of 1 x 10(-5) recommended for human radiation protection purposes by the International Commission on Radiological Protection (ICRP) for insoluble Pu oxides that are free of very small particles. Also, results from a laboratory study by Stanley (St75), in which large doses of 238Pu were orally administered daily to dairy cattle for 19 consecutive days, suggest that aged 239+240Pu at this arid grazing site may not be more biologically available to blood serum than fresh 239+240Pu oxide. The estimated fractions of 239+240Pu transferred from blood serum to tissues of adult grazing cattle were: femur (3.2 X 10(-2), 1.8; GM, GSE), vertebra (1.4 X 10(-1), 1.6), liver (2.3 X 10(-1), 2.0), muscle (1.3 X 10(-1), 1.9), female gonads (7.9 X 10(-5), 1.5), and kidney (1.4 X 10(-3), 1.7). The blood-to-tissue fractional transfers for cattle initially exposed in utero were greater than those exposed only as adults by a factor of about 4 for femur (statistically significant) and of about 2 for other tissues (not significant). The estimated (GM) fraction of inhaled Pu initially deposited in the pulmonary lung was 0.34 (GSE = 1.3) for adults and 0.15 (GSE = 1.3) for cattle initially exposed in utero (a statistically significant difference), which may be compared with the expected fraction of 0.11 at the study site using the ICRP lung model for humans. PMID:3346164

  17. Effect of cross-link density and hydrophilicity of PU on blood compatibility of hydrophobic PS/hydrophilic PU IPNs.

    PubMed

    Roh, H W; Song, M J; Han, D K; Lee, D S; Ahn, J H; Kim, S C

    1999-01-01

    To investigate the effect of the hydrophilic and hydrophobic microdomain structure on blood compatibility, a series of interpenetrating polymer networks (IPNs) composed of hydrophilic polyurethane (PU) and hydrophobic polystyrene (PS) was prepared. One series was prepared with varying cross-link densities of each network, the other with varying hydrophilicity of the PU component. All PU/PS IPNs exhibited microphase-separated structures that had dispersed PS domains in the continuous PU matrix. The domain size decreased with decreasing the hydrophilicity of the PU component and increasing the cross-link density of each network. As the cross-link density and hydrophobicity of the PU component was increased, an inward shift of Tgs was observed, which was due to the decrease in phase separation between the hydrophobic PS component and hydrophilic PU component. In the in vitro platelet adhesion test, as the microdomain size of PU/PS IPN surface decreased, the number of adhered platelets on the PU/PS IPN surface was reduced and deformation of the adhered platelets decreased. It could be concluded that blood compatibility of PU/PS IPN was mainly affected by the degree of mixing between PU and PS component, which was reflected by the domain size of PS rich phase. PMID:10091927

  18. Calculated gamma-ray spectra for keV neutron capture in /sup 240/Pu, /sup 242/Pu, and /sup 238/U

    SciTech Connect

    Reffo, G.; Fabbri, F.; Kappeler, F.; Wisshak, K.

    1983-03-01

    Capture gamma-ray spectra of /sup 240/Pu, /sup 242/Pu, and /sup 238/U were calculated in the framework of the spherical optical model and the statistical model. A consistent set of input parameters was determined from available experimental information or from model-guided systematics. The complete gamma-ray cascades were calculated considering all possible transitions up to multiplicity seven. All experimental information on level schemes and gamma-ray transition probabilities of the compound nuclei was explicitly included as input. The capture gamma-ray spectra were used to correct experimental data for the capture cross sections of /sup 240/Pu and /sup 242/Pu from a relative measurement using a Moxon-Rae detector with a graphite converter and with /sup 197/Au and /sup 238/U as standards. This correction is required to take into account that the detector efficiency is not exactly proportional to the gamma-ray energy. The resulting correction factors proved to be negligible for measurements relative to /sup 238/U; whereas, they are about 3% if gold is used as a standard.

  19. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    SciTech Connect

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-02-06

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  20. Recovery of 238PuO2 by Molten Salt Oxidation Processing of 238PuO2 Contaminated Combustibles (Part II)

    NASA Astrophysics Data System (ADS)

    Remerowski, Mary Lynn; Dozhier, C.; Krenek, K.; VanPelt, C. E.; Reimus, M. A.; Spengler, D.; Matonic, J.; Garcia, L.; Rios, E.; Sandoval, F.; Herman, D.; Hart, R.; Ewing, B.; Lovato, M.; Romero, J. P.

    2005-02-01

    Pu-238 heat sources are used to fuel radioisotope thermoelectric generators (RTG) used in space missions. The demand for this fuel is increasing, yet there are currently no domestic sources of this material. Much of the fuel is material reprocessed from other sources. One rich source of Pu-238 residual material is that from contaminated combustible materials, such as cheesecloth, ion exchange resins and plastics. From both waste minimization and production efficiency standpoints, the best solution is to recover this material. One way to accomplish separation of the organic component from these residues is a flameless oxidation process using molten salt as the matrix for the breakdown of the organic to carbon dioxide and water. The plutonium is retained in the salt, and can be recovered by dissolution of the carbonate salt in an aqueous solution, leaving the insoluble oxide behind. Further aqueous scrap recovery processing is used to purify the plutonium oxide. Recovery of the plutonium from contaminated combustibles achieves two important goals. First, it increases the inventory of Pu-238 available for heat source fabrication. Second, it is a significant waste minimization process. Because of its thermal activity (0.567 W per gram), combustibles must be packaged for disposition with much lower amounts of Pu-238 per drum than other waste types. Specifically, cheesecloth residues in the form of pyrolyzed ash (for stabilization) are being stored for eventual recovery of the plutonium.

  1. Evaluation of the 239Pu(n,2n) Integrated Cross Section

    SciTech Connect

    McNabb, D P; Anderson, J D; Bauer, R W; Becker, J A; Dietrich, F; Navratil, P; Chadwick, M B; Young, P G

    2001-01-25

    Recently, new cross section measurements by the GEANIE collaboration have been published for {sup 239}Pu(n, 2n{gamma}) [Ber00] and {sup 235}U(n, 2n{gamma}) [You00] from threshold to 20 MeV. When combined with nuclear reaction calculations [Che00, Cha99, Cha01], these measurements provide the most accurate information available on the shape and magnitude of the {sup 239}Pu(n, 2n) cross section for incident neutron energies, E{sub n} {approx}< 14 MeV. This new data has prompted a re-evaluation of the {sup 239}Pu(n, 2n) {sup 238}Pu reaction cross section considering all available experimental data. The data prior to the measurement of Bernstein et al. [Ber00] is illustrated in Figure 1a. These data sets were considered by previous evaluations [ENDL] of the {sup 239}Pu(n, 2n) cross section. The most precise experiment was an activation measurement done by Lougheed et al. [Lou00] for incident neutron energies, E{sub n}, between 13-15 MeV. In addition, there were two neutron-counting experiments, one by Mather et al. [Mat72] and one by Frehaut et al. [Fre85]. These two measurements cover a wide incident neutron range, with data points from threshold to E{sub n} {approx} 14 MeV. The available data sets are in poor agreement with each other and in some cases do not meet basic expectations. These experiments will be reviewed in detail. The new contributions to this evaluation are (1) the GEANIE data coupled with reaction modeling, illustrated in Figure 1b, and (2) the systematic use of other nuclear data in order to put constraints on the shape and magnitude of the {sup 239}Pu(n, 2n) cross section. The approach of this evaluation has been to use consistency arguments supported by nuclear data to resolve the measurement differences, with the goal of providing: (1) A comprehensive picture of our knowledge on the {sup 239}Pu(n, 2n) cross section; and (2) A new evaluation including the best possible estimate of the cross section and a one-sigma estimate the uncertainties. This

  2. Speciation and unusual reactivity in PuO2+x.

    PubMed

    Conradson, Steven D; Begg, Bruce D; Clark, David L; Den Auwer, Christophe; Espinosa-Faller, Francisco J; Gordon, Pamela L; Hess, Nancy J; Hess, Ryan; Keogh, D Webster; Morales, Luis A; Neu, Mary P; Runde, Wolfgang; Tait, C Drew; Veirs, D Kirk; Villella, Phillip M

    2003-06-16

    Pu L(3) XAFS measurements show that the excess oxygen in single phase PuO(2+)(x)() occurs as oxo groups with Pu-O distances of 1.83-1.91 A. This distance and the energy of the edge (via comparison with a large number of related compounds) are more consistent with a Pu(IV/V) than a Pu(IV/VI) mixture. Analogous to Pu(IV) colloids, although the Pu-Pu pair distribution remains single site even when it shows substantial disorder, the Pu-O distribution can display a number of additional shells at specific distances up to 3.4 A even in high fired materials when no oxo groups are present, implying intrinsic H(+)/OH(-)(/H(2)O). The number of oxo atoms increases when samples are equilibrated with humid air at ambient temperature, indicating that the Pu reactivity in this solid system differs notably from that of isolated complexes and demonstrating the importance of nanoscale cooperative phenomena and total free energy in determining its chemical properties. PMID:12793805

  3. Electronic Structure Calculations of delta-Pu Based Alloys

    SciTech Connect

    Landa, A; Soderlind, P; Ruban, A

    2003-11-13

    First-principles methods are employed to study the ground-state properties of {delta}-Pu-based alloys. The calculations show that an alloy component larger than {delta}-Pu has a stabilizing effect. Detailed calculations have been performed for the {delta}-Pu{sub 1-c}Am{sub c} system. Calculated density of Pu-Am alloys agrees well with the experimental data. The paramagnetic {yields} antiferromagnetic transition temperature (T{sub c}) of {delta}-Pu{sub 1-c}Am{sub c} alloys is calculated by a Monte-Carlo technique. By introducing Am into the system, one could lower T{sub c} from 548 K (pure Pu) to 372 K (Pu{sub 70}Am{sub 30}). We also found that, contrary to pure Pu where this transition destabilizes {delta}-phase, Pu{sub 3}Am compound remains stable in the antiferromagnetic phase that correlates with the recent discovery of a Curie-Weiss behavior of {delta}-Pu{sub 1-c}Am{sub c} at c {approx} 24 at. %.

  4. X-ray excited Auger transitions of Pu compounds

    SciTech Connect

    Nelson, Art J. Grant, William K.; Stanford, Jeff A.; Siekhaus, Wigbert J.; Allen, Patrick G.; McLean, William

    2015-05-15

    X-ray excited Pu core–valence–valence and core–core–valence Auger line-shapes were used in combination with the Pu 4f photoelectron peaks to characterize differences in the oxidation state and local electronic structure for Pu compounds. The evolution of the Pu 4f core-level chemical shift as a function of sputtering depth profiling and hydrogen exposure at ambient temperature was quantified. The combination of the core–valence–valence Auger peak energies with the associated chemical shift of the Pu 4f photoelectron line defines the Auger parameter and results in a reliable method for definitively determining oxidation states independent of binding energy calibration. Results show that PuO{sub 2}, Pu{sub 2}O{sub 3}, PuH{sub 2.7}, and Pu have definitive Auger line-shapes. These data were used to produce a chemical state (Wagner) plot for select plutonium oxides. This Wagner plot allowed us to distinguish between the trivalent hydride and the trivalent oxide, which cannot be differentiated by the Pu 4f binding energy alone.

  5. Thermophysical properties of α−Pu{sub 2}O{sub 3}: A new potential model

    SciTech Connect

    Günay, S. D. Akdere, Ü.; Taşseven, Ç.; Akgenç, B.

    2013-12-16

    α−Pu{sub 2}O{sub 3} is an important material among plutonium based materials in nuclear industry. Pure plutonium surfaces quickly oxidizes into α−Pu{sub 2}O{sub 3} and PuO{sub 2} which are in the form of layers one on another. Here we have investigated thermal properties of α−Pu{sub 2}O{sub 3} by molecular dynamics simulation by using a partially ionic semi-empirical rigid ion potential. Mechanical properties, thermal expansion, and heat capacity are calculated. Results were compared with available experimental data and quantum calculation [2]. Due to the experimental limitations such as toxicity and radiation effects, studying the physical properties of such materials from molecular dynamics simulations have vital importance.

  6. Adolescent pregnancy options.

    PubMed

    Resnick, M D

    1992-09-01

    The range of pregnancy options available to adolescents each have significant ramifications for future educational and economic achievement. The changing societal context of adolescent pregnancy decision-making are described, and the characteristics of adolescents who choose to terminate their pregnancy, parent their child, or place for adoption are examined. The role of significant others in decision-making and the implications of mandatory parental involvement in pregnancy decision-making is discussed, as well as the roles of schools in promoting the well-being and potential of adolescents considering pregnancy decisions. PMID:1434557

  7. Sintering of compacts of UN, (U,Pu)N, and PuN

    DOEpatents

    Tennery, V.J.; Godfrey, T.G.; Bomar, E.S.

    1973-10-16

    >A method is provided for preparing a densified compact of a metal nitride selected from the group consisting of UN, (U,Pu)N, and PuN which comprises heating a green compact of at least one selected nitride in the mononitride single-phase region, as displayed by a phase diagram of the mononitride of said compact, in a nitrogen atmosphere at a pressure of nitrogen less than 760 torr. At a given temperature, this process produces a singlephase structure and a maximal sintered density as measured by mercury displacement. (Official Gazette)

  8. Materials compatibility for 238Pu-HNO3/HF solution containment: 238Pu aqueous processing

    NASA Astrophysics Data System (ADS)

    Reimus, M. A.; Pansoy-Hjelvik, M. E.; Silver, G.; Brock, J.; Nixon, J.; Ramsey, K. B.; Moniz, P.

    2000-07-01

    The Power Source Technologies Group at Los Alamos National Laboratory is building a 238Pu Aqueous Scrap Recovery Line at the Plutonium Facility. The process line incorporates several unit operations including dissolution, filtration, ion exchange, and precipitation. During 1997-1999, studies were carried out to determine the chemistry used in the full-scale process. Other studies focussed on the engineering design of the operation. Part of the engineering design was to determine, in compatibility studies, the materials for reaction and storage vessels which will contain corrosive 238Pu-HNO3/HF solutions. The full-scale line is to be operational by the end of year 2000.

  9. Minnesota's Public School Choice Options.

    ERIC Educational Resources Information Center

    Colopy, Kelly W.; Tarr, Hope C.

    This document presents findings of a study that identified patterns of use among a broad array of open-enrollment options available to elementary and secondary students in Minnesota. During the period 1985-91, the Minnesota legislature passed several pieces of new legislation designed to: (1) increase the educational choices available to students,…

  10. Adsorption behaviour of PuF6 on UO2F2 by the use of 236Pu

    NASA Astrophysics Data System (ADS)

    Sato, Nobuaki; Matsuda, Minoru; Mitsugashira, Toshiaki; Kirishima, Akira

    2010-03-01

    To know the behavior of plutonium in the fluoride volatility process (FLUOREX PROCESS) for the spent nuclear fuel, both UO2 and PuO2 are fluorinated by fluorine forming volatile UF6 and PuF6, respectively. Then PuF6 is separated and recovered from UF6 by using adsorption materials such as uranyl fluoride UO2F2. In this paper, adsorption behavior of PuF6on UO2F2 was examined by the use of 236Pu tracer. First, the stability of UO2F2 in F2atmosphere was analyzed by TG-DTA method showing that uranium volatilized completely over 350 °C by the formation of UF6 and the adsorption of plutonium by UO2F2 should be done at temperatures lower than 250 °C. The behavior of PtF6 as a chemical analogue of PuF6 was also conducted for comparison and it showed that the deposition of PtF4 on UO2F2 at 200 °C. When the 236Pu doped U3O8 was reacted with 10%F2-He gas, the PuF6 vaporized at ca. 600 °C. Then adsorption of 236Pu on UO2F2 was observed by α ray measurement. The adsorption mechanism of Pu on UO2F2 was discussed with experimental data and thermodynamic consideration.

  11. Characterization of a Pu-bearing zirconolite-rich synroc

    SciTech Connect

    Buck, E.C.; Ebbinghaus, B.; Bakel, A.J.; Bates, J.K.

    1996-12-31

    A titanate-based ceramic waste form, rich in phases structurally related to zirconolite (CaZrTi{sub 2}O{sub 7}), is being developed as a possible method for immobilizing excess plutonium from dismantled nuclear weapons. As part of this program, Lawrence Livermore National Laboratory (LLNL) produced several ceramics that were then characterized at Argonne National Laboratory (ANL). The plutonium- loaded ceramic was found to contain a Pu-Gd zirconolite phase but also contained plutonium titanates, Gd-polymignyte, and a series of other phases. In addition, much of the Pu was remained as PuO{sub 2- x}. The Pu oxidation state in the zirconolite was determined to be mainly Pu{sup 4+}, although some Pu{sub 3+} was believed to be present.

  12. Iron Corrosion Observations: Pu(VI)-Fe Reduction Studies

    SciTech Connect

    Reed, Donald T.; Swanson, Juliet S.; Richmann, Michael K.; Lucchini, Jean-Francois; Borkowski, Marian

    2012-09-11

    Iron and Pu Reduction: (1) Very different appearances in iron reaction products were noted depending on pH, brine and initial iron phase; (2) Plutonium was associated with the Fe phases; (3) Green rust was often noted at the higher pH; (4) XANES established the green rust to be an Fe2/3 phase with a bromide center; and (5) This green rust phase was linked to Pu as Pu(IV).

  13. Ferro- and antiferro-magnetism in (Np, Pu)BC

    NASA Astrophysics Data System (ADS)

    Klimczuk, T.; Shick, A. B.; Kozub, A. L.; Griveau, J.-C.; Colineau, E.; Falmbigl, M.; Wastin, F.; Rogl, P.

    2015-04-01

    Two new transuranium metal boron carbides, NpBC and PuBC, have been synthesized. Rietveld refinements of powder XRD patterns of {Np,Pu}BC confirmed in both cases isotypism with the structure type of UBC. Temperature dependent magnetic susceptibility data reveal antiferromagnetic ordering for PuBC below TN = 44 K, whereas ferromagnetic ordering was found for NpBC below TC = 61 K. Heat capacity measurements prove the bulk character of the observed magnetic transition for both compounds. The total energy electronic band structure calculations support formation of the ferromagnetic ground state for NpBC and the antiferromagnetic ground state for PuBC.

  14. Effect of equilibration time on Pu desorption from goethite

    SciTech Connect

    Wong, Jennifer C.; Zavarin, Mavrik; Begg, James D.; Kersting, Annie B.; Powell, Brian A.

    2015-01-28

    Strongly sorbing ions such as plutonium may become irreversibly bound to mineral surfaces over time implicates near- and far-field transport of Pu. Batch adsorption–desorption data were collected as a function of time and pH to study the surface stability of Pu on goethite. Pu(IV) was adsorbed to goethite over the pH range 4.2 to 6.6 for different periods of time (1, 6, 15, 34 and 116 d). Moreover, following adsorption, Pu was leached from the mineral surface with desferrioxamine B (DFOB), a complexant capable of effectively competing with the goethite surface for Pu. The amount of Pu desorbed from the goethite was found to vary as a function of the adsorption equilibration time, with less Pu removed from the goethite following longer adsorption periods. This effect was most pronounced at low pH. Logarithmic desorption distribution ratios for each adsorption equilibration time were fit to a pH-dependent model. Model slopes decreased between 1 and 116 d adsorption time, indicating that overall Pu(IV) surface stability on goethite surfaces becomes less dependent on pH with greater adsorption equilibration time. The combination of adsorption and desorption kinetic data suggest that non-redox aging processes affect Pu sorption behavior on goethite.

  15. Effect of equilibration time on Pu desorption from goethite

    DOE PAGESBeta

    Wong, Jennifer C.; Zavarin, Mavrik; Begg, James D.; Kersting, Annie B.; Powell, Brian A.

    2015-01-28

    Strongly sorbing ions such as plutonium may become irreversibly bound to mineral surfaces over time implicates near- and far-field transport of Pu. Batch adsorption–desorption data were collected as a function of time and pH to study the surface stability of Pu on goethite. Pu(IV) was adsorbed to goethite over the pH range 4.2 to 6.6 for different periods of time (1, 6, 15, 34 and 116 d). Moreover, following adsorption, Pu was leached from the mineral surface with desferrioxamine B (DFOB), a complexant capable of effectively competing with the goethite surface for Pu. The amount of Pu desorbed from the goethitemore » was found to vary as a function of the adsorption equilibration time, with less Pu removed from the goethite following longer adsorption periods. This effect was most pronounced at low pH. Logarithmic desorption distribution ratios for each adsorption equilibration time were fit to a pH-dependent model. Model slopes decreased between 1 and 116 d adsorption time, indicating that overall Pu(IV) surface stability on goethite surfaces becomes less dependent on pH with greater adsorption equilibration time. The combination of adsorption and desorption kinetic data suggest that non-redox aging processes affect Pu sorption behavior on goethite.« less

  16. 137Cs and (239+240)Pu levels in the Asia-Pacific regional seas.

    PubMed

    Duran, E B; Povinec, P P; Fowler, S W; Airey, P L; Hong, G H

    2004-01-01

    137Cs and (239+240)Pu data in seawater, sediment and biota from the regional seas of Asia-Pacific extending from 50 degrees N to 60 degrees S latitude and 60 degrees E to 180 degrees E longitude based on the Asia-Pacific Marine Radioactivity Database (ASPAMARD) are presented and discussed. 137Cs levels in surface seawater have been declining to its present median value of about 3 Bq/m3 due mainly to radioactive decay, transport processes, and the absence of new significant inputs. (239+240)Pu levels in surface seawater are much lower, with a median of about 6 mBq/m3. (239+240)Pu appears to be partly scavenged by particles and is therefore more readily transported down the water column. As with seawater, (239+240)Pu concentrations are lower than 137Cs in surface sediment. The median 137Cs concentration in surface sediment is 1.4 Bq/kg dry, while that of (239+240)Pu is only 0.2 Bq/kg dry. The vertical profiles of both 137Cs and (239+240)Pu in the sediment column of coastal areas are different from deep seas which can be attributed to the higher sedimentation rates and additional contribution of run-offs from terrestrial catchment areas in the coastal zone. Comparable data for biota are far less extensive than those for seawater and sediment. The median 137Cs concentration in fish (0.2 Bq/kg wet) is higher than in crustaceans (0.1 Bq/kg wet) or mollusks (0.1 Bq/kg wet). Benchmark values (as of 2001) for 137Cs and (239+240)Pu concentrations in seawater, sediment and biota are established to serve as reference values against which the impact of future anthropogenic inputs can be assessed. ASPAMARD represents one of the most comprehensive compilations of available data on 137Cs and (239+240)Pu in particular, and other anthropogenic as well as natural radionuclides in seawater, sediment and biota from the Asia-Pacific regional seas. PMID:15245845

  17. 239Pu(n,2n) 238Pu cross section inferred from IDA calculations and GEANIE measurements

    SciTech Connect

    Chen, H; Ormand, W E; Dietrich, F S

    2000-09-01

    This report presents the latest {sup 239}Pu(n,2n){sup 238}Pu cross sections inferred from calculations performed with the nuclear reaction-modeling code system, IDA, coupled with experimental measurements of partial {gamma}-ray cross sections for incident neutron energies ranging from 5.68 to 17.18 MeV. It is found that the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section peaks at E{sub inc} {approx} 11.4 MeV with a peak value of approximately 326 mb. At E{sub inc} {approx} 14 MeV, the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section is found to be in good agreement with previous radio-chemical measurements by Lockheed. However, the shape of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross section differs significantly from previous evaluations of ENDL, ENDF/B-V and ENDF/B-VI. In our calculations, direct, preequilibrium, and compound reactions are included. Also considered in the modeling are fission and {gamma}-cascade processes in addition to particle emission. The main components of physics adopted and the parameters used in our calculations are discussed. Good agreement of the inferred {sup 239}Pu(n,2n){sup 238}Pu cross sections derived separately from IDA and GNASH calculations is shown. The two inferences provide an estimate of variations in the deduced {sup 239}Pu(n,2n){sup 238}Pu cross section originating from modeling.

  18. Free energy of formation of Cs 3PuCl 6 and CsPu 2Cl 7

    NASA Astrophysics Data System (ADS)

    Williamson, M. A.; Kleinschmidt, P. D.

    The free energy, enthalpy and entropy of formation of the compounds Cs 3PuCl 6 and CsPu 2Cl 7 have been determined by measuring the sublimation pressures for the reactions CsCl( s) / aiCsCl( g), {2}/{5}Cs 3PuCl 6(s) /ai {1}/{5}CsPu 2Cl 7(s) + CsCl(g) , and CsPu2Cl7( s) / ai 2 PuCl3( s) + CsCl( g). The pressures are measured using Knudsen effusion mass spectrometry over the temperature range 600 to 850 K. For the formation of Cs 3PuCl 6 from CsCl and PuCl 3, ΔG0298 = -77.3 ± 8.5 kJ/ mol, ΔH0298 = -82.1 ± 7.8 kJ/ mol, and ΔS0298 = -16.2 ± 10.9 J/ Kmol. For CsPu 2Cl 7, ΔG0298 = -39.4 ± 3.5 kJ/ mol, ΔH0298 = -40.8 ± 3.2 kJ/ mol, and ΔS0298 = -4.6 ± 4.2 J/ Kmol.

  19. Breast Cancer: Treatment Options

    MedlinePlus

    ... Cancer - Treatment Options Request Permissions Print to PDF Breast Cancer - Treatment Options Approved by the Cancer.Net Editorial ... recommendations for ovarian ablation . Hormonal therapy for metastatic breast cancer Hormonal therapies are also commonly used to treat ...

  20. 48 CFR 17.207 - Exercise of options.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 48 Federal Acquisition Regulations System 1 2014-10-01 2014-10-01 false Exercise of options. 17... METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.207 Exercise of options. (a) When... exercise options only after determining that— (1) Funds are available; (2) The requirement covered by...

  1. 48 CFR 17.207 - Exercise of options.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 48 Federal Acquisition Regulations System 1 2012-10-01 2012-10-01 false Exercise of options. 17... METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.207 Exercise of options. (a) When... exercise options only after determining that— (1) Funds are available; (2) The requirement covered by...

  2. 48 CFR 17.207 - Exercise of options.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 48 Federal Acquisition Regulations System 1 2011-10-01 2011-10-01 false Exercise of options. 17... METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.207 Exercise of options. (a) When... exercise options only after determining that— (1) Funds are available; (2) The requirement covered by...

  3. 48 CFR 17.207 - Exercise of options.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 1 2010-10-01 2010-10-01 false Exercise of options. 17... METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.207 Exercise of options. (a) When... exercise options only after determining that— (1) Funds are available; (2) The requirement covered by...

  4. 48 CFR 17.207 - Exercise of options.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 48 Federal Acquisition Regulations System 1 2013-10-01 2013-10-01 false Exercise of options. 17... METHODS AND CONTRACT TYPES SPECIAL CONTRACTING METHODS Options 17.207 Exercise of options. (a) When... exercise options only after determining that— (1) Funds are available; (2) The requirement covered by...

  5. Mixed waste management options

    SciTech Connect

    Owens, C.B.; Kirner, N.P.

    1991-12-31

    Disposal fees for mixed waste at proposed commercial disposal sites have been estimated to be $15,000 to $40,000 per cubit foot. If such high disposal fees are imposed, generators may be willing to apply extraordinary treatment or regulatory approaches to properly dispose of their mixed waste. This paper explores the feasibility of several waste management scenarios and attempts to answer the question: Can mixed waste be managed out of existence? Existing data on commercially generated mixed waste streams are used to identify the realm of mixed waste known to be generated. Each waste stream is evaluated from both a regulatory and technical perspective in order to convert the waste into a strictly low-level radioactive or a hazardous waste. Alternative regulatory approaches evaluated in this paper include a delisting petition, no migration petition, and a treatability variance. For each waste stream, potentially available treatment options are identified that could lead to these variances. Waste minimization methodology and storage for decay are also considered. Economic feasibility of each option is discussed broadly.

  6. Is Octavalent Pu(VIII) Possible? Mapping the Plutonium Oxyfluoride Series PuO(n)F(8-2n) (n = 0-4).

    PubMed

    Huang, Wei; Pyykkö, Pekka; Li, Jun

    2015-09-01

    While the oxidation state Pu(VIII) is shown to be less stable than Pu(V) in the PuO4 molecule, it is not clear if the more electronegative fluorine can help to stabilize Pu(VIII). Our calculations on PuO(n)F(8-2n) (n = 0-4) molecules notably confirm that PuO2F4 has both (1)D(4h) and (5)C(2v) minima with the oxidation states Pu(VIII) and Pu(V), respectively, with the latter having lower energy. The hybrid-DFT, CCSD(T), and CASSCF methods all give the same result. The results conform to a superoxide ligand when n ≥ 2. PuF8 in a (1)O(h) state can decompose to PuF6 and F2, and PuOF6 in a (1)C(2v) state also can break down to PuF6 and 1/2 O2. The Pu(VIII) anion PuO2F5(-) does have a D(5h) minimum, which also lies above a (5)C(2v) Pu(V) peroxide structure. However, the energy differences between the different minima are not large, indicating that metastable species with oxidation states higher than Pu(V) cannot be completely excluded. PMID:26309065

  7. New measurement of the 242Pu(n,γ) cross section at n_TOF

    NASA Astrophysics Data System (ADS)

    Lerendegui-Marco, J.; Guerrero, C.; Cortés-Giraldo, M. A.; Quesada, J. M.; Mendoza, E.; Cano-Ott, D.; Eberhardt, K.; Junghans, A.

    2016-03-01

    The use of MOX fuel (mixed-oxide fuel made of UO2 and PuO2) in nuclear reactors allows substituting a large fraction of the enriched Uranium by Plutonium reprocessed from spent fuel. With the use of such new fuel composition rich in Pu, a better knowledge of the capture and fission cross sections of the Pu isotopes becomes very important. In particular, a new series of cross section evaluations have been recently carried out jointly by the European (JEFF) and United States (ENDF) nuclear data agencies. For the case of 242Pu, the two only neutron capture time-of-flight measurements available, from 1973 and 1976, are not consistent with each other, which calls for a new time-of flight capture cross section measurement. In order to contribute to a new evaluation, we have perfomed a neutron capture cross section measurement at the n_TOF-EAR1 facility at CERN using four C6D6 detectors, using a high purity target of 95 mg. The preliminary results assessing the quality and limitations (background, statistics and γ-flash effects) of this new experimental data are presented and discussed, taking into account that the aimed accuracy of the measurement ranges between 7% and 12% depending on the neutron energy region.

  8. Evaluation of containment failure and cleanup time for Pu shots on the Z machine.

    SciTech Connect

    Darby, John L.

    2010-02-01

    Between November 30 and December 11, 2009 an evaluation was performed of the probability of containment failure and the time for cleanup of contamination of the Z machine given failure, for plutonium (Pu) experiments on the Z machine at Sandia National Laboratories (SNL). Due to the unique nature of the problem, there is little quantitative information available for the likelihood of failure of containment components or for the time to cleanup. Information for the evaluation was obtained from Subject Matter Experts (SMEs) at the Z machine facility. The SMEs provided the State of Knowledge (SOK) for the evaluation. There is significant epistemic- or state of knowledge- uncertainty associated with the events that comprise both failure of containment and cleanup. To capture epistemic uncertainty and to allow the SMEs to reason at the fidelity of the SOK, we used the belief/plausibility measure of uncertainty for this evaluation. We quantified two variables: the probability that the Pu containment system fails given a shot on the Z machine, and the time to cleanup Pu contamination in the Z machine given failure of containment. We identified dominant contributors for both the time to cleanup and the probability of containment failure. These results will be used by SNL management to decide the course of action for conducting the Pu experiments on the Z machine.

  9. Crystal Dynamics of (delta) fcc Pu-Ga by High Resolution Inelastic X-Ray Scattering

    SciTech Connect

    Wong, J; Krisch, M; Farber, D; Occelli, F; Xu, R; Chiang, T C; Clatterbuck, D; Schwartz, A J; Wall, M; Boro, C

    2004-09-28

    We have used a microbeam on large grain sample concept to carry out an inelastic x-ray scattering experiment to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features can be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium.

  10. Oxygen diffusion in UO2+x and (U,Pu)O2+-x

    SciTech Connect

    Andersson, Anders D.; Liu, Xiang-Yang

    2012-05-03

    In the first part of this report we revisit an earlier study of oxygen diffusion in UO{sub 2+x}, in which we used density functional theory (DFT) calculations to parameterize a kinetic Monte Carlo (kMC) model. The results from these earlier kMC simulations are reproduced in Fig. 1 and they indicate fairly good agreement with available experiments. This work was later expanded to include a larger temperature range. However, since the publication of this study there have been a number of advancements in DFT methodology for UO{sub 2} and UO{sub 2+x} providing increased accuracy. We have also gained better understanding of the oxygen clustering phenomena occurring in UO{sub 2+x}. For these two reasons, the DFT calculations of the migration barriers of single oxygen interstitials and di-interstitial clusters have been repeated using the LDA+U and GGA+U methodologies. The earlier study used regular GGA and, even though this method captures similar trends as the more advanced LDA+U and GGA+U techniques, it does not fulfill the quantitative requirements set by some applications. Additionally, we have identified a mechanism for the most stable quad-interstitial clusters to migrate and here we calculate the corresponding barriers within both the LDA+U and GGA+U methodologies. The new LDA+U and GGA+U data sets are analyzed in terms of available experiments. In the second part of this report we present initial results for the impact of Pu on oxygen diffusion in UO{sub 2}. The first step in understanding this process is to calculate the binding energies of oxygen vacancies and interstitials to a Pu ion in the UO{sub 2} matrix. Possible diffusion mechanisms are discussed for (U,Pu)O{sub 2-x}, (U,Pu)O{sub 2} and (U,Pu)O{sub 2+x}.

  11. [Not Available].

    PubMed

    Frenette, Marjolaine; Saint-Arnaud, Jocelyne

    2016-03-01

    Different care settings in Quebec use levels of medical intervention forms, also called levels of care (LOC), to determine the code status of patients and to improve end-of-life care planning. It is not currently possible to know whether the levels of care in hospitals benefit patients and staff in facilitating the decision making process of treatment options and resuscitation measures. No study, to the best of the authors' knowledge, has been published about LOC, particularly in Quebec and Canada. This literature review was undertaken on levels of care in order to clarify this topic. Relevant articles are discussed under different themes that are pertinent to LOC. The themes addressed in this article include care at the end of life, do-not-resuscitate orders, treatment withdrawal, and decision making at end of life. PMID:26880120

  12. PU.1 silencing leads to terminal differentiation of erythroleukemia cells

    SciTech Connect

    Atar, Orna; Levi, Ben-Zion . E-mail: blevi@technion.ac.il

    2005-04-22

    The transcription factor PU.1 plays a central role in development and differentiation of hematopoietic cells. Evidence from PU.1 knockout mice indicates a pivotal role for PU.1 in myeloid lineage and B-lymphocyte development. In addition, PU.1 is a key player in the development of Friend erythroleukemia disease, which is characterized by proliferation and differentiation arrest of proerythrocytes. To study the role of PU.1 in erythroleukemia, we have used murine erythroleukemia cells, isolated from Friend virus-infected mice. Expression of PU.1 small interfering RNA in these cells led to significant inhibition of PU.1 levels. This was accompanied by inhibition of proliferation and restoration in the ability of the proerythroblastic cells to produce hemoglobin, i.e., reversion of the leukemic phenotype. The data suggest that overexpression of PU.1 gene is the immediate cause for maintaining the leukemic phenotype of the disease by retaining the self-renewal capacity of transformed erythroblastic cells and by blocking the terminal differentiation program towards erythrocytes.

  13. Pu-238 fuel form activities, January 1-31, 1982

    SciTech Connect

    Not Available

    1982-03-01

    This monthly report for /sup 238/Pu fuel form activities has two main sections: SRP-PuFF facility and SRL fuel form activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  14. Pu-238 fuel form activities, January 1-31, 1981

    SciTech Connect

    Not Available

    1981-02-01

    This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  15. Pu-238 fuel form activities, January 1-31, 1983

    SciTech Connect

    Not Available

    1983-03-01

    This monthly report for /sup 238/Pu Fuel Form Activities has two main sections: SRP-PuFF facility and SRL Fuel Form Activities. The program status, budget information, and milestone schedules are discussed in each main section. The Work Breakdown Structure (WBS) for this program is shown. Only one monthly report per year is processed for EDB.

  16. Options for English Language Learners

    ERIC Educational Resources Information Center

    Minaya-Rowe, Liliana

    2008-01-01

    Between 69 percent and 90 percent of English language learners (ELLs) in middle and high schools were born in the United States and have been in U.S. schools since kindergarten still have not achieved the academic proficiency to succeed in an all-English mainstream program. Various ELL program options are available for school districts to…

  17. The environmental dependence of redox energetics of PuO2 and α-Pu2O3: A quantitative solution from DFT+U

    NASA Astrophysics Data System (ADS)

    Sun, Bo; Liu, Haifeng; Song, Haifeng; Zhang, Guangcai; Zheng, Hui; Zhao, Xiangeng; Zhang, Ping

    2012-08-01

    We report a comprehensive density functional theory (DFT)+U study of the energetics of charged and neutral oxygen defects in both PuO2 and α-Pu2O3, and present a quantitative determination of the equilibrium compositions of reduced PuO2 (PuO2 - x) as functions of environmental temperature and partial pressure of oxygen, which shows fairly agreement with corresponding high-temperature experiments. Under ambient conditions, the endothermic reduction of PuO2 to α-Pu2O3 is found to be facilitated by accompanying volume expansion of PuO2 - x and the possible migration of O-vacancy, whereas further reduction of α-Pu2O3 is predicted to be much more difficult. In contrast to the endothermic oxidation of PuO2, the oxidation of α-Pu2O3 is a stable exothermic process.

  18. Sputtering yield of Pu bombarded by fission Fragments from Cf

    SciTech Connect

    Danagoulian, Areg; Klein, Andreas; Mcneil, Wendy V; Yuan, Vincent W

    2008-01-01

    We present results on the yield of sputtering of Pu atoms from a Pu foil, bombarded by fission fragments from a {sup 252}Cf source in transmission geometry. We have found the number of Pu atoms/incoming fission fragments ejected to be 63 {+-} 1. In addition, we show measurements of the sputtering yield as a function of distance from the central axis, which can be understood as an angular distribution of the yield. The results are quite surprising in light of the fact that the Pu foil is several times the thickness of the range of fission fragment particles in Pu. This indicates that models like the binary collision model are not sufficient to explain this behavior.

  19. Fission xenon from extinct Pu-244 in 14,301.

    NASA Technical Reports Server (NTRS)

    Drozd, R.; Hohenberg, C. M.; Ragan, D.

    1972-01-01

    Xenon extracted in step-wise heating of lunar breccia 14,301 contains a fission-like component in excess of that attributable to uranium decay during the age of the solar system. There seems to be no adequate source for this component other than Pu-244. Verification that this component is in fact due to the spontaneous fission of extinct Pu-244 comes from the derived spectrum which is similar to that observed from artificially produced Pu-244. It thus appears that Pu-244 was extant at the time lunar crustal material cooled sufficiently to arrest the thermal diffusion of xenon. Subsequent history has apparently maintained the isotopic integrity of plutonium fission xenon. Of major importance are details of the storage itself. Either the fission component is the result of in situ fission of Pu-244 and subsequent storage in 14,301 material, or the fission xenon was stored in an intermediate reservoir before incorporation into 14,301.

  20. Laboratory studies of actinide partitioning relevant to 244Pu chronometry

    NASA Technical Reports Server (NTRS)

    Benjamin, T.; Heuser, W. R.; Burnett, D. S.

    1978-01-01

    Actinide partitioning and light lanthanide fractionation have been studied to gain an understanding of Pu chemistry under meteoritic and lunar conditions. The goal of the study was to identify conditions and samples from which chronological information can be retrieved. The laboratory investigations involved particle track radiography of the crystal/liquid partitioning of Th, U and Pu among diopsidic clinopyroxene, whitlockite and liquid. It is found that trivalent Pu plays an important role in partitioning for lunar and most meteoritic conditions. The use of Pu/Nd for relative age assessments is supported to some extent by the investigations; samples with unfractionated U, Th and Nd abundances (relative to average solar system values) may be suitable for Pu chronometry.

  1. TANK SPACE OPTIONS REPORT

    SciTech Connect

    WILLIS WL; AHRENDT MR

    2009-08-11

    Since this report was originally issued in 2001, several options proposed for increasing double-shell tank (DST) storage space were implemented or are in the process of implementation. Changes to the single-shell tank (SST) waste retrieval schedule, completion of DST space saving options, and the DST space saving options in progress have delayed the projected shortfall of DST storage space from the 2007-2011 to the 2018-2025 timeframe (ORP-11242, River Protection Project System Plan). This report reevaluates options from Rev. 0 and includes evaluations of new options for alleviating projected restrictions on SST waste retrieval beginning in 2018 because of the lack of DST storage space.

  2. LLNL Workshop on TEM of Pu

    SciTech Connect

    King, W.E.

    1996-09-10

    On Sept. 10, 1996, LLNL hosted a workshop aimed at answering the question: Is it possible to carry out transmission electron microscopy (TEM) on plutonium metal in an electron microscope located outside the LLNL plutonium facility. The workshop focused on evaluation of a proposed plan for Pu microscopy both from a technical and environment, health, and safety point of view. After review and modification of the plan, workshop participants unanimously concluded that: (1) the technical plan is sound, (2) this technical plan, including a proposal for a new TEM, provides significant improvements and unique capabilities compared with the effort at LANL and is therefore complementary, (3) there is no significant environment, health, and safety obstacle to this plan.

  3. Microscopic Calculations of 240Pu Fission

    SciTech Connect

    Younes, W; Gogny, D

    2007-09-11

    Hartree-Fock-Bogoliubov calculations have been performed with the Gogny finite-range effective interaction for {sup 240}Pu out to scission, using a new code developed at LLNL. A first set of calculations was performed with constrained quadrupole moment along the path of most probable fission, assuming axial symmetry but allowing for the spontaneous breaking of reflection symmetry of the nucleus. At a quadrupole moment of 345 b, the nucleus was found to spontaneously scission into two fragments. A second set of calculations, with all nuclear moments up to hexadecapole constrained, was performed to approach the scission configuration in a controlled manner. Calculated energies, moments, and representative plots of the total nuclear density are shown. The present calculations serve as a proof-of-principle, a blueprint, and starting-point solutions for a planned series of more comprehensive calculations to map out a large set of scission configurations, and the associated fission-fragment properties.

  4. Preparation of Pu{sup 239} sources

    SciTech Connect

    Holcomb, H.P.

    1988-08-05

    The Separations Technology Laboratory has prepared four sources to be used for calibrating a waste assay system (Passive/Active Neutron Assay) in Building 724-8G (Burial Ground). The four sources contain 0.5, 0.1, 0.05, and 0.01 grams Pu{sup 239}, respectively. The sources were prepared using aliquots from a single solution provided by the Quality Control (QC) group of Laboratories Department. The solution contained weapons-grade plutonium dissolved in nitric acid. Final solution acidity was 3M. Coulometry had been used to obtain a total plutonium content per unit volume. The weight percent of the plutonium isotopes present was obtained via mass spectrometry.

  5. Distinguishing Pu Metal from Pu Oxide and Determining alpha-ratio using Fast Neutron Counting

    SciTech Connect

    Verbeke, J. M.; Chapline, G. F.; Nakae, L. F.; Prasad, M. K.; Sheets, S. A.; Snyderman, N. J.

    2015-01-07

    We describe a new method for determining the ratio of the rate of (α, n) source neutrons to the rate of spontaneous fission neutrons, the so called α-ratio. This method is made possible by fast neutron counting with liquid scintillator detectors, which can determine the shape of the fast neutron spectrum. The method utilizes the spectral difference between fission spectrum neutrons from Pu metal and the spectrum of (α, n) neutrons from PuO2. Our method is a generalization of the Cifarelli-Hage method for determining keff for fissile assemblies, and also simultaneously determines keff along with the α-ratio.

  6. Performance of Cladding on MOX Fuel with Low 240Pu/239Pu Ratio

    SciTech Connect

    McCoy, Kevin; Blanpain, Patrick; Morris, Robert Noel

    2014-01-01

    The U.S. Department of Energy has decided to dispose of a portion of its surplus plutonium by reconstituting it into mixed oxide (MOX) fuel and irradiating it in commercial power reactors. As part of fuel qualification, four lead assemblies were manufactured and irradiated to a maximum fuel rod average burnup of 47.3 MWd/kg heavy metal. This was the world s first commercial irradiation of MOX fuel with a 240Pu/239Pu ratio less than 0.10. Five fuel rods with varying burnups and plutonium contents were selected from one of the assemblies and shipped to Oak Ridge National Laboratory for hot cell examination. This paper discusses the results of those examinations with emphasis on cladding performance. Exams relevant to the cladding included visual and eddy current exams, profilometry, microscopy, hydrogen analysis, gallium analysis, and mechanical testing. There was no discernible effect of the type of MOX fuel on the performance of the cladding.

  7. TOPEX satellite option study

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The basic design of the fleet satellite communication spacecraft (FLTSATCOM) can easily accommodate any of the three payload options for the ocean dynamic topography experiment (TOPEX). The principal mission requirements as well as the payload accommodations and communications systems needed for launching this payload are reviewed. The existing FLTSATCOM satellite design is identified and the approaches for the proposed propulsion system are described in addition to subsystems for mechanical; power; attitude and velocity control; and telemetry, tracking and control are described. The compatability of FLTSATCOM with the launch vehicle is examined and its capabilities vs TOPEX requirements are summarized. Undetermined changes needed to meet data storage, thermal control, and area to mass ratio requirements are discussed. Cost estimates are included for budgetary and planning purposes. The availability of the described design is assessed based on the continuing production of FLTSATCOM spacecraft during the schedule span planned for TOPEX.

  8. Achalasia: current treatment options.

    PubMed

    Familiari, Pietro; Greco, Santi; Volkanovska, Ance; Gigante, Giovanni; Cali, Anna; Boškoski, Ivo; Costamagna, Guido

    2015-01-01

    Achalasia is a rare esophageal motility disorder, characterized by impaired swallow-induced, lower esophageal sphincter (LES) relaxation and defective esophageal peristalsis. Unfortunately, there are no etiological therapies for achalasia. Patients present with dysphagia, chest pain and regurgitation of undigested food, often leading to weight loss. The currently available treatments have the common aim of relieving symptoms by decreasing the pressure of the LES. This can be achieved with some medications, by inhibiting the cholinergic innervation (botulinum toxin), by stretching (endoscopic dilation) or cutting (surgery) the LES. Recently, other therapeutic options, including per-oral endoscopic myotomy have been developed and are gaining international consensus. The authors report on the benefits and weaknesses of the different therapies and provide an updated approach to the management of achalasia. PMID:26186641

  9. Pediatric Glaucoma: Pharmacotherapeutic Options.

    PubMed

    Samant, Monica; Medsinge, Anagha; Nischal, Ken K

    2016-06-01

    Childhood glaucoma is a major therapeutic challenge for pediatric ophthalmologists and glaucoma specialists worldwide. Management depends on the etiology and age at presentation. A variety of drugs are available for the control of intraocular pressure in children; however, none of these drugs have been licensed by the regulatory agencies for use in children. Furthermore, evidence gained from randomized controlled trials in the pediatric population is sparse, and little is known regarding the use of newer anti-glaucoma preparations. This evidence-based review aims to discuss the available pharmacotherapeutic options for glaucoma in children. Topical adrenoceptor blockers, topical and systemic carbonic anhydrase inhibitors, prostaglandin (PG) analogs, adrenoceptor agonists, parasympathomimetics, and combined preparations are available for use in children, but usually as an off-label indication. Therefore, it is important to recognize that serious side effects have been reported, even with topical drops, and measures to reduce systemic absorption should be taken. Most drugs have been shown to have comparable ocular hypotensive effects, with the lowest occurrence of systemic side effects with PG analogs. Whereas a newly introduced prostaglandin analog, tafluprost, and some other preservative-free preparations have shown promising results in adult glaucoma patients, no pediatric reports are available as yet. Future studies may describe their role in treating pediatric glaucoma. This review also shares some suggested treatment pathways for primary congenital glaucoma (PCG), juvenile open angle glaucoma (JOAG), developmental glaucoma, aphakic/pseudophakic glaucoma, and uveitic glaucoma. PMID:27093864

  10. Resolving global versus local/regional Pu sources in the environment using sector ICP-MS

    USGS Publications Warehouse

    Ketterer, M.E.; Hafer, K.M.; Link, C.L.; Kolwaite, D.; Wilson, Jim; Mietelski, J.W.

    2004-01-01

    Sector inductively coupled plasma mass spectrometry is a versatile method for the determination of plutonium activities and isotopic compositions in samples containing this element at fallout levels. Typical detection limits for 239+240Pu are 0.1, 0.02 and 0.002 Bq kg -1Pu for samples sizes of 0.5 g, 3 g, and 50 g of soil, respectively. The application of sector ICP-MS-based Pu determinations is demonstrated in studies in sediment chronology, soil Pu inventory and depth distribution, and the provenance of global fallout versus local or regional Pu sources. A sediment core collected from Sloans Lake (Denver, Colorado, USA) exhibits very similar 137Cs and 239+240Pu activity profiles; 240Pu/239Pu atom ratios indicate possible small influences from the Nevada Test Site and/or the Rocky Flats Environmental Technology Site. An undisturbed soil profile from Lockett Meadow (Flagstaff, Arizona, USA) exhibits an exponential decrease in 239+240Pu activity versus depth; 240Pu/239Pu in the top 3 cm is slightly lower than the global fallout range of 0.180 ?? 0.014 due to possible regional influence of Nevada Test Site fallout. The 239??240Pu inventory at Lockett Meadow is 56 ?? 4 Bq m-2, consistent with Northern Hemisphere mid-latitude fallout. Archived NdF3 sources, prepared from Polish soils, demonstrate that substantial 239+240Pu from the 1986 Chernobyl disaster has been deposited in north eastern regions of Poland; compared to global fallout, Chernobyl Pu exhibits higher abundances of 240Pu and 241Pu. The ratios 240Pu/239pu and 241Pu/239Pu co-vary and range from 0.186-0.348 and 0.0029-0.0412, respectively, in forest soils (241Pu/239Pu = 0.2407??[240Pu/239Pu] - 0.0413; r2 = 0.9924). ?? The Royal Society of Chemistry 2004.

  11. Oxidation states, geometries, and electronic structures of plutonium tetroxide PuO4 isomers: is octavalent Pu viable?

    PubMed

    Huang, Wei; Xu, Wen-Hua; Su, Jing; Schwarz, W H E; Li, Jun

    2013-12-16

    In neutral chemical compounds, the highest known oxidation state of all elements in the Periodic Table is +VIII. While PuO4 is viewed as an exotic Pu(+VIII) complex, we have shown here that no stable electronic homologue of octavalent RuO4 and OsO4 exists for PuO4, even though Pu has the same number of eight valence electrons as Ru and Os. Using quantum chemical approaches at the levels of quasi-relativistic DFT, MP2, CCSD(T), and CASPT2, we find the ground state of PuO4 as a quintet (5)C2v-(PuO2)(+)(O2)(-) complex with the leading valence configuration of an (f(3))plutonyl(V) unit, loosely coupled to a superoxido (π*(3))O2(-) ligand. This stable isomer is likely detectable as a transient species, while the previously suggested planar (1)D4h-Pu(VIII)O4 isomer is only metastable. Through electronic structure analyses, the bonding and the oxidation states are explained and rationalized. We have predicted the characteristics of the electronic and vibrational spectra to assist future experimental identification of (PuO2)(+)(O2)(-) by IR, UV-vis, and ionization spectroscopy. PMID:24274785

  12. Internal Corrosion Analysis of Model 9975 Packaging Containing Pu or PuO{sub 2} During Shipping and Storage

    SciTech Connect

    Vormelker, P.

    1999-03-23

    The Materials Consultation Group of SRTC has completed an internal corrosion analysis of the Model 9975 packaging assembly containing either Pu or PuO2 for storage in K Reactor under ambient conditions for a period of 12 years. The 12-year storage period includes two years for shipping and up to ten years for storage.

  13. Early amplification options.

    PubMed

    Gabbard, Sandra Abbott; Schryer, Jennifer

    2003-01-01

    Children with permanent hearing loss have been remediated with hearing amplification devices for decades. The influx of young infants identified with hearing loss through successful newborn hearing screening programs has established a need for amplification resources for infants within the first six months of life. For the approximately two of every 1000 infants born who are identified with bilateral hearing loss [Mehl and Thomson, 1998, Pediatrics 101, p. e4], the use of amplification is commonly the first step in treating the sequella of their loss. The use of hearing aids, combined with early intervention, has been shown to significantly improve the speech and language skills of young children with hearing loss [Yoshinaga-Itano, 2000, Seminars in Hearing 21, p. 309]. Speech and language delays have contributed to compromised academic performance of school aged children with hearing loss [Johnson et al., 1997, Educational Audiology Handbook, Singular Publishing, San Diego]. Most hard-of-hearing and deaf children use hearing aids and other assistive listening devices every day throughout their lifetime and the life expectancy of a hearing aid is only five to eight years. The current challenge for pediatric audiologists is selecting and evaluating the available amplification to provide the best options for children and their families. Amplification technology has seen an explosion in growth the past few years and the options continue to expand rapidly. This article examines currently available amplification technology and reviews the selection criteria that may be used for infants and young children. Issues such as style, type, amplification features, signal processing strategies, and verification and validation tools are also discussed. PMID:14648816

  14. Fragment mass and kinetic energy distributions for /sup 242/Pu(sf), /sup 241/Pu(n/sub th/,f), and /sup 242/Pu(. gamma. ,f)

    SciTech Connect

    Thierens, H.; Jacobs, E.; D'hondt, P.; De Clercq, A.; Piessens, M.; De Frenne, D.

    1984-02-01

    Energy correlation measurements were performed for the spontaneous fission of /sup 242/Pu, the thermal-neutron-induced fission of /sup 241/Pu, and the photofission of /sup 242/Pu with 12-, 15-, 20-, and 30-MeV bremsstrahlung. The photofission cross section for /sup 242/Pu was determined up to 30 MeV. For /sup 242/Pu(sf) the overall kinetic energy distribution is strongly asymmetric and the overall mass distribution has a very high peak yield (9%). Important deviations of the average total kinetic energy release and the average light and heavy fragment masses and from the systematics of Unik et al. are also observed for this fissioning system. These effects can be explained in the framework of the static scission point model by the strong preferential formation of a shell-stabilized scission configuration with the neutron number of the heavy and light fragments in the vicinity of the spherical N = 82 neutron shell and the deformed N = 66 neutron shell, respectively. A decrease of with the average excitation energy , d/d = -0.30 +- 0.04, is observed in the photofission of /sup 242/Pu.

  15. Emerging Options for Emergency Contraception

    PubMed Central

    Koyama, Atsuko; Hagopian, Laura; Linden, Judith

    2013-01-01

    Emergency post-coital contraception (EC) is an effective method of preventing pregnancy when used appropriately. EC has been available since the 1970s, and its availability and use have become widespread. Options for EC are broad and include the copper intrauterine device (IUD) and emergency contraceptive pills such as levonorgestrel, ulipristal acetate, combined oral contraceptive pills (Yuzpe method), and less commonly, mifepristone. Some options are available over-the-counter, while others require provider prescription or placement. There are no absolute contraindications to the use of emergency contraceptive pills, with the exception of ulipristal acetate and mifepristone. This article reviews the mechanisms of action, efficacy, safety, side effects, clinical considerations, and patient preferences with respect to EC usage. The decision of which regimen to use is influenced by local availability, cost, and patient preference. PMID:24453516

  16. Lunar Cube Transfer Trajectory Options

    NASA Technical Reports Server (NTRS)

    Folta, David; Dichmann, Donald James; Clark, Pamela E.; Haapala, Amanda; Howell, Kathleen

    2015-01-01

    Numerous Earth-Moon trajectory and lunar orbit options are available for Cubesat missions. Given the limited Cubesat injection infrastructure, transfer trajectories are contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these transfers can be restricted by the selection or designs of Cubesat subsystems such as propulsion or communication. Nonetheless, many trajectory options can b e considered which have a wide range of transfer duration, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several options including deployment from low Earth orbit (LEO) geostationary transfer orbits (GTO) and higher energy direct lunar transfer and the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory.

  17. Lunar Cube Transfer Trajectory Options

    NASA Technical Reports Server (NTRS)

    Folta, David; Dichmann, Donald J.; Clark, Pamela; Haapala, Amanda; Howell, Kathleen

    2015-01-01

    Numerous Earth-Moon trajectory and lunar orbit options are available for Cubesat missions. Given the limited Cubesat injection infrastructure, transfer trajectories are contingent upon the modification of an initial condition of the injected or deployed orbit. Additionally, these transfers can be restricted by the selection or designs of Cubesat subsystems such as propulsion or communication. Nonetheless, many trajectory options can be considered which have a wide range of transfer durations, fuel requirements, and final destinations. Our investigation of potential trajectories highlights several options including deployment from low Earth orbit (LEO), geostationary transfer orbits (GTO), and higher energy direct lunar transfers and the use of longer duration Earth-Moon dynamical systems. For missions with an intended lunar orbit, much of the design process is spent optimizing a ballistic capture while other science locations such as Sun-Earth libration or heliocentric orbits may simply require a reduced Delta-V imparted at a convenient location along the trajectory.

  18. Determination of alpha-emitting Pu isotopes in environmental samples.

    PubMed

    Vioque, I; Manjón, G; García-Tenorio, R; El-Daoushy, F

    2002-04-01

    This paper presents an improved radiochemical procedure for the determination of alpha-emitting Pu isotopes in environmental samples (soils, sediments, vegetation) by alpha-particle spectrometry. Quantitative Pu recovery yields were obtained (average 60%), 0.1 mBq being the average minimum detectable activity by the complete technique. Special efforts were made to ensure the removal of traces of different natural alpha-emitting radionuclides, which can interfere with the correct determination of 239+240Pu and 238Pu concentrations. The radiochemical procedure was validated by application to reference material and by participation in intercomparison exercises. This radiochemical procedure was applied to the different layers of a high-resolution sediment core taken from a lake in Sweden. The 239+240Pu and 238Pu/239+240Pu profiles obtained in the high-resolution sediment core correctly reproduced the expected evolution of these quantities as observed historically in the atmosphere, validating the procedure for this purpose and showing the power of these radionuclides for dating purposes. PMID:12022654

  19. Attempt to detect primordial 244Pu on Earth

    NASA Astrophysics Data System (ADS)

    Lachner, Johannes; Dillmann, Iris; Faestermann, Thomas; Korschinek, Gunther; Poutivtsev, Mikhail; Rugel, Georg; Lierse von Gostomski, Christoph; Türler, Andreas; Gerstmann, Udo

    2012-01-01

    With a half-life of 81.1Myr, 244Pu could be both the heaviest and the shortest-lived nuclide present on Earth as a relic of the last supernova(e) that occurred before the formation of the Solar System. Hoffman [Nature (London)NATUAS0028-083610.1038/234132a0 234, 132 (1971)] reported on the detection of this nuclide (1.0×10-18 g 244Pu/g) in the rare-earth mineral bastnäsite with the use of a mass spectrometer. Up to now these findings were never reassessed. We describe the search for primordial 244Pu in a sample of bastnäsite with the method of accelerator mass spectrometry (AMS). It was performed with a highly sensitive setup, identifying the ions by the determination of their time-of-flight and energy. Using AMS, the stripping to high charge states allows the suppression of any molecular interference. During our measurements we observed no event of 244Pu. Therefore, we can give an upper limit for the abundance of 244Pu in our sample of the mineral bastnäsite of 370 atoms per gram (1.5×10-19 g 244Pu/g). The concentration of 244Pu in our sample of bastnäsite is significantly lower than the previously determined value.

  20. Electronic structure and chemical bonding in PuO2

    NASA Astrophysics Data System (ADS)

    Teterin, Yu. A.; Maslakov, K. I.; Teterin, A. Yu.; Ivanov, K. E.; Ryzhkov, M. V.; Petrov, V. G.; Enina, D. A.; Kalmykov, St. N.

    2013-06-01

    Quantitative analysis of the x-ray photoelectron spectra structure in the binding energy (BE) range of 0 eV-˜35 eV for plutonium dioxide (PuO2) valence electrons was done. The BEs and structure of the core electronic shells (35 eV-1250 eV BE), as well as the relativistic discrete variation calculation results for the finite fragments of the PuO2 lattice and the data of other authors, were taken into account. The experimental data show that the many-body effects and the multiplet splitting contribute to the spectral structure much less than the outer (0 eV-˜15 eV) and the inner (˜15 eV-˜35 eV) valence molecular orbitals (OVMO and IVMO, respectively). The filled Pu 5f electronic states were shown to form in the PuO2 valence band. The Pu 6p electrons participate in the formation of both the IVMO and the OVMO (bands). The filled Pu 6p3/2 and the O 2s electronic shells were found to take maximum part in the IVMO formation. The MO composition and the sequence order in the BE range of 0 eV-˜35 eV in PuO2 were established. The experimental and theoretical data allowed a quantitative MO scheme for PuO2, which is fundamental for understanding both the chemical bond nature in plutonium dioxide and the interpretation of other x-ray spectra of PuO2.

  1. Measurement of the 242Pu neutron capture cross section

    NASA Astrophysics Data System (ADS)

    Buckner, M. Q.; Wu, C. Y.; Henderson, R. A.; Bucher, B.; Bredeweg, T. A.; Baramsai, B.; Couture, A.; Jandel, M.; Mosby, S.; O'Donnell, J. M.; Ullmann, J. L.; Chyzh, A.; Dance Collaboration

    2015-10-01

    Precision (n,f) and (n, γ) cross sections are important for the network calculations of the radiochemical diagnostic chain for the U.S. DOE's Stockpile Stewardship Program. 242Pu(n, γ) cross section is relevant to the network calculations of Pu and Am. Additionally, new reactor concepts have catalyzed considerable interest in the measurement of improved cross sections for neutron-induced reactions on key actinides. To date, little or no experimental data has been reported on 242Pu(n, γ) for incident neutron energy below 50 keV. A new measurement of the 242Pu(n, γ) reaction was performed with the DANCE together with an improved PPAC for fission-fragment detection at LANSCE during FY14. The relative scale of the 242Pu(n, γ) cross section spans four orders of magnitude for incident neutron energies from thermal to ~ 30 keV. The absolute scale of the 242Pu(n, γ) cross section is set according to the measured 239Pu(n,f) resonance at 7.8 eV; the target was spiked with 239Pu for this measurement. The absolute 242Pu(n, γ) neutron capture cross section is ~ 30% higher than the cross section reported in ENDF for the 2.7 eV resonance. Latest results to be reported. Funded by U.S. DOE Contract No. DE-AC52-07NA27344 (LLNL) and DE-AC52-06NA25396 (LANL). U.S. DOE/NNSA Office of Defense Nuclear Nonproliferation Research and Development. Isotopes (ORNL).

  2. [Not Available].

    PubMed

    Gutiérrez-Tarango, M D; Berber, A

    1997-01-01

    An open, prospective trial was conducted to compare the efficacy of a bacterial extract (OM-85 BV) [;Broncho-Vaxom'] vs conventional management in the prevention of chronic, recurrent respiratory diseases in children. 61 children aged between 1 and 11 years who had presented three or more respiratory tract infections in the last 6 months were enrolled. 30 children (mean age 4.1 +/- 2.7 years) received one capsule a day of Broncho-Vaxom, 10 days a month, for 3 consecutive months, and 31 (mean age 3.8 +/- 2.0 years) received no Broncho-Vaxom and served as a control group. During the 6-month follow-up period, patients treated with Broncho-Vaxom showed a significant reduction in the average number of infections (2.25 +/- 0.58 vs 4.68 +/- 0.94, p < 0.05); they were ill a lesser number of days (11.8 +/- 3.67 vs 28.06 +/- 6.72, p < 0.05), were exposed to fewer antibacterial treatments (1.1 +/- 0.76 vs 2.52 +/- 0.85, p < 0.05), required less additional treatment with conventional drugs (2.17 +/- 0.59 vs 4.39 +/- 0.88, p < 0.05), and spent fewer days under treatment (14.27 +/- 7.27 vs 30 +/- 6.49, p < 0.05). In conclusion, Broncho-Vaxom appears to be a practical, safe option for lowering the incidence of respiratory tract infections in susceptible children. PMID:18370454

  3. Tissue, cellular, and subcellular distribution of /sup 241/Pu in the rat testes

    SciTech Connect

    Miller, S.C.; Bowman, B.M.

    1983-05-01

    The distribution and localization of /sup 241/Pu in rat testes were determined by quantitative autoradiography. Rats were given intravenous injection of /sup 241/Pu citrate and tissues were collected 1 week later. The tissue distribution of /sup 241/Pu was determined by light microscope autoradiography. Significant concentrations of /sup 241/Pu were observed in the interstitial tissue but not in seminiferous tubules. The cellular distribution and subcellular localization of /sup 241/Pu were determined by electron microscope autoradiography. Within the interstitial tissue, /sup 241/Pu was concentrated in microphages. There was no preferential localization of /sup 241/Pu in any other interstitial tissue components. Within interstitial tissue macrophages, /sup 241/Pu was concentrated in the lysosomal system of the cell. Other organellar compartments of the cell did not preferentially incorporate /sup 241/Pu. The association of /sup 241/Pu with the macrophage lysosomal system may explain the long retention times of Pu in testes as observed in experimental studies.

  4. Ethylene glycol poisoning in three dogs: Importance of early diagnosis and role of hemodialysis as a treatment option.

    PubMed

    Schweighauser, A; Francey, T

    2016-02-01

    Poisoning with ethylene glycol as contained in antifreeze can rapidly lead to irreversible acute renal failure and other organ damage. It carries a grave prognosis unless diagnosed early and adequate treatment is initiated within 8 hours of ingestion. Toxicity of ethylene glycol is related to the production of toxic metabolites by the enzyme alcohol dehydrogenase (ADH), leading to early signs of severe polyuria (PU) and polydipsia (PD), gastritis, ataxia and central nervous depression, followed by progressive dehydration, and ultimately oligoanuric renal failure. In addition to general supportive care, therapeutic interventions must include either antidotes blocking ADH-mediated metabolism or blood purification techniques to remove both the parent compound and the toxic metabolites. The goal of this case report is to describe three cases of acute antifreeze intoxication in dogs, and to discuss treatment options available for this poisoning. PMID:27145686

  5. Treatment strategies for atopic dermatitis: optimizing the available therapeutic options.

    PubMed

    Paller, Amy S; Simpson, Eric L; Eichenfield, Lawrence F; Ellis, Charles N; Mancini, Anthony J

    2012-09-01

    Bathing and moisturization to control dryness, applications of topical anti-inflammatory agents (including corticosteroids and calcineurin inhibitors [TCIs]) to control flares, minimization of the risk for infection, and relief of pruritus are the cornerstones of effective therapy for atopic dermatitis. Education of parents and patients is crucial to enhance adherence. Strategies for reduced Staphylococcus aureus colonization may help control re-emergence of flares following cessation of antimicrobial treatment for infection; these include dilute bleach baths and minimizing the risk for contamination of topical agents. In severe, refractory cases, more aggressive therapy with systemic immunosuppressants may be considered, but appropriate laboratory testing must be included as part of patient monitoring during treatment. The value of adjuvant therapy with wet wraps to "cool down" particularly erythematous and pruritic flares is becoming increasingly recognized. PMID:23021780

  6. What options are available for ordering MOPITT data?

    Atmospheric Science Data Center

    2015-10-29

    ASDC Data Pool: https://eosweb.larc.nasa.gov/datapool The Data Pool is an on-line data cache that provides FTP access to select ASDC data ... With the subset tool, you will receive only the data points that fall within your specified lat, long bounds. Without subsetting, ...

  7. Pain following Craniotomy: Reassessment of the Available Options

    PubMed Central

    Haldar, Rudrashish; Kaushal, Ashutosh; Gupta, Devendra; Srivastava, Shashi; Singh, Prabhat K.

    2015-01-01

    Pain following craniotomy has frequently been neglected because of the notion that postcraniotomy patients do not experience severe pain. However a gradual change in this outlook is observed because of increased sensitivity of neuroanaesthesiologists and neurosurgeons toward acute postcraniotomy pain. Multiple modalities exist for treating this variety of pain each with its own share of advantages and disadvantages. However, individually none of these modalities has been proclaimed as the best and applicable universally. A considerable amount of dispute remains to ascertain the appropriate therapeutic regimen for treating postcraniotomy pain in spite of numerous trials using different drugs and their combinations. This review aims to highlight the genesis, characteristics, and different strategies that are undertaken for management of acute postcraniotomy pain. Chronic postcraniotomy pain which can be debilitating sequelae is also discussed concisely. PMID:26495298

  8. Elastic properties of gamma-Pu by resonant ultrasound spectroscopy

    SciTech Connect

    Migliori, Albert; Betts, J; Trugman, A; Mielke, C H; Mitchell, J N; Ramos, M; Stroe, I

    2009-01-01

    Despite intense experimental and theoretical work on Pu, there is still little understanding of the strange properties of this metal. We used resonant ultrasound spectroscopy method to investigate the elastic properties of pure polycrystalline Pu at high temperatures. Shear and longitudinal elastic moduli of the {gamma}-phase of Pu were determined simultaneously and the bulk modulus was computed from them. A smooth linear and large decrease of all elastic moduli with increasing temperature was observed. We calculated the Poisson ratio and found that it increases from 0.242 at 519K to 0.252 at 571K.

  9. An Alternative Model for Electron Correlation in Pu

    SciTech Connect

    Yu, S; Tobin, J; Soderlind, P

    2007-10-23

    Using a density functional theory based approach that treats the 5f electrons relativistically, a Pu electronic structure with zero net magnetic moment is obtained, where the 5f orbital and 5f spin moments cancel each other. By combining the spin and orbital specific densities of states with state, spin and polarization specific transition moments, it is possible to reconstruct the experimentally observed photoemission spectra from Pu. Extrapolating to a spin-resolving Fano configuration, it is shown how this would resolve the extant controversy over Pu electronic structure.

  10. 239Pu Resonance Evaluation for Thermal Benchmark System Calculations

    NASA Astrophysics Data System (ADS)

    Leal, L. C.; Noguere, G.; de Saint Jean, C.; Kahler, A. C.

    2014-04-01

    Analyses of thermal plutonium solution critical benchmark systems have indicated a deficiency in the 239Pu resonance evaluation. To investigate possible solutions to this issue, the Organisation for Economic Co-operation and Development (OECD) Nuclear Energy Agency (NEA) Working Party for Evaluation Cooperation (WPEC) established Subgroup 34 to focus on the reevaluation of the 239Pu resolved resonance parameters. In addition, the impacts of the prompt neutron multiplicity (νbar) and the prompt neutron fission spectrum (PFNS) have been investigated. The objective of this paper is to present the results of the 239Pu resolved resonance evaluation effort.

  11. PU IMMOBILIZATION - INDUCTION MELTING ND OFFGAS TESTING

    SciTech Connect

    Marra, J

    2006-11-28

    The Cylindrical Induction Melter (CIM) at the Aiken County Technology Laboratory (ACTL) has been operated by the Savannah River National Laboratory (SRNL) to support the Pu Disposition Conceptual Design (CD-0) development effort. The primary purpose of this report is to summarize the offgas sampling tests conducted in the CIM to capture and analyze the particulate and vapors emitted from lanthanide borosilicate (LaBS) Frit X with HfO{sub 2} as a surrogate for PuO{sub 2} and added impurities. In addition, this report describes several initial tests of the CIM for the vitrification of LaBS Frit X with HfO{sub 2}. The activities required to produce Frit X from batch chemical oxides for subsequent milling to yield glass frit of nominally 20 micron particle size are also discussed. The tests with impurities added showed that alkali salts such as NaCl and KCl were substantially emitted into the offgas system as the salt particulate, HCl, or Cl{sub 2}. Retention of Na and K in the glass were about 80 and 55%, respectively. Chloride retention was about 35%; chloride remaining in the glass was 0.29-0.37 wt%. Based on a material balance, approximately 83% of F fed was retained in the glass at about 0.09 wt % (F could not be measured directly at this concentration). Transition metals (Ni, Cu, Fe, Mo, Cr) were also volatilized to varying extents. A very small amount (<0.1 g) of nickel compounds and KCl were found in crystals deposited on the melter offgas line. Overall, about 58-72% of the impurities added were volatilized. Virtually all of the particulate species were collected on the nominal 0.3 {micro}m filter. The particulate evolution rate ranged from 2-8 g/kg glass/h. The particulate was found to be as small as 0.2 {micro}m and have an approximate median size of 0.5 {micro}m. The particulate salt was also found to stick together by forming bridges between particles. Further runs without washable salts are recommended. Measurements of particle size distribution for use in

  12. [Not Available].

    PubMed

    Dorn, U; Landauer, F; Hofstaedter, T

    2016-06-01

    Gluteal tendinopathy as well as partial and full-thickness tears of gluteal tendons (gluteus minimus and/or medius tendon) were underestimated as a cause of chronic pain in the past, and treatment was most commonly based on the diagnosis of trochanteric bursitis. Tendinous pathologies can either stay asymptomatic or cause pain and muscular dysfunction, not necessarily being associated with osteoarthritis of the hip 1. As the terminus "rotator cuff tear of the hip" was published in 1997 2, its aetiopathogenesis was reconsidered, resulting in improvements in diagnosis and treatment. Nevertheless the adoption of those findings into clinical daily routine took time 3. Ultrasound and magnetic resonance imaging (MRI) as well as histopathologic examination questioned the relevance of acute bursitis being the only cause of greater trochanteric pain 4, 5, 6, while emphasizing degenerative tendinopathy causing those symptoms 6, 7, 8. The terminus "greater trochanteric pain syndrome" (GTPS) should hereby also include further pathologies, e.g. calcific tendinitis 1, 5. GTPS affects about 10-25 % of the adult population 5. Ultrasound and MRI are reliable, non-invasive methods for detecting tendinous and bursal pathologies 7, 8, 9; in 88 % of all patients with trochanteric pain, MRI gives pathological findings 10. Nevertheless, in 50 % of suspicious pertrochanteric pathologies, patients are free of symptoms 1, 10. In patients undergoing total hip arthroplasty, the incidence of intraoperative macroscopically identified gluteal tendon tears reaches up to 22 % 2, 11, 12, 13. Tendinous tears cause pain and constrained muscular function. Sole traumatic tears are rare, most commonly they are based on pre-existing defects. Tendinosis and partial tears are primarily treated conservatively. Hereby, therapeutic options are similar to those for rotator cuff pathologies of the shoulder. Topical infiltration of corticosteroids and physical therapy offer good

  13. Structural phase transition and 5f-electrons localization of PuSe explored by ab initio calculations

    SciTech Connect

    Cui Shouxin; Feng Wenxia; Hu Haiquan; Gong Zizheng; Liu Hong

    2010-04-15

    An investigation into the structural phase transformation, electronic and optical properties of PuSe under high pressure was conducted by using the full potential linearized augmented plane wave plus local orbitals (FP-LAPW+lo) method, in the presence and in the absence of spin-orbit coupling (SOC). Our results demonstrate that there exists a structural phase transition from rocksalt (B 1) structure to CsCl-type (B 2) structure at the transition pressure of 36.3 GPa (without SOC) and 51.3 GPa (with SOC). The electronic density of states (DOS) for PuSe show that the f-electrons of Pu are more localized and concentrated in a narrow peak near the Fermi level, which is consistent with the experimental studies. The band structure shows that B 1-PuSe is metallic. A pseudogap appears around the Fermi level of the total density of states of B 1 phase PuSe, which may contribute to its stability. The calculated reflectivity R(omega) shows agreement with the available experimental results. Furthermore, the absorption spectrum, refractive index, extinction coefficient, energy-loss spectrum and dielectric function were calculated. The origin of the spectral peaks was interpreted based on the electronic structures. - Abstract: Graphical Abstract Legend (TOC Figure): 5f-electrons are more localized by the analysis of the density of states (SOC). The origin spectra peaks was interpreted based on electronic structures.

  14. Approximate option pricing

    SciTech Connect

    Chalasani, P.; Saias, I.; Jha, S.

    1996-04-08

    As increasingly large volumes of sophisticated options (called derivative securities) are traded in world financial markets, determining a fair price for these options has become an important and difficult computational problem. Many valuation codes use the binomial pricing model, in which the stock price is driven by a random walk. In this model, the value of an n-period option on a stock is the expected time-discounted value of the future cash flow on an n-period stock price path. Path-dependent options are particularly difficult to value since the future cash flow depends on the entire stock price path rather than on just the final stock price. Currently such options are approximately priced by Monte carlo methods with error bounds that hold only with high probability and which are reduced by increasing the number of simulation runs. In this paper the authors show that pricing an arbitrary path-dependent option is {number_sign}-P hard. They show that certain types f path-dependent options can be valued exactly in polynomial time. Asian options are path-dependent options that are particularly hard to price, and for these they design deterministic polynomial-time approximate algorithms. They show that the value of a perpetual American put option (which can be computed in constant time) is in many cases a good approximation to the value of an otherwise identical n-period American put option. In contrast to Monte Carlo methods, the algorithms have guaranteed error bounds that are polynormally small (and in some cases exponentially small) in the maturity n. For the error analysis they derive large-deviation results for random walks that may be of independent interest.

  15. 48 CFR 1517.207 - Exercise of options.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ....705-1(a), exercise an option contingent upon the availability of funds. To exercise such an option... shall any action be taken which could be construed as creating a legal liability on the part of...

  16. Neutron Capture and Fission Measurement on ^238Pu at DANCE

    NASA Astrophysics Data System (ADS)

    Chyzh, Andrii; Wu, Ching-Yen; Kwan, Elaine; Henderson, Roger; Gostic, Jolie; Couture, Aaron; Young, Hye; Ullmann, John; O'Donnell, John; Jandel, Marian; Haight, Robert; Bredeweg, Todd

    2012-10-01

    Neutron capture and fission reactions on actinides are important in nuclear engineering and physics. DANCE (Detector for Advanced Neutron Capture Measurement, LANL) combined with PPAC (avalanche technique based fission tagging detector, LLNL) were used to study the neutron capture reactions in ^238Pu. Because of extreme spontaneous α-radioactivity in ^238Pu and associated safety issues, 3 separate experiments were performed in 2010-2012. The 1st measurement was done without fission tagging on a 396-μg thick target. The 2nd one was with PPAC on the same target. The 3rd final measurement was done on a thin target with a mass of 40 μg in order to reduce α-background load on PPAC. This was the first such measurement in a laboratory environment. The absolute ^238Pu(n,γ) cross section is presented together with the prompt γ-ray multiplicity in the ^238Pu(n,f) reaction.

  17. [ECG indices in dogs after inhalation of 239Pu].

    PubMed

    Karpova, V N

    1985-11-01

    Dogs of both sexes aged 2 to 4 were subjected to inhalation inoculation with polymer 239Pu or submicron 239PuO2 aerosols in amounts close to acute, subacute and chronically effective ones. ECG was recorded in standard, amplified and single leads (V3). All calculations were done by lead II. Signs of the right heart overburdening were noted in the presence of the P-pulmonale complex, deep S1 wave or cardiac electrical axis of SI-SII-SIII type. Signs of the right heart overburdening were revealed after inhalation of polimer 239Pu (70%). The absence of similar changes in damage caused by 239Pu could be attributed to its fast resorption from the lungs resulting in more moderate lesion of the respiratory organs. PMID:4068946

  18. Ferro- and antiferro-magnetism in (Np, Pu)BC

    SciTech Connect

    Klimczuk, T.; Kozub, A. L.; Griveau, J.-C.; Colineau, E.; Wastin, F.; Falmbigl, M.; Rogl, P.

    2015-04-01

    Two new transuranium metal boron carbides, NpBC and PuBC, have been synthesized. Rietveld refinements of powder XRD patterns of (Np,Pu)BC confirmed in both cases isotypism with the structure type of UBC. Temperature dependent magnetic susceptibility data reveal antiferromagnetic ordering for PuBC below T{sub N} = 44 K, whereas ferromagnetic ordering was found for NpBC below T{sub C} = 61 K. Heat capacity measurements prove the bulk character of the observed magnetic transition for both compounds. The total energy electronic band structure calculations support formation of the ferromagnetic ground state for NpBC and the antiferromagnetic ground state for PuBC.

  19. Radiation damage effects in candidate titanates for Pu disposition: Pyrochlore

    NASA Astrophysics Data System (ADS)

    Strachan, D. M.; Scheele, R. D.; Buck, E. C.; Icenhower, J. P.; Kozelisky, A. E.; Sell, R. L.; Elovich, R. J.; Buchmiller, W. C.

    2005-10-01

    Laboratory experiments on titanate ceramics were performed to verify whether certain assumptions are valid regarding the swelling, chemical durability, and microcracking that might occur as 239Pu decays. Titanate ceramics are the material of choice for the immobilization of surplus weapons-grade Pu. The short-lived isotope 238Pu, was incorporated into the ceramic formulation to accelerate the effects of radiation-induced damage. We report on the effects of this damage on the density (volumetric swelling <6%), crystal structure of pyrochlore-bearing specimens (amorphous after about 2 × 1018 α/g), and dissolution (no change from the fully crystalline specimen). Even though the specimens became amorphous during the tests, there was no evidence for microcracking in the photomicrographs from the scanning electron microscope. Thus, although pyrochlore is susceptible to radiation-induced damage, the material remains chemically and physically viable as a material for immobilizing surplus weapons-grade Pu.

  20. Capabilities for Testing the Electronic Configuration in Pu

    SciTech Connect

    Tobin, J G; Soderlind, P; Landa, A; Moore, K T; Schwartz, A J; Chung, B W; Wall, M A

    2006-11-08

    The benchmarking of theoretical modeling is crucial to the ultimate determination of the nature of the electronic structure of Pu. Examples of experimental techniques used for cross checking state of the art calculations will be given.

  1. On the electronic configuration in Pu: spectroscopy and theory

    SciTech Connect

    Tobin, J G; Soderlind, P; Landa, A; Moore, K T; Schwartz, A J; Chung, B W; Wall, M; Wills, J M; Eriksson, O; Haire, R; Kutepov, A L

    2006-10-11

    Photoelectron spectroscopy, synchrotron-radiation-based x-ray absorption, electron energy-loss spectroscopy, and density-functional calculations within the mixed-level and magnetic models, together with canonical band theory have been used to study the electron configuration in Pu. These methods suggest a 5f{sup n} configuration for Pu of 5 {le} n < 6, with n {ne} 6, contrary to what has recently been suggested in several publications. We show that the n = 6 picture is inconsistent with the usual interpretation of photoemission and x-ray absorption spectra. Instead, these spectra support the traditional conjecture of a 5f{sup 5} configuration in Pu as is obtained by density-functional theory. We further argue, based on 5f-band filling, that an n = 6 hypothesis is incompatible with the position of Pu in the actinide series and its monoclinic ground-state phase.

  2. Probing Actinide Electronic Structure through Pu Cluster Calculations

    DOE PAGESBeta

    Ryzhkov, Mickhail V.; Mirmelstein, Alexei; Yu, Sung-Woo; Chung, Brandon W.; Tobin, James G.

    2013-02-26

    The calculations for the electronic structure of clusters of plutonium have been performed, within the framework of the relativistic discrete-variational method. Moreover, these theoretical results and those calculated earlier for related systems have been compared to spectroscopic data produced in the experimental investigations of bulk systems, including photoelectron spectroscopy. Observation of the changes in the Pu electronic structure as a function of size provides powerful insight for aspects of bulk Pu electronic structure.

  3. Method of removing Pu(IV) polymer from nuclear fuel reclaiming liquid

    DOEpatents

    Tallent, Othar K.; Mailen, James C.; Bell, Jimmy T.; Arwood, Phillip C.

    1982-01-01

    A Pu(IV) polymer not extractable from a nuclear fuel reclaiming solution by conventional processes is electrolytically converted to Pu.sup.3+ and PuO.sub.2.sup.2+ ions which are subsequently converted to Pu.sup.4+ ions extractable by the conventional processes.

  4. Spatial and temporal distribution of Pu in the Northwest Pacific Ocean using modern coral archives.

    PubMed

    Lindahl, Patric; Andersen, Morten B; Keith-Roach, Miranda; Worsfold, Paul; Hyeong, Kiseong; Choi, Min-Seok; Lee, Sang-Hoon

    2012-04-01

    Historical (239)Pu activity concentrations and (240)Pu/(239)Pu atom ratios were determined in skeletons of dated modern corals collected from three locations (Chuuk Lagoon, Ishigaki Island and Iki Island) to identify spatial and temporal variations in Pu inputs to the Northwest Pacific Ocean. The main Pu source in the Northwest Pacific is fallout from atmospheric nuclear weapons testing which consists of global fallout and close-in fallout from the former US Pacific Proving Grounds (PPG) in the Marshall Islands. PPG close-in fallout dominated the Pu input in the 1950s, as was observed with higher (240)Pu/(239)Pu atom ratios (>0.30) at the Ishigaki site. Specific fallout Pu contamination from the Nagasaki atomic bomb and the Ivy Mike thermonuclear detonation at the PPG were identified at Ishigaki Island from the (240)Pu/(239)Pu atom ratios of 0.07 and 0.46, respectively. During the 1960s and 1970s, global fallout was the major Pu source to the Northwest Pacific with over 60% contribution to the total Pu. After the cessation of the atmospheric nuclear tests, the PPG again dominated the Pu input due to the continuous transport of remobilised Pu from the Marshall Islands along the North Equatorial Current and the subsequent Kuroshio Current. The Pu contributions from the PPG in recent coral bands (1984 onwards) varied over time with average estimated PPG contributions between 54% and 72% depending on location. PMID:21890207

  5. First metatarsophalangeal joint arthrodesis: current fixation options.

    PubMed

    Moon, Jared L; McGlamry, Michael C

    2011-04-01

    This article reviews the current literature on first metatarsophalangeal joint arthrodesis rates using various forms of fixation, as well as reviewing biomechanical studies comparing the strengths of the different fixation options that are available. PMID:21669346

  6. TECHNOLOGICAL OPTIONS FOR ACID RAIN CONTROL

    EPA Science Inventory

    Discussed are acid rain control options available to the electric utility industry. They include coal switching, flue gas desulfurization, and such emerging lower cost technologies as Limestone Injection Multistage Burners (LIMB) and Advanced Silicate (ADVACATE), both developed ...

  7. Unusual behaviour of (Np,Pu)B2C

    NASA Astrophysics Data System (ADS)

    Klimczuk, Tomasz; Boulet, Pascal; Griveau, Jean-Christophe; Colineau, Eric; Bauer, Ernst; Falmbigl, Matthias; Rogl, Peter; Wastin, Franck

    2015-02-01

    Two transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single-crystal X-ray data to be isotypic with the ThB2C-type (space group ?, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z = 9). Physical properties have been derived from polycrystalline bulk material in the temperature range from 2 to 300 K and in magnetic fields up to 9 T. Magnetic susceptibility and heat capacity data indicate the occurrence of antiferromagnetic ordering for NpB2C with a Neel temperature TN = 68 K. PuB2C is a Pauli paramagnet most likely due to a strong hybridization of s(p,d) electrons with the Pu-5f states. A pseudo-gap, as concluded from the Sommerfeld value and the electronic transport, is thought to be a consequence of the hybridization. The magnetic behaviour of {Np,Pu}B2C is consistent with the criterion of Hill.

  8. Unsafe coulomb excitation of {sup 240-244}Pu.

    SciTech Connect

    Wiedenhoever, I.

    1998-12-01

    The high spin states of {sup 240}Pu and {sup 244}Pu have been investigated with GAMMASPHERE at ATLAS, using Coulomb excitation with a {sup 208}Pb beam at energies above the Coulomb barrier. Data on a transfer channel leading to {sup 242}Pu were obtained as well. In the case of {sup 244}Pu, the yrast band was extended to 34{h_bar}, revealing the completed {pi}i{sub 13/2} alignment, a ''first'' for actinide nuclei. The yrast sequence of {sup 242}Pu was also extended to higher spin and a similar backbend was delineated. In contrast, while the ground state band of {sup 240}Pu was measured up to the highest rotational frequencies ever reported in the actinide region ({approximately} 300 keV), no sign of particle alignment was observed. In this case, several observables such as the large B(E1)/B(E2) branching ratios in the negative parity band, and the vanishing energy staggering between the negative and positive parity bands suggest that the strength of octupole correlations increases with rotational frequency. These stronger correlations may well be responsible for delaying or suppressing the {pi}i{sub 13/2} particle alignment.

  9. Electric retail market options: The customer perspective

    SciTech Connect

    Hadley, S.W.; Hillsman, E.L.

    1995-07-01

    This report describes various options that are now available for retail electric customers, or that may become available during the next few years as the electric utility industry restructures. These options include different ways of meeting demand for energy services, different providers of service or points of contact with providers, and different pricing structures for purchased services. Purpose of this document is to examine these options from the customer`s perspective: how might being a retail electric customer in 5--10 years differ from now? Seizing opportunities to reduce cost of electric service is likely to entail working with different service providers; thus, transaction costs are involved. Some of the options considered are speculative. Some transitional options include relocation, customer-built/operated transmission lines, municipalization, self-generation, and long-term contracts with suppliers. All these may change or diminish in a restructured industry. Brokers seem likely to become more common unless restructuring takes the form of mandatory poolcos (wholesale). Some options appear robust, ie, they are likely to become more common regardless of how restructuring is accomplished: increased competition among energy carriers (gas vs electric), real-time pricing, etc. This report identified some of the qualitative differences among the various options. For customers using large amounts of electricity, different alternatives are likely to affect greatly service price, transaction costs, tailoring service to customer preferences, and risks for customer. For retail customers using small amounts of electricity, there may be little difference among the options except service price.

  10. [Not Available].

    PubMed

    Zecchini, Céline; Chanoine, Sébastien; Chapuis, Claire; Claustre, Johanna; Schir, Edith; Allenet, Benoît; Raymond, Christel Saint; Bedouch, Pierrick

    2015-01-01

    Advances in lung transplantation allow the women of childbearing age to consider becoming mothers. When planning to become pregnant, a therapeutic drug management of immunosuppressive drugs and associated therapies is required. It must take into account teratogenic and fetotoxic drugs, as well as pharmacokinetic changes encountered during pregnancy. Increasingly data are currently available on the management of immunosuppressive drugs and associated therapies during pregnancy. We report the case management of drug therapy before and during pregnancy in two patients after a lung or heart-lung transplantation. To prevent the emergence of complications for mother and child, a literature review has been necessary to manage drug therapies of each patient. PMID:27393315

  11. AFCI Options Study

    SciTech Connect

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2009-09-01

    This report describes the background and framework for both organizing the discussion and providing information on the potential for nuclear energy R&D to develop alternative nuclear fuel cycles that would address the issues with the current implementations of nuclear power, including nuclear waste disposal, proliferation risk, safety, security, economics, and sustainability. The disposition of used fuel is the cause of many of the concerns, and the possible approaches to used fuel management identify a number of basic technology areas that need to be considered. The basic science in each of the technology areas is discussed, emphasizing what science is currently available, where scientific knowledge may be insufficient, and especially to identify specific areas where transformational discoveries may allow achievement of performance goals not currently attainable. These discussions lead to the wide range of technical options that have been the basis for past and current research and development on advanced nuclear fuel cycles in the United States. The results of this work are then briefly reviewed to show the extent to which such approaches are capable of addressing the issues with nuclear power, the potential for moving further, and the inherent limitations.

  12. Study of neutron-deficient isotopes of Fl in the 239Pu, 240Pu + 48Ca reactions

    NASA Astrophysics Data System (ADS)

    Voinov, A. A.; Utyonkov, V. K.; Brewer, N. T.; Oganessian, Yu Ts; Rykaczewski, K. P.; Abdullin, F. Sh; Dmitriev, S. N.; Grzywacz, R. K.; Itkis, M. G.; Miernik, K.; Polyakov, A. N.; Roberto, J. B.; Sagaidak, R. N.; Shirokovsky, I. V.; Shumeiko, M. V.; Tsyganov, Yu S.; Subbotin, V. G.; Sukhov, A. M.; Sabelnikov, A. V.; Vostokin, G. K.; Hamilton, J. H.; Stoyer, M. A.; Strauss, S. Y.

    2016-07-01

    The results of the experiments aimed at the synthesis of Fl isotopes in the 239Pu + 48Ca and 240Pu + 48Ca reactions are presented. The experiment was performed using the Dubna gas-filled recoil separator at the U400 cyclotron. In the 239Pu+48Ca experiment one decay of spontaneously fissioning 284Fl was detected at 245-MeV beam energy. In the 240Pu+48Ca experiment three decay chains of 285Fl were detected at 245 MeV and four decays were assigned to 284Fl at the higher 48Ca beam energy of 250 MeV. The α-decay energy of 285Fl was measured for the first time and decay properties of its descendants 281Cn, 277Ds, 273Hs, 269Sg, and 265Rf were determined more precisely. The cross section of the 239Pu(48Ca,3n)284Fl reaction was observed to be about 20 times lower than those predicted by theoretical models and 50 times less than the value measured in the 244Pu+48Ca reaction. The cross sections of the 240Pu(48Ca,4-3n)284,285Fl at both 48Ca energies are similar and exceed that observed in the reaction with lighter isotope 239Pu by a factor of 10. The decay properties of the synthesized nuclei and their production cross sections indicate rapid decrease of stability of superheavy nuclei with departing from the neutron number N=184 predicted to be the next magic number.

  13. Expensing options solves nothing.

    PubMed

    Sahlman, William A

    2002-12-01

    The use of stock options for executive compensation has become a lightning rod for public anger, and it's easy to see why. Many top executives grew hugely rich on the back of the gains they made on their options, profits they've been able to keep even as the value they were supposed to create disappeared. The supposed scam works like this: Current accounting regulations let companies ignore the cost of option grants on their income statements, so they can award valuable option packages without affecting reported earnings. Not charging the cost of the grants supposedly leads to overstated earnings, which purportedly translate into unrealistically high share prices, permitting top executives to realize big gains when they exercise their options. If an accounting anomaly is the problem, then the solution seems obvious: Write off executive share options against the current year's revenues. The trouble is, Sahlman writes, expensing option grants won't give us a more accurate view of earnings, won't add any information not already included in the financial statements, and won't even lead to equal treatment of different forms of executive pay. Far worse, expensing evades the real issue, which is whether compensation (options and other-wise) does what it's supposed to do--namely, help a company recruit, retain, and provide the right people with appropriate performance incentives. Any performance-based compensation system has the potential to encourage cheating. Only ethical management, sensible governance, adequate internal control systems, and comprehensive disclosure will save the investor from disaster. If, Sahlman warns, we pass laws that require the expensing of options, thinking that's fixed the fundamental flaws in corporate America's accounting, we will have missed a golden opportunity to focus on the much more extensive defects in the present system. PMID:12510541

  14. [Not Available].

    PubMed

    Kautzky-Willer, Alexandra

    2016-03-01

    Obesity is increasing worldwide in both sexes and a challenge for health professionals and the health care system. Women have more subcutaneous fat and are more insulin sensitive while men have more visceral and liver fat and higher cardiovascular risk. Women more often show the metabolically healthy obese phenotype than males. However, with increasing BMI the risk for type 2 diabetes and cardiovascular diseases increases more dramatically in women compared to males. Obese women suffer more from weight-related problems, have a higher rate of depression and seek more often medical help to reduce weight. Both biological factors and psychosocial factors contribute to the disease and interact with each other. In this special edition of the journal sex and gender aspects in prevention, treatment and development of complications will be discussed, as proposed by the Austrian Obesity Association. Data available from the Austrian population will be included in the Austrian Gender Obesity Report. PMID:26847444

  15. [Not Available].

    PubMed

    Blanchard, Elodie; de Lara, Manuel Tunon

    2013-01-01

    Pholcodine is an opioid that has been widely used worldwide since 1950 for the treatment of non-productive cough in children and adults. The results of early preclinical studies but also those of recent clinical trials have shown the antitussive efficacy of pholcodine to be superior to that of codeine, of longer duration, and with an equivalent or safer toxicity profile. Also, there is no risk of addiction. Concern had been raised over a possible cross-sensitisation with neuromuscular blocking agents. While a recent assessment of the available data by the European Medicines Agency (EMA) has confirmed the favourable risk-benefit ratio of pholcodine, further studies are needed to clear this point. PMID:27392673

  16. [Not Available].

    PubMed

    Olsen, Björn; Lundkvist, Åke

    2016-01-01

    Zika virus is a mosquito-borne flavivirus transmitted by Aedes mosquitos. The virus was discovered in 1947 in the Zika forest in Uganda. Symptomatic disease is usually mild and is characterized by maculopapular rash, headache, fever, arthralgia and conjunctivitis. Fatalities are rare. There is neither vaccine nor curative treatment available. In May 2015, the first observation of local virus transmission was reported from Brazil. During the expanding outbreak in the Americas, Zika virus infection has been associated with microcephaly in newborn and fetal losses in women infected with Zika virus during pregnancy. The main reason for the current epidemic in the Americas is the introduction of an Old World virus into a new ecosystem, with no background herd immunity in the population. It is likely that the spread of Zika virus will continue, affecting all countries in the Americas except for Chile and Canada. PMID:26978815

  17. Plutonium residue recovery (PuRR) project: Quarterly progress report, October--December 1988

    SciTech Connect

    Alire, R.M.; Coops, M.S.; Gregg, D.W.; Hickman, R.G.; Landrum, J.H.; Pittenger, L.C.; Johnson, G.K.; Johnson, I.; Mulcahey, T.P.; Piece, R.D.

    1989-02-01

    Substantial progress was made in several areas of the PuRR (plutonium residue recovery) program during the quarter. Criteria were developed for selecting process options, with the goal of process simplification. A modified flowsheet and material balance were selected that reflect these priorities. Efforts to effect a front-end separation by sedimentation were not successful. Experimental liquid-liquid extractions from alloys to salts based on valence change were performed. Results ranged from fair to good, but experimental equipment materials problems occurred. Also, substantial interference from the large excess of tramp metals present, which influence plutonium activity, suggested alternate approaches should be given priority. Estimates of the high-temperature thermodynamic functions of americium chlorides were calculated for the first time. 11 refs., 3 figs., 10 tabs.

  18. On the electrochemical formation of Pu-Al alloys in molten LiCl-KCl

    NASA Astrophysics Data System (ADS)

    Mendes, E.; Malmbeck, R.; Nourry, C.; Souček, P.; Glatz, J.-P.

    2012-01-01

    Properties of Pu-Al alloys were investigated in connection with development of pyrochemical methods for reprocessing of spent nuclear fuel. Electroseparation techniques in molten LiCl-KCl are being developed in ITU to group-selectively recover actinides from the mixture with fission products. In the process, actinides are electrochemically reduced on solid aluminium cathodes, forming solid actinide-aluminium alloys. This article is focused on electro-chemical characterisation of Pu-Al alloys in molten LiCl-KCl, on electrodeposition of Pu on solid Al electrodes and on determination of chemical composition and structure of the formed alloys. Cyclic voltammetry and chronopotentiometry were used to study Pu-Al alloys in the temperature range 400-550 °C. Pu is reduced to metal in one reduction step Pu 3+/Pu 0 on an inert W electrode. On a reactive Al electrode, the reduction of Pu 3+ to Pu 0 occurs at a more positive potential due to formation of Pu-Al alloys. The open circuit potential technique was used to identify the alloys formed. Stable deposits were obtained by potentiostatic electrolyses of LiCl-KCl-PuCl 3 melts on Al plates. XRD and SEM-EDX analyses were used to characterise the alloys, which were composed mainly of PuAl 4 with some PuAl 3. In addition, the preparation of PuCl 3 containing salt by carbochlorination of PuO 2 is described.

  19. Investigation of the oxidation states of Pu isotopes in a hydrochloric acid solution.

    PubMed

    Lee, M H; Kim, J Y; Kim, W H; Jung, E C; Jee, K Y

    2008-12-01

    The characteristics of the oxidation states of Pu in a hydrochloric acid solution were investigated and the results were applied to a separating of Pu isotopes from IAEA reference soils. The oxidation states of Pu(III) and Pu(IV) were prepared by adding hydroxylamine hydrochloride and sodium nitrite to a Pu stock solution, respectively. Also, the oxidation state of Pu(VI) was adjusted with concentrated HNO(3) and HClO(4). The stability of the various oxidation states of plutonium in a HCl solution with elapsed time after preparation were found to be in the following order: Pu(III) approximately Pu(VI)>Pu(IV)>Pu(V). The chemical recoveries of Pu(IV) in a 9M HCl solution with an anion exchange resin were similar to those of Pu(VI). This method for the determination of Pu isotopes with an anion exchange resin in a 9M HCl medium was applied to IAEA reference soils where the activity concentrations of (239,240)Pu and (238)Pu in IAEA-375 and IAEA-326 were consistent with the reference values reported by the IAEA. PMID:18674920

  20. [Not Available].

    PubMed

    Marugán de Miguelsanz, José Manuel; Torres Hinojal, María Del Carmen; Geijo Uribe, María Soraya; Redondo Del Río, María Paz; Mongil López, Beatriz; De Brito García-Sousa, Inés; Caballero Sanz, Irene; Eiros Bouza, José María

    2016-01-01

    Anorexia nervosa (AN) is the most prevalent of eating disorders in children and adolescents, and its treatment is long and complex, involving a multidisciplinary team. Nutritional rehabilitation and restoration of a healthy body weight is one of the central goals in the initial stages of inpatient treatment. However, current recommendations on initial energy requirements for these patients are inconsistent, with a clear lack of controlled studies, available scientific evidence and global consensus on the most effective and safe refeeding practices in hospitalized adolescents with anorexia nervosa (AN). Conservative refeeding recommendations have been classically established in order to prevent the refeeding syndrome. Nevertheless, various works have recently appeared advocating a higher initial caloric intake, without observing more complications or refeeding syndrome, and allowing a shorter average stay. We present our experience in the treatment of restricting AN with a conservative progressive treatment. We have obtained good results with this approach, which was well tolerated by patients, with no observing complications. As a consequence, the medical team could establish a pact about the therapeutic goals with the patients in an easier way. PMID:27513485

  1. [Not Available].

    PubMed

    Marugán de Miguelsanz, José Manuel; Torres Hinojal, María Del Carmen; Geijo Uribe, María Soraya; Redondo Del Río, María Paz; Mongil López, Beatriz; De Brito García-Sousa, Inés; Caballero Sanz, Irene; Eiros Bouza, José María

    2016-01-01

    Anorexia nervosa (AN) is the most prevalent of eating disorders in children and adolescents, and its treatment is long and complex, involving a multidisciplinary team. Nutritional rehabilitation and restoration of a healthy body weight is one of the central goals in the initial stages of inpatient treatment. However, current recommendations on initial energy requirements for these patients are inconsistent, with a clear lack of controlled studies, available scientific evidence and global consensus on the most effective and safe refeeding practices in hospitalized adolescents with anorexia nervosa (AN). Conservative refeeding recommendations have been classically established in order to prevent the refeeding syndrome. Nevertheless, various works have recently appeared advocating a higher initial caloric intake, without observing more complications or refeeding syndrome, and allowing a shorter average stay. We present our experience in the treatment of restricting AN with a conservative progressive treatment. We have obtained good results with this approach, which was well tolerated by patients, with no observing complications. As a consequence, the medical team could establish a pact about the therapeutic goals with the patients in an easier way. PMID:27444457

  2. Yale's Tuition Postponement Option

    ERIC Educational Resources Information Center

    Curran, William E.

    1973-01-01

    Discusses Yale's Tuition Postponement Option which bases a student's repayment obligation on the student's future income. Under this system, some students will pay Yale less than the amounts they postponed plus interest and some will pay more. (JF)

  3. Porphyria Treatment Options

    MedlinePlus

    ... only. For treatment options for Porphyria Cutanea Tarda (PCT) , Congenital Erythropoietic Protoporphyria (CEP) and Hepatoerythropoietic Porphyria (HEP) ... Contact Us About Porphyria AIP VP HCP ADP PCT EPP CEP HEP Diet and Nutrition History of ...

  4. Production and investigation of thin films of metal actinides (Pu, Am, Cm, Bk, Cf)

    NASA Astrophysics Data System (ADS)

    Radchenko, V. M.; Ryabinin, M. A.; Stupin, V. A.

    2010-03-01

    Under limited availability of transplutonium metals some special techniques and methods of their production have been developed that combine the process of metal reduction from a chemical compound and preparation of a sample for examination. In this situation the evaporation and condensation of metal onto a substrate becomes the only possible technology. Thin film samples of metallic 244Cm, 248Cm and 249Bk were produced by thermal reduction of oxides with thorium followed by deposition of the metals in the form of thin layers on tantalum substrates. For the production of 249Cf metal in the form of a thin layer the method of thermal reduction of oxide with lanthanum was used. 238Pu and 239Pu samples in the form of films were prepared by direct high temperature evaporation and condensation of the metal onto a substrate. For the production of 241Am films a gram sample of plutonium-241 metal was used containing about 18 % of americium at the time of production. Thermal decomposition of Pt5Am intermetallics in vacuum was used to produce americium metal with about 80% yield. Resistivity of the metallic 249Cf film samples was found to decrease exponentially with increasing temperature. The 249Cf metal demonstrated a tendency to form preferably a DHCP structure with the sample mass increasing. An effect of high specific activity on the crystal structure of 238Pu nuclide thin layers was studied either.

  5. [Not Available].

    PubMed

    Soret, Juliette; Kiladjian, Jean-Jacques

    2016-06-01

    THE ROLE OF RUXOLITINIB IN THE TREATMENT OF MYELOPROLIFERATIVE NEOPLASMS: The discovery of the JAK2V617F mutation in 2005, present in 95% of polycythemia vera (PV) and in 55% of myelofibrosis (MF) patients, opened the way for a new era of targeted therapies for myeloproliferative neoplasms. Ruxolitinib was the first-in-class Janus Kinase (JAK) inhibitor approved for the management of these diseases. In PV patients, conventional treatment strategies including aspirin, phlebotomy, cytoreductive agents such as hydroxyurea and interferon, clearly provide clinical benefits. However, some patients develop resistance or intolerance to these treatments. Ruxolitinib has been approved for PV patients who are resistant to or intolerant of hydroxyurea, based on the results of the phase 3 RESPONSE study. This study showed that ruxolitinib improves hematocrit control, reduces splenomegaly, and ameliorate disease-related symptoms as compared with best available therapy. In MF patients, the only curative treatment is allogeneic stem cell transplantation, but it remains restricted to a limited group of patients with poor prognosis and who are eligible for such procedure associated with non-negligible transplant-related mortality. Other treatments are palliative and unlikely to prolong survival. Ruxolitinib has been approved in the United States for MF patients with intermediate or high-risk disease, and in Europe for disease-related splenomegaly or symptoms in adults with MF, based on phase 3 COMFORT-I and COMFORT-II studies. These studies showed that ruxolitinib was able to reduce splenomegaly, ameliorate symptoms, and improve survival. However, the journey is not finished yet since there are still important unmet needs for MF patients, including improvement in cytopenias, and significant modification of disease natural history. PMID:27494970

  6. [Not Available].

    PubMed

    Demaeyer, Ph

    2016-01-01

    Medicine owes many to Hippocrate, but pneumology traces its origin back to antiquity, from Mesopotamia to ancient Rome. Regarding prehistory: if viscera of this period have not been kept, some bones were. Since Neanderthals, it is then possible to study osteoarticular pathologies (often chronic arthrosis). But no evidence of tuberculosis was found (all thoracic kyphosis are not tuberculosis). Tuberculosis probably appears during the Neolithic age, because of high concentration of population. In ancient times, pneumology was of course not a real medical specialty. However, respiratory illness already constituted a big part of antique medical practice. The purpose of the physician in antiquity was to establish a diagnosis, a prognostic and to propose a treatment. Prognostic revealed to be of great importance in ancient times, since therapeutic efficacy was limited. Contemporary physicians often neglect this part of their practice. In ancient times, physicians also tried to gradually eliminate magic-religious aspects in taking care of the patients. This review will propose a journey from Mesopotamia to ancient Egypt (and its medical papyrus). Very few sources are available concerning medicine in pre-Columbian cultures. However, it is well known that shamans had, besides their religious competences, a great pharmacopoeia. Because of these very few sources, this topic will not be added to this article. Little is known in Europa about chinese medicine before the Jesuit mission in China during the 17th and 18th centuries. Yet, chinese medicine grew in parallel with European's one. Some relevant elements of this medicine will hereafter be shown. PMID:27120938

  7. Phonon dispersion curves determination in (delta)-phase Pu-Ga alloys

    SciTech Connect

    Wong, J; Clatterbuck, D; Occelli, F; Farber, D; Schwartz, A; Wall, M; Boro, C; Krisch, M; Beraud, A; Chiang, T; Xu, R; Hong, H; Zschack, P; Tamura, N

    2006-02-07

    We have designed and successfully employed a novel microbeam on large grain sample concept to conduct high resolution inelastic x-ray scattering (HRIXS) experiments to map the full phonon dispersion curves of an fcc {delta}-phase Pu-Ga alloy. This approach obviates experimental difficulties with conventional inelastic neutron scattering due to the high absorption cross section of the common {sup 239}Pu isotope and the non-availability of large (mm size) single crystal materials for Pu and its alloys. A classical Born von-Karman force constant model was used to model the experimental results, and no less than 4th nearest neighbor interactions had to be included to account for the observation. Several unusual features including, a large elastic anisotropy, a small shear elastic modulus, (C{sub 11}-C{sub 12})/2, a Kohn-like anomaly in the T{sub 1}[011] branch, and a pronounced softening of the T[111] branch towards the L point in the Brillouin are found. These features may be related to the phase transitions of plutonium and to strong coupling between the crystal structure and the 5f valence instabilities. Our results represent the first full phonon dispersions ever obtained for any Pu-bearing material, thus ending a 40-year quest for this fundamental data. The phonon data also provide a critical test for theoretical treatments of highly correlated 5f electron systems as exemplified by recent dynamical mean field theory (DMFT) calculations for {delta}-plutonium. We also conducted thermal diffuse scattering experiments to study the T(111) dispersion at low temperatures with an attempt to gain insight into bending of the T(111) branch in relationship to the {delta} {yields} {alpha}{prime} transformation.

  8. A study of accelerated radiation damage effects in PuO2 and gadolinia-stabilized cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, doped with 238Pu

    NASA Astrophysics Data System (ADS)

    Burakov, B. E.; Yagovkina, M. A.

    2015-12-01

    Polycrystalline samples of cubic zirconia, Zr0.79Gd0.14Pu0.07O1.93, doped with approximately 9.9 wt.% 238Pu, and PuO2 containing 11.0 wt. % 238Pu (and main isotope is 239Pu) have been repeatedly studied during many years by X-ray diffraction analysis. At a temperature of 25 °C the unit-cell parameter of PuO2 increases depending on accumulated dose, and is accompanied by decrease of coherent scattering region (CSR). Self-irradiation of Zr0.79Gd0.14Pu0.07O1.93 is accompanied with repeated change of unit-cell parameter and CSR.

  9. OPTIONS FOR ABATING GREENHOUSE GASES FROM EXHAUST STREAMS.

    SciTech Connect

    FTHENAKIS,V.

    2001-12-01

    This report examines different alternatives for replacing, treating, and recycling greenhouse gases. It is concluded that treatment (abatement) is the only viable short-term option. Three options for abatement that were tested for use in semiconductor facilities are reviewed, and their performance and costs compared. This study shows that effective abatement options are available to the photovoltaic (PV) industry, at reasonable cost.

  10. Wastewater treatment plant cogeneration options

    SciTech Connect

    Stringfield, J.G.

    1995-12-31

    This paper reviews municipal sewage cogeneration and digester gas utilization options available to wastewater treatment plants, and will focus on utilizing the digester gas in combustion turbines and engine-generator systems. Defining the digestion and gas generation process is crucial to understanding the best gas utilization system. In municipal wastewater treatment plants biosolids (sludge) reduction is accomplished using aerobic or anaerobic digestion. The basic process of treating sewage solids with digestion is not new and has been practiced as far back as the nineteenth century. High energy usage consumed by aerobic blow systems supplying air to the process and the potential ``free`` energy generated by anaerobic digesters sometimes sways designers to select anaerobic over aerobic digestion. The following areas will be covered in this paper: gas utilization and cogeneration; definition of digestion process; sizing the cogeneration system and reviewing the systems components; emissions requirements and options; and capital, and O and M cost analysis.