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Sample records for actinide burn rate

  1. Actinide Burning in CANDU Reactors

    SciTech Connect

    Hyland, B.; Dyck, G.R.

    2007-07-01

    Actinide burning in CANDU reactors has been studied as a method of reducing the actinide content of spent nuclear fuel from light water reactors, and thereby decreasing the associated long term decay heat load. In this work simulations were performed of actinides mixed with natural uranium to form a mixed oxide (MOX) fuel, and also mixed with silicon carbide to form an inert matrix (IMF) fuel. Both of these fuels were taken to a higher burnup than has previously been studied. The total transuranic element destruction calculated was 40% for the MOX fuel and 71% for the IMF. (authors)

  2. Burning Rate Emulator

    NASA Video Gallery

    The Burning Rate Emulator is a gas fuel investigation attempting to emulate the burning of solids to improve our understanding of materials''flammability over a wide range of conditions. The approa...

  3. Effects of actinide burning on waste disposal at Yucca Mountain

    SciTech Connect

    Hirschfelder, J.

    1992-07-01

    Release rates of 15 radionuclides from waste packages expected to result from partitioning and transmutation of Light-Water Reactor (LWR) and Actinide-Burning Liquid-Metal Reactor (ALMR) spent fuel are calculated and compared to release rates from standard LWR spent fuel packages. The release rates are input to a model for radionuclide transport from the proposed geologic repository at Yucca Mountain to the water table. Discharge rates at the water table are calculated and used in a model for transport to the accessible environment, defined to be five kilometers from the repository edge. Concentrations and dose rates at the accessible environment from spent fuel and wastes from reprocessing, with partitioning and transmutation, are calculated. Partitioning and transmutation of LWR and ALMR spent fuel reduces the inventories of uranium, neptunium, plutonium, americium and curium in the high-level waste by factors of 40 to 500. However, because release rates of all of the actinides except curium are limited by solubility and are independent of package inventory, they are not reduced correspondingly. Only for curium is the repository release rate much lower for reprocessing wastes.

  4. PBXN-110 Burn Rate Estimate

    SciTech Connect

    Glascoe, E

    2008-08-11

    It is estimated that PBXN-110 will burn laminarly with a burn function of B = (0.6-1.3)*P{sup 1.0} (B is the burn rate in mm/s and P is pressure in MPa). This paper provides a brief discussion of how this burn behavior was estimated.

  5. Performance Comparison of Metallic, Actinide Burning Fuel in Lead-Bismuth and Sodium Cooled Fast Reactors

    SciTech Connect

    Weaver, Kevan Dean; Herring, James Stephen; Mac Donald, Philip Elsworth

    2001-04-01

    Various methods have been proposed to “incinerate” or “transmutate” the current inventory of trans-uranic waste (TRU) that exits in spent light-water-reactor (LWR) fuel, and weapons plutonium. These methods include both critical (e.g., fast reactors) and non-critical (e.g., accelerator transmutation) systems. The work discussed here is part of a larger effort at the Idaho National Engineering and Environmental Laboratory (INEEL) and at the Massachusetts Institute of Technology (MIT) to investigate the suitability of lead and lead-alloy cooled fast reactors for producing low-cost electricity as well as for actinide burning. The neutronics of non-fertile fuel loaded with 20 or 30-wt% light water reactor (LWR) plutonium plus minor actinides for use in a lead-bismuth cooled fast reactor are discussed in this paper, with an emphasis on the fuel cycle life and isotopic content. Calculations show that the average actinide burn rate is similar for both the sodium and lead-bismuth cooled cases ranging from -1.02 to -1.16 g/MWd, compared to a typical LWR actinide generation rate of 0.303 g/MWd. However, when using the same parameters, the sodium-cooled case went subcritical after 0.2 to 0.8 effective full power years, and the lead-bismuth cooled case ranged from 1.5 to 4.5 effective full power years.

  6. The EBR-II X501 Minor Actinide Burning Experiment

    SciTech Connect

    M. K. Meyer; S. L. Hayes; W. J. Carmack; H. Tsai

    2009-07-01

    The X501 experiment was conducted in EBR-II as part of the IFR (Integral Fast Reactor) program to demonstrate minor actinide burning through the use of a homogeneous recycle scheme. The X501 subassembly contained two metallic fuel elements loaded with relatively small quantities of americium and neptunium. Interest in the behavior of minor actinides (MA) during fuel irradiation has prompted further examination of existing X501 data, and generation of new data where needed in support of the U.S. waste transmutation effort. The X501 experiment is one of the few minor actinide-bearing fuel irradiation tests conducted worldwide and knowledge can be gained by understanding the changes in fuel behavior due to addition of MA’s. Of primary interest are the affect of the MA’s on fuel-cladding-chemical-interaction, and the redistribution behavior of americium. The quantity of helium gas release from the fuel and any effects of helium on fuel performance are also of interest. It must be stressed that information presented at this time is based on the limited PIE conducted in 1995-1996, and currently represents a set of observations rather than a complete understanding of fuel behavior. This paper provides a summary of the X501 fabrication, characterization, irradiation, and post irradiation examination.

  7. The EBR-II X501 Minor Actinide Burning Experiment

    SciTech Connect

    Jon Carmack; S. L. Hayes; M. K. Meyer; H. Tsai

    2008-06-01

    The X501 experiment was conducted in EBR-II as part of the IFR (Integral Fast Reactor) program to demonstrate minor actinide burning through the use of a homogeneous recycle scheme. The X501 subassembly contained two metallic fuel elements loaded with relatively small quantities of americium and neptunium. Interest in the behavior of minor actinides (MA) during fuel irradiation has prompted further examination of existing X501 data, and generation of new data where needed in support of the U.S. waste transmutation effort. The X501 experiment is one of the few minor actinide-bearing fuel irradiation tests conducted worldwide and knowledge can be gained by understanding the changes in fuel behavior due to addition of MA’s. Of primary interest are the affect of the MA’s on fuel-cladding-chemical-interaction, and the redistribution behavior of americium. The quantity of helium gas release from the fuel and any effects of helium on fuel performance are also of interest. It must be stressed that information presented at this time is based on the limited PIE conducted in 1995-1996, and currently represents a set of observations rather than a complete understanding of fuel behavior.

  8. The EBR-II X501 Minor Actinide Burning Experiment

    SciTech Connect

    W. J. Carmack; M. K. Meyer; S. L. Hayes; H. Tsai

    2008-01-01

    The X501 experiment was conducted in EBR II as part of the Integral Fast Reactor program to demonstrate minor actinide burning through the use of a homogeneous recycle scheme. The X501 subassembly contained two metallic fuel elements loaded with relatively small quantities of americium and neptunium. Interest in the behavior of minor actinides (MA) during fuel irradiation has prompted further examination of existing X501 data and generation of new data where needed in support of the U.S. waste transmutation effort. The X501 experiment is one of the few MA bearing fuel irradiation tests conducted worldwide, and knowledge can be gained by understanding the changes in fuel behavior due to addition of MAs. Of primary interest are the effect of the MAs on fuel cladding chemical interaction and the redistribution behavior of americium. The quantity of helium gas release from the fuel and any effects of helium on fuel performance are also of interest. It must be stressed that information presented at this time is based on the limited PIE conducted in 1995–1996 and, currently, represents a set of observations rather than a complete understanding of fuel behavior. This report provides a summary of the X501 fabrication, characterization, irradiation, and post irradiation examination.

  9. Nitramine propellants. [gun propellant burning rate

    NASA Technical Reports Server (NTRS)

    Cohen, N. S.; Strand, L. D. (Inventor)

    1978-01-01

    Nitramine propellants without a pressure exponent shift in the burning rate curves are prepared by matching the burning rate of a selected nitramine or combination of nitramines within 10% of burning rate of a plasticized active binder so as to smooth out the break point appearance in the burning rate curve.

  10. Suppressants for lowering propellant binder burning rate

    NASA Technical Reports Server (NTRS)

    Thompson, W. W.

    1972-01-01

    Addition of boron compound to lower burning rate of solid propellant binder is reported. Chemical reactions involved in propellant binder modification are described. Advantages of method for lowering burning rate are analyzed.

  11. Acoustic emission strand burning technique for motor burning rate prediction

    NASA Technical Reports Server (NTRS)

    Christensen, W. N.

    1978-01-01

    An acoustic emission (AE) method is being used to measure the burning rate of solid propellant strands. This method has a precision of 0.5% and excellent burning rate correlation with both subscale and large rocket motors. The AE procedure burns the sample under water and measures the burning rate from the acoustic output. The acoustic signal provides a continuous readout during testing, which allows complete data analysis rather than the start-stop clockwires used by the conventional method. The AE method helps eliminate such problems as inhibiting the sample, pressure increase and temperature rise, during testing.

  12. Health and environmental risk-related impacts of actinide burning on high-level waste disposal

    SciTech Connect

    Forsberg, C.W.

    1992-05-01

    The potential health and environmental risk-related impacts of actinide burning for high-level waste disposal were evaluated. Actinide burning, also called waste partitioning-transmutation, is an advanced method for radioactive waste management based on the idea of destroying the most toxic components in the waste. It consists of two steps: (1) selective removal of the most toxic radionuclides from high-level/spent fuel waste and (2) conversion of those radionuclides into less toxic radioactive materials and/or stable elements. Risk, as used in this report, is defined as the probability of a failure times its consequence. Actinide burning has two potential health and environmental impacts on waste management. Risks and the magnitude of high-consequence repository failure scenarios are decreased by inventory reduction of the long-term radioactivity in the repository. (What does not exist cannot create risk or uncertainty.) Risk may also be reduced by the changes in the waste characteristics, resulting from selection of waste forms after processing, that are superior to spent fuel and which lower the potential of transport of radionuclides from waste form to accessible environment. There are no negative health or environmental impacts to the repository from actinide burning; however, there may be such impacts elsewhere in the fuel cycle.

  13. The role of actinide burning and the Integral Fast Reactor in the future of nuclear power

    SciTech Connect

    Hollaway, W.R.; Lidsky, L.M.; Miller, M.M.

    1990-12-01

    A preliminary assessment is made of the potential role of actinide burning and the Integral Fast Reactor (IFR) in the future of nuclear power. The development of a usable actinide burning strategy could be an important factor in the acceptance and implementation of a next generation of nuclear power. First, the need for nuclear generating capacity is established through the analysis of energy and electricity demand forecasting models which cover the spectrum of bias from anti-nuclear to pro-nuclear. The analyses take into account the issues of global warming and the potential for technological advances in energy efficiency. We conclude, as do many others, that there will almost certainly be a need for substantial nuclear power capacity in the 2000--2030 time frame. We point out also that any reprocessing scheme will open up proliferation-related questions which can only be assessed in very specific contexts. The focus of this report is on the fuel cycle impacts of actinide burning. Scenarios are developed for the deployment of future nuclear generating capacity which exploit the advantages of actinide partitioning and actinide burning. Three alternative reactor designs are utilized in these future scenarios: The Light Water Reactor (LWR); the Modular Gas-Cooled Reactor (MGR); and the Integral Fast Reactor (FR). Each of these alternative reactor designs is described in some detail, with specific emphasis on their spent fuel streams and the back-end of the nuclear fuel cycle. Four separation and partitioning processes are utilized in building the future nuclear power scenarios: Thermal reactor spent fuel preprocessing to reduce the ceramic oxide spent fuel to metallic form, the conventional PUREX process, the TRUEX process, and pyrometallurgical reprocessing.

  14. Design of an Actinide Burning, Lead-Bismuth Cooled Reactor That Produces Low Cost Electricity

    SciTech Connect

    C. Davis; S. Herring; P. MacDonald; K. McCarthy; V. Shah; K. Weaver; J. Buongiorno; R. Ballinger; K. Doyoung; M. Driscoll; P. Hejzler; M. Kazimi; N. Todreas

    1999-07-01

    The purpose of this project is to investigate the suitability of lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The goal is to identify and analyze the key technical issues in core neutronics, materials, thermal-hydraulics, fuels, and economics associated with the development of this reactor concept. The choice of lead-bismuth for the reactor coolant is an actinide burning fast reactor offers enhanced safety and reliability. The advantages of lead-bismuth over sodium as a coolant are related to the following material characteristics: chemical inertness with air and water; higher atomic number; lower vapor pressure at operating temperatures; and higher boiling temperature. Given the status of the field, it was agreed that the focus of this investigation in the first two years will be on the assessment of approaches to optimize core and plant arrangements in order to provide maximum safety and economic potential in this type of reactor.

  15. High burn rate solid composite propellants

    NASA Astrophysics Data System (ADS)

    Manship, Timothy D.

    High burn rate propellants help maintain high levels of thrust without requiring complex, high surface area grain geometries. Utilizing high burn rate propellants allows for simplified grain geometries that not only make production of the grains easier, but the simplified grains tend to have better mechanical strength, which is important in missiles undergoing high-g accelerations. Additionally, high burn rate propellants allow for a higher volumetric loading which reduces the overall missile's size and weight. The purpose of this study is to present methods of achieving a high burn rate propellant and to develop a composite propellant formulation that burns at 1.5 inches per second at 1000 psia. In this study, several means of achieving a high burn rate propellant were presented. In addition, several candidate approaches were evaluated using the Kepner-Tregoe method with hydroxyl terminated polybutadiene (HTPB)-based propellants using burn rate modifiers and dicyclopentadiene (DCPD)-based propellants being selected for further evaluation. Propellants with varying levels of nano-aluminum, nano-iron oxide, FeBTA, and overall solids loading were produced using the HTPB binder and evaluated in order to determine the effect the various ingredients have on the burn rate and to find a formulation that provides the burn rate desired. Experiments were conducted to compare the burn rates of propellants using the binders HTPB and DCPD. The DCPD formulation matched that of the baseline HTPB mix. Finally, GAP-plasticized DCPD gumstock dogbones were attempted to be made for mechanical evaluation. Results from the study show that nano-additives have a substantial effect on propellant burn rate with nano-iron oxide having the largest influence. Of the formulations tested, the highest burn rate was a 84% solids loading mix using nano-aluminum nano-iron oxide, and ammonium perchlorate in a 3:1(20 micron: 200 micron) ratio which achieved a burn rate of 1.2 inches per second at 1000

  16. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production

    SciTech Connect

    Mac Donald, Philip Elsworth; Buongiorno, Jacopo; Davis, Cliff Bybee; Weaver, Kevan Dean

    2002-01-01

    The use of supercritical temperature and pressure light water as the coolant in a direct-cycle nuclear reactor offers potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to 46%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type recirculation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If a tight fuel rod lattice is adopted, it is possible to significantly reduce the neutron moderation and attain fast neutron energy spectrum conditions. In this project a supercritical water reactor concept with a simple, blanket-free, pancake-shaped core will be developed. This type of core can make use of either fertile or fertile-free fuel and retain the hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity.

  17. Fuel droplet burning rates at high pressures.

    NASA Technical Reports Server (NTRS)

    Canada, G. S.; Faeth, G. M.

    1973-01-01

    Combustion of methanol, ethanol, propanol-1, n-pentane, n-heptane, and n-decane was observed in air under natural convection conditions, at pressures up to 100 atm. The droplets were simulated by porous spheres, with diameters in the range from 0.63 to 1.90 cm. The pressure levels of the tests were high enough so that near-critical combustion was observed for methanol and ethanol. Due to the high pressures, the phase-equilibrium models of the analysis included both the conventional low-pressure approach as well as high-pressure versions, allowing for real gas effects and the solubility of combustion-product gases in the liquid phase. The burning-rate predictions of the various theories were similar, and in fair agreement with the data. The high-pressure theory gave the best prediction for the liquid-surface temperatures of ethanol and propanol-1 at high pressure. The experiments indicated the approach of critical burning conditions for methanol and ethanol at pressures on the order of 80 to 100 atm, which was in good agreement with the predictions of both the low- and high-pressure analysis.

  18. Burning Rate of Composite Propellants under the Conditions of Strain

    NASA Astrophysics Data System (ADS)

    Hu, Songqi; Chen, Jing; Wu, Guanjie; Liu, Yingji; Hua, Yijin

    2014-12-01

    In this work, a correlation between propellant burning rate and strain was established. In order to investigate the effects of strain and pressure, and to measure burning rate of composite propellants, a novel apparatus was designed and prepared. Burning rates of three formula composite propellants under different pressures and strains were measured using such device. Based on the measurements, a model for the analysis on the experimental results was proposed. It was demonstrated that the model corresponded with the experimental data if the propellant samples were under tensile strain increasing from 0 to 20%. Burning rate ratio and tensile strain obeyed the quadratic relationship, burning rate increased with strain, but there was no mutation in less than 20% deformation. Furthermore, burning rate ratio of composite propellants which had low Poisson ratio increased fast as tensile strain decreased. And the less binder component of composite propellants, the burning ratio changed more significantly under a given strain state. In addition, as the exposed area increased, the burning rate ratio became larger.

  19. High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant

    SciTech Connect

    Glascoe, E A; Tan, N

    2010-04-21

    High pressure deflagration rate measurements of a unique ammonium perchlorate (AP) based propellant are required to design the base burn motor for a Raytheon weapon system. The results of these deflagration rate measurements will be key in assessing safety and performance of the system. In particular, the system may experience transient pressures on the order of 100's of MPa (10's kPSI). Previous studies on similar AP based materials demonstrate that low pressure (e.g. P < 10 MPa or 1500 PSI) burn rates can be quite different than the elevated pressure deflagration rate measurements (see References and HPP results discussed herein), hence elevated pressure measurements are necessary in order understand the deflagration behavior under relevant conditions. Previous work on explosives have shown that at 100's of MPa some explosives will transition from a laminar burn mechanism to a convective burn mechanism in a process termed deconsolidative burning. The resulting burn rates that are orders-of-magnitude faster than the laminar burn rates. Materials that transition to the deconsolidative-convective burn mechanism at elevated pressures have been shown to be considerably more violent in confined heating experiments (i.e. cook-off scenarios). The mechanisms of propellant and explosive deflagration are extremely complex and include both chemical, and mechanical processes, hence predicting the behavior and rate of a novel material or formulation is difficult if not impossible. In this work, the AP/HTPB based material, TAL-1503 (B-2049), was burned in a constant volume apparatus in argon up to 300 MPa (ca. 44 kPSI). The burn rate and pressure were measured in-situ and used to calculate a pressure dependent burn rate. In general, the material appears to burn in a laminar fashion at these elevated pressures. The experiment was reproduced multiple times and the burn rate law using the best data is B = (0.6 {+-} 0.1) x P{sup (1.05{+-}0.02)} where B is the burn rate in mm/s and

  20. Accuracy of real time radiography burning rate measurement

    NASA Astrophysics Data System (ADS)

    Olaniyi, Bisola

    The design of a solid propellant rocket motor requires the determination of a propellant's burning-rate and its dependency upon environmental parameters. The requirement that the burning-rate be physically measured, establishes the need for methods and equipment to obtain such data. A literature review reveals that no measurement has provided the desired burning rate accuracy. In the current study, flash x-ray modeling and digitized film-density data were employed to predict motor-port area to length ratio. The pre-fired port-areas and base burning rate were within 2.5% and 1.2% of their known values, respectively. To verify the accuracy of the method, a continuous x-ray and a solid propellant rocket motor model (Plexiglas cylinder) were used. The solid propellant motor model was translated laterally through a real-time radiography system at different speeds simulating different burning rates. X-ray images were captured and the burning-rate was then determined. The measured burning rate was within 1.65% of the known values.

  1. Burn propagation rates of metals and alloys in gaseous oxygen

    NASA Technical Reports Server (NTRS)

    Benz, F. J.; Shaw, R. C.; Homa, J. M.

    1986-01-01

    The average burn rates of several metals and alloys were determined at oxygen pressures between 3.45 and 68.91 MPa (500 and 10,000 psig) and ambient temperature. Several materials were tested at elevated sample temperatures. The test materials were fabricated into solid cylindrical rods and mounted vertically in the test chamber. A magnesium igniter was positioned at the bottom end of each test specimen to promote upward burn propagations. Nickel 200 and copper 102 could not be ignited at all oxygen pressures tested whereas Monel 400 appeared to ignite but quickly self-extinguished. The other materials tested burned the entire length of the test sample. Aluminum 6061 exhibited the fastest burn propagation rate. Inconel 718 burned slower than aluminum but faster than the stainless steels (types 304 and 316). Increasing oxygen pressure generally increased the burn propagation rate of the materials. Increasing the ambient temperature of the test specimens for several materials to approximately 850 K (1070 F) had little effect upon the ignition or burn properties of nickel 200 or Monel 400. Type 316 stainless steel exhibited an increase in its burn propagation rate at this higher temperature.

  2. Iron/potassium perchlorate pellet burn rate measurements

    SciTech Connect

    Reed, J.W.; Walters, R.R.

    1995-01-25

    A burn rate test having several advantages for low gas-producing pyrotechnic compacts has been developed. The technique involves use of a high speed video motion analysis system that allows immediate turnaround and produces all required data for rate computation on magnetic tape and becomes immediately available on the display screen. The test technique provides a quick method for material qualification along with data for improved reliability and function. Burn rate data has been obtained for both UPI and Eagle Pitcher Iron/Potassium Perchlorate blends. The data obtained for the UPI blends cover a range of composition, pellet density, and ambient (before ignition) pellet temperature. Burn rate data for the E-P blends were extended to include surface conditions or particle size as a variable parameter.

  3. A Burning Rate Emulator (BRE) for Study in Microgravity

    NASA Technical Reports Server (NTRS)

    Markan, A.; Sunderland, P. B.; Quintiere, J. G.; DeRis, J.; Stocker, D. P.

    2015-01-01

    A gas-fueled burner, the Burning Rate Emulator (BRE), is used to emulate condensed-phase fuel flames. The design has been validated to easily measure the burning behavior of condensed-phase fuels by igniting a controlled stream of gas fuel and diluent. Four properties, including the heat of combustion, the heat of gasification, the surface temperature, and the laminar smoke point, are assumed to be sufficient to define the steady burning rate of a condensed-phase fuel. The heat of gasification of the fuel is determined by measuring the heat flux and the fuel flow rate. Microgravity BRE tests in the NASA 5.2 s drop facility have examined the burning of pure methane and ethylene (pure and 50 in N2 balance). Fuel flow rates, chamber oxygen concentration and initial pressure have been varied. Two burner sizes, 25 and 50 mm respectively, are chosen to examine the nature of initial microgravity burning. The tests reveal bubble-like flames that increase within the 5.2s drop but the heat flux received from the flame appears to asymptotically approach steady state. Portions of the methane flames appear to locally detach and extinguish at center, while its shape remains fixed, but growing. The effective heat of gasification is computed from the final measured net heat flux and the fuel flow rate under the assumption of an achieved steady burning. Heat flux (or mass flux) and flame position are compared with stagnant layer burning theory. The analysis offers the prospect of more complete findings from future longer duration ISS experiments.

  4. A model for the burning rates of composite propellants

    NASA Technical Reports Server (NTRS)

    Cohen, N. S.; Strand, L. D.

    1980-01-01

    An analytical model of the steady-state burning of composite solid propellants is presented. An improved burning rate model is achieved by incorporating an improved AP monopropellant model, a separate energy balance for the binder in which a portion of the diffusion flame is used to heat the binder, proper use of the binder regression rate in the model, and a model for the combustion of the energetic binder component of CMDB propellants. Also, an improved correlation and model of aluminum agglomeration is developed which properly describes compositional trends.

  5. Resistance of the boreal forest to high burn rates

    PubMed Central

    Héon, Jessie; Arseneault, Dominique; Parisien, Marc-André

    2014-01-01

    Boreal ecosystems and their large carbon stocks are strongly shaped by extensive wildfires. Coupling climate projections with records of area burned during the last 3 decades across the North American boreal zone suggests that area burned will increase by 30–500% by the end of the 21st century, with a cascading effect on ecosystem dynamics and on the boreal carbon balance. Fire size and the frequency of large-fire years are both expected to increase. However, how fire size and time since previous fire will influence future burn rates is poorly understood, mostly because of incomplete records of past fire overlaps. Here, we reconstruct the length of overlapping fires along a 190-km-long transect during the last 200 y in one of the most fire-prone boreal regions of North America to document how fire size and time since previous fire will influence future fire recurrence. We provide direct field evidence that extreme burn rates can be sustained by a few occasional droughts triggering immense fires. However, we also show that the most fire-prone areas of the North American boreal forest are resistant to high burn rates because of overabundant young forest stands, thereby creating a fuel-mediated negative feedback on fire activity. These findings will help refine projections of fire effect on boreal ecosystems and their large carbon stocks. PMID:25201981

  6. Resistance of the boreal forest to high burn rates.

    PubMed

    Héon, Jessie; Arseneault, Dominique; Parisien, Marc-André

    2014-09-23

    Boreal ecosystems and their large carbon stocks are strongly shaped by extensive wildfires. Coupling climate projections with records of area burned during the last 3 decades across the North American boreal zone suggests that area burned will increase by 30-500% by the end of the 21st century, with a cascading effect on ecosystem dynamics and on the boreal carbon balance. Fire size and the frequency of large-fire years are both expected to increase. However, how fire size and time since previous fire will influence future burn rates is poorly understood, mostly because of incomplete records of past fire overlaps. Here, we reconstruct the length of overlapping fires along a 190-km-long transect during the last 200 y in one of the most fire-prone boreal regions of North America to document how fire size and time since previous fire will influence future fire recurrence. We provide direct field evidence that extreme burn rates can be sustained by a few occasional droughts triggering immense fires. However, we also show that the most fire-prone areas of the North American boreal forest are resistant to high burn rates because of overabundant young forest stands, thereby creating a fuel-mediated negative feedback on fire activity. These findings will help refine projections of fire effect on boreal ecosystems and their large carbon stocks. PMID:25201981

  7. Burning rate for steel-cased, pressed binderless HMX

    NASA Technical Reports Server (NTRS)

    Fifer, R. A.; Cole, J. E.

    1980-01-01

    The burning behavior of pressed binderless HMX laterally confined in 6.4 mm i.d. steel cases was measured over the pressure range 1.45 to 338 MPa in a constant pressure strand burner. The measured regression rates are compared to those reported previously for unconfined samples. It is shown that lateral confinement results in a several-fold decrease in the regression rate for the coarse particle size HMX above the transition to super fast regression. For class E samples, confinement shifts the transition to super fast regression from low pressure to high pressure. These results are interpreted in terms of the previously proposed progressive deconsolidation mechanism. Preliminary holographic photography and closed bomb tests are also described. Theoretical one dimensional modeling calculations were carried out to predict the expected flame height (particle burn out distance) as a function of particle size and pressure for binderless HMX burning by a progressive deconsolidation mechanism.

  8. r-PROCESS Reaction Rates for the Actinides and Beyond

    NASA Astrophysics Data System (ADS)

    Panov, I. V.; Korneev, I. Yu.; Rauscher, T.; Thielemann, F.-K.

    2011-10-01

    We discuss the importance of different fission rates for the formation of heavy and superheavy nuclei in the astrophysical r-process. Neutron-induced reaction rates, including fission and neutron capture, are calculated in the temperature range 108 ≤ T(K) ≤ 1010 within the framework of the statistical model for targets with the atomic number 84 ≤ Z ≤ 118 (from Po to Uuo) from the neutron to the proton drip-line for different mass and fission barrier predictions based on Thomas-Fermi (TF), Extended Thomas-Fermi plus Strutinsky Integral (ETFSI), Finite-Range Droplet Model (FRDM) and Hartree-Fock-Bogolyubov (HFB) approaches. The contribution of spontaneous fission as well as beta-delayed fission to the recycling r-process is discussed. We also discuss the possibility of rate tests, based on mini r-processed yields in nuclear explosions.

  9. Burning rate response of liquid monopropellants to imposed pressure oscillations

    NASA Technical Reports Server (NTRS)

    Allison, C. B.

    1974-01-01

    The combustion characteristics of hydrazine strands were studied under both steady state and oscillatory conditions. A steady strand burner was used to measure steady strand burning rates, liquid temperature distributions and surface temperatures as a function of pressure in the pressure range of 0.32 to 42 atm. It was found that for subatmospheric pressures the burning rate varied as the square root of pressure; for pressures greater than atmospheric the burning rate varied linearly with pressure. A theoretical model of the strand combustion system was developed and matched to the steady burning rates by assuming a reaction order of one for subatmospheric pressures and a reaction order of two for pressures greater than atmospheric. The model was also found to be in good agreement with measurements of liquid temperature distributions and surface temperatures. The results show an increse in the response of the combustion process as interaction occurs with transient liquid phase effects, yielding a band of frequencies where the combustion process exerts sufficient amplifying power to provide a mechanism for driving combustion instability.

  10. Biomass burning fuel consumption rates: a field measurement database

    NASA Astrophysics Data System (ADS)

    van Leeuwen, T. T.; van der Werf, G. R.; Hoffmann, A. A.; Detmers, R. G.; Rücker, G.; French, N. H. F.; Archibald, S.; Carvalho, J. A., Jr.; Cook, G. D.; de Groot, W. J.; Hély, C.; Kasischke, E. S.; Kloster, S.; McCarty, J. L.; Pettinari, M. L.; Savadogo, P.; Alvarado, E. C.; Boschetti, L.; Manuri, S.; Meyer, C. P.; Siegert, F.; Trollope, L. A.; Trollope, W. S. W.

    2014-06-01

    Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. These fuel consumption (FC) rates depend on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from space and estimates are becoming more reliable due to improved algorithms and sensors, FC rates are either modeled or taken selectively from the literature. We compiled the peer-reviewed literature on FC rates for various biomes and fuel categories to better understand FC rates and variability, and to provide a~database that can be used to constrain biogeochemical models with fire modules. We compiled in total 76 studies covering 10 biomes including savanna (15 studies, average FC of 4.6 t DM (dry matter) ha-1), tropical forest (n = 19, FC = 126), temperate forest (n = 11, FC = 93), boreal forest (n = 16, FC = 39), pasture (n = 6, FC = 28), crop residue (n = 4, FC = 6.5), chaparral (n = 2, FC = 32), tropical peatland (n = 4, FC = 314), boreal peatland (n = 2, FC = 42), and tundra (n = 1, FC = 40). Within biomes the regional variability in the number of measurements was sometimes large, with e.g. only 3 measurement locations in boreal Russia and 35 sites in North America. Substantial regional differences were found within the defined biomes: for example FC rates of temperate pine forests in the USA were 38% higher than Australian forests dominated by eucalypt trees. Besides showing the differences between biomes, FC estimates were also grouped into different fuel classes. Our results highlight the large variability in FC rates, not only between biomes but also within biomes and fuel classes. This implies that care should be taken with using averaged values, and our comparison with FC rates from GFED3 indicates that also modeling studies have difficulty in representing the dynamics governing FC.

  11. Generation rate of carbon monoxide from burning charcoal.

    PubMed

    Ojima, Jun

    2011-01-01

    Charcoal, often used as cooking fuel at some restaurants, generates a significant amount of carbon monoxide (CO) during its combustion. Every year in Japan, a number of cooks and waiters/waitresses are poisoned by CO emanating from burning charcoal. Although certain ventilation is necessary to prevent the accumulation of CO, it is difficult to estimate the proper ventilation requirement for CO because the generation rate of CO from burning charcoal has not been established. In this study, several charcoals were evaluated in terms of CO generation rate. Sample charcoals were burned in a cooking stove to generate exhaust gas. For each sample, four independent variables -- the mass of the sample, the flow rate of the exhaust gas, CO concentration in the exhaust gas and the combustion time of the sample -- were measured, and the CO generation rate was calculated. The generation rate of CO from the charcoal was shown to be 137-185 ml/min/kW. Theoretical ventilation requirements for charcoals to prevent CO poisoning are estimated to be 41.2-55.6 m(3)/h/kW. PMID:21372432

  12. Mortality rates among 5321 patients with burns admitted to a burn unit in China: 1980-1998.

    PubMed

    Jie, Xiao; Baoren, Cai

    2003-05-01

    A retrospective study was conducted on 5321 burn patients hospitalized in a burn center in Jinzhou, China during the period 1980-1998. Of the 5321 patients, 57.8% were between 15 and 44 years old and 3.4% were > or =60 years old. Ninety-six percent had burns covering less than half of body surface area and 31.7% had only full thickness skin burn. The number of patients in the 1990s was three times that of the 1980s. Overall mortality rate was 0.86%. LA(50) for total body burn area (TBSA) and only full thickness skin burn (FTSB) was 94 and 87%, respectively. The high survival rate, may relate primarily to the low percentages of older patients and of patients with severe burns. Inhalation injuries, infection and MOD are the main causes of deaths in our patients and would be key targets to improve clinical care and in future study. PMID:12706617

  13. High-pressure burning rate studies of solid rocket propellants

    NASA Astrophysics Data System (ADS)

    Atwood, A. I.; Ford, K. P.; Wheeler, C. J.

    2013-03-01

    Increased rocket motor performance is a major driver in the development of solid rocket propellant formulations for chemical propulsion systems. The use of increased operating pressure is an option to improve performance potentially without the cost of reformulation. A technique has been developed to obtain burning rate data across a range of pressures from ambient to 345 MPa. The technique combines the use of a low loading density combustion bomb with a high loading density closed bomb technique. A series of nine ammonium perchlorate (AP) based propellants were used to demonstrate the use of the technique, and the results were compared to the neat AP burning rate "barrier". The effect of plasticizer, oxidizer particle size, catalyst, and binder type were investigated.

  14. Burns

    MedlinePlus

    ... doing so puts you in danger as well. Chemical and Electrical Burns For chemical and electrical burns, call 911 or your local ... the power source has been turned off. For chemical burns: Dry chemicals should be brushed off the ...

  15. Literature review of intrinsic actinide colloids related to spent fuel waste package release rates

    SciTech Connect

    Zhao, P.; Steward, S.A.

    1997-01-01

    Existence of actinide colloids provides an important mechanism in the migration of radionuclides and will be important in performance of a geologic repository for high-level nuclear waste. Actinide colloids have been formed during long-term unsaturated dissolution of spent fuel by groundwater. This article summarizes a literature search of actinide colloids. This report emphasizes the formation of intrinsic actinide colloids, because they would have the opportunity to form soon after groundwater contact with the spent fuel and before actinide-bearing groundwater reaches the surrounding geologic formations.

  16. Leading Edge Flame Detachment: Effect on Burning Rate of Ammonium Perchlorate Propellants

    NASA Technical Reports Server (NTRS)

    Price, E. W.; Chakravarthy, S. R.; Sambamurthi, J. K.; Sigman, R. K.

    1997-01-01

    Inner details of the transition from premixed to diffusion controlled burning are examined by considering the transition at the individual particle flamelet level. These considerations lead to prediction of observable singular burning rate behavior of bimodal AP formulations. Burning rate measurements verify the predictions, supporting the view that particle flamelets become detached and retreat to more remote premixed locations at definite (particles size dependent) pressures, revealed by the burning rate tests.

  17. Burn-rate studies with iron/potassium perchlorate heat pellets

    SciTech Connect

    Reed, J.W.; Walters, R.R.; Guidotti, R.A.; Jacobson, A.K.

    1991-12-31

    A detailed study was conducted on factors which could possibly influence the burn rate of Fe/KC10{sub 4} heat pellets. The burning process was monitored with a high-speed (1000 frames per second) video analysis system. The substrate and pellet thickness had little effect upon the burn rate of heat pellets. The pellet density, composition, and Fe particle size, however, affected the burn rates significantly. By proper adjustment of these parameters, the burn rate of heat pellets can be affected. This, in turn, can be used to influence the rise times of thermal batteries that use this type of pyrotechnic heat source.

  18. Burn-rate studies with iron/potassium perchlorate heat pellets

    SciTech Connect

    Reed, J.W.; Walters, R.R. ); Guidotti, R.A.; Jacobson, A.K. )

    1991-01-01

    A detailed study was conducted on factors which could possibly influence the burn rate of Fe/KC10{sub 4} heat pellets. The burning process was monitored with a high-speed (1000 frames per second) video analysis system. The substrate and pellet thickness had little effect upon the burn rate of heat pellets. The pellet density, composition, and Fe particle size, however, affected the burn rates significantly. By proper adjustment of these parameters, the burn rate of heat pellets can be affected. This, in turn, can be used to influence the rise times of thermal batteries that use this type of pyrotechnic heat source.

  19. The burning rate of energetic films of nanostructured porous silicon.

    PubMed

    Plummer, Andrew; Kuznetsov, Valerian; Joyner, Timothy; Shapter, Joe; Voelcker, Nicolas H

    2011-12-01

    A systematic study of nanoenergetic films consisting of nanostructured porous silicon impregnated with sodium perchlorate is carried out. The explosive properties of these films are investigated as a function of thickness, porosity, and confinement. The films' burning rates are investigated using fiber-optic velocity probes, demonstrating that flame-front velocities vary between approximately 1 and 500 m s(-1) and are very sensitive to the films' structural characteristics. Analysis of the flame profile by high-speed video is also presented, suggesting that the reaction type is a deflagration rather than a detonation. A strong plume of flame is emitted from the surface, indicating the potential for this material to perform useful work either as an initiator or as a propellant. The shape of the flame front transitioned from an inverted V at thin-film thicknesses to a neat square-shaped front once the material became self-confining at 50 μm. PMID:22009919

  20. REVIEW OF EXPERIMENTAL STUDIES INVESTIGATING THE RATE OF STRONTIUM AND ACTINIDE ADSORPTION BY MONOSODIUM TITANATE

    SciTech Connect

    Hobbs, D.

    2010-10-01

    A number of laboratory studies have been conducted to determine the influence of mixing and mixing intensity, solution ionic strength, initial sorbate concentrations, temperature, and monosodium titanate (MST) concentration on the rates of sorbate removal by MST in high-level nuclear waste solutions. Of these parameters, initial sorbate concentrations, ionic strength, and MST concentration have the greater impact on sorbate removal rates. The lack of a significant influence of mixing and mixing intensity on sorbate removal rates indicates that bulk solution transport is not the rate controlling step in the removal of strontium and actinides over the range of conditions and laboratory-scales investigated. However, bulk solution transport may be a significant parameter upon use of MST in a 1.3 million-gallon waste tank such as that planned for the Small Column Ion Exchange (SCIX) program. Thus, Savannah River National Laboratory (SRNL) recommends completing the experiments in progress to determine if mixing intensity influences sorption rates under conditions appropriate for this program. Adsorption models have been developed from these experimental studies that allow prediction of strontium (Sr), plutonium (Pu), neptunium (Np) and uranium (U) concentrations as a function of contact time with MST. Fairly good agreement has been observed between the predicted and measured sorbate concentrations in the laboratory-scale experiments.

  1. Burns

    MedlinePlus

    ... are burns treated? In many cases, topical antibiotics (skin creams or ointments) are used to prevent infection. For third-degree burns and some second-degree ones, immediate blood transfusion and/or extra fluids ... is skin grafting? There are two types of skin grafts. ...

  2. Design of an Actinide Burning, Lead or Lead-Bismuth Cooled Reactor That Produces Low Cost Electricty - FY-02 Annual Report

    SciTech Connect

    Mac Donald, Philip Elsworth; Buongiorno, Jacopo

    2002-10-01

    The purpose of this collaborative Idaho National Engineering and Environmental Laboratory (INEEL) and Massachusetts Institute of Technology (MIT) Laboratory Directed Research and Development (LDRD) project is to investigate the suitability of lead or lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The goal is to identify and analyze the key technical issues in core neutronics, materials, thermal-hydraulics, fuels, and economics associated with the development of this reactor concept. Work has been accomplished in four major areas of research: core neutronic design, plant engineering, material compatibility studies, and coolant activation. The publications derived from work on this project (since project inception) are listed in Appendix A. This is the third in a series of Annual Reports for this project, the others are also listed in Appendix A as FY-00 and FY-01 Annual Reports.

  3. Design of an Actinide Burning, Lead or Lead-Bismuth Cooled Reactor that Produces Low Cost Electricity FY-01 Annual Report, October 2001

    SciTech Connect

    Mac Donald, Philip Elsworth; Buongiorno, Jacopo; Davis, Cliff Bybee; Herring, James Stephen; Loewen, Eric Paul; Smolik, Galen Richard; Weaver, Kevan Dean; Todreas, N.

    2001-10-01

    The purpose of this collaborative Idaho National Engineering and Environmental Laboratory (INEEL) and Massachusetts Institute of Technology (MIT) Laboratory Directed Research and Development (LDRD) project is to investigate the suitability of lead or lead-bismuth cooled fast reactors for producing low-cost electricity as well as for actinide burning. The goal is to identify and analyze the key technical issues in core neutronics, materials, thermal-hydraulics, fuels, and economics associated with the development of this reactor concept. Work has been accomplished in four major areas of research: core neutronic design, plant engineering, material compatibility studies, and coolant activation. The publications derived from work on this project (since project inception) are listed in Appendix A.

  4. Effects of normal acceleration on transient burning rate augmentation of an aluminized solid propellant

    NASA Technical Reports Server (NTRS)

    Northam, G. B.

    1972-01-01

    Instantaneous burning rate data for a polybutadiene acrylic acid propellant, containing 16 weight percent aluminum, were calculated from the pressure histories of a test motor with 96.77 sq cm of burning area and a 5.08-cm-thick propellant web. Additional acceleration tests were conducted with reduced propellant web thicknesses of 3.81, 2.54, and 1.27 cm. The metallic residue collected from the various web thickness tests was characterized by weight and shape and correlated with the instantaneous burning rate measurements. Rapid depressurization extinction tests were conducted in order that surface pitting characteristics due to localized increased burning rate could be correlated with the residue analysis and the instantaneous burning rate data. The acceleration-induced burning rate augmentation was strongly dependent on propellant distance burned, or burning time, and thus was transient in nature. The results from the extinction tests and the residue analyses indicate that the transient rate augmentation was highly dependent on local enhancement of the combustion zone heat feedback to the surface by the growth of molten residue particles on or just above the burning surface. The size, shape, and number density of molten residue particles, rather than the total residue weight, determined the acceleration-induced burning rate augmentation.

  5. [Burns].

    PubMed

    Arai, Takao

    2016-02-01

    Burns extending deep into the skin and those affecting a wide surface area trigger various responses in the body and pose a serious threat to life. Therefore, the degree of severity needs to be determined accurately, and appropriate transfusion and local management should be provided accordingly. Systematic and meticulous management that considers not just the risk of death but also functional prognosis is essential from the early stage of burn injuries. Such management requires comprehensive care by a medical team concerning infections, nutrition and rehabilitation. This article outlines the current status of intensive care for severe burns. PMID:26915244

  6. Preliminary burn rate studies on TiH/sub 1. 65//KC10/sub 4/

    SciTech Connect

    Hingorani-Norenberg, S.L.; Moore, L.M.

    1988-01-01

    With a long-term goal of characterizing the burn-rate bahavior of several energetic materials, a series of experiments has been conducted to study the burn-rate behavior of titanium subhydride potassium perchlorate (TiH/sub 1.65//KC10/sub 4/). The current research investigates the variation of the burn rate of this material with increasing bulk density in a zero-free-volume closed bomb. Thus far the results indicate that the burn rate increases with increasing bulk density to a certain maximum, and then decreases with any additional increase in density. This dependence of burn rate on density is discussed in terms of conductive and convective burning. 12 refs., 6 figs.

  7. Turbulent burning rates of methane and methane-hydrogen mixtures

    SciTech Connect

    Fairweather, M.; Ormsby, M.P.; Sheppard, C.G.W.; Woolley, R.

    2009-04-15

    Methane and methane-hydrogen (10%, 20% and 50% hydrogen by volume) mixtures have been ignited in a fan stirred bomb in turbulence and filmed using high speed cine schlieren imaging. Measurements were performed at 0.1 MPa (absolute) and 360 K. A turbulent burning velocity was determined for a range of turbulence velocities and equivalence ratios. Experimental laminar burning velocities and Markstein numbers were also derived. For all fuels the turbulent burning velocity increased with turbulence velocity. The addition of hydrogen generally resulted in increased turbulent and laminar burning velocity and decreased Markstein number. Those flames that were less sensitive to stretch (lower Markstein number) burned faster under turbulent conditions, especially as the turbulence levels were increased, compared to stretch-sensitive (high Markstein number) flames. (author)

  8. Burns

    MedlinePlus

    ... to your body's tissues caused by heat, chemicals, electricity, sunlight, or radiation. Scalds from hot liquids and ... to infections because they damage your skin's protective barrier. Treatment for burns depends on the cause of ...

  9. Burns

    MedlinePlus

    ... of Surgery . 18th ed. Philadelphia, PA: Elsevier Saunders; 2007:chap 22. Holmes JH, Heimbach DM. Burns. In: Brunicardi FC, Andersen DK, Billiar TR, et al, eds. Schwartz's Principles of Surgery . 9th ed. New ...

  10. Predicted and measured effects of pressure and crossflow velocity on composite propellant burning rate

    NASA Technical Reports Server (NTRS)

    King, M. K.

    1980-01-01

    A theoretical model for prediction of burning rates of composite (ammonium perchlorate oxidizer) solid propellants as a function of pressure and crossflow velocity was developed. Included in this model is the capability for treatment of multimodal oxidizer particle sizes and metalized formulations. In addition, an experimental device for measuring the effects of crossflow velocity on propellant burning rate was developed and used to characterize a series of AP/HTPB propellants with systematically varied formulation parameters. Model predictions of zero-crossflow burning rate versus pressure characteristics were found to be in agreement with data, while the agreement between erosive burning predictions and data is, in general, good. The experimental data indicate that the dominant factor influencing the sensitivity of composite propellant burning rate to crossflow is the base (no-crossflow) burning rate versus pressure characteristics of the propellant (lower base burning rate leading to increased crossflow sensitivity). Finally, the model was used to examine the effects of motor scaling on erosive burning: erosive burning is predicted to diminish with increasing motor size, in agreement with experience.

  11. Results of Propellant Mixing Variable Study Using Precise Pressure-Based Burn Rate Calculations

    NASA Technical Reports Server (NTRS)

    Stefanski, Philip L.

    2014-01-01

    A designed experiment was conducted in which three mix processing variables (pre-curative addition mix temperature, pre-curative addition mixing time, and mixer speed) were varied to estimate their effects on within-mix propellant burn rate variability. The chosen discriminator for the experiment was the 2-inch diameter by 4-inch long (2x4) Center-Perforated (CP) ballistic evaluation motor. Motor nozzle throat diameters were sized to produce a common targeted chamber pressure. Initial data analysis did not show a statistically significant effect. Because propellant burn rate must be directly related to chamber pressure, a method was developed that showed statistically significant effects on chamber pressure (either maximum or average) by adjustments to the process settings. Burn rates were calculated from chamber pressures and these were then normalized to a common pressure for comparative purposes. The pressure-based method of burn rate determination showed significant reduction in error when compared to results obtained from the Brooks' modification of the propellant web-bisector burn rate determination method. Analysis of effects using burn rates calculated by the pressure-based method showed a significant correlation of within-mix burn rate dispersion to mixing duration and the quadratic of mixing duration. The findings were confirmed in a series of mixes that examined the effects of mixing time on burn rate variation, which yielded the same results.

  12. Analytical model of high pressure burning rates in a transient environment. [nitramine propellant combustion

    NASA Technical Reports Server (NTRS)

    Cohen, N. S.; Strand, L. D.

    1978-01-01

    A transient ballistics and combustion model is derived to represent the closed vessel experiment that is widely used to characterize the high pressure burning rates of solid propellants. The model is applied to explain why burning rates deduced from the closed vessel are in basic agreement with those measured from an equilibrium strand burner in the case of homogeneous propellants, but differ significantly in the case of nitramine composite propellants. Thermal profile time lag effects become small at high pressure because the burning rates become high. However, the development of the burning surface structure of those nitramine propellants which exhibit shifts in pressure exponent causes the mass burning rate to lag and then exceed the equilibrium value. It is necessary to consider this mechanism in applications dealing with high pressures and pressurization rates.

  13. Burning Rate Measurement of Solid Propellant Using Ultrasound — Approach and Initial Experiments

    NASA Astrophysics Data System (ADS)

    Song, Sung-Jin; Jeon, Jin Hong; Kim, Hak-Joon; Kim, In-Chul; Yoo, Ji-Chang; Jung, Jung Yong

    2006-03-01

    To measure the burning rate of a solid propellant as a function of pressure using ultrasound, in the present study, a burning camber and an ultrasonic measurement system are specially designed and fabricated. In addition, data acquisition and analysis programs are also developed to determine the burning rate vs. pressure curve from the measured ultrasonic signals and pressures during the tests. Using the developed system, the wave speeds of the propellant are measured in the pre-test and the interface and burning surface echoes are acquired during the burning test together with the pressure inside the bomb. Based on these measurements, the burning rates of two kinds of propellants are successfully determined and compared to those measured by a strand burner method for the verification of the developed system and the proposed data analysis approach. For a propellant with high burning rate, the result obtained by the ultrasonic measurement shows a very good agreement to that measured by the strand burner method. Unfortunately, however, for a propellant with slow burning rate the result shows fairly large discrepancy in the initial experiments carried out in the present study.

  14. Burn rates of pristine and degraded explosives at elevated temperatures and pressures

    SciTech Connect

    Chandler, J B; Maienschein, J L

    1998-08-10

    We measure the Laminar burn rates of explosives at extreme conditions (up to 520K and 1 GPa) in a hybrid strand burner, to provide reaction rate data for prediction of violence of thermal response. Data from a series of HMX-based explosives show that explosives with high binder content (15 wt%) burn smoothly over the entire pressure range regardless of particle size, while explosives with less binder eventually transition to a rapid erratic burn 10-100 times faster. When heated to ~ 440K, an HMX formulation with fine particles and 15% binder exhibits different burning behav- ior depending on the details of the temperature-pressure history, apparently as a result of the {beta} {yields} {delta} phase transition in HMX. Burn rates can be increased by 1000-fold under certain conditions.

  15. Burning rate of merged pool fire on the hollow square tray.

    PubMed

    Wang, Changjian; Guo, Jin; Ding, Yanming; Wen, Jennifer; Lu, Shouxiang

    2015-06-15

    In order to characterize fire merging, pool fires on hollow trays with varying side lengths were burned under quasi-quiescent condition and in a wind tunnel with the wind speed ranging from 0m/s to 7.5m/s. Burning rate and flame images were recorded in the whole combustion process. The results show that even though the pool surface area was kept identical for hollow trays of different sizes, the measured burning rates and fire evolutions were found to be significantly different. Besides the five stages identified by previous studies, an extra stage, fire merging, was observed. Fire merging appeared possibly at any of the first four stages and moreover resulted in 50-100% increases of the fire burning rates and heights in the present tests. The tests in wind tunnel suggested that, as the wind speed ranges from 0 m/s to 2 m/s, the burning rates decrease. However with further increase of the wind speed from 2 m/s to 7.5 m/s, the burning rate was found to increase for smaller hollow trays while it remains almost constant for larger hollow trays. Two empirical correlations are presented to predict critical burning rate of fire merging on the hollow tray. The predictions were found to be in reasonably good agreement with the measurements. PMID:25746567

  16. Measurement of Solid Rocket Propellant Burning Rate Using X-ray Imaging

    NASA Astrophysics Data System (ADS)

    Denny, Matthew D.

    The burning rate of solid propellants can be difficult to measure for unusual burning surface geometries, but X-ray imaging can be used to measure burning rate. The objectives of this work were to measure the baseline burning rate of an electrically-controlled solid propellant (ESP) formulation with real-time X-ray radiography and to determine the uncertainty of the measurements. Two edge detection algorithms were written to track the burning surface in X-ray videos. The edge detection algorithms were informed by intensity profiles of simulated 2-D X-ray images. With a 95% confidence level, the burning rates measured by the Projected-Slope Intersection algorithm in the two combustion experiments conducted were 0.0839 in/s +/-2.86% at an average pressure of 407 psi +/-3.6% and 0.0882 in/s +/-3.04% at 410 psi +/-3.9%. The uncertainty percentages were based on the statistics of a Monte Carlo analysis on burning rate.

  17. Biomass burning fuel consumption rates: a field measurement database

    NASA Astrophysics Data System (ADS)

    van Leeuwen, T. T.; van der Werf, G. R.; Hoffmann, A. A.; Detmers, R. G.; Rücker, G.; French, N. H. F.; Archibald, S.; Carvalho, J. A., Jr.; Cook, G. D.; de Groot, W. J.; Hély, C.; Kasischke, E. S.; Kloster, S.; McCarty, J. L.; Pettinari, M. L.; Savadogo, P.; Alvarado, E. C.; Boschetti, L.; Manuri, S.; Meyer, C. P.; Siegert, F.; Trollope, L. A.; Trollope, W. S. W.

    2014-12-01

    Landscape fires show large variability in the amount of biomass or fuel consumed per unit area burned. Fuel consumption (FC) depends on the biomass available to burn and the fraction of the biomass that is actually combusted, and can be combined with estimates of area burned to assess emissions. While burned area can be detected from space and estimates are becoming more reliable due to improved algorithms and sensors, FC is usually modeled or taken selectively from the literature. We compiled the peer-reviewed literature on FC for various biomes and fuel categories to understand FC and its variability better, and to provide a database that can be used to constrain biogeochemical models with fire modules. We compiled in total 77 studies covering 11 biomes including savanna (15 studies, average FC of 4.6 t DM (dry matter) ha-1 with a standard deviation of 2.2), tropical forest (n = 19, FC = 126 ± 77), temperate forest (n = 12, FC = 58 ± 72), boreal forest (n = 16, FC = 35 ± 24), pasture (n = 4, FC = 28 ± 9.3), shifting cultivation (n = 2, FC = 23, with a range of 4.0-43), crop residue (n = 4, FC = 6.5 ± 9.0), chaparral (n = 3, FC = 27 ± 19), tropical peatland (n = 4, FC = 314 ± 196), boreal peatland (n = 2, FC = 42 [42-43]), and tundra (n = 1, FC = 40). Within biomes the regional variability in the number of measurements was sometimes large, with e.g. only three measurement locations in boreal Russia and 35 sites in North America. Substantial regional differences in FC were found within the defined biomes: for example, FC of temperate pine forests in the USA was 37% lower than Australian forests dominated by eucalypt trees. Besides showing the differences between biomes, FC estimates were also grouped into different fuel classes. Our results highlight the large variability in FC, not only between biomes but also within biomes and fuel classes. This implies that substantial uncertainties are associated with using biome-averaged values to represent FC for whole

  18. Effects of propellant composition variables on acceleration-induced burning-rate augmentation of solid propellants

    NASA Technical Reports Server (NTRS)

    Northam, G. B.

    1972-01-01

    This work was conducted to define further the effects of propellant composition variables on the acceleration-induced burning rate augmentation of solid propellants. The rate augmentation at a given acceleration was found to be a nonlinear inverse function of the reference burning rate and not controlled by binder or catalyst type at a given reference rate. A nonaluminized propellant and a low rate double-base propellant exhibited strong transient rate augmentation due to surface pitting resulting from the retention of hot particles on the propellant surface.

  19. A miniscale ballistic test motor for propellant burning rate characterization from one motor firing

    NASA Astrophysics Data System (ADS)

    Rast, Robert H.; Boyles, Sharon M.; Obney, Phyllis

    1992-07-01

    A mini ballistic test motor for burn rate characterization from one motor firing has been developed. The small charge weight required for this motor allows ballistic characterization of small scale lot set evaluation and R&D propellant mixes in a rocket motor environment. This paper presents results comparing the mini-motor to the standard Naval Surface Warfare Center, Indian Head (IHDIVNAVSURFWARCEN) ballistic test motor, (BTM). Burn rate data from the standard BTM and mini BTM show excellent agreement.

  20. Dependence of density and burning rate of composite solid propellant on mixer size

    NASA Astrophysics Data System (ADS)

    Verma, Sumit; Ramakrishna, P. A.

    2014-01-01

    This paper examines the effect of mixer size on the density of the propellant and it also explores the role of the propellant density with regards to burning rate and burn rate pressure index. Propellant samples were prepared in the four different size (15, 70, 200 and 1000 g) mixers with identical input of ingredients to examine the effect of mixer size on density and burning rate of the composite solid propellant. It was noticed that density and burning rate of the propellant changes significantly with change in the mixer size from 15 g to 1000 g. This is because for the smaller mixers the surface area to volume ratio is large and the actual percentage of aluminum and ammonium perchlorate (especially coarse) that goes into the propellant reduces. High burning rate with decrease in mixer size is also accompanied with increase in burn rate pressure index. The composition analysis was also carried out and it is noticed that the actual percentage of the ingredients is different from the intended percentage of the ingredients and percentage change is more when the mixer size decreases.

  1. The direct effects of strain on burning rates of composite solid propellants

    NASA Technical Reports Server (NTRS)

    Langhenry, M. T.

    1984-01-01

    A mathematical model is developed to predict burn rate augmentation due to strain in a composite solid propellant. The model assumes the effect is due to the ability of the flame to penetrate the small fissures and voids that form when a propellant is strained. The number and size of these fissures is obtained by applying a flaw propagation analysis to randomly distributed flaws that form when the binder-oxidizer particle bonds break under stress. A flame height is calculated with Summerfield's burn rate equation and is used to compute the burn rate augmentation based upon the additional burn area created when the flame penetrates the fissures. Comparisons are made with data obtained from published sources. The existence of threshold pressure and strains, above which augmentation occurs, is verified although the model predicts a lower threshold pressure and higher threshold strain than expected. Further results and applications of the model are discussed.

  2. Addendum to High Pressure Burn Rate Measurements on an Ammonium Perchlorate Propellant

    SciTech Connect

    Glascoe, E A; Tan, N

    2010-11-08

    As part of a small follow-on study, the burn rate of the ammonium perchlorate (AP) based material TAL-1503 was studied at a relatively mild pressure. The goal of this final experiment was to burn TAL-1503 at the lowest pressures possible using the LLNL High Pressure Strand Burner (LLNL-HPSB). The following is a description of the experiment and the results with a brief discussion of data and a comparison to the higher pressure data. This is not meant to be a stand-alone report and readers should refer to the main report for experimental details and discussion. High pressure deflagration rate measurements of a unique AP/HTPB based material (TAL-1503) were performed using the LLNL high pressure strand burner apparatus. The material burns in a well behaved, laminar fashion between 20 and 300 MPa with a burn law of B = (0.6 {+-} 0.1) x P{sup (1.05{+-}0.02)} that was calculated based on the best data available from the experiments. In the pressure range of 2 and 10 MPa the material burned laminarly with a burn law of B = (2.0 {+-} 0.2) x P{sup (0.66{+-}0.05)}. In these results, B is the burn rate in mm/s and P is the pressure in units of MPa. Comparison of the TAL-1503 results with similar propellants that contain micrometer sized aluminum indicate that the burn rates are relatively unaffected by the aluminum. However, the pressure change is significantly larger when aluminum is present, most likely due to the high temperatures achieved from burning aluminum.

  3. Feasibility Study of Supercritical Light Water Cooled Fast Reactors for Actinide Burning and Electric Power Production, Progress Report for Work Through September 2002, 4th Quarterly Report

    SciTech Connect

    Mac Donald, Philip Elsworth

    2002-09-01

    The use of light water at supercritical pressures as the coolant in a nuclear reactor offers the potential for considerable plant simplification and consequent capital and O&M cost reduction compared with current light water reactor (LWR) designs. Also, given the thermodynamic conditions of the coolant at the core outlet (i.e. temperature and pressure beyond the water critical point), very high thermal efficiencies of the power conversion cycle are possible (i.e. up to about 45%). Because no change of phase occurs in the core, the need for steam separators and dryers as well as for BWR-type re-circulation pumps is eliminated, which, for a given reactor power, results in a substantially shorter reactor vessel and smaller containment building than the current BWRs. Furthermore, in a direct cycle the steam generators are not needed. If no additional moderator is added to the fuel rod lattice, it is possible to attain fast neutron energy spectrum conditions in a supercritical water-cooled reactor (SCWR). This type of core can make use of either fertile or fertile-free fuel and retain a hard spectrum to effectively burn plutonium and minor actinides from LWR spent fuel while efficiently generating electricity. One can also add moderation and design a thermal spectrum SCWR. The Generation IV Roadmap effort has identified the thermal spectrum SCWR (followed by the fast spectrum SCWR) as one of the advanced concepts that should be developed for future use. Therefore, the work in this NERI project is addressing both types of SCWRs.

  4. Reaction rate and composition dependence of the stability of thermonuclear burning on accreting neutron stars

    SciTech Connect

    Keek, L.; Cyburt, R. H.; Heger, A.

    2014-06-01

    The stability of thermonuclear burning of hydrogen and helium accreted onto neutron stars is strongly dependent on the mass accretion rate. The burning behavior is observed to change from Type I X-ray bursts to stable burning, with oscillatory burning occurring at the transition. Simulations predict the transition at a 10 times higher mass accretion rate than observed. Using numerical models we investigate how the transition depends on the hydrogen, helium, and CNO mass fractions of the accreted material, as well as on the nuclear reaction rates of 3α and the hot-CNO breakout reactions {sup 15}O(α, γ){sup 19}Ne and {sup 18}Ne(α, p){sup 21}Na. For a lower hydrogen content the transition is at higher accretion rates. Furthermore, most experimentally allowed reaction rate variations change the transition accretion rate by at most 10%. A factor 10 decrease of the {sup 15}O(α, γ){sup 19}Ne rate, however, produces an increase of the transition accretion rate of 35%. None of our models reproduce the transition at the observed rate, and depending on the true {sup 15}O(α, γ){sup 19}Ne reaction rate, the actual discrepancy may be substantially larger. We find that the width of the interval of accretion rates with marginally stable burning depends strongly on both composition and reaction rates. Furthermore, close to the stability transition, our models predict that X-ray bursts have extended tails where freshly accreted fuel prolongs nuclear burning.

  5. Growth rate predicts mortality of Abies concolor in both burned and unburned stands

    USGS Publications Warehouse

    van Mantgem, P.J.; Stephenson, N.L.; Mutch, L.S.; Johnson, V.G.; Esperanza, A.M.; Parsons, D.J.

    2003-01-01

    Tree mortality is often the result of both long-term and short-term stress. Growth rate, an indicator of long-term stress, is often used to estimate probability of death in unburned stands. In contrast, probability of death in burned stands is modeled as a function of short-term disturbance severity. We sought to narrow this conceptual gap by determining (i) whether growth rate, in addition to crown scorch, is a predictor of mortality in burned stands and (ii) whether a single, simple model could predict tree death in both burned and unburned stands. Observations of 2622 unburned and 688 burned Abies concolor (Gord. & Glend.) Lindl. (white fir) in the Sierra Nevada of California, U.S.A., indicated that growth rate was a significant predictor of mortality in the unburned stands, while both crown scorch and radial growth were significant predictors of mortality in the burned stands. Applying the burned stand model to unburned stands resulted in an overestimation of the unburned stand mortality rate. While failing to create a general model of tree death for A. concolor, our findings underscore the idea that similar processes may affect mortality in disturbed and undisturbed stands.

  6. Shell and explosive hydrogen burning. Nuclear reaction rates for hydrogen burning in RGB, AGB and Novae

    NASA Astrophysics Data System (ADS)

    Boeltzig, A.; Bruno, C. G.; Cavanna, F.; Cristallo, S.; Davinson, T.; Depalo, R.; deBoer, R. J.; Di Leva, A.; Ferraro, F.; Imbriani, G.; Marigo, P.; Terrasi, F.; Wiescher, M.

    2016-04-01

    The nucleosynthesis of light elements, from helium up to silicon, mainly occurs in Red Giant and Asymptotic Giant Branch stars and Novae. The relative abundances of the synthesized nuclides critically depend on the rates of the nuclear processes involved, often through non-trivial reaction chains, combined with complex mixing mechanisms. In this paper, we summarize the contributions made by LUNA experiments in furthering our understanding of nuclear reaction rates necessary for modeling nucleosynthesis in AGB stars and Novae explosions.

  7. The role of antioxidant micronutrients in the rate of recovery of burn patients: a systematic review.

    PubMed

    Adjepong, Mary; Agbenorku, Pius; Brown, Patricia; Oduro, Ibok

    2016-01-01

    Burn injury can be detrimental to the health of individuals, meanwhile victims lose proteins and micronutrients in wound exudates. Victims also experience extensive protein catabolism. These make them prone to malnutrition. Burn patients also suffer a lot of emotional trauma that reduce nutrient intake. The aim of this paper was to review primary evidence on the effect of antioxidant micronutrients on the recovery rate of burn patients. Electronic databases such as PubMed, BioMed, and Cochrane were systematically searched between January 1, 2014, and January 30, 2014. Keywords include vitamin A, vitamin C, vitamin E, ascorbic acid, zinc, copper, selenium, tocopherol, carotenoids, dietary intake, supplementation, wound healing, infection, recovery rate, and burn patients. The systematic search was done to retrieve all published data from 1990 to 2013. A total of 518 journal articles were obtained, and after the removal of duplicates, reviews, commentaries, and studies with non-human subjects, 11 papers were accepted for review. The review considered only papers that were published, and there might be some unpublished data that may have been omitted. Generally, the wound healing time and infection rates were reduced by the administration of the antioxidant micronutrients. The review revealed that there was no such published work in developing countries and children were excluded from most studies. It was also stated clearly that there was no uniformity in burn management; hence, there is a need for more studies on burn management in various populations. PMID:27574687

  8. MINING INTEGRAL ACTINIDES CROSS SECTIONS FROM REACTOR DATA

    SciTech Connect

    PUIGH RJ

    2009-09-11

    The conclusions of this paper are: (1) mining of actinide cross-sections from reactor data is a viable and inexpensive approach to confirm burn-up codes; (2) extensive data for actinides in Hanford test data ({approx} 200 radiochemical analyses); (3) not only cross-section values and reaction rates can be established but also possible benchmark like data can be constructed to test and validate reactor and criticality safety codes such as SCALE/KENO or MCNPX; and (4) analysis along multiple transmutation paths can be evaluated to show consistency.

  9. Effects of oblique air flow on burning rates of square ethanol pool fires.

    PubMed

    Tao, Changfa; He, Yaping; Li, Yuan; Wang, Xishi

    2013-09-15

    The effects of downward airflow on the burning rate and/or burning intensity of square alcohol pool fires for different airflow speeds and directions have been studied experimentally in an inclined wind tunnel. An interesting flame-wrapping phenomenon, caused by impingement of air flow, was observed. The mass burning intensity was found to increase with the airflow speed and the impinging angle. The fuel pan rim temperatures were also measured to study the effect of wind direction and speed on heat transfer from the flame to the fuel source. A model based on heat transfer analysis was developed to correlate the burning intensity with the pan rim characteristic temperature. A good correlation was established between the model results and the experimental results. PMID:23811377

  10. Heart Rate Variability as a Predictor of Death in Burn Patients.

    PubMed

    Loguidice, Michael J; Schutt, Robert C; Horton, Jureta W; Minei, Joseph P; Keeley, Ellen C

    2016-01-01

    Heart rate variability (HRV), a noninvasive technique used to quantify fluctuations in the interval between normal heart beats (NN), is a predictor of mortality in some patient groups. The aim of this study was to assess HRV in burn trauma patients as a predictor of mortality. The authors prospectively performed 24-hour Holter monitoring on burn patients and collected demographic information, burn injury details, and in-hospital clinical events. Analysis of HRV in the time and frequency domains was performed. A total of 40 burn patients with a mean age of 44 ± 15 years were enrolled. Mean %TBSA burn was 27 ± 22% for the overall population and was significantly higher in those who died compared with those who survived (55 ± 23% vs 19 ± 13%; P < .0001). There was a statistically significant inverse linear correlation between SD of NN intervals and %TBSA (r = -.337, R = 0.113, 95% CI = -0.587 to -0.028, two-tailed P = .034), as well as with ultra low frequency power and %TBSA burn (r = -0.351, R = 0.123, 95% CI = -0.152 to -0.009; P = .027). The receiver-operator characteristic showed the area under the curve for %TBSA as a predictor of death was 0.82 (P < .001), for SDANN was 0.94 (P < .0001), and for ultra low frequency power was 0.96 (P < .0001). Deranged HRV in the early postburn period is a strong predictor of death. PMID:26061155

  11. Stabilization Mechanisms and Burning Rates of Cylindrical Burner Flames

    NASA Technical Reports Server (NTRS)

    Eng, J. A.; Law, C. K.; Zhu, D. L.

    1994-01-01

    A study is conducted of the structure and response of curved (but unstretched), cylindrically-symmetric 1D premixed flames from a cylindrical porous burner. The study has employed (1) activation-energy asymptotics with one-step reaction constant and constant properties; (2) a numerical computation which encompassed detailed chemistry and transport behavior, and (3) drop-tower microgravity tests. Attention was given to the relative importance of heat loss vs. flow divergence as the dominant mechanism for flame stabilization; the results show that, with increasing flow discharge rate, the dominant flame stabilization mechanism changes from heat loss to flow divergence.

  12. Plasma physics effects on thermonuclear burn rate in the presence of hydrodynamic mix

    NASA Astrophysics Data System (ADS)

    Tang, Xian-Zhu; Guo, Zehua; Kagan, Grigory; McDevitt, Christopher; Srinivasan, Bhuvana

    2016-03-01

    Hydrodynamic mix can significantly degrade thermonuclear burn rate in an inertial confinement fusion (ICF) target. Successful mitigation requires a detailed understanding of the physical mechanisms by which mix affects burn. Here we summarize the roles of three distinct plasma physics effects on burn rate. The first is the well-known effect of enhanced thermal energy loss from the hot spot and the mitigating role of self-generated or externally-applied magnetic field. The second is the fuel ion separation via inter-species ion diffusion driven by the powerful thermodynamic forces exacerbated by mix during the implosion process. The third is the fusion reactivity modification by fast ion transport in a mix-dominated ICF target, where hot plasma is intermingled with cold fuel.

  13. High-rate Iranian blowout controlled while still burning

    SciTech Connect

    Bahmani, H.; Azarpanah, A. )

    1994-09-19

    Oil well firefighters used ingenuity and equipment designed in the field to cap a high-rate blowout well in Iran without extinguishing the fire. Well AZ-50, located about 25 km southeast of Ahwaz, Iran, blew out on Feb. 14, 1993, and was finally controlled on Mar. 31, 1993, by a firefighting team from the National Iranian Oil Co. The estimated open flow potential of producing Well AZ-50 was 60,000 bo/d and 50 MMsfd of associated gas, making this well among the world's largest blowouts. The well control operation was difficult because the flame height reached 117 m, the fluid velocity 2, 180 fps at the well-head, and the flame temperature 4,150 F. The paper describes operations.

  14. Comparison of soil infiltration rates in burned and unburned mountainous watersheds

    NASA Astrophysics Data System (ADS)

    Martin, Deborah A.; Moody, John A.

    2001-10-01

    Steady-state infiltration measurements were made at mountainous sites in New Mexico and Colorado, USA, with volcanic and granitic soils after wildfires and at comparable unburned sites. We measured infiltration in the New Mexico volcanic soils under two vegetation types, ponderosa pine and mixed conifer, and in the Colorado granitic soils under ponderosa pine vegetation. These measurements were made within high-severity burn areas using a portable infiltrometer with a 0·017 m2 infiltration area and artificial rainfall rates ranging from 97 to 440 mm h-1. Steady-state infiltration rates were less at all burned sites relative to unburned sites. The volcanic soil with ponderosa pine vegetation showed the greatest difference in infiltration rates with a ratio of steady-state infiltration rate in burned sites to unburned soils equal to 0·15. Volcanic soils with mixed conifer vegetation had a ratio (burned to unburned soils) of at most 0·38, and granitic soils with ponderosa pine vegetation had a ratio of 0·38. Steady-state infiltration rates on unburned volcanic and granitic soils with ponderosa pine vegetation are not statistically different. We present data on the particle-size distribution at all the study sites and examples of wetting patterns produced during the infiltration experiments. Published in 2001 John Wiley & Sons, Ltd.

  15. Comparison of soil infiltration rates in burned and unburned mountainous watersheds

    USGS Publications Warehouse

    Martin, D.A.; Moody, J.A.

    2001-01-01

    Steady-state infiltration measurements were made at mountainous sites in New Mexico and Colorado, USA, with volcanic and granitic soils after wildfires and at comparable unburned sites. We measured infiltration in the New Mexico volcanic soils under two vegetation types, ponderosa pine and mixed conifer, and in the Colorado granitic soils under ponderosa pine vegetation. These measurements were made within high-severity burn areas using a portable infiltrometer with a 0.017 m2 infiltration area and artificial rainfall rates ranging from 97 to 440 mm h-1. Steady-state infiltration rates were less at all burned sites relative to unburned sites. The volcanic soil with ponderosa pine vegetation showed the greatest difference in infiltration rates with a ratio of steady-state infiltration rate in burned sites to unburned soils equal to 0.15. Volcanic soils with mixed conifer vegetation had a ratio (burned to unburned soils) of at most 0.38, and granitic soils with ponderosa pine vegetation had a ratio of 0.38. Steady-state infiltration rates on unburned volcanic and granitic soils with ponderosa pine vegetation are not statistically different. We present data on the particle-size distribution at all the study sites and examples of wetting patterns produced during the infiltration experiments. Published in 2001 by John Wiley and Sons, Ltd.

  16. EFFECTS OF BURN RATE, WOOD SPECIES, MOISTURE CONTENT AND WEIGHT OF WOOD LOADED ON WOODSTOVE EMISSIONS

    EPA Science Inventory

    The report gives results of tests of four woodstove operating parameters (burn rate, wood moisture, wood load, and wood species) at two levels each using a half factorial experimental test design to determine statistically significant effects on the emission components CO, CO2, p...

  17. What could have caused pre-industrial biomass burning emissions to exceed current rates?

    NASA Astrophysics Data System (ADS)

    van der Werf, G. R.; Peters, W.; van Leeuwen, T. T.; Giglio, L.

    2012-08-01

    is considered "the burning continent". Our new modelling results, together with existing literature, indicate that no definitive conclusions can be drawn about unprecedentedly high or low biomass burning rates from current data analyses.

  18. What could have caused pre-industrial biomass burning emissions to exceed current rates?

    NASA Astrophysics Data System (ADS)

    van der Werf, G. R.; Peters, W.; van Leeuwen, T. T.; Giglio, L.

    2013-01-01

    ; satellite data indicates that the majority of savannas have not burned in the past 10 yr, even in Africa, which is considered "the burning continent". Although we have not considered increased charcoal burning or changes in OH concentrations as potential causes for the elevated CO concentrations found at SPO, it is unlikely they can explain the large increase found in the CO concentrations in ice core data. Confirmation of the CO ice core data would therefore call for radical new thinking about causes of variable global fire rates over recent centuries.

  19. Laminar burn rates of gun propellants measured in the high-pressure strand burner

    SciTech Connect

    Reaugh, J. E., LLNL

    1997-10-01

    The pressure dependence of the laminar burn rate of gun propellants plays a role in the design and behavior of high-performance guns. We have begun a program to investigate the effects of processing variables on the laminar burn rates, using our high-pressure strand burner to measure these rates at pressures exceeding 700 MPa. We have burned JA2 and M43 propellant samples, provided by Dr. Arpad Juhasz, ARL, from propellant lots previously used in round-robin tests. Our results at room temperature are in accord with other measurements. In addition, we present results measured for propellant that has been preheated to 50 C before burning. We used our thermochemical equilibrium code, CHEETAH, to help interpret the simultaneous pressure and temperature measurements taken during the testing, and show examples of its use. It has been modified to provide performance measures and equations of state for the products that are familiar to the gun-propellant community users of BLAKE.

  20. Actinides-1981

    SciTech Connect

    Not Available

    1981-09-01

    Abstracts of 134 papers which were presented at the Actinides-1981 conference are presented. Approximately half of these papers deal with electronic structure of the actinides. Others deal with solid state chemistry, nuclear physic, thermodynamic properties, solution chemistry, and applied chemistry.

  1. Erosive Augmentation of Solid Propellant Burning Rate: Motor Size Scaling Effect

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Cohen, Norman S.

    1990-01-01

    Two different independent variable forms, a difference form and a ratio form, were investigated for correlating the normalized magnitude of the measured erosive burning rate augmentation above the threshold in terms of the amount that the driving parameter (mass flux or Reynolds number) exceeds the threshold value for erosive augmentation at the test condition. The latter was calculated from the previously determined threshold correlation. Either variable form provided a correlation for each of the two motor size data bases individually. However, the data showed a motor size effect, supporting the general observation that the magnitude of erosive burning rate augmentation is reduced for larger rocket motors. For both independent variable forms, the required motor size scaling was attained by including the motor port radius raised to a power in the independent parameter. A boundary layer theory analysis confirmed the experimental finding, but showed that the magnitude of the scale effect is itself dependent upon scale, tending to diminish with increasing motor size.

  2. Plasma arginine and leucine kinetics and urea production rates in burn patients.

    PubMed

    Yu, Y M; Young, V R; Castillo, L; Chapman, T E; Tompkins, R G; Ryan, C M; Burke, J F

    1995-05-01

    We measured plasma arginine and leucine kinetics and rates of urea production (appearance) in 12 severely burned patients (mean body surface burn area, 48%) during a basal state (low-dose intravenous glucose) and while receiving routine, total parenteral nutrition ([TPN] fed state) including an L-amino acid mixture, supplying a generous level of nitrogen (mean, 0.36 g N.kg-1.d-1). The two nutritional states were studied in random order using a primed 4-hour constant intravenous tracer infusion protocol. Stable-nuclide-labeled tracers were L-[guanidino-13C]arginine, L-[1-13C]leucine, [18O]urea, and NaH13CO3 (prime only), with blood and expired air samples drawn at intervals to determine isotopic abundance of arginine, citrulline, ornithine, alpha-ketoisocaproate ([KIC] for leucine), and urea in plasma and 13CO2 in breath. Results are compared with data obtained in these laboratories in healthy adults. Leucine kinetics (flux and disappearance into protein synthesis) indicated the expected higher turnover in burn patients than in healthy controls. Mean leucine oxidation rates are also higher and compared well with values predicted from urea production rates, provided that urea nitrogen recycling via intestinal hydrolysis is taken into account. The plasma urea flux was also higher than for normal subjects. Arginine fluxes as measured in the systemic whole body, via the plasma pool, were correspondingly higher in burned patients than in healthy controls and were in good agreement with values predicted from leucine-KIC kinetics. However, systemic whole-body arginine flux measured via the plasma pool was only 20% of the arginine flux estimated from the urea flux plus the rate of protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7752916

  3. Evaluation of magnesium-aluminum eutectic to improve combustion efficiency in low burning rate propellants

    NASA Technical Reports Server (NTRS)

    Northam, B. G.; Sullivan, E. M.

    1973-01-01

    A previous investigation indicated that combustion efficiency of low burning-rate propellants could be improved if the aluminum fuel was replaced by aluminum particles coated with a magnesium-aluminum eutectic alloy (ALCAL). The purpose of the present investigation was to evaluate the possibility of improving the combustion efficiency of these propellants by admixing the eutectic with the aluminum rather than coating the aluminum. Tests of three propellants similar in every respect except for the metal fuel were conducted in test motors with 4.54 kg (10 lbm) of propellant. The first propellant used aluminum fuel; the second contained aluminum admixed with magnesium-aluminum eutectic; the third used ALCAL. The test results show the the admixed fuel gave better low burning-rate combustion efficiency than the other two. The test results also showed that the ALCAL was deficient in that much, if not all, of the coating material could be found as the fine particles in a bimodal mix of aluminum and eutectic. The combustion efficiency of low burning-rate aluminized propellants can be significantly improved by mixing a small amount of magnesium-aluminum alloy with the aluminum fuel.

  4. The influence of fuel mass load, oxygen supply and burning rate on emission factor and size distribution of carbonaceous particulate matter from indoor corn straw burning

    PubMed Central

    Shen, Guofeng; Xue, Miao; Wei, Siye; Chen, Yuanchen; Wang, Bing; Wang, Rong; Shen, Huizhong; Li, Wei; Zhang, Yanyan; Huang, Ye; Chen, Han; Wei, Wen; Zhao, Qiuyue; Li, Bin; Wu, Haisuo; Tao, Shu

    2014-01-01

    The uncertainty in emission estimation is strongly associated with the variation in emission factor which could be influenced by a variety of factors, like fuel property, stove type, fire management and even methods used in measurements. The impacts of these factors were usually complicated and often interacted with each other. In the present study, controlled burning experiments were conducted to investigate the influence of fuel mass load, air supply and burning rate on the emission of carbonaceous particulate matter (PM) from indoor corn straw burning. Their impacts on PM size distribution were also studied. The results showed that EFs of PM (EFPM), organic carbon (EFOC) and element carbon (EFEC) was independent of the fuel mass load. The differences among them under different burning rates or air supply amounts were also found to be insignificant (p > 0.05) in the tested circumstances. PM from the indoor corn straw burning was dominated by fine PM, and PM with diameter less than 2.1 μm contributed about 86.4±3.9% of the total. The size distribution of PM was also influenced by the burning rate and changed air supply conditions. On average, EFPM, EFOC and EFEC for corn straw burned in a residential cooking stove were 3.84±1.02, 0.846±0.895 and 0.391±0.350 g/kg, respectively. EFPM, EFOC and EFEC were found to be positively correlated with each other, but they were not significantly correlated with EF of co-emitted CO, suggesting a special attention should be paid to the use of CO acting as a surrogate for other incomplete pollutants. PMID:23923424

  5. Use of Crystalline Boron as a Burn Rate Retardant toward the Development of Green-Colored Handheld Signal Formulations

    NASA Astrophysics Data System (ADS)

    Sabatini, Jesse J.; Poret, Jay C.; Broad, Russell N.

    2011-10-01

    The effect of using crystalline boron in green-colored handheld signal formulations is described. Due to its chemically inert nature, crystalline boron served to reduce the burn rates of the formulations. By adjusting crystalline boron percentages in the formulations, the pyrotechnic system could be tuned to meet burn time specifications.

  6. The mechanism of burning rate catalysis in composite HTPB-AP propellant combustion

    SciTech Connect

    Fong, C.W.; Hamshere, B.L.

    1986-07-01

    Evidence has been presented in this study that binder thermal degradation is rate limiting at low pressures (2-7 MPa) in HTPB/AP propellant combustion when catalyzed by copper chromite, Cr(Salen-N-decyl)/sub 3/, and copper phthalocyanine. The condensed phase chemistry governing binder degradation is probably associated with breaking of the urethane linkages. The weak link degradation mechanism would allow formation of liquid or molten binder phases on the propellant surface. At higher pressures (8-14 MPa), the burning rate appears to be increasingly controlled by gas diffusion processes.

  7. Rates of post-fire vegetation recovery and fuel accumulation as a function of burn severity and time-since-burn in four western U.S. ecosystems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Vegetation recovery and fuel accumulation rates following wildfire are useful measures of ecosystem resilience, yet few studies have quantified these variables over 10 years post-fire. Conventional wisdom is that recovery time to pre-fire condition will be slower as a function of burn severity, as i...

  8. On the adequacy of certain experimental observables as measurements of flame burning rate

    SciTech Connect

    Najm, H.N.; Paul, P.H.; Mueller, C.J.; Wyckoff, P.S.

    1998-05-01

    This work presents detailed chemical kinetic computations and experimental measurements of a premixed stoichiometric N{sub 2}-diluted methane-air flame in two-dimensional unsteady vortical flow. The computed mole fraction of HCO is found to have excellent correlation with flame heat release rate over the whole range of unsteady curvature and strain-rate investigated, for the flame under consideration. HCO planar laser induced fluorescence (PLIF) imaging is discussed and demonstrated in a V-flame experiment. On the other hand, the authors find the utility of peak dilatation rate as an indicator of heat release rate to be dependent on the unsteady strain-rate and flame curvature environment, and the associated modification in diffusional thermal fluxes within the flame. The integrated dilatation rate is found to be more robust under unsteady strain-rate, but still questionable in regions of high flame curvature. They also study the utility of a particular formation for CO{sub 2}{sup *} chemiluminescence, OH, and CH PLIF imaging, as well as OH{sup *}, C{sub 2}{sup *}, and CH* chemiluminescence, as measurements of flame burning and heat release rates. Experimental results suggest that CH, OH{sup *}, C{sub 2}{sup *}, and CH{sup *} are not adequate indicators of local extinction; rather they provide signals of subtle shifts of hydrocarbon consumption among different chemical pathways. Moreover, numerical results suggest that both OH mole fraction and an existing CO{sub 2}{sup *} chemiluminescence model do not correlate with burning or heat release rate variations in regions of high unsteady flame curvature. The present numerical investigation uses a single flame/vortex condition and a specific 46-step C{sub (1)} chemical mechanism.

  9. Title efficacy of phosphodiesterase 5 inhibitor on distant burn-induced muscle autophagy, microcirculation, and survival rate.

    PubMed

    Hosokawa, Sachiko; Koseki, Hiroaki; Nagashima, Michio; Maeyama, Yoshihiro; Yomogida, Kentaro; Mehr, Chelsea; Rutledge, Madeleine; Greenfeld, Hannah; Kaneki, Masao; Tompkins, Ronald G; Martyn, J A Jeevendra; Yasuhara, Shingo E

    2013-05-01

    Skeletal muscle wasting is an exacerbating factor in the prognosis of critically ill patients. Using a systemic burn injury model in mice, we have established a role of autophagy in the resulting muscle wasting that is distant from the burn trauma. We provide evidence that burn injury increases the autophagy turnover in the distal skeletal muscle by conventional postmortem tissue analyses and by a novel in vivo microscopic method using an autophagy reporter gene (tandem fluorescent LC3). The effect of tadalafil, a phosphodiesterase 5 inhibitor (PDE5I), on burn-induced skeletal muscle autophagy is documented and extends our published results that PDE5Is attenuates muscle degeneration in a muscular dystrophy model. We also designed a translational experiment to examine the impact of PDE5I on whole body and demonstrated that PDE5I administration lessened muscle atrophy, mitigated microcirculatory disturbance, and improved the survival rate after burn injury. PMID:23512808

  10. Modeling Fluid Resuscitation by Formulating Infusion Rate and Urine Output in Severe Thermal Burn Adult Patients: A Retrospective Cohort Study

    PubMed Central

    Luo, Qizhi; Li, Wei; Zou, Xin; Dang, Yongming; Wu, Jun

    2015-01-01

    Acute burn injuries are among the most devastating forms of trauma and lead to significant morbidity and mortality. Appropriate fluid resuscitation after severe burn, specifically during the first 48 hours following injury, is considered as the single most important therapeutic intervention in burn treatment. Although many formulas have been developed to estimate the required fluid amount in severe burn patients, many lines of evidence showed that patients still receive far more fluid than formulas recommend. Overresuscitation, which is known as “fluid creep,” has emerged as one of the most important problems during the initial period of burn care. If fluid titration can be personalized and automated during the resuscitation phase, more efficient burn care and outcome will be anticipated. In the present study, a dynamic urine output based infusion rate prediction model was developed and validated during the initial 48 hours in severe thermal burn adult patients. The experimental results demonstrated that the developed dynamic fluid resuscitation model might significantly reduce the total fluid volume by accurately predicting hourly urine output and has the potential to aid fluid administration in severe burn patients. PMID:26090415

  11. THE IMPACT OF HELIUM-BURNING REACTION RATES ON MASSIVE STAR EVOLUTION AND NUCLEOSYNTHESIS

    SciTech Connect

    West, Christopher; Heger, Alexander; Austin, Sam M. E-mail: alexander.heger@monash.edu

    2013-05-20

    We study the sensitivity of presupernova evolution and supernova nucleosynthesis yields of massive stars to variations of the helium-burning reaction rates within the range of their uncertainties. The current solar abundances from Lodders are used for the initial stellar composition. We compute a grid of 12 initial stellar masses and 176 models per stellar mass to explore the effects of independently varying the {sup 12}C({alpha}, {gamma}){sup 16}O and 3{alpha} reaction rates, denoted R{sub {alpha},12} and R{sub 3{alpha}}, respectively. The production factors of both the intermediate-mass elements (A = 16-40) and the s-only isotopes along the weak s-process path ({sup 70}Ge, {sup 76}Se, {sup 80}Kr, {sup 82}Kr, {sup 86}Sr, and {sup 87}Sr) were found to be in reasonable agreement with predictions for variations of R{sub 3{alpha}} and R{sub {alpha},12} of {+-}25%; the s-only isotopes, however, tend to favor higher values of R{sub 3{alpha}} than the intermediate-mass isotopes. The experimental uncertainty (one standard deviation) in R{sub 3{alpha}}(R{sub {alpha},12}) is approximately {+-}10%({+-}25%). The results show that a more accurate measurement of one of these rates would decrease the uncertainty in the other as inferred from the present calculations. We also observe sharp changes in production factors and standard deviations for small changes in the reaction rates, due to differences in the convection structure of the star. The compactness parameter was used to assess which models would likely explode as successful supernovae, and hence contribute explosive nucleosynthesis yields. We also provide the approximate remnant masses for each model and the carbon mass fractions at the end of core-helium burning as a key parameter for later evolution stages.

  12. Thermal behaviors, nonisothermal decomposition reaction kinetics, thermal safety and burning rates of BTATz-CMDB propellant.

    PubMed

    Yi, Jian-Hua; Zhao, Feng-Qi; Wang, Bo-Zhou; Liu, Qian; Zhou, Cheng; Hu, Rong-Zu; Ren, Ying-Hui; Xu, Si-Yu; Xu, Kang-Zhen; Ren, Xiao-Ning

    2010-09-15

    The composite modified double base (CMDB) propellants (nos. RB0601 and RB0602) containing 3,6-bis (1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz) without and with the ballistic modifier were prepared and their thermal behaviors, nonisothermal decomposition reaction kinetics, thermal safety and burning rates were investigated. The results show that there are three mass-loss stages in TG curve and two exothermic peaks in DSC curve for the BTATz-CMDB propellant. The first two mass-loss stages occur in succession and the temperature ranges are near apart, and the decomposition peaks of the two stages overlap each other, inducing only one visible exothermic peak appear in DSC curve during 350-550 K. The reaction mechanisms of the main exothermal decomposition processes of RB0601 and RB0602 are all classified as chemical reaction, the mechanism functions are f(alpha)=(1-alpha)(2), and the kinetic equations are dalpha/dt = 10(19.24)(1-alpha)(2)e(-2.32x10(4)/T) and dalpha/dt = 10(20.32)(1-alpha)(2)e(-2.32x10(4)/T). The thermal safety evaluation on the BTATz-CMDB propellants was obtained. With the substitution of 26% RDX by BTATz and with the help of the ballistic modifier in the CMDB propellant formulation, the burning rate can be improved by 89.0% at 8 MPa and 47.1% at 22 MPa, the pressure exponent can be reduced to 0.353 at 14-20 MPa. PMID:20542638

  13. Calibration of reaction rates for the CREST reactive-burn model

    NASA Astrophysics Data System (ADS)

    Handley, Caroline

    2015-06-01

    In recent years, the hydrocode-based CREST reactive-burn model has had success in modelling a range of shock initiation and detonation propagation phenomena in polymer bonded explosives. CREST uses empirical reaction rates that depend on a function of the entropy of the non-reacted explosive, allowing the effects of initial temperature, porosity and double-shock desensitisation to be simulated without any modifications to the model. Until now, the sixteen reaction-rate coefficients have been manually calibrated by trial and error, using hydrocode simulations of a subset of sustained-shock initiation gas-gun experiments and the detonation size-effect curve for the explosive. This paper will describe the initial development of an automatic method for calibrating CREST reaction-rate coefficients, using the well-established Particle Swarm Optimisation (PSO) technique. The automatic method submits multiple hydrocode simulations for each ``particle'' and analyses the results to determine the ``misfit'' to gas-gun and size-effect data. Over ~40 ``generations,'' the PSO code finds a best set of reaction-rate coefficients that minimises the misfit. The method will be demonstrated by developing a new CREST model for EDC32, a conventional high explosive.

  14. Burning Rate of Energetic Materials with Thermal Expansion and Interface Curvature

    NASA Astrophysics Data System (ADS)

    Kuznetsov, Igor; Stewart, D. Scott

    2003-11-01

    We present a study of the flame structure of combusting solid propellants that focuses on the effects that can be attributed to the thermal properties in the solid, as well as on those of the gas/solid interface curvature. A nonlinear heat equation for a burning thermo-elastic solid with temperature-dependent specific heat, thermal expansion and thermal conductivity coefficients is solved with different model assumptions, analytically and numerically. Explicit expressions are derived for the regression rate of the propellant surface as a function of surface temperature. The structure of propellant flame is studied to identify the influence of temperature dependent material properties on the regression rate, surface temperature and flame stand-off distance. Results are displayed for HMX and AP and compared to experimental data and direct numerical simulation. The model is extended to two dimensions to study surface curvature effects in a limit of small curvature and analytical formula for the combusting surface regression rate as function of the curvature are obtained.

  15. An experimental study of the burn rate of TiH/sub 1. 65//KClO/sub 4/ pyrotechnic under confinement

    SciTech Connect

    Hingorani-Norenberg, S.L.R.

    1988-11-01

    Titanium subhydride potassium perchlorate is a pyrotechnic powder used extensively in valve actuators. The linear burn rate behavior of this material is of interest in the design of these actuators. In this study, the variation of the burn rate of TiH/sub 1.65//KClO/sub 4/ with bulk density in a zero-free-volume closed bomb is investigated. The data collected indicate that the burn rate of TiH/sub 1.65//KClO/sub 4/ increases with increasing bulk density to a maximum of approximately 700 m/s near 70% of the theoretical maximum density (TMD). Any additional increase in density appears to decrease the burn rate. This variation of burn rate with bulk density and the results of gas permeability measurements are discussed in terms of conductive and convective burning. 44 refs., 18 figs.

  16. MSFR TRU-burning potential and comparison with an SFR

    SciTech Connect

    Fiorina, C.; Cammi, A.; Franceschini, F.; Krepel, J.

    2013-07-01

    The objective of this work is to evaluate the Molten Salt Fast Reactor (MSFR) potential benefits in terms of transuranics (TRU) burning through a comparative analysis with a sodium-cooled FR. The comparison is based on TRU- and MA-burning rates, as well as on the in-core evolution of radiotoxicity and decay heat. Solubility issues limit the TRU-burning rate to 1/3 that achievable in traditional low-CR FRs (low-Conversion-Ratio Fast Reactors). The softer spectrum also determines notable radiotoxicity and decay heat of the equilibrium actinide inventory. On the other hand, the liquid fuel suggests the possibility of using a Pu-free feed composed only of Th and MA (Minor Actinides), thus maximizing the MA burning rate. This is generally not possible in traditional low-CR FRs due to safety deterioration and decay heat of reprocessed fuel. In addition, the high specific power and the lack of out-of-core cooling times foster a quick transition toward equilibrium, which improves the MSFR capability to burn an initial fissile loading, and makes the MSFR a promising system for a quick (i.e., in a reactor lifetime) transition from the current U-based fuel cycle to a novel closed Th cycle. (authors)

  17. Experimental Methodology for Estimation of Local Heat Fluxes and Burning Rates in Steady Laminar Boundary Layer Diffusion Flames.

    PubMed

    Singh, Ajay V; Gollner, Michael J

    2016-01-01

    Modeling the realistic burning behavior of condensed-phase fuels has remained out of reach, in part because of an inability to resolve the complex interactions occurring at the interface between gas-phase flames and condensed-phase fuels. The current research provides a technique to explore the dynamic relationship between a combustible condensed fuel surface and gas-phase flames in laminar boundary layers. Experiments have previously been conducted in both forced and free convective environments over both solid and liquid fuels. A unique methodology, based on the Reynolds Analogy, was used to estimate local mass burning rates and flame heat fluxes for these laminar boundary layer diffusion flames utilizing local temperature gradients at the fuel surface. Local mass burning rates and convective and radiative heat feedback from the flames were measured in both the pyrolysis and plume regions by using temperature gradients mapped near the wall by a two-axis traverse system. These experiments are time-consuming and can be challenging to design as the condensed fuel surface burns steadily for only a limited period of time following ignition. The temperature profiles near the fuel surface need to be mapped during steady burning of a condensed fuel surface at a very high spatial resolution in order to capture reasonable estimates of local temperature gradients. Careful corrections for radiative heat losses from the thermocouples are also essential for accurate measurements. For these reasons, the whole experimental setup needs to be automated with a computer-controlled traverse mechanism, eliminating most errors due to positioning of a micro-thermocouple. An outline of steps to reproducibly capture near-wall temperature gradients and use them to assess local burning rates and heat fluxes is provided. PMID:27285827

  18. Experimental Methodology for Estimation of Local Heat Fluxes and Burning Rates in Steady Laminar Boundary Layer Diffusion Flames

    PubMed Central

    Singh, Ajay V.; Gollner, Michael J.

    2016-01-01

    Modeling the realistic burning behavior of condensed-phase fuels has remained out of reach, in part because of an inability to resolve the complex interactions occurring at the interface between gas-phase flames and condensed-phase fuels. The current research provides a technique to explore the dynamic relationship between a combustible condensed fuel surface and gas-phase flames in laminar boundary layers. Experiments have previously been conducted in both forced and free convective environments over both solid and liquid fuels. A unique methodology, based on the Reynolds Analogy, was used to estimate local mass burning rates and flame heat fluxes for these laminar boundary layer diffusion flames utilizing local temperature gradients at the fuel surface. Local mass burning rates and convective and radiative heat feedback from the flames were measured in both the pyrolysis and plume regions by using temperature gradients mapped near the wall by a two-axis traverse system. These experiments are time-consuming and can be challenging to design as the condensed fuel surface burns steadily for only a limited period of time following ignition. The temperature profiles near the fuel surface need to be mapped during steady burning of a condensed fuel surface at a very high spatial resolution in order to capture reasonable estimates of local temperature gradients. Careful corrections for radiative heat losses from the thermocouples are also essential for accurate measurements. For these reasons, the whole experimental setup needs to be automated with a computer-controlled traverse mechanism, eliminating most errors due to positioning of a micro-thermocouple. An outline of steps to reproducibly capture near-wall temperature gradients and use them to assess local burning rates and heat fluxes is provided. PMID:27285827

  19. High Recovery Rate of Non-albicans Candida Species Isolated From Burn Patients With Candidemia in Iran

    PubMed Central

    Lotfi, Nazanin; Shokohi, Tahereh; Nouranibaladezaei, Seyed Zahra; Nasrolahi Omran, Ayatollah; Kondori, Nahid

    2015-01-01

    Background: Blood stream infections (BSIs) are major causes of morbidity and mortality in burn patients. Microorganisms responsible for BSI are generally bacteria; however, Candida spp. are the infection agents in as many as 8% of all cases. Burn wound colonization and infections are generally the first steps to systemic infection. Candidemia in burn patients has been associated with high mortality and a prolonged hospital stay. Objectives: Candidemia in burn patients has been defined as a preterminal event, leading to high morbidity and mortality rates among these patients. The aim of this study was to establish the incidence of candidemia in burn patients in Iran. Patients and Methods: We consecutively collected 405 blood samples from 113 burn patients. The yeast isolates were identified to the species level using conventional procedures. In vitro antifungal susceptibility of the Candida isolates to amphotericin B, fluconazole, voriconazole and caspofungin was performed using the Etest. Results: Twenty-seven samples (6.7%) of the blood cultures from 13 patients (12%) were positive for Candida species. Candida parapsilosis (38%) and C. tropicalis (38%) were the most commonly found Candida species, followed by C. albicans (15%) and C. guilliermondii (15%) in the patients. The incidence of candidemia was significantly correlated with increased duration of hospitalization, increased time of stay in the intensive care unit, and higher mortality. The antifungal susceptibility tests demonstrated that amphotericin B and voriconazole had the lowest minimum inhibitory concentrations (MICs) against Candida spp. Conclusions: Non-albicans Candida should be considered as significant pathogens in burned patients with candidemia. PMID:26587207

  20. Evaluation of low-speed diesel exhaust valve burning rate statistics from ten years service experience with 80 cylinders

    SciTech Connect

    Dragsted, J.; Lindhardt, P.

    1984-02-01

    Although judgement of exhaust valve seat burning rates are continuously made for maintenance effort planning with any valved engine installation no information of documentary character on the subject has to the author's knowledge ever entered the published literature. The basic reason is that uniformity of observation conditions are hard to combine with a number of observations sufficient to conclude on probability of exhaust valve seat burning - in low-speed 2-stroke engines due to low number of cylinders per ship - and in 4-stroke medium-speed engines due to uncertainty with regard to actual valve exposure profiles as multi-cylindered ships will normally have variable pitch propellers.

  1. Evaluation of Burning Test Rate Method for Flammable Solids to Increase air-Cargo Safety.

    PubMed

    Lukežič, Marjan; Marinšek, Marjan; Faganeli, Jadran

    2010-03-01

    This paper deals with a standard classification procedure for readily combustible solids and their assignment to the relevant packing groups according to international air-cargo legislation and regulations. The current International Air Transport Association and United Nations Orange Book regulations were used on chemically similar substances: hexamethylenetetramine and Dancook ignition briquettes, which are both assigned into the same Packing Group III. To critically evaluate the degree of hazard both chemicals present, a standard burning test rate as well as thermogravimetry, differential scanning calorimetry and evolved gas analysis measurements were performed. It was shown that relatively small changes in the chemical composition of the material may have essential influence on the package group determination. Taking into account all the facts collected in the experimental work, it was concluded that ignition briquettes will undergo spontaneous combustion if exposed to elevated temperatures and, from this point of view, represent higher risk than hexamethylenetetramine during air transportation. Therefore, ignition briquettes should be classified into Packing Group II. PMID:24061664

  2. Revision of the 15N(p, γ)16O reaction rate and oxygen abundance in H-burning zones

    NASA Astrophysics Data System (ADS)

    Caciolli, A.; Mazzocchi, C.; Capogrosso, V.; Bemmerer, D.; Broggini, C.; Corvisiero, P.; Costantini, H.; Elekes, Z.; Formicola, A.; Fülöp, Zs.; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Gyürky, Gy.; Imbriani, G.; Junker, M.; Lemut, A.; Marta, M.; Menegazzo, R.; Palmerini, S.; Prati, P.; Roca, V.; Rolfs, C.; Rossi Alvarez, C.; Somorjai, E.; Straniero, O.; Strieder, F.; Terrasi, F.; Trautvetter, H. P.; Vomiero, A.

    2011-09-01

    Context. The NO cycle takes place in the deepest layer of a H-burning core or shell, when the temperature exceeds T ≃ 30 × 106 K. The O depletion observed in some globular cluster giant stars, always associated with a Na enhancement, may be due to either a deep mixing during the red giant branch (RGB) phase of the star or to the pollution of the primordial gas by an early population of massive asymptotic giant branch (AGB) stars, whose chemical composition was modified by the hot bottom burning. In both cases, the NO cycle is responsible for the O depletion. Aims: The activation of this cycle depends on the rate of the 15N(p, γ)16O reaction. A precise evaluation of this reaction rate at temperatures as low as experienced in H-burning zones in stellar interiors is mandatory to understand the observed O abundances. Methods: We present a new measurement of the 15N(p, γ)16O reaction performed at LUNA covering for the first time the center of mass energy range 70-370 keV, which corresponds to stellar temperatures between 65 × 106 K and 780 × 106 K. This range includes the 15N(p, γ)16O Gamow-peak energy of explosive H-burning taking place in the external layer of a nova and the one of the hot bottom burning (HBB) nucleosynthesis occurring in massive AGB stars. Results: With the present data, we are also able to confirm the result of the previous R-matrix extrapolation. In particular, in the temperature range of astrophysical interest, the new rate is about a factor of 2 smaller than reported in the widely adopted compilation of reaction rates (NACRE or CF88) and the uncertainty is now reduced down to the 10% level.

  3. Kinetics of actinide complexation reactions

    SciTech Connect

    Nash, K.L.; Sullivan, J.C.

    1997-09-01

    Though the literature records extensive compilations of the thermodynamics of actinide complexation reactions, the kinetics of complex formation and dissociation reactions of actinide ions in aqueous solutions have not been extensively investigated. In light of the central role played by such reactions in actinide process and environmental chemistry, this situation is somewhat surprising. The authors report herein a summary of what is known about actinide complexation kinetics. The systems include actinide ions in the four principal oxidation states (III, IV, V, and VI) and complex formation and dissociation rates with both simple and complex ligands. Most of the work reported was conducted in acidic media, but a few address reactions in neutral and alkaline solutions. Complex formation reactions tend in general to be rapid, accessible only to rapid-scan and equilibrium perturbation techniques. Complex dissociation reactions exhibit a wider range of rates and are generally more accessible using standard analytical methods. Literature results are described and correlated with the known properties of the individual ions.

  4. Actinide metal processing

    DOEpatents

    Sauer, Nancy N.; Watkin, John G.

    1992-01-01

    A process of converting an actinide metal such as thorium, uranium, or plnium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is provided together with a low temperature process of preparing an actinide oxide nitrate such as uranyl nitrte. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.

  5. Actinide metal processing

    SciTech Connect

    Sauer, N.N.; Watkin, J.G.

    1992-03-24

    A process for converting an actinide metal such as thorium, uranium, or plutonium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is described together with a low temperature process for preparing an actinide oxide nitrate such as uranyl nitrate. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.

  6. Actinide metal processing

    SciTech Connect

    Sauer, N.N.; Watkin, J.G.

    1991-04-05

    This invention is comprised of a process of converting an actinide metal such as thorium, uranium, or plutonium to an actinide oxide material by admixing the actinide metal in an aqueous medium with a hypochlorite as an oxidizing agent for sufficient time to form the actinide oxide material and recovering the actinide oxide material is provided together with a low temperature process of preparing an actinide oxide nitrate such as uranyl nitrate. Additionally, a composition of matter comprising the reaction product of uranium metal and sodium hypochlorite is provided, the reaction product being an essentially insoluble uranium oxide material suitable for disposal or long term storage.

  7. Convective Heat Transfer Scaling of Ignition Delay and Burning Rate with Heat Flux and Stretch Rate in the Equivalent Low Stretch Apparatus

    NASA Technical Reports Server (NTRS)

    Olson, Sandra

    2011-01-01

    To better evaluate the buoyant contributions to the convective cooling (or heating) inherent in normal-gravity material flammability test methods, we derive a convective heat transfer correlation that can be used to account for the forced convective stretch effects on the net radiant heat flux for both ignition delay time and burning rate. The Equivalent Low Stretch Apparatus (ELSA) uses an inverted cone heater to minimize buoyant effects while at the same time providing a forced stagnation flow on the sample, which ignites and burns as a ceiling fire. Ignition delay and burning rate data is correlated with incident heat flux and convective heat transfer and compared to results from other test methods and fuel geometries using similarity to determine the equivalent stretch rates and thus convective cooling (or heating) rates for those geometries. With this correlation methodology, buoyant effects inherent in normal gravity material flammability test methods can be estimated, to better apply the test results to low stretch environments relevant to spacecraft material selection.

  8. Quantifying the Influence of Hillslope Form, Aspect and Burn Severity on Post-Wildfire Hillslope Erosion Rates

    NASA Astrophysics Data System (ADS)

    Perreault, L. M.; Yager, E. M.; Aalto, R. E.

    2010-12-01

    Wildfires can profoundly affect hillslope erosion rates by altering the physical and chemical attributes of the soil and denuding stabilizing vegetation. Increased hillslope erosion can raise stream channel sediment loads, which can change the channel morphology and impact aquatic habitat structure and downstream dam sedimentation. Current climate change predictions for the intermountain West forecast more frequent and severe droughts, and correspondingly more severe fire events, increasing the potential for post-fire erosion. Despite the widespread impacts of such erosion events, hillslope erosion processes remain poorly understood. Thus, to better understand these processes, we measure hillslope erosion rates in the mountainous terrain of central Idaho following a large, severe 2007 forest fire. Specifically, we use radionuclide (Lead-210, Cesium-137) inventories to quantify hillslope erosion rates in several watersheds with different burn severity (severe, moderate and unburned), on different aspects (north vs. south facing slopes), and on different hillslope forms (concave vs. convex profiles). In mid-latitude areas of high relief, aspect strongly influences the amount of solar radiation received and thus impacts local moisture conditions, vegetation and soil development, all of which can affect soil erosion rates. Hillslope form may influence the dominant erosion process, with convex profiles characterized by diffusive erosion, and concave profiles potentially enabling more overland flow, rill and gully formation. These variables, in addition to burn severity, are therefore likely to affect erosion rates. Our study quantifies the effect of burn severity, hillslope form, and aspect on the rates and processes of post-fire hillslope erosion. In addition, our study offers insight into the relatively novel use of radionuclide inventories to measure post-wildfire erosion rates. An improved quantitative understanding of hillslope erosion processes would enable us to

  9. Recurrence rates of burn contracture ankle equinus and other foot deformities in children treated with Ilizarov fixation.

    PubMed

    Carmichael, Kelly D; Maxwell, Seth C; Calhoun, Jason H

    2005-01-01

    The purpose of this study was to determine recurrence rates of pediatric foot and ankle burn deformities treated with the Ilizarov method. A total of 19 patients with 29 foot and ankle deformities were studied. The most common deformity treated was equinus (23). Rocker-bottom and cavus foot deformities were each treated three times. The average age of the patient at the time of the burn injury was 3.2 years, and the average age at the time of fixation was 9.4 years. Equinus contractures averaged -34 degrees (34 degrees of plantarflexion) before surgery and +7 degrees (7 degrees of dorsiflexion) after treatment with the Ilizarov fixator. The recurrence rate for all 29 ankles and feet was 69% (20/29). The recurrence rate for equinus contractures was 74% (17/23). The average time to recurrence was 17.3 months. Only short-term follow-up was available on four of the six feet and ankles that did not recur. Deformity correction in burned feet and ankles is difficult to obtain by any means. The authors recommend using the Ilizarov method to obtain correction of moderate to severe foot and ankle deformities in pediatric burn patients, but the correction obtained is not stable and deformity will likely recur. Parents and patients should anticipate adjunctive nonoperative and operative procedures to keep their feet plantigrade as they grow. In young children, the possibility of having additional surgeries, including repeat Ilizarov procedures, should be discussed. Even older children should expect additional surgeries to prevent recurrent deformities. PMID:15958908

  10. Titanium subhydride potassium perchlorate (TiH1.65/KClO4) burn rates from hybrid closed bomb-strand burner experiments.

    SciTech Connect

    Cooper, Marcia A.; Oliver, Michael S.

    2012-08-01

    A hybrid closed bomb-strand burner is used to measure the burning behavior of the titanium subhydride potassium perchlorate pyrotechnic with an equivalent hydrogen concentration of 1.65. This experimental facility allows for simultaneous measurement of the closed bomb pressure rise and pyrotechnic burn rate as detected by electrical break wires over a range of pressures. Strands were formed by pressing the pyrotechnic powders to bulk densities between 60% and 90% theoretical maximum density. The burn rate dependance on initial density and vessel pressure are measured. At all initial strand densities, the burn is observed to transition from conductive to convective burning within the strand. The measured vessel pressure history is further analyzed following the closed bomb analysis methods developed for solid propellants.

  11. Actinide sulfite tetrahydrate and actinide oxysulfite tetrahydrate

    SciTech Connect

    Baugh, D.; Watt, G.

    1980-07-08

    A compound is prepared that comprises an actinide sulfite tetrahydrate selected from the group consisting of uranium (IV) sulfite tetrahydrate and plutonium (IV) sulfite tetrahydrate. A compound is also prepared that comprises an actinide oxysulfite tetrahydrate selected from the group consisting of uranium (IV) oxysulfite tetrahydrate and plutonium (IV) oxysulfite tetrahydrate

  12. Joint Actinide Shock Physics Experimental Research - JASPER

    ScienceCinema

    None

    2015-01-09

    Commonly known as JASPER the Joint Actinide Shock Physics Experimental Research facility is a two stage light gas gun used to study the behavior of plutonium and other materials under high pressures, temperatures, and strain rates.

  13. Joint Actinide Shock Physics Experimental Research - JASPER

    SciTech Connect

    2014-10-31

    Commonly known as JASPER the Joint Actinide Shock Physics Experimental Research facility is a two stage light gas gun used to study the behavior of plutonium and other materials under high pressures, temperatures, and strain rates.

  14. Burns in diabetic patients

    PubMed Central

    Maghsoudi, Hemmat; Aghamohammadzadeh, Naser; Khalili, Nasim

    2008-01-01

    CONTEXT AND AIMS: Diabetic burn patients comprise a significant population in burn centers. The purpose of this study was to determine the demographic characteristics of diabetic burn patients. MATERIALS AND METHODS: Prospective data were collected on 94 diabetic burn patients between March 20, 2000 and March 20, 2006. Of 3062 burns patients, 94 (3.1%) had diabetes; these patients were compared with 2968 nondiabetic patients with burns. Statistical analysis was performed using the statistical analysis software SPSS 10.05. Differences between the two groups were evaluated using Student's t-test and the chi square test. P < 0.05 was considered as significant. RESULTS: The major mechanism of injury for the diabetic patients was scalding and flame burns, as was also the case in the nondiabetic burn patients. The diabetic burn patients were significantly older, with a lower percentage of total burn surface area (TBSA) than the nondiabetic burn population. There was significant difference between the diabetic and nondiabetic patients in terms of frequency of infection. No difference in mortality rate between diabetic and nondiabetic burn patients was observed. The most common organism in diabetic and nondiabetic burn patients was methicillin-resistant staphylococcus. Increasing %TBSA burn and the presence of inhalation injury are significantly associated with increased mortality following burn injury. CONCLUSIONS: Diabetics have a higher propensity for infection. Education for diabetic patients must include caution about potential burn mishaps and the complications that may ensue from burns. PMID:19902035

  15. Investigation of Biomass Combustion Rate of Fire Radiative Energy Using Multiple-Satellite-observed Active Fires and Landsat TM Burn Severities across the Continental United States

    NASA Astrophysics Data System (ADS)

    Li, F.; Zhang, X.; Kondragunta, S.

    2015-12-01

    Biomass burning is a major source of atmospheric aerosol and greenhouse gases that substantially influence climate and regional air quality. However, the accuracy of biomass burning emissions estimated using traditional method is limited by large uncertainties in burned area and fuel loading. Alternatively, fire radiative energy (FRE) has recently been demonstrated to be linearly related to biomass combustion, which potentially improves the estimation of biomass burning emissions. The FRE-based combustion rate is 0.368-0.453 kg/MJ according to field controlled experiments while it varies from 1.37-4.5 kg/MJ derived from satellite-based bottom-up and top-down aerosol optical thickness estimates. Here we investigate the FRE combustion rate in over 1000 burn scars from 2011 to 2012 across the Continental United States (CONUS). Specifically, FRE was calculated by combining the high spatial observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the high temporal observations from the Geostationary Operational Environmental Satellite (GOES). Biomass consumption in burn scars was modeled using Landsat TM 30m burn severities, 30m fuel loading from Fuel Characteristic Classification System, and combustion completeness compiled from recent literatures. The combustion rate was then investigated by correlating FRE to biomass consumption across CONUS and Bailey's ecoregions. Our results show that the combustion rate can be extracted from the linear relationship between biomass consumption and FRE. The combustion rate is 0.415±10% kg/MJ across CONUS, which is similar to the rate derived from field experiments. However, it varies from 0.18-1.9 kg/MJ among ecoregions. This implies that a single combustion rate could produce large uncertainty in the estimation of biomass consumption at large scales. We suggest that ecoregion specified combustion rates should help to improve the accuracy of quantifying biomass burning emissions regionally and globally.

  16. High-nitrogen-metal complexes as burning-rate modifiers for the aluminum-water propellant system

    SciTech Connect

    Tappan, Bryce C; Mason, Benjamin A

    2009-01-01

    The reactions of electropositive metals, such as aluminum, with water have long been utilized in explosive and propellant formulations, but until recently this has mostly been limited to the water formed as a product gas from the decomposition of another energetic system . Recently, however, with the increased availability of nano-particulate materials, the direct reaction of nano-aluminum (nAl) with water as an oxidizer has been investigated as a propellant system due to high reaction temperatures and the production of hydrogen as the primary gaseous species. This system could be useful for intra-planetary travel where non-terrestrial water is harvested for the oxidizer. Here we present the study of nAl, mixed at a stoichiometric ratio with water ({Phi} = 1) with the highly water soluble metal complexes of bis(tetrazolato)amine (BTA) added at 5, 15,30 and 50 wt% in the case of FeBTA and 5 and 15 wt% in the case of NiBTA and CoBTA. The basic structure of the BTA complexes is shown below where M = Fe, Ni or Co, and x = 3 for Fe and Co and x = 2 for Ni. The particle size of nAl studied was primarily 38 nm with various studies with the particle size of 80 nm. The FeBT A at a loading of 15 wt% gave the highest burning rate enhancement (4.6x at {approx}6.8 MPa), while retaining a low pressure exponent (0.21 compared to 0.24 for nA/H{sub 2}O). At 15 wt% the Ni and Co increased the burning rate, but also increased the pressure exponents. The burning rate of the FeBTA modified material with 80 nm Al decreased as the weight percent of FeBTA was increased, which also tracked decrease in the calculated specific impulse of the mixtures.

  17. Actinide-ion sensor

    DOEpatents

    Li, Shelly X; Jue, Jan-fong; Herbst, Ronald Scott; Herrmann, Steven Douglas

    2015-01-13

    An apparatus for the real-time, in-situ monitoring of actinide-ion concentrations. A working electrolyte is positioned within the interior of a container. The working electrolyte is separated from a reference electrolyte by a separator. A working electrode is at least partially in contact with the working electrolyte. A reference electrode is at least partially in contact with the reference electrolyte. A voltmeter is electrically connected to the working electrode and the reference electrode. The working electrolyte comprises an actinide-ion of interest. The separator is ionically conductive to the actinide-ion of interest. The separator comprises an actinide, Zr, and Nb. Preferably, the actinide of the separator is Am or Np, more preferably Pu. In one embodiment, the actinide of the separator is the actinide of interest. In another embodiment, the separator further comprises P and O.

  18. Modeling rates of life form cover change in burned and unburned alpine heathland subject to experimental warming.

    PubMed

    Camac, James S; Williams, Richard J; Wahren, Carl-Henrik; Jarrad, Frith; Hoffmann, Ary A; Vesk, Peter A

    2015-06-01

    Elevated global temperatures are expected to alter vegetation dynamics by interacting with physiological processes, biotic relationships and disturbance regimes. However, few studies have explicitly modeled the effects of these interactions on rates of vegetation change, despite such information being critical to forecasting temporal patterns in vegetation dynamics. In this study, we build and parameterize rate-change models for three dominant alpine life forms using data from a 7-year warming experiment. These models allowed us to examine how the interactions between experimental warming, the abundance of bare ground (a measure of past disturbance) and neighboring life forms (a measure of life form interaction) affect rates of cover change in alpine shrubs, graminoids and forbs. We show that experimental warming altered rates of life form cover change by reducing the negative effects of neighboring life forms and positive effects of bare ground. Furthermore, we show that our models can predict the observed direction and rate of life form cover change at burned and unburned long-term monitoring sites. Model simulations revealed that warming in unburned vegetation is expected to result in increased forb and shrub cover and decreased graminoid cover. In contrast, in burned vegetation, warming is predicted to slow post-fire regeneration in both graminoids and forbs and facilitate rapid expansion in shrub cover. These findings illustrate the applicability of modeling rates of vegetation change using experimental data. Our results also highlight the need to account for both disturbance and the abundance of other life forms when examining and forecasting vegetation dynamics under climatic change. PMID:25694042

  19. Fractal approach to the evaluation of burning rates in the vicinity of the piston in a spark-ignition engine

    SciTech Connect

    Foucher, F.; Mounaim-Rousselle, C.

    2005-11-01

    The burning rate in the vicinity of a piston is estimated from a fractal analysis. The fractal parameters are determined from laser sheet tomography flame images for methane-air mixtures with three equivalence ratios (1, 0.9, 0.8) in a transparent spark-ignition engine. Two imaging configurations were used: five horizontal planes placed at different distances from the piston (0, 1, 2, 3, and 5 mm) and a vertical one passed through the center of the combustion chamber. The methodology proposed by Foucher et al. [F. Foucher, S. Burnel, C. Mounaim-Rousselle, Proc. Combust. Inst. 29 (2002) 751-757] allows the effect of cyclic variations to be avoided. The fractal formulation is modified to take into account the flame-piston distance and flame quenching. Far from the piston, evolution of the fractal dimension versus q{sup '}/S{sub L}{sup 0} is found to be in good agreement with literature results. Near the piston, the fractal dimension evolves significantly when the distance is about twice the integral length scale and tends toward 2, the fractal dimension of a laminar flame front. The quenching ratio parameter Q{sub R} is introduced to consider the quenching of the flame by the piston. Finally, the burning rate is determined as a function of the distance between the wall and the mean flame contour and compared to a flame density approach, and similar results are found.

  20. Actinide extraction methods

    DOEpatents

    Peterman, Dean R [Idaho Falls, ID; Klaehn, John R [Idaho Falls, ID; Harrup, Mason K [Idaho Falls, ID; Tillotson, Richard D [Moore, ID; Law, Jack D [Pocatello, ID

    2010-09-21

    Methods of separating actinides from lanthanides are disclosed. A regio-specific/stereo-specific dithiophosphinic acid having organic moieties is provided in an organic solvent that is then contacted with an acidic medium containing an actinide and a lanthanide. The method can extend to separating actinides from one another. Actinides are extracted as a complex with the dithiophosphinic acid. Separation compositions include an aqueous phase, an organic phase, dithiophosphinic acid, and at least one actinide. The compositions may include additional actinides and/or lanthanides. A method of producing a dithiophosphinic acid comprising at least two organic moieties selected from aromatics and alkyls, each moiety having at least one functional group is also disclosed. A source of sulfur is reacted with a halophosphine. An ammonium salt of the dithiophosphinic acid product is precipitated out of the reaction mixture. The precipitated salt is dissolved in ether. The ether is removed to yield the dithiophosphinic acid.

  1. Physics studies of higher actinide consumption in an LMR

    SciTech Connect

    Hill, R.N.; Wade, D.C.; Fujita, E.K.; Khalil, H.S.

    1990-01-01

    The core physics aspects of the transuranic burning potential of the Integral Fast Reactor (IFR) are assessed. The actinide behavior in fissile self-sufficient IFR closed cycles of 1200 MWt size is characterized, and the transuranic isotopics and risk potential of the working inventory are compared to those from a once-through LWR. The core neutronic performance effects of rare-earth impurities present in the recycled fuel are addressed. Fuel cycle strategies for burning transuranics from an external source are discussed, and specialized actinide burner designs are described. 4 refs., 4 figs., 3 tabs.

  2. Research in actinide chemistry

    SciTech Connect

    Choppin, G.R.

    1993-01-01

    This research studies the behavior of the actinide elements in aqueous solution. The high radioactivity of the transuranium actinides limits the concentrations which can be studied and, consequently, limits the experimental techniques. However, oxidation state analogs (trivalent lanthanides, tetravalent thorium, and hexavalent uranium) do not suffer from these limitations. Behavior of actinides in the environment are a major USDOE concern, whether in connection with long-term releases from a repository, releases from stored defense wastes or accidental releases in reprocessing, etc. Principal goal of our research was expand the thermodynamic data base on complexation of actinides by natural ligands (e.g., OH[sup [minus

  3. Actinide recovery process

    DOEpatents

    Muscatello, Anthony C.; Navratil, James D.; Saba, Mark T.

    1987-07-28

    Process for the removal of plutonium polymer and ionic actinides from aqueous solutions by absorption onto a solid extractant loaded on a solid inert support such as polystyrenedivinylbenzene. The absorbed actinides can then be recovered by incineration, by stripping with organic solvents, or by acid digestion. Preferred solid extractants are trioctylphosphine oxide and octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide and the like.

  4. Thermodynamic Properties of Actinides and Actinide Compounds

    NASA Astrophysics Data System (ADS)

    Konings, Rudy J. M.; Morss, Lester R.; Fuger, Jean

    The necessity of obtaining accurate thermodynamic quantities for the actinide elements and their compounds was recognized at the outset of the Manhattan Project, when a dedicated team of scientists and engineers initiated the program to exploit nuclear energy for military purposes. Since the end of World War II, both fundamental and applied objectives have motivated a great deal of further study of actinide thermodynamics. This chapter brings together many research papers and critical reviews on this subject. It also seeks to assess, to systematize, and to predict important properties of the actinide elements, ions, and compounds, especially for species in which there is significant interest and for which there is an experimental basis for the prediction.

  5. Burning Issue: Handling Household Burns

    MedlinePlus

    ... hot objects or liquid, fire, friction, the sun, electricity, or certain chemicals. Each year, about a half- ... infant or elderly. the burn was caused by electricity, which can lead to “invisible” burns. Burns Burns ...

  6. Enclosure fire hazard analysis using relative energy release criteria. [burning rate and combustion control

    NASA Technical Reports Server (NTRS)

    Coulbert, C. D.

    1978-01-01

    A method for predicting the probable course of fire development in an enclosure is presented. This fire modeling approach uses a graphic plot of five fire development constraints, the relative energy release criteria (RERC), to bound the heat release rates in an enclosure as a function of time. The five RERC are flame spread rate, fuel surface area, ventilation, enclosure volume, and total fuel load. They may be calculated versus time based on the specified or empirical conditions describing the specific enclosure, the fuel type and load, and the ventilation. The calculation of these five criteria, using the common basis of energy release rates versus time, provides a unifying framework for the utilization of available experimental data from all phases of fire development. The plot of these criteria reveals the probable fire development envelope and indicates which fire constraint will be controlling during a criteria time period. Examples of RERC application to fire characterization and control and to hazard analysis are presented along with recommendations for the further development of the concept.

  7. Heat and mass transfer analysis for paraffin/nitrous oxide burning rate in hybrid propulsion

    NASA Astrophysics Data System (ADS)

    Ben-Basat (Sisi), Shani; Gany, Alon

    2016-03-01

    This research presents a physical-mathematical model for the combustion of liquefying fuels in hybrid combustors, accounting for blowing effect on the heat transfer. A particular attention is given to a paraffin/nitrous oxide hybrid system. The use of a paraffin fuel in hybrid propulsion has been considered because of its much higher regression rate enabling significantly higher thrust compared to that of common polymeric fuels. The model predicts the overall regression rate (melting rate) of the fuel and the different mechanisms involved, including evaporation, entrainment of droplets of molten material, and mass loss due to melt flow on the condensed fuel surface. Prediction of the thickness and velocity of the liquid (melt) layer formed at the surface during combustion was done as well. Applying the model for an oxidizer mass flux of 45 kg/(s m2) as an example representing experimental range, it was found that 21% of the molten liquid undergoes evaporation, 30% enters the gas flow by the entrainment mechanism, and 49% reaches the end of the combustion chamber as a flowing liquid layer. When increasing the oxidizer mass flux in the port, the effect of entrainment increases while that of the flowing liquid layer along the surface shows a relatively lower contribution. Yet, the latter is predicted to have a significant contribution to the overall mass loss. In practical applications it may cause reduced combustion efficiency and should be taken into account in the motor design, e.g., by reinforcing the paraffin fuel with different additives. The model predictions have been compared to experimental results revealing good agreement.

  8. Method for preparing actinide nitrides

    DOEpatents

    Bryan, G.H.; Cleveland, J.M.; Heiple, C.R.

    1975-12-01

    Actinide nitrides, and particularly plutonium and uranium nitrides, are prepared by reacting an ammonia solution of an actinide compound with an ammonia solution of a reactant or reductant metal, to form finely divided actinide nitride precipitate which may then be appropriately separated from the solution. The actinide nitride precipitate is particularly suitable for forming nuclear fuels.

  9. Cross sections for actinide burner reactors

    SciTech Connect

    Difilippo, F.C.

    1991-01-01

    Recent studies have shown the feasibility of burning higher actinides (i.e., transuranium (TRU) elements excluding plutonium) in ad hoc designed reactors (Actinide Burner Reactors: ABR) which, because of their hard neutron spectra, enhance the fission of TRU. The transmutation of long-lived radionuclides into stable or short-lived isotopes reduces considerably the burden of handling high-level waste from either LWR or Fast Breeder Reactors (FBR) fuels. Because of the large concentrations of higher actinides in these novel reactor designs the Doppler effect due to TRU materials is the most important temperature coefficient from the point of view of reactor safety. Here we report calculations of energy group-averaged capture and fission cross sections as function of temperature and dilution for higher actinides in the resolved and unresolved resonance regions. The calculations were done with the codes SAMMY in the resolved region and URR in the unresolved regions and compared with an independent calculation. 4 refs., 2 figs., 2 tabs.

  10. Plutonium and ''minor'' actinides: safe sequestration [rapid communication

    NASA Astrophysics Data System (ADS)

    Ewing, Rodney C.

    2005-01-01

    The actinides exhibit a number of unique chemical and nuclear properties. Of particular interest are the man-made actinides (Np, Pu, Cm and Am) that are produced in significant enough quantities that they are a source of energy in fission reactions, a source of fissile material for nuclear weapons and of environmental concern because of their long half-lives and radiotoxicity. During the past 50 yr, over 1400 mT of Pu and substantial quantities of the "minor" actinides, such as Np, Am and Cm, have been generated in nuclear reactors. There are two basic strategies for the disposition of these elements: (1) to "burn" or transmute the actinides using nuclear reactors or accelerators; (2) to "sequester" the actinides in chemically durable, radiation-resistant materials that are suitable for geologic disposal. There has been substantial interest in the use of isometric pyrochlore, A 2B 2O 7 (A=rare earths; B=Ti, Zr, Sn and Hf), for the immobilization of actinides, particularly plutonium. Systematic studies of rare-earth pyrochlores have led to the discovery that certain compositions (B=Zr, Hf) are stable to very high doses of α-decay event damage. The radiation stability of these compositions is closely related to the structural distortions that occur for specific pyrochlore compositions and the electronic structure of the B-site cation. This understanding provides the basis for designing materials for the safe, long-term immobilization and sequestration of actinides.

  11. Light elements burning reaction rates at stellar temperatures as deduced by the Trojan Horse measurements

    SciTech Connect

    Lamia, L.; Spitaleri, C.; La Cognata, M.; Palmerini, S.; Sergi, M. L.; Puglia, S. M. R.

    2015-02-24

    Experimental nuclear astrophysics aims at determining the reaction rates for astrophysically relevant reactions at their Gamow energies. For charged-particle induced reactions, the access to these energies is usually hindered, in direct measurements, by the presence of the Coulomb barrier between the interacting particles or by electron screening effects, which make hard the determination of the bare-nucleus S(E)-factor of interest for astrophysical codes. The use of the Trojan Horse Method (THM) appears as one of the most suitable tools for investigating nuclear processes of interest for astrophysics. Here, in view of the recent TH measurements, the main destruction channels for deuterium ({sup 2}H), for the two lithium {sup 6,7}Li isotopes, for the {sup 9}Be and the one for the two boron {sup 10,11}B isotopes will be discussed.

  12. Light elements burning reaction rates at stellar temperatures as deduced by the Trojan Horse measurements

    NASA Astrophysics Data System (ADS)

    Lamia, L.; Spitaleri, C.; La Cognata, M.; Palmerini, S.; Puglia, S. M. R.; Sergi, M. L.

    2015-02-01

    Experimental nuclear astrophysics aims at determining the reaction rates for astrophysically relevant reactions at their Gamow energies. For charged-particle induced reactions, the access to these energies is usually hindered, in direct measurements, by the presence of the Coulomb barrier between the interacting particles or by electron screening effects, which make hard the determination of the bare-nucleus S(E)-factor of interest for astrophysical codes. The use of the Trojan Horse Method (THM) appears as one of the most suitable tools for investigating nuclear processes of interest for astrophysics. Here, in view of the recent TH measurements, the main destruction channels for deuterium (2H ), for the two lithium 6,7Li isotopes, for the 9Be and the one for the two boron 10,11B isotopes will be discussed.

  13. Studies on the properties of hard-spectrum, actinide fissioning reactors. Final report

    SciTech Connect

    Nelson, J.B.; Prichard, A.W.; Schofield, P.E.; Robinson, A.H.; Spinrad, B.I.

    1980-01-01

    It is technically feasible to construct an operable (e.g., safe and stable) reactor to burn waste actinides rapidly. The heart of the concept is a driver core of EBR-II type, with a central radial target zone in which fuel elements, made entirely of waste actinides are exposed. This target fuel undergoes fission, as a result of which actinides are rapidly destroyed. Although the same result could be achieved in more conventionally designed LWR or LMFBR systems, the fast spectrum reactor does a much more efficient job, by virtue of the fact that in both LWR and LMFBR reactors, actinide fission is preceded by several captures before a fissile nuclide is formed. In the fast spectrum reactor that is called ABR (actinide burning reactor), these neutron captures are short-circuited.

  14. QUALITY ASSURANCE PROCEDURES: METHOD 28A MEASUREMENT OF AIR TO FUEL RATIO AND MINIMUM BURN RATE FOR WOOD-FIRED APPLIANCES

    EPA Science Inventory

    Quality assurance procedures are contained in this comprehensive document intended to be used as an aid for wood heater manufacturers and testing laboratories in performing measurement of air-to-fuel ratio and minimum burn rate determinations according to EPA protocol, Method 28A...

  15. Detailed calculations of minor actinide transmutation in a fast reactor

    SciTech Connect

    Takeda, Toshikazu

    2015-12-31

    The transmutation of minor actinides in a fast reactor is investigated by a new method to investigate the transmutation behavior of individual minor actinides. It is found that Np-237 and Am-241 mainly contributes to the transmutation rate though the transmutation behaviors are very different.

  16. Detailed calculations of minor actinide transmutation in a fast reactor

    NASA Astrophysics Data System (ADS)

    Takeda, Toshikazu

    2015-12-01

    The transmutation of minor actinides in a fast reactor is investigated by a new method to investigate the transmutation behavior of individual minor actinides. It is found that Np-237 and Am-241 mainly contributes to the transmutation rate though the transmutation behaviors are very different.

  17. Research in actinide chemistry

    SciTech Connect

    Not Available

    1991-01-01

    This report contains research results on studies of inorganic and organic complexes of actinide and lanthanide elements. Special attention is given to complexes of humic acids and to spectroscopic studies.

  18. Thermochemistry of the actinides

    SciTech Connect

    Kleinschmidt, P.D.

    1993-10-01

    The measurement of equilibria by Knudsen effusion techniques and the enthalpy of formation of the actinide atoms is briefly discussed. Thermochemical data on the sublimation of the actinide fluorides is used to calculate the enthalpies of formation and entropies of the gaseous species. Estimates are made for enthalpies and entropies of the tetrafluorides and trifluorides for those systems where data is not available. The pressure of important species in the tetrafluoride sublimation processes is calculated based on this thermochemical data.

  19. PRODUCTION OF ACTINIDE METAL

    DOEpatents

    Knighton, J.B.

    1963-11-01

    A process of reducing actinide oxide to the metal with magnesium-zinc alloy in a flux of 5 mole% of magnesium fluoride and 95 mole% of magnesium chloride plus lithium, sodium, potassium, calcium, strontium, or barium chloride is presented. The flux contains at least 14 mole% of magnesium cation at 600-- 900 deg C in air. The formed magnesium-zinc-actinide alloy is separated from the magnesium-oxide-containing flux. (AEC)

  20. Actinide recovery process

    DOEpatents

    Muscatello, A.C.; Navratil, J.D.; Saba, M.T.

    1985-06-13

    Process for the removal of plutonium polymer and ionic actinides from aqueous solutions by absorption onto a solid extractant loaded on a solid inert support such as polystyrene-divinylbenzene. The absorbed actinides can then be recovered by incineration, by stripping with organic solvents, or by acid digestion. Preferred solid extractants are trioctylphosphine oxide and octylphenyl-N,N-diisobutylcarbamoylmethylphosphine oxide and the like. 2 tabs.

  1. Biomass Burning

    Atmospheric Science Data Center

    2015-07-27

    Projects:  Biomass Burning Definition/Description:  Biomass Burning: This data set represents the geographical and temporal distribution of total amount of biomass burned. These data may be used in general circulation models (GCMs) and ...

  2. Beta-blockade lowers peripheral lipolysis in burn patients receiving growth hormone. Rate of hepatic very low density lipoprotein triglyceride secretion remains unchanged.

    PubMed Central

    Aarsland, A; Chinkes, D; Wolfe, R R; Barrow, R E; Nelson, S O; Pierre, E; Herndon, D N

    1996-01-01

    OBJECTIVE: The purpose of this study was to determine the effect of propranolol on peripheral lipolysis in massively burned children during treatment with recombinant human growth hormone (rhGH), and to ascertain whether decreased free fatty acid availability for re-esterification would alter the hepatic rate of secretion of triglycerides (TGs) bound to very low density lipoproteins (VLDLs). BACKGROUND: Fatty liver occurs in severely burned patients, often resulting in a twofold increase in liver size. This could be the result of an imbalance between increased provision of free fatty acids from peripheral lipolysis, coupled with no increase in fat oxidation, and insufficient rate of secretion of TGs from the liver. METHODS: In a cross-over study, six burned children were treated with either rhGH or rhGH plus propranolol. On the sixth day of treatment, isotopic tracer infusions were conducted to determine the rate of release of free fatty acid (Ra FFA) from peripheral tissue and the rate of secretion of VLDL-bound TGs by the liver. RESULTS: Exogenous rhGH increased Ra FFA in children with large third-degree burns. Propranolol decreased Ra FFA, but the rate of secretion of fatty acids in the form of VLDL-TG from the liver was maintained. Plasma FFA, as opposed to fatty acids newly synthesized in the liver, were the primary precursors for hepatic triglyceride synthesis. CONCLUSIONS: The administration of propranolol to burned children receiving rhGH is safe, has salutary cardiovascular effects, decreases the release of FFA from adipose tissue and increases the efficiency of the liver in secreting fatty acids as VLDL TGs. PMID:8645051

  3. Homogeneous ice nucleation from aqueous inorganic/organic particles representative of biomass burning: water activity, freezing temperatures, nucleation rates.

    PubMed

    Knopf, Daniel A; Rigg, Yannick J

    2011-02-10

    Homogeneous ice nucleation plays an important role in the formation of cirrus clouds with subsequent effects on the global radiative budget. Here we report on homogeneous ice nucleation temperatures and corresponding nucleation rate coefficients of aqueous droplets serving as surrogates of biomass burning aerosol. Micrometer-sized (NH(4))(2)SO(4)/levoglucosan droplets with mass ratios of 10:1, 1:1, 1:5, and 1:10 and aqueous multicomponent organic droplets with and without (NH(4))(2)SO(4) under typical tropospheric temperatures and relative humidities are investigated experimentally using a droplet conditioning and ice nucleation apparatus coupled to an optical microscope with image analysis. Homogeneous freezing was determined as a function of temperature and water activity, a(w), which was set at droplet preparation conditions. The ice nucleation data indicate that minor addition of (NH(4))(2)SO(4) to the aqueous organic droplets renders the temperature dependency of water activity negligible in contrast to the case of aqueous organic solution droplets. The mean homogeneous ice nucleation rate coefficient derived from 8 different aqueous droplet compositions with average diameters of ∼60 μm for temperatures as low as 195 K and a(w) of 0.82-1 is 2.18 × 10(6) cm(-3) s(-1). The experimentally derived freezing temperatures and homogeneous ice nucleation rate coefficients are in agreement with predictions of the water activity-based homogeneous ice nucleation theory when taking predictive uncertainties into account. However, the presented ice nucleation data indicate that the water activity-based homogeneous ice nucleation theory overpredicts the freezing temperatures by up to 3 K and corresponding ice nucleation rate coefficients by up to ∼2 orders of magnitude. A shift of 0.01 in a(w), which is well within the uncertainty of typical field and laboratory relative humidity measurements, brings experimental and predicted freezing temperatures and homogeneous ice

  4. Nonaqueous actinide hydride dissolution and production of actinide $beta$- diketonates

    DOEpatents

    Crisler, L.R.

    1975-11-11

    Actinide beta-diketonate complex molecular compounds are produced by reacting a beta-diketone compound with a hydride of the actinide material in a mixture of carbon tetrachloride and methanol. (auth)

  5. Impacts of Biomass Burning on the Land Use / Land Cover Dynamics in Northern Sub-Saharan Africa and Associated Alteration of Local Emission Rates

    NASA Astrophysics Data System (ADS)

    Ellison, L.; Ichoku, C. M.

    2015-12-01

    Biomass burning is a major anthropogenic event in Northern Sub-Saharan Africa (NSSA), which contributes 15-20% of the global annual total of particulate matter emissions from fires. This burning is mostly for agricultural, grazing or hunting purposes, and thus has a great potential for driving changes in the land use and land cover distribution in that region. The Moderate Resolution Imaging Spectroradiometer (MODIS) aboard both the Terra and Aqua spacecraft have two complimentary data products to support this research: the MOD14/MYD14 active fire products measuring fire locations and strengths, and the MCD12 land cover type product, which includes the International Geosphere Biosphere Programme (IGBP) land-cover classification system used in this analysis. More specifically, the MCD12Q1 tiled data product at 500 m was used to match against the 1 km active fire product resolution for the current analysis. Paired data between instantaneous fire measurements and the underlying land cover types for the particular year over the study period of 2003-2013 reveals a dominant burning of savanna, followed by cropland land cover type throughout the region. There are a few indications of the interchange between savanna and cropland due to burning practices. Even though the fire activity in the whole NSSA region is decreasing at a rate of 1.4%/yr during the study period, some land cover types in parts of NSSA show an increase, including local increases in sensitive land cover types such as forest and wetland, which could have serious ecological implications. The changes in the overall redistribution of biomass burning amongst the different land cover types in NSSA dictate that there is also a redistribution of biomass burning emissions. The extent of these changes will also be covered in this presentation.

  6. Elevated concentrations of actinides in mono lake.

    PubMed

    Anderson, R F; Bacon, M P; Brewer, P G

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply. PMID:17735740

  7. Elevated concentrations of actinides in Mono Lake

    SciTech Connect

    Anderson, R.F.; Bacon, M.P.; Brewer, P.G.

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply.

  8. Regional Changes in Charcoal-Burning Suicide Rates in East/Southeast Asia from 1995 to 2011: A Time Trend Analysis

    PubMed Central

    Chang, Shu-Sen; Chen, Ying-Yeh; Yip, Paul S. F.; Lee, Won Jin; Hagihara, Akihito; Gunnell, David

    2014-01-01

    Background Suicides by carbon monoxide poisoning resulting from burning barbecue charcoal reached epidemic levels in Hong Kong and Taiwan within 5 y of the first reported cases in the early 2000s. The objectives of this analysis were to investigate (i) time trends and regional patterns of charcoal-burning suicide throughout East/Southeast Asia during the time period 1995–2011 and (ii) whether any rises in use of this method were associated with increases in overall suicide rates. Sex- and age-specific trends over time were also examined to identify the demographic groups showing the greatest increases in charcoal-burning suicide rates across different countries. Methods and Findings We used data on suicides by gases other than domestic gas for Hong Kong, Japan, the Republic of Korea, Taiwan, and Singapore in the years 1995/1996–2011. Similar data for Malaysia, the Philippines, and Thailand were also extracted but were incomplete. Graphical and joinpoint regression analyses were used to examine time trends in suicide, and negative binomial regression analysis to study sex- and age-specific patterns. In 1995/1996, charcoal-burning suicides accounted for <1% of all suicides in all study countries, except in Japan (5%), but they increased to account for 13%, 24%, 10%, 7%, and 5% of all suicides in Hong Kong, Taiwan, Japan, the Republic of Korea, and Singapore, respectively, in 2011. Rises were first seen in Hong Kong after 1998 (95% CI 1997–1999), followed by Singapore in 1999 (95% CI 1998–2001), Taiwan in 2000 (95% CI 1999–2001), Japan in 2002 (95% CI 1999–2003), and the Republic of Korea in 2007 (95% CI 2006–2008). No marked increases were seen in Malaysia, the Philippines, or Thailand. There was some evidence that charcoal-burning suicides were associated with an increase in overall suicide rates in Hong Kong, Taiwan, and Japan (for females), but not in Japan (for males), the Republic of Korea, and Singapore. Rates of change in charcoal-burning suicide

  9. The effects of small changes in the input data on the determination of closed-bomb burning rates and surface area

    NASA Astrophysics Data System (ADS)

    Robbins, Frederick W.; Cieslewicz, Karen A.

    1993-03-01

    In order to ascertain the effects of small changes in the input data on the determination of closed-bomb burning rates, a series of related computer programs was developed. The computer programs allow a qualitative and quantitative evaluation of the effects of varying thermodynamic properties and, if desired, the propellant grain dimensions. Program listings and sample runs are included, along with Fortran listings of common form functions.

  10. Minor Actinides Recycling in PWRs

    SciTech Connect

    Delpech, M.; Golfier, H.; Vasile, A.; Varaine, F.; Boucher, L.; Greneche, D.

    2006-07-01

    Recycling of minor actinides in current and near future PWR is considered as one of the options of the general waste management strategy. This paper presents the analysis of this option both from the core physics and fuel cycle point of view. A first indicator of the efficiency of different neutron spectra for transmutation purposes is the capture to fission cross sections ratio which is less favourable by a factor between 5 to 10 in PWRs compared to fast reactors. Another indicator presented is the production of high ranking isotopes like Curium, Berkelium or Californium in the thermal or epithermal spectrum conditions of PWR cores by successive neutron captures. The impact of the accumulation of this elements on the fabrication process of such PWR fuels strongly penalizes this option. The main constraint on minor actinides loadings in PWR (or fast reactors) fuels are related to their direct impact (or the impact of their transmutation products) on the reactivity coefficients, the reactivity control means and the core kinetics parameters. The main fuel cycle physical parameters like the neutron source, the alpha decay power, the gamma and neutrons dose rate and the criticality aspects are also affected. Recent neutronic calculations based on a reference core of the Evolutionary Pressurized Reactor (EPR), indicates typical maximum values of 1 % loadings. Different fuel design options for minor actinides transmutation purposes in PWRs are presented: UOX and MOX, homogeneous and heterogeneous assemblies. In this later case, Americium loading is concentrated in specific pins of a standard UOX assembly. Recycling of Neptunium in UOX and MOX fuels was also studied to improve the proliferation resistance of the fuel. The impact on the core physics and penalties on Uranium enrichment were underlined in this case. (authors)

  11. Actinide transmutation in a thermal reactor

    SciTech Connect

    Facchini, A.; Sanjust, V.

    1993-12-31

    The long term radiotoxicity of nuclear wastes may be substantially reduced by long irradiation in thermal reactors. Preliminary calculations showed that appreciable quantities of the minor actinides and long lived fission products may be recycled in a power PWR, and that, a few centuries after 20--30 years of irradiation, they reach radiotoxicity levels comparable to those of the uranium quantity required to make the corresponding fuel amount. The purpose of the present work is to investigate the conceptual possibility of reducing the level of the long term radiotoxicity, due to Minor Actinides and Long-Lived Fission Products (MA/LLFP) produced in UO{sub 2} fuel, by long irradiation of them in a power PWR. More precisely the authors pursued the objective of determining what fraction of the MA/LLFP mixture produced in a 1,000 MWe PWR during its whole life, may be burned in a similar power reactor. A waste burning efficiency has been considered satisfactory if the long term radiotoxicity of the MA/LLFP contained in a given quantity of spent fuel reaches, a few centuries after its irradiation, the level corresponding to that of the amount of natural uranium required to produce the same quantity of fresh fuel. This waiting time is in fact necessary in any case for cooling the other fission products to a sufficiently low radioactivity level and is a time span not unreasonable when considering man-made barriers against the radionuclide diffusion into the biosphere.

  12. Research in actinide chemistry

    SciTech Connect

    Not Available

    1989-01-01

    Research continued to be focused broadly on the chemistry of the actinide cations in solution. While the direct concern is the actinide elements, their radioactivity limits the techniques which can be applied to their study. A major area of interest continues to be the thermodynamics of interaction of the f-elements with a broad spectrum of inorganic and organic ligands. Solvent extraction (for tracer levels), potentiometric and calorimetric titration and absorption spectrometry have been used to obtain stability constants and the associated enthalpy and entropy changes for complexation. A number of studies were performed to provide a better data base and a better understanding of the more significant species determining the behavior of actinides in natural waters (e.g., hydrolysis and silicate interaction). A second major area has been kinetics. NpO{sub 2}{sup 2+} reduction by hydroxy and carboxylic acids was studied to obtain an understanding of how such functional groups in humic substances may influence actinyl redox. The kinetics of dissociation of UO{sub 2}{sup 2+} and Ln{sup 3+} (La{sup 3+} = lanthanide element cations) from synthetic polyelectrolytes and humics provided significantly increased understanding of actinide complexation by these macromolecules. A third area of activity used laser induced fluorescence to study the hydration state of Eu(III) in a number of systems. Finally, several other studies, not in these major areas, were conducted. These included investigation of NpO{sub 2}{sup +} cation-cation complexes, the extraction of Am(III) by MX (M = Li, Na, NH{sub 4}{sup +}, K{sup +}; X = ClO{sub 4}{sup {minus}}, Cl{sup {minus}}, NO{sub 3}{sup {minus}}, BrO{sub 3}{sup {minus}}) over a concentration range from 0.01 M to saturated and the thermodynamics of synergistic extraction of actinides by crown ethers and {beta}-diketonates. 23 refs., 1 fig.

  13. The combustion of large particles of char in bubbling fluidized beds: The dependence of Sherwood number and the rate of burning on particle diameter

    SciTech Connect

    Dennis, J.S.; Hayhurst, A.N.; Scott, S.A.

    2006-11-15

    Particles of char derived from a variety of fuels (e.g., biomass, sewage sludge, coal, or graphite), with diameters in excess of {approx}1.5mm, burn in fluidized bed combustors containing smaller particles of, e.g., sand, such that the rate is controlled by the diffusion both of O{sub 2} to the burning solid and of the products CO and CO{sub 2} away from it into the particulate phase. It is therefore important to characterize these mass transfer processes accurately. Measurements of the burning rate of char particles made from sewage sludge suggest that the Sherwood number, Sh, increases linearly with the diameter of the fuel particle, d{sub char} (for d{sub char}>{approx}1.5mm). This linear dependence of Sh on d{sub char} is expected from the basic equation Sh=2{epsilon}{sub mf}(1+d{sub char}/2{delta}{sub diff})/{tau}, provided the thickness of the boundary layer for mass transfer, {delta}{sub diff}, is constant in the region of interest (d{sub char}>{approx}1.5mm). Such a dependence is not seen in the empirical equations currently used and based on the Frossling expression. It is found here that for chars made from sewage sludge (for d{sub char}>{approx}1.5mm), the thickness of the boundary layer for mass transfer in a fluidized bed, {delta}{sub diff}, is less than that predicted by empirical correlations based on the Frossling expression. In fact, {delta}{sub diff} is not more than the diameter of the fluidized sand particles. Finally, the experiments in this study indicate that models based on surface renewal theory should be rejected for a fluidized bed, because they give unrealistically short contact times for packets of fluidized particles at the surface of a burning sphere. The result is the new correlation Sh = 2{epsilon}{sub mf}/{tau} + (A{sub cush}/A{sub char})(d{sub char}/ {delta}{sub diff}) for the dependence of Sh on d{sub char}, the diameter of a burning char particle. This equation is based on there being a gas-cushion of fluidizing gas underneath a

  14. Gas core reactors for actinide transmutation. [uranium hexafluoride

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Rust, J. H.; Wan, P. T.; Chow, S.

    1979-01-01

    The preliminary design of a uranium hexafluoride actinide transmutation reactor to convert long-lived actinide wastes to shorter-lived fission product wastes was analyzed. It is shown that externally moderated gas core reactors are ideal radiators. They provide an abundant supply of thermal neutrons and are insensitive to composition changes in the blanket. For the present reactor, an initial load of 6 metric tons of actinides is loaded. This is equivalent to the quantity produced by 300 LWR-years of operation. At the beginning, the core produces 2000 MWt while the blanket generates only 239 MWt. After four years of irradiation, the actinide mass is reduced to 3.9 metric tonnes. During this time, the blanket is becoming more fissile and its power rapidly approaches 1600 MWt. At the end of four years, continuous refueling of actinides is carried out and the actinide mass is held constant. Equilibrium is essentially achieved at the end of eight years. At equilibrium, the core is producing 1400 MWt and the blanket 1600 MWt. At this power level, the actinide destruction rate is equal to the production rate from 32 LWRs.

  15. Rapid actinide-separation methods

    SciTech Connect

    Maxwell, S.L. III

    1997-12-31

    New high-speed actinide-separation methods have been developed by the Savannah River Site Central Laboratory that can be applied to nuclear materials process samples, waste solutions and environmental samples. As part of a reengineering effort to improve efficiencies and reduce operating costs, solvent extraction methods (TTA, Hexone, TBP and TIOA) used for over thirty years in the SRS Central Laboratory were replaced with new rapid extraction column methods able to handle a variety of difficult sample matrices and actinide levels. Significant costs savings were realized and costly mixed-waste controls were avoided by using applied vacuum and 50-100 micron particle-size resins from Eichrom Industries. TEVA Resin{reg_sign}, UTEVA Resin{reg_sign}, and TRU Resin{reg_sign} columns are used with flow rates of approximately two to three milliliters per minute to minimize sample turnaround times. Single-column, dual-column and sequential-cartridge methods for plutonium, uranium, neptunium, americium and curium were developed that enable rapid, cost-effective separations prior to alpha-particle counting, thermal ionization and inductively coupled plasma mass spectrometry, and laser phosphorescence measurements.

  16. Engineering-Scale Distillation of Cadmium for Actinide Recovery

    SciTech Connect

    J.C. Price; D. Vaden; R.W. Benedict

    2007-10-01

    During the recovery of actinide products from spent nuclear fuel, cadmium is separated from the actinide products by a distillation process. Distillation occurs in an induction-heated furnace called a cathode processor capable of processing kilogram quantities of cadmium. Operating parameters have been established for sufficient recovery of the cadmium based on mass balance and product purity. A cadmium distillation rate similar to previous investigators has also been determined. The development of cadmium distillation for spent fuel treatment enhances the capabilities for actinide recovery processes.

  17. Impact of actinide recycle on nuclear fuel cycle health risks

    SciTech Connect

    Michaels, G.E.

    1992-06-01

    The purpose of this background paper is to summarize what is presently known about potential impacts on the impacts on the health risk of the nuclear fuel cycle form deployment of the Advanced Liquid Metal Reactor (ALMR){sup 1} and Integral Fast Reactor (IF){sup 2} technology as an actinide burning system. In a companion paper the impact on waste repository risk is addressed in some detail. Therefore, this paper focuses on the remainder of the fuel cycle.

  18. Device for Detecting Actinides, Method for Detecting Actinides

    SciTech Connect

    Stevens, Fred J.; Wilkins-Stevens, Priscilla

    1998-10-29

    A heavy metal detector is provided comprising a first molecule and a second molecule, whereby the first and second molecules interact in a predetermined manner; a first region on the first molecule adapted to interact with an actinide; and a second region on the second molecule adapted to interact with the actinide, whereby the interactions of the actinide with the regions effect the predetermined manner of interaction between the molecules.

  19. The Influence of Fuel Moisture, Charge Size, Burning Rate and Air Ventilation Conditions on Emissions of PM, OC, EC, Parent PAHs, and Their Derivatives from Residential Wood Combustion

    PubMed Central

    Shen, Guofeng; Xue, Miao; Wei, Siye; Chen, Yuanchen; Wang, Bin; Wang, Rong; Lv, Yan; Shen, Huizhong; Li, Wei; Zhang, Yanyan; Huang, Ye; Chen, Han; Wei, Wen; Zhao, Qiuyue; Li, Bin; Wu, Haisuo; TAO, Shu

    2014-01-01

    Controlled combustion experiments were conducted to investigate the influence of fuel charge size, moisture, air ventilation and burning rate on the emission factors (EFs) of carbonaceous particulate matter, parent polycyclic aromatic hydrocarbons (pPAHs) and their derivatives from residential wood combustion in a typical brick cooking stove. Measured EFs were found to be independent of fuel charge size, but increased with increasing fuel moisture. Pollution emissions from a normal burning under an adequate air supply condition were the lowest for most pollutants, while more pollutants were emitted when the oxygen deficient atmosphere was formed in stove chamber during fast burning. The impact of these 4 factors on particulate matter size distribution was also studied. Modified combustion efficiency and the four investigated factors explained 68, 72, and 64% of total variations in EFs of PM, organic carbon, and oxygenated PAHs, respectively, but only 36, 38 and 42% of the total variations in EFs of elemental carbon, pPAHs and nitro-PAHs, respectively. PMID:24520723

  20. The β-decay rates of 59Fe isotopes in shell burning environments and their influences on the production of 60Fe in massive star

    NASA Astrophysics Data System (ADS)

    Li, K.; Lam, Y. H.; Qi, C.; Tang, X.; Zhang, N.

    2016-02-01

    The experimental B(GT) strengths of the 59Fe excited states were employed to determine the transition strengths which greatly contribute 59Fe stellar β-decay at typical carbon shell burning temperature. The result has been compared with the theoretical rates FFN (Fuller-Fowler-Newman) and LMP (Langanke&Martinez-Pinedo). Impact of the newly determined rate on the synthesis of cosmic γ emitter 60Fe has also been studied using one-zone model calculation. Our results show 59Fe stellar β-decay rate plays an important role in the 60Fe nucleosynthesis. However the uncertainty of the decay rate is rather large due to the error of B(GT) strength that requires further studies.

  1. Burn rates of TiH2/KClO4/Viton and output testing of NASA SKD26100098-301 pressure cartridges

    NASA Technical Reports Server (NTRS)

    Holy, John A.

    1993-01-01

    The burn rates of the pyrotechnic TiH2/KClO4/Viton with a mass ratio of 30/65/5 have been measured as a function of pressure in nitrogen up to 312 MPa(45 Kpsi). The burn rates were fit to R = a pn, with a = 2.055 cm/sec/MPan and n = 0.472 between 0.15 MPa (22 psi) and 21.6 MPa (3.13 Kpsi) and a = 4.38 cm/sec/MPan and n = 0.266 between 70 MPa (10.15 Kpsi) and 312 MPa (45.25 Kpsi). The decrease in slope at the higher pressures is attributed to a diffusion limited reaction. No acoustically driven flame instabilities or large conductive-to-convective burn transitions were observed. Solid reaction products were analyzed by x-ray diffraction and scanning electron microscopy (SEM). X-ray diffraction detected only TiO2 and KC1. SEM showed that the particle size of the reaction products increased as the nitrogen pressure increased. There were no anomalous characteristics of the burn of this pyrotechnic that could be interpreted as a cause of the o-ring blow-by problem in the forward shear bolt assembly. Three NASA SKD26100098-301 pressure cartridges were fired into a fixed volume vessel that was sealed with an O-ring. A maximum pressure of 181.7 MPa(26,350 psi) was reached in around 100 ,mu sec for two shots fired into a volume of 16.3 cm3(0.996 in3). A maximum pressure of 33,460 psi was reached for one shot fired into a volume of 9.55 cm3(0.583 in3). The O-ring burned through on one shot in the larger volume and leaked on the other two thereby simulating the effects of an O-ring leak. The results imply that the piston in the shear bolt assembly would receive a large impulse even if there was a leak in an O-ring seal.

  2. Novel Separation of Actinides

    SciTech Connect

    Mariella, R

    2011-02-17

    The separation of actinides and other elements of interest for nuclear forensics and threat reduction is currently performed using decades-old chemistries and ion-exchange columns. We propose to determine the technical feasibility of a novel method for separating actinide ions in solution. This method is based upon isotachophoresis (ITP), which has been applied in the purification of pharmaceuticals and other biochemical applications. This technique has the potential to separate inorganic ions more effectively than existing methods, which is key to analyzing very small samples. We will perform a quantitative assessment of the effectiveness of specific isotachophoretic approaches including predicting the physical and chemical properties, such as ion mobility, of inorganic ions under specific solvent conditions using a combination of ab initio calculations and semi-empirical methods. We expect to obtain a thorough understanding of the analytical systems parameters under which ITP is most effective for the separation of inorganic samples, including the influence of the double layer surrounding actinide ions, the Debye length for different ions and ion complexes, and Debye-Hueckel limits. Inorganic separations are key to nuclear forensics for countering terrorism and nuclear proliferation. If found to be feasible and potentially superior to currently used separation approaches, ITP could provide the conceptual basis for an improved means to separate samples of nuclear explosion debris for nuclear forensic analysis, in support of the Laboratory's missions in homeland and national security.

  3. Are High-Severity Fires Burning at Much Higher Rates Recently than Historically in Dry-Forest Landscapes of the Western USA?

    PubMed Central

    Baker, William L.

    2015-01-01

    Dry forests at low elevations in temperate-zone mountains are commonly hypothesized to be at risk of exceptional rates of severe fire from climatic change and land-use effects. Their setting is fire-prone, they have been altered by land-uses, and fire severity may be increasing. However, where fires were excluded, increased fire could also be hypothesized as restorative of historical fire. These competing hypotheses are not well tested, as reference data prior to widespread land-use expansion were insufficient. Moreover, fire-climate projections were lacking for these forests. Here, I used new reference data and records of high-severity fire from 1984–2012 across all dry forests (25.5 million ha) of the western USA to test these hypotheses. I also approximated projected effects of climatic change on high-severity fire in dry forests by applying existing projections. This analysis showed the rate of recent high-severity fire in dry forests is within the range of historical rates, or is too low, overall across dry forests and individually in 42 of 43 analysis regions. Significant upward trends were lacking overall from 1984–2012 for area burned and fraction burned at high severity. Upward trends in area burned at high severity were found in only 4 of 43 analysis regions. Projections for A.D. 2046–2065 showed high-severity fire would generally be still operating at, or have been restored to historical rates, although high projections suggest high-severity fire rotations that are too short could ensue in 6 of 43 regions. Programs to generally reduce fire severity in dry forests are not supported and have significant adverse ecological impacts, including reducing habitat for native species dependent on early-successional burned patches and decreasing landscape heterogeneity that confers resilience to climatic change. Some adverse ecological effects of high-severity fires are concerns. Managers and communities can improve our ability to live with high-severity fire

  4. Are High-Severity Fires Burning at Much Higher Rates Recently than Historically in Dry-Forest Landscapes of the Western USA?

    PubMed

    Baker, William L

    2015-01-01

    Dry forests at low elevations in temperate-zone mountains are commonly hypothesized to be at risk of exceptional rates of severe fire from climatic change and land-use effects. Their setting is fire-prone, they have been altered by land-uses, and fire severity may be increasing. However, where fires were excluded, increased fire could also be hypothesized as restorative of historical fire. These competing hypotheses are not well tested, as reference data prior to widespread land-use expansion were insufficient. Moreover, fire-climate projections were lacking for these forests. Here, I used new reference data and records of high-severity fire from 1984-2012 across all dry forests (25.5 million ha) of the western USA to test these hypotheses. I also approximated projected effects of climatic change on high-severity fire in dry forests by applying existing projections. This analysis showed the rate of recent high-severity fire in dry forests is within the range of historical rates, or is too low, overall across dry forests and individually in 42 of 43 analysis regions. Significant upward trends were lacking overall from 1984-2012 for area burned and fraction burned at high severity. Upward trends in area burned at high severity were found in only 4 of 43 analysis regions. Projections for A.D. 2046-2065 showed high-severity fire would generally be still operating at, or have been restored to historical rates, although high projections suggest high-severity fire rotations that are too short could ensue in 6 of 43 regions. Programs to generally reduce fire severity in dry forests are not supported and have significant adverse ecological impacts, including reducing habitat for native species dependent on early-successional burned patches and decreasing landscape heterogeneity that confers resilience to climatic change. Some adverse ecological effects of high-severity fires are concerns. Managers and communities can improve our ability to live with high-severity fire in

  5. Thermal decomposition of energetic materials; 65: Conversion of insensitive explosives (NTO, ANTA) and related compounds to polymeric melon-like cyclic azine burn-rate suppressants

    SciTech Connect

    Williams, G.K.; Palopoli, S.F.; Brill, T.B. . Dept. of Chemistry)

    1994-08-01

    Selected triazole, tetrazole, triazine, tetrazine, furazan, and acyclic backbone compounds are shown by IR spectroscopy to convert to polymeric, melon-like, cyclic azine residues upon heating to T [ge] 500 C. These compounds include the insensitive explosives 3-nitro-1,2,4-triazol-5-one (NTO), 3-amino-5-nitro-1,2,4-triazole (ANTA), and nitroguanidine. The melon-like residue could suppress the burn rate if these compounds are formulated into solid rocket propellants. The IR-active gaseous products from thermolysis are determined as a function of pressure and are related to the atom connectivity in the parent molecules.

  6. Environmental speciation of actinides.

    PubMed

    Maher, Kate; Bargar, John R; Brown, Gordon E

    2013-04-01

    Although minor in abundance in Earth's crust (U, 2-4 ppm; Th, 10-15 ppm) and in seawater (U, 0.003 ppm; Th, 0.0007 ppm), light actinides (Th, Pa, U, Np, Pu, Am, and Cm) are important environmental contaminants associated with anthropogenic activities such as the mining and milling of uranium ores, generation of nuclear energy, and storage of legacy waste resulting from the manufacturing and testing of nuclear weapons. In this review, we discuss the abundance, production, and environmental sources of naturally occurring and some man-made light actinides. As is the case with other environmental contaminants, the solubility, transport properties, bioavailability, and toxicity of actinides are dependent on their speciation (composition, oxidation state, molecular-level structure, and nature of the phase in which the contaminant element or molecule occurs). We review the aqueous speciation of U, Np, and Pu as a function of pH and Eh, their interaction with common inorganic and organic ligands in natural waters, and some of the common U-containing minerals. We also discuss the interaction of U, Np, Pu, and Am solution complexes with common Earth materials, including minerals, colloids, gels, natural organic matter (NOM), and microbial organisms, based on simplified model system studies. These surface interactions can inhibit (e.g., sorption to mineral surfaces, formation of insoluble biominerals) or enhance (e.g., colloid-facilitated transport) the dispersal of light actinides in the biosphere and in some cases (e.g., interaction with dissimilatory metal-reducing bacteria, NOM, or Mn- and Fe-containing minerals) can modify the oxidation states and, consequently, the behavior of redox-sensitive light actinides (U, Np, and Pu). Finally, we review the speciation of U and Pu, their chemical transformations, and cleanup histories at several U.S. Department of Energy field sites that have been used to mill U ores, produce fissile materials for reactors and weapons, and store

  7. Final Technical Progress Report Long term risk from actinides in the environment: Modes of mobility

    SciTech Connect

    Thomas B. Kirchner

    2002-03-22

    The key source of uncertainty in assessing actinide mobility is the relative importance of transport by: (1) wind erosion, (2) water erosion, and (3) vertical migration. Each of these three processes depends on several environmental factors and they compete with one another. A scientific assessment of the long-term risks associated with actinides in surface soils depends on better quantifying each of these three modes of mobility. The objective from our EMSP study was to quantify the mobility of soil actinides by wind erosion, water erosion, and vertical migration at three semiarid sites where actinide mobility is a key technical, social and legal issue. This EMSP project was the first to evaluate all three factors at a site. The approach has been to investigate both short- and long-term issues based on field and lab studies and model comparisons. Our results demonstrate the importance of incorporating threshold responses into a modeling framework that accounts for environmental factors and natural disturbances that trigger large changes in actinide mobility. The study measured erosional losses of sediment and fallout cesium (an actinide analogue) from field plots located near WIPP in 1998. The results highlight the large effect of burning as a disturbance on contaminant transport and mobility via runoff and erosion. The results show that runoff, erosion, and actinide transport are (1) strongly site specific-differences in radionuclide transport between WIPP and Rocky Flats differed by a factor of twelve because of soil and vegetation differences, and (2) are strongly impacted by disturbances such as fire, which can increase runoff, erosion, and actinide transport by more than an order of magnitude. In addition, a laboratory experiment using soil columns was conducted to investigate the vertical transport of contaminants in sandy soils. Nine columns of soil collected from the vicinity of the WIPP site were prepared. The column consisted of a piece of PVC pipe 20 cm

  8. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2012-09-01

    In October-November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4-27.9% of non-methane organic compounds (NMOCs) and ~21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13-195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The ΔHCN/ΔCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also support an

  9. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    NASA Astrophysics Data System (ADS)

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2013-02-01

    In October-November 2011 we measured trace gas emission factors from seven prescribed fires in South Carolina (SC), US, using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analysis. A total of 97 trace gas species were quantified from both airborne and ground-based sampling platforms, making this one of the most detailed field studies of fire emissions to date. The measurements include the first emission factors for a suite of monoterpenes produced by heating vegetative fuels during field fires. The first quantitative FTIR observations of limonene in smoke are reported along with an expanded suite of monoterpenes measured by WAS including α-pinene, β-pinene, limonene, camphene, 4-carene, and myrcene. The known chemistry of the monoterpenes and their measured abundance of 0.4-27.9% of non-methane organic compounds (NMOCs) and ~ 21% of organic aerosol (mass basis) suggests that they impacted secondary formation of ozone (O3), aerosols, and small organic trace gases such as methanol and formaldehyde in the sampled plumes in the first few hours after emission. The variability in the initial terpene emissions in the SC fire plumes was high and, in general, the speciation of the initially emitted gas-phase NMOCs was 13-195% different from that observed in a similar study in nominally similar pine forests in North Carolina ~ 20 months earlier. It is likely that differences in stand structure and environmental conditions contributed to the high variability observed within and between these studies. Similar factors may explain much of the variability in initial emissions in the literature. The ΔHCN/ΔCO emission ratio, however, was found to be fairly consistent with previous airborne fire measurements in other coniferous-dominated ecosystems, with the mean for these studies being 0.90 ± 0.06%, further confirming the value of HCN as a biomass burning tracer. The SC results also

  10. In-situ mineralization of actinides with phytic acid

    SciTech Connect

    Nash, K.L.; Jensen, M.P.; Morss, L.R.; Appelman, E.H.

    1997-12-31

    A new approach to the remediation of actinide contamination is described. A hydrolytically unstable organophosphorus compound, phytic acid, is introduced into the contaminated environment. In the short term (up to several hundred years), phytate acts as a cation exchanger to absorb mobile actinide ions from ground waters. Ultimately, phytate decomposes to release phosphate and promote the formation of insoluble phosphate mineral phases, considered an ideal medium to immobilize actinides, as it forms compounds with the lowest solubility of any candidate mineral species. This overview will discuss the rate of hydrolysis of phytic acid, the formation of lanthanide/actinide phosphate mineral forms, the cation exchange behavior of insoluble phytate, and results from laboratory demonstration of the application to soils from the Fernald site.

  11. Effects of the Distributions of Energy or Charge Transfer Rates on Spectral Hole Burning in Pigment-Protein Complexes at Low Temperatures

    SciTech Connect

    Herascu, N.; Ahmouda, S.; Picorel, R.; Seibert, M.; Jankowiak, R.; Zazubovich, V.

    2011-12-22

    Effects of the distributions of excitation energy transfer (EET) rates (homogeneous line widths) on the nonphotochemical (resonant) spectral hole burning (SHB) processes in photosynthetic chlorophyll-protein complexes (reaction center [RC] and CP43 antenna of Photosystem II from spinach) are considered. It is demonstrated that inclusion of such a distribution results in somewhat more dispersive hole burning kinetics. More importantly, however, inclusion of the EET rate distributions strongly affects the dependence of the hole width on the fractional hole depth. Different types of line width distributions have been explored, including those resulting from Foerster type EET between weakly interacting pigments as well as Gaussian ones, which may be a reasonable approximation for those resulting, for instance, from so-called extended Foerster models. For Gaussian line width distributions, it is possible to determine the parameters of both line width and tunneling parameter distributions from SHB data without a priori knowledge of any of them. Concerning more realistic asymmetric distributions, we demonstrate, using the simple example of CP43 antenna, that one can use SHB modeling to estimate electrostatic couplings between pigments and support or exclude assignment of certain pigment(s) to a particular state.

  12. PROCESS OF PRODUCING ACTINIDE METALS

    DOEpatents

    Magel, T.T.

    1959-07-14

    The preparation of actinide metals in workable, coherent form is described. In general, the objects of the invention are achieved by heating a mixture of an oxide and a halide of an actinide metal such as uranium with an alkali metal on alkaline earth metal reducing agent in the presence of iodine.

  13. The thermal decomposition of 1,3,5-trinitrohexahydro-1,3,5-triazine (RDX) and RDXd6 at high temperatures. [burning rate

    NASA Technical Reports Server (NTRS)

    Miller, P. J.; Nauflett, G. W.; Carlson, D. W.; Brasch, J. W., Sr.

    1980-01-01

    The ballistics behavior of nitramine propellants containing RDX in an inert binder was examined. It is shown that at 2000 to 5000 psi, depending on the particle size, a slope break or discontinuity in the log burning rate versus log pressure curve occurs. It is shown that at higher pressures the nitramine decomposition proceeds predominately by C-N bond rupture and gives CH2 and N20. At still higher pressures (after the slope break) the decomposition proceeds by N-N rupture. The decomposition of RDX was investigated from 170 to 800 C at atmospheric pressure. The major decomposition products were CH2, CO, CO2, N20, N2, and H20. The ratio of the products varied with the pyrolysis rate and temperature.

  14. Actinide halide complexes

    DOEpatents

    Avens, L.R.; Zwick, B.D.; Sattelberger, A.P.; Clark, D.L.; Watkin, J.G.

    1992-11-24

    A compound is described of the formula MX[sub n]L[sub m] wherein M is a metal atom selected from the group consisting of thorium, plutonium, neptunium or americium, X is a halide atom, n is an integer selected from the group of three or four, L is a coordinating ligand selected from the group consisting of aprotic Lewis bases having an oxygen-, nitrogen-, sulfur-, or phosphorus-donor, and m is an integer selected from the group of three or four for monodentate ligands or is the integer two for bidentate ligands, where the sum of n+m equals seven or eight for monodentate ligands or five or six for bidentate ligands. A compound of the formula MX[sub n] wherein M, X, and n are as previously defined, and a process of preparing such actinide metal compounds are described including admixing the actinide metal in an aprotic Lewis base as a coordinating solvent in the presence of a halogen-containing oxidant.

  15. Actinide halide complexes

    DOEpatents

    Avens, Larry R.; Zwick, Bill D.; Sattelberger, Alfred P.; Clark, David L.; Watkin, John G.

    1992-01-01

    A compound of the formula MX.sub.n L.sub.m wherein M is a metal atom selected from the group consisting of thorium, plutonium, neptunium or americium, X is a halide atom, n is an integer selected from the group of three or four, L is a coordinating ligand selected from the group consisting of aprotic Lewis bases having an oxygen-, nitrogen-, sulfur-, or phosphorus-donor, and m is an integer selected from the group of three or four for monodentate ligands or is the integer two for bidentate ligands, where the sum of n+m equals seven or eight for monodentate ligands or five or six for bidentate ligands, a compound of the formula MX.sub.n wherein M, X, and n are as previously defined, and a process of preparing such actinide metal compounds including admixing the actinide metal in an aprotic Lewis base as a coordinating solvent in the presence of a halogen-containing oxidant, are provided.

  16. Managing Inventories of Heavy Actinides

    SciTech Connect

    Wham, Robert M; Patton, Bradley D

    2011-01-01

    The Department of Energy (DOE) has stored a limited inventory of heavy actinides contained in irradiated targets, some partially processed, at the Savannah River Site (SRS) and Oak Ridge National Laboratory (ORNL). The 'heavy actinides' of interest include plutonium, americium, and curium isotopes; specifically 242Pu and 244Pu, 243Am, and 244/246/248Cm. No alternate supplies of these heavy actinides and no other capabilities for producing them are currently available. Some of these heavy actinide materials are important for use as feedstock for producing heavy isotopes and elements needed for research and commercial application. The rare isotope 244Pu is valuable for research, environmental safeguards, and nuclear forensics. Because the production of these heavy actinides was made possible only by the enormous investment of time and money associated with defense production efforts, the remaining inventories of these rare nuclear materials are an important part of the legacy of the Nuclear Weapons Program. Significant unique heavy actinide inventories reside in irradiated Mark-18A and Mark-42 targets at SRS and ORNL, with no plans to separate and store the isotopes for future use. Although the costs of preserving these heavy actinide materials would be considerable, for all practical purposes they are irreplaceable. The effort required to reproduce these heavy actinides today would likely cost billions of dollars and encompass a series of irradiation and chemical separation cycles for at least 50 years; thus, reproduction is virtually impossible. DOE has a limited window of opportunity to recover and preserve these heavy actinides before they are disposed of as waste. A path forward is presented to recover and manage these irreplaceable National Asset materials for future use in research, nuclear forensics, and other potential applications.

  17. Biomass Burning

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.; Cofer, Wesley R., III; Pinto, Joseph P.

    1993-01-01

    Biomass burning may be the overwhelming regional or continental-scale source of methane (CH4) as in tropical Africa and a significant global source of CH4. Our best estimate of present methane emissions from biomass burning is about 51.9 Tg/yr, or 10% of the annual methane emissions to the atmosphere. Increased frequency of fires that may result as the Earth warms up may result in increases in this source of atmospheric methane.

  18. Measurements of VOC/SVOC emission factors from burning incenses in an environmental test chamber: influence of temperature, relative humidity, and air exchange rate.

    PubMed

    Manoukian, A; Buiron, D; Temime-Roussel, B; Wortham, H; Quivet, E

    2016-04-01

    This study investigates the influence of three environmental indoor parameters (i.e., temperature, relative humidity, and air exchange rate) on the emission of 13 volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) during incense burning. Experiments have been carried out using an environmental test chamber. Statistical results from a classical two-level full factorial design highlight the predominant effect of ventilation on emission factors. The higher the ventilation, the higher the emission factor. Moreover, thanks to these results, an estimation of the concentration range for the compounds under study can be calculated and allows a quick look of indoor pollution induced by incense combustion. Carcinogenic substances (i.e., benzene, benzo(a)pyrene, and formaldehyde) produced from the incense combustion would be predicted in typical living indoors conditions to reach instantaneous concentration levels close to or higher than air quality exposure threshold values. PMID:26614451

  19. Negative pressure dependence of mass burning rates of H{sub 2}/CO/O{sub 2}/diluent flames at low flame temperatures

    SciTech Connect

    Burke, Michael P.; Chaos, Marcos; Dryer, Frederick L.; Ju, Yiguang

    2010-04-15

    Experimental measurements of burning rates, analysis of the key reactions and kinetic pathways, and modeling studies were performed for H{sub 2}/CO/O{sub 2}/diluent flames spanning a wide range of conditions: equivalence ratios from 0.85 to 2.5, flame temperatures from 1500 to 1800 K, pressures from 1 to 25 atm, CO fuel fractions from 0 to 0.9, and dilution concentrations of He up to 0.8, Ar up to 0.6, and CO{sub 2} up to 0.4. The experimental data show negative pressure dependence of burning rate at high pressure, low flame temperature conditions for all equivalence ratios and CO fractions as high as 0.5. Dilution with CO{sub 2} was observed to strengthen the pressure and temperature dependence compared to Ar-diluted flames of the same flame temperature. Simulations were performed to extend the experimentally studied conditions to conditions typical of gas turbine combustion in Integrated Gasification Combined Cycle processes, including preheated mixtures and other diluents such as N{sub 2} and H{sub 2}O. Substantial differences are observed between literature model predictions and the experimental data as well as among model predictions themselves - up to a factor of three at high pressures. The present findings suggest the need for several rate constant modifications of reactions in the current hydrogen models and raise questions about the sufficiency of the set of hydrogen reactions in most recent hydrogen models to predict high pressure flame conditions relevant to controlling NO{sub x} emissions in gas turbine combustion. For example, the reaction O + OH + M = HO{sub 2} + M is not included in most hydrogen models but is demonstrated here to significantly impact predictions of lean high pressure flames using rates within its uncertainty limits. Further studies are required to reduce uncertainties in third body collision efficiencies for and fall-off behavior of H + O{sub 2}(+M) = HO{sub 2}(+M) in both pure and mixed bath gases, in rate constants for HO{sub 2

  20. Negative pressure dependence of mass burning rates of H{sub 2}/CO/O{sub 2}/diluent flames at low flame temperatures

    SciTech Connect

    Burke, M. P.; Chaos, M.; Dryer, F. L.; Ju, Yiguang

    2010-01-01

    Experimental measurements of burning rates, analysis of the key reactions and kinetic pathways, and modeling studies were performed for H{sub 2}/CO/O{sub 2}/diluent flames spanning a wide range of conditions: equivalence ratios from 0.85 to 2.5, flame temperatures from 1500 to 1800 K, pressures from 1 to 25 atm, CO fuel fractions from 0 to 0.9, and dilution concentrations of He up to 0.8, Ar up to 0.6, and CO{sub 2} up to 0.4. The experimental data show negative pressure dependence of burning rate at high pressure, low flame temperature conditions for all equivalence ratios and CO fractions as high as 0.5. Dilution with CO{sub 2} was observed to strengthen the pressure and temperature dependence compared to Ar-diluted flames of the same flame temperature. Simulations were performed to extend the experimentally studied conditions to conditions typical of gas turbine combustion in Integrated Gasification Combined Cycle processes, including preheated mixtures and other diluents such as N{sub 2} and H{sub 2}O. Substantial differences are observed between literature model predictions and the experimental data as well as among model predictions themselves – up to a factor of three at high pressures. The present findings suggest the need for several rate constant modifications of reactions in the current hydrogen models and raise questions about the sufficiency of the set of hydrogen reactions in most recent hydrogen models to predict high pressure flame conditions relevant to controlling NO{sub x} emissions in gas turbine combustion. For example, the reaction O + OH + M = HO{sub 2} + M is not included in most hydrogen models but is demonstrated here to significantly impact predictions of lean high pressure flames using rates within its uncertainty limits. Further studies are required to reduce uncertainties in third body collision efficiencies for and fall-off behavior of H + O{sub 2}(+M) = HO{sub 2}(+M) in both pure and mixed bath gases, in rate constants for HO{sub 2

  1. Environmental research on actinide elements

    SciTech Connect

    Pinder, J.E. III; Alberts, J.J.; McLeod, K.W.; Schreckhise, R.G.

    1987-08-01

    The papers synthesize the results of research sponsored by DOE's Office of Health and Environmental Research on the behavior of transuranic and actinide elements in the environment. Separate abstracts have been prepared for the 21 individual papers. (ACR)

  2. Burning rubber

    SciTech Connect

    Not Available

    1987-09-01

    Mario Andretti, look out You are about to be surpassed in the burning rubber category by a joint venture between Oxford Energy Company and General Electric. The two companies are building the first whole tire-to-energy facility in the US in Modesto, California. This $41 million facility does not require tires to be shredded prior to incineration; it has the capacity to burn 700 tires per minute. The electricity generated will be provided to a utility company. Oxford says there are two billion waste tires on the ground and this number is increasing by 220 million a year. Of that amount, only 18 million a year are recycled.

  3. Conceptual design of minor actinides burner with an accelerator-driven subcritical system.

    SciTech Connect

    Cao, Y.; Gohar, Y.

    2011-11-04

    In the environmental impact study of the Yucca Mountain nuclear waste repository, the limit of spent nuclear fuel (SNF) for disposal is assessed at 70,000 metric tons of heavy metal (MTHM), among which 63,000 MTHM are the projected SNF discharge from U.S. commercial nuclear power plants though 2011. Within the 70,000 MTHM of SNF in storage, approximately 115 tons would be minor actinides (MAs) and 585 tons would be plutonium. This study describes the conceptual design of an accelerator-driven subcritical (ADS) system intended to utilize (burn) the 115 tons of MAs. The ADS system consists of a subcritical fission blanket where the MAs fuel will be burned, a spallation neutron source to drive the fission blanket, and a radiation shield to reduce the radiation dose to an acceptable level. The spallation neutrons are generated from the interaction of a 1 GeV proton beam with a lead-bismuth eutectic (LBE) or liquid lead target. In this concept, the fission blanket consists of a liquid mobile fuel and the fuel carrier can be LBE, liquid lead, or molten salt. The actinide fuel materials are dissolved, mixed, or suspended in the liquid fuel carrier. Therefore, fresh fuel can be fed into the fission blanket to adjust its reactivity and to control system power during operation. Monte Carlo analyses were performed to determine the overall parameters of an ADS system utilizing LBE as an example. Steady-state Monte Carlo simulations were studied for three fission blanket configurations that are similar except that the loaded amount of actinide fuel in the LBE is either 5, 7, or 10% of the total volume of the blanket, respectively. The neutron multiplication factor values of the three configurations are all approximately 0.98 and the MA initial inventories are each approximately 10 tons. Monte Carlo burnup simulations using the MCB5 code were performed to analyze the performance of the three conceptual ADS systems. Preliminary burnup analysis shows that all three conceptual ADS

  4. Burn Teams and Burn Centers: The Importance of a Comprehensive Team Approach to Burn Care

    PubMed Central

    Al-Mousawi, Ahmed M.; Mecott-Rivera, Gabriel A.; Jeschke, Marc G.; Herndon, David N.

    2009-01-01

    Synopsis Advances in burn care have been colossal, but while extra work is needed, it is clear that the organized effort of burn teams can continue making improvements in survival rates and quality of life possible for patients. Burn patients are unique, representing the most severe model of trauma,33 and hence this necessitates treatment in the best facilities available for that endeavor. Burn centers have developed to meet these intricate needs but can only function productively and most efficiently through well organized, multifaceted, patient-centered teams in areas of clinical care and research. PMID:19793550

  5. Fast burning propellants

    SciTech Connect

    Colgate, S.A.; Roos, G.E.

    1987-07-21

    A solid or semisolid propellant is described comprising grains of propellant or propellant components bonded together to create voids within the propellant volume. The grains are of near-uniform size and have less than about a 20% size variation between the largest and smallest grains, the voids comprising from about 10% to about 50% of the propellant volume. The grains are bonded together with sufficient strength to substantially delay the fluidization of the propellant by the onset of Taylor unstable burning. The propellant has a rapid burn rate of from about 10 cm sec/sup -1/ to about 10/sup 4/cm sec/sup -1/.

  6. Burning Man

    ERIC Educational Resources Information Center

    Cech, Scott J.

    2006-01-01

    Former Baltimore cop and teacher Ed Burns isn't a masochist. The writer-producer for "The Wire," a critically applauded HBO series about life and death on the streets of Baltimore, is just feverishly trying to save public schools. He thinks American education is hopelessly screwed up, but that it's also the country's only hope. So it makes sense…

  7. Burning mechanism and regression rate of RX-35-AU and RX-35-AV as a function of HMX particle size measured by the hybrid closed bomb-strand burner

    SciTech Connect

    Tao, W.C.; Costantino, M.S.; Ornellas, D.L.

    1990-04-01

    In this study, the average surface regression rate of two HMX-based cast explosives, RX-35-AU and RX-35-AV, is measured to pressures above 750 MPa using a hybrid closed bomb-strand burner. The hybrid design allows the simultaneous measurement of pressure and regression rate over a large range of pressures in each experiment. Nitroglycerin/Triacetin (75/25) and polyethylene glycol (PEG) are used as the energetic plasticizer and polymeric binder, respectively, in both formulations. The HMX solids loading in each formulation is 50 wt %, consisting of a narrow particle size distribution of 6--8 {mu}m for RX-35-AU and 150--177 {mu}m for RX-35-AV. Of special interest are the regression rate and burning mechanism as a function of the initial particle size distribution and the mechanical properties fo the cast explosives. In general, the regression rate for the larger particle size formulation, RX-35-AV, is two to three times faster compared to that for RX-35-AU. Up to 750 MPa and independent of the initial confinement pressure, RX-35-AU exhibits a planar burning mechanism with the regression rate obeying the classical aP{sup n} formalism. For RX-35-AV, however, the burning behavior is erratic for samples ignited at 200 MPa confinement pressure. At confinement pressures above 400 MPa, the regression exhibits more of a planar burning mechanism. The unstable combustion behavior for RX-35-AV at lower confinement pressures is related to several mechanisms: (1) an abrupt increase in surface area due to particle fracture and subsequent translation and rotation, resulting in debonding and creating porosity, (2) thixotropic'' separation of the binder and nitramine, causing the significantly greater fracture damage to the nitramine during the loading cycle, (3) microscopic damage to the nitramine crystals that increase its intrinsic burning rate. 12 refs., 8 figs., 2 tabs.

  8. 33rd Actinide Separations Conference

    SciTech Connect

    McDonald, L M; Wilk, P A

    2009-05-04

    Welcome to the 33rd Actinide Separations Conference hosted this year by the Lawrence Livermore National Laboratory. This annual conference is centered on the idea of networking and communication with scientists from throughout the United States, Britain, France and Japan who have expertise in nuclear material processing. This conference forum provides an excellent opportunity for bringing together experts in the fields of chemistry, nuclear and chemical engineering, and actinide processing to present and discuss experiences, research results, testing and application of actinide separation processes. The exchange of information that will take place between you, and other subject matter experts from around the nation and across the international boundaries, is a critical tool to assist in solving both national and international problems associated with the processing of nuclear materials used for both defense and energy purposes, as well as for the safe disposition of excess nuclear material. Granlibakken is a dedicated conference facility and training campus that is set up to provide the venue that supports communication between scientists and engineers attending the 33rd Actinide Separations Conference. We believe that you will find that Granlibakken and the Lake Tahoe views provide an atmosphere that is stimulating for fruitful discussions between participants from both government and private industry. We thank the Lawrence Livermore National Laboratory and the United States Department of Energy for their support of this conference. We especially thank you, the participants and subject matter experts, for your involvement in the 33rd Actinide Separations Conference.

  9. Actinides and Life's Origins

    NASA Astrophysics Data System (ADS)

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uranium- and thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3rd by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  10. Actinides and Life's Origins.

    PubMed

    Adam, Zachary

    2007-12-01

    There are growing indications that life began in a radioactive beach environment. A geologic framework for the origin or support of life in a Hadean heavy mineral placer beach has been developed, based on the unique chemical properties of the lower-electronic actinides, which act as nuclear fissile and fertile fuels, radiolytic energy sources, oligomer catalysts, and coordinating ions (along with mineralogically associated lanthanides) for prototypical prebiotic homonuclear and dinuclear metalloenzymes. A four-factor nuclear reactor model was constructed to estimate how much uranium would have been required to initiate a sustainable fission reaction within a placer beach sand 4.3 billion years ago. It was calculated that about 1-8 weight percent of the sand would have to have been uraninite, depending on the weight percent, uranium enrichment, and quantity of neutron poisons present within the remaining placer minerals. Radiolysis experiments were conducted with various solvents with the use of uraniumand thorium-rich minerals (metatorbernite and monazite, respectively) as proxies for radioactive beach sand in contact with different carbon, hydrogen, oxygen, and nitrogen reactants. Radiation bombardment ranged in duration of exposure from 3 weeks to 6 months. Low levels of acetonitrile (estimated to be on the order of parts per billion in concentration) were conclusively identified in 2 setups and tentatively indicated in a 3(rd) by gas chromatography/mass spectrometry. These low levels have been interpreted within the context of a Hadean placer beach prebiotic framework to demonstrate the promise of investigating natural nuclear reactors as power production sites that might have assisted the origins of life on young rocky planets with a sufficiently differentiated crust/mantle structure. Future investigations are recommended to better quantify the complex relationships between energy release, radioactive grain size, fissionability, reactant phase, phosphorus

  11. Demographics of pediatric burns in Vellore, India.

    PubMed

    Light, Timothy D; Latenser, Barbara A; Heinle, Jackie A; Stolpen, Margaret S; Quinn, Keely A; Ravindran, Vinitha; Chacko, Jacob

    2009-01-01

    The American Burn Association, Children's Burn Foundation, and Christian Medical College in Vellore, India have partnered together to improve pediatric burn care in Southern India. We report the demographics and outcomes of burns in this center, and create a benchmark to measure the effect of the partnership. A comparison to the National Burn Repository is made to allow for generalization and assessment to other burn centers, and to control for known confounders such as burn size, age, and mechanism. Charts from the pediatric burn center in Vellore, India were retrospectively reviewed and compared with data in the American Burn Association National Burn Registry (NBR) for patients younger than 16 years. One hundred nineteen pediatric patients with burns were admitted from January 2004 through April 2007. Average age was 3.8 years; average total body surface area burn was 24%: 64% scald, 30% flame, 6% electric. Annual death rate was 10%, with average fatal total body surface area burn was 40%. Average lengths of stay for survivors was 15 days. Delay of presentation was common (45% of all patients). Thirty-five of 119 patients received operations (29%). Flame burn patients were older (6.1 years vs 2.6 years), larger (30 vs 21%), had a higher fatality rate (19.4 vs 7.7%), and more of them were female (55 vs 47%) compared with scald burn patients. Electric burn patients were oldest (8.3 years) and all male. When compared with data in the NBR, average burn size was larger in Vellore (24 vs 9%). The mortality rate was higher in Vellore (10.1 vs 0.5%). The average mortal burn size in Vellore was smaller (40 vs 51%). Electric burns were more common in Vellore (6.0 vs 1.6%). Contact burns were almost nonexistent in Vellore (0.9 vs 13.1%). The differences in pediatric burn care from developing health care systems to burn centers in the US are manifold. Nonpresentation of smaller cases, and incomplete data in the NBR explain many of the differences. However, burns at this

  12. Nuclear waste forms for actinides

    PubMed Central

    Ewing, Rodney C.

    1999-01-01

    The disposition of actinides, most recently 239Pu from dismantled nuclear weapons, requires effective containment of waste generated by the nuclear fuel cycle. Because actinides (e.g., 239Pu and 237Np) are long-lived, they have a major impact on risk assessments of geologic repositories. Thus, demonstrable, long-term chemical and mechanical durability are essential properties of waste forms for the immobilization of actinides. Mineralogic and geologic studies provide excellent candidate phases for immobilization and a unique database that cannot be duplicated by a purely materials science approach. The “mineralogic approach” is illustrated by a discussion of zircon as a phase for the immobilization of excess weapons plutonium. PMID:10097054

  13. Actinide cation-cation complexes

    SciTech Connect

    Stoyer, N.J.; Seaborg, G.T.

    1994-12-01

    The +5 oxidation state of U, Np, Pu, and Am is a linear dioxo cation (AnO{sub 2}{sup +}) with a formal charge of +1. These cations form complexes with a variety of other cations, including actinide cations. Other oxidation states of actinides do not form these cation-cation complexes with any cation other than AnO{sub 2}{sup +}; therefore, cation-cation complexes indicate something unique about AnO{sub 2}{sup +} cations compared to actinide cations in general. The first cation-cation complex, NpO{sub 2}{sup +}{center_dot}UO{sub 2}{sup 2+}, was reported by Sullivan, Hindman, and Zielen in 1961. Of the four actinides that form AnO{sub 2}{sup +} species, the cation-cation complexes of NpO{sub 2}{sup +} have been studied most extensively while the other actinides have not. The only PuO{sub 2}{sup +} cation-cation complexes that have been studied are with Fe{sup 3+} and Cr{sup 3+} and neither one has had its equilibrium constant measured. Actinides have small molar absorptivities and cation-cation complexes have small equilibrium constants; therefore, to overcome these obstacles a sensitive technique is required. Spectroscopic techniques are used most often to study cation-cation complexes. Laser-Induced Photacoustic Spectroscopy equilibrium constants for the complexes NpO{sub 2}{sup +}{center_dot}UO{sub 2}{sup 2+}, NpO{sub 2}{sup +}{center_dot}Th{sup 4+}, PuO{sub 2}{sup +}{center_dot}UO{sub 2}{sup 2+}, and PuO{sub 2}{sup +}{center_dot}Th{sup 4+} at an ionic strength of 6 M using LIPAS are 2.4 {plus_minus} 0.2, 1.8 {plus_minus} 0.9, 2.2 {plus_minus} 1.5, and {approx}0.8 M{sup {minus}1}.

  14. Actinide Thermodynamics at Elevated Temperatures

    SciTech Connect

    Friese, Judah I.; Rao, Linfeng; Xia, Yuanxian; Bachelor, Paula P.; Tian, Guoxin

    2007-11-16

    The postclosure chemical environment in the proposed Yucca Mountain repository is expected to experience elevated temperatures. Predicting migration of actinides is possible if sufficient, reliable thermodynamic data on hydrolysis and complexation are available for these temperatures. Data are scarce and scattered for 25 degrees C, and nonexistent for elevated temperatures. This collaborative project between LBNL and PNNL collects thermodynamic data at elevated temperatures on actinide complexes with inorganic ligands that may be present in Yucca Mountain. The ligands include hydroxide, fluoride, sulfate, phosphate and carbonate. Thermodynamic parameters of complexation, including stability constants, enthalpy, entropy and heat capacity of complexation, are measured with a variety of techniques including solvent extraction, potentiometry, spectrophotometry and calorimetry

  15. Mathematical modeling of the effects of aerobic and anaerobic chelate bioegradation on actinide speciation.

    SciTech Connect

    Banaszak, J.E.; VanBriesen, J.; Rittmann, B.E.; Reed, D.T.

    1998-03-19

    Biodegradation of natural and anthropogenic chelating agents directly and indirectly affects the speciation, and, hence, the mobility of actinides in subsurface environments. We combined mathematical modeling with laboratory experimentation to investigate the effects of aerobic and anaerobic chelate biodegradation on actinide [Np(IV/V), Pu(IV)] speciation. Under aerobic conditions, nitrilotriacetic acid (NTA) biodegradation rates were strongly influenced by the actinide concentration. Actinide-chelate complexation reduced the relative abundance of available growth substrate in solution and actinide species present or released during chelate degradation were toxic to the organisms. Aerobic bio-utilization of the chelates as electron-donor substrates directly affected actinide speciation by releasing the radionuclides from complexed form into solution, where their fate was controlled by inorganic ligands in the system. Actinide speciation was also indirectly affected by pH changes caused by organic biodegradation. The two concurrent processes of organic biodegradation and actinide aqueous chemistry were accurately linked and described using CCBATCH, a computer model developed at Northwestern University to investigate the dynamics of coupled biological and chemical reactions in mixed waste subsurface environments. CCBATCH was then used to simulate the fate of Np during anaerobic citrate biodegradation. The modeling studies suggested that, under some conditions, chelate degradation can increase Np(IV) solubility due to carbonate complexation in closed aqueous systems.

  16. Burning vasculitis.

    PubMed

    Chadha, Priyanka; Hobday, Dorian; Fitzgerald O'Connor, Edmund; D'Cruz, David

    2016-01-01

    We present the case of a 69-year-old man who was found collapsed close to a heat source and admitted to hospital for severe sepsis. He was also found to have widespread blistering and ulceration of his right leg; however, a history was unobtainable due to reduced consciousness levels. The leg lesions had the initial appearance of mixed depth burns and a management plan was made to transfer the patient to a burns unit for debridement. It was subsequently noted that the patient had a previous diagnosis of seropositive erosive rheumatoid arthritis. A biopsy of the leg lesion was performed and a diagnosis of rheumatoid vasculitis confirmed. Treatment with systemic steroids, intravenous antibiotics and intravenous immunoglobulin therapy for severe hypogammaglobulinaemia was started, and the patient was not transferred for surgical debridement. Rheumatoid vasculitis is a rare and extremely serious complication of rheumatoid arthritis that can manifest in a number of ways, occasionally mimicking other conditions. This case is essential to raise awareness of rare, severe rheumatoid vasculitis and of the potential for its misdiagnosis as a mixed depth burn. PMID:27118745

  17. Selection of actinide chemical analogues for WIPP tests

    SciTech Connect

    Villarreal, R.; Spall, D.

    1995-07-05

    The Department of Energy must demonstrate the effectiveness of the Waste Isolation Pilot Plant (WIPP) as a permanent repository for the disposal of transuranic (TRU) waste. Performance assessments of the WIPP require that estimates of the transportability and outcome of the radionuclides (actinides) be determined from disposal rooms that may become either partially or completely filled with brine. Federal regulations limit the amount of radioactivity that may be unintentionally released to the accessible environment by any mechanism during the post closure phase up to 10,000 years. Thermodynamic models have been developed to predict the concentrations of actinides in the WIPP disposal rooms under various situations and chemical conditions. These models are based on empirical and theoretical projections of the chemistry that might be present in and around the disposal room zone for both near and long-term periods. The actinides that are known to be present in the TRU wastes (and are included in the model) are Th, U, Np, Pu, and Am. Knowledge of the chemistry that might occur in the disposal rooms when the waste comes in contact with brine is important in understanding the range of oxidation states that might be present under different conditions. There is a need to establish the mechanisms and resultant rate of transport, migration, or effective retardation of actinides beyond the disposal rooms to the boundary of the accessible environment. The influence of the bulk salt rock, clay sediments and other geologic matrices on the transport behavior of actinides must be determined to establish the overall performance and capability of the WIPP in isolating waste from the environment. Tests to determine the capabilities of the WIPP geologic formations in retarding actinide species in several projected oxidation states would provide a means to demonstrate the effectiveness of the WIPP in retaining TRU wastes.

  18. Separations of actinides, lanthanides and other metals

    DOEpatents

    Smith, Barbara F.; Jarvinen, Gordon D.; Ensor, Dale D.

    1995-01-01

    An organic extracting solution comprised of a bis(acylpyrazolone or a substituted bis(acylpyrazolone) and an extraction method useful for separating certain elements of the actinide series of the periodic table having a valence of four from one other, and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also from one or more of the substances in a group consisting of hexavalent actinides, trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals and also useful for separating hexavalent actinides from one or more of the substances in a group consisting of trivalent actinides, trivalent lanthanides, trivalent iron, trivalent aluminum, divalent metals, and monovalent metals.

  19. Experimental Evaluation of Actinide Transport in a Fractured Granodiorite

    SciTech Connect

    Dittrich, Timothy M.; Reimus, Paul W.

    2015-03-16

    The objective of this study was to demonstrate and evaluate new experimental methods for quantifying the potential for actinide transport in deep fractured crystalline rock formations. We selected a fractured granodiorite at the Grimsel Test Site (GTS) in Switzerland as a model system because field experiments have already been conducted with uranium and additional field experiments using other actinides are planned at the site. Thus, working on this system provides a unique opportunity to compare lab experiment results with fieldscale observations. Rock cores drilled from the GTS were shipped to Los Alamos National Laboratory, characterized by x-ray diffraction and microscopy, and used in batch sorption and column breakthrough experiments. Solutions with pH 6.8 and 8.8 were tested. Solutions were switched to radionuclide-free synthetic Grimsel groundwater after near-steady actinide/colloid breakthrough occurred in column experiments. We are currently evaluating actinide adsorption/desorption rates as a function of water chemistry (initial focus on pH), with future testing planned to evaluate the influence of carbonate concentrations, flow rates, and mineralogy in solutions and suspensions with bentonite colloids. (auth)

  20. The Burn Wound Microenvironment

    PubMed Central

    Rose, Lloyd F.; Chan, Rodney K.

    2016-01-01

    Significance: While the survival rate of the severely burned patient has improved significantly, relatively little progress has been made in treatment or prevention of burn-induced long-term sequelae, such as contraction and fibrosis. Recent Advances: Our knowledge of the molecular pathways involved in burn wounds has increased dramatically, and technological advances now allow large-scale genomic studies, providing a global view of wound healing processes. Critical Issues: Translating findings from a large number of in vitro and preclinical animal studies into clinical practice represents a gap in our understanding, and the failures of a number of clinical trials suggest that targeting single pathways or cytokines may not be the best approach. Significant opportunities for improvement exist. Future Directions: Study of the underlying molecular influences of burn wound healing progression will undoubtedly continue as an active research focus. Increasing our knowledge of these processes will identify additional therapeutic targets, supporting informed clinical studies that translate into clinical relevance and practice. PMID:26989577

  1. Protocolized Resuscitation of Burn Patients.

    PubMed

    Cancio, Leopoldo C; Salinas, Jose; Kramer, George C

    2016-10-01

    Fluid resuscitation of burn patients is commonly initiated using modified Brooke or Parkland formula. The fluid infusion rate is titrated up or down hourly to maintain adequate urine output and other endpoints. Over-resuscitation leads to morbid complications. Adherence to paper-based protocols, flow sheets, and clinical practice guidelines is associated with decreased fluid resuscitation volumes and complications. Computerized tools assist providers. Although completely autonomous closed-loop control of resuscitation has been demonstrated in animal models of burn shock, the major advantages of open-loop and decision-support systems are identifying trends, enhancing situational awareness, and encouraging burn team communication. PMID:27600131

  2. Occupational Burns Treated in Emergency Departments

    PubMed Central

    Reichard, Audrey A.; Konda, Srinivas; Jackson, Larry L.

    2015-01-01

    Background Despite reported declines, occupational burn injuries remain a workplace safety concern. More severe burns may result in costly medical treatment and long-term physical and psychological consequences. Methods We used the National Electronic Injury Surveillance System—Occupational Supplement to produce national estimates of burns treated in emergency departments (EDs). We analyzed data trends from 1999 to 2008 and provided detailed descriptions of 2008 data. Results From 1999 to 2008 there were 1,132,000 (95% CI: ±192,300) nonfatal occupational burns treated in EDs. Burn numbers and rates declined approximately 40% over the 10 years. In 2008, men and younger workers 15–24 years old had the highest rates. Scalds and thermal burns accounted for more than 60% of burns. Accommodation and food service, manufacturing, and construction industries had the largest number of burns. Conclusions Despite declining burn rates, emphasis is needed on reducing burn hazards to young food service workers and using job specific hazard analyses to prevent burns. PMID:25678457

  3. "Computational Modeling of Actinide Complexes"

    SciTech Connect

    Balasubramanian, K

    2007-03-07

    We will present our recent studies on computational actinide chemistry of complexes which are not only interesting from the standpoint of actinide coordination chemistry but also of relevance to environmental management of high-level nuclear wastes. We will be discussing our recent collaborative efforts with Professor Heino Nitsche of LBNL whose research group has been actively carrying out experimental studies on these species. Computations of actinide complexes are also quintessential to our understanding of the complexes found in geochemical, biochemical environments and actinide chemistry relevant to advanced nuclear systems. In particular we have been studying uranyl, plutonyl, and Cm(III) complexes are in aqueous solution. These studies are made with a variety of relativistic methods such as coupled cluster methods, DFT, and complete active space multi-configuration self-consistent-field (CASSCF) followed by large-scale CI computations and relativistic CI (RCI) computations up to 60 million configurations. Our computational studies on actinide complexes were motivated by ongoing EXAFS studies of speciated complexes in geo and biochemical environments carried out by Prof Heino Nitsche's group at Berkeley, Dr. David Clark at Los Alamos and Dr. Gibson's work on small actinide molecules at ORNL. The hydrolysis reactions of urnayl, neputyl and plutonyl complexes have received considerable attention due to their geochemical and biochemical importance but the results of free energies in solution and the mechanism of deprotonation have been topic of considerable uncertainty. We have computed deprotonating and migration of one water molecule from the first solvation shell to the second shell in UO{sub 2}(H{sub 2}O){sub 5}{sup 2+}, UO{sub 2}(H{sub 2}O){sub 5}{sup 2+}NpO{sub 2}(H{sub 2}O){sub 6}{sup +}, and PuO{sub 2}(H{sub 2}O){sub 5}{sup 2+} complexes. Our computed Gibbs free energy(7.27 kcal/m) in solution for the first time agrees with the experiment (7.1 kcal

  4. Safe management of actinides in the nuclear fuel cycle: Role of mineralogy

    NASA Astrophysics Data System (ADS)

    Ewing, Rodney C.

    2011-02-01

    During the past 60 years, more than 1800 metric tonnes of Pu, and substantial quantities of the "minor" actinides, such as Np, Am and Cm, have been generated in nuclear reactors. Some of these transuranium elements can be a source of energy in fission reactions (e.g., 239Pu), a source of fissile material for nuclear weapons (e.g., 239Pu and 237Np), and of environmental concern because of their long-half lives and radiotoxicity (e.g., 239Pu and 237Np). There are two basic strategies for the disposition of these heavy elements: (1) to "burn" or transmute the actinides using nuclear reactors or accelerators; (2) to "sequester" the actinides in chemically durable, radiation-resistant materials that are suitable for geologic disposal. There has been substantial interest in the use of actinide-bearing minerals, especially isometric pyrochlore, A 2B 2O 7 (A = rare earths; B = Ti, Zr, Sn, Hf), for the immobilization of actinides, particularly plutonium, both as inert matrix fuels and nuclear waste forms. Systematic studies of rare-earth pyrochlores have led to the discovery that certain compositions (B = Zr, Hf) are stable to very high doses of alpha-decay event damage. Recent developments in our understanding of the properties of heavy element solids have opened up new possibilities for the design of advanced nuclear fuels and waste forms.

  5. Plutonium and minor actinide utilisation in a pebble-bed high temperature reactor

    SciTech Connect

    Petrov, B. Y.; Kuijper, J. C.; Oppe, J.; De Haas, J. B. M.

    2012-07-01

    This paper contains results of the analysis of the pebble-bed high temperature gas-cooled PUMA reactor loaded with plutonium and minor actinide (Pu/MA) fuel. Starting from knowledge and experience gained in the Euratom FP5 projects HTR-N and HTR-N1, this study aims at demonstrating the potential of high temperature reactors to utilize or transmute Pu/MA fuel. The work has been performed within the Euratom FP6 project PUMA. A number of different fuel types and fuel configurations have been analyzed and compared with respect to incineration performance and safety-related reactor parameters. The results show the excellent plutonium and minor actinide burning capabilities of the high temperature reactor. The largest degree of incineration is attained in the case of an HTR fuelled by pure plutonium fuel as it remains critical at very deep burnup of the discharged pebbles. Addition of minor actinides to the fuel leads to decrease of the achievable discharge burnup and therefore smaller fraction of actinides incinerated during reactor operation. The inert-matrix fuel design improves the transmutation performance of the reactor, while the 'wallpaper' fuel does not have advantage over the standard fuel design in this respect. After 100 years of decay following the fuel discharge, the total amount of actinides remains almost unchanged for all of the fuel types considered. Among the plutonium isotopes, only the amount of Pu-241 is reduced significantly due to its relatively short half-life. (authors)

  6. Process for recovering actinide values

    DOEpatents

    Horwitz, E. Philip; Mason, George W.

    1980-01-01

    A process for rendering actinide values recoverable from sodium carbonate scrub waste solutions containing these and other values along with organic compounds resulting from the radiolytic and hydrolytic degradation of neutral organophosphorous extractants such as tri-n butyl phosphate (TBP) and dihexyl-N,N-diethyl carbamylmethylene phosphonate (DHDECAMP) which have been used in the reprocessing of irradiated nuclear reactor fuels. The scrub waste solution is preferably made acidic with mineral acid, to form a feed solution which is then contacted with a water-immiscible, highly polar organic extractant which selectively extracts the degradation products from the feed solution. The feed solution can then be processed to recover the actinides for storage or recycled back into the high-level waste process stream. The extractant is recycled after stripping the degradation products with a neutral sodium carbonate solution.

  7. Actinide abundances in ordinary chondrites

    NASA Technical Reports Server (NTRS)

    Hagee, B.; Bernatowicz, T. J.; Podosek, F. A.; Johnson, M. L.; Burnett, D. S.

    1990-01-01

    Measurements of actinide and light REE (LREE) abundances and of phosphate abundances in equilibrated ordinary chondrites were obtained and were used to define the Pu abundance in the solar system and to determine the degree of variation of actinide and LREE abundances. The results were also used to compare directly the Pu/U ratio with the earlier obtained ratio determined indirectly, as (Pu/Nd)x(Nd/U), assuming that Pu behaves chemically as a LREE. The data, combined with high-accuracy isotope-dilution data from the literature, show that the degree of gram-scale variability of the Th, U, and LREE abundances for equilibrated ordinary chondrites is a factor of 2-3 for absolute abundances and up to 50 percent for relative abundances. The observed variations are interpreted as reflecting the differences in the compositions and/or proportions of solar nebula components accreted to ordinary chondrite parent bodies.

  8. Actinide chemistry in ionic liquids.

    PubMed

    Takao, Koichiro; Bell, Thomas James; Ikeda, Yasuhisa

    2013-04-01

    This Forum Article provides an overview of the reported studies on the actinide chemistry in ionic liquids (ILs) with a particular focus on several fundamental chemical aspects: (i) complex formation, (ii) electrochemistry, and (iii) extraction behavior. The majority of investigations have been dedicated to uranium, especially for the 6+ oxidation state (UO2(2+)), because the chemistry of uranium in ordinary solvents has been well investigated and uranium is the most abundant element in the actual nuclear fuel cycles. Other actinides such as thorium, neptunium, plutonium, americium, and curiumm, although less studied, are also of importance in fully understanding the nuclear fuel engineering process and the safe geological disposal of radioactive wastes. PMID:22873132

  9. Actinide Studies with Ultracold Neutrons

    NASA Astrophysics Data System (ADS)

    Broussard, Leah

    2014-03-01

    Understanding the effects of sputtering due to nuclear fission is crucial to the nuclear industry and has wide-reaching applications, including nuclear energy, space science, and national defense. A new program at the Los Alamos Neutron Science Center uses ultracold neutrons (UCN) to induce fission in actinides such as uranium and plutonium. UCN are an ideal tool for finely controlling induced fission as a function of depth in an actinide sample. The mechanism for fission-induced surface damage is not well understood, especially regarding the effect of a surface oxide layer. We will discuss our experimental strategy for studies of UCN-induced fission and the ejected material, and present preliminary data from enriched and depleted uranium. We gratefully acknowledge the support of the G. T. Seaborg Institute for Transactinium Science and the U.S. Department of Energy through the LANL/LDRD Program for this work.

  10. Actinide Waste Forms and Radiation Effects

    NASA Astrophysics Data System (ADS)

    Ewing, R. C.; Weber, W. J.

    Over the past few decades, many studies of actinides in glasses and ceramics have been conducted that have contributed substantially to the increased understanding of actinide incorporation in solids and radiation effects due to actinide decay. These studies have included fundamental research on actinides in solids and applied research and development related to the immobilization of the high level wastes (HLW) from commercial nuclear power plants and processing of nuclear weapons materials, environmental restoration in the nuclear weapons complex, and the immobilization of weapons-grade plutonium as a result of disarmament activities. Thus, the immobilization of actinides has become a pressing issue for the twenty-first century (Ewing, 1999), and plutonium immobilization, in particular, has received considerable attention in the USA (Muller et al., 2002; Muller and Weber, 2001). The investigation of actinides and

  11. Actinide recovery techniques utilizing electromechanical processes

    SciTech Connect

    Westphal, B.R.; Benedict, R.W.

    1994-01-01

    Under certain conditions, the separation of actinides using electromechanical techniques may be an effective means of residue processing. The separation of granular mixtures of actinides and other materials discussed in this report is based on appreciable differences in the magnetic and electrical properties of the actinide elements. In addition, the high density of actinides, particularly uranium and plutonium, may render a simultaneous separation based on mutually complementary parameters. Both high intensity magnetic separation and electrostatic separation have been investigated for the concentration of an actinide waste stream. Waste stream constituents include an actinide metal alloy and broken quartz shards. The investigation of these techniques is in support of the Integral Fast Reactor (IFR) concept currently being developed at Argonne National Laboratory under the auspices of the Department of Energy.

  12. Ram Burn Observations (RAMBO)

    NASA Astrophysics Data System (ADS)

    2002-12-01

    Ram Burn Observations (RAMBO) is a Department of Defense experiment that observes shuttle Orbital Maneuvering System engine burns for the purpose of improving plume models. On STS-107 the appropriate sensors will observe selected rendezvous and orbit adjust burns.

  13. Burning Mouth Syndrome and "Burning Mouth Syndrome".

    PubMed

    Rifkind, Jacob Bernard

    2016-03-01

    Burning mouth syndrome is distressing to both the patient and practitioner unable to determine the cause of the patient's symptoms. Burning mouth syndrome is a diagnosis of exclusion, which is used only after nutritional deficiencies, mucosal disease, fungal infections, hormonal disturbances and contact stomatitis have been ruled out. This article will explore the many causes and treatment of patients who present with a chief complaint of "my mouth burns," including symptomatic treatment for those with burning mouth syndrome. PMID:27209717

  14. Modeling Deep Burn TRISO particle nuclear fuel

    NASA Astrophysics Data System (ADS)

    Besmann, T. M.; Stoller, R. E.; Samolyuk, G.; Schuck, P. C.; Golubov, S. I.; Rudin, S. P.; Wills, J. M.; Coe, J. D.; Wirth, B. D.; Kim, S.; Morgan, D. D.; Szlufarska, I.

    2012-11-01

    Under the DOE Deep Burn program TRISO fuel is being investigated as a fuel form for consuming plutonium and minor actinides, and for greater efficiency in uranium utilization. The result will thus be to drive TRISO particulate fuel to very high burn-ups. In the current effort the various phenomena in the TRISO particle are being modeled using a variety of techniques. The chemical behavior is being treated utilizing thermochemical analysis to identify phase formation/transformation and chemical activities in the particle, including kernel migration. Density functional theory is being used to understand fission product diffusion within the plutonia oxide kernel, the fission product's attack on the SiC coating layer, as well as fission product diffusion through an alternative coating layer, ZrC. Finally, a multiscale approach is being used to understand thermal transport, including the effect of radiation damage induced defects, in a model SiC material.

  15. Electrochemical decontamination of actinide processing gloveboxes

    SciTech Connect

    Lugo, J.L.; Wedman, D.E.; Nelson, T.O.

    1997-12-31

    Electrochemical technology for the decontamination of metallic surfaces has been successfully demonstrated. Highly enriched uranium and stainless steel surfaces are readily decontaminated to Low Level Waste (LLW) criteria using this process. This process is similar to electropolishing and utilizes the anodic dissolution of the substrate material to generate a clean surface. The surface contaminants are thus removed and collected along with the stripped substrate material as a compact precipitate. This separation allows the electrolyte to be recycled indefinitely. Using an alkaline Sodium Sulfate electrolyte solution, we are able to decontaminate to low levels of alpha activity, gloveboxes previously used in Actinide processing. Surfaces with contamination levels > 1,000,000 cpm alpha activity have been decontaminated to levels as low as 7,000. The process is rapid with decontamination occurring at a rate of over 3 square cm/sec.

  16. Erosive burning of solid propellants

    NASA Technical Reports Server (NTRS)

    King, Merrill K.

    1993-01-01

    Presented here is a review of the experimental and modeling work concerning erosive burning of solid propellants (augmentation of burning rate by flow of product gases across a burning surface). A brief introduction describes the motor design problems caused by this phenomenon, particularly for low port/throat area ratio motors and nozzleless motors. Various experimental techniques for measuring crossflow sensitivity of solid propellant burning rates are described, with the conclusion that accurate simulation of the flow, including upstream flow development, in actual motors is important since the degree of erosive burning depends not only on local mean crossflow velocity and propellant nature, but also upon this upstream development. In the modeling area, a brief review of simplified models and correlating equations is presented, followed by a description of more complex numerical analysis models. Both composite and double-base propellant models are reviewed. A second generation composite model is shown to give good agreement with data obtained in a series of tests in which composite propellant composition and heterogeneity (particle size distribution) were systematically varied. Finally, the use of numerical models for the development of erosive burning correlations is described, and a brief discussion of scaling is presented.

  17. Actinide partitioning-transmutation program final report. I. Overall assessment

    SciTech Connect

    Croff, A.G.; Blomeke, J.O.; Finney, B.C.

    1980-06-01

    This report is concerned with an overall assessment of the feasibility of and incentives for partitioning (recovering) long-lived nuclides from fuel reprocessing and fuel refabrication plant radioactive wastes and transmuting them to shorter-lived or stable nuclides by neutron irradiation. The principal class of nuclides considered is the actinides, although a brief analysis is given of the partitioning and transmutation (P-T) of /sup 99/Tc and /sup 129/I. The results obtained in this program permit us to make a comparison of the impacts of waste management with and without actinide recovery and transmutation. Three major conclusions concerning technical feasibility can be drawn from the assessment: (1) actinide P-T is feasible, subject to the acceptability of fuels containing recycle actinides; (2) technetium P-T is feasible if satisfactory partitioning processes can be developed and satisfactory fuels identified (no studies have been made in this area); and (3) iodine P-T is marginally feasible at best because of the low transmutation rates, the high volatility, and the corrosiveness of iodine and iodine compounds. It was concluded on the basis of a very conservative repository risk analysis that there are no safety or cost incentives for actinide P-T. In fact, if nonradiological risks are included, the short-term risks of P-T exceed the long-term benefits integrated over a period of 1 million years. Incentives for technetium and iodine P-T exist only if extremely conservative long-term risk analyses are used. Further RD and D in support of P-T is not warranted.

  18. Crystalline matrices for immobilization of actinides: Corrosion resistance in water

    NASA Astrophysics Data System (ADS)

    Yudintsev, S. V.; Aleksandrova, E. V.; Livshits, T. S.; Mal'kovskii, V. I.; Bychkova, Ya. V.; Tagirov, B. R.

    2014-10-01

    The rate of leaching of actinide-simulating rare-earth elements from two types of crystalline matrices consisting of titanate and titanozirconate phases was examined. The experiments were carried out at 95°C in distilled water. The rates of REE leaching from the samples were below 10-3 g/m2 day, which satisfied the requirements for the characteristics of matrices for immobilization of actinides. After passing the treated solutions through filters of 450 to 25 nm pore sizes, the REE content was changed slightly or not at all. This fact points to the minor role or to the absence of the colloidal form of REE in the solutions after the experiments.

  19. Use of Thorium for Transmutation of Plutonium and Minor Actinides in PWRs

    SciTech Connect

    Shwageraus, Eugene; Hejzlar, Pavel; Kazimi, Mujid S.

    2004-07-15

    An assessment is made of the potential for Th-based fuel to minimize Pu and minor actinide (MA) production in pressurized water reactors (PWRs). Destruction rates and residual amounts of Pu and MA in the fuel used for transmutation are examined. In particular, sensitivity of these two parameters to the fuel lattice hydrogen to heavy metal (H/HM) ratio and to the fuel composition was systematically investigated. All burnup calculations were performed using CASMO4, the fuel assembly burnup code. The results indicate that up to 1000 kg of reactor-grade Pu can be burned in Th-based fuel assemblies per gigawatt (electric) year. Up to 75% of initial Pu can be destroyed per passage through reactor core. Addition of MA to the fuel mixture degrades the burning efficiency. The theoretically achievable limit for total transuranium (TRU) destruction per passage through the core is 50%. Efficient MA and Pu destruction in Th-based fuel generally requires a higher degree of neutron moderation and, therefore, higher fuel lattice H/HM ratio than typically used in the current generation of PWRs. Reactivity coefficients evaluation demonstrated the feasibility of designing a Th-Pu-MA fueled core with negative Doppler and moderator temperature coefficients. Introduction of TRU-containing fuels to a PWR core inevitably leads to lower control material worths and smaller delayed-neutron yields than with conventional UO{sub 2} cores. Therefore, a major challenge associated with the introduction of Th-TRU fuels to PWRs will be the design of the whole core and reactor control features to ensure safe reactor operation.

  20. Work-related burns in Washington State, 1994 to 1998.

    PubMed

    Baggs, James; Curwick, Christy; Silverstein, Barbara

    2002-07-01

    This article describes an investigation of work-related burns in Washington State during 1994-1998. Workers' compensation data were used to describe the general characteristics of burn injuries, estimate industrial claims rates, and compare nonhospitalized and hospitalized burn cases. The completeness of workers' compensation data as a source for surveillance was evaluated. During 1994-1998, a total of 20,213 burn claims were accepted by the workers' compensation system. Hospitalized burn cases represented only 1.5% of burn claims but incurred 55% of the costs. In addition, workers' compensation data underestimated the frequency and rate of burns. Although workers' compensation claims rates decreased during 1994-1998, work-related burns remain a problem in Washington State. Several industries (e.g., roofing, foundries, and aluminum smelting) were identified as priorities for prevention of burn hospitalizations, which incur the greater cost and time loss. PMID:12134534

  1. Factors influencing the transport of actinides in the groundwater environment. Final report

    SciTech Connect

    Sheppard, J.C.; Kittrick, J.A.

    1983-07-31

    This report summarizes investigations of factors that significantly influence the transport of actinide cations in the groundwater environment. Briefly, measurements of diffusion coefficients for Am(III), Cm(III), and Np(V) in moist US soils indicated that diffusion is negligible compared to mass transport in flowing groundwater. Diffusion coefficients do, however, indicate that, in the absence of flowing water, actinide elements will migrate only a few centimeters in a thousand years. The remaining investigations were devoted to the determination of distribution ratios (K/sub d/s) for representative US soils, factors influencing them, and chemical and physical processes related to transport of actinides in groundwaters. The computer code GARD was modified to include complex formation to test the importance of humic acid complexing on the rate of transport of actinides in groundwaters. Use of the formation constant and a range of humic acid, even at rather low concentrations of 10/sup -5/ to 10/sup -6/ molar, significantly increases the actinide transport rate in a flowing aquifer. These computer calculations show that any strong complexing agent will have a similar effect on actinide transport in the groundwater environment. 32 references, 9 figures.

  2. Analysis of large soil samples for actinides

    DOEpatents

    Maxwell, III; Sherrod L.

    2009-03-24

    A method of analyzing relatively large soil samples for actinides by employing a separation process that includes cerium fluoride precipitation for removing the soil matrix and precipitates plutonium, americium, and curium with cerium and hydrofluoric acid followed by separating these actinides using chromatography cartridges.

  3. Prompt fission neutron spectra of actinides

    DOE PAGESBeta

    Capote, R.; Chen, Y. -J.; Hambsch, F. -J.; Kornilov, N. V.; Lestone, J. P.; Litaize, O.; Morillon, B.; Neudecker, D.; Oberstedt, S.; Ohsawa, T.; et al

    2016-01-06

    Here, the energy spectrum of prompt neutrons emitted in fission (PFNS) plays a very important role in nuclear science and technology. A Coordinated Research Project (CRP) "Evaluation of Prompt Fission Neutron Spectra of Actinides" was established by the IAEA Nuclear Data Section in 2009, with the major goal to produce new PFNS evaluations with uncertainties for actinide nuclei.

  4. Actinide abundances in ordinary chondrites

    USGS Publications Warehouse

    Hagee, B.; Bernatowicz, T.J.; Podosek, F.A.; Johnson, M.L.; Burnett, D.S.; Tatsumoto, M.

    1990-01-01

    Measurements of 244Pu fission Xe, U, Th, and light REE (LREE) abundances, along with modal petrographic determinations of phosphate abundances, were carried out on equilibrated ordinary chondrites in order to define better the solar system Pu abundance and to determine the degree of variation of actinide and LREE abundances. Our data permit comparison of the directly measured Pu/ U ratio with that determined indirectly as (Pu/Nd) ?? (Nd/U) assuming that Pu behaves chemically as a LREE. Except for Guaren??a, and perhaps H chondrites in general, Pu concentrations are similar to that determined previously for St. Se??verin, although less precise because of higher trapped Xe contents. Trapped 130Xe 136Xe ratios appear to vary from meteorite to meteorite, but, relative to AVCC, all are similar in the sense of having less of the interstellar heavy Xe found in carbonaceous chondrite acid residues. The Pu/U and Pu/Nd ratios are consistent with previous data for St. Se??verin, but both tend to be slightly higher than those inferred from previous data on Angra dos Reis. Although significant variations exist, the distribution of our Th/U ratios, along with other precise isotope dilution data for ordinary chondrites, is rather symmetric about the CI chondrite value; however, actinide/(LREE) ratios are systematically lower than the CI value. Variations in actinide or LREE absolute and relative abundances are interpreted as reflecting differences in the proportions and/or compositions of more primitive components (chondrules and CAI materials?) incorporated into different regions of the ordinary chondrite parent bodies. The observed variations of Th/U, Nd/U, or Ce/U suggest that measurements of Pu/U on any single equilibrated ordinary chondrite specimen, such as St. Se??verin, should statistically be within ??20-30% of the average solar system value, although it is also clear that anomalous samples exist. ?? 1990.

  5. Separation of actinides from lanthanides

    DOEpatents

    Smith, Barbara F.; Jarvinen, Gordon D.; Ryan, Robert R.

    1989-01-01

    An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4-dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  6. Separation of actinides from lanthanides

    DOEpatents

    Smith, B.F.; Jarvinen, G.D.; Ryan, R.R.

    1988-03-31

    An organic extracting solution and an extraction method useful for separating elements of the actinide series of the periodic table from elements of the lanthanide series, where both are in trivalent form is described. The extracting solution consists of a primary ligand and a secondary ligand, preferably in an organic solvent. The primary ligand is a substituted monothio-1,3-dicarbonyl, which includes a substituted 4-acyl-2-pyrazolin-5-thione, such as 4-benzoyl-2,4- dihydro-5-methyl-2-phenyl-3H-pyrazol-3-thione (BMPPT). The secondary ligand is a substituted phosphine oxide, such as trioctylphosphine oxide (TOPO).

  7. Exploring actinide materials through synchrotron radiation techniques.

    PubMed

    Shi, Wei-Qun; Yuan, Li-Yong; Wang, Cong-Zhi; Wang, Lin; Mei, Lei; Xiao, Cheng-Liang; Zhang, Li; Li, Zi-Jie; Zhao, Yu-Liang; Chai, Zhi-Fang

    2014-12-10

    Synchrotron radiation (SR) based techniques have been utilized with increasing frequency in the past decade to explore the brilliant and challenging sciences of actinide-based materials. This trend is partially driven by the basic needs for multi-scale actinide speciation and bonding information and also the realistic needs for nuclear energy research. In this review, recent research progresses on actinide related materials by means of various SR techniques were selectively highlighted and summarized, with the emphasis on X-ray absorption spectroscopy, X-ray diffraction and scattering spectroscopy, which are powerful tools to characterize actinide materials. In addition, advanced SR techniques for exploring future advanced nuclear fuel cycles dealing with actinides are illustrated as well. PMID:25169914

  8. Actinide ion sensor for pyroprocess monitoring

    DOEpatents

    Jue, Jan-fong; Li, Shelly X.

    2014-06-03

    An apparatus for real-time, in-situ monitoring of actinide ion concentrations which comprises a working electrode, a reference electrode, a container, a working electrolyte, a separator, a reference electrolyte, and a voltmeter. The container holds the working electrolyte. The voltmeter is electrically connected to the working electrode and the reference electrode and measures the voltage between those electrodes. The working electrode contacts the working electrolyte. The working electrolyte comprises an actinide ion of interest. The reference electrode contacts the reference electrolyte. The reference electrolyte is separated from the working electrolyte by the separator. The separator contacts both the working electrolyte and the reference electrolyte. The separator is ionically conductive to the actinide ion of interest. The reference electrolyte comprises a known concentration of the actinide ion of interest. The separator comprises a beta double prime alumina exchanged with the actinide ion of interest.

  9. Actinide co-conversion by internal gelation

    SciTech Connect

    Robisson, Anne-Charlotte; Dauby, Jacques; Dumont-Shintu, Corinne; Machon, Estelle; Grandjean, Stephane

    2007-07-01

    Suitable microstructures and homogenous microspheres of actinide compounds are of interest for future nuclear fuel or transmutation target concepts to prevent the generation and dispersal of actinide powder. Sol-gel routes are being investigated as one of the possible solutions for producing these compounds. Preliminary work is described involving internal gelation to synthesize mixed compounds including minor actinides, particularly mixed actinide or mixed actinide-inert element compounds. A parameter study is discussed to highlight the importance of the initial broth composition for obtaining gel microspheres without major defects (cracks, craters, etc.). In particular, conditions are defined to produce gel beads from Zr(IV)/Y(III)/Ce(III) or Zr(IV)/An(III) systems. After gelation, the heat treatment of these microspheres is described for the purpose of better understanding the formation of cracks after calcination and verifying the effective synthesis of an oxide solid-solution. (authors)

  10. AECL/US INERI - Development of Inert Matrix Fuels for Plutonium and Minor Actinide Management in Power Reactors -- Fuel Requirements and Down-Select Report

    SciTech Connect

    William Carmack; Randy D. Lee; Pavel Medvedev; Mitch Meyer; Michael Todosow; Holly B. Hamilton; Juan Nino; Simon Philpot; James Tulenko

    2005-06-01

    potential advantage for more efficient destruction of plutonium and minor actinides (MA) relative to MOX fuel. Greater efficiency in plutonium reduction results in greater flexibility in managing plutonium inventories and in developing strategies for disposition of MA, as well as a potential for fuel cycle cost savings. Because fabrication of plutonium-bearing (and MA-bearing) fuel is expensive relative to UO{sub 2} in terms of both capital and production, cost benefit can be realized through a reduction in the number of plutonium-bearing elements required for a given burn rate. In addition, the choice of matrix material may be manipulated either to facilitate fuel recycling or to make plutonium recovery extremely difficult. In addition to plutonium/actinide management, an inert matrix fuel having high thermal conductivity may have operational and safety benefits; lower fuel temperatures could be used to increase operating and safety margins, uprate reactor power, or a combination of both. The CANDU reactor offers flexibility in plutonium management and MA burning by virtue of online refueling, a simple bundle design, and good neutron economy. A full core of inert matrix fuel containing either plutonium or a plutonium-actinide mix can be utilized, with plutonium destruction efficiencies greater than 90%, and high (>60%) actinide destruction efficiencies. The Advanced CANDU Reactor (ACR) could allow additional possibilities in the design of an IMF bundle, since the tighter lattice pitch and light-water coolant reduce or eliminate the need to suppress coolant void reactivity, allowing the center region of the bundle to include additional fissile material and to improve actinide burning. The ACR would provide flexibility for management of plutonium and MA from the existing LWR fleet, and would be complementary to the AFCI program in the U.S. Many of the fundamental principles concerning the use of IMF are nearly identical in LWRs and the ACR, including fuel

  11. Pathophysiology of burns.

    PubMed

    Keck, Maike; Herndon, David H; Kamolz, Lars P; Frey, Manfred; Jeschke, Marc G

    2009-01-01

    Burn injury represents a significant problem worldwide. Advances in therapy strategies, based on better understanding of the pathophysiologic responses after burn injury have improved the clinical outcome of patients with burn injuries over the past years. This article describes the present understanding of the pathophysiology of a burn injury including both the local and systemic responses, focusing on the many facets of organ and systemic effects directly resulting from hypovolemia and circulating mediators following burn trauma. PMID:19652939

  12. Toddlers at High Risk of Chemical Eye Burns

    MedlinePlus

    ... fullstory_160258.html Toddlers at High Risk of Chemical Eye Burns: Study Access to household cleaning products ... and 2 years have relatively high rates of chemical eye burns, with everyday cleaners a common cause, ...

  13. Behavior of actinides in the Integral Fast Reactor fuel cycle

    SciTech Connect

    Courtney, J.C.; Lineberry, M.J.

    1994-06-01

    The Integral Fast Reactor (IFR) under development by Argonne National Laboratory uses metallic fuels instead of ceramics. This allows electrorefining of spent fuels and presents opportunities for recycling minor actinide elements. Four minor actinides ({sup 237}Np, {sup 240}Pu, {sup 241}Am, and {sup 243}Am) determine the waste storage requirements of spent fuel from all types of fission reactors. These nuclides behave the same as uranium and other plutonium isotopes in electrorefining, so they can be recycled back to the reactor without elaborate chemical processing. An experiment has been designed to demonstrate the effectiveness of the high-energy neutron spectra of the IFR in consuming these four nuclides and plutonium. Eighteen sets of seven actinide and five light metal targets have been selected for ten day exposure in the Experimental Breeder Reactor-2 which serves as a prototype of the IFR. Post-irradiation analyses of the exposed targets by gamma, alpha, and mass spectroscopy are used to determine nuclear reaction-rates and neutron spectra. These experimental data increase the authors` confidence in their ability to predict reaction rates in candidate IFR designs using a variety of neutron transport and diffusion programs.

  14. Clinical forensic evidence in burns: rescuer burns.

    PubMed

    Kumar, Pramod; Gopal, Kirun; Ramnani, Sunil

    2006-12-01

    In the literature no systematic study is available on rescuer burn for victims of burn injury. This is a retrospective study of nine patients (five admitted and four outpatients) were treated in this hospital as rescuer burns in 3.5 years. All nine patients were males. Average age of the patient treated on outpatient basis was 47 years (ranging between 44 and 52) and total burn area ranged for 1-4%. Average age of the five patients treated on inpatient basis was 32.6 years (ranging between 30 and 34). The total burn area ranged from 14.5 to 38%. During the period of study, in addition to nine rescuer burns, one patient sustained burn before the rescue attempt due to the victim hugging the rescuer. Based on the study of patterns of burn, these patients were found to have three grades of burn injury: Grade 1--upper extremity involvement only. (A) only one upper extremity involvement, (B) both upper extremities involvement, Grade 2--upper extremity/extremities and face involvement, Grade 3--upper extremity/extremities, face-neck, adjacent chest and lower extremity involvement. PMID:17011132

  15. Measurements of reactive trace gases and variable O3 formation rates in some South Carolina biomass burning plumes

    SciTech Connect

    Akagi, S. K.; Yokelson, R. J.; Burling, I. R.; Meinardi, S.; Simpson, I.; Blake, D. R.; McMeeking, G. R.; Sullivan, A.; Lee, T.; Kreidenweis, S.; Urbanski, S.; Reardon, J.; Griffith, D. W. T.; Johnson, T. J.; Weise, D. R.

    2013-02-01

    In October-November 2011 we measured the trace gas emission factors from 7 prescribed fires in South Carolina, U.S. using two Fourier transform infrared spectrometer (FTIR) systems and whole air sampling (WAS) into canisters followed by gas-chromatographic analyses. The fires were intended to emulate high-intensity burns as they were lit during the dry season and in most cases represented stands that had not been treated with prescribed burns in 10+ years, if at all. A total of 97 trace gas species are reported here from both airborne and ground-based platforms making this one of the most detailed field studies of fire emissions to date. The measurements included the first data for a suite of monoterpene compounds emitted via distillation of plant tissues during real fires. The known chemistry of the monoterpenes and their measured abundance of ~0.40% of CO (molar basis), ~3.9% of NMOC (molar basis), and ~21% of organic aerosol (mass basis), suggests that they impacted post-emission formation of ozone, aerosol, and small organic trace gases such as methanol and formaldehyde in the sampled plumes. The variability in the terpene emissions in South Carolina (SC) fire plumes was high and, in general, the speciation of the emitted gas-phase non-methane organic compounds was surprisingly different from that observed in a similar study in nominally similar pine forests in North Carolina ~20 months earlier. It is likely that the slightly different ecosystems, time of year and the precursor variability all contributed to the variability in plume chemistry observed in this study and in the literature. The ΔHCN/ΔCO emission ratio, however, is fairly consistent at 0.9 ± 0.06 % for airborne fire measurements in coniferous-dominated ecosystems further confirming the value of HCN as a good biomass burning indicator/tracer. The SC results also support an earlier finding that C3-C4 alkynes may be of use as biomass burning indicators on the time-scale of

  16. Correlation and relativistic effects in actinide ions

    SciTech Connect

    Safronova, U. I.; Safronova, M. S.

    2011-11-15

    Wavelengths, line strengths, and transition rates are calculated for the multipole (E1, M1, E2, M2, E3, and M3) transitions between the excited 6s{sup 2}6p{sup 5}nl and 6s6p{sup 6}nl states and the ground 6s{sup 2}6p{sup 6} state in Ac{sup 3+}, Th{sup 4+}, and U{sup 6+} Rn-like ions. Relativistic many-body perturbation theory (RMBPT), including the Breit interaction, is used to evaluate energies and transition rates for multipole transitions in these hole-particle systems. The RMBPT method agrees with multiconfigurational Dirac-Fock (MCDF) calculations in lowest order, includes all second-order correlation corrections, and includes corrections from negative-energy states. The calculations start from a [Xe]4f{sup 14}5d{sup 10}6s{sup 2}6p{sup 6} Dirac-Fock potential. First-order perturbation theory is used to obtain intermediate-coupling coefficients, and second-order RMBPT is used to determine the matrix elements. Evaluated multipole matrix elements for transitions from excited states to the ground states are used to determine the line strengths, transition rates, and multipole polarizabilities. This work provides a number of yet unmeasured properties of these actinide ions for various applications and for benchmark tests of theory and experiment.

  17. How Does the Freezer Burn Our Food?

    ERIC Educational Resources Information Center

    Schmidt, Shelly J.; Lee, Joo Won

    2009-01-01

    Freezer burn is a common problem that significantly affects the color, texture, and flavor of frozen foods. Food science students should be able to clearly explain the causes and consequences of freezer burn. However, it is difficult to find a modern, detailed, accurate, yet concise, explanation of the mechanism and factors influencing the rate of…

  18. Equations for Composite-Propellant Burning

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Cohen, N. S.

    1983-01-01

    Reported study of composite-propellant burning summarizes recent advances in understanding behavior of propellant formulations based on ammonium perchlorate (AOP), binder, and aluminum in various proportions and particle size distributions. Approach presented incorporates adapted version of earlier model for monopropellant AP. Objective is to predict burning-rate characteristics of composite propellants at high pressure.

  19. Evaluation of Heterogeneous Options: Effects of MgO versus UO2 Matrix Selection for Minor Actinide Targets in a Sodium Fast Reactor

    SciTech Connect

    M. Pope; S. Bays; R. Ferrer

    2008-03-01

    The primary focus of this work was to compare MgO with UO2 as target matrix material options for burning minor actinides in a transmutation target within a sodium fast reactor. This analysis compared the transmutation performance of target assemblies having UO2 matrix to those having specifically MgO inert matrix.

  20. Decontamination of matrices containing actinide oxides

    SciTech Connect

    Villarreal, Robert

    1997-12-01

    There is provided a method for removing actinides and actinide oxides, particularly fired actinides, from soil and other contaminated matrices, comprising: (a) contacting a contaminated material with a solution of at least one inhibited fluoride and an acid to form a mixture; (b) heating the mixture of contaminated material and solution to a temperature in the range from about 30 C to about 90 C while stirring; (c) separating the solution from any undissolved matrix material in the mixture; (d) washing the undissolved matrix material to remove any residual materials; and (e) drying and returning the treated matrix material to the environment.

  1. Experimental studies of actinides in molten salts

    SciTech Connect

    Reavis, J.G.

    1985-06-01

    This review stresses techniques used in studies of molten salts containing multigram amounts of actinides exhibiting intense alpha activity but little or no penetrating gamma radiation. The preponderance of studies have used halides because oxygen-containing actinide compounds (other than oxides) are generally unstable at high temperatures. Topics discussed here include special enclosures, materials problems, preparation and purification of actinide elements and compounds, and measurements of various properties of the molten volts. Property measurements discussed are phase relationships, vapor pressure, density, viscosity, absorption spectra, electromotive force, and conductance. 188 refs., 17 figs., 6 tabs.

  2. Actinide removal from spent salts

    DOEpatents

    Hsu, Peter C.; von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Adamson, Martyn G.

    2002-01-01

    A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

  3. PF-4 actinide disposition strategy

    SciTech Connect

    Margevicius, Robert W

    2010-05-28

    The dwindling amount of Security Category I processing and storage space across the DOE Complex has driven the need for more effective storage of nuclear materials at LANL's Plutonium Facility's (PF-4's) vault. An effort was begun in 2009 to create a strategy, a roadmap, to identify all accountable nuclear material and determine their disposition paths, the PF-4 Actinide Disposition Strategy (PADS). Approximately seventy bins of nuclear materials with similar characteristics - in terms of isotope, chemical form, impurities, disposition location, etc. - were established in a database. The ultimate disposition paths include the material to remain at LANL, disposition to other DOE sites, and disposition to waste. If all the actions described in the document were taken, over half of the containers currently in the PF-4 vault would been eliminated. The actual amount of projected vault space will depend on budget and competing mission requirements, however, clearly a significant portion of the current LANL inventory can be either dispositioned or consolidated.

  4. Subsurface interactions of actinide species and microorganisms : implications for the bioremediation of actinide-organic mixtures.

    SciTech Connect

    Banaszak, J.E.; Reed, D.T.; Rittmann, B.E.

    1999-02-12

    By reviewing how microorganisms interact with actinides in subsurface environments, we assess how bioremediation controls the fate of actinides. Actinides often are co-contaminants with strong organic chelators, chlorinated solvents, and fuel hydrocarbons. Bioremediation can immobilize the actinides, biodegrade the co-contaminants, or both. Actinides at the IV oxidation state are the least soluble, and microorganisms accelerate precipitation by altering the actinide's oxidation state or its speciation. We describe how microorganisms directly oxidize or reduce actinides and how microbiological reactions that biodegrade strong organic chelators, alter the pH, and consume or produce precipitating anions strongly affect actinide speciation and, therefore, mobility. We explain why inhibition caused by chemical or radiolytic toxicities uniquely affects microbial reactions. Due to the complex interactions of the microbiological and chemical phenomena, mathematical modeling is an essential tool for research on and application of bioremediation involving co-contamination with actinides. We describe the development of mathematical models that link microbiological and geochemical reactions. Throughout, we identify the key research needs.

  5. RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY SOIL SAMPLES

    SciTech Connect

    Maxwell, S.; Culligan, B.; Noyes, G.

    2009-11-09

    A new rapid method for the determination of actinides in soil and sediment samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used for samples up to 2 grams in emergency response situations. The actinides in soil method utilizes a rapid sodium hydroxide fusion method, a lanthanum fluoride soil matrix removal step, and a streamlined column separation process with stacked TEVA, TRU and DGA Resin cartridges. Lanthanum was separated rapidly and effectively from Am and Cm on DGA Resin. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha sources are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency soil samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinides in soil results were reported within 4-5 hours with excellent quality.

  6. RAPID SEPARATION METHOD FOR ACTINIDES IN EMERGENCY AIR FILTER SAMPLES

    SciTech Connect

    Maxwell, S.; Noyes, G.; Culligan, B.

    2010-02-03

    A new rapid method for the determination of actinides and strontium in air filter samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations. The actinides and strontium in air filter method utilizes a rapid acid digestion method and a streamlined column separation process with stacked TEVA, TRU and Sr Resin cartridges. Vacuum box technology and rapid flow rates are used to reduce analytical time. Alpha emitters are prepared using cerium fluoride microprecipitation for counting by alpha spectrometry. The purified {sup 90}Sr fractions are mounted directly on planchets and counted by gas flow proportional counting. The method showed high chemical recoveries and effective removal of interferences. This new procedure was applied to emergency air filter samples received in the NRIP Emergency Response exercise administered by the National Institute for Standards and Technology (NIST) in April, 2009. The actinide and {sup 90}Sr in air filter results were reported in {approx}4 hours with excellent quality.

  7. Burning and Burnout.

    ERIC Educational Resources Information Center

    Christensen, Jane

    1981-01-01

    Examines the extended metaphor of "burnout" as it applies to the teaching profession. Examines three ancient Celtic invocations for the better tending of fires, which reveal ways that teachers can burn with enthusiasm without burning out from apathy. (RL)

  8. Burns and Fire Safety

    MedlinePlus

    ... common among older children. 5 6 7 8 • Tap water burns most often occur in the bathroom and ... Feldman KW, Schaller RT, Feldman JA, McMillon M. Tap water scald burns in children. Pediatrics. 1978; 62(1): ...

  9. First Aid: Burns

    MedlinePlus

    ... You can get burned by heat, fire, radiation, sunlight, electricity, chemicals or hot or boiling water. There ... skin. The burned area will be sensitive to sunlight for up to one year, so you should ...

  10. Droplet burning at zero G

    NASA Technical Reports Server (NTRS)

    Williams, F. A.

    1978-01-01

    Questions of the importance and feasibility of performing experiments on droplet burning at zero gravity in Spacelab were studied. Information on the physics and chemistry of droplet combustion, with attention directed specifically to the chemical kinetics, heat and mass transfer, and fluid mechanics of the phenomena involved, are presented. The work was divided into three phases, the justification, the feasibility, and the conceptual development of a preliminary design. Results from the experiments performed revealed a few new facts concerning droplet burning, notably burning rates in excess of theoretical prediction and a phenomenon of flash extinction, both likely traceable to accumulation of carbon produced by gas-phase pyrolysis in the fuel-rich zone enclosed by the reaction surface. These experiments also showed that they were primarily due to timing difficulties.

  11. Nutrition in Burns: Galveston Contributions

    PubMed Central

    Rodriguez, Noe A.; Jeschke, Marc G.; Williams, Felicia N.; Kamolz, Lars-Peter; Herndon, David N.

    2013-01-01

    Aggressive nutrition support is recommended following severe burn injury. Initially, such injury results in a prolonged and persistent hypermetabolic response mediated by a 10- to 20-fold elevation in plasma catecholamines, cortisol, and inflammatory mediators. This response leads to twice-normal metabolic rates, whole-body catabolism, muscle wasting, and severe cachexia. Thus, it is relevant to review the literature on nutrition in burns to adjust/update treatment. Failure to meet the increased substrate requirements may result in impaired wound healing, multiorgan dysfunction, increased susceptibility to infection, and death. Therefore, aggressive nutrition support is essential to ensure adequate burn care, attenuate the hypermetabolic response, optimize wound healing, minimize devastating catabolism, and reduce morbidity and mortality. Here, the authors provide nutrition recommendations gained from prospective trials, retrospective analyses, and expert opinions based on the authors' practices in Galveston, Texas, and Vienna, Austria. PMID:21975669

  12. Economics of pediatric burns.

    PubMed

    Bass, Michael J; Phillips, Linda G

    2008-07-01

    Sustaining a burn injury sets in motion a cycle of pain, disfigurement, and a search for survival. In pediatric burns, the injury extends to the parents where fear, ignorance, and helplessness forever change their lives. Pediatric burn injuries are caused by fire, hot liquids, clothing irons, hair curlers, caustic substances like drain cleaner, the grounding of an electrical source, and exposure to radiation. Efficiency in the delivery of pediatric burn care is critical. Maximizing resource utilization means continual self-evaluation and economic analysis of therapeutic modalities. Griffiths et al found that most childhood burns are due to scalds, which can be treated for $1061 per percent burn. Paddock et al reduced the cost of treating superficial pediatric burns and reduced the length of stay in hospital using silver-impregnated gauze over traditional methods. Barrett et al found improved cosmesis of skin grafts using cultured epithelial autografts but at a substantially increased cost. Corpron et al showed that pediatric burn units that treat burns >10% total body surface area and operative treatment of pediatric burns regardless of size generate positive revenue. There is a paucity of evidentiary pediatric burn economic data. More research is needed to address areas of pediatric burn care inefficiency. Improving knowledge of cost in all health care endeavors will create competition and drive down expenditures. PMID:18650705

  13. First Aid: Burns

    MedlinePlus

    ... Story" 5 Things to Know About Zika & Pregnancy First Aid: Burns KidsHealth > For Parents > First Aid: Burns Print A A A Text Size Scald ... THIS TOPIC Kitchen: Household Safety Checklist Fireworks Safety First Aid: Sunburn Firesetting Fire Safety Burns Household Safety: Preventing ...

  14. California Burn Scars

    Atmospheric Science Data Center

    2014-05-15

    article title:  Burn Scars Across Southern California     ... California between October 21 and November 18, 2003. Burn scars and vegetation changes wrought by the fires are illustrated in these ... Nov 18, 2003 Images:  California Burn Scars location:  United States region:  ...

  15. Overview of actinide chemistry in the WIPP

    SciTech Connect

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

    2009-01-01

    The year 2009 celebrates 10 years of safe operations at the Waste Isolation Pilot Plant (WIPP), the only nuclear waste repository designated to dispose defense-related transuranic (TRU) waste in the United States. Many elements contributed to the success of this one-of-the-kind facility. One of the most important of these is the chemistry of the actinides under WIPP repository conditions. A reliable understanding of the potential release of actinides from the site to the accessible environment is important to the WIPP performance assessment (PA). The environmental chemistry of the major actinides disposed at the WIPP continues to be investigated as part of the ongoing recertification efforts of the WIPP project. This presentation provides an overview of the actinide chemistry for the WIPP repository conditions. The WIPP is a salt-based repository; therefore, the inflow of brine into the repository is minimized, due to the natural tendency of excavated salt to re-seal. Reducing anoxic conditions are expected in WIPP because of microbial activity and metal corrosion processes that consume the oxygen initially present. Should brine be introduced through an intrusion scenario, these same processes will re-establish reducing conditions. In the case of an intrusion scenario involving brine, the solubilization of actinides in brine is considered as a potential source of release to the accessible environment. The following key factors establish the concentrations of dissolved actinides under subsurface conditions: (1) Redox chemistry - The solubility of reduced actinides (III and IV oxidation states) is known to be significantly lower than the oxidized forms (V and/or VI oxidation states). In this context, the reducing conditions in the WIPP and the strong coupling of the chemistry for reduced metals and microbiological processes with actinides are important. (2) Complexation - For the anoxic, reducing and mildly basic brine systems in the WIPP, the most important

  16. Electronic structure and correlation effects in actinides

    SciTech Connect

    Albers, R.C.

    1998-12-01

    This report consists of the vugraphs given at a conference on electronic structure. Topics discussed are electronic structure, f-bonding, crystal structure, and crystal structure stability of the actinides and how they are inter-related.

  17. Advanced Aqueous Separation Systems for Actinide Partitioning

    SciTech Connect

    Nash, Kenneth L.; Clark, Sue; Meier, G Patrick; Alexandratos, Spiro; Paine, Robert; Hancock, Robert; Ensor, Dale

    2012-03-21

    One of the most challenging aspects of advanced processing of spent nuclear fuel is the need to isolate transuranium elements from fission product lanthanides. This project expanded the scope of earlier investigations of americium (Am) partitioning from the lanthanides with the synthesis of new separations materials and a centralized focus on radiochemical characterization of the separation systems that could be developed based on these new materials. The primary objective of this program was to explore alternative materials for actinide separations and to link the design of new reagents for actinide separations to characterizations based on actinide chemistry. In the predominant trivalent oxidation state, the chemistry of lanthanides overlaps substantially with that of the trivalent actinides and their mutual separation is quite challenging.

  18. BWR Assembly Optimization for Minor Actinide Recycling

    SciTech Connect

    G. Ivan Maldonado; John M. Christenson; J.P. Renier; T.F. Marcille; J. Casal

    2010-03-22

    The Primary objective of the proposed project is to apply and extend the latest advancements in LWR fuel management optimization to the design of advanced boiling water reactor (BWR) fuel assemblies specifically for the recycling of minor actinides (MAs).

  19. Preparation of actinide targets by electrodeposition

    NASA Astrophysics Data System (ADS)

    Trautmann, N.; Folger, H.

    1989-10-01

    Actinide targets with varying thicknesses on different substrates have been prepared by electrodeposition either from aqueous solutions or from solutions of their nitrates in isopropyl alcohol. With these techniques the actinides can be deposited almost quantitatively on various backing materials within 15 to 30 min. Targets of thorium, uranium, neptunium, plutonium, americium, curium and californium with areal densities from almost carrier-free up to 1.4 mg/cm 2 on thin beryllium, carbon, titanium, tantalum and platinum foils have been prepared. In most cases, prior to the deposition, the actinides had to be purified chemically and for some of them, due to the limited amount of material available, recycling procedures were required. Applications of actinide targets in heavy-ion reactions are briefly discussed.

  20. PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

    DOEpatents

    Moore, R.H.

    1962-09-01

    BS>A process is given for preparing alloys of aluminum with plutonium, uranium, and/or thorium by chlorinating actinide oxide dissolved in molten alkali metal chloride with hydrochloric acid, chlorine, and/or phosgene, adding aluminum metal, and passing air and/or water vapor through the mass. Actinide metal is formed and alloyed with the aluminum. After cooling to solidification, the alloy is separated from the salt. (AEC)

  1. Transmutation of actinides in power reactors.

    PubMed

    Bergelson, B R; Gerasimov, A S; Tikhomirov, G V

    2005-01-01

    Power reactors can be used for partial short-term transmutation of radwaste. This transmutation is beneficial in terms of subsequent storage conditions for spent fuel in long-term storage facilities. CANDU-type reactors can transmute the main minor actinides from two or three reactors of the VVER-1000 type. A VVER-1000-type reactor can operate in a self-service mode with transmutation of its own actinides. PMID:16604724

  2. Synergism of trivalent actinides and lanthanides

    SciTech Connect

    Mathur, J.N.

    1983-01-01

    The synergism of trivalent actinides and lanthanides has been reviewed critically. Different systems including ..beta..-di-ketones and several other chelating agents with various neutral donors have been discussed. The thermodynamic parameters, effect of diluents, auto-synergism and synergism with eutectic mixtures have been discussed in the case of trivalent actinides and lanthanides. Also the mechanism of synergism and the various possible uses of this phenomenon have been referred to with the possible data available. 160 references, 4 tables.

  3. Structural and magnetic characterization of actinide materials

    SciTech Connect

    Cort, B.; Allen, T.H.; Lawson, A.C.

    1998-12-31

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The authors have successfully used neutron scattering techniques to investigate physicochemical properties of elements, compounds, and alloys of the light actinides. The focus of this work is to extend the fundamental research capability and to address questions of practical importance to stockpile integrity and long-term storage of nuclear material. Specific subject areas are developing neutron diffraction techniques for smaller actinide samples; modeling of inelastic scattering data for actinide metal hydrides; characterizing actinide oxide structures; and investigating aging effects in actinides. These studies utilize neutron scattering supported by equilibrium studies, kinetics, and x-ray diffraction. Major accomplishments include (1) development of encapsulation techniques for small actinide samples and neutron diffraction studies of AmD{sub 2.4} and PuO{sub 2.3}; (2) refinement of lattice dynamics model to elucidate hydrogen-hydrogen and hydrogen-metal interactions in rare-earth and actinide hydrides; (3) kinetic studies with PuO{sub 2} indicating that the recombination reaction is faster than radiolytic decomposition of adsorbed water but a chemical reaction produces H{sub 2}; (4) PVT studies of the reaction between PuO{sub 2} and water demonstrate that PuO{sub 2+x} and H{sub 2} form and that PuO{sub 2} is not the thermodynamically stable form of the oxide in air; and (5) model calculations of helium in growth in aged plutonium predicting bubble formation only at grain boundaries at room temperature. The work performed in this project has application to fundamental properties of actinides, aging, and long-term storage of plutonium.

  4. Rapid determination of actinides in seawater samples

    DOE PAGESBeta

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.; Utsey, Robin C.; McAlister, Daniel R.

    2014-03-09

    A new rapid method for the determination of actinides in seawater samples has been developed at the Savannah River National Laboratory. The actinides can be measured by alpha spectrometry or inductively-coupled plasma mass spectrometry. The new method employs novel pre-concentration steps to collect the actinide isotopes quickly from 80 L or more of seawater. Actinides are co-precipitated using an iron hydroxide co-precipitation step enhanced with Ti+3 reductant, followed by lanthanum fluoride co-precipitation. Stacked TEVA Resin and TRU Resin cartridges are used to rapidly separate Pu, U, and Np isotopes from seawater samples. TEVA Resin and DGA Resin were used tomore » separate and measure Pu, Am and Cm isotopes in seawater volumes up to 80 L. This robust method is ideal for emergency seawater samples following a radiological incident. It can also be used, however, for the routine analysis of seawater samples for oceanographic studies to enhance efficiency and productivity. In contrast, many current methods to determine actinides in seawater can take 1–2 weeks and provide chemical yields of ~30–60 %. This new sample preparation method can be performed in 4–8 h with tracer yields of ~85–95 %. By employing a rapid, robust sample preparation method with high chemical yields, less seawater is needed to achieve lower or comparable detection limits for actinide isotopes with less time and effort.« less

  5. Recent progress in actinide borate chemistry

    SciTech Connect

    Wang, Shuao; Alekseev, Evgeny V.; Depmeier, Wulf; Albrecht-Schmitt, Thomas E.

    2011-01-01

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB₅O₆(OH)₆][BO(OH)₂]·2.5H₂O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO4- Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials.

  6. Recent progress in actinide borate chemistry.

    PubMed

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2011-10-21

    The use of molten boric acid as a reactive flux for synthesizing actinide borates has been developed in the past two years providing access to a remarkable array of exotic materials with both unusual structures and unprecedented properties. [ThB(5)O(6)(OH)(6)][BO(OH)(2)]·2.5H(2)O possesses a cationic supertetrahedral structure and displays remarkable anion exchange properties with high selectivity for TcO(4)(-). Uranyl borates form noncentrosymmetric structures with extraordinarily rich topological relationships. Neptunium borates are often mixed-valent and yield rare examples of compounds with one metal in three different oxidation states. Plutonium borates display new coordination chemistry for trivalent actinides. Finally, americium borates show a dramatic departure from plutonium borates, and there are scant examples of families of actinides compounds that extend past plutonium to examine the bonding of later actinides. There are several grand challenges that this work addresses. The foremost of these challenges is the development of structure-property relationships in transuranium materials. A deep understanding of the materials chemistry of actinides will likely lead to the development of advanced waste forms for radionuclides present in nuclear waste that prevent their transport in the environment. This work may have also uncovered the solubility-limiting phases of actinides in some repositories, and allows for measurements on the stability of these materials. PMID:21915396

  7. Rapid determination of actinides in seawater samples

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.; Utsey, Robin C.; McAlister, Daniel R.

    2014-03-09

    A new rapid method for the determination of actinides in seawater samples has been developed at the Savannah River National Laboratory. The actinides can be measured by alpha spectrometry or inductively-coupled plasma mass spectrometry. The new method employs novel pre-concentration steps to collect the actinide isotopes quickly from 80 L or more of seawater. Actinides are co-precipitated using an iron hydroxide co-precipitation step enhanced with Ti+3 reductant, followed by lanthanum fluoride co-precipitation. Stacked TEVA Resin and TRU Resin cartridges are used to rapidly separate Pu, U, and Np isotopes from seawater samples. TEVA Resin and DGA Resin were used to separate and measure Pu, Am and Cm isotopes in seawater volumes up to 80 L. This robust method is ideal for emergency seawater samples following a radiological incident. It can also be used, however, for the routine analysis of seawater samples for oceanographic studies to enhance efficiency and productivity. In contrast, many current methods to determine actinides in seawater can take 1–2 weeks and provide chemical yields of ~30–60 %. This new sample preparation method can be performed in 4–8 h with tracer yields of ~85–95 %. By employing a rapid, robust sample preparation method with high chemical yields, less seawater is needed to achieve lower or comparable detection limits for actinide isotopes with less time and effort.

  8. Hypnosis for the treatment of burn pain.

    PubMed

    Patterson, D R; Everett, J J; Burns, G L; Marvin, J A

    1992-10-01

    The clinical utility of hypnosis for controlling pain during burn wound debridement was investigated. Thirty hospitalized burn patients and their nurses submitted visual analog scales (VAS) for pain during 2 consecutive daily wound debridements. On the 1st day, patients and nurses submitted baseline VAS ratings. Before the next day's would debridement, Ss received hypnosis, attention and information, or no treatment. Only hypnotized Ss reported significant pain reductions relative to pretreatment baseline. This result was corroborated by nurse VAS ratings. Findings indicate that hypnosis is a viable adjunct treatment for burn pain. Theoretical and practical implications and future research directions are discussed. PMID:1383302

  9. Epidemiology of burns throughout the World. Part II: intentional burns in adults.

    PubMed

    Peck, Michael D

    2012-08-01

    A significant number of burns and deaths from fire are intentionally wrought. Rates of intentional burns are unevenly distributed throughout the world; India has a particularly high rate in young women whereas in Europe rates are higher in men in mid-life. Data from hospitalized burn patients worldwide reveal incidence rates for assault by fire and scalds ranging from 3% to 10%. The average proportion of the body surface area burned in an assault by fire or scalds is approximately 20%. In different parts of the world, attempted burning of others or oneself can be attributed to different motives. Circumstances under which assaults occur fall largely into the categories of interpersonal conflict, including spousal abuse, elder abuse, or interactions over contentious business transactions. Contributing social factors to assaults by burning include drug and alcohol abuse, non-constructive use of leisure time, non-participation in religious and community activities, unstable relationships, and extramarital affairs. Although the incidence of self-mutilation and suicide attempts by burning are relatively low, deliberate self-harm carries a significant risk of death, with an overall mortality rate of 65% worldwide. In those who resort to self-immolation, circumstantial themes reflect domestic discord, family dysfunction, and the social ramifications of unemployment. Preventing injurious burn-related violence requires a multifaceted approach, including legislation and enforcement, education, and advocacy. Better standardized assessment tools are needed to screen for risks of abuse and for psychiatric disorders in perpetrators. PMID:22325849

  10. Minor actinide transmutation in thorium and uranium matrices in heavy water moderated reactors

    SciTech Connect

    Bhatti, Zaki; Hyland, B.; Edwards, G.W.R.

    2013-07-01

    The irradiation of Th{sup 232} breeds fewer of the problematic minor actinides (Np, Am, Cm) than the irradiation of U{sup 238}. This characteristic makes thorium an attractive potential matrix for the transmutation of these minor actinides, as these species can be transmuted without the creation of new actinides as is the case with a uranium fuel matrix. Minor actinides are the main contributors to long term decay heat and radiotoxicity of spent fuel, so reducing their concentration can greatly increase the capacity of a long term deep geological repository. Mixing minor actinides with thorium, three times more common in the Earth's crust than natural uranium, has the additional advantage of improving the sustainability of the fuel cycle. In this work, lattice cell calculations have been performed to determine the results of transmuting minor actinides from light water reactor spent fuel in a thorium matrix. 15-year-cooled group-extracted transuranic elements (Np, Pu, Am, Cm) from light water reactor (LWR) spent fuel were used as the fissile component in a thorium-based fuel in a heavy water moderated reactor (HWR). The minor actinide (MA) transmutation rates, spent fuel activity, decay heat and radiotoxicity, are compared with those obtained when the MA were mixed instead with natural uranium and taken to the same burnup. Each bundle contained a central pin containing a burnable neutron absorber whose initial concentration was adjusted to have the same reactivity response (in units of the delayed neutron fraction β) for coolant voiding as standard NU fuel. (authors)

  11. An effective burn prevention program initiated by a recovered burn patient group.

    PubMed

    Schmeer, S; Stern, N; Monafo, W W

    1986-01-01

    The US death rate from house fires has remained constant during the past 50 years despite a sharp decline in mortality from other fires and causes of burns. The concensus is that smoke alarms can effectively decrease the incidence of this lethal type of burn injury. Our organization of recovered burn patients has focused its efforts around procuring and installing smoke alarms in areas of substandard housing, which predominantly account for house fire deaths and injuries in St. Louis. This effort has resulted in an effective burn prevention program ("Alarms for Life"), which also serves as a model for other communities. PMID:3429488

  12. Emergent burn care.

    PubMed

    Harvey, J S; Watkins, G M; Sherman, R T

    1984-02-01

    The estimated 32,600,000 fires that occur annually in the United States produce over 300,000 injuries and 7,500 deaths. Ten percent of hospitalized burn victims die as a direct result of the burn. Initial evaluation and management of the burn patient are critical. The history should include the burn source, time of injury, burn environment, and combustible products. The burn size is best estimated by the Lund and Browder chart, and the burn depth is determined by clinical criteria. Pulmonary involvement and circumferential thoracic or extremity burns require detection and aggressive treatment to maintain organ viability. Hospitalization is usually necessary for adults with burns larger than 10% of the total body surface area (TBSA) or children with burns larger than 5% of TBSA. Major burns, those of 25% or more of TBSA or of 10% or more of full thickness, should be considered for treatment at a burn center, as well as children or elderly victims with burns of greater than 10% TBSA. Lactated Ringer's solution, infused at 4 ml/kg/% TBSA, is generally advocated for initial fluid restoration. After the acute phase (48 hours), replacement of evaporative and hypermetabolic fluid loss is necessary. These losses may constitute 3 to 5 liters per day for a 40% to 70% TBSA burn. Blood transfusion is often required because of persistent loss of red blood cells (8% per day for about ten days). Many electrolyte abnormalities may occur in the first two weeks. Pulmonary injury commonly is lethal. Circumoral burns, oropharyngeal burns, and carbonaceous sputum are indicative of inhalation injury, but arterial blood gas determinations, fiberoptic bronchoscopy, and xenon lung scans are useful for confirming the diagnosis. Humidified oxygen, intubation, positive-pressure ventilation, and pulmonary toilet are the mainstays of therapy for inhalation injury. Wound care is initially directed at preservation of vital function by escharotomy, if restrictive eschar impairs ventilatory or

  13. Erosive Burning Study Utilizing Ultrasonic Measurement Techniques

    NASA Technical Reports Server (NTRS)

    Furfaro, James A.

    2003-01-01

    A 6-segment subscale motor was developed to generate a range of internal environments from which multiple propellants could be characterized for erosive burning. The motor test bed was designed to provide a high Mach number, high mass flux environment. Propellant regression rates were monitored for each segment utilizing ultrasonic measurement techniques. These data were obtained for three propellants RSRM, ETM- 03, and Castor@ IVA, which span two propellant types, PBAN (polybutadiene acrylonitrile) and HTPB (hydroxyl terminated polybutadiene). The characterization of these propellants indicates a remarkably similar erosive burning response to the induced flow environment. Propellant burnrates for each type had a conventional response with respect to pressure up to a bulk flow velocity threshold. Each propellant, however, had a unique threshold at which it would experience an increase in observed propellant burn rate. Above the observed threshold each propellant again demonstrated a similar enhanced burn rate response corresponding to the local flow environment.

  14. Erosive burning research. [for solid-propellant rocket engines

    NASA Technical Reports Server (NTRS)

    Strand, L.; Yang, L. C.; Nguyen, M. H.; Cohen, N. S.

    1986-01-01

    A status report is given on the results for the completed tests in a series of motor firings being carried out to measure the effects of the parameters that are considered to most strongly influence the scaling to larger rocket motor sizes of the transition to/or threshold conditions for erosive burning rate augmentation. Propellant burning rates at locations along the axis of the test motors are measured with a newly developed plasma capacitance gauge technique. The measured results are compared with erosive-burning predictions from a supporting ballistics analysis. The completed motor firings have successfully demonstrated response to the designed test variables. The trends with varying propellant burning rate, chamber pressure, and mass flow rate are consistent with existing results, but no pronounced effect of surface roughness has been observed. Rather, the influence of propellant oxidizer particle size on erosive burning is through its effect on the base, no-corssflow burning rate.

  15. Characterization of burn injuries using terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Arbab, M. Hassan; Dickey, Trevor C.; Winebrenner, Dale P.; Chen, Antao; Mourad, Pierre D.

    2011-03-01

    The accuracy rates of the clinical assessment techniques used in grading burn injuries remain significantly low for partial thickness burns. In this paper, we present experimental results from terahertz characterization of 2nd and 3rd degree burn wounds induced on a rat model. Reflection measurements were obtained from the surface of both burned and normal skin using pulsed terahertz spectroscopy. Signal processing techniques are described for interpretation of the acquired terahertz waveform and differentiation of burn wounds. Furthermore, the progression of burn injuries is shown by comparison between acute characterization and 72-hours survival studies. While the water content of healthy and desiccated skin has been considered as a source of terahertz signal contrast, it is demonstrated that other biological effects such as formation of post-burn interstitial edema as well as the density of the discrete scattering structures in the skin (such as hair follicles, sweat glands, etc.) play a significant role in the terahertz response of the burn wounds.

  16. Chemical reduction of actinides probed by resonant inelastic X-ray scattering.

    PubMed

    Butorin, Sergei M; Shuh, David K; Kvashnina, Kristina O; Guo, Jinghua; Werme, Lars; Nordgren, Joseph

    2013-12-01

    The study addresses the possibilities of immobilizing the mobile species of actinides in the geosphere using metallic iron. Sorption on corroding iron is well-known, but there have been uncertainties with regard to the possibilities of reducing the actinyl species to sparingly soluble oxides and, thereby, permanently immobilizing them. Resonant inelastic X-ray scattering (RIXS) measurements at the actinide 5d edges on Fe foils exposed to uranium(VI) and neptunium(V) solutions in groundwater unambigiously indicate reduction of actinides to, respectively, uranium(IV) and neptunium(IV) on iron surfaces. The reduction manifests itself in an appearance of distinct specific signatures of uranium(IV) and neptunium(IV) in the RIXS profile of 5f-5f excitations. Such signatures and RIXS intensity/cross-section behavior with varying energy of incident photons can be reproduced by model atomic-multiplet calculations of the RIXS spectra. By normalizing the RIXS signal of corresponding 5f-5f excitations to core-to-core 6p-to-5d characteristic fluorescence transitions of actinides, their reduction rates on Fe samples with different exposure to actinide solutions can be estimated. Observed reduction implies similar processes in the nuclear waste canister thus suggesting reduced probability of nuclear waste release with ground waters from the canister. PMID:24187957

  17. Burns associated with fondues.

    PubMed Central

    Laliberté, D; Beaucage, C; Watts, N

    1992-01-01

    OBJECTIVE: To describe the causes of burns associated with fondues. DESIGN: Descriptive case series. PATIENTS: All 17 patients admitted to a burn centre between Apr. 1, 1985, and Mar. 31, 1990, whose burns were associated with fondue. Eleven agreed to complete a telephone interview. RESULTS: The age of the 17 patients varied from 2 to 56 (mean 27) years. Two causes were identified: spilling of the contents of the fondue pot and explosion of the fondue fuel when added to the burner during a meal. The telephone interview revealed that eight people other than the respondents were burned during the same accidents. CONCLUSION: Although we identified only badly burned patients the problem may be more extensive. The knowledge of specific causes of burns from handling fondue equipment indicates that preventive action should be undertaken. More epidemiologic information is needed to obtain a precise estimate of the magnitude of this public health problem. PMID:1393897

  18. Burns and epilepsy.

    PubMed

    Berrocal, M

    1997-01-01

    This is a report of the first descriptive analytic study of a group of 183 burn patients, treated in the Burn Unit at the University Hospital of Cartagena, Colombia during the period since January 1985 until December 1990. There is presented experience with the selected group of 24 patients in whom the diagnosis of burn was associated with epilepsy. There is also analysed and described the gravity of the scars sequels, neurological disorders, the complication of the burn and an impact of this problem on the patient, his (her) family and the community. It is very important to report that there was found Neurocisticercosis in 66.6% of the group of burn patients with epilepsy, and it is probably the first risk factor of burn in this group. PMID:9212488

  19. Pediatric cutaneous bleach burns.

    PubMed

    Lang, Cathleen; Cox, Matthew

    2013-07-01

    Bleach is a common household product which can cause caustic injuries. Its effects on mucosal tissues and the eye have been well-described in the literature. However, there is little information published regarding the appearance and effect of bleach on a child's skin. We report three children who sustained chemical burns after contact with bleach. All three children sustained accidental bleach burns while at home, and each child had a distinct brown discoloration to the skin from the injury. All three children had treatment and follow-up for their burns. Two of the children sustained more severe burns, which were extensive and required more time to heal. There was also long-term scarring associated with the severe burns. Like most burns, pain control is required until the injury heals. PMID:23545350

  20. TUCS/phosphate mineralization of actinides

    SciTech Connect

    Nash, K.L.

    1997-10-01

    This program has as its objective the development of a new technology that combines cation exchange and mineralization to reduce the concentration of heavy metals (in particular actinides) in groundwaters. The treatment regimen must be compatible with the groundwater and soil, potentially using groundwater/soil components to aid in the immobilization process. The delivery system (probably a water-soluble chelating agent) should first concentrate the radionuclides then release the precipitating anion, which forms thermodynamically stable mineral phases, either with the target metal ions alone or in combination with matrix cations. This approach should generate thermodynamically stable mineral phases resistant to weathering. The chelating agent should decompose spontaneously with time, release the mineralizing agent, and leave a residue that does not interfere with mineral formation. For the actinides, the ideal compound probably will release phosphate, as actinide phosphate mineral phases are among the least soluble species for these metals. The most promising means of delivering the precipitant would be to use a water-soluble, hydrolytically unstable complexant that functions in the initial stages as a cation exchanger to concentrate the metal ions. As it decomposes, the chelating agent releases phosphate to foster formation of crystalline mineral phases. Because it involves only the application of inexpensive reagents, the method of phosphate mineralization promises to be an economical alternative for in situ immobilization of radionuclides (actinides in particular). The method relies on the inherent (thermodynamic) stability of actinide mineral phases.

  1. Nonaqueous method for dissolving lanthanide and actinide metals

    DOEpatents

    Crisler, L.R.

    1975-11-11

    Lanthanide and actinide beta-diketonate complex molecular compounds are produced by reacting a beta-diketone compound with a lanthanide or actinide element in the elemental metallic state in a mixture of carbon tetrachloride and methanol.

  2. Outpatient burn management.

    PubMed

    Warner, Petra M; Coffee, Tammy L; Yowler, Charles J

    2014-08-01

    Most burn patients have injuries that may be treated on an outpatient basis. Newer silver-based dressings and improved medications for the treatment of pain and pruritus have led to further growth of outpatient care. The final barrier of distance from the burn center will decrease with the growth of telemedicine. It is incumbent for burn centers to develop outpatient guidelines to facilitate this growth of outpatient care. PMID:25085094

  3. Transuranic Waste Burning Potential of Thorium Fuel in a Fast Reactor - 12423

    SciTech Connect

    Wenner, Michael; Franceschini, Fausto; Ferroni, Paolo; Sartori, Alberto; Ricotti, Marco

    2012-07-01

    Westinghouse Electric Company (referred to as 'Westinghouse' in the rest of this paper) is proposing a 'back-to-front' approach to overcome the stalemate on nuclear waste management in the US. In this approach, requirements to further the societal acceptance of nuclear waste are such that the ultimate health hazard resulting from the waste package is 'as low as reasonably achievable'. Societal acceptability of nuclear waste can be enhanced by reducing the long-term radiotoxicity of the waste, which is currently driven primarily by the protracted radiotoxicity of the transuranic (TRU) isotopes. Therefore, a transition to a more benign radioactive waste can be accomplished by a fuel cycle capable of consuming the stockpile of TRU 'legacy' waste contained in the LWR Used Nuclear Fuel (UNF) while generating waste which is significantly less radio-toxic than that produced by the current open U-based fuel cycle (once through and variations thereof). Investigation of a fast reactor (FR) operating on a thorium-based fuel cycle, as opposed to the traditional uranium-based is performed. Due to a combination between its neutronic properties and its low position in the actinide chain, thorium not only burns the legacy TRU waste, but it does so with a minimal production of 'new' TRUs. The effectiveness of a thorium-based fast reactor to burn legacy TRU and its flexibility to incorporate various fuels and recycle schemes according to the evolving needs of the transmutation scenario have been investigated. Specifically, the potential for a high TRU burning rate, high U-233 generation rate if so desired and low concurrent production of TRU have been used as metrics for the examined cycles. Core physics simulations of a fast reactor core running on thorium-based fuels and burning an external TRU feed supply have been carried out over multiple cycles of irradiation, separation and reprocessing. The TRU burning capability as well as the core isotopic content have been characterized

  4. Burns in Malawi

    PubMed Central

    Virich, G.; Lavy, C.B.D.

    2006-01-01

    Summary Objective: To describe burns seen at the largest hospital in Malawi. Methods: In a prospective study conducted at Queen Elizabeth Central Hospital, Blantyre, Malawi, a series of twelve accidental burns was analysed over a four-week period. Results: Hot water was the commonest source of burns (6 out of 12). Open-fire and petroleum lamp accidents were the commonest cause of burns among epileptic patients. Males were affected more than females (male:female ratio = 8:4). Most burns were superficial (11 out of 12). One patient had deep burns requiring grafting. All patients were treated with topical silver sulphadiazine and a combination antibiotic regime. Children aged six yr or under were a major subgroup at risk of suffering burns (7 out of 12) and only one patient was aged over 30 yr. Lack of anti-epileptic medication resulted in potentially avoidable burns in four epileptic patients. Conclusions: There is a need for cheap preventive health promotion measures as well as the provision of simple resources as most burns encountered can be managed effectively by simple measures. PMID:21991045

  5. American Burn Association

    MedlinePlus

    About ABA Governance History Committees & SIGs Awards Membership Past Presidents International Outreach Legislative Agenda Health Policy News and Activities Educational Resources Prevention Posters Awards FAQs Burn Awareness ...

  6. Pediatric facial burns.

    PubMed

    Kung, Theodore A; Gosain, Arun K

    2008-07-01

    Despite major advances in the area of burn management, burn injury continues to be a leading cause of pediatric mortality and morbidity. Facial burns in particular are devastating to the affected child and result in numerous physical and psychosocial sequelae. Although many of the principles of adult burn management can be applied to a pediatric patient with facial burns, the surgeon must be cognizant of several important differences. Facial burns and subsequent scar formation can drastically affect the growth potential of a child's face. Structures such as the nose and teeth may become deformed due to abnormal external forces caused by contractures. Serious complications such as occlusion amblyopia and microstomia must be anticipated and urgently addressed to avert permanent consequences, whereas other reconstructive procedures can be delayed until scar maturation occurs. Furthermore, because young children are actively developing the concept of self, severe facial burns can alter a child's sense of identity and place the child at high risk for future emotional and psychologic disturbances. Surgical reconstruction of burn wounds should proceed only after thorough planning and may involve a variety of skin graft, flap, and tissue expansion techniques. The most favorable outcome is achieved when facial resurfacing is performed with respect to the aesthetic units of the face. Children with facial burns remain a considerable challenge to their caregivers, and these patients require long-term care by a multidisciplinary team of physicians and therapists to optimize functional, cosmetic, and psychosocial outcomes. PMID:18650717

  7. Predictors of Muscle Protein Synthesis after Severe Pediatric Burns

    PubMed Central

    Diaz, Eva C.; Herndon, David N.; Lee, Jinhyung; Porter, Craig; Cotter, Matthew; Suman, Oscar E.; Sidossis, Labros S.; Børsheim, Elisabet

    2015-01-01

    Background Following a major burn, skeletal muscle protein synthesis rate increases, but is often insufficient to compensate for massively elevated muscle protein breakdown rates. Given the long-term nature of the pathophysiologic response to burn injury, we hypothesized that muscle protein synthesis rate would be chronically elevated in severely burned children. The objectives of this study were to characterize muscle protein synthesis rate of burned children over a period of 24 months post-injury, and identify predictors that influence this response. Study design 87 children with ≥40% total body surface area (TBSA) burn were included. Patients participated in stable isotope infusion studies at 1, 2 and ~ 4 weeks post-burn, and at 6, 12 and 24 months post-injury to determine skeletal muscle fractional synthesis rate. Generalized estimating equations with log link normal distribution were applied to account for clustering of patients and control for patient characteristics. Results Patients (8±6 years) had large (62, 51–72% TBSA) and deep (47±21% TBSA third degree) burns. Muscle fractional synthesis rate was elevated throughout the first 12 months post-burn compared to established values from healthy young adults. Muscle fractional synthesis rate was lower in boys, children >3 years old, and when burns were >80% TBSA. Conclusions Muscle protein synthesis is elevated for at least one year after injury, suggesting that greater muscle protein turnover is a component of the long-term pathophysiological response to burn trauma. Muscle protein synthesis is highly affected by gender, age and burn size in severely burned children. These findings may explain the divergence in net protein balance and lean body mass in different populations of burn victims. PMID:25807408

  8. Ultratrace analysis of transuranic actinides by laser-induced fluorescence

    DOEpatents

    Miller, S.M.

    1983-10-31

    Ultratrace quantities of transuranic actinides are detected indirectly by their effect on the fluorescent emissions of a preselected fluorescent species. Transuranic actinides in a sample are coprecipitated with a host lattice material containing at least one preselected fluorescent species. The actinide either quenches or enhances the laser-induced fluorescence of the preselected fluorescent species. The degree of enhancement or quenching is quantitatively related to the concentration of actinide in the sample.

  9. Ultratrace analysis of transuranic actinides by laser-induced fluorescence

    DOEpatents

    Miller, Steven M.

    1988-01-01

    Ultratrace quantities of transuranic actinides are detected indirectly by their effect on the fluorescent emissions of a preselected fluorescent species. Transuranic actinides in a sample are coprecipitated with a host lattice material containing at least one preselected fluorescent species. The actinide either quenches or enhances the laser-induced fluorescence of the preselected fluorescent species. The degree of enhancement or quenching is quantitatively related to the concentration of actinide in the sample.

  10. THEORY FOR THE XPS OF ACTINIDES

    SciTech Connect

    Bagus, Paul S.; Ilton, Eugene S.

    2013-08-01

    Two aspects of the electronic structure of actinide oxides that significantly affect the XPS spectra are described; these aspects are also important for the materials properties of the oxides. The two aspects considered are: (1) The spin-orbit coupling of the open 5f shell electrons in actinide cations and how this coupling affects the electronic structure. And, (2) the covalent character of the metal oxygen interaction in actinide compounds. Because of this covalent character, there are strong departures from the nominal oxidation states that are significantly larger in core-hole states than in the ground state. The consequences for the XPS of this covalent character are examined. A proper understanding of the way in which they influence the XPS makes it possible to use the XPS to correctly characterize the electronic structure of the oxides.

  11. Minior Actinide Doppler Coefficient Measurement Assessment

    SciTech Connect

    Nolan E. Hertel; Dwayne Blaylock

    2008-04-10

    The "Minor Actinide Doppler Coefficient Measurement Assessment" was a Department of Energy (DOE) U-NERI funded project intended to assess the viability of using either the FLATTOP or the COMET critical assembly to measure high temperature Doppler coefficients. The goal of the project was to calculate using the MCNP5 code the gram amounts of Np-237, Pu-238, Pu-239, Pu-241, AM-241, AM-242m, Am-243, and CM-244 needed to produce a 1E-5 in reactivity for a change in operating temperature 800C to 1000C. After determining the viability of using the assemblies and calculating the amounts of each actinide an experiment will be designed to verify the calculated results. The calculations and any doncuted experiments are designed to support the Advanced Fuel Cycle Initiative in conducting safety analysis of advanced fast reactor or acceoerator-driven transmutation systems with fuel containing high minor actinide content.

  12. Preparation of actinide-metal research materials

    SciTech Connect

    Aaron, W.S.; Culpepper, C.A.; Campbell, K.B.

    1986-01-01

    The preparation of actinide-metal research materials is one of many functions of the Isotope Research Materials Laboratory (IRML) at Oak Ridge National Laboratory. Research samples of uranium, plutonium, americium, and curium, typically from milligram quantities up to approx. 100 g, are prepared as pure metals or alloys to customer specifications. Larger quantities, up to many kilograms, of the lower activity actinides, such as /sup 235/U, /sup 238/U, and /sup 232/Th, are also fabricated into custom research forms. Physical forms of these metals include rolled foils or sheets, castings (ingot, rod, or special shapes), and evaporated or sputtered films. The actinide-metal processing capabilities of the IRML are continuing to be improved and applied to a wide variety of custom material preparations to meet the needs of the world-wide research community.

  13. The Actinide-Lanthanide Separation Process

    SciTech Connect

    Lumetta, Gregg J.; Gelis, Artem V.; Carter, Jennifer C.; Niver, Cynthia M.; Smoot, Margaret R.

    2014-02-21

    The Actinide-Lanthanide SEParation (ALSEP) process is described. The process uses an extractant phase consisting of either N,N,N',N'-tetraoctyldiglycolamide (TODGA) or N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]). The neutral TODGA or T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid media. Switching the aqueous phase chemistry to a citrate buffered diethylenetriaminepentaacetic acid (DTPA) solution at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus resulting in separation of these two groups of elements.

  14. FINAL REPORT. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Investigation of behavior of actinides in alkaline media containing Al(III) showed that no aluminate complexes of actinides in oxidation states (III-VII) were formed in alkaline solutions. At alkaline precipitation (pH 10-14) of actinides in presence of Al(III) formation of alumi...

  15. RECOVERY OF ACTINIDES FROM AQUEOUS NITRIC ACID SOLUTIONS

    DOEpatents

    Ader, M.

    1963-11-19

    A process of recovering actinides is presented. Tetravalent actinides are extracted from rare earths in an aqueous nitric acid solution with a ketone and back-extracted from the ketone into an aqueous medium. The aqueous actinide solution thus obtained, prior to concentration by boiling, is sparged with steam to reduce its ketone to a maximum content of 3 grams per liter. (AEC)

  16. Complexation of Actinides in Solution: Thermodynamic Measurementsand Structural Characterization

    SciTech Connect

    Rao, L.

    2007-02-01

    This paper presents a brief introduction of the studies of actinide complexation in solution at Lawrence Berkeley National Laboratory. An integrated approach of thermodynamic measurements and structural characterization is taken to obtain fundamental understanding of actinide complexation in solution that is of importance in predicting the behavior of actinides in separation processes and environmental transport.

  17. Actinide Lanthanide Separation Process – ALSEP

    SciTech Connect

    Gelis, Artem V.; Lumetta, Gregg J.

    2014-01-29

    Separation of the minor actinides (Am, Cm) from the lanthanides at an industrial scale remains a significant technical challenge for closing the nuclear fuel cycle. To increase the safety of used nuclear fuel (UNF) reprocessing, as well as reduce associated costs, a novel solvent extraction process has been developed. The process allows for partitioning minor actinides, lanthanides and fission products following uranium/plutonium/neptunium removal; minimizing the number of separation steps, flowsheets, chemical consumption, and waste. This new process, Actinide Lanthanide SEParation (ALSEP), uses an organic solvent consisting of a neutral diglycolamide extractant, either N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) or N,N,N',N'-tetraoctyldiglycolamide (TODGA), and an acidic extractant 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]), dissolved in an aliphatic diluent (e.g. n-dodecane). The An/Ln co-extraction is conducted from moderate-to-strong nitric acid, while the selective stripping of the minor actinides from the lanthanides is carried out using a polyaminocarboxylic acid/citrate buffered solution at pH anywhere between 3 and 4.5. The extraction and separation of the actinides from the fission products is very effective in a wide range of HNO3 concentrations and the minimum separation factors for lanthanide/Am exceed 30 for Nd/Am, reaching > 60 for Eu/Am under some conditions. The experimental results presented here demonstrate the great potential for a combined system, consisting of a neutral extractant such as T2EHDGA or TODGA, and an acidic extractant such as HEH[EHP], for separating the minor actinides from the lanthanides.

  18. Burns and military clothing.

    PubMed

    McLean, A D

    2001-02-01

    Burn injury is a ubiquitous threat in the military environment. The risks during combat are well recognised, but the handling of fuel, oil, munitions and other hot or flammable materials during peacetime deployment and training also imposes an inherent risk of accidental burn injury. Over the last hundred years, the burn threat in combat has ranged from nuclear weapons to small shoulder-launched missiles. Materials such as napalm and white phosphorus plainly present a risk of burn, but the threat extends to encompass personnel in vehicles attacked by anti-armour weapons, large missiles, fuel-air explosives and detonations/conflagrations on weapons platforms such as ships. Large numbers of burn casualties were caused at Pearl Harbor, in Hiroshima and Nagasaki, Vietnam, during the Arab/Israeli Wars and in the Falkland Islands conflict. The threat from burns is unlikely to diminish, indeed new developments in weapons seek to exploit the vulnerability of the serviceman and servicewoman to burns. Clothing can be a barrier to some types of burn--both inherently in the properties of the material, but also by trapping air between clothing layers. Conversely, ignition of the clothing may exacerbate a burn. There is hearsay that burnt clothing products within a wound may complicate the clinical management, or that materials that melt (thermoplastic materials) should not be worn if there is a burn threat. This paper explores the incidence of burn injury, the mechanisms of heat transfer to bare skin and skin covered by materials, and the published evidence for the complication of wound management by materials. Even light-weight combat clothing can offer significant protection to skin from short duration flash burns; the most vulnerable areas are the parts of the body not covered--face and hands. Multilayered combat clothing can offer significant protection for short periods from engulfment by flames; lightweight tropical wear with few layers offers little protection. Under

  19. Strong correlations in actinide redox reactions

    NASA Astrophysics Data System (ADS)

    Horowitz, S. E.; Marston, J. B.

    2011-02-01

    Reduction-oxidation (redox) reactions of the redox couples An(VI)/An(V), An(V)/An(IV), and An(IV)/An(III), where An is an element in the family of early actinides (U, Np, and Pu), as well as Am(VI)/Am(V) and Am(V)/Am(III), are modeled by combining density functional theory with a generalized Anderson impurity model that accounts for the strong correlations between the 5f electrons. Diagonalization of the Anderson impurity model yields improved estimates for the redox potentials and the propensity of the actinide complexes to disproportionate.

  20. Stability of tetravalent actinides in perovskites

    SciTech Connect

    Williams, C.W.; Morss, L.R.; Choi, I.K.

    1983-01-01

    This paper reports the first determination of the enthalpy of formation of a complex actinide(IV) oxide: ..delta..H/sup 0//sub f/ (BaUO/sub 3/, s, 298 K) = -1690 +- 10 kJ mol/sup -1/. The preparation and properties of this and other actinide(IV) complex oxides are described and are compared with other perovskites BaMO/sub 3/. The relative stabilities of tetravalent and hexavalent uranium in various environments are compared in terms of the oxidation-reduction behavior of uranium in geological nuclear waste storage media; in perovskite, uranium(IV) is very unstable in comparison with uranium(VI).

  1. Systematization of actinides using cluster analysis

    SciTech Connect

    Kopyrin, A.A.; Terent`eva, T.N.; Khramov, N.N.

    1994-11-01

    A representation of the actinides in multidimensional property space is proposed for systematization of these elements using cluster analysis. Literature data for their atomic properties are used. Owing to the wide variation of published ionization potentials, medians are used to estimate them. Vertical dendograms are used for classification on the basis of distances between the actinides in atomic-property space. The properties of actinium and lawrencium are furthest removed from the main group. Thorium and mendelevium exhibit individualized properties. A cluster based on the einsteinium-fermium pair is joined by californium.

  2. Preparation of actinide-metal research

    SciTech Connect

    Aaron, W.S.; Culpepper, C.A.; Campbell, K.B.

    1986-01-01

    The preparation of actinide-metal research materials is one of many functions of the Isotope Research Materials Laboratory (IRML) at Oak Ridge National Lab. Research samples of uranium, plutonium, americium, and curium, typically from milligram quantities up to approx. 100 g, are prepared as pure metals or alloys to customer specifications. Larger quantities, up to many kilograms, of the lower activity actinides, such as /sup 235/U, /sup 238/U, and /sup 232/Th, are also fabricated into custom research forms. Physical forms of these metals include rolled foils or sheets, castings (ingot, rod, or special shapes), and evaporated or sputtered films.

  3. Spin-orbit coupling in actinide cations

    NASA Astrophysics Data System (ADS)

    Bagus, Paul S.; Ilton, Eugene S.; Martin, Richard L.; Jensen, Hans Jørgen Aa.; Knecht, Stefan

    2012-09-01

    The limiting case of Russell-Saunders coupling, which leads to a maximum spin alignment for the open shell electrons, usually explains the properties of high spin ionic crystals with transition metals. For actinide compounds, the spin-orbit splitting is large enough to cause a significantly reduced spin alignment. Novel concepts are used to explain the dependence of the spin alignment on the 5f shell occupation. We present evidence that the XPS of ionic actinide materials may provide direct information about the angular momentum coupling within the 5f shell.

  4. Root Disease, Longleaf Pine Mortality, and Prescribed Burning

    SciTech Connect

    Otrosina, W.J; C.H. Walkinshaw; S.J. Zarnoch; S-J. Sung; B.T. Sullivan

    2001-01-01

    Study to determine factors involved in decline of longleaf pine associated with prescribed burning. Trees having symptoms were recorded by crown rating system based upon symptom severity-corresponded to tree physiological status-increased in hot burn plots. Root pathogenic fungi widespread throughout the study site. Histological studies show high fine root mortality rate in the hot burn treatment. Decline syndrome is complexed by root pathogens, soil factors, root damage and dysfunction.

  5. Instrumented tube burns: theoretical and experimental observations

    SciTech Connect

    Yarrington, Cole Davis; Obrey, Stephen J; Foley, Timothy J; Son, Steven F

    2009-01-01

    The advent of widely available nanoscale energetic composites has resulted in a flurry of novel applications. One of these applications is the use of nanomaterials in energetic compositions. In compositions that exhibit high sensitivity to stimulus, these materials are often termed metastable intermolecular composites (MIC). More generally, these compositions are simply called nanoenergetics. Researchers have used many different experimental techniques to analyze the various properties of nanoenergetic systems. Among these various techniques, the confined tube burn is a simple experiment that is capable of obtaining much data related to the combustion of these materials. The purpose of this report is to review the current state of the confined tube burn experiment, including the drawbacks of the technique and possible remedies. As this report is intended to focus on the specific experimental technique, data from many different energetic materials, and experimental configurations will be presented. The qualitative and quantitative data that can be gathered using confined tube burn experiments include burning rates, total impulse, pressure rise rate, and burning rate differences between different detector types. All of these measurements lend insight into the combustion properties and mechanisms of specific nanoenergetics. Finally, certain data indicates a more complicated flow scenario which may need to be considered when developing burn tube models.

  6. Burning Mouth Syndrome.

    PubMed

    Kamala, K A; Sankethguddad, S; Sujith, S G; Tantradi, Praveena

    2016-01-01

    Burning mouth syndrome (BMS) is multifactorial in origin which is typically characterized by burning and painful sensation in an oral cavity demonstrating clinically normal mucosa. Although the cause of BMS is not known, a complex association of biological and psychological factors has been identified, suggesting the existence of a multifactorial etiology. As the symptom of oral burning is seen in various pathological conditions, it is essential for a clinician to be aware of how to differentiate between symptom of oral burning and BMS. An interdisciplinary and systematic approach is required for better patient management. The purpose of this study was to provide the practitioner with an understanding of the local, systemic, and psychosocial factors which may be responsible for oral burning associated with BMS, and review of treatment modalities, therefore providing a foundation for diagnosis and treatment of BMS. PMID:26962284

  7. Burning Mouth Syndrome

    PubMed Central

    Kamala, KA; Sankethguddad, S; Sujith, SG; Tantradi, Praveena

    2016-01-01

    Burning mouth syndrome (BMS) is multifactorial in origin which is typically characterized by burning and painful sensation in an oral cavity demonstrating clinically normal mucosa. Although the cause of BMS is not known, a complex association of biological and psychological factors has been identified, suggesting the existence of a multifactorial etiology. As the symptom of oral burning is seen in various pathological conditions, it is essential for a clinician to be aware of how to differentiate between symptom of oral burning and BMS. An interdisciplinary and systematic approach is required for better patient management. The purpose of this study was to provide the practitioner with an understanding of the local, systemic, and psychosocial factors which may be responsible for oral burning associated with BMS, and review of treatment modalities, therefore providing a foundation for diagnosis and treatment of BMS. PMID:26962284

  8. Gunpowder-related burns.

    PubMed

    Navarro-Monzonis, A; Benito-Ruiz, J; Baena-Montilla, P; Mena-Yago, A; de la Cruz-Ferrer, L I

    1992-04-01

    Gunpowder misuse is a frequent cause of burn injury in our area. The injuries are mostly minor lesions which may be treated on an outpatient basis, the more serious injuries need surgical treatment. Experience of the management of these burns is reported by reviewing 123 clinical charts of patients admitted between 1983 and 1990. The most frequent victims are teenage males who are involved mainly in accidents in the street. The most serious burns followed work-related accidents, with a fatal outcome in 47 per cent of the patients. The serious burns are usually deep dermal or full skin thickness. A common pattern affects groins, genitalia, hypogastrium and hands, and are produced when fireworks ignite in the pockets of the patient's trousers. The management of these lesions does not differ from burns caused by other agents, although attention should be paid to the presence of associated lesions, chiefly to eyes, ears and hands, due to the shockwave and shrapnel. PMID:1590935

  9. Coal burning process

    SciTech Connect

    Cowan, F.C.; Cowan, T.L.

    1980-02-05

    This process is for devolatilizing coal to produce a volatile hydrocarbon gas leaving a residue of unburned coal. The volatile hydrocarbon gas and other coal or said residual coal are thereafter burned together in a common furnace. The volatilization of the coal may be carried out substantially endothermically, and preferably on the plant site where the burning of the volatilized hydrocarbon takes place together with other coal or the residue coal. The volatile matter is removed from the coal in a volatile state before the residue coal exits from the burner nozzle and then enters the combustion chamber where the volatilized hydrocarbon gas and residue coal are burned together. The removed volatilized hydrocarbon gas can be placed within the same coal burning plant to join with the unburned residual coal, passing to the burner to burn therewith.

  10. Photonuclear reactions of actinide and pre-actinide nuclei at intermediate energies

    SciTech Connect

    Mukhopadhyay, Tapan; Basu, D. N.

    2007-12-15

    Photonuclear reaction is described with an approach based on the quasideuteron nuclear photoabsorption model followed by the process of competition between light particle evaporation and fission for the excited nucleus. Thus fission process is considered as a decay mode. The evaporation-fission process of the compound nucleus is simulated in a Monte Carlo framework. Photofission reaction cross sections are analysed in a systematic manner in the energy range {approx}50-70 MeV for the actinides {sup 232}Th, {sup 233}U, {sup 235}U, {sup 238}U, and {sup 237}Np and the pre-actinide nuclei {sup 208}Pb and {sup 209}Bi. The study reproduces satisfactorily well the available experimental data of photofission cross sections at energies {approx}50-70 MeV and the increasing trend of nuclear fissility with the fissility parameter Z{sup 2}/A for the actinides and pre-actinides at intermediate energies ({approx}20-140 MeV)

  11. Nanofiber applications for burn care.

    PubMed

    Hromadka, Michael; Collins, James B; Reed, Courtney; Han, Li; Kolappa, Kamal K; Cairns, Bruce A; Andrady, Tony; van Aalst, John A

    2008-01-01

    Nanotechnology is a growing field of manufactured materials with sizes less than 1 mum, and it is particularly useful in the field of medicine because these applications replicate components of a cell's in vivo environment. Nanofibers, which mimic collagen fibrils in the extracellular matrix (ECM), can be created from a host of natural and synthetic compounds and have multiple properties that may be beneficial to burn wound care. These properties include a large surface-area-to-volume ratio, high porosity, improved cell adherence, proliferation and migration, and controlled in vivo degradation rates. The large surface area of nanofiber mats allows for increased interaction with compounds and provides a mechanism for sustained release of antibiotics, analgesics, or growth factors into burn wounds; high porosity allows diffusion of nutrients and waste. Improved cell function on these scaffolds will promote healing. Controlled degradation rates of these scaffolds will promote scaffold absorption after its function is no longer required. The objective of this article is to review the current literature describing nanofibers and their potential application to burn care. PMID:18779672

  12. Biomass burning a driver for global change

    SciTech Connect

    Levine, J.S.; Cofer, W.R. III; Cahoon, D.R. Jr.; Winstead, E.L.

    1995-03-01

    Recent research has identified another biospheric process that has instantaneous and longer term effects on the production of atmospheric gases: biomass burning. Biomass burning includes the burning of the world`s vegetation-forests, savannas. and agricultural lands, to clear the land and change its use. Only in the past decade have researchers realized the important contributions of biomass burning to the global budgets of many radiatively and chemically active gases - carbon dioxide, methane, nitric oxide, tropospheric ozone, methyl chloride - and elemental carbon particulates. International field experiments and satellite data are yielding a clearer understanding of this important global source of atmospheric gases and particulates. It is seen that in addition to being a significant instantaneous global source of atmospheric gases and particulates, burning enhances the biogenic emissions of nitric oxide and nitrous oxide from the world`s soils. Biomass burning affects the reflectivity and emissivity of the Earth`s surface as well as the hydrological cycle by changing rates of land evaporation and water runoff. For these reasons, it appears that biomass burning is a significant driver of global change. 20 refs., 4 figs., 2 tabs.

  13. The scaling of the threshold conditions for solid propellant erosive burning

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Nguyen, M. H.; Cohen, N. S.

    1988-01-01

    Rocket test firings were performed to measure the transition length threshold conditions while systematically varying various rocket motor parameters. These include the crossflow velocity, the chamber pressure, the propellant nonerosive burning rate, the propellant surface roughness, and the motor port diameter. The erosive burning trends with varying propellant burning rate, motor chamber pressure, and mass flow rate are consistent with published results.

  14. Trends in actinide processing at Hanford

    SciTech Connect

    Harmon, H.D.

    1993-09-01

    In 1989, the mission at the Hanford Site began a dramatic and sometimes painful transition. The days of production--as we used to know it--are over. Our mission officially has become waste management and environmental cleanup. This mission change didn`t eliminate many jobs--in fact, budgets have grown dramatically to support the new mission. Most all of the same skilled crafts, engineers, and scientists are still required for the new mission. This change has not eliminated the need for actinide processing, but it has certainly changed the focus that our actinide chemists and process engineers have. The focus used to be on such things as increasing capacity, improving separations efficiency, and product purity. Minimizing waste had become a more important theme in recent years and it is still a very important concept in the waste management and environmental cleanup arena. However, at Hanford, a new set of words dominates the actinide process scene as we work to deal with actinides that still reside in a variety of forms at the Hanford Site. These words are repackage, stabilize, remove, store and dispose. Some key activities in each of these areas are described in this report.

  15. Optical properties of actinide and lanthanide ions

    SciTech Connect

    Hessler, J.P.; Carnall, W.T.

    1980-01-01

    This paper reviews some of the recent developments in this area of spectroscopy, emphasizing the optical properties of the tripositive lanthanide and actinide ions. In particular, the single ion properties of line positon, intensity, width, and fluorescence lifetime are discussed. 53 reference, 3 figures, 4 tables.

  16. Actinide valences in xenotime and monazite

    NASA Astrophysics Data System (ADS)

    Vance, E. R.; Zhang, Y.; McLeod, T.; Davis, J.

    2011-02-01

    Tetravalent U, Np and Pu can be substituted by ceramic methods into the rare earth site of xenotime and monazite in air atmospheres using Ca ions as charge compensators, while no evidence of penta- or hexavalent actinide ions was found. Some Pu 3+ and Np 3+ can be incorporated in xenotime samples fired in a reducing atmosphere.

  17. Rapid determination of actinides in asphalt samples

    SciTech Connect

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

    2014-01-12

    A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organics present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.

  18. COMPLEXANTS FOR ACTINIDE ELEMENT COORDINATION AND IMMOBILIZATION

    EPA Science Inventory

    We propose that inorganic clusters known as polyoxoanions (POAs) can be exploited as complexants for actinide (An) ion coordination and immobilization. Our objective is to develop rugged, stoichiometrically well-defined POAs that act as molecular containers of An elements. Poly...

  19. Actinide measurements by AMS using fluoride matrices

    NASA Astrophysics Data System (ADS)

    Cornett, R. J.; Kazi, Z. H.; Zhao, X.-L.; Chartrand, M. G.; Charles, R. J.; Kieser, W. E.

    2015-10-01

    Actinides can be measured by alpha spectroscopy (AS), mass spectroscopy or accelerator mass spectrometry (AMS). We tested a simple method to separate Pu and Am isotopes from the sample matrix using a single extraction chromatography column. The actinides in the column eluent were then measured by AS or AMS using a fluoride target matrix. Pu and Am were coprecipitated with NdF3. The strongest AMS beams of Pu and Am were produced when there was a large excess of fluoride donor atoms in the target and the NdF3 precipitates were diluted about 6-8 fold with PbF2. The measured concentrations of 239,240Pu and 241Am agreed with the concentrations in standards of known activity and with two IAEA certified reference materials. Measurements of 239,240Pu and 241Am made at A.E. Lalonde AMS Laboratory agree, within their statistical uncertainty, with independent measurements made using the IsoTrace AMS system. This work demonstrated that fluoride targets can produce reliable beams of actinide anions and that the measurement of actinides using fluorides agree with published values in certified reference materials.

  20. Actinide Targets for Neutron Cross Section Measurements

    SciTech Connect

    John D. Baker; Christopher A. McGrath

    2006-10-01

    The Advanced Fuel Cycle Initiative (AFCI) and the Generation IV Reactor Initiative have demonstrated a lack of detailed neutron cross-sections for certain "minor" actinides, those other than the most common (235U, 238U, and 239Pu). For some closed-fuel-cycle reactor designs more than 50% of reactivity will, at some point, be derived from "minor" actinides that currently have poorly known or in some cases not measured (n,?) and (n,f) cross sections. A program of measurements under AFCI has begun to correct this. One of the initial hurdles has been to produce well-characterized, highly isotopically enriched, and chemically pure actinide targets on thin backings. Using a combination of resurrected techniques and new developments, we have made a series of targets including highly enriched 239Pu, 240Pu, and 242Pu. Thus far, we have electrodeposited these actinide targets. In the future, we plan to study reductive distillation to achieve homogeneous, adherent targets on thin metal foils and polymer backings. As we move forward, separated isotopes become scarcer, and safety concerns become greater. The chemical purification and electodeposition techniques will be described.

  1. Rapid determination of actinides in asphalt samples

    DOE PAGESBeta

    Maxwell, Sherrod L.; Culligan, Brian K.; Hutchison, Jay B.

    2014-01-12

    A new rapid method for the determination of actinides in asphalt samples has been developed that can be used in emergency response situations or for routine analysis If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or a nuclear accident such as the accident at the Fukushima Nuclear Power Plant in March, 2011 occurs, there will be an urgent need for rapid analyses of many different environmental matrices, including asphalt materials, to support dose mitigation and environmental clean up. The new method for the determination of actinides in asphalt utilizes a rapid furnace step to destroy bitumen and organicsmore » present in the asphalt and sodium hydroxide fusion to digest the remaining sample. Sample preconcentration steps are used to collect the actinides and a new stacked TRU Resin + DGA Resin column method is employed to separate the actinide isotopes in the asphalt samples. The TRU Resin plus DGA Resin separation approach, which allows sequential separation of plutonium, uranium, americium and curium isotopes in asphalt samples, can be applied to soil samples as well.« less

  2. Environmental Impact of the Nuclear Fuel Cycle: Fate of Actinides

    SciTech Connect

    Ewing, Rodney C.; Runde, W.; Albrecht-Schmitt, Thomas E.

    2011-01-31

    The resurgence of nuclear power as a strategy for reducing greenhouse gas (GHG) emissions has, in parallel, revived interest in the environmental impact of actinides. Just as GHG emissions are the main environmental impact of the combustion of fossil fuels, the fate of actinides, consumed and produced by nuclear reactions, determines whether nuclear power is viewed as an environmentally “friendly” source of energy. In this article, we summarize the sources of actinides in the nuclear fuel cycle, how actinides are separated by chemical processing, the development of actinide-bearing materials, and the behavior of actinides in the environment. At each stage, actinides present a unique and complicated behavior because of the 5f electronic configurations.

  3. Serious occupational burn injuries treated at a regional burn center.

    PubMed

    Taylor, Allison J; McGwin, Gerald; Cross, James M; Smith, Donald R; Birmingham, Barbara R; Rue, Loring W

    2002-01-01

    This article will present the epidemiology of occupational burn injuries among patients admitted to a regional burn center. Patients admitted to University of Alabama at Birmingham University Hospital Burn Center between November 1994 and December 1999 for occupational burn injuries were studied. Descriptive statistics were generated for demographic, clinical, and outcome characteristics. Approximately one-quarter of all burn center admissions had sustained occupational burn injuries. The most common burns were flame, electrical, and scald burns. The most heavily represented occupations were "manufacturing" (19.1%), "electrician" (16.2%), and "laborer" (16.2%). Burn type varied with occupation. Over $16 million in hospital charges was accrued by patients sustaining occupational burn injuries. Understanding the epidemiology of serious burn injuries in the workplace is crucial to directing prevention efforts toward worker groups at highest risk. PMID:12142576

  4. Evidence of erosive burning in shuttle solid rocket motor

    NASA Technical Reports Server (NTRS)

    Martin, C. L.

    1983-01-01

    Known models of Shuttle Solid Rocket Motor (SRM) performance have failed to produce pressure-time traces which accurately matched actual motor performance, especially during the first 5 seconds after ignition and during the last quarter of web burn time. Efforts to compensate for these differences in model reconstruction and actual performance resulted in resorting to the use of a Burning Anomaly Rate Function (BARF). It was suspected that propellant erosive burning was primarily responsible for the variation of model from actual results. The three dimensional Hercules Grain Design and Internal Ballistics Evaluation Program was made operational and slightly modified and an extensive trial and error effort was begun to test the hypothesis of erosive burning as an explanation of the burning anomaly. It was found that introduction of erosive burning (using Green's erosive burning equation) over portions of the aft segment grain and above a threshold gas Mach number did, in fact, give excellent agreement with the actual motor trace.

  5. Children with burns referred for child abuse evaluation: Burn characteristics and co-existent injuries.

    PubMed

    Pawlik, Marie-Christin; Kemp, Alison; Maguire, Sabine; Nuttall, Diane; Feldman, Kenneth W; Lindberg, Daniel M

    2016-05-01

    Intentional burns represent a serious form of physical abuse that must be identified to protect children from further harm. This study is a retrospectively planned secondary analysis of the Examining Siblings To Recognize Abuse (ExSTRA) network data. Our objective was to describe the characteristics of burns injuries in children referred to Child Abuse Pediatricians (CAPs) in relation to the perceived likelihood of abuse. We furthermore compare the extent of diagnostic investigations undertaken in children referred to CAPs for burn injuries with those referred for other reasons. Within this dataset, 7% (215/2890) of children had burns. Children with burns were older than children with other injuries (median age 20 months vs. 10 months). Physical abuse was perceived as likely in 40.9% (88) and unlikely in 59.1% (127). Scalds accounted for 52.6% (113) and contact burns for 27.6% (60). Several characteristics of the history and burn injury were associated with a significantly higher perceived likelihood of abuse, including children with reported inflicted injury, absent or inadequate explanation, hot water as agent, immersion scald, a bilateral/symmetric burn pattern, total body surface area ≥10%, full thickness burns, and co-existent injuries. The rates of diagnostic testing were significantly lower in children with burns than other injuries, yet the yield of skeletal survey and hepatic transaminases testing were comparable between the two groups. This would imply that children referred to CAPs for burns warrant the same level of comprehensive investigations as those referred for other reasons. PMID:27088728

  6. [The Nutrition Care of Severe Burn Patients].

    PubMed

    Hsieh, Yu-Hsiu

    2016-02-01

    In addition to recent advances in burn patient care techniques such as maintaining warm circumambient temperature, the early excision of wounds, and the use of closed dressing, providing nutrition support through early feeding has proven instrumental in greatly increasing the survival rate of burn patients. Severe burns complicated by many factors initiate tremendous physiological stress that leads to postburn hypermetabolism that includes enhanced tissue catabolism, the loss of muscle mass, and decreases in the body's reservoirs of protein and energy. These problems have become the focus of burn therapy. Treating severe burns aims not only to enhance survival rates but also to restore normal bodily functions as completely as possible. Recent research evaluating the application of anabolic agents and immune-enhance formula for severe burns therapy has generated significant controversy. Inadequate caloric intake is one of the main differences among the related studies, with the effect of many special nutrients such as bran acid amides not taken into consideration. Therefore, considering the sufficiency of caloric and protein intake is critical in assessing effectiveness. Only after patients receive adequate calories and protein may the effect of special nutrients such as glutamine and supplements be evaluated effectively. PMID:26813059

  7. Investigation of critical burning of fuel droplets

    NASA Technical Reports Server (NTRS)

    Allison, C. B.; Canada, G. S.; Faeth, G. M.

    1972-01-01

    Measurements were made on the burning of liquid hydrazine, MMH, and UDMH in a combustion gas environment. The experimental range of these tests involved gas temperatures of 1660-2530 K, oxygen concentrations of 0-42% by mass and droplet diameters (employing both droplets and porous spheres) of 0.11-1.91 cm. at atmospheric pressure. A simplified hybrid combustion theory was developed which was found to correlate the present results as well as the experimental measurements of other investigators. Measurements were also made of the monopropellant strand burning rates and liquid surface temperatures of a number of nitrate ester fuels and hydrazine at elevated pressures. The temperature measurements for the nitrate esters were found to be in good agreement with a theoretical model which allowed for gas solubility in the liquid phase at high pressures. Experimental results were also obtained on the burning rates and liquid surface temperatures of a number of paraffin and alcohol fuels burning in air pressures up to 72 atm. For these tests, the fuels were burned from porous spheres in a natural convection environment. Initial findings on a pressurized flat flame burner are also described as well as the design of an oscillatory combustion apparatus to test the response of burning liquid fuels.

  8. Energy Expenditure and Caloric Balance After Burn

    PubMed Central

    Hart, David W.; Wolf, Steven E.; Herndon, David N.; Chinkes, David L.; Lal, Sophia O.; Obeng, Michael K.; Beauford, Robert B.; Mlcak RT, Ronald P.

    2002-01-01

    Objective Resting energy expenditure (REE) is commonly measured in critical illness to determine caloric “demands” and thus nutritive needs. Summary Background Data The purpose of this study was to 1) determine whether REE is associated with clinical outcomes and 2) determine whether an optimal caloric delivery rate based on REE exists to offset erosion of lean mass after burn. Methods From 1995 to 2001, REE was measured by indirect calorimetry in 250 survivors of 10 to 99%TBSA burns. Caloric intake and REE were correlated with muscle protein catabolism, length of stay, ventilator dependence, sepsis, and mortality. From 1998 to 2000, 42 patients (>60%TBSA burns) received continuous enteral nutrition at a spectrum of caloric balance between 1.0x REE kcal/d –1.8x REE kcal/d. Serial body composition was measured by dual energy x-ray absorptiometry. Lean mass, fat mass, morbidity, and mortality were determined. Results REE/predicted basal metabolic rate correlated directly with burn size, sepsis, ventilator dependence, and muscle protein catabolism (P < .05). Declining REE correlated with mortality (P < .05). 2) Erosion of lean body mass was not attenuated by increased caloric balance, however, fat mass increased with caloric supply (P < .05). Conclusion In surviving burned patients, caloric delivery beyond 1.2 × REE results in increased fat mass without changes in lean body mass. Declining energy expenditure appears to be a harbinger of mortality in severely burned patients. PMID:11753055

  9. Burn injury in children.

    PubMed

    Zámecníková, I; Stĕtinský, J; Tymonová, J; Kadlcík, M

    2005-01-01

    The authors have analyzed the data files of 580 child patients up to 15 years of age who were hospitalized at the Burn Center of the FNsP Hospital in Ostrava in the years 1999 - 2003. The authors focused on mechanisms of burn injury in relation to the age of a child as well as extent, depth, localization, and local treatment of the injury. The data file was divided to four age groups: up to two years of age, 2 - 5 years of age, 5 - 10 years of age, and 10 - 15 years of age. As regards the mechanisms of injury, the authors have analyzed scalding by hot liquids, burns due to contact with a hot object, burns due to electric current, explosion, and injury caused by burning clothing. Injury by scalding prevails to a very significant degree in the youngest children. In the second age group the incidence of burn following contact with hot objects increases, as does the percentage of children injured by burning of clothing in children aged 5 - 10. The older children have increased prevalence of injuries caused by explosions. The greatest average extent of an injury is from burning of clothing. Most of the areas are burned deeply, localized in more areas of the body, and almost half of the cases required surgical intervention. Scalding comes second in terms of average extent of an injury. More than half of the injured areas are superficial, and areas of injury are different in the individual age groups. We addressed about a fifth of the cases surgically. The explosion of combustible materials caused a smaller extent of injury, on average, taking third place. The injuries were predominantly superficial, most commonly involving the head, trunk, and upper extremities. In none of the cases it was necessary for us to operate. Burn injuries caused by contact with hot objects are of a smaller extent. More than half of the burned areas are deep, localized most commonly in the upper extremities. Surgical intervention was necessary in more than half the cases. In terms of average

  10. Minor burn injuries in children: inpatient versus outpatient treatment?

    PubMed Central

    La Ferla, G. A.; Fyfe, A. H.; Drainer, I. K.

    1983-01-01

    Seventy-two children with minor superficial burns presented at our casualty department over a 5-month period. Half were treated as inpatients and the other half as outpatients. The colonisation rates were similar in the two groups. Colonised and sterile burns treated as inpatients showed no significant difference in healing rates. The healing time, however, was prolonged in colonised outpatient treated burns. Cosmetic results were satisfactory overall. In the absence of a definite benefit from inpatient treatment, outpatient care of a child with a minor burn should therefore be used if circumstances allow. PMID:6357035

  11. Minor burns - aftercare

    MedlinePlus

    ... put a thin layer of ointment, such as petroleum jelly or aloe vera, on the burn. The ... is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation ...

  12. New Fashioned Book Burning.

    ERIC Educational Resources Information Center

    Gardner, Robert

    1997-01-01

    Reports on results of a teacher's experiment in book burning as a lesson accompanying the teaching of Ray Bradbury's "Fahrenheit 451." Discusses student reactions and the purpose of or justification for the experimental lesson. (TB)

  13. Burns (For Parents)

    MedlinePlus

    ... you drowsy, or in bed. Don't use fireworks or sparklers. Bathroom Set the thermostat on your ... For Kids For Parents MORE ON THIS TOPIC Fireworks Safety First Aid: Burns First Aid: Sunburn Sun ...

  14. Burn Depth Monitor

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Supra Medical Systems is successfully marketing a device that detects the depth of burn wounds in human skin. To develop the product, the companyused technology developed by NASA Langley physicists looking for better ultrasonic detection of small air bubbles and cracks in metal. The device is being marketed to burn wound analysis and treatment centers. Through a Space Act agreement, NASA and the company are also working to further develop ultrasonic instruments for new medical applications.

  15. Burn Depth Monitor

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Supra Medical Systems is successfully marketing a device that detects the depth of burn wounds in human skin. To develop the product, the company used technology developed by NASA Langley physicists looking for better ultrasonic detection of small air bubbles and cracks in metal. The device is being marketed to burn wound analysis and treatment centers. Through a Space Act agreement, NASA and the company are also working to further develop ultrasonic instruments for new medical applications

  16. Burn Depth Monitor

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Supra Medical Systems is successfully marketing a device that detects the depth of burn wounds in human skin. To develop the product, the company used technology developed by NASA Langley physicists looking for better ultrasonic detection of small air bubbles and cracks in metal. The device is being marketed to burn wound analysis and treatment centers. Through a Space Act agreement, NASA and the company are also working to further develop ultrasonic instruments for new medical applications.

  17. Candidemia in major burns patients.

    PubMed

    Renau Escrig, Ana I; Salavert, Miguel; Vivó, Carmen; Cantón, Emilia; Pérez Del Caz, M Dolores; Pemán, Javier

    2016-06-01

    Major burn patients have characteristics that make them especially susceptible to candidemia, but few studies focused on this have been published. The objectives were to evaluate the epidemiological, microbiological and clinical aspects of candidemia in major burn patients, determining factors associated with a poorer prognosis and mortality. We conducted a retrospective observational study of candidemia between 1996 and 2012 in major burn patients admitted to the La Fe University Hospital, Valencia, Spain. The study included 36 episodes of candidemia in the same number of patients, 55.6% men, mean age 37.33 years and low associated comorbidity. The incidence of candidemia varied between 0.26 and 6.09 episodes/1000 days stay in the different years studied. Candida albicans was the most common species (61.1%) followed by Candida parapsilosis (27.8%). Candidemia by C. krusei, C. glabrata or C. tropicalis were all identified after 2004. Central vascular catheter (CVC) was established as a potential source of candidemia in 36.1%, followed by skin and soft tissues of thermal injury (22.2%) and urinary tract (8.3%). Fluconazole was used in 19 patients (52.7%) and its in vitro resistance rate was 13.9%. The overall mortality was 47.2%, and mortality related to candidemia was 30.6%. Factors associated with increased mortality were those related to severe infection and shock. CVC was the most usual focus of candidemia. Fluconazole was the most common antifungal drug administered. The management of candidemia in major burn patients is still a challenge. PMID:26931414

  18. Synthesis of actinide nitrides, phosphides, sulfides and oxides

    DOEpatents

    Van Der Sluys, William G.; Burns, Carol J.; Smith, David C.

    1992-01-01

    A process of preparing an actinide compound of the formula An.sub.x Z.sub.y wherein An is an actinide metal atom selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, x is selected from the group consisting of one, two or three, Z is a main group element atom selected from the group consisting of nitrogen, phosphorus, oxygen and sulfur and y is selected from the group consisting of one, two, three or four, by admixing an actinide organometallic precursor wherein said actinide is selected from the group consisting of thorium, uranium, plutonium, neptunium, and americium, a suitable solvent and a protic Lewis base selected from the group consisting of ammonia, phosphine, hydrogen sulfide and water, at temperatures and for time sufficient to form an intermediate actinide complex, heating said intermediate actinide complex at temperatures and for time sufficient to form the actinide compound, and a process of depositing a thin film of such an actinide compound, e.g., uranium mononitride, by subliming an actinide organometallic precursor, e.g., a uranium amide precursor, in the presence of an effectgive amount of a protic Lewis base, e.g., ammonia, within a reactor at temperatures and for time sufficient to form a thin film of the actinide compound, are disclosed.

  19. Ball lightning burn.

    PubMed

    Selvaggi, Gennaro; Monstrey, Stan; von Heimburg, Dennis; Hamdi, Mustapha; Van Landuyt, Koen; Blondeel, Phillip

    2003-05-01

    Ball lightning is a rare physical phenomenon, which is not yet completely explained. It is similar to lightning but with different, peculiar characteristics. It can be considered a mix of fire and electricity, concentrated in a fireball with a diameter of 20-cm that most commonly appears suddenly, even in indoor conditions, during a thunderstorm. It moves quickly for several meters, can change direction, and ultimately disappears. During a great storm, a 28-year-old man and his 5-year-old daughter sustained burn wounds after ball lightning came from the outdoors through a chimney. These two patients demonstrated signs of fire and electrical injuries. The father, who lost consciousness, sustained superficial second-degree burn wounds bilaterally on the zygomatic area and deep second-degree burn wounds on his right hand (total body surface area, 4%). His daughter demonstrated superficial second-degree burn wounds on the left part of the face and deep second-degree and third-degree burn wounds (total body surface area, 30%) on the left neck, both upper arms, and the back. In this article, the authors report the first two cases of burn injuries resulting from ball lightning contact indoors. The literature on this rare phenomenon is reviewed to elucidate the nature of ball lightning. Emphasis is placed on the nature of injuries after ball lightning contact, the therapy used, and the long-term complications. PMID:12792547

  20. Sample preparation for actinide solid state research

    NASA Astrophysics Data System (ADS)

    Spirlet, J. C.

    1982-09-01

    The actinide elements (5f elements) and their compounds constitute a very interesting group for solid state research. The electronic properties of the 5f elements show intermediate behavior between the well-understood, completely localized 4f system (lanthanides) and the 3d system (transition elements). The possibility of understanding some unexplained properties of the 3d elements through a systematic investigation of the electronic structures of the actinides considerably increased interest in samples with well-defined composition and structure and with well-known purity. In some cases, single crystals of low defect densities and high purity levels are needed to allow sophisticated investigations of physical properties. Actinide compounds are easily obtained at a high purity level by direct synthesis from pure elements using noncontaminating techniques. Examples of these techniques are the reaction of the actinide metal powder with the vapor of an oxidant in a sealed quartz ampoule, leviation melting on a water-cooled pedestal or melting in a Huking crucible. Actinide metals are produced by metallothermic reduction of commercially available oxides or carbides or by the van Arkel purification process. The metals are refined to the desired purity level by evaporation in vacuum for the more volatile elements (Ac, Pu, Am, Cm, Bk) and by the van Arkel process for the metals with low vapor pressure. Single crystals of actinide compounds have been grown by chemical vapor transport methods (oxides, chalcogenides), high temperature solution growth techniques (oxides), and pulling from the melt by the Czochralski method (oxides, intermetallics). Thin solid films have been prepared by vacuum evaporation or by focused ion-beam sputtering. The materials are analyzed for trace-level impurity content by inductively-coupled plasma spectroscopy, by spark source mass spectroscopy and by secondary-ion mass spectroscopy. The chemical composition of the compounds is determined by

  1. Electrorecovery of actinides at room temperature

    SciTech Connect

    Stoll, Michael E; Oldham, Warren J; Costa, David A

    2008-01-01

    There are a large number of purification and processing operations involving actinide species that rely on high-temperature molten salts as the solvent medium. One such application is the electrorefining of impure actinide metals to provide high purity material for subsequent applications. There are some drawbacks to the electrodeposition of actinides in molten salts including relatively low yields, lack of accurate potential control, maintaining efficiency in a highly corrosive environment, and failed runs. With these issues in mind we have been investigating the electrodeposition of actinide metals, mainly uranium, from room temperature ionic liquids (RTILs) and relatively high-boiling organic solvents. The RTILs we have focused on are comprised of 1,3-dialkylimidazolium or quaternary ammonium cations and mainly the {sup -}N(SO{sub 2}CF{sub 3}){sub 2} anion [bis(trif1uoromethylsulfonyl)imide {equivalent_to} {sup -}NTf{sub 2}]. These materials represent a class of solvents that possess great potential for use in applications employing electrochemical procedures. In order to ascertain the feasibility of using RTILs for bulk electrodeposition of actinide metals our research team has been exploring the electron transfer behavior of simple coordination complexes of uranium dissolved in the RTIL solutions. More recently we have begun some fundamental electrochemical studies on the behavior of uranium and plutonium complexes in the organic solvents N-methylpyrrolidone (NMP) and dimethylsulfoxide (DMSO). Our most recent results concerning electrodeposition will be presented in this account. The electrochemical behavior of U(IV) and U(III) species in RTILs and the relatively low vapor pressure solvents NMP and DMSO is described. These studies have been ongoing in our laboratory to uncover conditions that will lead to the successful bulk electrodeposition of actinide metals at a working electrode surface at room temperature or slightly elevated temperatures. The RTILs we

  2. Burn size determines the inflammatory and hypermetabolic response

    PubMed Central

    Jeschke, Marc G; Mlcak, Ronald P; Finnerty, Celeste C; Norbury, William B; Gauglitz, Gerd G; Kulp, Gabriela A; Herndon, David N

    2007-01-01

    Background Increased burn size leads to increased mortality of burned patients. Whether mortality is due to inflammation, hypermetabolism or other pathophysiologic contributing factors is not entirely determined. The purpose of the present study was to determine in a large prospective clinical trial whether different burn sizes are associated with differences in inflammation, body composition, protein synthesis, or organ function. Methods Pediatric burned patients were divided into four burn size groups: <40% total body surface area (TBSA) burn, 40–59% TBSA burn, 60–79% TBSA burn, and >80% TBSA burn. Demographic and clinical data, hypermetabolism, the inflammatory response, body composition, the muscle protein net balance, serum and urine hormones and proteins, and cardiac function and changes in liver size were determined. Results One hundred and eighty-nine pediatric patients of similar age and gender distribution were included in the study (<40% TBSA burn, n = 43; 40–59% TBSA burn, n = 79; 60–79% TBSA burn, n = 46; >80% TBSA burn, n = 21). Patients with larger burns had more operations, a greater incidence of infections and sepsis, and higher mortality rates compared with the other groups (P < 0.05). The percentage predicted resting energy expenditure was highest in the >80% TBSA group, followed by the 60–79% TBSA burn group (P < 0.05). Children with >80% burns lost the most body weight, lean body mass, muscle protein and bone mineral content (P < 0.05). The urine cortisol concentration was highest in the 80–99% and 60–79% TBSA burn groups, associated with significant myocardial depression and increased change in liver size (P < 0.05). The cytokine profile showed distinct differences in expression of IL-8, TNF, IL-6, IL-12p70, monocyte chemoattractant protein-1 and granulocyte–macrophage colony-stimulating factor (P < 0.05). Conclusion Morbidity and mortality in burned patients is burn size dependent, starts at a 60% TBSA burn and is due to an

  3. The media glorifying burns: a hindrance to burn prevention.

    PubMed

    Greenhalgh, David G; Palmieri, Tina L

    2003-01-01

    The media have a profound influence on the actions of children and adults. Burns and burn prevention tend to be ignored or even mocked. The purpose of this presentation is to reveal the callousness of the media in its dealings with burns and burn prevention. Printed materials with a relationship to burns, risk of burning, or disrespect for the consequences of burns were collected. The materials were tabulated into four categories: comics, advertisements (ads), articles that made light of burns, and television shows that portrayed behavior that would risk burn injury. Most burn-related materials were found in comics or advertisements. Several comics made light of high-risk behavior with flames, scald injury, contact injury, or burns. In addition, several advertisements showed people on fire or actions that could easily lead to burns. Several articles and televisions shows portrayed high-risk behavior that, in some instances, led to copycat injuries. Flames are frequently used to sell items that target adolescent boys or young men. The high incidence injuries that frequent this population parallel the high-risk behaviors portrayed by the media. The media portrays flames and high-risk behavior for burn injury as being cool, funny, and without consequence. The use of flames on clothing and recreational equipment (skateboards, hot rods) particularly targets the high-risk adolescent male. The burn community should make the media aware of the harm it causes with its callous depiction and glorification of burns. PMID:12792237

  4. Comparison of actinide production in traveling wave and pressurized water reactors

    SciTech Connect

    Osborne, A.G.; Smith, T.A.; Deinert, M.R.

    2013-07-01

    The geopolitical problems associated with civilian nuclear energy production arise in part from the accumulation of transuranics in spent nuclear fuel. A traveling wave reactor is a type of breed-burn reactor that could, if feasible, reduce the overall production of transuranics. In one possible configuration, a cylinder of natural or depleted uranium would be subjected to a fast neutron flux at one end. The neutrons would transmute the uranium, producing plutonium and higher actinides. Under the right conditions, the reactor could become critical, at which point a self-stabilizing fission wave would form and propagate down the length of the reactor cylinder. The neutrons from the fission wave would burn the fissile nuclides and transmute uranium ahead of the wave to produce additional fuel. Fission waves in uranium are driven largely by the production and fission of {sup 239}Pu. Simulations have shown that the fuel burnup can reach values greater than 400 MWd/kgIHM, before fission products poison the reaction. In this work we compare the production of plutonium and minor actinides produced in a fission wave to that of a UOX fueled light water reactor, both on an energy normalized basis. The nuclide concentrations in the spent traveling wave reactor fuel are computed using a one-group diffusion model and are verified using Monte Carlo simulations. In the case of the pressurized water reactor, a multi-group collision probability model is used to generate the nuclide quantities. We find that the traveling wave reactor produces about 0.187 g/MWd/kgIHM of transuranics compared to 0.413 g/MWd/kgIHM for a pressurized water reactor running fuel enriched to 4.95 % and burned to 50 MWd/kgIHM. (authors)

  5. Review of composite propellant burn rate modeling

    NASA Technical Reports Server (NTRS)

    Cohen, N. S.

    1979-01-01

    Steady-state combustion modeling of composite solid propellants is discussed with emphasis on the Beckstead-Derr-Price (BDP) model. The BDP model and some revisions are considered with respect to the analysis of monomodal ammonium perchlorate/inert binder propellants: topics examined include continuity relations, surface area relations, characteristic surface dimension, flame heights, and energy balance. Application of the BDP model to more complicated propellants containing multiple active ingredients is described. These propellants include multimodal, mixed oxidizer, active binder, aluminized, catalyzed, and nitramine propellants. Example cases of modeling (with comparison to experimental data) are presented, and strengths and weaknesses of current modeling approaches are evaluated.

  6. Characteristics of elderly Japanese patients with severe burns.

    PubMed

    Morita, Seiji; Higami, Shigeo; Yamagiwa, Takeshi; Iizuka, Shinichi; Nakagawa, Yoshihide; Yamamoto, Isotoshi; Inokuchi, Sadaki

    2010-11-01

    In this study, we report the clinical characteristics of elderly Japanese patients with severe burns. We studied the clinical features of 76 adult patients with severe burns, 35 of whom (46.1%) were ≥65 years old. We evaluated the characteristics of patients with respect to each type of burn. In addition, we studied the rate of death and survival in the elderly and also between the elderly and non-elderly patients. The following parameters were either assessed or compared between the elderly and non-elderly: gender, average age, vital signs (Glasgow Coma Scale, systolic blood pressure, heart rate and respiratory rate) and PaO(2)/FiO(2) (P/F) ratio at admission, cause of burn and a history of physical or psychiatric disease. Further, we investigated whether the burn was caused by attempting suicide and determined the percent total body surface area (%TBSA), second- and third-degree burn area, burn index (BI), prognostic burn index (PBI), presence of tracheal burns, presence of alcohol intoxication and overdose poisoning, presence of tracheal intubation, outcome and cause of death. The male:female ratio of the elderly patients was 17:18 (average age, 78.1 (8.2) years). Burns were mostly caused by flame (26/35), followed by scalding (8/35). Ten patients had attempted suicide. The %TBSA, second-degree burn area, third-degree burn area, BI and PBI, respectively were 46.6% (26.7%), 15.3% (19.0%), 35.6% (26.0%), 41.1 (25.2) and 119.2 (25.9). Of the 35 patients, 23 died. The notable characteristics of the elderly patients who died were flame as the cause of the burns: high %TBSA, BI and PBI, and a high rate of tracheal intubation. Elderly patients constituted approximately 45% of our study population. Most burns were caused by flames. The incidence of accidental bathtub-related burns was higher and that of suicide attempts was lower in the elderly patients, as compared with the non-elderly patients. Severe burns were fatal for elderly patients. Therefore, elderly

  7. [Invasive yeast infections in severely burned patients].

    PubMed

    Renau, Ana Isabel; García-Vidal, Carolina; Salavert, Miguel

    2016-01-01

    Currently, there are few studies on candidaemia in the severely burned patient. These patients share the same risk factors for invasive fungal infections as other critically ill patients, but have certain characteristics that make them particularly susceptible. These include the loss of skin barrier due to extensive burns, fungal colonisation of the latter, and the use of hydrotherapy or other topical therapies (occasionally with antimicrobials). In addition, the increased survival rate achieved in recent decades in critically burned patients due to the advances in treatment has led to the increase of invasive Candida infections. This explains the growing interest in making an earlier and more accurate diagnosis, as well as more effective treatments to reduce morbidity and mortality of candidaemia in severe burned patients. A review is presented on all aspects of the burned patient, including the predisposition and risk factors for invasive candidiasis, pathogenesis of candidaemia, underlying immunodeficiency, local epidemiology and antifungal susceptibility, evolution and prognostic factors, as well as other non-Candida yeast infections. Finally, we include specific data on our local experience in the management of candidaemia in severe burned patients, which may serve to quantify the problem, place it in context, and offer a realistic perspective. PMID:27395025

  8. NEW METHOD FOR DETERMINATION OF ACTINIDES AND STRONTIUM IN ANIMAL TISSUE

    SciTech Connect

    Maxwell, S; Jay Hutchison, J; Don Faison, D

    2007-05-07

    The analysis of actinides in animal tissue samples is very important for environmental monitoring. There is a need to measure actinide isotopes with very low detection limits in animal tissue samples, including fish, deer, hogs, beef and shellfish. A new, rapid actinide separation method has been developed and implemented that allows the measurement of plutonium, neptunium, uranium, americium, curium and strontium isotopes in large animal tissue samples (100-200 g) with high chemical recoveries and effective removal of matrix interferences. This method uses stacked TEVA Resin{reg_sign}, TRU Resin{reg_sign} and DGA-Resin{reg_sign} cartridges from Eichrom Technologies (Darien, IL, USA) that allows the rapid separation of plutonium (Pu), neptunium (Np), uranium (U), americium (Am), and curium (Cm) using a single multi-stage column combined with alpha spectrometry. Sr-90 is collected on Sr Resin{reg_sign} from Eichrom Technologies (Darien, IL, USA). After acid digestion and furnace heating of the animal tissue samples, the actinides and Sr-89/90 are separated using column extraction chromatography. This method has been shown to be effective over a wide range of animal tissue matrices. By using vacuum box cartridge technology with rapid flow rates, sample preparation time is minimized.

  9. Georgia Institute of Technology research on the Gas Core Actinide Transmutation Reactor (GCATR)

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Rust, J. H.; Schneider, A.; Hohl, F.

    1976-01-01

    The program reviewed is a study of the feasibility, design, and optimization of the GCATR. The program is designed to take advantage of initial results and to continue work carried out on the Gas Core Breeder Reactor. The program complements NASA's program of developing UF6 fueled cavity reactors for power, nuclear pumped lasers, and other advanced technology applications. The program comprises: (1) General Studies--Parametric survey calculations performed to examine the effects of reactor spectrum and flux level on the actinide transmutation for GCATR conditions. The sensitivity of the results to neutron cross sections are to be assessed. Specifically, the parametric calculations of the actinide transmutation are to include the mass, isotope composition, fission and capture rates, reactivity effects, and neutron activity of recycled actinides. (2) GCATR Design Studies--This task is a major thrust of the proposed research program. Several subtasks are considered: optimization criteria studies of the blanket and fuel reprocessing, the actinide insertion and recirculation system, and the system integration. A brief review of the background of the GCATR and ongoing research is presented.

  10. Actinide phosphonate complexes in aqueous solutions

    SciTech Connect

    Nash, K.L.

    1993-10-01

    Complexes formed by actinides with carboxylic acids, polycarboxylic acids, and aminopolycarboxylic acids play a central role in both the basic and process chemistry of the actinides. Recent studies of f-element complexes with phosphonic acid ligands indicate that new ligands incorporating doubly ionizable phosphonate groups (-PO{sub 3}H{sub 2}) have many properties which are unique chemically, and promise more efficient separation processes for waste cleanup and environmental restoration. Simple diphosphonate ligands form much stronger complexes than isostructural carboxylates, often exhibiting higher solubility as well. In this manuscript recent studies of the thermodynamics and kinetics of f-element complexation by 1,1 and 1,2 diphosphonic acid ligands are described.

  11. Microbial Transformations of Actinides and Other Radionuclides

    SciTech Connect

    Francis,A.J.; Dodge, C. J.

    2009-01-07

    Microorganisms can affect the stability and mobility of the actinides and other radionuclides released from nuclear fuel cycle and from nuclear fuel reprocessing plants. Under appropriate conditions, microorganisms can alter the chemical speciation, solubility and sorption properties and thus could increase or decrease the concentrations of radionuclides in solution in the environment and the bioavailability. Dissolution or immobilization of radionuclides is brought about by direct enzymatic action or indirect non-enzymatic action of microorganisms. Although the physical, chemical, and geochemical processes affecting dissolution, precipitation, and mobilization of radionuclides have been extensively investigated, we have only limited information on the effects of microbial processes and biochemical mechanisms which affect the stability and mobility of radionuclides. The mechanisms of microbial transformations of the major and minor actinides U, Pu, Cm, Am, Np, the fission products and other radionuclides such as Ra, Tc, I, Cs, Sr, under aerobic and anaerobic conditions in the presence of electron donors and acceptors are reviewed.

  12. Burn care in South Africa: a micro cosmos of Africa.

    PubMed

    Rode, H; Cox, S G; Numanoglu, A; Berg, A M

    2014-07-01

    Burn injuries in Africa are common with between 300,000 and 17.5 million children under 5 years sustaining burn injuries annually, resulting in a high estimated fatality rate. These burns are largely environmentally conditioned and therefore preventable. The Western Cape Province in South Africa can be regarded as a prototype of paediatric burns seen on the continent, with large numbers, high morbidity and mortality rates and an area inclusive of all factors contributing to this extraordinary burden of injury. Most of the mechanisms to prevent burns are not easily modified due to the restraint of low socio-economic homes, overcrowding, unsafe appliances, multiple and complex daily demands on families and multiple psycho-social stressors. Children <4 years are at highest risk of burns with an average annual rate of 6.0/10,000 child-years. Burn care in South Africa is predominantly emergency driven and variable in terms of organization, clinical management, facilities and staffing. Various treatment strategies were introduced. The management of HIV positive children poses a problem, as well as the conflict of achieving equity of burn care for all children. Without alleviating poverty, developing minimum standards for housing, burn education, safe appliances and legislation, we will not be able to reduce the "curse of poor people" and will continue to treat the consequences. PMID:24906348

  13. In vitro removal of actinide (IV) ions

    DOEpatents

    Weitl, Frederick L.; Raymond, Kenneth N.

    1982-01-01

    A compound of the formula: ##STR1## wherein X is hydrogen or a conventional electron-withdrawing group, particularly --SO.sub.3 H or a salt thereof; n is 2, 3, or 4; m is 2, 3, or 4; and p is 2 or 3. The present compounds are useful as specific sequestering agents for actinide (IV) ions. Also described is a method for the 2,3-dihydroxybenzamidation of azaalkanes.

  14. Separation of Californium from other Actinides

    DOEpatents

    Mailen, J C; Ferris, L M

    1973-09-25

    A method is provided for separating californium from a fused fluoride composition containing californium and at least one element selected from the group consisting of plutonium, americium, curium, uranium, thorium, and protactinium which comprises contacting said fluoride composition with a liquid bismuth phase containing sufficient lithium or thorium to effect transfer of said actinides to the bismuth phase and then contacting the liquid bismuth phase with molten LiCl to effect selective transfer of californium to the chloride phase.

  15. Surrogate Reactions in the Actinide Region

    SciTech Connect

    Burke, J T; Bernstein, L A; Scielzo, N D; Bleuel, D L; Lesher, S R; Escher, J; Ahle, L; Dietrich, F S; Hoffman, R D; Norman, E B; Sheets, S A; Phair, L; Fallon, P; Clark, R M; Gibelin, J; Jewett, C; Lee, I Y; Macchiavelli, A O; McMahan, M A; Moretto, L G; Rodriguez-Vieitez, E; Wiedeking, M; Lyles, B F; Beausang, C W; Allmond, J M; Ai, H; Cizewski, J A; Hatarik, R; O'Malley, P D; Swan, T

    2008-01-30

    Over the past three years we have studied various surrogate reactions (d,p), ({sup 3}He,t), ({alpha},{alpha}{prime}) on several uranium isotopes {sup 234}U, {sup 235}U, {sup 236}U, and {sup 238}U. An overview of the STARS/LIBERACE surrogate research program as it pertains to the actinides is discussed. A summary of results to date will be presented along with a discussion of experimental difficulties encountered in surrogate experiments and future research directions.

  16. Actinide behavior in a freshwater pond

    SciTech Connect

    Trabalka, J.R.; Bogle, M.A.; Scott, T.G.

    1983-01-01

    Long-term investigations of solution chemistry in an alkaline freshwater pond have revealed that actinide oxidation state behavior, particularly that of plutonium, is complex. The Pu(V,VI) fraction was predominant in solution, but it varied over the entire range reported from other natural aquatic environments, in this case, as a result of intrinsic biological and chemical cycles (redox and pH-dependent phenomena). A strong positive correlation between plutonium (Pu), but not uranium (U), and hydroxyl ion over the observation period, especially when both were known to be in higher oxidation states, was particularly notable. Coupled with other examples of divergent U and Pu behavior, this result suggests that Pu(V), or perhaps a mixture of Pu(V,VI), was the prevalent oxidation state in solution. Observations of trivalent actinide sorption behavior during an algal bloom, coupled with the association with a high-molecular weight (nominally 6000 to 10,000 mol wt) organic fraction in solution, indicate that solution-detritus cycling of organic carbon, in turn, may be the primary mechanism in amercium-curium (Am-Cm) cycling. Sorption by sedimentary materials appears to predominate over other factors controlling effective actinide solubility and may explain, at least partially, the absence of an expected strong positive correlation between carbonate and dissolved U. 49 references, 6 figures, 12 tables.

  17. Actinide and lanthanide separation process (ALSEP)

    SciTech Connect

    Guelis, Artem V.

    2013-01-15

    The process of the invention is the separation of minor actinides from lanthanides in a fluid mixture comprising, fission products, lanthanides, minor actinides, rare earth elements, nitric acid and water by addition of an organic chelating aid to the fluid; extracting the fluid with a solvent comprising a first extractant, a second extractant and an organic diluent to form an organic extractant stream and an aqueous raffinate. Scrubbing the organic stream with a dicarboxylic acid and a chelating agent to form a scrubber discharge. The scrubber discharge is stripped with a simple buffering agent and a second chelating agent in the pH range of 2.5 to 6.1 to produce actinide and lanthanide streams and spent organic diluents. The first extractant is selected from bis(2-ethylhexyl)hydrogen phosphate (HDEHP) and mono(2-ethylhexyl)2-ethylhexyl phosphonate (HEH(EHP)) and the second extractant is selected from N,N,N,N-tetra-2-ethylhexyl diglycol amide (TEHDGA) and N,N,N',N'-tetraoctyl-3-oxapentanediamide (TODGA).

  18. Recovery of actinides from actinide-aluminium alloys by chlorination: Part II

    NASA Astrophysics Data System (ADS)

    Souček, P.; Cassayre, L.; Eloirdi, R.; Malmbeck, R.; Meier, R.; Nourry, C.; Claux, B.; Glatz, J.-P.

    2014-04-01

    A chlorination route is being investigated for recovery of actinides from actinide-aluminium alloys, which originate from pyrochemical recovery of actinides from spent metallic nuclear fuel by electrochemical methods in molten LiCl-KCl. In the present work, the most important steps of this route were experimentally tested using U-Pu-Al alloy prepared by electrodeposition of U and Pu on solid aluminium plate electrodes. The investigated processes were vacuum distillation for removal of the salt adhered on the electrode, chlorination of the alloy by chlorine gas and sublimation of the AlCl3 formed. The processes parameters were set on the base of a previous thermochemical study and an experimental work using pure UAl3 alloy. The present experimental results indicated high efficiency of salt distillation and chlorination steps, while the sublimation step should be further optimised.

  19. Development of the Actinide-Lanthanide Separation (ALSEP) Process

    SciTech Connect

    Lumetta, Gregg J.; Carter, Jennifer C.; Niver, Cynthia M.; Gelis, Artem V.

    2014-09-30

    Separating the minor actinide elements (Am and Cm) from acidic high-level raffinates arising from the reprocessing of irradiated nuclear fuel is an important step in closing the nuclear fuel cycle. Most proposed approaches to this problem involve two solvent extraction steps: 1) co-extraction of the trivalent lanthanides and actinides, followed by 2) separation of the actinides from the lanthanides. The objective of our work is to develop a single solvent-extraction process for isolating the minor actinide elements. We report here a solvent containing N,N,N',N'-tetra(2 ethylhexyl)diglycolamide (T2EHDGA) combined with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (HEH[EHP]) that can be used to separate the minor actinides in a single solvent-extraction process. T2EHDGA serves to co-extract the trivalent actinide and lanthanide ions from nitric acid solution. Switching the aqueous phase chemistry to a citrate buffered solution of N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid at pH 2.5 to 4 results in selective transfer of the actinides to the aqueous phase, thus affecting separation of the actinides from the lanthanides. Separation factors between the lanthanides and actinides are approximately 20 in the pH range of 3 to 4, and the distribution ratios are not highly dependent on the pH in this system.

  20. Bidentate organophosphorus solvent extraction process for actinide recovery and partition

    DOEpatents

    Schulz, Wallace W.

    1976-01-01

    A liquid-liquid extraction process for the recovery and partitioning of actinide values from acidic nuclear waste aqueous solutions, the actinide values including trivalent, tetravalent and hexavalent oxidation states is provided and includes the steps of contacting the aqueous solution with a bidentate organophosphorous extractant to extract essentially all of the actinide values into the organic phase. Thereafter the respective actinide fractions are selectively partitioned into separate aqueous solutions by contact with dilute nitric or nitric-hydrofluoric acid solutions. The hexavalent uranium is finally removed from the organic phase by contact with a dilute sodium carbonate solution.

  1. Impact of Including Higher Actinides in Fast Reactor Transmutation Analyses

    SciTech Connect

    B. Forget; M. Asgari; R. Ferrer; S. Bays

    2007-09-01

    Previous fast reactor transmutation studies generally disregarded higher mass minor actinides beyond Cm-246 due to various considerations including deficiencies in nuclear cross-section data. Although omission of these higher mass actinides does not significantly impact the neutronic calculations and fuel cycle performance parameters follow-on neutron dose calculations related to fuel recycling, transportation and handling are significantly impacted. This report shows that including the minor actinides in the equilibrium fast reactor calculations will increase the predicted neutron emission by about 30%. In addition a sensitivity study was initiated by comparing the impact of different cross-section evaluation file for representing these minor actinides.

  2. Flammability Analysis For Actinide Oxides Packaged In 9975 Shipping Containers

    SciTech Connect

    Laurinat, James E.; Askew, Neal M.; Hensel, Steve J.

    2013-03-21

    Packaging options are evaluated for compliance with safety requirements for shipment of mixed actinide oxides packaged in a 9975 Primary Containment Vessel (PCV). Radiolytic gas generation rates, PCV internal gas pressures, and shipping windows (times to reach unacceptable gas compositions or pressures after closure of the PCV) are calculated for shipment of a 9975 PCV containing a plastic bottle filled with plutonium and uranium oxides with a selected isotopic composition. G-values for radiolytic hydrogen generation from adsorbed moisture are estimated from the results of gas generation tests for plutonium oxide and uranium oxide doped with curium-244. The radiolytic generation of hydrogen from the plastic bottle is calculated using a geometric model for alpha particle deposition in the bottle wall. The temperature of the PCV during shipment is estimated from the results of finite element heat transfer analyses.

  3. Burning trees and bridges

    NASA Technical Reports Server (NTRS)

    Levine, Joel S.

    1990-01-01

    Most burning of biomass is the result of human activity, and on a global scale it is increasing. Tropospheric concentrations of CO2, CO, CH4, non-methane hydrocarbons, and ozone are all increasing with time; global biomass burning may make an important contribution to this increase and thus to potential global climate change. The nitrogen cycle also can have important climatic effects. Nitrous oxide put into the atmosphere by biomass burning is a greenhouse gas 250 times more powerful (molecule for molecule) than carbon dioxide. Nitric oxide, as well as being a photochemical precursor of ozone, a major pollutant in the troposphere, produces nitric acid, the fastest-growing component of acid rain. Hence, the new bridge in the nitrogen cycle is of more than mere technical interest.

  4. Advanced Aqueous Separation Systems for Actinide Partitioning

    SciTech Connect

    Nash, Ken; Martin, Leigh; Lumetta, Gregg

    2015-04-02

    One of the most challenging aspects of advanced processing of used nuclear fuel is the separation of transplutonium actinides from fission product lanthanides. This separation is essential if actinide transmutation options are to be pursued in advanced fuel cycles, as lanthanides compete with actinides for neutrons in both thermal and fast reactors, thus limiting efficiency. The separation is difficult because the chemistry of Am3+ and Cm3+ is nearly identical to that of the trivalent lanthanides (Ln3+). The prior literature teaches that two approaches offer the greatest probability of devising a successful group separation process based on aqueous processes: 1) the application of complexing agents containing ligand donor atoms that are softer than oxygen (N, S, Cl-) or 2) changing the oxidation state of Am to the IV, V, or VI state to increase the essential differences between Am and lanthanide chemistry (an approach utilized in the PUREX process to selectively remove Pu4+ and UO22+ from fission products). The latter approach offers the additional benefit of enabling a separation of Am from Cm, as Cm(III) is resistant to oxidation and so can easily be made to follow the lanthanides. The fundamental limitations of these approaches are that 1) the soft(er) donor atoms that interact more strongly with actinide cations than lanthanides form substantially weaker bonds than oxygen atoms, thus necessitating modification of extraction conditions for adequate phase transfer efficiency, 2) soft donor reagents have been seen to suffer slow phase transfer kinetics and hydro-/radiolytic stability limitations and 3) the upper oxidation states of Am are all moderately strong oxidants, hence of only transient stability in media representative of conventional aqueous separations systems. There are examples in the literature of both approaches having been described. However, it is not clear at present that any extant process is sufficiently robust for application at the scale

  5. Use of Information Theory Concepts for Developing Contaminated Site Detection Method: Case for Fission Product and Actinides Accumulation Modeling

    SciTech Connect

    Harbachova, N.V.; Sharavarau, H.A.

    2006-07-01

    Information theory concepts and their fundamental importance for environmental pollution analysis in light of experience of Chernobyl accident in Belarus are discussed. An information and dynamic models of the radionuclide composition formation in the fuel of the Nuclear Power Plant are developed. With the use of code DECA numerical calculation of actinides (58 isotopes are included) and fission products (650 isotopes are included) activities has been carried out and their dependence with the fuel burn-up of the RBMK-type reactor have been investigated. (authors)

  6. Burning mouth syndrome.

    PubMed

    Jimson, Sudha; Rajesh, E; Krupaa, R Jayasri; Kasthuri, M

    2015-04-01

    Burning mouth syndrome (BMS) is a complex disorder that is characterized by warm or burning sensation in the oral mucosa without changes on physical examination. It occurs more commonly in middle-aged and elderly women and often affects the tip of the tongue, lateral borders, lips, hard and soft palate. This condition is probably of multi-factorial origin, often idiopathic, and its etiopathogensis is unknown. BMS can be classified into two clinical forms namely primary and secondary BMS. As a result, a multidisciplinary approach is required for better control of the symptoms. In addition, psychotherapy and behavioral feedback may also help eliminate the BMS symptoms. PMID:26015707

  7. Uncoupled skeletal muscle mitochondria contribute to hypermetabolism in severely burned adults

    PubMed Central

    Herndon, David N.; Børsheim, Elisabet; Chao, Tony; Reidy, Paul T.; Borack, Michael S.; Rasmussen, Blake B.; Chondronikola, Maria; Saraf, Manish K.; Sidossis, Labros S.

    2014-01-01

    Elevated metabolic rate is a hallmark of the stress response to severe burn injury. This response is mediated in part by adrenergic stress and is responsive to changes in ambient temperature. We hypothesize that uncoupling of oxidative phosphorylation in skeletal muscle mitochondria contributes to increased metabolic rate in burn survivors. Here, we determined skeletal muscle mitochondrial function in healthy and severely burned adults. Indirect calorimetry was used to estimate metabolic rate in burn patients. Quadriceps muscle biopsies were collected on two separate occasions (11 ± 5 and 21 ± 8 days postinjury) from six severely burned adults (68 ± 19% of total body surface area burned) and 12 healthy adults. Leak, coupled, and uncoupled mitochondrial respiration was determined in permeabilized myofiber bundles. Metabolic rate was significantly greater than predicted values for burn patients at both time points (P < 0.05). Skeletal muscle oxidative capacity, citrate synthase activity, a marker of mitochondrial abundance, and mitochondrial sensitivity to oligomycin were all lower in burn patients vs. controls at both time points (P < 0.05). A greater proportion of maximal mitochondrial respiration was linked to thermogenesis in burn patients compared with controls (P < 0.05). Increased metabolic rate in severely burned adults is accompanied by derangements in skeletal muscle mitochondrial function. Skeletal muscle mitochondria from burn victims are more uncoupled, indicating greater heat production within skeletal muscle. Our findings suggest that skeletal muscle mitochondrial dysfunction contributes to increased metabolic rate in burn victims. PMID:25074988

  8. Management of acute burns and burn shock resuscitation.

    PubMed

    Faldmo, L; Kravitz, M

    1993-05-01

    Initial management of minor and moderate, uncomplicated burn injury focuses on wound management and patient comfort. Initial management of patients with major burn injury requires airway support, fluid resuscitation for burn shock, treatment for associated trauma and preexisting medical conditions, management of adynamic ileus, and initial wound treatment. Fluid resuscitation, based on assessment of the extent and depth of burn injury, requires administration of intravenous fluids using resuscitation formula guidelines for the initial 24 hours after injury. Inhalation injury complicates flame burns and increases morbidity and mortality. Electrical injury places patients at risk for cardiac arrest, metabolic acidosis, and myoglobinuria. Circumferential full-thickness burns to extremities compromise circulation and require escharotomy or fasciotomy. Circumferential torso burns compromise air exchange and cardiac return. Loss of skin function places patients at risk for hypothermia, fluid and electrolyte imbalances, and systemic sepsis. The first 24 hours after burn injury require aggressive medical management to assure survival and minimize complications. PMID:8489882

  9. CHARACTERIZATION OF EMISSIONS FROM BURNING INCENSE

    EPA Science Inventory

    The primary objective of this study was to improve the characterization of particulate matter emissions from burning incense. Emissions of particulate matter were measured for 23 different types of incense using a cyclone/filter method. Emission rates for PM2.5 (particulate matte...

  10. FEASIBILITY OF BURNING COAL IN CATALYTIC COMBUSTORS

    EPA Science Inventory

    The report gives results of a study, showing that pulverized coal can be burned in a catalytic combustor. Pulverized coal combustion in catalytic beds is markedly different from gaseous fuel combustion. Gas combustion gives uniform bed temperatures and reaction rates over the ent...

  11. Diabetes mellitus and burns. Part II-outcomes from burn injuries and future directions

    PubMed Central

    Goutos, Ioannis; Nicholas, Rebecca Spenser; Pandya, Atisha A; Ghosh, Sudip J

    2015-01-01

    Diabetes mellitus is an increasingly prevalent comorbidity in patients presenting to burn facilities. Diabetic patients tend to be older and present in a delayed manner with deeper injuries predominantly affecting the lower limb. Morbidity from burns is higher in this cohort including a longer length of hospital stay, greater need for surgical interventions and increased rate of infective complications. Nevertheless, there seems to be little effect of diabetes on associated mortality. The second part of this review article concentrates on the epidemiological profile of diabetic burn patients and the effect of the disease on morbidity and mortality. In addition, we present a review of therapeutic adjuncts, which may hold promise for the future management of this cohort of burn patients. PMID:26064798

  12. The FLUORINE-17(PROTON, PHOTON)NEON-18 and Oxygen -14(ALPHA Particle, PROTON)FLUORINE-17 Reaction Rates and the Structure of NEON-18 (NEON-18, FLUORINE-17, Oxygen -14, Astrophysical Hydrogen Burning)

    NASA Astrophysics Data System (ADS)

    Hahn, Kevin Insik

    1993-01-01

    The 14O(alpha,p) 17F and ^ {17}F(p,gamma)18Ne reactions play crucial roles in the advanced stages of astrophysical hydrogen burning. The ^{14 }O(alpha,p)^ {17}F(p,gamma) ^ {18}Ne(beta^+nu) 18F(p,alpha)^ {15}O reaction sequence can provide a path around the relatively slow positron decay of 14O in the HCNO cycle, while the similar reaction sequence, ^{14 }O(alpha ,p) 17F(p,gamma)^ {18}Ne(beta ^+nu) 18F(p,gamma)^ {19}Ne, can provide an alternate path from the HCNO cycle to the rp-process. The 17F(p,gamma)18Ne reaction rate could provide the principal source of 18O. Under some astrophysical conditions, the ^{14 }O(alpha,p)^ {17}F reaction is expected to compete with the 15O(alpha, gamma)19Ne reaction in providing a path through which nuclei involved in the HCNO cycle can be transformed into heavier nuclei with Z >= 10.. In order to better determine the rates of these two reactions, we measured the properties of the resonances in 18Ne; the excitation energies, the spins, and the partial and total widths of the relevant resonances. By comparing the previously observed states in 18Ne to the well-studied isospin mirror nucleus, ^{18 }O, it is clear that there are a number of missing levels in 18Ne in the region rm Ex > 4 MeV. These missing states in ^ {18}Ne could be important in determining the 17F(p, gamma)18rm Ne and 14O(alpha ,p)17F reaction rates. We have studied the ^{12 }C(12C,^6He)^{18 }Ne, 20rm Ne(p{,}t)18Ne, and 16O(^3He{, }n)18Ne reactions to measure new nuclear structure information of ^{18 }Ne. From our experiments, we have the following major results: (a) an evidence of the 3^+ <=vel at E_{rm x} = 4.56 MeV, (b) new levels at E_ {rm x} = 6.15 MeV, 7.12 MeV, 7.35 MeV, 7.62 MeV, 8.30 MeV, (8.45 MeV), 8.55 MeV, 8.94 MeV, and 9.58 MeV. (c) new J^pi assignments to the 5.11/5.15-MeV doublet and the 6.15-MeV state. Our discovery of the 3^+<=vel at an energy ~230 keV higher than calculated by Wiescher, Gorres, and Thielemann causes the contribution of the 17 F

  13. Self-inflicted burns in Mosul: a cross-sectional study

    PubMed Central

    Al-Zacko, S.M.

    2012-01-01

    Summary A cross-sectional study was conducted to investigate the different characteristics of attempted suicide by self-inflicted burn cases compared with other accidental burn cases admitted to the Burns Unit in Al-Jumhoori Teaching Hospital in Mosul over a one-year period from March 1, 2011 to March 1, 2012. Of 459 burn cases, 103 (22.44%) had self-inflicted burns. The mean total body surface area of suicide attempters was 61%, markedly higher than in other cases (20%) (P= 0.0001). Among all self-inflicted burn cases, burns were caused by flame, while scald was the commonest cause (56.5%) in accidental burns. There was a significant difference in the sex ratio between self-inflicted burn cases (1:11.9) and accidental burn cases (1:1) (P = 0.0001). Case fatality rates for self-inflicted burn and accidental burn cases were 80.6% and 14.9%, respectively. The overall mean ages for self-inflicted burn and accidental burn cases were 24.3 and 15.6 years, respectively. Compared to all other burn cases, self-inflicted burn cases had a significantly larger mean percentage of surface body area burned (61.0±28.2 versus 20.7±15.8; P = 0.0001). In conclusion, self-inflicted burns remain a common cause of admission to our burn unit. The extent of burns is often large, since most suicide attempters use an accelerant that accounts for the high mortality in this group. PMID:23467337

  14. Biomass Burning Observation Project Science Plan

    SciTech Connect

    Kleinman, KI; Sedlacek, AJ

    2013-09-01

    Aerosols from biomass burning perturb Earth’s climate through the direct radiative effect (both scattering and absorption) and through influences on cloud formation and precipitation and the semi-direct effect. Despite much effort, quantities important to determining radiative forcing such as the mass absorption coefficients (MAC) of light-absorbing carbon, secondary organic aerosol (SOA) formation rates, and cloud condensation nuclei (CCN) activity remain in doubt. Field campaigns in northern temperate latitudes have been overwhelmingly devoted to other aerosol sources in spite of biomass burning producing about one-third of the fine particles (PM2.5) in the U.S.

  15. TRIAL BURNS: METHODS PERSPECTIVE

    EPA Science Inventory

    When conducting a trial burn, it is necessary to make a number of measurements in order to adequately define the performance of the incinerator. n addition to flue gas emissions for particulate matter, HCl, and selected organics, it is also necessary to measure selected organics ...

  16. Accumulative eschar after burn.

    PubMed

    Ma, Fushun

    2016-02-01

    Eschar formation is a potential sequela of burn injuries. Definitive management may include escharectomy and eschar debridement. After eschar removal, the wound can be covered with a skin graft or reepithelialization. For prolonged refractory eschar on the fingertips, topical use of rb-bFGF after debridement can achieve an optimal outcome. PMID:26862412

  17. The Earth Could Burn.

    ERIC Educational Resources Information Center

    Yarrow, Ruth

    1982-01-01

    Environmental educators are worried about the ultimate ecological threat--nuclear war, which could burn thousands of square miles, sterilize the soil, destroy 70 percent of the ozone layer letting in lethal ultraviolet rays, and cause severe radiation sickness. Educators must inform themselves, teach others, contact government representatives, and…

  18. TIRES, OPEN BURNING

    EPA Science Inventory

    The chapter describes available information on the health effects from open burning of rubber tires. It concentrates on the three known sources of detailed measurements: (1) a small-scale emissions characterization study performed by the U.S. EPA in a facility designed to simulat...

  19. Chemical burn or reaction

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/000059.htm Chemical burn or reaction To use the sharing features on this page, please enable JavaScript. Chemicals that touch skin can lead to a reaction on the skin, throughout the body, or both. ...

  20. [Treatment of hydrofluoric acid burns].

    PubMed

    Thiele, B; Winter, U J; Mahrle, G; Steigleder, G K

    1986-01-31

    A chemical-plant worker sustained hydrofluoric acid burns during cleaning procedures. Intra-arterial perfusion and intralesional injections of calcium gluconate solution prevented progression of the burns into deeper tissue layers. PMID:3943470

  1. Biomass Burning Data and Information

    Atmospheric Science Data Center

    2015-04-21

    ... of total amount of biomass burned. These data may be used in general circulation models (GCMs) and in photochemical models of the ... Biomass Burning Discipline:  Tropospheric Chemistry Field Campaigns Aerosols Platform:  ...

  2. Oxidative dissolution of actinide oxides in H 2O 2 containing aqueous solution - A preliminary study

    NASA Astrophysics Data System (ADS)

    Pehrman, Reijo; Amme, Marcus; Roth, Olivia; Ekeroth, Ella; Jonsson, Mats

    2010-02-01

    Oxidative dissolution of spent nuclear fuel is an important issue in the safety assessment of a future geological repository for spent nuclear fuel. Although UO 2 constitutes, in terms of mass, the majority of the spent fuel material, its main radiotoxicity is (after extended storage times) contained in actinides with half lives shorter than that of 238-uranium, such as isotopes of Np and Pu. Relatively little information is available on the dissolution behavior of Np and Pu in comparable environments. This work investigates the oxidative dissolution of NpO 2 and PuO 2 in non-complexing aqueous solutions containing H 2O 2 and compares their behavior with that of UO 2. We have found that oxidative dissolution takes place for all three actinides in the presence of H 2O 2. Based on the obtained dissolution rates, we would not expect the dissolution of the actinides to be congruent. Instead, in a system without complexing agent, the release rates of Np and Pu are expected to be lower than the U release rate.

  3. POTENTIAL BENCHMARKS FOR ACTINIDE PRODUCTION IN HANFORD REACTORS

    SciTech Connect

    PUIGH RJ; TOFFER H

    2011-10-19

    A significant experimental program was conducted in the early Hanford reactors to understand the reactor production of actinides. These experiments were conducted with sufficient rigor, in some cases, to provide useful information that can be utilized today in development of benchmark experiments that may be used for the validation of present computer codes for the production of these actinides in low enriched uranium fuel.

  4. Process for making a ceramic composition for immobilization of actinides

    DOEpatents

    Ebbinghaus, Bartley B.; Van Konynenburg, Richard A.; Vance, Eric R.; Stewart, Martin W.; Walls, Philip A.; Brummond, William Allen; Armantrout, Guy A.; Herman, Connie Cicero; Hobson, Beverly F.; Herman, David Thomas; Curtis, Paul G.; Farmer, Joseph

    2001-01-01

    Disclosed is a process for making a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile. The process comprises oxidizing the actinides, milling the oxides to a powder, blending them with ceramic precursors, cold pressing the blend and sintering the pressed material.

  5. Process for Making a Ceramic Composition for Immobilization of Actinides

    SciTech Connect

    Ebbinghaus, Bartley B.; Van Konynenburg, Richard A.; Vance, Eric R.; Stewart, Martin W.; Walls, Philip A.; Brummond, William Allen; Armantrout, Guy A.; Curtis, Paul G.; Hobson, Beverly F.; Farmer, Joseph; Herman, Connie Cicero; Herman, David Thomas

    1999-06-22

    Disclosed is a process for making a ceramic composition for the immobilization of actinides, particularly uranium and plutonium. The ceramic is a titanate material comprising pyrochlore, brannerite and rutile. The process comprises oxidizing the actinides, milling the oxides to a powder, blending them with ceramic precursors, cold pressing the blend and sintering the pressed material.

  6. Improved method for extracting lanthanides and actinides from acid solutions

    DOEpatents

    Horwitz, E.P.; Kalina, D.G.; Kaplan, L.; Mason, G.W.

    1983-07-26

    A process for the recovery of actinide and lanthanide values from aqueous acidic solutions uses a new series of neutral bi-functional extractants, the alkyl(phenyl)-N,N-dialkylcarbamoylmethylphosphine oxides. The process is suitable for the separation of actinide and lanthanide values from fission product values found together in high-level nuclear reprocessing waste solutions.

  7. Study of actinide chemistry in saturated potassium fluoride solution

    NASA Technical Reports Server (NTRS)

    Cohen, D.; Thalmayer, C. E.

    1969-01-01

    Study concerning the chemistry of actinides in saturated KF solution included work with neptunium, uranium, and americium. Solubilities, absorption spectra, oxidation-reduction reactions, and solid compounds which can be produced in KF solution were examined. The information is used for preparation of various materials from salts of the actinides.

  8. Ventilator associated pneumonia in major paediatric burns.

    PubMed

    Rogers, Alan David; Deal, Cailin; Argent, Andrew Charles; Hudson, Donald Anthony; Rode, Heinz

    2014-09-01

    More than three-quarters of deaths related to major burns are a consequence of infection, which is frequently ventilator associated pneumonia (VAP). A retrospective study was performed, over a five-year period, of ventilated children with major burns. 92 patients were included in the study; their mean age was 3.5 years and their mean total body surface area burn was 30%. 62% of the patients sustained flame burns, and 31% scalds. The mean ICU stay was 10.6 days (range 2-61 days) and the mean ventilation time was 8.4 days (range 2-45 days). There were 59 documented episodes of pneumonia in 52 patients with a rate of 30 infections per 1000 ventilator days. Length of ventilation and the presence of inhalational injury correlate with the incidence of VAP. 17.4% of the patients died (n=16); half of these deaths may be attributed directly to pneumonia. Streptococcus pneumonia, Pseudomonas aeruginosa, Acinetobacter baumanii and Staphylococcus aureus were the most prominent aetiological organisms. Broncho-alveolar lavage was found to be more specific and sensitive at identifying the organism than other methods. This study highlights the importance of implementing strictly enforced strategies for the prevention, detection and management of pneumonia in the presence of major burns. PMID:24468505

  9. In Situ Burning of Oil Spills

    PubMed Central

    Evans, David D.; Mulholland, George W.; Baum, Howard R.; Walton, William D.; McGrattan, Kevin B.

    2001-01-01

    For more than a decade NIST conducted research to understand, measure and predict the important features of burning oil on water. Results of that research have been included in nationally recognized guidelines for approval of intentional burning. NIST measurements and predictions have played a major role in establishing in situ burning as a primary oil spill response method. Data are given for pool fire burning rates, smoke yield, smoke particulate size distribution, smoke aging, and polycyclic aromatic hydrocarbon content of the smoke for crude and fuel oil fires with effective diameters up to 17.2 m. New user-friendly software, ALOFT, was developed to quantify the large-scale features and trajectory of wind blown smoke plumes in the atmosphere and estimate the ground level smoke particulate concentrations. Predictions using the model were tested successfully against data from large-scale tests. ALOFT software is being used by oil spill response teams to help assess the potential impact of intentional burning. PMID:27500022

  10. Photofission of Actinides with Linearly Polarized Photons

    SciTech Connect

    Dale, D. S.; Cole, P. L.; Conn, A.; Forest, T. A.; Kosinov, O.; Setiniyaz, S.; Shapovlov, R.; Starovoitova, V.; Swanson, J.; Bodily, R.; Kelley, K.

    2010-08-04

    Idaho State University and the Idaho Accelerator Center are developing a polarized photon facility in the 10 MeV region using the off axis bremsstrahlung technique. Initial tests have been performed with the aim of using the high analyzing power of the photodisintegration of the deuteron to measure the beam polarization. A program is currently underway to measure the potential angular asymmetries of neutrons arising from the angular distribution of the fission fragments from photofission with linearly polarized photons. In this paper, we describe the Idaho State University Polarized Photon Facility, present results of commissioning runs, and describe potential application of polarized photofission in detecting actinides for homeland security and safeguards applications.

  11. Actinide management with commercial fast reactors

    NASA Astrophysics Data System (ADS)

    Ohki, Shigeo

    2015-12-01

    The capability of plutonium-breeding and minor-actinide (MA) transmutation in the Japanese commercial sodium-cooled fast reactor offers one of practical solutions for obtaining sustainable energy resources as well as reducing radioactive toxicity and inventory. The reference core design meets the requirement of flexible breeding ratio from 1.03 to 1.2. The MA transmutation amount has been evaluated as 50-100 kg/GWey if the MA content in fresh fuel is 3-5 wt%, where about 30-40% of initial MA can be transmuted in the discharged fuel.

  12. Actinide management with commercial fast reactors

    SciTech Connect

    Ohki, Shigeo

    2015-12-31

    The capability of plutonium-breeding and minor-actinide (MA) transmutation in the Japanese commercial sodium-cooled fast reactor offers one of practical solutions for obtaining sustainable energy resources as well as reducing radioactive toxicity and inventory. The reference core design meets the requirement of flexible breeding ratio from 1.03 to 1.2. The MA transmutation amount has been evaluated as 50-100 kg/GW{sub e}y if the MA content in fresh fuel is 3-5 wt%, where about 30-40% of initial MA can be transmuted in the discharged fuel.

  13. Status of nuclear data for actinides

    SciTech Connect

    Guzhovskii, B.Y.; Gorelov, V.P.; Grebennikov, A.N.

    1995-10-01

    Nuclear data required for transmutation problem include many actinide nuclei. In present paper the analysis of neutron fission, capture, (n,2n) and (n,3n) reaction cross sections at energy region from thermal point to 14 MeV was carried out for Th, Pa, U, Np, Pu, Am and Cm isotops using modern evaluated nuclear data libraries and handbooks of recommended nuclear data. Comparison of these data indicates on substantial discrepancies in different versions of files, that connect with quality and completeness of original experimental data.

  14. {alpha} Decay of Deformed Actinide Nuclei

    SciTech Connect

    Stewart, T.L.; Kermode, M.W.; Beachey, D.J.; Rowley, N.; Grant, I.S.; Kruppa, A.T.

    1996-07-01

    {alpha} decay through a deformed potential barrier produces significant mixing of angular momenta when mapped from the nuclear interior to the outside. Using experimental branching ratios and either semiclassical or coupled-channels transmission matrices, we have found that there is a set of internal amplitudes which is essentially constant for all even-even actinide nuclei. These same amplitudes also give good results for the known anisotropic {alpha}-particle emission of the favored decays of odd nuclei in the same mass region. {copyright} {ital 1996 The American Physical Society.}

  15. Thorium Fuel Options for Sustained Transuranic Burning in Pressurized Water Reactors - 12381

    SciTech Connect

    Rahman, Fariz Abdul; Lee, John C.; Franceschini, Fausto; Wenner, Michael

    2012-07-01

    burn TRU in a thermal spectrum, while satisfying top-level operational and safety constraints. Various assembly designs have been proposed to assess the TRU burning potential of Th-based fuel in PWRs. In addition to typical homogeneous loading patterns, heterogeneous configurations exploiting the breeding potential of thorium to enable multiple cycles of TRU irradiation and burning have been devised. The homogeneous assembly design, with all pins featuring TRU in Th, has the benefit of a simple loading pattern and the highest rate of TRU transmutation, but it can be used only for a few cycles due to the rapid rise in the TRU content of the recycled fuel, which challenges reactivity control, safety coefficients and fuel handling. Due to its simple loading pattern, such assembly design can be used as the first step of Th implementation, achieving up to 3 times larger TRU transmutation rate than conventional U-MOX, assuming same fraction of MOX assemblies in the core. As the next step in thorium implementation, heterogeneous assemblies featuring a mixed array of Th-U and Th-U-TRU pins, where the U is in-bred from Th, have been proposed. These designs have the potential to enable burning an external supply of TRU through multiple cycles of irradiation, recovery (via reprocessing) and recycling of the residual actinides at the end of each irradiation cycle. This is achieved thanks to a larger breeding of U from Th in the heterogeneous assemblies, which reduces the TRU supply and thus mitigates the increase in the TRU core inventory for the multi-recycled fuel. While on an individual cycle basis the amount of TRU burned in the heterogeneous assembly is reduced with respect to the homogeneous design, TRU burning rates higher than single-pass U-MOX fuel can still be achieved, with the additional benefits of a multi-cycle transmutation campaign recycling all TRU isotopes. Nitride fuel, due its higher density and U breeding potential, together with its better thermal properties

  16. Optimisation of composite metallic fuel for minor actinide transmutation in an accelerator-driven system

    NASA Astrophysics Data System (ADS)

    Uyttenhove, W.; Sobolev, V.; Maschek, W.

    2011-09-01

    A potential option for neutralization of minor actinides (MA) accumulated in spent nuclear fuel of light water reactors (LWRs) is their transmutation in dedicated accelerator-driven systems (ADS). A promising fuel candidate dedicated to MA transmutation is a CERMET composite with Mo metal matrix and (Pu, Np, Am, Cm)O 2-x fuel particles. Results of optimisation studies of the CERMET fuel targeting to increasing the MA transmutation efficiency of the EFIT (European Facility for Industrial Transmutation) core are presented. In the adopted strategy of MA burning the plutonium (Pu) balance of the core is minimized, allowing a reduction in the reactivity swing and the peak power form-factor deviation and an extension of the cycle duration. The MA/Pu ratio is used as a variable for the fuel optimisation studies. The efficiency of MA transmutation is close to the foreseen theoretical value of 42 kg TW -1 h -1 when level of Pu in the actinide mixture is about 40 wt.%. The obtained results are compared with the reference case of the EFIT core loaded with the composite CERCER fuel, where fuel particles are incorporated in a ceramic magnesia matrix. The results of this study offer additional information for the EFIT fuel selection.

  17. Minor Actinide Recycle in Sodium Cooled Fast Reactors Using Heterogeneous Targets

    SciTech Connect

    Samuel Bays; Pavel Medvedev; Michael Pope; Rodolfo Ferrer; Benoit Forget; Mehdi Asgari

    2009-04-01

    This paper investigates the plausible design of transmutation target assemblies for minor actinides (MA) in Sodium Fast Reactors (SFR). A heterogeneous recycling strategy is investigated, whereby after each reactor pass, un-burned MAs from the targets are blended with MAs produced by the driver fuel and additional MAs from Spent Nuclear Fuel (SNF). A design iteration methodology was adopted for customizing the core design, target assembly design and matrix composition design. The overall design was constrained against allowable peak or maximum in-core performances. While respecting these criteria, the overall design was adjusted to reduce the total number of assemblies fabricated per refueling cycle. It was found that an inert metal-hydride MA-Zr-Hx target matrix gave the highest transmutation efficiency, thus allowing for the least number of targets to be fabricated per reactor cycle.

  18. Separation of actinides from lanthanides utilizing molten salt electrorefining

    SciTech Connect

    Grimmett, D.L.; Fusselman, S.P.; Roy, J.J.; Gay, R.L.; Krueger, C.L.; Storvick, T.S.; Inoue, T.; Hijikata, T.; Takahashi, N.

    1996-10-01

    TRUMP-S (TRansUranic Management through Pyropartitioning Separation) is a pyrochemical process being developed to separate actinides form fission products in nuclear waste. A key process step involving molten salt electrorefining to separate actinides from lanthanides has been studied on a laboratory scale. Electrorefining of U, Np, Pu, Am, and lanthanide mixtures from molten cadmium at 450 C to a solid cathode utilizing a molten chloride electrolyte resulted in > 99% removal of actinides from the molten cadmium and salt phases. Removal of the last few percent of actinides is accompanied by lowered cathodic current efficiency and some lanthanide codeposition. Actinide/lanthanide separation ratios on the cathode are ordered U > Np > Pu > Am and are consistent with predictions based on equilibrium potentials.

  19. Actinides and Rare Earths Topical Conference (Code AC)

    SciTech Connect

    Tobin, J G

    2009-11-24

    Actinide and the Rare Earth materials exhibit many unique and diverse physical, chemical and magnetic properties, in large part because of the complexity of their f electronic structure. This Topical Conference will focus upon the chemistry, physics and materials science in Lanthanide and Actinide materials, driven by 4f and 5f electronic structure. Particular emphasis will be placed upon 4f/5f magnetic structure, surface science and thin film properties. For the actinides, fundamental actinide science and its role in resolving technical challenges posed by actinide materials will be stressed. Both basic and applied experimental approaches, including synchrotron-radiation-based investigations, as well as theoretical modeling and computational simulations, are planned to be part of the Topical Conference. Of particular importance are the issues related to the potential renaissance in Nuclear Fuels, including synthesis, oxidation, corrosion, intermixing, stability in extreme environments, prediction of properties via benchmarked simulations, separation science, environmental impact and disposal of waste products.

  20. Research in actinide chemistry. Progress report, 1990--1993

    SciTech Connect

    Choppin, G.R.

    1993-04-01

    This research studies the behavior of the actinide elements in aqueous solution. The high radioactivity of the transuranium actinides limits the concentrations which can be studied and, consequently, limits the experimental techniques. However, oxidation state analogs (trivalent lanthanides, tetravalent thorium, and hexavalent uranium) do not suffer from these limitations. Behavior of actinides in the environment are a major USDOE concern, whether in connection with long-term releases from a repository, releases from stored defense wastes or accidental releases in reprocessing, etc. Principal goal of our research was expand the thermodynamic data base on complexation of actinides by natural ligands (e.g., OH{sup {minus}}, CO{sub 3}{sup 2{minus}}, PO{sub 4}{sup 3{minus}}, humates). The research undertakes fundamental studies of actinide complexes which can increase understanding of the environmental behavior of these elements.

  1. Actinide-Aluminate Speciation in Alkaline Radioactive Waste

    SciTech Connect

    Dr. David L. Clark; Dr. Alexander M. Fedosseev

    2001-12-21

    Investigation of behavior of actinides in alkaline media containing AL(III) showed that no aluminate complexes of actinides in oxidation states (IIII-VIII) were formed in alkaline solutions. At alkaline precipitation IPH (10-14) of actinides in presence of AL(III) formation of aluminate compounds is not observed. However, in precipitates contained actinides (IIV)<(VI), and to a lesser degree actinides (III), some interference of components takes place that is reflected in change of solid phase properties in comparison with pure components or their mechanical mixture. The interference decreases with rise of precipitation PH and at PH 14 is exhibited very feebly. In the case of NP(VII) the individual compound with AL(III) is obtained, however it is not aluminate of neptunium(VII), but neptunate of aluminium(III) similar to neptunates of other metals obtained earlier.

  2. BURN DATA COORDINATING CENTER (BDCC)

    EPA Science Inventory

    The Burn Data Coordinating Center (BDCC) began collecting data in 1994 and is currently the largest burn database in the country. Pediatric burn data was added in 1998. The BMS database contains over 2,800 cases supporting clinical research and research on outcomes including empl...

  3. The overall patterns of burns

    PubMed Central

    Almoghrabi, A.; Abu Shaban, N.

    2011-01-01

    Summary Burn patterns differ across the whole world and not only in relation to lack of education, overcrowding, and poverty. Cultures, habits, traditions, psychiatric illness, and epilepsy are strongly correlated to burn patterns. However, burns may also occur because of specific religious beliefs and activities, social events and festivals, traditional medical practices, occupational activities, and war. PMID:22639565

  4. PGN Prescribed Burn Research Summary

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Since 1997, we have been studying the effects of prescribed burns conducted during late winter on shortgrass steppe on the Pawnee National Grassland. During 1997 – 2002, we studied burns on the western (Crow Valley) portion of the Pawnee by comparing plant growth on burns conducted by the Forest Ser...

  5. Role of antioxidants in the treatment of burn lesions.

    PubMed

    Al-Jawad, F H; Sahib, A S; Al-Kaisy, A A

    2008-12-31

    Burns are a major health problem worldwide, with high mortality and morbidity in addition to causing changes in the quality of life of burn patients. Utilizing antioxidant therapeutic strategies depending on new mechanisms involved in the pathogenesis of burns-related "oxidative stress" may be considered a promising step in burns management. This study involved 180 burn patients of varying age and either sex and with varying burns percentages. The patients were subdivided into six groups (A, B, C, D, E, and F); each group thus included 30 patients. Patients in groups B, C, D, E, and F were treated with antioxidants (vitamin E with vitamin C, zinc sulphate, allopurinol, melatonin, and N-acetylcysteine respectively) while group A was treated according to hospital policy, without any antioxidant; also, healthy subjects (group G) were involved in the study as a control group for comparison.In each group we examined serum malondialdehyde and serum glutathione levels, serum zinc and copper levels, liver function, renal function, mortality rate, and healing time, using standard methods. It was found that the administration of antioxidants to burn patients produced significant improvement in the parameters studied compared with group A (no antioxidant given). This study clearly shows the importance of the therapeutic targeting of oxidative stress in the treatment of burns. It is important to consider antioxidant a most effective weapon that must be added to the arsenal available in the combating of burn complications. PMID:21991135

  6. Burn injuries in Zaria: a one year prospective study.

    PubMed

    Kalayi, G D

    1994-05-01

    Fifty three patients admitted for burn care during a 12 month period from September 1987 to August 1988 were prospectively studied. There were 36 males (60%) and 21 females (40%) with ages ranging from 3 months to 60 years. Children aged 0-4 constituted 40% but 32 (60%) were younger than 16 years. Flame burns affected 26 (49%) patients, scalds in 22 (12%), electrical burns affected four patients and chemical burn was in one. Scald was the commonest injury among children aged 0-4 (70%). Flame, affected 33% of those aged 16 and above. Clothing fire was the commonest flame injury and it was a cause of very extensive injury (mean % BSA 45). Kerosene burn, gas and clothing burns caused the most extensive injury with a mean % BSA 46, 41 and 45 respectively. The commonest complication was burn wound sepsis most frequently by a gram-negative bacilli (65.63%) of which Pseudomonas aeruginosa were that commonest organisms. Pseudomonas and Staphylococcus aureus were about same frequency. Duration of hospital stay ranged from 6 days to 300 days with a mean of 46.52 days. 8 patients absconded, two were transferred to a hospital near their home and 9 died, giving a mortality rate of 17%. Since burn injuries are largely preventable, it is important to define clearly the social, cultural and economic factors which contribute to burn causation in order to combat them effectively. PMID:7925065

  7. Amputation Following Hand Escharotomy in Patients with Burn Injury

    PubMed Central

    Schulze, Scott M.; Choo, Joshua; Cooney, Damon; Moore, Alyssa L.; Sebens, Matt; Neumeister, Michael W.; Wilhelmi, Bradon J.

    2016-01-01

    Objective: Hand burns are commonly seen in patients with burn injury. In the past, focus was on lifesaving measures, but with advances in burn care during the last century, the paradigm shifted to digital salvage and eventually to functional digital salvage. Good outcomes are heavily dependent on the care that is rendered during the initial management of the burn. Methods: A retrospective medical record review was conducted through the Central Illinois Regional Burn Center Patient Registry. Patients with burn injury treated with upper extremity and hand escharotomy between January 1, 2000, and December 31, 2005, were included in the study. Results: We identified a total of 34 patients with 57 burned hands. Six hands required delayed amputation of digits despite recognition of neurovascular compromise and escharotomy, yielding a 10% amputation rate. No correlation could be drawn with regard to total body surface area, age, or sex. Conclusion: Important principles in the acute phase include early splinting, recognition of the need for escharotomy and complete escharotomy when necessary, early excision and grafting, and involvement of occupational therapy for splinting and to guide both active and passive exercises. Although uncommon, some extremity burns may require subsequent amputation despite prompt attention and optimal treatment. In our case series, the need for amputation after successful escharotomies of salvageable digits was associated with full-thickness and electrical burns. PMID:26977219

  8. Is proportion burned severely related to daily area burned?

    NASA Astrophysics Data System (ADS)

    Birch, Donovan S.; Morgan, Penelope; Kolden, Crystal A.; Hudak, Andrew T.; Smith, Alistair M. S.

    2014-05-01

    The ecological effects of forest fires burning with high severity are long-lived and have the greatest impact on vegetation successional trajectories, as compared to low-to-moderate severity fires. The primary drivers of high severity fire are unclear, but it has been hypothesized that wind-driven, large fire-growth days play a significant role, particularly on large fires in forested ecosystems. Here, we examined the relative proportion of classified burn severity for individual daily areas burned that occurred during 42 large forest fires in central Idaho and western Montana from 2005 to 2007 and 2011. Using infrared perimeter data for wildfires with five or more consecutive days of mapped perimeters, we delineated 2697 individual daily areas burned from which we calculated the proportions of each of three burn severity classes (high, moderate, and low) using the differenced normalized burn ratio as mapped for large fires by the Monitoring Trends in Burn Severity project. We found that the proportion of high burn severity was weakly correlated (Kendall τ = 0.299) with size of daily area burned (DAB). Burn severity was highly variable, even for the largest (95th percentile) in DAB, suggesting that other variables than fire extent influence the ecological effects of fires. We suggest that these results do not support the prioritization of large runs during fire rehabilitation efforts, since the underlying assumption in this prioritization is a positive relationship between severity and area burned in a day.

  9. Longitudinal burn scar quantification.

    PubMed

    Nedelec, Bernadette; Correa, José A; de Oliveira, Ana; LaSalle, Leo; Perrault, Isabelle

    2014-12-01

    Quantitative studies of the clinical recovery of burn scars are currently lacking. Previous reports validate the objective, precise, diagnostic capabilities of high-frequency ultrasound to measure thickness, the Cutometer(®) to measure pliability and the Mexameter(®) to measure erythema and pigmentation of scars. Thus, we prospectively quantified clinical characteristics of patient-matched, after burn hypertrophic scar (HSc), donor site scar (D) and normal skin (N) using these instruments. One investigator measured 3 sites (HSc, D, N) in 46 burn survivors at 3, 6, and 12 months after-burn. A mixed model regression analysis, adjusting p-values for multiplicity of testing, was used to compare means among sites and time points. Participants were 41.2±13.5 years old, 87% males, predominantly Caucasian, with an average of 19.5% body surface area burned. HSc thickness decreased significantly between 3 and 6, 6 and 12, and 3 and 12 months (all p<0.0001), but remained thicker than D and N skin (all p<0.0001). Pliability differed significantly between HSc, D and N sites at all time points (all p<0.0001), with HSc and D increasing between 3 and 12 months (p<0.05) but not reaching normal. HSc and D sites were significantly more erythematous than normal skin (p<0.05) at 3 and 6 months but D sites approached normal by 12 months. The only time points at which pigmentation significantly differed were the HSc and D sites at 6 months. Thickness, pliability, erythema and pigmentation of N skin remained similar over the 12 months. We found that post-burn HSc thickness, pliability and erythema differed significantly from D and N skin at 3, 6, and 12 months and does not return to normal by 12 months after-injury; however, significant improvements towards normal can be expected. Donor sites are redder than normal skin at 3 and 6 months but can be expected to return to normal by 12 months. Although the color of HSc and D sites change markedly with time these color changes are

  10. Chemical Debridement of Burns

    PubMed Central

    Levenson, Stanley M.; Kan, Dorinne; Gruber, Charles; Crowley, Leo V.; Lent, Richard; Watford, Alvin; Seifter, Eli

    1974-01-01

    The development of effective, non-toxic (local and systemic) methods for the rapid chemical (enzymatic and non-enzymatic) debridement of third degree burns would dramatically reduce the morbidity and mortality of severely burned patients. Sepsis is still the major cause of death of patients with extensive deep burns. The removal of the devitalized tissue, without damage to unburned skin or skin only partially injured by burning, and in ways which would permit immediate (or very prompt) skin grafting, would lessen substantially the problems of sepsis, speed convalescence and the return of these individuals to society as effective human beings, and would decrease deaths. The usefulness and limitations of surgical excision for patients with extensive third degree burns are discussed. Chemical debridement lends itself to complementary use with surgical excision and has the potential advantage over surgical excision in not requiring anesthesia or a formal surgical operation. The authors' work with the chemical debridement of burns, in particular the use of Bromelain, indicates that this approach will likely achieve clinical usefulness. The experimental studies indicate that rapid controlled debridement, with minimal local and systemic toxicity, is possible, and that effective chemotherapeutic agents may be combined with the Bromelain without either interfering with the actions of the other. The authors believe that rapid (hours) debridement accomplished by the combined use of chemical debriding and chemotherapeutic agents will obviate the possibility of any increase in infection, caused by the use of chemical agents for debridement, as reported for Paraenzyme21 and Travase.39,48 It is possible that the short term use of systemic antibiotics begun just before and continued during, and for a short time after, the rapid chemical debridement may prove useful for the prevention of infection, as appears to be the case for abdominal operations of the clean-contaminated and

  11. 40 CFR 49.10411 - Permits for general open burning, agricultural burning, and forestry and silvicultural burning.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., agricultural burning, and forestry and silvicultural burning. 49.10411 Section 49.10411 Protection of... for general open burning, agricultural burning, and forestry and silvicultural burning. (a) Beginning... obtain approval of a permit under § 49.134 Rule for forestry and silvicultural burning permits....

  12. STUDY OF THE EFFECTIVENESS OF A CATALYTIC COMBUSTION DEVICE ON A WOOD BURNING APPLIANCE

    EPA Science Inventory

    The report gives results of operating a wood stove, incorporating a catalytic combustor, while burning air-dried oak at low burning rates. Gas composition was measured continuously both at the entrance of the catalyst (after the gases had left the burning wood) and at the exit of...

  13. Nucleosynthesis of neutron-rich heavy nuclei during explosive helium burning in a 15 solar-mass supernova

    NASA Technical Reports Server (NTRS)

    Blake, J. B.; Woosley, S. E.; Weaver, T. A.; Schramm, D. N.

    1980-01-01

    The production of heavy nuclei during explosive helium burning has been calculated using the Weaver and Woosley self-consistent model of a complete 15 solar-mass star and the n-process code of Blake and Schramm. It was found that the resulting neutron-rich heavy nuclei are not produced in the relative abundances of solar-system r-process material (such as a Pt peak) nor are any actinides produced. Basically insufficient neutrons are available.

  14. Biomass burning and the production of methane. Draft report

    SciTech Connect

    Levine, J.S.; Cofer, W.R.; Pinto, J.P.

    1992-01-22

    Biomass burning and its environmental implications have also become important research elements of the International Geosphere-Biosphere Program and the International Global Atmospheric Chemistry Project. The production of atmospheric methane (CH4) by biomass burning will be assessed. The production of methane and other gaseous and particle carbon species resulting from biomass burning will be outlined. Field measurements and laboratory studies to quantify the emission ratio of methane and other carbon species will be reviewed. The historic database suggests that global biomass burning is increasing with time and is controlled by human activities. Present estimates indicate that biomass burning contributes between about 20 to about 60 Teragrams per year of carbon in the form of methane to the atmosphere. This represents only 5 to 15% of the global annual emissions of methane. Measurements do indicate that biomass burning is the overwhelming source of CH4 in tropical Africa. However, if the rate of global biomass burning increases at the rate that it has been over the last few decades, then the production of methane from biomass burning may become much more important on a global scale in the future.

  15. Actinide Solubility and Speciation in the WIPP

    SciTech Connect

    Reed, Donald T.

    2015-11-02

    The presentation begins with the role and need for nuclear repositories (overall concept, international updates (Sweden, Finland, France, China), US approach and current status), then moves on to the WIPP TRU repository concept (design, current status--safety incidents of February 5 and 14, 2014, path forward), and finally considers the WIPP safety case: dissolved actinide concentrations (overall approach, oxidation state distribution and redox control, solubility of actinides, colloidal contribution and microbial effects). The following conclusions are set forth: (1) International programs are moving forward, but at a very slow and somewhat sporadic pace. (2) In the United States, the Salt repository concept, from the perspective of the long-term safety case, remains a viable option for nuclear waste management despite the current operational issues/concerns. (3) Current model/PA prediction (WIPP example) are built on redundant conservatisms. These conservatisms are being addressed in the ongoing and future research to fill existing data gaps--redox control of plutonium by Fe(0, II), thorium (analog) solubility studies in simulated brine, contribution of intrinsic and biocolloids to the mobile concentration, and clarification of microbial ecology and effects.

  16. Fusion-Fission Burner for Transuranic Actinides

    NASA Astrophysics Data System (ADS)

    Choi, Chan

    2013-10-01

    The 14-MeV DT fusion neutron spectrum from mirror confinement fusion can provide a unique capability to transmute the transuranic isotopes from light water reactors (LWR). The transuranic (TRU) actinides, high-level radioactive wastes, from spent LWR fuel pose serious worldwide problem with long-term decay heat and radiotoxicity. However, ``transmuted'' TRU actinides can not only reduce the inventory of the TRU in the spent fuel repository but also generate additional energy. Typical commercial LWR fuel assemblies for BWR (boiling water reactor) and PWR (pressurized water reactor) measure its assembly lengths with 4.470 m and 4.059 m, respectively, while its corresponding fuel rod lengths are 4.064 m and 3.851 m. Mirror-based fusion reactor has inherently simple geometry for transmutation blanket with steady-state reactor operation. Recent development of gas-dynamic mirror configuration has additional attractive feature with reduced size in central plasma chamber, thus providing a unique capability for incorporating the spent fuel assemblies into transmutation blanket designs. The system parameters for the gas-dynamic mirror-based hybrid burner will be discussed.

  17. Evaluation of actinide biosorption by microorganisms

    SciTech Connect

    Happel, A.M.

    1996-06-01

    Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams may preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.

  18. [Chemical and electrical burns].

    PubMed

    Sanchez, Raymond

    2002-12-15

    Chemical burns are less frequent in routine practice, but could be very serious owing to the complexity and severity of their actions. Influx of casualty after a civil disaster (industrial explosion) or military (war or terrorism) is possible. The action of these agents could be prolonged and deep. In addition to the skin, respiratory lesions and general intoxication could be observed. The urgent local treatment rely essentially on prolonged washing. Prevention and adequate emergency care could limit the serious consequences of these accidents. Accidents (thermal burns or electrisations) due to high or low voltage electricity are frequent. The severity is linked with the affected skin but especially with internal lesions, muscular, neurological or cardiac lesions. All cases of electrisation need hospital care. Locally, the lesions are often deep with difficult surgical repairs and often require amputation. Aesthetic and functional sequela are therefore frequent. Secondary complications could appear several months after the accident: cataract, dysesthesia and hypotonia. PMID:12621941

  19. Burns and beauty nails

    PubMed Central

    Bélanger, Richard E; Marcotte, Marie-Eve; Bégin, François

    2013-01-01

    A case involving a five-month-old girl brought to the emergency department with burns over her abdomen is described. The child was reported to have spilled two small bottles of beauty nail adhesive on her clothes while her mother was preparing dinner. After undressing the infant, the mother discovered several lesions on the child’s abdomen and quickly sought medical attention. Given the unusual circumstances of the presentation, the child was hospitalized for both treatment and supervision. The beauty nail adhesive contained cyanoacrylate. In addition to its well-appreciated adhesive capacity, cyanoacrylate, in the presence of cotton or other tissues, is known to produce an exothermic reaction that may cause burns. Cyanoacrylate-based products, due to their possible adverse effects, should be kept away from children as advised. Odd injuries should always raise concerns about the possibility of inflicted injury. PMID:24421671

  20. Erosive burning threshold conditions in solid rocket motors

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Cohen, N. S.

    1989-01-01

    Erosive burning has been predicted to be enhanced by factors that increase the level of turbulence close to the propellant surface, such a high cross flow velocity, low surface blowing rate, propellant surface roughness, and adverse pressure gradient. A study is reported which was carried out with the objective of measuring the effects of these parameters on the scaling to larger rocket motor sizes of the transition to, or threshold conditions for, erosive burning rate augmentation. The results are used to develop a scaling criterion for the threshold conditions for erosive burning.

  1. Radiolytic Degradation in Lanthanide/Actinide Separation Ligands–NOPOPO: Radical Kinetics and Efficiencies Determinations

    SciTech Connect

    Katy L. Swancutt; Stephen P. Mezyk; Richard D. Tillotson; Sylvie Pailloux; Manab Chakravarty; Robert T. Paine; Leigh R. Martin

    2011-07-01

    Trivalent lanthanide/actinide separations from used nuclear fuel occurs in the presence radiation fields that degrades the extraction ligands and solvents. Here we have investigated the stability of a new ligand for lanthanide/actinide separation; 2,6-bis[(di(2-ethylhexyl)phosphino)methyl] pyridine N,P,P-trioxide, TEH(NOPOPO). The impact of {gamma}-radiolysis on the distribution ratios for actinide (Am) and Lanthanide (Eu) extraction both in the presence and absence of an acidic aqueous phase by TEH(NOPOPO) was determined. Corresponding reaction rate constants for the two major radicals, hydroxyl and nitrate, were determined for TEH(NOPOPO) in the aqueous phase, with room temperature values of (3.49 {+-} 0.10) x 10{sup 9} and (1.95 {+-} 0.15) x 10{sup 8} M{sup -1} s{sup -1}, respectively. The activation energy for this reaction was found to be 30.2 {+-} 4.1 kJ mol{sup -1}. Rate constants for two analogues (2-methylphosphonic acid pyridine N,P-dioxide and 2,6-bis(methylphosphonic acid) pyridine N,P,P-trioxide) were also determined to assist in determining the major reaction pathways.

  2. Hospitalized burn injuries in Massachusetts: an assessment of incidence and product involvement.

    PubMed Central

    Rossignol, A M; Boyle, C M; Locke, J A; Burke, J F

    1986-01-01

    We assessed the frequency of hospitalized burn injuries in Massachusetts, and product involvement in causing burns, by reviewing the hospital inpatient records and emergency room logbooks for 240 of New England's 256 acute-care hospitals. Children less than two years of age, males, and Blacks experienced higher burns rates than did older individuals, females, or Whites. Products frequently associated with burn injuries included those involved in food preparation and consumption, flammable liquids, and clothing. PMID:3766835

  3. The Effect of Burn Center Volume on Mortality in a Pediatric Population: An Analysis of the National Burn Repository

    PubMed Central

    Hodgman, Erica I.; Saeman, Melody R.; Subramanian, Madhu

    2016-01-01

    The effect of burn center volume on mortality has been demonstrated in adults. The authors sought to evaluate whether such a relationship existed in burned children. The National Burn Repository, a voluntary registry sponsored by the American Burn Association, was queried for all data points on patients aged 18 years or less and treated from 2002 to 2011. Facilities were divided into quartiles based on average annual burn volume. Demographics and clinical characteristics were compared across groups, and univariate and multivariate logistic regressions were performed to evaluate relationships between facility volume, patient characteristics, and mortality. The authors analyzed 38,234 patients admitted to 88 unique facilities. Children under age 4 years or with larger burns were more likely to be managed at high-volume and very high–volume centers (57.12 and 53.41%, respectively). Overall mortality was low (0.85%). Comparing mortality across quartiles demonstrated improved unadjusted mortality rates at the low- and high-volume centers compared with the medium-volume and very high–volume centers although univariate logistic regression did not find a significant relationship. However, multivariate analysis identified burn center volume as a significant predictor of decreased mortality after controlling for patient characteristics including age, mechanism of injury, burn size, and presence of inhalation injury. Mortality among pediatric burn patients is low and was primarily related to patient and injury characteristics, such as burn size, inhalation injury, and burn cause. Average annual admission rate had a significant but small effect on mortality when injury characteristics were considered. PMID:26146907

  4. Coal burning arrangement

    SciTech Connect

    Wormser, A.F.

    1981-03-03

    Pyrolyzing pulverized coal to form char and volatiles, separating the char from the volatiles, burning the char in heattransfer relationship with a stoichiometric excess of air, forming thereby ash and a mixture of gases, the excess of air being chosen to produce in the ash a temperature below the fusion temperature thereof, separating the mixture of gases from the ash , and thereafter burning the volatiles in the mixture of gases. Also, coal burning apparatus which comprises, in combination a spouted bed pyrolyzer, a fluidized bed combustor, a first cyclone , a second cyclone, and an afterburner, the pyrolyzer being connected to accept pulverized coal and to discharge char to the combustor and gaseous materials with entrained particulate material to the first cyclone, the first cyclone being connected to deliver gases to the afterburner, the combustor being connected to accept also a combustion supporting gas and to deliver to the second cyclone gaseous materials with entrained particulate material, and the second cyclone being connected to deliver gaseous material to the afterburner.

  5. Burns caused by carburetors.

    PubMed

    Still, Joseph; Law, Edward; Orlet, Hermann; Wilson, Joan

    2003-01-01

    During a 10-year period 4645 patients were admitted to the Joseph M. Still Burn Center with acute burns. Of these, 83 (1.79%) were caused by carburetor-related accidents. There were 79 males and 4 females. Ages ranged from 10 to 72 years. Burn size ranged from 1 to 97.5% (mean, 12.3%). There was one death in the group. Eighteen patients required only topical care; 65 patients required a total of 108 operations for debridement and grafting. Length of stay ranged from 1 to 63 days (mean, 11 days). The mechanism of injury was usually the same; in 81 cases the accident occurred while someone was pouring gasoline into a carburetor. In 63 cases the vehicle was an automobile or pickup truck. Explosions resulted in 12 instances; in 65 instances fires were started. These injuries are serious, expensive, fairly common, and may be life threatening. Proper handling of gasoline is stressed. Newer vehicles have fuel injector systems, which may gradually eliminate the problem over time, because pouring gasoline is not required. PMID:12543992

  6. On the burning behavior of pulverized coal chars

    SciTech Connect

    Mitchell, Reginald E.; Ma, Liqiang; Kim, BumJick

    2007-11-15

    A model that predicts the physical changes that pulverized coal char particles undergo during combustion has been developed. In the model, a burning particle is divided into a number of concentric annular volume elements. The mass loss rate, specific surface area, and apparent density in each volume element depend upon the local particle conditions, which vary as a consequence of the adsorbed oxygen and gas-phase oxygen concentration gradients inside the particle. The model predicts the particle's burning rate, temperature, diameter, apparent density, and specific surface area as combustion proceeds, given ambient conditions and initial char properties. A six-step heterogeneous reaction mechanism is used to describe carbon reactivity to oxygen. A distributed activation energy approach is used to account for the variation in desorption energies of adsorbed O-atoms on the carbonaceous surface. Model calculations support the three burning zones established for the oxidation of pulverized coal chars. The model indicates two types of zone II behavior, however. Under weak zone II burning conditions, constant-diameter burning occurs up to 30% to 50% conversion before burning commences with reductions in both size and apparent density. Under strong zone II conditions, particles burn with reductions in both size and apparent density after an initial short period (conversion) of constant-diameter burning. Model predictions reveal that early in the oxidation process, there is mass loss at constant diameter under all zone II burning conditions. Such weak and strong burning behavior cannot be predicted with the commonly used power-law model for the mode of burning employing a single value for the burning mode parameter. Model calculations also reveal how specific surface area evolves when oxidation occurs in the zone II burning regime. Based on the calculated results, a surface area submodel that accounts for the effects of pore growth and coalescence during combustion under

  7. Instant release fraction and matrix release of high burn-up UO2 spent nuclear fuel: Effect of high burn-up structure and leaching solution composition

    NASA Astrophysics Data System (ADS)

    Serrano-Purroy, D.; Clarens, F.; González-Robles, E.; Glatz, J. P.; Wegen, D. H.; de Pablo, J.; Casas, I.; Giménez, J.; Martínez-Esparza, A.

    2012-08-01

    Two weak points in Performance Assessment (PA) exercises regarding the alteration of Spent Nuclear Fuel (SNF) are the contribution of the so-called Instant Release Fraction (IRF) and the effect of High Burn-Up Structure (HBS). This manuscript focuses on the effect of HBS in matrix (long term) and instant release of a Pressurised Water Reactor (PWR) SNF irradiated in a commercial reactor with a mean Burn-Up (BU) of 60 GWd/tU. In order to study the HBS contribution, two samples from different radial positions have been prepared. One from the centre of the SNF, labelled CORE, and one from the periphery, enriched with HBS and labelled OUT. Static leaching experiments have been carried out with two synthetic leaching solutions: bicarbonate (BIC) and Bentonitic Granitic Groundwater (BGW), and in all cases under oxidising conditions. IRF values have been calculated from the determined Fraction of Inventory in Aqueous Phase (FIAP). In all studied cases, some radionuclides (RN): Rb, Sr and Cs, have shown higher release rates than uranium, especially at the beginning of the experiment, and have been considered as IRF. Redox sensitive RN like Mo and Tc have been found to dissolve slightly faster than uranium and further studies might be needed to confirm if they can also be considered part of the IRF. Most of the remaining studied RN, mainly actinides and lanthanides, have been found to dissolve congruently with the uranium matrix. Finally, Zr, Ru and Rh presented lower release rates than the matrix. Higher matrix release has been determined for CORE than for OUT samples showing that the formation of HBS might have a protective effect against the oxidative corrosion of the SNF. On the contrary, no significant differences have been observed between the two studied leaching solutions (BIC and BGW). Two different IRF contributions have been determined. One corresponding to the fraction of inventory segregated in the external open grain boundaries, directly available to water and

  8. Electric field effects on droplet burning

    NASA Astrophysics Data System (ADS)

    Patyal, Advitya; Kyritsis, Dimitrios; Matalon, Moshe

    2015-11-01

    The effects of an externally applied electric field are studied on the burning characteristics of a spherically symmetric fuel drop including the structure, mass burning rate and extinction characteristics of the diffusion flame. A reduced three-step chemical kinetic mechanism that reflects the chemi-ionization process for general hydrocarbon fuels has been proposed to capture the production and destruction of ions inside the flame zone. Due to the imposed symmetry, the effect of the ionic wind is simply to modify the pressure field. Our study thus focuses exclusively on the effects of Ohmic heating and kinetic effects on the burning process. Two distinguished limits of weak and strong field are identified, highlighting the relative strength of the internal charge barrier compared to the externally applied field, and numerically simulated. For both limits, significantly different charged species distributions are observed. An increase in the mass burning rate is noticed with increasing field in either limit with negligible change in the flame temperature. Increasing external voltages pushes the flame away from the droplet and causes a strengthening of the flame with a reduction in the extinction Damkhöler number.

  9. Biomass Burning Emissions from Fire Remote Sensing

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles

    2010-01-01

    Knowledge of the emission source strengths of different (particulate and gaseous) atmospheric constituents is one of the principal ingredients upon which the modeling and forecasting of their distribution and impacts depend. Biomass burning emissions are complex and difficult to quantify. However, satellite remote sensing is providing us tremendous opportunities to measure the fire radiative energy (FRE) release rate or power (FRP), which has a direct relationship with the rates of biomass consumption and emissions of major smoke constituents. In this presentation, we will show how the satellite measurement of FRP is facilitating the quantitative characterization of biomass burning and smoke emission rates, and the implications of this unique capability for improving our understanding of smoke impacts on air quality, weather, and climate. We will also discuss some of the challenges and uncertainties associated with satellite measurement of FRP and how they are being addressed.

  10. Burns in mobile home fires--descriptive study at a regional burn center.

    PubMed

    Mullins, Robert F; Alarm, Badrul; Huq Mian, Mohammad Anwarul; Samples, Jancie M; Friedman, Bruce C; Shaver, Joseph R; Brandigi, Claus; Hassan, Zaheed

    2009-01-01

    Death from fires and burns are the sixth most common cause of unintentional injury death in the United States. More than (3/4) of burn deaths occurring in the United States are in the home. Mobile home fires carry twice the death rate as other dwellings. The aim of the study was to describe the characteristics of deaths and injuries in mobile home fire admitted in a regional Burn Center and to identify possible risk factors. A cross-sectional retrospective study was carried out among all burn patients admitted to a regional Burn Center between January 2002 and December 2004 (3469 patients). The study included patients who suffered a burn injury from a mobile home fire. The demographic characteristics of the patients, location of mobile home, associated inhalation injury, source of fire, comorbidity of the victims, employment status, insurance status, family history of burns, and outcomes of the treatment were incorporated in a data collection record. There were 65 burn patients in mobile home fires admitted to the Burn Center during the studied period. The average age of the patients was 39 years (ranging from 2 to 81 years, SD=16.06), 77% were male, 67% were white, and 79% were the residents in the suburban areas of Georgia, South Carolina, North Carolina, and Florida. The average TBSA of burns was about 21% (ranging from 1 to 63%, SD=17.66), 63% of the patients had associated inhalation, three inhalation injury only, and 69% patients required ventilator support. The average length of stay per TBSA percentage of burn was 1.01 days (P=0.00), controlling for age, preexisting medical comorbidities, and inhalation injury. About 88% of the patients had preexisting medical comorbid conditions, 74% were smokers, 64% reported as alcoholic, and 72% had at least some form of health insurance coverage. In 40% of the cases, the cause of the fire was unknown, 31% were caused by accidental explosions, such as electric, gasoline, or kerosene appliances, and 29% were due to other

  11. On the suitability of lanthanides as actinide analogs

    SciTech Connect

    Raymond, Kenneth; Szigethy, Geza

    2008-07-01

    With the current level of actinide materials used in civilian power generation and the need for safe and efficient methods for the chemical separation of these species from their daughter products and for long-term storage requirements, a detailed understanding of actinide chemistry is of great importance. Due to the unique bonding properties of the f-elements, the lanthanides are commonly used as structural and chemical models for the actinides, but differences in the bonding between these 4f and 5f elements has become a question of immediate applicability to separations technology. This brief overview of actinide coordination chemistry in the Raymond group at UC Berkeley/LBNL examines the validity of using lanthanide analogs as structural models for the actinides, with particular attention paid to single crystal X-ray diffraction structures. Although lanthanides are commonly accepted as reasonable analogs for the actinides, these comparisons suggest the careful study of actinide materials independent of their lanthanide analogs to be of utmost importance to present and future efforts in nuclear industries. (authors)

  12. On the Suitability of Lanthanides as Actinide Analogs

    SciTech Connect

    Szigethy, Geza; Raymond, Kenneth N.

    2008-04-11

    With the current level of actinide materials used in civilian power generation and the need for safe and efficient methods for the chemical separation of these species from their daughter products and for long-term storage requirements, a detailed understanding of actinide chemistry is of great importance. Due to the unique bonding properties of the f-elements, the lanthanides are commonly used as structural and chemical models for the actinides, but differences in the bonding between these 4f and 5f elements has become a question of immediate applicability to separations technology. This brief overview of actinide coordination chemistry in the Raymond group at UC Berkeley/LBNL examines the validity of using lanthanide analogs as structural models for the actinides, with particular attention paid to single crystal X-ray diffraction structures. Although lanthanides are commonly accepted as reasonable analogs for the actinides, these comparisons suggest the careful study of actinide materials independent of their lanthanide analogs to be of utmost importance to present and future efforts in nuclear industries.

  13. End point control of an actinide precipitation reactor

    SciTech Connect

    Muske, K.R.; Palmer, M.J.

    1997-10-01

    The actinide precipitation reactors in the nuclear materials processing facility at Los Alamos National Laboratory are used to remove actinides and other heavy metals from the effluent streams generated during the purification of plutonium. These effluent streams consist of hydrochloric acid solutions, ranging from one to five molar in concentration, in which actinides and other metals are dissolved. The actinides present are plutonium and americium. Typical actinide loadings range from one to five grams per liter. The most prevalent heavy metals are iron, chromium, and nickel that are due to stainless steel. Removal of these metals from solution is accomplished by hydroxide precipitation during the neutralization of the effluent. An end point control algorithm for the semi-batch actinide precipitation reactors at Los Alamos National Laboratory is described. The algorithm is based on an equilibrium solubility model of the chemical species in solution. This model is used to predict the amount of base hydroxide necessary to reach the end point of the actinide precipitation reaction. The model parameters are updated by on-line pH measurements.

  14. Thin extractive membrane for monitoring actinides in aqueous streams.

    PubMed

    Chavan, Vivek; Paul, Sumana; Pandey, Ashok K; Kalsi, P C; Goswami, A

    2013-09-15

    Alpha spectrometry and solid state nuclear track detectors (SSNTDs) are used for monitoring ultra-trace amount of alpha emitting actinides in different aqueous streams. However, these techniques have limitations i.e. alpha spectrometry requires a preconcentration step and SSNTDs are not chemically selective. Therefore, a thin polymer inclusion membrane (PIM) supported on silanized glass was developed for preconcentraion and determination of ultra-trace concentration of actinides by α-spectrometry and SSNTDs. PIMs were formed by spin coating on hydrophobic glass slide or solvent casting to form thin and self-supported membranes, respectively. Sorption experiments indicated that uptakes of actinides in the PIM were highly dependent on acidity of solution i.e. Am(III) sorbed up to 0.1 molL(-1) HNO₃, U(VI) up to 0.5 molL(-1) HNO₃ and Pu(IV) from HNO₃ concentration as high as 4 molL(-1). A scheme was developed for selective sorption of target actinide in the PIM by adjusting acidity and oxidation state of actinide. The actinides sorbed in PIMs were quantified by alpha spectrometry and SSNTDs. For SSNTDs, neutron induced fission-fragment tracks and α-particle tracks were registered in Garware polyester and CR-39 for quantifications of natural uranium and α-emitting actinides ((241)Am/(239)Pu/(233)U), respectively. Finally, the membranes were tested to quantify Pu in 4 molL(-1) HNO3 solutions and synthetic urine samples. PMID:23747462

  15. Separation of actinides from spent nuclear fuel: A review.

    PubMed

    Veliscek-Carolan, Jessica

    2016-11-15

    This review summarises the methods currently available to extract radioactive actinide elements from solutions of spent nuclear fuel. This separation of actinides reduces the hazards associated with spent nuclear fuel, such as its radiotoxicity, volume and the amount of time required for its' radioactivity to return to naturally occurring levels. Separation of actinides from environmental water systems is also briefly discussed. The actinide elements typically found in spent nuclear fuel include uranium, plutonium and the minor actinides (americium, neptunium and curium). Separation methods for uranium and plutonium are reasonably well established. On the other hand separation of the minor actinides from lanthanide fission products also present in spent nuclear fuel is an ongoing challenge and an area of active research. Several separation methods for selective removal of these actinides from spent nuclear fuel will be described. These separation methods include solvent extraction, which is the most commonly used method for radiochemical separations, as well as the less developed but promising use of adsorption and ion-exchange materials. PMID:27427893

  16. Actinide Sub-Actinide Flux Ratio Estimated from NASA Challenger Space Shuttle Borne Passive Detector Experiment

    NASA Astrophysics Data System (ADS)

    Basu, Basudhara; Bhattacharyya, D. P.; Biswas, S.; O'Sullivan, D.; Thompson, A.

    A video trace analysis of 117 ultra heavy cosmic nuclei detected by NASA space shuttle borne lexan detectors has been presented here. The major axes of the elliptical track etch pits in the long hour etched detectors have been measured using a Hund microscope computerized for the measurements using a Pentium. The major axes distribution exhibits the existence of ultra heavy nuclei of charges of Z ranging from 72 to 96 compatible with the expected results from restricted energy loss calculations. The estimated actinide sub-actinide flux ratio has been found to be 0.0636±0.0248 which is comparable to the earlier observations by Fowler et al., Thompson et al. and O'Sullivan.

  17. Method and apparatus to measure the depth of skin burns

    DOEpatents

    Dickey, Fred M.; Holswade, Scott C.

    2002-01-01

    A new device for measuring the depth of surface tissue burns based on the rate at which the skin temperature responds to a sudden differential temperature stimulus. This technique can be performed without physical contact with the burned tissue. In one implementation, time-dependent surface temperature data is taken from subsequent frames of a video signal from an infrared-sensitive video camera. When a thermal transient is created, e.g., by turning off a heat lamp directed at the skin surface, the following time-dependent surface temperature data can be used to determine the skin burn depth. Imaging and non-imaging versions of this device can be implemented, thereby enabling laboratory-quality skin burn depth imagers for hospitals as well as hand-held skin burn depth sensors the size of a small pocket flashlight for field use and triage.

  18. 5f-electron localization in the actinide metals: thorides, actinides and the Mott transition

    NASA Astrophysics Data System (ADS)

    Lawson, A. C.

    2016-03-01

    For the light actinides Ac-Cm, the numbers of localized and itinerant 5f-electrons are determined by comparing various estimates of the f-electron counts. At least one itinerant f-electron is found for each element, Pa-Cm. These results resolve certain disagreements among electron counts determined by different methods and are consistent with the Mott transition model and with the picture of the 5f-electrons' dual nature.

  19. Determination of PM10 and its ion composition emitted from biomass burning in the chamber for estimation of open burning emissions.

    PubMed

    Sillapapiromsuk, Sopittaporn; Chantara, Somporn; Tengjaroenkul, Urai; Prasitwattanaseree, Sukon; Prapamontol, Tippawan

    2013-11-01

    Biomass samples including agricultural waste (rice straw and maize residue) and forest leaf litter were collected from Chiang Mai Province, Thailand for the burning experiment in the self-designed stainless steel chamber to simulate the emissions of PM10. The burning of leaf litter emitted the highest PM10 (1.52±0.65 g kg(-1)). The PM10-bound ions emitted from the burning of rice straw and maize residue showed the same trend, which was K(+)>Cl(-)>SO4(2-)>NH4(+)>NO3(-). However, the emissions from maize residue burning were ~1.5-2.0 times higher than those from the rice straw burning. The ion content emitted from leaf litter burning was almost the same for all ion species. Noticeably, K(+) and Cl(-) concentrations were ~2-4 times lower than those emitted from agricultural waste burning. It can be deduced that K(+) and Cl(-) were highly emitted from agricultural waste burning due to the use of fertilizer and herbicides in the field, respectively. Based on emission values obtained from the chamber, the pollutant emission rate from open burning was calculated. Burned areas in Chiang Mai Province were 3510 and 866 km(2) in 2010 and 2011, respectively. Forest burning was 71-88%, while agricultural land burning accounted for 12-29% (rice field: crop field=1:3) of total burned area. Therefore, emissions of PM10 from open burning in Chiang Mai were 3051 ton (2010) and 705 ton (2011). Major ions emitted from agricultural waste burning were found to be K(+) and Cl(-), while those from forest burning were SO4(2-) and K(+). PMID:23891258

  20. Separations and Actinide Science -- 2005 Roadmap

    SciTech Connect

    Not Available

    2005-09-01

    The Separations and Actinide Science Roadmap presents a vision to establish a separations and actinide science research (SASR) base composed of people, facilities, and collaborations and provides new and innovative nuclear fuel cycle solutions to nuclear technology issues that preclude nuclear proliferation. This enabling science base will play a key role in ensuring that Idaho National Laboratory (INL) achieves its long-term vision of revitalizing nuclear energy by providing needed technologies to ensure our nation's energy sustainability and security. To that end, this roadmap suggests a 10-year journey to build a strong SASR technical capability with a clear mission to support nuclear technology development. If nuclear technology is to be used to satisfy the expected growth in U.S. electrical energy demand, the once-through fuel cycle currently in use should be reconsidered. Although the once-through fuel cycle is cost-effective and uranium is inexpensive, a once-through fuel cycle requires long-term disposal to protect the environment and public from long-lived radioactive species. The lack of a current disposal option (i.e., a licensed repository) has resulted in accumulation of more than 50,000 metric tons of spent nuclear fuel. The process required to transition the current once-through fuel cycle to full-recycle will require considerable time and significant technical advancement. INL's extensive expertise in aqueous separations will be used to develop advanced separations processes. Computational chemistry will be expanded to support development of future processing options. In the intermediate stage of this transition, reprocessing options will be deployed, waste forms with higher loading densities and greater stability will be developed, and transmutation of long-lived fission products will be explored. SASR will support these activities using its actinide science and aqueous separations expertise. In the final stage, full recycle will be enabled by

  1. Core Optimization of a Deep-Burn Pebble Bed Reactor

    SciTech Connect

    Brian Boer; Abderrafi M. Ougouag

    2010-06-01

    Achieving a high fuel burnup in the Deep-Burn (DB) pebble bed reactor design, while remaining within the limits for fuel temperature, power peaking and temperature reactivity feedback, is challenging. The high content of Pu and Minor Actinides in the Deep-Burn fuel significantly impacts the thermal neutron energy spectrum as compared to a ’standard’ UO2 fueled core. This can result in power and temperature peaking in the pebble bed core in locally thermalized regions near the graphite reflectors. Furthermore, the interplay of the Pu resonances of the neutron absorption cross sections at low-lying energies can lead to a positive temperature reactivity coefficient for the graphite moderator at certain operating conditions. The DB concept focuses on the destruction of spent fuel transuranics in TRISO coated particle fueled gas-cooled reactors with the aim of a fractional fuel burnup of 60-70% in fissions per initial metal atom (FIMA), using a single-pass, multi in-core fuel (re)cycling scheme. In principle, the DB pebble bed concept employs the same reactor designs as the present low enriched uranium core designs, i.e. the 400 MWth Pebble Bed Modular Reactor (PBMR-400). A Pu and Minor Actinide fueled PBMR-400 design serves as the starting point for a core optimization study. The fuel temperature, power peak, temperature reactivity coefficients, and burnup capabilities of the modified designs are analyzed with the PEBBED code. A code-to-code coupling with the PASTA code allows for the analysis of the TRISO fuel performance for both normal and Loss Of Forced Cooling conditions. An improved core design is sought, maximizing the fuel discharge burnup, while retaining negative temperature reactivity feedback coefficients for the entire temperature range and avoiding high fuel temperatures (fuel failure probabilities).

  2. Chemistry of tetravalent actinide phosphates-Part I

    SciTech Connect

    Brandel, V. . E-mail: vbrandel@neuf.fr; Dacheux, N. . E-mail: dacheux@ipno.in2p3.fr

    2004-12-01

    The chemistry and crystal structure of phosphates of tetravalent cations, including that of actinides was reviewed several times up to 1985. Later, new compounds were synthesized and characterized. In more recent studies, it was found that some of previously reported phases, especially those of thorium, uranium and neptunium, were wrongly identified. In the light of these new facts an update review and classification of the tetravalent actinide phosphates is proposed in the two parts of this paper. Their crystal structure and some chemical properties are also compared to non-actinide cation phosphates.

  3. Separating the Minor Actinides Through Advances in Selective Coordination Chemistry

    SciTech Connect

    Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Carter, Jennifer C.

    2012-08-22

    This report describes work conducted at the Pacific Northwest National Laboratory (PNNL) in Fiscal Year (FY) 2012 under the auspices of the Sigma Team for Minor Actinide Separation, funded by the U.S. Department of Energy Office of Nuclear Energy. Researchers at PNNL and Argonne National Laboratory (ANL) are investigating a simplified solvent extraction system for providing a single-step process to separate the minor actinide elements from acidic high-level liquid waste (HLW), including separating the minor actinides from the lanthanide fission products.

  4. Process to remove actinides from soil using magnetic separation

    DOEpatents

    Avens, Larry R.; Hill, Dallas D.; Prenger, F. Coyne; Stewart, Walter F.; Tolt, Thomas L.; Worl, Laura A.

    1996-01-01

    A process of separating actinide-containing components from an admixture including forming a slurry including actinide-containing components within an admixture, said slurry including a dispersion-promoting surfactant, adjusting the pH of the slurry to within a desired range, and, passing said slurry through a pretreated matrix material, said matrix material adapted to generate high magnetic field gradients upon the application of a strong magnetic field exceeding about 0.1 Tesla whereupon a portion of said actinide-containing components are separated from said slurry and remain adhered upon said matrix material is provided.

  5. Explosive burns during abusive inhalation of butane gas.

    PubMed

    Oh, S J; Lee, S E; Burm, J S; Chung, C H; Lee, J W; Chang, Y C; Kim, D C

    1999-06-01

    Explosion burns during abusive inhalation of butane gas rarely occurred in the past, but recently it has become a social problem among groups of teenagers. This cause constitutes 1.6% of admissions due to flame burn at the burn unit of Hallym Medical Center. A retrospective review during a five-year period identified 48 patients. The male to female ratio was 3:1. The mean age of patients was 16 years and 8 months. The places where the accidents occurred were commonly bedrooms or motel rooms. There were nine group settings of 27 patients at the time of the accident. Inhalation injury (n = 12) was noted on admission. The average burn size was 28.5 percent of the total body surface area. All patients sustained burn injury on the face, arms and hands and 24 patients among them had extended burn areas on the trunk and/or lower extremity. 22 patients (mean hospital stay; 51.6 d) required skin grafting and 12 patients (mean hospital stay; 22.3 d) were treated with conservative management. The mortality rate was 10.4 percent. Explosion burns during abusive inhalation of butane gas can result in mortality as well as major burn injuries. PMID:10431983

  6. Theoretical atomic volumes of the light actinides

    SciTech Connect

    Jones, M. D.; Boettger, J. C.; Albers, R. C.; Singh, D. J.

    2000-02-15

    The zero-pressure zero-temperature equilibrium volumes and bulk moduli are calculated for the light actinides Th through Pu using two independent all-electron, full-potential, electronic-structure methods: the full-potential linear augmented-plane-wave method and the linear combinations of Gaussian-type orbitals-fitting function method. The results produced by these two distinctly different electronic-structure techniques are in good agreement with each other, but differ significantly from previously published calculations using the full-potential linear muffin-tin-orbital (FP-LMTO) method. The theoretically calculated equilibrium volumes are in some cases nearly 10% larger than the previous FP-LMTO calculations, bringing them much closer to the experimentally observed volumes. We also discuss the anomalous upturn in equilibrium volume seen experimentally for {alpha}-Pu. (c) 2000 The American Physical Society.

  7. Aqueous processing of actinides at Savannah River

    SciTech Connect

    Gray, J.H.

    1990-01-01

    A number of changes affecting the DP-Complex are having an impact on operations at the Savannah River Site (SRS). In order for SRS to continue as a major contributor within the DP-Complex and remain in position to respond to requests based on new initiatives, programs aimed at redirecting the actinide processing activities have been started. One area undergoing process modifications is F-Canyon, where most of the plutonium feedstocks are processed. Programs already underway that are affecting the dissolution of plutonium materials in canyon dissolvers and the purification of aqueous streams in the second plutonium solvent extraction cycle are discussed. Issues influencing program direction involve environmental concerns, waste minimization, health protection, storage limitations, and material recycle. Each of these issues is discussed in relation to operations in F-Canyon and results based on initial development studies are presented.

  8. Complexation of actinides with derivatives of oxydiaceticacid

    SciTech Connect

    Rao, Linfeng; Tian, Guoxin

    2006-01-04

    Complexation of Np(V), U(VI) and Nd(III) with dimethyl-3-oxa-glutaramic acid (DMOGA) and tetramethyl-3-oxa-glutaramide (TMOGA) was studied in comparison with the complexation with oxydiacetic acid (ODA). Stability constants and enthalpy of complexation were determined by potentiometry, spectrophotometry and calorimetry. Thermodynamic parameters, in conjunction with structural information of solid compounds, indicate that DMOGA and TMOGA form tridentate complexes with the ether-oxygen participating in bonding with actinide/lanthanide ions. The trends in the stability constants, enthalpy and entropy of complexation are discussed in terms of the difference in the hydration of the amide groups and carboxylate groups and the difference in the charge density of the metal ions.

  9. Aqueous recovery of actinides from aluminum alloys

    SciTech Connect

    Gray, J.H.; Chostner, D.F.; Gray, L.W.

    1989-01-01

    Early in the 1980's, a joint Rocky Flats/Savannah River program was established to recover actinides from scraps and residues generated during Rocky Flats purification operations. The initial program involved pyrochemical treatment of Molten Salt Extraction (MSE) chloride salts and Electrorefining (ER) anode heel metal to form aluminum alloys suitable for aqueous processing at Savannah River. Recently Rocky Flats has expressed interest in expanding the aluminum alloy program to include treatment of chloride salt residues from a modified Molten Salt Extraction process and from the Electrorefining purification operations. Samples of the current aluminum alloy buttons were prepared at Rocky Flats and sent to Savannah River Laboratory for flowsheet development and characterization of the alloys. A summary of the scrub alloy-anode heel alloy program will be presented along with recent results from aqueous dissolution studies of the new aluminum alloys. 2 figs., 4 tabs.

  10. Temperature Responses during Exercise in a Hot Environment in Severely Burned Children

    PubMed Central

    McEntire, Serina J.; Chinkes, David L.; Herndon, David N.; Suman, Oscar E.

    2014-01-01

    Objective We have previously described thermoregulatory responses of severely burned children during submaximal exercise in a thermoneutral environment. However, the thermoregulatory response of burned children to exercise in the heat is not well understood and could have important safety implications for rehabilitation. Study design Children (n=10) with >40% total body surface area burns and non-burned children (n=10) performed a 30 minute bout of treadmill exercise at 75% of their peak aerobic power in a heated environment. Intestinal temperature, burned and unburned skin temperature, and heart rate were recorded pre-exercise, every 2 minutes during exercise, and during recovery. Results Three of the 10 burned children completed the exercise bout in the heat; however, all of the non-burned children completed the 30 minute bout. One burned child reached a core body temperature > 39°C at minute 23. Burned children had a significantly higher core body temperature thru the first 12 minutes of exercise compared to non-burned children. However, 9 of 10 (90%) burned children did not become hyperthermic during exercise in the heat. Conclusion Specific to this study, hyperthermia did not typically occur in burned children, relative to non-burned children. Whether this is due to an intolerance to exercise in the heat or to an inability to generate sufficient heat during exercise needs to be explored further. PMID:20616652

  11. Effects of cimetidine on fluid requirement during resuscitation of third-degree burns.

    PubMed

    Tanaka, H; Wada, T; Simazaki, S; Hanumadass, M; Reyes, H M; Matsuda, T

    1991-01-01

    Seventy percent body surface area third-degree burns were produced in four groups of six guinea pigs each, after which all were resuscitated with Ringer's lactate solution. Group 1 received 4 ml/kg/%burn. Group 2 received 1 ml/kg/%burn with cimetidine, which was begun at 0.5 hours after burn injury. Group 3 received 1 ml/kg/%burn with cimetidine, which was begun at 1 hour after burn injury. Group 4 received 1 ml/kg/%burn without cimetidine. There were no significant differences among any of the groups in blood pressures or heart rates during the study period. Group 4 showed significantly higher hematocrit values than group 2 at 4 hours after burn injury and thereafter. The cardiac outputs of group 2 were the same statistically as those of group 1. The cardiac outputs of group 3 were significantly lower than those that received cimetidine early (group 2), though still higher than those of the 1 ml control group (group 4) at 4 hours after burn injury and thereafter. At 24 hours after burn injury, the water content of the burned skin of group 2 was significantly lower than that of the other groups. We conclude that in third-degree burns, cimetidine therapy can effectively reduce burn edema and the amount of required resuscitation fluid. Early administration is better than late administration of cimetidine. PMID:1752876

  12. Actinide cross section program at ORELA

    SciTech Connect

    Dabbs, J.W.T.

    1980-01-01

    The actinide cross section program at ORELA, the Oak Ridge Electron Linear Accelerator, is aimed at obtaining accurate neutron cross sections (primarily fission, capture, and total) for actinide nuclides which occur in fission reactors. Such cross sections, measured as a function of neutron energy over as wide a range of energies as feasible, comprise a data base that permits calculated predictions of the formation and removal of these nuclides in reactors. The present program is funded by the Division of Basic Energy Sciences of DOE, and has components in several divisions at ORNL. For intensively ..cap alpha..-active nuclides, many of the existing fission cross section data have been provided by underground explosions. New measurement techniques, developed at ORELA, now permit linac measurements on fissionable nuclides with alpha half-lives as short as 28 years. Capture and capture-plus-fission measurements utilize scintillation detectors (of capture ..gamma.. rays and fission neutrons) in which pulse shape discrimination plays an important role. Total cross sections can be measured at ORELA on samples of only a few milligrams. A simultaneous program of chemical and isotopic analyses of samples irradiated in EBR-II is in progress to provide benchmarks for the existing differential measurements. These analyses are being studied with updated versions of ORIGEN and with sensitivity determinations. Calculations of the sensitivity to cross section changes of various aspects of the nuclear fuel cycle are also being made. Even in this relatively mature field, many cross sections still require improvements to provide an adequate data base. Examples of recent techniques and measurements are presented. 12 figures, 3 tables.

  13. QUANTIFICATION OF ACTINIDE ALPHA-RADIATION DAMAGE IN MINERALS AND CERAMICS

    SciTech Connect

    Farnan, Ian E.; Cho, Herman M.; Weber, William J.

    2007-01-11

    There are large amounts of heavy alpha-emitters in nuclear waste and nuclear materials inventories stored in various sites around the world. These include plutonium and minor actinides such as americium and curium. In preparation for geological disposal there is a consensus that actinides that have been separated from spent nuclear fuel should be immobilised within mineral-based ceramics rather than glass. Over the long-term, the alpha-decay taking place in these ceramics will severely disrupt their crystalline structure and reduce their durability. A fundamental property in predicting cumulative radiation damage is the number of atoms permanently displaced per alpha–decay. Currently, this number is estimated as 1000-2000 atoms/alpha decay event. Here, we report nuclear magnetic resonance, spin-counting experiments that measure close to 5000 atoms/alpha decay event in radiation damaged natural zircons. New radiological NMR measurements on highly radioactive, 239Pu zircon show damage similar to that created by 238U and 232Th in mineral zircons at the same dose, indicating no significant effect of dose rate. Based on these measurements, the initially crystalline structure of a 10 wt% 239Pu zircon would be amorphous after only 1400 years in a geological repository. These measurements establish a basis for assessing the long-term structural durability of actinide-containing ceramics based on an atomistic understanding of the fundamental damage event.

  14. Burning Mouth Syndrome.

    PubMed

    Klasser, Gary D; Grushka, Miriam; Su, Nan

    2016-08-01

    Burning mouth syndrome (BMS) is an enigmatic, misunderstood, and under-recognized painful condition. Symptoms associated with BMS can be varied, thereby providing a challenge for practitioners and having a negative impact on oral health-related quality of life for patients. Management also remains a challenge for practitioners because it is currently only targeted for symptom relief without a definitive cure. There is an urgent need for further investigations to determine the efficacy of different therapies because this is the only way viable therapeutic options can be established for patients with this chronic and painful syndrome. PMID:27475513

  15. Complicated Burn Resuscitation.

    PubMed

    Harrington, David T

    2016-10-01

    More than 4 decades after the creation of the Brooke and Parkland formulas, burn practitioners still argue about which formula is the best. So it is no surprise that there is no consensus about how to resuscitate a thermally injured patient with a significant comorbidity such as heart failure or cirrhosis or how to resuscitate a patient after an electrical or inhalation injury or a patient whose resuscitation is complicated by renal failure. All of these scenarios share a common theme in that the standard rule book does not apply. All will require highly individualized resuscitations. PMID:27600129

  16. Marginally Stable Nuclear Burning

    NASA Technical Reports Server (NTRS)

    Strohmayer, Tod E.; Altamirano, D.

    2012-01-01

    Thermonuclear X-ray bursts result from unstable nuclear burning of the material accreted on neutron stars in some low mass X-ray binaries (LMXBs). Theory predicts that close to the boundary of stability oscillatory burning can occur. This marginally stable regime has so far been identified in only a small number of sources. We present Rossi X-ray Timing Explorer (RXTE) observations of the bursting, high- inclination LMXB 4U 1323-619 that reveal for the first time in this source the signature of marginally stable burning. The source was observed during two successive RXTE orbits for approximately 5 ksec beginning at 10:14:01 UTC on March 28, 2011. Significant mHz quasi- periodic oscillations (QPO) at a frequency of 8.1 mHz are detected for approximately 1600 s from the beginning of the observation until the occurrence of a thermonuclear X-ray burst at 10:42:22 UTC. The mHz oscillations are not detected following the X-ray burst. The average fractional rms amplitude of the mHz QPOs is 6.4% (3 - 20 keV), and the amplitude increases to about 8% below 10 keV.This phenomenology is strikingly similar to that seen in the LMXB 4U 1636-53. Indeed, the frequency of the mHz QPOs in 4U 1323-619 prior to the X-ray burst is very similar to the transition frequency between mHz QPO and bursts found in 4U 1636-53 by Altamirano et al. (2008). These results strongly suggest that the observed QPOs in 4U 1323-619 are, like those in 4U 1636-53, due to marginally stable nuclear burning. We also explore the dependence of the energy spectrum on the oscillation phase, and we place the present observations within the context of the spectral evolution of the accretion-powered flux from the source.

  17. SystemBurn

    2012-08-30

    SystemBurn is a tool for creating a synthetic computational load for the purpose of measuring how much power a computer will draw under that type of load. The loads include fundamental library function calls like matrix multiply, memory copies, fourier transforms, bit manipulation, I/O, network packet transfers, and some code contrived to cause the processor to dray more or less power. The code produces some diagnostic and progress output, but the actual measurements would bemore » recorded from the power panels within the computer room.« less

  18. Applicability of RELAP5-3D for Thermal-Hydraulic Analyses of a Sodium-Cooled Actinide Burner Test Reactor

    SciTech Connect

    C. B. Davis

    2006-07-01

    The Actinide Burner Test Reactor (ABTR) is envisioned as a sodium-cooled, fast reactor that will burn the actinides generated in light water reactors to reduce nuclear waste and ease proliferation concerns. The RELAP5-3D computer code is being considered as the thermal-hydraulic system code to support the development of the ABTR. An evaluation was performed to determine the applicability of RELAP5-3D for the analysis of a sodium-cooled fast reactor. The applicability evaluation consisted of several steps, including identifying the important transients and phenomena expected in the ABTR, identifying the models and correlations that affect the code’s calculation of the important phenomena, and evaluating the applicability of the important models and correlations for calculating the important phenomena expected in the ABTR. The applicability evaluation identified code improvements and additional models needed to simulate the ABTR. The accuracy of the calculated thermodynamic and transport properties for sodium was also evaluated.

  19. One-group fission cross sections for plutonium and minor actinides inserted in calculated neutron spectra of fast reactor cooled with lead-208 or lead-bismuth eutectic

    SciTech Connect

    Khorasanov, G. L.; Blokhin, A. I.

    2012-07-01

    The paper is dedicated to one-group fission cross sections of Pu and MA in LFRs spectra with the aim to increase these values by choosing a coolant which hardens neutron spectra. It is shown that replacement of coolant from Pb-Bi with Pb-208 in the fast reactor RBEC-M, designed in Russia, leads to increasing the core mean neutron energy. As concerns fuel Pu isotopes, their one-group fission cross sections become slightly changed, while more dramatically Am-241 one-group fission cross section is changed. Another situation occurs in the lateral blanket containing small quantities of minor actinides. It is shown that as a result of lateral blanket mean neutron energy hardening the one-group fission cross sections of Np-237, Am-241 and Am-243 increases up to 8-11%. This result allows reducing the time of minor actinides burning in FRs. (authors)

  20. Utilization of Plutonium and Higher Actinides in the HTGR as Possibility to Maintain Long-Term Operation on One Fuel Loading

    SciTech Connect

    Tsvetkova, Galina V.; Peddicord, Kenneth L.

    2002-07-01

    Promising existing nuclear reactor concepts together with new ideas are being discussed worldwide. Many new studies are underway in order to identify prototypes that will be analyzed and developed further as systems for Generation IV. The focus is on designs demonstrating full inherent safety, competitive economics and proliferation resistance. The work discussed here is centered on a modularized small-size High Temperature Gas-cooled Reactor (HTGR) concept. This paper discusses the possibility of maintaining long-term operation on one fuel loading through utilization of plutonium and higher actinides in the small-size pebble-bed reactor (PBR). Acknowledging the well-known flexibility of the PBR design with respect to fuel composition, the principal limitations of the long-term burning of plutonium and higher actinides are considered. The technological challenges and further research are outlined. The results allow the identification of physical features of the PBR that significantly influence flexibility of the design and its applications. (authors)

  1. Reactive burn models and ignition & growth concept

    SciTech Connect

    Menikoff, Ralph S; Shaw, Milton S

    2010-01-01

    Plastic-bonded explosives are heterogeneous materials. Experimentally, shock initiation is sensitive to small amounts of porosity, due to the formation of hot spots (small localized regions of high temperature). This leads to the Ignition and Growth concept, introduced by Lee and Tarver in 1980, as the basis for reactive burn models. A homogeneized burn rate needs to account for three mesoscale physical effects (i) the density of burnt hot spots, which depends on the lead shock strength; (ii) the growth of the burn fronts triggered by hot spots, which depends on the local deflagration speed; (iii) a geometric factor that accounts for the overlap of deflagration wavelets from adjacent hot spots. These effects can be combined and the burn model defined by specifying the reaction progress variable {lambda}(t) as a function of a dimensionless reaction length {tau}{sub hs}(t)/{ell}{sub hs}, rather than by xpecifying an explicit burn rate. The length scale {ell}{sub hs} is the average distance between hot spots, which is proportional to [N{sub hs}(P{sub s})]{sup -1/3}, where N{sub hs} is the number density of hot spots activated by the lead shock. The reaction length {tau}{sub hs}(t) = {line_integral}{sub 0}{sup t} D(P(t'))dt' is the distance the burn front propagates from a single hot spot, where D is the deflagration speed and t is the time since the shock arrival. A key implementation issue is how to determine the lead shock strength in conjunction with a shock capturing scheme. They have developed a robust algorithm for this purpose based on the Hugoniot jump condition for the energy. The algorithm utilizes the time dependence of density, pressure and energy within each cell. The method is independent of the numerical dissipation used for shock capturing. It is local and can be used in one or more space dimensions. The burn model has a small number of parameters which can be calibrated to fit velocity gauge data from shock initiation experiments.

  2. Pathogenic alteration in severe burn wounds.

    PubMed

    Fu, Yang; Xie, Bing; Ben, DaoFeng; Lv, KaiYang; Zhu, ShiHui; Lu, Wei; Tang, HongTai; Cheng, DaSheng; Ma, Bing; Wang, GuangYi; Xiao, ShiChu; Wang, GuangQing; Xia, ZhaoFan

    2012-02-01

    The present study aims to define the trend of time related changes with local bacterial alteration of bacterial resistance in severe burns in our burn center during a 12-year period. Retrospective analysis of microbiological results on severely burned wounds between 1998 and 2009 was carried out. A study of 3615 microbial isolates was performed. Staphylococcus aureus was the most commonly isolated pathogen (38.2%) followed by A. baumannii (16.2%), Streptococcus viridans (11.4%), Pseudomonas aeruginosa (10.4%), coagulase-negative staphylococci (CNS, 9.2%). The species ratios of S. aureus and A. baumannii increased significantly from 1st to 8th week of hospitalization, while those of Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci decreased during the same period. Bacterial resistance rates were compared between the periods 1998-2003 and 2004-2009. Vancomycin remained as the most sensitive antibiotic in S. aureus including methicillin-resistant S. aureus (MRSA). It was very likely that the majority of infections caused by Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci occurred in the early stage of burn course and the majority of infections caused by A. baumannii occurred 4 weeks after admission. The use of different antibiotics was probably the major contributor to these trends. PMID:22100426

  3. Actinide targets for the synthesis of super-heavy elements

    SciTech Connect

    Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; Ezold, Julie G.; Felker, Leslie Kevin; Rykaczewski, Krzysztof Piotr; Hogle, Susan L.

    2015-06-18

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

  4. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am - the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting ...

  5. Actinide targets for the synthesis of super-heavy elements

    NASA Astrophysics Data System (ADS)

    Roberto, J. B.; Alexander, C. W.; Boll, R. A.; Burns, J. D.; Ezold, J. G.; Felker, L. K.; Hogle, S. L.; Rykaczewski, K. P.

    2015-12-01

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing the production of rare actinides including 249Bk, 251Cf, and 254Es are described.

  6. Separation of Minor Actinides from Lanthanides by Dithiophosphinic Acid Extractants

    SciTech Connect

    D. R. Peterman; M. R. Greenhalgh; R. D. Tillotson; J. R. Klaehn; M. K. Harrup; T. A. Luther; J. D. Law; L. M. Daniels

    2008-09-01

    The selective extraction of the minor actinides (Am(III) and Cm(III)) from the lanthanides is an important part of advanced reprocessing of spent nuclear fuel. This separation would allow the Am/Cm to be fabricated into targets and recycled to a reactor and the lanthanides to be dispositioned. This separation is difficult to accomplish due to the similarities in the chemical properties of the trivalent actinides and lanthanides. Research efforts at the Idaho National Laboratory have identified an innovative synthetic pathway yielding new regiospecific dithiophosphinic acid (DPAH) extractants. The synthesis provides DPAH derivatives that can address the issues concerning minor actinide separation and extractant stability. For this work, two new symmetric DPAH extractants have been prepared. The use of these extractants for the separation of minor actinides from lanthanides will be discussed.

  7. Actinide targets for the synthesis of super-heavy elements

    DOE PAGESBeta

    Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; Ezold, Julie G.; Felker, Leslie Kevin; Rykaczewski, Krzysztof Piotr; Hogle, Susan L.

    2015-06-18

    Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing themore » production of rare actinides including 249Bk, 251Cf, and 254Es are described.« less

  8. Vitamin C in Burn Resuscitation.

    PubMed

    Rizzo, Julie A; Rowan, Matthew P; Driscoll, Ian R; Chung, Kevin K; Friedman, Bruce C

    2016-10-01

    The inflammatory state after burn injury is characterized by an increase in capillary permeability that results in protein and fluid leakage into the interstitial space, increasing resuscitative requirements. Although the mechanisms underlying increased capillary permeability are complex, damage from reactive oxygen species plays a major role and has been successfully attenuated with antioxidant therapy in several disease processes. However, the utility of antioxidants in burn treatment remains unclear. Vitamin C is a promising antioxidant candidate that has been examined in burn resuscitation studies and shows efficacy in reducing the fluid requirements in the acute phase after burn injury. PMID:27600125

  9. [Burns caused by paint thinner].

    PubMed

    Benbrahim, A; Jerrah, H; Diouri, M; Bahechar, N; Boukind, E H

    2009-12-31

    Flame deriving from paint thinner is not a rare cause of burns in Morocco and we thus considered it useful to conduct an epidemiological survey of paint thinner flame burns (PTFB) in the National Burns Centre (NBC) in the Ibn-Rochd University Hospital Centre in Casablanca, Morocco. The research covered the 10-month period from September 2007 to June 2008.The aim of our work was to present the characteristic features of such burns in order to prevent them by increasing public knowledge regarding the risks involved in using paint thinner, i.e. burns in particular. During the period in question, we colligated 17 cases of PTFB out of a total number of 356 patients admitted to the NBC for acute burns of all aetiologies. The patients' average was 32 yr and they were nearly all male (16 men/1 woman), with past histories of drug addiction and/or delinquency. They were all of low-level socioeconomic class and lived mainly in shanty towns. The burn was often secondary to street violence (92% of the cases).The mean burn surface area was 23% and the burns were often deep and located mainly in the upper limbs and the trunk. PMID:21991179

  10. Human mitochondrial oxidative capacity is acutely impaired following burn trauma

    PubMed Central

    Cree, Melanie G.; Fram, Ricki Y.; Herndon, David N.; Qian, Ting; Angel, Carlos; Green, Justin M.; Mlcak, Ronald; Aarsland, Asle; Wolfe, Robert R.

    2008-01-01

    Background Mitochondrial proteins and genes are damaged after burn injury in animals but have not previously been assessed in human burn patients. Methods The rates of maximal muscle mitochondrial oxidative capacity(ATP production) and uncoupled oxidation(heat production) for both palmitate and pyruvate were measured in muscle biopsies from 40 children sustaining burns >40% body surface area and from 13 healthy children controls. Results Maximal mitochondrial oxidation of pyruvate and palmitate were reduced in burn patients compared to controls (4.0±0.2:1.9±0.1 µmolO2/citrate synthase activity/mg protein/min pyruvate; Control:Burn;P<0.001 and 3.0±0.1:0.9±0.03 µmolO2/citrate synthase activity/mg protein/min palmatyl CoA; Control:Burn;P=0.003). Uncoupled oxidation was the same between groups. Conclusions The maximal coupled mitochondrial oxidative capacity is severely impaired after burn injury, although there are no alterations in the rate of uncoupled oxidative capacity. It may be that the ratio of these indicates that a larger portion of energy production in trauma patients is wasted through uncoupling, rather than used for healing. PMID:18639661

  11. Burns: Treatment and Outcomes

    PubMed Central

    Burd, Andrew

    2010-01-01

    Burns can cause extensive and devastating injuries of the head and neck. Prevention of the initial injury must always be a priority, but once an injury has occurred, then prevention of progression of the damage together with survival of the patient must be the immediate goals. The acute care will have a major influence on the subsequent scarring, reconstructive need, and long-term outcome. In the majority of cases, the reconstruction will involve restoration of form and function to the soft tissues, and the methods used will depend very much on the extent of scarring locally and elsewhere in the body. In nearly all cases, a significant improvement in functional and aesthetic outcomes can be achieved, which, in conjunction with intensive psychosocial rehabilitation, can lead to high-quality patient outcomes. With the prospect of facial transplantation being a clinical reality, the reconstructive spectrum has opened up even further, and, with appropriate reconstruction and support, no patient should be left economically deprived or socially isolated after a burn injury. PMID:22550448

  12. Burning mouth syndrome

    PubMed Central

    Gurvits, Grigoriy E; Tan, Amy

    2013-01-01

    Burning mouth syndrome is a debilitating medical condition affecting nearly 1.3 million of Americans. Its common features include a burning painful sensation in the mouth, often associated with dysgeusia and xerostomia, despite normal salivation. Classically, symptoms are better in the morning, worsen during the day and typically subside at night. Its etiology is largely multifactorial, and associated medical conditions may include gastrointestinal, urogenital, psychiatric, neurologic and metabolic disorders, as well as drug reactions. BMS has clear predisposition to peri-/post menopausal females. Its pathophysiology has not been fully elucidated and involves peripheral and central neuropathic pathways. Clinical diagnosis relies on careful history taking, physical examination and laboratory analysis. Treatment is often tedious and is aimed at correction of underlying medical conditions, supportive therapy, and behavioral feedback. Drug therapy with alpha lipoic acid, clonazepam, capsaicin, and antidepressants may provide symptom relief. Psychotherapy may be helpful. Short term follow up data is promising, however, long term prognosis with treatment is lacking. BMS remains an important medical condition which often places a recognizable burden on the patient and health care system and requires appropriate recognition and treatment. PMID:23429751

  13. 40 CFR 49.11021 - Permits for general open burning, agricultural burning, and forestry and silvicultural burning.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., agricultural burning, and forestry and silvicultural burning. 49.11021 Section 49.11021 Protection of... burning, and forestry and silvicultural burning. (a) Beginning January 1, 2007, a person must apply for... under § 49.134 Rule for forestry and silvicultural burning permits....

  14. 40 CFR 49.11021 - Permits for general open burning, agricultural burning, and forestry and silvicultural burning.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., agricultural burning, and forestry and silvicultural burning. 49.11021 Section 49.11021 Protection of... burning, and forestry and silvicultural burning. (a) Beginning January 1, 2007, a person must apply for... under § 49.134 Rule for forestry and silvicultural burning permits....

  15. 40 CFR 49.11021 - Permits for general open burning, agricultural burning, and forestry and silvicultural burning.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., agricultural burning, and forestry and silvicultural burning. 49.11021 Section 49.11021 Protection of... burning, and forestry and silvicultural burning. (a) Beginning January 1, 2007, a person must apply for... under § 49.134 Rule for forestry and silvicultural burning permits....

  16. 40 CFR 49.11021 - Permits for general open burning, agricultural burning, and forestry and silvicultural burning.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., agricultural burning, and forestry and silvicultural burning. 49.11021 Section 49.11021 Protection of... burning, and forestry and silvicultural burning. (a) Beginning January 1, 2007, a person must apply for... under § 49.134 Rule for forestry and silvicultural burning permits....

  17. Suicide by burning: a retrospective review of the Akron Regional Burn Center.

    PubMed

    Krummen, D M; James, K; Klein, R L

    1998-03-01

    At the Akron Regional Burn Center from January 1978 through March 1995, 36 cases of attempted suicide by burning were identified in 34 patients. The overall incidence rate was 1 per cent of all burn center admissions to this institution. Of these patients, 21 of 34 were male and 13 of 34 were female. There were 10 of 34 lethal cases. A high incidence of prior psychiatric illness was identified. In all, 22 of 34 patients had a prior psychiatric diagnosis. Depression was the most common psychiatric diagnosis by history. The method most commonly used was a flame with the addition of a flammable liquid. These results are presented, discussed and compared to a review of the literature on the topic. PMID:9625241

  18. [Combat burn injury. The Afghanistan and Iraq military campaign experience].

    PubMed

    Ivchenko, E V; Golota, A S; Kondratenko, D G; Krassiĭ, A B

    2014-08-01

    The current article briefly reviews the experience of combat burns care obtained in the course of 2001-2013 military campaign in Afghanistan and Iraq as it has been covered in the foreign scientific medical publications. The following topics are covered: statistics, the prehospital medical care, aeromedical evacuation, the Burn Center of the US Army Institute of Surgical Research. The new method.of the .initial intravenous infusion rate estimation, so called the "Rule of 10 formula, is marked: At the end, the list of freely available publications summarized the modern combat burns care experience is presented. PMID:25546957

  19. A numerical study of Li-SF6 wick combustion - Forced and mixed convective burning

    NASA Technical Reports Server (NTRS)

    Damaso, R. C.; Chen, L.-D.

    1992-01-01

    A numerical study is conducted to study Li-SF6 wick diffusion flames under mixed convective burning conditions at a pressure of 0.01 MPa. Both planar and cylindrical wicks are considered. The model is based on a conserved scalar approach. The objective of this study is to assess the effects of particular parameters on the burning rate and heat transfer. The flat-plate solution yields a fuel mass burning rate per unit surface area following the x exp -1/2 dependence of the classical similarity solution, where x is the streamwise distance. Cylindrical wick geometries yield enhanced burning rates over planar wicks. For the case of mixed convective burning, the burning rate results approach either the forced or natural convective burning limits as ambient streamwise velocity is changed. Critical Richardson numbers specifying these burning limits are determined for a given condition. Reducing gravity results in a lower burning rate because the influence of natural convection is diminished. Under reduced gravity of 1/1000 of the sea-level value, mixed convective burning nearly resembles forced convection.

  20. Actinide Source Term Program, position paper. Revision 1

    SciTech Connect

    Novak, C.F.; Papenguth, H.W.; Crafts, C.C.; Dhooge, N.J.

    1994-11-15

    The Actinide Source Term represents the quantity of actinides that could be mobilized within WIPP brines and could migrate with the brines away from the disposal room vicinity. This document presents the various proposed methods for estimating this source term, with a particular focus on defining these methods and evaluating the defensibility of the models for mobile actinide concentrations. The conclusions reached in this document are: the 92 PA {open_quotes}expert panel{close_quotes} model for mobile actinide concentrations is not defensible; and, although it is extremely conservative, the {open_quotes}inventory limits{close_quotes} model is the only existing defensible model for the actinide source term. The model effort in progress, {open_quotes}chemical modeling of mobile actinide concentrations{close_quotes}, supported by a laboratory effort that is also in progress, is designed to provide a reasonable description of the system and be scientifically realistic and supplant the {open_quotes}Inventory limits{close_quotes} model.

  1. Analysis of the Gas Core Actinide Transmutation Reactor (GCATR)

    NASA Technical Reports Server (NTRS)

    Clement, J. D.; Rust, J. H.

    1977-01-01

    Design power plant studies were carried out for two applications of the plasma core reactor: (1) As a breeder reactor, (2) As a reactor able to transmute actinides effectively. In addition to the above applications the reactor produced electrical power with a high efficiency. A reactor subsystem was designed for each of the two applications. For the breeder reactor, neutronics calculations were carried out for a U-233 plasma core with a molten salt breeding blanket. A reactor was designed with a low critical mass (less than a few hundred kilograms U-233) and a breeding ratio of 1.01. The plasma core actinide transmutation reactor was designed to transmute the nuclear waste from conventional LWR's. The spent fuel is reprocessed during which 100% of Np, Am, Cm, and higher actinides are separated from the other components. These actinides are then manufactured as oxides into zirconium clad fuel rods and charged as fuel assemblies in the reflector region of the plasma core actinide transmutation reactor. In the equilibrium cycle, about 7% of the actinides are directly fissioned away, while about 31% are removed by reprocessing.

  2. Nucleosynthesis of neutron-rich heavy nuclei during explosive helium burning in massive stars

    NASA Technical Reports Server (NTRS)

    Blake, J. B.; Woosley, S. E.; Weaver, T. A.; Schramm, D. N.

    1981-01-01

    The production of heavy nuclei during explosive helium burning has been calculated using a hydrodynamical model of a 15-solar mass (Type II) supernova and an n-process nuclear reaction network. It is found that the resulting neutron-rich heavy nuclei are not produced in the relative abundances of solar-system r-process material, especially in the vicinity of Pt, nor are any actinides produced. These deficiencies reflect an inadequate supply of neutrons. However, some neutron-rich isotopes, normally associated with the r-process, are produced which may be significant for the production of isotopic anomalies in meteorites.

  3. Global burned area and biomass burning emissions from small fires

    NASA Astrophysics Data System (ADS)

    Randerson, J. T.; Chen, Y.; van der Werf, G. R.; Rogers, B. M.; Morton, D. C.

    2012-12-01

    In several biomes, including croplands, wooded savannas, and tropical forests, many small fires occur each year that are well below the detection limit of the current generation of global burned area products derived from moderate resolution surface reflectance imagery. Although these fires often generate thermal anomalies that can be detected by satellites, their contributions to burned area and carbon fluxes have not been systematically quantified across different regions and continents. Here we developed a preliminary method for combining 1-km thermal anomalies (active fires) and 500 m burned area observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the influence of these fires. In our approach, we calculated the number of active fires inside and outside of 500 m burn scars derived from reflectance data. We estimated small fire burned area by computing the difference normalized burn ratio (dNBR) for these two sets of active fires and then combining these observations with other information. In a final step, we used the Global Fire Emissions Database version 3 (GFED3) biogeochemical model to estimate the impact of these fires on biomass burning emissions. We found that the spatial distribution of active fires and 500 m burned areas were in close agreement in ecosystems that experience large fires, including savannas across southern Africa and Australia and boreal forests in North America and Eurasia. In other areas, however, we observed many active fires outside of burned area perimeters. Fire radiative power was lower for this class of active fires. Small fires substantially increased burned area in several continental-scale regions, including Equatorial Asia (157%), Central America (143%), and Southeast Asia (90%) during 2001-2010. Globally, accounting for small fires increased total burned area by approximately by 35%, from 345 Mha/yr to 464 Mha/yr. A formal quantification of uncertainties was not possible, but sensitivity

  4. Global Burned Area and Biomass Burning Emissions from Small Fires

    NASA Technical Reports Server (NTRS)

    Randerson, J. T.; Chen, Y.; vanderWerf, G. R.; Rogers, B. M.; Morton, D. C.

    2012-01-01

    In several biomes, including croplands, wooded savannas, and tropical forests, many small fires occur each year that are well below the detection limit of the current generation of global burned area products derived from moderate resolution surface reflectance imagery. Although these fires often generate thermal anomalies that can be detected by satellites, their contributions to burned area and carbon fluxes have not been systematically quantified across different regions and continents. Here we developed a preliminary method for combining 1-km thermal anomalies (active fires) and 500 m burned area observations from the Moderate Resolution Imaging Spectroradiometer (MODIS) to estimate the influence of these fires. In our approach, we calculated the number of active fires inside and outside of 500 m burn scars derived from reflectance data. We estimated small fire burned area by computing the difference normalized burn ratio (dNBR) for these two sets of active fires and then combining these observations with other information. In a final step, we used the Global Fire Emissions Database version 3 (GFED3) biogeochemical model to estimate the impact of these fires on biomass burning emissions. We found that the spatial distribution of active fires and 500 m burned areas were in close agreement in ecosystems that experience large fires, including savannas across southern Africa and Australia and boreal forests in North America and Eurasia. In other areas, however, we observed many active fires outside of burned area perimeters. Fire radiative power was lower for this class of active fires. Small fires substantially increased burned area in several continental-scale regions, including Equatorial Asia (157%), Central America (143%), and Southeast Asia (90%) during 2001-2010. Globally, accounting for small fires increased total burned area by approximately by 35%, from 345 Mha/yr to 464 Mha/yr. A formal quantification of uncertainties was not possible, but sensitivity

  5. Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS

    SciTech Connect

    Perkasa, Y. S.; Waris, A. Kurniadi, R. Su'ud, Z.

    2014-09-30

    Comparative studies of actinide and sub-actinide fission cross section calculation from MCNP6 and TALYS have been conducted. In this work, fission cross section resulted from MCNP6 prediction will be compared with result from TALYS calculation. MCNP6 with its event generator CEM03.03 and LAQGSM03.03 have been validated and verified for several intermediate and heavy nuclides fission reaction data and also has a good agreement with experimental data for fission reaction that induced by photons, pions, and nucleons at energy from several ten of MeV to about 1 TeV. The calculation that induced within TALYS will be focused mainly to several hundred MeV for actinide and sub-actinide nuclides and will be compared with MCNP6 code and several experimental data from other evaluator.

  6. Oral Rehydration Therapy in Burn Patients

    ClinicalTrials.gov

    2014-04-24

    Burn Any Degree Involving 20-29 Percent of Body Surface; Burn Any Degree Involving 30-39 Percent of Body Surface; Burn Any Degree Involving 40-49 Percent of Body Surface; Burn Any Degree Involving 50-59 Percent of Body Surface; Burn Any Degree Involving 60-65 Percent of Body Surface

  7. A rare complication of radiofrequency ablation: skin burn.

    PubMed

    Ertuğrul, İlker; Karagöz, Tevfik; Aykan, Hayrettin H

    2015-10-01

    Radiofrequency ablation is the first-line treatment for arrhythmias with high success and low complication rates. Skin burns have been reported rarely after electrophysiological procedures, especially procedures in which higher-power energy is used and multiple ablations are performed. Here, we report a case of skin burn that developed after radiofrequency ablation for ventricular tachycardia originating from the right ventricular outflow tract. PMID:25613639

  8. Burning of CP Titanium (Grade 2) in Oxygen-Enriched Atmospheres

    NASA Technical Reports Server (NTRS)

    Stoltzfus, Joel M.; Jeffers, Nathan; Gallus, Timothy D.

    2012-01-01

    The flammability in oxygen-enriched atmospheres of commercially pure (CP) titanium rods as a function of diameter and test gas pressure was determined. Test samples of varying diameters were ignited at the bottom and burned upward in 70% O2/balance N2 and in 99.5+% O2 at various pressures. The burning rate of each ignited sample was determined by observing the apparent regression rate of the melting interface (RRMI) of the burning samples. The burning rate or RRMI increased with decreasing test sample diameter and with increasing test gas pressure and oxygen concentration

  9. Total intravenous anesthesia for major burn surgery

    PubMed Central

    Cancio, Leopoldo C; Cuenca, Phillip B; Walker, Stephen C; Shepherd, John M

    2013-01-01

    Total intravenous anesthesia (TIVA) is frequently used for major operations requiring general anesthesia in critically ill burn patients. We reviewed our experience with this approach. Methods: During a 22-month period, 547 major burn surgeries were performed in this center’s operating room and were staffed by full-time burn anesthesiologists. The records of all 123 TIVA cases were reviewed; 112 records were complete and were included. For comparison, 75 cases were selected at random from a total of 414 non-TIVA general anesthetics. Some patients had more than one operation during the study: as appropriate for the analysis in question, each operation or each patient was entered as an individual case. For inter-patient analysis, exposure to 1 or more TIVAs was used to categorize a patient as member of the TIVA group. Results: Excision and grafting comprised 78.2% of the operations. 14 TIVA regimens were used, employing combinations of 4 i.v. drugs: ketamine (K, 91 cases); i.v. methadone (M, 62); fentanyl (F, 58); and propofol (P, 21). The most common regimens were KM (34 cases); KF (26); KMF (16); and K alone (8). Doses used often exceeded those used in non-burn patients. TIVA was preferred for those patients who were more critically ill prior to surgery, with a higher ASA score (3.87 vs. 3.11). Consistent with this, inhalation injury (26.7 vs. 1.6%), burn size (TBSA, 36.3 vs. 15.8%), and full-thickness burn size (FULL, 19.8 vs. 6.5%) were higher in TIVA than in non-TIVA patients. Despite this, intraoperative pressor use was as common in TIVA as in non-TIVA cases (23.9 vs. 22.7%). Conclusions: TIVA was used in patients whose inhalation injury rate and TBSA were greater than those of non-TIVA patients. TIVA cases were not associated with increased hemodynamic instability. TIVA is a viable approach to general anesthesia in critically ill burn patients. PMID:23638329

  10. CORE ANALYSIS, DESIGN AND OPTIMIZATION OF A DEEP-BURN PEBBLE BED REACTOR

    SciTech Connect

    B. Boer; A. M. Ougouag

    2010-05-01

    Achieving a high burnup in the Deep-Burn pebble bed reactor design, while remaining within the limits for fuel temperature, power peaking and temperature reactivity feedback, is challenging. The high content of Pu and Minor Actinides in the Deep-Burn fuel significantly impacts the thermal neutron energy spectrum. This can result in power and temperature peaking in the pebble bed core in locally thermalized regions near the graphite reflectors. Furthermore, the interplay of the Pu resonances of the neutron absorption cross sections at low-lying energies can lead to a positive temperature reactivity coefficient for the graphite moderator at certain operating conditions. To investigate the aforementioned effects a code system using existing codes has been developed for neutronic, thermal-hydraulic and fuel depletion analysis of Deep-Burn pebble bed reactors. A core analysis of a Deep-Burn Pebble Bed Modular Reactor (400 MWth) design has been performed for two Deep-Burn fuel types and possible improvements of the design with regard to power peaking and temperature reactivity feedback are identified.

  11. Burning crude oil without pollution

    NASA Technical Reports Server (NTRS)

    Houseman, J.

    1979-01-01

    Crude oil can be burned at drilling sites by two-stage combustion process without producing pollution. Process allows easier conformance to strict federal or state clean air standards without installation of costly pollution removal equipment. Secondary oil recovery can be accomplished with injection of steam heating by burning oil.

  12. Animal models in burn research.

    PubMed

    Abdullahi, A; Amini-Nik, S; Jeschke, M G

    2014-09-01

    Burn injury is a severe form of trauma affecting more than 2 million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury, to elucidate the pathophysiology, and to explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research. PMID:24714880

  13. Animal Models in Burn Research

    PubMed Central

    Abdullahi, A.; Amini-Nik, S.; Jeschke, M.G

    2014-01-01

    Burn injury is a severe form of trauma affecting more than two million people in North America each year. Burn trauma is not a single pathophysiological event but a devastating injury that causes structural and functional deficits in numerous organ systems. Due to its complexity and the involvement of multiple organs, in vitro experiments cannot capture this complexity nor address the pathophysiology. In the past two decades, a number of burn animal models have been developed to replicate the various aspects of burn injury; to elucidate the pathophysiology and explore potential treatment interventions. Understanding the advantages and limitations of these animal models is essential for the design and development of treatments that are clinically relevant to humans. This review paper aims to highlight the common animal models of burn injury in order to provide investigators with a better understanding of the benefits and limitations of these models for translational applications. While many animal models of burn exist, we limit our discussion to the skin healing of mouse, rat, and pig. Additionally, we briefly explain hypermetabolic characteristics of burn injury and the animal model utilized to study this phenomena. Finally, we discuss the economic costs associated with each of these models in order to guide decisions of choosing the appropriate animal model for burn research. PMID:24714880

  14. Aztreonam pharmacokinetics in burn patients.

    PubMed Central

    Friedrich, L V; White, R L; Kays, M B; Brundage, D M; Yarbrough, D

    1991-01-01

    The pharmacokinetics of aztreonam in eight adult patients with severe burn injuries (total body surface area burn, 49% +/- 21% [mean +/- standard deviation]) were studied. The time of initiation of study following burn injury was 7.0 +/- 1.4 days. Four patients at first dose and at steady state were studied. Aztreonam concentrations were measured by high-performance liquid chromatography, and a two-compartment model was used to fit the data. No significant differences in any pharmacokinetic parameters between first dose and steady state were observed. Volume of distribution of the central compartment after first dose (0.14 liters/kg) and volume of distribution at steady state (0.31 liters/kg) were approximately 30% higher than those reported for other patient populations. Total drug clearance and renal drug clearance when normalized to creatinine clearance (CLCR) were similar to those previously reported for other critically ill patients. CLCR was strongly correlated with renal drug clearance (r = 0.94) and total drug clearance (r = 0.95). The extent and degree of burn (percent second or third degree burn) were poorly correlated with all pharmacokinetic parameters with the exception of the volume of distribution at steady state, which was correlated with both total body surface area burn (r = 0.95) and percent second degree burn (r = 0.83). Aztreonam pharmacokinetics are altered as a result of thermal injury; however, CLCR can be used to assess the clearance of aztreonam in burn patients. PMID:2014982

  15. A Heterogeneous Sodium Fast Reactor Designed to Transmute Minor Actinide Actinide Waste Isotopes into Plutonium Fuel

    SciTech Connect

    Samuel E. Bays

    2011-02-01

    An axial heterogeneous sodium fast reactor design is developed for converting minor actinide waste isotopes into plutonium fuel. The reactor design incorporates zirconium hydride moderating rods in an axial blanket above the active core. The blanket design traps the active core’s axial leakage for the purpose of transmuting Am-241 into Pu-238. This Pu-238 is then co-recycled with the spent driver fuel to make new driver fuel. Because Pu-238 is significantly more fissile than Am-241 in a fast neutron spectrum, the fissile worth of the initial minor actinide material is upgraded by its preconditioning via transmutation in the axial targets. Because, the Am-241 neutron capture worth is significantly stronger in a moderated epithermal spectrum than the fast spectrum, the axial targets serve as a neutron trap which recovers the axial leakage lost by the active core. The sodium fast reactor proposed by this work is designed as an overall transuranic burner. Therefore, a low transuranic conversion ratio is achieved by a degree of core flattening which increases axial leakage. Unlike a traditional “pancake” design, neutron leakage is recovered by the axial target/blanket system. This heterogeneous core design is constrained to have sodium void and Doppler reactivity worth similar to that of an equivalent homogeneous design. Because minor actinides are irradiated only once in the axial target region; elemental partitioning is not required. This fact enables the use of metal targets with electrochemical reprocessing. Therefore, the irradiation environment of both drivers and targets was constrained to ensure applicability of the established experience database for metal alloy sodium fast reactor fuels.

  16. 30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 30 Mineral Resources 3 2013-07-01 2013-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted...

  17. 30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 30 Mineral Resources 3 2014-07-01 2014-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted...

  18. 30 CFR 816.87 - Coal mine waste: Burning and burned waste utilization.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 3 2010-07-01 2010-07-01 false Coal mine waste: Burning and burned waste...-SURFACE MINING ACTIVITIES § 816.87 Coal mine waste: Burning and burned waste utilization. (a) Coal mine... extinguishing operations. (b) No burning or burned coal mine waste shall be removed from a permitted...

  19. Smartphones and burn size estimation: "Rapid Burn Assessor".

    PubMed

    Kamolz, L P; Lumenta, D B; Parvizi, D; Dirnberger, J; Owen, R; Höller, J; Giretzlehner, M

    2014-06-30

    Estimation of the total body surface area burned (%TBSA) following a burn injury is used in determining whether to transfer the patient to a burn center and the required fluid resuscitation volumes. Unfortunately, the commonly applied methods of estimation have revealed inaccuracies, which are mostly related to human error. To calculate the %TBSA (quotient), it is necessary to divide the burned surface area (Burned BSA) (numerator in cm2) by the total body surface area (Total BSA) (denominator in cm2). By using everyday objects (eg. credit cards, smartphones) with well-defined surface areas as reference for estimations of Burned BSA on the one hand and established formulas for Total BSA calculation on the other (eg. Mosteller), we propose an approximation method to assess %TBSA more accurately than the established methods. To facilitate distribution, and respective user feedback, we have developed a smartphone app integrating all of the above parameters, available on popular mobile device platforms. This method represents a simple and ready-to-use clinical decision support system which addresses common errors associated with estimations of Burned BSA (=numerator). Following validation and respective user feedback, it could be deployed for testing in future clinical trials. This study has a level of evidence of IV and is a brief report based on clinical observation, which points to further study. PMID:26170784

  20. Paediatric suicidal burns: A growing concern.

    PubMed

    Segu, Smitha; Tataria, Rachana

    2016-06-01

    An alarming rise in rates of paediatric population committing self-immolation acts is a growing social and medical problem. In recent times there seems to be a rising concern in paediatric population. A study was conducted at a government tertiary care burn centre over 5 years in paediatric age group of <18 years who had committed self-immolation. Demographic data, aetiology, burn severity, associated illnesses, treatment and outcomes of the patients were collected with preventive strategies. Of total 89 patients, 12 patients were below 12 years (children) and 77 between 12-18 years (adolescent) with female preponderance. Majority belonged to lower middle and upper lower class families. Most had deep partial thickness burns. Psychiatric and personality disorder were found in 24.03% and 31.46% patients respectively. Kerosene was the main agent chosen to inflict injury. The average length of hospital stay was 19.8 days. The crude mortality rate observed was 38.2%. With cultural and socio-economic changes children and adolescents are exposed to increased levels of stress and peer pressure leaving them vulnerable. A multidisciplinary care involving medical, psychological and social support is required. Identifying children at risk and proper counselling and support can form an important strategy at prevention rather than cure. PMID:26803366