WorldWideScience

Sample records for actinides combined estimation

  1. Subsurface Biogeochemistry of Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Kersting, Annie B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Univ. Relations and Science Education; Zavarin, Mavrik [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Glenn T. Seaborg Inst.

    2016-06-29

    A major scientific challenge in environmental sciences is to identify the dominant processes controlling actinide transport in the environment. It is estimated that currently, over 2200 metric tons of plutonium (Pu) have been deposited in the subsurface worldwide, a number that increases yearly with additional spent nuclear fuel (Ewing et al., 2010). Plutonium has been shown to migrate on the scale of kilometers, giving way to a critical concern that the fundamental biogeochemical processes that control its behavior in the subsurface are not well understood (Kersting et al., 1999; Novikov et al., 2006; Santschi et al., 2002). Neptunium (Np) is less prevalent in the environment; however, it is predicted to be a significant long-term dose contributor in high-level nuclear waste. Our focus on Np chemistry in this Science Plan is intended to help formulate a better understanding of Pu redox transformations in the environment and clarify the differences between the two long-lived actinides. The research approach of our Science Plan combines (1) Fundamental Mechanistic Studies that identify and quantify biogeochemical processes that control actinide behavior in solution and on solids, (2) Field Integration Studies that investigate the transport characteristics of Pu and test our conceptual understanding of actinide transport, and (3) Actinide Research Capabilities that allow us to achieve the objectives of this Scientific Focus Area (SFA and provide new opportunities for advancing actinide environmental chemistry. These three Research Thrusts form the basis of our SFA Science Program (Figure 1).

  2. Actinide chemistry using singlet-paired coupled cluster and its combinations with density functionals

    CERN Document Server

    Garza, Alejandro J; Scuseria, Gustavo E

    2015-01-01

    Singlet-paired coupled cluster doubles (CCD0) is a simplification of CCD that relinquishes a fraction of dynamic correlation in order to be able to describe static correlation. Combinations of CCD0 with density functionals that recover specifically the dynamic correlation missing in the former have also been developed recently. Here, we assess the accuracy of CCD0 and CCD0+DFT (and variants of these using Brueckner orbitals) as compared to well-established quantum chemical methods for describing ground-state properties of singlet actinide molecules. The $f^0$ actinyl series (UO$_2^{2+}$, NpO$_2^{2+}$, PuO$_2^{2+}$), the isoelectronic NUN, and Thorium (ThO, ThO$^{2+}$) and Nobelium (NoO, NoO$_2$) oxides are studied.

  3. Actinides-1981

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Feasibility of actinide separation from UREX-like raffinates using a combination of sulfur- and oxygen-donor extractants

    Energy Technology Data Exchange (ETDEWEB)

    Peter R. Zalupski; Dean R. Peterman; Catherine L. Riddle

    2013-09-01

    A synergistic combination of bis(o-trifluoromethylphenyl)dithiosphosphinic acid and trioctylphosphine oxide has been recently shown to selectively remove uranium, neptunium, plutonium and americium from aqueous environment containing up to 0.5 M nitric acid and 5.5 g/L fission products. Here the feasibility of performing this complete actinide recovery from aqueous mixtures is forecasted for a new organic formulation containing sulfur donor extractant of modified structure based on Am(III) and Eu(III) extraction data. A mixture of bis(bis-m,m-trifluoromethyl)phenyl)-dithiosphosphinic acid and TOPO in toluene enhances the extraction performance, accomplishing Am/Eu differentiation in aqueous mixtures up to 1 M nitric acid. The new organic recipe is also less susceptible to oxidative damage resulting from radiolysis.

  5. Chemistry of actinides; Chimie des actinides

    Energy Technology Data Exchange (ETDEWEB)

    Vitorge, P. [CEA/Saclay, Dept. d' Entreposage et de Stockage des Dechets (DESD), 91 - Gif-sur-Yvette (France)

    1999-07-01

    This article gives the basic data of the actinides chemistry, describes then qualitatively the main parts of the fuel cycle and concludes with quantitative data. The theoretical recalls give qualitative notions to explain the chemical reactivity of actinides and to understand thus the values of the thermodynamic data which allow quantitative anticipations at equilibrium. The Thermodynamic Data Base (TDB) of the NEA-OECD and the CEA in France have recently estimated some of them in using and developing methodologies whose some are presented here. Some current problems of actinides chemistry are described: analysis of the possibilities to (1)improve the reprocessing of long-lived actinides (2)anticipate their behaviour in the environment in order to compare the impact of the different options of the wastes management. The Pourbaix diagrams summarize the chemistry in solution; the author has added information on the solubility, the influence of the ionic strength and of the complexes formation in bicarbonate/carbonate (HCO{sub 3}{sup -}/CO{sub 3}{sup 2-}) media. The discussion on the choice of the equilibrium constants allows to point out the particular points, the dubiousness and the data which have to be proved. (O.M.)

  6. A Shrinkage Estimator for Combination of Bioassays

    Institute of Scientific and Technical Information of China (English)

    Jian Xiong; D.G. Chen; Zhen-hai Yang

    2007-01-01

    A shrinkage estimator and a maximum likelihood estimator are proposed in this paper for combination of bioassays. The shrinkage estimator is obtained in closed form which incorporates prior information just on the common log relative potency after the homogeneity test for combination of bioassays is accepted. It is a practical improvement over other estimators which require iterative procedure to obtain the estimator for the relative potency. A real data is also used to show the superiorities for the newly-proposed procedures.

  7. A Bayesian Framework for Combining Valuation Estimates

    CERN Document Server

    Yee, Kenton K

    2007-01-01

    Obtaining more accurate equity value estimates is the starting point for stock selection, value-based indexing in a noisy market, and beating benchmark indices through tactical style rotation. Unfortunately, discounted cash flow, method of comparables, and fundamental analysis typically yield discrepant valuation estimates. Moreover, the valuation estimates typically disagree with market price. Can one form a superior valuation estimate by averaging over the individual estimates, including market price? This article suggests a Bayesian framework for combining two or more estimates into a superior valuation estimate. The framework justifies the common practice of averaging over several estimates to arrive at a final point estimate.

  8. Estimation of combined sewer overflow discharge

    DEFF Research Database (Denmark)

    Ahm, Malte; Thorndahl, Søren Liedtke; Nielsen, Jesper Ellerbæk;

    2016-01-01

    Combined sewer overflow (CSO) structures are constructed to effectively discharge excess water during heavy rainfall, to protect the urban drainage system from hydraulic overload. Consequently, most CSO structures are not constructed according to basic hydraulic principles for ideal measurement...... weirs. It can, therefore, be a challenge to quantify the discharges from CSOs. Quantification of CSO discharges are important in relation to the increased environmental awareness of the receiving water bodies. Furthermore, CSO discharge quantification is essential for closing the rainfall-runoff mass......-balance in combined sewer catchments. A closed mass-balance is an advantage for calibration of all urban drainage models based on mass-balance principles. This study presents three different software sensor concepts based on local water level sensors, which can be used to estimate CSO discharge volumes from hydraulic...

  9. The Actinide Transition Revisited by Gutzwiller Approximation

    Science.gov (United States)

    Xu, Wenhu; Lanata, Nicola; Yao, Yongxin; Kotliar, Gabriel

    2015-03-01

    We revisit the problem of the actinide transition using the Gutzwiller approximation (GA) in combination with the local density approximation (LDA). In particular, we compute the equilibrium volumes of the actinide series and reproduce the abrupt change of density found experimentally near plutonium as a function of the atomic number. We discuss how this behavior relates with the electron correlations in the 5 f states, the lattice structure, and the spin-orbit interaction. Our results are in good agreement with the experiments.

  10. Preparation, properties, and some recent studies of the actinide metals

    Energy Technology Data Exchange (ETDEWEB)

    Haire, R.G.

    1985-01-01

    The actinide elements form a unique series of metals. The variation in their physial properties combined with the varying availability of the different elements offers a challenge to the preparative scientist. This article provides a brief review of selected methods used for preparing ..mu..g to kg amounts of the actinide metals and the properties of these metals. In addition, some recent studies on selected actinide metals are discussed. 62 refs.

  11. Actinides: How well do we know their stellar production?

    Science.gov (United States)

    Goriely, S.; Arnould, M.

    2001-12-01

    The reliable evaluation of the r-process production of the actinides and careful estimates of the uncertainties affecting these predictions are key ingredients especially in nucleo-cosmochronology studies based on the analysis of very metal-poor stars or on the composition of meteorites. This type of information is also required in order to make the best possible use of future high precision data on the actinide composition of galactic cosmic rays, of the local interstellar medium, or of meteoritic grains of presumed circumstellar origin. This paper provides the practitioners in these various fields with the most detailed and careful analysis of the r-process actinide production available to-date. This study is based on a version of the multi-event canonical model of the r-process which discards the largely used waiting point approximation. It considers also different combinations of models for the calculation of nuclear masses, beta -decay and fission rates. Two variants of the model used to predict nuclear reaction rates are adopted. In addition, the influence of the level of Pb and Bi production by the r-process on the estimated actinide production is evaluated by relying on the solar abundances of these two elements. In total, thirty-two different cases are presented, and are considered to give a fair picture of the level of reliability of the predictions of the actinide production, at least in the framework of a simple r-process model. This simplicity is imposed by our inability to identify the proper astrophysical sites for the r-process. As a guide to the practitioners, constraints on the actinide yield predictions and associated uncertainties are suggested on grounds of the measured abundances of r-nuclides, including Th and U, in the star CS 31082-001, and under the critical and questionable assumption of the ``universality'' of the r-process. We also define alternative constraints based on the nucleo-cosmochronological results derived from the present

  12. PREFACE: Actinides 2009

    Science.gov (United States)

    Rao, Linfeng; Tobin, James G.; Shuh, David K.

    2010-07-01

    This volume of IOP Conference Series: Materials Science and Engineering consists of 98 papers that were presented at Actinides 2009, the 8th International Conference on Actinide Science held on 12-17 July 2009 in San Francisco, California, USA. This conference was jointly organized by Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory. The Actinides conference series started in Baden-Baden, Germany (1975) and this first conference was followed by meetings at Asilomar, CA, USA (1981), Aix-en-Provence, France (1985), Tashkent, USSR (1989), Santa Fe, NM, USA (1993), Baden-Baden, Germany (1997), Hayama, Japan (2001), and Manchester, UK (2005). The Actinides conference series provides a regular venue for the most recent research results on the chemistry, physics, and technology of the actinides and heaviest elements. Actinides 2009 provided a forum spanning a diverse range of scientific topics, including fundamental materials science, chemistry, physics, environmental science, and nuclear fuels. Of particular importance was a focus on the key roles that basic actinide chemistry and physics research play in advancing the worldwide renaissance of nuclear energy. Editors Linfeng Rao Lawrence Berkeley National Laboratory (lrao@lbl.gov) James G Tobin Lawrence Livermore National Laboratory (tobin1@llnl.gov) David K Shuh Lawrence Berkeley National Laboratory (dkshuh@lbl.gov)

  13. TUCS/phosphate mineralization of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L. [Argonne National Lab., IL (United States)

    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.

  14. Actinides and Life's Origins.

    Science.gov (United States)

    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

  15. Distribution of actinides in SFR1; Aktinidfoerdelning i SFR1

    Energy Technology Data Exchange (ETDEWEB)

    Ingemansson, Tor [ALARA Engineering, Skultuna (Sweden)

    2000-02-01

    The amount of actinides in the Swedish repository for intermediate level radioactive wastes has been estimated. The sources for the actinides are mainly the purification filters of the reactors and the used fuel pools. Defect fuel elements are the originating source of the actinides. It is estimated that the 12 Swedish reactors, in total, have had 2.2 kg of fuel dissolved in their systems since start-up. About 880 g of this amount has been brought to the intermediate-level repository.

  16. On the combination of correlated estimates of a physics observable

    Energy Technology Data Exchange (ETDEWEB)

    Nisius, Richard [Max-Planck-Institut fuer Physik (Werner-Heisenberg-Institut), Muenchen (Germany)

    2014-08-15

    The combination of a number of correlated estimates of a given observable is frequently performed using the Best Linear Unbiased Estimate (BLUE) method. Most features of such a combination can already be seen by analysing the special case of a pair of estimates from two correlated estimators of the observable. Two important parameters of this combination are the weight of the less precise estimate and the ratio of uncertainties of the combined result and the more precise estimate. Derivatives of these quantities are derived with respect to the correlation and the ratio of uncertainties of the two estimates. The impact of using either absolute or relative uncertainties in the BLUEcombination is investigated on a number of examples including Peelle's Pertinent Puzzle. Using an example, a critical assessment is performed of suggested methods to deal with the fact that both the correlation and the ratio of uncertainties of a pair of estimates are typically only known with some uncertainty. Finally, a proposal is made to decide on the usefulness of a combination and to perform it. The proposal is based on possible improvements with respect to the most precise estimate by including additional estimates. This procedure can be applied to the general case of several observables. (orig.)

  17. Bias estimates used in lieu of validation of fission products and minor actinides in MCNP Keff calculations for PWR burnup credit casks

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, Don [ORNL; Marshall, William BJ J [ORNL; Wagner, John C [ORNL; Bowen, Douglas G [ORNL

    2015-09-01

    The U.S. Nuclear Regulatory Commission (NRC) Division of Spent Fuel Storage and Transportation recently issued Interim Staff Guidance (ISG) 8, Revision 3. This ISG provides guidance for burnup credit (BUC) analyses supporting transport and storage of PWR pressurized water reactor (PWR) fuel in casks. Revision 3 includes guidance for addressing validation of criticality (keff) calculations crediting the presence of a limited set of fission products and minor actinides (FP&MA). Based on previous work documented in NUREG/CR-7109, recommendation 4 of ISG-8, Rev. 3, includes a recommendation to use 1.5 or 3% of the FP&MA worth to conservatively cover the bias due to the specified FP&MAs. This bias is supplementary to the bias and bias uncertainty resulting from validation of keff calculations for the major actinides in SNF and does not address extension to actinides and fission products beyond those identified herein. The work described in this report involves comparison of FP&MA worths calculated using SCALE and MCNP with ENDF/B-V, -VI, and -VII based nuclear data and supports use of the 1.5% FP&MA worth bias when either SCALE or MCNP codes are used for criticality calculations, provided the other conditions of the recommendation 4 are met. The method used in this report may also be applied to demonstrate the applicability of the 1.5% FP&MA worth bias to other codes using ENDF/B V, VI or VII based nuclear data. The method involves use of the applicant s computational method to generate FP&MA worths for a reference SNF cask model using specified spent fuel compositions. The applicant s FP&MA worths are then compared to reference values provided in this report. The applicants FP&MA worths should not exceed the reference results by more than 1.5% of the reference FP&MA worths.

  18. Device for Detecting Actinides, Method for Detecting Actinides

    Energy Technology Data Exchange (ETDEWEB)

    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. Density estimation in tiger populations: combining information for strong inference

    Science.gov (United States)

    Gopalaswamy, Arjun M.; Royle, J. Andrew; Delampady, Mohan; Nichols, James D.; Karanth, K. Ullas; Macdonald, David W.

    2012-01-01

    A productive way forward in studies of animal populations is to efficiently make use of all the information available, either as raw data or as published sources, on critical parameters of interest. In this study, we demonstrate two approaches to the use of multiple sources of information on a parameter of fundamental interest to ecologists: animal density. The first approach produces estimates simultaneously from two different sources of data. The second approach was developed for situations in which initial data collection and analysis are followed up by subsequent data collection and prior knowledge is updated with new data using a stepwise process. Both approaches are used to estimate density of a rare and elusive predator, the tiger, by combining photographic and fecal DNA spatial capture–recapture data. The model, which combined information, provided the most precise estimate of density (8.5 ± 1.95 tigers/100 km2 [posterior mean ± SD]) relative to a model that utilized only one data source (photographic, 12.02 ± 3.02 tigers/100 km2 and fecal DNA, 6.65 ± 2.37 tigers/100 km2). Our study demonstrates that, by accounting for multiple sources of available information, estimates of animal density can be significantly improved.

  20. Combinations of Estimation of Distribution Algorithms and Other Techniques

    Institute of Scientific and Technical Information of China (English)

    Qingfu Zhang; Jianyong Sun; Edward Tsang

    2007-01-01

    This paper summaries our recent work on combining estimation of distribution algorithms (EDA) and other techniques for solving hard search and optimization problems: a) guided mutation, an offspring generator in which the ideas from EDAs and genetic algorithms are combined together, we have shown that an evolutionary algorithm with guided mutation outperforms the best GA for the maximum clique problem, b) evolutionary algorithms refining a heuristic, we advocate a strategy for solving a hard optimization problem with complicated data structure, and c) combination of two different local search techniques and EDA for numerical global optimization problems, its basic idea is that not all the new generated points are needed to be improved by an expensive local search.

  1. Actinides in irradiated graphite of RBMK-1500 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Plukienė, R., E-mail: rita@ar.fi.lt; Plukis, A.; Barkauskas, V.; Gudelis, A.; Gvozdaitė, R.; Duškesas, G.; Remeikis, V.

    2014-10-01

    Highlights: • Activation of actinides in the graphite of the RBMK-1500 reactor was analyzed. • Numerical modeling using SCALE 6.1 and MCNPX was used for actinide calculation. • Measurements of the irradiated graphite sample were used for model validation. • Results are important for further decommissioning process of the RBMK type reactors. - Abstract: The activation of graphite in the nuclear power plants is the problem of high importance related with later graphite reprocessing or disposal. The activation of actinide impurities in graphite due to their toxicity determines a particular long term risk to waste management. In this work the activation of actinides in the graphite constructions of the RBMK-1500 reactor is determined by nuclear spectrometry measurements of the irradiated graphite sample from the Ignalina NPP Unit I and by means of numerical modeling using two independent codes SCALE 6.1 (using TRITON-VI sequence) and MCNPX (v2.7 with CINDER). Both models take into account the 3D RBMK-1500 reactor core fragment with explicit graphite construction including a stack and a sleeve but with a different simplification level concerning surrounding graphite and construction of control roads. The verification of the model has been performed by comparing calculated and measured isotope ratios of actinides. Also good prediction capabilities of the actinide activation in the irradiated graphite have been found for both calculation approaches. The initial U impurity concentration in the graphite model has been adjusted taking into account the experimental results. The specific activities of actinides in the irradiated RBMK-1500 graphite constructions have been obtained and differences between numerical simulation results, different structural parts (sleeve and stack) as well as comparison with previous results (Ancius et al., 2005) have been discussed. The obtained results are important for further decommissioning process of the Ignalina NPP and other RBMK

  2. Selective extraction of trivalent actinides from lanthanides with dithiophosphinic acids and tributylphosphate

    Energy Technology Data Exchange (ETDEWEB)

    Jarvinen, G.; Barrans, R.; Schroeder, N.; Wade, K.; Jones, M.; Smith, B.F. [Los Alamos National Lab., NM (United States); Mills, J.; Howard, G. [Texas Tech Univ., Lubbock, TX (United States); Freiser, H.; Muralidharan, S. [Arizona Univ., Tucson, AZ (United States)

    1995-01-01

    A variety of chemical systems have been developed to separate trivalent actinides from lanthanides based on the slightly stronger complexation of the trivalent actinides with ligands that contain soft donor atoms. The greater stability of the actinide complexes in these systems has often been attributed to a slightly greater covalent bonding component for the actinide ions relative to the lanthanide ions. The authors have investigated several synergistic extraction systems that use ligands with a combination of oxygen and sulfur donor atoms that achieve a good group separation of the trivalent actinides and lanthanides. For example, the combination of dicyclohexyldithiophosphinic acid and tributylphosphate has shown separation factors of up to 800 for americium over europium in a single extraction stage. Such systems could find application in advanced partitioning schemes for nuclear waste.

  3. Potential radiation dose from eating fish exposed to actinide contamination

    Energy Technology Data Exchange (ETDEWEB)

    Emery, R.M.; Klopfer, D.C.; Baker, D.A.; Soldat, J.K.

    1980-01-01

    The purpose of this work is to establish a maximum potential for transporting actinides to man via fish consumption. The study took place in U-Pond, a nuclear waste pond on the Hanford Site. It has concentrations of /sup 238/U, /sup 238/Pu, /sup 239,240/Pu and /sup 241/Am that are approximately three orders of magnitude greater than background levels. Fish living in the pond contain higher actinide concentrations than those observed in fish from any other location. Experiments were performed in U-pond to determine maximum quantities of actinides that could accumulate in fillets and whole bodies of two centrarchid fish species. Doses to hypothetical consumers were then estimated by assuming that actinide behavior in their bodies was similar to that defined for Standard Man by the International Commission on Radiological Protection. Results indicate that highest concentrations occurring in bluegill or bass muscle after more than a year's exposure to the pond would not be sufficient to produce a significant radiation dose to a human consumer, even if he ate 0.5 kg (approx.1 lb) of these fillets every day for 70 years. Natural predators (heron or coyote), having lifetime diets of whole fish from U-Pond, would receive less radiation dose from the ingested actinides than from natural background sources. 34 refs., 5 figs., 4 tabs.

  4. Production of heavy actinides in incomplete fusion reactions

    Science.gov (United States)

    Antonenko, N. V.; Cherepanov, E. A.; Iljinov, A. S.; Mebel, M. V.

    1994-10-01

    We present preliminary results of calculations by the phenomenological model of the estimated yield of some heavy actinide isotopes. It is assumed that these isotopes are produced as a result of multinucleon transfers followed by neutrons and charged particle emission A.S. Iljinov and E.A. Cherepanov (1980). The yield P(sub Z, N)(E*) of primary excited actinides is found using the model of N.V. Antonenko and R.V. Jolos (1991). Absolute cross-sections for different binary reaction channels are obtained by summing the cross-sections for all subchannels with an appreciable yield according to J. Wilczynski et al. (1980).

  5. Recovery and chemical purification of actinides at JRC, Karlsruhe

    Science.gov (United States)

    Bokelund, H.; Apostolidis, C.; Glatz, J.-P.

    1989-07-01

    The application of actinide elements in research and in technology is many times subject to rather stringent purity requirements; often a nuclear grade quality is specified. The additional possible demand for a high isotopic purity is a special feature in the handling of these elements. The amount of actinide elements contained in or adhering to materials declared as waste should be low for safety reasons and out of economic considerations. The release of transuranium elements to the environment must be kept negligible. For these and for other reasons a keen interest in the separation of actinides from various materials exists, either for a re-use through recycling, or for their safe confinement in waste packages. This paper gives a short review of the separation methods used for recovery and purification of actinide elements over the past years in the European Institute for Transuranium Elements. The methods described here involve procedures based on precipitation, ion exchange or solvent extraction; often used in a combination. The extraction methods were preferably applied in a Chromatographie column mode. The actinide elements purified and/or separated from each other by the above methods include uranium, neptunium, plutonium, americium, curium, and californium. For the various elements the work was undertaken with different aims, ranging from reprocessing and fabrication of nuclear fuels on a kilogramme scale, over the procurement of alpha-free waste, to the preparation of neutron sources of milligramme size.

  6. Advanced Aqueous Separation Systems for Actinide Partitioning

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Ken [Washington State Univ., Pullman, WA (United States); Martin, Leigh [Idaho National Lab. (INL), Idaho Falls, ID (United States); Lumetta, Gregg [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-04-02

    necessary for commercial fuel processing supporting transmutation of transplutonium elements. This research project continued basic themes investigated by this research group during the past decade. In the Fuel Cycle Research and Development program at DOE, the current favorite process for accomplishing the separation of trivalent actinides from fission product lanthanides is the TALSPEAK process. TALSPEAK is a solvent extraction method (developed at Oak Ridge National Lab in the 1960s) based on the combination of a cation exchanging extractant (e.g., HDEHP), an actinide-selective aminopolycarboxylate complexing agent (e.g., DTPA), and a carboxylic acid buffer to control pH in the range of 3-4. Considerable effort has been expended in this research group during the past 8 years to elaborate the details of TALSPEAK in the interest of developing improved approaches to the operation of TALSPEAK-like systems. In this project we focused on defining aggregation phenomena in conventional TALSPEAK separations, on supporting the development of Advanced TALSPEAK processes, on profiling the aqueous complexation kinetics of lanthanides in TALSPEAK relevant aqueous media, on the design of new diglycolamide and N-donor extractants, and on characterizing cation-cation complexes of pentavalent actinides.

  7. Combining ungrouped and grouped wildfire data to estimate fire risk

    KAUST Repository

    Hernandez-Magallanes, I.

    2013-10-11

    © 2013 John Wiley & Sons, Ltd. Frequently, models are required to combine information obtained from different data sources and on different scales. In this work, we are interested in estimating the risk of wildfire ignition in the USA for a particular time and location by merging two levels of data, namely, individual points and aggregate count of points into areas. The data for federal lands consist of the point location and time of each fire. Nonfederal fires are aggregated by county for a particular year. The probability model is based on the wildfire point process. Assuming a smooth intensity function, a locally weighted likelihood fit is used, which incorporates the group effect. A logit model is used under the assumption of the existence of a latent process, and fuel conditions are included as a covariate. The model assessment is based on a residual analysis, while the False Discovery Rate detects spatial patterns. A benefit of the proposed model is that there is no need of arbitrary aggregation of individual fires into counts. A map of predicted probability of ignition for the Midwest US in 1990 is included. The predicted ignition probabilities and the estimated total number of expected fires are required for the allocation of resources.

  8. 33rd Actinide Separations Conference

    Energy Technology Data Exchange (ETDEWEB)

    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. Calculation of cohesive energy of actinide metals

    Institute of Scientific and Technical Information of China (English)

    钱存富; 陈秀芳; 余瑞璜; 耿平; 段占强

    1997-01-01

    According to empirical electron theory of solids and molecules (EET), an equation for calculating the cohesive energy of actinide metals is given, the cohesive energy of 9 actinide metals with known crystal structure is calculated, which is identical with the experimental values on the whole, and the cohesive energy of 6 actinide metals with unknown crystal structure is forecast.

  10. Preliminary considerations concerning actinide solubilities

    Energy Technology Data Exchange (ETDEWEB)

    Newton, T.W.; Bayhurst, B.P.; Daniels, W.R.; Erdal, B.R.; Ogard, A.E.

    1980-01-01

    Work at the Los Alamos Scientific Laboratory on the fundamental solution chemistry of the actinides has thus far been confined to preliminary considerations of the problems involved in developing an understanding of the precipitation and dissolution behavior of actinide compounds under environmental conditions. Attempts have been made to calculate solubility as a function of Eh and pH using the appropriate thermodynamic data; results have been presented in terms of contour maps showing lines of constant solubility as a function of Eh and pH. Possible methods of control of the redox potential of rock-groundwater systems by the use of Eh buffers (redox couples) is presented.

  11. Estimating the stabilities of actinide aqueous species. Influence of sulfoxy-anions on uranium(IV) geochemistry and discussion of Pa(V) first hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Vitorge, P.; You, D.; Vercouter, Th. [CEA Saclay, Laboratoire de Speciation des Radionucleides et des Molecules (LSRM), DEN/DANS/DPC/SECR, 91 - Gif sur Yvette (France); Vitorge, P.; Descostes, M. [CEA Saclay, UMR 8587, DEN/DANS/DPC/SECR, 91 - Gif sur Yvette (France); Phrommavanh, V.; Beaucaire, C. [CEA Saclay, Laboratoire de Mesures et Modelisation de la Migration des Radionucleides (L3MR), DEN/DANS/DPC/SECR, 91 - Gif sur Yvette (France); Siboulet, B. [CEA Marcoule, DEN/DRCP/SCPS, 30 (France); Marsden, C.J. [Universite Paul-Sabatier, Laboratoire de Physique Quantique, CNRS UMR 5626, 31 - Toulouse (France); Gaudet, J.P. [Laboratoire d' Etude des Transferts en Hydrologie et Environnement (LTHE), UMR 5564, CNRS/INPG/IRD/UJF, 38 - Grenoble (France)

    2007-10-15

    Qualitative chemical information is used as a guideline for correlations between equilibrium constants or between equilibrium constants and atomic charges (deduced from quantum mechanics calculations). Pa(V) and Nb(V) hydrolysis constants are also recalculated from experimental data. logK{sup 0}{sub 1}(An{sup I}3V/RO{sup 2-}{sub 2})=6.5{sub 9} {+-} 0.5{sub 5} (S{sub 2}O{sub 3}{sup 2-}), 10.0{sub 6} {+-} 0.8{sub 8} (SO{sub 3}{sup 2-}), 11.9{sub 7} {+-} 1.0{sub 7} (CO{sub 3}{sup 2-}), and 10.0{sub 5} {+-} 0.8{sub 8} (HPO{sub 4}{sup 2-}) are estimated based on the trend of affinity for An cations in the series CO{sub 3}{sup 2-} {>=} HPO{sub 4}{sup 2-} {approx} SO{sub 3}{sup 2-} {>=} SO{sub 4}{sup 2-} {approx} S{sub 2}O{sub 3}{sup 2-}. These ideas and values are used to discuss U(IV) chemistry in S-containing ground-waters. (authors)

  12. Environmental research on actinide elements

    Energy Technology Data Exchange (ETDEWEB)

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

    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)

  13. Human age estimation combining third molar and skeletal development.

    Science.gov (United States)

    Thevissen, P W; Kaur, J; Willems, G

    2012-03-01

    The wide prediction intervals obtained with age estimation methods based on third molar development could be reduced by combining these dental observations with age-related skeletal information. Therefore, on cephalometric radiographs, the most accurate age-estimating skeletal variable and related registration method were searched and added to a regression model, with age as response and third molar stages as explanatory variable. In a pilot set up on a dataset of 496 (283 M; 213 F) cephalometric radiographs, the techniques of Baccetti et al. (2005) (BA), Seedat et al. (2005) (SE), Caldas et al. (2007) and Rai et al. (2008) (RA) were verified. In the main study, data from 460 (208 F, 224 M) individuals in an age range between 3 and 26 years, for which at the same day an orthopantogram and a cephalogram were taken, were collected. On the orthopantomograms, the left third molar development was registered using the scoring system described by Gleiser and Hunt (1955) and modified by Köhler (1994) (GH). On the cephalograms, cervical vertebrae development was registered according to the BA and SE techniques. A regression model, with age as response and the GH scores as explanatory variable, was fitted to the data. Next, information of BA, SE and BA + SE was, respectively, added to this model. From all obtained models, the determination coefficients and the root mean squared errors were calculated. Inclusion of information from cephalograms based on the BA, as well as the SE, technique improved the amount of explained variance in age acquired from panoramic radiographs using the GH technique with 48%. Inclusion of cephalometric BA + SE information marginally improved the previous result (+1%). The RMSE decreased with 1.93, 1.85 and 2.03 years by adding, respectively, BA, SE and BA + SE information to the GH model. The SE technique allows clinically the fastest and easiest registration of the degree of development of the cervical vertebrae. Therefore, the choice of

  14. Actinides How well do we know their stellar production?

    CERN Document Server

    Goriely, S

    2001-01-01

    The reliable evaluation of the r-process production of the actinides and careful estimates of the uncertainties affecting these predictions are key ingredients especially in nucleo-cosmochronology studies based on the analysis of very metal-poor stars or on the composition of meteorites. This type of information is also required in order to make the best possible use of future high precision data on the actinide composition of galactic cosmic rays, of the local interstellar medium, or of meteoritic grains of presumed circumstellar origin. This paper provides the practitioners in these various fields with the most detailed and careful analysis of the r-process actinide production available to-date. In total, thirty-two different multi-event canonical calculations using different nuclear ingredients or astrophysics conditions are presented, and are considered to give a fair picture of the level of reliability of the predictions of the actinide production, at least in the framework of a simple r-process model. T...

  15. Potential radiation dose from eating fish exposed to actinide contamination

    Energy Technology Data Exchange (ETDEWEB)

    Emery, R.M.; Klopfer, D.C.; Baker, D.A.; Soldat, J.K. (Battelle Pacific Northwest Labs., Richland, WA (USA))

    1981-04-01

    The purpose of this work is to establish a maximum potential for transporting actinides to man via fish consumption. The study took place in U-pond, a nuclear waste pond on the Hanford Site. It has concentrations of /sup 238/U, /sup 238/Pu, sup(239,240)Pu and /sup 241/Am that are approx. 3 orders of magnitude greater than background levels. Fish living in the pond contain higher actinide concentrations than those observed in fish from any other location. Experiments were performed in U-Pond to determine maximum quantities of actinides that could accumulate in fillets and whole bodies of two centrarchid fish species. Doses to hypothetical consumers were then estimated. Results indicate that highest concentrations occurring in bluegill or bass muscle after more than a year's exposure to the pond would not be sufficient to produce a significant radiation dose to a human consumer, even if he ate 0.5 kg (of the order of 1 lb) of these fillets every day for 70 yr. Natural predators (heron or coyote), having lifetime diets of whole fish from U-Pond, would receive less radiation dose from the ingested actinides than from natural background sources.

  16. Combining Facial Dynamics With Appearance for Age Estimation

    NARCIS (Netherlands)

    Dibeklioğlu, H.; Alnajar, F.; Salah, A.A.; Gevers, T.

    2015-01-01

    Estimating the age of a human from the captured images of his/her face is a challenging problem. In general, the existing approaches to this problem use appearance features only. In this paper, we show that in addition to appearance information, facial dynamics can be leveraged in age estimation. We

  17. NMR studies of actinide dioxides

    Energy Technology Data Exchange (ETDEWEB)

    Tokunaga, Y. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)], E-mail: tokunaga.yo@jaea.go.jp; Sakai, H.; Fujimoto, T.; Kambe, S.; Walstedt, R.E.; Ikushima, K.; Yasuoka, H. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Aoki, D.; Homma, Y. [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Haga, Y.; Matsuda, T.D.; Ikeda, S.; Yamamoto, E.; Nakamura, A. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Shiokawa, Y. [Institute for Materials Research, Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Nakajima, K.; Arai, Y. [Department of Nuclear Energy System, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Onuki, Y. [Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan); Department of Physics, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2007-10-11

    {sup 17}O NMR measurements have been performed on a series of the actinide dioxides, UO{sub 2}, NpO{sub 2} and PuO{sub 2}. Although the {sup 17}O NMR spectra in these materials are similar at higher temperatures, the low-temperature spectra present are significantly different. In UO{sub 2} we have observed a wide spectrum, forming a rectangular shape below T{sub N}=30 K. In NpO{sub 2}, on the other hand, the spectra broaden rather gradually and exhibit a two-peak structure below T{sub 0}=26 K. In PuO{sub 2}, neither spectrum broadening nor splitting has been observed. We show that these NMR spectra clearly indicate the different nature of the low-temperature magnetic ground states in these actinide compounds.

  18. Nuclear data uncertainty analysis on a minor actinide burner for transmuting spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hangbok

    1998-08-01

    A comprehensive sensitivity and uncertainty analysis was performed on a 1200 MWt minor actinides burner designed for a low burnup reactivity swing, negative doppler coefficient, and low sodium void worth. Sensitivities of the performance parameters were generated using depletion perturbation methods for the constrained close fuel cycle of the reactor. The uncertainty analysis was performed using the sensitivity and covariance data taken from ENDF-B/V and other published sources. The uncertainty analysis of a liquid metal reactor for burning minor actinide has shown that uncertainties in the nuclear data of several key minor actinide isotopes can introduce large uncertainties in the predicted performance of the core. The relative uncertainties in the burnup swing, doppler coefficient, and void worth were conservatively estimated to be 180 %, 97 %, and 46 %, respectively. An analysis was performed to prioritize the minor actinide reactions for reducing the uncertainties. (author). 41 refs., 17 tabs., 1 fig.

  19. Combined imaging and velocity estimation by Joint Migration Inversion

    NARCIS (Netherlands)

    Staal, X.R.

    2015-01-01

    Seismic imaging projects aim to reveal the structure of the earths crust from seismic data. These projects typically include three separate processing steps, being: • attenuation of multiple reflections in the seismic data. • estimating seismic wave propagation velocities from the seismic data. • ma

  20. Development of a remote bushing for actinide vitrification

    Energy Technology Data Exchange (ETDEWEB)

    Schumacher, R.F.; Ramsey, W.G.; Johnson, F.M. [and others

    1996-12-31

    The Savannah River Site (SRS) and the Savannah River Technology Center (SRTC) are combining their existing experience in handling highly radioactive, special nuclear materials with commercial glass fiberization technology in order to assemble a small vitrification system for radioactive actinide solutions. The vitrification system or {open_quotes}brushing{close_quotes}, is fabricated from platinum-rhodium alloy and is based on early marble remelt fiberization technology. Advantages of this unique system include its relatively small size, reliable operation, geometrical safety (nuclear criticality), and high temperature capability. The bushing design should be capable of vitrifying a number of the actinide nuclear materials, including solutions of americium/curium, neptunium, and possibly plutonium. State of the art, mathematical and oil model studies are being combined with basic engineering evaluations to verify and improve the thermal and mechanical design concepts.

  1. Chemical and Ceramic Methods Toward Safe Storage of Actinides

    Energy Technology Data Exchange (ETDEWEB)

    P.E.D. Morgan; R.M. Housley; J.B. Davis; M.L. DeHaan

    2005-08-19

    A very import, extremely-long-term, use for monazite as a radwaste encapsulant has been proposed. THe use of ceramic La-monazite for sequestering actinides (isolating them from the environment), especially plutonium and some other radioactive elements )e.g., fission-product rare earths), had been especially championed by Lynn Boatner of ORNL. Monazite may be used alone or, copying its compatibility with many other minerals in nature, may be used in diverse composite combinations.

  2. Prompt fission neutron spectrum of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Capote, R. [International Atomic Energy Agency, Vienna (Austria); Chen, Y. -J. [China Institute of Atomic Energy, Beijing (China); Hambsch, F. J. [European Commission, Joint Research Centre - IRRM, Geel (Belgium); Jurado, B. [CENBG, CNRS/IN2P3, Gradignan (France); Kornilov, N. [Ohio Univ., Athens, OH (United States); Lestone, J. P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Litaize, O. [CEA, DEN, DER, SPRC, Saint-Paul-Lez-Durance (France); Morillon, B. [CEA, DAM, DIF, Arpajon (France); Neudecker, D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Oberstedt, S. [European Commission, Joint Research Centre - IRRM, Geel (Belgium); Ohsawa, T. [Kinki Univ., Osaka-fu (Japan); Otuka, N. [International Atomic Energy Agency, Vienna (Austria); Pronyaev, V. G. [Institute of Physics and Power Engineering, Obninsk (Russian Federation); Saxena, A. [Bhabha Atomic Research Centre, Mumbai (India); Schmidt, K. H. [CENBG, CNRS/IN2P3, Gradignan (France); Serot, O. [CEA, DEN, DER, SPRC, Saint-Paul-Lez-Durance (France); Shcherbakov, O. A. [Petersburg Nuclear Physics Institute of NRC " Kurchatov Institute" , Gatchina (Russian Federation); Shu, N. -C. [China Institute of Atomic Energy, Beijing (China); Smith, D. L. [Argonne National Lab. (ANL), Argonne, IL (United States); Talou, P. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Trkov, A. [International Atomic Energy Agency, Vienna (Austria); Tudora, A. C. [Univ. of Bucharest, Magurele (Romania); Vogt, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of California, Davis, CA (United States); Vorobyev, A. S. [Petersburg Nuclear Physics Institute of NRC " Kurchatov Institute" , Gatchina (Russian Federation)

    2016-01-06

    Here, the energy spectrum of prompt neutron 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.

  3. Estimating Risk and Return Combinations for New Derivatives Funds

    Directory of Open Access Journals (Sweden)

    Alexandre Bona

    2004-12-01

    Full Text Available Active funds are typically managed by placing bets against a well defined passive bench-mark. In this context, when examining the launching of a new actively managed fund with a target expected excess rate of return relative to the benchmark equal to µ, asset managers face the problem of estimating the risk σ of excess rates of return. This estimate is critical to examine whether the product is commercially feasible and to define risk limits for the manager, if the product is launched. This paper proceeds to examine the solution to this problem assuming an especial form of the binomial model, in the context of the market timing structure advanced by Merton (1981. The paper shows that two variables are relevant for the solution of the proposed problem. The first, and the most relevant, is the skill level of the manager. A ore skilled manager is able to operate a less risky product with the same target excess rate of return µ. The second relevant variable is the trade-off between risk and return determined by existing investment opportunities in the market. The smaller the increases in risk exposure required to obtain an increase in excess returns, the less risky the product will be After solving the problem under specific assumptions, the paper proceeds to test empirically their validity using a representative sample of hedge funds in the Brazilian market. The empirical results strongly support the validity of the required assumptions.

  4. Combining estimates of interest in prognostic modelling studies after multiple imputation: current practice and guidelines

    Directory of Open Access Journals (Sweden)

    Holder Roger L

    2009-07-01

    Full Text Available Abstract Background Multiple imputation (MI provides an effective approach to handle missing covariate data within prognostic modelling studies, as it can properly account for the missing data uncertainty. The multiply imputed datasets are each analysed using standard prognostic modelling techniques to obtain the estimates of interest. The estimates from each imputed dataset are then combined into one overall estimate and variance, incorporating both the within and between imputation variability. Rubin's rules for combining these multiply imputed estimates are based on asymptotic theory. The resulting combined estimates may be more accurate if the posterior distribution of the population parameter of interest is better approximated by the normal distribution. However, the normality assumption may not be appropriate for all the parameters of interest when analysing prognostic modelling studies, such as predicted survival probabilities and model performance measures. Methods Guidelines for combining the estimates of interest when analysing prognostic modelling studies are provided. A literature review is performed to identify current practice for combining such estimates in prognostic modelling studies. Results Methods for combining all reported estimates after MI were not well reported in the current literature. Rubin's rules without applying any transformations were the standard approach used, when any method was stated. Conclusion The proposed simple guidelines for combining estimates after MI may lead to a wider and more appropriate use of MI in future prognostic modelling studies.

  5. Choice of common bean parents based on combining ability estimates

    Directory of Open Access Journals (Sweden)

    Machado Cristina de Fátima

    2002-01-01

    Full Text Available The obtention of genetically improved cultivars is the main objective of breeding programs, whose efficiency is increased by a careful choice of parents. Based on both general (GCA and specific (SCA combining abilities for grain yield, the purpose of this research was to choose the most promising populations of common beans, for line selection. GCA and SCA were measured by means of a complete diallel without reciprocals, using twelve cultivars/lines. Parents and corresponding F2 segregating populations were evaluated for grain yield by a 9 x 9 triple square lattice design. It was found that the segregating populations differed in grain yield, with predominant SCA effects, but with significant GCA effects as well. Among the populations derived from parents with positive GCA values, Aporé x CI-128, CI-128 x Pérola, PF-9029975 x Ouro Negro, and CI-128 x Ouro Negro also showed positive SCA values and high grain yields, therefore being the most promising populations for grain yield improvement. The highest values of specific combining ability were observed in populations H-4-7 x ESAL 693, CI-128 x Pérola, and A-285 Rudá x IAC Carioca Aruã, which must be the most segregating ones. Hybrid combinations with a high SCA deriving from at least one parent with high GCA were: Pérola x CI-128 and Ouro Negro x Pérola. Although line ESAL 693 presented the lowest GCA value, one of its derived populations, ESAL 693 x H-4-7, had the highest SCA and heterosis values. The high correlation between heterosis and SCA indicates that heterosis can be useful when SCA is not available.

  6. Actinide ion sensor for pyroprocess monitoring

    Science.gov (United States)

    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.

  7. Catalytic Organic Transformations Mediated by Actinide Complexes

    Directory of Open Access Journals (Sweden)

    Isabell S. R. Karmel

    2015-10-01

    Full Text Available This review article presents the development of organoactinides and actinide coordination complexes as catalysts for homogeneous organic transformations. This chapter introduces the basic principles of actinide catalysis and deals with the historic development of actinide complexes in catalytic processes. The application of organoactinides in homogeneous catalysis is exemplified in the hydroelementation reactions, such as the hydroamination, hydrosilylation, hydroalkoxylation and hydrothiolation of alkynes. Additionally, the use of actinide coordination complexes for the catalytic polymerization of α-olefins and the ring opening polymerization of cyclic esters is presented. The last part of this review article highlights novel catalytic transformations mediated by actinide compounds and gives an outlook to the further potential of this field.

  8. Simultaneous estimation of ranitidine and domperidone in combined dosage form

    Directory of Open Access Journals (Sweden)

    Charde M

    2006-01-01

    Full Text Available The development of Vireodt′s method for simultaneous estimation of ranitidine and domperidone involves absorbance measurement at 326 nm and 287 nm corresponding to the respective absorption maxima. Both the drugs obey Beer Lambert′s law in the range of 3.0-50 µg/ml for ranitidine and 0.2-3.5 µg/ml for domperidone. The tablet formulation (Random, Mankind was evaluated for the percent content of both the drugs at the selected wavelengths. The method developed was validated to determine its accuracy, precision, specificity and ruggedness. The recovery study was carried out by standard addition method. The average percent recovery was found to be 99.65±0.47 for ranitidine and 100.06±0.18 for domperidone.

  9. Sensitivity analysis of minor actinides transmutation to physical and technological parameters

    Directory of Open Access Journals (Sweden)

    Kooyman Timothée

    2015-01-01

    Full Text Available Minor actinides transmutation is one of the three main axis defined by the 2006 French law for management of nuclear waste, along with long-term storage and use of a deep geological repository. Transmutation options for critical systems can be divided in two different approaches: (a homogeneous transmutation, in which minor actinides are mixed with the fuel. This exhibits the drawback of “polluting” the entire fuel cycle with minor actinides and also has an important impact on core reactivity coefficients such as Doppler Effect or sodium void worth for fast reactors when the minor actinides fraction increases above 3 to 5% depending on the core; (b heterogeneous transmutation, in which minor actinides are inserted into transmutation targets which can be located in the center or in the periphery of the core. This presents the advantage of decoupling the management of the minor actinides from the conventional fuel and not impacting the core reactivity coefficients. In both cases, the design and analyses of potential transmutation systems have been carried out in the frame of Gen IV fast reactor using a “perturbation” approach in which nominal power reactor parameters are modified to accommodate the loading of minor actinides. However, when designing such a transmutation strategy, parameters from all steps of the fuel cycle must be taken into account, such as spent fuel heat load, gamma or neutron sources or fabrication feasibility. Considering a multi-recycling strategy of minor actinides, an analysis of relevant estimators necessary to fully analyze a transmutation strategy has been performed in this work and a sensitivity analysis of these estimators to a broad choice of reactors and fuel cycle parameters has been carried out. No threshold or percolation effects were observed. Saturation of transmutation rate with regards to several parameters has been observed, namely the minor actinides volume fraction and the irradiation time

  10. An estimation of Erinaceidae phylogeny: a combined analysis approach.

    Directory of Open Access Journals (Sweden)

    Kai He

    Full Text Available BACKGROUND: Erinaceidae is a family of small mammals that include the spiny hedgehogs (Erinaceinae and the silky-furred moonrats and gymnures (Galericinae. These animals are widely distributed across Eurasia and Africa, from the tundra to the tropics and the deserts to damp forests. The importance of these animals lies in the fact that they are the oldest known living placental mammals, which are well represented in the fossil record, a rarity fact given their size and vulnerability to destruction during fossilization. Although the Family has been well studied, their phylogenetic relationships remain controversial. To test previous phylogenetic hypotheses, we combined molecular and morphological data sets, including representatives of all the genera. METHODOLOGY AND PRINCIPAL FINDINGS: We included in the analyses 3,218 bp mitochondrial genes, one hundred and thirty-five morphological characters, twenty-two extant erinaceid taxa, and five outgroup taxa. Phylogenetic relationships were reconstructed using both partitioned and combined data sets. As in previous analyses, our results strongly support the monophyly of both subfamilies (Galericinae and Erinaceinae, the Hylomys group (to include Neotetracus and Neohylomys, and a sister-relationship of Atelerix and Erinaceus. As well, we verified that the extremely long branch lengths within the Galericinae are consistent with their fossil records. Not surprisingly, we found significant incongruence between the phylogenetic signals of the genes and the morphological characters, specifically in the case of Hylomys parvus, Mesechinus, and relationships between Hemiechinus and Paraechinus. CONCLUSIONS: Although we discovered new clues to understanding the evolutionary relationships within the Erinaceidae, our results nonetheless, strongly suggest that more robust analyses employing more complete taxon sampling (to include fossils and multiple unlinked genes would greatly enhance our understanding of the

  11. Combining multi-atlas segmentation with brain surface estimation

    Science.gov (United States)

    Huo, Yuankai; Carass, Aaron; Resnick, Susan M.; Pham, Dzung L.; Prince, Jerry L.; Landman, Bennett A.

    2016-03-01

    Whole brain segmentation (with comprehensive cortical and subcortical labels) and cortical surface reconstruction are two essential techniques for investigating the human brain. The two tasks are typically conducted independently, however, which leads to spatial inconsistencies and hinders further integrated cortical analyses. To obtain self-consistent whole brain segmentations and surfaces, FreeSurfer segregates the subcortical and cortical segmentations before and after the cortical surface reconstruction. However, this "segmentation to surface to parcellation" strategy has shown limitation in various situations. In this work, we propose a novel "multi-atlas segmentation to surface" method called Multi-atlas CRUISE (MaCRUISE), which achieves self-consistent whole brain segmentations and cortical surfaces by combining multi-atlas segmentation with the cortical reconstruction method CRUISE. To our knowledge, this is the first work that achieves the reliability of state-of-the-art multi-atlas segmentation and labeling methods together with accurate and consistent cortical surface reconstruction. Compared with previous methods, MaCRUISE has three features: (1) MaCRUISE obtains 132 cortical/subcortical labels simultaneously from a single multi-atlas segmentation before reconstructing volume consistent surfaces; (2) Fuzzy tissue memberships are combined with multi-atlas segmentations to address partial volume effects; (3) MaCRUISE reconstructs topologically consistent cortical surfaces by using the sulci locations from multi-atlas segmentation. Two data sets, one consisting of five subjects with expertly traced landmarks and the other consisting of 100 volumes from elderly subjects are used for validation. Compared with CRUISE, MaCRUISE achieves self-consistent whole brain segmentation and cortical reconstruction without compromising on surface accuracy. MaCRUISE is comparably accurate to FreeSurfer while achieving greater robustness across an elderly population.

  12. Superabsorbing gel for actinide, lanthanide, and fission product decontamination

    Science.gov (United States)

    Kaminski, Michael D.; Mertz, Carol J.

    2016-06-07

    The present invention provides an aqueous gel composition for removing actinide ions, lanthanide ions, fission product ions, or a combination thereof from a porous surface contaminated therewith. The composition comprises a polymer mixture comprising a gel forming cross-linked polymer and a linear polymer. The linear polymer is present at a concentration that is less than the concentration of the cross-linked polymer. The polymer mixture is at least about 95% hydrated with an aqueous solution comprising about 0.1 to about 3 percent by weight (wt %) of a multi-dentate organic acid chelating agent, and about 0.02 to about 0.6 molar (M) carbonate salt, to form a gel. When applied to a porous surface contaminated with actinide ions, lanthanide ions, and/or other fission product ions, the aqueous gel absorbs contaminating ions from the surface.

  13. Ionic Interactions in Actinide Tetrahalides

    Science.gov (United States)

    Akdeniz, Z.; Karaman, A.; Tosi, M. P.

    2001-05-01

    We determine a model of the ionic interactions in AX 4 compounds (where A is an atom in the actinide series from Th to Am and X = F, Cl, Br or I) by an analysis of data on the static and dynamic structure of their molecular monomers. The potential energy function that we adopt is taken from earlier work on rare-earth trihalides [Z. Akdeniz, Z. Q q e k and M. P. Tosi, Z. Naturforsch. 55a, 861 (2000)] and in particular allows for the electronic polarizability of the actinide ion. This polarizability quantitatively determines the antisymmetric-bending vibrational mode, but its magnitude remains compatible with a symmetric tetrahedral shape of the molecule at equilibrium. The fluorides have an especially high degree of ionic character, and the interionic-force parameters for each halide of the U, Np, Pu and Am series show regular trends, suggesting that extrapolations to the other transuranic-element halides may usefully be made. The Th compounds show some deviations from these trends, and the interionic-force model that we determine for ThCl4 differs somewhat from that obtained in a previous study. We therefore return on the evaluation of the relative stability of charged oligomers of ThCl4 and ZrCl4 and find confirmation of our earlier results on this problem.

  14. The ALMR actinide burning system

    Energy Technology Data Exchange (ETDEWEB)

    Quinn, J.E. (General Electric Co., San Jose, CA (United States))

    1993-01-01

    The advanced liquid-metal reactor (ALMR) actinide burning system is being developed under the sponsorship of the US Department of Energy to bring its unique capabilities to fruition for deployment in the early 21st century. The system consists of four major parts: the reactor plant, the metal fuel and its recycle, the processing of light water reactor (LWR) spent fuel to extract the actinides, and the development of a residual waste package. This paper addresses the status and outlook for each of these four major elements. The ALMR is being developed by an industrial group under the leadership of General Electric (GE) in a cost-sharing arrangement with the US Department of Energy. This effort is nearing completion of the advanced conceptual design phase and will enter the preliminary design phase in 1994. The innovative modular reactor design stresses simplicity, economics, reliability, and availability. The design has evolved from GE's PRISM design initiative and has progressed to the final stages of a prelicensing review by the US Nuclear Regulatory Commission (NRC); a safety evaluation report is expected by the end of 1993. All the major issues identified during this review process have been technically resolved. The next design phases will focus on implementation of the basic safety philosophy of passive shutdown to a safe, stable condition, even without scram, and passive decay heat removal. Economic projections to date show that it will be competitive with non- nuclear and advanced LWR nuclear alternatives.

  15. Ridge regression estimator: combining unbiased and ordinary ridge regression methods of estimation

    Directory of Open Access Journals (Sweden)

    Sharad Damodar Gore

    2009-10-01

    Full Text Available Statistical literature has several methods for coping with multicollinearity. This paper introduces a new shrinkage estimator, called modified unbiased ridge (MUR. This estimator is obtained from unbiased ridge regression (URR in the same way that ordinary ridge regression (ORR is obtained from ordinary least squares (OLS. Properties of MUR are derived. Results on its matrix mean squared error (MMSE are obtained. MUR is compared with ORR and URR in terms of MMSE. These results are illustrated with an example based on data generated by Hoerl and Kennard (1975.

  16. A literature review of actinide-carbonate mineral interactions

    Energy Technology Data Exchange (ETDEWEB)

    Stout, D.L. [Missouri Univ., Columbia, MO (United States). Dept. of Geological Sciences; Carroll, S.A. [Lawrence Livermore National Lab., CA (United States)

    1993-10-01

    Chemical retardation of actinides in groundwater systems is a potentially important mechanism for assessing the performance of the Waste Isolation Pilot Plant (WIPP), a facility intended to demonstrate safe disposal of transuranic waste. Rigorous estimation of chemical retardation during transport through the Culebra Dolomite, a water-bearing unit overlying the WIPP, requires a mechanistic understanding of chemical reactions between dissolved elements and mineral surfaces. This report represents a first step toward this goal by examining the literature for pertinent experimental studies of actinide-carbonate interactions. A summary of existing models is given, along with the types of experiments on which these models are based. Articles pertaining to research into actinide interactions with carbonate minerals are summarized. Select articles involving trace element-carbonate mineral interactions are also reviewed and may serve as templates for future research. A bibliography of related articles is included. Americium(III), and its nonradioactive analog neodymium(III), partition strongly from aqueous solutions into carbonate minerals. Recent thermodynamic, kinetic, and surface studies show that Nd is preferentially removed from solution, forming a Nd-Ca carbonate solid solution. Neptunium(V) is rapidly removed from solution by carbonates. Plutonium incorporation into carbonates is complicated by multiple oxidation states. Little research has been done on the radium(H) and thorium(IV) carbonate systems. Removal of uranyl ion from solution by calcite is limited to monolayer surface coverage.

  17. Experimental studies of actinides in molten salts

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Spin and orbital moments in actinide compounds

    DEFF Research Database (Denmark)

    Lebech, B.; Wulff, M.; Lander, G.H.

    1991-01-01

    experiments designed to determine the magnetic moments at the actinide and transition-metal sublattice sites in compounds such as UFe2, NpCo2, and PuFe2 and to separate the spin and orbital components at the actinide sites. The results show, indeed, that the ratio of the orbital to spin moment is reduced......The extended spatial distribution of both the transition-metal 3d electrons and the actinide 5f electrons results in a strong interaction between these electron states when the relevant elements are alloyed. A particular interesting feature of this hybridization, which is predicted by single...

  19. Recovery of actinides from actinide-aluminium alloys by chlorination: Part I

    OpenAIRE

    Cassayre, Laurent; Soucek, Pavel; Mendes, Eric; Malmbeck, Rikard; Nourry, Christophe; Eloirdi, Rachel; Glatz, Jean-Paul

    2011-01-01

    Pyrochemical processes in molten LiCl–KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide–aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorina...

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  1. Combined CD and DGD Monitoring Based on Data-Aided Channel Estimation

    DEFF Research Database (Denmark)

    Pittalà, Fabio; Hauske, Fabian N.; Ye, Yabin;

    2011-01-01

    By use of a training sequence, fast and robust CD and DGD estimation is demonstrated for a 112 Gbit/s PDM-QPSK system over a wide range of combined channel impairments.......By use of a training sequence, fast and robust CD and DGD estimation is demonstrated for a 112 Gbit/s PDM-QPSK system over a wide range of combined channel impairments....

  2. Overview of actinide chemistry in the WIPP

    Energy Technology Data Exchange (ETDEWEB)

    Borkowski, Marian [Los Alamos National Laboratory; Lucchini, Jean - Francois [Los Alamos National Laboratory; Richmann, Michael K [Los Alamos National Laboratory; Reed, Donald T [Los Alamos National Laboratory; Khaing, Hnin [Los Alamos National Laboratory; Swanson, Juliet [Los Alamos National Laboratory

    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

  3. BWR Assembly Optimization for Minor Actinide Recycling

    Energy Technology Data Exchange (ETDEWEB)

    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).

  4. Advanced Aqueous Separation Systems for Actinide Partitioning

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. Predictive Modeling in Actinide Chemistry and Catalysis

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Ping [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-16

    These are slides from a presentation on predictive modeling in actinide chemistry and catalysis. The following topics are covered in these slides: Structures, bonding, and reactivity (bonding can be quantified by optical probes and theory, and electronic structures and reaction mechanisms of actinide complexes); Magnetic resonance properties (transition metal catalysts with multi-nuclear centers, and NMR/EPR parameters); Moving to more complex systems (surface chemistry of nanomaterials, and interactions of ligands with nanoparticles); Path forward and conclusions.

  6. Lattice effects in the light actinides

    Energy Technology Data Exchange (ETDEWEB)

    Lawson, A.C.; Cort, B.; Roberts, J.A.; Bennett, B.I.; Brun, T.O.; Dreele, R.B. von [Los Alamos National Lab., NM (United States); Richardson, J.W. Jr. [Argonne National Lab., IL (United States)

    1998-12-31

    The light actinides show a variety of lattice effects that do not normally appear in other regions of the periodic table. The article will cover the crystal structures of the light actinides, their atomic volumes, their thermal expansion behavior, and their elastic behavior as reflected in recent thermal vibration measurements made by neutron diffraction. A discussion of the melting points will be given in terms of the thermal vibration measurements. Pressure effects will be only briefly indicated.

  7. Transmutation of actinides in power reactors.

    Science.gov (United States)

    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.

  8. Thermodynamic study on the complexation of Trivalent actinide and lanthanide cation by N-donor ligands in homogeneous conditions; Etude thermodynamique de la complexation des ions actinide (III) et lanthanide (III) par des ligands polyazotes en milieu homogene

    Energy Technology Data Exchange (ETDEWEB)

    Miguirditchian, M

    2004-07-01

    Polydentate N-donor ligands, alone or combined with a synergic acid, may selectively extract minor actinides(III) from lanthanide(III) ions, allowing to develop separation processes of long-live radioelements. The aim of the researches carried out during this thesis was to better understand the chemical mechanisms of the complexation of f-elements by Adptz, a tridentate N-donor ligand, in homogeneous conditions. A thermodynamic approach was retained in order to estimate, from an energetic point of view, the influence of the different contributions to the reaction, and to acquire a complete set of thermodynamic data on this reaction. First, the influence of the nature of the cation on the thermodynamics was considered. The stability constants of the 1/1 complexes were systematically determined by UV-visible spectrophotometry for every lanthanide ion (except promethium) and for yttrium in a mixed solvent methanol/water in volume proportions 75/25%. The thermodynamic parameters ({delta}H{sup 0} {delta}{sup S}) of complexation were estimated by the van't Hoff method and by micro-calorimetry. The trends of the variations across the lanthanide series are compared with similar studies. The same methods were applied to the study of three actinide(III) cations: plutonium, americium and curium. The comparison of these values with those obtained for the lanthanides highlights the increase of stability of these complexes by a factor of 20 in favor of the actinide cations. This gap is explained by a more exothermic reaction and is associated, in the data interpretation, to a higher covalency of the actinide(III)-nitrogen bond. Then, the influence of the change of solvent composition on the thermodynamic of complexation was studied. The thermodynamic parameters of the complexation of europium(III) by Adptz were determined for several fractions of methanol. The stability of the complex formed increases with the percentage of methanol in the mixed solvent, owing to an

  9. Advances in computational actinide chemistry in China

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Dongqi; Wu, Jingyi; Chai, Zhifang [Chinese Academy of Sciences, Beijing (China). Multidisciplinary Initiative Center; Su, Jing [Chinese Academy of Sciences, Shanghai (China). Div. of Nuclear Materials Science and Engineering; Li, Jun [Tsinghua Univ., Beijing (China). Dept. of Chemistry and Laboratory of Organic Optoelectronics and Molecular Engineering

    2014-04-01

    The advances in computational actinide chemistry made in China are reviewed. Several areas relevant to chemistry of actinides in gas, liquid, and solid phases have been explored. However, we limit the scope to selected contributions in the chemistry of molecular actinide systems in gas and liquid phases. These studies may be classified into two categories: treatment of relativistic effects, which cover the development of two- and four-component Hamiltonians and the optimization of relativistic pseudopotentials, and the applications of theoretical methods in actinide chemistry. The applications include (1) the electronic structures of actinocene, noble gas complexes, An-C multiple bonding compounds, uranyl and its isoelectronic species, fluorides and oxides, molecular systems with metal-metal bonding in their isolated forms (U{sub 2}, Pu{sub 2}) and in fullerene (U{sub 2} rate at C{sub 60}), and the excited states of actinide complexes; (2) chemical reactions, including oxidation, hydrolysis of UF{sub 6}, ligand exchange, reactivities of thorium oxo and sulfido metallocenes, CO{sub 2}/CS{sub 2} functionalization promoted by trivalent uranium complex; and (3) migration of actinides in the environment. A future outlook is discussed. (orig.)

  10. Combining the boundary shift integral and tensor-based morphometry for brain atrophy estimation

    Science.gov (United States)

    Michalkiewicz, Mateusz; Pai, Akshay; Leung, Kelvin K.; Sommer, Stefan; Darkner, Sune; Sørensen, Lauge; Sporring, Jon; Nielsen, Mads

    2016-03-01

    Brain atrophy from structural magnetic resonance images (MRIs) is widely used as an imaging surrogate marker for Alzheimers disease. Their utility has been limited due to the large degree of variance and subsequently high sample size estimates. The only consistent and reasonably powerful atrophy estimation methods has been the boundary shift integral (BSI). In this paper, we first propose a tensor-based morphometry (TBM) method to measure voxel-wise atrophy that we combine with BSI. The combined model decreases the sample size estimates significantly when compared to BSI and TBM alone.

  11. Estimation of unemployment rates using small area estimation model by combining time series and cross-sectional data

    Science.gov (United States)

    Muchlisoh, Siti; Kurnia, Anang; Notodiputro, Khairil Anwar; Mangku, I. Wayan

    2016-02-01

    Labor force surveys conducted over time by the rotating panel design have been carried out in many countries, including Indonesia. Labor force survey in Indonesia is regularly conducted by Statistics Indonesia (Badan Pusat Statistik-BPS) and has been known as the National Labor Force Survey (Sakernas). The main purpose of Sakernas is to obtain information about unemployment rates and its changes over time. Sakernas is a quarterly survey. The quarterly survey is designed only for estimating the parameters at the provincial level. The quarterly unemployment rate published by BPS (official statistics) is calculated based on only cross-sectional methods, despite the fact that the data is collected under rotating panel design. The study purpose to estimate a quarterly unemployment rate at the district level used small area estimation (SAE) model by combining time series and cross-sectional data. The study focused on the application and comparison between the Rao-Yu model and dynamic model in context estimating the unemployment rate based on a rotating panel survey. The goodness of fit of both models was almost similar. Both models produced an almost similar estimation and better than direct estimation, but the dynamic model was more capable than the Rao-Yu model to capture a heterogeneity across area, although it was reduced over time.

  12. Method and system to estimate variables in an integrated gasification combined cycle (IGCC) plant

    Science.gov (United States)

    Kumar, Aditya; Shi, Ruijie; Dokucu, Mustafa

    2013-09-17

    System and method to estimate variables in an integrated gasification combined cycle (IGCC) plant are provided. The system includes a sensor suite to measure respective plant input and output variables. An extended Kalman filter (EKF) receives sensed plant input variables and includes a dynamic model to generate a plurality of plant state estimates and a covariance matrix for the state estimates. A preemptive-constraining processor is configured to preemptively constrain the state estimates and covariance matrix to be free of constraint violations. A measurement-correction processor may be configured to correct constrained state estimates and a constrained covariance matrix based on processing of sensed plant output variables. The measurement-correction processor is coupled to update the dynamic model with corrected state estimates and a corrected covariance matrix. The updated dynamic model may be configured to estimate values for at least one plant variable not originally sensed by the sensor suite.

  13. Phosphonates as alternative to tributyl phosphate for the separation of actinides from fission products

    Energy Technology Data Exchange (ETDEWEB)

    Vyas, Chirag K.; Joshirao, Pranav M.; Manchanda, Vijay K. [Sungkyunkwan Univ., Suwon (Korea, Republic of). Dept. of Energy Science; Rao, C.V.S. Brahmmananda; Jayalakshmi, S. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2015-06-01

    The present work investigates the role of increase in the basicity of organophosphorus extractant (dialkylalkyl phosphonates) on the uptake of actinides and fission products vis-a-vis tributyl phosphate (TBP), currently employed as a universal extractant. Two dialkylalkyl phosphonates viz. dibutylpropyl phosphonate (DBPrP) and dibutylpentyl phosphonate (DBPeP) were synthesized, characterized and evaluated for their solvent extraction behavior towards U(VI), Th(IV), Eu(III) and Tc(VII) in nitric acid medium ranging from 0.01-6 M. It was observed that increasing the basicity of the phosphoryl oxygen enhanced the uptake of the actinides and the distribution coefficient values were significantly larger as compared to TBP. The limiting organic concentration (LOC) value was estimated for Th(IV) for these extractants and compared with the TBP system. The separation factors of actinides with phosphonates over Tc(VII) are distinctly better than that with TBP.

  14. The uncertainty analysis of a liquid metal reactor for burning minor actinides from light water reactors

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hang Bok [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1998-12-31

    The neutronics analysis of a liquid metal reactor for burning minor actinides has shown that uncertainties in the nuclear data of several key minor actinide isotopes can introduce large uncertainties in the predicted performance of the core. A comprehensive sensitivity and uncertainty analysis was performed on a 1200 MWth actinide burner designed for a low burnup reactivity swing, negative doppler coefficient, and low sodium void worth. Sensitivities were generated using depletion perturbation methods for the equilibrium cycle of the reactor and covariance data was taken ENDF-B/V and other published sources. The relative uncertainties in the burnup swing, doppler coefficient, and void worth were conservatively estimated to be 180%, 97%, and 46%, respectively. 5 refs., 1 fig., 3 tabs. (Author)

  15. Studies on fluoride complexing of hexavalent actinides using a fluoride ion selective electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sawant, R.M.; Chaudhuri, N.K.; Rizvi, G.H.; Patil, S.K.

    1985-08-01

    Complex formation between actinide(VI) and fluoride ions in aqueous solutions was investigated using a fluoride ion selective electrode (F-ISE). As fairly high acidity used to suppress hydrolysis of the actinide(VI) ions, significant liquid junction potentials (Esub(j)) existed in the system. An iterative procedure was developed for computing free hydrogen ion concentration (Hsup(+)) as it could not be measured directly, using data obtained with F-ISE. Esub(j) values were estimated from known (Hsup(+)) and the stability constants of fluoride complexes of actinide(VI) ions were calculated following King and Gallagher's method using a computer program. The stability constants were found to follow the order U(VI) > Np(VI) > Pu(VI). (author). 18 refs.; 3 figs.; 9 tables.

  16. A speed estimation unit for induction motors based on adaptive linear combiner

    Energy Technology Data Exchange (ETDEWEB)

    Marei, Mostafa I.; Shaaban, Mostafa F.; El-Sattar, Ahmed A. [Department of Electrical Power and Machines, Faculty of Engineering, Ain Shams University, Cairo 11517 (Egypt)

    2009-07-15

    This paper presents a new induction motor speed estimation technique, which can estimate the rotor resistance as well, from the measured voltage and current signals. Moreover, the paper utilizes a novel adaptive linear combiner (ADALINE) structure for speed and rotor resistance estimations. This structure can deal with the multi-output systems and it is called MO-ADALINE. The model of the induction motor is arranged in a linear form, in the stationary reference frame, to cope with the proposed speed estimator. There are many advantages of the proposed unit such as wide speed range capability, immunity against harmonics of measured waveforms, and precise estimation of the speed and the rotor resistance at different dynamic changes. Different types of induction motor drive systems are used to evaluate the dynamic performance and to examine the accuracy of the proposed unit for speed and rotor resistance estimation. (author)

  17. Surface energy and work function of the light actinides

    DEFF Research Database (Denmark)

    Kollár, J.; Vitos, Levente; Skriver, Hans Lomholt

    1994-01-01

    We have calculated the surface energy and work function of the light actinides Fr, Ra, Ac, Th, Pa, U, Np, and Pu by means of a Green's-function technique based on the linear-muffin-tin-orbitals method within the tight-binding representation. In these calculations we apply an energy functional which...... combines the kinetic energy calculated within the atomic-sphere approximation with Coulomb- and exchange-correlation-energy terms calculated by means of the complete nonspherically symmetric charge density derived from the atomic-sphere potential within nonoverlapping and space-filling cells....... The calculated surface energies and work functions are in good agreement with the limited experimental data....

  18. Actinide transmutation in nuclear reactors

    Energy Technology Data Exchange (ETDEWEB)

    Bultman, J.H.

    1995-01-17

    An optimization method is developed to maximize the burning capability of the ALMR while complying with all constraints imposed on the design for reliability and safety. This method leads to a maximal transuranics enrichment, which is being limited by constraints on reactivity. The enrichment can be raised by using the neutrons less efficiently by increasing leakage from the fuel. With the developed optimization method, a metallic and an oxide fueled ALMR were optimized. Both reactors perform equally well considering the burning of transuranics. However, metallic fuel has a much higher heat conductivity coefficient, which in general leads to better safety characteristics. In search of a more effective waste transmuter, a modified Molten Salt Reactor was designed. A MSR operates on a liquid fuel salt which makes continuous refueling possible, eliminating the issue of the burnup reactivity loss. Also, a prompt negative reactivity feedback is possible for an overmoderated reactor design, even when the Doppler coefficient is positive, due to the fuel expansion with fuel temperature increase. Furthermore, the molten salt fuel can be reprocessed based on a reduction process which is not sensitive to the short-lived spontaneously fissioning actinides. (orig./HP).

  19. PF-4 actinide disposition strategy

    Energy Technology Data Exchange (ETDEWEB)

    Margevicius, Robert W [Los Alamos National Laboratory

    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.

  20. Combining Lidar and Synthetic Aperture Radar Data to Estimate Forest Biomass: Status and Prospects

    Directory of Open Access Journals (Sweden)

    Sanna Kaasalainen

    2015-01-01

    Full Text Available Research activities combining lidar and radar remote sensing have increased in recent years. The main focus in combining lidar-radar forest remote sensing has been on the retrieval of the aboveground biomass (AGB, which is a primary variable related to carbon cycle in land ecosystems, and has therefore been identified as an essential climate variable. In this review, we summarize the studies combining lidar and radar in estimating forest AGB. We discuss the complementary use of lidar and radar according to the relevance of the added value. The most promising prospects for combining lidar and radar data are in the use of lidar-derived ground elevations for improving large-area biomass estimates from radar, and in upscaling of lidar-based AGB data across large areas covered by spaceborne radar missions.

  1. Combining Satellite Microwave Radiometer and Radar Observations to Estimate Atmospheric Latent Heating Profiles

    Science.gov (United States)

    Grecu, Mircea; Olson, William S.; Shie, Chung-Lin; L'Ecuyer, Tristan S.; Tao, Wei-Kuo

    2009-01-01

    In this study, satellite passive microwave sensor observations from the TRMM Microwave Imager (TMI) are utilized to make estimates of latent + eddy sensible heating rates (Q1-QR) in regions of precipitation. The TMI heating algorithm (TRAIN) is calibrated, or "trained" using relatively accurate estimates of heating based upon spaceborne Precipitation Radar (PR) observations collocated with the TMI observations over a one-month period. The heating estimation technique is based upon a previously described Bayesian methodology, but with improvements in supporting cloud-resolving model simulations, an adjustment of precipitation echo tops to compensate for model biases, and a separate scaling of convective and stratiform heating components that leads to an approximate balance between estimated vertically-integrated condensation and surface precipitation. Estimates of Q1-QR from TMI compare favorably with the PR training estimates and show only modest sensitivity to the cloud-resolving model simulations of heating used to construct the training data. Moreover, the net condensation in the corresponding annual mean satellite latent heating profile is within a few percent of the annual mean surface precipitation rate over the tropical and subtropical oceans where the algorithm is applied. Comparisons of Q1 produced by combining TMI Q1-QR with independently derived estimates of QR show reasonable agreement with rawinsonde-based analyses of Q1 from two field campaigns, although the satellite estimates exhibit heating profile structure with sharper and more intense heating peaks than the rawinsonde estimates. 2

  2. Monazite as a suitable actinide waste form

    Energy Technology Data Exchange (ETDEWEB)

    Schlenz, Hartmut; Heuser, Julia; Schmitz, Stephan; Bosbach, Dirk [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie und Klimaforschung (IEK), Nukleare Entsorgung und Reaktorsicherheit (IEK-6); Neumann, Andreas [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energie und Klimaforschung (IEK), Nukleare Entsorgung und Reaktorsicherheit (IEK-6); RWTH Aachen Univ. (Germany). Inst. for Crystallography

    2013-03-01

    The conditioning of radioactive waste from nuclear power plants and in some countries even of weapons plutonium is an important issue for science and society. Therefore the research on appropriate matrices for the immobilization of fission products and actinides is of great interest. Beyond the widely used borosilicate glasses, ceramics are promising materials for the conditioning of actinides like U, Np, Pu, Am, and Cm. Monazite-type ceramics with general composition LnPO{sub 4} (Ln = La to Gd) and solid solutions of monazite with cheralite or huttonite represent important materials in this field. Monazite appears to be a promising candidate material, especially because of its outstanding properties regarding radiation resistance and chemical durability. This article summarizes the most recent results concerning the characterization of monazite and respective solid solutions and the study of their chemical, thermal, physical and structural properties. The aim is to demonstrate the suitability of monazite as a secure and reliable waste form for actinides. (orig.)

  3. Electronic Structure of the Actinide Metals

    DEFF Research Database (Denmark)

    Johansson, B.; Skriver, Hans Lomholt

    1982-01-01

    Some recent experimental photoelectron spectroscopic results for the actinide metals are reviewed and compared with the theoretical picture of the basic electronic structure that has been developed for the actinides during the last decade. In particular the experimental data confirm the change from...... itinerant to localized 5f electron behaviour calculated to take place between plutonium and americium. From experimental data it is shown that the screening of deep core-holes is due to 5f electrons for the lighter actinide elements and 6d electrons for the heavier elements. A simplified model for the full...... LMTO electronic structure calculations is introduced. In this model the spd and 5f electronic contributions are treated as separable entities. It is shown that the model reproduces quite well the results from the full treatment. The equilibrium volume, cohesive energy and bulk modulus are calculated...

  4. Combining satellite altimetry and gravimetry data to improve Antarctic mass balance and gia estimates

    NARCIS (Netherlands)

    Gunter, B.C.; Didova, O.; Riva, R.E.M.; van den Broeke, M.R.; Ligtenberg, S.R.M.; Lenaerts, J.T.M.; King, M.; Urban, T.

    2012-01-01

    This study explores an approach that simultaneously estimates Antarctic mass balance and glacial isostatic adjustment (GIA) through the combination of satellite gravity and altimetry data sets. The results improve upon previous efforts by incorporating reprocessed data sets over a longer period of t

  5. Actinide and fission product separation and transmutation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-07-01

    The second international information exchange meeting on actinide and fission product separation and transmutation, took place in Argonne National Laboratory in Illinois United States, on 11-13 November 1992. The proceedings are presented in four sessions: Current strategic system of actinide and fission product separation and transmutation, progress in R and D on partitioning processes wet and dry, progress in R and D on transmutation and refinements of neutronic and other data, development of the fuel cycle processes fuel types and targets. (A.L.B.)

  6. Spin–orbit coupling in actinide cations

    DEFF Research Database (Denmark)

    Bagus, Paul S.; Ilton, Eugene S.; Martin, Richard L.

    2012-01-01

    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....

  7. Correlation of retention of lanthanide and actinide complexes with stability constants and their speciation

    Energy Technology Data Exchange (ETDEWEB)

    Datta, A.; Sivaraman, N.; Viswanathan, K.S.; Ghosh, Suddhasattwa; Srinivasan, T.G.; Vasudeva Rao, P.R. [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Chemistry Group

    2013-03-01

    The present study describes a correlation that is developed from retention of lanthanide and actinide complexes with the stability constant. In these studies, an ion-pairing reagent, camphor-10-sulphonic acid (CSA) was used as the modifier and organic acids such as {alpha}-hydroxy isobutyric acid ({alpha}-HIBA), mandelic acid, lactic acid and tartaric acid were used as complexing reagent for elution. From these studies, a correlation has been established between capacity factor of a metal ion, concentration of ion-pairing reagent and complexing agent with the stability constant of metal complex. Based on these studies, it has been shown that the stability constant of lanthanide and actinide complexes can be estimated using a single lanthanide calibrant. Validation of the method was carried out with the complexing agents such as {alpha}-HIBA and lactic acid. It was also demonstrated that data from a single chromatogram can be used for estimation of stability constant at various ionic strengths. These studies also demonstrated that the method can be applied for estimation of stability constant of actinides with a ligand whose value is not reported yet, e.g., ligands of importance in the lanthanide-actinide separations, chelation therapy etc. The chromatographic separation method is fast and the estimation of stability constant can be done in a very short time, which is a significant advantage especially in dealing with radioactive elements. The stability constant data was used to derive speciation data of plutonium in different oxidation states as well as that of americium with {alpha}-HIBA. The elution behavior of actinides such as Pu and Am from reversed phase chromatographic technique could be explained based on these studies. (orig.)

  8. Searching for primordial non-Gaussianity in Planck CMB maps using a combined estimator

    CERN Document Server

    Novaes, C P; Ferreira, I S; Wuensche, C A

    2013-01-01

    The extensive search for deviations from Gaussianity in cosmic microwave background radiation (CMB) data is very important due to the information about the very early moments of the universe encoded there. Recent analyses from Planck CMB data do not exclude the presence of non-Gaussianity of small amplitude, although they are consistent with the Gaussian hypothesis. The use of different techniques is essential to provide information about types and amplitudes of non-Gaussianities in the CMB data. In particular, we find interesting to construct an estimator based upon the combination of two powerful statistical tools that appears to be sensitive enough to detect tiny deviations from Gaussianity in CMB maps. This estimator combines the Minkowski functionals with a Neural Network, maximizing a tool widely used to study non-Gaussian signals with a reinforcement of another tool designed to identify patterns in a data set. We test our estimator by analyzing simulated CMB maps contaminated with different amounts of ...

  9. Pyrochlore as nuclear waste form. Actinide uptake and chemical stability

    Energy Technology Data Exchange (ETDEWEB)

    Finkeldei, Sarah Charlotte

    2015-07-01

    imitate a realistic waste form 5 mol% and 10 mol% Pu-pyrochlores were synthesised. To this end, a wet chemical synthesis route was developed. Characterisation by XRD, SEM and EDX indicates a homogeneous structural uptake of Pu- 239 into pyrochlore. Extensive dissolution studies were carried out on Nd{sub 2}O{sub 3} - ZrO{sub 2} pyrochlores using static and dynamic experimental setups including variations of pH, temperature and chemical composition. Typical for all experiments is an initial incongruent dissolution with a preferential Nd release. The higher initial rates decreased with time until a steady state was reached oftentimes approaching a congruent dissolution of Nd and Zr. The steady state of the Zr release was reached after 10 - 20 days in experiments at 110 C and c(H{sup +}) = 0.1 mol/L. Differences in the Zr-O and Nd-O bonding strengths may be partly responsible for the higher initial release rate of Nd. The activation energy E{sub a} (Zr-based pyrochlore) = 47 kJ/mol and E{sub a} = 28 kJ/mol for the defect fluorite indicated a surface controlled dissolution mechanism. A rough estimation for a Nd{sub 2}Zr{sub 2}O{sub 7} pyrochlore leads to a dissolution rate in the order of 10{sup -10} gm{sup -2}d{sup -1} under repository relevant conditions, demonstrating its ability to serve as a highly durable nuclear waste form. Complementary to the macroscopic approach microscopic observations were made to gain a more detailed view into the dissolution. SEM and vertical scanning interferometry provided new insights into the dissolution kinetics at grain boundaries and the surface retreat of individual grains. These microscopic methods indicate a temporal evolution of the surface reactivity. The combination of macroscopic and microscopic dissolution studies allowed first insights into the dissolution mechanism of a ZrO{sub 2} - Nd{sub 2}O{sub 3} pyrochlore series which is essential for a profound understanding of the chemical stability of a nuclear waste form.

  10. A Bayesian Combined Model for Time-Dependent Turning Movement Proportions Estimation at Intersections

    Directory of Open Access Journals (Sweden)

    Pengpeng Jiao

    2014-01-01

    Full Text Available Time-dependent turning movement flows are very important input data for intelligent transportation systems but are impossible to be detected directly through current traffic surveillance systems. Existing estimation models have proved to be not accurate and reliable enough during all intervals. An improved way to address this problem is to develop a combined model framework that can integrate multiple submodels running simultaneously. This paper first presents a back propagation neural network model to estimate dynamic turning movements, as well as the self-adaptive learning rate approach and the gradient descent with momentum method for solving. Second, this paper develops an efficient Kalman filtering model and designs a revised sequential Kalman filtering algorithm. Based on the Bayesian method using both historical data and currently estimated results for error calibration, this paper further integrates above two submodels into a Bayesian combined model framework and proposes a corresponding algorithm. A field survey is implemented at an intersection in Beijing city to collect both time series of link counts and actual time-dependent turning movement flows, including historical and present data. The reported estimation results show that the Bayesian combined model is much more accurate and stable than other models.

  11. Scalar Static Polarizabilities of Lanthanides and Actinides

    CERN Document Server

    Dzuba, V A; Flambaum, V V

    2014-01-01

    We calculate scalar static polarizabilities for lanthanides and actinides, the atoms with open $4f$ or $5f$ subshell. We show that polarizabilities of the low states are approximately the same for all states of given configuration and present a way of calculating them reducing valence space to just two or three valence electrons occupying $6s$ and $5d$ states for lanthanides or $7s$ and $6d$ states for actinides while $4f$ and $5f$ states are considered to be in the core. Configuration interaction technique is used to calculate polarizabilities of lanthanides and actinides for all states of the $4f^n6s^2$ and $4f^{n-1}6s^25d$ configurations of lanthanides and all states of the $5f^{n}7s^2$ and $5f^{n-1}7s^26d$ configurations of actinides. Polarizability of the electron core (including f-orbitals) has been calculated in the RPA approximation.

  12. Actinide and fission product partitioning and transmutation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    The third international information exchange meeting on actinide and fission product partitioning and transmutation, took place in Cadarache France, on 12-14 December 1994. The proceedings are presented in six sessions : an introduction session, the major programmes and international cooperation, the systems studies, the reactors fuels and targets, the chemistry and a last discussions session. (A.L.B.)

  13. Actinide valences in xenotime and monazite

    Energy Technology Data Exchange (ETDEWEB)

    Vance, E.R. [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC, NSW 2232 (Australia); Zhang, Y., E-mail: yzx@ansto.gov.au [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC, NSW 2232 (Australia); McLeod, T.; Davis, J. [Institute of Materials Engineering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001 Kirrawee DC, NSW 2232 (Australia)

    2011-02-28

    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{sup 3+} and Np{sup 3+} can be incorporated in xenotime samples fired in a reducing atmosphere.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  15. Combined time-resolved laser fluorescence spectroscopy and extended X-ray absorption fine structure spectroscopy study on the complexation of trivalent actinides with chloride at T = 25-200 °C.

    Science.gov (United States)

    Skerencak-Frech, Andrej; Fröhlich, Daniel R; Rothe, Jörg; Dardenne, Kathy; Panak, Petra J

    2014-01-21

    The complexation of trivalent actinides (An(III)) with chloride is studied in the temperature range from 25 to 200 °C by spectroscopic methods. Time-resolved laser fluorescence spectroscopy (TRLFS) is applied to determine the thermodynamic data of Cm(III)-Cl(-) complexes, while extended X-ray absorption fine structure spectroscopy (EXAFS) is used to determine the structural data of the respective Am(III) complexes. The experiments are performed in a custom-built high-temperature cell which is modified for the respective spectroscopic technique. The TRLFS results show that at 25 °C the speciation is dominated mainly by the Cm(3+) aquo ion. Only a minor fraction of the CmCl(2+) complex is present in solution. As the temperature increases, the fraction of this species decreases further. Simultaneously, the fraction of the CmCl2(+) complex increases strongly with the temperature. Also, the CmCl3 complex is formed to a minor extent at T > 160 °C. The conditional stability constant log β'2 is determined as a function of the temperature and extrapolated to zero ionic strength with the specific ion interaction theory approach. The log β°2(T) values increase by more than 3 orders of magnitude in the studied temperature range. The temperature dependency of log β°2 is fitted by the extended van't Hoff equation to determine ΔrH°m, ΔrS°m, and ΔrC°p,m. The EXAFS results support these findings. The results confirm the absence of americium(III) chloride complexes at T = 25 and 90 °C ([Am(III)] = 10(-3) m, [Cl(-)] = 3.0 m), and the spectra are described by 9-10 oxygen atoms at a distance of 2.44-2.48 Å. At T = 200 °C two chloride ligands are present in the inner coordination sphere of Am(III) at a distance of 2.78 Å.

  16. Simultaneous derivative spectrophotometric estimation of aceclofenac and tramadol with paracetamol in combination solid dosage forms

    Directory of Open Access Journals (Sweden)

    Srinivasan K

    2007-01-01

    Full Text Available A derivative spectrophotometric procedure has been developed for the simultaneous determination of individual combination of aceclofenac and tramadol with paracetamol in combined tablet preparation. Tablet extracts of the drugs were prepared in distilled water. The zero crossing point technique and the compensation technique were used to estimate the amount of each drug in the combined formulations, and were compared. The results were found to be accurate and free from interferences. The procedure is rapid, simple, nondestructive, and does not require solutions of equations. Calibration graphs are linear (r=0.9999, with a zero intercept up to 24 mg/ml of each drug in combination with paracetamol. Detection limits at the p = 0.05 level of significance were calculated to be 0.5 mg/ml of aceclofenac, tramadol and paracetamol respectively.

  17. Estimation of Heterosis and Combining Ability in Petunia (Petunia hybrida Hort.

    Directory of Open Access Journals (Sweden)

    Hassan BAYAT

    2012-08-01

    Full Text Available Combining ability and heterosis were estimated for ornamental and vegetative traits of four petunia (Petunia hybrida Hort. inbred lines viz. L5 (P1, L8 (P2, L11 (P3 and L17 (P4 and their diallel hybrids in horticultural research farm of Ferdowsi University of Mashhad, Iran in 2011. The measured traits were plant height at first flower, number of leaf to first flower, flower diameter, flower tube length, internode length, stem diameter, plant height at flowering stage, plant spreading, number of branches per plant, leaf length and width. The results of combining ability for all studied traits revealed that both additive and non-additive gene effects contributed to the inheritance of the traits. Estimates of general combining ability effects showed that parent P3 was a good general combiner for most of the studied traits. For flower diameter, hybrid combination P1 � P2 had the highest significant positive specific combining ability effects. Reciprocal effects were significant for all traits and hybrid combination P1 � P2 had the highest significant positive reciprocal effects for flower tube length and plant height. Heterosis was found significant relative to both the mid parent and batter parent for all traits. For flower diameter, the highest positive values of heterotic effects were recorded in hybrid combination P2 � P3 both relative to the parental mean (37.3% and relative to the better parent (33.9%. It is obvious that heterotic effects represent an important resource in hybrid breeding of petunia.

  18. Improving radar rainfall estimation by merging point rainfall measurements within a model combination framework

    Science.gov (United States)

    Hasan, Mohammad Mahadi; Sharma, Ashish; Mariethoz, Gregoire; Johnson, Fiona; Seed, Alan

    2016-11-01

    While the value of correcting raw radar rainfall estimates using simultaneous ground rainfall observations is well known, approaches that use the complete record of both gauge and radar measurements to provide improved rainfall estimates are much less common. We present here two new approaches for estimating radar rainfall that are designed to address known limitations in radar rainfall products by using a relatively long history of radar reflectivity and ground rainfall observations. The first of these two approaches is a radar rainfall estimation algorithm that is nonparametric by construction. Compared to the traditional gauge adjusted parametric relationship between reflectivity (Z) and ground rainfall (R), the suggested new approach is based on a nonparametric radar rainfall estimation method (NPR) derived using the conditional probability distribution of reflectivity and gauge rainfall. The NPR method is applied to the densely gauged Sydney Terrey Hills radar network, where it reduces the RMSE in rainfall estimates by 10%, with improvements observed at 90% of the gauges. The second of the two approaches is a method to merge radar and spatially interpolated gauge measurements. The two sources of information are combined using a dynamic combinatorial algorithm with weights that vary in both space and time. The weight for any specific period is calculated based on the error covariance matrix that is formulated from the radar and spatially interpolated rainfall errors of similar reflectivity periods in a cross-validation setting. The combination method reduces the RMSE by about 20% compared to the traditional Z-R relationship method, and improves estimates compared to spatially interpolated point measurements in sparsely gauged areas.

  19. Combined Parameter and State Estimation Problem in a Complex Domain: RF Hyperthermia Treatment Using Nanoparticles

    Science.gov (United States)

    Bermeo Varon, L. A.; Orlande, H. R. B.; Eliçabe, G. E.

    2016-09-01

    The particle filter methods have been widely used to solve inverse problems with sequential Bayesian inference in dynamic models, simultaneously estimating sequential state variables and fixed model parameters. This methods are an approximation of sequences of probability distributions of interest, that using a large set of random samples, with presence uncertainties in the model, measurements and parameters. In this paper the main focus is the solution combined parameters and state estimation in the radiofrequency hyperthermia with nanoparticles in a complex domain. This domain contains different tissues like muscle, pancreas, lungs, small intestine and a tumor which is loaded iron oxide nanoparticles. The results indicated that excellent agreements between estimated and exact value are obtained.

  20. Adventures in Actinide Chemistry: A Year of Exploring Uranium and Thorium in Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Pagano, Justin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-01-08

    The first part of this collection of slides is concerned with considerations when working with actinides. The topics discussed in the document as a whole are the following: Actinide chemistry vs. transition metal chemistry--tools we can use; New synthetic methods to obtain actinide hydrides; Actinide metallacycles: synthesis, structure, and properties; and Reactivity of actinide metallacycles.

  1. Actinides input to the dose in the irradiated graphite of RBMK-1500 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Plukienė, R., E-mail: rita@ar.fi.lt [Institute of Physics, Center for Physical Sciences and Technology, Savanorių pr. 231, LT-02300 Vilnius (Lithuania); Plukis, A.; Puzas, A.; Gvozdaitė, R.; Barkauskas, V.; Duškesas, G. [Institute of Physics, Center for Physical Sciences and Technology, Savanorių pr. 231, LT-02300 Vilnius (Lithuania); Cizdziel, J.V.; Bussan, D. [University of Mississippi, Department of Chemistry and Biochemistry, 305 Coulter Hall, University, Oxford, MS 38677 (United States); Remeikis, V. [Institute of Physics, Center for Physical Sciences and Technology, Savanorių pr. 231, LT-02300 Vilnius (Lithuania)

    2016-04-15

    Highlights: • Actinides input to the dose in RBMK-1500 reactor graphite was estimated. • SCALE 6.1 and MCNPX models were used to calculate actinides specific activities. • ORIGEN-ARP was used for gamma power, neutron source and effective dose calculation. • Concentrations of Pu, Am and Cm isotopes in the RBMK graphite sample were measured. • {sup 244}Cm was found to be a critical contributor to effective dose of the personnel. - Abstract: The purpose of this work is to indicate the actinides input to the total radiation dose caused by the irradiated graphite of the RBMK-1500 reactor in comparison to the dose delivered by other nuclides. We used computer codes (SCALE 6.1 and MCNPX 2.7) to estimate the dose rate delivered by actinides giving special attention to the {sup 244}Cm isotope as a critical contributor to the total activity of actinides in the spent graphite for approximately up to 200 years. The concentrations of Pu, Am and Cm isotopes in the graphite sample from the Ignalina Nuclear Power Plant (NPP) Unit 1 have been measured with the inductively coupled plasma mass spectrometer and specific isotope ratios have been compared with alpha spectrometric results as well as with the values simulated by the computer codes. Good agreement of the experimental results and the simulated ratios serves as an additional confirmation of validity of the calculation models. The effective doses rates of inhalation and ingestion for personnel, gamma radiation power, and nuclides, which constitute the neutron source in the irradiated RBMK-1500 graphite constructions, have also been identified. The obtained results are important for decommissioning of the Ignalina NPP and other NPPs with graphite-moderated reactors.

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

    Science.gov (United States)

    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.

  3. Linear inverse source estimate of combined EEG and MEG data related to voluntary movements.

    Science.gov (United States)

    Babiloni, F; Carducci, F; Cincotti, F; Del Gratta, C; Pizzella, V; Romani, G L; Rossini, P M; Tecchio, F; Babiloni, C

    2001-12-01

    A method for the modeling of human movement-related cortical activity from combined electroencephalography (EEG) and magnetoencephalography (MEG) data is proposed. This method includes a subject's multi-compartment head model (scalp, skull, dura mater, cortex) constructed from magnetic resonance images, multi-dipole source model, and a regularized linear inverse source estimate based on boundary element mathematics. Linear inverse source estimates of cortical activity were regularized by taking into account the covariance of background EG and MEG sensor noise. EEG (121 sensors) and MEG (43 sensors) data were recorded in separate sessions whereas normal subjects executed voluntary right one-digit movements. Linear inverse source solution of EEG, MEG, and EEG-MEG data were quantitatively evaluated by using three performance indexes. The first two indexes (Dipole Localization Error [DLE] and Spatial Dispersion [SDis]) were used to compute the localization power for the source solutions obtained. Such indexes were based on the information provided by the column of the resolution matrix (i.e., impulse response). Ideal DLE values tend to zero (the source current was correctly retrieved by the procedure). In contrast, high DLE values suggest severe mislocalization in the source reconstruction. A high value of SDis at a source space point mean that such a source will be retrieved by a large area with the linear inverse source estimation. The remaining performance index assessed the quality of the source solution based on the information provided by the rows of the resolution matrix R, i.e., resolution kernels. The i-th resolution kernels of the matrix R describe how the estimation of the i-th source is distorted by the concomitant activity of all other sources. A statistically significant lower dipole localization error was observed and lower spatial dispersion in source solutions produced by combined EEG-MEG data than from EEG and MEG data considered separately (P < 0

  4. Bayesian Estimation of Precipitation from Satellite Passive Microwave Observations Using Combined Radar-Radiometer Retrievals

    Science.gov (United States)

    Grecu, Mircea; Olson, William S.

    2006-01-01

    Precipitation estimation from satellite passive microwave radiometer observations is a problem that does not have a unique solution that is insensitive to errors in the input data. Traditionally, to make this problem well posed, a priori information derived from physical models or independent, high-quality observations is incorporated into the solution. In the present study, a database of precipitation profiles and associated brightness temperatures is constructed to serve as a priori information in a passive microwave radiometer algorithm. The precipitation profiles are derived from a Tropical Rainfall Measuring Mission (TRMM) combined radar radiometer algorithm, and the brightness temperatures are TRMM Microwave Imager (TMI) observed. Because the observed brightness temperatures are consistent with those derived from a radiative transfer model embedded in the combined algorithm, the precipitation brightness temperature database is considered to be physically consistent. The database examined here is derived from the analysis of a month-long record of TRMM data that yields more than a million profiles of precipitation and associated brightness temperatures. These profiles are clustered into a tractable number of classes based on the local sea surface temperature, a radiometer-based estimate of the echo-top height (the height beyond which the reflectivity drops below 17 dBZ), and brightness temperature principal components. For each class, the mean precipitation profile, brightness temperature principal components, and probability of occurrence are determined. The precipitation brightness temperature database supports a radiometer-only algorithm that incorporates a Bayesian estimation methodology. In the Bayesian framework, precipitation estimates are weighted averages of the mean precipitation values corresponding to the classes in the database, with the weights being determined according to the similarity between the observed brightness temperature principal

  5. Combining Breeding Bird Survey and distance sampling to estimate density of migrant and breeding birds

    Science.gov (United States)

    Somershoe, S.G.; Twedt, D.J.; Reid, B.

    2006-01-01

    We combined Breeding Bird Survey point count protocol and distance sampling to survey spring migrant and breeding birds in Vicksburg National Military Park on 33 days between March and June of 2003 and 2004. For 26 of 106 detected species, we used program DISTANCE to estimate detection probabilities and densities from 660 3-min point counts in which detections were recorded within four distance annuli. For most species, estimates of detection probability, and thereby density estimates, were improved through incorporation of the proportion of forest cover at point count locations as a covariate. Our results suggest Breeding Bird Surveys would benefit from the use of distance sampling and a quantitative characterization of habitat at point count locations. During spring migration, we estimated that the most common migrant species accounted for a population of 5000-9000 birds in Vicksburg National Military Park (636 ha). Species with average populations of 300 individuals during migration were: Blue-gray Gnatcatcher (Polioptila caerulea), Cedar Waxwing (Bombycilla cedrorum), White-eyed Vireo (Vireo griseus), Indigo Bunting (Passerina cyanea), and Ruby-crowned Kinglet (Regulus calendula). Of 56 species that bred in Vicksburg National Military Park, we estimated that the most common 18 species accounted for 8150 individuals. The six most abundant breeding species, Blue-gray Gnatcatcher, White-eyed Vireo, Summer Tanager (Piranga rubra), Northern Cardinal (Cardinalis cardinalis), Carolina Wren (Thryothorus ludovicianus), and Brown-headed Cowbird (Molothrus ater), accounted for 5800 individuals.

  6. Electrorecovery of actinides at room temperature

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, Michael E [Los Alamos National Laboratory; Oldham, Warren J [Los Alamos National Laboratory; Costa, David A [Los Alamos National Laboratory

    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

  7. Recovery of actinides from actinide-aluminium alloys by chlorination: Part I

    Science.gov (United States)

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

    2011-07-01

    Pyrochemical processes in molten LiCl-KCl are being developed in ITU for recovery of actinides from spent nuclear fuel. The fuel is anodically dissolved to the molten salt electrolyte and actinides are electrochemically reduced on solid aluminium cathodes forming solid actinide-aluminium alloys. A chlorination route is being investigated for recovery of actinides from the alloys. This route consists in three steps: Vacuum distillation for removal of the salt adhered on the electrode, chlorination of the actinide-aluminium alloys by chlorine gas and sublimation of the formed AlCl 3. A thermochemical study showed thermodynamic feasibility of all three steps. On the basis of the conditions identified by the calculations, experiments using pure UAl 3 alloy were carried out to evaluate and optimise the chlorination step. The work was focused on determination of the optimal temperature and Cl 2/UAl 3 molar ratio, providing complete chlorination of the alloy without formation of volatile UCl 5 and UCl 6. The results showed high efficient chlorination at a temperature of 150 °C.

  8. Combining measurements to estimate properties and characterization extent of complex biochemical mixtures; applications to Heparan Sulfate

    Science.gov (United States)

    Pradines, Joël R.; Beccati, Daniela; Lech, Miroslaw; Ozug, Jennifer; Farutin, Victor; Huang, Yongqing; Gunay, Nur Sibel; Capila, Ishan

    2016-04-01

    Complex mixtures of molecular species, such as glycoproteins and glycosaminoglycans, have important biological and therapeutic functions. Characterization of these mixtures with analytical chemistry measurements is an important step when developing generic drugs such as biosimilars. Recent developments have focused on analytical methods and statistical approaches to test similarity between mixtures. The question of how much uncertainty on mixture composition is reduced by combining several measurements still remains mostly unexplored. Mathematical frameworks to combine measurements, estimate mixture properties, and quantify remaining uncertainty, i.e. a characterization extent, are introduced here. Constrained optimization and mathematical modeling are applied to a set of twenty-three experimental measurements on heparan sulfate, a mixture of linear chains of disaccharides having different levels of sulfation. While this mixture has potentially over two million molecular species, mathematical modeling and the small set of measurements establish the existence of nonhomogeneity of sulfate level along chains and the presence of abundant sulfate repeats. Constrained optimization yields not only estimations of sulfate repeats and sulfate level at each position in the chains but also bounds on these levels, thereby estimating the extent of characterization of the sulfation pattern which is achieved by the set of measurements.

  9. Actinide Isotopes for the Synthesis of Superheavy Nuclei

    Science.gov (United States)

    Roberto, J. B.; Alexander, C. W.; Boll, R. A.; Dean, D. J.; Ezold, J. G.; Felker, L. K.; Rykaczewski, K. P.

    2014-09-01

    Recent research resulting in the synthesis of isotopes of new elements 113-118 has demonstrated the importance of actinide targets in superheavy element research. Oak Ridge National Laboratory (ORNL) has unique facilities for the production and processing of actinide target materials, including the High Flux Isotope Reactor (HFIR) and the Radiochemical Engineering Development Center (REDC). These facilities have provided actinide target materials that have been used for the synthesis of all superheavy (SHE) elements above Copernicium (element 112). In this paper, the use of actinide targets for SHE research and discovery is described, including recent results for element 117 using 249Bk target material from ORNL. ORNL actinide capabilities are reviewed, including production and separation/purification, availabilities of actinide materials, and future opportunities including novel target materials such as 251Cf.

  10. Estimation of Heterosis, Combining ability and Gene action in Pigeonpea [Cajanus cajan (L. Millsp.

    Directory of Open Access Journals (Sweden)

    Yamanura,, *Lokesha R., Dharmaraj, P.S., Muniswamy, S. and Diwan, J.R.

    2014-06-01

    Full Text Available Eight cytoplasmic-genetic male sterile lines with A2 (Cajanus scarabaeoides and A4 (Cajanus cajanifolius cytoplasm were crossed with 10 testers in a line × tester design. Resultant 80 experimental hybrids were evaluated along with parents and check (Maruti in lattice design with two replications. Combining ability analysis evinced predominance of non-additive gene effects for 10 characters indicating relevance of heterosis breeding for improving yield attributes. The gca effects of parents revealed that ICPA-2078, GT-308A, PKV-TATA, ARCCV-2 and GPHR-08-11 were good general combiners for seed yield and its direct components. The estimates of sca effects revealed that nine experimental hybrids had significant, desirable and positive sca effects for seed yield. The cross combination ICPA-2092 x VIPUL, ICPA-2078 x BSMR-856 and ICPA-2078 x ARCCV-2 were good specific combiners for number of secondary branches, number of pods per plant, seed yield per plant. These parental combinations are being used for exploitation of hybrid vigour.

  11. Actinide and fission product separation and transmutation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1991-07-01

    The first international information exchange meeting on actinide and fission product separation and transmutation, took place in Mito in Japan, on 6-8 November 1990. It starts with a number of general overview papers to give us some broad perspectives. Following that it takes a look at some basic facts about physics and about the quantities of materials it is talking about. Then it proceeds to some specific aspects of partitioning, starting with evolution from today commercially applied processes and going on to other possibilities. At the end of the third session it takes a look at the significance of partitioning and transmutation of actinides before it embarks on two sessions on transmutation, first in reactors and second in accelerators. The last session is designed to throw back into the discussion the main points which need to be looked at when considering future work in this area. (A.L.B.)

  12. Microbial Transformations of Actinides and Other Radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    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.

  13. ESTIMATING TOTAL GLOMERULAR NUMBER IN HUMAN KIDNEYS WITH A PHYSICAL DISECTOR/FRACTIONATOR COMBINATION

    Directory of Open Access Journals (Sweden)

    Kelli J Johnson

    2011-05-01

    Full Text Available End-stage renal disease (ESRD has emerged as a major health issue for Australian Aborigines. This phenomenon is paralleled in other populations that have adopted a Westernised lifestyle, including African Americans. It has been suggested that abnormal glomerular hypertrophy (glomerulomegaly is an important predisposing factor for ESRD. The pathogenesis of glomerulomegaly remains unknown. It may represent a compensatory hypertrophic response to decreased nephron endowment during fetal development. Alternatively, glomerulomegaly may represent an abnormal haemodynamic/metabolic response to repeated infections, including renal infections during postnatal life. Since glomerular number and size are important issues associated with ESRD, an optimum quantitative method is required for estimating these parameters in human kidneys. The total number of glomeruli in the normal human kidney appears to vary by a factor of three or more, ranging from approximately 300,000 to more than 1 million. Recently, unbiased stereological methods for estimating total glomerular number in kidneys have been developed. The general aim of the present study was to evaluate (in terms of precision and efficiency a stereological method for estimating total glomerular number in human kidneys; the physical disector/fractionator combination. This method provided consistent estimates of total glomerular number. Estimates of total glomerular number obtained for four human kidneys ranged from 364,161 to 586,094 (coefficients of variation 9.2% to 20.0%. Mean glomerular volume for the four kidneys ranged from 6.04 to 10.32 μm3 x 106. These results indicate that this method is a precise and consistent method for estimating total glomerular number in human kidneys. The simple sampling technique developed in this study will be employed in future studies to determine if there is a difference in total glomerular, and hence nephron, number between Australian Aborigines and Caucasians, and

  14. Advanced techniques in actinide spectroscopy (ATAS 2014). Abstract book

    Energy Technology Data Exchange (ETDEWEB)

    Foerstendorf, Harald; Mueller, Katharina; Steudtner, Robin (eds.)

    2014-07-01

    In 2012, The Institute of Resource Ecology at the Helmholtz-Zentrum Dresden Rossendorf organized the first international workshop of Advanced Techniques in Actinide Spectroscopy (ATAS). A very positive feedback and the wish for a continuation of the workshop were communicated from several participants to the scientific committee during the workshop and beyond. Today, the ATAS workshop has been obviously established as an international forum for the exchange of progress and new experiences on advanced spectroscopic techniques for international actinide and lanthanide research. In comparison to already established workshops and conferences on the field of radioecology, one main focus of ATAS is to generate synergistic effects and to improve the scientific discussion between spectroscopic experimentalists and theoreticians. The exchange of ideas in particular between experimental and theoretical applications in spectroscopy and the presentation of new analytical techniques are of special interest for many research institutions working on the improvement of transport models of toxic elements in the environment and the food chain as well as on reprocessing technologies of nuclear and non-nuclear waste. Spectroscopic studies in combination with theoretical modelling comprise the exploration of molecular mechanisms of complexation processes in aqueous or organic phases and of sorption reactions of the contaminants on mineral surfaces to obtain better process understanding on a molecular level. As a consequence, predictions of contaminant's migration behaviour will become more reliable and precise. This can improve the monitoring and removal of hazardous elements from the environment and hence, will assist strategies for remediation technologies and risk assessment. Particular emphasis is placed on the results of the first inter-laboratory Round-Robin test on actinide spectroscopy (RRT). The main goal of RRT is the comprehensive molecular analysis of the actinide

  15. SPECIFIC SEQUESTERING AGENTS FOR THE ACTINIDES

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, Kenneth N.; Smith, William L.; Weitl, Frederick L.; Durbin, Patricia W.; Jones, E.Sarah; Abu-Dari, Kamal; Sofen, Stephen R.; Cooper, Stephen R.

    1979-09-01

    This paper summarizes the current status of a continuing project directed toward the synthesis and characterization of chelating agents which are specific for actinide ions - especially Pu(IV) - using a biomimetic approach that relies on the observation that Pu(IV) and Fe(III) has marked similarities that include their biological transport and distribution in mammals. Since the naturally-occurring Fe(III) sequestering agents produced by microbes commonly contain hydroxamate and catecholate functional groups, these groups should complex the actinides very strongly and macrocyclic ligands incorporating these moieties are being prepared. We have reported the isolation and structure analysis of an isostructural series of tetrakis(catecholato) complexes with the general stoichiometry Na{sub 4}[M(C{sub 6}H{sub 4}O{sub 2}){sub 4}] • 21 H{sub 2}O (M = Th, U, Ce, Hf). These complexes are structural archetypes for the cavity that must be formed if an actinide-specific sequestering agent is to conform ideally to the coordination requirements of the central metal ion. The [M(cat){sub 4}]{sup 4-} complexes have the D{sub 2d} symmetry of the trigonal-faced dodecahedron.. The complexes Th [R'C(0)N(O)R]{sub 4} have been prepared where R = isopropyl and R' = t-butyl or neopentyl. The neopentyl derivative is also relatively close to an idealized D{sub 2d} dodecahedron, while the sterically more hindered t-butyl compound is distorted toward a cubic geometry. The synthesis of a series of 2, 3-dihydroxy-benzoyl amide derivatives of linear and cyclic tetraaza- and diazaalkanes is reported. Sulfonation of these compounds improves the metal complexation and in vivo removal of plutonium from test animals. These results substantially exceed the capabilities of compounds presently used for the therapeutic treatment of actinide contamination.

  16. Actinide and fission product partitioning and transmutation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    The fourth international information exchange meeting on actinide and fission product partitioning and transmutation, took place in Mito City in Japan, on 111-13 September 1996. The proceedings are presented in six sessions: the major programmes and international cooperation, the partitioning and transmutation programs, feasibility studies, particular separation processes, the accelerator driven transmutation, and the chemistry of the fuel cycle. (A.L.B.)

  17. Improved estimation of hydraulic conductivity by combining stochastically simulated hydrofacies with geophysical data.

    Science.gov (United States)

    Zhu, Lin; Gong, Huili; Chen, Yun; Li, Xiaojuan; Chang, Xiang; Cui, Yijiao

    2016-03-01

    Hydraulic conductivity is a major parameter affecting the output accuracy of groundwater flow and transport models. The most commonly used semi-empirical formula for estimating conductivity is Kozeny-Carman equation. However, this method alone does not work well with heterogeneous strata. Two important parameters, grain size and porosity, often show spatial variations at different scales. This study proposes a method for estimating conductivity distributions by combining a stochastic hydrofacies model with geophysical methods. The Markov chain model with transition probability matrix was adopted to re-construct structures of hydrofacies for deriving spatial deposit information. The geophysical and hydro-chemical data were used to estimate the porosity distribution through the Archie's law. Results show that the stochastic simulated hydrofacies model reflects the sedimentary features with an average model accuracy of 78% in comparison with borehole log data in the Chaobai alluvial fan. The estimated conductivity is reasonable and of the same order of magnitude of the outcomes of the pumping tests. The conductivity distribution is consistent with the sedimentary distributions. This study provides more reliable spatial distributions of the hydraulic parameters for further numerical modeling.

  18. Combining optimization methods with response spectra curve-fitting toward improved damping ratio estimation

    Science.gov (United States)

    Brewick, Patrick T.; Smyth, Andrew W.

    2016-12-01

    The authors have previously shown that many traditional approaches to operational modal analysis (OMA) struggle to properly identify the modal damping ratios for bridges under traffic loading due to the interference caused by the driving frequencies of the traffic loads. This paper presents a novel methodology for modal parameter estimation in OMA that overcomes the problems presented by driving frequencies and significantly improves the damping estimates. This methodology is based on finding the power spectral density (PSD) of a given modal coordinate, and then dividing the modal PSD into separate regions, left- and right-side spectra. The modal coordinates were found using a blind source separation (BSS) algorithm and a curve-fitting technique was developed that uses optimization to find the modal parameters that best fit each side spectra of the PSD. Specifically, a pattern-search optimization method was combined with a clustering analysis algorithm and together they were employed in a series of stages in order to improve the estimates of the modal damping ratios. This method was used to estimate the damping ratios from a simulated bridge model subjected to moving traffic loads. The results of this method were compared to other established OMA methods, such as Frequency Domain Decomposition (FDD) and BSS methods, and they were found to be more accurate and more reliable, even for modes that had their PSDs distorted or altered by driving frequencies.

  19. Actinide and lanthanide separation process (ALSEP)

    Science.gov (United States)

    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).

  20. Parameter Estimation for Blur Image Combining Defocus and Motion Blur using Cepstrum Analysis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The degraded parameters recognition is very important for the restoration of blurred images. There are two common types of blurs for most camera systems. One is the defocus blur due to the optical system's defocus phenomenon and the other is the motion blur due to the relative movement between the objectives and the camera.Compared with the recognition for the blurred image with only one blur model, the parameter estimation for the picture combining defocus and motion blur models is a more complicated mission. A method was proposed for computer to estimate the parameters of defocus blur and motion blur in cepstrum area simultaneously. According to characters of both blur models in the frequency domain, an adjustment approach was suggested in the frequency area and then convert to the cepstrum field to increase the accuracy of measurement.

  1. Sigma Team for Advanced Actinide Recycle FY2015 Accomplishments and Directions

    Energy Technology Data Exchange (ETDEWEB)

    Moyer, Bruce A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-30

    The Sigma Team for Minor Actinide Recycle (STAAR) has made notable progress in FY 2015 toward the overarching goal to develop more efficient separation methods for actinides in support of the United States Department of Energy (USDOE) objective of sustainable fuel cycles. Research in STAAR has been emphasizing the separation of americium and other minor actinides (MAs) to enable closed nuclear fuel recycle options, mainly within the paradigm of aqueous reprocessing of used oxide nuclear fuel dissolved in nitric acid. Its major scientific challenge concerns achieving selectivity for trivalent actinides vs lanthanides. Not only is this challenge yielding to research advances, but technology concepts such as ALSEP (Actinide Lanthanide Separation) are maturing toward demonstration readiness. Efforts are organized in five task areas: 1) combining bifunctional neutral extractants with an acidic extractant to form a single process solvent, developing a process flowsheet, and demonstrating it at bench scale; 2) oxidation of Am(III) to Am(VI) and subsequent separation with other multivalent actinides; 3) developing an effective soft-donor solvent system for An(III) selective extraction using mixed N,O-donor or all-N donor extractants such as triazinyl pyridine compounds; 4) testing of inorganic and hybrid-type ion exchange materials for MA separations; and 5) computer-aided molecular design to identify altogether new extractants and complexants and theory-based experimental data interpretation. Within these tasks, two strategies are employed, one involving oxidation of americium to its pentavalent or hexavalent state and one that seeks to selectively complex trivalent americium either in the aqueous phase or the solvent phase. Solvent extraction represents the primary separation method employed, though ion exchange and crystallization play an important role. Highlights of accomplishments include: Confirmation of the first-ever electrolytic oxidation of Am(III) in a

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

    Science.gov (United States)

    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.

  3. Hydrothermal decomposition of actinide(IV oxalates: a new aqueous route towards reactive actinide oxide nanocrystals

    Directory of Open Access Journals (Sweden)

    Walter Olaf

    2016-01-01

    Full Text Available The hydrothermal decomposition of actinide(IV oxalates (An= Th, U, Pu at temperatures between 95 and 250 °C is shown to lead to the production of highly crystalline, reactive actinide oxide nanocrystals (NCs. This aqueous process proved to be quantitative, reproducible and fast (depending on temperature. The NCs obtained were characterised by X-ray diffraction and TEM showing their size to be smaller than 15 nm. Attempts to extend this general approach towards transition metal or lanthanide oxalates failed in the 95–250 °C temperature range. The hydrothermal decomposition of actinide oxalates is therefore a clean, flexible and powerful approach towards NCs of AnO2 with possible scale-up potential.

  4. Large-scale dark diversity estimates: new perspectives with combined methods.

    Science.gov (United States)

    Ronk, Argo; de Bello, Francesco; Fibich, Pavel; Pärtel, Meelis

    2016-09-01

    Large-scale biodiversity studies can be more informative if observed diversity in a study site is accompanied by dark diversity, the set of absent although ecologically suitable species. Dark diversity methodology is still being developed and a comparison of different approaches is needed. We used plant data at two different scales (European and seven large regions) and compared dark diversity estimates from two mathematical methods: species co-occurrence (SCO) and species distribution modeling (SDM). We used plant distribution data from the Atlas Florae Europaeae (50 × 50 km grid cells) and seven different European regions (10 × 10 km grid cells). Dark diversity was estimated by SCO and SDM for both datasets. We examined the relationship between the dark diversity sizes (type II regression) and the overlap in species composition (overlap coefficient). We tested the overlap probability according to the hypergeometric distribution. We combined the estimates of the two methods to determine consensus dark diversity and composite dark diversity. We tested whether dark diversity and completeness of site diversity (log ratio of observed and dark diversity) are related to various natural and anthropogenic factors differently than simple observed diversity. Both methods provided similar dark diversity sizes and distribution patterns; dark diversity is greater in southern Europe. The regression line, however, deviated from a 1:1 relationship. The species composition overlap of two methods was about 75%, which is much greater than expected by chance. Both consensus and composite dark diversity estimates showed similar distribution patterns. Both dark diversity and completeness measures exhibit relationships to natural and anthropogenic factors different than those exhibited by observed richness. In summary, dark diversity revealed new biodiversity patterns which were not evident when only observed diversity was examined. A new perspective in dark diversity studies

  5. Combining Geological and Geophysical Data in Volcanic Hazard Estimation for Dominica, Lesser Antilles

    Science.gov (United States)

    George, O.; Latchman, J. L.; Connor, C.; Malservisi, R.; Connor, L.

    2014-12-01

    Risk posed by volcanic eruptions are generally quantified in a few ways; in the short term geophysical data such as seismic activity or ground deformation are used to assess the state of volcanic unrest while statistical approaches such as spatial density estimates are used for long term hazard assessment. Spatial density estimates have been used in a number of monogenetic volcanic fields for hazard map generation and utilize the age, location and volumes of previous eruptions to calculate the probability of a new event occurring at a given location within this field. In a previously unpublished study, spatial density estimates of the Lesser Antilles volcanic arc showed the island of Dominica to have the highest likelihood of future vent formation. In this current study, this technique was used in combination with relocated seismic events occurring beneath Dominica within the last ~ 20 years as well as InSAR images of ground deformation to generate a hazard map which not only takes into consideration the past events but also the current state of unrest. Here, geophysical data serve as a weighting factor in the estimates with those centers showing more vigorous activity receiving stronger favorability in the assessment for future activity. In addition to this weighting, the bandwidth utilized in the 2D-radially symmetric kernel density function was optimized using the SAMSE method so as to find the value which best minimizes the error in the estimate. The end results of this study are dynamic volcanic hazards maps which will be readily updatable as changes in volcanic unrest occurs within the system.

  6. Estimating national forest carbon stocks and dynamics: combining models and remotely sensed information

    Science.gov (United States)

    Smallman, Luke; Williams, Mathew

    2016-04-01

    Forests are a critical component of the global carbon cycle, storing significant amounts of carbon, split between living biomass and dead organic matter. The carbon budget of forests is the most uncertain component of the global carbon cycle - it is currently impossible to quantify accurately the carbon source/sink strength of forest biomes due to their heterogeneity and complex dynamics. It has been a major challenge to generate robust carbon budgets across landscapes due to data scarcity. Models have been used but outputs have lacked an assessment of uncertainty, making a robust assessment of their reliability and accuracy challenging. Here a Metropolis Hastings - Markov Chain Monte Carlo (MH-MCMC) data assimilation framework has been used to combine remotely sensed leaf area index (MODIS), biomass (where available) and deforestation estimates, in addition to forest planting and clear-felling information from the UK's national forest inventory, an estimate of soil carbon from the Harmonized World Database (HWSD) and plant trait information with a process model (DALEC) to produce a constrained analysis with a robust estimate of uncertainty of the UK forestry carbon budget between 2000 and 2010. Our analysis estimates the mean annual UK forest carbon sink at -3.9 MgC ha-1yr-1 with a 95 % confidence interval between -4.0 and -3.1 MgC ha-1 yr-1. The UK national forest inventory (NFI) estimates the mean UK forest carbon sink to be between -1.4 and -5.5 MgC ha-1 yr-1. The analysis estimate for total forest biomass stock in 2010 is estimated at 229 (177/232) TgC, while the NFI an estimated total forest biomass carbon stock of 216 TgC. Leaf carbon area (LCA) is a key plant trait which we are able to estimate using our analysis. Comparison of median estimates for LCA retrieved from the analysis and a UK land cover map show higher and lower values for LCA are estimated areas dominated by needle leaf and broad leaf forests forest respectively, consistent with ecological

  7. FY2011 Annual Report for the Actinide Isomer Detection Project

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Glen A.; Francy, Christopher J.; Ressler, Jennifer J.; Erikson, Luke E.; Tatishvili, Gocha; Hatarik, R.

    2011-10-01

    This project seeks to identify a new signature for actinide element detection in active interrogation. This technique works by exciting and identifying long-lived nuclear excited states (isomers) in the actinide isotopes and/or primary fission products. Observation of isomers in the fission products will provide a signature for fissile material. For the actinide isomers, the decay time and energy of the isomeric state is unique to a particular isotope, providing an unambiguous signature for SNM. This project entails isomer identification and characterization and neutron population studies. This document summarizes activities from its third year - completion of the isomer identification characterization experiments and initialization of the neutron population experiments. The population and decay of the isomeric state in 235U remain elusive, although a number of candidate gamma rays have been identified. In the course of the experiments, a number of fission fragment isomers were populated and measured [Ressler 2010]. The decays from these isomers may also provide a suitable signature for the presence of fissile material. Several measurements were conducted throughout this project. This report focuses on the results of an experiment conducted collaboratively by PNNL, LLNL and LBNL in December 2010 at LBNL. The measurement involved measuring the gamma-rays emitted from an HEU target when bombarded with 11 MeV neutrons. This report discussed the analysis and resulting conclusions from those measurements. There was one strong candidate, at 1204 keV, of an isomeric signature of 235U. The half-life of the state is estimated to be 9.3 {mu}s. The measured time dependence fits the decay time structure very well. Other possible explanations for the 1204-keV state were investigated, but they could not explain the gamma ray. Unfortunately, the relatively limited statistics of the measurement limit, and the lack of understanding of some of the systematic of the experiment, limit

  8. Estimation of sitting posture by using the combination of ground reaction force

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Hye Ob; Park, Suk Yung [KAIST, Daejeon (Korea, Republic of)

    2015-04-15

    To avoid back pain and related diseases, an appropriate sitting posture should be maintained. Inertial measurement units (IMUs) or marker-less motion cameras, such as Kinect, has recently been used to achieve simpler posture measurements than optical motion capture camera systems. However, multiple IMUs can affect the natural posture of users. The space requirement to guarantee reliable camera data is also somewhat excessive (>1 m) for some personal space setups. Therefore, we propose an unobtrusive method for estimating sitting posture on the basis of ground reaction force measurement, which can be achieved without the use of markers or additional space for measurement. To eliminate additional measurement information other than the ground reaction force underneath the chair and desk, we modeled the posture as a multi-segment rigid body. Several assumptions were proposed and verified to simplify the model and data processing without deteriorating the posture information. Furthermore, to examine whether the combined GRF information provides the appropriateness of the posture, we performed sitting tests for various postures. Results showed that the combinations of GRF measurement could reasonably estimate the sitting posture by the simplified rigid body model and could reliably differentiate the inappropriate forward bent posture. The results showed that the proposed method could serve as a sensing mechanism of posture monitoring systems.

  9. FAO-56 Dual Model Combined with Multi-Sensor Remote Sensing for Regional Evapotranspiration Estimations

    Directory of Open Access Journals (Sweden)

    Rim Amri

    2014-06-01

    Full Text Available The main goal of this study is to evaluate the potential of the FAO-56 dual technique for the estimation of regional evapotranspiration (ET and its constituent components (crop transpiration and soil evaporation, for two classes of vegetation (olives trees and cereals in the semi-arid region of the Kairouan plain in central Tunisia. The proposed approach combines the FAO-56 technique with remote sensing (optical and microwave, not only for vegetation characterization, as proposed in other studies but also for the estimation of soil evaporation, through the use of satellite moisture products. Since it is difficult to use ground flux measurements to validate remotely sensed data at regional scales, comparisons were made with the land surface model ISBA-A-gs which is a physical SVAT (Soil–Vegetation–Atmosphere Transfer model, an operational tool developed by Météo-France. It is thus shown that good results can be obtained with this relatively simple approach, based on the FAO-56 technique combined with remote sensing, to retrieve temporal variations of ET. The approach proposed for the daily mapping of evapotranspiration at 1 km resolution is approved in two steps, for the period between 1991 and 2007. In an initial step, the ISBA-A-gs soil moisture outputs are compared with ERS/WSC products. Then, the output of the FAO-56 technique is compared with the output generated by the SVAT ISBA-A-gs model.

  10. Nondestructive and rapid concurrent estimation of paracetamol and nimesulide in their combined dosage form using raman spectroscopic technique

    Directory of Open Access Journals (Sweden)

    Gargi R Lakhwani

    2013-01-01

    Full Text Available A rapid, nondestructive Raman spectroscopic method was developed for quantitative estimation of paracetamol and nimesulide in their combined dosage form. A Raman univariate calibration model was developed by measuring the peak intensities of paracetamol and nimesulide at 853 cm−1 and 1336 cm−1 , respectively. The developed method was successfully applied for in situ, concurrent estimation of paracetamol and nimesulide in their combined dosage and method was also validated according to International Conference on Harmonisation guidelines. Thus, the developed Raman spectroscopic method can be applied for simultaneous estimation of paracetamol and nimesulide in their combined dosage form as a process analytical technology tool by pharmaceutical industries for routine quality control.

  11. Estimating antimalarial drugs consumption in Africa before the switch to artemisinin-based combination therapies (ACTs

    Directory of Open Access Journals (Sweden)

    Vreeke Ed

    2007-07-01

    Full Text Available Abstract Background Having reliable forecasts is critical now for producers, malaria-endemic countries and agencies in order to adapt production and procurement of the artemisinin-based combination treatments (ACTs, the new first-line treatments of malaria. There is no ideal method to quantify drug requirements for malaria. Morbidity data give uncertain estimations. This study uses drug consumption to provide elements to help estimate quantities and financial requirements of ACTs. Methods The consumption of chloroquine, sulphadoxine/pyrimethamine and quinine both through the private and public sector was assessed in five sub-Saharan Africa countries with different epidemiological patterns (Senegal, Rwanda, Tanzania, Malawi, Zimbabwe. From these data the number of adult treatments per capita was calculated and the volumes and financial implications derived for the whole of Africa. Results Identifying and obtaining data from the private sector was difficult. The quality of information on drug supply and distribution in countries must be improved. The number of adult treatments per capita and per year in the five countries ranged from 0.18 to 0.50. Current adult treatment prices for ACTs range US$ 1–1.8. Taking the upper range for both volumes and costs, the highest number of adult treatments consumed for Africa was estimated at 314.5 million, corresponding to an overall maximum annual need for financing ACT procurement of US$ 566.1 million. In reality, both the number of cases treated and the cost of treatment are likely to be lower (projections for the lowest consumption estimate with the least expensive ACT would require US $ 113 million per annum. There were substantial variations in the market share between public and private sources among these countries (the public sector share ranging from 98% in Rwanda to 33% in Tanzania. Conclusion Additional studies are required to build a more robust methodology, and to assess current consumptions

  12. Machine Learning on Images: Combining Passive Microwave and Optical Data to Estimate Snow Water Equivalent

    Science.gov (United States)

    Dozier, J.; Tolle, K.; Bair, N.

    2014-12-01

    We have a problem that may be a specific example of a generic one. The task is to estimate spatiotemporally distributed estimates of snow water equivalent (SWE) in snow-dominated mountain environments, including those that lack on-the-ground measurements. Several independent methods exist, but all are problematic. The remotely sensed date of disappearance of snow from each pixel can be combined with a calculation of melt to reconstruct the accumulated SWE for each day back to the last significant snowfall. Comparison with streamflow measurements in mountain ranges where such data are available shows this method to be accurate, but the big disadvantage is that SWE can only be calculated retroactively after snow disappears, and even then only for areas with little accumulation during the melt season. Passive microwave sensors offer real-time global SWE estimates but suffer from several issues, notably signal loss in wet snow or in forests, saturation in deep snow, subpixel variability in the mountains owing to the large (~25 km) pixel size, and SWE overestimation in the presence of large grains such as depth and surface hoar. Throughout the winter and spring, snow-covered area can be measured at sub-km spatial resolution with optical sensors, with accuracy and timeliness improved by interpolating and smoothing across multiple days. So the question is, how can we establish the relationship between Reconstruction—available only after the snow goes away—and passive microwave and optical data to accurately estimate SWE during the snow season, when the information can help forecast spring runoff? Linear regression provides one answer, but can modern machine learning techniques (used to persuade people to click on web advertisements) adapt to improve forecasts of floods and droughts in areas where more than one billion people depend on snowmelt for their water resources?

  13. Build-up of actinides in irradiated fuel rods of the ET-RR-1 reactor

    Energy Technology Data Exchange (ETDEWEB)

    Adib, M.; Naguib, K.; Morcos, H.N

    2001-09-01

    The content concentrations of actinides are calculated as a function of operating reactor regime and cooling time at different percentage of fuel burn-up. The build-up transmutation equations of actinides content in an irradiated fuel are solved numerically .A computer code BAC was written to operate on a PC computer to provide the required calculations. The fuel element of 10% {sup 235}U enrichment of ET-RR-1 reactor was taken as an example for calculations using the BAC code. The results are compared with other calculations for the ET-RR-1 fuel rod. An estimation of fissile build-up content of a proposed new fuel of 20% {sup 235}U enrichment for ET-RR-1 reactor is given. The sensitivity coefficients of build-up plutonium concentrations as a function of cross-section data uncertainties are also calculated.

  14. Chemistry of lower valent actinide halides

    Energy Technology Data Exchange (ETDEWEB)

    Lau, K.H.; Hildenbrand, D.L.

    1992-01-01

    This research effort was concerned almost entirely with the first two members of the actinide series, thorium and uranium, although the work was later extended to some aspects of the neptunium-fluorine system in a collaborative program with Los Alamos National Laboratory. Detailed information about the lighter actinides will be helpful in modeling the properties of the heavier actinide compounds, which will be much more difficult to study experimentally. In this program, thermochemical information was obtained from high temperature equilibrium measurements made by effusion-beam mass spectrometry and by effusion-pressure techniques. Data were derived primarily from second-law analysis so as to avoid potential errors in third-law calculations resulting from uncertainties in spectroscopic and molecular constants. This approach has the additional advantage of yielding reaction entropies that can be checked for consistency with various molecular constant assignments for the species involved. In the U-F, U-Cl, and U-Br systems, all of the gaseous species UX, UX{sub 2}, UX{sub 3}, UX{sub 4}, and UX{sub 5}, where X represents the halogen, were identified and characterized; the corresponding species ThX, ThX{sub 2}, ThX{sub 3}, and ThX{sub 4} were studied in the Th-F, Th-Cl, and Th-Br systems. A number of oxyhalide species in the systems U-0-F, U-0-Cl, Th-0-F, and Th-O-Cl were studied thermochemically. Additionally, the sublimation thermodynamics of NpF{sub 4}(s) and NpO{sub 2}F{sub 2}(s) were studied by mass spectrometry.

  15. A Combined Network Architecture Using Art2 and Back Propagation for Adaptive Estimation of Dynamic Processes

    Directory of Open Access Journals (Sweden)

    Einar Sørheim

    1990-10-01

    Full Text Available A neural network architecture called ART2/BP is proposed. Thc goal has been to construct an artificial neural network that learns incrementally an unknown mapping, and is motivated by the instability found in back propagation (BP networks: after first learning pattern A and then pattern B, a BP network often has completely 'forgotten' pattern A. A network using both supervised and unsupervised training is proposed, consisting of a combination of ART2 and BP. ART2 is used to build and focus a supervised backpropagation network consisting of many small subnetworks each specialized on a particular domain of the input space. The ART2/BP network has the advantage of being able to dynamically expand itself in response to input patterns containing new information. Simulation results show that the ART2/BP network outperforms a classical maximum likelihood method for the estimation of a discrete dynamic and nonlinear transfer function.

  16. Actinide management with commercial fast reactors

    Science.gov (United States)

    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.

  17. Electronic structure and magnetism in actinide compounds

    Energy Technology Data Exchange (ETDEWEB)

    Durakiewicz, T. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)]. E-mail: tomasz@lanl.gov; Joyce, J.J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Lander, G.H. [JRC, Institute of Transuranium Elements, Postfach 2340, 76125 Karlsruhe (Germany); Olson, C.G. [Ames Laboratory, Iowa State University, Ames, Iowa 5011 (United States); Butterfield, M.T. [Lawrence Livermoore National Laboratory, Livermoore, CA 94550 (United States); Guziewicz, E. [Institute of Physics, Polish Academy of Sciences, 02-668 Warsaw (Poland); Batista, C.D. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Arko, A.J. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Morales, L. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Mattenberger, K. [Laboratorium fur Festkorperphysik, ETH, CH-8093, Zurich (Switzerland); Vogt, O. [Laboratorium fur Festkorperphysik, ETH, CH-8093, Zurich (Switzerland)

    2006-05-01

    A close relationship between electronic structure and magnetic properties is observed in actinide compounds. The exact nature of this relationship is under investigation. We present examples of a direct link between electronic structure and ordered magnetic moment and/or magnetization. Specifically, results obtained for cubic U, Np and Pu compounds and quasi-2D U compounds are be presented. In the case of cubic compounds, a direct relationship between binding energy of valence band features and magnetic moment will be discussed. A Stoner-like mechanism and simple mean-field explanation is proposed for ferromagnetic UTe.

  18. Status of nuclear data for actinides

    Energy Technology Data Exchange (ETDEWEB)

    Guzhovskii, B.Y.; Gorelov, V.P.; Grebennikov, A.N. [Russia Federal Nuclear Centre, Arzamas (Russian Federation)] [and others

    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.

  19. Calculated Bulk Properties of the Actinide Metals

    DEFF Research Database (Denmark)

    Skriver, Hans Lomholt; Andersen, O. K.; Johansson, B.

    1978-01-01

    Self-consistent relativistic calculations of the electronic properties for seven actinides (Ac-Am) have been performed using the linear muffin-tin orbitals method within the atomic-sphere approximation. Exchange and correlation were included in the local spin-density scheme. The theory explains...... the variation of the atomic volume and the bulk modulus through the 5f series in terms of an increasing 5f binding up to plutonium followed by a sudden localisation (through complete spin polarisation) in americium...

  20. Actinide management with commercial fast reactors

    Energy Technology Data Exchange (ETDEWEB)

    Ohki, Shigeo [Japan Atomic Energy Agency, 4002, Narita-cho, O-arai-machi, Higashi-Ibaraki-gun, Ibaraki 311-1393 (Japan)

    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.

  1. Fission cross section measurements for minor actinides

    Energy Technology Data Exchange (ETDEWEB)

    Fursov, B. [IPPE, Obninsk (Russian Federation)

    1997-03-01

    The main task of this work is the measurement of fast neutron induced fission cross section for minor actinides of {sup 238}Pu, {sup 242m}Am, {sup 243,244,245,246,247,248}Cm. The task of the work is to increase the accuracy of data in MeV energy region. Basic experimental method, fissile samples, fission detectors and electronics, track detectors, alpha counting, neutron generation, fission rate measurement, corrections to the data and error analysis are presented in this paper. (author)

  2. Estimation of Regurgitant Volume and Orifice in Aortic Regurgitation Combining CW Doppler and Parameter Estimation in a Windkessel Like Model

    Directory of Open Access Journals (Sweden)

    Bjørn A.J. Angelsen

    1991-01-01

    Full Text Available A method for noninvasive estimation of regurgitant orifice and volume in aortic regurgitation is proposed and tested in anaesthesized open chested pigs. The method can be used with noninvasive measurement of regurgitant jet velocity with continuous wave ultrasound Doppler measurements together with cuff measurements of systolic and diastolic systemic pressure in the arm. These measurements are then used for parameter estimation in a Windkessel-like model which include the regurgitant orifice as a parameter. The aortic volume compliance and the peripheral resistance are also included as parameters and estimated in the same process. For the test of the method, invasive measurements in the open chest pigs are used. Electromagnetic flow measurements in the ascending aorta and pulmonary artery are used for control, and a correlation between regurgitant volume obtained from parameter estimation and electromagnetic flow measurements of 0.95 over a range from 2.1 to 17.8 mL is obtained.

  3. Combining Satellite and Ground Magnetic Measurements to Improve Estimates of Electromagnetic Induction Transfer Functions

    Science.gov (United States)

    Balasis, G.; Egbert, G. D.

    2005-12-01

    Electromagnetic (EM) induction studies using satellite and ground-based magnetic data may ultimately provide critical new constraints on the electrical conductivity of Earth's mantle. Unlike ground-based observatories, which leave large areas of the Earth (especially the ocean basins) unsampled, satellites have the potential for nearly complete global coverage. However, because the number of operating satellites is limited, spatially complex (especially non-zonal) external current sources are sampled relatively poorly by satellites at any fixed time. The comparatively much larger number of ground-based observatories provides more complete synoptic sampling of external source structure. By combining data from both satellites and observatories models of external sources can be improved, leading to more reliable global mapping of Earth conductivity. For example, estimates of EM induction transfer functions estimated from night-side CHAMP data have been previously shown to have biases which depend systematically on local time (LT). This pattern of biases suggests that a purely zonal model does not adequately describe magnetospheric sources. As a first step toward improved modeling of spatial complexity in sources, we have applied empirical orthogonal function (EOF) methods to exploratory analysis of night-side observatory data. After subtraction of the predictions of the CM4 comprehensive model, which includes a zonally symmetric storm-time correction based on Dst, we find significant non-axisymmetric, but large scale coherent variability in the mid-latitude night-side observatory residuals. Over the restricted range of local times (18:00-6:00) and latitudes (50°S to 50°N) considered, the dominant spatial mode of variability is reasonably approximated by a q21 quadrupole spherical harmonic. Temporal variability of this leading EOF mode is well correlated with Dst. Strategies for moving beyond this initial exploratory EOF analysis to combine observatory data with

  4. Age estimation in forensic sciences: Application of combined aspartic acid racemization and radiocarbon analysis

    Energy Technology Data Exchange (ETDEWEB)

    Alkass, K; Buchholz, B A; Ohtani, S; Yamamoto, T; Druid, H; Spalding, S L

    2009-11-02

    Age determination of unknown human bodies is important in the setting of a crime investigation or a mass disaster, since the age at death, birth date and year of death, as well as gender, can guide investigators to the correct identity among a large number of possible matches. Traditional morphological methods used by anthropologists to determine age are often imprecise, whereas chemical analysis of tooth dentin, such as aspartic acid racemization has shown reproducible and more precise results. In this paper we analyze teeth from Swedish individuals using both aspartic acid racemization and radiocarbon methodologies. The rationale behind using radiocarbon analysis is that above-ground testing of nuclear weapons during the cold war (1955-1963) caused an extreme increase in global levels of carbon-14 ({sup 14}C) which have been carefully recorded over time. Forty-four teeth from 41 individuals were analyzed using aspartic acid racemization analysis of tooth crown dentin or radiocarbon analysis of enamel and ten of these were split and subjected to both radiocarbon and racemization analysis. Combined analysis showed that the two methods correlated well (R2=0.66, p < 0.05). Radiocarbon analysis showed an excellent precision with an overall absolute error of 0.6 {+-} 04 years. Aspartic acid racemization also showed a good precision with an overall absolute error of 5.4 {+-} 4.2 years. Whereas radiocarbon analysis gives an estimated year of birth, racemization analysis indicates the chronological age of the individual at the time of death. We show how these methods in combination can also assist in the estimation of date of death of an unidentified victim. This strategy can be of significant assistance in forensic casework involving dead victim identification.

  5. Combining multistate capture-recapture data with tag recoveries to estimate demographic parameters

    Science.gov (United States)

    Kendall, W.L.; Conn, P.B.; Hines, J.E.

    2006-01-01

    Matrix population models that allow an animal to occupy more than one state over time are important tools for population and evolutionary ecologists. Definition of state can vary, including location for metapopulation models and breeding state for life history models. For populations whose members can be marked and subsequently re-encountered, multistate mark-recapture models are available to estimate the survival and transition probabilities needed to construct population models. Multistate models have proved extremely useful in this context, but they often require a substantial amount of data and restrict estimation of transition probabilities to those areas or states subjected to formal sampling effort. At the same time, for many species, there are considerable tag recovery data provided by the public that could be modeled in order to increase precision and to extend inference to a greater number of areas or states. Here we present a statistical model for combining multistate capture-recapture data (e.g., from a breeding ground study) with multistate tag recovery data (e.g., from wintering grounds). We use this method to analyze data from a study of Canada Geese (Branta canadensis) in the Atlantic Flyway of North America. Our analysis produced marginal improvement in precision, due to relatively few recoveries, but we demonstrate how precision could be further improved with increases in the probability that a retrieved tag is reported.

  6. Solar resources estimation combining digital terrain models and satellite images techniques

    Energy Technology Data Exchange (ETDEWEB)

    Bosch, J.L.; Batlles, F.J. [Universidad de Almeria, Departamento de Fisica Aplicada, Ctra. Sacramento s/n, 04120-Almeria (Spain); Zarzalejo, L.F. [CIEMAT, Departamento de Energia, Madrid (Spain); Lopez, G. [EPS-Universidad de Huelva, Departamento de Ingenieria Electrica y Termica, Huelva (Spain)

    2010-12-15

    One of the most important steps to make use of any renewable energy is to perform an accurate estimation of the resource that has to be exploited. In the designing process of both active and passive solar energy systems, radiation data is required for the site, with proper spatial resolution. Generally, a radiometric stations network is used in this evaluation, but when they are too dispersed or not available for the study area, satellite images can be utilized as indirect solar radiation measurements. Although satellite images cover wide areas with a good acquisition frequency they usually have a poor spatial resolution limited by the size of the image pixel, and irradiation must be interpolated to evaluate solar irradiation at a sub-pixel scale. When pixels are located in flat and homogeneous areas, correlation of solar irradiation is relatively high, and classic interpolation can provide a good estimation. However, in complex topography zones, data interpolation is not adequate and the use of Digital Terrain Model (DTM) information can be helpful. In this work, daily solar irradiation is estimated for a wide mountainous area using a combination of Meteosat satellite images and a DTM, with the advantage of avoiding the necessity of ground measurements. This methodology utilizes a modified Heliosat-2 model, and applies for all sky conditions; it also introduces a horizon calculation of the DTM points and accounts for the effect of snow covers. Model performance has been evaluated against data measured in 12 radiometric stations, with results in terms of the Root Mean Square Error (RMSE) of 10%, and a Mean Bias Error (MBE) of +2%, both expressed as a percentage of the mean value measured. (author)

  7. Advancing Chemistry with the Lanthanide and Actinide Elements: Final Report, September 2013

    Energy Technology Data Exchange (ETDEWEB)

    Evans, William John [Univ. of California, Irvine, CA (United States). Dept. of Chemistry

    2013-09-11

    The objective of this research is to use the unique chemistry available from complexes of the lanthanides and actinides, as well as related heavy metals such as scandium, yttrium, and bismuth to advance chemistry in energy-related areas. The lanthanides and actinides have a combination of properties in terms of size, charge, electropositive character, and f valence orbitals that provides special opportunities to probe reactivity and catalysis in ways not possible with the other metals in the periodic table. We seek to discover reaction pathways and structural types that reveal new options in reaction chemistry related to energy. Identification of new paradigms in structure and reactivity should stimulate efforts to develop new types of catalytic processes that at present are not under consideration because either the transformation or the necessary intermediates are unknown.

  8. Actinide Solubility and Speciation in the WIPP

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Donald T. [Los Alamos National Laboratory

    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.

  9. Cross Time-Frequency Analysis for Combining Information of Several Sources: Application to Estimation of Spontaneous Respiratory Rate from Photoplethysmography

    Science.gov (United States)

    Peláez-Coca, M. D.; Orini, M.; Lázaro, J.; Bailón, R.; Gil, E.

    2013-01-01

    A methodology that combines information from several nonstationary biological signals is presented. This methodology is based on time-frequency coherence, that quantifies the similarity of two signals in the time-frequency domain. A cross time-frequency analysis method, based on quadratic time-frequency distribution, has been used for combining information of several nonstationary biomedical signals. In order to evaluate this methodology, the respiratory rate from the photoplethysmographic (PPG) signal is estimated. The respiration provokes simultaneous changes in the pulse interval, amplitude, and width of the PPG signal. This suggests that the combination of information from these sources will improve the accuracy of the estimation of the respiratory rate. Another target of this paper is to implement an algorithm which provides a robust estimation. Therefore, respiratory rate was estimated only in those intervals where the features extracted from the PPG signals are linearly coupled. In 38 spontaneous breathing subjects, among which 7 were characterized by a respiratory rate lower than 0.15 Hz, this methodology provided accurate estimates, with the median error {0.00; 0.98} mHz ({0.00; 0.31}%) and the interquartile range error {4.88; 6.59} mHz ({1.60; 1.92}%). The estimation error of the presented methodology was largely lower than the estimation error obtained without combining different PPG features related to respiration. PMID:24363777

  10. Cross Time-Frequency Analysis for Combining Information of Several Sources: Application to Estimation of Spontaneous Respiratory Rate from Photoplethysmography

    Directory of Open Access Journals (Sweden)

    M. D. Peláez-Coca

    2013-01-01

    Full Text Available A methodology that combines information from several nonstationary biological signals is presented. This methodology is based on time-frequency coherence, that quantifies the similarity of two signals in the time-frequency domain. A cross time-frequency analysis method, based on quadratic time-frequency distribution, has been used for combining information of several nonstationary biomedical signals. In order to evaluate this methodology, the respiratory rate from the photoplethysmographic (PPG signal is estimated. The respiration provokes simultaneous changes in the pulse interval, amplitude, and width of the PPG signal. This suggests that the combination of information from these sources will improve the accuracy of the estimation of the respiratory rate. Another target of this paper is to implement an algorithm which provides a robust estimation. Therefore, respiratory rate was estimated only in those intervals where the features extracted from the PPG signals are linearly coupled. In 38 spontaneous breathing subjects, among which 7 were characterized by a respiratory rate lower than 0.15 Hz, this methodology provided accurate estimates, with the median error {0.00; 0.98} mHz ({0.00; 0.31}% and the interquartile range error {4.88; 6.59} mHz ({1.60; 1.92}%. The estimation error of the presented methodology was largely lower than the estimation error obtained without combining different PPG features related to respiration.

  11. Thin extractive membrane for monitoring actinides in aqueous streams.

    Science.gov (United States)

    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.

  12. Separation of actinides from spent nuclear fuel: A review.

    Science.gov (United States)

    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.

  13. End point control of an actinide precipitation reactor

    Energy Technology Data Exchange (ETDEWEB)

    Muske, K.R. [Villanova Univ., PA (United States). Dept. of Chemical Engineering; Palmer, M.J. [Los Alamos National Lab., NM (United States)

    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. A practical algorithm for estimating surface soil moisture using combined optical and thermal infrared data

    Science.gov (United States)

    Leng, Pei; Song, Xiaoning; Duan, Si-Bo; Li, Zhao-Liang

    2016-10-01

    Surface soil moisture (SSM) is a critical variable for understanding the energy and water exchange between the land and atmosphere. A multi-linear model was recently developed to determine SSM using ellipse variables, namely, the center horizontal coordinate (x0), center vertical coordinate (y0), semi-major axis (a) and rotation angle (θ), derived from the elliptical relationship between diurnal cycles of land surface temperature (LST) and net surface shortwave radiation (NSSR). However, the multi-linear model has a major disadvantage. The model coefficients are calculated based on simulated data produced by a land surface model simulation that requires sufficient meteorological measurements. This study aims to determine the model coefficients directly using limited meteorological parameters rather than via the complicated simulation process, decreasing the dependence of the model coefficients on meteorological measurements. With the simulated data, a practical algorithm was developed to estimate SSM based on combined optical and thermal infrared data. The results suggest that the proposed approach can be used to determine the coefficients associated with all ellipse variables based on historical meteorological records, whereas the constant term varies daily and can only be determined using the daily maximum solar radiation in a prediction model. Simulated results from three FLUXNET sites over 30 cloud-free days revealed an average root mean square error (RMSE) of 0.042 m3/m3 when historical meteorological records were used to synchronously determine the model coefficients. In addition, estimated SSM values exhibited generally moderate accuracies (coefficient of determination R2 = 0.395, RMSE = 0.061 m3/m3) compared to SSM measurements at the Yucheng Comprehensive Experimental Station.

  15. Nuclear Air-Brayton Combined Cycle Power Conversion Design, Physical Performance Estimation and Economic Assessment

    Science.gov (United States)

    Andreades, Charalampos

    The combination of an increased demand for electricity for economic development in parallel with the widespread push for adoption of renewable energy sources and the trend toward liberalized markets has placed a tremendous amount of stress on generators, system operators, and consumers. Non-guaranteed cost recovery, intermittent capacity, and highly volatile market prices are all part of new electricity grids. In order to try and remediate some of these effects, this dissertation proposes and studies the design and performance, both physical and economic, of a novel power conversion system, the Nuclear Air-Brayton Combined Cycle (NACC). The NACC is a power conversion system that takes a conventional industrial frame type gas turbine, modifies it to accept external nuclear heat at 670°C, while also maintaining its ability to co-fire with natural gas to increase temperature and power output at a very quick ramp rate. The NACC addresses the above issues by allowing the generator to gain extra revenue through the provision of ancillary services in addition to energy payments, the grid operator to have a highly flexible source of capacity to back up intermittent renewable energy sources, and the consumer to possibly see less volatile electricity prices and a reduced probability of black/brown outs. This dissertation is split into six sections that delve into specific design and economic issues related to the NACC. The first section describes the basic design and modifications necessary to create a functional externally heated gas turbine, sets a baseline design based upon the GE 7FB, and estimates its physical performance under nominal conditions. The second section explores the off-nominal performance of the NACC and characterizes its startup and shutdown sequences, along with some of its safety measures. The third section deals with the power ramp rate estimation of the NACC, a key performance parameter in a renewable-heavy grid that needs flexible capacity. The

  16. Scenarios for the transmutation of actinides in CANDU reactors

    Energy Technology Data Exchange (ETDEWEB)

    Hyland, Bronwyn, E-mail: hylandb@aecl.ca [Atomic Energy of Canada Limited, Chalk River Laboratories, Chalk River, Ontario, K0J 1J0 (Canada); Gihm, Brian, E-mail: gihmb@aecl.ca [Atomic Energy of Canada Limited, 2251 Speakman Drive, Mississauga, Ontario, L5K 1B2 (Canada)

    2011-12-15

    With world stockpiles of used nuclear fuel increasing, the need to address the long-term utilization of this resource is being studied. Many of the transuranic (TRU) actinides in nuclear spent fuel produce decay heat for long durations, resulting in significant nuclear waste management challenges. These actinides can be transmuted to shorter-lived isotopes to reduce the decay heat period or consumed as fuel in a CANDU(R) reactor. Many of the design features of the CANDU reactor make it uniquely adaptable to actinide transmutation. The small, simple fuel bundle simplifies the fabrication and handling of active fuels. Online refuelling allows precise management of core reactivity and separate insertion of the actinides and fuel bundles into the core. The high neutron economy of the CANDU reactor results in high TRU destruction to fissile-loading ratio. This paper provides a summary of actinide transmutation schemes that have been studied in CANDU reactors at AECL, including the works performed in the past. The schemes studied include homogeneous scenarios in which actinides are uniformly distributed in all fuel bundles in the reactor, as well as heterogeneous scenarios in which dedicated channels in the reactor are loaded with actinide targets and the rest of the reactor is loaded with fuel. The transmutation schemes that are presented reflect several different partitioning schemes. Separation of americium, often with curium, from the other actinides enables targeted destruction of americium, which is a main contributor to the decay heat 100-1000 years after discharge from the reactor. Another scheme is group-extracted transuranic elements, in which all of the transuranic elements, plutonium (Pu), neptunium (Np), americium (Am), and curium (Cm) are extracted together and then transmuted. This paper also addresses ways of utilizing the recycled uranium, another stream from the separation of spent nuclear fuel, in order to drive the transmutation of other actinides.

  17. Combination of radar and daily precipitation data to estimate meaningful sub-daily point precipitation extremes

    Science.gov (United States)

    Bárdossy, András; Pegram, Geoffrey

    2017-01-01

    The use of radar measurements for the space time estimation of precipitation has for many decades been a central topic in hydro-meteorology. In this paper we are interested specifically in daily and sub-daily extreme values of precipitation at gauged or ungauged locations which are important for design. The purpose of the paper is to develop a methodology to combine daily precipitation observations and radar measurements to estimate sub-daily extremes at point locations. Radar data corrected using precipitation-reflectivity relationships lead to biased estimations of extremes. Different possibilities of correcting systematic errors using the daily observations are investigated. Observed gauged daily amounts are interpolated to unsampled points and subsequently disaggregated using the sub-daily values obtained by the radar. Different corrections based on the spatial variability and the subdaily entropy of scaled rainfall distributions are used to provide unbiased corrections of short duration extremes. Additionally a statistical procedure not based on a matching day by day correction is tested. In this last procedure as we are only interested in rare extremes, low to medium values of rainfall depth were neglected leaving a small number of L days of ranked daily maxima in each set per year, whose sum typically comprises about 50% of each annual rainfall total. The sum of these L day maxima is first iterpolated using a Kriging procedure. Subsequently this sum is disaggregated to daily values using a nearest neighbour procedure. The daily sums are then disaggregated by using the relative values of the biggest L radar based days. Of course, the timings of radar and gauge maxima can be different, so the method presented here uses radar for disaggregating daily gauge totals down to 15 min intervals in order to extract the maxima of sub-hourly through to daily rainfall. The methodologies were tested in South Africa, where an S-band radar operated relatively continuously at

  18. Separating the Minor Actinides Through Advances in Selective Coordination Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Self-interaction corrected local spin density calculations of actinides

    DEFF Research Database (Denmark)

    Petit, Leon; Svane, Axel; Szotek, Z

    2010-01-01

    We use the self-interaction corrected local spin-density approximation in order to describe localization-delocalization phenomena in the strongly correlated actinide materials. Based on total energy considerations, the methodology enables us to predict the ground-state valency configuration...... of the actinide ions in these compounds from first principles. Here we review a number of applications, ranging from electronic structure calculations of actinide metals, nitrides and carbides to the behaviour under pressure of intermetallics, and O vacancies in PuO2....

  20. Combining chemical and isotopic measurements to estimate pesticide degradation rates in a fractured-rock aquifer

    Science.gov (United States)

    Farlin, Julien; Gallé, Tom; Bayerle, Michael; Pittois, Denis; El-Khabbaz, Hassanya; Schreglmann, Kathrin; Höche, Martina; Elsner, Martin

    2013-04-01

    Encouraged by new regulatory requirements for pesticide registration and authorization, the transport and environmental fate of these compounds in the different environmental compartments has been studied extensively. Degradation rates vary widely depending on hydraulic and chemical characteristics, with the strongest degradation usually occuring in the topsoil. Nonetheless, significant pesticide attenuation may still take place during transport in the aquifer, since residence times are generally much longer than in the soil. Ideally, pesticide transformation in the aquifer needs to be determined under real field conditions. Mass balance calculations however are complicated by the fact that the initial pesticide mass leached from the soil is often not known precisely enough. In this study, isotopic and classical pesticide concentration measurements were combined with groundwater dating techniques to assess the degradation rate of atrazine and its metabolite desethylatrazine in a fractured sandstone. The mass balance problem was solved by introducing the desethylatrazine to atrazine ratio, a relative measure which was used to quantify the advancement of atrazine degradation with increasing transport time in the subsurface. The extent of transformation of the parent compound was finally estimated from the shift in the isotopic signal between soil application and the outlet of the groundwater system.

  1. SIMULTANEOUS ESTIMATION OF VALSARTAN AND HYDROCHLOROTHIAZIDE IN FIXED DOSE COMBINATION IN UV SPECTROPHOTOMETRY

    Directory of Open Access Journals (Sweden)

    M. M. Deshpande et al.

    2012-01-01

    Full Text Available Valsartan (VAL and Hydrochlorothiazide (HTZ are used in combination in treatment of Hypertension. Two simple, accurate, precise, economical and reproducible UV spectrophotometric methods have been developed for the estimation of Valsartan and Hydrochlorothiazide in Pharmaceutical formulation. Method I- Absorption ratio method (Q-analysis using two wavelengths, 265nm (isobestic point at which both the drugs exhibit absorbance 249nm (λmax of Valsartan and Method II- Area under Curve method. For the second method Area under the Curve in the range of 249 -259nm and 261-281nm was selected for the analysis of Valsartan and Hydrochlorothiazide respectively. Linearity for detector response was observed in the concentration range of 2-24g/ml & 2-14g/ml for Valsartan and Hydrochlorothiazide respectively. The results of analysis have been validated statistically and by recovery studies the value of standard deviation was satisfactory and recovery studies ranging from 99.54 - 99.97 % for Valsartan and 99.75 - 101.04 % for Hydrochlorothiazide were indicative of the accuracy and precision of the proposed method The proposed methods were successfully applied for the determination of Valsartan and Hydrochlorothiazide in commercial pharmaceutical preparation. All two methods were validated statistically as per ICH guidelines.

  2. On-line topical importance estimation: an effective focused crawling algorithm combining link and content analysis

    Institute of Scientific and Technical Information of China (English)

    Can WANG; Zi-yu GUAN; Chun CHEN; Jia-jun BU; Jun-feng WANG; Huai-zhong LIN

    2009-01-01

    Focused crawling is an important technique for topical resource discovery on the Web. The key issue in focusedcrawling is to prioritize uncrawled uniform resource locators (URLs) in the frontier to focus the crawling on relevant pages.Traditional focused crawlers mainly rely on content analysis. Link-based techniques are not effectively exploited despite their usefulness. In this paper, we propose a new frontier prioritizing algorithm, namely the on-line topical importance estimation (OTIE) algorithm. OTIE combines link-and content-based analysis to evaluate the priority of an uncrawled URL in the frontier. We performed real crawling experiments over 30 topics selected from the Open Directory Project (ODP) and compared harvest rate and target recall of the four crawling algorithms: breadth-first, link-context-prediction, on-line page importance computation (OPlC) and our OTIE. Experimental results showed that OTIE significantly outperforms the other three algorithms on the average target recall while maintaining an acceptable harvest rate. Moreover, OTIE is much faster than the traditional focused crawling algorithm.

  3. Human dental age estimation combining third molar(s) development and tooth morphological age predictors.

    Science.gov (United States)

    Thevissen, P W; Galiti, D; Willems, G

    2012-11-01

    In the subadult age group, third molar development, as well as age-related morphological tooth information can be observed on panoramic radiographs. The aim of present study was to combine, in subadults, panoramic radiographic data based on developmental stages of third molar(s) and morphological measurements from permanent teeth, in order to evaluate its added age-predicting performances. In the age range between 15 and 23 years, 25 gender-specific radiographs were collected within each age category of 1 year. Third molar development was classified and registered according the 10-point staging and scoring technique proposed by Gleiser and Hunt (1955), modified by Köhler (1994). The Kvaal (1995) measuring technique was applied on the indicated teeth from the individuals' left side. Linear regression models with age as response and third molar-scored stages as explanatory variables were developed, and morphological measurements from permanent teeth were added. From the models, determination coefficients (R (2)) and root-mean-square errors (RMSE) were calculated. Maximal-added age information was reported as a 6 % R² increase and a 0.10-year decrease of RMSE. Forensic dental age estimations on panoramic radiographic data in the subadult group (15-23 year) should only be based on third molar development.

  4. SPECTROPHOTOMETRIC METHOD FOR SIMULTANEOUS ESTIMATION OF MESALAMINE AND PREDNISOLONE IN COMBINED ORAL DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Dr. Sanjay Jain et al

    2012-10-01

    Full Text Available The objective of this study was to develop simple, precise, accurate, reproducible and economical vireodt's method for simultaneous estimation of mesalamine (MSM and prednisolone (PRD in combined oral dosage form. The method involved measurement of absorbance at two wavelengths, 332nm and 246nm, λmax of MSM and PRD, respectively in phosphate buffer (pH 7.4 with dimethyl formamide (DMF as cosolvent. The linearity was obtained in the concentration range of 5-50 µg/ml and 2-20 µg/ml for MSM and PRD, respectively. The average percent recovery of MSM and PRD was found to be 99.19+0.78% and 99.71+0.82%, respectively. The accuracy and precision were determined and recovery studies confirmed the accuracy of the developed method that was carried out following the International Conference on Harmonization (ICH guidelines. The recovery study was carried out by standard addition method. The proposed method was found to be rapid, specific, precise, accurate, and reproducible and can be successfully applied for the routine analysis of MSM and PRD in pharmaceutical dosage form.

  5. Combined Resistivity and Shear Wave Velocity Soil-type Estimation Beneath a Coastal Protection Levee.

    Science.gov (United States)

    Lorenzo, J. M.; Goff, D.; Hayashi, K.

    2015-12-01

    Unconsolidated Holocene deltaic sediments comprise levee foundation soils in New Orleans, USA. Whereas geotechnical tests at point locations are indispensable for evaluating soil stability, the highly variable sedimentary facies of the Mississippi delta create difficulties to predict soil conditions between test locations. Combined electrical resistivity and seismic shear wave studies, calibrated to geotechnical data, may provide an efficient methodology to predict soil types between geotechnical sites at shallow depths (0- 10 m). The London Avenue Canal levee flank of New Orleans, which failed in the aftermath of Hurricane Katrina, 2005, presents a suitable site in which to pioneer these geophysical relationships. Preliminary cross-plots show electrically resistive, high-shear-wave velocity areas interpreted as low-permeability, resistive silt. In brackish coastal environments, low-resistivity and low-shear-wave-velocity areas may indicate both saturated, unconsolidated sands and low-rigidity clays. Via a polynomial approximation, soil sub-types of sand, silt and clay can be estimated by a cross-plot of S-wave velocity and resistivity. We confirm that existent boring log data fit reasonably well with the polynomial approximation where 2/3 of soil samples fall within their respective bounds—this approach represents a new classification system that could be used for other mid-latitude, fine-grained deltas.

  6. The estimation of tax-benefit automatic stabilizers in Serbia: A combined micro-macro approach

    Directory of Open Access Journals (Sweden)

    Ranđelović Saša

    2013-01-01

    Full Text Available The large volatility of GDP due to the economic crisis, particularly in transition economies, has brought the issue of automatic stabilizers back into the focus of economic policy. The vast majority of empirical literature in this field relates to the estimation of the size of automatic stabilizers in developed countries, usually based on macroeconomic data. On the other hand empirical literature on this topic based on micro data, particularly for transition economies, is limited. This paper provides an evaluation of the size of automatic stabilizers in one transition economy (Serbia, by combining tax-benefit simulation modelling based on micro data and econometric methods based on macroeconomic data. The results show that, in the case of shock, around 17% of fall in market income would be absorbed by automatic stabilizers. Although the stabilizing effects of the tax-benefit system in Serbia are lower than in other European countries, the total size of automatic stabilizers is close to the average value in these countries, due to the higher elasticity of demand to income. The results also show that progressivity-enhancing income tax reform would only slightly increase automatic stabilizers, due to the large informal economy and the large share of agriculture in total households’ income.

  7. Estimation of load redistribution on a cable-stayed bridge using a combination of sensing techniques

    Science.gov (United States)

    Zonta, Daniele; Esposito, Paolo; Molignoni, Marco; Pozzi, Matteo; Zandonini, Riccardo; Wang, Ming; Zhao, Yang; Inaudi, Daniele; Posenato, Daniele; Glisic, Branko

    2012-04-01

    The motivation of this work is the installation of a monitoring system on a new cable-stayed bridge spanning the Adige River 10 km north of the town of Trento. This is a statically indeterminate structure, having a composite steel-concrete deck of length 260 m overall, supported by 12 stay cables, 6 per deck side. These are full locked steel cables of diameters 116 mm and 128 mm, designed for operational loads varying from 5000 to 8000 kN. The structural redundancy suggests that plastic load redistribution among the cables can be expected in the long term. To monitor such load redistribution, the owner decided to install a monitoring system to measure cable stress; the precision specified was of the order of few MPa. However no cable release or any form of on-site calibration involving tension change was allowed. The solution found was a combination of built-on-site electromagnetic and fiber-optic elongation gauges, these appropriately distributed on both the cables and the anchorages. We discuss how the set of gauges allows tension and elongation measurement with the appropriate precision, and compare the initial monitoring results with the tension estimates made using a non-destructive vibration test.

  8. Gamma spectroscopy of neutron rich actinide nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Birkenbach, Benedikt; Geibel, Kerstin; Vogt, Andreas; Hess, Herbert; Reiter, Peter; Steinbach, Tim; Schneiders, David [Koeln Univ. (Germany). IKP; Collaboration: AGATA-Collaboration

    2013-07-01

    Excited states in neutron-rich actinide Th and U nuclei were investigated after multi nucleon transfer reactions employing the AGATA demonstrator and PRISMA setup at LNL (INFN, Italy). A primary {sup 136}Xe beam of 1 GeV hitting a {sup 238}U target was used to produce the nuclei of interest. Beam-like reaction products of Xe- and Ba isotopes after neutron transfer were selected by the PRISMA spectrometer. The recoil like particles were registered by a MCP detector inside the scattering chamber. Coincident γ-rays from excited states in beam and target like particles were measured with the position sensitive AGATA HPGe detectors. Improved Doppler correction and quality of the γ-spectra is based on the novel γ-ray tracking technique which was successfully exploited. First results on the collective properties of various Th and U isotopes are discussed.

  9. Solidification of simulated actinides by natural zircon

    Institute of Scientific and Technical Information of China (English)

    YANG Jian-Wen; LUO Shang-Geng

    2004-01-01

    Natural zircon was used as precursor material to produce a zircon waste form bearing 20wt% simulated actinides (Nd2O3 and UO2) through a solid state reaction by a typical synroc fabrication process. The fabricated zircon waste form has relatively good physical properties (density 5.09g/cm3, open porosity 4.0%, Vickers hardness 715kg/mm2). The XRD, SEM/EDS and TEM/EDS analyses indicate that there are zircon phases containing waste elements formed through the reaction. The chemical durability and radiation stability are determined by the MCC-1method and heavy ion irradiation; the results show that the zircon waste form is highly leach resistance and relatively stable under irradiation (amorphous dose 0.7dpa). From this study, the method of using a natural mineral to solidify radioactive waste has proven to be feasible.

  10. Factors affecting the placental transfer of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Sikov, M.R.; Kelman, B.J. (Pacific Northwest Laboratory, Richland, WA (USA))

    1989-01-01

    The primary goal of this paper is to consider factors that affect the availability and transport of actinides from maternal blood, through the placenta, to the conceptus. These factors, of particular importance in scaling results from animals to man, include the route and temporal pattern of administration, the mass and physicochemical state of material administered, metabolism of the pregnant animal and fetal organs or tissue, and species-specific changes in placental structure relative to stage of gestation at exposure. Preliminary concepts for descriptive and kinetic models are proposed to integrate these results, to identify additional information required for developing more comprehensive models, and to provide a basis for scaling to human pregnancies for purposes of radiation dosimetry.

  11. Sigma Team for Minor Actinide Separation: PNNL FY 2011 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Lumetta, Gregg J.; Braley, Jenifer C.; Sinkov, Sergey I.; Levitskaia, Tatiana G.; Carter, Jennifer C.; Warner, Marvin G.; Pittman, Jonathan W.

    2011-08-13

    This report summarizes work conducted in FY 2011 at PNNL to investigate new methods of separating the minor actinide elements (Am and Cm) from the trivalent lanthanide elements, and separation of Am from Cm. For the former, work focused on a solvent extraction system combining an acidic extractant (HDEHP) with a neutral extractant (CMPO) to form a hybrid solvent extraction system referred to as TRUSPEAK (combining the TRUEX and TALSPEAK processes). For the latter, ligands that strongly bing uranyl ion were investigated for stabilizing corresponding americyl ion.

  12. Pyrometallurgical processes for recovery of actinide elements

    Energy Technology Data Exchange (ETDEWEB)

    Battles, J.E.; Laidler, J.J.; McPheeters, C.C.; Miller, W.E.

    1994-01-01

    A metallic fuel alloy, nominally U-20-Pu-lOZr, is the key element of the Integral Fast Reactor (IFR) fuel cycle. Metallic fuel permits the use of an innovative, simple pyrometallurgical process, known as pyroprocessing, (the subject of this report), which features fused salt electrorefining of the spent fuel. Electrorefining separates the actinide elements from fission products, without producing a separate stream of plutonium. The plutonium-bearing product is contaminated with higher actinides and with a minor amount of rare earth fission products, making it diversion resistant while still suitable as a fuel material in the fast spectrum of the IFR core. The engineering-scale demonstration of this process will be conducted in the refurbished EBR-II Fuel Cycle Facility, which has entered the start-up phase. An additional pyrometallurgical process is under development for extracting transuranic (TRU) elements from Light Water Reactor (LWR) spent fuel in a form suitable for use as a feed to the IFR fuel cycle. Four candidate extraction processes have been investigated and shown to be chemically feasible. The main steps in each process are oxide reduction with calcium or lithium, regeneration of the reductant and recycle of the salt, and separation of the TRU product from the bulk uranium. Two processes, referred to as the lithium and salt transport (calcium reductant) processes, have been selected for engineering-scale demonstration, which is expected to start in late 1993. An integral part of pyroprocessing development is the treatment and packaging of high-level waste materials arising from the operations, along with the qualification of these waste forms for disposal in a geologic repository.

  13. Studies of actinides in a superanoxic fjord

    Energy Technology Data Exchange (ETDEWEB)

    Roos, P.

    1997-04-01

    Water column and sediment profiles of Pu, Am, Th and U have been obtained in the superanoxic Framvaren fjord, southern Norway. The concentration of bomb test fallout Pu, Am as well as `dissolved` Th in the bottom water are the highest recorded in the marine environment. The behaviour of the actinides in the anoxic water mass is to a large extent governed by the behaviour of the colloidal material. Ultrafiltration reveals that 40-60% of the actinides are associated to the large colloids, surprisingly this is valid also for U. The sediment acts as a source for Pu, Am, and Th to the water column but primarily as a sink for U. The remobilization of Pu, Am and Th is evident from the water column profiles which have similar diffusion shape profiles as other constituents originating from the sediments. The vertical eddy diffusion coefficient calculated from the Pu profile is in the same order of magnitude as reported from the H{sub 2}S profile. Decreased bottom water concentrations (but a constant water column inventory) between 1989 and 1995 as well as pore water Pu concentrations nearly identical to the overlaying bottom water indicates that the present Pu flux from the sediments are low. Contrary to Pu and Am, the water column Th inventory ({sup 232}Th and {sup 230}Th) continues to increase. The flux of {sup 232}Th from the sediments was determined from changes in water column inventory between 1989 and 1995 and from a pore water profile to be in the order of 2-8 Bq/m{sup 2}/y. 208 refs.

  14. Radiochemical studies of neutron deficient actinide isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Williams, K.E.

    1978-04-01

    The production of neutron deficient actinide isotopes in heavy ion reactions was studied using alpha, gamma, x-ray, and spontaneous fission detection systems. A new isotope of berkelium, /sup 242/Bk, was produced with a cross-section of approximately 10 ..mu..b in reactions of boron on uranium and nitrogen on thorium. It decays by electron capture with a half-life of 7.0 +- 1.3 minutes. The alpha-branching ratio for this isotope is less than 1% and the spontaneous fission ratio is less than 0.03%. Studies of (Heavy Ion, pxn) and (Heavy Ion, ..cap alpha..xn) transfer reactions in comparison with (Heavy ion, xn) compound nucleus reactions revealed transfer reaction cross-sections equal to or greater than the compound nucleus yields. The data show that in some cases the yield of an isotope produced via a (H.I.,pxn) or (H.I.,..cap alpha..xn) reaction may be higher than its production via an xn compound nucleus reaction. These results have dire consequences for proponents of the ''Z/sub 1/ + Z/sub 2/ = Z/sub 1+2/'' philosophy. It is no longer acceptable to assume that (H.I.,pxn) and (H.I.,..cap alpha..xn) product yields are of no consequence when studying compound nucleus reactions. No evidence for spontaneous fission decay of /sup 228/Pu, /sup 230/Pu, /sup 232/Cm, or /sup 238/Cf was observed indicating that strictly empirical extrapolations of spontaneous fission half-life data is inadequate for predictions of half-lives for unknown neutron deficient actinide isotopes.

  15. AMS of actinides in groundwater: development of a new procedure for trace analysis of Np, Pu, Am and Cm isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Quinto, Francesca; Lagos, Markus; Plaschke, Markus; Schaefer, Thorsten; Geckeis, Horst [Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (KIT-INE), Hermann-von Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Steier, Peter [VERA Laboratory, Faculty of Physics, University of Vienna, Waehringer Strasse 17, A-1090 Vienna (Austria)

    2014-07-01

    In order to assess the actinides contamination in groundwater, their geochemistry is intensely studied in field and laboratory experiments focusing on speciation and ways of transport through the aquifers. A challenge lies in the analysis of actinides below ppq levels. We present a new analytical protocol suited to the measurement by accelerator mass spectrometry of Np, Pu, Am and Cm isotopes without previous chemical separation from each other. The actinides are quantitatively co-precipitated with Fe-hydroxide from the groundwater specimens. This procedure allows the pre-concentration of the actinides from the bulk elements and their incorporation into a sample matrix suited to the AMS measurements. The chemical yield of the co-precipitation is estimated measuring samples with suitable spikes by HR ICP-MS. At the AMS sytem: (a) the ionization yield of Np, Pu, Am and Cm in the given sample matrix, (b) the maximum number of nuclides per sample allowing detection limits below 0.01 ppq, and (c) the influence of the laboratory background on the results, are determined.

  16. Element Partitioning in Glass-Ceramic Designed for Actinides Immobilization

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    <正>Glass-ceramics were designed for immobilization of actinides. In order to immobilizing more wastes in the matrix and to develop the optimum formulation for the glass-ceramic, it is necessary to study the

  17. Advanced techniques for actinide spectroscopy (ATAS 2012). Abstract book

    Energy Technology Data Exchange (ETDEWEB)

    Foerstendorf, Harald; Mueller, Katharina; Steudtner, Robin (eds.)

    2012-07-01

    The abstract book of the International workshop on advanced techniques for actinide spectroscopy (ATAS 2012) include contributions concerning the following issues: environmental applications, NMR spectroscopy, vibrational spectroscopy, X-ray spectroscopy and theory, technical application: separation processes, emission spectroscopy.

  18. SIMULTANEOUS ESTIMATION OF DICLOFENAC SODIUM AND TOLPERISONE HYDROCHLORIDE IN COMBINED PHARMACEUTICAL FORMULATION

    Directory of Open Access Journals (Sweden)

    Bhavesh Gevriya* and R.C. Mashru

    2013-01-01

    Full Text Available Three simple, rapid, precise and accurate spectrophotometric methods have been developed for simultaneous analysis of Tolperisone Hydrochloride (TOL and Diclofenac Sodium (DIC in their combined dosage form. Method A, Simultaneous equation method (Vierodt’s method applies measurement of absorptivities at two wavelengths, 261.00 nm (λmax of Tolperisone Hydrochloride and 279.00 nm, (λmax of Diclofenac Sodium in zero order spectra. The concentrations can be calculated from the derived equations. Method B, Q-Absorbance equation method. It involves formation of Q-absorbance equation at 233.50 nm (isoabsorptive point and 261.00 nm (λmax of Tolperisone Hydrochloride in zero order spectra. Method C, Zero crossing first derivative spectrophotometry involves measurement of absorbance at 249.20 nm (for Tolperisone Hydrochloride and 227.40 nm (for Diclofenac Sodium in first derivative spectra. Developed methods were validated according to ICH guidelines. The calibration graph follows Beer’s law in the range of 6.0 to 18.0 μg/ml for Tolperisone Hydrochloride and 2.0 to 6.0 μg/ml for Diclofenac Sodium with R square value greater than 0.999. Accuracy of all methods was determined by recovery studies and showed % recovery between 98 to 102%. Intraday and interday precision was checked for all methods and mean %RSD was found to be less than 2 for all the methods. The methods were successfully applied for estimation of Tolperisone Hydrochloride and Diclofenac Sodium in marketed formulation.

  19. Dental age estimation in Japanese individuals combining permanent teeth and third molars.

    Science.gov (United States)

    Ramanan, Namratha; Thevissen, Patrick; Fleuws, Steffen; Willems, G

    2012-12-01

    The study aim was, firstly, to verify the Willems et al. model on a Japanese reference sample. Secondly to develop a Japanese reference model based on the Willems et al. method and to verify it. Thirdly to analyze the age prediction performance adding tooth development information of third molars to permanent teeth. Retrospectively 1877 panoramic radiographs were selected in the age range between 1 and 23 years (1248 children, 629 sub-adults). Dental development was registered applying Demirjian 's stages of the mandibular left permanent teeth in children and Köhler stages on the third molars. The children's data were, firstly, used to validate the Willems et al. model (developed a Belgian reference sample), secondly, split ino a training and a test sample. On the training sample a Japanese reference model was developed based on the Willems method. The developed model and the Willems et al; model were verified on the test sample. Regression analysis was used to detect the age prediction performance adding third molar scores to permanent tooth scores. The validated Willems et al. model provided a mean absolute error of 0.85 and 0.75 years in females and males, respectively. The mean absolute error in the verified Willems et al. and the developed Japanese reference model was 0.85, 0.77 and 0.79, 0.75 years in females and males, respectively. On average a negligible change in root mean square error values was detected adding third molar scores to permanent teeth scores. The Belgian sample could be used as a reference model to estimate the age of the Japanese individuals. Combining information from the third molars and permanent teeth was not providing clinically significant improvement of age predictions based on permanent teeth information alone.

  20. Analysis of the Gas Core Actinide Transmutation Reactor (GCATR)

    Science.gov (United States)

    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.

  1. Precipitation Estimation Using Combined Radar/Radiometer Measurements Within the GPM Framework

    Science.gov (United States)

    Hou, Arthur

    2012-01-01

    satellite of JAXA, (3) the Multi-Frequency Microwave Scanning Radiometer (MADRAS) and the multi-channel microwave humidity sounder (SAPHIR) on the French-Indian Megha- Tropiques satellite, (4) the Microwave Humidity Sounder (MHS) on the National Oceanic and Atmospheric Administration (NOAA)-19, (5) MHS instruments on MetOp satellites launched by the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), (6) the Advanced Technology Microwave Sounder (ATMS) on the National Polar-orbiting Operational Environmental Satellite System (NPOESS) Preparatory Project (NPP), and (7) ATMS instruments on the NOAA-NASA Joint Polar Satellite System (JPSS) satellites. Data from Chinese and Russian microwave radiometers may also become available through international collaboration under the auspices of the Committee on Earth Observation Satellites (CEOS) and Group on Earth Observations (GEO). The current generation of global rainfall products combines observations from a network of uncoordinated satellite missions using a variety of merging techniques. GPM will provide next-generation precipitation products characterized by: (1) more accurate instantaneous precipitation estimate (especially for light rain and cold-season solid precipitation), (2) intercalibrated microwave brightness temperatures from constellation radiometers within a consistent framework, and (3) unified precipitation retrievals from constellation radiometers using a common a priori hydrometeor database constrained by combined radar/radiometer measurements provided by the GPM Core Observatory.

  2. A method to combine non-probability sample data with probability sample data in estimating spatial means of environmental variables.

    Science.gov (United States)

    Brus, D J; de Gruijter, J J

    2003-04-01

    In estimating spatial means of environmental variables of a region from data collected by convenience or purposive sampling, validity of the results can be ensured by collecting additional data through probability sampling. The precision of the pi estimator that uses the probability sample can be increased by interpolating the values at the nonprobability sample points to the probability sample points, and using these interpolated values as an auxiliary variable in the difference or regression estimator. These estimators are (approximately) unbiased, even when the nonprobability sample is severely biased such as in preferential samples. The gain in precision compared to the pi estimator in combination with Simple Random Sampling is controlled by the correlation between the target variable and interpolated variable. This correlation is determined by the size (density) and spatial coverage of the nonprobability sample, and the spatial continuity of the target variable. In a case study the average ratio of the variances of the simple regression estimator and pi estimator was 0.68 for preferential samples of size 150 with moderate spatial clustering, and 0.80 for preferential samples of similar size with strong spatial clustering. In the latter case the simple regression estimator was substantially more precise than the simple difference estimator.

  3. [Estimating forest canopy cover by combining spaceborne ICESat-GLAS waveforms and mul- tispectral Landsat-TM images].

    Science.gov (United States)

    2015-06-01

    The spatial distribution of forest canopy cover is a critical indicator for evaluating the forest productivity and decomposition rates. With the Wangqing Forest Region in Jilin Province of China as the study area, this study first estimated the forest canopy cover using spaceborne LiDAR IC- ESat-GLAS waveforms and Landsat-TM multispectral images, respectively, and then GLAS data and TM images were combined to further estimate forest canopy cover by using multiple linear regression and BP neural network. The results showed that when the forest canopy cover was estimated with single data source, the determination coefficient of model was 0.762 for GLAS data and 0.598 for TM data. When the forest canopy cover was estimated by combining GLAS data and TM data, the determination coefficient of model was 0.841 for multiple linear regression, and the simulation precision was 0.851 for BP neural network. The study indicated that the combination of ICESat-GLAS data and Landsat-TM images could exploit the advantages of multi-source remote sensing data and improve the estimating accuracy of forest canopy cover, and it was expected to provide a promising way for spatially continuous mapping of forest canopy cover in future.

  4. Comparison of Point and Line Features and Their Combination for Rigid Body Motion Estimation

    DEFF Research Database (Denmark)

    Pilz, Florian; Pugeault, Nicolas; Krüger, Norbert

    2009-01-01

    means of SIFT descriptors). All features are then matched across stereo and time, and we use these correspondences to estimate the RBM by solving the 3D-2D pose estimation problem. We test dierent feature sets on various stereo image sequences, recorded in realistic outdoor and indoor scenes. We...

  5. Combined Yamamoto approach for simultaneous estimation of adsorption isotherm and kinetic parameters in ion-exchange chromatography.

    Science.gov (United States)

    Rüdt, Matthias; Gillet, Florian; Heege, Stefanie; Hitzler, Julian; Kalbfuss, Bernd; Guélat, Bertrand

    2015-09-25

    Application of model-based design is appealing to support the development of protein chromatography in the biopharmaceutical industry. However, the required efforts for parameter estimation are frequently perceived as time-consuming and expensive. In order to speed-up this work, a new parameter estimation approach for modelling ion-exchange chromatography in linear conditions was developed. It aims at reducing the time and protein demand for the model calibration. The method combines the estimation of kinetic and thermodynamic parameters based on the simultaneous variation of the gradient slope and the residence time in a set of five linear gradient elutions. The parameters are estimated from a Yamamoto plot and a gradient-adjusted Van Deemter plot. The combined approach increases the information extracted per experiment compared to the individual methods. As a proof of concept, the combined approach was successfully applied for a monoclonal antibody on a cation-exchanger and for a Fc-fusion protein on an anion-exchange resin. The individual parameter estimations for the mAb confirmed that the new approach maintained the accuracy of the usual Yamamoto and Van Deemter plots. In the second case, offline size-exclusion chromatography was performed in order to estimate the thermodynamic parameters of an impurity (high molecular weight species) simultaneously with the main product. Finally, the parameters obtained from the combined approach were used in a lumped kinetic model to simulate the chromatography runs. The simulated chromatograms obtained for a wide range of gradient lengths and residence times showed only small deviations compared to the experimental data.

  6. Effect of oxidation state and ionic strength on sorption of actinides (Th, U, Np, Am) to geologic media [Abstract and References Only

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Richmann, Michael K. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Reed, Donald T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-10-30

    The degree of conservatism in the estimated sorption partition coefficients (Kds) used in a performance assessment model is being evaluated based on a complementary batch and column method. The main focus of this work is to investigate the role of ionic strength, solution chemistry, and oxidation state (III-VI) in actinide sorption to dolomite rock. Based on redox conditions and solution chemistry expected at the WIPP, possible actinide species include Pu(III), Pu(IV), U(IV), U(VI), Np(IV), Np(V), Am(III), and Th(IV).

  7. Combined Parameter and State Estimation Algorithms for Multivariable Nonlinear Systems Using MIMO Wiener Models

    Directory of Open Access Journals (Sweden)

    Houda Salhi

    2016-01-01

    Full Text Available This paper deals with the parameter estimation problem for multivariable nonlinear systems described by MIMO state-space Wiener models. Recursive parameters and state estimation algorithms are presented using the least squares technique, the adjustable model, and the Kalman filter theory. The basic idea is to estimate jointly the parameters, the state vector, and the internal variables of MIMO Wiener models based on a specific decomposition technique to extract the internal vector and avoid problems related to invertibility assumption. The effectiveness of the proposed algorithms is shown by an illustrative simulation example.

  8. Criticality investigations for the fixed bed nuclear reactor using thorium fuel mixed with plutonium or minor actinides

    Energy Technology Data Exchange (ETDEWEB)

    Sahin, Suemer [Beykoz Lojistik Meslek Yueksekokulu, Beykoz, Istanbul (Turkey)], E-mail: sumer@gazi.edu.tr; Sahin, Haci Mehmet; Acir, Adem [Beykoz Lojistik Meslek Yueksekokulu, Istanbul (Turkey); Al-Kusayer, Tawfik Ahmed [King Saud University, College of Engineering, P.O. Box 800, Riyadh 11421 (Saudi Arabia)

    2009-08-15

    Prospective fuels for a new reactor type, the so called fixed bed nuclear reactor (FBNR) are investigated with respect to reactor criticality. These are (1) low enriched uranium (LEU); (2) weapon grade plutonium + ThO{sub 2}; (3) reactor grade plutonium + ThO{sub 2}; and (4) minor actinides in the spent fuel of light water reactors (LWRs) + ThO{sub 2}. Reactor grade plutonium and minor actinides are considered as highly radio-active and radio-toxic nuclear waste products so that one can expect that they will have negative fuel costs. The criticality calculations are conducted with SCALE5.1 using S{sub 8}-P{sub 3} approximation in 238 neutron energy groups with 90 groups in thermal energy region. The study has shown that the reactor criticality has lower values with uranium fuel and increases passing to minor actinides, reactor grade plutonium and weapon grade plutonium. Using LEU, an enrichment grade of 9% has resulted with k{sub eff} = 1.2744. Mixed fuel with weapon grade plutonium made of 20% PuO{sub 2} + 80% ThO{sub 2} yields k{sub eff} = 1.2864. Whereas a mixed fuel with reactor grade plutonium made of 35% PuO{sub 2} + 65% ThO{sub 2} brings it to k{sub eff} = 1.267. Even the very hazardous nuclear waste of LWRs, namely minor actinides turn out to be high quality nuclear fuel due to the excellent neutron economy of FBNR. A relatively high reactor criticality of k{sub eff} = 1.2673 is achieved by 50% MAO{sub 2} + 50% ThO{sub 2}. The hazardous actinide nuclear waste products can be transmuted and utilized as fuel in situ. A further output of the study is the possibility of using thorium as breeding material in combination with these new alternative fuels.

  9. Simulation with Ideal Switch Models Combined with Measured Loss Data Provides a Good Estimate of Power Loss

    Institute of Scientific and Technical Information of China (English)

    StigMunk-Nielsen; Lucian; N; Tutelea; Ulrik; Jager

    2007-01-01

    Ideally, converter losses should be determined without using an excessive amount of simulation time. State-of-the-art power semiconductor models provide good accuracy,unfortunately they often require a very long simulation time. This paper describes how to estimate power losses from simulation using ideal switches combined with measured power loss data. The semiconductor behavior is put into a look-up table,which replaces the advanced semiconductor models and shortens the simulation time.To extract switching and conduction losses, a converter is simulated and the semiconductor power losses are estimated. Measurement results on a laboratory converter are compared with the estimated losses and a good agreement is shown. Using the ideal switch simulation and the post processing power estimation program,a ten to twenty fold increase in simulation speed is obtained,compared to simulations using advanced models of semiconductors.

  10. Profiling and annotation combined method for multimedia application specific MPSoC performance estimation

    Institute of Scientific and Technical Information of China (English)

    Kai HUANG; Xiao-xu ZHANG; Si-wen XIU; Dan-dan ZHENG; Min YU; De MA; Kai HUANG; Gang CHEN; Xiao-lang YAN

    2015-01-01

    Accurate and fast performance estimation is necessary to drive design space exploration and thus support important design decisions. Current techniques are either time consuming or not accurate enough. In this paper, we solve these problems by presenting a hybrid method for multimedia multiprocessor system-on-chip (MPSoC) performance estimation. A general coverage analysis tool GNU gcov is employed to profi le the execution statistics during the native simulation. To tackle the complexity and keep the analysis and simulation manageable, the orthogonalization of communication and computation parts is adopted. The estimation result of the computation part is annotated to a transaction accurate model for further analysis, by which a gradual refi nement of MPSoC performance estimation is supported. The implementation and its experimental results prove the feasibility and efficiency of the proposed method.

  11. Combining four dimensional variational data assimilation and particle filtering for estimating volcanic ash emissions

    Science.gov (United States)

    Franke, Philipp; Elbern, Hendrik

    2016-04-01

    Estimating volcanic ash emissions is a very challenging task due to limited monitoring capacities of the ash plume and nonlinear processes in the atmosphere, which renders application of source strength and injection height estimations difficult. Most models, which estimate volcanic ash emissions, make strong simplifications of the dispersion of volcanic ash and corresponding atmospheric processes. The objective of this work is to estimate volcanic ash emissions and simulate the ensuing dispersion applying a full chemistry transport model in a hybrid approach by using its adjoint as well as an ensemble of model runs to quantify forecast uncertainties. Therefore, the four dimensional variational data assimilation version of the EURAD-IM chemistry transport model is extended to include a Sequential Importance Resampling Smoother (SIRS), introducing novel weighting and resampling strategies. In the main SIRS step the ensemble members exchange high rated emission patterns while rejecting emission patterns with low value for the forecast. The emission profiles of the ensemble members are perturbed afterwards to guarantee different emissions for all ensemble members. First identical twin experiments show the ability of the system to estimate the temporal and vertical distribution of volcanic ash emissions. The 4D-var data assimilation algorithm of the new system additionally provides quantitative emission estimation.

  12. Electrochemical decontamination system for actinide processing gloveboxes

    Energy Technology Data Exchange (ETDEWEB)

    Wedman, D.E.; Lugo, J.L.; Ford, D.K.; Nelson, T.O.; Trujillo, V.L.; Martinez, H.E.

    1998-03-01

    An electrolytic decontamination technology has been developed and successfully demonstrated at Los Alamos National Laboratory (LANL) for the decontamination of actinide processing gloveboxes. The technique decontaminates the interior surfaces of stainless steel gloveboxes utilizing a process similar to electropolishing. The decontamination device is compact and transportable allowing it to be placed entirely within the glovebox line. In this way, decontamination does not require the operator to wear any additional personal protective equipment and there is no need for additional air handling or containment systems. Decontamination prior to glovebox decommissioning reduces the potential for worker exposure and environmental releases during the decommissioning, transport, and size reduction procedures which follow. The goal of this effort is to reduce contamination levels of alpha emitting nuclides for a resultant reduction in waste level category from High Level Transuranic (TRU) to low Specific Activity (LSA, less than or equal 100 nCi/g). This reduction in category results in a 95% reduction in disposal and disposition costs for the decontaminated gloveboxes. The resulting contamination levels following decontamination by this method are generally five orders of magnitude below the LSA specification. Additionally, the sodium sulfate based electrolyte utilized in the process is fully recyclable which results in the minimum of secondary waste. The process bas been implemented on seven gloveboxes within LANL`s Plutonium Facility at Technical Area 55. Of these gloveboxes, two have been discarded as low level waste items and the remaining five have been reused.

  13. A Combined State of Charge Estimation Method for Lithium-Ion Batteries Used in a Wide Ambient Temperature Range

    Directory of Open Access Journals (Sweden)

    Fei Feng

    2014-05-01

    Full Text Available Ambient temperature is a significant factor that influences the characteristics of lithium-ion batteries, which can produce adverse effects on state of charge (SOC estimation. In this paper, an integrated SOC algorithm that combines an advanced ampere-hour counting (Adv Ah method and multistate open-circuit voltage (multi OCV method, denoted as “Adv Ah + multi OCV”, is proposed. Ah counting is a simple and general method for estimating SOC. However, the available capacity and coulombic efficiency in this method are influenced by the operating states of batteries, such as temperature and current, thereby causing SOC estimation errors. To address this problem, an enhanced Ah counting method that can alter the available capacity and coulombic efficiency according to temperature is proposed during the SOC calculation. Moreover, the battery SOCs between different temperatures can be mutually converted in accordance with the capacity loss. To compensate for the accumulating errors in Ah counting caused by the low precision of current sensors and lack of accurate initial SOC, the OCV method is used for calibration and as a complement. Given the variation of available capacities at different temperatures, rated/non-rated OCV–SOCs are established to estimate the initial SOCs in accordance with the Ah counting SOCs. Two dynamic tests, namely, constant- and alternated-temperature tests, are employed to verify the combined method at different temperatures. The results indicate that our method can provide effective and accurate SOC estimation at different ambient temperatures.

  14. Photofission of actinide and pre-actinide nuclei in the quasideuteron and delta energy regions

    CERN Document Server

    Berman, B L; Cole, P L; Dodge, W R; Feldman, G; Sanabria, J C; Kolb, N; Pywell, R E; Vogt, J; Nedorezov, V; Sudov, A; Kezerashvili, G Ya

    1999-01-01

    The photofission cross sections for the actinide nuclei sup 2 sup 3 sup 2 Th, sup 2 sup 3 sup 3 sup , sup 2 sup 3 sup 5 sup , sup 2 sup 3 sup 8 U, and sup 2 sup 3 sup 7 Np have been measured from 68 to 264 MeV and those for the pre-actinide nuclei sup 1 sup 9 sup 7 Au and sup N sup A sup T Pb from 122 to 222 MeV at the Saskatchewan Accelerator Laboratory, using monoenergetic tagged photons and novel parallel-plate avalanche detectors for the fission fragments. The aim of the experiment was to obtain a comprehensive and self-consistent data set and to investigate previous anomalous results in this energy region. The fission probability for transuranic nuclei is expected to be close to unity here. However, important discrepancies have been confirmed for sup 2 sup 3 sup 7 Np and sup 2 sup 3 sup 2 Th, compared with sup 2 sup 3 sup 8 U, which have serious implications for the inferred total photoabsorption strengths, and hence call into question the 'Universal Curve' for photon absorption at these energies. High-s...

  15. Studies on Neutron, Photon (Bremsstrahlung and Proton Induced Fission of Actinides and Pre-Actinides

    Directory of Open Access Journals (Sweden)

    H. Naik

    2015-08-01

    Full Text Available We present the yields of various fission products determined in the reactor neutron, 3.7-18.1 MeV quasi-mono energetic neutron, 8-80 MeV bremsstrahlung and 20-45 MeV proton induced fission of 232Th and 238U using radiochemical and off-line beta or gamma ray counting. The yields of the fission products in the bremsstrahlung induced fission natPb and 209Bi with 50- 70 MeV and 2.5 GeV based on off-line gamma ray spectrometric technique were also presented. From the yields of fission products, the mass chains yields were obtained using charge distribution correction. From the mass yield distribution, the peak-to-valley (P/V ratio was obtained. The role of excitation energy on the peak-to-valley ratio and fine structure such as effect of shell closure proximity and even-odd effect of mass yield distribution were examined. The higher yields of the fission products around A=133-134, 138-140 and 143-144 and their complementary products explained from the nuclear structure effect and role of standard I and II mode of asymmetric fission. In the neutron, photon (bremsstrahlung and proton induced fission, the asymmetric mass distribution for actinides (Th, U and symmetric distribution for pre-actinides (Pb, Bi were explained from different type of potential fission barrier

  16. Estimation Methods for Multicollinearity Proplem Combined with High Leverage Data Points

    Directory of Open Access Journals (Sweden)

    Moawad El-Fallah

    2011-01-01

    Full Text Available Problem statement: Least Squares (LS method has been the most popular method for estimating the parameters of a model due to its optimal properties and ease of computation. LS estimated regression may be seriously affected by multicollinearity which is a near linear dependency between two or more explanatory variables in the regression models. Although LS estimates are unbiased in the presence of multicollinearity, they will be imprecise with inflated standard errors of the estimated regression coefficients. Approach: In this study, we will study some alternative regression methods for estimating the regression parameters in the presence of multiple high leverage points which cause multicollinearity problem. These methods are mainly depend on a one step reweighted least square, where the initial weight functions were determined by the Diagnostic-Robust Generalized Potentials (DRGP. The proposed alternative methods in this study are called GM-DRGP-L1, GMDRGP- LTS, M-DRGP, MM-DRGP and DRGP-MM. Results: The empirical results of this study indicated that, the DRGP-MM and the GM-DRGP-LTS offers a substantial improvement over other methods for correcting the problems of high leverage points enhancing multicollinearity. Conclusion: The study had established that the DRGP-MM and the GM-DRGP-LTS methods were recommended to solve the multicollinearity problem with high leverage data points.

  17. Development of the Chalmers Grouped Actinide Extraction Process

    Directory of Open Access Journals (Sweden)

    Halleröd Jenny

    2015-12-01

    Full Text Available Several solvents for Grouped ActiNide EXtraction (GANEX processes have been investigated at Chalmers University of Technology in recent years. Four different GANEX solvents; cyclo-GANEX (CyMe4- -BTBP, 30 vol.% tri-butyl phosphate (TBP and cyclohexanone, DEHBA-GANEX (CyMe4-BTBP, 20 vol.% N,N-di-2(ethylhexyl butyramide (DEHBA and cyclohexanone, hexanol-GANEX (CyMe4-BTBP, 30 vol.% TBP and hexanol and FS-13-GANEX (CyMe4-BTBP, 30 vol.% TBP and phenyl trifluoromethyl sulfone (FS-13 have been studied and the results are discussed and compared in this work. The cyclohexanone based solvents show fast and high extraction of the actinides but a somewhat poor diluent stability in contact with the acidic aqueous phase. FS-13-GANEX display high separation factors between the actinides and lanthanides and a good radiolytic and hydrolytic stability. However, the distribution ratios of the actinides are lower, compared to the cyclohexanone based solvents. The hexanol-GANEX is a cheap solvent system using a rather stable diluent but the actinide extraction is, however, comparatively low.

  18. The actinides-a beautiful ending of the Periodic Table

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Boerje [Condensed Matter Theory Group, Department of Physics, Uppsala University, Box 530, S-751 21 Uppsala (Sweden); Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, Brinellvaegen 23, SE-100 44 Stockholm (Sweden)], E-mail: borje.johansson@fysik.uu.se; Li, Sa [Applied Materials Physics, Department of Materials Science and Engineering, Royal Institute of Technology, Brinellvaegen 23, SE-100 44 Stockholm (Sweden); Department of Physics, Virginia Commonwealth University, Richmond, VA 23284 (United States)

    2007-10-11

    The 5f elements, actinides, show many properties which have direct correspondence to the 4f transition metals, the lanthanides. The remarkable similarity between the solid state properties of compressed Ce and the actinide metals is pointed out in the present paper. The {alpha}-{gamma} transition in Ce is considered as a Mott transition, namely, from delocalized to localized 4f states. An analogous behavior is also found for the actinide series, where the sudden volume increase from Pu to Am can be viewed upon as a Mott transition within the 5f shell as a function of the atomic number Z. On the itinerant side of the Mott transition, the earlier actinides (Pa-Pu) show low symmetry structures at ambient conditions; while across the border, the heavier elements (Am-Cf) present the dhcp structure, an atomic arrangement typical for the trivalent lanthanide elements with localized 4f magnetic moments. The reason for an isostructural Mott transition of the f electron in Ce, as opposed to the much more complicated cases in the actinides, is identified. The strange appearance of the {delta}-phase (fcc) in the phase diagram of Pu is another consequence of the border line behavior of the 5f electrons. The path leading from {delta}-Pu to {alpha}-Pu is identified.

  19. A Summary of Actinide Enrichment Technologies and Capability Gaps

    Energy Technology Data Exchange (ETDEWEB)

    Patton, Bradley D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Robinson, Sharon M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-01-01

    The evaluation performed in this study indicates that a new program is needed to efficiently provide a national actinide radioisotope enrichment capability to produce milligram-to-gram quantities of unique materials for user communities as summarized in Table 1. This program xiv should leverage past actinide enrichment, the recent advances in stable isotope enrichment, and assessments of the future requirements to cost effectively develop this capability while establishing an experience base for a new generation of researchers in this vital area. Preliminary evaluations indicate that an EMIS device would have the capability to meet the future needs of the user community for enriched actinides. The EMIS technology could be potentially coupled with other enrichment technologies, such as irradiation, as pre-enrichment and/or post-enrichment systems to increase the throughput, reduce losses of material, and/or reduce operational costs of the base EMIS system. Past actinide enrichment experience and advances in the EMIS technology applied in stable isotope separations should be leveraged with this new evaluation information to assist in the establishment of a domestic actinide radioisotope enrichment capability.

  20. Hydrophilic actinide complexation studied by solvent extraction radiotracer technique

    Energy Technology Data Exchange (ETDEWEB)

    Rydberg, J. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Nuclear Chemistry and Radiochemistry Consultant Group, Vaestra Froelunda (Sweden)

    1996-10-01

    Actinide migration in the ground water is enhanced by the formation of water soluble complexes. It is essential to the risk analysis of a wet repository to know the concentration of central atoms and the ligands in the ground water, and the stability of complexes formed between them. Because the chemical behavior at trace concentrations often differ from that at macro concentrations, it is important to know the chemical behavior of actinides at trace concentrations in ground water. One method used for such investigations is the solvent extraction radiotracer (SXRT) technique. This report describes the SXRT technique in some detail. A particular reason for this analysis is the claim that complex formation constants obtained by SXRT are less reliable than results obtained by other techniques. It is true that several difficulties are encountered in the application of SXRT technique to actinide solution, such as redox instability, hydrophilic complexation by side reactions and sorption, but it is also shown that a careful application of the SXRT technique yields results as reliable as by any other technique. The report contains a literature survey on solvent extraction studies of actinide complexes formed in aqueous solutions, particularly by using the organic reagent thenoyltrifluoroacetone (TTA) dissolved in benzene or chloroform. Hydrolysis constants obtained by solvent extraction are listed as well as all actinide complexes studied by SX with inorganic and organic ligands. 116 refs, 11 tabs.

  1. An estimation method for InSAR interferometric phase combined with image auto-coregistration

    Institute of Scientific and Technical Information of China (English)

    LI Hai; LI Zhenfang; LIAO Guisheng; BAO Zheng

    2006-01-01

    In this paper we propose a method to estimate the InSAR interferometric phase of the steep terrain based on the terrain model of local plane by using the joint subspace projection technique proposed in our previous paper. The method takes advantage of the coherence information of neighboring pixel pairs to auto-coregister the SAR images and employs the projection of the joint signal subspace onto the corresponding joint noise subspace to estimate the terrain interferometric phase. The method can auto-coregister the SAR images and reduce the interferometric phase noise simultaneously. Theoretical analysis and computer simulation results show that the method can provide accurate estimate of the interferometric phase (interferogram) of very steep terrain even if the coregistration error reaches one pixel. The effectiveness of the method is verified via simulated data and real data.

  2. Combining Front Vehicle Detection with 3D Pose Estimation for a Better Driver Assistance

    Directory of Open Access Journals (Sweden)

    Yu Peng

    2012-09-01

    Full Text Available Driver assistant systems enhance traffic safety and efficiency. The accurate 3D pose of a front vehicle can help a driver to make the right decision on the road. We propose a novel real‐time system to estimate the 3D pose of the front vehicle. This system consists of two parallel threads: vehicle rear tracking and mapping. The vehicle rear is first identified in the video captured by an onboard camera, after license plate localization and foreground extraction. The 3D pose estimation technique is then employed with respect to the extracted vehicle rear. Most current 3D pose estimation techniques need prior models or a stereo initialization with user cooperation. It is extremely difficult to obtain prior models due to the varying appearance of vehicles’ rears. Moreover, it is unsafe to ask for drivers’ cooperation when a vehicle is running. In our system, two initial keyframes for stereo algorithms are automatically extracted by vehicle rear detection and tracking. Map points are defined as a collection of point features extracted from the vehicle’s rear with their 3D information. These map points are inferences that relate the 2D features detected in following vehicles’ rears with the 3D world. The relative 3D pose of the onboard camera to the front vehicle rear is then estimated through matching the map points with point features detected on the front vehicle rear. We demonstrate the capabilities of our system by testing on real‐time and synthesized videos. In order to make the experimental analysis visible, we demonstrated an estimated 3D pose through augmented reality, which needs accurate and real‐time 3D pose estimation.

  3. Estimation of psychological stress in humans: a combination of theory and practice.

    Science.gov (United States)

    Sood, Parul; Priyadarshini, Sushri; Aich, Palok

    2013-01-01

    Stress has long been known to increase susceptibility to health disorders. In 2009, American Psychological Association further established association of stress to serious health problems. However, a quantitative and accurate way to evaluate and estimate stress status of individuals is still a big challenge. It has been shown, in large animal models using cattle, that psychological stress can be quantified as well as disease susceptibility could be predicted through biomarker discovery. Taking cue from those studies, we have evaluated and estimated psychological stress level of individuals theoretically and validated experimentally. Various biomarkers have also been identified which can be associated to psychological stress to predict stress status of unknown individuals.

  4. An inverse problem of temperature estimation for the combination of the linear and nonlinear resistances

    Directory of Open Access Journals (Sweden)

    Slavica M. Perovich

    2011-06-01

    Full Text Available The subject of the theoretical analysis presented in this paper is an analytical approach to the temperature estimation, as an inverse problem, for different thermistors – linear resistances structures: series and parallel ones, by the STFT - Special Trans Functions Theory (S.M. Perovich. The mathematical formulae genesis of both cases is given. Some numerical and graphical simulations in MATHEMATICA program have been realized. The estimated temperature intervals for strongly determined values of the equivalent resistances of the nonlinear structures are given, as well.

  5. Ventilation system of actinides handling facility in Oarai-branch of Tohoku University

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Yoshimitsu; Watanabe, Makoto; Hara, Mituo; Shikama, Tatsuo; Kayano, Hideo; Mitsugashira, Toshiaki [Oarai Branch, Institute for Materials Research, Tohoku Univ., Oarai, Ibaraki (Japan)

    1999-09-01

    We have reported the development of the facility for handling actinides in Tohoku University at the second KAERI-JAERI joint seminar on PIE technology. Actinide isotopes have most hazurdous {alpha}-radioactivity. Therefore, a specially designed facility is necessary to carry out experimental study for actinide physics and chemistry. In this paper, we will describe the ventilation system and monitoring system for actinide handling facility. (author)

  6. Study of the actinide-lanthanide separation from nuclear waste by a new pyrochemical process; Etude de la separation actinides-lanthanides des dechets nucleaires par un procede pyrochimique nouveau

    Energy Technology Data Exchange (ETDEWEB)

    Lemort, F. [CEA Marcoule, Departement de Retraitement, des Dechets et du Demantelement, 30 - Bagnols-sur-Ceze (France)]|[Institut National Polytechnique, 38 - Grenoble (France)

    1997-01-01

    The theoretical extraction and separation of platinoids, actinides and lanthanides is allowed by thermodynamic using two adapted reducing agents: zinc and magnesium. Thereby, a pyrochemical method for the nuclear waste processing has been devised. The high temperature handling of the elements in fluoride forms and their processing by a reactive metallic phase required special precautions. The study of the behavior of matter in exploratory systems allowed the development of an experimental technology for the treatment and contacting of phases. The thermodynamical analysis of the experimental results shows the feasibility of the process. A model was developed to predict the distribution coefficients of zirconium, uranium and lanthanum as a function of the system composition. An estimation method was proposed in order to evaluate the distribution coefficients in diluted solution of all the actinides and lanthanides existing in the fission products between LiF CaF{sub 2} and Zn-Mg at 720 deg C. Coupled with the experimental results, the estimates results may be extrapolated to concentrated solutions allowing predictions of the separation of all actinides and lanthanides. The rapidity of element transfer is induced by a thermal effect caused by the high exothermicity of the reduction by magnesium. The kinetic coefficients have been linked with the reduction enthalpy of each element. Moreover, the kinetics seem limited by chemical reaction and not by mass transfer. (author) 66 refs.

  7. Combining Propensity Score Methods and Complex Survey Data to Estimate Population Treatment Effects

    Science.gov (United States)

    Stuart, Elizabeth A.; Dong, Nianbo; Lenis, David

    2016-01-01

    Complex surveys are often used to estimate causal effects regarding the effects of interventions or exposures of interest. Propensity scores (Rosenbaum & Rubin, 1983) have emerged as one popular and effective tool for causal inference in non-experimental studies, as they can help ensure that groups being compared are similar with respect to a…

  8. A combined vision-inertial fusion approach for 6-DoF object pose estimation

    Science.gov (United States)

    Li, Juan; Bernardos, Ana M.; Tarrío, Paula; Casar, José R.

    2015-02-01

    The estimation of the 3D position and orientation of moving objects (`pose' estimation) is a critical process for many applications in robotics, computer vision or mobile services. Although major research efforts have been carried out to design accurate, fast and robust indoor pose estimation systems, it remains as an open challenge to provide a low-cost, easy to deploy and reliable solution. Addressing this issue, this paper describes a hybrid approach for 6 degrees of freedom (6-DoF) pose estimation that fuses acceleration data and stereo vision to overcome the respective weaknesses of single technology approaches. The system relies on COTS technologies (standard webcams, accelerometers) and printable colored markers. It uses a set of infrastructure cameras, located to have the object to be tracked visible most of the operation time; the target object has to include an embedded accelerometer and be tagged with a fiducial marker. This simple marker has been designed for easy detection and segmentation and it may be adapted to different service scenarios (in shape and colors). Experimental results show that the proposed system provides high accuracy, while satisfactorily dealing with the real-time constraints.

  9. Detection limits for actinides in a monochromatic, wavelength-dispersive x-ray fluorescence instrument

    Energy Technology Data Exchange (ETDEWEB)

    Collins, Michael L [Los Alamos National Laboratory; Havrilla, George J [Los Alamos National Laboratory

    2009-01-01

    Recent developments in x-ray optics have made it possible to examine the L x-rays of actinides using doubly-curved crystals in a bench-top device. A doubly-curved crystal (DCC) acts as a focusing monochromatic filter for polychromatic x-rays. A Monochromatic, Wavelength-Dispersive X-Ray Fluorescence (MWDXRF) instrument that uses DCCs to measure Cm and Pu in reprocessing plant liquors was proposed in 2007 by the authors at Los Alamos National Laboratory. A prototype design of this MWDXRF instrument was developed in collaboration with X-ray Optical Systems Inc. (XOS), of East Greenbush, New York. In the MWDXRF instrument, x-rays from a Rhodium-anode x-ray tube are passed through a primary DCC to produce a monochromatic beam of 20.2-keV photons. This beam is focused on a specimen that may contain actinides. The 20.2-keV interrogating beam is just above the L3 edge of Californium; each actinide (with Z = 90 to 98) present in the specimen emits characteristic L x-rays as the result of L3-shell vacancies. In the LANL-XOS prototype MWDXRf, these x-rays enter a secondary DCC optic that preferentially passes 14.961-keV photons, corresponding to the L-alpha-1 x-ray peak of Curium. In the present stage of experimentation, Curium-bearing specimens have not been analyzed with the prototype MWDXRF instrument. Surrogate materials for Curium include Rubidium, which has a K-beta-l x-ray at 14.961 keV, and Yttrium, which has a K-alpha-1 x-ray at 14.958 keV. In this paper, the lower limit of detection for Curium in the LANL-XOS prototype MWDXRF instrument is estimated. The basis for this estimate is described, including a description of computational models and benchmarking techniques used. Detection limits for other actinides are considered, as well as future safeguards applications for MWDXRF instrumentation.

  10. Prompt Fission Neutron Spectra of Actinides

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-01-01

    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. The following technical areas were addressed: (i) experiments and uncertainty quantification (UQ): New data for neutron-induced fission of 233U, 235U, 238U, and 239Pu have been measured, and older data have been compiled and reassessed. There is evidence from the experimental work of this CRP that a very small percentage of neutrons emitted in fission are actually scission neutrons; (ii) modeling: The Los Alamos model (LAM) continues to be the workhorse for PFNS evaluations. Monte Carlo models have been developed that describe the fission phenomena microscopically, but further development is needed to produce PFNS evaluations meeting the uncertainty targets; (iii) evaluation methodologies: PFNS evaluations rely on the use of the least-squares techniques for merging experimental and model data. Considerable insight was achieved on how to deal with the problem of too small uncertainties in PFNS evaluations. The importance of considering that all experimental PFNS data are “shape” data was stressed; (iv) PFNS evaluations: New evaluations, including covariance data, were generated for major actinides including 1) non-model GMA evaluations of the 235U(nth,f), 239Pu(nth,f), and 233U(nth,f) PFNS based exclusively on experimental data (0.02 ≤ E ≤ 10 MeV), which resulted in PFNS average energies E of 2.00±0.01, 2.073±0.010, and 2.030±0.013 MeV, respectively; 2) LAM evaluations of neutron-induced fission spectra on uranium and plutonium targets with improved UQ for incident energies from thermal up to 30 MeV; and 3) Point-by-Point calculations for 232Th, 234U and 237Np targets; and (v) data

  11. Actinide (III) solubility in WIPP Brine: data summary and recommendations

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-09-01

    The solubility of actinides in the +3 oxidation state is an important input into the Waste Isolation Pilot Plant (WIPP) performance assessment (PA) models that calculate potential actinide release from the WIPP repository. In this context, the solubility of neodymium(III) was determined as a function of pH, carbonate concentration, and WIPP brine composition. Additionally, we conducted a literature review on the solubility of +3 actinides under WIPP-related conditions. Neodymium(III) was used as a redox-invariant analog for the +3 oxidation state of americium and plutonium, which is the oxidation state that accounts for over 90% of the potential release from the WIPP through the dissolved brine release (DBR) mechanism, based on current WIPP performance assessment assumptions. These solubility data extend past studies to brine compositions that are more WIPP-relevant and cover a broader range of experimental conditions than past studies.

  12. Fluoride-conversion synthesis of homogeneous actinide oxide solid solutions

    Energy Technology Data Exchange (ETDEWEB)

    Silva, G W Chinthaka M [ORNL; Hunn, John D [ORNL; Yeamans, Charles B. [University of California, Berkeley; Cerefice, Gary S. [University of Nevada, Las Vegas; Czerwinski, Ken R. [University of Nevada, Las Vegas

    2011-01-01

    Here, a novel route to synthesize (U, Th)O2 solid solutions at a relatively low temperature of 1100 C is demonstrated. First, the separate actinide oxides reacted with ammonium bifluoride to form ammonium actinide fluorides at room temperature. Subsequently, this mixture was converted to the actinide oxide solid solution using a two-phased heat treatment, first at 610 C in static air, then at 1100 C in flowing argon. Solid solutions obeying Vegard s Law were synthesized for ThO2 content from 10 to 90 wt%. Microscopy showed that the (U, Th)O2 solid solutions synthesized with this method to have considerably high crystallinity and homogeneity, suggesting the suitability of material thus synthesized for sintering into nuclear fuel pellets at low temperatures.

  13. Actinide consumption: Nuclear resource conservation without breeding

    Energy Technology Data Exchange (ETDEWEB)

    Hannum, W.H.; Battles, J.E.; Johnson, T.R.; McPheeters, C.C.

    1991-01-01

    A new approach to the nuclear power issue based on a metallic fast reactor fuel and pyrometallurgical processing of spent fuel is showing great potential and is approaching a critical demonstration phase. If successful, this approach will complement and validate the LWR reactor systems and the attendant infrastructure (including repository development) and will alleviate the dominant concerns over the acceptability of nuclear power. The Integral Fast Reactor (IFR) concept is a metal-fueled, sodium-cooled pool-type fast reactor supported by a pyrometallurgical reprocessing system. The concept of a sodium cooled fast reactor is broadly demonstrated by the EBR-II and FFTF in the US; DFR and PFR in the UK; Phenix and SuperPhenix in France; BOR-60, BN-350, BN-600 in the USSR; and JOYO in Japan. The metallic fuel is an evolution from early EBR-II fuels. This fuel, a ternary U-Pu-Zr alloy, has been demonstrated to be highly reliable and fault tolerant even at very high burnup (160-180,000 MWd/MT). The fuel, coupled with the pool type reactor configuration, has been shown to have outstanding safety characteristics: even with all active safety systems disabled, such a reactor can survive a loss of coolant flow, a loss of heat sink, or other major accidents. Design studies based on a small modular approach show not only its impressive safety characteristics, but are projected to be economically competitive. The program to explore the feasibility of actinide recovery from spent LWR fuel is in its initial phase, but it is expected that technical feasibility could be demonstrated by about 1995; DOE has not yet committed funds to achieve this objective. 27 refs.

  14. GM-PHD Filter Combined with Track-Estimate Association and Numerical Interpolation

    Directory of Open Access Journals (Sweden)

    Jinguang Chen

    2015-01-01

    Full Text Available For the standard Gaussian mixture probability hypothesis density (GM-PHD filter, the number of targets can be overestimated if the clutter rate is too high or underestimated if the detection rate is too low. These problems seriously affect the accuracy of multitarget tracking for the number and the value of measurements and clutters cannot be distinguished and recognized. Therefore, we proposed an improved GM-PHD filter to tackle these problems. Firstly, a track-estimate association was implemented in the filtering process to detect and remove false-alarm targets. Secondly, a numerical interpolation technique was used to compensate the missing targets caused by low detection rate. At the end of this paper, simulation results were presented to demonstrate the proposed GM-PHD algorithm is more effective in estimating the number and state of targets than the previous ones.

  15. Measurement of Actinides in Molybdenum-99 Solution Analytical Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Soderquist, Chuck Z. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Weaver, Jamie L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-11-01

    This document is a companion report to a previous report, PNNL 24519, Measurement of Actinides in Molybdenum-99 Solution, A Brief Review of the Literature, August 2015. In this companion report, we report a fast, accurate, newly developed analytical method for measurement of trace alpha-emitting actinide elements in commercial high-activity molybdenum-99 solution. Molybdenum-99 is widely used to produce 99mTc for medical imaging. Because it is used as a radiopharmaceutical, its purity must be proven to be extremely high, particularly for the alpha emitting actinides. The sample of 99Mo solution is measured into a vessel (such as a polyethylene centrifuge tube) and acidified with dilute nitric acid. A gadolinium carrier is added (50 µg). Tracers and spikes are added as necessary. Then the solution is made strongly basic with ammonium hydroxide, which causes the gadolinium carrier to precipitate as hydrous Gd(OH)3. The precipitate of Gd(OH)3 carries all of the actinide elements. The suspension of gadolinium hydroxide is then passed through a membrane filter to make a counting mount suitable for direct alpha spectrometry. The high-activity 99Mo and 99mTc pass through the membrane filter and are separated from the alpha emitters. The gadolinium hydroxide, carrying any trace actinide elements that might be present in the sample, forms a thin, uniform cake on the surface of the membrane filter. The filter cake is first washed with dilute ammonium hydroxide to push the last traces of molybdate through, then with water. The filter is then mounted on a stainless steel counting disk. Finally, the alpha emitting actinide elements are measured by alpha spectrometry.

  16. Estimating Cleanup Times Associated With Combining Source-Area Remediation With Monitored Natural Attenuation

    Science.gov (United States)

    2008-02-01

    by the U.S. Government in 1941 to store and dispose of military explosives . In 2000, the military mission in this area ceased causing the site to...at are primarily due to the discharge of water containing TCE, hydraulic fluid and ethylene glycol, along with the steam -cleaning operation of...downgradient monitoring wells (KBA-13A and USGS- 5) in the pretreatment plume, the range in the estimated composite retardation factor for total

  17. Improving Weather Radar Precipitation Estimates by Combining two Types of Radars

    DEFF Research Database (Denmark)

    Nielsen, Jesper Ellerbæk; Thorndahl, Søren Liedtke; Rasmussen, Michael R.

    2014-01-01

    the two radar types achieves a radar product with both long range and high temporal resolution. It is validated that the blended radar product performs better than the individual radars based on ground observations from laser disdrometers. However, the data combination is challenged by lower performance...

  18. [Estimation of combining ability of specialized types of the big white breed].

    Science.gov (United States)

    Berezovskiĭ, N D; Giria, V N

    1991-01-01

    The combining ability of the specialized intrabreed types of Estonian Big White (EBW-1) and Ukrainian Big White (UBW) selections of pigs has been studied by the results of their productivity using the first Griffing method (1956). Close agreement of theoretical and practical indices by the characters under study proves the possibility of applying this method to predict efficiency of interlinear big hybridization.

  19. [Estimation of combining ability of specialized types of the Big White breeds].

    Science.gov (United States)

    Berezovskiĭ, N D; Giria, V N

    1992-01-01

    The combining ability of the specialized intrabreed types of Estonia Big White (EBW-1) and Ukrainian Big White (UBW) breeding of pigs has been studied by the results of their productivity using the first Griffing method (1956). A close coincidence of theoretical and practical indices by the studied sings, proves the ability to use this method for prediction of interline hybridization of pigs.

  20. Estimating Net Primary Production of Swedish Forest Landscapes by Combining Mechanistic Modeling and Remote Sensing

    DEFF Research Database (Denmark)

    Tagesson, Håkan Torbern; Smith, Benjamin; Løfgren, Anders;

    2009-01-01

    The aim of this study was to investigate a combination of satellite images of leaf area index (LAI) with processbased vegetation modeling for the accurate assessment of the carbon balances of Swedish forest ecosystems at the scale of a landscape. Monthly climatologic data were used as inputs in a...

  1. Estimation of diversity and combining abilities in Helianthus annuus L. under water stress and normal conditions.

    Science.gov (United States)

    Saba, M; Khan, F A; Sadaqat, H A; Rana, I A

    2016-10-24

    Sunflower cannot produce high yields under water-limiting conditions. The aim of the present study was to prevent the impediments on yield and to develop varieties with high-yield potential under water scarce conditions. For achieving this objective, it is necessary to detect parents with desirable traits that mainly depend on the action of genes controlling the trait under improvement, combining ability, and genetic makeup of the parents. Heterosis can also be used to pool the desirable genes from genetically divergent varieties and these divergent parents could be detected by molecular studies. Ten tolerant and five susceptible tester lines were selected, crossed, and tested for genetic diversity using simple sequence repeat primers. We identified two parents (A-10.8 and G-60) that showed maximum (46.7%) genetic dissimilarity. On an average 3.1 alleles per locus were detected for twenty pair of primers. Evaluation of mean values revealed that under stress conditions the mean performances of the genotypes were reduced for all traits under study. Parent A-10.8 was consistent as a good general combiner for achene yield per plant under both non-stress and stress conditions. Line A-10.8 in the hybrid A-10.8 x G-60 proved to be a good combiner as it showed negative specific combining ability (SCA) effects for plant height and internodal length and positive SCA effects for head weight, achene yield per plant, and membrane stability index. Valuable information on gene action, combining ability, and heterosis was generated, which could be used in further breeding programs.

  2. Electronic structure and ionicity of actinide oxides from first principles

    DEFF Research Database (Denmark)

    Petit, Leon; Svane, Axel; Szotek, Z.

    2010-01-01

    The ground-state electronic structures of the actinide oxides AO, A2O3, and AO2 (A=U, Np, Pu, Am, Cm, Bk, and Cf) are determined from first-principles calculations, using the self-interaction corrected local spin-density approximation. Emphasis is put on the degree of f-electron localization, whi...... lanthanide oxides. The ionic nature of the actinide oxides emerges from the fact that only those compounds will form where the calculated ground-state valency agrees with the nominal valency expected from a simple charge counting....

  3. SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

    Science.gov (United States)

    Hildebrandt, R.A.; Hyman, H.H.; Vogler, S.

    1962-08-14

    A process of countercurrently extracting an aqueous mineral acid feed solution for the separation of actinides from lanthanides dissolved therern is described. The feed solution is made acid-defrcient with alkali metal hydroxide prior to.contact with acid extractant; during extraction, however, acid is transferred from organic to aqueous solution and the aqueous solution gradually becomes acid. The acid-deficient phase ' of the process promotes the extraction of the actinides, while the latter acid phase'' of the process improves retention of the lanthanides in the aqueous solution. This provides for an improved separation. (AEC)

  4. Physics studies of higher actinide consumption in an LMR

    Energy Technology Data Exchange (ETDEWEB)

    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.

  5. New cubic structure compounds as actinide host phases

    Energy Technology Data Exchange (ETDEWEB)

    Stefanovsky, S V [SIA Radon, 7th Rostovskii lane 2/14, Moscow 119121 (Russian Federation); Yudintsev, S V; Livshits, T S, E-mail: profstef@mtu-net.ru [Institute of Geology of Ore Deposits, Petrography, Mineralogy and Geochemistry RAS, Staromonetny lane 35, Moscow 119017 (Russian Federation)

    2010-03-15

    Various compounds with fluorite (cubic zirconia) and fluorite-derived (pyrochlore, zirconolite) structures are considered as promising actinide host phases at immobilization of actinide-bearing nuclear wastes. Recently some new cubic compounds - stannate and stannate-zirconate pyrochlores, murataite and related phases, and actinide-bearing garnet structure compounds were proposed as perspective matrices for complex actinide wastes. Zirconate pyrochlore (ideally Gd{sub 2}Zr{sub 2}O{sub 7}) has excellent radiation resistance and high chemical durability but requires high temperatures (at least 1500 deg. C) to be produced by hot-pressing from sol-gel derived precursor. Partial Sn{sup 4+} substitution for Zr{sup 4+} reduces production temperature and the compounds REE{sub 2}ZrSnO{sub 7} may be hot-pressed or cold pressed and sintered at {approx}1400 deg. C. Pyrochlore, A{sub 2}B{sub 2}O{sub 7-x} (two-fold elementary fluorite unit cell), and murataite, A{sub 3}B{sub 6}C{sub 2}O{sub 20-y} (three-fold fluorite unit cell), are end-members of the polysomatic series consisting of the phases whose structures are built from alternating pyrochlore and murataite blocks (nano-sized modules) with seven- (2C/3C/2C), five- (2C/3C), eight- (3C/2C/3C) and three-fold (3C - murataite) fluorite unit cells. Actinide content in this series reduces in the row: 2C (pyrochlore) > 7C > 5C > 8C > 3C (murataite). Due to congruent melting murataite-based ceramics may be produced by melting and the firstly segregated phase at melt crystallization is that with the highest fraction of the pyrochlore modules in its structure. The melts containing up to 10 wt. % AnO{sub 2} (An = Th, U, Np, Pu) or REE/An fraction of HLW form at crystallization zoned grains composed sequentially of the 5C {yields} 8C {yields} 3C phases with the highest actinide concentration in the core and the lowest - in the rim of the grains. Radiation resistance of the 'murataite' is comparable to titanate pyrochlores. One

  6. Thermally unstable complexants/phosphate mineralization of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K. [Argonne National Lab., IL (United States)

    1996-10-01

    In situ immobilization is an approach to isolation of radionuclides from the hydrosphere that is receiving increasing attention. Rather than removing the actinides from contaminated soils, this approach transforms the actinides into intrinsically insoluble mineral phases resistant to leaching by groundwater. The principal advangates of this concept are the low cost and low risk of operator exposure and/or dispersion of the radionuclides to the wider environment. The challenge of this approach is toe accomplish the immobilization without causing collateral damage to the environment (the cure shouldn`t be worse than the disease) and verification of system performance.

  7. New molecules for the separation of actinides (III): the picolinamides

    Energy Technology Data Exchange (ETDEWEB)

    Cordier, P.Y.; Condamines, N.; Berthon, L.; Madic, C.

    1994-12-31

    Minor actinide partitioning from high level liquid wastes produced during the reprocessing of nuclear fuels by the Purex process, requires the design of new extracting molecules. These new extractants must be able to separate, for example, actinides from lanthanides. This separation is very difficult, due to the similar chemical properties of these metallic species, but it can possibly be reached by using extractants with soft donor atoms (N or S). Some new molecules : the picolinamides are investigated in this way. The general chemical formula and the behaviour of these compounds in acidic media are given. (O.L.). 3 refs.

  8. An Improved Estimation of Regional Fractional Woody/Herbaceous Cover Using Combined Satellite Data and High-Quality Training Samples

    Directory of Open Access Journals (Sweden)

    Xu Liu

    2017-01-01

    Full Text Available Mapping vegetation cover is critical for understanding and monitoring ecosystem functions in semi-arid biomes. As existing estimates tend to underestimate the woody cover in areas with dry deciduous shrubland and woodland, we present an approach to improve the regional estimation of woody and herbaceous fractional cover in the East Asia steppe. This developed approach uses Random Forest models by combining multiple remote sensing data—training samples derived from high-resolution image in a tailored spatial sampling and model inputs composed of specific metrics from MODIS sensor and ancillary variables including topographic, bioclimatic, and land surface information. We emphasize that effective spatial sampling, high-quality classification, and adequate geospatial information are important prerequisites of establishing appropriate model inputs and achieving high-quality training samples. This study suggests that the optimal models improve estimation accuracy (NMSE 0.47 for woody and 0.64 for herbaceous plants and show a consistent agreement with field observations. Compared with existing woody estimate product, the proposed woody cover estimation can delineate regions with subshrubs and shrubs, showing an improved capability of capturing spatialized detail of vegetation signals. This approach can be applicable over sizable semi-arid areas such as temperate steppes, savannas, and prairies.

  9. Non-compound nucleus fission in actinide and pre-actinide regions

    Indian Academy of Sciences (India)

    R Tripathi; S Sodaye; K Sudarshan

    2015-08-01

    In this article, some of our recent results on fission fragment/product angular distributions are discussed in the context of non-compound nucleus fission. Measurement of fission fragment angular distribution in 28Si+176Yb reaction did not show a large contribution from the non-compound nucleus fission. Data on the evaporation residue cross-sections, in addition to those on mass and angular distributions, are necessary for better understanding of the contribution from non-compound nucleus fission in the pre-actinide region. Measurement of mass-resolved angular distribution of fission products in 20Ne+232Th reaction showed an increase in angular anisotropy with decreasing asymmetry of mass division. This observation can be explained based on the contribution from pre-equilibrium fission. Results of these studies showed that the mass dependence of anisotropy may possibly be used to distinguish pre-equilibrium fission and quasifission.

  10. The 'granite encapsulation' route to the safe disposal of Pu and other actinides

    Energy Technology Data Exchange (ETDEWEB)

    Gibb, F.G.F. [Immobilisation Science Laboratory, Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD (United Kingdom)], E-mail: f.gibb@sheffield.ac.uk; Taylor, K.J. [Department of Geography, University of Sheffield, Sheffield S10 2TN (United Kingdom); Burakov, B.E. [Laboratory of Applied Mineralogy and Radiogeochemistry, V.G. Khlopin Radium Institute, St. Petersburg 194021 (Russian Federation)

    2008-03-15

    Waste actinides, including plutonium, present a long-term management problem and a serious security issue. Immobilisation in mineral or ceramic waste forms for interim storage is a widely proposed first step. The safest, most secure geological disposal for Pu is in very deep boreholes and we propose that the key step to combination of these immobilisation and disposal concepts is encapsulation of the waste form in cylinders of recrystallized granite. We discuss the underpinning science, focusing on experimental work, and consider implementation. Finally, we present and discuss analyses of zircon, UO{sub 2} and Ce-doped cubic zirconia from high pressure and temperature experiments in granitic melts that demonstrate the viability of this solution and that actinides can be isolated from the environment for millions, maybe hundreds of millions, of years.

  11. SIMULTANEOUS ESTIMATION OF DICLOFENAC SODIUM AND TOLPERISONE HYDROCHLORIDE IN COMBINED PHARMACEUTICAL FORMULATION

    OpenAIRE

    Bhavesh Gevriya* and R.C. Mashru

    2013-01-01

    Three simple, rapid, precise and accurate spectrophotometric methods have been developed for simultaneous analysis of Tolperisone Hydrochloride (TOL) and Diclofenac Sodium (DIC) in their combined dosage form. Method A, Simultaneous equation method (Vierodt’s method) applies measurement of absorptivities at two wavelengths, 261.00 nm (λmax of Tolperisone Hydrochloride) and 279.00 nm, (λmax of Diclofenac Sodium) in zero order spectra. The concentrations can be calculated from the derived equati...

  12. LINE X TESTER ANALYSIS IN COMBINING ABILITIES ESTIMATION OF SUNFLOWER OIL CONTENT

    Directory of Open Access Journals (Sweden)

    Ivica Liović

    2012-12-01

    Full Text Available Results of line x tester analysis for 15 sunflower genotypes of the Agricultural Institute Osijek are presented in this paper. Three A lines (cms and three Rf testers with different oil content level (low, medium, high in all combinations (nine crosses were crossed in 2010. In 2011, the lines, testers and their crosses were sown in field trials at two locations (Karanac and Osijek. The oil content was determined after harvesting, whereas line x tester analysis was conducted based on the obtained results. Variance of lines and testers, which refers to the general combining ability (GCA was much higher than the variance of line x tester, related to specific combining ability (SCA. It showed on dominant role of the additive component of genetic variance in the inheritance of oil content. Statistically significant differences were not determined between the GCA and SCA effects. The highest values of GCA for oil content had line 2 (medium oil content and tester 6 (high oil content at both locations. The largest contribution for oil content had lines (57.81 and 51.28 % followed by testers (28.88 and 26.27 % and the lowest accounts for interaction (13.31 and 22.45 % at both locations (Karanac and Osijek.

  13. An Independent Component Analysis Algorithm through Solving Gradient Equation Combined with Kernel Density Estimation

    Institute of Scientific and Technical Information of China (English)

    XUE Yun-feng; WANG Yu-jia; YANG Jie

    2009-01-01

    A new algorithm for linear instantaneous independent component analysis is proposed based on max-imizing the log-likelihood contrast function which can be changed into a gradient equation. An iterative method is introduced to solve this equation efficiently. The unknown probability density functions as well as their first and second derivatives in the gradient equation are estimated by kernel density method. Computer simulations on artificially generated signals and gray scale natural scene images confirm the efficiency and accuracy of the proposed algorithm.

  14. Actinide(IV) Deposits on Bone: Potential Role of the Osteopontin-Thorium Complex.

    Science.gov (United States)

    Creff, Gaëlle; Safi, Samir; Roques, Jérôme; Michel, Hervé; Jeanson, Aurélie; Solari, Pier-Lorenzo; Basset, Christian; Simoni, Eric; Vidaud, Claude; Den Auwer, Christophe

    2016-01-04

    In case of a nuclear event, contamination (broad or limited) of the population or of specific workers might occur. In such a senario, the fate of actinide contaminants may be of first concern, in particular with regard to human target organs like the skeleton. To improve our understanding of the toxicological processes that might take place, a mechanistic approach is necessary. For instance, ∼50% of Pu(IV) is known from biokinetic data to accumulate in bone, but the underlining mechanisms are almost unknown. In this context, and to obtain a better description of the toxicological mechanisms associated with actinides(IV), we have undertaken the investigation, on a molecular scale, of the interaction of thorium(IV) with osteopontin (OPN) a hyperphosphorylated protein involved in bone turnover. Thorium is taken here as a simple model for actinide(IV) chemistry. In addition, we have selected a phosphorylated hexapeptide (His-pSer-Asp-Glu-pSer-Asp-Glu-Val) that is representative of the peptidic sequence involved in the bone interaction. For both the protein and the biomimetic peptide, we have determined the local environment of Th(IV) within the bioactinidic complex, combining isothermal titration calorimetry, attenuated total reflectance Fourier transform infrared spectroscopy, theoretical calculations with density functional theory, and extended X-ray absorption fine structure spectroscopy at the Th LIII edge. The results demonstrate a predominance of interaction of metal with the phosphate groups and confirmed the previous physiological studies that have highlighted a high affinity of Th(IV) for the bone matrix. Data are further compared with those of the uranyl case, representing the actinyl(V) and actinyl(VI) species. Last, our approach shows the importance of developing simplified systems [Th(IV)-peptide] that can serve as models for more biologically relevant systems.

  15. Estimating Forest Aboveground Biomass by Combining Optical and SAR Data: A Case Study in Genhe, Inner Mongolia, China.

    Science.gov (United States)

    Shao, Zhenfeng; Zhang, Linjing

    2016-06-07

    Estimation of forest aboveground biomass is critical for regional carbon policies and sustainable forest management. Passive optical remote sensing and active microwave remote sensing both play an important role in the monitoring of forest biomass. However, optical spectral reflectance is saturated in relatively dense vegetation areas, and microwave backscattering is significantly influenced by the underlying soil when the vegetation coverage is low. Both of these conditions decrease the estimation accuracy of forest biomass. A new optical and microwave integrated vegetation index (VI) was proposed based on observations from both field experiments and satellite (Landsat 8 Operational Land Imager (OLI) and RADARSAT-2) data. According to the difference in interaction between the multispectral reflectance and microwave backscattering signatures with biomass, the combined VI (COVI) was designed using the weighted optical optimized soil-adjusted vegetation index (OSAVI) and microwave horizontally transmitted and vertically received signal (HV) to overcome the disadvantages of both data types. The performance of the COVI was evaluated by comparison with those of the sole optical data, Synthetic Aperture Radar (SAR) data, and the simple combination of independent optical and SAR variables. The most accurate performance was obtained by the models based on the COVI and optical and microwave optimal variables excluding OSAVI and HV, in combination with a random forest algorithm and the largest number of reference samples. The results also revealed that the predictive accuracy depended highly on the statistical method and the number of sample units. The validation indicated that this integrated method of determining the new VI is a good synergistic way to combine both optical and microwave information for the accurate estimation of forest biomass.

  16. DEVELOPMENT AND VALIDATION OF SPECTROPHOTOMETRIC METHODS FOR SIMULTANEOUS ESTIMATION OF METOPROLOL SUCCINATE AND TELMISARTAN IN COMBINED PHARMACEUTICAL FORMULATION

    Directory of Open Access Journals (Sweden)

    Mayur Modi*, Rikin Shah and R.C. Mashru

    2012-05-01

    Full Text Available Four simple, rapid, precise, economical and accurate spectrophotometric methods have been developed for simultaneous analysis of Metoprolol succinate and Telmisartan in their combined dosage form. Method 1, First derivative simultaneous equation method (Vierodt’s method. It employs formation and solving of simultaneous equation using two wavelengths 230.2 nm (λmax of Metoprolol succinate and 237 nm (λmax of Telmisartan in first derivative spectra. Method 2, First derivative Q-Absorbance equation method. It involves, formation of Q-absorbance equation at 231.8 nm (isoabsorptive point and 237 nm (λmax of Telmisartan in first derivative spectra. Method 3, Absorbance correction method, involves measurement of absorbance at 296.6 nm for estimation of TEL and measurement of corrected absorbance at 223 nm for estimation of MET. Method 4, Combination of First derivative dual wavelength ,which uses the difference in absorbance at 282.4 nm and 284.6 nm for estimation of MET and zero crossing first derivative spectrophotometry involves measurement of amplitudes at 330 nm for estimation of TEL in first derivative spectra. Developed methods were validated according to ICH guidelines. The calibration graph follows Beer’s law in the range of 3-20 µg/ml for MET and 4-16 µg/ml for TEL with R square value greater than 0.999. Accuracy of all methods was determined by recovery studies and showed % recovery between 99 to 101%. Intraday and interday precision was checked for all methods and mean %RSD was found to be less than 2 for all the methods. The methods were successfully applied for estimation of MET and TEL in marketed formulation.

  17. Estimation of paleotemperature from racemization of aspartic acid in combination with radiocarbon age

    Science.gov (United States)

    Minami, Masayo; Takeyama, Masami; Mimura, Koichi; Nakamura, Toshio

    2007-06-01

    We tried to estimate paleotemperatures from two chosen fossils by measuring D/L aspartic acid ratios and radiocarbon ages of the XAD-2-treated hydrolysate fractions in the fossils. The D/L aspartic acid ratio was measured with a gas chromatograph and radiocarbon dating was performed using a Tandetron AMS system at Nagoya University. The radiocarbon age of a fossil mammoth molar collected from Bykovsky Peninsula, eastern Siberia, was found to be 35,170 ± 300 BP as an average value for the XAD-treated hydrolysate fractions. The aspartic acid in the mammoth molar showed a little evidence of racemization, which might be due to in vivo racemization during the lifetime and then suggests negligible or no postmortem racemization during burial in permafrost. From four animal bone fossils collected from a shell mound excavated at the Awazu submarine archeological site in Lake Biwa, Shiga, Japan, the racemization-based effective mean temperature was calculated to be 15-16 °C using the D/L aspartic acid ratio of about 0.11 and the 14C age of 4500 BP for the XAD-2-treated hydrolysate fractions in the fossils. The average annual temperature was estimated to be 11-12 °C, which approximates to the temperature that the fossils experienced during burial at the site. Although the application of racemization ratios in fossils as paleotemperature indicators is surrounded with many difficulties, the results obtained in this study suggest its feasibility.

  18. Estimation of paleotemperature from racemization of aspartic acid in combination with radiocarbon age

    Energy Technology Data Exchange (ETDEWEB)

    Minami, Masayo [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan)]. E-mail: minami@nendai.nagoya-u.ac.jp; Takeyama, Masami [Department of Earth and Planetary Sciences, School of Science, Nagoya 464-8602 (Japan); Mimura, Koichi [Graduate School of Environmental Studies, Nagoya University, Nagoya 464-8602 (Japan); Nakamura, Toshio [Center for Chronological Research, Nagoya University, Nagoya 464-8602 (Japan)

    2007-06-15

    We tried to estimate paleotemperatures from two chosen fossils by measuring D/L aspartic acid ratios and radiocarbon ages of the XAD-2-treated hydrolysate fractions in the fossils. The D/L aspartic acid ratio was measured with a gas chromatograph and radiocarbon dating was performed using a Tandetron AMS system at Nagoya University. The radiocarbon age of a fossil mammoth molar collected from Bykovsky Peninsula, eastern Siberia, was found to be 35,170 {+-} 300 BP as an average value for the XAD-treated hydrolysate fractions. The aspartic acid in the mammoth molar showed a little evidence of racemization, which might be due to in vivo racemization during the lifetime and then suggests negligible or no postmortem racemization during burial in permafrost. From four animal bone fossils collected from a shell mound excavated at the Awazu submarine archeological site in Lake Biwa, Shiga, Japan, the racemization-based effective mean temperature was calculated to be 15-16 deg. C using the D/L aspartic acid ratio of about 0.11 and the {sup 14}C age of 4500 BP for the XAD-2-treated hydrolysate fractions in the fossils. The average annual temperature was estimated to be 11-12 deg. C, which approximates to the temperature that the fossils experienced during burial at the site. Although the application of racemization ratios in fossils as paleotemperature indicators is surrounded with many difficulties, the results obtained in this study suggest its feasibility.

  19. Derivative Spectrophotometric Method for Estimation of Antiretroviral Drugs in Fixed Dose Combinations

    Directory of Open Access Journals (Sweden)

    Mohite P.B.

    2012-06-01

    Full Text Available Purpose: Lamivudine is cytosine and zidovudine is cytidine and is used as an antiretroviral agents. Both drugs are available in tablet dosage forms with a dose of 150 mg for LAM and 300 mg ZID respectively. Method: The method employed is based on first order derivative spectroscopy. Wavelengths 279 nm and 300 nm were selected for the estimation of the Lamovudine and Zidovudine respectively by taking the first order derivative spectra. The conc. of both drugs was determined by proposed method. The results of analysis have been validated statistically and by recovery studies as per ICH guidelines. Result: Both the drugs obey Beer’s law in the concentration range 10-50 μg mL-1,for LAM and ZID; with regression 0.9998 and 0.9999, intercept – 0.0677 and – 0.0043 and slope 0.0457 and 0.0391 for LAM and ZID, respectively.The accuracy and reproducibility results are close to 100% with 2% RSD. Conclusion: A simple, accurate, precise, sensitive and economical procedures for simultaneous estimation of Lamovudine and Zidovudine in tablet dosage form have been developed.

  20. Molecular and electronic structure of actinide hexa-cyanoferrates; Structure moleculaire et electronique des hexacyanoferrates d'actinides

    Energy Technology Data Exchange (ETDEWEB)

    Bonhoure, I

    2001-07-01

    The goal of this work is to improve our knowledge on the actinide-ligand bond properties. To this end, the hexacyanoferrate entities have been used as pre-organized ligand. We have synthesized, using mild chemistry, the following series of complexes: An{sup IV}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Th, U, Np, Pu); Am{sup III}[Fe{sup III}(CN){sub 6}].xH{sub 2}O; Pu {sup III}[Co{sup III}(CN){sub 6}].xH{sub 2}O and K(H?)An{sup III}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Pu, Am). The metal oxidation states have been obtained thanks to the {nu}{sub CN}, stretching vibration and to the actinide L{sub III} absorption edge studies. As Prussian Blue, the An{sup IV}[Fe{sup II}(CN){sub 6}].xH{sub 2}O (An = Np, Pu) are class II of Robin and Day compounds. X-ray Diffraction has shown besides that these complexes crystallize in the P6{sub 3}/m space group, as the isomorphic LaKFe(CN){sub 6}.4H{sub 2}O complex used as structural model. The EXAFS oscillations at the iron K edge and at the An L{sub III} edge allowed to determine the An-N, An-O, Fe-C and Fe-N distances. The display of the multiple scattering paths for both edges explains the actinide contribution absence at the iron edge, whereas the iron signature is present at the actinide edge. We have shown that the actinide coordination sphere in actinides hexa-cyanoferrates is comparable to the one of lanthanides. However, the actinides typical behavior towards the lanthanides is brought to the fore by the An{sup IV} versus Ln{sup III} ions presence in this family of complexes. Contrarily to the 4f electrons, the 5f electrons influence the electronic properties of the compounds of this family. However, the gap between the An-N and Ln-N distances towards the corresponding metals ionic radii do not show any covalence bond evolution between the actinide and lanthanide series. (author)

  1. Two smart spectrophotometric methods for the simultaneous estimation of Simvastatin and Ezetimibe in combined dosage form

    Science.gov (United States)

    Magdy, Nancy; Ayad, Miriam F.

    2015-02-01

    Two simple, accurate, precise, sensitive and economic spectrophotometric methods were developed for the simultaneous determination of Simvastatin and Ezetimibe in fixed dose combination products without prior separation. The first method depends on a new chemometrics-assisted ratio spectra derivative method using moving window polynomial least square fitting method (Savitzky-Golay filters). The second method is based on a simple modification for the ratio subtraction method. The suggested methods were validated according to USP guidelines and can be applied for routine quality control testing.

  2. Estimating Sea Surface Salinity and Wind Using Combined Passive and Active L-Band Microwave Observations

    Science.gov (United States)

    Yueh, Simon H.; Chaubell, Mario J.

    2012-01-01

    Several L-band microwave radiometer and radar missions have been, or will be, operating in space for land and ocean observations. These include the NASA Aquarius mission and the Soil Moisture Active Passive (SMAP) mission, both of which use combined passive/ active L-band instruments. Aquarius s passive/active L-band microwave sensor has been designed to map the salinity field at the surface of the ocean from space. SMAP s primary objectives are for soil moisture and freeze/thaw detection, but it will operate continuously over the ocean, and hence will have significant potential for ocean surface research. In this innovation, an algorithm has been developed to retrieve simultaneously ocean surface salinity and wind from combined passive/active L-band microwave observations of sea surfaces. The algorithm takes advantage of the differing response of brightness temperatures and radar backscatter to salinity, wind speed, and direction, thus minimizing the least squares error (LSE) measure, which signifies the difference between measurements and model functions of brightness temperatures and radar backscatter. The algorithm uses the conjugate gradient method to search for the local minima of the LSE. Three LSE measures with different measurement combinations have been tested. The first LSE measure uses passive microwave data only with retrieval errors reaching 1 to 2 psu (practical salinity units) for salinity, and 1 to 2 m/s for wind speed. The second LSE measure uses both passive and active microwave data for vertical and horizontal polarizations. The addition of active microwave data significantly improves the retrieval accuracy by about a factor of five. To mitigate the impact of Faraday rotation on satellite observations, the third LSE measure uses measurement combinations invariant under the Faraday rotation. For Aquarius, the expected RMS SSS (sea surface salinity) error will be less than about 0.2 psu for low winds, and increases to 0.3 psu at 25 m/s wind speed

  3. Estimation of BDS DCB Combining GIM and Different Zero-mean Constraints

    Directory of Open Access Journals (Sweden)

    YAO Yibin

    2017-02-01

    Full Text Available As the limited number of the BeiDou Navigation Satellite System (BDS satellites and tracking stations currently, it's difficult to attain daily DCBs solution with precisely high accuracy based on BeiDou single system. In order to overcome the weakness above, two different zero-mean constraints for BDS satellites, called constraint one and constraint two, respectively, are used to estimate DCBs of BDS based on BeiDou observations from the multi-GNSS experiment (MGEX network and global ionosphere maps (GIM from the Center for Orbit Determination in Europe (CODE. The results show that the systematic difference of the overall trend under two different constraints is consistent, and the systematic difference of DCBC2I-C7I and DCBC2I-C6I is -3.3 ns and 1.2 ns, respectively. The systematic difference between BDS satellite DCBs and receiver DCBs has the same absolute value, but opposite signs instead. Compared to constraint one, The DCBs estimation of IGSO/MEO satellites under constraint two are more stable (the improvement of satellites DCBC2I-C7I and DCBC2I-C6I STD are up to 21%, 13%, respectively, the stability of IGSO and MEO satellites (STDs are within 0.1 ns, 0.2 ns, respectively is better than that of GEO satellites (STDs are 0.15~0.32 ns. DCB estimation of constraint one is not only consistent with the CAS/DLR products (Bias:-0.4~0.2 ns, but also takes into account the stability of BDS satellites DCB. Under the two different constraints, there is no obvious change in BDS receiver DCBs, meaning that the selection of constraints has no obvious influence on the stability of BDS receivers DCBs. The overall stability of BDS receiver DCBs is better than 1 ns. Due to the accuracy discrepancy of GIM in different latitudes, the stability of BDS receiver DCBs in the middle-high latitude (STDs are within 0.4 ns is better than that in low latitude region (STDs are 0.8~1 ns.

  4. Combined evaluation of optical and microwave satellite dataset for soil moisture deficit estimation

    Science.gov (United States)

    Srivastava, Prashant K.; Han, Dawei; Islam, Tanvir; Singh, Sudhir Kumar; Gupta, Manika; Gupta, Dileep Kumar; Kumar, Pradeep

    2016-04-01

    Soil moisture is a key variable responsible for water and energy exchanges from land surface to the atmosphere (Srivastava et al., 2014). On the other hand, Soil Moisture Deficit (or SMD) can help regulating the proper use of water at specified time to avoid any agricultural losses (Srivastava et al., 2013b) and could help in preventing natural disasters, e.g. flood and drought (Srivastava et al., 2013a). In this study, evaluation of Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) and soil moisture from Soil Moisture and Ocean Salinity (SMOS) satellites are attempted for prediction of Soil Moisture Deficit (SMD). Sophisticated algorithm like Adaptive Neuro Fuzzy Inference System (ANFIS) is used for prediction of SMD using the MODIS and SMOS dataset. The benchmark SMD estimated from Probability Distributed Model (PDM) over the Brue catchment, Southwest of England, U.K. is used for all the validation. The performances are assessed in terms of Nash Sutcliffe Efficiency, Root Mean Square Error and the percentage of bias between ANFIS simulated SMD and the benchmark. The performance statistics revealed a good agreement between benchmark and the ANFIS estimated SMD using the MODIS dataset. The assessment of the products with respect to this peculiar evidence is an important step for successful development of hydro-meteorological model and forecasting system. The analysis of the satellite products (viz. SMOS soil moisture and MODIS LST) towards SMD prediction is a crucial step for successful hydrological modelling, agriculture and water resource management, and can provide important assistance in policy and decision making. Keywords: Land Surface Temperature, MODIS, SMOS, Soil Moisture Deficit, Fuzzy Logic System References: Srivastava, P.K., Han, D., Ramirez, M.A., Islam, T., 2013a. Appraisal of SMOS soil moisture at a catchment scale in a temperate maritime climate. Journal of Hydrology 498, 292-304. Srivastava, P.K., Han, D., Rico

  5. Winter wheat mapping combining variations before and after estimated heading dates

    Science.gov (United States)

    Qiu, Bingwen; Luo, Yuhan; Tang, Zhenghong; Chen, Chongcheng; Lu, Difei; Huang, Hongyu; Chen, Yunzhi; Chen, Nan; Xu, Weiming

    2017-01-01

    Accurate and updated information on winter wheat distribution is vital for food security. The intra-class variability of the temporal profiles of vegetation indices presents substantial challenges to current time series-based approaches. This study developed a new method to identify winter wheat over large regions through a transformation and metric-based approach. First, the trend surfaces were established to identify key phenological parameters of winter wheat based on altitude and latitude with references to crop calendar data from the agro-meteorological stations. Second, two phenology-based indicators were developed based on the EVI2 differences between estimated heading and seedling/harvesting dates and the change amplitudes. These two phenology-based indicators revealed variations during the estimated early and late growth stages. Finally, winter wheat data were extracted based on these two metrics. The winter wheat mapping method was applied to China based on the 250 m 8-day composite Moderate Resolution Imaging Spectroradiometer (MODIS) 2-band Enhanced Vegetation Index (EVI2) time series datasets. Accuracy was validated with field survey data, agricultural census data, and Landsat-interpreted results in test regions. When evaluated with 653 field survey sites and Landsat image interpreted data, the overall accuracy of MODIS-derived images in 2012-2013 was 92.19% and 88.86%, respectively. The MODIS-derived winter wheat areas accounted for over 82% of the variability at the municipal level when compared with agricultural census data. The winter wheat mapping method developed in this study demonstrates great adaptability to intra-class variability of the vegetation temporal profiles and has great potential for further applications to broader regions and other types of agricultural crop mapping.

  6. Combining ability and heritability estimates of main agronomic characters in rapeseed breeding lines using line × tester analysis

    Directory of Open Access Journals (Sweden)

    Rameeh Valiollah

    2012-01-01

    Full Text Available To estimate the general and specific combining ability (GCA and SCA effects of plant height, yield components, seed yield and oil content, three testers and six lines of spring type of rapeseed varieties were crossed using line × tester fashion. Significant mean squares of parents and crosses for all the traits indicated significant genetic variation among the parents and their F1 crosses. Significant mean squares of parents vs crosses revealed significant average heterosis for all the traits except seeds per pod, 1000-seed weight and oil content. High narrow-sense heritability estimates for all the traits except seeds per pod, indicating the importance of additive genetic effects for these traits. Due to more importance of additive genetic effects for most of the traits, only a few of the crosses exhibited significant SCA effects. A significant positive correlation between seed yield and some of yield components including pods on main axis, pods per plant and 1000-seed weight indicates that these traits can be used as suitable selection criteria for improving of seed yield. The crosses including Opt × R01, RG06 × R01, RG06 × R08 and RGS3 × R08 with 3241.91, 3213.68, 3334.28 and 3237.45 kg ha-1 of seed yield detected as prior combinations for improving of this trait and all of these combinations had also positive SCA effect for this trait.

  7. Combined Use of Airborne Lidar and DBInSAR Data to Estimate LAI in Temperate Mixed Forests

    Science.gov (United States)

    Peduzzi, Alicia; Wynne, Randolph Hamilton; Thomas, Valerie A.; Nelson, Ross F.; Reis, James J.; Sanford, Mark

    2012-01-01

    The objective of this study was to determine whether leaf area index (LAI) in temperate mixed forests is best estimated using multiple-return airborne laser scanning (lidar) data or dual-band, single-pass interferometric synthetic aperture radar data (from GeoSAR) alone, or both in combination. In situ measurements of LAI were made using the LiCor LAI-2000 Plant Canopy Analyzer on 61 plots (21 hardwood, 36 pine, 4 mixed pine hardwood; stand age ranging from 12-164 years; mean height ranging from 0.4 to 41.2 m) in the Appomattox-Buckingham State Forest, Virginia, USA. Lidar distributional metrics were calculated for all returns and for ten one meter deep crown density slices (a new metric), five above and five below the mode of the vegetation returns for each plot. GeoSAR metrics were calculated from the X-band backscatter coefficients (four looks) as well as both X- and P-band interferometric heights and magnitudes for each plot. Lidar metrics alone explained 69% of the variability in LAI, while GeoSAR metrics alone explained 52%. However, combining the lidar and GeoSAR metrics increased the R2 to 0.77 with a CV-RMSE of 0.42. This study indicates the clear potential for X-band backscatter and interferometric height (both now available from spaceborne sensors), when combined with small-footprint lidar data, to improve LAI estimation in temperate mixed forests.

  8. Preparation of actinide targets and sources using nonaqueous electrodeposition

    Energy Technology Data Exchange (ETDEWEB)

    Fowler, M.M.; Gursky, J.C.; Wilhelmy, J.B. (Los Alamos National Lab., NM (USA))

    1991-05-15

    Application of the method of 'molecular plating' to prepare actinide targets suitable for accelerator bombardment is presented. Two example applications involving {sup 229}Th and {sup 254}Es are discussed along with the merits and liabilities of the method. (orig.).

  9. Nuclear fuel cycle-oriented actinides separation in China

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jing; He, Xihong; Wang, Jianchen [Tsinghua Univ., Beijing (China). Inst. of Nuclear and New Energy Technology

    2014-04-01

    In the last decades, the separation of actinides was widely and continuously studied in China. A few kinds of salt-free reductants to adjust Pu and Np valences have been investigated. N,N-dimethylhydroxylamine is a good reductant with high reduction rate constants for the co-reduction of Pu(IV) and Np(VI), and monomethylhydrazine is a simple compound for the individual reduction of Np(VI). Advanced PUREX based on Organic Reductants (APOR) was proposed. Trialkylphosphine oxide (TRPO) with a single functional group was found to possess strong affinity to tri-, tetra- and hexa-valent actinides. TRPO process has been first explored in China for actinides partitioning from high level waste and the good partitioning performance was demonstrated by the hot test. High extraction selectivity for trivalent actinides over lanthanides by dialkyldithiophosphinic acids was originally found in China. A separation process based on purified Cyanex 301 for the separation of Am from lanthanides was presented and successfully tested in a battery of miniature centrifugal contactors. (orig.)

  10. RAPID SEPARATION OF ACTINIDES AND RADIOSTRONTIUM IN VEGETATION SAMPLES

    Energy Technology Data Exchange (ETDEWEB)

    Maxwell, S.

    2010-06-01

    A new rapid method for the determination of actinides and radiostrontium in vegetation samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations or for routine analysis. The actinides in vegetation method utilizes a rapid sodium hydroxide fusion method, a lanthanum fluoride 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. Alpha emitters are prepared using rare earth 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. The actinide and {sup 90}Sr in vegetation sample analysis can be performed in less than 8 h with excellent quality for emergency samples. The rapid fusion technique is a rugged sample digestion method that ensures that any refractory actinide particles or vegetation residue after furnace heating is effectively digested.

  11. Functionalized pyrazines as ligands for minor actinide extraction and catalysis

    NARCIS (Netherlands)

    Nikishkin, N.

    2013-01-01

    The research presented in this thesis concerns the design of ligands for a wide range of applications, from nuclear waste treatment to catalysis. The strategies employed to design actinide-selective extractants, for instance, comprise the fine tuning of the ligand electronic properties as well as us

  12. Actinide biocolloid formation in brine by halophilic bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J. [Brookhaven National Lab., Upton, NY (United States); Harris, R.; Beveridge, T.J. [Univ. of Guelph, Ontario (Canada); Brady, P.V.; Papenguth, H.W. [Sandia National Labs., Albuquerque, NM (United States)

    1998-12-31

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  13. ACTINIDE BIOCOLLOID FORMATION IN BRINE BY HALOPHILIC BACTERIA

    Energy Technology Data Exchange (ETDEWEB)

    GILLOW,J.B.; FRANCIS,A.J.; DODGE,C.J.; HARRIS,R.; BEVERIDGE,T.J.; BRADY,P.B.; PAPENGUTH,H.W.

    1998-11-09

    The authors examined the ability of a halophilic bacterium (WIPP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited solubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellularly as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  14. Actinide Biocolloid Formation in Brine by Halophilic Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Gillow, J.B.; Francis, A.J.; Dodge, C.J.; Harris, R.; Beveridge, T.J.; Brady, P.V.; Papenguth, H.W.

    1999-07-28

    We examined the ability of a halophilic bacterium (WFP 1A) isolated from the Waste Isolation Pilot Plant (WIPP) site to accumulate uranium in order to determine the potential for biocolloid facilitated actinide transport. The bacterial cell Surface functional groups involved in the complexation of the actinide were determined by titration. Uranium, added as uranyl nitrate, was removed from solution at pH 5 by cells but at pH 7 and 9 very little uranium was removed due to its limited volubility. Although present as soluble species, uranyl citrate at pH 5, 7, and 9, and uranyl carbonate at pH 9 were not removed by the bacterium because they were not bioavailable due to their neutral or negative charge. Addition of uranyl EDTA to brine at pH 5, 7, and 9 resulted in the immediate precipitation of U. Transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS) analysis revealed that uranium was not only associated with the cell surface but also accumulated intracellulary as uranium-enriched granules. Extended X-ray absorption fine structure (EXAFS) analysis, of the bacterial cells indicated the bulk sample contained more than one uranium phase. Nevertheless these results show the potential for the formation of actinide bearing bacterial biocolloids that are strictly regulated by the speciation and bioavailability of the actinide.

  15. Experimental Evaluation of Actinide Transport in a Fractured Granodiorite

    Energy Technology Data Exchange (ETDEWEB)

    Dittrich, Timothy M. [Los Alamos National Laboratory; Reimus, Paul W. [Los Alamos National Laboratory

    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)

  16. Estimation of annual energy production using dynamic wake meandering in combination with ambient CFD solutions

    Science.gov (United States)

    Hahn, S.; Machefaux, E.; Hristov, Y. V.; Albano, M.; Threadgill, R.

    2016-09-01

    In the present study, combination of the standalone dynamic wake meandering (DWM) model with Reynolds-averaged Navier-Stokes (RANS) CFD solutions for ambient ABL flows is introduced, and its predictive performance for annual energy production (AEP) is evaluated against Vestas’ SCADA data for six operating wind farms over semi-complex terrains under neutral conditions. The performances of conventional linear and quadratic wake superposition techniques are also compared, together with the in-house implemention of successive hierarchical merging approaches. As compared to our standard procedure based on the Jensen model in WindPRO, the overall results are promising, leading to a significant improvement in AEP accuracy for four of the six sites. While the conventional linear superposition shows the best performance for the improved four sites, the hierarchical square superposition shows the least deteriorated result for the other two sites.

  17. Predictions of Actinide Solubilities under Near-Field Conditions Expected in the WIPP

    Science.gov (United States)

    Brush, L. H.; Xiong, Y.

    2009-12-01

    , EDTA, and oxalate in TRU waste. The oxidation-state analogy was then used to extend the +III model to Pu(III), and the +IV model to Pu(IV), U(IV), and Np(IV). The solubility of U(VI) was estimated. For the recent WIPP Compliance Recertification Application PA Baseline Calculations, we calculated actinide solubilities with fCO2 buffered at 3.14 × 10-6 atm by the brucite-hydromagnesite carbonation reaction, with pH maintained at ~9 by the brucite dissolution-precipitation reaction, and with estimated concentrations of the organic ligands in brines from the Salado and the Castile Fm., which underlies the Salado. The calculated +III, +IV, and +V solubilities are 1.56 × 10-6, 5.64 × 10-8, and 4.07 × 10-7 M, respectively, in Salado brine; and 1.51 × 10-6, 6.98 × 10-8, and 8.75 × 10-7 M in Castile brine. The U(VI) solubility estimated for both brines is 1 × 10-3 M. This research is funded by WIPP programs administered by the U.S. Department of Energy. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

  18. Innovative SANEX process for trivalent actinides separation from PUREX raffinate

    Energy Technology Data Exchange (ETDEWEB)

    Sypula, Michal

    2013-07-01

    Recycling of nuclear spent fuel and reduction of its radiotoxicity by separation of long-lived radionuclides would definitely help to close the nuclear fuel cycle ensuring sustainability of the nuclear energy. Partitioning of the main radiotoxicity contributors followed by their conversion into short-lived radioisotopes is known as partitioning and transmutation strategy. To ensure efficient transmutation of the separated elements (minor actinides) the content of lanthanides in the irradiation targets has to be minimised. This objective can be attained by solvent extraction using highly selective ligands that are able to separate these two groups of elements from each other. The objective of this study was to develop a novel process allowing co-separation of minor actinides and lanthanides from a high active acidic feed solution with subsequent actinide recovery using just one cycle, so-called innovative SANEX process. The conditions of each step of the process were optimised to ensure high actinide separation efficiency. Additionally, screening tests of several novel lipophilic and hydrophilic ligands provided by University of Twente were performed. These tests were aiming in better understanding the influence of the extractant structural modifications onto An(III)/Ln(III) selectivity and complexation properties. Optimal conditions for minor actinides separation were found and a flow-sheet of a new innovative SANEX process was proposed. Tests using a single centrifugal contactor confirmed high Eu(III)/Am(III) separation factor of 15 while the lowest SF{sub Ln/Am} obtained was 6,5 (for neodymium). In addition, a new masking agent for zirconium was found as a substitution for oxalic acid. This new masking agent (CDTA) was also able to mask palladium without any negative influence on An(III)/Ln(III). Additional tests showed no influence of CDTA on plutonium present in the feed solution unlike oxalic acid which causes Pu precipitation. Therefore, CDTA was proposed as

  19. Deterioration estimation of paintings by means of combined 3D and hyperspectral data analysis

    Science.gov (United States)

    Granero-Montagud, Luís.; Portalés, Cristina; Pastor-Carbonell, Begoña.; Ribes-Gómez, Emilio; Gutiérrez-Lucas, Antonio; Tornari, Vivi; Papadakis, Vassilis; Groves, Roger M.; Sirmacek, Beril; Bonazza, Alessandra; Ozga, Izabela; Vermeiren, Jan; van der Zanden, Koen; Föster, Matthias; Aswendt, Petra; Borreman, Albert; Ward, Jon D.; Cardoso, António; Aguiar, Luís.; Alves, Filipa; Ropret, Polonca; Luzón-Nogué, José María.; Dietz, Christian

    2013-05-01

    Deterioration of artwork, in particular paintings, can be produced by environmental factors such as temperature fluctuations, relative humidity variations, ultraviolet radiation and biological factors among others. The effects of these parameters produce changes in both the painting structure and chemical composition. While well established analytical methodologies, such as those based in Raman Spectroscopy and FTIR Spectroscopy require the extraction of a sample for its inspection, other approaches such as hyperspectral imaging and 3D scanning present advantages for in-situ, noninvasive analysis of artwork. In this paper we introduce a novel system and the related methodology to acquire process, generate and analyze 4D data of paintings. Our system is based on non-contact techniques and is used to develop analytical tools which extract rich 3D and hyperspectral maps of the objects, which are processed to obtain accurate quantitative estimations of the deterioration and degradation present in the piece of art. In particular, the construction of 4D data allows the identification of risk maps on the painting representation, which can allow the curators and restorers in the task of painting state evaluation and prioritize intervention actions.

  20. COMBINING FEATURE SCALING ESTIMATION WITH SVM CLASSIFIER DESIGN USING GA APPROACH

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This letter adopts a GA (Genetic Algorithm) approach to assist in learning scaling of features that are most favorable to SVM (Support Vector Machines) classifier, which is named as GA-SVM. The relevant coefficients of various features to the classification task, measured by real-valued scaling, are estimated efficiently by using GA. And GA exploits heavy-bias operator to promote sparsity in the scaling of features. There are many potential benefits of this method:Feature selection is performed by eliminating irrelevant features whose scaling is zero, an SVM classifier that has enhanced generalization ability can be learned simultaneously. Experimental comparisons using original SVM and GA-SVM demonstrate both economical feature selection and excellent classification accuracy on junk e-mail recognition problem and Internet ad recognition problem. The experimental results show that comparing with original SVM classifier, the number of support vector decreases significantly and better classification results are achieved based on GA-SVM. It also demonstrates that GA can provide a simple, general, and powerful framework for tuning parameters in optimal problem, which directly improves the recognition performance and recognition rate of SVM.

  1. A new model for estimating subsurface ice content based on combined electrical and seismic data sets

    Directory of Open Access Journals (Sweden)

    C. Hauck

    2011-06-01

    Full Text Available Detailed knowledge of the material properties and internal structures of frozen ground is one of the prerequisites in many permafrost studies. In the absence of direct evidence, such as in-situ borehole measurements, geophysical methods are an increasingly interesting option for obtaining subsurface information on various spatial and temporal scales. The indirect nature of geophysical soundings requires a relation between the measured variables (e.g. electrical resistivity, seismic velocity and the actual subsurface constituents (rock, water, air, ice. In this work, we present a model which provides estimates of the volumetric fractions of these four constituents from tomographic electrical and seismic images. The model is tested using geophysical data sets from two rock glaciers in the Swiss Alps, where ground truth information in form of borehole data is available. First results confirm the applicability of the so-called 4-phase model, which allows to quantify the contributions of ice-, water- and air within permafrost areas as well as detecting solid bedrock. Apart from a similarly thick active layer with enhanced air content for both rock glaciers, the two case studies revealed a heterogeneous distribution of ice and unfrozen water within Muragl rock glacier, where bedrock was detected at depths of 20–25 m, but a comparatively homogeneous ice body with only minor heterogeneities within Murtèl rock glacier.

  2. Combining sap flow meas- urement-based canopy stomatal conductance and 13C discrimination to estimate forest carbon assimilation

    Institute of Scientific and Technical Information of China (English)

    ZHAO Ping; LU Ping; MA Ling; SUN Guchou; RAO Xingquan; CAI Xian; ZENG Xiaoping

    2005-01-01

    The available methods for studying C uptake of forest and their problems in practices are reviewed, and a new approach to combining sap flow and 13C techniques is proposed in this paper. This approach, obtained through strict mathematic derivation, combines sap flow measurement-based canopy stomatal conductance and 13C discrimination to estimate instantaneous carbon assimilation rate of a forest. Namely the mean canopy stomatal conductance (gc) acquired from accurate measurement of sap flux density is integrated with the relationship between 13C discrimination (() and Ci/Ca (intercellular/ambient CO2 concentrations) and with that between Anet (net photosynthetic rate) and gCO2 (stomatal conductance for CO2) so that a new relation between forest C uptake and ( as well as gc is established. It is a new method of such kind for studying the C exchange between forest and atmosphere based on experimental ecology.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Sequestering agents for the removal of actinides from waste streams

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, K.N.; White, D.J.; Xu, Jide; Mohs, T.R. [Univ. of California, Berkeley, CA (United States)

    1997-10-01

    The goal of this project is to take a biomimetic approach toward developing new separation technologies for the removal of radioactive elements from contaminated DOE sites. To achieve this objective, the authors are investigating the fundamental chemistry of naturally occurring, highly specific metal ion sequestering agents and developing them into liquid/liquid and solid supported actinide extraction agents. Nature produces sideophores (e.g., Enterobactin and Desferrioxamine B) to selectivity sequester Lewis acidic metal ions, in particular Fe(III), from its surroundings. These chelating agents typically use multiple catechols or hydroxamic acids to form polydentate ligands that chelate the metal ion forming very stable complexes. The authors are investigating and developing analogous molecules into selective chelators targeting actinide(IV) ions, which display similar properties to Fe(III). By taking advantage of differences in charge, preferred coordination number, and pH stability range, the transition from nature to actinide sequestering agents has been applied to the development of new and highly selective actinide extraction technologies. Additionally, the authors have shown that these chelating ligands are versatile ligands for chelating U(VI). In particular, they have been studying their coordination chemistry and fundamental interactions with the uranyl ion [UO{sub 2}]{sup 2+}, the dominant form of uranium found in aqueous media. With an understanding of this chemistry, and results obtained from in vivo uranium sequestration studies, it should be possible to apply these actinide(IV) extraction technologies to the development of new extraction agents for the removal of uranium from waste streams.

  5. Combining flow routing modelling and direct velocity measurement for optimal discharge estimation

    Directory of Open Access Journals (Sweden)

    G. Corato

    2011-03-01

    Full Text Available A new procedure is proposed for estimating river discharge hydrographs during flood events, using only water level data measured at a gauged site, as well as 1-D shallow water modelling and sporadic maximum surface flow velocity measurements. During flood, the piezometric level is surmised constant in the vertical plane of the river section, where the top of the banks is always above the river level, and is well represented by the recorded stage hydrograph. The river is modelled along the reach directly located downstream the upstream gauged section, where discharge hydrograph is sought after. For the stability with respect to the topographic error, as well as for the simplicity of the data required to satisfy the boundary conditions, a diffusive hydraulic model is adopted for flow routing. Assigned boundary conditions are: (1 the recorded stage hydrograph at the upstream river site and (2 the zero diffusion condition at the downstream end of the reach. The MAST algorithm is used for the numerical solution of the flow routing problem, which is embedded in the Brent algorithm used for the computation of the optimum Manning coefficient. Based on synthetic tests concerning a broad prismatic channel, the optimal reach length is chosen so that the approximated downstream boundary condition effects on discharge hydrograph assessment at upstream end are negligible. The roughness Manning coefficient is calibrated by using sporadic instantaneous surface velocity measurements during the rising limb of flood that are turned into instantaneous discharges through the solid of velocity estimated by a two-dimensional entropic model. Several historical events, occurring in three gauged sites along the upper Tiber River wherein a reliable rating curve is available, have been used for the validation. The analysis outcomes can be so summarized: (1 criteria adopted for selecting the optimal channel length and based on synthetic tests have been proved reliable by

  6. Permeability Estimation of Grosmont Formation, Alberta, Canada by Statistically Combining Well-logs and Core Measurements

    Science.gov (United States)

    Choi, J.; Keehm, Y.

    2011-12-01

    Permeability estimation in carbonate reservoirs is quite challenging since they are very heterogeneous. Moreover, the amount of core measurement data is commonly limited. In this paper, we present permeability maps for Grosmont formation in Canada with very limited permeability data, using bi-variated probability density function (porosity and permeability) conditioned to geological information. Grosmont formation consists of four units: Lower Grosmont (LG); Upper Grosmont (UG1); Upper Grosmont 2 (UG2); and Upper Grosmont 3 (UG3). From the previous studies, UG2 and UG3 are more promising reservoir units since they have larger porosity and permeability with vuggy pores and fractures by diagenesis (dolomitization and karstification). Thus, we applied our method to these two units. We first investigated core measurement data (porosity and permeability) and compared them to local geological aspects, such as the degree of diagenesis and vicinity of unconformity. Then we could divide the study area into 6 groups, and we established a bivariated probability density function (pdf) for each group and each unit (total of 12 pdfs) with core measurements of porosity and permeability. In the next step, we created porosity maps using well-log data for UG2 and UG3. The final step is to generate permeability maps for UG2 and UG3 by drawing a permeability value from the bivariated pdf conditioned to porosity. The final results show more realistic permeability maps for Grosmont formation when compared to conventional kriging results. Moreover, the strengths of this approach is (1) that it can use geological information and (2) that it can handle the variability of permeability, which can be naturally occurred in carbonate reservoirs. Acknowledgement: This work was supported by the Energy Resources R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2008RER11P0430302009).

  7. Classification of Kidney Transplant Recipients Using a Combination of Estimated GFR and Albuminuria Reflects Risk

    Science.gov (United States)

    White, Christine A.; Akbari, Ayub; Talreja, Hari; Lalani, Neha; Knoll, Greg A.

    2016-01-01

    Background The 2012 Kidney Dialysis Initiative Global Outcomes chronic kidney disease (CKD) classification scheme subdivides stage 3 CKD and incorporates the urinary albumin-to-creatinine ratio (ACR). The aim of this study was to evaluate whether the novel scheme provides graded risk in kidney transplant recipients (KTRs). Methods Prevalent KTRs with available laboratory data were included. The primary outcome was a composite of doubling of serum creatinine, graft failure, or death. Patients were stratified using the CKD-Epidemiolgic Collaboration equation, and ACR and the event rate per 1000 patient-years in each CKD category were calculated. Results There were 269 KTRs with a mean follow-up of 4.5 ± 2.0 years. There was a graded increase in outcomes with increasing ACR and decreasing estimated glomerular filtration rate (eGFR). For the primary outcome, the event rate was 15.3 (95% confidence interval, 4.2-39.2) per 1000 patient-years for those with an eGFR greater than 60 mL/min per 1.73 m2 and an ACR less than 30 mg/g, whereas it was 375 (95% confidence interval, 193.8-655.1) for those with an eGFR less than 30 mL/min per 1.73 m2 and an ACR greater than 300 mg/g. Conclusions The novel Kidney Dialysis Initiative Global Outcomes classification scheme provides graded risk for important clinical events in KTRs. This information can be used to identify high-risk patients and to tailor follow-up and management strategies aimed at improving outcomes.

  8. Combined Ultrasound Imaging and Biomechanical Modeling to Estimate Triceps Brachii Musculotendon Changes in Stroke Survivors

    Directory of Open Access Journals (Sweden)

    Le Li

    2016-01-01

    Full Text Available The aim of this study was to investigate the changes of musculotendon parameters of triceps brachii in persons after stroke based on subject-specific biomechanical modeling technique combined with in vivo ultrasound measurement. Five chronic stroke survivors and five normal control subjects were recruited. B-mode ultrasound was applied to measure muscle pennation angle and the optimal length of three heads of triceps’ brachii at different joint angle positions in resting and isometric contraction. Measured ultrasound data were used to reduce the unknown parameters during the modeling optimization process. The results showed that pennation angles varied with joint angles, and the longhead TRI pennation from stroke group was smaller than the literature value. The maximum isometric muscle stress from persons after stroke was significantly smaller than that found in the unimpaired subjects. The prediction of joint torque fits well with the measured data from the control group, whereas the prediction error is larger in results from persons after stroke. In vivo parameters from ultrasound data could help to build a subject-specific biomechanical model of elbow extensor for both unimpaired and hemiplegic subjects, and then the results driven from the model could enhance the understanding of motor function changes for persons after stroke.

  9. The development of path integration: combining estimations of distance and heading.

    Science.gov (United States)

    Smith, Alastair D; McKeith, Laura; Howard, Christina J

    2013-12-01

    Efficient daily navigation is underpinned by path integration, the mechanism by which we use self-movement information to update our position in space. This process is well understood in adulthood, but there has been relatively little study of path integration in childhood, leading to an underrepresentation in accounts of navigational development. Previous research has shown that calculation of distance and heading both tend to be less accurate in children as they are in adults, although there have been no studies of the combined calculation of distance and heading that typifies naturalistic path integration. In the present study, 5-year-olds and 7-year-olds took part in a triangle-completion task, where they were required to return to the start point of a multi-element path using only idiothetic information. Performance was compared to a sample of adult participants, who were found to be more accurate than children on measures of landing error, heading error, and distance error. Seven-year-olds were significantly more accurate than 5-year-olds on measures of landing error and heading error, although the difference between groups was much smaller for distance error. All measures were reliably correlated with age, demonstrating a clear development of path integration abilities within the age range tested. Taken together, these data make a strong case for the inclusion of path integration within developmental models of spatial navigational processing.

  10. SECOND DERIVATIVE SPECTROPHOTOMETRIC METHOD FOR THE ESTIMATION OF RIFAMPICIN AND PIPERINE IN THEIR COMBINED DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Khamar Jenil C.

    2012-04-01

    Full Text Available The present manuscript describe simple, sensitive, rapid, accurate, precise and cost effective Second derivative spectrophotometric zero crossing point method for the simultaneous determination of Rifampicin and Piperine in combined capsule dosage form. The utility of Second derivative data processing program is its ability to calculate unknown concentration of components of interest in a mixture containing an interfering component. The Second order derivative absorption at 341 nm (zero cross point for Piperine was used for Rifampicin and 241 nm (zero cross point for Rifampicin was used for Piperine. The linearity was obtained in the concentration range of 10-60 μg/ml for Rifampicin and 2-20 μg/ml for Piperine. The method was successfully applied to pharmaceutical dosage form because no interference from the capsule excipients was found. The suitability of these methods for the quantitative determination of Rifampicin and Piperine was proved by validation. The proposed methods were found to be simple and sensitive for the routine quality control application of Rifampicin and Piperine in pharmaceutical capsule dosage form. The results of analysis have been validated statistically and by recovery studies.

  11. Estimation of Winter Wheat Biomass and Yield by Combining the AquaCrop Model and Field Hyperspectral Data

    Directory of Open Access Journals (Sweden)

    Xiuliang Jin

    2016-11-01

    Full Text Available Knowledge of spatial and temporal variations in crop growth is important for crop management and stable crop production for the food security of a country. A combination of crop growth models and remote sensing data is a useful method for monitoring crop growth status and estimating crop yield. The objective of this study was to use spectral-based biomass values generated from spectral indices to calibrate the AquaCrop model using the particle swarm optimization (PSO algorithm to improve biomass and yield estimations. Spectral reflectance and concurrent biomass and yield were measured at the Xiaotangshan experimental site in Beijing, China, during four winter wheat-growing seasons. The results showed that all of the measured spectral indices were correlated with biomass to varying degrees. The normalized difference matter index (NDMI was the best spectral index for estimating biomass, with the coefficient of determination (R2, root mean square error (RMSE, and relative RMSE (RRMSE values of 0.77, 1.80 ton/ha, and 25.75%, respectively. The data assimilation method (R2 = 0.83, RMSE = 1.65 ton/ha, and RRMSE = 23.60% achieved the most accurate biomass estimations compared with the spectral index method. The estimated yield was in good agreement with the measured yield (R2 = 0.82, RMSE = 0.55 ton/ha, and RRMSE = 8.77%. This study offers a new method for agricultural resource management through consistent assessments of winter wheat biomass and yield based on the AquaCrop model and remote sensing data.

  12. Multi-dimensional constraint relativistic mean field model and applications in actinide and transfermium nuclei

    CERN Document Server

    Lu, Bing-Nan; Zhao, En-Guang; Zhou, Shan-Gui

    2013-01-01

    In this contribution we present some results of potential energy surfaces of actinide and transfermium nuclei from multi-dimensional constrained relativistic mean field (MDC-RMF) models. Recently we developed multi-dimensional constrained covariant density functional theories (MDC-CDFT) in which all shape degrees of freedom $\\beta_{\\lambda\\mu}$ with even $\\mu$ are allowed and the functional can be one of the following four forms: the meson exchange or point-coupling nucleon interactions combined with the non-linear or density-dependent couplings. In MDC-RMF models, the pairing correlations are treated with the BCS method. With MDC-RMF models, the potential energy surfaces of even-even actinide nuclei were investigated and the effect of triaxiality on the fission barriers in these nuclei was discussed. The non-axial reflection-asymmetric $\\beta_{32}$ shape in some transfermium nuclei with $N=150$, namely $^{246}$Cm, $^{248}$Cf, $^{250}$Fm, and $^{252}$No were also studied.

  13. Advancing Chemistry with the Lanthanide and Actinide Elements Final Report, September 2013

    Energy Technology Data Exchange (ETDEWEB)

    Evans, William John [Univ. of California, Irvine, CA (United States)

    2013-09-11

    The objective of this research is to use the unique chemistry available from complexes of the lanthanides and actinides, as well as related heavy metals such as scandium, yttrium, and bismuth to advance chemistry in energy-related areas. The lanthanides and actinides have a combination of properties in terms of size, charge, electropositive character, and f valence orbitals that provides special opportunities to probe reactivity and catalysis in ways not possible with the other metals in the periodic table. We seek to discover reaction pathways and structural types that reveal new options in reaction chemistry related to energy. Identification of new paradigms in structure and reactivity should stimulate efforts to develop new types of catalytic processes that at present are not under consideration because either the transformation or the necessary intermediates are unknown. This project is one half of my laboratory’s DOE research which was split 50:50 between Catalysis and Heavy Element Chemistry programs in 2010. Hence, this report is for a half-project.

  14. DEVELOPMENT AND VALIDATION OF SPECTROPHOTOMETRIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF SALBUTAMOL SULPHATE AND CETIRIZINE HYDROCHLORIDE IN COMBINED DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Sharma Deepak

    2012-07-01

    Full Text Available Salbutamol Sulphate (SAL and Cetirizine HCl (CET is used for the treatment of asthma and allergy. A simple, economical, accurate and precise method for simultaneous estimation of Salbutamol Sulphate (SAL and Cetirizine HCl (CET in combined dosage form has been developed. Simultaneous equation method based on measurement of absorbance at two wavelengths 276 nm and 230 nm, λmax of Salbutamol Sulphate (SAL and Cetirizine HCl (CET in 6.8 pH phosphate buffer. Both these drugs obeyed Beer Lambert’s law in the concentration range of 10-100 µg/ml for SAL and 2-20 µg/ml for CET. The high values of correlation coefficient (R2 indicated good linearity of calibration curve for both the drugs. The accuracy and precision of method was determined and the method validated stastically. Result of percentage recovery study confirms the accuracy of proposed method. The results of validation parameters indicates the accuracy of proposed methods for estimation of SAL and CET. Simultaneous equation method can be employed for routine analysis of SAL and CET in combined dosage form.

  15. Combining Volcano Monitoring Timeseries Analyses with Bayesian Belief Networks to Update Hazard Forecast Estimates

    Science.gov (United States)

    Odbert, Henry; Hincks, Thea; Aspinall, Willy

    2015-04-01

    Volcanic hazard assessments must combine information about the physical processes of hazardous phenomena with observations that indicate the current state of a volcano. Incorporating both these lines of evidence can inform our belief about the likelihood (probability) and consequences (impact) of possible hazardous scenarios, forming a basis for formal quantitative hazard assessment. However, such evidence is often uncertain, indirect or incomplete. Approaches to volcano monitoring have advanced substantially in recent decades, increasing the variety and resolution of multi-parameter timeseries data recorded at volcanoes. Interpreting these multiple strands of parallel, partial evidence thus becomes increasingly complex. In practice, interpreting many timeseries requires an individual to be familiar with the idiosyncrasies of the volcano, monitoring techniques, configuration of recording instruments, observations from other datasets, and so on. In making such interpretations, an individual must consider how different volcanic processes may manifest as measureable observations, and then infer from the available data what can or cannot be deduced about those processes. We examine how parts of this process may be synthesised algorithmically using Bayesian inference. Bayesian Belief Networks (BBNs) use probability theory to treat and evaluate uncertainties in a rational and auditable scientific manner, but only to the extent warranted by the strength of the available evidence. The concept is a suitable framework for marshalling multiple strands of evidence (e.g. observations, model results and interpretations) and their associated uncertainties in a methodical manner. BBNs are usually implemented in graphical form and could be developed as a tool for near real-time, ongoing use in a volcano observatory, for example. We explore the application of BBNs in analysing volcanic data from the long-lived eruption at Soufriere Hills Volcano, Montserrat. We show how our method

  16. Internal contamination by actinides after wounding: a robust rodent model for assessment of local and distant actinide retention.

    Science.gov (United States)

    Griffiths, N M; Wilk, J C; Abram, M C; Renault, D; Chau, Q; Helfer, N; Guichet, C; Van der Meeren, A

    2012-08-01

    Internal contamination by actinides following wounding may occur in nuclear fuel industry workers or subsequent to terrorist activities, causing dissemination of radioactive elements. Contamination by alpha particle emitting actinides can result in pathological effects, either local or distant from the site of entry. The objective of the present study was to develop a robust experimental approach in the rat for short- and long- term actinide contamination following wounding by incision of the skin and muscles of the hind limb. Anesthetized rats were contaminated with Mixed OXide (MOX, uranium, plutonium oxides containing 7.1% plutonium) or plutonium nitrate (Pu nitrate) following wounding by deep incision of the hind leg. Actinide excretion and tissue levels were measured as well as histological changes from 2 h to 3 mo. Humid swabs were used for rapid evaluation of contamination levels and proved to be an initial guide for contamination levels. Although the activity transferred from wound to blood is higher after contamination with a moderately soluble form of plutonium (nitrate), at 7 d most of the MOX (98%) or Pu nitrate (87%) was retained at the wound site. Rapid actinide retention in liver and bone was observed within 24 h, which increased up to 3 mo. After MOX contamination, a more rapid initial urinary excretion of americium was observed compared with plutonium. At 3 mo, around 95% of activity remained at the wound site, and excretion of Pu and Am was extremely low. This experimental approach could be applied to other situations involving contamination following wounding including rupture of the dermal, vascular, and muscle barriers.

  17. Kriging-Based Parameter Estimation Algorithm for Metabolic Networks Combined with Single-Dimensional Optimization and Dynamic Coordinate Perturbation.

    Science.gov (United States)

    Wang, Hong; Wang, Xicheng; Li, Zheng; Li, Keqiu

    2016-01-01

    The metabolic network model allows for an in-depth insight into the molecular mechanism of a particular organism. Because most parameters of the metabolic network cannot be directly measured, they must be estimated by using optimization algorithms. However, three characteristics of the metabolic network model, i.e., high nonlinearity, large amount parameters, and huge variation scopes of parameters, restrict the application of many traditional optimization algorithms. As a result, there is a growing demand to develop efficient optimization approaches to address this complex problem. In this paper, a Kriging-based algorithm aiming at parameter estimation is presented for constructing the metabolic networks. In the algorithm, a new infill sampling criterion, named expected improvement and mutual information (EI&MI), is adopted to improve the modeling accuracy by selecting multiple new sample points at each cycle, and the domain decomposition strategy based on the principal component analysis is introduced to save computing time. Meanwhile, the convergence speed is accelerated by combining a single-dimensional optimization method with the dynamic coordinate perturbation strategy when determining the new sample points. Finally, the algorithm is applied to the arachidonic acid metabolic network to estimate its parameters. The obtained results demonstrate the effectiveness of the proposed algorithm in getting precise parameter values under a limited number of iterations.

  18. FPGA-Based Implementation of All-Digital QPSK Carrier Recovery Loop Combining Costas Loop and Maximum Likelihood Frequency Estimator

    Directory of Open Access Journals (Sweden)

    Kaiyu Wang

    2014-01-01

    Full Text Available This paper presents an efficient all digital carrier recovery loop (ADCRL for quadrature phase shift keying (QPSK. The ADCRL combines classic closed-loop carrier recovery circuit, all digital Costas loop (ADCOL, with frequency feedward loop, maximum likelihood frequency estimator (MLFE so as to make the best use of the advantages of the two types of carrier recovery loops and obtain a more robust performance in the procedure of carrier recovery. Besides, considering that, for MLFE, the accurate estimation of frequency offset is associated with the linear characteristic of its frequency discriminator (FD, the Coordinate Rotation Digital Computer (CORDIC algorithm is introduced into the FD based on MLFE to unwrap linearly phase difference. The frequency offset contained within the phase difference unwrapped is estimated by the MLFE implemented just using some shifter and multiply-accumulate units to assist the ADCOL to lock quickly and precisely. The joint simulation results of ModelSim and MATLAB show that the performances of the proposed ADCRL in locked-in time and range are superior to those of the ADCOL. On the other hand, a systematic design procedure based on FPGA for the proposed ADCRL is also presented.

  19. Combining remote sensing and GIS climate modelling to estimate daily forest evapotranspiration in a Mediterranean mountain area

    Directory of Open Access Journals (Sweden)

    J. Cristóbal

    2011-01-01

    Full Text Available Evapotranspiration monitoring allows us to assess the environmental stress on forest and agricultural ecosystems. Nowadays, Remote Sensing and Geographical Information Systems (GIS are the main techniques used for calculating evapotranspiration at catchment and regional scales. In this study we present a methodology, based on the energy balance equation (B-method, that combines remote sensing imagery with GIS climate modelling to estimate daily evapotranspiration (ETd for several dates between 2003 and 2005. The three main variables needed to compute ETd were obtained as follows: (i Land surface temperature by means of the Landsat-5 TM and Landsat-7 ETM+ thermal band, (ii air temperature by means of multiple regression analysis and spatial interpolation from meteorological ground stations data at satellite pass, and (iii net radiation by means of the radiative balance. We calculated ETd using remote sensing data at different spatial and temporal scales (TERRA/AQUA MODIS and Landsat-5 TM/Landsat-7 ETM+ and combining three different approaches to calculate the B parameter. We then compared these estimates with sap flow measurements from a Scots pine (Pinus sylvestris L. stand in a Mediterranean mountain area. This procedure allowed us to better understand the limitations of ETd modelling and how it needs to be improved, especially in heterogeneous forest areas. The method using Landsat data resulted in a good agreement, with a mean RMSE value of about 0.6 mm day−1 and an estimation error of ±30%. The poor agreement obtained using MODIS data reveals that ETd retrieval from coarse resolution remote sensing data is troublesome in these heterogeneous areas, and therefore further research is necessary on this issue.

  20. Combined Use of Airborne Lidar and DBInSAR Data to Estimate LAI in Temperate Mixed Forests

    Directory of Open Access Journals (Sweden)

    Ross F. Nelson

    2012-06-01

    Full Text Available The objective of this study was to determine whether leaf area index (LAI in temperate mixed forests is best estimated using multiple-return airborne laser scanning (lidar data or dual-band, single-pass interferometric synthetic aperture radar data (from GeoSAR alone, or both in combination. In situ measurements of LAI were made using the LiCor LAI-2000 Plant Canopy Analyzer on 61 plots (21 hardwood, 36 pine, 4 mixed pine hardwood; stand age ranging from 12-164 years; mean height ranging from 0.4 to 41.2 m in the Appomattox-Buckingham State Forest, Virginia, USA. Lidar distributional metrics were calculated for all returns and for ten one meter deep crown density slices (a new metric, five above and five below the mode of the vegetation returns for each plot. GeoSAR metrics were calculated from the X-band backscatter coefficients (four looks as well as both X- and P-band interferometric heights and magnitudes for each plot. Lidar metrics alone explained 69% of the variability in LAI, while GeoSAR metrics alone explained 52%. However, combining the lidar and GeoSAR metrics increased the R2 to 0.77 with a CV-RMSE of 0.42. This study indicates the clear potential for X-band backscatter and interferometric height (both now available from spaceborne sensors, when combined with small-footprint lidar data, to improve LAI estimation in temperate mixed forests.

  1. Solubility of actinides and surrogates in nuclear glasses; Solubilite des actinides et de leurs simulants dans les verres nucleaires. Limites d'incorporation et comprehension des mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    Lopez, Ch

    2003-07-01

    The nuclear wastes are currently incorporated in borosilicate glass matrices. The resulting glass must be perfectly homogeneous. The work discussed here is a study of actinide (thorium and plutonium) solubility in borosilicate glass, undertaken to assess the extent of actinide solubility in the glass and to understand the mechanisms controlling actinide solubilization. Glass specimens containing; actinide surrogates were used to prepare and optimize the fabrication of radioactive glass samples. These preliminary studies revealed that actinide Surrogates solubility in the glass was enhanced by controlling the processing temperature, the dissolution kinetic of the surrogate precursors, the glass composition and the oxidizing versus reducing conditions. The actinide solubility was investigated in the borosilicate glass. The evolution of thorium solubility in borosilicate glass was determined for temperatures ranging from 1200 deg C to 1400 deg C.Borosilicate glass specimens containing plutonium were fabricated. The experimental result showed that the plutonium solubility limit ranged from 1 to 2.5 wt% PuO{sub 2} at 1200 deg C. A structural approach based on the determination of the local structure around actinides and their surrogates by EXAFS spectroscopy was used to determine their structural role in the glass and the nature of their bonding with the vitreous network. This approach revealed a correlation between the length of these bonds and the solubility of the actinides and their surrogates. (author)

  2. Theory of the crystal structures of the actinide metals; Theorie des structures cristallines des metaux actinides

    Energy Technology Data Exchange (ETDEWEB)

    Penicaud, M. [CEA Bruyeres-le-Chatel, 91 (France)

    2005-07-01

    We describe, by bands calculation methods, the delocalized-localized transition of 5f electrons in the series of actinide metals, at ambient conditions, which happens between {alpha}-Pu and Am, and which is characterized by the change from the open and complex monoclinic crystal structure to the double hexagonal close-packed structure, and by the density collapse from 19.86 g.cm{sup -3} to 13.67 g.cm{sup -3}. The case of the alloy stabilized Pu in the high temperature {delta} phase (face centered cubic) is treated. Its ambient experimental density (15.92 g.cm{sup -3}) is obtained with a localization of the only 5f5/2 electrons. We find a 5f5/2 density of states peak pinned at the Fermi level, in agreement with photoelectron spectroscopy, and the high value of the electronic specific heat coefficient. The crystalline stability under pressure of U, Np, Pu and Am is examined. We find theoretically, at high pressure in Am, the stability of the recently discovered experimentally Am IV structure which is primitive-orthorhombic with four atoms in the unit cell. We calculate this structure also stable for Pu, for which it is proposed that the sequence is: {alpha}-Pu {yields} Am IV {yields} body-centered cubic. (author)

  3. Combining non-precise historical information with instrumental measurements for flood frequency estimation: a fuzzy Bayesian approach

    Science.gov (United States)

    Salinas, Jose Luis; Kiss, Andrea; Viglione, Alberto; Blöschl, Günter

    2016-04-01

    Efforts of the historical environmental extremes community during the last decades have resulted in the obtention of long time series of historical floods, which in some cases range longer than 500 years in the past. In hydrological engineering, historical floods are useful because they give additional information which improves the estimates of discharges with low annual exceedance probabilities, i.e. with high return periods, and additionally might reduce the uncertainty in those estimates. In order to use the historical floods in formal flood frequency analysis, the precise value of the peak discharges would ideally be known, but in most of the cases, the information related to historical floods is given, quantitatively, in a non-precise manner. This work presents an approach on how to deal with the non-precise historical floods, by linking the descriptions in historical records to fuzzy numbers representing discharges. These fuzzy historical discharges are then introduced in a formal Bayesian inference framework, taking into account the arithmetics of non-precise numbers modelled by fuzzy logic theory, to obtain a fuzzy version of the flood frequency curve combining the fuzzy historical flood events and the instrumental data for a given location. Two case studies are selected from the historical literature, representing different facets of the fuzziness present in the historical sources. The results from the cases studies are given in the form of the fuzzy estimates of the flood frequency curves together with the fuzzy 5% and 95% Bayesian credibility bounds for these curves. The presented fuzzy Bayesian inference framework provides a flexible methodology to propagate in an explicit way the imprecision from the historical records into the flood frequency estimate, which allows to assess the effect that the incorporation of non-precise historical information can have in the flood frequency regime.

  4. Improved Actinide Neutron Capture Cross Sections Using Accelerator Mass Spectrometry

    Science.gov (United States)

    Bauder, W.; Pardo, R. C.; Kondev, F. G.; Kondrashev, S.; Nair, C.; Nusair, O.; Palchan, T.; Scott, R.; Seweryniak, D.; Vondrasek, R.; Collon, P.; Paul, M.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2014-09-01

    The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are developing a technique to inject solid material into the ECR with laser ablation. With laser ablation, we can better control material injection and potentially increase efficiency in the ECR, thus creating less contamination in the source and reducing cross talk. I will present work on the laser ablation system and preliminary results from our AMS measurements. The MANTRA (Measurement of Actinide Neutron TRAnsmutations) project will improve energy-integrated neutron capture cross section data across the actinide region. These data are incorporated into nuclear reactor models and are an important piece in understanding Generation IV reactor designs. We will infer the capture cross sections by measuring isotopic ratios from actinide samples, irradiated in the Advanced Test Reactor at INL, with Accelerator Mass Spectrometry (AMS) at ATLAS (ANL). The superior sensitivity of AMS allows us to extract multiple cross sections from a single sample. In order to analyze the large number of samples needed for MANTRA and to meet the goal of extracting multiple cross sections per sample, we have made a number of modifications to the AMS setup at ATLAS. In particular, we are

  5. Stochastic semi-continuous simulation for extreme flood estimation in catchments with combined rainfall-snowmelt flood regimes

    Science.gov (United States)

    Lawrence, D.; Paquet, E.; Gailhard, J.; Fleig, A. K.

    2014-05-01

    Simulation methods for extreme flood estimation represent an important complement to statistical flood frequency analysis because a spectrum of catchment conditions potentially leading to extreme flows can be assessed. In this paper, stochastic, semi-continuous simulation is used to estimate extreme floods in three catchments located in Norway, all of which are characterised by flood regimes in which snowmelt often has a significant role. The simulations are based on SCHADEX, which couples a precipitation probabilistic model with a hydrological simulation such that an exhaustive set of catchment conditions and responses is simulated. The precipitation probabilistic model is conditioned by regional weather patterns, and a bottom-up classification procedure was used to define a set of weather patterns producing extreme precipitation in Norway. SCHADEX estimates for the 1000-year (Q1000) discharge are compared with those of several standard methods, including event-based and long-term simulations which use a single extreme precipitation sequence as input to a hydrological model, statistical flood frequency analysis based on the annual maximum series, and the GRADEX method. The comparison suggests that the combination of a precipitation probabilistic model with a long-term simulation of catchment conditions, including snowmelt, produces estimates for given return periods which are more in line with those based on statistical flood frequency analysis, as compared with the standard simulation methods, in two of the catchments. In the third case, the SCHADEX method gives higher estimates than statistical flood frequency analysis and further suggests that the seasonality of the most likely Q1000 events differs from that of the annual maximum flows. The semi-continuous stochastic simulation method highlights the importance of considering the joint probability of extreme precipitation, snowmelt rates and catchment saturation states when assigning return periods to floods

  6. Combining remote sensing and GIS climate modelling to estimate daily forest evapotranspiration in a Mediterranean mountain area

    Directory of Open Access Journals (Sweden)

    J. Cristóbal

    2011-05-01

    Full Text Available Evapotranspiration monitoring allows us to assess the environmental stress on forest and agricultural ecosystems. Nowadays, Remote Sensing and Geographical Information Systems (GIS are the main techniques used for calculating evapotranspiration at catchment and regional scales. In this study we present a methodology, based on the energy balance equation (B-method, that combines remote sensing imagery with GIS-based climate modelling to estimate daily evapotranspiration (ETd for several dates between 2003 and 2005. The three main variables needed to compute ETd were obtained as follows: (i Land surface temperature by means of the Landsat-5 TM and Landsat-7 ETM+ thermal band, (ii air temperature by means of multiple regression analysis and spatial interpolation from meteorological ground stations data at satellite pass, and (iii net radiation by means of the radiative balance. We calculated ETd using remote sensing data at different spatial and temporal scales (Landsat-7 ETM+, Landsat-5 TM and TERRA/AQUA MODIS, with a spatial resolution of 60, 120 and 1000 m, respectively and combining three different approaches to calculate the B parameter, which represents an average bulk conductance for the daily-integrated sensible heat flux. We then compared these estimates with sap flow measurements from a Scots pine (Pinus sylvestris L. stand in a Mediterranean mountain area. This procedure allowed us to better understand the limitations of ETd modelling and how it needs to be improved, especially in heterogeneous forest areas. The method using Landsat data resulted in a good agreement, R2 test of 0.89, with a mean RMSE value of about 0.6 mm day−1 and an estimation error of ±30 %. The poor agreement obtained using TERRA/AQUA MODIS, with a mean RMSE value of 1.8 and 2.4 mm day−1 and an estimation error of about ±57 and 50 %, respectively. This

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

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Y.; Gohar, Y. (Nuclear Engineering Division)

    2011-11-04

    systems consume about 1.2 tons of actinides per year and produce 3 GW thermal power, with a proton beam power of 25 MW. Total MA fuel that would be consumed in the first 10 years of operation is 9.85, 11.80, or 12.68 tons, respectively, for the systems with 5, 7, or 10% actinide fuel particles loaded in the LBE. The corresponding annual MA fuel transmutation rate after reaching equilibrium at 10 years of operation is 0.83, 0.94, or 1.02 tons/year, respectively. Assuming that the ADS systems can be operated for 35 full-power years, the total MAs consumed in the three ADS systems are 30.6, 35.3, and 37.2 tons, respectively. For the three configurations, it is estimated that 3.8, 3.3, or 3.1 ADS system units are required to utilize the entire 115 tons of MA fuel in the SNF inventory, respectively.

  8. Recovery of minor actinides from irradiated superfact fuels

    Energy Technology Data Exchange (ETDEWEB)

    Apoltolidis, C.; Glatz, J.P.; Molinet, R.; Nicholl, A.; Pagliosa, G.; Romer, K.; Bokelund, H.; Koch, L. [European Commission, JRC, Institute fuer Transuranium Elements, Karlsruhe (Germany)

    1995-12-31

    It could be demonstrated that the reprocessing of fast reactor oxide fuels containing up to 45 % MA (Np and Am), irradiated in the PHENIX reactor in the frame of a transmutation study, is possible. The fuels were dissolved under PUREX type conditions in order to determine their behaviour in the head-end step of the reprocessing process. For one of the fuels containing 20 % Am and 20 % Np before irradiation, an almost complete partitioning of actinides from the dissolver solution could be achieved. Chromatographic extraction was used for the separation of the main bulk elements U, Pu and Np, whereas centrifugal extractors were used to separate the minor actinides from the remaining high level liquid wastes (HLLW). For the relevant radio-toxic isotopes a high recovery rate from the irradiation targets was reached. Those elements are thus available for new fuel fabrication. (authors) 12 refs.

  9. Radioanalytical determination of actinides and fission products in Belarus soils.

    Science.gov (United States)

    Michel, H; Gasparro, J; Barci-Funel, G; Dalmasso, J; Ardisson, G; Sharovarov, G

    1999-04-01

    Alpha emitting actinides such as plutonium, americium or curium were measured by alpha-spectrometry after radiochemical separation. The short range of alpha-particles within matter requires, after a pre-concentration process, a succession of isolation and purification steps based on the valence states modification of the researched elements. For counting, actinides were electrodeposited in view to obtain the mass-less source necessary to avoid self-absorption of the emitted radiations. Activity concentrations of gamma-emitting fission products were calculated after measurement with high purity germanium detectors (HPGe). These different methods were used to analyse soils sampled in the Republic of Belarus, not far from the Chernobyl nuclear plant.

  10. Accuracy Improvement of Neutron Nuclear Data on Minor Actinides

    Directory of Open Access Journals (Sweden)

    Harada Hideo

    2015-01-01

    Full Text Available Improvement of accuracy of neutron nuclear data for minor actinides (MAs and long-lived fission products (LLFPs is required for developing innovative nuclear system transmuting these nuclei. In order to meet the requirement, the project entitled as “Research and development for Accuracy Improvement of neutron nuclear data on Minor ACtinides (AIMAC” has been started as one of the “Innovative Nuclear Research and Development Program” in Japan at October 2013. The AIMAC project team is composed of researchers in four different fields: differential nuclear data measurement, integral nuclear data measurement, nuclear chemistry, and nuclear data evaluation. By integrating all of the forefront knowledge and techniques in these fields, the team aims at improving the accuracy of the data. The background and research plan of the AIMAC project are presented.

  11. Actinide-specific sequestering agents and decontamination applications

    Energy Technology Data Exchange (ETDEWEB)

    Smith, William L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials and Molecular Research Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry; Raymond, Kenneth N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Materials and Molecular Research Division; Univ. of California, Berkeley, CA (United States). Dept. of Chemistry

    1981-04-07

    With the commercial development of nuclear reactors, the actinides have become very important industrial elements. A major concern of the nuclear industry is the biological hazard associated with nuclear fuels and their wastes. The acute chemical toxicity of tetravalent actinides, as exemplified by Th(IV), is similar to Cr(III) or Al(III). However, the acute toxicity of 239Pu(IV) is similar to strychnine, which is much more toxic than any of the non-radioactive metals such as mercury. Although the more radioactive isotopes of the transuranium elements are more acutely toxic by weight than plutonium, the acute toxicities of 239Pu, 241Am, and 244Cm are nearly identical in radiation dose, ~100 μCi/kg in rodents. Finally and thus, the extreme acute toxicity of 239Pu is attributed to its high specific activity of alpha emission.

  12. Status of measurements of fission neutron spectra of Minor Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Drapchinsky, L.; Shiryaev, B. [V.G. Khlopin Radium Inst., Saint Petersburg (Russian Federation)

    1997-03-01

    The report considers experimental and theoretical works on studying the energy spectra of prompt neutrons emitted in spontaneous fission and neutron induced fission of Minor Actinides. It is noted that neutron spectra investigations were done for only a small number of such nuclei, most measurements, except those of Cf-252, having been carried out long ago by obsolete methods and imperfectapparatus. The works have no detailed description of experiments, analysis of errors, detailed numerical information about results of experiments. A conclusion is made that the available data do not come up to modern requirements. It is necessary to make new measurements of fission prompt neutron spectra of transuranium nuclides important for the objectives of working out a conception of minor actinides transmutation by means of special reactors. (author)

  13. Simultaneous Estimation and Validation of Atorvastatin Calcium and Aspirin in Combined Capsule Dosage Form by RP HPLC Method

    Directory of Open Access Journals (Sweden)

    B. V. Suma

    2012-01-01

    Full Text Available A new simple, specific, precise and accurate revere phase liquid chromatography method has been developed for estimation of atorvastatin calcium (AST and ASPIRIN (ASP simultaneously in a combined capsule dosage forms. The chromatographic separation was achieved on a 5 – micron C 18 column (250x 4.6mm using a mobile phase consisting of a mixture of Acetonitrile: Ammonium Acetate buffer 0.02M (68:32 pH 4.5. The flow rate was maintained at 0.8 ml/min. The detection of the constituents was done using UV detector at 245 nm for AST and ASP. The retention time of AST and ASP were found be 4.5915 ± 0.0031 min and 3.282 ±0.0024 min respectively. The developed method was validated for accuracy, linearity, precision, limit of detection (LOD and limit of quantification (LOQ and robustness as per the ICH guidelines.

  14. Chromatographic development of validated analytical method for the estimation of tapentadol and paracetamol in combined dosage form

    Directory of Open Access Journals (Sweden)

    Manoj S. Charde

    2014-01-01

    Full Text Available A simple, sensitive an isocratic RP-HPLC method for the estimation of  TAP (Tapentadol and PARA (Paracetamol in combined dosage form using Inertsil ODS C-18 column (250×4.6 mm, 5 µ in an isocratic mode with mobile phase comprising  Buffer (1mL TEA :  ACN : MeOH in the ratio of (75:20:5 v/v/v. The flow rate was 1.2 mL/ min and effluent was monitored at 220 nm. The retention times were found to be 6.88 min for TAP and 3.78 min for PARA. The assay exhibited a linear dynamic range of 11.89- 28.55 µg/mL for TAP and 64.95- 155.90 µg/mL for PARA.

  15. Comparative Study of f-Element Electronic Structure across a Series of Multimetallic Actinide, Lanthanide-Actinide and Lanthanum-Actinide Complexes Possessing Redox-Active Bridging Ligands

    Energy Technology Data Exchange (ETDEWEB)

    Schelter, Eric J.; Wu, Ruilian; Veauthier, Jacqueline M.; Bauer, Eric D.; Booth, Corwin H.; Thomson, Robert K.; Graves, Christopher R.; John, Kevin D.; Scott, Brian L.; Thompson, Joe D.; Morris, David E.; Kiplinger, Jaqueline L.

    2010-02-24

    A comparative examination of the electronic interactions across a series of trimetallic actinide and mixed lanthanide-actinide and lanthanum-actinide complexes is presented. Using reduced, radical terpyridyl ligands as conduits in a bridging framework to promote intramolecular metal-metal communication, studies containing structural, electrochemical, and X-ray absorption spectroscopy are presented for (C{sub 5}Me{sub 5}){sub 2}An[-N=C(Bn)(tpy-M{l_brace}C{sub 5}Me4R{r_brace}{sub 2})]{sub 2} (where An = Th{sup IV}, U{sup IV}; Bn = CH{sub 2}C{sub 6}H{sub 5}; M = La{sup III}, Sm{sup III}, Yb{sup III}, U{sup III}; R = H, Me, Et) to reveal effects dependent on the identities of the metal ions and R-groups. The electrochemical results show differences in redox energetics at the peripheral 'M' site between complexes and significant wave splitting of the metal- and ligand-based processes indicating substantial electronic interactions between multiple redox sites across the actinide-containing bridge. Most striking is the appearance of strong electronic coupling for the trimetallic Yb{sup III}-U{sup IV}-Yb{sup III}, Sm{sup III}-U{sup IV}-Sm{sup III}, and La{sup III}-U{sup IV}-La{sup III} complexes, [8]{sup -}, [9b]{sup -} and [10b]{sup -}, respectively, whose calculated comproportionation constant K{sub c} is slightly larger than that reported for the benchmark Creutz-Taube ion. X-ray absorption studies for monometallic metallocene complexes of U{sup III}, U{sup IV}, and U{sup V} reveal small but detectable energy differences in the 'white-line' feature of the uranium L{sub III}-edges consistent with these variations in nominal oxidation state. The sum of this data provides evidence of 5f/6d-orbital participation in bonding and electronic delocalization in these multimetallic f-element complexes. An improved, high-yielding synthesis of 4{prime}-cyano-2,2{prime}:6{prime},2{double_prime}-terpyridine is also reported.

  16. EXAFS studies of actinide ions in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Karim, D P; Georgopoulos, P; Knapp, G S

    1979-01-01

    The applicability of the EXAFS technique in the study of actinide systems is discussed. Uranium L/sub III/-edge spectra obtained on an in-lab rotating anode EXAFS facility are presented and analyzed for crystalline UO/sub 2/F/sub 2/ and aqueous solutions containing hexavalent uranium ions. Methods for the extension of the technique to more dilute systems are discussed.

  17. Future nuclear fuel cycles: Prospect and challenges for actinide recycling

    Science.gov (United States)

    Warin, Dominique

    2010-03-01

    The global energy context pleads in favour of a sustainable development of nuclear energy since the demand for energy will likely increase, whereas resources will tend to get scarcer and the prospect of global warming will drive down the consumption of fossil fuel. In this context, nuclear power has the worldwide potential to curtail the dependence on fossil fuels and thereby to reduce the amount of greenhouse gas emissions while promoting energy independence. How we deal with nuclear radioactive waste is crucial in this context. In France, the public's concern regarding the long-term waste management made the French Governments to prepare and pass the 1991 and 2006 Acts, requesting in particular the study of applicable solutions for still minimizing the quantity and the hazardousness of final waste. This necessitates High Active Long Life element (such as the Minor Actinides MA) recycling, since the results of fuel cycle R&D could significantly change the challenges for the storage of nuclear waste. HALL recycling can reduce the heat load and the half-life of most of the waste to be buried to a couple of hundred years, overcoming the concerns of the public related to the long-life of the waste and thus aiding the "burying approach" in securing a "broadly agreed political consensus" of waste disposal in a geological repository. This paper presents an overview of the recent R and D results obtained at the CEA Atalante facility on innovative actinide partitioning hydrometallurgical processes. For americium and curium partitioning, these results concern improvements and possible simplifications of the Diamex-Sanex process, whose technical feasibility was already demonstrated in 2005. Results on the first tests of the Ganex process (grouped actinide separation for homogeneous recycling) are also discussed. In the coming years, next steps will involve both better in-depth understanding of the basis of these actinide partitioning processes and, for the new promising

  18. Validation of minor actinides fission neutron cross-sections

    Directory of Open Access Journals (Sweden)

    Pešić Milan P.

    2015-01-01

    Full Text Available Verification of neutron fission cross-sections of minor actinides from some recently available evaluated nuclear data libraries was carried out by comparison of the reaction rates calculated by the MCNP6.1 computer code to the experimental values. The experimental samples, containing thin layers of 235U, 237Np, 238,239,240,241Pu, 242mAm, 243Cm, 245Cm, and 247Cm, deposited on metal support and foils of 235U (pseudo-alloy 27Al + 235U, 238U, natIn, 64Zn, 27Al, and multi-component sample alloy 27Al + 55Mn + natCu + natLu + 197Au, were irradiated in the channels of the tank containing fluorine salts 0.52NaF + 0.48ZrF4, labelled as the Micromodel Salt Blanket, inserted in the lattice centre of the MAKET heavy water critical assembly at the Institute for Theoretical and Experimental Physics, Moscow. This paper is a continuation of earlier initiated scientific-research activities carried out for validation of the evaluated fission cross-sections of actinides that were supposed to be used for the quality examination of the fuel design of the accelerator driven systems or fast reactors, and consequently, determination of transmutation rates of actinides, and therefore, determination of operation parameters of these reactor facilities. These scientific-research activities were carried out within a frame of scientific projects supported by the International Science and Technology Center and the International Atomic Energy Agency co-ordinated research activities, from 1999 to 2010. Obtained results confirm that further research is needed in evaluations in order to establish better neutron cross-section data for the minor actinides and selected nuclides which could be used in the accelerator driven systems or fast reactors.

  19. Chemical properties of the heavier actinides and transactinides

    Energy Technology Data Exchange (ETDEWEB)

    Hulet, E.K.

    1981-01-01

    The chemical properties of each of the elements 99 (Es) through 105 are reviewed and their properties correlated with the electronic structure expected for 5f and 6d elements. A major feature of the heavier actinides, which differentiates them from the comparable lanthanides, is the increasing stability of the divalent oxidation state with increasing atomic number. The divalent oxidation state first becomes observable in the anhydrous halides of californium and increases in stability through the series to nobelium, where this valency becomes predominant in aqueous solution. In comparison with the analogous 4f electrons, the 5f electrons in the latter part of the series are more tightly bound. Thus, there is a lowering of the 5f energy levels with respect to the Fermi level as the atomic number increases. The metallic state of the heavier actinides has not been investigated except from the viewpoint of the relative volatility among members of the series. In aqueous solutions, ions of these elements behave as a normal trivalent actinides and lanthanides (except for nobelium). Their ionic radii decrease with increasing nuclear charge which is moderated because of increased screening of the outer 6p electrons by the 5f electrons. The actinide series of elements is completed with the element lawrencium (Lr) in which the electronic configuration is 5f/sup 14/7s/sup 2/7p. From Mendeleev's periodicity and Dirac-Fock calculations, the next group of elements is expected to be a d-transition series corresponding to the elements Hf through Hg. The chemical properties of elements 104 and 105 only have been studied and they indeed appear to show the properties expected of eka-Hf and eka-Ta. However, their nuclear lifetimes are so short and so few atoms can be produced that a rich variety of chemical information is probably unobtainable.

  20. Design of unique pins for irradiation of higher actinides in a fast reactor

    Energy Technology Data Exchange (ETDEWEB)

    Basmajian, J.A.; Birney, K.R.; Weber, E.T.; Adair, H.L.; Quinby, T.C.; Raman, S.; Butler, J.K.; Bateman, B.C.; Swanson, K.M.

    1982-03-01

    The actinides produced by transmutation reactions in nuclear reactor fuels are a significant factor in nuclear fuel burnup, transportation and reprocessing. Irradiation testing is a primary source of data of this type. A segmented pin design was developed which provides for incorporation of multiple specimens of actinide oxides for irradiation in the UK's Prototype Fast Reactor (PFR) at Dounreay Scotland. Results from irradiation of these pins will extend the basic neutronic and material irradiation behavior data for key actinide isotopes.

  1. Cost estimation of hypertension management based on home blood pressure monitoring alone or combined office and ambulatory blood pressure measurements.

    Science.gov (United States)

    Boubouchairopoulou, Nadia; Karpettas, Nikos; Athanasakis, Kostas; Kollias, Anastasios; Protogerou, Athanase D; Achimastos, Apostolos; Stergiou, George S

    2014-10-01

    This study aims at estimating the resources consumed and subsequent costs for hypertension management, using home blood pressure (BP) monitoring (HBPM) alone versus combined clinic measurements and ambulatory blood pressure monitoring (C/ABPM). One hundred sixteen untreated hypertensive subjects were randomized to use HBPM or C/ABPM for antihypertensive treatment initiation and titration. Health resources utilized within 12-months follow-up, their respective costs, and hypertension control were assessed. The total cost of the first year of hypertension management was lower in HBPM than C/ABPM arm (€1336.0 vs. €1473.5 per subject, respectively; P cost was identical in both arms. There was no difference in achieved BP control and drug expenditure (HBPM: €233.1 per subject; C/ABPM: €247.6 per subject; P = not significant), whereas the cost of BP measurements and/or visits was higher in C/ABPM arm (€393.9 vs. €516.9, per patient, respectively P cost for subsequent years (>1) was €348.9 and €440.2 per subject, respectively for HBPM and C/ABPM arm and €2731.4 versus €3234.3 per subject, respectively (P cost than C/ABPM, and the same trend is observed in 5-year projection. The results on the resources consumption can be used to make cost estimates for other health-care systems.

  2. Energy estimation of combined heating and cooling systems%冷热联供系统的能耗估算

    Institute of Scientific and Technical Information of China (English)

    陈君燕

    2001-01-01

    阐述了利用热电联产热、锅炉房供热和废热驱动的各种冷热联供系统的能耗估算方法。对热电联产情况考虑了汽轮机进排气参数等条件的变化对供热供冷能耗的影响。给出了一定条件下各种系统包括热泵系统的供热供冷一次能耗率,并与常规系统作了比较。%Represents an energy estimation method for combined heating and cooling systems (CHC) operated by heat from cogeneration systems or heating boilers and waste heat, with consideration of effects of variation in inlet and outlet steam properties of the turbine on the heating and cooling energy consumption. Gives estimation of the primary energy ratio of heating and cooling for systems including the heat pump system and comparison with those for conventional systems.

  3. Estimating Plasmodium falciparum transmission rates in low-endemic settings using a combination of community prevalence and health facility data.

    Science.gov (United States)

    Yukich, Joshua; Briët, Olivier; Bretscher, Michael T; Bennett, Adam; Lemma, Seblewengel; Berhane, Yemane; Eisele, Thomas P; Keating, Joseph; Smith, Thomas

    2012-01-01

    As some malaria control programs shift focus from disease control to transmission reduction, there is a need for transmission data to monitor progress. At lower levels of transmission, it becomes increasingly more difficult to measure precisely, for example through entomological studies. Many programs conduct regular cross sectional parasite prevalence surveys, and have access to malaria treatment data routinely collected by ministries of health, often in health management information systems. However, by themselves, these data are poor measures of transmission. In this paper, we propose an approach for combining annual parasite incidence and treatment data with cross-sectional parasite prevalence and treatment seeking survey data to estimate the incidence of new infections in the human population, also known as the force of infection. The approach is based on extension of a reversible catalytic model. The accuracy of the estimates from this model appears to be highly dependent on levels of detectability and treatment in the community, indicating the importance of information on private sector treatment seeking and access to effective and appropriate treatment.

  4. Estimation of net ecosystem carbon exchange for the conterminous United States by combining MODIS and AmeriFlux data

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jingfeng; Zhuang, Qianlai; Baldocchi, Dennis D.; Bolstad, Paul V.; Burns, Sean P.; Chen, Jiquan; Cook, David R.; Curtis, Peter S.; Drake, Bert G.; Foster, David R.; Gu, Lianhong; Hadley, Julian L.; Hollinger, David Y.; Katul, Gabriel G.; Law, Beverly E.; Litvak, Marcy; Ma, Siyan; Martin, Timothy A.; Matamala, Roser; McNulty, Steve; Meyers, Tilden P.; Monson, Russell K.; Munger, J. William; Noormets, Asko; Oechel, Walter C.; Oren, Ram; Richardson, Andrew D.; Schmid, Hans Peter; Scott, Russell L.; Starr, Gregory; Sun, Ge; Suyker, Andrew E.; Torn, Margaret S.; Paw, Kyaw; Verma, Shashi B.; Wharton, Sonia; Wofsy, Steven C.

    2008-10-01

    Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board the National Aeronautics and Space Administration's (NASA) Terra satellite to scale up AmeriFlux NEE measurements to the continental scale. We first combined MODIS and AmeriFlux data for representative U.S. ecosystems to develop a predictive NEE model using a modified regression tree approach. The predictive model was trained and validated using eddy flux NEE data over the periods 2000-2004 and 2005-2006, respectively. We found that the model predicted NEE well (r = 0.73, p < 0.001). We then applied the model to the continental scale and estimated NEE for each 1 km x 1 km cell across the conterminous U.S. for each 8-day interval in 2005 using spatially explicit MODIS data. The model generally captured the expected spatial and seasonal patterns of NEE as determined from measurements and the literature. Our study demonstrated that our empirical approach is effective for scaling up eddy flux NEE measurements to the continental scale and producing wall-to-wall NEE estimates across multiple biomes. Our estimates may provide an independent dataset from simulations with biogeochemical models and inverse modeling approaches for examining the spatiotemporal patterns of NEE and constraining terrestrial carbon budgets over large areas.

  5. Estimation of Net Ecosystem Carbon Exchange for the Conterminous UnitedStates by Combining MODIS and AmeriFlux Data

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Jingfeng; Zhuang, Qianlai; Baldocchi, Dennis D.; Law, Beverly E.; Richardson, Andrew D.; Chen, Jiquan; Oren, Ram; Starr, Gregory; Noormets, Asko; Ma, Siyan; Verma, Shashi B.; Wharton, Sonia; Wofsy, Steven C.; Bolstad, Paul V.; Burns, Sean P.; Cook, David R.; Curtis, Peter S.; Drake, Bert G.; Falk, Matthias; Fischer, Marc L.; Foster, David R.; Gu, Lianhong; Hadley, Julian L.; Hollinger, David Y.; Katul, Gabriel G.; Litvak, Marcy; Martin, Timothy A.; Matamala, Roser; McNulty, Steve; Meyers, Tilden P.; Monson, Russell K.; Munger, J. William; Oechel, Walter C.; U, Kyaw Tha Paw; Schmid, Hans Peter; Scott, Russell L.; Sun, Ge; Suyker, Andrew E.; Torn, Margaret S.

    2009-03-06

    Eddy covariance flux towers provide continuous measurements of net ecosystem carbon exchange (NEE) for a wide range of climate and biome types. However, these measurements only represent the carbon fluxes at the scale of the tower footprint. To quantify the net exchange of carbon dioxide between the terrestrial biosphere and the atmosphere for regions or continents, flux tower measurements need to be extrapolated to these large areas. Here we used remotely-sensed data from the Moderate Resolution Imaging Spectrometer (MODIS) instrument on board NASA's Terra satellite to scale up AmeriFlux NEE measurements to the continental scale. We first combined MODIS and AmeriFlux data for representative U.S. ecosystems to develop a predictive NEE model using a regression tree approach. The predictive model was trained and validated using NEE data over the periods 2000-2004 and 2005-2006, respectively. We found that the model predicted NEE reasonably well at the site level. We then applied the model to the continental scale and estimated NEE for each 1 km x 1 km cell across the conterminous U.S. for each 8-day period in 2005 using spatially-explicit MODIS data. The model generally captured the expected spatial and seasonal patterns of NEE. Our study demonstrated that our empirical approach is effective for scaling up eddy flux NEE measurements to the continental scale and producing wall-to-wall NEE estimates across multiple biomes. Our estimates may provide an independent dataset from simulations with biogeochemical models and inverse modeling approaches for examining the spatiotemporal patterns of NEE and constraining terrestrial carbon budgets for large areas.

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

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, J.C. [Louisiana State Univ., Baton Rouge, LA (United States). Nuclear Science Center; Lineberry, M.J. [Argonne National Lab., Idaho Falls, ID (United States). Technology Development Div.

    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.

  7. Crystalline matrices for the immobilization of plutonium and actinides

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, E.B.; Burakov, E.E.; Galkin, Ya.B.; Starchenko, V.A.; Vasiliev, V.G. [V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation)

    1996-05-01

    The management of weapon plutonium, disengaged as a result of conversion, is considered together with the problem of the actinide fraction of long-lived high level radioactive wastes. It is proposed to use polymineral ceramics based on crystalline host-phases: zircon ZrSiO{sub 4} and zirconium dioxide ZrO{sub 2}, for various variants of the management of plutonium and actinides (including the purposes of long-term safe storage or final disposal from the human activity sphere). It is shown that plutonium and actinides are able to form with these phases on ZrSiO{sub 4} and ZrO{sub 2} was done on laboratory level by the hot pressing method, using the plasmochemical calcination technology. To incorporate simulators of plutonium into the structure of ZrSiO{sub 4} and ZrO{sub 2} in the course of synthesis, an original method developed by the authors as a result of studying the high-uranium zircon (Zr,U) SiO{sub 4} form Chernobyl {open_quotes}lavas{close_quotes} was used.

  8. Actinides and lanthanides under pressure: the pseudopotential approach; Actinides et terres rares sous pression: approche pseudopotentiel

    Energy Technology Data Exchange (ETDEWEB)

    Richard, N

    2002-07-01

    In the Density Functional Theory Framework, the pseudopotential formalism offers a broader scope of study than other theoretical methods such as global relaxation of the parameters of the cell or ab initio molecular dynamics simulations. This method has been widely used to study light elements or transition metals but never to study f elements. We have generated two non local norm conserving Trouillier-Martins pseudopotentials (one in LDA and one in GGA) for the cerium. To check the validity of the pseudopotentials, we have calculated the equilibrium volume and the incompressibility modulus and compared our results to previous all-electron calculations. If the GGA and non linear core corrections are used, the equation of state is in a good agreement with the experimental equation of state. A static study of the previously proposed high pressure phases give a transitions fcc-a''(I)-bct. Using the pseudopotentials we have generated, an ab initio molecular dynamics simulation at constant pressure, in the region between 5 and 12 GPa where the stable phase of cerium is not well defined, lead us to predict that a centred monoclinic structure, as the a''(I) phase previously observed in some experiments, is the most stable phase. We have also generated pseudopotentials for the light actinides (Th, Pa, U and Np). We have study their phase transitions under pressure at zero temperature. We compared our results with all electron results. The structure parameters have always been relaxed in this study. And for the first time in pseudopotential calculation, the spin-orbit coupling has been taken into account. The curves describing the variation of the volume or the incompressibility modulus depending on the elements and the phase transitions are always in agreement with the one found in the all electron calculations. (author)

  9. Utilization of Minor Actinides (Np, Am, Cm) in Nuclear Power Reactor

    Science.gov (United States)

    Gerasimov, A.; Bergelson, B.; Tikhomirov, G.

    2014-06-01

    Calculation research of the utilization process of minor actinides (transmutation with use of power released) is performed for specialized power reactor of the VVER type operating on the level of electric power of 1000 MW. Five subsequent cycles are considered for the reactor with fuel elements containing minor actinides along with enriched uranium. It was shown that one specialized reactor for the one cycle (900 days) can utilize minor actinides from several VVER-1000 reactors without any technological and structural modifications. Power released because of minor actinide fission is about 4% with respect to the total power

  10. Improved estimation of flood parameters by combining space based SAR data with very high resolution digital elevation data

    Directory of Open Access Journals (Sweden)

    H. Zwenzner

    2009-05-01

    Full Text Available Severe flood events turned out to be the most devastating catastrophes for Europe's population, economy and environment during the past decades. The total loss caused by the August 2002 flood is estimated to be 10 billion Euros for Germany alone. Due to their capability to present a synoptic view of the spatial extent of floods, remote sensing technology, and especially synthetic aperture radar (SAR systems, have been successfully applied for flood mapping and monitoring applications. However, the quality and accuracy of the flood masks and derived flood parameters always depends on the scale and the geometric precision of the original data as well as on the classification accuracy of the derived data products. The incorporation of auxiliary information such as elevation data can help to improve the plausibility and reliability of the derived flood masks as well as higher level products. This paper presents methods to improve the matching of flood masks with very high resolution digital elevation models as derived from LiDAR measurements for example. In the following, a cross section approach is presented that allows the dynamic fitting of the position of flood mask profiles according to the underlying terrain information from the DEM. This approach is tested in two study areas, using different input data sets. The first test area is part of the Elbe River (Germany where flood masks derived from Radarsat-1 and IKONOS during the 2002 flood are used in combination with a LiDAR DEM of 1 m spatial resolution. The other test data set is located on the River Severn (UK and flood masks derived from the TerraSAR-X satellite and aerial photos acquired during the 2007 flood are used in combination with a LiDAR DEM of 2 m pixel spacing. By means of these two examples the performance of the matching technique and the scaling effects are analysed and discussed. Furthermore, the systematic flood mapping capability of the different imaging systems are

  11. Fission fragment angular distributions in pre-actinide nuclei

    Science.gov (United States)

    Banerjee, Tathagata; Nath, S.; Jhingan, A.; Kaur, Gurpreet; Dubey, R.; Yadav, Abhishek; Laveen, P. V.; Shamlath, A.; Shareef, M.; Gehlot, J.; Saneesh, N.; Prasad, E.; Sugathan, P.; Pal, Santanu

    2016-10-01

    Background: Complete fusion of two nuclei leading to formation of a heavy compound nucleus (CN) is known to be hindered by various fission-like processes, in which the composite system reseparates after capture of the target and the projectile inside the potential barrier. As a consequence of these non-CN fission (NCNF) processes, fusion probability (PCN) starts deviating from unity. Despite substantial progress in understanding, the onset and the experimental signatures of NCNF and the degree of its influence on fusion have not yet been unambiguously identified. Purpose: This work aims to investigate the presence of NCNF, if any, in pre-actinide nuclei by systematic study of fission angular anisotropies and fission cross sections (σfis) in a number of nuclear reactions carried out at and above the Coulomb barrier (VB) . Method: Fission fragment angular distributions were measured for six 28Si-induced reactions involving isotopically enriched targets of 169Tm,176Yb,175Lu,180Hf,181Ta, and 182W leading to probable formation of CN in the pre-actinide region, at a laboratory energy (Elab) range of 129-146 MeV. Measurements were performed with large angular coverage (θlab=41∘ -170∘) in which fission fragments (FFs) were detected by nine hybrid telescope (E -Δ E ) detectors. Extracted fission angular anisotropies and σfis were compared with statistical model (SM) predictions. Results: Barring two reactions involving targets with large non-zero ground state spin (J ) , viz., 175Lu(7/2+) and 181Ta(7/2+) , experimental fission angular anisotropies were found to be higher in comparison with predictions of the statistical saddle point model (SSPM), at Ec .m . near VB. Comparison of present results with those from neighboring systems revealed that experimental anisotropies increasingly deviated from SSPM predictions as one moved from pre-actinide to actinide nuclei. For reactions involving targets with large nonzero J , this deviation was subdued. Comparison between

  12. Positron Spectroscopy of Hydrothermally Grown Actinide Oxides

    Science.gov (United States)

    2014-03-27

    setup with PVC shelf but co-linear detectors and close to lab bench, and (c) final setup with elevation above lab bench, detector angling, PEEK...29: Exponential/Gaussian fit for source only data. The estimated contributions from each component are 46.8% from air and 53.2% from plastic ...air, 39.0% from plastic , and 15.1% from copper

  13. DISTRIBUTION OF ACTINIDES BETWEEN THE AQUEOUS AND ORGANIC PHASES IN THE TALSPEAK PROCESS

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T.; Kyser, E.

    2010-09-02

    dependent upon the actinide's valence. Since our plans included the measurement of Pu(III) distribution coefficients using a Np(V) solution containing small amounts of {sup 238}Pu, it was necessary to demonstrate that the desired oxidation states of Np and Pu are produced and could be stabilized in a buffered lactate solution containing diethylenetriaminepentaacetic (DTPA). The stability of Np(V) and Pu(III) in lactic acid/DTPA solutions was evaluated by ultraviolet-visible (UV-vis) spectroscopy. To perform the evaluation, Np and Pu were added to solutions containing either hydroxylamine nitrate (HAN) or ferrous sulfamate (FS) as the reductant and nominally 1.5 M lactic acid/0.05 M DTPA. The pH of the solution was subsequently adjusted to nominally 2.8 as would be performed in the TALSPEAK process. In the valence adjustment study, we found that it was necessary to reduce Pu to Pu(III) prior to combining with the lactic acid and DTPA. The Pu reduction was performed using either HAN or FS. When FS was used, Np was reduced to Np(IV). The spectroscopic studies showed that Np(V) and Pu(III) are not stable in lactic acid/DTPA solutions. The stability of Np(IV)- and Pu(IV)-DTPA complexes are much greater than the stability of the Np(V)- and Pu(III)-DTPA complexes, and as a result, Np is slowly reduced to Np(IV) and Pu is slowly oxidized to Pu(IV) due to the reduced activity of the more stable complexes. When Np(V) was added to a solution containing a 1.5 M lactic acid/ammonium lactate buffer and 0.05 M DTPA, approximately 50% of the Np was reduced to Np(IV) in the first day. The fraction of Np(V) in the solution continued to diminish with time and was essentially reduced to Np(IV) after one week. When Pu(III) was added to a lactic acid/DTPA solution of the same composition, the spectrum recorded following at least two days after preparation of the solution continued to show some sign of Pu(III). The Pu(III) was completely oxidized to Pu(IV) after 3-4 days. The UV

  14. Estimating hantavirus risk in southern Argentina: a GIS-based approach combining human cases and host distribution.

    Science.gov (United States)

    Andreo, Veronica; Neteler, Markus; Rocchini, Duccio; Provensal, Cecilia; Levis, Silvana; Porcasi, Ximena; Rizzoli, Annapaola; Lanfri, Mario; Scavuzzo, Marcelo; Pini, Noemi; Enria, Delia; Polop, Jaime

    2014-01-14

    We use a Species Distribution Modeling (SDM) approach along with Geographic Information Systems (GIS) techniques to examine the potential distribution of hantavirus pulmonary syndrome (HPS) caused by Andes virus (ANDV) in southern Argentina and, more precisely, define and estimate the area with the highest infection probability for humans, through the combination with the distribution map for the competent rodent host (Oligoryzomys longicaudatus). Sites with confirmed cases of HPS in the period 1995-2009 were mostly concentrated in a narrow strip (~90 km × 900 km) along the Andes range from northern Neuquén to central Chubut province. This area is characterized by high mean annual precipitation (~1,000 mm on average), but dry summers (less than 100 mm), very low percentages of bare soil (~10% on average) and low temperatures in the coldest month (minimum average temperature -1.5 °C), as compared to the HPS-free areas, features that coincide with sub-Antarctic forests and shrublands (especially those dominated by the invasive plant Rosa rubiginosa), where rodent host abundances and ANDV prevalences are known to be the highest. Through the combination of predictive distribution maps of the reservoir host and disease cases, we found that the area with the highest probability for HPS to occur overlaps only 28% with the most suitable habitat for O. longicaudatus. With this approach, we made a step forward in the understanding of the risk factors that need to be considered in the forecasting and mapping of risk at the regional/national scale. We propose the implementation and use of thematic maps, such as the one built here, as a basic tool allowing public health authorities to focus surveillance efforts and normally scarce resources for prevention and control actions in vast areas like southern Argentina.

  15. Estimating Hantavirus Risk in Southern Argentina: A GIS-Based Approach Combining Human Cases and Host Distribution

    Directory of Open Access Journals (Sweden)

    Veronica Andreo

    2014-01-01

    Full Text Available We use a Species Distribution Modeling (SDM approach along with Geographic Information Systems (GIS techniques to examine the potential distribution of hantavirus pulmonary syndrome (HPS caused by Andes virus (ANDV in southern Argentina and, more precisely, define and estimate the area with the highest infection probability for humans, through the combination with the distribution map for the competent rodent host (Oligoryzomys longicaudatus. Sites with confirmed cases of HPS in the period 1995–2009 were mostly concentrated in a narrow strip (~90 km × 900 km along the Andes range from northern Neuquén to central Chubut province. This area is characterized by high mean annual precipitation (~1,000 mm on average, but dry summers (less than 100 mm, very low percentages of bare soil (~10% on average and low temperatures in the coldest month (minimum average temperature −1.5 °C, as compared to the HPS-free areas, features that coincide with sub-Antarctic forests and shrublands (especially those dominated by the invasive plant Rosa rubiginosa, where rodent host abundances and ANDV prevalences are known to be the highest. Through the combination of predictive distribution maps of the reservoir host and disease cases, we found that the area with the highest probability for HPS to occur overlaps only 28% with the most suitable habitat for O. longicaudatus. With this approach, we made a step forward in the understanding of the risk factors that need to be considered in the forecasting and mapping of risk at the regional/national scale. We propose the implementation and use of thematic maps, such as the one built here, as a basic tool allowing public health authorities to focus surveillance efforts and normally scarce resources for prevention and control actions in vast areas like southern Argentina.

  16. Discrete fragment model for apparent formation constants of actinide ions with humic substances

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, Takayuki; Yoshida, Hatsumi; Aoyama, Shunsuke; Kobayashi, Taishi; Takagi, Ikuji [Kyoto Univ. (Japan). Dept. of Nuclear Engineering; Moriyama, Hirotake [Kyoto Univ., Osaka (Japan). Research Reactor Inst.

    2015-09-01

    A semi-empirical thermodynamic model was applied to estimate the apparent formation constants of actinide ions, i.e., Th(IV), Pu(IV) and Np(V), with humic substances (HSs), including humic and fulvic acids, over a wide range of solution conditions, i.e., pH, ionic strength, and HS and metal concentrations. The hypothetical HSs consist of humic and fulvic acids with nine types of simple organic ligands, which include aromatic and aliphatic carboxyl groups and phenol groups, as binding sites. The abundance of each binding site in the hypothetical HSs was determined via a fitting analysis using an acid-dissociation dataset for several HSs. To determine the apparent formation constant of a given metal ion with HSs, 54 specific binding sites were considered, including nine monodentate sites (1:1 metal/ligand complexes) and 45 bidentate sites (1:2 metal/ligand complexes). The formation constant of each monodentate binding was determined from the experimental data, while those of the bidentate bindings were determined by considering two monodentate bindings and the chelating effect, for which one of the adjustable parameters was introduced in the model. Introduction of the other parameter, which is related to the fraction of monodentate to bidentate sites (i.e., the heterogeneity), afforded the parameter values with good correlation with the apparent formation constant data. The present model with adjusted parameter values well reproduced the experimental apparent complex formation constants for actinide ion interaction with HSs in a wide range of solution conditions except for those obtained at trace concentrations.

  17. Solar r-process-constrained actinide production in neutrino-driven winds of supernovae

    Science.gov (United States)

    Goriely, S.; Janka, H.-Th.

    2016-07-01

    Long-lived radioactive nuclei play an important role as nucleo-cosmochronometers and as cosmic tracers of nucleosynthetic source activity. In particular, nuclei in the actinide region like thorium, uranium, and plutonium can testify to the enrichment of an environment by the still enigmatic astrophysical sources that are responsible for the production of neutron-rich nuclei by the rapid neutron-capture process (r-process). Supernovae and merging neutron-star (NS) or NS-black hole binaries are considered as most likely sources of the r-nuclei. But arguments in favour of one or the other or both are indirect and make use of assumptions; they are based on theoretical models with remaining simplifications and shortcomings. An unambiguous observational determination of a production event is still missing. In order to facilitate searches in this direction, e.g. by looking for radioactive tracers in stellar envelopes, the interstellar medium or terrestrial reservoirs, we provide improved theoretical estimates and corresponding uncertainty ranges for the actinide production (232Th, 235, 236, 238U, 237Np, 244Pu, and 247Cm) in neutrino-driven winds of core-collapse supernovae. Since state-of-the-art supernova models do not yield r-process viable conditions - but still lack, for example, the effects of strong magnetic fields - we base our investigation on a simple analytical, Newtonian, adiabatic and steady-state wind model and consider the superposition of a large number of contributing components, whose nucleosynthesis-relevant parameters (mass weight, entropy, expansion time-scale, and neutron excess) are constrained by the assumption that the integrated wind nucleosynthesis closely reproduces the Solar system distribution of r-process elements. We also test the influence of uncertain nuclear physics.

  18. Estimation of raw material performance in mammalian cell culture using near infrared spectra combined with chemometrics approaches.

    Science.gov (United States)

    Lee, Hae Woo; Christie, Andrew; Liu, Jun Jay; Yoon, Seongkyu

    2012-01-01

    Understanding variability in raw materials and their impacts on product quality is of critical importance in the biopharmaceutical manufacturing processes. For this purpose, several spectroscopic techniques have been studied for raw material characterization, providing fast and nondestructive ways to measure quality of raw materials. However, investigations of correlation between spectra of raw materials and cell culture performance have been scarce due to their complexity and uncertainty. In this study, near-infrared spectra and bioassays of multiple soy hydrolysate lots manufactured by different vendors were analyzed using chemometrics approaches in order to address variability of raw materials as well as correlation between raw material properties and corresponding cell culture performance. Principal component analysis revealed that near-infrared spectra of different soy lots contain enough physicochemical information about soy hydrolysates to allow identification of lot-to-lot variability as well as vendor-to-vendor differences. The identified compositional variability was further analyzed in order to estimate cell growth and protein production of two mammalian cell lines under the condition of varying soy dosages using partial least square regression combined with optimal variable selection. The performance of the resulting models demonstrates the potential of near-infrared spectroscopy as a robust lot selection tool for raw materials while providing a biological link between chemical composition of raw materials and cell culture performance.

  19. Combining culture-dependent and -independent methodologies for estimation of richness of estuarine bacterioplankton consuming riverine dissolved organic matter.

    Science.gov (United States)

    Kisand, Veljo; Wikner, Johan

    2003-06-01

    Three different methods for analyzing natural microbial community diversity were combined to maximize an estimate of the richness of bacterioplankton catabolizing riverine dissolved organic matter (RDOM). We also evaluated the ability of culture-dependent quantitative DNA-DNA hybridization, a 16S rRNA gene clone library, and denaturing gradient gel electrophoresis (DGGE) to detect bacterial taxa in the same sample. Forty-two different cultivatable strains were isolated from rich and poor solid media. In addition, 50 unique clones were obtained by cloning of the bacterial 16S rDNA gene amplified by PCR from the community DNA into an Escherichia coli vector. Twenty-three unique bands were sequenced from 12 DGGE profiles, excluding a composite fuzzy band of the Cytophaga-Flavobacterium group. The different methods gave similar distributions of taxa at the genus level and higher. However, the match at the species level among the methods was poor, and only one species was identified by all three methods. Consequently, all three methods identified unique subsets of bacterial species, amounting to a total richness of 97 operational taxonomic units in the experimental system. The confidence in the results was, however, dependent on the current precision of the phylogenetic determination and definition of the species. Bacterial consumers of RDOM in the studied estuary were primarily both cultivatable and uncultivable taxa of the Cytophaga-Flavobacterium group, a concordant result among the methods applied. Culture-independent methods also suggested several not-yet-cultivated beta-proteobacteria to be RDOM consumers.

  20. Combining Meteosat-10 satellite image data with GPS tropospheric path delays to estimate regional integrated water vapor (IWV) distribution

    Science.gov (United States)

    Leontiev, Anton; Reuveni, Yuval

    2017-02-01

    Using GPS satellites signals, we can study different processes and coupling mechanisms that can help us understand the physical conditions in the lower atmosphere, which might lead or act as proxies for severe weather events such as extreme storms and flooding. GPS signals received by ground stations are multi-purpose and can also provide estimates of tropospheric zenith delays, which can be converted into accurate integrated water vapor (IWV) observations using collocated pressure and temperature measurements on the ground. Here, we present for the first time the use of Israel's dense regional GPS network for extracting tropospheric zenith path delays combined with near-real-time Meteosat-10 water vapor (WV) and surface temperature pixel intensity values (7.3 and 10.8 µm channels, respectively) in order to assess whether it is possible to obtain absolute IWV (kg m-2) distribution. The results show good agreement between the absolute values obtained from our triangulation strategy based solely on GPS zenith total delays (ZTD) and Meteosat-10 surface temperature data compared with available radiosonde IWV absolute values. The presented strategy can provide high temporal and special IWV resolution, which is needed as part of the accurate and comprehensive observation data integrated in modern data assimilation systems and is required for increasing the accuracy of regional numerical weather prediction systems forecast.

  1. Simultaneous Estimation of Gemcitabine Hydrochloride and Capecitabine Hydrochloride in Combined Tablet Dosage Form by RP-HPLC Method

    Directory of Open Access Journals (Sweden)

    V. Rajesh

    2011-01-01

    Full Text Available A new reverse phase high performance liquid chromatography (RP-HPLC method has been developed for the simultaneous estimation of gemcitabine hydrochloride and capecitabine hydrochloride in combined tablet dosage form. An inertsil ODS-3 C-18 column having dimensions of 250×4.6 mm and particle size of 5 µm, with mobile phase containing a mixture of acetonitrile : water : triethyelamine in the ratio of (70 : 28 : 2v/v was used. The pH of mobile phase was adjusted to 4.0 with ortho-phosphoric acid. The flow rate was 1 mL/min and the column effluents were monitored at 260 nm. The retention time for gemcitabine hydrochloride and capecitabine hydrochloride was found to be 2.76 and 2.3 min respectively. The proposed method was validated in terms of linearity, accuracy, precision, limit of detection, limit of quantitation and robustness. The method was found to be linear in the range of 10-50 µg/mL and 4-24 µg/mL for gemcitabine hydrochloride and capecitabine hydrochloride, with regression coefficient r = 0.999 and r = 0.999, respectively.

  2. COMBINING LIDAR ESTIMATES OF BIOMASS AND LANDSAT ESTIMATES OF STAND AGE FOR SPATIALLY EXTENSIVE VALIDATION OF MODELED FOREST PRODUCTIVITY. (R828309)

    Science.gov (United States)

    Extensive estimates of forest productivity are required to understand the relationships between shifting land use, changing climate and carbon storage and fluxes. Aboveground net primary production of wood (NPPAw) is a major component of total NPP and...

  3. Helium and fission gas behaviour in magnesium aluminate spinel and zirconia for actinide transmutation

    NARCIS (Netherlands)

    Damen, P.M.G.

    2003-01-01

    In order to reduce the long-term radiotoxicity of spent nuclear fuel, many studies are performed on partitioning and transmutation of actinides. In such a scenario, the long-lived radio-isotopes (mostly actinides) are partitioned from the nuclear waste, and subsequently transmuted or fissioned in a

  4. Invisible structures in the X-ray absorption spectra of actinides

    NARCIS (Netherlands)

    Kvashnina, Kristina O.; De Groot, Frank M F

    2014-01-01

    The X-ray absorption spectra of actinides are discussed with an emphasis on the fundamental effects that influence their spectral shape, including atomic multiplet theory, charge transfer theory and crystal field theory. Many actinide spectra consist of a single peak and it is shown that the use of

  5. Actinide Partitioning and Transmutation Program. Progress report, April 1--June 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    Tedder, D. W.; Blomeke, J. O. [comps.

    1977-10-01

    Experimental work on the 16 tasks comprising the Actinide Partitioning and Transmutation Program was continued. Summaries of work are given on Purex Process modifications, actinide recovery, Am-Cm recovery, radiation effects on ion exchangers, LMFBR transmutation studies, thermal reactor transmutation studies, fuel cycle studies, and partitioning-transmutation evaluation. (JRD)

  6. Systematic Characteristics of Fast Neutron Fission Cross Sections for Actinide Nuclei

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The neutron fission cross sections of actinide nuclei are important data for the design of nuclear reactor and nuclear engineering, and so on. So far, there has been a certain amount of experimental data for the fission cross sections of actinide nuclei. However,

  7. Trace analysis of actinides in the environment using resonance ionization mass spectrometry; Spurenanalyse von Aktiniden in der Umwelt mittels Resonanzionisations-Massenspektrometrie

    Energy Technology Data Exchange (ETDEWEB)

    Raeder, Sebastian

    2011-04-12

    In this work the resonant ionization of neutral atoms using laser radiation was applied and optimized for ultra-trace analysis of the actinides thorium, uranium, neptunium and plutonium. The sensitive detection of these actinides is a challange for the monitoring and quantification of radioactive releases from nuclear facilities. Using resonance ionization spectroscopy combined with a newly developed quadrupole-mass-spectrometer, numerous energy levels in the atomic structure of these actinides could be identified. With this knowledge efficient excitation schemes for the mentioned actinides could be identified and characterised. The applied in-source-ionization ensures for a high detection efficiency due to the good overlap of laser radiation with the atomic beam and allows therefore for a low sample consumption which is required for the analysis of radio nuclides. The selective excitation processes in the resonant ionization method supresses unwanted contaminations and was optimized for analytical detection of ultra-trace amounts in environmental samples as well as for determination of isotopic compositions. The efficient in-source-ionization combined with high power pulsed laser radiation allows for detections efficiency up to 1%. For plutonium detection limits in the range of 10{sup 4}-10{sup 5} atoms could be demonstrated for synthetic samples as well as for first environmental samples. The usage of narrow bandwidth continuous wave lasers in combination with a transversal overlap of the laser radiation and the free propagating atomic beam enable for resolving individual isotopic shifts of the resonant transitions. This results in a high selectivity against dominant neighboring isotopes but with a significant loss in detection efficiency. For the ultra-trace isotope {sup 236}U a detection limit down to 10{sup -9} for the isotope ratio N ({sup 236}U)/N ({sup 238}U) could be determined.

  8. Final Report on Actinide Glass Scintillators for Fast Neutron Detection

    Energy Technology Data Exchange (ETDEWEB)

    Bliss, Mary; Stave, Jean A.

    2012-10-01

    This is the final report of an experimental investigation of actinide glass scintillators for fast-neutron detection. It covers work performed during FY2012. This supplements a previous report, PNNL-20854 “Initial Characterization of Thorium-loaded Glasses for Fast Neutron Detection” (October 2011). The work in FY2012 was done with funding remaining from FY2011. As noted in PNNL-20854, the glasses tested prior to July 2011 were erroneously identified as scintillators. The decision was then made to start from “scratch” with a literature survey and some test melts with a non-radioactive glass composition that could later be fabricated with select actinides, most likely thorium. The normal stand-in for thorium in radioactive waste glasses is cerium in the same oxidation state. Since cerium in the 3+ state is used as the light emitter in many scintillating glasses, the next most common substitute was used: hafnium. Three hafnium glasses were melted. Two melts were colored amber and a third was clear. It barely scintillated when exposed to alpha particles. The uses and applications for a scintillating fast neutron detector are important enough that the search for such a material should not be totally abandoned. This current effort focused on actinides that have very high neutron capture energy releases but low neutron capture cross sections. This results in very long counting times and poor signal to noise when working with sealed sources. These materials are best for high flux applications and access to neutron generators or reactors would enable better test scenarios. The total energy of the neutron capture reaction is not the only factor to focus on in isotope selection. Many neutron capture reactions result in energetic gamma rays that require large volumes or high densities to detect. If the scintillator is to separate neutrons from gamma rays, the capture reactions should produce heavy particles and few gamma rays. This would improve the detection of a

  9. Impurities that cause difficulty in stripping actinides from commercial tetraalkylcarbamoylmethylphosphonates

    Energy Technology Data Exchange (ETDEWEB)

    Bahner, C. T.; Shoun, R. R.; McDowell, W. J.

    1977-09-01

    Dihexyl((diethylcarbamoyl)methyl)phosphonate (DHDECMP) in diethylbenzene extracts actinides well from 6 M nitric acid solution, but commercially available DHDECMP contains impurities which interfere with stripping the actinides from the organic extract. DHDECMP purified by molecular distillation does not contain these impurities, but the pot residue contains increased concentrations of them. Heating the purified DHDECMP causes the formation of products which interfere with stripping in the same way, suggesting that high temperatures employed in the manufacture of DHDECMP may produce the offending impurities. These impurities can be separated from the heat-decomposed material or the pot residues by dilution with a large volume of hexanes (causing part of the impurities to separate as a second liquid phase) followed by equilibration of the hexane solution with dilute alkali. After the treatment with hexane and dilute alkali, the DHDECMP is readily recovered and functions well in the actinide extraction process. Dibutyl((dibutylcarbamoyl)methyl)-phosphonate (DBDBCMP) and di(2-ethylhexyl)((diethylcarbamoyl)-methyl)phosphonate (DEHDECMP) are purified less effectively by these methods. Similar separation methods using diethylbenzene or CCl/sub 4/ as solvent do not remove impurities as completely as the hexane process. Impurities can also be removed from a benzene solution of the DHDECMP pot residue by passing it through a column packed with silica gel or diethylaminoethyl cellulose. These impurities have been separated into fractions for analytical examination by use of various solvents and by column chromatography. Hexyl hydrogen ((diethylcarbamoyl)methyl)-phosphonate has been identified tentatively as a principal objectionable impurity. Dihexyl phosphoric acid and possibly dihexylphosphonate have been identified in other fractions.

  10. MINOR ACTINIDE SEPARATIONS USING ION EXCHANGERS OR IONIC LIQUIDS

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D.; Visser, A.; Bridges, N.

    2011-09-20

    This project seeks to determine if (1) inorganic-based ion exchange materials or (2) electrochemical methods in ionic liquids can be exploited to provide effective Am and Cm separations. Specifically, we seek to understand the fundamental structural and chemical factors responsible for the selectivity of inorganic-based ion-exchange materials for actinide and lanthanide ions. Furthermore, we seek to determine whether ionic liquids can serve as the electrolyte that would enable formation of higher oxidation states of Am and other actinides. Experiments indicated that pH, presence of complexants and Am oxidation state exhibit significant influence on the uptake of actinides and lanthanides by layered sodium titanate and hybrid zirconium and tin phosphonate ion exchangers. The affinity of the ion exchangers increased with increasing pH. Greater selectivity among Ln(III) ions with sodium titanate materials occurs at a pH close to the isoelectric potential of the ion exchanger. The addition of DTPA decreased uptake of Am and Ln, whereas the addition of TPEN generally increases uptake of Am and Ln ions by sodium titanate. Testing confirmed two different methods for producing Am(IV) by oxidation of Am(III) in ionic liquids (ILs). Experimental results suggest that the unique coordination environment of ionic liquids inhibits the direct electrochemical oxidation of Am(III). The non-coordinating environment increases the oxidation potential to a higher value, while making it difficult to remove the inner coordination of water. Both confirmed cases of Am(IV) were from the in-situ formation of strong chemical oxidizers.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  12. Fission of actinides using a table-top laser

    CERN Document Server

    Schwoerer, H; Sauerbrey, R; Galy, J; Magill, J; Rondinella, V; Schenkel, R; Butz, T

    2003-01-01

    Powerful table-top lasers are now available in the laboratory and can be used to induce nuclear reactions. We report the first demonstration of nuclear fission using a high repetition rate table-top laser with intensities of 10 sup 2 sup 0 W/cm sup 2. Actinide photo-fission has been achieved in both sup 2 sup 3 sup 8 U and sup 2 sup 3 sup 2 Th from the high-energy Bremsstrahlung radiation produced by laser acceleration of electrons. The fission products were identified by time-resolved gamma-spectroscopy. (authors)

  13. Detection of Actinides via Nuclear Isomer De-Excitation

    Energy Technology Data Exchange (ETDEWEB)

    Francy, Christopher J. [Oregon State Univ., Corvallis, OR (United States)

    2009-07-01

    This dissertation discusses a data collection experiment within the Actinide Isomer Identification project (AID). The AID project is the investigation of an active interrogation technique that utilizes nuclear isomer production, with the goal of assisting in the interdiction of illicit nuclear materials. In an attempt to find and characterize isomers belonging to 235U and its fission fragments, a 232Th target was bombarded with a monoenergetic 6Li ion beam, operating at 45 MeV.

  14. LOW FALSE POSITIVE RATE OF KEPLER CANDIDATES ESTIMATED FROM A COMBINATION OF SPITZER AND FOLLOW-UP OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Désert, Jean-Michel; Brown, Timothy M. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Charbonneau, David; Torres, Guillermo; Fressin, François; Ballard, Sarah; Latham, David W. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bryson, Stephen T.; Borucki, William J. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Knutson, Heather A. [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Batalha, Natalie M. [San Jose State University, San Jose, CA 95192 (United States); Deming, Drake [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Ford, Eric B. [University of Florida, Gainesville, FL 32611 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Gilliland, Ronald L. [Center for Exoplanets and Habitable Worlds, The Pennsylvania State University, University Park, PA 16802 (United States); Seager, Sara, E-mail: desert@colorado.edu [Massachusetts Institute of Technology, Cambridge, MA 02159 (United States)

    2015-05-01

    NASA’s Kepler mission has provided several thousand transiting planet candidates during the 4 yr of its nominal mission, yet only a small subset of these candidates have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the Spitzer Space Telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) among the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital, and planetary parameter space, and we observe their transits with Spitzer at 4.5 μm. We use these observations to measures the candidate’s transit depths and infrared magnitudes. An authentic planet produces an achromatic transit depth (neglecting the modest effect of limb darkening). Conversely a bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the transit depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5% and depending on the Kepler Objects of Interest. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3σ. This observational result, which uses the achromatic property of planetary transit signals that is not investigated

  15. Investigating Marine Boundary Layer Parameterizations for Improved Off-Shore Wind Predictions by Combining Observations with Models via State Estimation

    Science.gov (United States)

    Delle Monache, Luca; Hacker, Josh; Kosovic, Branko; Lee, Jared; Vandenberghe, Francois; Wu, Yonghui; Clifton, Andrew; Hawkins, Sam; Nissen, Jesper; Rostkier-Edelstein, Dorita

    2014-05-01

    Despite advances in model representation of the spatial and temporal evolution of the atmospheric boundary layer (ABL) a fundamental understanding of the processes shaping the Marine Boundary Layer (MBL) is still lacking. As part of a project funded by the U.S. Department of Energy, we are tackling this problem by combining available atmosphere and ocean observations with advanced coupled atmosphere-wave models, and via state estimation (SE) methodologies. The over-arching goal is to achieve significant advances in the scientific understanding and prediction of the underlying physical processes of the MBL, with an emphasis on the coupling between the atmosphere and the ocean via momentum and heat fluxes. We are using the single-column model (SCM) and three-dimensional (3D) versions of the Weather Research and Forecasting (WRF) model, observations of MBL structure as provided by coastal and offshore remote sensing platforms and meteorological towers, and probabilistic SE. We are systematically investigating the errors in the treatment of the surface layer of the MBL, identifying structural model inadequacies associated with its representation. We expect one key deficiency of current model representations of the surface layer of the MBL that can have a profound effect on fluxes estimates: the use of Monin-Obukhov similarity theory (MOST). This theory was developed for continental ABLs using land-based measurements, which accounts for mechanical and thermal forcing on turbulence but neglects the influence of ocean waves. We have developed an atmosphere-wave coupled modeling system by interfacing WRF with a wave model (Wavewatch III - WWIII), which is used for evaluating errors in the representation of wave-induced forcing on the energy balance at the interface between atmosphere and ocean. The Data Assimilation Research Testbed (DART) includes the SE algorithms that provide the framework for obtaining spatial and temporal statistics of wind-error evolution (and hence

  16. Octupole correlations in excited 0{sup +} states of the actinides

    Energy Technology Data Exchange (ETDEWEB)

    Spieker, Mark; Endres, Janis; Zilges, Andreas [Institute for Nuclear Physics, University of Cologne (Germany); Bucurescu, Dorel; Pascu, Sorin; Zamfir, Nicolae-Victor [Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest (Romania); Faestermann, Thomas [Physik Department, Technische Universitaet Muenchen, Munich (Germany); Hertenberger, Ralf; Wirth, Hans-Friedrich [Fakultaet fuer Physik, Ludwig-Maximilians-Universitaet Muenchen, Munich (Germany)

    2014-07-01

    New experimental data has once again shown the importance of the octupole degree of freedom in the actinides. To further study possible admixtures of double-octupole structures to the wave function of positive-parity states, a high-resolution (p,t) experiment on {sup 242}Pu has been recently performed at the Q3D magnetic spectrograph in Munich. Excited 0{sup +} states were populated in {sup 240}Pu up to an excitation energy of 3 MeV. The new data allowed for a stringent test of the predictions of the spdf interacting boson model. In order to find possible double-octupole 0{sup +} candidates in the actinides, the signature of close-lying first and second excited 0{sup +} states has been proposed. It is found that the observation of this signature coincides with an E1 γ-decay of the first excited 0{sup +} state, while this state is strongly populated in the (p,t) reaction.

  17. Actinide Solubility and Speciation in the WIPP [PowerPoint

    Energy Technology Data Exchange (ETDEWEB)

    Reed, Donald T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    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.

  18. Actinide production from xenon bombardments of curium-248

    Energy Technology Data Exchange (ETDEWEB)

    Welch, R.B.

    1985-01-01

    Production cross sections for many actinide nuclides formed in the reaction of /sup 129/Xe and /sup 132/Xe with /sup 248/Cm at bombarding energies slightly above the coulomb barrier were determined using radiochemical techniques to isolate these products. These results are compared with cross sections from a /sup 136/Xe + /sup 248/Cm reaction at a similar energy. When compared to the reaction with /sup 136/Xe, the maxima in the production cross section distributions from the more neutron deficient projectiles are shifted to smaller mass numbers, and the total cross section increases for the production of elements with atomic numbers greater than that of the target, and decreases for lighter elements. These results can be explained by use of a potential energy surface (PES) which illustrates the effect of the available energy on the transfer of nucleons and describes the evolution of the di-nuclear complex, an essential feature of deep-inelastic reactions (DIR), during the interaction. The other principal reaction mechanism is the quasi-elastic transfer (QE). Analysis of data from a similar set of reactions, /sup 129/Xe, /sup 132/Xe, and /sup 136/Xe with /sup 197/Au, aids in explaining the features of the Xe + Cm product distributions, which are additionally affected by the depletion of actinide product yields due to deexcitation by fission. The PES is shown to be a useful tool to predict the general features of product distributions from heavy ion reactions.

  19. Heat capacities of lanthanide and actinide monazite-type ceramics

    Science.gov (United States)

    Kowalski, Piotr M.; Beridze, George; Vinograd, Victor L.; Bosbach, Dirk

    2015-09-01

    (Ln, An)xPO4 monazite-type ceramics are considered as potential matrices for the disposal of nuclear waste. In this study we computed the heat capacities and the standard entropies of these compounds using density functional perturbation theory. The calculations of lanthanide monazites agree well with the existing experimental data and provide information on the variation of the standard heat capacities and entropies along the lanthanide series. The results for AnPO4 monazites are similar to those obtained for the isoelectronic lanthanide compounds. This suggests that the missing thermodynamic data on actinide monazites could be similarly computed or assessed based on the properties of their lanthanide analogs. However, the computed heat capacity of PuPO4 appear to be significantly lower than the measured data. We argue that this discrepancy might indicate potential problems with the existing experimental data or with their interpretation. This shows a need for further experimental studies of the heat capacities of actinide-bearing, monazite-type ceramics.

  20. Actinides transmutation - a comparison of results for PWR benchmark

    Energy Technology Data Exchange (ETDEWEB)

    Claro, Luiz H. [Instituto de Estudos Avancados (IEAv/CTA), Sao Jose dos Campos, SP (Brazil)], e-mail: luizhenu@ieav.cta.br

    2009-07-01

    The physical aspects involved in the Partitioning and Transmutation (P and T) of minor actinides (MA) and fission products (FP) generated by reactors PWR are of great interest in the nuclear industry. Besides these the reduction in the storage of radioactive wastes are related with the acceptability of the nuclear electric power. From the several concepts for partitioning and transmutation suggested in literature, one of them involves PWR reactors to burn the fuel containing plutonium and minor actinides reprocessed of UO{sub 2} used in previous stages. In this work are presented the results of the calculations of a benchmark in P and T carried with WIMSD5B program using its new cross sections library generated from the ENDF-B-VII and the comparison with the results published in literature by other calculations. For comparison, was used the benchmark transmutation concept based in a typical PWR cell and the analyzed results were the k{infinity} and the atomic density of the isotopes Np-239, Pu-241, Pu-242 and Am-242m, as function of burnup considering discharge of 50 GWd/tHM. (author)

  1. The EBR-II X501 Minor Actinide Burning Experiment

    Energy Technology Data Exchange (ETDEWEB)

    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.

  2. Stabilization of actinides and lanthanides in unusually high oxidation states

    Energy Technology Data Exchange (ETDEWEB)

    Eller, P.G.; Penneman, R.A.

    1986-01-01

    Chemical environments can be chosen which stabilize actinides and lanthanides in unusually high or low oxidation states and in unusual coordination. In many cases, one can rationalize the observed species as resulting from strong charge/size influences provided by specific sites in host lattices (e.g., Tb(IV) in BaTbO/sub 3/ or Am(IV) in polytungstate anions). In other cases, the unusual species can be considered from an acid-base viewpoint (e.g., U(III) in AsF/sub 5//HF solution or Pu(VII) in Li/sub 5/PuO/sub 6/). In still other cases, an interplay of steric and redox effects can lead to interesting comparisons (e.g., instability of double fluoride salts of Pu(V) and Pu(VI) relative to U, Np, and Am analogues). Generalized ways to rationalize compounds containing actinides and lanthanides in unusual valences (particularly high valences), including the above and numerous other examples, will form the focus of this paper. Recently developed methods for synthesizing high valent f-element fluorides using superoxidizers and superacids at low temperatures will also be described. 65 refs., 8 figs., 9 tabs.

  3. APPLICATION OF ABSORPTION SPECTROSCOPY TO ACTINIDE PROCESS ANALYSIS AND MONITORING

    Energy Technology Data Exchange (ETDEWEB)

    Lascola, R.; Sharma, V.

    2010-06-03

    The characteristic strong colors of aqueous actinide solutions form the basis of analytical techniques for actinides based on absorption spectroscopy. Colorimetric measurements of samples from processing activities have been used for at least half a century. This seemingly mature technology has been recently revitalized by developments in chemometric data analysis. Where reliable measurements could formerly only be obtained under well-defined conditions, modern methods are robust with respect to variations in acidity, concentration of complexants and spectral interferents, and temperature. This paper describes two examples of the use of process absorption spectroscopy for Pu analysis at the Savannah River Site, in Aiken, SC. In one example, custom optical filters allow accurate colorimetric measurements of Pu in a stream with rapid nitric acid variation. The second example demonstrates simultaneous measurement of Pu and U by chemometric treatment of absorption spectra. The paper concludes with a description of the use of these analyzers to supplement existing technologies in nuclear materials monitoring in processing, reprocessing, and storage facilities.

  4. Energy-Dependent Fission Q Values Generalized for All Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, R

    2008-09-25

    We generalize Madland's parameterization of the energy release in fission to obtain the dependence of the fission Q values on incident neutron energy, E{sub n}, for all major and minor actinides. These Q(E{sub n}) parameterizations are included in the ENDL2008 release. This paper describes calculations of energy-dependent fission Q values based on parameterizations of the prompt energy release in fission [1], developed by Madland [1] to describe the prompt energy release in neutron-induced fission of {sup 235}U, {sup 238}U, and {sup 239}Pu. The energy release is then related to the energy deposited during fission so that experimentally measurable quantities can be used to obtain the Q values. A discussion of these specific parameterizations and their implementation in the processing code for Monte Carlo neutron transport, MCFGEN, [2] is described in Ref. [3]. We extend this model to describe Q(E) for all actinides, major and minor, in the Evaluated Nuclear Data Library (ENDL) 2008 release, ENDL2008.

  5. Multi-nucleon transfer experiments in the actinide region

    Energy Technology Data Exchange (ETDEWEB)

    Geibel, Kerstin; Reiter, Peter; Birkenbach, Benedikt [Institut fuer Kernphysik, Universitaet zu Koeln (Germany); Valiente-Dobon, Jose Javier; Recchia, Francesco [Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro (Italy); Gadea, Andres [IFIC, CSIC-Universidad de Valencia (Spain); Lenzi, Silvia [Dipartimento di Fisica, University of Padova (Italy)

    2012-07-01

    Two experiments at the PRISMA-CLARA-Setup at the LNL in Legnaro were analysed focussing on the target-like reaction products in the actinide region after multi-nucleon transfer reactions. Both experiments use {sup 238}U as target; a {sup 70}Zn-beam with 460 MeV and a {sup 136}Xe-beam with 926 MeV were employed. Kinematic correlations between the reaction partners are used to obtain information about the unobserved target-like reaction products by the analysis of the beam-like particles identified with the PRISMA-spectrometer. Clean {gamma}-spectra from neutron-rich actinide nuclei are obtained with the CLARA-array. An extension of the ground state rotational band in {sup 240}U and insights in neutron-rich Th-isotopes were achieved. Based on relative cross section distributions for various reaction channels the perspectives and limitations for in-beam {gamma}-spectroscopy with this experimental method in this mass region are discussed.

  6. Influence of dose distribution on risk of lung cancer occurrence after actinide oxide inhalation; Influence de la distribution de dose sur le risque d'apparition de cancers pulmonaires apres inhalation d'oxydes d'actinides

    Energy Technology Data Exchange (ETDEWEB)

    Fritsch, P.; Dudoignon, N.; Guillet, K.; Rateau, G.; Delforge, J. [Lab. de Radiotoxicologie, CEA/DSV/DRR/SRCA, Bruyeres le Chatel (France)

    2002-07-01

    The aim of this work was to estimate risk of lung tumour occurrence after inhalation of actinide oxides from published studies and rat studies in progress. For the same delivered dose, the risk increases when homogeneity of irradiation increases, i.e., the number of particles deposited after inhalation increases (small particles and (or) low specific alpha activity). The dose-effect relationships reported appear linear up to a few gray, depending on the aerosol considered, and then the slope decreases. This slope, which corresponds with the risk, can vary over one order of magnitude de ending on the aerosol used. An effective threshold at about 1 Gy was not observed for the most homogeneous dose distributions. A dosimetric and biological approach is proposed to provide a more realistic risk estimate. (author)

  7. Phytosiderophore Effects on Subsurface Actinide Contaminants: Potential for Phytostabilization and Phytoextraction

    Energy Technology Data Exchange (ETDEWEB)

    Ruggiero, Christy

    2005-06-01

    This project seeks to understand the influence of phytosiderophore-producing plants (grasses, including crops such as wheat and barley) on the biogeochemistry of actinide and other metal contaminants in the subsurface environment, and to determine the potential of phytosiderophore-producing plants for phytostabilization and phytoextraction of actinides and some metal soil contaminants. Phytosiderophores are secreted by graminaceous plants such as barley and wheat for the solubilization, mobilization and uptake of Fe and other essential nutrients from soils. The ability for these phytosiderophores to chelate and absorb actinides using the same uptake system as for Fe is being investigated though characterization of actinide-phytosiderophore complexes (independently of plants), and characterization of plant uptake of such complexes. We may also show possible harm caused by these plants through increased chelation of actinides that increase in actinide mobilization & migration in the subsurface environment. This information can then be directly applied by either removal of harmful plants, or can be used to develop plant-based soil stabilization/remediation technologies. Such technologies could be the low-cost, low risk solution to many DOE actinide contamination problems.

  8. A method to combine non-probability sample data with probability sample data in estimating spatial means of environmental variables

    NARCIS (Netherlands)

    Brus, D.J.; Gruijter, de J.J.

    2003-01-01

    In estimating spatial means of environmental variables of a region from data collected by convenience or purposive sampling, validity of the results can be ensured by collecting additional data through probability sampling. The precision of the pi estimator that uses the probability sample can be in

  9. Interaction of actinides with amino acids: from peptides to proteins; Interaction des actinides avec les acides amines: du peptide a la proteine

    Energy Technology Data Exchange (ETDEWEB)

    Jeanson, A

    2008-09-15

    Structural information on complexes of actinides with molecules of biological interest is required to better understand the mechanisms of actinides transport in living organisms, and can contribute to develop new decorporation treatments. Our study is about Th(IV), Np(IV), Pu(IV) and uranyl(VI) cations, which have a high affinity for some protein domains, and Fe(III), which is the natural cation of these biological systems. In this work, chelation of actinides has been brought to light with UV-visible-Near Infra Red spectroscopy, NMR, EPR, and ultrafiltration. Determination of the structure of the complexation site has been undertaken with Exafs measurements, and of the tertiary structure of the protein with SANS measurements. The first approach was to describe the interaction modes between actinides and essential chemical functions of proteins. Thus, the Ac-AspAspProAspAsp-NH{sub 2} peptide was studied as a possible chelate of actinides. Polynuclear species with {mu}-oxo or {mu}-hydroxo bridges were identified. The iron complex is binuclear, and the actinide ones have a higher nuclearity. The second approach was to study a real case of complexation of actinide with a protein: transferrin. Results show that around physiological ph a mononuclear complex is formed with Np(IV) and Pu(IV), while transferrin does not complex Th(IV) in the same conditions. Characteristic distances of M-transferrin complexes (M = Fe, Np, Pu) were determined. Moreover, the protein seems to be in its close conformation with Pu(IV), and in its open form with Np(IV) and UO{sub 2}{sup 2+}. (author)

  10. Potential incursion of marine sediment inland during storms: the radiological importance of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Wilkins, B.T.; Green, N.; Haslam, I.K. [National Radiological Protection Board, Chilton, Didcot, Oxon (United Kingdom); Huntley, D.A.; Dyer, K.R.; Cavrot, D.; Tooley, M.J. [Institute for Marine Studies, University of Plymouth, Drake Circus, Plymouth PL44 8AA, Devon (United Kingdom); Zong, Y. [Environmental Research Centre, University of Durham, Science Laboratories, Parks Road, Durham (United Kingdom)

    1999-08-01

    An assessment of the possible future incursion of marine sediment inland in Cumbria and Lancashire has been carried out. The assessment indicated that material from the patch of clay and silt offshore from Sellafield would not be readily mobilised and would not be brought ashore during a single-storm event. Several low-lying areas are potentially at risk of flooding as a result of severe storms, but any marine sediment deposited inland would have come from the nearshore zone. The original assessment, published in 1996, was made using measurement data for 1988. The results indicated that, in many cases, external irradiation was the most important contributor to the doses to those involved in clean-up operations and to residents, {sup 137}Cs being the radionuclide of importance. The predicted doses were a small fraction of the principal limit recommended by ICRP for members of the public. In this paper, the dose estimates have been refined using newly available data for 1995. Since 1988, activity concentrations of {sup 137}Cs have declined markedly because of remobilisation from the sediment, but changes in the values of {sup 241}Am and Pu are much less. As a result, the predicted overall doses to the various population groups are lower than those estimated previously, and in many cases actinides have become the radionuclides of importance. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. Advanced Extraction Methods for Actinide/Lanthanide Separations

    Energy Technology Data Exchange (ETDEWEB)

    Scott, M.J.

    2005-12-01

    The separation of An(III) ions from chemically similar Ln(III) ions is perhaps one of the most difficult problems encountered during the processing of nuclear waste. In the 3+ oxidation states, the metal ions have an identical charge and roughly the same ionic radius. They differ strictly in the relative energies of their f- and d-orbitals, and to separate these metal ions, ligands will need to be developed that take advantage of this small but important distinction. The extraction of uranium and plutonium from nitric acid solution can be performed quantitatively by the extraction with the TBP (tributyl phosphate). Commercially, this process has found wide use in the PUREX (plutonium uranium extraction) reprocessing method. The TRUEX (transuranium extraction) process is further used to coextract the trivalent lanthanides and actinides ions from HLLW generated during PUREX extraction. This method uses CMPO [(N, N-diisobutylcarbamoylmethyl) octylphenylphosphineoxide] intermixed with TBP as a synergistic agent. However, the final separation of trivalent actinides from trivalent lanthanides still remains a challenging task. In TRUEX nitric acid solution, the Am(III) ion is coordinated by three CMPO molecules and three nitrate anions. Taking inspiration from this data and previous work with calix[4]arene systems, researchers on this project have developed a C3-symmetric tris-CMPO ligand system using a triphenoxymethane platform as a base. The triphenoxymethane ligand systems have many advantages for the preparation of complex ligand systems. The compounds are very easy to prepare. The steric and solubility properties can be tuned through an extreme range by the inclusion of different alkoxy and alkyl groups such as methyoxy, ethoxy, t-butoxy, methyl, octyl, t-pentyl, or even t-pentyl at the ortho- and para-positions of the aryl rings. The triphenoxymethane ligand system shows promise as an improved extractant for both tetravalent and trivalent actinide recoveries form

  12. Remote sensing estimation of the total phosphorus concentration in a large lake using band combinations and regional multivariate statistical modeling techniques.

    Science.gov (United States)

    Gao, Yongnian; Gao, Junfeng; Yin, Hongbin; Liu, Chuansheng; Xia, Ting; Wang, Jing; Huang, Qi

    2015-03-15

    Remote sensing has been widely used for ater quality monitoring, but most of these monitoring studies have only focused on a few water quality variables, such as chlorophyll-a, turbidity, and total suspended solids, which have typically been considered optically active variables. Remote sensing presents a challenge in estimating the phosphorus concentration in water. The total phosphorus (TP) in lakes has been estimated from remotely sensed observations, primarily using the simple individual band ratio or their natural logarithm and the statistical regression method based on the field TP data and the spectral reflectance. In this study, we investigated the possibility of establishing a spatial modeling scheme to estimate the TP concentration of a large lake from multi-spectral satellite imagery using band combinations and regional multivariate statistical modeling techniques, and we tested the applicability of the spatial modeling scheme. The results showed that HJ-1A CCD multi-spectral satellite imagery can be used to estimate the TP concentration in a lake. The correlation and regression analysis showed a highly significant positive relationship between the TP concentration and certain remotely sensed combination variables. The proposed modeling scheme had a higher accuracy for the TP concentration estimation in the large lake compared with the traditional individual band ratio method and the whole-lake scale regression-modeling scheme. The TP concentration values showed a clear spatial variability and were high in western Lake Chaohu and relatively low in eastern Lake Chaohu. The northernmost portion, the northeastern coastal zone and the southeastern portion of western Lake Chaohu had the highest TP concentrations, and the other regions had the lowest TP concentration values, except for the coastal zone of eastern Lake Chaohu. These results strongly suggested that the proposed modeling scheme, i.e., the band combinations and the regional multivariate

  13. Thermodynamics of actinide complexation in solution at elevated temperatures: application of variable-temperature titration calorimetry.

    Science.gov (United States)

    Rao, Linfeng

    2007-06-01

    Studies of actinide complexation in solution at elevated temperatures provide insight into the effect of solvation and the energetics of complexation, and help to predict the chemical behavior of actinides in nuclear waste processing and disposal where temperatures are high. This tutorial review summarizes the data on the complexation of actinides at elevated temperatures and describes the methodology for thermodynamic measurements, with the emphasis on variable-temperature titration calorimetry, a highly valuable technique to determine the enthalpy and, under appropriate conditions, the equilibrium constants of complexation as well.

  14. Intelligent Sensor Based Bayesian Neural Network for Combined Parameters and States Estimation of a Brushed DC Motor

    Directory of Open Access Journals (Sweden)

    Hacene MELLAH

    2016-07-01

    Full Text Available The objective of this paper is to develop an Artificial Neural Network (ANN model to estimate simultaneously, parameters and state of a brushed DC machine. The proposed ANN estimator is novel in the sense that his estimates simultaneously temperature, speed and rotor resistance based only on the measurement of the voltage and current inputs. Many types of ANN estimators have been designed by a lot of researchers during the last two decades. Each type is designed for a specific application. The thermal behavior of the motor is very slow, which leads to large amounts of data sets. The standard ANN use often Multi-Layer Perceptron (MLP with Levenberg-Marquardt Backpropagation (LMBP, among the limits of LMBP in the case of large number of data, so the use of MLP based on LMBP is no longer valid in our case. As solution, we propose the use of Cascade-Forward Neural Network (CFNN based Bayesian Regulation backpropagation (BRBP. To test our estimator robustness a random white-Gaussian noise has been added to the sets. The proposed estimator is in our viewpoint accurate and robust.

  15. Safe management of actinides in the nuclear fuel cycle: Role of mineralogy; La gestion des actinides dans le cycle du combustible nucleaire: le role de la mineralogie

    Energy Technology Data Exchange (ETDEWEB)

    Ewing, R.C. [Department of Nuclear Engineering and Radiological Sciences, Department of Geological Sciences, Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-1005 (United States)

    2011-02-15

    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., {sup 239}Pu), a source of fissile material for nuclear weapons (e.g., {sup 239}Pu and {sup 237}Np), and of environmental concern because of their long-half lives and radiotoxicity (e.g., {sup 239}Pu and {sup 237}Np). 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{sub 2}B{sub 2}O{sub 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. (author)

  16. First ionization potential of the heaviest actinide lawrencium, element 103

    Science.gov (United States)

    Sato, Tetsuya K.; Asai, Masato; Borschevsky, Anastasia; Stora, Thierry; Sato, Nozomi; Kaneya, Yusuke; Tsukada, Kazuaki; Düllmann, Christoph E.; Eberhardt, Klaus; Eliav, Ephraim; Ichikawa, Shinichi; Kaldor, Uzi; Kratz, Jens V.; Miyashita, Sunao; Nagame, Yuichiro; Ooe, Kazuhiro; Osa, Akihiko; Renisch, Dennis; Runke, Jörg; Schädel, Matthias; Thörle-Pospiech, Petra; Toyoshima, Atsushi; Trautmann, Norbert

    2016-12-01

    The first ionization potential (IP1) of element 103, lawrencium (Lr), has been successfully determined for the first time by using a newly developed method based on a surface ionization process. The measured IP1 value is 4.963 eV. This value is the smallest among those of actinide elements and is in excellent agreement with the value of 4.963(15) eV predicted by state-of-the-art relativistic calculations also performed in this work. Our results strongly support that the Lr atom has an electronic configuration of [Rn]7s25f147p, which is influenced by strong relativistic effects. The present work provides a reliable benchmark for theoretical calculations and also opens the way for studies on atomic properties of heavy elements with atomic number Z > 100. Moreover, the present achievement has triggered a controversy on the position of lutetium (Lu) and Lr in the Periodic Table of Elements.

  17. Chemistry of tetravalent actinides phosphates. The thorium phosphate-diphosphate as immobilisation matrix of actinides; Chimie des phosphates d'actinides tetravalents. Le phosphate-diphosphate de thorium en tant que matrice d'imobilisation des actinides

    Energy Technology Data Exchange (ETDEWEB)

    Dacheux, N

    2002-07-01

    The author presents in this document its scientific works from 1992 to 2001, in order to obtain the enabling to manage scientific and chemical researches at the university Paris Sud Orsay. The first part gives an abstract of the thesis on the characterizations, lixiviation and synthesis of uranium and thorium based phosphate matrix in the framework of the search for a ceramic material usable in the radioactive waste storage. The second part presents briefly the researches realized at the CEA, devoted to a reliable, independent and accurate measure of some isotopes activity. The last part presents the abstracts of researches activities from 1996 to 2001 on the tetravalent actinides phosphates chemistry, the sintering of PDT and solid solutions of PDTU and the kinetic and thermodynamical studies of the PDT dissolution. Many references and some publication in full text are provided. (A.L.B.)

  18. Facilities for preparing actinide or fission product-based targets

    CERN Document Server

    Sors, M

    1999-01-01

    Research and development work is currently in progress in France on the feasibility of transmutation of very long-lived radionuclides such as americium, blended with an inert medium such as magnesium oxide and pelletized for irradiation in a fast neutron reactor. The process is primarily designed to produce ceramics for nuclear reactors, but could also be used to produce targets for accelerators. The Actinide Development Laboratory is part of the ATALANTE complex at Marcoule, where the CEA investigates reprocessing, liquid and solid waste treatment and vitrification processes. The laboratory produces radioactive sources; after use, their constituents are recycled, notably through R and D programs requiring such materials. Recovered americium is purified, characterized and transformed for an experiment known as ECRIX, designed to demonstrate the feasibility of fabricating americium-based ceramics and to determine the reactor transmutation coefficients.

  19. Pillared metal(IV) phosphate-phosphonate extraction of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Burns, J.D.; Clearfield, A. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry; Borkowski, M.; Reed, D.T. [Los Alamos National Laboratory, Carlsbad, NM (United States). Earth and Environmental Sciences Div.

    2012-07-01

    Four pillared metal(IV) phosphate-phosphonate ion exchange materials were synthesized and characterized. Studies were conducted to determine their affinity for the lanthanides (Ln's) and actinides (An's). It was determined that by simply manipulating the metal source (Zr or Sn) and the phosphate source (H{sub 3}PO{sub 4} or Na{sub 3}PO{sub 4}) large differences were seen in the extraction of the Ln and An species. K{sub d} values higher than 4 x 10{sup 5} were observed for the AnO{sub 2}{sup 2+} species in nitric acid at pH 2. These basic uptake experiments are important, as the data they provide may indicate the possibility of a separation of Ln's from An's or even more notably americium from curium and Ln's. (orig.)

  20. Angular distributions in the neutron-induced fission of actinides

    CERN Multimedia

    In 2003 the n_TOF Collaboration performed the fission cross section measurement of several actinides ($^{232}$Th, $^{233}$U, $^{234}$U, $^{237}$Np) at the n_TOF facility using an experImental setup made of Parallel Plate Avalanche Counters (PPAC). The method based on the detection of the 2 fragments in coincidence allowed to clearly disentangle the fission reactions among other types of reactions occurring in the spallation domain. We have been therefore able to cover the very broad neutron energy range 1eV-1GeV, taking full benefit of the unique characteristics of the n_TOF facility. Figure 1 shows an example obtained in the case of $^{237}$Np where the n_ TOF measurement showed that the cross section was underestimated by a large factor in the resonance region.

  1. ENHANCING ADVANCED CANDU PROLIFERATION RESISTANCE FUEL WITH MINOR ACTINIDES

    Energy Technology Data Exchange (ETDEWEB)

    Gray S. Chang

    2010-05-01

    The advanced nuclear system will significantly advance the science and technology of nuclear energy systems and to enhance the spent fuel proliferation resistance. Minor actinides (MA) are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs can play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. In this work, an Advanced CANDU Reactor (ACR) fuel unit lattice cell model with 43 UO2 fuel rods will be used to investigate the effectiveness of a Minor Actinide Reduction Approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance. The main MARA objective is to increase the 238Pu / Pu isotope ratio by using the transuranic nuclides (237Np and 241Am) in the high burnup fuel and thereby increase the proliferation resistance even for a very low fuel burnup. As a result, MARA is a very effective approach to enhance the proliferation resistance for the on power refueling ACR system nuclear fuel. The MA transmutation characteristics at different MA loadings were compared and their impact on neutronics criticality assessed. The concept of MARA, significantly increases the 238Pu/Pu ratio for proliferation resistance, as well as serves as a burnable absorber to hold-down the initial excess reactivity. It is believed that MARA can play an important role in atoms for peace and the intermediate term of nuclear energy reconnaissance.

  2. Experimental study of kinetic and mechanism of dissolution of apatite structured minerals. Application to the prediction of the long term behavior of an actinides storage host matrix; Etude experimentale de la cinetique et des mecanismes d'alteration de mineraux apatitiques. Application au comportement d'une ceramique de confinement d'actinides mineurs

    Energy Technology Data Exchange (ETDEWEB)

    Chairat, C

    2005-11-15

    The motivation for this study is to assess the potential of using apatite structured ceramics as long-lived actinide storage hosts. To assess their ability to resist aqueous corrosion, the dissolution of natural fluoro-apatite and synthetic Nd-britholite (neodymium is a proxy for the trivalent actinides) was studied. Mineral surfaces were characterized using a combined spectrometric, electrokinetic and potentiometric approach and dissolution rates were measured in closed and open system reactors as a function of solution composition. Experimental results suggest apatitic minerals dissolve via distinct step sequence: 1) fluoride release, 2) release of the calcium situated in the M1, and 3) the simultaneous removal of phosphate and calcium II via the breaking of only Ca-O bonds. TST based rate equations based in this mechanism accurately describe fluoro-apatite and synthetic britholite dissolution rates as a function of solution composition. Nd release rates are limited by precipitation of Nd-rhabdophane. (author)

  3. Review and needs in actinide chemistry in relation with biological purposes

    Energy Technology Data Exchange (ETDEWEB)

    Ansoborlo, E.; Moulin, V.; Bion, L.; Doizi, D.; Moulin, C.; Cote, G.; Madic, C.; Van der Lee, J

    2004-07-01

    In case of accidental release of radionuclides in the environment, actinides could occur and may present an healthy risk for human beings. In order to study their behavior in human organism (metabolism, retention, excretion), it is of prime importance to know solution actinide chemistry, and more particularly thermodynamic constants, which will allow to determine their speciation: speciation governs biological availability and toxicity of elements and is also of great interest for decorporation purposes. In this framework, a CEA working group on speciation has been created in order to share data both on thermodynamic constants and on speciation analytical methods, interesting chemists, environmentalists and biologists. It has been focused, in a first time, on actinides. The purpose of this paper is to present the state of the art on actinide speciation within biological media and to focus on the lack of information in order to orientate future research. (authors)

  4. Organophosphorus reagents in actinide separations: Unique tools for production, cleanup and disposal

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K. L.

    2000-01-12

    Interactions of actinide ions with phosphate and organophosphorus reagents have figured prominently in nuclear science and technology, particularly in the hydrometallurgical processing of irradiated nuclear fuel. Actinide interactions with phosphorus-containing species impact all aspects from the stability of naturally occurring actinides in phosphate mineral phases through the application of the bismuth phosphate and PUREX processes for large-scale production of transuranic elements to the development of analytical separation and environment restoration processes based on new organophosphorus reagents. In this report, an overview of the unique role of organophosphorus compounds in actinide production, disposal, and environment restoration is presented. The broad utility of these reagents and their unique chemical properties is emphasized.

  5. SACSESS – the EURATOM FP7 project on actinide separation from spent nuclear fuels

    Directory of Open Access Journals (Sweden)

    Bourg Stéphane

    2015-12-01

    Full Text Available Recycling of actinides by their separation from spent nuclear fuel, followed by transmutation in fast neutron reactors of Generation IV, is considered the most promising strategy for nuclear waste management. Closing the fuel cycle and burning long-lived actinides allows optimizing the use of natural resources and minimizing the long-term hazard of high-level nuclear waste. Moreover, improving the safety and sustainability of nuclear power worldwide. This paper presents the activities striving to meet these challenges, carried out under the Euratom FP7 collaborative project SACSESS (Safety of Actinide Separation Processes. Emphasis is put on the safety issues of fuel reprocessing and waste storage. Two types of actinide separation processes, hydrometallurgical and pyrometallurgical, are considered, as well as related aspects of material studies, process modeling and the radiolytic stability of solvent extraction systems. Education and training of young researchers in nuclear chemistry is of particular importance for further development of this field.

  6. Radiochemical separation of actinides for their determination in environmental samples and waste products

    Energy Technology Data Exchange (ETDEWEB)

    Gleisberg, B. [Nuclear Engineering and Analytics Rossendorf, Inc. (VKTA), Dresden (Germany)

    1997-03-01

    The determination of low level activities of actinides in environmental samples and waste products makes high demands on radiochemical separation methods. Artificial and natural actinides were analyzed in samples form the surrounding areas of NPP and of uranium mines, incorporation samples, solutions containing radioactive fuel, solutions and solids resutling from the process, and in wastes. The activities are measured by {alpha}-spectrometry and {gamma}-spectrometry. (DG)

  7. Actinides in molecules: exotic properties probed by X-ray Absorption Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Den Auwer, C.; Moisy, P.; Guilbaud, P.; Guillaumont, D.; Simoni, E.; Conradson, S.D

    2004-07-01

    Dealing with actinide elements in molecular chemistry may result in particularly attractive and exotic physico-chemical properties. In solution, one of the spectroscopic tools able to selectively probe the structural or electronic properties of these molecules is the X-ray absorption process. Different aspects of absorption edge or EXAFS analysis related to actinide studies are presented, including phenomenological and semi-quantitative approaches. (authors)

  8. From carbon to actinides: A new universal 1MV accelerator mass spectrometer at ANSTO

    Science.gov (United States)

    Wilcken, K. M.; Hotchkis, M.; Levchenko, V.; Fink, D.; Hauser, T.; Kitchen, R.

    2015-10-01

    A new 1 MV NEC pelletron AMS system at ANSTO is presented. The spectrometer comprises large radius magnets for actinide measurements. A novel feature of the system is fast switching between isotopes both at low and high energy sections allowing measurements of up to 8 isotopes within a single sequence. Technical details and layout of the spectrometer is presented. Performance data for 14C, 10Be, 26Al and actinides demonstrate the system is ready for routine AMS measurements.

  9. From carbon to actinides: A new universal 1MV accelerator mass spectrometer at ANSTO

    Energy Technology Data Exchange (ETDEWEB)

    Wilcken, K.M., E-mail: klaus.wilcken@ansto.gov.au [Australian Nuclear Science & Technology Organisation, Sydney, New South Wales (Australia); Hotchkis, M.; Levchenko, V.; Fink, D. [Australian Nuclear Science & Technology Organisation, Sydney, New South Wales (Australia); Hauser, T.; Kitchen, R. [National Electrostatics Corporation, 7540 Graber Road, Middleton, WI 53562-0310 (United States)

    2015-10-15

    A new 1 MV NEC pelletron AMS system at ANSTO is presented. The spectrometer comprises large radius magnets for actinide measurements. A novel feature of the system is fast switching between isotopes both at low and high energy sections allowing measurements of up to 8 isotopes within a single sequence. Technical details and layout of the spectrometer is presented. Performance data for {sup 14}C, {sup 10}Be, {sup 26}Al and actinides demonstrate the system is ready for routine AMS measurements.

  10. Optimizing estimates of annual variations and trends in geocenter motion and J2 from a combination of GRACE data and geophysical models

    Science.gov (United States)

    Sun, Yu; Riva, Riccardo; Ditmar, Pavel

    2016-11-01

    The focus of the study is optimizing the technique for estimating geocenter motion and variations in J2 by combining data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission with output from an Ocean Bottom Pressure model and a Glacial Isostatic Adjustment (GIA) model. First, we conduct an end-to-end numerical simulation study. We generate input time-variable gravity field observations by perturbing a synthetic Earth model with realistically simulated errors. We show that it is important to avoid large errors at short wavelengths and signal leakage from land to ocean, as well as to account for self-attraction and loading effects. Second, the optimal implementation strategy is applied to real GRACE data. We show that the estimates of annual amplitude in geocenter motion are in line with estimates from other techniques, such as satellite laser ranging (SLR) and global GPS inversion. At the same time, annual amplitudes of C10 and C11 are increased by about 50% and 20%, respectively, compared to estimates based on Swenson et al. (2008). Estimates of J2 variations are by about 15% larger than SLR results in terms of annual amplitude. Linear trend estimates are dependent on the adopted GIA model but still comparable to some SLR results.

  11. Regularized estimation of magnitude and phase of multi-coil b1 field via Bloch-Siegert B1 mapping and coil combination optimizations.

    Science.gov (United States)

    Zhao, Feng; Fessler, Jeffrey A; Wright, Steven M; Noll, Douglas C

    2014-10-01

    Parallel excitation requires fast and accurate B1 map estimation. Bloch-Siegert (BS) B1 mapping is very fast and accurate over a large dynamic range. When applied to multi-coil systems, however, this phase-based method may produce low signal-to-noise ratio estimates in low magnitude regions due to localized excitation patterns of parallel excitation systems. Also, the imaging time increases with the number of coils. In this work, we first propose to modify the standard BS B1 mapping sequence so that it avoids the scans required by previous B1 phase estimation methods. A regularized method is then proposed to jointly estimate the magnitude and phase of multi-coil B1 maps from BS B1 mapping data, improving estimation quality by using the prior knowledge of the smoothness of B1 magnitude and phase. Lastly, we use Cramer-Rao lower bound analysis to optimize the coil combinations, to improve the quality of the raw data for B1 estimation. The proposed methods are demonstrated by simulations and phantom experiments.

  12. Multi-view 3D human pose estimation combining single-frame recovery, temporal integration and model adaptation

    NARCIS (Netherlands)

    Hofmann, K.M.; Gavrilla, D.M.

    2009-01-01

    We present a system for the estimation of unconstrained 3D human upper body movement from multiple cameras. Its main novelty lies in the integration of three components: single frame pose recovery, temporal integration and model adaptation. Single frame pose recovery consists of a hypothesis generat

  13. Multi-view 3D human pose estimation combining single-frame recovery, temporal integration and model adaptation

    NARCIS (Netherlands)

    Hofmann, K.M.; Gavrila, D.M.

    2009-01-01

    We present a system for the estimation of unconstrained 3D human upper body movement from multiple cameras. Its main novelty lies in the integration of three components: single-frame pose recovery, temporal integration and model adaptation. Single-frame pose recovery consists of a hypothesis generat

  14. Estimating and comparing incidence and prevalence of chronic diseases by combining GP registry data: The role of uncertainty

    NARCIS (Netherlands)

    P.H.M. van Baal (Pieter); P.M. Engelfriet (Peter); R.T. Hoogenveen (Rudolf); M.J. Poos (Marinus J.); C. van den Dungen (Catharina); H.C. Boshuizen (Hendriek)

    2011-01-01

    textabstractBackground: Estimates of disease incidence and prevalence are core indicators of public health. The manner in which these indicators stand out against each other provide guidance as to which diseases are most common and what health problems deserve priority. Our aim was to investigate ho

  15. CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES

    Energy Technology Data Exchange (ETDEWEB)

    Nash, Kenneth L.

    2008-11-20

    In this project, both the fundamental chemistry of actinides in alkaline solutions (relevant to those present in Hanford-style waste storage tanks), and their dissolution from sludge simulants (and interactions with supernatants) have been investigated under representative sludge leaching procedures. The leaching protocols were designed to go beyond conventional alkaline sludge leaching limits, including the application of acidic leachants, oxidants and complexing agents. The simulant leaching studies confirm in most cases the basic premise that actinides will remain in the sludge during leaching with 2-3 M NaOH caustic leach solutions. However, they also confirm significant chances for increased mobility of actinides under oxidative leaching conditions. Thermodynamic data generated improves the general level of experiemental information available to predict actinide speciation in leach solutions. Additional information indicates that improved Al removal can be achieved with even dilute acid leaching and that acidic Al(NO3)3 solutions can be decontaminated of co-mobilized actinides using conventional separations methods. Both complexing agents and acidic leaching solutions have significant potential to improve the effectiveness of conventional alkaline leaching protocols. The prime objective of this program was to provide adequate insight into actinide behavior under these conditions to enable prudent decision making as tank waste treatment protocols develop.

  16. Solar r-process-constrained actinide production in neutrino-driven winds of supernovae

    CERN Document Server

    Goriely, S

    2016-01-01

    Long-lived radioactive nuclei play an important role as nucleo-cosmochronometers and as cosmic tracers of nucleosynthetic source activity. In particular nuclei in the actinide region like thorium, uranium, and plutonium can testify to the enrichment of an environment by the still enigmatic astrophysical sources that are responsible for the production of neutron-rich nuclei by the rapid neutron-capture process (r-process). Supernovae and merging neutron-star (NS) or NS-black hole binaries are considered as most likely sources of the r-nuclei. But arguments in favour of one or the other or both are indirect and make use of assumptions; they are based on theoretical models with remaining simplifications and shortcomings. An unambiguous observational determination of a production event is still missing. In order to facilitate searches in this direction, e.g.\\ by looking for radioactive tracers in stellar envelopes, the interstellar medium or terrestrial reservoirs, we provide improved theoretical estimates and co...

  17. Characterization of actinide targets by low solid-angle alpha particle counting

    CERN Document Server

    Denecke, B; Pauwels, J; Robouch, P; Gilliam, D M; Hodge, P; Hutchinson, J M R; Nico, J S

    1999-01-01

    Actinide samples were characterized in an interlaboratory comparison between IRMM and NIST, including alpha-particle counting at defined low solid angle and counting in a 2 pi proportional gas counter. For this comparison, nine sup 2 sup 3 sup 3 UF sub 4 samples with high uniformity in the layer thickness were prepared at IRMM by deposition under vacuum. Polished silicon wafers were used as source substrates, and these were rotated during the deposition using a planetary rotation system. The estimated uncertainties for the defined low solid-angle methods were about 0.1% at both NIST and IRMM. The agreement of reported alpha-particle emission rates in the energy range 2.5-5.09 MeV was better than or equal to 0.02% for the defined solid-angle methods. When comparing total alpha-particle emission rates over the larger energy range 0-9 MeV (which includes all emissions from the daughter nuclides and the impurities), the agreement of the defined solid-angle methods was better than or equal to 0.05%. The 2 pi propo...

  18. Monte Carlo Modeling of Minor Actinide Burning in Fissile Spallation Targets

    Science.gov (United States)

    Malyshkin, Yury; Pshenichnov, Igor; Mishustin, Igor; Greiner, Walter

    2014-06-01

    Minor actinides (MA) present a harmful part of spent nuclear fuel due to their long half-lives and high radio-toxicity. Neutrons produced in spallation targets of Accelerator Driven Systems (ADS) can be used to transmute and burn MA. Non-fissile targets are commonly considered in ADS design. However, additional neutrons from fission reactions can be used in targets made of fissile materials. We developed a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems) for simulating neutron production and transport in different spallation targets. MCADS is suitable for calculating spatial distributions of neutron flux and energy deposition, neutron multiplication factors and other characteristics of produced neutrons and residual nuclei. Several modifications of the Geant4 source code described in this work were made in order to simulate targets containing MA. Results of MCADS simulations are reported for several cylindrical targets made of U+Am, Am or Am2O3 including more complicated design options with a neutron booster and a reflector. Estimations of Am burning rates are given for the considered cases.

  19. Potential Geophysical Field Transformations and Combined 3D Modelling for Estimation the Seismic Site Effects on Example of Israel

    Science.gov (United States)

    Eppelbaum, Lev; Meirova, Tatiana

    2015-04-01

    It is well-known that the local seismic site effects may have a significant contribution to the intensity of damage and destruction (e.g., Hough et al., 1990; Regnier et al., 2000; Bonnefoy-Claudet et al., 2006; Haase et al., 2010). The thicknesses of sediments, which play a large role in amplification, usually are derived from seismic velocities. At the same time, thickness of sediments may be determined (or defined) on the basis of 3D combined gravity-magnetic modeling joined with available geological materials, seismic data and borehole section examination. Final result of such investigation is a 3D physical-geological model (PGM) reflecting main geological peculiarities of the area under study. Such a combined study needs in application of a reliable 3D mathematical algorithm of computation together with advanced methodology of 3D modeling. For this analysis the developed GSFC software was selected. The GSFC (Geological Space Field Calculation) program was developed for solving a direct 3-D gravity and magnetic prospecting problem under complex geological conditions (Khesin et al., 1996; Eppelbaum and Khesin, 2004). This program has been designed for computing the field of Δg (Bouguer, free-air or observed value anomalies), ΔZ, ΔX, ΔY , ΔT , as well as second derivatives of the gravitational potential under conditions of rugged relief and inclined magnetization. The geological space can be approximated by (1) three-dimensional, (2) semi-infinite bodies and (3) those infinite along the strike closed, L.H. non-closed, R.H. on-closed and open). Geological bodies are approximated by horizontal polygonal prisms. The program has the following main advantages (besides abovementioned ones): (1) Simultaneous computing of gravity and magnetic fields; (2) Description of the terrain relief by irregularly placed characteristic points; (3) Computation of the effect of the earth-air boundary by the method of selection directly in the process of interpretation; (4

  20. Actinides reduction by recycling in a thermal reactor; Reduccion de actinidos por reciclado en un reactor termico

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J. R.; Martinez C, E.; Balboa L, H., E-mail: ramon.ramirez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

    2014-10-15

    This work is directed towards the evaluation of an advanced nuclear fuel cycle in which radioactive actinides could be recycled to remove most of the radioactive material; firstly a production reference of actinides in standard nuclear fuel of uranium at the end of its burning in a BWR reactor is established, after a fuel containing plutonium is modeled to also calculate the actinides production in MOX fuel type. Also it proposes a design of fuel rod containing 6% of actinides in a matrix of uranium from the tails of enrichment, then four standard uranium fuel rods are replaced by actinides rods to evaluate the production and transmutation thereof, the same procedure was performed in the fuel type MOX and the end actinide reduction in the fuel was evaluated. (Author)

  1. Estimating dispersal and gene flow in the neotropical freshwater turtle Hydromedusa maximiliani (Chelidae by combining ecological and genetic methods

    Directory of Open Access Journals (Sweden)

    Souza Franco L.

    2002-01-01

    Full Text Available Hydromedusa maximiliani is a vulnerable neotropical freshwater turtle endemic to mountainous regions of the Atlantic rainforest in southeastern Brazil. Random amplified polymorphic DNA (RAPD was used to estimate the gene flow and dispersal for individuals inhabiting rivers and streams within a drainage. Nine primers generated 27 scoreable bands, of which 9 (33% were polymorphic and produced 12 RAPD phenotypes. The gene flow estimates (Nm among turtles inhabiting different rivers and streams were variable, ranging from 0.09 to 3.00 (mean: 0.60. For some loci, the rates of gene flow could offset population differentiation (Nm > 1, whereas for others random genetic drift could result in population divergence (Nm < 1. Since the genetic variation of this turtle seems to be structured according to the natural hierarchical system of rivers and streams within drainages, management programs involving translocations between different regions across the geographical range of H. maximiliani should be viewed with caution.

  2. Combining METEOSAT-10 satellite image data with GPS tropospheric path delays to estimate regional Integrated Water Vapor (IWV) distribution

    OpenAIRE

    2016-01-01

    Using GPS satellites signals, we can study different processes and coupling mechanisms that can help us understand the physical conditions in the upper atmosphere, which might lead or act as proxies for severe weather events such as extreme storms and flooding. GPS signals received by ground stations are multi-purpose and can also provide estimates of tropospheric zenith delays, which can be converted into mm-accuracy Precipitable Water Vapor (PWV) using collocated pressure and temperature me...

  3. Vertical profiles of aerosol optical properties and the solar heating rate estimated by combining sky radiometer and lidar measurements

    Science.gov (United States)

    Kudo, Rei; Nishizawa, Tomoaki; Aoyagi, Toshinori

    2016-07-01

    The SKYLIDAR algorithm was developed to estimate vertical profiles of aerosol optical properties from sky radiometer (SKYNET) and lidar (AD-Net) measurements. The solar heating rate was also estimated from the SKYLIDAR retrievals. The algorithm consists of two retrieval steps: (1) columnar properties are retrieved from the sky radiometer measurements and the vertically mean depolarization ratio obtained from the lidar measurements and (2) vertical profiles are retrieved from the lidar measurements and the results of the first step. The derived parameters are the vertical profiles of the size distribution, refractive index (real and imaginary parts), extinction coefficient, single-scattering albedo, and asymmetry factor. Sensitivity tests were conducted by applying the SKYLIDAR algorithm to the simulated sky radiometer and lidar data for vertical profiles of three different aerosols, continental average, transported dust, and pollution aerosols. The vertical profiles of the size distribution, extinction coefficient, and asymmetry factor were well estimated in all cases. The vertical profiles of the refractive index and single-scattering albedo of transported dust, but not those of transported pollution aerosol, were well estimated. To demonstrate the performance and validity of the SKYLIDAR algorithm, we applied the SKYLIDAR algorithm to the actual measurements at Tsukuba, Japan. The detailed vertical structures of the aerosol optical properties and solar heating rate of transported dust and smoke were investigated. Examination of the relationship between the solar heating rate and the aerosol optical properties showed that the vertical profile of the asymmetry factor played an important role in creating vertical variation in the solar heating rate. We then compared the columnar optical properties retrieved with the SKYLIDAR algorithm to those produced with the more established scheme SKYRAD.PACK, and the surface solar irradiance calculated from the SKYLIDAR

  4. Improving Estimation of the Prognosis of Childhood Psychopathology; Combination of DSM-III-R/DISC Diagnoses and CBCL Scores

    Science.gov (United States)

    Ferdinand, Robert F.; Visser, Jeroen Heijmens; Hoogerheide, Kirsten N.; van der Ende, Jan; Kasius, Marianne C.; Koot, Hans M.; Verhulst, Frank C.

    2004-01-01

    Objective: To compare the predictive validity of the clinical-diagnostic and the empirical-quantitative approach to assessment of childhood psychopathology, and to investigate the usefulness of combining both approaches. Method: A referred sample (N = 96), aged 6 to 12 years at initial assessment, was followed up across--on average--a period of…

  5. Estimated average annual rate of change of CD4(+) T-cell counts in patients on combination antiretroviral therapy

    DEFF Research Database (Denmark)

    Mocroft, Amanda; Phillips, Andrew N; Ledergerber, Bruno;

    2010-01-01

    BACKGROUND: Patients receiving combination antiretroviral therapy (cART) might continue treatment with a virologically failing regimen. We sought to identify annual change in CD4(+) T-cell count according to levels of viraemia in patients on cART. METHODS: A total of 111,371 CD4(+) T-cell counts ...

  6. TAILORING INORGANIC SORBENTS FOR SRS STRONTIUM AND ACTINIDE SEPARATIONS: OPTIMIZED MONOSODIUM TITANATEPHASE II INTERIM REPORT FOR EXTERNAL RELEASE

    Energy Technology Data Exchange (ETDEWEB)

    Hobbs, D; Michael Poirier, M; Mark Barnes, M; Mary Thompson, M

    2006-08-31

    This document provides an interim summary report of Phase II testing activities for the development of a modified monosodium titanate (MST) that exhibits improved strontium and actinide removal characteristics compared to the baseline MST materials. The activities included determining the key synthesis conditions for preparation of the modified MST, preparation of the modified MST at a larger laboratory scale, demonstration of the strontium and actinide removal characteristics with actual tank waste supernate and characterization of the modified MST. Key findings and conclusions include the following: (1) Samples of the modified MST prepared by Method 2 and Method 3 exhibited the best combination of strontium and actinide removal. (2) We selected Method 3 to scale up and test performance with actual waste solution. (3) We successfully prepared three batches of the modified MST using the Method 3 procedure at a 25-gram scale. (4) Performance tests indicated successful scale-up to the 25-gram scale with excellent performance and reproducibility among each of the three batches. For example, the plutonium decontamination factors (6-hour contact time) for the modified MST samples averaged 13 times higher than that of the baseline MST sample at half the sorbent concentration (0.2 g L{sup -1} for modified MST versus 0.4 g L{sup -1} for baseline MST). (5) Performance tests with actual waste supernate demonstrated that the modified MST exhibited better strontium and plutonium removal performance than that of the baseline MST. For example, the decontamination factors for the modified MST measured 2.6 times higher for strontium and between 5.2 to 11 times higher for plutonium compared to the baseline MST sample. The modified MST did not exhibit improved neptunium removal performance over that of the baseline MST. (6) Two strikes of the modified MST provided increased removal of strontium and actinides from actual waste compared to a single strike. The improved performance

  7. Combining directed acyclic graphs and the change-in-estimate procedure as a novel approach to adjustment-variable selection in epidemiology

    Directory of Open Access Journals (Sweden)

    Evans David

    2012-10-01

    Full Text Available Abstract Background Directed acyclic graphs (DAGs are an effective means of presenting expert-knowledge assumptions when selecting adjustment variables in epidemiology, whereas the change-in-estimate procedure is a common statistics-based approach. As DAGs imply specific empirical relationships which can be explored by the change-in-estimate procedure, it should be possible to combine the two approaches. This paper proposes such an approach which aims to produce well-adjusted estimates for a given research question, based on plausible DAGs consistent with the data at hand, combining prior knowledge and standard regression methods. Methods Based on the relationships laid out in a DAG, researchers can predict how a collapsible estimator (e.g. risk ratio or risk difference for an effect of interest should change when adjusted on different variable sets. Implied and observed patterns can then be compared to detect inconsistencies and so guide adjustment-variable selection. Results The proposed approach involves i. drawing up a set of plausible background-knowledge DAGs; ii. starting with one of these DAGs as a working DAG, identifying a minimal variable set, S, sufficient to control for bias on the effect of interest; iii. estimating a collapsible estimator adjusted on S, then adjusted on S plus each variable not in S in turn (“add-one pattern” and then adjusted on the variables in S minus each of these variables in turn (“minus-one pattern”; iv. checking the observed add-one and minus-one patterns against the pattern implied by the working DAG and the other prior DAGs; v. reviewing the DAGs, if needed; and vi. presenting the initial and all final DAGs with estimates. Conclusion This approach to adjustment-variable selection combines background-knowledge and statistics-based approaches using methods already common in epidemiology and communicates assumptions and uncertainties in a standardized graphical format. It is probably best suited to

  8. State estimation of an acid gas removal (AGR) plant as part of an integrated gasification combined cycle (IGCC) plant with CO2 capture

    Energy Technology Data Exchange (ETDEWEB)

    Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.

    2012-01-01

    An accurate estimation of process state variables not only can increase the effectiveness and reliability of process measurement technology, but can also enhance plant efficiency, improve control system performance, and increase plant availability. Future integrated gasification combined cycle (IGCC) power plants with CO2 capture will have to satisfy stricter operational and environmental constraints. To operate the IGCC plant without violating stringent environmental emission standards requires accurate estimation of the relevant process state variables, outputs, and disturbances. Unfortunately, a number of these process variables cannot be measured at all, while some of them can be measured, but with low precision, low reliability, or low signal-to-noise ratio. As a result, accurate estimation of the process variables is of great importance to avoid the inherent difficulties associated with the inaccuracy of the data. Motivated by this, the current paper focuses on the state estimation of an acid gas removal (AGR) process as part of an IGCC plant with CO2 capture. This process has extensive heat and mass integration and therefore is very suitable for testing the efficiency of the designed estimators in the presence of complex interactions between process variables. The traditional Kalman filter (KF) (Kalman, 1960) algorithm has been used as a state estimator which resembles that of a predictor-corrector algorithm for solving numerical problems. In traditional KF implementation, good guesses for the process noise covariance matrix (Q) and the measurement noise covariance matrix (R) are required to obtain satisfactory filter performance. However, in the real world, these matrices are unknown and it is difficult to generate good guesses for them. In this paper, use of an adaptive KF will be presented that adapts Q and R at every time step of the algorithm. Results show that very accurate estimations of the desired process states, outputs or disturbances can be

  9. UV-visible spectrophotometric simultaneous estimation of paracetamol and nabumetone by AUC method in combined tablet dosage form

    OpenAIRE

    Rote, Ambadas R.; Kumbhoje, Prasanna A.; Bhambar, Rajendra S.

    2012-01-01

    Introduction: The present study deals with development and validation of a simple, rapid, sensitive and economic area under curve method for simultaneous estimation of paracetamol and nabumetone in bulk and tablet dosage form. Materials and Method: Area under curve method includes determination of area of paracetamol and nabumetone at absorption maxima, which for paracetamol was 248.8 ± 10 nm and for nabumetone was 269.2 ± 10 nm. Beer's law was obeyed in the concentration range of 5–25 μg/mL ...

  10. Quantum Mechanical Studies of the Early Actinide Compounds

    Science.gov (United States)

    Obodo, Kingsley Onyebuchi

    This study involves the investigation of the early actinide systems using ab initio techniques based on density functional theory (DFT). It was motivated by: (i) the incomplete description of these systems using conventional DFT because they are strongly correlated, (ii) the usefulness of these systems in nuclear energy generation, (iii) the complexity that arises in experimentally studying these systems due to their inherent radioactive nature and (iv) their limited availability. The results obtained from this study are divided into two broad sections. The first comprises chapters 3 and 4 while the second comprises chapters 5 and 6. Thorium based compounds are studied in chapters 3 and 4. In the first section, the Hubbard U parameter is not necessary to accurately describe the electronic, elastic and mechanical properties of these systems. In the second, the inclusion of the Hubbard U parameter is shown to be paramount for the accurate description of most compounds considered. Chapter 3 presents the electronic, structural and bonding character of thorium based nitrides. We obtained the result that Th2N2 NH, which is crystallographically equivalent to metallic Th2N 3, is insulating. Chapter 4 demonstrates that the formation of a meta-stable thorium-titanium based alloy is plausible and also further information on bonding, electronic and elastic properties of the determined meta-stable alloy is provided. This has provided important new knowledge about these bulk systems. In Chapter 5 the DFT + U based study on Pa and its oxides is presented. The electronic, structural and bonding character of these systems was studied. We found that PaO2 is a Mott-Hubbard insulator with an indirect band gap of 3.48 eV within the generalized gradient approximation GGA + U. Chapter 6 discusses various actinide nitrides. We explored the electronic properties, elastic properties, lattice dynamics and the energetics of the various compounds using GGA + U. Also, we investigated the effect

  11. Study of Photon Strength Functions of Actinides: the case of U-235, Np-238 and Pu-241

    CERN Document Server

    Guerrero, C; Cano-Ott, D; Martinez, T; Mendoza, E; Villamarin, D; Colonna, N; Meaze, M H; Marrone, S; Tagliente, G; Terlizzi, R; Belloni, F; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C; Aerts, G; Berthoumieux, E; Dridi, W; Gunsing, F; Pancin, J; Perrot, L; Plukis, A; Alvarez, H; Duran, I; Paradela, C; Andriamonje, S; Calviani, M; Chiaveri, E; Gonzalez-Romero, E; Kadi, Y; Vicente, M C; Vlachoudis, V; Andrzejewski, J; Marganiec, J; Assimakopoulos, P; Karadimos, D; Karamanis, D; Papachristodoulou, C; Patronis, N; Audouin, L; David, S; Ferrant, L; Isaev, S; Stephan, C; Tassan-Got, L; Badurek, G; Jericha, E; Leeb, H; Oberhummer, H; Pigni, M T; Baumann, P; Kerveno, M; Lukic, S; Rudolf, G; Becvar, F; Krticka, M; Calvino, F; Capote, R; Carrillo De Albornoz, A; Marques, L; Salgado, J; Tavora, L; Vaz, P; Cennini, P; Dahlfors, M; Ferrari, A; Gramegna, F; Herrera-Martinez, A; Mastinu, P; Praena, J; Sarchiapone, L; Wendler, H; Chepel, V; Ferreira-Marques, R; Goncalves, I; Lindote, A; Lopes, I; Neves, F; Cortes, G; Poch, A; Pretel, C; Couture, A; Cox, J; O'brien, S; Wiescher, M; Dillman, I; Kappeler, F; Mosconi, M; Plag, R; Voss, F; Walter, S; Wisshak, K; Dolfini, R; Rubbia, C; Domingo-Pardo, C; Tain, J L; Eleftheriadis, C; Savvidis, I; Frais-Koelbl, H; Griesmayer, E; Furman, W; Konovalov, V; Goverdovski, A; Ketlerov, V; Haas, B; Haight, R; Reifarth, R; Heil, M; Igashira, M; Koehler, P; Kossionides, E; Lampoudis, C; Lozano, M; Quesada, J; Massimi, C; Vannini, G; Mengoni, A; Oshima, M; Papadopoulos, C; Vlastou, R; Pavlik, A; Pavlopoulos, P; Plompen, A; Rullhusen, P; Rauscher, T; Rosetti, M; Ventura, A

    2011-01-01

    The decay from excited levels in medium and heavy nuclei can be described in a statistical approach by means of Photon Strength Functions and Level Density distributions combined with the theory of the compound. The study of electromagnetic cascades following neutron capture by means of high efficiency detectors has been shown to be well suited for probing the properties of the Photon Strength Function of heavy (high level density) and/or radioactive (high background) nuclei. In this work we have investigated for the first time the validity of the recommended PSF for actinides, in particular 235U, 238Np and 241Pu. Our study includes the search for resonance structures in the PSF below Sn and draws conclusions regarding their existence and their characteristics in terms of energy, width and electromagnetic nature.

  12. Loading Actinides in Multilayered Structures for Nuclear Waste Treatment: The First Case Study of Uranium Capture with Vanadium Carbide MXene.

    Science.gov (United States)

    Wang, Lin; Yuan, Liyong; Chen, Ke; Zhang, Yujuan; Deng, Qihuang; Du, Shiyu; Huang, Qing; Zheng, Lirong; Zhang, Jing; Chai, Zhifang; Barsoum, Michel W; Wang, Xiangke; Shi, Weiqun

    2016-06-29

    Efficient nuclear waste treatment and environmental management are important hurdles that need to be overcome if nuclear energy is to become more widely used. Herein, we demonstrate the first case of using two-dimensional (2D) multilayered V2CTx nanosheets prepared by HF etching of V2AlC to remove actinides from aqueous solutions. The V2CTx material is found to be a highly efficient uranium (U(VI)) sorbent, evidenced by a high uptake capacity of 174 mg g(-1), fast sorption kinetics, and desirable selectivity. Fitting of the sorption isotherm indicated that the sorption followed a heterogeneous adsorption model, most probably due to the presence of heterogeneous adsorption sites. Density functional theory calculations, in combination with X-ray absorption fine structure characterizations, suggest that the uranyl ions prefer to coordinate with hydroxyl groups bonded to the V-sites of the nanosheets via forming bidentate inner-sphere complexes.

  13. Estimating Dbh of Trees Employing Multiple Linear Regression of the best Lidar-Derived Parameter Combination Automated in Python in a Natural Broadleaf Forest in the Philippines

    Science.gov (United States)

    Ibanez, C. A. G.; Carcellar, B. G., III; Paringit, E. C.; Argamosa, R. J. L.; Faelga, R. A. G.; Posilero, M. A. V.; Zaragosa, G. P.; Dimayacyac, N. A.

    2016-06-01

    Diameter-at-Breast-Height Estimation is a prerequisite in various allometric equations estimating important forestry indices like stem volume, basal area, biomass and carbon stock. LiDAR Technology has a means of directly obtaining different forest parameters, except DBH, from the behavior and characteristics of point cloud unique in different forest classes. Extensive tree inventory was done on a two-hectare established sample plot in Mt. Makiling, Laguna for a natural growth forest. Coordinates, height, and canopy cover were measured and types of species were identified to compare to LiDAR derivatives. Multiple linear regression was used to get LiDAR-derived DBH by integrating field-derived DBH and 27 LiDAR-derived parameters at 20m, 10m, and 5m grid resolutions. To know the best combination of parameters in DBH Estimation, all possible combinations of parameters were generated and automated using python scripts and additional regression related libraries such as Numpy, Scipy, and Scikit learn were used. The combination that yields the highest r-squared or coefficient of determination and lowest AIC (Akaike's Information Criterion) and BIC (Bayesian Information Criterion) was determined to be the best equation. The equation is at its best using 11 parameters at 10mgrid size and at of 0.604 r-squared, 154.04 AIC and 175.08 BIC. Combination of parameters may differ among forest classes for further studies. Additional statistical tests can be supplemented to help determine the correlation among parameters such as Kaiser- Meyer-Olkin (KMO) Coefficient and the Barlett's Test for Spherecity (BTS).

  14. Combined inverse-forward artificial neural networks for fast and accurate estimation of the diffusion coefficients of cartilage based on multi-physics models.

    Science.gov (United States)

    Arbabi, Vahid; Pouran, Behdad; Weinans, Harrie; Zadpoor, Amir A

    2016-09-06

    Analytical and numerical methods have been used to extract essential engineering parameters such as elastic modulus, Poisson׳s ratio, permeability and diffusion coefficient from experimental data in various types of biological tissues. The major limitation associated with analytical techniques is that they are often only applicable to problems with simplified assumptions. Numerical multi-physics methods, on the other hand, enable minimizing the simplified assumptions but require substantial computational expertise, which is not always available. In this paper, we propose a novel approach that combines inverse and forward artificial neural networks (ANNs) which enables fast and accurate estimation of the diffusion coefficient of cartilage without any need for computational modeling. In this approach, an inverse ANN is trained using our multi-zone biphasic-solute finite-bath computational model of diffusion in cartilage to estimate the diffusion coefficient of the various zones of cartilage given the concentration-time curves. Robust estimation of the diffusion coefficients, however, requires introducing certain levels of stochastic variations during the training process. Determining the required level of stochastic variation is performed by coupling the inverse ANN with a forward ANN that receives the diffusion coefficient as input and returns the concentration-time curve as output. Combined together, forward-inverse ANNs enable computationally inexperienced users to obtain accurate and fast estimation of the diffusion coefficients of cartilage zones. The diffusion coefficients estimated using the proposed approach are compared with those determined using direct scanning of the parameter space as the optimization approach. It has been shown that both approaches yield comparable results.

  15. Combining robust state estimation with nonlinear model predictive control to regulate the acute inflammatory response to pathogen.

    Science.gov (United States)

    Zitelli, Gregory; Djouadi, Seddik M; Day, Judy D

    2015-10-01

    The inflammatory response aims to restore homeostasis by means of removing a biological stress, such as an invading bacterial pathogen. In cases of acute systemic inflammation, the possibility of collateral tissue damage arises, which leads to a necessary down-regulation of the response. A reduced ordinary differential equations (ODE) model of acute inflammation was presented and investigated in [10]. That system contains multiple positive and negative feedback loops and is a highly coupled and nonlinear ODE. The implementation of nonlinear model predictive control (NMPC) as a methodology for determining proper therapeutic intervention for in silico patients displaying complex inflammatory states was initially explored in [5]. Since direct measurements of the bacterial population and the magnitude of tissue damage/dysfunction are not readily available or biologically feasible, the need for robust state estimation was evident. In this present work, we present results on the nonlinear reachability of the underlying model, and then focus our attention on improving the predictability of the underlying model by coupling the NMPC with a particle filter. The results, though comparable to the initial exploratory study, show that robust state estimation of this highly nonlinear model can provide an alternative to prior updating strategies used when only partial access to the unmeasurable states of the system are available.

  16. Paving the way for the synthesis of a series of divalent actinide complexes: a theoretical perspective.

    Science.gov (United States)

    Wu, Q-Y; Lan, J-H; Wang, C-Z; Cheng, Z-P; Chai, Z-F; Gibson, J K; Shi, W-Q

    2016-02-21

    Recently, the +2 formal oxidation state in soluble molecular complexes for lanthanides (La-Nd, Sm-Lu) and actinides (Th and U) has been discovered [W. J. Evans, et al., J. Am. Chem. Soc., 2011, 133, 15914; J. Am. Chem. Soc., 2012, 134, 8420; J. Am. Chem. Soc., 2013, 135, 13310; Chem. Sci., 2015, 6, 517]. To explore the nature of the bonding and stabilities of the low-valent actinide complexes, a series of divalent actinide species, [AnCp'3](-) (An[double bond, length as m-dash]Th-Am, Cp' = [η(5)-C5H4(SiMe3)](-)) have been investigated in THF solution using scalar relativistic density functional theory. The electronic structures and electron affinity properties were systematically studied to identify the interactions between the +2 actinide ions and Cp' ligands. The ground state electron configurations for the [AnCp'3](-) species are [ThCp'3](-) 6d(2), [PaCp'3](-) 5f(2)6d(1), [UCp'3](-) 5f(3)6d(1), [NpCp'3](-) 5f(5), [PuCp'3](-) 5f(6), and [AmCp'3](-) 5f(7), respectively, according to the MO analysis. The total bonding energy decreases from the Th- to the Am-complex and the electrostatic interactions mainly dominate the bonding between the actinide atom and ligands. The electron affinity analysis suggests that the reduction reaction of AnCp'3→ [AnCp'3](-) should become increasingly facile across the actinide series from Th to Am, in accord with the known An(iii/ii) reduction potentials. This work expands the knowledge on the low oxidation state chemistry of actinides, and further motivates and guides the synthesis of related low oxidation state compounds of 5f elements.

  17. Optimal Model-Based Fault Estimation and Correction for Particle Accelerators and Industrial Plants Using Combined Support Vector Machines and First Principles Models

    Energy Technology Data Exchange (ETDEWEB)

    Sayyar-Rodsari, Bijan; Schweiger, Carl; /SLAC /Pavilion Technologies, Inc., Austin, TX

    2010-08-25

    Timely estimation of deviations from optimal performance in complex systems and the ability to identify corrective measures in response to the estimated parameter deviations has been the subject of extensive research over the past four decades. The implications in terms of lost revenue from costly industrial processes, operation of large-scale public works projects and the volume of the published literature on this topic clearly indicates the significance of the problem. Applications range from manufacturing industries (integrated circuits, automotive, etc.), to large-scale chemical plants, pharmaceutical production, power distribution grids, and avionics. In this project we investigated a new framework for building parsimonious models that are suited for diagnosis and fault estimation of complex technical systems. We used Support Vector Machines (SVMs) to model potentially time-varying parameters of a First-Principles (FP) description of the process. The combined SVM & FP model was built (i.e. model parameters were trained) using constrained optimization techniques. We used the trained models to estimate faults affecting simulated beam lifetime. In the case where a large number of process inputs are required for model-based fault estimation, the proposed framework performs an optimal nonlinear principal component analysis of the large-scale input space, and creates a lower dimension feature space in which fault estimation results can be effectively presented to the operation personnel. To fulfill the main technical objectives of the Phase I research, our Phase I efforts have focused on: (1) SVM Training in a Combined Model Structure - We developed the software for the constrained training of the SVMs in a combined model structure, and successfully modeled the parameters of a first-principles model for beam lifetime with support vectors. (2) Higher-order Fidelity of the Combined Model - We used constrained training to ensure that the output of the SVM (i.e. the

  18. Optimal Model-Based Fault Estimation and Correction for Particle Accelerators and Industrial Plants Using Combined Support Vector Machines and First Principles Models

    Energy Technology Data Exchange (ETDEWEB)

    Sayyar-Rodsari, Bijan; Schweiger, Carl; /SLAC /Pavilion Technologies, Inc., Austin, TX

    2010-08-25

    Timely estimation of deviations from optimal performance in complex systems and the ability to identify corrective measures in response to the estimated parameter deviations has been the subject of extensive research over the past four decades. The implications in terms of lost revenue from costly industrial processes, operation of large-scale public works projects and the volume of the published literature on this topic clearly indicates the significance of the problem. Applications range from manufacturing industries (integrated circuits, automotive, etc.), to large-scale chemical plants, pharmaceutical production, power distribution grids, and avionics. In this project we investigated a new framework for building parsimonious models that are suited for diagnosis and fault estimation of complex technical systems. We used Support Vector Machines (SVMs) to model potentially time-varying parameters of a First-Principles (FP) description of the process. The combined SVM & FP model was built (i.e. model parameters were trained) using constrained optimization techniques. We used the trained models to estimate faults affecting simulated beam lifetime. In the case where a large number of process inputs are required for model-based fault estimation, the proposed framework performs an optimal nonlinear principal component analysis of the large-scale input space, and creates a lower dimension feature space in which fault estimation results can be effectively presented to the operation personnel. To fulfill the main technical objectives of the Phase I research, our Phase I efforts have focused on: (1) SVM Training in a Combined Model Structure - We developed the software for the constrained training of the SVMs in a combined model structure, and successfully modeled the parameters of a first-principles model for beam lifetime with support vectors. (2) Higher-order Fidelity of the Combined Model - We used constrained training to ensure that the output of the SVM (i.e. the

  19. Reversible optical sensor for the analysis of actinides in solution; Capteur optique reversible pour l'analyse des actinides en solution

    Energy Technology Data Exchange (ETDEWEB)

    Lesage, B.; Picard, S. [CEA Marcoule, Dept. de Radiochimie et Procedes, Service de Chimie des Procedes de Separation, Lab. de Chimie des Actinides, 30 (France); Serein-Spirau, F.; Lereporte, J.P. [Ecole Nationale Superieure de Chimie de Montpellier (ENSCM), CNRS UMR 5076, Lab. Heterochimie Moleculaire et Macromoleculaire, 34 - Montpellier (France)

    2007-07-01

    In this work is presented a concept of reversible optical sensor for actinides. It is composed of a p doped conducing polymer support and of an anion complexing the actinides. The chosen conducing polymer is the thiophene-2,5-di-alkoxy-benzene whose solubility and conductivity are perfectly known. The actinides selective ligand is a lacunar poly-oxo-metallate such as P{sub 2}W{sub 17}O{sub 61}{sup 10-} or SiW{sub 11}O{sub 39}{sup 8-} which are strong anionic complexing agents of actinides at the oxidation state (IV) even in a very acid medium. The sensor is prepared by spin coating of the composite mixture 'polymer + ligand' on a conducing glass electrode and then tested towards its optical and electrochemical answer in presence of uranium (IV). The absorption change due to the formation of cations complexes by poly-oxo-metallate reveals the presence of uranium (IV). After the measurement, the sensor is regenerated by anodic polarization of the support and oxidation of the uranium (IV) into uranium (VI) which weakly interacts with the poly-oxo-metallate and is then released in solution. (O.M.)

  20. ABSORPTION RATIO METHOD FOR ESTIMATION OF DROTAVERINE HYDROCHLORIDE AND MEFENAMIC ACID IN THEIR COMBINED TABLET DOSAGE FORM

    OpenAIRE

    Sakhare Ram Suresh; Jamkhande Prasad Govindrao

    2012-01-01

    A new, simple, accurate and sensitive UV-spectrophotometric absorption Ratio method has been developed for simultaneous determination of Drotaverine Hydrochloride and Mefenamic Acid in their combined Tablet dosage form. The method is based upon determination of Drotaverine HCl and Mefenamic Acid at 239 nm, and 280nm in Methanol. Drotaverine HCl and Mefenamic Acid at isoabsorptive λmax 239 nm and at 280 nm λmax Mefenamic acid shows linearity in the concentration range of 3-30 μg/ml and 3 -30...

  1. ABSORPTION RATIO METHOD FOR ESTIMATION OF DROTAVERINE HYDROCHLORIDE AND MEFENAMIC ACID IN THEIR COMBINED TABLET DOSAGE FORM

    Directory of Open Access Journals (Sweden)

    Sakhare Ram Suresh

    2012-10-01

    Full Text Available A new, simple, accurate and sensitive UV-spectrophotometric absorption Ratio method has been developed for simultaneous determination of Drotaverine Hydrochloride and Mefenamic Acid in their combined Tablet dosage form. The method is based upon determination of Drotaverine HCl and Mefenamic Acid at 239 nm, and 280nm in Methanol. Drotaverine HCl and Mefenamic Acid at isoabsorptive λmax 239 nm and at 280 nm λmax Mefenamic acid shows linearity in the concentration range of 3-30 μg/ml and 3 -30 μg/ml respectively. The method was validated statistically.

  2. Combined Use of Satellite Observations with Urban Surface Characteristics to Estimate PM Concentrations by Employing Mixed-Effects Models

    Science.gov (United States)

    Beloconi, Anton; Benas, Nikolaos; Chrysoulakis, Nektarios; Kamarianakis, Yiannis

    2008-11-01

    Linear mixed effects models were developed for the estimation of the average daily Particulate Matter (PM) concentration spatial distribution over the area of Greater London (UK). Both fine (PM2.5) and coarse (PM10) concentrations were predicted for the 2002- 2012 time period, based on satellite data. The latter included Aerosol Optical Thickness (AOT) at 3×3 km spatial resolution, as well as the Surface Relative Humidity, Surface Temperature and K-Index derived from MODIS (Moderate Resolution Imaging Spectroradiometer) sensor. For a meaningful interpretation of the association among these variables, all data were homogenized with regard to spatial support and geographic projection, thus addressing the change of support problem and leading to a valid statistical inference. To this end, spatial (2D) and spatio- temporal (3D) kriging techniques were applied to in-situ particulate matter concentrations and the leave-one- station-out cross-validation was performed on a daily level to gauge the quality of the predictions. Satellite- derived covariates displayed clear seasonal patterns; in order to work with data which is stationary in mean, for each covariate, deviations from its estimated annual profiles were computed using nonlinear least squares and nonlinear absolute deviations. High-resolution land- cover and morphology static datasets were additionally incorporated in the analysis in order to catch the effects of nearby emission sources and sequestration sites. For pairwise comparisons of the particulate matter concentration means at distinct land-cover classes, the pairwise comparisons method for unequal sample sizes, known as Tukey's method, was performed. The use of satellite-derived products allowed better assessment of space-time interactions of PM, since these daily spatial measurements were able to capture differences in PM concentrations between grid cells, while the use of high- resolution land-cover and morphology static datasets allowed accounting for

  3. Multi-technique combination of space geodesy observations: Impact of the Jason-2 satellite on the GPS satellite orbits estimation

    Science.gov (United States)

    Zoulida, Myriam; Pollet, Arnaud; Coulot, David; Perosanz, Félix; Loyer, Sylvain; Biancale, Richard; Rebischung, Paul

    2016-10-01

    In order to improve the Precise Orbit Determination (POD) of the GPS constellation and the Jason-2 Low Earth Orbiter (LEO), we carry out a simultaneous estimation of GPS satellite orbits along with Jason-2 orbits, using GINS software. Along with GPS station observations, we use Jason-2 GPS, SLR and DORIS observations, over a data span of 6 months (28/05/2011-03/12/2011). We use the Geophysical Data Records-D (GDR-D) orbit estimation standards for the Jason-2 satellite. A GPS-only solution is computed as well, where only the GPS station observations are used. It appears that adding the LEO GPS observations results in an increase of about 0.7% of ambiguities fixed, with respect to the GPS-only solution. The resulting GPS orbits from both solutions are of equivalent quality, agreeing with each other at about 7 mm on Root Mean Square (RMS). Comparisons of the resulting GPS orbits to the International GNSS Service (IGS) final orbits show the same level of agreement for both the GPS-only orbits, at 1.38 cm in RMS, and the GPS + Jason2 orbits at 1.33 cm in RMS. We also compare the resulting Jason-2 orbits with the 3-technique Segment Sol multi-missions d'ALTimétrie, d'orbitographie et de localisation précise (SSALTO) POD products. The orbits show good agreement, with 2.02 cm of orbit differences global RMS, and 0.98 cm of orbit differences RMS on the radial component.

  4. A combination of docking, QM/MM methods, and MD simulation for binding affinity estimation of metalloprotein ligands.

    Science.gov (United States)

    Khandelwal, Akash; Lukacova, Viera; Comez, Dogan; Kroll, Daniel M; Raha, Soumyendu; Balaz, Stefan

    2005-08-25

    To alleviate the problems in the receptor-based design of metalloprotein ligands due to inadequacies in the force-field description of coordination bonds, a four-tier approach was devised. Representative ligand-metalloprotein interaction energies are obtained by subsequent application of (1) docking with metal-binding-guided selection of modes, (2) optimization of the ligand-metalloprotein complex geometry by combined quantum mechanics and molecular mechanics (QM/MM) methods, (3) conformational sampling of the complex with constrained metal bonds by force-field-based molecular dynamics (MD), and (4) a single point QM/MM energy calculation for the time-averaged structures. The QM/MM interaction energies are, in a linear combination with the desolvation-characterizing changes in the solvent-accessible surface areas, correlated with experimental data. The approach was applied to structural correlation of published binding free energies of a diverse set of 28 hydroxamate inhibitors to zinc-dependent matrix metalloproteinase 9 (MMP-9). Inclusion of steps 3 and 4 significantly improved both correlation and prediction. The two descriptors explained 90% of variance in inhibition constants of all 28 inhibitors, ranging from 0.08 to 349 nM, with the average unassigned error of 0.318 log units. The structural and energetic information obtained from the time-averaged MD simulation results helped understand the differences in binding modes of related compounds.

  5. Estimation of PKCδ autophosphorylation in U87 MG glioma cells: combination of experimental, conceptual and numerical approaches.

    Science.gov (United States)

    Misuth, Matus; Joniova, Jaroslava; Belej, Dominik; Hrivnak, Stanislav; Horvath, Denis; Huntosova, Veronika

    2016-05-09

    Golgi apparatus (GA) is a center for lipid metabolism and the final target of ceramide pathway, which may result in apoptosis. In this work localization of highly hydrophobic hypericin is followed by time-resolved imaging of NBDC6 (fluorescent ceramide) in U87 MG glioma cells. Decrease of NBDC6 fluorescence lifetimes in cells indicates that hypericin can also follow this pathway. It is known that both, ceramide and hypericin can significantly influence protein kinase C (PKC) activity. Western blotting analysis shows increase of PKCδ autophosphorylation at Ser645 (p(S645)PKCδ) in glioma cells incubated with 500 nM hypericin and confocal-fluorescence microscopy distinguishes p(S645)PKCδ localization between GA related compartments and nucleus. Experimental and numerical methods are combined to study p(S645)PKCδ in U87 MG cell line. Image processing based on conceptual qualitative description is combined with numerical treatment via simple exponential saturation model which describes redistribution of p(S645)PKCδ between nucleus and GA related compartments after hypericin administration. These results suggest, that numerical methods can significantly improve quantification of biomacromolecules (p(S645)PKCδ) directly from the fluorescence images and such obtained outputs are complementary if not equal to typical used methods in biology.

  6. On the valence fluctuation in the early actinide metals

    Energy Technology Data Exchange (ETDEWEB)

    Söderlind, P., E-mail: soderlind@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Landa, A.; Tobin, J.G.; Allen, P. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Medling, S.; Booth, C.H. [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Bauer, E.D.; Cooley, J.C. [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Sokaras, D.; Weng, T.-C.; Nordlund, D. [Stanford Synchrotron Radiation Lightsource, SLAC National Laboratory, Menlo Park, CA 94025 (United States)

    2016-02-15

    Highlights: • We make a connection between experimentally observed valence fluctuations and density functional theory. • We present a new model for valence fluctuations. • We present new experimental data for uranium and valence fluctuations. - Abstract: Recent X-ray measurements suggest a degree of valence fluctuation in plutonium and uranium intermetallics. We are applying a novel scheme, in conjunction with density functional theory, to predict 5f configuration fractions of states with valence fluctuations for the early actinide metals. For this purpose we perform constrained integer f-occupation calculations for the α phases of uranium, neptunium, and plutonium metals. For plutonium we also investigate the δ phase. The model predicts uranium and neptunium to be dominated by the f{sup 3} and f{sup 4} configurations, respectively, with only minor contributions from other configurations. For plutonium (both α and δ phase) the scenario is dramatically different. Here, the calculations predict a relatively even distribution between three valence configurations. The δ phase has a greater configuration fraction of f{sup 6} compared to that of the α phase. The theory is consistent with the interpretations of modern X-ray experiments and we present resonant X-ray emission spectroscopy results for α-uranium.

  7. First ionization potential of the heaviest actinide lawrencium, element 103

    Directory of Open Access Journals (Sweden)

    Sato Tetsuya K.

    2016-01-01

    Full Text Available The first ionization potential (IP1 of element 103, lawrencium (Lr, has been successfully determined for the first time by using a newly developed method based on a surface ionization process. The measured IP1 value is 4.9630.080.07 eV. This value is the smallest among those of actinide elements and is in excellent agreement with the value of 4.963(15 eV predicted by state-of-the-art relativistic calculations also performed in this work. Our results strongly support that the Lr atom has an electronic configuration of [Rn]7s25f147p11/2, which is influenced by strong relativistic effects. The present work provides a reliable benchmark for theoretical calculations and also opens the way for studies on atomic properties of heavy elements with atomic number Z > 100. Moreover, the present achievement has triggered a controversy on the position of lutetium (Lu and Lr in the Periodic Table of Elements.

  8. Functionalization of mesoporous materials for lanthanide and actinide extraction.

    Science.gov (United States)

    Florek, Justyna; Giret, Simon; Juère, Estelle; Larivière, Dominic; Kleitz, Freddy

    2016-10-14

    Among the energy sources currently available that could address our insatiable appetite for energy and minimize our CO2 emission, solar, wind, and nuclear energy currently occupy an increasing portion of our energy portfolio. The energy associated with these sources can however only be harnessed after mineral resources containing valuable constituents such as actinides (Ac) and rare earth elements (REEs) are extracted, purified and transformed into components necessary for the conversion of energy into electricity. Unfortunately, the environmental impacts resulting from their manufacture including the generation of undesirable and, sometimes, radioactive wastes and the non-renewable nature of the mineral resources, to name a few, have emerged as challenges that should be addressed by the scientific community. In this perspective, the recent development of functionalized solid materials dedicated to selective elemental separation/pre-concentration could provide answers to several of the above-mentioned challenges. This review focuses on recent advances in the field of mesoporous solid-phase (SP) sorbents designed for REEs and Ac liquid-solid extraction. Particular attention will be devoted to silica and carbon sorbents functionalized with commonly known ligands, such as phosphorus or amide-containing functionalities. The extraction performances of these new systems are discussed in terms of sorption capacity and selectivity. In order to support potential industrial applications of the silica and carbon-based sorbents, their main drawbacks and advantages are highlighted and discussed.

  9. Iron (III) Matrix Effects on Mineralization and Immobilization of Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Cynthia-May S. Gong; Tyler A. Sullens; Kenneth R. Czerwinski

    2006-01-01

    Abstract - A number of models for the Yucca Mountain Project nuclear waste repository use studies of actinide sorption onto well-defined iron hydroxide materials. In the case of a waste containment leak, however, a complex interaction between dissolved waste forms and failed containment vessel components can lead to immediate precipitation of migratory iron and uranyl in the silicate rich near-field environment. Use of the Fe(III) and UO22+ complexing agent acetohydroxamic acid (AHA) as a colorimetric agent for visible spectrophotometry is well-known. Using the second derivative of these spectra a distinct shift in iron complexation in the presence of silicate is seen that is not seen with uranyl or alone. Silica also decreases the ability of uranyl and ferric solutions to absorb hydroxide, hastening precipitation. These ferric silicate precipitates are highly amorphous and soluble. Precipitates formed in the presence of uranyl below ~1 mol% exhibit lower solubility than precipitates from up to 50 mol % and of uranyl silicates alone.

  10. Actinide-specific complexing agents: their structural and solution chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Raymond, K.N.; Freeman, G.E.; Kappel, M.J.

    1983-07-01

    The synthesis of a series of tetracatecholate ligands designed to be specific for Pu(IV) and other actinide(IV) ions has been achieved. Although these compounds are very effective as in vivo plutonium removal agents, potentiometric and voltammetric data indicate that at neutral pH full complexation of the Pu(IV) ion by all four catecholate groups does not occur. Spectroscopic results indicate that the tetracatecholates, 3,4,3-LICAMS and 3,4,3-LICAMC, complex Am(III). The Am(IV)/(III)-catecholate couple (where catecholate = 3,4,3-LICAMS or 3,4,3-LICAMC) is not observed, but may not be observable due to the large currents associated with ligand oxidation. However, within the potential range where ligand oxidation does not occur, these experiments indicate that the reduction potential of free Am(IV)/(III) is probably greater than or equal to + 2.6 V vs NHE or higher. Proof of the complexation of americium in the trivalent oxidation state by 3,4,3-LICAMS and 3,4,3-LICAMC elimates the possibility of tetracatholates stabilizing Am(IV) in vivo.

  11. Structural organization and spectroscopy of peptide-actinide(IV) complexes; Organisation structurale et spectroscopie de peptides susceptibles de complexer les actinides(IV)

    Energy Technology Data Exchange (ETDEWEB)

    Dahou, S.

    2010-11-05

    The contamination of living organisms by actinide elements is at the origin of both radiological and chemical toxicity that may lead to severe dysfunction. Most of the data available on the actinide interaction with biological systems are macroscopic physiological measurements and are lacking a molecular description of the systems. Because of the intricacy of these systems, classical biochemical methods are difficult to implement. Our strategy consisted in designing simplified biomimetic peptides, and describing the corresponding intramolecular interactions with actinides. A carboxylic pentapeptide of the form DDPDD has been at the starting point of this work in order to further assess the influence of the peptide sequence on the topology of the complexes.To do so, various linear (Asp/Ala permutations, peptoids) and cyclic analogues have been synthesized. Furthermore, in order to include the hydroxamic function (with a high affinity for Fe(III)) in the peptide, both desferrioxamine and acetohydroxamic acid have been investigated. However because of difficulties in synthesis, we have not been able to test these peptides. Three actinide cations have been considered at oxidation state +IV (Th, Np, Pu) and compared to Fe(III), often considered as a biological surrogate of Pu(IV). The spatial arrangement of the peptide around the cation has been probed by spectrophotometry and X-ray Absorption Spectroscopy. The spectroscopic data and EXAFS data adjustment lead us to rationalize the topology of the complexes as a function of the peptide sequence: mix hydroxy polynuclear species for linear and cyclic peptides, mononuclear for the desferrioxamine complexes. Furthermore, significant differences have appeared between Fe(III) and actinide(IV), related to differences of reactivity in aqueous medium. (author)

  12. Synthesis and Evaluation of new Polyfunctional Molecules for Group Actinide Extraction; Synthese et evaluation de Nouvelles Molecules Polyfonctionnelles pour la Separation Groupee des Actinides

    Energy Technology Data Exchange (ETDEWEB)

    Marie, C.

    2009-10-15

    The aim of this project is to design new extracting molecules for spent nuclear fuel reprocessing. In order to minimize the long-term residual radiotoxicity of the waste, the GANEX process is an option based on homogeneous recycling of actinides. All actinides (U, Np, Pu, Am, Cm), present in a highly acidic aqueous solution, would be extracted together and separated from fission products (especially from lanthanides) using liquid-liquid extraction. In this context, twenty new bi-topic ligands constituted of a nitrogen poly-aromatic unit functionalized by amide groups were synthesized. Liquid-liquid extraction tests with these ligands dissolved alone in the organic phase show that N, N, N', N'-tetra-alkyl-6, 6''(2, 2':6', 2''-terpyridine)-diamides are able to selectively extract actinides at different oxidation states (Np(V et VI), U(VI), Pu(IV), Am(III), Cm(III)) from an aqueous solution 3M HNO{sub 3}. Nevertheless, actinides(III) are poorly extracted. According to crystallographic structures of complexes with Nd(III) and U(VI) determined by X-rays diffraction, these ligands are penta-dentate. In solution (methanol), complexes stoichiometries (1:1) of Nd(III), U(VI) and Pu(IV) were determined by electro-spray ionization mass spectrometry. Stability constants, evaluated by UV-visible spectrophotometry in MeOH/H{sub 2}O solutions, confirm the selectivity of ligands toward actinides(III) with respect to lanthanides(III). Associate to nuclear magnetic resonance experiments and DFT calculations (Density Functional Theory), a better knowledge of their coordination mode was achieved. (author)

  13. A combined method to estimate parameters of the thalamocortical model from a heavily noise-corrupted time series of action potential

    Science.gov (United States)

    Wang, Ruofan; Wang, Jiang; Deng, Bin; Liu, Chen; Wei, Xile; Tsang, K. M.; Chan, W. L.

    2014-03-01

    A combined method composing of the unscented Kalman filter (UKF) and the synchronization-based method is proposed for estimating electrophysiological variables and parameters of a thalamocortical (TC) neuron model, which is commonly used for studying Parkinson's disease for its relay role of connecting the basal ganglia and the cortex. In this work, we take into account the condition when only the time series of action potential with heavy noise are available. Numerical results demonstrate that not only this method can estimate model parameters from the extracted time series of action potential successfully but also the effect of its estimation is much better than the only use of the UKF or synchronization-based method, with a higher accuracy and a better robustness against noise, especially under the severe noise conditions. Considering the rather important role of TC neuron in the normal and pathological brain functions, the exploration of the method to estimate the critical parameters could have important implications for the study of its nonlinear dynamics and further treatment of Parkinson's disease.

  14. A combined method to estimate parameters of the thalamocortical model from a heavily noise-corrupted time series of action potential

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ruofan; Wang, Jiang; Deng, Bin, E-mail: dengbin@tju.edu.cn; Liu, Chen; Wei, Xile [Department of Electrical and Automation Engineering, Tianjin University, Tianjin (China); Tsang, K. M.; Chan, W. L. [Department of Electrical Engineering, The Hong Kong Polytechnic University, Kowloon (Hong Kong)

    2014-03-15

    A combined method composing of the unscented Kalman filter (UKF) and the synchronization-based method is proposed for estimating electrophysiological variables and parameters of a thalamocortical (TC) neuron model, which is commonly used for studying Parkinson's disease for its relay role of connecting the basal ganglia and the cortex. In this work, we take into account the condition when only the time series of action potential with heavy noise are available. Numerical results demonstrate that not only this method can estimate model parameters from the extracted time series of action potential successfully but also the effect of its estimation is much better than the only use of the UKF or synchronization-based method, with a higher accuracy and a better robustness against noise, especially under the severe noise conditions. Considering the rather important role of TC neuron in the normal and pathological brain functions, the exploration of the method to estimate the critical parameters could have important implications for the study of its nonlinear dynamics and further treatment of Parkinson's disease.

  15. [Hyper spectral estimation method for soil alkali hydrolysable nitrogen content based on discrete wavelet transform and genetic algorithm in combining with partial least squares DWT-GA-PLS)].

    Science.gov (United States)

    Chen, Hong-Yan; Zhao, Geng-Xing; Li, Xi-Can; Wang, Xiang-Feng; Li, Yu-Ling

    2013-11-01

    Taking the Qihe County in Shandong Province of East China as the study area, soil samples were collected from the field, and based on the hyperspectral reflectance measurement of the soil samples and the transformation with the first deviation, the spectra were denoised and compressed by discrete wavelet transform (DWT), the variables for the soil alkali hydrolysable nitrogen quantitative estimation models were selected by genetic algorithms (GA), and the estimation models for the soil alkali hydrolysable nitrogen content were built by using partial least squares (PLS) regression. The discrete wavelet transform and genetic algorithm in combining with partial least squares (DWT-GA-PLS) could not only compress the spectrum variables and reduce the model variables, but also improve the quantitative estimation accuracy of soil alkali hydrolysable nitrogen content. Based on the 1-2 levels low frequency coefficients of discrete wavelet transform, and under the condition of large scale decrement of spectrum variables, the calibration models could achieve the higher or the same prediction accuracy as the soil full spectra. The model based on the second level low frequency coefficients had the highest precision, with the model predicting R2 being 0.85, the RMSE being 8.11 mg x kg(-1), and RPD being 2.53, indicating the effectiveness of DWT-GA-PLS method in estimating soil alkali hydrolysable nitrogen content.

  16. MultipLa--a tool for the combined overall estimation of various types of manual handling tasks.

    Science.gov (United States)

    Karlheinz, Schaub; Max, Bierwirth; Michaela, Kugler; Ralph, Bruder

    2012-01-01

    In the 1990ies the German Federal Institute for Occupational Safety and Health (FIOSH) published "Key Indicator Methods" (KIM) for the evaluation of manual material handling tasks. These methods served as a national German implementation of the EU Manual Handling Directive (90/269/EEC). These methods allow the evaluation of individual handling tasks like lifting or pushing. KIM tools do not allow evaluating complex handling tasks like a combined lifting and pushing task. With respect to the needs at shop floor level (e.g. logistics), MultipLa tries to bridge that gap by means of an EXCEL based worksheet using the KIM philosophy. In the past several algorithms for a risk assessment had been developed. At the moment MultipLa is in a test phase at several automotive OEMs.

  17. MOLECULAR SPECTROSCPY AND REACTIONS OF ACTINIDES IN THE GAS PHASE AND CRYOGENIC MATRICES

    Energy Technology Data Exchange (ETDEWEB)

    Heaven, Michael C.; Gibson, John K.; Marcalo, Joaquim

    2009-02-01

    In this chapter we review the spectroscopic data for actinide molecules and the reaction dynamics for atomic and molecular actinides that have been examined in the gas phase or in inert cryogenic matrices. The motivation for this type of investigation is that physical properties and reactions can be studied in the absence of external perturbations (gas phase) or under minimally perturbing conditions (cryogenic matrices). This information can be compared directly with the results from high-level theoretical models. The interplay between experiment and theory is critically important for advancing our understanding of actinide chemistry. For example, elucidation of the role of the 5f electrons in bonding and reactivity can only be achieved through the application of experimentally verified theoretical models. Theoretical calculations for the actinides are challenging due the large numbers of electrons that must be treated explicitly and the presence of strong relativistic effects. This topic has been reviewed in depth in Chapter 17 of this series. One of the goals of the experimental work described in this chapter has been to provide benchmark data that can be used to evaluate both empirical and ab initio theoretical models. While gas-phase data are the most suitable for comparison with theoretical calculations, there are technical difficulties entailed in generating workable densities of gas-phase actinide molecules that have limited the range of species that have been characterized. Many of the compounds of interest are refractory, and problems associated with the use of high temperature vapors have complicated measurements of spectra, ionization energies, and reactions. One approach that has proved to be especially valuable in overcoming this difficulty has been the use of pulsed laser ablation to generate plumes of vapor from refractory actinide-containing materials. The vapor is entrained in an inert gas, which can be used to cool the actinide species to room

  18. Estimation of sediment residence times in subtropical highland catchments of central Mexico combining river gauging and fallout radionuclides

    Science.gov (United States)

    Evrard, Olivier; Némery, Julien; Gratiot, Nicolas; Duvert, Clément; Lefèvre, Irène; Ayrault, Sophie; Esteves, Michel; Bonté, Philippe

    2010-05-01

    Subtropical regions of the world are affected by intense soil erosion associated with deforestation, overgrazing and cropping intensification. This land degradation leads to important on-site (e.g. decrease in soil fertility) and off-site impacts (e.g. reservoir sedimentation, water pollution). This study determined the mean sediment residence times in soils and rivers of three catchments (3 - 12 km²) with contrasted land uses (i.e. cropland, forests, rangelands, extended gully networks) located in highlands of the transvolcanic belt of central Mexico. Calculations were based on rainfall and river gauging as well as on fallout radionuclide measurements (Be-7, Cs-137, Pb-210). Atmospheric deposition of Be-7 and Pb-210 was estimated based on the analysis of rainfall precipitated samples. Rainfall samples were collected all throughout the rainy season in order to take account of the temporal variations of the radionuclide fluxes. Furthermore, sampling of suspended sediment was conducted at the outlet of each catchment during most of the storms that occurred throughout the 2009 rainy season. Be-7, Cs-137 and Pb-210 concentrations of this sediment were determined by gamma-spectrometry. A two-box balance model was then used to estimate the sediment residence time and the inventory of radionuclides in the three selected catchments. This model subdivided each catchment into two boxes: (i) a "soil-box" characterised by low transport velocities and hence long radionuclide residence times and (ii) a "river-box" covering the river surface and its surroundings characterised by quicker exchanges and shorter radionuclide residence times. Input and output fluxes of sediment and radionuclides were taken into account in each box. Radioactive decay during the residence time of sediment was also considered. The mean residence time of sediment in soils ranged between 13,300 - 28,500 years. In contrast, sediment residence time in rivers was much shorter, fluctuating between 28 and 393

  19. Numerical experiment to estimate the validity of negative ion diagnostic using photo-detachment combined with Langmuir probing

    Energy Technology Data Exchange (ETDEWEB)

    Oudini, N. [Laboratoire des plasmas de décharges, Centre de Développement des Technologies Avancées, Cité du 20 Aout BP 17 Baba Hassen, 16081 Algiers (Algeria); Sirse, N.; Ellingboe, A. R. [Plasma Research Laboratory, School of Physical Sciences and NCPST, Dublin City University, Dublin 9 (Ireland); Benallal, R. [Unité de Recherche Matériaux et Energies Renouvelables, BP 119, Université Abou Bekr Belkaïd, Tlemcen 13000 (Algeria); Taccogna, F. [Istituto di Metodologie Inorganiche e di Plasmi, CNR, via Amendola 122/D, 70126 Bari (Italy); Aanesland, A. [Laboratoire de Physique des Plasmas, (CNRS, Ecole Polytechnique, Sorbonne Universités, UPMC Univ Paris 06, Univ Paris-Sud), École Polytechnique, 91128 Palaiseau Cedex (France); Bendib, A. [Laboratoire d' Electronique Quantique, Faculté de Physique, USTHB, El Alia BP 32, Bab Ezzouar, 16111 Algiers (Algeria)

    2015-07-15

    This paper presents a critical assessment of the theory of photo-detachment diagnostic method used to probe the negative ion density and electronegativity α = n{sub -}/n{sub e}. In this method, a laser pulse is used to photo-detach all negative ions located within the electropositive channel (laser spot region). The negative ion density is estimated based on the assumption that the increase of the current collected by an electrostatic probe biased positively to the plasma is a result of only the creation of photo-detached electrons. In parallel, the background electron density and temperature are considered as constants during this diagnostics. While the numerical experiments performed here show that the background electron density and temperature increase due to the formation of an electrostatic potential barrier around the electropositive channel. The time scale of potential barrier rise is about 2 ns, which is comparable to the time required to completely photo-detach the negative ions in the electropositive channel (∼3 ns). We find that neglecting the effect of the potential barrier on the background plasma leads to an erroneous determination of the negative ion density. Moreover, the background electron velocity distribution function within the electropositive channel is not Maxwellian. This is due to the acceleration of these electrons through the electrostatic potential barrier. In this work, the validity of the photo-detachment diagnostic assumptions is questioned and our results illustrate the weakness of these assumptions.

  20. CO2 migration and sequestration by combined capillary and solubility trapping: theory, experiments, and capacity estimates at the basin scale

    Science.gov (United States)

    Juanes, Ruben

    2011-11-01

    The large-scale injection and storage of carbon dioxide (CO2) into deep saline aquifers is a promising tool for reducing atmospheric CO2 emissions to mitigate climate change. Success of geologic sequestration relies on trapping the buoyant CO2, to minimize the risk of leakage into shallower formations through pre- existing wells, fractures or faults. However, traditional reservoir-simulation tools are currently unable to resolve the impact of small-scale trapping processes on fluid flow at the scale of a geologic basin. Here, we formulate a sharp-interface mathematical model for the post-injection migration of a CO2 plume driven by groundwater flow in a sloping aquifer, subject to both capillary trapping and CO2 dissolution by convective mixing. We develop semi-analytical solutions that elucidate the nontrivial interplay between the two trapping mechanisms, and how their synergetic action controls plume migration. We validate the theory by means of laboratory experiments with analogue fluids to study how convective mixing arrests the buoyant current. We use our findings to estimate the dimensionless rate of solubility trapping for several large saline aquifers in the United States, and assess the importance of solubility trapping in practice.

  1. Estimated radiation pneumonitis risk after photon versus proton therapy alone or combined with chemotherapy for lung cancer

    DEFF Research Database (Denmark)

    Vogelius, Ivan R.; Westerly, David C; Aznar, Marianne Camille

    2011-01-01

    of clinical G3RP at zero CERD is 5% for tomotherapy (range: 1-18 %) and 14% for 3D-CRT (range 2-49%). When the CERD exceeds 9 Gy, however, the risk of RP with the tomotherapy plans become higher than the 3D-CRT plans. The IMPT plans are less toxic both at zero CERD (mean 2%, range 1-5%) and at CERD = 10 Gy...... treatment plans are compared in 18 non-small cell lung cancer patients previously treated with helical tomotherapy; the tomotherapy plan, an intensity modulated proton therapy plan (IMPT) and a three dimensional conformal radiotherapy (3D-CRT) plan. All plans are optimized without consideration...... of the chemotherapy effect. The effect of chemotherapy is modeled as an independent cell killing process using a uniform chemotherapy equivalent radiation dose (CERD) added to the entire organ at risk. We estimate the risk of grade 3 or higher RP (G3RP) using the critical volume model. Results. The mean risk...

  2. Minor actinide fission induced by multi-nucleon transfer reaction in inverse kinematics

    Directory of Open Access Journals (Sweden)

    Taieb J.

    2010-03-01

    Full Text Available In the framework of nuclear waste incineration and design of new generation nuclear reactors, experimental data on fission probabilities and on fission fragment yields of minor actinides are crucial to design prototypes. Transfer-induced fission has proven to be an efficient method to study fission probabilities of actinides which cannot be investigated with standard techniques due to their high radioactivity. We report on the preliminary results of an experiment performed at GANIL that investigates fission probabilities with multi-nucleon transfer reactions in inverse kinematics between a 238U beam on a 12C target. Actinides from U to Cm were produced with an excitation energy range from 0 to 30 MeV. In addition, inverse kinematics allowed to characterize the fission fragments in mass and charge. A key point of the analysis resides in the identification of the actinides produced in the different transfer channels. The new annular telescope SPIDER was used to tag the target-like recoil nucleus of the transfer reaction and to determine the excitation energy of the actinide. The fission probability for each transfer channel is accessible and the preliminary results for 238U are promising.

  3. Application of chemical structure and bonding of actinide oxide materials for forensic science

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Marianne Perry [Los Alamos National Laboratory

    2010-01-01

    We are interested in applying our understanding of actinide chemical structure and bonding to broaden the suite of analytical tools available for nuclear forensic analyses. Uranium- and plutonium-oxide systems form under a variety of conditions, and these chemical species exhibit some of the most complex behavior of metal oxide systems known. No less intriguing is the ability of AnO{sub 2} (An: U, Pu) to form non-stoichiometric species described as AnO{sub 2+x}. Environmental studies have shown the value of utilizing the chemical signatures of these actinide oxide materials to understand transport following release into the environment. Chemical speciation of actinide-oxide samples may also provide clues as to the age, source, or process history of the material. The scientific challenge is to identify, measure and understand those aspects of speciation of actinide analytes that carry information about material origin and history most relevant to forensics. Here, we will describe our efforts in material synthesis and analytical methods development that we will use to provide the fundamental science to characterize actinide oxide molecular structures for forensic science. Structural properties and initial results to measure structural variability of uranium oxide samples using synchrotron-based X-ray Absorption Fine Structure will be discussed.

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

    Science.gov (United States)

    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. Technical requirements for the actinide source-term waste test program

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, M.L.F.; Molecke, M.A.

    1993-10-01

    This document defines the technical requirements for a test program designed to measure time-dependent concentrations of actinide elements from contact-handled transuranic (CH TRU) waste immersed in brines similar to those found in the underground workings of the Waste Isolation Pilot Plant (WIPP). This test program wig determine the influences of TRU waste constituents on the concentrations of dissolved and suspended actinides relevant to the performance of the WIPP. These influences (which include pH, Eh, complexing agents, sorbent phases, and colloidal particles) can affect solubilities and colloidal mobilization of actinides. The test concept involves fully inundating several TRU waste types with simulated WIPP brines in sealed containers and monitoring the concentrations of actinide species in the leachate as a function of time. The results from this program will be used to test numeric models of actinide concentrations derived from laboratory studies. The model is required for WIPP performance assessment with respect to the Environmental Protection Agency`s 40 CFR Part 191B.

  6. Spectrum parameter estimation in Brillouin scattering distributed temperature sensor based on cuckoo search algorithm combined with the improved differential evolution algorithm

    Science.gov (United States)

    Zhang, Yanjun; Yu, Chunjuan; Fu, Xinghu; Liu, Wenzhe; Bi, Weihong

    2015-12-01

    In the distributed optical fiber sensing system based on Brillouin scattering, strain and temperature are the main measuring parameters which can be obtained by analyzing the Brillouin center frequency shift. The novel algorithm which combines the cuckoo search algorithm (CS) with the improved differential evolution (IDE) algorithm is proposed for the Brillouin scattering parameter estimation. The CS-IDE algorithm is compared with CS algorithm and analyzed in different situation. The results show that both the CS and CS-IDE algorithm have very good convergence. The analysis reveals that the CS-IDE algorithm can extract the scattering spectrum features with different linear weight ratio, linewidth combination and SNR. Moreover, the BOTDR temperature measuring system based on electron optical frequency shift is set up to verify the effectiveness of the CS-IDE algorithm. Experimental results show that there is a good linear relationship between the Brillouin center frequency shift and temperature changes.

  7. DEVELOPMENT OF UV SPECTROPHOTOMETRIC METHOD FOR THE SIMULTANEOUS ESTIMATION OF ABACAVIR AND LAMIVUDINE IN COMBINED TABLET DOSAGE FORM USING MULTICOMPONENT MODE

    Directory of Open Access Journals (Sweden)

    V. P. Nagulwar* and K.P. Bhusari

    2012-07-01

    Full Text Available A simple, accurate, precise, economical analytical method has been developed for the simultaneous estimation of abacavir and lamivudine in pure bulk drug and in combined tablet dosage form by UV spectrophotometry in multicomponent mode. The standard solutions of abacavir and lamivudine in mixture of acetonitrile and methanol were diluted with distilled water individually to get the concentration of (20 µg/mL and 10 µg/mL and the scanning range between 200 nm to 350 nm was selected. The sampling wavelengths 224, 241, 257, 280 and 296 nm was selected and the concentrations of individual drugs in five mixed standard solutions were fed to the multicomponent mode of the instrument. The results of analysis have been validated as per ICH guidelines and were found to be satisfactory. Hence, present study gives excellent methods for the determination of both the drugs in combined tablet formulation with relative ease.

  8. Thermally unstable complexants: Stability of lanthanide/actinide complexes, thermal instability of the ligands, and applications in actinide separations

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L.; Rickert, P.G.

    1991-01-01

    Water soluble complexing agents are commonly used in separations to enhance the selectivity of both ion exchange and solvent extraction processes. Applications of this type in the treatment of nuclear wastes using conventional complexing agents have found mixed success due to the nature of the complexants. In addition, the residual solutions containing these species have led to potentially serious complications in waste storage. To overcome some of the limitations of carboxylic acid and aminopolycarboxylate ligands, we have initiated a program to investigate the complexing ability, thermal/oxidative instability, and separation potential of a group of water soluble organophosphorus compounds which we call Thermally Unstable Complexants, or simply TUCS. Complexants of this type appear to be superior to conventional analogues in a number of respects. In this report, we will summarize our research to date on the actinide/lanthanide complexes with a series of substituted methanediphosphonic acids, the kinetics of their oxidative decomposition, and a few applications which have been developed for their use. 17 refs., 5 figs., 3 tab.

  9. Intraocular Lens Power Estimation in Combined Phacoemulsification and Pars Plana Vitrectomy in Eyes with Epiretinal Membranes: A Case-Control Study

    Science.gov (United States)

    Kim, Min; Kim, Hyoung Eun; Lee, Dong Hyun; Koh, Hyoung Jun; Lee, Sung Chul

    2015-01-01

    Purpose To evaluate the accuracy of postoperative refractive outcomes of combined phacovitrectomy for epiretinal membrane (ERM) in comparison to cataract surgery alone. Materials and Methods Thirty-nine eyes that underwent combined phacovitrectomy with intraocular lens (IOL) implantation for cataract and ERM (combined surgery group) and 39 eyes that received phacoemulsification for cataract (control group) were analyzed, retrospectively. The predicted preoperative refractive aim was compared with the results of postoperative refraction. Results In the combined surgery group, refractive prediction error by A-scan and IOLMaster were -0.305±0.717 diopters (D) and -0.356±0.639 D, respectively, compared to 0.215±0.541 and 0.077±0.529 in the control group, showing significantly more myopic change compared to the control group (p=0.001 and p=0.002, respectively). Within each group, there was no statistically significant difference in refractive prediction error between A-scan and IOLMaster (all p>0.05). IOL power calculation using adjusted A-scan measurement of axial length based on the macular thickness of the normal contralateral eye still resulted in significant postoperative refractive error (all ppower estimation in eyes with cataract and ERM, sequential surgery for ERM and cataract may need to be considered. PMID:25837189

  10. Combining double difference and amplitude ratio approaches for Q estimates at the NW Bohemia earthquake swarm region

    Science.gov (United States)

    Kriegerowski, Marius; Cesca, Simone; Krüger, Frank; Dahm, Torsten; Horálek, Josef

    2016-04-01

    Aside from the propagation velocity of seismic waves, their attenuation can provide a direct measure of rock properties in the sampled subspace. We present a new attenuation tomography approach exploiting relative amplitude spectral ratios of earthquake pairs. We focus our investigation on North West Bohemia - a region characterized by intense earthquake swarm activity in a confined source region. The inter-event distances are small compared to the epicentral distances to the receivers meeting a fundamental requirement of the method. Due to the similar event locations also the ray paths are very similar. Consequently, the relative spectral ratio is affected mostly by rock properties along the path of the vector distance and thus representative of the focal region. In order to exclude effects of the seismic source spectra, only the high frequency content beyond the corner frequency is taken into consideration. This requires high quality as well as high sampling records. Future improvements in that respect can be expected from the ICDP proposal "Eger rift", which includes plans to install borehole monitoring in the investigated region. 1D and 3D synthetic tests show the feasibility of the presented method. Furthermore, we demonstrate influences of perturbations in source locations and travel time estimates on the determination of Q. Errors in Q scale linearly with errors in the differential travel times. These sources of errors can be attributed to the complex velocity structure of the investigated region. A critical aspect is the signal-to-noise ratio, which imposes a strong limitation and emphasizes the demand for high quality recordings. Hence, the presented method is expected to benefit from bore hole installations. Since we focus our analysis on the NW Bohemia case study example, a synthetic earthquake catalog incorporating source characteristics deduced from preceding moment tensor inversions coupled with a realistic velocity model provides us with a realistic

  11. Research in actinide chemistry. Progress report, March 1, 1980-February 28, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Choppin, G.R.

    1981-01-01

    Visible spectroscopy, NMR (/sup 1/H/sub 1/, /sup 6/C/sub 13/, /sup 57/La/sub 139/) spectroscopy, potentiometry, and calorimetry were used in lanthanide studies which have allowed much more thorough interpretation of actinide tracer studies. In the last several years, the studies were expanded to include actinides in the IV, V and VI oxidation states. Part of the research during this time was directed to investigation of actinide interaction with naturally occurring polyelectrolytes such as humic and fulvic acids. Since redox reactions seemingly occur in some of these interactions, a study of plutonium and neptunium redox behavior in the presence of organic complexing agents was started. Preliminary data are given for reduction of Np(VI) by various organic acids.

  12. Study of the behavior of actinides continuously recycled in a hard spectrum reactor

    Energy Technology Data Exchange (ETDEWEB)

    Schofield, P.E.

    1980-12-01

    The behavior of actinides continuously recycled through the central region of an EBR-II type reactor was studied. Such a reactor would convert long-lived nuclear wastes to short-lived isotopes, and simultaneously produce useful power. This process is proposed as an alternative to the geological isolation of long-lived actinide wastes. A driver region of 50% U-235 enriched fuel provided a nearly-constant spectrum and flux that was extremely hard compared to standard LMFBRs. This resulted in a high fission-to-capture ratio for most isotopes. The original actinide fuel was the discharge from a LWR, cooled for two years, with 99.9% of the uranium and plutonium removed by chemical processing. Comparison was made between removal of both Pu and U and removal of only U in subsequent cycles. The latter case resulted in substantial quantities of trans-plutonics burned per cycle.

  13. Standard practice for alternate actinide calibration for inductively coupled plasma-mass spectrometry

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2004-01-01

    1.1 This practice provides guidance for an alternate linear calibration for the determination of selected actinide isotopes in appropriately prepared aqueous solutions by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). This alternate calibration is mass bias adjusted using thorium-232 (232Th) and uranium-238 (238U) standards. One of the benefits of this standard practice is the ability to calibrate for the analysis of highly radioactive actinides using calibration standards at much lower specific activities. Environmental laboratories may find this standard practice useful if facilities are not available to handle the highly radioactive standards of the individual actinides of interest. 1.2 The instrument response for a series of determinations of known concentration of 232Th and 238U defines the mass versus response relationship. For each standard concentration, the slope of the line defined by 232Th and 238U is used to derive linear calibration curves for each mass of interest using interference equ...

  14. Mangrove Blue Carbon stocks and change estimation from PolInSAR, Lidar and High Resolution Stereo Imagery combined with Forest Cover change mapping

    Science.gov (United States)

    Zalles, V.; Fatoyinbo, T. E.; Simard, M.; Lagomasino, D.; Lee, S. K.; Trettin, C.; Feliciano, E. A.; Hansen, M.; John, P.

    2015-12-01

    Mangroves and tidal wetlands have the highest carbon density among terrestrial ecosystems. Although they only represent 3 % of the total forest area (or 0.01 % of land area), C emissions from mangrove destruction alone at current rates could be equivalent to 10 % of carbon emissions from deforestation. One of the main challenges to implementing carbon mitigation projects is measuring carbon, efficiently, effectively, and safely. In mangroves especially, the extreme difficulty of the terrain has hindered the establishment of sufficient field plots needed to accurately measure carbon on the scale necessary to relate remotely sensed measurements with field measurements at accuracies required for REDD and other C trading mechanisms. In this presentation we will showcase the methodologies for, and the remote sensing products necessary to implement MRV (monitoring, reporting and verification) systems in Coastal Blue Carbon ecosystems. Specifically, we will present new methods to estimate aboveground biomass stocks and change in mangrove ecosystems using remotely sensed data from Interferometric SAR from the TanDEM-X mission, commercial airborne Lidar, High Resolution Stereo-imagery, and timeseries analysis of Landsat imagery in combination with intensive field measurements of above and belowground carbon stocks. Our research is based on the hypothesis that by combining field measurements, commercial airborne Lidar, optical and Pol-InSAR data, we are able to estimate Mangrove blue carbon storage with an error under 20% at the project level and permit the evaluation of UNFCCC mechanisms for the mitigation of carbon emissions from coastal ecosystems.

  15. Minor Actinides Loading Optimization for Proliferation Resistant Fuel Design - BWR

    Energy Technology Data Exchange (ETDEWEB)

    G. S. Chang; Hongbin Zhang

    2009-09-01

    One approach to address the United States Nuclear Power (NP) 2010 program for the advanced light water reactor (LWR) (Gen-III+) intermediate-term spent fuel disposal need is to reduce spent fuel storage volume while enhancing proliferation resistance. One proposed solution includes increasing burnup of the discharged spent fuel and mixing minor actinide (MA) transuranic nuclides (237Np and 241Am) in the high burnup fuel. Thus, we can reduce the spent fuel volume while increasing the proliferation resistance by increasing the isotopic ratio of 238Pu/Pu. For future advanced nuclear systems, MAs are viewed more as a resource to be recycled, and transmuted to less hazardous and possibly more useful forms, rather than simply disposed of as a waste stream in an expensive repository facility. MAs play a much larger part in the design of advanced systems and fuel cycles, not only as additional sources of useful energy, but also as direct contributors to the reactivity control of the systems into which they are incorporated. A typical boiling water reactor (BWR) fuel unit lattice cell model with UO2 fuel pins will be used to investigate the effectiveness of adding MAs (237Np and/or 241Am) to enhance proliferation resistance and improve fuel cycle performance for the intermediate-term goal of future nuclear energy systems. However, adding MAs will increase plutonium production in the discharged spent fuel. In this work, the Monte-Carlo coupling with ORIGEN-2.2 (MCWO) method was used to optimize the MA loading in the UO2 fuel such that the discharged spent fuel demonstrates enhanced proliferation resistance, while minimizing plutonium production. The axial averaged MA transmutation characteristics at different burnup were compared and their impact on neutronics criticality and the ratio of 238Pu/Pu discussed.

  16. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    Energy Technology Data Exchange (ETDEWEB)

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  17. New unsymmetrical digycolamide ligands for trivalent actinide separation

    Energy Technology Data Exchange (ETDEWEB)

    Ravi, Jammu; Venkatesan, K.A.; Antony, M.P.; Srinivasan, T.G.; Rao, P.R. Vasudeva [Indira Gandhi Centre for Atomic Research, Kalpakkam (India). Fuel Chemistry Div.

    2014-10-01

    New unsymmetrical diglycolamides (UDGAs), N,N-di-butyl-N',N'-di-dodecyl-3-oxapentane-1,5-diamide (C{sub 12}-C{sub 4}), N,N-di-dodecyl-N',N'-di-hexyl-3-oxapentane-1,5-diamide (C{sub 12}-C{sub 6}), N,N-di-decyl-N',N'-di-dodecyl-3-oxapentane-1,5-diamide (C{sub 12}-C{sub 10}) have been synthesized, and evaluated for the separation of americium(III) and europium(III) from nitric acid medium. The extraction behavior of Am(III), Eu(III), and Sr(II) in a solution of these UDGAs in n-dodecane was studied as a function of concentration of nitric acid in the aqueous phase. The distribution ratio of Am(III) and Eu(III) increased with increase in the concentration of nitric acid. The third phase formation behavior of nitric acid and neodymium(III) in 0.1 M UDGA/n-dodecane was studied. The third phase formation was not observed in all these UDGAs in n-dodecane (0.1 M), when the concentration of Nd(III) was ∝ 500 mM in 3-4M nitric acid. The stoichiometry of Am(III)-UDGA was determined from the slope analysis of the extraction data, which indicated the formation of 1:3 complex in all cases. Our studies revealed that the UDGA ligands with dodecyl group attached to one amidic nitrogen atom is inevitable for preventing third phase formation and the alkyl group at the other amidic nitrogen can be varied from butyl to decyl group for obtaining efficient extraction of trivalent actinides from high-level nuclear waste. (orig.)

  18. Estimating 13.8-GHz Path-Integrated Attenuation from 10.7-GHz Brightness Temperatures for the TRMM Combined PR-TMI Precipitation Algorithm.

    Science.gov (United States)

    Smith, Eric A.; Turk, F. Joseph; Farrar, Michael R.; Mugnai, Alberto; Xiang, Xuwu

    1997-04-01

    This study presents research in support of the design and implementation of a combined radar-radiometer algorithm to be used for precipitation retrieval during the Tropical Rainfall Measuring Mission (TRMM). The combined algorithm approach is expected to overcome various difficulties that arise with a radar-only approach, particularly related to estimates of path-integrated attenuation (PIA) along the TRMM radar beam. A technique is described for estimating PIA at the 13.8-GHz frequency of the TRMM precipitation radar (PR) from 10.7-GHz brightness temperature TB measurements obtained from the TRMM microwave imager. Because the PR measures at an attenuating frequency, an independent estimate of PIA is used to constrain the solution to the radar equation, which incorporates effects of attenuation propagation along a radar beam. Through the use of variational or probabilistic techniques, the independent PIA calculations provide a means to adjust for errors that accumulate in estimates of range-dependent rain rates at progressively increasing range positions from radar reflectivity vectors. The accepted radar approach for obtaining PIA from ocean-viewing radar reflectivity measurements is called the surface reference technique, a scheme based on the difference in ocean surface cross sections between cloud-free and raining radar pixels. This technique has encountered problems, which are discussed and analyzed with the aid of coordinated aircraft radar (Airborne Rain Mapping Radar) and radiometer (Advanced Microwave Precipitation Radiometer) measurements obtained during the west Pacific Tropical Ocean Global Atmosphere Coupled Ocean-Atmosphere Response Experiment in 1993. The derived relationship expressing 13.8-GHz PIAs as a function of 10.7-GHz TB's is based on statistical fitting of many thousands of radiative transfer (RTE) calculations in which the relevant physical and radiative parameters affecting transmission, absorption, and scattering in a raining column and

  19. Combining eddy-covariance measurements and Penman-Monteith type models to estimate evapotranspiration of flooded and aerobic rice

    Science.gov (United States)

    Facchi, Arianna; Masseroni, Daniele; Gharsallah, Olfa; Gandolfi, Claudio

    2014-05-01

    and the size of the footprint area at each monitoring time step (30-min). Two sets of half-hourly ET values, each one concerning one of the two treatments, were therefore obtained, each one comprising about 10-15% of the daytime time steps over the whole agricultural season. To confirm the reliability of the measured ET fluxes, the energy balance closure was computed for the two fields and resulted in an imbalance lower than 10% for both the irrigation treatments. The two eddy covariance data-sets were then used to calibrate three Penman-Monteith type models: one for the estimation of the rice crop transpiration (T), the second for the soil evaporation (ES), and the third for the evaporation from the water covering the soil in the case of flooded rice fields (EH20). Models were implemented using the available agro-meteorological data detected over the rice canopies and the periodically measured values of crop parameters (leaf area index, crop height). Finally, the calibrated models were used to compute the complete hourly ET data series for the three irrigation regimes.

  20. Wideband high-resolution direction of arrival estimation method based on the pressure-velocity combined processing using the acoustic vector sensor array

    Institute of Scientific and Technical Information of China (English)

    BAI Xingyu; YANG Desen; ZHAO Chunhui

    2007-01-01

    In order to solve the problem of DOA (Direction of Arrival) estimation of underwater distant wideband targets, a novel coherent signal-subspace method based on the cross spectral matrix of pressure and particle velocity using the Acoustic Vector Sensor Array (AVSA)is proposed in this paper. The proposed method is different from existing AVSA based DOA estimation methods in using particle velocity information of Acoustic Vector Sensor (AVS) as an independent array element. It is entirely based on the combined information processing of pressure and particle velocity, namely, the P-V cross spectrum, has better DOA estimation performance than existing methods in isotropic noise field. By theoretical analysis, both focusing principle and eigendecomposition theory based on the P-V cross spectral matrix are given.At the same time, the corresponding criteria for source number detection is also presented.Computer simulations with data from lake trials demonstrate that the proposed method is effective and obviously outperforms existing methods in resolution and accuracy in the case of low Signal-to-Noise Ratio (SNR).

  1. Combined Estimation of Hydrogeologic Conceptual Model, Parameter, and Scenario Uncertainty with Application to Uranium Transport at the Hanford Site 300 Area

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Philip D.; Ye, Ming; Rockhold, Mark L.; Neuman, Shlomo P.; Cantrell, Kirk J.

    2007-07-30

    This report to the Nuclear Regulatory Commission (NRC) describes the development and application of a methodology to systematically and quantitatively assess predictive uncertainty in groundwater flow and transport modeling that considers the combined impact of hydrogeologic uncertainties associated with the conceptual-mathematical basis of a model, model parameters, and the scenario to which the model is applied. The methodology is based on a n extension of a Maximum Likelihood implementation of Bayesian Model Averaging. Model uncertainty is represented by postulating a discrete set of alternative conceptual models for a site with associated prior model probabilities that reflect a belief about the relative plausibility of each model based on its apparent consistency with available knowledge and data. Posterior model probabilities are computed and parameter uncertainty is estimated by calibrating each model to observed system behavior; prior parameter estimates are optionally included. Scenario uncertainty is represented as a discrete set of alternative future conditions affecting boundary conditions, source/sink terms, or other aspects of the models, with associated prior scenario probabilities. A joint assessment of uncertainty results from combining model predictions computed under each scenario using as weight the posterior model and prior scenario probabilities. The uncertainty methodology was applied to modeling of groundwater flow and uranium transport at the Hanford Site 300 Area. Eight alternative models representing uncertainty in the hydrogeologic and geochemical properties as well as the temporal variability were considered. Two scenarios represent alternative future behavior of the Columbia River adjacent to the site were considered. The scenario alternatives were implemented in the models through the boundary conditions. Results demonstrate the feasibility of applying a comprehensive uncertainty assessment to large-scale, detailed groundwater flow

  2. Estimation of ability and item parameters in mathematics testing by using the combination of 3PLM/ GRM and MCM/ GPCM scoring model

    Directory of Open Access Journals (Sweden)

    Abadyo Abadyo

    2015-06-01

    Full Text Available The main purpose of the study was to investigate the superiority of scoring by utilizing the combination of MCM/GPCM model in comparison to 3PLM/GRM model within a mixed-item format of Mathematics tests. To achieve the purpose, the impact of two scoring models was investigated based on the test length, the sample size, and the M-C item proportion within the mixed-item format test and the investigation was conducted on the aspects of: (1 estimation of ability and item parameters, (2 optimalization of TIF, (3 standard error rates, and (4 model fitness on the data. The investigation made use of simulated data that was generated based on fixed effects factorial design 2 x 3 x 3 x 3 and 5 replications resulting in 270 data sets. The data were analyzed by means of fixed effect MANOVA on Root Mean Square Error (RMSE of the ability and RMSE and Root Mean Square Deviation (RNSD of the itemparameters in order to identify the significant main effects at level of a = .05; on the other hand, the interaction effects were incorporated into the error term for statistical testing. The -2LL statistics were also used in order to evaluate the moel fitness on the data set. The results of the study show that the combination of MCM/GPCM model provide higher accurate estimation than that of 3PLM/GRM model. In addition, the test information given by the combination of MCM/GPCM model is three times hhigher than that of 3PLM/GRM model although the test information cannot offer a solid conclusion in relation to the sample size and the M-C item proportion on each test length which provides the optimal score of thest information. Finally, the differences of fit statistics between the two models of scoring determine the position of MCM/GPCM model rather than that of 3PLM/GRM model.

  3. Functionalized ionic liquids: new agents for the extraction of actinides/lanthanides

    Energy Technology Data Exchange (ETDEWEB)

    Ouadi, A.; Hesemann, P.; Billard, I.; Gaillard, C.; Gadenne, B.; Moreau, Joel J.E; Moutiers, G.; Mariet, C.; Labet, A

    2004-07-01

    The potentialities of hydrophobic ionic liquids BumimPF{sub 6} and BumimTf{sub 2}N for their use in the nuclear fuel cycle were investigated, in particular for the liquid liquid extraction. We demonstrate that the use of RTILs in replacement of the organic diluents for actinides partitioning is promising. In our contribution, we present the synthesis of several task-specific ionic liquids. Our results show that grafting metal complexing groups increases the affinity of metals to the IL phase and gives rise to suitable media for the liquid-liquid extraction of actinides. (authors)

  4. Equilibrium distribution of actinides including Cm between molten LiCl-KCl eutectic and liquid cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, T.; Kinoshita, K.; Inoue, T. [Central Research Inst. of Electric Power Industry, Tokyo (Japan); Ougier, M.; Malmbeck, R.; Glatz, J.P. [Joint Research Centre, Karlsruhe (Germany). Inst. for Transuranium Elements

    2008-07-01

    Equilibrium distribution of actinides both in molten LiCl-KCl eutectic and liquid cadmium were measured from the concentration data obtained in electrorefining tests and reductive extraction tests. Separation factors for U, Np, Am, Cm against Pu were derived in the practical temperature range of 700 K to 783 K. The derived separation factors are consistent with the reported values measured at 773 K and 723 K. The temperature dependence for Cm is different compared to the other actinides (U, Np and Am). This behavior remains unclear and additional experimental measurements of distribution coefficient of Cm are required before ruling on the real behavior. (orig.)

  5. Oxyhydroxy Silicate Colloids: A New Type of Waterborne Actinide(IV) Colloids

    OpenAIRE

    Zänker, Harald; Weiss, Stephan; Hennig, Christoph; Brendler, Vinzenz; Ikeda‐Ohno, Atsushi

    2016-01-01

    Abstract At the near‐neutral and reducing aquatic conditions expected in undisturbed ore deposits or in closed nuclear waste repositories, the actinides Th, U, Np, and Pu are primarily tetravalent. These tetravalent actinides (AnIV) are sparingly soluble in aquatic systems and, hence, are often assumed to be immobile. However, AnIV could become mobile if they occur as colloids. This review focuses on a new type of AnIV colloids, oxyhydroxy silicate colloids. We herein discuss the chemical cha...

  6. Accurate labeling of the light-actinide O4,5 ionization edges

    Energy Technology Data Exchange (ETDEWEB)

    Moore, K; der Laan, G v

    2006-08-23

    In this short article the accurate labeling of the O4,5 edges of the light actinides is addressed. The O4 and O5 edges are both contained in what is termed the ''giant resonance'' and the smaller ''pre-peak'' that is observed is a consequence of first-order perturbation by the 5d spin-orbit interaction. Thus, the small prepeak in the actinide 5d {yields} 5f transition should not be labeled the O5 peak, but rather the {Delta}S=1 peak.

  7. Microcalorimeter Q-spectroscopy for rapid isotopic analysis of trace actinide samples

    Energy Technology Data Exchange (ETDEWEB)

    Croce, M.P., E-mail: mpcroce@lanl.gov [Los Alamos National Laboratory, Los Alamos, NM (United States); Bond, E.M.; Hoover, A.S.; Kunde, G.J.; Mocko, V.; Rabin, M.W.; Weisse-Bernstein, N.R.; Wolfsberg, L.E. [Los Alamos National Laboratory, Los Alamos, NM (United States); Bennett, D.A.; Hays-Wehle, J.; Schmidt, D.R.; Ullom, J.N. [National Institute of Standards and Technology, Boulder, CO (United States)

    2015-06-01

    We are developing superconducting transition-edge sensor (TES) microcalorimeters that are optimized for rapid isotopic analysis of trace actinide samples by Q-spectroscopy. By designing mechanically robust TESs and simplified detector assembly methods, we have developed a detector for Q-spectroscopy of actinides that can be assembled in minutes. We have characterized the effects of each simplification and present the results. Finally, we show results of isotopic analysis of plutonium samples with Q-spectroscopy detectors and compare the results to mass spectrometry.

  8. A comparison of new reagents and processes for hydrometallurgical processing of actinides

    Energy Technology Data Exchange (ETDEWEB)

    Nash, K.L. [Argonne National Lab., IL (United States). Chemistry Div

    2001-07-01

    The future viability of nuclear power as an electricity generation technology depends greatly on addressing all aspects of radioactive waste disposal. A closed fuel cycle with recycle and burnup of actinides is one important option for solving long-term waste sequestration issues. The 50 years of accumulated experience in application of solvent extraction to the processing of spent nuclear fuels uniquely qualifies this technology for actinide partitioning. However, employment of new reagents and development of new processes must be reconciled with century 21 expectations for environment protection. The interrelationship between the separations potential and waste disposal aspects of new reagents and processes are discussed in this report. (author)

  9. Angular distribution in the neutron-induced fission of actinides

    Directory of Open Access Journals (Sweden)

    Leong L.S.

    2013-12-01

    Full Text Available Above 1 MeV of incident neutron energy the fission fragment angular distribution (FFAD has generally a strong anisotropic behavior due to the combination of the incident orbital momentum and the intrinsic spin of the fissioning nucleus. This effect has to be taken into account for the efficiency estimation of devices used for fission cross section measurements. In addition it bears information on the spin deposition mechanism and on the structure of transitional states. We designed and constructed a detection device, based on Parallel Plate Avalanche Counters (PPAC, for measuring the fission fragment angular distributions of several isotopes, in particular 232Th. The measurement has been performed at n_TOF at CERN taking advantage of the very broad energy spectrum of the neutron beam. Fission events were recognized by back to back detection in coincidence in two position-sensitive detectors surrounding the targets. The detection efficiency, depending mostly on the stopping of fission fragments in backings and electrodes, has been computed with a Geant4 simulation and validated by the comparison to the measured case of 235U below 3 keV where the emission is isotropic. In the case of 232Th, the result is in good agreement with previous data below 10 MeV, with a good reproduction of the structures associated to vibrational states and the opening of second chance fission. In the 14 MeV region our data are much more accurate than previous ones which are broadly scattered.

  10. Analysis of methane potentials of steam-exploded wheat straw and estimation of energy yields of combined ethanol and methane production.

    Science.gov (United States)

    Bauer, Alexander; Bösch, Peter; Friedl, Anton; Amon, Thomas

    2009-06-01

    Agrarian biomass as a renewable energy source can contribute to a considerable CO(2) reduction. The overriding goal of the European Union is to cut energy consumption related greenhouse gas emission in the EU by 20% until the year 2020. This publication aims at optimising the methane production from steam-exploded wheat straw and presents a theoretical estimation of the ethanol and methane potential of straw. For this purpose, wheat straw was pretreated by steam explosion using different time/temperature combinations. Specific methane yields were analyzed according to VDI 4630. Pretreatment of wheat straw by steam explosion significantly increased the methane yield from anaerobic digestion by up to 20% or a maximum of 331 l(N)kg(-1) VS compared to untreated wheat straw. Furthermore, the residual anaerobic digestion potential of methane after ethanol fermentation was determined by enzymatic hydrolysis of pretreated wheat straw using cellulase. Based on the resulting glucose concentration the ethanol yield and the residual sugar available for methane production were calculated. The theoretical maximum ethanol yield of wheat straw was estimated to be 0.249 kg kg(-1) dry matter. The achievable maximum ethanol yield per kg wheat straw dry matter pretreated by steam explosion and enzymatic hydrolysis was estimated to be 0.200 kg under pretreatment conditions of 200 degrees C and 10 min corresponding to 80% of the theoretical maximum. The residual methane yield from straw stillage was estimated to be 183 l(N)kg(-1) wheat straw dry matter. Based on the presented experimental data, a concept is proposed that processes wheat straw for ethanol and methane production. The concept of an energy supply system that provides more than two forms of energy is met by (1) upgrading obtained ethanol to fuel-grade quality and providing methane to CHP plants for the production of (2) electric energy and (3) utility steam that in turn can be used to operate distillation columns in the

  11. Estimating biomass of mixed and uneven-aged forests using spectral data and a hybrid model combining regression trees and linear models

    Directory of Open Access Journals (Sweden)

    López-Serrano PM

    2016-04-01

    Full Text Available The Sierra Madre Occidental mountain range (Durango, Mexico is of great ecological interest because of the high degree of environmental heterogeneity in the area. The objective of the present study was to estimate the biomass of mixed and uneven-aged forests in the Sierra Madre Occidental by using Landsat-5 TM spectral data and forest inventory data. We used the ATCOR3® atmospheric and topographic correction module to convert remotely sensed imagery digital signals to surface reflectance values. The usual approach of modeling stand variables by using multiple linear regression was compared with a hybrid model developed in two steps: in the first step a regression tree was used to obtain an initial classification of homogeneous biomass groups, and multiple linear regression models were then fitted to each node of the pruned regression tree. Cross-validation of the hybrid model explained 72.96% of the observed stand biomass variation, with a reduction in the RMSE of 25.47% with respect to the estimates yielded by the linear model fitted to the complete database. The most important variables for the binary classification process in the regression tree were the albedo, the corrected readings of the short-wave infrared band of the satellite (2.08-2.35 µm and the topographic moisture index. We used the model output to construct a map for estimating biomass in the study area, which yielded values of between 51 and 235 Mg ha-1. The use of regression trees in combination with stepwise regression of corrected satellite imagery proved a reliable method for estimating forest biomass.

  12. Surrogate Measurements of Actinide (n,2n) Cross Sections with NeutronSTARS

    Energy Technology Data Exchange (ETDEWEB)

    Casperson, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Burke, J. T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Hughes, R. O. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Akindele, O. A. [Univ. of California, Berkeley, CA (United States); Koglin, J. D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Wang, B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Tamashiro, A. [Oregon State Univ., Corvallis, OR (United States)

    2016-09-27

    Directly measuring (n,2n) cross sections on short-lived actinides presents a number of experimental challenges. The surrogate reaction technique is an experimental method for measuring cross sections on short-­lived isotopes, and it provides a unique solution for measuring (n,2n) cross sections. This technique involves measuring a charged-­particle reaction cross section, where the reaction populates the same compound nucleus as the reaction of interest. To perform these surrogate (n,2n) cross section measurements, a silicon telescope array has been placed along a beam line at the Texas A&M University Cyclotron Institute, which is surrounded by a large tank of gadolinium-doped liquid scintillator, which acts as a neutron detector. The combination of the charge-particle and neutron-detector arrays is referred to as NeutronSTARS. In the analysis procedure for calculating the (n,2n) cross section, the neutron detection efficiency and time structure plays an important role. Due to the lack of availability of isotropic, mono-energetic neutron sources, modeling is an important component in establishing this efficiency and time structure. This report describes the NeutronSTARS array, which was designed and commissioned during this project. It also describes the surrogate reaction technique, specifically referencing a 235U(n,2n) commissioning measurement that was fielded during the past year. Advanced multiplicity analysis techniques have been developed for this work, which should allow for efficient analysis of 241Pu(n,2n) and 239Pu(n,2n) cross section measurements

  13. Actinide Sorption in a Brine/Dolomite Rock System: Evaluating the Degree of Conservatism in Kd Ranges used in Performance Assessment Modeling for the WIPP Nuclear Waste Repository

    Science.gov (United States)

    Dittrich, T. M.; Reed, D. T.

    2015-12-01

    The Waste Isolation Pilot Plant (WIPP) near Carlsbad, NM is the only operating nuclear waste repository in the US and has been accepting transuranic (TRU) waste since 1999. The WIPP is located in a salt deposit approximately 650 m below the surface and performance assessment (PA) modeling for a 10,000 year period is required to recertify the operating license with the US EPA every five years. The main pathway of concern for environmental release of radioactivity is a human intrusion caused by drilling into a pressurized brine reservoir below the repository. This could result in the flooding of the repository and subsequent transport in the high transmissivity layer (dolomite-rich Culebra formation) above the waste disposal rooms. We evaluate the degree of conservatism in the estimated sorption partition coefficients (Kds) ranges used in the PA based on an approach developed with granite rock and actinides (Dittrich and Reimus, 2015; Dittrich et al., 2015). Sorption onto the waste storage material (Fe drums) may also play a role in mobile actinide concentrations. We will present (1) a conceptual overview of how Kds are used in the PA model, (2) technical background of the evolution of the ranges and (3) results from batch and column experiments and model predictions for Kds with WIPP dolomite and clays, brine with various actinides, and ligands (e.g., acetate, citrate, EDTA) that could promote transport. The current Kd ranges used in performance models are based on oxidation state and are 5-400, 0.5-10,000, 0.03-200, and 0.03-20 mL g-1 for elements with oxidation states of III, IV, V, and VI, respectively. Based on redox conditions predicted in the brines, possible actinide species include Pu(III), Pu(IV), U(IV), U(VI), Np(IV), Np(V), Am(III), and Th(IV). We will also discuss the challenges of upscaling from lab experiments to field scale predictions, the role of colloids, and the effect of engineered barrier materials (e.g., MgO) on transport conditions. Dittrich

  14. This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CPIS05), Combination of Irrigation Sources (CIS) on agricultural land by county (nri_is05)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set represents the estimated percentage of the 1-km grid cell that is covered by or subject to the agricultural conservation practice (CPIS05), Combination...

  15. Chemical and ceramic methods toward safe storage of actinides using monazite. 1998 annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Morgan, P.E.D. [Rockwell International Corp., Thousand, Oaks, CA (US); Boatner, L.A. [Oak Ridge National Lab., TN (US)

    1998-06-01

    'The use of ceramic monazite, (La,Ce)PO{sub 4}, for sequestering actinides, especially plutonium, and some other radioactive waste elements (rare earths e.g.) and thus isolating them from the environment has been championed by Lynn Boatner of ORNL. It may be used alone or, as it is compatible with many other minerals in nature, can be used in composite combinations. Natural monazite, which almost invariably contains Th and U, is often formed in hydrothermal pegmatites and is extremely water resistant--examples are known where the mineral has been washed out of rocks (becoming a placer mineral as on the beach sands of India, Australia, Brazil etc.) then reincorporated into new rocks with new crystal overgrowths and then washed out again--being 2.5--3 billion years old. During this demanding water treatment it has retained Th and U. Where very low levels of water attack have been seen (in more siliceous waters), the Th is tied up as new ThSiO{sub 4} and remains immobile. Lest it be thought that rare-earths are rare or expensive, this is not so. In fact, the less common lanthanides such as gadolinium, samarium, europium, and terbium, are necessarily extracted and much used by, e.g., the electronics industry, leaving La and Ce as not-sufficiently-used by-products. The recent development of large scale use of Nd in Nd-B-Fe magnets has further exaggerated this. Large deposits of the parent mineral bastnaesite are present in the USA and in China. (Mineral monazite itself is not preferred due to its thorium content.) In the last 5 years it has become apparent show that monazite (more specifically La-monazite) is an unrecognized/becoming-interesting ceramic material. PuPO4 itself has the monazite structure; the PO{sub 4} 3-unit strongly stabilizes actinides and rare earths in their trivalent state. Monazite melts without decomposition (in a closed system) at 2,074 C and, being compatible with common ceramic oxides such as alumina, mullite, zirconia and YAG, is useful

  16. Assessment of SFR fuel pin performance codes under advanced fuel for minor actinide transmutation

    Energy Technology Data Exchange (ETDEWEB)

    Bouineau, V.; Lainet, M.; Chauvin, N.; Pelletier, M. [French Alternative Energies and Atomic Energy Commission - CEA, CEA Cadarache, DEN/DEC/SESC, 13108 Saint Paul lez Durance (France); Di Marcello, V.; Van Uffelen, P.; Walker, C. [European Commission, Joint Research Centre, Institute for Transuranium Elements, Hermann-von-Helmholtz-Platz 1, D- 76344 Eggenstein-Leopoldshafen (Germany)

    2013-07-01

    Americium is a strong contributor to the long term radiotoxicity of high activity nuclear waste. Transmutation by irradiation in nuclear reactors of long-lived nuclides like {sup 241}Am is, therefore, an option for the reduction of radiotoxicity and residual power packages as well as the repository area. In the SUPERFACT Experiment four different oxide fuels containing high and low concentrations of {sup 237}Np and {sup 241}Am, representing the homogeneous and heterogeneous in-pile recycling concepts, were irradiated in the PHENIX reactor. The behavior of advanced fuel materials with minor actinide needs to be fully characterized, understood and modeled in order to optimize the design of this kind of fuel elements and to evaluate its performances. This paper assesses the current predictability of fuel performance codes TRANSURANUS and GERMINAL V2 on the basis of post irradiation examinations of the SUPERFACT experiment for pins with low minor actinide content. Their predictions have been compared to measured data in terms of geometrical changes of fuel and cladding, fission gases behavior and actinide and fission product distributions. The results are in good agreement with the experimental results, although improvements are also pointed out for further studies, especially if larger content of minor actinide will be taken into account in the codes. (authors)

  17. Method of loading organic materials with group III plus lanthanide and actinide elements

    Science.gov (United States)

    Bell, Zane W.; Huei-Ho, Chuen; Brown, Gilbert M.; Hurlbut, Charles

    2003-04-08

    Disclosed is a composition of matter comprising a tributyl phosphate complex of a group 3, lanthanide, actinide, or group 13 salt in an organic carrier and a method of making the complex. These materials are suitable for use in solid or liquid organic scintillators, as in x-ray absorption standards, x-ray fluorescence standards, and neutron detector calibration standards.

  18. Sorption Speciation of Lanthanides/Actinides on Minerals by TRLFS, EXAFS and DFT Studies: A Review

    Directory of Open Access Journals (Sweden)

    Xiaoli Tan

    2010-11-01

    Full Text Available Lanthanides/actinides sorption speciation on minerals and oxides by means of time resolved laser fluorescence spectroscopy (TRLFS, extended X-ray absorption fine structure spectroscopy (EXAFS and density functional theory (DFT is reviewed in the field of nuclear disposal safety research. The theoretical aspects of the methods are concisely presented. Examples of recent research results of lanthanide/actinide speciation and local atomic structures using TRLFS, EXAFS and DFT are discussed. The interaction of lanthanides/actinides with oxides and minerals as well as their uptake are also of common interest in radionuclide chemistry. Especially the sorption and inclusion of radionuclides into several minerals lead to an improvement in knowledge of minor components in solids. In the solid-liquid interface, the speciation and local atomic structures of Eu(III, Cm(III, U(VI, and Np(IV/VI in several natural and synthetic minerals and oxides are also reviewed and discussed. The review is important to understand the physicochemical behavior of lanthanides/actinides at a molecular level in the natural environment.

  19. A calculation for radial expectation values of helium like actinide ions (Z=89-93)

    Science.gov (United States)

    Ürer, G.; Arslan, M.; Balkaya, E.; Keçeli, A.

    2016-03-01

    Radial expectation values, , for helium like actinides (ZAc=89, ZTh=90, ZPa=91, ZU=92, and ZNp=93) are reported using the Multiconfiguration Hartree-Fock (MCHF) within the framework Breit-Pauli corrections. Atomic data as energy levels, wavelengths, weighted oscillator strengths, and transition probabilities for allowed and forbidden transitions need these calculations. The obtained results are compared available works.

  20. Rapid radiochemical method for determination of actinides in emergency concrete and brick samples.

    Science.gov (United States)

    Maxwell, Sherrod L; Culligan, Brian K; Kelsey-Wall, Angel; Shaw, Patrick J

    2011-09-02

    A new rapid method for the determination of actinides in emergency concrete and brick samples has been developed at the Savannah River Site Environmental Lab (Aiken, SC, USA) that can be used in emergency response situations or for routine analysis. If a radiological dispersive device (RDD), Improvised Nuclear Device (IND) or nuclear accident occurs, there will be a urgent need for rapid analyses of many different environmental matrices, including building materials such as concrete and brick, to support dose mitigation and environmental clean-up. The new method for actinides in concrete and brick method utilizes a rapid sodium hydroxide fusion method, a lanthanum fluoride matrix removal step, and a column separation process with stacked TEVA, TRU and DGA Resin cartridges. Alpha emitters are prepared using rare earth microprecipitation for counting by alpha spectrometry. The method showed high chemical recoveries and effective removal of interferences. The determination of actinides in concrete and brick sample analysis can be performed in less than 8h with excellent quality for emergency samples. The rapid fusion technique is a rugged sample digestion method that ensures that any refractory actinide particles are effectively digested.

  1. Mechanical behaviour and diffusion of gas during neutron irradiation of actinides in ceramic inert matrices

    NARCIS (Netherlands)

    Neeft, E.A.C.

    2004-01-01

    Fission of actinides from nuclear waste in inert matrices (materials without uranium) can reduce the period in time that nuclear waste is more radiotoxic than uranium ore that is the rock from which ordinary reactor fuel is made. A pioneering study is performed with the inert matrices: MgO, MgAl2O4,

  2. New limit of $^{244}$Pu on Earth points to rarity of actinide nucleosynthesis

    CERN Document Server

    Wallner, A; Feige, J; Feldstein, C; Knie, K; Korschinek, G; Kutschera, W; Ofan, A; Paul, M; Quinto, F; Rugel, G; Steier, P

    2015-01-01

    Half of the heavy elements including all actinides are produced in r-process nucleosynthesis whose sites and history still remain a mystery. If continuously produced, the Interstellar Medium (ISM) is expected to build up a quasi-steady state of abundances of short-lived nuclides (with half-lives <100My), including actinides produced in r-process nucleosynthesis. Their existence in today's ISM would serve as a radioactive clock and would establish that their production was recent. In particular $^{244}$Pu, a radioactive actinide nuclide (81 My half-life), can place strong constraints on recent r-process frequency and production yield. Here we report on the detection of live interstellar $^{244}$Pu, archived in Earth's deep-sea floor during the last 25 My, at abundances lower by about two orders of magnitude than expected from continuous production in the Galaxy. This large discrepancy may signal a rarity of actinide r-process nucleosynthesis sites, compatible with neutron-star mergers or with a small subset...

  3. A Screened Hybrid DFT Study of Actinide Oxides, Nitrides, and Carbides

    Energy Technology Data Exchange (ETDEWEB)

    Wen, Xiaodong; Martin, Richard L.; Scuseria, Gustavo E.; Rudin, Sven P.; Batista, Enrique R.

    2013-06-27

    A systematic study of the structural, electronic, and magnetic properties of actinide oxides, nitrides, and carbides (AnX1–2 with X = C, N, O) is performed using the Heyd–Scuseria–Ernzerhof (HSE) hybrid functional. Our computed results show that the screened hybrid HSE functional gives a good description of the electronic and structural properties of actinide dioxides (strongly correlated insulators) when compared with available experimental data. However, there are still some problems reproducing the electronic properties of actinide nitrides and carbides (strongly correlated metals). In addition, in order to compare with the results by HSE, the structures, electronic, and magnetic properties of these actinide compounds are also investigated in the PBE and PBE+U approximation. Interestingly, the density of states of UN obtained with PBE compares well with the experimental photoemission spectra, in contrast to the hybrid approximation. This is presumably related to the need of additional screening in the Hartree–Fock exchange term of the metallic phases.

  4. Possibility of fusion power reactor to transmute minor actinides of spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Serikov, A. E-mail: serikov@nfi.kiae.ru; Shatalov, G.; Sheludjakov, S.; Shpansky, Yu.; Vasiliev, N

    2002-12-01

    A possibility to use fusion power reactor (FPR) is considered for burning long-life elements of spent nuclear fuel in parallel with energy production. In this study a principal design of FPR blanket was examined for transmutation of long-life minor actinides (Np, Am, Cm). A production of minor actinide isotopes is equal to 20-30 kg/1 GW{sub (e)} year for now operating fission reactors, and their amounts will rise with the expected growth of fission reactor power. These isotopes have long-life time and can be dangerous in big amounts in future. Plutonium isotopes are not included in an assumption that they will be used in fission reactors. The major goals of the study were to determine FPR blanket composition corresponding to fast transmutation rate of actinides and tritium self-supply simultaneously. Tritium breeding ratio (TBR) was obtained at level 1.11 for water cooling and reached up 1.56 in variant with helium-cooled assemblies with Np nitride. It was concluded that rows with actinides from processed waste fuel should be arranged near the plasma first wall. Advantages of helium above water cooling are observed in the twice-increased loading of waste fissionable materials and essential increase of achievable TBR. Burnout of Np, Am, Cm would remain at a level {approx}40-50% after 4 full power years.

  5. Comparison of experimental and theoretical binding and transition energies in the actinide region. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Krause, M.O.; Nestor, C.W. Jr.

    1977-01-01

    The status of experimental and theoretical binding and transition energy determinations is reviewed extending the comparison between experiment and theory to encompass representative series of data for all actinides. This comprehensive comparison reveals areas where improvements may be indicated, showing whether theoretical treatments including all known contributions to the lowest order would be adequate in all instances. 45 references. (JFP)

  6. The use of fractal dimension analysis in estimation of blood vessels shape in transplantable mammary adenocarcinoma in Wistar rats after photodynamic therapy combined with cysteine protease inhibitors.

    Science.gov (United States)

    Jurczyszyn, Kamil; Osiecka, Beata J; Ziółkowski, Piotr

    2012-01-01

    Fractal dimension analysis (FDA) is modern mathematical method widely used to describing of complex and chaotic shapes when classic methods fail. The main aim of this study was evaluating the influence of photodynamic therapy (PDT) with cystein proteases inhibitors (CPI) on the number and morphology of blood vessels inside tumor and on increase of effectiveness of combined therapy in contrast to PDT and CPI used separately. Animals were divided into four groups: control, treated using only PDT, treated using only CPI and treated using combined therapy, PDT and CPI. Results showed that time of animal survival and depth of necrosis inside tumor were significantly higher in CPI+PDT group in contrast to other groups. The higher value of fractal dimension (FD) was observed in control group, while the lowest value was found in the group which was treated by cystein protease inhibitors. The differences between FD were observed in CPI group and PDT+CPI group in comparison to control group. Our results revealed that fractal dimension analysis is a very useful tool in estimating differences between irregular shapes like blood vessels in PDT treated tumors. Thus, the implementation of FDA algorithms could be useful method in evaluating the efficacy of PDT.

  7. Development and Validation of a Stability Indicating Liquid Chromatographic Method for Simultaneous Estimation of Arterolane Maleate and Piperaquine Phosphate in Combined Dosage Form

    Directory of Open Access Journals (Sweden)

    G. Srinivas Reddy

    2014-01-01

    Full Text Available A novel stability indicating isocratic, reversed phase-liquid-chromatographic method has been developed for the simultaneous quantitative determination of Arterolane maleate And Piperaquine phosphate in combined-dosage form. A thermo hypersil BDS C18 (250*4.6*5µ column with mobile phase containing water pH 2.8 adjusted with ortho phosphoric acid: methanol in the ratio of (60: 40, v/v was used. The flow rate was 1.0 mL/min, column temperature was 30°C and effluents were monitored at 241 nm. The retention times of Arterolane Maleate and Piperaquine Phosphate were 1.864min and 3.047min, respectively. Correlation co-efficient for Arterolane Maleate and Piperaquine Phosphate was found to be 0.99 and 0.99, respectively. The proposed method was validated with respect to linearity, accuracy, precision, specificity, and robustness. Recovery of Arterolane Maleate and Piperaquine Phosphate in formulations was found to be in the range of 97-103% and 97-103% respectively confirms the non-interferences of the excipients in the formulation. Arterolane Maleate and Piperaquine Phosphate were exposed to stress conditions like acidic hydrolysis, basic hydrolysis, oxidative, photolytic, humidity and thermal conditions. Due to its simplicity, rapidness and high precision, the method was successfully applied to the estimation of Arterolane Maleate and Piperaquine Phosphate in combined dosage form.

  8. The Use of Fractal Dimension Analysis in Estimation of Blood Vessels Shape in Transplantable Mammary Adenocarcinoma in Wistar Rats after Photodynamic Therapy Combined with Cysteine Protease Inhibitors

    Directory of Open Access Journals (Sweden)

    Kamil Jurczyszyn

    2012-01-01

    Full Text Available Fractal dimension analysis (FDA is modern mathematical method widely used to describing of complex and chaotic shapes when classic methods fail. The main aim of this study was evaluating the influence of photodynamic therapy (PDT with cystein proteases inhibitors (CPI on the number and morphology of blood vessels inside tumor and on increase of effectiveness of combined therapy in contrast to PDT and CPI used separately. Animals were divided into four groups: control, treated using only PDT, treated using only CPI and treated using combined therapy, PDT and CPI. Results showed that time of animal survival and depth of necrosis inside tumor were significantly higher in CPI+PDT group in contrast to other groups. The higher value of fractal dimension (FD was observed in control group, while the lowest value was found in the group which was treated by cystein protease inhibitors. The differences between FD were observed in CPI group and PDT+CPI group in comparison to control group. Our results revealed that fractal dimension analysis is a very useful tool in estimating differences between irregular shapes like blood vessels in PDT treated tumors. Thus, the implementation of FDA algorithms could be useful method in evaluating the efficacy of PDT.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  10. ENHANCED CHEMICAL CLEANING OF SRS WASTE TANKS TO IMPROVE ACTINIDE SOLUBILITY

    Energy Technology Data Exchange (ETDEWEB)

    Rudisill, T.; Thompson, M.

    2011-09-20

    Processes for the removal of residual sludge from SRS waste tanks have historically used solutions containing up to 0.9 M oxalic acid to dissolve the remaining material following sludge removal. The selection of this process was based on a comparison of a number of studies performed to evaluate the dissolution of residual sludge. In contrast, the dissolution of the actinide mass, which represents a very small fraction of the waste, has not been extensively studied. The Pu, Np, and Am in the sludge is reported to be present as hydrated and crystalline oxides. To identify aqueous solutions which have the potential to increase the solubility of the actinides, the alkaline and mildly acidic test solutions shown below were selected as candidates for use in a series of solubility experiments. The efficiency of the solutions in solubilizing the actinides was evaluated using a simulated sludge prepared by neutralizing a HNO{sub 3} solution containing Pu, Np, and Am. The hydroxide concentration was adjusted to a 1.2 M excess and the solids were allowed to age for several weeks prior to starting the experiments. The sludge was washed with 0.01 M NaOH to prepare the solids for use. Following the addition of an equal portion of the solids to each test solution, the concentrations of Pu, Np, and Am were measured as a function of time over a 792 h (33 day) period to provide a direct comparison of the efficiency of each solution in solubilizing the actinide elements. Although the composition of the sludge was limited to the hydrated actinide oxides (and did not contain other components of demonstrated importance), the results of the study provides guidance for the selection of solutions which should be evaluated in subsequent tests with a more realistic surrogate sludge and actual tank waste.

  11. Actinide ion extraction using room temperature ionic liquids: opportunities and challenges for nuclear fuel cycle applications.

    Science.gov (United States)

    Mohapatra, Prasanta Kumar

    2017-02-14

    Studies on the extraction of actinide ions from radioactive feeds have great relevance in nuclear fuel cycle activities, mainly in the back end processes focused on reprocessing and waste management. Room temperature ionic liquid (RTIL) based diluents are becoming increasingly popular due to factors such as more efficient extraction vis-à-vis molecular diluents, higher metal loading, higher radiation resistance, etc. The fascinating chemistry of the actinide ions in RTIL based solvent systems due to complex extraction mechanisms makes it a challenging area of research. By the suitable tuning of the cationic and anionic parts of the ionic liquids, their physical properties such as density, dielectric constant and viscosity can be changed which are considered key parameters in metal ion extraction. Aqueous solubility of the RTILs, which can lead to significant loss in the solvent inventory, can be avoided by appending the extractant moieties onto the ionic liquid. While the low vapour pressure and non-flammability of the ionic liquids make them appear as 'green' diluents, their aqueous solubility raises concerns of environmental hazards. The present article gives a summary of studies carried out on actinide ion extraction and presents perspectives of its applications in the nuclear fuel cycle. The article discusses various extractants used for actinide ion extraction and at many places, comparison is made vis-à-vis molecular diluents which includes the nature of the extracted species and the mechanism of extraction. Results of studies on rare earth elements are also included in view of their similarities with the trivalent minor actinides.

  12. Bioreduction amenability testing of actinide contaminated soils. The systems: Am{sup 241}-Pu{sup 238}, Am{sup 241}-Pu{sup 239/40}, U

    Energy Technology Data Exchange (ETDEWEB)

    Korich, D.G.; Sharp, J.E. [MBX Systems, Inc., Tucson, AZ (United States)

    1995-01-01

    Bioreductive processing of actinide contaminated soils can achieve extraction levels in excess of 97% for both plutonium and uranium contaminants. Reasonable reaction rates of 4 to 6 day resident times for Pu-Am have been demonstrated on 4 gram sample charges. Longer reaction times of 17 days required for uranium extraction can be improved by soil sample preconditioning and/or an increase in process reagent concentrations. The environmentally benign treatment process operates at pH 6--7, preserves the original soil matrix, and utilizes standard processing equipment. The process reagent component (inoculum SD-1 and biological growth medium PX100{trademark}) are available for utilization in an integrated system. Process techniques developed by MBX, involving graduated volume bioreactors have been proven to alleviate biological toxicity problems in treatment leachates. Bioreduction processing of actinide contaminated soils, preconditioning of soil charges, and recycling or vegetation of unacceptable tailings can be combined to provide an effective and environmentally attractive method of remediation. The soil test program was designed to determine the applicability of the MBX bioreductive technology to solubilize Pu and Am from RFP, Mound and LANL soils and uranium from Hanford and Fernald soils.

  13. Monazite-type ceramics for conditioning of minor actinides. Structural characterization and properties

    Energy Technology Data Exchange (ETDEWEB)

    Babelot, Carole

    2013-07-01

    The minor actinides (MA) neptunium, americium, and curium are mainly responsible for the long-term radiotoxicity of the High Active Waste (HAW) generated during the nuclear power operation. If these long-lived radionuclides are removed from the HAW by partitioning and converted by neutron fission (transmutation) into shorter-lived or stable elements, the remaining waste loses most of its long-term radiotoxicity. Thus, partitioning and transmutation (P and T) are considered as attractive options for reducing the burden on geological disposals. As an alternative, these separated MA can also be conditioned (P and C strategy) in specifically adapted ceramics to ensure their safe final disposal over long periods. At the moment, spent fuel elements are foreseen either for direct disposal in deep geological repositories or for reprocessing. The highly active liquid waste that is produced during reprocessing is conditioned industrially using a vitrification process before final disposal. Although the widely used borosilicate glasses meet most of the specifications needed, ceramic host matrices appear to be even more suitable in terms of resistance to corrosion. The development of new materials based on tailor-made highly specific ceramics with extremely stable behavior would make it possible to improve the final storage of long-lived high-level radiotoxic waste. In the framework of this PhD research project, monazite-type ceramics were chosen as promising host matrices for the conditioning of trivalent actinides. The focus on the monazite-type ceramics is justified by their properties such as high chemical durability. REPO{sub 4} ceramics are named monazite for RE = La - Gd (monoclinic symmetry) and xenotime for RE = Tb - Lu and Y (tetragonal symmetry). The objective of this study is to contribute to the understanding of the alteration behavior of such ceramics under the repository conditions. REPO{sub 4} (with RE = La, Eu) is prepared by hydrothermal synthesis at 200 C

  14. DWPF Flowsheet Studies with Simulants to Determine Modular Caustic Side Solvent Extraction Unit Solvent Partitioning and Verify Actinide Removal Process Incorporation Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Herman, C

    2006-04-21

    The Actinide Removal Process (ARP) facility and the Modular Caustic Side Solvent Extraction Unit (MCU) are scheduled to begin processing salt waste in fiscal year 2007. A portion of the streams generated in the salt processing facilities will be transferred to the Defense Waste Processing Facility (DWPF) to be incorporated in the glass matrix. Before the streams are introduced, a combination of impact analyses and research and development studies must be performed to quantify the impacts on DWPF processing. The Process Science & Engineering (PS&E) section of the Savannah River National Laboratory (SRNL) was requested via Technical Task Request (TTR) HLW/DWPF/TTR-2004-0031 to evaluate the impacts on DWPF processing. Simulant Chemical Process Cell (CPC) flowsheet studies have been performed using previous composition and projected volume estimates for the ARP sludge/monosodium titanate (MST) stream. Due to changes in the flammability control strategy for DWPF for salt processing, the incorporation strategy for ARP has changed and additional ARP flowsheet tests were necessary to validate the new processing strategy. The last round of ARP testing included the incorporation of the MCU stream and identified potential processing issues with the MCU solvent. The identified issues included the potential carry-over and accumulation of the MCU solvent components in the CPC condensers and in the recycle stream to the Tank Farm. Therefore, DWPF requested SRNL to perform additional MCU flowsheet studies to better quantify the organic distribution in the CPC vessels. The previous MCU testing used a Sludge Batch 4 (SB4) simulant since it was anticipated that both of these facilities would begin salt processing during SB4 processing. The same sludge simulant recipe was used in this round of ARP and MCU testing to minimize the number of changes between the two phases of testing so a better comparison could be made. ARP and MCU stream simulants were made for this phase of testing

  15. Estimation of small surface displacements in the Upper Rhine Graben area from a combined analysis of PS-InSAR, levelling and GNSS data

    Science.gov (United States)

    Fuhrmann, T.; Caro Cuenca, M.; Knöpfler, A.; van Leijen, F. J.; Mayer, M.; Westerhaus, M.; Hanssen, R. F.; Heck, B.

    2015-10-01

    The intra-plate deformation of the Upper Rhine Graben (URG) located in Central Europe is investigated using geodetic measurement techniques. We present a new approach to calculate a combined velocity field from InSAR, levelling and GNSS measurements. As the expected tectonic movements in the URG area are small (less than 1 mm a-1), the best possible solutions for linear velocity rates from single-technique analyses are estimated in a first step. Second, we combine the velocity rates obtained from InSAR (line of sight velocity rates in ascending and descending image geometries), levelling (vertical velocity rates) and GNSS (horizontal velocity rates) using least-squares adjustment (LSA). Focusing on the Northern URG area, we analyse SAR data on four different image stacks (ERS ascending, ERS descending, Envisat ascending, Envisat descending) using the Persistent Scatterer (PS) approach. The linear velocity rates in ascending and descending image geometries, respectively, are estimated in an LSA from joint time-series analysis of ERS and Envisat data. Vertical velocity rates from levelling are obtained from a consistent adjustment of more than 40 000 measured height differences using a kinematic displacement model. Horizontal velocity rates in east and north direction are calculated from a time-series analysis of daily coordinate estimates at 76 permanently operating GNSS sites in the URG region. As the locations, at which the measurement data of PS-InSAR, levelling and GNSS reside, do not coincide, spatial interpolation is needed during several steps of the rigorous processing. We use Ordinary Kriging to interpolate from a given set of data points to the locations of interest with a special focus on the modeling and propagation of errors. The final 3-D velocity field is calculated at a 200 m grid, which carries values only close to the location of PS points, resulting in a mean horizontal and vertical precision of 0.30 and 0.13 mm a-1, respectively. The vertical

  16. Usefulness of in vitro combination assays of mitochondrial dysfunction and apoptosis for the estimation of potential risk of idiosyncratic drug induced liver injury.

    Science.gov (United States)

    Goda, Keisuke; Takahashi, Tadakazu; Kobayashi, Akio; Shoda, Toshiyuki; Kuno, Hideyuki; Sugai, Shoichiro

    2016-01-01

    Drug-induced liver injury (DILI) is one of the serious and frequent drug-related adverse events. This adverse event is a main reason for regulatory action pertaining to drugs, including restrictions in clinical indications and withdrawal from clinical trials or the marketplace. Idiosyncratic DILI especially has become a major clinical concern because of its unpredictable nature, frequent hospitalization, need for liver transplantation and high mortality. The estimation of the potential for compounds to induce idiosyncratic DILI is very difficult in non-clinical studies because the precise mechanism of idiosyncratic DILI is still unknown. Recently, many in vitro assays which indicate a possibility of the prediction of the idiosyncratic DILI have been reported. Among these, some in vitro assays focus on the effects of compounds on mitochondrial function and the apoptotic effects of compounds on human hepatocytes. In this study, we measured oxygen consumption rate (OCR) and caspase-3/7 activity as an endpoint of mitochondrial dysfunction and apoptosis, respectively, with human hepatocytes after treatment with compounds causing idiosyncratic DILI (troglitazone, leflunomide, ranitidine and diclofenac). Troglitazone and leflunomide decreased the OCR but did not affect caspase-3/7 activity. Ranitidine increased caspase-3/7 activity but did not affect the OCR. Diclofenac decreased the OCR and increased caspase-3/7 activity. Acetaminophen and ethanol, which are also hepatotoxicants but do not induce idiosyncratic DILI, did not affect the OCR or caspase-3/7 activity. These results indicate that a combination assay of mitochondrial dysfunction and apoptosis is useful for the estimation of potential risk of compounds to induce idiosyncratic DILI.

  17. MOLECULAR SPECTROSCPY AND REACTIONS OF ACTINIDES IN THE GAS PHASE AND CRYOGENIC MATRICES

    Energy Technology Data Exchange (ETDEWEB)

    Heaven, Michael C.; Gibson, John K.; Marcalo, Joaquim

    2009-02-01

    In this chapter we review the spectroscopic data for actinide molecules and the reaction dynamics for atomic and molecular actinides that have been examined in the gas phase or in inert cryogenic matrices. The motivation for this type of investigation is that physical properties and reactions can be studied in the absence of external perturbations (gas phase) or under minimally perturbing conditions (cryogenic matrices). This information can be compared directly with the results from high-level theoretical models. The interplay between experiment and theory is critically important for advancing our understanding of actinide chemistry. For example, elucidation of the role of the 5f electrons in bonding and reactivity can only be achieved through the application of experimentally verified theoretical models. Theoretical calculations for the actinides are challenging due the large numbers of electrons that must be treated explicitly and the presence of strong relativistic effects. This topic has been reviewed in depth in Chapter 17 of this series. One of the goals of the experimental work described in this chapter has been to provide benchmark data that can be used to evaluate both empirical and ab initio theoretical models. While gas-phase data are the most suitable for comparison with theoretical calculations, there are technical difficulties entailed in generating workable densities of gas-phase actinide molecules that have limited the range of species that have been characterized. Many of the compounds of interest are refractory, and problems associated with the use of high temperature vapors have complicated measurements of spectra, ionization energies, and reactions. One approach that has proved to be especially valuable in overcoming this difficulty has been the use of pulsed laser ablation to generate plumes of vapor from refractory actinide-containing materials. The vapor is entrained in an inert gas, which can be used to cool the actinide species to room

  18. Estimation of the stand ages of tropical secondary forests after shifting cultivation based on the combination of WorldView-2 and time-series Landsat images

    Science.gov (United States)

    Fujiki, Shogoro; Okada, Kei-ichi; Nishio, Shogo; Kitayama, Kanehiro

    2016-09-01

    We developed a new method to estimate stand ages of secondary vegetation in the Bornean montane zone, where local people conduct traditional shifting cultivation and protected areas are surrounded by patches of recovering secondary vegetation of various ages. Identifying stand ages at the landscape level is critical to improve conservation policies. We combined a high-resolution satellite image (WorldView-2) with time-series Landsat images. We extracted stand ages (the time elapsed since the most recent slash and burn) from a change-detection analysis with Landsat time-series images and superimposed the derived stand ages on the segments classified by object-based image analysis using WorldView-2. We regarded stand ages as a response variable, and object-based metrics as independent variables, to develop regression models that explain stand ages. Subsequently, we classified the vegetation of the target area into six age units and one rubber plantation unit (1-3 yr, 3-5 yr, 5-7 yr, 7-30 yr, 30-50 yr, >50 yr and 'rubber plantation') using regression models and linear discriminant analyses. Validation demonstrated an accuracy of 84.3%. Our approach is particularly effective in classifying highly dynamic pioneer vegetation younger than 7 years into 2-yr intervals, suggesting that rapid changes in vegetation canopies can be detected with high accuracy. The combination of a spectral time-series analysis and object-based metrics based on high-resolution imagery enabled the classification of dynamic vegetation under intensive shifting cultivation and yielded an informative land cover map based on stand ages.

  19. Development and Validation of an RP-HPLC Method for Estimation of Chlorpheniramine Maleate, Ibuprofen, and Phenylephrine Hydrochloride in Combined Pharmaceutical Dosage Form

    Directory of Open Access Journals (Sweden)

    Pinak M. Sanchaniya

    2013-01-01

    Full Text Available The objective of this paper is to develope a simple, precise, accurate, and reproducible reversed phase high performance liquid chromatographic method for the quantitative determination of chlorpheniramine maleate, ibuprofen, and phenylephrine hydrochloride in combined pharmaceutical dosage form. Analysis was carried out using acetonitrile : mathanol : phoshphate buffer (50 : 20 : 30, v/v/v, pH 5.6 mobile phase at 1.0 mL/min flow rate and Sunfire C 18 column (5 μm × 250 mm × 4.6 mm as stationary phase with detection wavelength of 220 nm. The retention times of chlorpheniramine maleate (CPM, ibuprofen (IBU, and phenylephrine hydrochloride (PHE were 4.2 min, 13.6 min, and 2.7 min, respectively. The proposed method was validated with respect to linearity, accuracy, precision, specificity, and robustness. The linearity for chlorpheniramine maleate, ibuprofen, and phenylephrine hydrochloride was in the range of 0.5–2.5 μg/mL, 25–125 μg/mL, and 1.25–6.25 μg/mL, respectively. The % recoveries of all the three drugs were found to be 99.44–101.61%, 99.39–101.79%, and 98.66–101.83%. LOD were found to be 32, 120, and 68 ng/mL for CPM, IBU, and PHE, respectively. The method was successfully applied to the estimation of chlorpheniramine maleate, ibuprofen, and phenylephrine hydrochloride in combined pharmaceutical dosage form.

  20. A two-step combination of top-down and bottom-up fire emission estimates at regional and global scales: strengths and main uncertainties

    Science.gov (United States)

    Sofiev, Mikhail; Soares, Joana; Kouznetsov, Rostislav; Vira, Julius; Prank, Marje

    2016-04-01

    Top-down emission estimation via inverse dispersion modelling is used for various problems, where bottom-up approaches are difficult or highly uncertain. One of such areas is the estimation of emission from wild-land fires. In combination with dispersion modelling, satellite and/or in-situ observations can, in principle, be used to efficiently constrain the emission values. This is the main strength of the approach: the a-priori values of the emission factors (based on laboratory studies) are refined for real-life situations using the inverse-modelling technique. However, the approach also has major uncertainties, which are illustrated here with a few examples of the Integrated System for wild-land Fires (IS4FIRES). IS4FIRES generates the smoke emission and injection profile from MODIS and SEVIRI active-fire radiative energy observations. The emission calculation includes two steps: (i) initial top-down calibration of emission factors via inverse dispersion problem solution that is made once using training dataset from the past, (ii) application of the obtained emission coefficients to individual-fire radiative energy observations, thus leading to bottom-up emission compilation. For such a procedure, the major classes of uncertainties include: (i) imperfect information on fires, (ii) simplifications in the fire description, (iii) inaccuracies in the smoke observations and modelling, (iv) inaccuracies of the inverse problem solution. Using examples of the fire seasons 2010 in Russia, 2012 in Eurasia, 2007 in Australia, etc, it is pointed out that the top-down system calibration performed for a limited number of comparatively moderate cases (often the best-observed ones) may lead to errors in application to extreme events. For instance, the total emission of 2010 Russian fires is likely to be over-estimated by up to 50% if the calibration is based on the season 2006 and fire description is simplified. Longer calibration period and more sophisticated parameterization

  1. Estimation of Carbon Budgets for Croplands by Combining High Resolution Remote Sensing Data with a Crop Model and Validation Ground Data

    Science.gov (United States)

    Mangiarotti, S.; Veloso, A.; Ceschia, E.; Tallec, T.; Dejoux, J. F.

    2015-12-01

    Croplands occupy large areas of Earth's land surface playing a key role in the terrestrial carbon cycle. Hence, it is essential to quantify and analyze the carbon fluxes from those agro-ecosystems, since they contribute to climate change and are impacted by the environmental conditions. In this study we propose a regional modeling approach that combines high spatial and temporal resolutions (HSTR) optical remote sensing data with a crop model and a large set of in-situ measurements for model calibration and validation. The study area is located in southwest France and the model that we evaluate, called SAFY-CO2, is a semi-empirical one based on the Monteith's light-use efficiency theory and adapted for simulating the components of the net ecosystem CO2 fluxes (NEE) and of the annual net ecosystem carbon budgets (NECB) at a daily time step. The approach is based on the assimilation of satellite-derived green area index (GAI) maps for calibrating a number of the SAFY-CO2 parameters linked to crop phenology. HSTR data from the Formosat-2 and SPOT satellites were used to produce the GAI maps. The experimental data set includes eddy covariance measurements of net CO2 fluxes from two experimental sites and partitioned into gross primary production (GPP) and ecosystem respiration (Reco). It also includes measurements of GAI, biomass and yield between 2005 and 2011, focusing on the winter wheat crop. The results showed that the SAFY-CO2 model correctly reproduced the biomass production, its dynamic and the yield (relative errors about 24%) in contrasted climatic, environmental and management conditions. The net CO2 flux components estimated with the model were overall in agreement with the ground data, presenting good correlations (R² about 0.93 for GPP, 0.77 for Reco and 0.86 for NEE). The evaluation of the modelled NECB for the different site-years highlighted the importance of having accurate estimates of each component of the NECB. Future works aim at considering

  2. Potentiometric Sensor for Real-Time Remote Surveillance of Actinides in Molten Salts

    Energy Technology Data Exchange (ETDEWEB)

    Natalie J. Gese; Jan-Fong Jue; Brenda E. Serrano; Guy L. Fredrickson

    2012-07-01

    A potentiometric sensor is being developed at the Idaho National Laboratory for real-time remote surveillance of actinides during electrorefining of spent nuclear fuel. During electrorefining, fuel in metallic form is oxidized at the anode while refined uranium metal is reduced at the cathode in a high temperature electrochemical cell containing LiCl-KCl-UCl3 electrolyte. Actinides present in the fuel chemically react with UCl3 and form stable metal chlorides that accumulate in the electrolyte. This sensor will be used for process control and safeguarding of activities in the electrorefiner by monitoring the concentrations of actinides in the electrolyte. The work presented focuses on developing a solid-state cation conducting ceramic sensor for detecting varying concentrations of trivalent actinide metal cations in eutectic LiCl-KCl molten salt. To understand the basic mechanisms for actinide sensor applications in molten salts, gadolinium was used as a surrogate for actinides. The ß?-Al2O3 was selected as the solid-state electrolyte for sensor fabrication based on cationic conductivity and other factors. In the present work Gd3+-ß?-Al2O3 was prepared by ion exchange reactions between trivalent Gd3+ from GdCl3 and K+-, Na+-, and Sr2+-ß?-Al2O3 precursors. Scanning electron microscopy (SEM) was used for characterization of Gd3+-ß?-Al2O3 samples. Microfocus X-ray Diffraction (µ-XRD) was used in conjunction with SEM energy dispersive X-ray spectroscopy (EDS) to identify phase content and elemental composition. The Gd3+-ß?-Al2O3 materials were tested for mechanical and chemical stability by exposing them to molten LiCl-KCl based salts. The effect of annealing on the exchanged material was studied to determine improvements in material integrity post ion exchange. The stability of the ß?-Al2O3 phase after annealing was verified by µ-XRD. Preliminary sensor tests with different assembly designs will also be presented.

  3. Neutron capture measuremetns on minor actinides at the n_TOF facility at CERN: past, present and future

    OpenAIRE

    Cano Ott, Daniel; Colonna, Nicola; Tagliente, G.; Belloni, Fabio; Calviño Tavares, Francisco; Cortés Rossell, Guillem Pere; Poch Parés, Agustí; Pretel Sánchez, Carme

    2011-01-01

    The successful development of advanced nuclear systems for sustainable energy production and nuclear waste management depends on high quality nuclear data libraries. Recent sensitivity stud- ies and reports [1-3] have identi ed the need for substantially improving the accuracy of neutron cross-section data for minor actinides. The n TOF collaboration has initiated an ambitious exper- imental program for the measurement of neutron capture cross sections of minor actinides. Two e...

  4. Validated Stability Indicating RP-HPLC Method for Simultaneous Estimation of Codeine Phosphate and Chlorpheniramine Maleate from Their Combined Liquid Dosage Form

    Directory of Open Access Journals (Sweden)

    Ramakrishna Kommana

    2013-01-01

    Full Text Available The present paper describes the development of quick stability indicating RP-HPLC method for the simultaneous estimation of codeine phosphate and chlorpheniramine maleate in the presence of its degradation products, generated from forced degradation studies. The developed method separates codeine phosphate and chlorpheniramine maleate in impurities/degradation products. Codeine phosphate and chlorpheniramine maleate and their combination drug product were exposed to acid, base, oxidation, dry heat, and photolytic stress conditions, and the stressed samples were analysed by proposed method. The proposed HPLC method utilizes the Shimadzu HPLC system on a Phenomenex C18 column (, 5 μ using a mixture of 1% o-phosphoric acid in water : acetonitrile : methanol (78 : 10 : 12 mobile phase with pH adjusted to 3.0 in an isocratic elution mode at a flow rate of 1 mL/min, at 23°C with a load of 20 μL. The detection was carried out at 254 nm. The retention time of codeine phosphate and chlorpheniramine maleate was found to be around 3.47 min and 9.45 min, respectively. The method has been validated with respect to linearity, robustness, precision, accuracy, limit of detection (LOD, and limit of quantification (LOQ. The developed validated stability indicating HPLC method was found to be simple, accurate, and reproducible for the determination of instability of these drugs in bulk and commercial products.

  5. Lanthanides and actinides extraction by calixarenes containing CMPO groups; Extraction des lanthanides et des actinides au moyen de calixarenes portant des groupements CMPO

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Carrera, A

    2001-07-01

    In the framework of the French program SPIN concerning the radioactive waste management, researches are performed to develop processes allowing the separation of long-lived radioisotopes in order to their transmutation or their specific conditioning. These studies deal with the extraction and the separation of trivalent lanthanides and actinides in acid solution. Many systems ''calixarene-diluent-aqueous phase'' are examined by extraction liquid-liquid and membrane transport. The extraction efficiency and the selectivity of the synthesized calixarene-CMPO and of the CMPO are compared with these cations, as the nitric acid extraction by these molecules. (A.L.B.)

  6. A Lane consistent optical model potential for nucleon scattering on actinide nuclei with extended coupling

    Science.gov (United States)

    Quesada, José Manuel; Capote, Roberto; Soukhovitski, Efrem S.; Chiba, Satoshi

    2016-03-01

    An extension for odd-A actinides of a previously derived dispersive coupledchannel optical model potential (OMP) for 238U and 232Th nuclei is presented. It is used to fit simultaneously all the available experimental databases including neutron strength functions for nucleon scattering on 232Th, 233,235,238U and 239Pu nuclei. Quasi-elastic (p,n) scattering data on 232Th and 238U to the isobaric analogue states of the target nucleus are also used to constrain the isovector part of the optical potential. For even-even (odd) actinides almost all low-lying collective