Complexation of lanthanides and actinides by acetohydroxamic acid

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, R.J.; Sinkov, S.I.; Choppin, G.R.

2008-07-01

Acetohydroxamic acid (AHA) has been proposed as a suitable reagent for the complexant-based, as opposed to reductive, stripping of plutonium and neptunium ions from the tributylphosphate solvent phase in advanced PUREX or UREX processes designed for future nuclear-fuel reprocessing. Stripping is achieved by the formation of strong hydrophilic complexes with the tetravalent actinides in nitric acid solutions. To underpin such applications, knowledge of the complexation constants of AHA with all relevant actinide (5f) and lanthanide (4f) ions is therefore important. This paper reports the determination of stability constants of AHA with the heavier lanthanide ions (Dy-Yb) and also U(IV) andmore » Th(IV) ions. Comparisons with our previously published AHA stability-constant data for 4f and 5f ions are made. (authors)« less

Magnetic susceptibilities of actinide 3d-metal intermetallic compounds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Muniz, R.B.; d'Albuquerque e Castro, J.; Troper, A.

1988-04-15

We have numerically calculated the magnetic susceptibilities which appear in the Hartree--Fock instability criterion for actinide 3d transition-metal intermetallic compounds. This calculation is based on a previous tight-binding description of these actinide-based compounds (A. Troper and A. A. Gomes, Phys. Rev. B 34, 6487 (1986)). The parameters of the calculation, which starts from simple tight-binding d and f bands are (i) occupation numbers, (ii) ratio of d-f hybridization to d bandwidth, and (iii) electron-electron Coulomb-type interactions.

Actinide migration in Johnston Atoll soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, S. F.; Bates, J. K.; Buck, E. C.

1997-02-01

Characterization of the actinide content of a sample of contaminated coral soil from Johnston Atoll, the site of three non-nuclear destructs of nuclear warhead-carrying THOR missiles in 1962, revealed that >99% of the total actinide content is associated with discrete bomb fragments. After removal of these fragments, there was an inverse correlation between actinide content and soil particle size in particles from 43 to 0.4 {micro}m diameter. Detailed analyses of this remaining soil revealed no discrete actinide phase in these soil particles, despite measurable actinide content. Observations indicate that exposure to the environment has caused the conversion of relatively insolublemore » actinide oxides to the more soluble actinyl oxides and actinyl carbonate coordinated complexes. This process has led to dissolution of actinides from discrete particles and migration to the surrounding soil surfaces, resulting in a dispersion greater than would be expected by physical transport of discrete particles alone.« less

Dual roles of f electrons in mixing Al 3 p character into d -orbital conduction bands for lanthanide and actinide dialuminides

DOE PAGES

Altman, Alison B.; Pemmaraju, C. D.; Alayoglu, Selim; ...

2018-01-15

Correlated electron phenomena in lanthanide and actinide materials are driven by a complex interplay between the f and d orbitals. Here in this study, aluminum K-edge x-ray absorption spectroscopy and density functional theory calculations are used to evaluate the electronic structure of the dialuminides, MAl 2 (M = Ce, Sm, Eu, Yb, Lu, U, and Pu). The results show how the energy and occupancy of the 4f or 5f orbitals impacts mixing of Al 3p character into the 5d or 6d conduction bands, which has implications for understanding the magnetic and structural properties of correlated electron systems.

Actinide metal processing

DOEpatents

Sauer, Nancy N.; Watkin, John G.

1992-01-01

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

Actinide metal processing

DOEpatents

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

1992-03-24

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

Actinide-ion sensor

DOEpatents

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

2015-01-13

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

Siderocalin-mediated recognition, sensitization, and cellular uptake of actinides.

PubMed

Allred, Benjamin E; Rupert, Peter B; Gauny, Stacey S; An, Dahlia D; Ralston, Corie Y; Sturzbecher-Hoehne, Manuel; Strong, Roland K; Abergel, Rebecca J

2015-08-18

Synthetic radionuclides, such as the transuranic actinides plutonium, americium, and curium, present severe health threats as contaminants, and understanding the scope of the biochemical interactions involved in actinide transport is instrumental in managing human contamination. Here we show that siderocalin, a mammalian siderophore-binding protein from the lipocalin family, specifically binds lanthanide and actinide complexes through molecular recognition of the ligands chelating the metal ions. Using crystallography, we structurally characterized the resulting siderocalin-transuranic actinide complexes, providing unprecedented insights into the biological coordination of heavy radioelements. In controlled in vitro assays, we found that intracellular plutonium uptake can occur through siderocalin-mediated endocytosis. We also demonstrated that siderocalin can act as a synergistic antenna to sensitize the luminescence of trivalent lanthanide and actinide ions in ternary protein-ligand complexes, dramatically increasing the brightness and efficiency of intramolecular energy transfer processes that give rise to metal luminescence. Our results identify siderocalin as a potential player in the biological trafficking of f elements, but through a secondary ligand-based metal sequestration mechanism. Beyond elucidating contamination pathways, this work is a starting point for the design of two-stage biomimetic platforms for photoluminescence, separation, and transport applications.

Siderocalin-mediated recognition, sensitization, and cellular uptake of actinides

PubMed Central

Allred, Benjamin E.; Rupert, Peter B.; Gauny, Stacey S.; An, Dahlia D.; Ralston, Corie Y.; Sturzbecher-Hoehne, Manuel; Strong, Roland K.; Abergel, Rebecca J.

2015-01-01

Synthetic radionuclides, such as the transuranic actinides plutonium, americium, and curium, present severe health threats as contaminants, and understanding the scope of the biochemical interactions involved in actinide transport is instrumental in managing human contamination. Here we show that siderocalin, a mammalian siderophore-binding protein from the lipocalin family, specifically binds lanthanide and actinide complexes through molecular recognition of the ligands chelating the metal ions. Using crystallography, we structurally characterized the resulting siderocalin–transuranic actinide complexes, providing unprecedented insights into the biological coordination of heavy radioelements. In controlled in vitro assays, we found that intracellular plutonium uptake can occur through siderocalin-mediated endocytosis. We also demonstrated that siderocalin can act as a synergistic antenna to sensitize the luminescence of trivalent lanthanide and actinide ions in ternary protein–ligand complexes, dramatically increasing the brightness and efficiency of intramolecular energy transfer processes that give rise to metal luminescence. Our results identify siderocalin as a potential player in the biological trafficking of f elements, but through a secondary ligand-based metal sequestration mechanism. Beyond elucidating contamination pathways, this work is a starting point for the design of two-stage biomimetic platforms for photoluminescence, separation, and transport applications. PMID:26240330

Overview of actinide chemistry in the WIPP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borkowski, Marian; Lucchini, Jean - Francois; Richmann, Michael K

2009-01-01

inorganic complexants are expected to be carbonate/bicarbonate and hydroxide. There are also organic complexants in TRU waste with the potential to strongly influence actinide solubility. (3) Intrinsic and pseudo-actinide colloid formation - Many actinide species in their expected oxidation states tend to form colloids or strongly associate with non actinide colloids present (e.g., microbial, humic and organic). In this context, the relative importance of actinides, based on the TRU waste inventory, with respect to the potential release of actinides from the WIPP, is greater for plutonium and americium, and to less extent for uranium and thorium. The most important oxidation states for WIPP-relevant conditions are III and IV. We will present an update of the literature on WIPP-specific data, and a summary of the ongoing research related to actinide chemistry in the WIPP performed by the Los Alamos National Laboratory (LANL) Actinide Chemistry and Repository Science (ACRSP) team located in Carlsbad, NM [Reed 2007, Lucchini 2007, and Reed 2006].« less

A relativistic density functional study of the role of 5f electrons in atomic and molecular adsorptions on actinide surfaces

NASA Astrophysics Data System (ADS)

Huda, Muhammad Nurul

Atomic and molecular adsorptions of oxygen and hydrogen on actinide surfaces have been studied within the generalized gradient approximations to density functional theory (GGA-DFT). The primary goal of this work is to understand the details of the adsorption processes, such as chemisorption sites, energies, adsorption configurations and activation energies for dissociation of molecules; and the signature role of the plutonium 5f electrons. The localization of the 5f electrons remains one of central questions in actinides and one objective here is to understand the extent to which localizations plays a role in adsorption on actinide surfaces. We also investigated the magnetism of the plutonium surfaces, given the fact that magnetism in bulk plutonium is a highly controversial issue, and the surface magnetism of it is not a well explored territory. Both the non-spin-polarized and spin-polarized calculations have been performed to arrive at our conclusions. We have studied both the atomic and molecular hydrogen and oxygen adsorptions on plutonium (100) and (111) surfaces. We have also investigated the oxygen molecule adsorptions on uranium (100) surface. Comparing the adsorption on uranium and plutonium (100) surfaces, we have seen that O2 chemisorption energy for the most favorable adsorption site on uranium surface has higher chemisorption energy, 9.492 eV, than the corresponding plutonium site, 8.787 eV. Also degree of localization of 5f electrons is less for uranium surface. In almost all of the cases, the most favorable adsorption sites are found where the coordination numbers are higher. For example, we found center sites are the most favorable sites for atomic adsorptions. In general oxygen reacts more strongly with plutonium surface than hydrogen. We found that atomic oxygen adsorption energy on (100) surface is 3.613 eV more than that of the hydrogen adsorptions, considering only the most favorable site. This is also true for molecular adsorptions, as the

Aqueous Electrochemical Mechanisms in Actinide Residue Processing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morris, David E.; Burns, Carol J.; Smith, Wayne H.

2000-12-31

as the Catalyzed Electrochemical Plutonium Oxide Dissolution (CEPOD) process pioneered by workers at Pacific Northwest National Laboratory in the mid-1970s [2]. The basis for most of these mediated electrochemical oxidation/reduction (MEO/R) processes is the generation of a dissolved electrochemical catalyst, such as Ag2+, which is capable of oxidizing or reducing solid-phase actinide species or actinide sorbates via 7 heterogeneous electron transfer to oxidation states that have significantly greater solubilities (e.g., PuO2(s) to PuO2 2+ (dissolved)). The solubilized actinide can then be recovered by ion exchange or other mechanisms. These aqueous electrochemical methods for residue treatment have been considered in many of the ''trade studies'' to evaluate options for stabilization of the various categories of residue materials. While some concerns generally arise (e.g., large secondary waste volumes could results since the process stream normally goes th rough anion exchange or precipitation steps to remove the actinide), the real utility and versatility of these methods should not be overlooked. They are low temperature, ambient pressure processes that operate in a non-corrosive environment. In principle, they can be designed to be highly selective for the actinides (i.e., no substrate degradation occurs), they can be utilized for many categories of residue materials with little or no modification in hardware or operating conditions, and they can conceivably be engineered to minimize secondary waste stream volume. However, some fundamental questions remain concerning the mechanisms through which these processes act, and how the processes might be optimized to maximize efficiency while minimizing secondary waste. In addition, given the success achieved to date on the limited set of residues, further research is merited to extend the range of applicability of these electrochemical methods to other residue and waste streams. The principal goal of the work described

Comparative Photoemission Study of Actinide (Am, Pu, Np and U) Metals, Nitrides, and Hydrides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gouder, Thomas; Seibert, Alice; Rebizant, Jean

2007-07-01

Core-level and valence-band spectra of Pu and the other early actinide compounds show remarkable systematics, which can be understood in the framework of final state screening. We compare the early actinide (U, Np, Pu and Am) metals, nitrides and hydrides and a few other specific compounds (PuSe, PuS, PuCx, PuSix) prepared as thin films by sputter deposition. In choosing these systems, we combine inherent 5f band narrowing, due to 5f orbital contraction throughout the actinide series, with variations of the chemical environment in the compounds. Goal of this work was to learn more on the electronic structure of the earlymore » actinide systems and to achieve the correct interpretation of their photoemission spectra. The highly correlated nature of the 5f states in systems, which are on the verge to localization, makes this a challenging task, because of the peculiar interplay between ground state DOS and final-state effects. Their influence can be estimated by doing systematic studies on systems with different (5f) bandwidths. We conclude on the basis of such systematic experiments that final-state effects due to strong e-e correlations in narrow 5f-band systems lead to multiplet like structures, analogous to those observed in the case of systems with localized electron states. Such observations in essentially band-like 5f-systems was first surprising, but the astonishing similarity of photoemission spectra of very different chemical systems (e.g. PuSe, Pu{sub 2}C{sub 3}..) points to a common origin, relating them to atomic features rather than material dependent density of states (DOS) features. (authors)« less

Role of 5f electrons in the structural stability of light actinide (Th-U) mononitrides under pressure.

PubMed

Modak, P; Verma, Ashok K

2016-03-28

Pressure induced structural sequences and their mechanism for light actinide (Th-U) mononitrides were studied as a function of 5f-electron number using first-principles total energy and electronic structure calculations. Zero pressure lattice constants, bulk module and C11 elastic module vary systematically with 5f-electron number implying its direct role on crystal binding. There is a critical 5f-electron number below which the system makes B1-B2 and above it B1-R3̄m-B2 structural sequence under pressure. Also, the B1-B2 transition pressure increases with increasing 5f-electron number whereas an opposite trend is obtained for the B1-R3̄m transition pressure. The ascending of N p anti-bonding states through the Fermi level at high pressure is responsible for the structural instability of the system. Above the critical 5f-electron number in the system a narrow 5f-band occurs very close to the Fermi level which allows the system to lower its symmetry via band Jahn-Teller type lattice distortion and the system undergoes a B1-R3̄m phase transition. However, below the critical 5f-electron number this mechanism is not favorable due to a lack of sufficient 5f-state occupancy and thus the system undergoes a B1-B2 phase transition like other ionic solids.

Actinide extraction methods

DOEpatents

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

2010-09-21

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

Electronic structure of free and doped actinides: N and Z dependences of energy levels and electronic structure parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulagin, N.

2005-02-15

Theoretical study of electronic structure of antinide ions and its dependence on N and Z are presented in this paper. The main 5f{sup N} and excited 5f{sup N}n'l'{sup N'} configurations of actinides have been studied using Hartree-Fock-Pauli approximation. Results of calculations of radial integrals and the energy of X-ray lines for all 5f ions with electronic state AC{sup +1}-AC{sup +4} show approximate dependence on N and Z. A square of N and cubic of Z are ewalized for the primary electronic parameters of the actinides. Theoretical values of radial integrals for free actinides and for ions in a cluster AC{supmore » +n}:[L]{sub k} are compared, too.« less

Actinide oxide photodiode and nuclear battery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sykora, Milan; Usov, Igor

Photodiodes and nuclear batteries may utilize actinide oxides, such a uranium oxide. An actinide oxide photodiode may include a first actinide oxide layer and a second actinide oxide layer deposited on the first actinide oxide layer. The first actinide oxide layer may be n-doped or p-doped. The second actinide oxide layer may be p-doped when the first actinide oxide layer is n-doped, and the second actinide oxide layer may be n-doped when the first actinide oxide layer is p-doped. The first actinide oxide layer and the second actinide oxide layer may form a p/n junction therebetween. Photodiodes including actinide oxidesmore » are better light absorbers, can be used in thinner films, and are more thermally stable than silicon, germanium, and gallium arsenide.« less

Actinides-1981

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

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.

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

DOEpatents

Crisler, L.R.

1975-11-11

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

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

NASA Astrophysics Data System (ADS)

Brush, L. H.; Xiong, Y.

2009-12-01

The Waste Isolation Pilot Plant (WIPP) is a U.S. Department of Energy (DOE) repository in southeast New Mexico for defense-related transuranic (TRU) waste. The repository, which opened in March 1999, is located at a subsurface depth of 655 m (2150 ft) in the Salado Fm., a Permian bedded-salt formation. The repository will eventually contain the equivalent of 844,000 208 L (55 gal) drums of TRU waste. After filling the rooms and access drifts and installing panel closures, creep closure of the salt will crush the steel waste containers in most cases and encapsulate the waste. The WIPP actinide source term model used for long-term performance assessment (PA) of the repository comprises dissolved and suspended submodels (solubilities and colloids). This presentation will describe the solubilities. From the standpoint of long-term PA, the order of importance of the radioelements in the TRU waste to be emplaced in the WIPP is Pu ~ Am >> U > Th >> Np ~ Cm and fission products. The DOE has included all of these actinides, but not fission products, in the WIPP Actinide Source Term Program (ASTP). Anoxic corrosion of Fe- and Al-base metals and microbial consumption of cellulosic, plastic, and rubber materials will produce gas and create strongly reducing conditions in the WIPP after closure. The use of MgO as an engineered barrier to consume microbially produced CO2 will result in low fCO2 and basic pH. Under these conditions, Th, U, Np, Pu, and Am will speciate essentially entirely as Th(IV), U(IV), Np(IV), Pu(III), and Am(III); or Th(IV), U(VI), Np(V), Pu(IV), and Am(III). The DOE has developed thermodynamic speciation-and-solubility models for +III, +IV, and +V actinides in brines. Experimental data for Nd, Am, and Cm species were used to parameterize the +III Pitzer activity-coefficient model; data for Th species were used for the +IV model; and data for Np(V) species were used for the +V model. These models include the effects of the organic ligands acetate, citrate

Method for preparing actinide nitrides

DOEpatents

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

1975-12-01

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

Correlation consistent basis sets for actinides. I. The Th and U atoms.

PubMed

Peterson, Kirk A

2015-02-21

New correlation consistent basis sets based on both pseudopotential (PP) and all-electron Douglas-Kroll-Hess (DKH) Hamiltonians have been developed from double- to quadruple-zeta quality for the actinide atoms thorium and uranium. Sets for valence electron correlation (5f6s6p6d), cc - pV nZ - PP and cc - pV nZ - DK3, as well as outer-core correlation (valence + 5s5p5d), cc - pwCV nZ - PP and cc - pwCV nZ - DK3, are reported (n = D, T, Q). The -PP sets are constructed in conjunction with small-core, 60-electron PPs, while the -DK3 sets utilized the 3rd-order Douglas-Kroll-Hess scalar relativistic Hamiltonian. Both series of basis sets show systematic convergence towards the complete basis set limit, both at the Hartree-Fock and correlated levels of theory, making them amenable to standard basis set extrapolation techniques. To assess the utility of the new basis sets, extensive coupled cluster composite thermochemistry calculations of ThFn (n = 2 - 4), ThO2, and UFn (n = 4 - 6) have been carried out. After accurately accounting for valence and outer-core correlation, spin-orbit coupling, and even Lamb shift effects, the final 298 K atomization enthalpies of ThF4, ThF3, ThF2, and ThO2 are all within their experimental uncertainties. Bond dissociation energies of ThF4 and ThF3, as well as UF6 and UF5, were similarly accurate. The derived enthalpies of formation for these species also showed a very satisfactory agreement with experiment, demonstrating that the new basis sets allow for the use of accurate composite schemes just as in molecular systems composed only of lighter atoms. The differences between the PP and DK3 approaches were found to increase with the change in formal oxidation state on the actinide atom, approaching 5-6 kcal/mol for the atomization enthalpies of ThF4 and ThO2. The DKH3 atomization energy of ThO2 was calculated to be smaller than the DKH2 value by ∼1 kcal/mol.

Proximity of f0(1500 ) and f0(1710 ) to the scalar glueball

NASA Astrophysics Data System (ADS)

Fariborz, Amir H.; Azizi, Azizollah; Asrar, Abdorreza

2015-12-01

Within a nonlinear chiral Lagrangian framework, the underlying mixings among quark-antiquark, four-quark and glue components of f0(1500 ) and f0(1710 ) are studied in a global picture that includes all isosinglet scalar mesons below 2 GeV. The quark components are introduced in the Lagrangian in terms of two separate nonets (a quark-antiquark nonet and a four-quark nonet) which can mix with each other and with a scalar glueball. An iterative Monte Carlo simulation is developed to study the 14 free parameters of the Lagrangian by a simultaneous fit to more than 20 experimental data and constraints on the mass spectrum, decay widths, and decay ratios of the isosinglet scalars below 2 GeV. Moreover, constraints on the mass spectrum and decay widths of isodoublet and isovector scalars below 2 GeV as well as pion-pion scattering amplitude are also taken into account. In the leading order of the model and within the overall experimental uncertainties, the ranges of variation of the model parameters are determined. This leads to a set of points in the 14-dimensional parameter space at which the overall disagreement with experiment is no larger than the overall experimental uncertainties. The insights gained in this global picture, due to the complexities of the mixings as well as the experimental uncertainties, are mainly qualitative but are relatively robust, and reveal that the lowest scalar glueball hides between f0(1500 ) and f0(1710 ) , resulting in a considerable mixing with various quark components of these two states. The overall current experimental and theoretical uncertainties do not allow us to pin down the exact glue components of isosinglet states; nevertheless it is shown that the f0(1500 ) and f0(1710 ) have the highest glue component. While this global study does not allow precision predictions for each individual state, it provides useful "family" correlations among the isosinglet states that are found insightful in probing the substructure of scalars

Influence of a Heterocyclic Nitrogen-Donor Group on the Coordination of Trivalent Actinides and Lanthanides by Aminopolycarboxylate Complexants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grimes, Travis S.; Heathman, Colt R.; Jansone-Popova, Santa

Here, the novel metal chelator N-2-(pyridylmethyl)diethylenetriamine- N,N',N",N"-tetraacetic acid (DTTA-PyM) was designed to replace a single oxygen-donor acetate group of the well-known aminopolycarboxylate complexant diethylenetriamine- N,N,N',N",N"-pentaacetic acid (DTPA) with a nitrogen-donor 2-pyridylmethyl. Potentiometric, spectroscopic, computational, and radioisotope distribution methods show distinct differences for the 4f and 5f coordination environments and enhanced actinide binding due to the nitrogen-bearing heterocyclic moiety. The Am 3+, Cm 3+, and Ln 3+ complexation studies for DTTA-PyM reveal an enhanced preference, relative to DTPA, for trivalent actinide binding. Fluorescence studies indicate no changes to the octadentate coordination of trivalent curium, while evidence of heptadentate complexation of trivalentmore » europium is found in mixtures containing EuHL (aq) complexes at the same aqueous acidity. The denticity change observed for Eu 3+ suggests that complex protonation occurs on the pyridyl nitrogen. Formation of the CmHL (aq) complex is likely due to the protonation of an available carboxylate group because the carbonyl oxygen can maintain octadentate coordination through a rotation. The observed suppressed protonation of the pyridyl nitrogen in the curium complexes may be attributed to stronger trivalent actinide binding by DTTA-PyM. Density functional theory calculations indicate that added stabilization of the actinide complexes with DTTA-PyM may originate from π-back-bonding interactions between singly occupied 5f orbitals of Am 3+ and the pyridyl nitrogen. The differences between the stabilities of trivalent actinide chelates (Am 3+, Cm 3+) and trivalent lanthanide chelates (La 3+–Lu 3+) are observed in liquid–liquid extraction systems, yielding unprecedented 4f/5f differentiation when using DTTA-PyM as an aqueous holdback reagent. In addition, the enhanced nitrogen-donor softness of the new DTTA-PyM chelator was perturbed

Rapid determination of alpha emitters using Actinide resin.

PubMed

Navarro, N; Rodriguez, L; Alvarez, A; Sancho, C

2004-01-01

The European Commission has recently published the recommended radiological protection criteria for the clearance of building and building rubble from the dismantling of nuclear installations. Radionuclide specific clearance levels for actinides are very low (between 0.1 and 1 Bq g(-1)). The prevalence of natural radionuclides in rubble materials makes the verification of these levels by direct alpha counting impossible. The capability of Actinide resin (Eichrom Industries, Inc.) for extracting plutonium and americium from rubble samples has been tested in this work. Besides a strong affinity for actinides in the tri, tetra and hexavalent oxidation states, this extraction chromatographic resin presents an easy recovery of absorbed radionuclides. The retention capability was evaluated on rubble samples spiked with certified radionuclide standards (239Pu and 241Am). Samples were leached with nitric acid, passed through a chromatographic column containing the resin and the elution fraction was measured by LSC. Actinide retention varies from 60% to 80%. Based on these results, a rapid method for the verification of clearance levels for actinides in rubble samples is proposed.

Ground-state configurations and theoretical soft-x-ray emission of highly charged actinide ions

NASA Astrophysics Data System (ADS)

Sheil, J.; Kilbane, D.; O'Sullivan, G.; Liu, L.; Suzuki, C.

2017-12-01

It is well known that the lanthanide and actinide elements are formed by the filling of 4 f and 5 f subshells which occurs after the filling of 5 d and 6 d subshells, respectively, has begun. With increasing ionization one expects the energy levels to eventually regroup to their hydrogenic ordering, i.e., in terms of principal quantum number. In the lanthanides, the 4 f electron binding energy overtakes that of 5 p near the 6th or 7th ion stage and 5 s near the 14th or 15th ion stage, leading to dramatic rearrangements of ground-state configurations. In this paper we report on the results of a study to explore the effects of increasing ionization on the ground-state configurations of actinide ions as a result of 5 f and 6 p or 6 s level crossings. It is seen that the effects generally occur later and are more strongly influenced by spin-orbit splitting than in the lanthanides. The near degeneracies of 5 f and 6 l energies in these stages lead to configuration interaction (CI) amongst configurations with variable numbers of 5 f and 6 p electrons. The effects of CI on the level complexity are explored for ions along the Rn I sequence and are found to lead to the formation of "compound states" as predicted for the lanthanides. The extreme ultraviolet and soft x-ray spectra of medium and highly charged lanthanides are dominated by emission from unresolved transition arrays (UTAs) of the type Δ n =0 , 4 p64 dN +1-4 p54 dN +2+4 p64 dN4 f , which, in general, overlap in adjacent ion stages of a particular element. Here, the corresponding Δ n =0 , 5 p65 dN +1-5 p55 dN +2+5 p65 dN5 f UTAs have been studied theoretically with the aid of Hartree-Fock with configuration interaction calculations. As well as predicting the wavelengths and spectral details of the anticipated features, the calculations show that the effects of configuration interaction are quite different for the two different families of Δ n =0 transitions and, once more, spin-orbit interactions play a major

Physical and chemical characterization of actinides in soil from Johnston Atoll

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wolf, S.F.; Bates, J.K.; Buck, E.C.

1997-02-01

Characterization of the actinide content of a sample of contaminated coral soil from Johnston Atoll, the site of three non-nuclear destructs of nuclear warhead-carrying THOR missiles in 1962, revealed that >99% of the total actinide content is associated with discrete bomb fragments. After removal of these fragments, there was an inverse correlation between actinide content and soil particle size in particles from 43 to 0.4 {mu}m diameter. Detailed analyses of this remaining soil revealed no discrete actinide phase in these soil particles, despite measurable actinide content. Observations indicate that exposure to the environment has caused the conversion of relatively insolublemore » actinide oxides to the more soluble actinyl oxides and actinyl carbonate coordinated complexes. This process has led to dissolution of actinides from discrete particles and migration to the surrounding soil surfaces, resulting in a dispersion greater than would be expected by physical transport of discrete particles alone. 26 refs., 4 figs., 1 tab.« less

Process to remove actinides from soil using magnetic separation

DOEpatents

Avens, Larry R.; Hill, Dallas D.; Prenger, F. Coyne; Stewart, Walter F.; Tolt, Thomas L.; Worl, Laura A.

1996-01-01

A process of separating actinide-containing components from an admixture including forming a slurry including actinide-containing components within an admixture, said slurry including a dispersion-promoting surfactant, adjusting the pH of the slurry to within a desired range, and, passing said slurry through a pretreated matrix material, said matrix material adapted to generate high magnetic field gradients upon the application of a strong magnetic field exceeding about 0.1 Tesla whereupon a portion of said actinide-containing components are separated from said slurry and remain adhered upon said matrix material is provided.

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

NASA Astrophysics Data System (ADS)

Garza, Alejandro J.; Sousa Alencar, Ana G.; Scuseria, Gustavo E.

2015-12-01

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 f0 actinyl series (UO22+, NpO23+, PuO24+), the isoelectronic NUN, and thorium (ThO, ThO2+) and nobelium (NoO, NoO2) oxides are studied.

Dihydroorotate dehydrogenase inhibitor F901318 has potent in vitro activity against Scedosporium species and Lomentospora prolificans.

PubMed

Wiederhold, Nathan P; Law, Derek; Birch, Michael

2017-07-01

Scedosporium species and Lomentospora prolificans are increasing causes of invasive infections in immunocompromised hosts and many isolates are resistant to available antifungals. Our objective was to assess the in vitro potency of F901318, a member of the orotomide class of antifungals, against Scedosporium species and L. prolificans . The in vitro potency of F901318 was evaluated against 66 Scedosporium and 7 L. prolificans clinical isolates using the CLSI M38-A2 reference standard. Scedosporium species included Scedosporium apiospermum ( n  =   43), Scedosporium aurantiacum ( n  =   6), Scedosporium dehoogii ( n  =   2) and Scedosporium boydii ( n  =   15). Positive comparators included amphotericin B, caspofungin, posaconazole and voriconazole. Against S. apiospermum and S. boydii F901318 geometric mean MICs/MECs (0.079 and 0.046 mg/L, respectively) were significantly lower than those observed with amphotericin (3.404 and 5.595 mg/L), posaconazole (1.937 and 1.823 mg/L), voriconazole (0.784 and 0.630 mg/L) and caspofungin (5.703 and 7.639 mg/L) ( P  <   0.001). Against S. aurantiacum and S. dehoogii the F901318 MIC range (0.12-0.5 mg/L) was also lower than those for the other antifungals (0.5 to >8 mg/L). F901318 also maintained activity against L. prolificans isolates (range 0.12-0.25 mg/L) in contrast to other antifungals, of which none demonstrated in vitro activity. F901318 demonstrated potent in vitro activity against Scedosporium species and L. prolificans . This activity was maintained against isolates that had significantly reduced susceptibility to the other antifungals. Further studies are warranted to evaluate the in vivo efficacy of F901318 against Scedosporium species and L. prolificans . © The Author 2017. Published by Oxford University Press on behalf of the British Society for Antimicrobial Chemotherapy. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Correlation consistent basis sets for actinides. I. The Th and U atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peterson, Kirk A., E-mail: kipeters@wsu.edu

New correlation consistent basis sets based on both pseudopotential (PP) and all-electron Douglas-Kroll-Hess (DKH) Hamiltonians have been developed from double- to quadruple-zeta quality for the actinide atoms thorium and uranium. Sets for valence electron correlation (5f6s6p6d), cc − pV nZ − PP and cc − pV nZ − DK3, as well as outer-core correlation (valence + 5s5p5d), cc − pwCV nZ − PP and cc − pwCV nZ − DK3, are reported (n = D, T, Q). The -PP sets are constructed in conjunction with small-core, 60-electron PPs, while the -DK3 sets utilized the 3rd-order Douglas-Kroll-Hess scalar relativistic Hamiltonian. Bothmore » series of basis sets show systematic convergence towards the complete basis set limit, both at the Hartree-Fock and correlated levels of theory, making them amenable to standard basis set extrapolation techniques. To assess the utility of the new basis sets, extensive coupled cluster composite thermochemistry calculations of ThF{sub n} (n = 2 − 4), ThO{sub 2}, and UF{sub n} (n = 4 − 6) have been carried out. After accurately accounting for valence and outer-core correlation, spin-orbit coupling, and even Lamb shift effects, the final 298 K atomization enthalpies of ThF{sub 4}, ThF{sub 3}, ThF{sub 2}, and ThO{sub 2} are all within their experimental uncertainties. Bond dissociation energies of ThF{sub 4} and ThF{sub 3}, as well as UF{sub 6} and UF{sub 5}, were similarly accurate. The derived enthalpies of formation for these species also showed a very satisfactory agreement with experiment, demonstrating that the new basis sets allow for the use of accurate composite schemes just as in molecular systems composed only of lighter atoms. The differences between the PP and DK3 approaches were found to increase with the change in formal oxidation state on the actinide atom, approaching 5-6 kcal/mol for the atomization enthalpies of ThF{sub 4} and ThO{sub 2}. The DKH3 atomization energy of ThO{sub 2} was calculated to be smaller than

The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

NASA Astrophysics Data System (ADS)

Gregson, Matthew; Lu, Erli; Mills, David P.; Tuna, Floriana; McInnes, Eric J. L.; Hennig, Christoph; Scheinost, Andreas C.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Kerridge, Andrew; Liddle, Stephen T.

2017-02-01

Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal-ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle.

The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes.

PubMed

Gregson, Matthew; Lu, Erli; Mills, David P; Tuna, Floriana; McInnes, Eric J L; Hennig, Christoph; Scheinost, Andreas C; McMaster, Jonathan; Lewis, William; Blake, Alexander J; Kerridge, Andrew; Liddle, Stephen T

2017-02-03

Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal-ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle.

The inverse-trans-influence in tetravalent lanthanide and actinide bis(carbene) complexes

PubMed Central

Gregson, Matthew; Lu, Erli; Mills, David P.; Tuna, Floriana; McInnes, Eric J. L.; Hennig, Christoph; Scheinost, Andreas C.; McMaster, Jonathan; Lewis, William; Blake, Alexander J.; Kerridge, Andrew; Liddle, Stephen T.

2017-01-01

Across the periodic table the trans-influence operates, whereby tightly bonded ligands selectively lengthen mutually trans metal–ligand bonds. Conversely, in high oxidation state actinide complexes the inverse-trans-influence operates, where normally cis strongly donating ligands instead reside trans and actually reinforce each other. However, because the inverse-trans-influence is restricted to high-valent actinyls and a few uranium(V/VI) complexes, it has had limited scope in an area with few unifying rules. Here we report tetravalent cerium, uranium and thorium bis(carbene) complexes with trans C=M=C cores where experimental and theoretical data suggest the presence of an inverse-trans-influence. Studies of hypothetical praseodymium(IV) and terbium(IV) analogues suggest the inverse-trans-influence may extend to these ions but it also diminishes significantly as the 4f orbitals are populated. This work suggests that the inverse-trans-influence may occur beyond high oxidation state 5f metals and hence could encompass mid-range oxidation state actinides and lanthanides. Thus, the inverse-trans-influence might be a more general f-block principle. PMID:28155857

The chemo-mechanical coupled model for F(1)F(0)-motor.

PubMed

Xu, Lizhong; Liu, Fang

2012-04-01

F(1)F(0)-motor (ATP synthase) is the universal enzyme in biological energy conversion that is present in the membranes of mitochondria, chloroplasts and bacteria. It uses the energy of the proton gradient across the membrane to synthesize ATP. Previous theory and model about rotation of the ATP synthase is reviewed, then a novel chemo-mechanical coupled model for rotation of the F(1)F(0)-motor is proposed. In the model, more events are considered simultaneously that includes the movement of F(1), the movement of F(0), reactions at F(1) and reactions at F(0). Using the model, the possible substep modes of the rotation for F(1)F(0) are predicted, the dependence of the motor efficiency and its rotation rate on the rigidity of the γ shaft is investigated. We conclude that the γ shaft has a large rotation rate for a limited driving potential because two ends of the γ shaft can rotate alternately for its flexibility. The flexibility also makes the efficiency of F(1)F(0) drop because elastic twisting deformation power is needed during alternate rotation of the γ shaft at two ends. Copyright © 2012 Elsevier Ltd. All rights reserved.

Actinide Waste Forms and Radiation Effects

NASA Astrophysics Data System (ADS)

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

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

Actinides in the Geosphere

NASA Astrophysics Data System (ADS)

Runde, Wolfgang; Neu, Mary P.

Since the 1950s actinides have been used to benefit industry, science, health, and national security. The largest industrial application, electricity generation from uranium and thorium fuels, is growing worldwide. Thus, more actinides are being mined, produced, used and processed than ever before. The future of nuclear energy hinges on how these increasing amounts of actinides are contained in each stage of the fuel cycle, including disposition. In addition, uranium and plutonium were built up during the Cold War between the United States and the Former Soviet Union for defense purposes and nuclear energy.

Actinide recovery process

DOEpatents

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

1987-07-28

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

Separations of actinides, lanthanides and other metals

DOEpatents

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

1995-01-01

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

Actinide recovery process

DOEpatents

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

1985-06-13

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

Emergence of californium as the second transitional element in the actinide series

PubMed Central

Cary, Samantha K.; Vasiliu, Monica; Baumbach, Ryan E.; Stritzinger, Jared T.; Green, Thomas D.; Diefenbach, Kariem; Cross, Justin N.; Knappenberger, Kenneth L.; Liu, Guokui; Silver, Mark A.; DePrince, A. Eugene; Polinski, Matthew J.; Van Cleve, Shelley M.; House, Jane H.; Kikugawa, Naoki; Gallagher, Andrew; Arico, Alexandra A.; Dixon, David A.; Albrecht-Schmitt, Thomas E.

2015-01-01

A break in periodicity occurs in the actinide series between plutonium and americium as the result of the localization of 5f electrons. The subsequent chemistry of later actinides is thought to closely parallel lanthanides in that bonding is expected to be ionic and complexation should not substantially alter the electronic structure of the metal ions. Here we demonstrate that ligation of californium(III) by a pyridine derivative results in significant deviations in the properties of the resultant complex with respect to that predicted for the free ion. We expand on this by characterizing the americium and curium analogues for comparison, and show that these pronounced effects result from a second transition in periodicity in the actinide series that occurs, in part, because of the stabilization of the divalent oxidation state. The metastability of californium(II) is responsible for many of the unusual properties of californium including the green photoluminescence. PMID:25880116

Emergence of californium as the second transitional element in the actinide series

DOE PAGES

Cary, Samantha K.; Vasiliu, Monica; Baumbach, Ryan E.; ...

2015-04-16

A break in periodicity occurs in the actinide series between plutonium and americium as the result of the localization of 5f electrons. The subsequent chemistry of later actinides is thought to closely parallel lanthanides in that bonding is expected to be ionic and complexation should not substantially alter the electronic structure of the metal ions. Here we demonstrate that ligation of californium(III) by a pyridine derivative results in significant deviations in the properties of the resultant complex with respect to that predicted for the free ion. We expand on this by characterizing the americium and curium analogues for comparison, andmore » show that these pronounced effects result from a second transition in periodicity in the actinide series that occurs, in part, because of the stabilization of the divalent oxidation state. As a result, the metastability of californium(II) is responsible for many of the unusual properties of californium including the green photoluminescence.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2013-07-01

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

Applications of time-resolved laser fluorescence spectroscopy to the environmental biogeochemistry of actinides.

PubMed

Collins, Richard N; Saito, Takumi; Aoyagi, Noboru; Payne, Timothy E; Kimura, Takaumi; Waite, T David

2011-01-01

Time-resolved laser fluorescence spectroscopy (TRLFS) is a useful means of identifying certain actinide species resulting from various biogeochemical processes. In general, TRLFS differentiates chemical species of a fluorescent metal ion through analysis of different excitation and emission spectra and decay lifetimes. Although this spectroscopic technique has largely been applied to the analysis of actinide and lanthanide ions having fluorescence decay lifetimes on the order of microseconds, such as UO , Cm, and Eu, continuing development of ultra-fast and cryogenic TRLFS systems offers the possibility to obtain speciation information on metal ions having room-temperature fluorescence decay lifetimes on the order of nanoseconds to picoseconds. The main advantage of TRLFS over other advanced spectroscopic techniques is the ability to determine in situ metal speciation at environmentally relevant micromolar to picomolar concentrations. In the context of environmental biogeochemistry, TRLFS has principally been applied to studies of (i) metal speciation in aqueous and solid phases and (ii) the coordination environment of metal ions sorbed to mineral and bacterial surfaces. In this review, the principles of TRLFS are described, and the literature reporting the application of this methodology to the speciation of actinides in systems of biogeochemical interest is assessed. Significant developments in TRLFS methodology and advanced data analysis are highlighted, and we outline how these developments have the potential to further our mechanistic understanding of actinide biogeochemistry. American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.

Synthesis of actinide nitrides, phosphides, sulfides and oxides

DOEpatents

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

1992-01-01

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

Speciation of the trivalent f-elements Eu(III) and Cm(III) in digestive media.

PubMed

Wilke, Claudia; Barkleit, Astrid; Stumpf, Thorsten; Ikeda-Ohno, Atsushi

2017-10-01

In case radioactive materials are released into the environment, their incorporation into our digestive system would be a significant concern. Trivalent f-elements, i.e., trivalent actinides and lanthanides, could potentially represent a serious health risk due to their chemo- and radiotoxicity, nevertheless the biochemical behavior of these elements are mostly unknown even to date. This study, therefore, focuses on the chemical speciation of trivalent f-elements in the human gastrointestinal tract. To simulate the digestive system artificial digestive juices (saliva, gastric juice, pancreatic juice and bile fluid) were prepared. The chemical speciation of lanthanides (as Eu(III)) and actinides (as Cm(III)) was determined experimentally by time-resolved laser-induced fluorescence spectroscopy (TRLFS) and the results were compared with thermodynamic modeling. The results indicate a dominant inorganic species with phosphate/carbonate in the mouth, while the aquo ion is predominantly formed with a minor contribution of the enzyme pepsin in the stomach. In the intestinal tract the most significant species are with the protein mucin. We demonstrated the first experimental results on the chemical speciation of trivalent f-elements in the digestive media by TRLFS. The results highlight a significant gap in chemical speciation between experiments and thermodynamic modeling due to the limited availability of thermodynamic stability constants particularly for organic species. Chemical speciation strongly influences the in vivo behavior of metal ions. Therefore, the results of this speciation study will help to enhance the assessment of health risks and to improve decorporation strategies after ingestion of these (radio-)toxic heavy metal ions. Copyright © 2017 Elsevier Inc. All rights reserved.

Superresolution microscopy reveals spatial separation of UCP4 and F0F1-ATP synthase in neuronal mitochondria

PubMed Central

Klotzsch, Enrico; Smorodchenko, Alina; Löfler, Lukas; Moldzio, Rudolf; Parkinson, Elena; Schütz, Gerhard J.; Pohl, Elena E.

2015-01-01

Because different proteins compete for the proton gradient across the inner mitochondrial membrane, an efficient mechanism is required for allocation of associated chemical potential to the distinct demands, such as ATP production, thermogenesis, regulation of reactive oxygen species (ROS), etc. Here, we used the superresolution technique dSTORM (direct stochastic optical reconstruction microscopy) to visualize several mitochondrial proteins in primary mouse neurons and test the hypothesis that uncoupling protein 4 (UCP4) and F0F1-ATP synthase are spatially separated to eliminate competition for the proton motive force. We found that UCP4, F0F1-ATP synthase, and the mitochondrial marker voltage-dependent anion channel (VDAC) have various expression levels in different mitochondria, supporting the hypothesis of mitochondrial heterogeneity. Our experimental results further revealed that UCP4 is preferentially localized in close vicinity to VDAC, presumably at the inner boundary membrane, whereas F0F1-ATP synthase is more centrally located at the cristae membrane. The data suggest that UCP4 cannot compete for protons because of its spatial separation from both the proton pumps and the ATP synthase. Thus, mitochondrial morphology precludes UCP4 from acting as an uncoupler of oxidative phosphorylation but is consistent with the view that UCP4 may dissipate the excessive proton gradient, which is usually associated with ROS production. PMID:25535394

The Scalar Resonances a0/f0(980) at COSY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buescher, M.

2006-02-11

Fundamental properties of the scalar resonances a0/f0(980), like their masses, widths and couplings to KK-bar, are poorly known. In particular, precise knowledge of the latter quantity would be of great importance since it can be related to the KK-bar content of these resonances.An experimental program is under way at COSY-Juelich aiming at the extraction of the isospin violating a0/f0 mixing amplitude {lambda} which is in leading order proportional to the product of the coupling constants of the a0 and f0 to kaons. a0/f0 production is studied in pp, pn and dd interactions, both for the KK-bar and the {pi}{eta}/{pi}{pi} decays,more » using the ANKE and WASA spectrometers. The latter will be available for measurements at COSY in 2007.As a first step, isovector KK-bar production has been measured in the reaction pp {yields} dK+K-bar0. The data reveal dominance of the a{sub 0}{sup +} channel, thus demonstrating the feasibility of scalar meson studies at COSY. Analyses of KK-bar- and K-bard-FSI effects yield the corresponding scattering lengths, a(KK-bar)I=1 = -(0.02 {+-} 0.03) - i(0.61 {+-} 0.05) fm and vertical bar Re a(K-bard) vertical bar {<=}1.3 fm, Im a(K-bard){<=}1.3 fm.« less

Actinide ion sensor for pyroprocess monitoring

DOEpatents

Jue, Jan-fong; Li, Shelly X.

2014-06-03

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

Positron Spectroscopy of Hydrothermally Grown Actinide Oxides

DTIC Science & Technology

2014-03-27

POSITRON SPECTROSCOPY OF HYDROTHERMALLY GROWN ACTINIDE OXIDES THESIS Edward C. Schneider...United States Government. AFIT-ENP-14-M-33 POSITRON SPECTROSCOPY OF HYDROTHERMALLY GROWN ACTINIDE OXIDES THESIS...33 POSITRON SPECTROSCOPY OF HYDROTHERMALLY GROWN ACTINIDE OXIDES Edward C. Schneider, BS Captain, USAF Approved

Seventeen-Coordinate Actinide Helium Complexes.

PubMed

Kaltsoyannis, Nikolas

2017-06-12

The geometries and electronic structures of molecular ions featuring He atoms complexed to actinide cations are explored computationally using density functional and coupled cluster theories. A new record coordination number is established, as AcHe 17 3+ , ThHe 17 4+ , and PaHe 17 4+ are all found to be true geometric minima, with the He atoms clearly located in the first shell around the actinide. Analysis of AcHe n 3+ (n=1-17) using the quantum theory of atoms in molecules (QTAIM) confirms these systems as having closed shell, charge-induced dipole bonding. Excellent correlations (R 2 >0.95) are found between QTAIM metrics (bond critical point electron densities and delocalization indices) and the average Ac-He distances, and also with the incremental He binding energies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Trivalent Lanthanide/Actinide Separation Using Aqueous-Modified TALSPEAK Chemistry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Travis S. Grimes; Richard D. Tillotson; Leigh R. Martin

TALSPEAK is a liquid/liquid extraction process designed to separate trivalent lanthanides (Ln3+) from minor actinides (MAs) Am3+ and Cm3+. Traditional TALSPEAK organic phase is comprised of a monoacidic dialkyl bis(2-ethylhexyl)phosphoric acid extractant (HDEHP) in diisopropyl benzene (DIPB). The aqueous phase contains a soluble aminopolycarboxylate diethylenetriamine-N,N,N’,N”,N”-pentaacetic acid (DTPA) in a concentrated (1.0-2.0 M) lactic acid (HL) buffer with the aqueous acidity typically adjusted to pH 3.0. TALSPEAK balances the selective complexation of the actinides by DTPA against the electrostatic attraction of the lanthanides by the HDEHP extractant to achieve the desired trivalent lanthanide/actinide group separation. Although TALSPEAK is considered a successfulmore » separations scheme, recent fundamental studies have highlighted complex chemical interactions occurring in the aqueous and organic phases during the extraction process. Previous attempts to model the system have shown thermodynamic models do not accurately predict the observed extraction trends in the p[H+] range 2.5-4.8. In this study, the aqueous phase is modified by replacing the lactic acid buffer with a variety of simple and longer-chain amino acid buffers. The results show successful trivalent lanthanide/actinide group separation with the aqueous-modified TALSPEAK process at pH 2. The amino acid buffer concentrations were reduced to 0.5 M (at pH 2) and separations were performed without any effect on phase transfer kinetics. Successful modeling of the aqueous-modified TALSPEAK process (p[H+] 1.6-3.1) using a simplified thermodynamic model and an internally consistent set of thermodynamic data is presented.« less

Ionic Interactions in Actinide Tetrahalides

NASA Astrophysics Data System (ADS)

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.

Exploring actinide materials through synchrotron radiation techniques.

PubMed

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

2014-12-10

Synchrotron radiation (SR) based techniques have been utilized with increasing frequency in the past decade to explore the brilliant and challenging sciences of actinide-based materials. This trend is partially driven by the basic needs for multi-scale actinide speciation and bonding information and also the realistic needs for nuclear energy research. In this review, recent research progresses on actinide related materials by means of various SR techniques were selectively highlighted and summarized, with the emphasis on X-ray absorption spectroscopy, X-ray diffraction and scattering spectroscopy, which are powerful tools to characterize actinide materials. In addition, advanced SR techniques for exploring future advanced nuclear fuel cycles dealing with actinides are illustrated as well. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

GGA + U studies of the early actinide mononitrides and dinitrides

NASA Astrophysics Data System (ADS)

Obodo, K. O.; Chetty, N.

2013-11-01

We present a detailed comparative study of the electronic and mechanical properties of the early actinide mononitrides and dinitrides within the framework of the Perdew-Burke-Ernzerhof generalized gradient approximation (GGA [PBE]) and GGA + U implementations of density functional theory with the inclusion of spin-orbit coupling. The dependence of selected observables of these materials on the effective U-parameter is investigated in detail. The properties include the lattice constant, bulk modulus, charge density distribution, hybridization of the atomic orbitals, energy of formation and the lattice dynamics. The inclusion of the Hubbard U parameter results in a proper description of the 5f electrons, and is subsequently used in the determination of the structural and electronic properties of these compounds. The mononitrides and dinitrides of the early actinides are metallic except for UN2, which is a semiconductor. These actinide nitrides are non-magnetic with the exception of UN, NpN, PuN, NpN2 and PuN2 that are magnetic systems with orbital-dependent magnetic moments oriented in the z-axis. We observed that ThN2 is elastically unstable to isotropic pressure. We discovered that UN2 is thermodynamically unstable, but may be stabilized by N vacancy formation.

Study of extraterrestrial disposal of radioactive wastes. Part 3: Preliminary feasibility screening study of space disposal of the actinide radioactive wastes with 1 percent and 0.1 percent fission product contamination

NASA Technical Reports Server (NTRS)

Hyland, R. E.; Wohl, M. L.; Finnegan, P. M.

1973-01-01

A preliminary study was conducted of the feasibility of space disposal of the actinide class of radioactive waste material. This waste was assumed to contain 1 and 0.1 percent residual fission products, since it may not be feasible to completely separate the actinides. The actinides are a small fraction of the total waste but they remain radioactive much longer than the other wastes and must be isolated from human encounter for tens of thousands of years. Results indicate that space disposal is promising but more study is required, particularly in the area of safety. The minimum cost of space transportation would increase the consumer electric utility bill by the order of 1 percent for earth escape and 3 percent for solar escape. The waste package in this phase of the study was designed for normal operating conditions only; the design of next phase of the study will include provisions for accident safety. The number of shuttle launches per year required to dispose of all U.S. generated actinide waste with 0.1 percent residual fission products varies between 3 and 15 in 1985 and between 25 and 110 by 2000. The lower values assume earth escape (solar orbit) and the higher values are for escape from the solar system.

PRODUCTION OF ACTINIDE METAL

DOEpatents

Knighton, J.B.

1963-11-01

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

The structure, mixing angle, mass and couplings of the light scalar f0(500) and f0(980) mesons

NASA Astrophysics Data System (ADS)

Agaev, S. S.; Azizi, K.; Sundu, H.

2018-06-01

The mixing angle, mass and couplings of the light scalar mesons f0 (500) and f0 (980) are calculated in the framework of QCD two-point sum rule approach by assuming that they are tetraquarks with diquark-antidiquark structures. The mesons are treated as mixtures of the heavy | H > = ([ su ] [ s bar u bar ] + [ sd ] [ s bar d bar ]) /√{ 2 } and light | L > = [ ud ] [ u bar d bar ] scalar diquark-antidiquark components. We extract from corresponding sum rules the mixing angles φH and φL of these states and evaluate the masses and couplings of the particles f0 (500) and f0 (980).

Electric dipole moments of actinide atoms and RaO molecule

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flambaum, V. V.

We have calculated the atomic electric dipole moments (EDMs) induced in {sup 229}Pa and {sup 225}Ac by their respective nuclear Schiff moments S. The results are d({sup 229}Pa)=-9.5x10{sup -17} [S/(e fm)]e cm=-1.1x10{sup -20}{eta} e cm and d({sup 225}Ac)=-8.6x10{sup -17} [S/(e fm)]e cm=-0.8x10{sup -21}{eta} e cm. EDM of {sup 229}Pa is 3x10{sup 4} times larger than {sup 199}Hg EDM and 40 times larger than {sup 225}Ra EDM. Possible use of actinides in solid state experiments is also discussed. The (T,P)-odd spin-axis interaction in RaO molecule is 500 times larger than in TlF.

PROCESS OF PRODUCING ACTINIDE METALS

DOEpatents

Magel, T.T.

1959-07-14

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

Nuclear waste forms for actinides

PubMed Central

Ewing, Rodney C.

1999-01-01

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

Gas core reactors for actinide transmutation. [uranium hexafluoride

NASA Technical Reports Server (NTRS)

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

1979-01-01

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

On the valence fluctuation in the early actinide metals

DOE PAGES

Soderlind, P.; Landa, A.; Tobin, J. G.; ...

2015-12-15

In this study, 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 3 and f 4 configurations, respectively, with only minor contributions from other configurations. For plutonium (both αmore » 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 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.« less

Final Project Report for ER15351 “A Study of New Actinide Zintl Ion Materials”

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peter K. Dorhout

2007-11-12

The structural chemistry of actinide main-group metal materials provides the fundamental basis for the understanding of structural coordination chemistry and the formation of materials with desired or predicted structural features. The main-group metal building blocks, comprising sulfur-group, phosphorous-group, or silicon-group elements, have shown versatility in oxidation state, coordination, and bonding preferences. These building blocks have allowed us to elucidate a series of structures that are unique to the actinide elements, although we can find structural relationships to transition metal and 4f-element materials. In the past year, we investigated controlled metathesis and self-propagating reactions between actinide metal halides and alkali metalmore » salts of main-group metal chalcogenides such as K-P-S salts. Ternary plutonium thiophosphates have resulted from these reactions at low temperature in sealed ampules. we have also focused efforts to examine reactions of Th, U, and Pu halide salts with other alkali metal salts such as Na-Ge-S and Na-Si-Se and copper chloride to identify if self-propagating reactions may be used as a viable reaction to prepare new actinide materials and we prepared a series of U and Th copper chalcogenide materials. Magnetic measurements continued to be a focus of actinide materials prepared in our laboratory. We also contributed to the XANES work at Los Alamos by preparing materials for study and for comparison with environmental samples.« less

Influence of microorganisms on the oxidation state distribution of multivalent actinides under anoxic conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, Donald Timothy; Borkowski, Marian; Lucchini, Jean - Francois

2010-12-10

The fate and potential mobility of multivalent actinides in the subsurface is receiving increased attention as the DOE looks to cleanup the many legacy nuclear waste sites and associated subsurface contamination. Plutonium, uranium and neptunium are the near-surface multivalent contaminants of concern and are also key contaminants for the deep geologic disposal of nuclear waste. Their mobility is highly dependent on their redox distribution at their contamination source as well as along their potential migration pathways. This redox distribution is often controlled, especially in the near-surface where organic/inorganic contaminants often coexist, by the direct and indirect effects of microbial activity.more » Under anoxic conditions, indirect and direct bioreduction mechanisms exist that promote the prevalence of lower-valent species for multivalent actinides. Oxidation-state-specific biosorption is also an important consideration for long-term migration and can influence oxidation state distribution. Results of ongoing studies to explore and establish the oxidation-state specific interactions of soil bacteria (metal reducers and sulfate reducers) as well as halo-tolerant bacteria and Archaea for uranium, neptunium and plutonium will be presented. Enzymatic reduction is a key process in the bioreduction of plutonium and uranium, but co-enzymatic processes predominate in neptunium systems. Strong sorptive interactions can occur for most actinide oxidation states but are likely a factor in the stabilization of lower-valent species when more than one oxidation state can persist under anaerobic microbiologically-active conditions. These results for microbiologically active systems are interpreted in the context of their overall importance in defining the potential migration of multivalent actinides in the subsurface.« less

PREPARATION OF ACTINIDE-ALUMINUM ALLOYS

DOEpatents

Moore, R.H.

1962-09-01

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

Superabsorbing gel for actinide, lanthanide, and fission product decontamination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaminski, Michael D.; Mertz, Carol J.

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)more » 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.« less

RECOVERY OF ACTINIDES FROM AQUEOUS NITRIC ACID SOLUTIONS

DOEpatents

Ader, M.

1963-11-19

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

Rapid determination of actinides in seawater samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

2014-03-09

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

Preparation of actinide boride materials via solid-state metathesis reactions and actinide dicarbollide precursors

NASA Astrophysics Data System (ADS)

Lupinetti, Anthony J.; Fife, Julie; Garcia, Eduardo; Abney, Kent D.

2000-07-01

Information gaps exist in the knowledge base needed for choosing among the alternate processes to be used in the safe conversion of fissile materials to optimal forms for safe interim storage, long-term storage, and ultimate disposition. The current baseline storage technology for various wastes uses borosilicate glasses.1 The focus of this paper is the synthesis of actinide-containing ceramic materials at low and moderate temperatures (200 °C-1000 °C) using molecular and polymeric actinide borane and carborane complexes.

Separation of actinides from lanthanides utilizing molten salt electrorefining

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grimmett, D.L.; Fusselman, S.P.; Roy, J.J.

1996-10-01

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

Prompt fission neutron spectra of actinides

DOE PAGES

Capote, R.; Chen, Y. -J.; Hambsch, F. -J.; ...

2016-01-06

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

Isoliquiritigenin-Induced Differentiation in Mouse Melanoma B16F0 Cell Line

PubMed Central

Chen, Xiaoyu; Zhang, Bo; Yuan, Xuan; Yang, Fan; Liu, Jinglei; Zhao, Hong; Liu, Liangliang; Wang, Yanming; Wang, Zhenhua; Zheng, Qiusheng

2012-01-01

The chemotherapeutical treatment is very limited for malignant melanoma, a highly lethal disease occurs globally. Natural products derived from traditional Chinese medicine licorice are attractive in quest new treatments due to their anti-tumor activities. A new dietary flavonoid isoliquiritigenin (ISL) were thus investigated to indentify its anti-melanoma activities on mouse melanoma B16F0 cells in present study. Using biochemical and free radical biological experiments in vitro, we identified the pro-differentiated profiles of ISL and evaluated the role of reactive oxygen species (ROS) during B16F0 cell differentiation. The data showed a strong dose-response relationship between ISL exposure and the characteristics of B16F0 differentiation in terms of morphology changes and melanogenesis. The accumulated intercellular ROS during exposure are necessary to support ISL-induced differentiation, which was proven by additional redox modulators. It was confirmed further by the relative activities of enzymes and genes modulated melanogenesis in ISL-treatments with or without ROS modulators. The tumorigenicity of ISL-treated cells was limited significantly by using the colony formation assay in vitro and an animal model assay in vivo respectively. Our research demonstrated that isoliquiritigenin is a differentiation-inducing agent, and its mechanisms involve ROS accumulation facilitating melanogenesis. PMID:23304254

Isoliquiritigenin-induced differentiation in mouse melanoma B16F0 cell line.

PubMed

Chen, Xiaoyu; Zhang, Bo; Yuan, Xuan; Yang, Fan; Liu, Jinglei; Zhao, Hong; Liu, Liangliang; Wang, Yanming; Wang, Zhenhua; Zheng, Qiusheng

2012-01-01

The chemotherapeutical treatment is very limited for malignant melanoma, a highly lethal disease occurs globally. Natural products derived from traditional Chinese medicine licorice are attractive in quest new treatments due to their anti-tumor activities. A new dietary flavonoid isoliquiritigenin (ISL) were thus investigated to indentify its anti-melanoma activities on mouse melanoma B16F0 cells in present study. Using biochemical and free radical biological experiments in vitro, we identified the pro-differentiated profiles of ISL and evaluated the role of reactive oxygen species (ROS) during B16F0 cell differentiation. The data showed a strong dose-response relationship between ISL exposure and the characteristics of B16F0 differentiation in terms of morphology changes and melanogenesis. The accumulated intercellular ROS during exposure are necessary to support ISL-induced differentiation, which was proven by additional redox modulators. It was confirmed further by the relative activities of enzymes and genes modulated melanogenesis in ISL-treatments with or without ROS modulators. The tumorigenicity of ISL-treated cells was limited significantly by using the colony formation assay in vitro and an animal model assay in vivo respectively. Our research demonstrated that isoliquiritigenin is a differentiation-inducing agent, and its mechanisms involve ROS accumulation facilitating melanogenesis.

Fusion barrier characteristics of actinides

NASA Astrophysics Data System (ADS)

Manjunatha, H. C.; Sridhar, K. N.

2018-03-01

We have studied fusion barrier characteristics of actinide compound nuclei with atomic number range 89 ≤ Z ≤ 103 for all projectile target combinations. After the calculation of fusion barrier heights and positions, we have searched for their parameterization. We have achieved the empirical formula for fusion barrier heights (VB), positions (RB), curvature of the inverted parabola (ħω) of actinide compound nuclei with atomic number range 89 ≤ Z ≤ 103 for all projectile target combinations (6 actinides with the simple inputs of mass number (A) and atomic number (Z) of projectile-targets.

Crystal growth methods dedicated to low solubility actinide oxalates

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tamain, C., E-mail: christelle.tamain@cea.fr; Arab-Chapelet, B.; Rivenet, M.

Two novel crystal growth syntheses dedicated to low solubility actinide-oxalate systems and adapted to glove box handling are described. These methods based on the use of precursors of either actinide metal or oxalic acid have been optimized on lanthanide systems (analogue of actinides(III)) and then assessed on real actinide systems. They allow the synthesis of several actinide oxalate single crystals, Am{sub 2}(C{sub 2}O{sub 4}){sub 3}(H{sub 2}O){sub 3}·xH{sub 2}O, Th(C{sub 2}O{sub 4}){sub 2}·6H{sub 2}O, M{sub 2+x}[Pu{sup IV}{sub 2−x}Pu{sup III}{sub x}(C{sub 2}O{sub 4}){sub 5}]·nH{sub 2}O and M{sub 1−x}[Pu{sup III}{sub 1−x}Pu{sup IV}{sub x}(C{sub 2}O{sub 4}){sub 2}·H{sub 2}O]·nH{sub 2}O. It is the first timemore » that these well-known compounds are formed by crystal growth methods, thus enabling direct structural studies on transuranic element systems and acquisition of basic data beyond deductions from isomorphic (or not) lanthanide compounds. Characterizations by X-ray diffraction, UV–visible solid spectroscopy, demonstrate the potentialities of these two crystal growth methods to obtain oxalate compounds. - Graphical abstract: Two new single crystal growth methods dedicated to actinide oxalate compounds. - Highlights: • Use of diester as oxalate precursor for crystal growth of actinide oxalates. • Use of actinide oxide as precursor for crystal growth of actinide oxalates. • Crystal growth of Pu(III) and Am(III) oxalates. • Crystal growth of mixed Pu(III)/Pu(IV) oxalates.« less

Analysis of large soil samples for actinides

DOEpatents

Maxwell, III; Sherrod, L [Aiken, SC

2009-03-24

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

Transmutation of actinides in power reactors.

PubMed

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

2005-01-01

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

The R-Process Alliance: 2MASS J09544277+5246414, the Most Actinide-enhanced R-II Star Known

NASA Astrophysics Data System (ADS)

Holmbeck, Erika M.; Beers, Timothy C.; Roederer, Ian U.; Placco, Vinicius M.; Hansen, Terese T.; Sakari, Charli M.; Sneden, Christopher; Liu, Chao; Lee, Young Sun; Cowan, John J.; Frebel, Anna

2018-06-01

We report the discovery of a new actinide-boost star, 2MASS J09544277+5246414, originally identified as a very bright (V = 10.1), extremely metal-poor ([Fe/H] = ‑2.99) K giant in the LAMOST survey, and found to be highly r-process-enhanced (r-II; [Eu/Fe] = +1.28]), during the snapshot phase of the R-Process Alliance (RPA). Based on a high signal-to-noise ratio (S/N), high-resolution spectrum obtained with the Harlan J. Smith 2.7 m telescope, this star is the first confirmed actinide-boost star found by RPA efforts. With an enhancement of [Th/Eu] = +0.37, 2MASS J09544277+5246414 is also the most actinide-enhanced r-II star yet discovered, and only the sixth metal-poor star with a measured uranium abundance ([U/Fe] = +1.40). Using the Th/U chronometer, we estimate an age of 13.0 ± 4.7 Gyr for this star. The unambiguous actinide-boost signature of this extremely metal-poor star, combined with additional r-process-enhanced and actinide-boost stars identified by the RPA, will provide strong constraints on the nature and origin of the r-process at early times.

Chromium chains as polydentate fluoride ligands for actinides and group IV metals.

PubMed

Leng, Ji-Dong; Kostopoulos, Andreas K; Isherwood, Liam H; Ariciu, Ana-Maria; Tuna, Floriana; Vitórica-Yrezábal, Iñigo J; Pritchard, Robin G; Whitehead, George F S; Timco, Grigore A; Mills, David P; Winpenny, Richard E P

2018-05-08

The reactions of {Cr6} horseshoe chains {[nPr2NH2]3[Cr6F11(O2CtBu)10]}2, 1 and precursors of actinides and group IV metals led to a series of ring complexes [nPr2NH2][Cr7TiF6O2(O2CtBu)16], 2, [nPr2NH2][Cr6Ti2F5O3(O2CtBu)16], 3, [Cr6ThF7(O2CtBu)15 (Me2SO)], 4, [(nPr2NH2)2(Cr6Th2F12(O2CtBu)16)], 5 and [nPr2NH2][Cr6U2O2F8(O2CtBu)16(Me2SO)], 6. X-ray structure studies indicate that the {Cr6} chains maintain their structures in these complexes, acting as polydentate fluoride ligands. Their static magnetic properties were measured and fitted by isotropic exchange Hamiltonian. In accordance with 1, the magnetic exchanges between CrIII are antiferromagnetic, while the exchange interactions can be modified by the tetravalent metals. For compound 6, ferromagnetic exchanges JCr-U and JU-U are obtained. EPR spectra of compounds 2-5 were measured at Q band and were simulated. The spectrum of 2 has the same profile as {Cr7Cd} and {Cr7Zn} rings with a ground state S = 3/2. 3, 4 and 5 give similar EPR spectra with S = 0 ground states.

Analysis of the Gas Core Actinide Transmutation Reactor (GCATR)

NASA Technical Reports Server (NTRS)

Clement, J. D.; Rust, J. H.

1977-01-01

Design power plant studies were carried out for two applications of the plasma core reactor: (1) As a breeder reactor, (2) As a reactor able to transmute actinides effectively. In addition to the above applications the reactor produced electrical power with a high efficiency. A reactor subsystem was designed for each of the two applications. For the breeder reactor, neutronics calculations were carried out for a U-233 plasma core with a molten salt breeding blanket. A reactor was designed with a low critical mass (less than a few hundred kilograms U-233) and a breeding ratio of 1.01. The plasma core actinide transmutation reactor was designed to transmute the nuclear waste from conventional LWR's. The spent fuel is reprocessed during which 100% of Np, Am, Cm, and higher actinides are separated from the other components. These actinides are then manufactured as oxides into zirconium clad fuel rods and charged as fuel assemblies in the reflector region of the plasma core actinide transmutation reactor. In the equilibrium cycle, about 7% of the actinides are directly fissioned away, while about 31% are removed by reprocessing.

Nonaqueous method for dissolving lanthanide and actinide metals

DOEpatents

Crisler, L.R.

1975-11-11

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

High-resolution X-ray absorption spectroscopy as a probe of crystal-field and covalency effects in actinide compounds

DOE PAGES

Butorin, Sergei M.; Kvashnina, Kristina O.; Vegelius, Johan R.; ...

2016-07-01

Applying the high-energy resolution fluorescence-detection (HERFD) mode of X-ray absorption spectroscopy (XAS), we were able to probe, for the first time to our knowledge, the crystalline electric field (CEF) splittings of the 5f shell directly in the HERFD-XAS spectra of actinides. Using ThO 2 as an example, data measured at the Th 3d edge were interpreted within the framework of the Anderson impurity model. Because the charge-transfer satellites were also resolved in the HERFD-XAS spectra, the analysis of these satellites revealed that ThO 2 is not an ionic compound as previously believed. The Th 6d occupancy in the ground statemore » was estimated to be twice that of the Th 5f states. Here, we demonstrate that HERFD-XAS allows for characterization of the CEF interaction and degree of covalency in the ground state of actinide compounds as it is extensively done for 3d transition metal systems.« less

Impact of minor actinide recycling on sustainable fuel cycle options

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heidet, F.; Kim, T. K.; Taiwo, T. A.

The recent Evaluation and Screening study chartered by the U.S. Department of Energy, Office of Nuclear Energy, has identified four fuel cycle options as being the most promising. Among these four options, the two single-stage fuel cycles rely on a fast reactor and are differing in the fact that in one case only uranium and plutonium are recycled while in the other case minor actinides are also recycled. The two other fuel cycles are two-stage and rely on both fast and thermal reactors. They also differ in the fact that in one case only uranium and plutonium are recycled whilemore » in the other case minor actinides are also recycled. The current study assesses the impact of recycling minor actinides on the reactor core design, its performance characteristics, and the characteristics of the recycled material and waste material. The recycling of minor actinides is found not to affect the reactor core performance, as long as the same cycle length, core layout and specific power are being used. One notable difference is that the required transuranics (TRU) content is slightly increased when minor actinides are recycled. The mass flows are mostly unchanged given a same specific power and cycle length. Although the material mass flows and reactor performance characteristics are hardly affected by recycling minor actinides, some differences are observed in the waste characteristics between the two fuel cycles considered. The absence of minor actinides in the waste results in a different buildup of decay products, and in somewhat different behaviors depending on the characteristic and time frame considered. Recycling of minor actinides is found to result in a reduction of the waste characteristics ranging from 10% to 90%. These results are consistent with previous studies in this domain and depending on the time frame considered, packaging conditions, repository site, repository strategy, the differences observed in the waste characteristics could be beneficial and help

Phytosiderophore effects on subsurface actinide contaminants: potential for phytostabilization and phytoextraction.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruggiero, C. E.; Twary, S. N.; Deladurantaye, E.

2003-01-01

In recognition of the need for a safe, effective technology for long term Pu/Th/Actinide stabilization or removal from soils, we have begun an investigation of the potential for phytoremediation (phytostabilization and/or phytoextraction) of Pu and other actinide soil contaminants at DOE sites using phytosiderophore producing plants, and are investigating the contribution of phytosiderophores to actinide mobility in the subsurface environment. Phytoremediation and Phytostabilization have been proven to be a cost-effective, safe, efficient, and publicly acceptable technology for clean up and/or stabilization of contaminant metals . However, no phyto-based technologies have been developed for stabilization or removal of plutonium from soilsmore » and groundwater, and very few have been investigated for other actinides . Current metal-phytostabilization and phytoremediation techniques, predominately based around lead, nickel, and other soft-metal phytoextraction, will almost certainly be inadequate for plutonium due its distinct chemical properties . Phytosiderophore-based phytoremediation may provide technically and financially practical methods for remediation and long-term stewardship of soils that have low to moderate, near surface actinide contamination . We plan to demonstrate potential benefits of phytosiderophore-producing plants for long-term actinide contaminant stabilization by the plant's prevention of soil erosion and actinide migration through hydraulic control and/or through actinide removal through phytoextraction . We may also show possible harm caused by these plants through increased presence of actinide chelators that could increase actinide mobilization and migration in the subsurface environment. This information can then be directly applied by either removal of harmful plants, or be used to develop plant-based soil stabilization/remediation technologies .« less

Actinides in deer tissues at the rocky flats environmental technology site.

PubMed

Todd, Andrew S; Sattelberg, R Mark

2005-11-01

Limited hunting of deer at the future Rocky Flats National Wildlife Refuge has been proposed in U.S. Fish and Wildlife planning documents as a compatible wildlife-dependent public use. Historically, Rocky Flats site activities resulted in the contamination of surface environmental media with actinides, including isotopes of americium, plutonium, and uranium. In this study, measurements of actinides [Americium-241 (241Am); Plutonium-238 (238Pu); Plutonium-239,240 (239,240Pu); uranium-233,244 (233,234U); uranium-235,236 (235,236U); and uranium-238 (238U)] were completed on select liver, muscle, lung, bone, and kidney tissue samples harvested from resident Rocky Flats deer (N = 26) and control deer (N = 1). In total, only 17 of the more than 450 individual isotopic analyses conducted on Rocky Flats deer tissue samples measured actinide concentrations above method detection limits. Of these 17 detects, only 2 analyses, with analytical uncertainty values added, exceeded threshold values calculated around a 1 x 10(-6) risk level (isotopic americium, 0.01 pCi/g; isotopic plutonium, 0.02 pCi/g; isotopic uranium, 0.2 pCi/g). Subsequent, conservative risk calculations suggest minimal human risk associated with ingestion of these edible deer tissues. The maximum calculated risk level in this study (4.73 x 10(-6)) is at the low end of the U.S. Environmental Protection Agency's acceptable risk range.

Rapid determination of actinides in asphalt samples

DOE PAGES

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

2014-01-12

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

Simultaneous real-time PCR detection of Fusarium asiaticum, F. ussurianum and F. vorosii, representing the Asian clade of the F. graminearum species complex.

PubMed

Fernández-Ortuño, Dolores; Waalwijk, Cees; Van der Lee, Theo; Fan, Jieru; Atkins, Sarah; West, Jonathan S; Fraaije, Bart A

2013-08-16

Due to the repeated discovery of new members of the Fusarium graminearum species complex (FGSC), some of the F. graminearum sensu stricto (s.s.)-specific qPCR assays developed to date have since been shown to be non-specific. In this study, a probe-based qPCR method was developed, targeting a sterol 14-alpha demethylase (CYP51) paralogue, CYP51C unique to the genus Fusarium, for the simultaneous detection of F. asiaticum, F. ussurianum and F. vorosii. Specificity of the assay was demonstrated for a wide range of Fusarium species, including all tested FGSC members (n=6), originating from different hosts and geographic regions. Alongside a previously published assay for detection of F. graminearum, we were able to show that members of the Asian clade of the FGSC (i.e. F. asiaticum, F. ussurianum and F. vorosii) were the primary etiological agent in wheat seeds samples originating from Central-East China. The grain samples from the UK tested negative for the presence of the FGSC's Asian clade and positive for presence of F. graminearum. It is likely that only F. graminearum s.s. is present in the UK, but the presence of other FGSC members cannot be ruled out and need further investigation. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of obstruent consonants on the F0 contour

NASA Astrophysics Data System (ADS)

Hanson, Helen M.

2003-10-01

When a vowel follows an obstruent consonant, the fundamental frequency in the first few tens of milliseconds of the vowel is influenced by the voicing characteristics of the consonant. The goal of the research reported here is to model this influence, with the intention of improving generation of F0 contours in rule-based speech synthesis. Data have been recorded from 10 subjects. Stops, fricatives, and the nasal /m/ were paired with the vowels /i,opena/ to form CVm syllables. The syllables mVm served as baselines with which to compare the obstruents. The target syllables were embedded in carrier sentences. Intonation was varied so that each target syllable was produced with either a high, low, or no pitch accent. Results vary among subjects, but in general, obstruent effects on F0 primarily occur when the syllable carries a high pitch. In that case, F0 is increased relative to the baseline following voiceless obstruents, but F0 closely follows the baseline following voiced obstruents. After voiceless obstruents, F0 may be increased for up to 80 ms following voicing onset. When a syllable carries a low or no pitch accent, F0 is increased slightly following all obstruents. [Work supported by NIH Grant No. DC04331.

New cubic structure compounds as actinide host phases

NASA Astrophysics Data System (ADS)

Stefanovsky, S. V.; Yudintsev, S. V.; Livshits, T. S.

2010-03-01

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 Gd2Zr2O7) has excellent radiation resistance and high chemical durability but requires high temperatures (at least 1500 °C) to be produced by hot-pressing from sol-gel derived precursor. Partial Sn4+ substitution for Zr4+ reduces production temperature and the compounds REE2ZrSnO7 may be hot-pressed or cold pressed and sintered at ~1400 °C. Pyrochlore, A2B2O7-x (two-fold elementary fluorite unit cell), and murataite, A3B6C2O20-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. % AnO2 (An = Th, U, Np, Pu) or REE/An fraction of HLW form at crystallization zoned grains composed sequentially of the 5C → 8C → 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 more promising actinide hosts are ferrites with garnet structure. The matrices containing sometime complex fluorite

Qualitative analysis of ionospheric disorders in Solok earthquake (March 6, 2007) viewed from anomalous critical frequency of layer F (f0F2) and genesis spread F

NASA Astrophysics Data System (ADS)

Pujiastuti, D.; Daniati, S.; Taufiqurrahman, E.; Mustafa, B.; Ednofri

2018-03-01

A qualitative analysis has been conducted by comparing the critical frequency anomalies of layer F (f0F2) and Spread F events to see the correlation with seismic activity before the Solok earthquake (March 6, 2007) in West Sumatra. The ionospherics data used was taken using the FMCW ionosonde at LAPAN SPD Kototabang, Palupuah, West Sumatra. The process of ionogramme scaling is done first to get the daily value of f0F2. The value of f0F2 is then compared with its monthly median to see the daily variations that appear. Anomalies of f0F2 and Spread F events were observed from February 20, 2007 to March 6, 2007. The presence of f0F2 anomalies was the negative deviation and the presence of Spread F before earthquake events were recommended as Solok earthquake precursors as they occurred when geomagneticsics and solar activities were normal.

Method for extracting lanthanides and actinides from acid solutions by modification of Purex solvent

DOEpatents

Horwitz, E.P.; Kalina, D.G.

1984-05-21

A process has been developed for the extraction of multivalent lanthanide and actinide values from acidic waste solutions, and for the separation of these values from fission product and other values, which utilizes a new series of neutral bi-functional extractants, the alkyl(phenyl)-N, N-dialkylcarbamoylmethylphosphine oxides, in combination with a phase modifier to form an extraction solution. The addition of the extractant to the Purex process extractant, tri-n-butylphosphate in normal paraffin hydrocarbon diluent, will permit the extraction of multivalent lanthanide and actinide values from 0.1 to 12.0 molar acid solutions.

Superconducting fluctuation effect in CaFe0.88Co0.12AsF

NASA Astrophysics Data System (ADS)

Xiao, H.; Gao, B.; Ma, Y. H.; Li, X. J.; Mu, G.; Hu, T.

2016-11-01

Out-of-plane angular dependent torque measurements were performed on CaFe0.88Co0.12AsF single crystals. Superconducting fluctuations, featured by magnetic field enhanced and exponential temperature dependent diamagnetism, are observed above the superconducting transition temperature T c, which is similar to that of cuprate superconductors, but less pronounced. In addition, the ratio of T c versus superfluid density follows well the Uemura line of high-T c cuprates, which suggests the exotic nature of the superconductivity in CaFe0.88Co0.12AsF.

Towards Synthesis and Usage of Actinide-Bearing REE Phosphate age Standards: A Progress Report

NASA Astrophysics Data System (ADS)

Pyle, J. M.; Cherniak, D. J.

2006-05-01

Electron microprobe (EMP) dates result from a concentration-time unit conversion, so use of a concentration- based (rather than isotope-ratio based) fictive age standard is warranted. This observation has motivated our mineral synthesis program, aimed at producing actinide-doped REE phosphate EMP dating standards that meet the following criteria: 1) known concentrations of U, Th, and Pb; 2) homogeneous intragrain distribution of all components; 3) of suitable size, either as a single-crystal or polycrystalline sintered ceramic. Single-crystal synthesis of actinide-doped LaPO4 by flux-growth methods results in disproportionation of lanthanide and flux, alkali, and actinide components into phosphate and oxide phases, respectively, and flux- growth methods were abandoned. Actinide-doped La phosphate is successfully prepared by high-T annealing and hydrothermal processing of microcrystalline phosphate; both homogeneity and charge-balance of (Ca, Th, Pb)-bearing LaPO4 increase with increasing solvent acidity during cold-seal hydrothermal synthesis. A combination of pressing and high-T (1400° C) sintering transforms fine-grained (0.1-10 μm) run- products to ceramic pellets with 90-95% theoretical density. Our most recent runs focused on a target composition of La80(CaTh)17(CaU)2(PbTh)1PO4 processed with 6% 2M HCl at 820° C, 0.75 kbar for 1 week. The run products are 0.1-2 μm crystals identified by XRD as La-actinide phosphate solid solution. 2 μm grains (N=16) give a composition (mean±2 sd) of La79.77(1.26)(CaTh)17.87(1.00)(CaU)1.53(0.42)(PbTh)0.82(0.09)PO4. Th (8.07-9.13 wt. %) is homogeneous at the level of analytical precision, and the Pb concentration range (3500-4350 ppm) is restricted relative to untreated precipitate. Uranium concentration values are more variable (6500-10000 ppm). This run yields a fictive age of 702±4 Ma (mean±2 se), compared to the fictive age of 794 Ma for the target composition.

Bidentate organophosphorus solvent extraction process for actinide recovery and partition

DOEpatents

Schulz, Wallace W.

1976-01-01

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

Probing new physics in B→f0(980)K decays

NASA Astrophysics Data System (ADS)

Giri, A. K.; Mawlong, B.; Mohanta, R.

2006-12-01

We study the hadronic decay modes B±(0)→f0(980)K±(0), involving a scalar and a pseudoscalar meson in the final state. These decay modes are dominated by the loop induced b→sq¯q(q=s,u,d) penguins along with a small b→u tree level transition (for B+→f0K+) and annihilation diagrams. Therefore, the standard model expectation of direct CP violation is negligibly small and the mixing-induced CP violation parameter in the mode B0→f0KS is expected to give the same value of sin⁡(2β), as extracted from B0→J/ψKS but with opposite sign. Using the generalized factorization approach we find the direct CP violation in the decay mode B+→f0K+ to be of the order of few percent. We then study the effect of the R-parity violating supersymmetric model and show that the direct CP violating asymmetry in B+→f0(980)K+ could be as large as ˜80% and the mixing-induced CP asymmetry in B0→f0KS (i.e., -Sf0KS) could deviate significantly from that of sin⁡(2β)J/ψKS.

Imaging the Formation of High-Energy Dispersion Anomalies in the Actinide UCoGa5

NASA Astrophysics Data System (ADS)

Das, Tanmoy; Durakiewicz, Tomasz; Zhu, Jian-Xin; Joyce, John J.; Sarrao, John L.; Graf, Matthias J.

2012-10-01

We use angle-resolved photoemission spectroscopy to image the emergence of substantial dispersion and spectral-weight anomalies in the electronic renormalization of the actinide compound UCoGa5 that was presumed to belong to a conventional Fermi-liquid family. Kinks or abrupt breaks in the slope of the quasiparticle dispersion are detected both at low (approximately 130 meV) and high (approximately 1 eV) binding energies below the Fermi energy, ruling out any significant contribution of phonons. We perform numerical calculations to demonstrate that the anomalies are adequately described by coupling between itinerant fermions and spin fluctuations arising from the particle-hole continuum of the spin-orbit-split 5f states of uranium. These anomalies resemble the “waterfall” phenomenon of the high-temperature copper-oxide superconductors, suggesting that spin fluctuations are a generic route toward multiform electronic phases in correlated materials as different as high-temperature superconductors and actinides.

Growth of congruently melting Ca0.59Sr0.41F2 crystals and study of their properties

NASA Astrophysics Data System (ADS)

Karimov, D. N.; Komar'kova, O. N.; Sorokin, N. I.; Bezhanov, V. A.; Chernov, S. P.; Popov, P. A.; Sobolev, B. P.

2010-05-01

Homogeneous crystals of Ca0.59Sr0.41F2 alloy (sp. gr., Fm bar 3 m, a = 0.56057 nm), corresponding to the point of minimum in the melting curve in the CaF2-SrF2 phase diagram, have been grown by the vertical Bridgman method. The optical, mechanical, electrical, and thermophysical properties of Ca0.59Sr0.41F2 and MF2 crystals ( M = Ca, Sr) have been studied and comparatively analyzed. Ca0.59Sr0.41F2 crystals are transparent in the range of 0.133-11.5 μm, have refractive index n D = 1.436, microhardness H μ = 2.63 ± 0.10 GPa, ion conductivity σ = 5 × 10-5 S/cm at 825 K, and thermal conductivity k = 4.0 W m-1 K-1 at 300 K. It is shown that the optical properties of Ca0.59Sr0.41F2 crystals are intermediate between those of CaF2 and SrF2, whereas their mechanical and electrical characteristics are better than the latter compounds.

A Summary of Actinide Enrichment Technologies and Capability Gaps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patton, Bradley D.; Robinson, Sharon M.

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. This program 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 electromagnetic isotope separation (EMIS) device would have the capability to meet the future needs of the user community for enriched actinides. Themore » 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.« less

Synthesis of Actinide Fluoride Complexes Using Trimethyltin Fluoride as a Mild and Selective Fluorinating Reagent

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kagan, Benjamin D.; Lichtscheidl, Alejandro G.; Erickson, Karla A.

Trimethyltin fluoride (Me₃SnF) is a mild and selective reagent for the installation of actinide fluoride bonds as demonstrated by the room temperature synthesis of a variety of organometallic and inorganic thorium(IV), uranium(IV), and uranium(V) fluoride complexes ((1,2,4-tBu₃C₅H₂)₂ThF₂, (C₅Me₅)₂U(F)(O-2,6-iPr₂C₆H₃), U(F)(O-2,6-tBu₂C₆H₃)₃, U(F)[N(SiMe₃)₂]₃ (C₅Me₅)₂UF₂(L) (L = O=PMe₃, O=PPh₃, O=PCy₃), and (C₅Me₅)₂U(F)(=N-2,6-iPr₂C₆H₃)) from their corresponding chloride, bromide, and iodide analogues. From these reactions, the new (C₅Me₅)₂UF₂(L) (L = O=PPh₃, O=PCy₃) uranium fluoride complexes were isolated and characterized by NMR spectroscopy and X-ray crystallography.

Synthesis of Actinide Fluoride Complexes Using Trimethyltin Fluoride as a Mild and Selective Fluorinating Reagent

DOE PAGES

Kagan, Benjamin D.; Lichtscheidl, Alejandro G.; Erickson, Karla A.; ...

2017-11-07

Trimethyltin fluoride (Me₃SnF) is a mild and selective reagent for the installation of actinide fluoride bonds as demonstrated by the room temperature synthesis of a variety of organometallic and inorganic thorium(IV), uranium(IV), and uranium(V) fluoride complexes ((1,2,4-tBu₃C₅H₂)₂ThF₂, (C₅Me₅)₂U(F)(O-2,6-iPr₂C₆H₃), U(F)(O-2,6-tBu₂C₆H₃)₃, U(F)[N(SiMe₃)₂]₃ (C₅Me₅)₂UF₂(L) (L = O=PMe₃, O=PPh₃, O=PCy₃), and (C₅Me₅)₂U(F)(=N-2,6-iPr₂C₆H₃)) from their corresponding chloride, bromide, and iodide analogues. From these reactions, the new (C₅Me₅)₂UF₂(L) (L = O=PPh₃, O=PCy₃) uranium fluoride complexes were isolated and characterized by NMR spectroscopy and X-ray crystallography.

Imatinib mesylate induction of ROS-dependent apoptosis in melanoma B16F0 cells.

PubMed

Chang, Shao-Ping; Shen, Shing-Chuan; Lee, Woan-Rouh; Yang, Ling-Ling; Chen, Yen-Chou

2011-06-01

Imatinib mesylate (STI571), a protein tyrosine kinase inhibitor, was shown to reduce the viability of several cancer cell lines via apoptosis induction; however, the role of reactive oxygen species (ROS) in STI571-induced melanoma cell apoptosis is still undefined. In this study, we investigated the contribution of ROS to STI571-induced apoptosis in melanoma B16F0 cells, and the apoptotic mechanism elicited by STI571 was illustrated. Using an in vitro cell culture system, the effects of STI571 on ROS production, cell cycle progression, caspase activation, and mitochondrial functions were examined via Western blotting, a flow cytometric analysis, an enzyme activity assay, and a DNA integrity assay. In pharmacological studies, the ROS scavenger, N-acetyl cysteine (NAC), the NADPH oxidase inhibitor, dipheylene iodide (DPI), and mitogen-activated protein kinase (MAPK) inhibitors (PD98059, SP600125, and SB203580) were applied to investigate the mechanism. STI571 reduced the viability of melanoma cells B16F0, but not human skin fibroblasts WS1, via apoptosis induction. Besides, apoptosis induced by STI571 was inhibited by the addition of NAC and DPI, and an increase in the intracellular peroxide level by STI571 was identified in melanoma B16F0 cells. Activation of caspases 3 and 9 enzyme activities accompanied by disrupting the mitochondria membrane potential in according with stimulating JNK and p38 protein phosphorylation was identified in STI571-treated B16F0 cells. STI571-mediated a ROS-dependent apoptosis potentiated by JNK inhibitor SP600125 was first identified in melanoma B16F0 cells. Our results support the idea that ROS-dependent apoptosis in STI571-treated melanoma cells B16F0. The combination of a JNK inhibitor with STI571 for treating melanomas is suggested for further in vivo studies. Copyright © 2011 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

Actinide halide complexes

DOEpatents

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

1992-01-01

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

Actinide halide complexes

DOEpatents

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

1992-11-24

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

LIBS Spectral Data for a Mixed Actinide Fuel Pellet Containing Uranium, Plutonium, Neptunium and Americium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Judge, Elizabeth J.; Berg, John M.; Le, Loan A.

2012-06-18

interactions occurring within the plasma, such as collisional energy transfer, that might be a factor in the reduction in neptunium emission lines. Neptunium has to be analyzed alone using LIBS to further understand the dynamics that may be occurring in the plasma of the mixed actinide fuel pellet sample. The LIBS data suggests that the emission spectrum for the mixed actinide fuel pellet is not simply the sum of the emission spectra of the pure samples but is dependent on the species present in the plasma and the interactions and reactions that occur within the plasma. Finally, many of the neptunium lines are in the near infrared region which is drastically reduced in intensity by the current optical setup and possibly the sensitivity of the emission detector in the spectral region. Once the optics are replaced and the optical collection system is modified and optimized, the probability of observing emission lines for neptunium might be increased significantly. The mixed actinide fuel pellet was analyzed under the experimental conditions listed in Table 1. The LIBS spectra of the fuel pellet are shown in Figures 1-49. The spectra are labeled with the observed wavelength and atomic species (both neutral (I) and ionic (II)). Table 2 is a complete list of the observed and literature based emission wavelengths. The literature wavelengths have references including NIST Atomic Spectra Database (NIST), B.A. Palmer et al. 'An Atlas of Uranium Emission Intensities in a Hollow Cathode Discharge' taken at the Kitt Peak National Observatory (KPNO), R.L. Kurucz 1995 Atomic Line Data from the Smithsonian Astrophysical Observatory (SAO), J. Blaise et al. 'The Atomic Spectrum of Plutonium' from Argonne National Laboratory (BFG), and M. Fred and F.S. Tomkins, 'Preliminary Term Analysis of Am I and Am II Spectra' (FT). The dash (-) shown under Ionic State indicates that the ionic state of the transition was not available. In the spectra, the dash (-) is replaced with a question mark (?). Peaks

Chronopotentiometry of refractory metals, actinides and oxyanions in molten salts: A review

NASA Technical Reports Server (NTRS)

Bansal, Narottam P.

1992-01-01

The applications of chronopotentiometry to the study of electrochemical behavior of three technologically important areas of refractory metals, actinides, and oxyanions in molten salts are critically reviewed. Chronopotentiometry is a very versatile diagnostic tool to understand the reaction mechanism of the electrode processes for the electrochemical reduction/oxidation of these electroactive species in molten salt solutions. Well adherent, compact, and uniformly thick coatings of refractory metals may be electrodeposited from their solutions in molten salts.

Perception of relative location of F0 within the speaking range

NASA Astrophysics Data System (ADS)

Honorof, Douglas N.; Whalen, D. H.

2003-10-01

It has been argued that intrinsic fundamental frequency (IF0) is an automatic consequence of vowel production [Whalen et al., J. Phon. 27, 125-142 (1999)], yet speakers do not adjust F0 so as to overcome IF0. It may be that so adjusting F0 would distort information about F0 range-information important to the interpretation of F0. Therefore, a speech production/perception experiment was designed to determine whether listeners can perceive position within a speaker-specific F0 range on the basis of isolated tokens. Ten male and ten female adult native speakers of US English were recorded speaking (not singing) the vowel /a/ on eight different pitches spaced throughout speaker-specific ranges. Recordings were randomized across speakers. Naive listeners made pitch-magnitude estimates of the location of F0 relative to each speaker's range. Preliminary results show correlations between estimated and actual location within the range. Adjusting F0 to compensate for IF0 differences between vowels would seem to obscure voice quality in such a way as to make it difficult for the listener to recover relative F0, requiring a greater perceptual adjustment than simply normalizing for IF0. [Work supported by NIH Grant No. DC02717.

Tunnel-structured Na 0.66[Mn 0.66Ti 0.34]O 2-xF x(x <0.1) cathode for high performance sodium-ion batteries

DOE PAGES

Wang, Qin-Chao; Qiu, Qi-Qi; Xiao, Na; ...

2018-03-13

Sodium-ion batteries (SIBs) are attracting significant research attentions for large-scale energy storage applications. Cathode material is the vital part of SIBs to determine the capacity and cycle performance. Here, a series of F-doped Na 0.66[Mn 0.66Ti 0.34]O 2-xF x (x < 0.1) cathodes with tunnel structure are designed and synthesized aiming to enlarge the sodium diffusion paths. The lattice parameters of unit cell are tuned successfully by adjusting F doping amount. Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 with the optimized stoichiometry exhibits a reversible capacity of 97 mAh g -1 and promising cycle performance (85 mAh g -1 is maintainedmore » at 2C after 1000 cycles) with extremely low voltage polarization. More significantly, Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 exhibits superior low temperature performance, owing to the much enhanced thermodynamics and kinetics benefited from F doping. In conclusion, this strategy may open new opportunities to design advanced intercalation-type cathode materials for sodium ion batteries, especially for low-temperature applications.« less

Tunnel-structured Na 0.66[Mn 0.66Ti 0.34]O 2-xF x(x <0.1) cathode for high performance sodium-ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Qin-Chao; Qiu, Qi-Qi; Xiao, Na

Sodium-ion batteries (SIBs) are attracting significant research attentions for large-scale energy storage applications. Cathode material is the vital part of SIBs to determine the capacity and cycle performance. Here, a series of F-doped Na 0.66[Mn 0.66Ti 0.34]O 2-xF x (x < 0.1) cathodes with tunnel structure are designed and synthesized aiming to enlarge the sodium diffusion paths. The lattice parameters of unit cell are tuned successfully by adjusting F doping amount. Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 with the optimized stoichiometry exhibits a reversible capacity of 97 mAh g -1 and promising cycle performance (85 mAh g -1 is maintainedmore » at 2C after 1000 cycles) with extremely low voltage polarization. More significantly, Na 0.66[Mn 0.66Ti 0.34]O 1.94F 0.06 exhibits superior low temperature performance, owing to the much enhanced thermodynamics and kinetics benefited from F doping. In conclusion, this strategy may open new opportunities to design advanced intercalation-type cathode materials for sodium ion batteries, especially for low-temperature applications.« less

The Framework for 0-D Atmospheric Modeling (F0AM) v3.1

NASA Technical Reports Server (NTRS)

Wolfe, Glenn M.; Marvin, Margaret R.; Roberts, Sandra J.; Travis, Katherine R.; Liao, Jin

2016-01-01

The Framework for 0-D Atmospheric Modeling(F0AM) is a flexible and user-friendly MATLAB-based platform for simulation of atmospheric chemistry systems. The F0AM interface incorporates front-end configuration of observational constraints and model setups, making it readily adaptable to simulation of photochemical chambers, Lagrangian plumes, and steady-state or time-evolving solar cycles. Six different chemical mechanisms and three options for calculation of photolysis frequencies are currently available. Example simulations are presented to illustrate model capabilities and, more generally, highlight some of the advantages and challenges of 0-D box modeling.

Actinide targets for the synthesis of super-heavy elements

DOE PAGES

Roberto, J.; Alexander, Charles W.; Boll, Rose Ann; ...

2015-06-18

Since 2000, six new super-heavy elements with atomic numbers 113 through 118 have been synthesized in hot fusion reactions of 48Ca beams on actinide targets. These target materials, including 242Pu, 244Pu, 243Am, 245Cm, 248Cm, 249Cf, and 249Bk, are available in very limited quantities and require specialized production and processing facilities resident in only a few research centers worldwide. This report describes the production and chemical processing of heavy actinide materials for super-heavy element research, current availabilities of these materials, and related target fabrication techniques. The impact of actinide materials in super-heavy element discovery is reviewed, and strategies for enhancing themore » production of rare actinides including 249Bk, 251Cf, and 254Es are described.« less

Impact of Including Higher Actinides in Fast Reactor Transmutation Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

B. Forget; M. Asgari; R. Ferrer

2007-09-01

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

Actinide and lanthanide separation process (ALSEP)

DOEpatents

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).

What Does f[subscript xx]f[subscript yy] - f[superscript 2][subscript xy] Greater than 0 "Really" Mean?

ERIC Educational Resources Information Center

McCartin, Brian J.

2008-01-01

This note presents geometric and physical interpretations of the sufficient condition for a critical point to be a strict relative extremum: f[subscript xx]f[subscript yy] - f[superscript 2][subscript xy] greater than 0. The role of the double derivative f[subscript xy] in this inequality will be highlighted in these interpretations. (Contains 14…

Hydrothermal Synthesis and Crystal Structures of Actinide Compounds

NASA Astrophysics Data System (ADS)

Runde, Wolfgang; Neu, Mary P.

Since the 1950s actinides have been used to benefit industry, science, health, and national security. The largest industrial application, electricity generation from uranium and thorium fuels, is growing worldwide. Thus, more actinides are being mined, produced, used and processed than ever before. The future of nuclear energy hinges on how these increasing amounts of actinides are contained in each stage of the fuel cycle, including disposition. In addition, uranium and plutonium were built up during the Cold War between the United States and the Former Soviet Union for defense purposes and nuclear energy. These stockpiles have been significantly reduced in the last decade.

Study on separation of minor actinides from HLLW with new extractant of TODGA-DHOA/Kerosene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Guo-an; Zhu, Wen-bin; Li, Feng-feng

2013-07-01

The extraction behavior of U, Np, Pu, Am, rare earth elements and Sr from nitric acid solutions by TODGA/dodecan, DHOA/dodecane and TODGA-DHOA/dodecane were investigated, respectively. Based on experimental results, a separation process was proposed for minor actinide isolation from high level liquid waste (HLLW): the TODGA-DHOA/kerosene system. The multi-stage counter-current cascade experiments were carried out for the purpose by 0.1 mol/l TODGA-1.0 mol/l DHOA/kerosene with miniature mixer- settler contactor rigs (8 stages for extraction, 6 stages for scrubbing, 8 stages for first stripping, 8 stages for second stripping). The results show that the recovery efficiencies of the actinides and lanthanidesmore » are more than 99.9%, whereas less than 1% Sr was extracted by 0.1 mol/l TODGA - 1.0 mol/l DHOA/kerosene. The stripping efficiencies of U, Np and Pu are more than 95% in the first stripping step by 0.5 mol/l HNO{sub 3} + 0.5 mol/l AHA(aceto-hydroxamic acid), all of the remained actinides and lanthanides can be stripped by 0.01 mol/l HNO{sub 3} in the second stripping step. 99% Sr was extracted by 0.1 mol/l TODGA/kerosene, so Sr can be recovered efficiently directly from the raffinate by 0.1 mol/l TODGA/kerosene. (authors)« less

Multifaceted Modularity: A Key for Stepwise Building of Hierarchical Complexity in Actinide Metal–Organic Frameworks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dolgopolova, Ekaterina A.; Ejegbavwo, Otega A.; Martin, Corey R.

Growing necessity for efficient nuclear waste management is a driving force for development of alternative architectures towards fundamental understanding of mechanisms involved in actinide integration inside extended structures. In this manuscript, metal-organic frameworks (MOFs) were investigated as a model system for engineering radionuclide containing materials through utilization of unprecedented MOF modularity, which cannot be replicated in any other type of materials. Through the implementation of recent synthetic advances in the MOF field, hierarchical complexity of An-materials were built stepwise, which was only feasible due to preparation of the first examples of actinide-based frameworks with “unsaturated” metal nodes. The first successfulmore » attempts of solid-state metathesis and metal node extension in An-MOFs are reported, and the results of the former approach revealed drastic differences in chemical behavior of extended structures versus molecular species. Successful utilization of MOF modularity also allowed us to structurally characterize the first example of bimetallic An-An nodes. To the best of our knowledge, through combination of solid-state metathesis, guest incorporation, and capping linker installation, we were able to achieve the highest Th wt% in mono- and bi-actinide frameworks with minimal structural density. Overall, combination of a multistep synthetic approach with homogeneous actinide distribution and moderate solvothermal conditions could make MOFs an exceptionally powerful tool to address fundamental questions responsible for chemical behavior of An-based extended structures, and therefore, shed light on possible optimization of nuclear waste administration.« less

Comparative electronic structure of a lanthanide and actinide diatomic oxide: Nd versus U

NASA Astrophysics Data System (ADS)

Krauss, M.; Stevens, W. J.

2003-01-01

Using a modified version of the Alchemy electronic structure code and relativistic pseudopotentials, the electronic structure of the ground and low lying excited states of UO, NdO, and NdO + have been calculated at the Hartree-Fock (HF) and multiconfiguration self-consistent field (MCSCF) levels of theory. Including results from an earlier study of UO + this provides the information for a comparative analysis of a lanthanide and an actinide diatomic oxide. UO and NdO are both described formally as M +2 O -2 and the cations as M +3 O -2 , but the HF and MCSCF calculations show that these systems are considerably less ionic due to large charge back-transfer in the πorbitals. The electronic states putatively arise from the ligand field (oxygen anion) perturbed f 4 , sf 3 , df 3 , sdf 2 , or s 2 f 2 states of M +2 and f 3 , sf 2 or df 2 states of M +3 . Molecular orbital results show a substantial stabilization of the sf 3 or s 2 f 2 configurations relative to the f 4 or df 3 configurations that are the even or odd parity ground states in the M +2 free ion. The compact f and d orbitals are more destabilized by the anion field than the diffuse s orbital. The ground states of the neutral species are dominated by orbitals arising from the M +2 sf 3 term, and all the potential energy curves arising from this configuration are similar, which allows an estimate of the vibrational frequencies for UO and NdO of 862 cm -1 and 836 cm -1 , respectively. For NdO + and UO + the excitation energies for the Ωstates were calculated with a valence configuration interaction method using ab initio effective spin-orbit operators to couple the molecular orbital configurations. The results for NdO + are very comparable with the results for UO + , and show the vibrational and electronic states to be interleaved.

Fuel Sustainability And Actinide Production Of Doping Minor Actinide In Water-Cooled Thorium Reactor

NASA Astrophysics Data System (ADS)

Permana, Sidik

2017-07-01

Fuel sustainability of nuclear energy is coming from an optimum fuel utilization of the reactor and fuel breeding program. Fuel cycle option becomes more important for fuel cycle utilization as well as fuel sustainability capability of the reactor. One of the important issues for recycle fuel option is nuclear proliferation resistance issue due to production plutonium. To reduce the proliferation resistance level, some barriers were used such as matrial barrier of nuclear fuel based on isotopic composition of even mass number of plutonium isotope. Analysis on nuclear fuel sustainability and actinide production composition based on water-cooled thorium reactor system has been done and all actinide composition are recycled into the reactor as a basic fuel cycle scheme. Some important parameters are evaluated such as doping composition of minor actinide (MA) and volume ratio of moderator to fuel (MFR). Some feasible parameters of breeding gains have been obtained by additional MA doping and some less moderation to fuel ratios (MFR). The system shows that plutonium and MA are obtained low compositions and it obtains some higher productions of even mass plutonium, which is mainly Pu-238 composition, as a control material to protect plutonium to be used as explosive devices.

Method for extracting lanthanides and actinides from acid solutions by modification of purex solvent

DOEpatents

Horwitz, E. Philip; Kalina, Dale G.

1986-01-01

A process for the recovery of actinide and lanthanide values from aqueous solutions with an extraction solution containing an organic extractant having the formula: ##STR1## where .phi. is phenyl, R.sup.1 is a straight or branched alkyl or alkoxyalkyl containing from 6 to 12 carbon atoms and R.sup.2 is an alkyl containing from 3 to 6 carbon atoms and phase modifiers in a water-immiscible hydrocarbon diluent. The addition of the extractant to the Purex process extractant, tri-n-butylphosphate in normal paraffin hydrocarbon diluent, will permit the extraction of multivalent lanthanide and actinide values from 0.1 to 12.0 molar acid solutions.

Laboratory actinide partitioning - Whitlockite/liquid and influence of actinide concentration levels

NASA Technical Reports Server (NTRS)

Benjamin, T. M.; Jones, J. H.; Heuser, W. R.; Burnett, D. S.

1983-01-01

The partition coefficients between synthetic whitlockite (beta Ca-phosphate) and coexisting silicate melts are determined for the actinide elements Th, U and Pu. Experiments were performed at 1 bar pressure and 1250 C at oxygen fugacities from 10 to the -8.5 to 10 to the -0.7 bars, and partitioning was determined from trace element radiography combined with conventional electron microprobe analysis. Results show Pu to be more readily incorporated into crystalline phases than U or Th under reducing conditions, which is attributed to the observation that Pu exists primarily in the trivalent state, while U and Th are tetravalent. Corrected partition coefficients for whitlockite of 3.6, less than or equal to 0.6, 1.2, 0.5 and less than or equal to 0.002 are estimated for Pu(+3), Pu(+4), Th(+4), U(+4) and U(+6), respectively. Experiments performed at trace levels and percent levels of UO2 indicate that Si is involved in U substitution in whitlockite, and show a reduced partition coefficient at higher concentrations of U that can be explained by effects on melt structure or the fraction of tetravalent U.

Crystal growth methods dedicated to low solubility actinide oxalates

NASA Astrophysics Data System (ADS)

Tamain, C.; Arab-Chapelet, B.; Rivenet, M.; Grandjean, S.; Abraham, F.

2016-04-01

Two novel crystal growth syntheses dedicated to low solubility actinide-oxalate systems and adapted to glove box handling are described. These methods based on the use of precursors of either actinide metal or oxalic acid have been optimized on lanthanide systems (analogue of actinides(III)) and then assessed on real actinide systems. They allow the synthesis of several actinide oxalate single crystals, Am2(C2O4)3(H2O)3·xH2O, Th(C2O4)2·6H2O, M2+x[PuIV2-xPuIIIx(C2O4)5]·nH2O and M1-x[PuIII1-xPuIVx(C2O4)2·H2O]·nH2O. It is the first time that these well-known compounds are formed by crystal growth methods, thus enabling direct structural studies on transuranic element systems and acquisition of basic data beyond deductions from isomorphic (or not) lanthanide compounds. Characterizations by X-ray diffraction, UV-visible solid spectroscopy, demonstrate the potentialities of these two crystal growth methods to obtain oxalate compounds.

Defect Structures of La1 - y Sr y F3 - y , La1 - y Ba y F3 - y , and Nd1 - y Ca y F3 - y ( y = 0.05, 0.10) Nonstoichiometric Tysonite Phases

NASA Astrophysics Data System (ADS)

Chernaya, T. S.; Verin, I. A.; Khrykina, O. N.; Bolotina, N. B.

2018-01-01

Characteristic features of defect structures of La1 - y Sr y F3 - y , La1 - y Ba y F3 - y , and Nd1 - y Ca y F3 - y ( y = 0.05, 0.10) nonstoichiometric phases of different compositions are determined from X-ray diffraction data. Interest in subtle details of their structure is determined by the possibility of ion transport over fluorine vacancies and by a strong compositional dependence of the ionic conductivity. The La0.95Sr0.05F2.95, La0.95Ba0.05F2.95, and Nd0.95Ca0.05F2.95 phases, as well as the La0.9Ba0.1F2.9 phase, crystallize as β-LaF3 (sp. gr. P3̅c1, Z = 6). The La0.9Sr0.1F2.9 and Nd0.9Ca0.1F2.9 phases lose their superstructure and are described by a cell whose volume is three times smaller (sp. gr. P63/ mmc, Z = 2). Defects of crystal structure R1 - y M y F3 - y are not exhausted by vacancies in fluorine positions. All crystals with a "large" cell are twinned according to the merohedral twin law. The majority of atomic positions in models with a "small" cell are split by group symmetry elements and are occupied statistically.

Systematization of actinides using cluster analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

1994-11-01

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

Contribution of extracellular ATP on the cell-surface F1F0-ATP synthase-mediated intracellular triacylglycerol accumulation.

PubMed

Kita, Toshiyuki; Arakaki, Naokatu

2015-01-01

Cell-surface F1F0-ATP synthase was involved in the cell signaling mediating various biological functions. Recently, we found that cell-surface F1F0-ATP synthase plays a role on intracellular triacylglycerol accumulation in adipocytes, and yet, the underlying mechanisms remained largely unknown. In this study, we investigated the role of extracellular ATP on the intracellular triacylglycerol accumulation. We demonstrated that significant amounts of ATP were produced extracellularly by cultured 3T3-L1 adipocytes and that the antibodies against α and β subunits of F1F0-ATP synthase inhibited the extracellular ATP production. Piceatannol, a F1F0-ATP synthase inhibitor, and apyrase, an enzyme which degrades extracellular ATP, suppressed triacylglycerol accumulation. The selective P2Y1 receptor antagonist MRS2500 significantly inhibited triacylglycerol accumulation, whereas the selective P2X receptor antagonist NF279 has less effect. The present results indicate that cell-surface F1F0-ATP synthase on adipocytes is functional in extracellular ATP production and that the extracellular ATP produced contributes, at least in part, to the cell-surface F1F0-ATP synthase-mediated intracellular triacylglycerol accumulation in adipocytes through P2Y1 receptor.

Multiconfigurational nature of 5f orbitals in uranium and plutonium intermetallics

PubMed Central

Booth, C.H.; Jiang, Yu; Wang, D.L.; Mitchell, J.N.; Tobash, P.H.; Bauer, E.D.; Wall, M.A.; Allen, P.G.; Sokaras, D.; Nordlund, D.; Weng, T.-C.; Torrez, M.A.; Sarrao, J.L.

2012-01-01

Uranium and plutonium’s 5f electrons are tenuously poised between strongly bonding with ligand spd-states and residing close to the nucleus. The unusual properties of these elements and their compounds (e.g., the six different allotropes of elemental plutonium) are widely believed to depend on the related attributes of f-orbital occupancy and delocalization for which a quantitative measure is lacking. By employing resonant X-ray emission spectroscopy (RXES) and X-ray absorption near-edge structure (XANES) spectroscopy and making comparisons to specific heat measurements, we demonstrate the presence of multiconfigurational f-orbital states in the actinide elements U and Pu and in a wide range of uranium and plutonium intermetallic compounds. These results provide a robust experimental basis for a new framework toward understanding the strongly-correlated behavior of actinide materials. PMID:22706643

Novel Separation of Actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mariella, R

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

Chlorogenic acid, rutin and hyperoside content in Fragaria vesca, F. viridis and F. moschata in Lithuania.

PubMed

Bagdonaite, Edita; Jakstas, Valdas; Raudonis, Raimondas; Janulis, Valdimaras

2013-01-01

In Lithuania, two species of the genus Fragaria L. (Rosaceae), F. vesca L. and F. viridis Weston, occur naturally in the wild and two others, F. moschata Weston and F. × ananassa Duchesne ex Rozier are found escaped from cultivation. The main objective of this study was to establish the variation pattern in the content of chlorogenic acid, rutin and hyperoside in leaves and fruits of the native Lithuanian species. In this work, the chemical polymorphisms of different Fragaria species were studied by growing plants side by side under the same cultivated field conditions. F. vesca fruits had the highest rutin (1.38 ± 0.19 mg g(-1) DM), hyperoside (0.69 ± 0.10 mg g(-1) DM) and chlorogenic acid (2.25 ± 0.34 mg g(-1) DM) content, followed by F. viridis and F. moschata. Our results showed that the leaves should be taken into account as important rutin and hyperoside contributors for strawberries.

Measurement of direct f0(980) photoproduction on the proton.

PubMed

Battaglieri, M; De Vita, R; Szczepaniak, A P; Adhikari, K P; Aghasyan, M; Amaryan, M J; Ambrozewicz, P; Anghinolfi, M; Asryan, G; Avakian, H; Bagdasaryan, H; Baillie, N; Ball, J P; Baltzell, N A; Batourine, V; Bedlinskiy, I; Bellis, M; Benmouna, N; Berman, B L; Bibrzycki, L; Biselli, A S; Bookwalter, C; Bouchigny, S; Boiarinov, S; Bradford, R; Branford, D; Briscoe, W J; Brooks, W K; Bültmann, S; Burkert, V D; Calarco, J R; Careccia, S L; Carman, D S; Casey, L; Chen, S; Cheng, L; Clinton, E; Cole, P L; Collins, P; Crabb, D; Crannell, H; Crede, V; Cummings, J P; Dale, D; Daniel, A; Dashyan, N; De Masi, R; De Sanctis, E; Degtyarenko, P V; Deur, A; Dhamija, S; Dharmawardane, K V; Dickson, R; Djalali, C; Dodge, G E; Donnelly, J; Doughty, D; Dugger, M; Dzyubak, O P; Egiyan, H; Egiyan, K S; El Fassi, L; Elouadrhiri, L; Eugenio, P; Fedotov, G; Fersch, R; Forest, T A; Fradi, A; Gabrielyan, M Y; Gan, L; Garçon, M; Gasparian, A; Gavalian, G; Gevorgyan, N; Gilfoyle, G P; Giovanetti, K L; Girod, F X; Glamazdin, O; Goett, J; Goetz, J T; Gohn, W; Golovatch, E; Gordon, C I O; Gothe, R W; Graham, L; Griffioen, K A; Guidal, M; Guler, N; Guo, L; Gyurjyan, V; Hadjidakis, C; Hafidi, K; Hakobyan, H; Hakobyan, R S; Hanretty, C; Hardie, J; Hassall, N; Heddle, D; Hersman, F W; Hicks, K; Hleiqawi, I; Holtrop, M; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Ito, M M; Jenkins, D; Jo, H S; Johnstone, J R; Joo, K; Juengst, H G; Kageya, T; Kalantarians, N; Keller, D; Kellie, J D; Khandaker, M; Khetarpal, P; Kim, W; Klein, A; Klein, F J; Klimenko, A V; Konczykowski, P; Kossov, M; Krahn, Z; Kramer, L H; Kubarovsky, V; Kuhn, J; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Lachniet, J; Laget, J M; Langheinrich, J; Lawrence, D; Lee, T; Lesniak, L; Li, Ji; Livingston, K; Lowry, M; Lu, H Y; Maccormick, M; Malace, S; Markov, N; Mattione, P; McCracken, M E; McKinnon, B; Mecking, B A; Melone, J J; Mestayer, M D; Meyer, C A; Mibe, T; Mikhailov, K; Mineeva, T; Minehart, R; Mirazita, M; Miskimen, R; Mochalov, V; Mokeev, V; Moreno, B; Moriya, K; Morrow, S A; Moteabbed, M; Munevar, E; Mutchler, G S; Nadel-Turonski, P; Nakagawa, I; Nasseripour, R; Niccolai, S; Niculescu, G; Niculescu, I; Niczyporuk, B B; Niroula, M R; Niyazov, R A; Nozar, M; Osipenko, M; Ostrovidov, A I; Park, K; Park, S; Pasyuk, E; Paris, M; Paterson, C; Pereira, S Anefalos; Pierce, J; Pivnyuk, N; Pocanic, D; Pogorelko, O; Pozdniakov, S; Price, J W; Prok, Y; Protopopescu, D; Raue, B A; Riccardi, G; Ricco, G; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Sabatié, F; Saini, M S; Salamanca, J; Salgado, C; Sandorfi, A; Santoro, J P; Sapunenko, V; Schott, D; Schumacher, R A; Serov, V S; Sharabian, Y G; Sharov, D; Shvedunov, N V; Smith, E S; Smith, L C; Sober, D I; Sokhan, D; Starostin, A; Stavinsky, A; Stepanyan, S; Stepanyan, S S; Stokes, B E; Stoler, P; Stopani, K A; Strakovsky, I I; Strauch, S; Taiuti, M; Tedeschi, D J; Teymurazyan, A; Tkabladze, A; Tkachenko, S; Todor, L; Tur, C; Ungaro, M; Vineyard, M F; Vlassov, A V; Watts, D P; Wei, X; Weinstein, L B; Weygand, D P; Williams, M; Wolin, E; Wood, M H; Yegneswaran, A; Yurov, M; Zana, L; Zhang, J; Zhao, B; Zhao, Z W

2009-03-13

We report on the results of the first measurement of exclusive f_{0}(980) meson photoproduction on protons for E_{gamma}=3.0-3.8 GeV and -t=0.4-1.0 GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the pi;{+}pi;{-} channel by performing a partial wave analysis of the reaction gammap-->ppi;{+}pi;{-}. Clear evidence of the f_{0}(980) meson was found in the interference between P and S waves at M_{pi;{+}pi;{-}} approximately 1 GeV. The S-wave differential cross section integrated in the mass range of the f_{0}(980) was found to be a factor of about 50 smaller than the cross section for the rho meson. This is the first time the f_{0}(980) meson has been measured in a photoproduction experiment.

Measurement of Direct f0(980) Photoproduction on the Proton

NASA Astrophysics Data System (ADS)

Battaglieri, M.; de Vita, R.; Szczepaniak, A. P.; Adhikari, K. P.; Aghasyan, M.; Amaryan, M. J.; Ambrozewicz, P.; Anghinolfi, M.; Asryan, G.; Avakian, H.; Bagdasaryan, H.; Baillie, N.; Ball, J. P.; Baltzell, N. A.; Batourine, V.; Bedlinskiy, I.; Bellis, M.; Benmouna, N.; Berman, B. L.; Bibrzycki, L.; Biselli, A. S.; Bookwalter, C.; Bouchigny, S.; Boiarinov, S.; Bradford, R.; Branford, D.; Briscoe, W. J.; Brooks, W. K.; Bültmann, S.; Burkert, V. D.; Calarco, J. R.; Careccia, S. L.; Carman, D. S.; Casey, L.; Chen, S.; Cheng, L.; Clinton, E.; Cole, P. L.; Collins, P.; Crabb, D.; Crannell, H.; Crede, V.; Cummings, J. P.; Dale, D.; Daniel, A.; Dashyan, N.; de Masi, R.; de Sanctis, E.; Degtyarenko, P. V.; Deur, A.; Dhamija, S.; Dharmawardane, K. V.; Dickson, R.; Djalali, C.; Dodge, G. E.; Donnelly, J.; Doughty, D.; Dugger, M.; Dzyubak, O. P.; Egiyan, H.; Egiyan, K. S.; El Fassi, L.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fersch, R.; Forest, T. A.; Fradi, A.; Gabrielyan, M. Y.; Gan, L.; Garçon, M.; Gasparian, A.; Gavalian, G.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Glamazdin, O.; Goett, J.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gordon, C. I. O.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Gyurjyan, V.; Hadjidakis, C.; Hafidi, K.; Hakobyan, H.; Hakobyan, R. S.; Hanretty, C.; Hardie, J.; Hassall, N.; Heddle, D.; Hersman, F. W.; Hicks, K.; Hleiqawi, I.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Ito, M. M.; Jenkins, D.; Jo, H. S.; Johnstone, J. R.; Joo, K.; Juengst, H. G.; Kageya, T.; Kalantarians, N.; Keller, D.; Kellie, J. D.; Khandaker, M.; Khetarpal, P.; Kim, W.; Klein, A.; Klein, F. J.; Klimenko, A. V.; Konczykowski, P.; Kossov, M.; Krahn, Z.; Kramer, L. H.; Kubarovsky, V.; Kuhn, J.; Kuhn, S. E.; Kuleshov, S. V.; Kuznetsov, V.; Lachniet, J.; Laget, J. M.; Langheinrich, J.; Lawrence, D.; Lee, T.; Lesniak, L.; Li, Ji; Livingston, K.; Lowry, M.; Lu, H. Y.; MacCormick, M.; Malace, S.; Markov, N.; Mattione, P.; McCracken, M. E.; McKinnon, B.; Mecking, B. A.; Melone, J. J.; Mestayer, M. D.; Meyer, C. A.; Mibe, T.; Mikhailov, K.; Mineeva, T.; Minehart, R.; Mirazita, M.; Miskimen, R.; Mochalov, V.; Mokeev, V.; Moreno, B.; Moriya, K.; Morrow, S. A.; Moteabbed, M.; Munevar, E.; Mutchler, G. S.; Nadel-Turonski, P.; Nakagawa, I.; Nasseripour, R.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Niczyporuk, B. B.; Niroula, M. R.; Niyazov, R. A.; Nozar, M.; Osipenko, M.; Ostrovidov, A. I.; Park, K.; Park, S.; Pasyuk, E.; Paris, M.; Paterson, C.; Pereira, S. Anefalos; Pierce, J.; Pivnyuk, N.; Pocanic, D.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Riccardi, G.; Ricco, G.; Ripani, M.; Ritchie, B. G.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salamanca, J.; Salgado, C.; Sandorfi, A.; Santoro, J. P.; Sapunenko, V.; Schott, D.; Schumacher, R. A.; Serov, V. S.; Sharabian, Y. G.; Sharov, D.; Shvedunov, N. V.; Smith, E. S.; Smith, L. C.; Sober, D. I.; Sokhan, D.; Starostin, A.; Stavinsky, A.; Stepanyan, S.; Stepanyan, S. S.; Stokes, B. E.; Stoler, P.; Stopani, K. A.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tedeschi, D. J.; Teymurazyan, A.; Tkabladze, A.; Tkachenko, S.; Todor, L.; Tur, C.; Ungaro, M.; Vineyard, M. F.; Vlassov, A. V.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Weygand, D. P.; Williams, M.; Wolin, E.; Wood, M. H.; Yegneswaran, A.; Yurov, M.; Zana, L.; Zhang, J.; Zhao, B.; Zhao, Z. W.

2009-03-01

We report on the results of the first measurement of exclusive f0(980) meson photoproduction on protons for Eγ=3.0-3.8GeV and -t=0.4-1.0GeV2. Data were collected with the CLAS detector at the Thomas Jefferson National Accelerator Facility. The resonance was detected via its decay in the π+π- channel by performing a partial wave analysis of the reaction γp→pπ+π-. Clear evidence of the f0(980) meson was found in the interference between P and S waves at Mπ+π-˜1GeV. The S-wave differential cross section integrated in the mass range of the f0(980) was found to be a factor of about 50 smaller than the cross section for the ρ meson. This is the first time the f0(980) meson has been measured in a photoproduction experiment.

Photochemical route to actinide-transition metal bonds: synthesis, characterization and reactivity of a series of thorium and uranium heterobimetallic complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ward, Ashleigh; Lukens, Wayne; Lu, Connie

2014-04-01

A series of actinide-transition metal heterobimetallics has been prepared, featuring thorium, uranium and cobalt. Complexes incorporating the binucleating ligand N[-(NHCH2PiPr2)C6H4]3 and Th(IV) (4) or U(IV) (5) with a carbonyl bridged [Co(CO)4]- unit were synthesized from the corresponding actinide chlorides (Th: 2; U: 3) and Na[Co(CO)4]. Irradiation of the isocarbonyls with ultraviolet light resulted in the formation of new species containing actinide-metal bonds in good yields (Th: 6; U: 7); this photolysis method provides a new approach to a relatively rare class of complexes. Characterization by single-crystal X-ray diffraction revealed that elimination of the bridging carbonyl is accompanied by coordination ofmore » a phosphine arm from the N4P3 ligand to the cobalt center. Additionally, actinide-cobalt bonds of 3.0771(5) and 3.0319(7) for the thorium and uranium complexes, respectively, were observed. The solution state behavior of the thorium complexes was evaluated using 1H, 1H-1H COSY, 31P and variable-temperature NMR spectroscopy. IR, UV-Vis/NIR, and variable-temperature magnetic susceptibility measurements are also reported.« less

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dittrich, Timothy M.; Richmann, Michael K.; Reed, Donald T.

2015-10-30

The degree of conservatism in the estimated sorption partition coefficients (K ds) 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).

Gas core reactors for actinide transmutation and breeder applications

NASA Technical Reports Server (NTRS)

Clement, J. D.; Rust, J. H.

1978-01-01

This work consists of design power plant studies for four types of reactor systems: uranium plasma core breeder, uranium plasma core actinide transmuter, UF6 breeder and UF6 actinide transmuter. The plasma core systems can be coupled to MHD generators to obtain high efficiency electrical power generation. A 1074 MWt UF6 breeder reactor was designed with a breeding ratio of 1.002 to guard against diversion of fuel. Using molten salt technology and a superheated steam cycle, an efficiency of 39.2% was obtained for the plant and the U233 inventory in the core and heat exchangers was limited to 105 Kg. It was found that the UF6 reactor can produce high fluxes (10 to the 14th power n/sq cm-sec) necessary for efficient burnup of actinide. However, the buildup of fissile isotopes posed severe heat transfer problems. Therefore, the flux in the actinide region must be decreased with time. Consequently, only beginning-of-life conditions were considered for the power plant design. A 577 MWt UF6 actinide transmutation reactor power plant was designed to operate with 39.3% efficiency and 102 Kg of U233 in the core and heat exchanger for beginning-of-life conditions.

Thermodynamic constants for actinide oxides and oxyhydroxides relevant to actinide volatility calculations for thermal oxidation processes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ebbinghaus, B.B.; Krikorian, O.H.

The purpose of this report is to provide input of thermodynamic data on actinide volatilities to EERC for use in their computer code for modeling of metal volatilities in incinerators. It is also anticipated that the data may be documented later in an EPA sponsored ``Metals Bible.`` It should be noted that only upper limits for the volatility of PuO{sub 2}(s) due to PuO{sub 3}(g) and PuO{sub 2}(OH){sub 2}(g) and the volatility of AmO{sub 2} in PuO{sub 2}(s) due to AmO{sub 3}(g) and AmO{sub 2}(OH){sub 2}(g) could be set. The data on the americium vapor species are intended for calculationsmore » where AmO{sub 2} is present as a solid solution in PuO{sub 2}(s).« less

Method for extracting lanthanides and actinides from acid solutions by modification of Purex solvent

DOEpatents

Horwitz, E.P.; Kalina, D.G.

1986-03-04

A process is described for the recovery of actinide and lanthanide values from aqueous solutions with an extraction solution containing an organic extractant having the formula as shown in a diagram where [phi] is phenyl, R[sup 1] is a straight or branched alkyl or alkoxyalkyl containing from 6 to 12 carbon atoms and R[sup 2] is an alkyl containing from 3 to 6 carbon atoms and phase modifiers in a water-immiscible hydrocarbon diluent. The addition of the extractant to the Purex process extractant, tri-n-butylphosphate in normal paraffin hydrocarbon diluent, will permit the extraction of multivalent lanthanide and actinide values from 0.1 to 12.0 molar acid solutions. 6 figs.

Study on the leaching behavior of actinides from nuclear fuel debris

NASA Astrophysics Data System (ADS)

Kirishima, Akira; Hirano, Masahiko; Akiyama, Daisuke; Sasaki, Takayuki; Sato, Nobuaki

2018-04-01

For the prediction of the leaching behavior of actinides contained in the nuclear fuel debris generated by the Fukushima Daiichi nuclear power plant accident in Japan, simulated fuel debris consisting of a UO2-ZrO2 solid solution doped with 137Cs, 237Np, 236Pu, and 241Am tracers was synthesized and investigated. The synthesis of the debris was carried out by heat treatment at 1200 °C at different oxygen partial pressures, and the samples were subsequently used for leaching tests with Milli-Q water and seawater. The results of the leaching tests indicate that the leaching of actinides depends on the redox conditions under which the debris was generated; for example, debris generated under oxidative conditions releases more actinide nuclides to water than that generated under reductive conditions. Furthermore, we found that, as Zr(IV) increasingly substituted U(IV) in the fluorite crystal structure of the debris, the actinide leaching from the debris decreased. In addition, we found that seawater leached more actinides from the debris than pure water, which seems to be caused by the complexation of actinides by carbonate ions in seawater.

Predictive Modeling in Actinide Chemistry and Catalysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Ping

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.

On-line Monitoring of Actinide Concentrations in Molten Salt Electrolyte

DOE Office of Scientific and Technical Information (OSTI.GOV)

Curtis W. Johnson; Mary Lou Dunzik-Gougar; Shelly X. Li

2006-11-01

Pyroprocessing, a treatment method for spent nuclear fuel (SNF), is currently being studied at the Idaho National Laboratory. The key operation of pyroprocessing which takes place in an electrorefiner is the electrochemical separation of actinides from other constituents in spent fuel. Efficient operation of the electrorefiner requires online monitoring of actinide concentrations in the molten salt electrolyte. Square-wave voltammetry (SWV) and normal pulse voltammetry (NPV) are being investigated to assess their applicability to the measurement of actinide concentrations in the electrorefiner.

Actinide geochemistry: from the molecular level to the real system.

PubMed

Geckeis, Horst; Rabung, Thomas

2008-12-12

Geochemical processes leading to either mobilization or retention of radionuclides in an aquifer system are significantly influenced by their interaction with rock, sediment and colloid surfaces. Therefore, a sound safety assessment of nuclear waste disposal requires the elucidation and quantification of those processes. State-of-the-art analytical techniques as e.g. laser- and X-ray spectroscopy are increasingly applied to study solid-liquid interface reactions to obtain molecular level speciation insight. We have studied the sorption of trivalent lanthanides and actinides onto aluminium oxides, hydroxides and purified clay minerals by the time-resolved laser fluorescence spectroscopy and X-ray-absorption spectroscopy. Chemical constitution and structure of surface bound actinides are proposed based on spectroscopic information. Open questions still remain with regard to the exact nature of mineral surface ligands and the mineral/water interface. Similarities of spectroscopic data obtained for M(III) sorbed onto gamma-alumina, and clay minerals suggest the formation of very comparable inner-sphere surface complexes such as S-O-An(III)(OH)x(2-x)(H2O)5-x at pH > 5. Those speciation data are found consistent with those predicted by surface complexation modelling. The applicability of data obtained for pure mineral phases to actinide sorption onto heterogeneously composed natural clay rock is examined by experiments and by geochemical modelling. Good agreement of experiment and model calculations is found for U(VI) and trivalent actinide/lanthanide sorption to natural clay rock. The agreement of spectroscopy, geochemical modelling and batch experiments with natural rock samples and purified minerals increases the reliability in model predictions. The assessment of colloid borne actinide migration observed in various laboratory and field studies calls for detailed information on actinide-colloid interaction. Kinetic stabilization of colloid bound actinides can be due

Colloid-borne forms of tetravalent actinides: A brief review

NASA Astrophysics Data System (ADS)

Zänker, Harald; Hennig, Christoph

2014-02-01

Tetravalent actinides, An(IV), are usually assumed to be little mobile in near-neutral environmental waters because of their low solubility. However, there are certain geochemical scenarios during which mobilization of An(IV) in a colloid-borne (waterborne) form cannot be ruled out. A compilation of colloid-borne forms of tetravalent actinides described so far for laboratory experiments together with several examples of An(IV) colloids observed in field experiments and real-world scenarios are given. They are intended to be a knowledge base and a tool for those who have to interpret actinide behavior under environmental conditions. Synthetic colloids containing structural An(IV) and synthetic colloids carrying adsorbed An(IV) are considered. Their behavior is compared with the behavior of An(IV) colloids observed after the intentional or unintentional release of actinides into the environment. A list of knowledge gaps as to the behavior of An(IV) colloids is provided and items which need further research are highlighted.

Pocket formula for nuclear deformations of actinides

NASA Astrophysics Data System (ADS)

Manjunatha, H. C.; Sridhar, K. N.

2018-06-01

We have formulated a pocket formula for quadrupole (β2), octupole (β3), hexadecapole (β4) and hexacontatetrapole (β6) deformation of the nuclear ground state of all isotopes of actinide nuclei (89 < Z < 103). This formula is first of its kind and produces a nuclear deformation of all isotopes actinide nuclei 89 < Z < 103 with simple inputs of Z and A. Hence, this formula is useful in the fields of nuclear physics to study the structure and interaction of nuclei.

Magnetocrystalline anisotropy in UMn 2 Ge 2 and related Mn-based actinide ferromagnets

DOE PAGES

Parker, David S.; Ghimire, Nirmal; Singleton, John; ...

2015-05-04

We presenmore » t magnetization isotherms in pulsed magnetic fields up to 62 Tesla, supported by first principles calculations, demonstrating a huge uniaxial magnetocrystalline anisotropy energy - approximately 20 MJ/m 3 - in UMn 2 Ge 2 . This large anisotropy results from the extremely strong spin-orbit coupling affecting the uranium 5 f electrons, which in the calculations exhibit a substantial orbital moment exceeding 2 μ B. Finally, we also find from theoretical calculations that a number of isostructural Mn-actinide compounds are expected to have similarly large anisotropy.« less

Simultaneous F 0-F 1 modifications of Arabic for the improvement of natural-sounding

NASA Astrophysics Data System (ADS)

Ykhlef, F.; Bensebti, M.

2013-03-01

Pitch (F 0) modification is one of the most important problems in the area of speech synthesis. Several techniques have been developed in the literature to achieve this goal. The main restrictions of these techniques are in the modification range and the synthesised speech quality, intelligibility and naturalness. The control of formants in a spoken language can significantly improve the naturalness of the synthesised speech. This improvement is mainly dependent on the control of the first formant (F 1). Inspired by this observation, this article proposes a new approach that modifies both F 0 and F 1 of Arabic voiced sounds in order to improve the naturalness of the pitch shifted speech. The developed strategy takes a parallel processing approach, in which the analysis segments are decomposed into sub-bands in the wavelet domain, modified in the desired sub-band by using a resampling technique and reconstructed without affecting the remained sub-bands. Pitch marking and voicing detection are performed in the frequency decomposition step based on the comparison of the multi-level approximation and detail signals. The performance of the proposed technique is evaluated by listening tests and compared to the pitch synchronous overlap and add (PSOLA) technique in the third approximation level. Experimental results have shown that the manipulation in the wavelet domain of F 0 in conjunction with F 1 guarantees natural-sounding of the synthesised speech compared to the classical pitch modification technique. This improvement was appropriate for high pitch modifications.

Soft X-ray scanning transmission X-ray microscopy (STXM) of actinide particles.

PubMed

Nilsson, Hans J; Tyliszczak, Tolek; Wilson, Richard E; Werme, Lars; Shuh, David K

2005-09-01

A descriptive account is given of our most recent research on the actinide dioxides with the Advanced Light Source Molecular Environmental Science (ALS-MES) Beamline 11.0.2 soft X-ray scanning transmission X-ray microscope (STXM) at the Lawrence Berkeley National Laboratory (LBNL). The ALS-MES STXM permits near-edge X-ray absorption fine structure (NEXAFS) and imaging with 30-nm spatial resolution. The first STXM spectromicroscopy NEXAFS spectra at the actinide 4d5/2 edges of the imaged transuranic particles, NpO2 and PuO2, have been obtained. Radiation damage induced by the STXM was observed in the investigation of a mixed oxidation state particle (Np(V,VI)) and was minimized during collection of the actual spectra at the 4d5/2 edge of the Np(V,VI) solid. A plutonium elemental map was obtained from an irregular PuO2 particle with the dimensions of 650 x 650 nm. The Pu 4d5/2 NEXAFS spectra were collected at several different locations from the PuO2 particle and were identical. A representative oxygen K-edge spectrum from UO2 was collected and resembles the oxygen K-edge from the bulk material. The unique and current performance of the ALS-MES STXM at extremely low energies (ca. 100 eV) that may permit the successful measurement of the actinide 5d edge is documented. Finally, the potential of STXM as a tool for actinide investigations is briefly discussed.

Detection of race-specific resistance against Puccinia coronata f. sp. avenae in Brachypodium species.

PubMed

Omidvar, Vahid; Dugyala, Sheshanka; Li, Feng; Rottschaefer, Susan; Miller, Marisa; Ayliffe, Michael; Moscou, Matthew James; Kianian, Shahryar F; Figueroa, Melania

2018-06-20

Oat crown rust caused by Puccinia coronata f. sp. avenae is the most destructive foliar disease of cultivated oat. Characterization of genetic factors controlling resistance responses to Puccinia coronata f. sp. avenae in non-host species could provide new resources for developing disease protection strategies in oat. We examined symptom development and fungal colonization levels of a collection of Brachypodium distachyon and B. hybridum accessions infected with three North American P. coronata f. sp. avenae isolates. Our results demonstrated that colonization phenotypes are dependent on both host and pathogen genotypes, indicating a role for race-specific responses in these interactions. These responses were independent of the accumulation of reactive oxygen species. Expression analysis of several defense-related genes suggested that salicylic acid and ethylene-mediated signaling, but not jasmonic acid are components of resistance reaction to P. coronata f. sp. avenae. Our findings provide the basis to conduct a genetic inheritance study to examine if effector-triggered immunity contributes to non-host resistance to P. coronata f. sp. avenae in Brachypodium species.

Photochemical route to actinide-transition metal bonds: synthesis, characterization and reactivity of a series of thorium and uranium heterobimetallic complexes.

PubMed

Ward, Ashleigh L; Lukens, Wayne W; Lu, Connie C; Arnold, John

2014-03-05

A series of actinide-transition metal heterobimetallics has been prepared, featuring thorium, uranium, and cobalt. Complexes incorporating the binucleating ligand N[ο-(NHCH2P(i)Pr2)C6H4]3 with either Th(IV) (4) or U(IV) (5) and a carbonyl bridged [Co(CO)4](-) unit were synthesized from the corresponding actinide chlorides (Th: 2; U: 3) and Na[Co(CO)4]. Irradiation of the resulting isocarbonyls with ultraviolet light resulted in the formation of new species containing actinide-metal bonds in good yields (Th: 6; U: 7); this photolysis method provides a new approach to a relatively unusual class of complexes. Characterization by single-crystal X-ray diffraction revealed that elimination of the bridging carbonyl and formation of the metal-metal bond is accompanied by coordination of a phosphine arm from the N4P3 ligand to the cobalt center. Additionally, actinide-cobalt bonds of 3.0771(5) Å and 3.0319(7) Å for the thorium and uranium complexes, respectively, were observed. The solution-state behavior of the thorium complexes was evaluated using (1)H, (1)H-(1)H COSY, (31)P, and variable-temperature NMR spectroscopy. IR, UV-vis/NIR, and variable-temperature magnetic susceptibility measurements are also reported.

An optimization methodology for heterogeneous minor actinides transmutation

NASA Astrophysics Data System (ADS)

Kooyman, Timothée; Buiron, Laurent; Rimpault, Gérald

2018-04-01

In the case of a closed fuel cycle, minor actinides transmutation can lead to a strong reduction in spent fuel radiotoxicity and decay heat. In the heterogeneous approach, minor actinides are loaded in dedicated targets located at the core periphery so that long-lived minor actinides undergo fission and are turned in shorter-lived fission products. However, such targets require a specific design process due to high helium production in the fuel, high flux gradient at the core periphery and low power production. Additionally, the targets are generally manufactured with a high content in minor actinides in order to compensate for the low flux level at the core periphery. This leads to negative impacts on the fuel cycle in terms of neutron source and decay heat of the irradiated targets, which penalize their handling and reprocessing. In this paper, a simplified methodology for the design of targets is coupled with a method for the optimization of transmutation which takes into account both transmutation performances and fuel cycle impacts. The uncertainties and performances of this methodology are evaluated and shown to be sufficient to carry out scoping studies. An illustration is then made by considering the use of moderating material in the targets, which has a positive impact on the minor actinides consumption but a negative impact both on fuel cycle constraints (higher decay heat and neutron) and on assembly design (higher helium production and lower fuel volume fraction). It is shown that the use of moderating material is an optimal solution of the transmutation problem with regards to consumption and fuel cycle impacts, even when taking geometrical design considerations into account.

Separation of actinides using capillary extraction chromatography-inductively coupled plasma mass spectrometry.

PubMed

Peterson, Dominic S; Montoya, Velma M

2009-08-01

Trace levels of actinides have been separated on capillary extraction chromatography columns. Detection of the actinides was achieved using an inductively coupled plasma mass spectrometer, which was coupled with the extraction chromatography system. In this study, we compare 30-cm long, 4.6 mm i.d. columns to capillary columns (750 microm i.d.) with lengths from 30 cm up to 150 cm. The columns that were tested were packed with TRU resin. We were able to separate a mixture of five actinides ((232)Th, (238)U, (237)Np, (239)Pu, and (241)Am). This work has application to rapid bioassay as well as automated separations of actinide materials.

FRAMES-2.0 Software System: Frames 2.0 Pest Integration (F2PEST)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Castleton, Karl J.; Meyer, Philip D.

2009-06-17

The implementation of the FRAMES 2.0 F2PEST module is described, including requirements, design, and specifications of the software. This module integrates the PEST parameter estimation software within the FRAMES 2.0 environmental modeling framework. A test case is presented.

Synthesis and Characterization of Templated Ion Exchange Resins for the Selective Complexion of Actinide Ions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murrray, George M.; Uy, O. Manuel

The purpose of this research is to develop polymeric extractants for the selective complexation of uranyl ions (and subsequently other actinyl and actinide ions) from aqueous solutions. Selectivity for a specific actinide ion is obtained by providing the polymers with cavities lined with complexing ligands so arranged as to match the charge, coordination number, coordination geometry, and size of the actinide ion. These cavity-containing polymers are produced by using a specific actinide ion (or surrogate) as a template around which monomeric complexing ligands are polymerized. The polymers provide useful sequestering agents for removing actinide ions from wastes and will formmore » the basis for a variety of analytical techniques for actinide determination.« less

Visible Thrombolysis Acceleration of a Nanomachine Powered by Light-Driving F0F1-ATPase Motor

NASA Astrophysics Data System (ADS)

Duan, Xiaoxia; Liu, Lifeng; Jiang, Weijian; Yue, Jiachang

2015-05-01

We report on thrombolysis acceleration of a nanomachine powered by light-driving δ-subunit-free F0F1-ATPase motor. It is composed of a mechanical device, locating device, energy storage device, and propeller. The rotory δ-subunit-free F0F1-ATPase motor acts as a mechanical device, which was obtained by reconstructing an original chromatophore extracted from Rhodospirillum rubrum. We found that the bioactivity of the F0F1-ATPase motor improved greatly after reconstruction. The zeta potential of the nanomachine is about -23.4 mV. Cytotoxicity induced by the nanomachine was measured using cell counting kit (CCK)-8 assay. The A549 cells incubated with different fractional concentrations of the nanomachine within 48 h did not show obvious cytotoxicity. The locating device helps the nanomachine bind to the thrombi. Energy was easily stored by exposing the nanomachine to 600-nm-wavelength irradiation, which promoted activity of the motor. The rotation of the long propeller accelerated thrombolysis of a blood clot in vitro in the presence of urokinase (UK). This result was based on visual inspection and confirmed by a series of tests.

Behaviour of complexes of f-elements in the environment - An experimental and theoretical analysis

NASA Astrophysics Data System (ADS)

Ivanova, Bojidarka; Spiteller, Michael

2017-01-01

The paper provides a comprehensive study of lanthanide and actinide complexes to a matter of key area in the field of the chemistry, i.e. environmental analytical chemistry. The content has involved: (i) solution and sorption behaviour of lanthanides (Lnn+, Ln = Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Py, Ho, Er, Tm, Yb and Lu) onto Y(O)O(H) minerals (Y = Fe, Mn or Si); (ii) ligand exchange processes with participation of inorganic OH-, F-, Cl-, Br-, SO42-, SO32-, IO3-, NO32-, CO32- and/or HCO3- ligands as well as mixed ligand complexes, including solvent molecules such as {[LnOR]2+}, {[Ln(OR)2]+} (R = CH3OH, CH3CH2CH2OH) and {[Ln(CH3CN)x(H2O)z]3+} (x = 6-8, z = 0-4); (iii) the actinide speciation has involved different oxidation states (+4)-(+6) and ions {[UOH]3+}, {[UX]3+} (X = F or Cl), {[UFx]y+/-} (x = 2-6, y = 0-2), {[U(CO3)x]y-} (x = 4 or 5, y = 4 or 6), {[U(SO4)]2+], {[U(NO3)]3+}, {[U(NO3)2]2+}, [[UO2(CO3)3]5-}, {[(UO2)x(OH)z]y+/-} (x = 1-4, y = 1 or 2, z = 1-7), {[UO2Fx]y+/-} (x = 1-4, y = 1 or 2), {[UO2(CO3)x]y-} (x = 2, or 3, y = 2, or 4), {[(UO2)2(CO3)(OH)3]-}, {[(UO2)3O(OH)2(HCO3)]+}, {[(UO2)11(CO3)6(OH)12]2-}, {[UO2(SO4)x]y-}, (x = 2 or 3, y = 2 or 4), {[UO2SiO(OH)3]+}, {[AnCx]y+/-} (x,y = 1 and 2), {[CAnH]+/-}, {[CxAny]0} (x,y = 2 and 3), {[AnHx]y+} (x = 1-3, y = 0-5), {[AnXn]m+/-} (n = 1-6, m = 1-4, X = F-, Br-, I-), {[AnOxFz]y+/-} (x, z = 1 or 2, y = 0, 1 and 2), {[AnNx]y+} (x = 1 and 2), {[AnxOz(OH)n]y+/-} (x = 1-3, z = 1-4, y = 0, 1 or 2, n = 0 or 1) and Ann+ (n = 0-6) at An = Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No and Lr, respectively. Correlation analysis between thermodynamic parameters, accounting for different surface interactions of adsorbed species and experimental mass spectrometric data, including liquid, semi-liquid and solid-state measurements in a large set of experimental conditions such as pH = 2-13, low and intermediate ionic strength, solvent type, ε = 0-78.0, variety of solvent proton accepting and donating numbers and T = 25

Process for recovering actinide values

DOEpatents

Horwitz, E. Philip; Mason, George W.

1980-01-01

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

Actinide Sputtering Induced by Fission with Ultra-cold Neutrons

NASA Astrophysics Data System (ADS)

Venuti, Michael; Shi, Tan; Fellers, Deion; Morris, Christopher; Makela, Mark

2017-09-01

Understanding the effects of actinide sputtering due to nuclear fission is important for a wide range of applications, including nuclear fuel storage, space science, and national defense. A new program at the Los Alamos Neutron Science Center uses ultracold neutrons (UCN) to induce fission in actinides such as uranium and plutonium. By controlling the energy of UCN, it is possible to induce fission at the sample surface within a well-defined depth. It is therefore an ideal tool for studying the effects of fission-induced sputtering as a function of interaction depth. Since the mechanism for fission-induced surface damage is not well understood, especially for samples with a surface oxide layer, this work has the potential to separate the various damage mechanisms proposed in previous works. During the irradiation with UCN, fission events are monitored by coincidence counting between prompt gamma rays using NaI detectors. Alpha spectroscopy of the ejected actinide material is performed in a custom-built ionization chamber to determine the amount of sputtered material. Actinide samples with various sample properties and surface conditions are irradiated and analyzed. In this presentation, we will discuss our experimental setup and present the preliminary results.

Pitch (F0) and formant profiles of human vowels and vowel-like baboon grunts: The role of vocalizer body size and voice-acoustic allometry

NASA Astrophysics Data System (ADS)

Rendall, Drew; Kollias, Sophie; Ney, Christina; Lloyd, Peter

2005-02-01

Key voice features-fundamental frequency (F0) and formant frequencies-can vary extensively between individuals. Much of the variation can be traced to differences in the size of the larynx and vocal-tract cavities, but whether these differences in turn simply reflect differences in speaker body size (i.e., neutral vocal allometry) remains unclear. Quantitative analyses were therefore undertaken to test the relationship between speaker body size and voice F0 and formant frequencies for human vowels. To test the taxonomic generality of the relationships, the same analyses were conducted on the vowel-like grunts of baboons, whose phylogenetic proximity to humans and similar vocal production biology and voice acoustic patterns recommend them for such comparative research. For adults of both species, males were larger than females and had lower mean voice F0 and formant frequencies. However, beyond this, F0 variation did not track body-size variation between the sexes in either species, nor within sexes in humans. In humans, formant variation correlated significantly with speaker height but only in males and not in females. Implications for general vocal allometry are discussed as are implications for speech origins theories, and challenges to them, related to laryngeal position and vocal tract length. .

The F0F1-ATP Synthase Complex Contains Novel Subunits and Is Essential for Procyclic Trypanosoma brucei

PubMed Central

Zíková, Alena; Schnaufer, Achim; Dalley, Rachel A.; Panigrahi, Aswini K.; Stuart, Kenneth D.

2009-01-01

The mitochondrial F0F1 ATP synthase is an essential multi-subunit protein complex in the vast majority of eukaryotes but little is known about its composition and role in Trypanosoma brucei, an early diverged eukaryotic pathogen. We purified the F0F1 ATP synthase by a combination of affinity purification, immunoprecipitation and blue-native gel electrophoresis and characterized its composition and function. We identified 22 proteins of which five are related to F1 subunits, three to F0 subunits, and 14 which have no obvious homology to proteins outside the kinetoplastids. RNAi silencing of expression of the F1 α subunit or either of the two novel proteins showed that they are each essential for the viability of procyclic (insect stage) cells and are important for the structural integrity of the F0F1-ATP synthase complex. We also observed a dramatic decrease in ATP production by oxidative phosphorylation after silencing expression of each of these proteins while substrate phosphorylation was not severely affected. Our procyclic T. brucei cells were sensitive to the ATP synthase inhibitor oligomycin even in the presence of glucose contrary to earlier reports. Hence, the two novel proteins appear essential for the structural organization of the functional complex and regulation of mitochondrial energy generation in these organisms is more complicated than previously thought. PMID:19436713

Coordination Chemistry of a Strongly-Donating Hydroxylamine with Early Actinides: An Investigation of Redox Properties and Electronic Structure

DOE Office of Scientific and Technical Information (OSTI.GOV)

McSkimming, Alex; Su, Jing; Cheisson, Thibault

Separations of f-block elements are a critical aspect of nuclear waste processing. Redox-based separations offer promise, but challenges remain in stabilizing and differentiating actinides in high oxidation states. The investigation of new ligand types that provide thermodynamic stabilization to high-valent actinides is essential for expanding their fundamental chemistry and to elaborate new separation techniques and storage methods. We report herein the preparation and characterization of Th and U complexes of the pyridyl-hydroxylamine ligand, N-tert-butyl-N-(pyridin-2-yl)hydroxylamine (pyNO–). Electrochemical studies performed on the homoleptic complexes [M(pyNO) 4] (M = Th, U) revealed significant stabilization of the U complex upon one-electron oxidation. The saltmore » [U(pyNO) 4] + was isolated by chemical oxidation of [U(pyNO) 4]; spectroscopic and computational data support assignment as a U V cation.« less

Coordination Chemistry of a Strongly-Donating Hydroxylamine with Early Actinides: An Investigation of Redox Properties and Electronic Structure

DOE PAGES

McSkimming, Alex; Su, Jing; Cheisson, Thibault; ...

2018-03-23

Separations of f-block elements are a critical aspect of nuclear waste processing. Redox-based separations offer promise, but challenges remain in stabilizing and differentiating actinides in high oxidation states. The investigation of new ligand types that provide thermodynamic stabilization to high-valent actinides is essential for expanding their fundamental chemistry and to elaborate new separation techniques and storage methods. We report herein the preparation and characterization of Th and U complexes of the pyridyl-hydroxylamine ligand, N-tert-butyl-N-(pyridin-2-yl)hydroxylamine (pyNO–). Electrochemical studies performed on the homoleptic complexes [M(pyNO) 4] (M = Th, U) revealed significant stabilization of the U complex upon one-electron oxidation. The saltmore » [U(pyNO) 4] + was isolated by chemical oxidation of [U(pyNO) 4]; spectroscopic and computational data support assignment as a U V cation.« less

The Prompt Fission Neutron Spectrum of 235U for Einc 0.7-5.0 MeV

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gomez, Jaime A.; Devlin, Matthew James; Haight, Robert Cameron

2017-03-23

The Chi-Nu experiment aims to accurately measure the prompt fission neutron spectrum (PFNS) for the major actinides. At the Los Alamos Neutron Science Center (LANSCE), fission can be induced using the white neutron source. Using a two arm time of flight (T.O.F) technique; Chi-Nu presents a preliminary result of the low energy component of the 235U PFNS measured using an array of 22-Lithium glass scintillators.

The roles of 4f- and 5f-orbitals in bonding: A magnetochemical, crystal field, density functional theory, and multi-reference wavefunction study

DOE PAGES

Lukens, Wayne W.; Speldrich, Manfred; Yang, Ping; ...

2016-05-31

The electronic structures of 4f 3/5f 3 Cp" 3M and Cp" 3M·alkylisocyanide complexes, where Cp" is 1,3-bis-(trimethylsilyl)cyclopentadienyl, are explored with a focus on the splitting of the f-orbitals, which provides information about the strengths of the metal–ligand interactions. While the f-orbital splitting in many lanthanide complexes has been reported in detail, experimental determination of the f-orbital splitting in actinide complexes remains rare in systems other than halide and oxide compounds, since the experimental approach, crystal field analysis, is generally significantly more difficult for actinide complexes than for lanthanide complexes. In this study, a set of analogous neodymium(III) and uranium(III) tris-cyclopentadienylmore » complexes and their isocyanide adducts was characterized by electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility. The crystal field model was parameterized by combined fitting of EPR and susceptibility data, yielding an accurate description of f-orbital splitting. The isocyanide derivatives were also studied using density functional theory, resulting in f-orbital splitting that is consistent with crystal field fitting, and by multi-reference wavefunction calculations that support the electronic structure analysis derived from the crystal-field calculations. The results highlight that the 5f-orbitals, but not the 4f-orbitals, are significantly involved in bonding to the isocyanide ligands. The main interaction between isocyanide ligand and the metal center is a σ-bond, with additional 5f to π* donation for the uranium complexes. As a result, while interaction with the isocyanide π*-orbitals lowers the energies of the 5f xz2 and 5f yz2-orbitals, spin–orbit coupling greatly reduces the population of 5f xz2 and 5f yz2 in the ground state.« less

Actinide abundances in ordinary chondrites

NASA Technical Reports Server (NTRS)

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

1990-01-01

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

Improved method for extracting lanthanides and actinides from acid solutions

DOEpatents

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

1983-07-26

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

Process for making a ceramic composition for immobilization of actinides

DOEpatents

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

2001-01-01

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

Characteristic of molten fluoride salt system LiF-BeF2 (Flibe) and LiF-NaF-KF (Flinak) as coolant and fuel carrier in molten salt reactor (MSR)

NASA Astrophysics Data System (ADS)

Bahri, Che Nor Aniza Che Zainul; Al-Areqi, Wadee'ah Mohd; Ruf, Mohd'Izzat Fahmi Mohd; Majid, Amran Ab.

2017-01-01

Interest of fluoride salts have recently revived due to the high temperature application in nuclear reactors. Molten Salt Reactor (MSR) was designed to operate at high temperature in range 700 - 800°C and its fuel is dissolved in a circulating molten fluoride salt mixture. Molten fluoride salts are stable at high temperature, have good heat transfer properties and can dissolve high concentration of actinides and fission product. The aim of this paper was to discuss the physical properties (melting temperature, density and heat capacity) of two systems fluoride salt mixtures i.e; LiF-BeF2 (Flibe) and LiF-NaF-KF (Flinak) in terms of their application as coolant and fuel solvent in MSR. Both of these salts showed almost same physical properties but different applications in MSR. The advantages and the disadvantages of these fluoride salt systems will be discussed in this paper.

Triangle singularity enhancing isospin violation in {\\bar{{\\rm{B}}}}_{{\\rm{s}}}^{0}\\to {\\rm{J}}/{\\rm{\\psi }}{\\pi }^{0}{{\\rm{f}}}_{0}(980)

NASA Astrophysics Data System (ADS)

Liang, Wei-Hong; Sakai, S.; Xie, Ju-Jun; Oset, E.

2018-04-01

We perform calculations for the {\\bar{{{B}}}}{{s}}0\\to {{J}}/{{\\psi }}{π }0{{{f}}}0(980) and {\\bar{{{B}}}}{{s}}0\\to {{J}}/{{\\psi }}{π }0{{{a}}}0(980) reactions, showing that the first is isospin-suppressed while the second is isospin-allowed. The reaction proceeds via a triangle mechanism, with {\\bar{{{B}}}}{{s}}0\\to {{J}}/{{\\psi }}{{{K}}}{{* }}\\bar{{{K}}}+{{c}}.{{c}}., followed by the decay K* → Kπ and a further fusion of {{K}}\\bar{{{K}}} into the {{{f}}}0(980) or a0(980). We show that the mechanism develops a singularity around the π0 f0(980) or π0 a0(980) invariant mass of 1420 MeV, where the π0 f0 and π0 a0 decay modes are magnified and also the ratio of π0 f0 to π0 a0 production. Using experimental information for the {\\bar{{{B}}}}{{s}}0\\to {{J}}/{{\\psi }}{{{K}}}{{* }}\\bar{{{K}}}+{{c}}.{{c}}. decay, we are able to obtain absolute values for the reactions studied which fall into the experimentally accessible range. The reactions proposed and the observables evaluated, when contrasted with actual experiments, should be very valuable to obtain information on the nature of the low lying scalar mesons. Supported by National Natural Science Foundation of China (11565007, 11747307, 11647309, 11735003, 11475227), the Youth Innovation Promotion Association CAS (2016367). This work is also partly supported by the Spanish Ministerio de Economia y Com- petitividad and European FEDER funds (FIS2011-28853-C02-01, FIS2011-28853-C02-02, FIS2014-57026-REDT, FIS2014-51948-C2-1-P, FIS2014-51948-C2-2-P) and the Generalitat Valenciana in the program Prometeo (II-2014/068)

Two new rodent models for actinide toxicity studies. [/sup 237/Pu, /sup 241/Am

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, G.N.; Jones, C.W.; Gardner, P.A.

1981-04-01

Two small rodent species, the grasshopper mouse (Onychomys leucogaster) and the deer mouse (Peromyscus maniculatus), have tenacious and high retention in the liver and skeleton of plutonium and americium following intraperitoneal injection of Pu and Am in citrate solution. Liver retention of Pu and Am in the grasshopper mouse is higher than liver retention in the deer mouse. Both of these rodents are relatively long-lived, breed well in captivity, and adapt suitably to laboratory conditions. It is suggested that these two species of mice, in which plutonium retention is high and prolonged in both the skeleton and liver, as itmore » is in man, may be useful animal models for actinide toxicity studies.« less

Design, construction, operation, and evaluation of solar systems for industrial process-heat applications in the intermediate-temperature range (212/sup 0/F to 550/sup 0/F). Environmental assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1982-01-01

The environmental impacts are assessed for a proposed 50,000 square foot field of single axis tracking, concentrating solar collectors along the Ohio River in southern Ohio. The facility is planned to produce process steam for use in the production of polystyrene. Absorbed solar energy would heat an aliphatic hydrocarbon synthetic heat transfer fluid to a maximum temperature of 500/sup 0/F. The existing environment is briefly described, particularly regarding air quality. The potential environmental impacts of the solar process heat system on the air, water, soil, endangered species and archaeological and historical resources are examined, including risks due to flood andmore » glare and a comparison of alternatives. Also included are a Consent Judgment relating to two coal-fired boilers in violation of EPA regulations, property data of Gulf Synfluid 4CS (a candidate heat transfer fluid), piping and instrumentation diagrams and schematics, site grade and drainage plan, geological survey map, subsurface soil investigation, Ohio endangered species list, Ohio Archaeological Counsel certification list, and a study of heat transfer fluids and their properties. (LEW)« less

The separation of lanthanides and actinides in supercritical fluid carbon dioxide

DOE PAGES

Mincher, Bruce J.; Wai, Chien M.; Fox, Robert V.; ...

2015-10-28

Supercritical fluid carbon dioxide presents an attractive alternative to conventional solvents for recovery of the actinides and lanthanides. Carbon dioxide is a good solvent for fluorine and phosphate-containing ligands, including the traditional tributylphosphate ligand used in process-scale uranium separations. Actinide and lanthanide oxides may even be directly dissolved in carbon dioxide containing the complexes formed between these ligands and mineral acids, obviating the need for large volumes of acids for leaching and dissolution, and the corresponding organic liquid–liquid solvent extraction solutions. As a result, examples of the application of this novel technology for actinide and lanthanide separations are presented.

Actinide Sputtering Induced by Fission with Ultra-cold Neutrons

NASA Astrophysics Data System (ADS)

Shi, Tan; Venuti, Michael; Fellers, Deion; Martin, Sean; Morris, Chris; Makela, Mark

2017-09-01

Understanding the effects of actinide sputtering due to nuclear fission is important for a wide range of applications, including nuclear fuel storage, space science, and national defense. A new program at the Los Alamos Neutron Science Center uses ultracold neutrons (UCN) to induce fission in actinides such as uranium and plutonium. By controlling the UCN energy, it is possible to induce fission at the sample surface within a well-defined depth. It is therefore an ideal tool for studying the effects of fission-induced sputtering as a function of interaction depth. Since the mechanism for fission-induced surface damage is not well understood, this work has the potential to deconvolve the various damage mechanisms. During the irradiation with UCN, NaI detectors are used to monitor the fission events and were calibrated by monitoring fission fragments with an organic scintillator. Alpha spectroscopy of the ejected actinide material is performed in an ion chamber to determine the amount of sputtered material. Actinide samples with various sample properties and surface conditions are irradiated and analyzed. In this talk, I will discuss our experimental setup and present the preliminary results from the testing of multiple samples. This work has been supported by Los Alamos National Laboratory and Seaborg Summer Research Fellowship.

CHARACTERIZATION OF ACTINIDES IN SIMULATED ALKALINE TANK WASTE SLUDGES AND LEACHATES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nash, Kenneth L.

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 actinidesmore » 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.« less

The magnetic properties of BaCo0.5Ni0.5F4

NASA Astrophysics Data System (ADS)

Xu, Qingyu; Dai, Chuanjun; Han, Zhida; Li, Qi

2018-05-01

The family of BaMF4 with M of magnetic 3d transition metal ions is the typical multiferroic material. Pure phase solid solution of BaCoF4 and BaNiF4 with molar ratio of 1:1 (BaCo0.5Ni0.5F4) is prepared by solid state reaction, which has been confirmed by X ray diffraction patterns. Field dependent magnetization measurements only show the linear curve with temperature down to 5 K, indicating the antiferromagnetic nature. Compared with BaCoF4 and BaNiF4, no significant enhancement of magnetization is observed, indicating the absence of ferrimagnetism and the random distribution of Co and Ni ions. The low temperature magnetic anomalies are studied by zero field cooled (ZFC) and field cooled (FC) temperature dependent magnetization (M-T) measurements. A bifurcation between FC and ZFC M-T curves happens at 118 K, indicating the onset of 2-dimensional antiferromagnetism. The magnetization maximum at 87 K is attributed to the 2-dimensional antiferromagnetic clusters, followed by the drastic decrease of magnetization, which is due to the onset of 3-dimensional antiferromagnetism. A dip is observed in FC M-T curve at 40 K, which is attributed to the 3-dimensional antiferromagnetic clusters. A drastic increase of magnetization is observed at 9 K, which is due to the uncompensated isolated spins. Exchange bias is clearly observed, with blocking temperature of 90 K. The contribution from surface spin glass has been excluded by the AC magnetization measurements, and the mechanism has been explained by the exchange coupling between the two antiferromagnetic phases.

Communication—Quantitative Voltammetric Analysis of High Concentration Actinides in Molten Salts

DOE PAGES

Hoyt, Nathaniel C.; Willit, James L.; Williamson, Mark A.

2017-01-18

Previous electroanalytical studies have shown that cyclic voltammetry can provide accurate quantitative measurements of actinide concentrations at low weight loadings in molten salts. However, above 2 wt%, the techniques were found to underpredict the concentrations of the reactant species. Here this work will demonstrate that much of the discrepancy is caused by uncompensated resistance and cylindrical diffusion. An improved electroanalytical approach has therefore been developed using the results of digital simulations to take these effects into account. This approach allows for accurate electroanalytical predictions across the full range of weight loadings expected to be encountered in operational nuclear fuel processingmore » equipment.« less

Communication—Quantitative Voltammetric Analysis of High Concentration Actinides in Molten Salts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoyt, Nathaniel C.; Willit, James L.; Williamson, Mark A.

Previous electroanalytical studies have shown that cyclic voltammetry can provide accurate quantitative measurements of actinide concentrations at low weight loadings in molten salts. However, above 2 wt%, the techniques were found to underpredict the concentrations of the reactant species. Here this work will demonstrate that much of the discrepancy is caused by uncompensated resistance and cylindrical diffusion. An improved electroanalytical approach has therefore been developed using the results of digital simulations to take these effects into account. This approach allows for accurate electroanalytical predictions across the full range of weight loadings expected to be encountered in operational nuclear fuel processingmore » equipment.« less

Superconductivity in REO0.5F0.5BiS2 with high-entropy-alloy-type blocking layers

NASA Astrophysics Data System (ADS)

Sogabe, Ryota; Goto, Yosuke; Mizuguchi, Yoshikazu

2018-05-01

We synthesized new REO0.5F0.5BiS2 (RE: rare earth) superconductors with high-entropy-alloy-type (HEA-type) REO blocking layers. The lattice constant a systematically changed in the HEA-type samples with the RE concentration and the RE ionic radius. A sharp superconducting transition was observed in the resistivity measurements for all the HEA-type samples, and the transition temperature of the HEA-type samples was higher than that of typical REO0.5F0.5BiS2. The sharp superconducting transition and the enhanced superconducting properties of the HEA-type samples may indicate the effectiveness of the HEA states of the REO blocking layers in the REO0.5F0.5BiS2 system.

A Screened Hybrid DFT Study of Actinide Oxides, Nitrides, and Carbides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wen, Xiaodong; Martin, Richard L.; Scuseria, Gustavo E.

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 thesemore » 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.« less

In-cell NMR reveals potential precursor of toxic species from SOD1 fALS mutants

NASA Astrophysics Data System (ADS)

Luchinat, Enrico; Barbieri, Letizia; Rubino, Jeffrey T.; Kozyreva, Tatiana; Cantini, Francesca; Banci, Lucia

2014-11-01

Mutations in the superoxide dismutase 1 (SOD1) gene are related to familial cases of amyotrophic lateral sclerosis (fALS). Here we exploit in-cell NMR to characterize the protein folding and maturation of a series of fALS-linked SOD1 mutants in human cells and to obtain insight into their behaviour in the cellular context, at the molecular level. The effect of various mutations on SOD1 maturation are investigated by changing the availability of metal ions in the cells, and by coexpressing the copper chaperone for SOD1, hCCS. We observe for most of the mutants the occurrence of an unstructured SOD1 species, unable to bind zinc. This species may be a common precursor of potentially toxic oligomeric species, that are associated with fALS. Coexpression of hCCS in the presence of copper restores the correct maturation of the SOD1 mutants and prevents the formation of the unstructured species, confirming that hCCS also acts as a molecular chaperone.

An Advanced TALSPEAK Concept for Separating Minor Actinides. Part 1. Process Optimization and Flowsheet Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lumetta, Gregg J.; Levitskaia, Tatiana G.; Wilden, Andreas

A system is being developed to separate trivalent actinides from lanthanide fission product elements that uses 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester to extract the lanthanide ions into an organic phase, while the actinide ions are held in the citrate-buffered aqueous phase by complexation to N-(2-hydroxyethyl)ethylenediamine-N,N',N'-triacetic acid (HEDTA). Earlier investigations of this system using a 2-cm centrifugal contactor revealed that the relatively slow extraction of Sm3+, Eu3+, and Gd3+ resulted in low separation factors from Am3+. In the work reported here, adjustments to the aqueous phase chemistry were made to improve the extraction rates. The results suggest that increasing the concentration ofmore » the citric acid buffer from 0.2 to 0.6 mol/L, and lowering the pH from 3.1 to 2.6, significantly improved lanthanide extraction rates resulting in an actinide/lanthanide separation system suitable for deployment in centrifugal contactors. Experiments performed to evaluate whether the lanthanide extraction rates can be improved by replacing aqueous HEDTA with nitrilotriacetic acid (NTA) exhibited promising results. However, NTA exhibited an unsatisfactorily high distribution value for Am3+ under the extraction conditions examined.« less

Actinide Sorption in Rainier Mesa Tunnel Waters from the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, P; Zavarin, M; Leif, R

2007-12-17

The sorption behavior of americium (Am), plutonium (Pu), neptunium (Np), and uranium (U) in perched Rainier Mesa tunnel water was investigated. Both volcanic zeolitized tuff samples and groundwater samples were collected from Rainier Mesa, Nevada Test Site, NV for a series of batch sorption experiments. Sorption in groundwater with and without the presence of dissolved organic matter (DOM) was investigated. Am(III) and Pu(IV) are more soluble in groundwater that has high concentrations of DOM. The sorption K{sub d} for Am(III) and Pu(IV) on volcanic zeolitized tuff was up to two orders of magnitude lower in samples with high DOM (15more » to 19 mg C/L) compared to samples with DOM removed (< 0.4 mg C/L) or samples with naturally low DOM (0.2 mg C/L). In contrast, Np(V) and U(VI) sorption to zeolitized tuff was much less affected by the presence of DOM. The Np(V) and U(VI) sorption Kds were low under all conditions. Importantly, the DOM was not found to significantly sorb to the zeolitized tuff during these experiment. The concentration of DOM in groundwater affects the transport behavior of actinides in the subsurface. The mobility of Am(III) and Pu(IV) is significantly higher in groundwater with elevated levels of DOM resulting in potentially enhanced transport. To accurately model the transport behavior of actinides in groundwater at Rainier Mesa, the low actinide Kd values measured in groundwater with high DOM concentrations must be incorporated in predictive transport models.« less

Synthesis and electrochemical properties of layered Li[Ni 0.333Co 0.333Mn 0.293Al 0.04]O 2- zF z cathode materials prepared by the sol-gel method

NASA Astrophysics Data System (ADS)

Liao, Li; Wang, Xianyou; Luo, Xufang; Wang, Ximing; Gamboa, Sergio; Sebastian, P. J.

The cathode-active materials, layered Li[Ni 0.333Co 0.333Mn 0.293Al 0.04]O 2- zF z (0 ≤ z ≤ 0.1), were synthesized from a sol-gel precursor at 900 °C in air. The influence of Al-F co-substitution on the structural and electrochemical properties of the as-prepared samples was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical experiments. The results showed that Li[Ni 0.333Co 0.333Mn 0.293Al 0.04]O 2- zF z has a typical hexagonal structure with a single phase, the particle sizes of the samples tended to increase with increasing fluorine content. It has been found that Li[Ni 0.333Co 0.333Mn 0.293Al 0.04]O 1.95F 0.05 showed an improved cathodic behavior and discharge capacity retention compared to the undoped samples in the voltage range of 3.0-4.3 V. The electrodes prepared from Li[Ni 0.333Co 0.333Mn 0.293Al 0.04]O 1.95F 0.05 delivered an initial discharge capacity of 158 mAh -1 g and an initial coulombic efficiency is 91.3%, and the capacity retention at the 20th cycle was 94.9%. Though the F-doped samples had lower initial capacities, they showed better cycle performances compared with F-free samples. Therefore, this is a promising material for a lithium-ion battery.

Angular dependent torque measurements on CaFe0.88Co0.12AsF

NASA Astrophysics Data System (ADS)

Xiao, H.; Gao, B.; Ma, Y. H.; Li, X. J.; Mu, G.; Hu, T.

2016-08-01

Out-of-plane angular dependent torque measurements were performed on CaFe0.88Co0.12AsF (Ca1 1 1 1) single crystals. In the normal state, the torque data shows \\sin 2θ angular dependence and H 2 magnetic field dependence, as a result of paramagnetism. In the mixed state, the torque signal is a combination of the vortex torque and paramagnetic torque, and the former allows the determination of the anisotropy parameter γ. At T   =  11.5 K, γ (11.5 K ≃ 0.5 T c)  =  19.1, which is similar to the result of SmFeAsO0.8F0.2, γ ≃ 23 at T≃ 0.4{{T}\\text{c}} . So the 11 1 1 is more anisotropic compared to 11 and 122 families of iron-based superconductors. This may suggest that the electronic coupling between layers in 1 1 1 1 is less effective than in 11 and 122 families.

Synthesis and characterisation of PuPO4 - a potential analytical standard for EPMA actinide quantification

NASA Astrophysics Data System (ADS)

Wright, K. E.; Popa, K.; Pöml, P.

2018-01-01

Transmutation nuclear fuels contain weight percentage quantities of actinide elements, including Pu, Am and Np. Because of the complex spectra presented by actinide elements using electron probe microanalysis (EPMA), it is necessary to have relatively pure actinide element standards to facilitate overlap correction and accurate quantitation. Synthesis of actinide oxide standards is complicated by their multiple oxidation states, which can result in inhomogeneous standards or standards that are not stable at atmospheric conditions. Synthesis of PuP4 results in a specimen that exhibits stable oxidation-reduction chemistry and is sufficiently homogenous to serve as an EPMA standard. This approach shows promise as a method for producing viable actinide standards for microanalysis.

Mixed Metal Phosphonate- Phosphate Resins for Separation of Lanthanides from Actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clearfield, Abraham

As indicated in the previous annual report the goals of this project are to develop procedures for efficient separation of lanthanides from actinides and curium from americium. These processes are required for the nuclear fuel cycle to minimize the waste and recover the valuable actinides. The basis for our study is that we have prepared a group of compounds that are porous and favor the uptake of ions with charges 3+ and 4+ over ions of lesser charge. The general formula for these materials is M(O 3PC 6H 4PO 3) 1-x/2(APO 4)x·nH 2O: where M=Zr 4+, Sn 4+, A=H, Na,more » or K and X=O, 0.5, 0.8, 1.0, 1.33 and 1.61-3. One of our tasks is to determine which members of this group of compounds are effective in carrying out the required separations. A difficulty in obtaining this required information is that the compounds are amorphous. That is they are not crystalline, therefore we need to resort to synchrotron data to obtain structural data which will be presented in detail. This information will be provided as a separate section.« less

Fluorometric determination of Vibrio parahaemolyticus using an F0F1-ATPase-based aptamer and labeled chromatophores.

PubMed

Duan, Nuo; Wu, Shijia; Zhang, Huiling; Zou, Ying; Wang, Zhouping

2018-05-18

An F 0 F 1 -ATPase-based aptasensor is described for the fluorometric determination of Vibrio parahaemolyticus. Chromatophores containing F 0 F 1 -ATPases were first prepared from Rhodospirillum rubrum cells. Then, an aptamer-functionalized chromatophore acts as the capture probe, and a chromatophore labeled with the pH probe fluorescein acts as the signalling probe. In the presence of V. parahaemolyticus, the rotation rate of F 0 F 1 -ATPase is decreased due to the formation of the aptamer-chromatophore complex. This leads to a retarded proton flux out of the chromatophores. As a result, the pH value inside the chromatophores is reduced, and the fluorescence of the pH probe F1300 is accordingly decreased. The relative fluorescence varies linearly over the 15 to 1.5 × 10 6  cfu·mL -1 Vibrio parahaemolyticus concentration range, and the limit of detection is 15 cfu·mL -1 . The method was applied to analyze artificially contaminated salmon samples where it showed excellent perfomance. Graphical abstract In this assay, aptamer functionalized chromatophores act as a capture probe, and the fluoresce in labeled chromatophores as signalling probe. The formation of aptamer-chromatophore complex leads to a retarded proton flux out of the chromatophores. As a result, the pH value inside the chromatophores is reduced, and fluorescence intensity is accordingly decreased.

Anisotropy of critical correlations in moderately delocalized cerium and actinide systems

NASA Astrophysics Data System (ADS)

Kioussis, Nicholas; Cooper, Bernard R.

1986-09-01

The equilibrium and excitation magnetic behavior of a class of cerium and light actinide compounds have been explained previously, in a theory first developed by Siemann and Cooper, in terms of a band-f-electron anisotropic hybridization-mediated two-ion interaction of the Coqblin-Schrieffer type. Using the same theory, we present here a calculation, within the random-phase approximation, of the longitudinal component of the static wave-vector-dependent susceptibility in the paramagnetic phase. The calculations have been performed in the presence of a cubic crystal field (CF) and yield results for the ratio of inverse critical correlation lengths, κ/κ⊥, parallel and perpendicular to the moment direction, that compare well with those of diffuse critical neutron scattering experiments. In Ce3+ (f1) compounds, we find that as the CF interaction (Γ7 ground state) predominates over the two-ion interaction, the relative strength of the coupling within the ferromagnetic \\{001\\} planes (with moments perpendicular to the planes) and that between the \\{001\\} planes is gradually reversed, resulting in a ratio κ/κ⊥ smaller than unity, as is experimentally observed. We also present results for the effect of differing intraionic (L-S, intermediate, and j-j) coupling on κ/κ⊥ for the case of Pu3+(f5) and U3+(f3) compounds.

Quantum Chemical Studies of Actinides and Lanthanides: From Small Molecules to Nanoclusters

NASA Astrophysics Data System (ADS)

Vlaisavljevich, Bess

Research into actinides is of high interest because of their potential applications as an energy source and for the environmental implications therein. Global concern has arisen since the development of the actinide concept in the 1940s led to the industrial scale use of the commercial nuclear energy cycle and nuclear weapons production. Large quantities of waste have been generated from these processes inspiring efforts to address fundamental questions in actinide science. In this regard, the objective of this work is to use theory to provide insight and predictions into actinide chemistry, where experimental work is extremely challenging because of the intrinsic difficulties of the experiments themselves and the safety issues associated with this type of chemistry. This thesis is a collection of theoretical studies of actinide chemistry falling into three categories: quantum chemical and matrix isolation studies of small molecules, the electronic structure of organoactinide systems, and uranyl peroxide nanoclusters and other solid state actinide compounds. The work herein not only spans a wide range of systems size but also investigates a range of chemical problems. Various quantum chemical approaches have been employed. Wave function-based methods have been used to study the electronic structure of actinide containing molecules of small to middle-size. Among these methods, the complete active space self consistent field (CASSCF) approach with corrections from second-order perturbation theory (CASPT2), the generalized active space SCF (GASSCF) approach, and Moller-Plesset second-order perturbation theory (MP2) have been employed. Likewise, density functional theory (DFT) has been used along with analysis tools like bond energy decomposition, bond orders, and Bader's Atoms in Molecules. From these quantum chemical results, comparison with experimentally obtained structures and spectra are made.

Support for Students and Young Scientists to Participate in the 2009 Actinides Conference to be held in San Francisco, CA, Sunday, 12 July 2009 -- Friday, 17 July 2009

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raymond, Kenneth N.

2011-04-08

Early career scientist were provided support to attend and participate in the Actinides 2009 (AN2009) International Conference held in San Francisco, California from 12-17 July 2011. This is the premier conference in the field of actinide chemistry, physics, and materials science of the actinide elements. Participation in the preeminent scientific meeting in actinide science keeps the U.S at the forefront of developments in this key field. The specific involvement of early career scientists combats the loss of expertise in the aforementioned critical areas related to f-element chemistry such as energy, homeland, and environmental security. Without these trained scientists, the U.S.more » will not be able to properly exploit nuclear technology to its fullest and will not be able to address its energy needs in either an environmentally safe or cost–effective manner nor will it be able to provide for its national defense. Furthermore, the early career scientists added greatly to the scientific content of the meeting and stimulates early career scientists to remain in the filed of actinide science. Providing support for participation in the AN2009 Conference via registration fee waivers, hotel cost support, and travel cost support, was extremely effective in securing the participation of early career scientists that would have not otherwise been able to attend.« less

Advancing the scientific basis of trivalent actinide-lanthanide separations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nash, K.L.

For advanced fuel cycles designed to support transmutation of transplutonium actinides, several options have been demonstrated for process-scale aqueous separations for U, Np, Pu management and for partitioning of trivalent actinides and fission product lanthanides away from other fission products. The more difficult mutual separation of Am/Cm from La-Tb remains the subject of considerable fundamental and applied research. The chemical separations literature teaches that the most productive alternatives to pursue are those based on ligand donor atoms less electronegative than O, specifically N- and S-containing complexants and chloride ion (Cl{sup -}). These 'soft-donor' atoms have exhibited usable selectivity in theirmore » bonding interactions with trivalent actinides relative to lanthanides. In this report, selected features of soft donor reagent design, characterization and application development will be discussed. The roles of thiocyanate, aminopoly-carboxylic acids and lactate in separation processes are detailed. (authors)« less

Method for the concentration and separation of actinides from biological and environmental samples

DOEpatents

Horwitz, E. Philip; Dietz, Mark L.

1989-01-01

A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting.

Alternative Chemical Cleaning Methods for High Level Waste Tanks: Actual Waste Testing with SRS Tank 5F Sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

King, William D.; Hay, Michael S.

Solubility testing with actual High Level Waste tank sludge has been conducted in order to evaluate several alternative chemical cleaning technologies for the dissolution of sludge residuals remaining in the tanks after the exhaustion of mechanical cleaning and sludge sluicing efforts. Tests were conducted with archived Savannah River Site (SRS) radioactive sludge solids that had been retrieved from Tank 5F in order to determine the effectiveness of an optimized, dilute oxalic/nitric acid cleaning reagent toward dissolving the bulk non-radioactive waste components. Solubility tests were performed by direct sludge contact with the oxalic/nitric acid reagent and with sludge that had beenmore » pretreated and acidified with dilute nitric acid. For comparison purposes, separate samples were also contacted with pure, concentrated oxalic acid following current baseline tank chemical cleaning methods. One goal of testing with the optimized reagent was to compare the total amounts of oxalic acid and water required for sludge dissolution using the baseline and optimized cleaning methods. A second objective was to compare the two methods with regard to the dissolution of actinide species known to be drivers for SRS tank closure Performance Assessments (PA). Additionally, solubility tests were conducted with Tank 5 sludge using acidic and caustic permanganate-based methods focused on the “targeted” dissolution of actinide species.« less

Relaxation of Actinide Surfaces: An All Electron Study

NASA Astrophysics Data System (ADS)

Atta-Fynn, Raymond; Dholabhai, Pratik; Ray, Asok

2006-10-01

Fully relativistic full potential density functional calculations with a linearized augmented plane wave plus local orbitals basis (LAPW + lo) have been performed to investigate the relaxations of heavy actinide surfaces, namely the (111) surface of fcc δ-Pu and the (0001) surface of dhcp Am using WIEN2k. This code uses the LAPW + lo method with the unit cell divided into non-overlapping atom-centered spheres and an interstitial region. The APW+lo basis is used to describe all s, p, d, and f states and LAPW basis to describe all higher angular momentum states. Each surface was modeled by a three-layer periodic slab separated by 60 Bohr vacuum with four atoms per surface unit cell. In general, we have found a contraction of the interlayer separations for both Pu and Am. We will report, in detail, the electronic and geometric structures of the relaxed surfaces and comparisons with the respective non-relaxed surfaces.

Multifaceted Modularity: A Key for Stepwise Building of Hierarchical Complexity in Actinide Metal-Organic Frameworks.

PubMed

Dolgopolova, Ekaterina A; Ejegbavwo, Otega A; Martin, Corey R; Smith, Mark D; Setyawan, Wahyu; Karakalos, Stavros G; Henager, Charles H; Zur Loye, Hans-Conrad; Shustova, Natalia B

2017-11-22

Growing necessity for efficient nuclear waste management is a driving force for development of alternative architectures toward fundamental understanding of mechanisms involved in actinide (An) integration inside extended structures. In this manuscript, metal-organic frameworks (MOFs) were investigated as a model system for engineering radionuclide containing materials through utilization of unprecedented MOF modularity, which cannot be replicated in any other type of materials. Through the implementation of recent synthetic advances in the MOF field, hierarchical complexity of An-materials was built stepwise, which was only feasible due to preparation of the first examples of actinide-based frameworks with "unsaturated" metal nodes. The first successful attempts of solid-state metathesis and metal node extension in An-MOFs are reported, and the results of the former approach revealed drastic differences in chemical behavior of extended structures versus molecular species. Successful utilization of MOF modularity also allowed us to structurally characterize the first example of bimetallic An-An nodes. To the best of our knowledge, through combination of solid-state metathesis, guest incorporation, and capping linker installation, we were able to achieve the highest Th wt % in mono- and biactinide frameworks with minimal structural density. Overall, the combination of a multistep synthetic approach with homogeneous actinide distribution and moderate solvothermal conditions could make MOFs an exceptionally powerful tool to address fundamental questions responsible for chemical behavior of An-based extended structures and, therefore, shed light on possible optimization of nuclear waste administration.

Managing Zirconium Chemistry and Phase Compatibility in Combined Process Separations for Minor Actinide Partitioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wall, Nathalie; Nash, Ken; Martin, Leigh

In response to the NEUP Program Supporting Fuel Cycle R&D Separations and Waste Forms call DEFOA- 0000799, this report describes the results of an R&D project focusing on streamlining separation processes for advanced fuel cycles. An example of such a process relevant to the U.S. DOE FCR&D program would be one combining the functions of the TRUEX process for partitioning of lanthanides and minor actinides from PUREX(UREX) raffinates with that of the TALSPEAK process for separating transplutonium actinides from fission product lanthanides. A fully-developed PUREX(UREX)/TRUEX/TALSPEAK suite would generate actinides as product(s) for reuse (or transmutation) and fission products as waste.more » As standalone, consecutive unit-operations, TRUEX and TALSPEAK employ different extractant solutions (solvating (CMPO, octyl(phenyl)-N,Ndiisobutylcarbamoylmethylphosphine oxide) vs. cation exchanging (HDEHP, di-2(ethyl)hexylphosphoric acid) extractants), and distinct aqueous phases (2-4 M HNO 3 vs. concentrated pH 3.5 carboxylic acid buffers containing actinide selective chelating agents). The separate processes may also operate with different phase transfer kinetic constraints. Experience teaches (and it has been demonstrated at the lab scale) that, with proper control, multiple process separation systems can operate successfully. However, it is also recognized that considerable economies of scale could be achieved if multiple operations could be merged into a single process based on a combined extractant solvent. The task of accountability of nuclear materials through the process(es) also becomes more robust with fewer steps, providing that the processes can be accurately modeled. Work is underway in the U.S. and Europe on developing several new options for combined processes (TRUSPEAK, ALSEP, SANEX, GANEX, ExAm are examples). There are unique challenges associated with the operation of such processes, some relating to organic phase chemistry, others arising from the

Unconventional superconductivity in CaFe0.85Co0.15AsF evidenced by torque measurements

NASA Astrophysics Data System (ADS)

Xiao, Hong; Li, X. J.; Mu, G.; Hu, T.

Out-of-plane angular dependent torque measurements were performed on CaFe0.85Co0.15AsF single crystals. Abnormal superconducting fluctuation, featured by enhanced diamagnetism with magnetic field, is detected up to about 1.5 times superconducting transition temperature Tc. Compared to cuprate superconductors, the fluctuation effect in iron-based superconductor is less pronounced. Anisotropy parameter γ is obtained from the mixed state torque data and it is found that γ shows both magnetic field and temperature depenence, pointing to multiband superconductivity. The temperature dependence of penetration depth λ (T) suggests unconventional superconductivity in CaFe0.85Co0.15AsF.

Starmerella camargoi f.a., sp. nov., Starmerella ilheusensis f.a., sp. nov., Starmerella litoralis f.a., sp. nov., Starmerella opuntiae f.a., sp. nov., Starmerella roubikii f.a., sp. nov. and Starmerella vitae f.a., sp. nov., isolated from flowers and bees, and transfer of related Candida species to the genus Starmerella as new combinations.

PubMed

Santos, Ana Raquel O; Leon, Marina P; Barros, Katharina O; Freitas, Larissa F D; Hughes, Alice F S; Morais, Paula B; Lachance, Marc-André; Rosa, Carlos A

2018-04-01

Six novel yeast species, Starmerella camargoi f.a., sp. nov., Starmerella ilheusensis f.a., sp. nov., Starmerella litoralis f.a., Starmerella opuntiae f.a., sp. nov., sp. nov., Starmerella roubikii f.a., sp. nov. and Starmerella vitae f.a, sp. nov. are proposed to accommodate 19 isolates recovered from ephemeral flowers or bees in Brazil, Costa Rica and Belize. Sequence analysis of the ITS-5.8S region (when available) and the D1/D2 domains of the large subunit of the rRNA gene showed that the six novel yeasts are phylogenetically related to several species of the Starmerella clade. The type strains are Starmerella camargoi f.a., sp. nov. UFMG-CM-Y595 T (=CBS 14130 T ; Mycobank number MB 822640), Starmerella ilheusensis f.a., sp. nov. UFMG-CM-Y596 T (=CBS CBS14131 T ; MB 822641), Starmerella litoralis f.a., sp. nov. UFMG-CM-Y603 T (=CBS14104 T ; MB 822642), Starmerella opuntiae f.a., sp. nov. UFMG-CM-Y286 T (=CBS 13466 T ; MB 822643), Starmerella roubikii f.a., sp. nov. UWOPS 01-191.1 (=CBS 15148; MB 822645) and Starmerella vitae f.a., sp. nov. UWOPS 00-107.2 (=CBS 15147 T ; MB 822646). In addition, 25 species currently assigned to the genus Candida are reassigned formally to the genus Starmerella.

Method for the concentration and separation of actinides from biological and environmental samples

DOEpatents

Horwitz, E.P.; Dietz, M.L.

1989-05-30

A method and apparatus for the quantitative recover of actinide values from biological and environmental sample by passing appropriately prepared samples in a mineral acid solution through a separation column of a dialkyl(phenyl)-N,N-dialylcarbamoylmethylphosphine oxide dissolved in tri-n-butyl phosphate on an inert substrate which selectively extracts the actinide values. The actinide values can be eluted either as a group or individually and their presence quantitatively detected by alpha counting. 3 figs.

Use of PCR To Demonstrate Presence of Adenovirus Species B, C, or F as Well as Coinfection with Two Adenovirus Species in Children with Flu-Like Symptoms

PubMed Central

Echavarria, Marcela; Maldonado, Daniela; Elbert, Gabriela; Videla, Cristina; Rappaport, Ruth; Carballal, Guadalupe

2006-01-01

Adenovirus (AdV) respiratory infections have usually been associated with species B, C, and E. In this study, we detected 9.4% of AdVs by PCR in 500 nasal swabs from 319 children with influenza-like symptoms. AdV typing by PCR with specific probes showed species C, B, and F as well as coinfection with two species. Coinfection with two AdV species and the presence of species F in respiratory samples are novel findings that should be further investigated. PMID:16455929

A theoretical study of F0-F1 interaction with application to resonant speaking and singing voice.

PubMed

Titze, Ingo R

2004-09-01

An interactive source-filter system, consisting of a three-mass body-cover model of the vocal folds and a wave reflection model of the vocal tract, was used to test the dependence of vocal fold vibration on the vocal tract. The degree of interaction is governed by the epilarynx tube, which raises the vocal tract impedance to match the impedance of the glottis. The key component of the impedance is inertive reactance. Whenever there is inertive reactance, the vocal tract assists the vocal folds in vibration. The amplitude of vibration and the glottal flow can more than double, and the oral radiated power can increase up to 10 dB. As F0 approaches F1, the first formant frequency, the interactive source-filter system loses its advantage (because inertive reactance changes to compliant reactance) and the noninteractive system produces greater vocal output. Thus, from a voice training and control standpoint, there may be reasons to operate the system in either interactive and noninteractive modes. The harmonics 2F0 and 3F0 can also benefit from being positioned slightly below F1.

Single crystals of the fluorite nonstoichiometric phase Eu{0.916/2+}Eu{0.084/3+}F2.084 (conductivity, transmission, and hardness)

NASA Astrophysics Data System (ADS)

Sobolev, B. P.; Turkina, T. M.; Sorokin, N. I.; Karimov, D. N.; Komar'kova, O. N.; Sulyanova, E. A.

2010-07-01

The nonstoichiometric phase EuF2+ x has been obtained via the partial reduction of EuF3 by elementary Si at 900-1100°C. Eu{0.916/2+}Eu{0.084/3+}F2.084 (EuF2.084) single crystals have been grown from melt by the Bridgman method in a fluorinating atmosphere. These crystals belong to the CaF2 structure type (sp. gr. Fm bar 3 m) with the cubic lattice parameter a = 5.8287(2) Å, are transparent in the spectral range of 0.5-11.3 μm, and have microhardness H μ = 3.12 ± 0.13 GPa and ionic conductivity σ = 1.4 × 10-5 S/cm at 400°C with the ion transport activation energy E a = 1.10 ± 0.05 eV. The physicochemical characteristics of the fluorite phases in the EuF2 - EuF3 systems are similar to those of the phases in the SrF2 - EuF3 and SrF2 - GdF3 systems due to the similar lattice parameters of the EuF2 and SrF2 components. Europium difluoride supplements the list of fluorite components MF2 ( M = Ca, Sr, Ba, Cd, Pb), which are crystal matrices for nonstoichiometric (nanostructured) fluoride materials M 1 - x R x F2 + x ( R are rare earth elements).

Development of a standardized sequential extraction protocol for simultaneous extraction of multiple actinide elements

DOE PAGES

Faye, Sherry A.; Richards, Jason M.; Gallardo, Athena M.; ...

2017-02-07

Sequential extraction is a useful technique for assessing the potential to leach actinides from soils; however, current literature lacks uniformity in experimental details, making direct comparison of results impossible. This work continued development toward a standardized five-step sequential extraction protocol by analyzing extraction behaviors of 232Th, 238U, 239,240Pu and 241Am from lake and ocean sediment reference materials. Results produced a standardized procedure after creating more defined reaction conditions to improve method repeatability. A NaOH fusion procedure is recommended following sequential leaching for the complete dissolution of insoluble species.

Actinide Solubility and Speciation in the WIPP [PowerPoint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reed, Donald T.

2015-11-02

The presentation begins with the role and need for nuclear repositories (overall concept, international updates (Sweden, Finland, France, China), US approach and current status), then moves on to the WIPP TRU repository concept (design, current status--safety incidents of February 5 and 14, 2014, path forward), and finally considers the WIPP safety case: dissolved actinide concentrations (overall approach, oxidation state distribution and redox control, solubility of actinides, colloidal contribution and microbial effects). The following conclusions are set forth: (1) International programs are moving forward, but at a very slow and somewhat sporadic pace. (2) In the United States, the Salt repositorymore » 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.« less

Development and Perceptual Evaluation of Amplitude-Based F0 Control in Electrolarynx Speech

ERIC Educational Resources Information Center

Saikachi, Yoko; Stevens, Kenneth N.; Hillman, Robert E.

2009-01-01

Purpose: Current electrolarynx (EL) devices produce a mechanical speech quality that has been largely attributed to the lack of natural fundamental frequency (F0) variation. In order to improve the quality of EL speech, in the present study the authors aimed to develop and evaluate an automatic F0 control scheme, in which F0 was modulated based on…

Electronic Structure of Transition Metal Clusters, Actinide Complexes and Their Reactivities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan Balasubramanian

2009-07-18

This is a continuing DOE-BES funded project on transition metal and actinide containing species, aimed at the electronic structure and spectroscopy of transition metal and actinide containing species. While a long term connection of these species is to catalysis and environmental management of high-level nuclear wastes, the immediate relevance is directly to other DOE-BES funded experimental projects at DOE-National labs and universities. There are a number of ongoing gas-phase spectroscopic studies of these species at various places, and our computational work has been inspired by these experimental studies and we have also inspired other experimental and theoretical studies. Thus ourmore » studies have varied from spectroscopy of diatomic transition metal carbides to large complexes containing transition metals, and actinide complexes that are critical to the environment. In addition, we are continuing to make code enhancements and modernization of ALCHEMY II set of codes and its interface with relativistic configuration interaction (RCI). At present these codes can carry out multi-reference computations that included up to 60 million configurations and multiple states from each such CI expansion. ALCHEMY II codes have been modernized and converted to a variety of platforms such as Windows XP, and Linux. We have revamped the symbolic CI code to automate the MRSDCI technique so that the references are automatically chosen with a given cutoff from the CASSCF and thus we are doing accurate MRSDCI computations with 10,000 or larger reference space of configurations. The RCI code can also handle a large number of reference configurations, which include up to 10,000 reference configurations. Another major progress is in routinely including larger basis sets up to 5g functions in thee computations. Of course higher angular momenta functions can also be handled using Gaussian and other codes with other methods such as DFT, MP2, CCSD(T), etc. We have also calibrated our

AlF 3 Surface-Coated Li[Li 0.2 Ni 0.17 Co 0.07 Mn 0.56 ]O 2 Nanoparticles with Superior Electrochemical Performance for Lithium-Ion Batteries

DOE PAGES

Sun, Shuwei; Yin, Yanfeng; Wan, Ning; ...

2015-06-24

For Li-rich layered cathode materials considerable attention has been paid owing to their high capacity performance for Li-ion batteries (LIBs). In our work, layered Li-rich Li[Li 0.2Ni 0.17Co 0.07Mn 0.56]O 2 nanoparticles are surface-modified with AlF 3 through a facile chemical deposition method. The AlF 3 surface layers have little impact on the structure of the material and act as buffers to prevent the direct contact of the electrode with the electrolyte; thus, they enhance the electrochemical performance significantly. The 3 wt% AlF 3-coated Li-rich electrode exhibits the best cycling capability and has a considerably enhanced capacity retention of 83.1%more » after 50 cycles. Moreover, the rate performance and thermal stability of the 3 wt% AlF3-coated electrode are also clearly improved. Finally, surface analysis indicates that the AlF 3 coating layer can largely suppress the undesirable growth of solid electrolyte interphase (SEI) film and, therefore, stabilizes the structure upon cycling.« less

Method for extracting lanthanides and actinides from acid solutions

DOEpatents

Horwitz, E. Philip; Kalina, Dale G.; Kaplan, Louis; Mason, George W.

1985-01-01

A process for the recovery of actinide and lanthanide values from aqueous acidic solutions with an organic extractant having the formula: ##STR1## where .phi. is phenyl, R.sup.1 is a straight or branched alkyl or alkoxyalkyl containing from 6 to 12 carbon atoms and R.sup.2 is an alkyl containing from 3 to 6 carbon atoms. The process is suitable for the separation of actinide and lanthanide values from fission product values found together in high level nuclear reprocessing waste solutions.

Actinide abundances in ordinary chondrites

USGS Publications Warehouse

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

1990-01-01

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

Room temperature electrodeposition of actinides from ionic solutions

DOEpatents

Hatchett, David W.; Czerwinski, Kenneth R.; Droessler, Janelle; Kinyanjui, John

2017-04-25

Uranic and transuranic metals and metal oxides are first dissolved in ozone compositions. The resulting solution in ozone can be further dissolved in ionic liquids to form a second solution. The metals in the second solution are then electrochemically deposited from the second solutions as room temperature ionic liquid (RTIL), tri-methyl-n-butyl ammonium n-bis(trifluoromethansulfonylimide) [Me.sub.3N.sup.nBu][TFSI] providing an alternative non-aqueous system for the extraction and reclamation of actinides from reprocessed fuel materials. Deposition of U metal is achieved using TFSI complexes of U(III) and U(IV) containing the anion common to the RTIL. TFSI complexes of uranium were produced to ensure solubility of the species in the ionic liquid. The methods provide a first measure of the thermodynamic properties of U metal deposition using Uranium complexes with different oxidation states from RTIL solution at room temperature.

Probing spin dynamics and quantum relaxation in Li Y0.998 Ho0.002 F4 via 19F NMR

NASA Astrophysics Data System (ADS)

Graf, M. J.; Lascialfari, A.; Borsa, F.; Tkachuk, A. M.; Barbara, B.

2006-01-01

We report measurements of F19 nuclear spin-lattice relaxation 1/T1 as a function of temperature and external magnetic field in a LiY0.998Ho0.002F4 single crystal, a single-ion magnet exhibiting interesting quantum effects. The F19 1/T1 is found to depend on the coupling with the diluted rare-earth (RE) moments, making it an effective probe of the rare-earth spin dynamics. The results for 1/T1 show a behavior similar to that observed in molecular nanomagnets, a result which we attribute to the discreteness of the energy levels in both cases. At intermediate temperatures the lifetime broadening of the crystal field split RE magnetic levels follows a T3 power law. At low temperature the field dependence of 1/T1 shows peaks in correspondence to the critical magnetic fields for energy level crossings (LC). A key result of this study is that the broadening of the levels at LC is found to become extremely small at low temperatures, about 1.7mT , a value which is comparable to the weak dipolar fields at the RE lattice positions. Thus, unlike the molecular magnets, decoherence effects are strongly suppressed, and it may be possible to measure directly the level repulsions at avoided level crossings.

Actinide targets for fundamental research in nuclear physics

NASA Astrophysics Data System (ADS)

Eberhardt, K.; Düllmann, Ch. E.; Haas, R.; Mokry, Ch.; Runke, J.; Thörle-Pospiech, P.; Trautmann, N.

2018-05-01

Thin actinide layers deposited on various substrates are widely used as calibration sources in nuclear spectroscopy. Other applications include fundamental research in nuclear chemistry and -physics, e.g., the chemical and physical properties of super-heavy elements (SHE, Z > 103) or nuclear reaction studies with heavy ions. For the design of future nuclear reactors like fast-fission reactors and accelerator-driven systems for transmutation of nuclear waste, precise data for neutron absorption as well as neutron-induced fission cross section data for 242Pu with neutrons of different energies are of particular importance, requiring suitable Pu-targets. Another application includes studies of nuclear transitions in 229Th harvested as α-decay recoil product from a thin layer of its 233U precursor. For this, a thin and very smooth layer of 233U is used. We report here on the production of actinide layers mostly obtained by Molecular Plating (MP). MP is currently the only fabrication method in cases where the desired actinide material is available only in very limited amounts or possesses a high specific activity. Here, deposition is performed from organic solution applying a current density of 1-2 mA/cm2. Under these conditions target thicknesses of 500-1000 μg/cm2 are possible applying a single deposition step with deposition yields approaching 100 %. For yield determination α-particle spectroscopy, γ-spectroscopy and Neutron Activation Analysis is routinely used. Layer homogeneity is checked with Radiographic Imaging. As an alternative technique to MP the production of thin lanthanide and actinide layers by the so-called "Drop on Demand"-technique applied e.g., in ink-jet printing is currently under investigation.

Group Hexavalent Actinide Separations: A New Approach to Used Nuclear Fuel Recycling

DOE PAGES

Burns, Jonathan D.; Moyer, Bruce A.

2016-08-17

Hexavalent Np, Pu, and Am individually, and as a group, have all been cocrystallized with UO 2(NO 3) 2∙ 6H 2O, constituting the first demonstration of an An(VI) group cocrystalliza- tion. The hexavalent dioxo cations of Np, Pu, and Am cocrystallize with UO 2(NO 3) 2∙ 6H 2O in near proportion with a simple reduction in temperature, while the lower valence states, An(III) and An(IV), are only slightly removed from solution. A separation of An(VI) species from An(III) ions by crystallization has been demonstrated, with an observed separation factor of 14. Separation of An(VI) species from key fission products, 95Zr,more » 95Nb, 137Cs, and 144Ce, has also been demonstrated by crystallization, with separation factors ranging from 6.5 to 71 in the absence of Am(VI), while in the presence of Am(VI), the separation factors were reduced to 0.99 7.7. One interesting observation is that Am(VI) shows increased stability in the cocrystallized form, with no reduction observed after 13 days, as opposed to in solution, in which >50% is reduced after only 10 days. The ability to cocrystallize and stabilize hexavalent actinides from solution, especially Am(VI), introduces a new separations approach that can be applied to closing the nuclear fuel cycle.« less

Group Hexavalent Actinide Separations: A New Approach to Used Nuclear Fuel Recycling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burns, Jonathan D.; Moyer, Bruce A.

Hexavalent Np, Pu, and Am individually, and as a group, have all been cocrystallized with UO 2(NO 3) 2∙ 6H 2O, constituting the first demonstration of an An(VI) group cocrystalliza- tion. The hexavalent dioxo cations of Np, Pu, and Am cocrystallize with UO 2(NO 3) 2∙ 6H 2O in near proportion with a simple reduction in temperature, while the lower valence states, An(III) and An(IV), are only slightly removed from solution. A separation of An(VI) species from An(III) ions by crystallization has been demonstrated, with an observed separation factor of 14. Separation of An(VI) species from key fission products, 95Zr,more » 95Nb, 137Cs, and 144Ce, has also been demonstrated by crystallization, with separation factors ranging from 6.5 to 71 in the absence of Am(VI), while in the presence of Am(VI), the separation factors were reduced to 0.99 7.7. One interesting observation is that Am(VI) shows increased stability in the cocrystallized form, with no reduction observed after 13 days, as opposed to in solution, in which >50% is reduced after only 10 days. The ability to cocrystallize and stabilize hexavalent actinides from solution, especially Am(VI), introduces a new separations approach that can be applied to closing the nuclear fuel cycle.« less

Properties of pure single crystals of actinide compounds

NASA Astrophysics Data System (ADS)

Vogt, O.

1989-07-01

Actinide research started with substances of poor quality and a multitude of "unexplainable" results mostly found on powder samples of doubtful quality exerted some pressure on the crystal growers. As an example we may mention the measurements on UP. Type I antiferromagnetism was found below 123 K by neutron diffraction experiments on powdered samples. At 23 K another transition becomes apparent in susceptibility measurements. The change of the magnetic moments associated with this transition remained unexplained. It was only after the discovery of multi k structures in other actinide compounds that the need was seen to perform even inelastic neutron diffraction experiments on single crystals so that finally the true nature of the transition in UP could be revealed. NpAs is another illustrative example for the fact that sometimes it takes decades to get a clear understanding for things even so simple as macroscopic magnetic properties. The main reason for the need of single crystals is certainly the anisotropy of the magnetic moment encountered in all actinide compounds. Self-heating effects may prevent research on big crystals or might call for isotopic purity of certain samples.

Sigma Team for Advanced Actinide Recycle FY2015 Accomplishments and Directions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moyer, Bruce A.

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 researchmore » 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

Electronic, structural, and thermodynamic properties of mixed actinide dioxides (U, Pu, Am) O2 from hybrid density functional theory

NASA Astrophysics Data System (ADS)

Ma, Li; Ray, Asok K.

2010-03-01

As a continuation of our studies of pure actinide metals using hybrid density functional theory,footnotetextR. Atta-Fynn and A. K. Ray, Europhysics Letters, 85, 27008-p1- p6 (2009); Chemical Physics Letters, 482, 223-227 (2009). we present here a systematic study of the electronic and geometric structure properties of mixed actinide dioxides, U0.5Pu0.5O2, U0.5Am0.5O2, Pu0.5Am0.5 O2 and U0.8Pu0.2O2. The fraction of exact Hartree-Fock exchange used was 40%. To investigate the effect of spin-orbit coupling on the ground state electronic and geometric structure properties, computations have been carried out at two theoretical levels, one at the scalar-relativistic level with no spin-orbit coupling and one at the fully relativistic level with spin-orbit coupling. Thermodynamic properties have been calculated by a coupling of first-principles calculation and lattice dynamics.

Measurements of time-dependent CP violation in B0→ωKS0, f0(980)KS0, KS0π0 and K+K-KS0 decays

NASA Astrophysics Data System (ADS)

Chao, Y.; Chen, K.-F.; Miyake, H.; Tajima, O.; Trabelsi, K.; Abe, K.; Abe, K.; Adachi, I.; Aihara, H.; Anipko, D.; Bakich, A. M.; Barberio, E.; Bitenc, U.; Bizjak, I.; Blyth, S.; Bondar, A.; Bračko, M.; Browder, T. E.; Chang, M.-C.; Chang, P.; Chen, A.; Chen, W. T.; Cheon, B. G.; Chistov, R.; Choi, Y.; Choi, Y. K.; Cole, S.; Dalseno, J.; Danilov, M.; Dash, M.; Dragic, J.; Drutskoy, A.; Eidelman, S.; Fratina, S.; Gabyshev, N.; Golob, B.; Ha, H.; Haba, J.; Hara, K.; Hara, T.; Hastings, N. C.; Hayashii, H.; Hazumi, M.; Heffernan, D.; Higuchi, T.; Hokuue, T.; Hoshi, Y.; Hou, W.-S.; Hsiung, Y. B.; Iijima, T.; Ikado, K.; Inami, K.; Ishikawa, A.; Ishino, H.; Itoh, R.; Iwasaki, M.; Iwasaki, Y.; Kaji, H.; Kang, J. H.; Kapusta, P.; Kawai, H.; Kawasaki, T.; Kim, H. J.; Kim, H. O.; Kim, Y. J.; Kinoshita, K.; Korpar, S.; Križan, P.; Krokovny, P.; Kulasiri, R.; Kumar, R.; Kuo, C. C.; Kuzmin, A.; Kwon, Y.-J.; Lee, M. J.; Lesiak, T.; Limosani, A.; Lin, S.-W.; Liventsev, D.; Matsumoto, T.; McOnie, S.; Miyabayashi, K.; Miyata, H.; Miyazaki, Y.; Mizuk, R.; Mohapatra, D.; Moloney, G. R.; Nakahama, Y.; Nakano, E.; Nakao, M.; Natkaniec, Z.; Nishida, S.; Nitoh, O.; Ogawa, S.; Okuno, S.; Olsen, S. L.; Onuki, Y.; Ozaki, H.; Pakhlov, P.; Pakhlova, G.; Park, C. W.; Pestotnik, R.; Piilonen, L. E.; Sakai, Y.; Satoyama, N.; Schietinger, T.; Schneider, O.; Schwartz, A. J.; Seidl, R.; Senyo, K.; Sevior, M. E.; Shapkin, M.; Shibuya, H.; Singh, J. B.; Somov, A.; Soni, N.; Stanič, S.; Starič, M.; Stoeck, H.; Sumisawa, K.; Sumiyoshi, T.; Suzuki, S.; Takasaki, F.; Tamai, K.; Tanaka, M.; Taylor, G. N.; Teramoto, Y.; Tian, X. C.; Tikhomirov, I.; Tsukamoto, T.; Uehara, S.; Ueno, K.; Unno, Y.; Uno, S.; Ushiroda, Y.; Usov, Y.; Varner, G.; Varvell, K. E.; Villa, S.; Vinokurova, A.; Wang, C. H.; Watanabe, Y.; Won, E.; Yabsley, B. D.; Yamaguchi, A.; Yamashita, Y.; Yamauchi, M.; Yusa, Y.; Zhilich, V.; Zhulanov, V.; Zupanc, A.

2007-11-01

We present measurements of time-dependent CP asymmetries in B0→ωKS0, f0(980)KS0, KS0π0 and K+K-KS0 decays based on a sample of 535×106 BB¯ pairs collected at the Υ(4S) resonance with the Belle detector at the KEKB energy-asymmetric e+e- collider. One neutral B meson is fully reconstructed in one of the specified decay channels, and the flavor of the accompanying B meson is identified from its decay products. CP-violation parameters for each of the decay modes are obtained from the asymmetries in the distributions of the proper-time intervals between the two B decays.

Crystalline matrices for the immobilization of plutonium and actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, E.B.; Burakov, E.E.; Galkin, Ya.B.

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 pressingmore » 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.« less

Actinide electronic structure and atomic forces

NASA Astrophysics Data System (ADS)

Albers, R. C.; Rudin, Sven P.; Trinkle, Dallas R.; Jones, M. D.

2000-07-01

We have developed a new method[1] of fitting tight-binding parameterizations based on functional forms developed at the Naval Research Laboratory.[2] We have applied these methods to actinide metals and report our success using them (see below). The fitting procedure uses first-principles local-density-approximation (LDA) linear augmented plane-wave (LAPW) band structure techniques[3] to first calculate an electronic-structure band structure and total energy for fcc, bcc, and simple cubic crystal structures for the actinide of interest. The tight-binding parameterization is then chosen to fit the detailed energy eigenvalues of the bands along symmetry directions, and the symmetry of the parameterization is constrained to agree with the correct symmetry of the LDA band structure at each eigenvalue and k-vector that is fit to. By fitting to a range of different volumes and the three different crystal structures, we find that the resulting parameterization is robust and appears to accurately calculate other crystal structures and properties of interest.

Protein-Protein Docking with F2Dock 2.0 and GB-Rerank

PubMed Central

Chowdhury, Rezaul; Rasheed, Muhibur; Keidel, Donald; Moussalem, Maysam; Olson, Arthur; Sanner, Michel; Bajaj, Chandrajit

2013-01-01

Motivation Computational simulation of protein-protein docking can expedite the process of molecular modeling and drug discovery. This paper reports on our new F2 Dock protocol which improves the state of the art in initial stage rigid body exhaustive docking search, scoring and ranking by introducing improvements in the shape-complementarity and electrostatics affinity functions, a new knowledge-based interface propensity term with FFT formulation, a set of novel knowledge-based filters and finally a solvation energy (GBSA) based reranking technique. Our algorithms are based on highly efficient data structures including the dynamic packing grids and octrees which significantly speed up the computations and also provide guaranteed bounds on approximation error. Results The improved affinity functions show superior performance compared to their traditional counterparts in finding correct docking poses at higher ranks. We found that the new filters and the GBSA based reranking individually and in combination significantly improve the accuracy of docking predictions with only minor increase in computation time. We compared F2 Dock 2.0 with ZDock 3.0.2 and found improvements over it, specifically among 176 complexes in ZLab Benchmark 4.0, F2 Dock 2.0 finds a near-native solution as the top prediction for 22 complexes; where ZDock 3.0.2 does so for 13 complexes. F2 Dock 2.0 finds a near-native solution within the top 1000 predictions for 106 complexes as opposed to 104 complexes for ZDock 3.0.2. However, there are 17 and 15 complexes where F2 Dock 2.0 finds a solution but ZDock 3.0.2 does not and vice versa; which indicates that the two docking protocols can also complement each other. Availability The docking protocol has been implemented as a server with a graphical client (TexMol) which allows the user to manage multiple docking jobs, and visualize the docked poses and interfaces. Both the server and client are available for download. Server: http://www.cs.utexas.edu/~bajaj/cvc/software/f

Structural study of the ammonium octafluoroneptunate, [NH 4] 4NpF 8

DOE PAGES

Poineau, Frederic; Silva, Chinthaka M.; Yeamans, Charles B.; ...

2016-04-21

The [NH 4] 4NpF 8 salt was prepared from the solid-state reaction of NpO 2 with NH 4HF 2 and characterized by powder X-ray diffraction and X-ray absorption fine structure spectroscopy. The diffraction results confirm the compound to be isostructural to [NH 4] 4UF 8 with the following lattice parameter (a = 13.054(4) Å, b = 6.681(2) Å, c = 13.676(5) Å, ß = 121.14 Å). For the first time, a Neptunium fluoride complex has been characterized by XAFS spectroscopy. The energy position of the white line and inflection of the XANES spectra of [NH 4] 4NpF 8 are consistentmore » with the presence of Np(IV). Adjustment of the EXAFS spectra indicates that the coordination number (7.4±1.5) and the average Np-F distance (2.26(1) Å) are consistent with the presence of the NpF8 dodecahedron. The average Np-F distance is ~0.02 Å shorter than the U-F distance in [NH 4] 4UF 8 and is a result of the actinide contraction.« less

Joint Actinide Shock Physics Experimental Research - JASPER

ScienceCinema

None

2018-01-16

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

Actinide removal from spent salts

DOEpatents

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

2002-01-01

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

Method for decontamination of nickel-fluoride-coated nickel containing actinide-metal fluorides

DOEpatents

Windt, Norman F.; Williams, Joe L.

1983-01-01

The invention is a process for decontaminating particulate nickel contaminated with actinide-metal fluorides. In one aspect, the invention comprises contacting nickel-fluoride-coated nickel with gaseous ammonia at a temperature effecting nickel-catalyzed dissociation thereof and effecting hydrogen-reduction of the nickel fluoride. The resulting nickel is heated to form a melt and a slag and to effect transfer of actinide metals from the melt into the slag. The melt and slag are then separated. In another aspect, nickel containing nickel oxide and actinide metals is contacted with ammonia at a temperature effecting nickel-catalyzed dissociation to effect conversion of the nickel oxide to the metal. The resulting nickel is then melted and separated as described. In another aspect nickel-fluoride-coated nickel containing actinide-metal fluorides is contacted with both steam and ammonia. The resulting nickel then is melted and separated as described. The invention is characterized by higher nickel recovery, efficient use of ammonia, a substantial decrease in slag formation and fuming, and a valuable increase in the service life of the furnace liners used for melting.

Testing actinide fission yield treatment in CINDER90 for use in MCNP6 burnup calculations

DOE PAGES

Fensin, Michael Lorne; Umbel, Marissa

2015-09-18

Most of the development of the MCNPX/6 burnup capability focused on features that were applied to the Boltzman transport or used to prepare coefficients for use in CINDER90, with little change to CINDER90 or the CINDER90 data. Though a scheme exists for best solving the coupled Boltzman and Bateman equations, the most significant approximation is that the employed nuclear data are correct and complete. Thus, the CINDER90 library file contains 60 different actinide fission yields encompassing 36 fissionable actinides (thermal, fast, high energy and spontaneous fission). Fission reaction data exists for more than 60 actinides and as a result, fissionmore » yield data must be approximated for actinides that do not possess fission yield information. Several types of approximations are used for estimating fission yields for actinides which do not possess explicit fission yield data. The objective of this study is to test whether or not certain approximations of fission yield selection have any impact on predictability of major actinides and fission products. Further we assess which other fission products, available in MCNP6 Tier 3, result in the largest difference in production. Because the CINDER90 library file is in ASCII format and therefore easily amendable, we assess reasons for choosing, as well as compare actinide and major fission product prediction for the H. B. Robinson benchmark for, three separate fission yield selection methods: (1) the current CINDER90 library file method (Base); (2) the element method (Element); and (3) the isobar method (Isobar). Results show that the three methods tested result in similar prediction of major actinides, Tc-99 and Cs-137; however, certain fission products resulted in significantly different production depending on the method of choice.« less

Analogue Study of Actinide Transport at Sites in Russia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Novikov, A P; Simmons, A M; Halsey, W G

2003-02-12

The U. S. Department of Energy (DOE) and the Russian Academy of Sciences (RAS) are engaged in a three-year cooperative study to observe the behavior of actinides in the natural environment at selected disposal sites and/or contamination sites in Russia. The purpose is to develop experimental data and models for actinide speciation, mobilization and transport processes in support of geologic repository design, safety and performance analyses. Currently at the mid-point of the study, the accomplishments to date include: evaluation of existing data and data needs, site screening and selection, initial data acquisition, and development of preliminary conceptual models.

Development of ion beam sputtering techniques for actinide target preparation

NASA Astrophysics Data System (ADS)

Aaron, W. S.; Zevenbergen, L. A.; Adair, H. L.

1985-06-01

Ion beam sputtering is a routine method for the preparation of thin films used as targets because it allows the use of a minimum quantity of starting material, and losses are much lower than most other vacuum deposition techniques. Work is underway in the Isotope Research Materials Laboratory (IRML) at ORNL to develop the techniques that will make the preparation of actinide targets up to 100 μg/cm 2 by ion beam sputtering a routinely available service from IRML. The preparation of the actinide material in a form suitable for sputtering is a key to this technique, as is designing a sputtering system that allows the flexibility required for custom-ordered target production. At present, development work is being conducted on low-activity actinides in a bench-top system. The system will then be installed in a hood or glove box approved for radioactive materials handling where processing of radium, actinium, and plutonium isotopes among others will be performed.

Zirconium behaviour during electrorefining of actinide-zirconium alloy in molten LiCl-KCl on aluminium cathodes

NASA Astrophysics Data System (ADS)

Meier, R.; Souček, P.; Malmbeck, R.; Krachler, M.; Rodrigues, A.; Claux, B.; Glatz, J.-P.; Fanghänel, Th.

2016-04-01

A pyrochemical electrorefining process for the recovery of actinides from metallic nuclear fuel based on actinide-zirconium alloys (An-Zr) in a molten salt is being investigated. In this process actinides are group-selectively recovered on solid aluminium cathodes as An-Al alloys using a LiCl-KCl eutectic melt at a temperature of 450 °C. In the present study the electrochemical behaviour of zirconium during electrorefining was investigated. The maximum amount of actinides that can be oxidised without anodic co-dissolution of zirconium was determined at a selected constant cathodic current density. The experiment consisted of three steps to assess the different stages of the electrorefining process, each of which employing a fresh aluminium cathode. The results indicate that almost a complete dissolution of the actinides without co-dissolution of zirconium is possible under the applied experimental conditions.

Cruentaren A Binds F1F0 ATP Synthase To Modulate the Hsp90 Protein Folding Machinery

PubMed Central

2015-01-01

The molecular chaperone Hsp90 requires the assistance of immunophilins, co-chaperones, and partner proteins for the conformational maturation of client proteins. Hsp90 inhibition represents a promising anticancer strategy due to the dependence of numerous oncogenic signaling pathways upon Hsp90 function. Historically, small molecules have been designed to inhibit ATPase activity at the Hsp90 N-terminus; however, these molecules also induce the pro-survival heat shock response (HSR). Therefore, inhibitors that exhibit alternative mechanisms of action that do not elicit the HSR are actively sought. Small molecules that disrupt Hsp90-co-chaperone interactions can destabilize the Hsp90 complex without induction of the HSR, which leads to inhibition of cell proliferation. In this article, selective inhibition of F1F0 ATP synthase by cruentaren A was shown to disrupt the Hsp90-F1F0 ATP synthase interaction and result in client protein degradation without induction of the HSR. PMID:24450340

Synthesis and characterization of F-doped Cs{sub 0.33}WO{sub 3−x}F{sub x} particles with improved near infrared shielding ability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jingxiao; Luo, Jiayu; Shi, Fei, E-mail: shifei@dlpu.edu.cn

2015-01-15

F-doped Cs{sub 0.33}WO{sub 3−x}F{sub x} particles were successfully synthesized by the hydrothermal method with hydrofluoric acid as fluorine source, and a new kind of heat insulating films were prepared from dispersion of Cs{sub 0.33}WO{sub 3−x}F{sub x} nanoparticles in polyvinyl alcohol (PVA) aqueous solution. The effects of F doping on the crystal structure and morphology of Cs{sub 0.33}WO{sub 3−x}F{sub x} particles as well as the near-infrared (NIR) shielding ability and heat insulation properties of Cs{sub 0.33}WO{sub 3−x}F{sub x} films were investigated. The results indicated that HF acid addition could promote the formation of rod-like Cs{sub 0.33}WO{sub 3−x}F{sub x} particles during hydrothermalmore » synthesis and increase the yield of Cs{sub 0.33}WO{sub 3−x}F{sub x} powders. Moreover, the as-prepared films from dispersion solution of Cs{sub 0.33}WO{sub 3−x}F{sub x} particles exhibited higher near-infrared (NIR) shielding ability and heat insulating properties than that of the undoped Cs{sub 0.33}WO{sub 3} film. Particularly, the as-prepared Cs{sub 0.33}WO{sub 3−x}F{sub x} sample with F/W (molar ratio)=0.45 showed best NIR shielding ability and transparent heat insulating performance. The formation mechanism of nanorod-like particles and the effects of F doping on the properties of Cs{sub 0.33}WO{sub 3−x}F{sub x} products were discussed. - Graphical abstract: F-doped Cs{sub 0.33}WO{sub 3−x}F{sub x} particles were successfully synthesized by the hydrothermal method with hydrofluoric acid as fluorine source. HF acid addition in the precursor solution could increase the yield of Cs{sub 0.33}WO{sub 3−x}F{sub x} powders and promote the formation of rod-like Cs{sub 0.33}WO{sub 3−x}F{sub x} particles. Moreover, the as-prepared Cs{sub 0.33}WO{sub 3−x}F{sub x} films from dispersion solution of Cs{sub 0.33}WO{sub 3−x}F{sub x} particles exhibited higher near-infrared (NIR) shielding ability and heat insulating properties than that of the

Recovery of actinides from actinide-aluminium alloys by chlorination: Part III - Chlorination with HCl(g)

NASA Astrophysics Data System (ADS)

Meier, Roland; Souček, Pavel; Walter, Olaf; Malmbeck, Rikard; Rodrigues, Alcide; Glatz, Jean-Paul; Fanghänel, Thomas

2018-01-01

Two steps of a pyrochemical route for the recovery of actinides from spent metallic nuclear fuel are being investigated at JRC-Karlsruhe. The first step consists in electrorefining the fuel in molten salt medium implying aluminium cathodes. The second step is a chlorination process for the separation of actinides (An) from An-Al alloys formed on the cathodes. The chlorination process, in turn, consists of three steps; the distillation of adhered salt (1), the chlorination of An-Al by HCl/Cl2 under formation of AlCl3 and An chlorides (2), and the subsequent sublimation of AlCl3 (3). In the present work UAl2, UAl3, NpAl2, and PuAl2 were chlorinated with HCl(g) in a temperature range between 300 and 400 °C forming UCl4, NpCl4 or PuCl3 as the major An containing phases, respectively. Thermodynamic calculations were carried out to support the experimental work. The results showed a high chlorination efficiency for all used starting materials and indicated that the sublimation step may not be necessary when using HCl(g).

A Study of the Hadronic Production of $D^0$ and $$\\overline{D}\\,{^0}$$ Mesons: $$x_F$$ and $$p_t$$ Distributions (in Portuguese)

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Mello Neto, Joao Torres

Using a 250 Ge V hadron beam incident on thin targets foils of Be, Al, Cu and W, themore » $$x_F$$ and $$p_t$$ distributions of $D^0$ and $$\\bar{D}^0$$ were measured from Fermilab experiment E769 using the decay mode $$D^0 \\to K^- \\pi^+$$ and c.c. The measurements were made with the $$\\pi^-$$ induced sample, 607 ± 29 events. Fitting the $$x_F$$ distribution to (1- $$x_F)^{\\eta}$$ it was measured $$\\eta$$ = 3.86 ± 0.25 ± 0.10 for $$D0/\\bar{D}^0$$ , $$\\eta$$ = 3.89 ± 0.40 for $D^0$ and $$\\eta$$ = 3.74 ± 0.34 for $$\\bar{D}^0$$ • Fitting the $$p^2_t$$ distribuition to exp $$bp^2_t$$;, it was measured $b$ = 1.05 ± 0.06 ± 0.02 for $$DO/\\bar{D}^0$$ $b$ = 1.12 ± 0.09 for $D^0$ and $b$ = 1.00 ± 0.07 for $$\\bar{D}^0$$. The $$x_F$$ distribution is consistent with the perturbative QCD calculations.« less

Progress toward accurate high spatial resolution actinide analysis by EPMA

NASA Astrophysics Data System (ADS)

Jercinovic, M. J.; Allaz, J. M.; Williams, M. L.

2010-12-01

High precision, high spatial resolution EPMA of actinides is a significant issue for geochronology, resource geochemistry, and studies involving the nuclear fuel cycle. Particular interest focuses on understanding of the behavior of Th and U in the growth and breakdown reactions relevant to actinide-bearing phases (monazite, zircon, thorite, allanite, etc.), and geochemical fractionation processes involving Th and U in fluid interactions. Unfortunately, the measurement of minor and trace concentrations of U in the presence of major concentrations of Th and/or REEs is particularly problematic, especially in complexly zoned phases with large compositional variation on the micro or nanoscale - spatial resolutions now accessible with modern instruments. Sub-micron, high precision compositional analysis of minor components is feasible in very high Z phases where scattering is limited at lower kV (15kV or less) and where the beam diameter can be kept below 400nm at high current (e.g. 200-500nA). High collection efficiency spectrometers and high performance electron optics in EPMA now allow the use of lower overvoltage through an exceptional range in beam current, facilitating higher spatial resolution quantitative analysis. The U LIII edge at 17.2 kV precludes L-series analysis at low kV (high spatial resolution), requiring careful measurements of the actinide M series. Also, U-La detection (wavelength = 0.9A) requires the use of LiF (220) or (420), not generally available on most instruments. Strong peak overlaps of Th on U make highly accurate interference correction mandatory, with problems compounded by the ThMIV and ThMV absorption edges affecting peak, background, and interference calibration measurements (especially the interference of the Th M line family on UMb). Complex REE bearing phases such as monazite, zircon, and allanite have particularly complex interference issues due to multiple peak and background overlaps from elements present in the activation

Atomistic modeling of the solid-state chemistry of actinide materials

NASA Astrophysics Data System (ADS)

Shuller, Lindsay C.

Materials that incorporate actinides are critical to the nuclear fuel cycle, either as nuclear fuels or nuclear waste forms. In this thesis, I examine four materials: i) ThO2-UO2 solid solutions, ii) binary ThO2-CeO2-ZrO2 solid solutions, iii) Np-doped studtite, iv) Np-doped boltwoodite. Computational methods, particularly density functional theory (DFT) calculations and Monte-Carlo (MC) simulations, are used to determine the energetics and structures of these actinide-bearing materials. The solid-solution behavior of nuclear fuels and nuclear waste forms indicate the thermodynamic stability of the material, which is important for understanding the in-reactor fuel properties and long-term stability of used fuel. The ThxU1-xO2 and ThxCe 1-xO2 binaries are almost completely miscible; however, DeltaGmix reveals a small tendency for the systems to exsolve (e.g., DeltaEexsoln(Th xU1-xO2) = 0.13 kJ/(mol cations) at 750 K). Kinetic hindrances (e.g., interfacial energy) may inhibit exsolution, especially at the low temperatures necessary to stabilize the nanoscale exsolution lamellae observed in the ThxU1-xO2 and Ce xZr1-xO2 binaries. Miscibility in the Zr-bearing binaries is limited. At 1400 °C, only 3.6 and 0.09 mol% ZrO2 is miscible in CeO2 and ThO2, respectively. The incorporation of minor amounts of Np5+,6+ into uranium alteration phases, e.g., studtite [UO2O2 (H2O)4] or boltwoodite [K(UO2)(SiO 3OH)(H2O)1.5] , may limit the mobility of aqueous neptunyl complexes released from oxidized nuclear fuels. Np6+-incorporation into studtite requires less energy than Np5+-incorporation (e.g., with source/sink = Np2O5/UO 3 DeltaEincorp(Np6+) = 0.42 eV and DeltaEincorp(Np5+) = 1.12 eV). In addition, Np6+ is completely miscible in studtite at room temperature with respect to a hypothetical Np6+-studtite. Electronic structure calculations provide insight into Np-bonding in studtite. The Np 5f orbitals are within the band gap of studtite, resulting in the narrowing of the band gap

Mycotoxin production of selected Fusarium species at different culture conditions.

PubMed

Kokkonen, Meri; Ojala, Laura; Parikka, Päivi; Jestoi, Marika

2010-09-30

The toxin producing capacity of seven Fusarium species (F. langsethiae, F. sporotrichioides, F. poae, F. avenaceum, F. tricinctum, F. graminearum and F. culmorum) and the effect of culture conditions on the toxin production were studied. The strains were isolated from Finnish grains and cultivated on a grain mixture at three different water activity/temperature combinations (i.e. 0.994/15 degrees C; 0.994/25 degrees C; 0.960/25 degrees C). The mycotoxins produced were analyzed with a multi-toxin method based on liquid chromatography-tandem mass spectrometry enabling the simultaneous determination of 18 different Fusarium toxins. The general toxin profiles revealed F. langsethiae and F. sporotrichioides as producers of diacetoxyscirpenol, neosolaniol, HT-2 and T-2-toxins. F. sporotrichioides produced additionally beauvericin. In the F. poae cultures, only beauvericin was detected. F. avenaceum and F. tricinctum were capable of producing enniatins, moniliformin and antibiotic Y, and F. graminearum and F. culmorum produced zearalenone, deoxynivalenol and 3-acetyl deoxynivalenol. Differences existed in the quantitative toxin production between the individual strains representing the same species. Additionally, the culture conditions affected the range and amounts of toxins produced. In general, a(w) 0.994 and temperature of 15 degrees C favoured the type-A trichothecene production of F. langsethiae and F. sporotrichioides. The beauvericin production of F. sporotrichioides occurred more favourably at a(w) 0.960 and 25 degrees C. F. poae produced the highest concentrations of beauvericin under two different conditions, namely at a(w) 0.994/15 degrees C and a(w) 0.960/25 degrees C. None of the combinations particularly favoured toxin production of F. avenaceum, with all three toxins being produced extensively at all culture conditions. F. tricinctum produced enniatins most efficiently at a(w) 0.994/25 degrees C. The moniliformin production of both these two species

Processing F0 with cochlear implants: Modulation frequency discrimination and speech intonation recognition.

PubMed

Chatterjee, Monita; Peng, Shu-Chen

2008-01-01

Fundamental frequency (F0) processing by cochlear implant (CI) listeners was measured using a psychophysical task and a speech intonation recognition task. Listeners' Weber fractions for modulation frequency discrimination were measured using an adaptive, 3-interval, forced-choice paradigm: stimuli were presented through a custom research interface. In the speech intonation recognition task, listeners were asked to indicate whether resynthesized bisyllabic words, when presented in the free field through the listeners' everyday speech processor, were question-like or statement-like. The resynthesized tokens were systematically manipulated to have different initial-F0s to represent male vs. female voices, and different F0 contours (i.e. falling, flat, and rising) Although the CI listeners showed considerable variation in performance on both tasks, significant correlations were observed between the CI listeners' sensitivity to modulation frequency in the psychophysical task and their performance in intonation recognition. Consistent with their greater reliance on temporal cues, the CI listeners' performance in the intonation recognition task was significantly poorer with the higher initial-F0 stimuli than with the lower initial-F0 stimuli. Similar results were obtained with normal hearing listeners attending to noiseband-vocoded CI simulations with reduced spectral resolution.

Processing F0 with Cochlear Implants: Modulation Frequency Discrimination and Speech Intonation Recognition

PubMed Central

Chatterjee, Monita; Peng, Shu-Chen

2008-01-01

Fundamental frequency (F0) processing by cochlear implant (CI) listeners was measured using a psychophysical task and a speech intonation recognition task. Listeners’ Weber fractions for modulation frequency discrimination were measured using an adaptive, 3-interval, forced-choice paradigm: stimuli were presented through a custom research interface. In the speech intonation recognition task, listeners were asked to indicate whether resynthesized bisyllabic words, when presented in the free field through the listeners’ everyday speech processor, were question-like or statement-like. The resynthesized tokens were systematically manipulated to have different initial F0s to represent male vs. female voices, and different F0 contours (i.e., falling, flat, and rising) Although the CI listeners showed considerable variation in performance on both tasks, significant correlations were observed between the CI listeners’ sensitivity to modulation frequency in the psychophysical task and their performance in intonation recognition. Consistent with their greater reliance on temporal cues, the CI listeners’ performance in the intonation recognition task was significantly poorer with the higher initial-F0 stimuli than with the lower initial-F0 stimuli. Similar results were obtained with normal hearing listeners attending to noiseband-vocoded CI simulations with reduced spectral resolution. PMID:18093766

SOLVENT EXTRACTION PROCESS FOR SEPARATING ACTINIDE AND LANTHANIDE METAL VALUES

DOEpatents

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)

Correlation consistent basis sets for actinides. II. The atoms Ac and Np-Lr

NASA Astrophysics Data System (ADS)

Feng, Rulin; Peterson, Kirk A.

2017-08-01

New correlation consistent basis sets optimized using the all-electron third-order Douglas-Kroll-Hess (DKH3) scalar relativistic Hamiltonian are reported for the actinide elements Ac and Np through Lr. These complete the series of sets reported previously for Th-U [K. A. Peterson, J. Chem. Phys. 142, 074105 (2015); M. Vasiliu et al., J. Phys. Chem. A 119, 11422 (2015)]. The new sets range in size from double- to quadruple-zeta and encompass both those optimized for valence (6s6p5f7s6d) and outer-core electron correlations (valence + 5s5p5d). The final sets have been contracted for both the DKH3 and eXact 2-component (X2C) Hamiltonians, yielding cc-pVnZ-DK3/cc-pVnZ-X2C sets for valence correlation and cc-pwCVnZ-DK3/cc-pwCVnZ-X2C sets for outer-core correlation (n = D, T, Q in each case). In order to test the effectiveness of the new basis sets, both atomic and molecular benchmark calculations have been carried out. In the first case, the first three atomic ionization potentials (IPs) of all the actinide elements Ac-Lr have been calculated using the Feller-Peterson-Dixon (FPD) composite approach, primarily with the multireference configuration interaction (MRCI) method. Excellent convergence towards the respective complete basis set (CBS) limits is achieved with the new sets, leading to good agreement with experiment, where these exist, after accurately accounting for spin-orbit effects using the 4-component Dirac-Hartree-Fock method. For a molecular test, the IP and atomization energy (AE) of PuO2 have been calculated also using the FPD method but using a coupled cluster approach with spin-orbit coupling accounted for using the 4-component MRCI. The present calculations yield an IP0 for PuO2 of 159.8 kcal/mol, which is in excellent agreement with the experimental electron transfer bracketing value of 162 ± 3 kcal/mol. Likewise, the calculated 0 K AE of 305.6 kcal/mol is in very good agreement with the currently accepted experimental value of 303.1 ± 5 kcal

Correlation consistent basis sets for actinides. II. The atoms Ac and Np-Lr.

PubMed

Feng, Rulin; Peterson, Kirk A

2017-08-28

New correlation consistent basis sets optimized using the all-electron third-order Douglas-Kroll-Hess (DKH3) scalar relativistic Hamiltonian are reported for the actinide elements Ac and Np through Lr. These complete the series of sets reported previously for Th-U [K. A. Peterson, J. Chem. Phys. 142, 074105 (2015); M. Vasiliu et al., J. Phys. Chem. A 119, 11422 (2015)]. The new sets range in size from double- to quadruple-zeta and encompass both those optimized for valence (6s6p5f7s6d) and outer-core electron correlations (valence + 5s5p5d). The final sets have been contracted for both the DKH3 and eXact 2-component (X2C) Hamiltonians, yielding cc-pVnZ-DK3/cc-pVnZ-X2C sets for valence correlation and cc-pwCVnZ-DK3/cc-pwCVnZ-X2C sets for outer-core correlation (n = D, T, Q in each case). In order to test the effectiveness of the new basis sets, both atomic and molecular benchmark calculations have been carried out. In the first case, the first three atomic ionization potentials (IPs) of all the actinide elements Ac-Lr have been calculated using the Feller-Peterson-Dixon (FPD) composite approach, primarily with the multireference configuration interaction (MRCI) method. Excellent convergence towards the respective complete basis set (CBS) limits is achieved with the new sets, leading to good agreement with experiment, where these exist, after accurately accounting for spin-orbit effects using the 4-component Dirac-Hartree-Fock method. For a molecular test, the IP and atomization energy (AE) of PuO 2 have been calculated also using the FPD method but using a coupled cluster approach with spin-orbit coupling accounted for using the 4-component MRCI. The present calculations yield an IP 0 for PuO 2 of 159.8 kcal/mol, which is in excellent agreement with the experimental electron transfer bracketing value of 162 ± 3 kcal/mol. Likewise, the calculated 0 K AE of 305.6 kcal/mol is in very good agreement with the currently accepted experimental value of 303.1 ± 5 kcal

Dielectric, Piezoelectric, and Vibration Properties of the LiF-Doped (Ba0.95Ca0.05)(Ti0.93Sn0.07)O₃ Lead-Free Piezoceramic Sheets.

PubMed

Cheng, Chien-Min; Chen, Kai-Huang; Lee, Da-Huei; Jong, Fuh-Cheng; Chen, Mei-Li; Chang, Jhih-Kai

2018-01-24

By the conventional solid state reaction method, a small amount of lithium fluoride (LiF) was used as the sintering promoter to improve the sintering and piezoelectric characteristics of (Ba 0.95 Ca 0.05 )(Ti 0.93 Sn 0.07 )O₃ (BCTS) lead-free piezoceramic sheets. Using X-ray diffraction (XRD) and a scanning electron microscope (SEM), the inferences of the crystalline and surface microstructures were obtained and analyzed. Then, the impedance analyzer and d 33 -meter were used to measure the dielectric and piezoelectric characteristics. In this study, the optimum sintering temperature of the BCTS sheets decreased from 1450 °C to 1390 °C due to LiF doping. For the 0.07 wt % LiF-doped BCTS sheets sintered at 1390 °C, the piezoelectric constant (d 33 ) is 413 pC/N, the electric-mechanical coupling coefficient (k p ) is 47.5%, the dielectric loss (tan δ) is 3.9%, and the dielectric constant (ε r ) is 8100, which are all close to or even better than that of the pure undoped BCTS ceramics. The Curie temperature also improved, from 85 °C for pure BCTS to 140 °C for BCTS-0.07 LiF sheets. Furthermore, by using the vibration system and fixing 1.5 g tip mass at the end of the sheets, as the vibration frequency is 20 Hz, the proposed piezoelectric ceramic sheets also reveal a good energy harvesting performance at the maximum output peak voltage of 4.6 V, which is large enough and can be applied in modern low-power electronic products.

Effect of Nb and F co-doping on Li1.2Mn0.54Ni0.13Co0.13O2 cathode material for high-performance lithium-ion batteries

NASA Astrophysics Data System (ADS)

Ming, Lei; Zhang, Bao; Cao, Yang; Zhang, Jia-Feng; Wang, Chun-Hui; Wang, Xiao-Wei; Li, Hui

2018-04-01

The Li1.2Mn0.54-xNbxCo0.13Ni0.13O2-6xF6x (x=0, 0.01, 0.03, 0.05) is prepared by traditional solid-phase method, and the Nb and F ions have been successfully doped into Mn and O sites of layered materials Li1.2Mn0.54Co0.13Ni0.13O2, respectively. The incorporating Nb ion in Mn site could effectively restrain the migration of transtion metal ions during long-term cycling, and keep the stability of the crystal structure. The Li1.2Mn0.54-xNbxCo0.13Ni0.13O2-6xF6x shows suppressed voltage fade and higher capacity retention of 98.1 after 200 cycles at rate of 1 C. The replacement of O2- by the strongly electronegative F- was beneficial for suppressed the structure change of Li2MnO3 from the eliminating of oxygen in initial charge process. Therefore, the initial coulomb efficiency of doped Li1.2Mn0.54-xNbxCo0.13Ni0.13O2-6xF6x gets improved, which is higher than that of pure Li1.2Mn0.54Co0.13Ni0.13O2. In addition, the Nb and F co-doping could effectively enhance the transfer of lithium-ion and electrons, and thus improving rate performance.

Evaluation of actinide biosorption by microorganisms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Happel, A.M.

1996-06-01

Conventional methods for removing metals from aqueous solutions include chemical precipitation, chemical oxidation or reduction, ion exchange, reverse osmosis, electrochemical treatment and evaporation. The removal of radionuclides from aqueous waste streams has largely relied on ion exchange methods which can be prohibitively costly given increasingly stringent regulatory effluent limits. The use of microbial cells as biosorbants for heavy metals offers a potential alternative to existing methods for decontamination or recovery of heavy metals from a variety of industrial waste streams and contaminated ground waters. The toxicity and the extreme and variable conditions present in many radionuclide containing waste streams maymore » preclude the use of living microorganisms and favor the use of non-living biomass for the removal of actinides from these waste streams. In the work presented here, we have examined the biosorption of uranium by non-living, non-metabolizing microbial biomass thus avoiding the problems associated with living systems. We are investigating biosorption with the long term goal of developing microbial technologies for the remediation of actinides.« less

Synthesis, structure and electrochemical properties of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F fluoride-phosphate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fedotov, Stanislav S.; Skoltech Center for Electrochemical Energy Storage, Skolkovo Institute of Science and Technology, 143026 Moscow; Kuzovchikov, Sergey M.

2016-10-15

LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F fluoride-phosphate was synthesized via conventional solid-state and novel freeze-drying routes. The crystal structure was refined based on neutron powder diffraction (NPD) data and validated by electron diffraction (ED) and high-resolution transmission electron microscopy (HRTEM). The alkali ions are ordered in LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F and the transition metals jointly occupy the same crystallographic sites. The oxidation state and oxygen coordination environment of the Fe atoms were verified by {sup 57}Fe Mössbauer spectroscopy. Electrochemical tests of the LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F cathode material demonstrated a reversible activity of the Fe{sup 3+}/Fe{sup 2+} redox couple at the electrodemore » potential near 3.4 V and minor activity of the Co{sup 3+}/Co{sup 2+} redox couple over 5 V vs Li/Li{sup +}. The material exhibited the discharge capacity of more than 82% (theo.) regarding Fe{sup 3+}/Fe{sup 2+} in the 2.4÷4.6 V vs Li/Li{sup +} potential range. - Graphical abstract: The ball-polyhedral representation of the LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F crystal structure. The MO{sub 4}F{sub 2} units are depicted as blue octahedra, PO{sub 4} units as orange tetrahedra, sodium atoms are designated as yellow (Na1), lithium – red and brown (Li2, Li3 resp.), fluorine – green, oxygen – violet spheres. - Highlights: • Freeze-drying method was successfully applied to the synthesis of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F. • The crystal structure of LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F was refined based on NPD and validated by ED and HRTEM. • LiNaCo{sub 0.5}Fe{sub 0.5}PO{sub 4}F demonstrated a reversible Li de/intercalation in the 2.5÷4.6 V vs Li/Li{sup +} range.« less

Measurement of the ratio B (Bs0 → J / ψf0 (980)) / B (Bs0 → J / ψϕ (1020)) in pp collisions at √{ s} = 7 TeV

NASA Astrophysics Data System (ADS)

Khachatryan, V.; Sirunyan, A. M.; Tumasyan, A.; Adam, W.; Bergauer, T.; Dragicevic, M.; Erö, J.; Friedl, M.; Frühwirth, R.; Ghete, V. M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Kiesenhofer, W.; Knünz, V.; Krammer, M.; Krätschmer, I.; Liko, D.; Mikulec, I.; Rabady, D.; Rahbaran, B.; Rohringer, H.; Schöfbeck, R.; Strauss, J.; Treberer-Treberspurg, W.; Waltenberger, W.; Wulz, C.-E.; Mossolov, V.; Shumeiko, N.; Suarez Gonzalez, J.; Alderweireldt, S.; Bansal, S.; Cornelis, T.; De Wolf, E. A.; Janssen, X.; Knutsson, A.; Lauwers, J.; Luyckx, S.; Ochesanu, S.; Rougny, R.; Van De Klundert, M.; Van Haevermaet, H.; Van Mechelen, P.; Van Remortel, N.; Van Spilbeeck, A.; Blekman, F.; Blyweert, S.; D'Hondt, J.; Daci, N.; Heracleous, N.; Keaveney, J.; Lowette, S.; Maes, M.; Olbrechts, A.; Python, Q.; Strom, D.; Tavernier, S.; Van Doninck, W.; Van Mulders, P.; Van Onsem, G. P.; Villella, I.; Caillol, C.; Clerbaux, B.; De Lentdecker, G.; Dobur, D.; Favart, L.; Gay, A. P. R.; Grebenyuk, A.; Léonard, A.; Mohammadi, A.; Perniè, L.; Randle-conde, A.; Reis, T.; Seva, T.; Thomas, L.; Vander Velde, C.; Vanlaer, P.; Wang, J.; Zenoni, F.; Adler, V.; Beernaert, K.; Benucci, L.; Cimmino, A.; Costantini, S.; Crucy, S.; Fagot, A.; Garcia, G.; Mccartin, J.; Ocampo Rios, A. A.; Poyraz, D.; Ryckbosch, D.; Salva Diblen, S.; Sigamani, M.; Strobbe, N.; Thyssen, F.; Tytgat, M.; Yazgan, E.; Zaganidis, N.; Basegmez, S.; Beluffi, C.; Bruno, G.; Castello, R.; Caudron, A.; Ceard, L.; Da Silveira, G. G.; Delaere, C.; du Pree, T.; Favart, D.; Forthomme, L.; Giammanco, A.; Hollar, J.; Jafari, A.; Jez, P.; Komm, M.; Lemaitre, V.; Nuttens, C.; Pagano, D.; Perrini, L.; Pin, A.; Piotrzkowski, K.; Popov, A.; Quertenmont, L.; Selvaggi, M.; Vidal Marono, M.; Vizan Garcia, J. M.; Beliy, N.; Caebergs, T.; Daubie, E.; Hammad, G. H.; Aldá Júnior, W. L.; Alves, G. A.; Brito, L.; Correa Martins Junior, M.; Dos Reis Martins, T.; Molina, J.; Mora Herrera, C.; Pol, M. E.; Rebello Teles, P.; Carvalho, W.; Chinellato, J.; Custódio, A.; Da Costa, E. M.; De Jesus Damiao, D.; De Oliveira Martins, C.; Fonseca De Souza, S.; Malbouisson, H.; Matos Figueiredo, D.; Mundim, L.; Nogima, H.; Prado Da Silva, W. L.; Santaolalla, J.; Santoro, A.; Sznajder, A.; Tonelli Manganote, E. J.; Vilela Pereira, A.; Bernardes, C. A.; Dogra, S.; Fernandez Perez Tomei, T. R.; Gregores, E. M.; Mercadante, P. G.; Novaes, S. F.; Padula, Sandra S.; Aleksandrov, A.; Genchev, V.; Hadjiiska, R.; Iaydjiev, P.; Marinov, A.; Piperov, S.; Rodozov, M.; Stoykova, S.; Sultanov, G.; Vutova, M.; Dimitrov, A.; Glushkov, I.; Litov, L.; Pavlov, B.; Petkov, P.; Bian, J. G.; Chen, G. M.; Chen, H. S.; Chen, M.; Cheng, T.; Du, R.; Jiang, C. H.; Plestina, R.; Romeo, F.; Tao, J.; Wang, Z.; Asawatangtrakuldee, C.; Ban, Y.; Liu, S.; Mao, Y.; Qian, S. J.; Wang, D.; Xu, Z.; Zhang, L.; Zou, W.; Avila, C.; Cabrera, A.; Chaparro Sierra, L. F.; Florez, C.; Gomez, J. P.; Gomez Moreno, B.; Sanabria, J. C.; Godinovic, N.; Lelas, D.; Polic, D.; Puljak, I.; Antunovic, Z.; Kovac, M.; Brigljevic, V.; Kadija, K.; Luetic, J.; Mekterovic, D.; Sudic, L.; Attikis, A.; Mavromanolakis, G.; Mousa, J.; Nicolaou, C.; Ptochos, F.; Razis, P. A.; Rykaczewski, H.; Bodlak, M.; Finger, M.; Finger, M.; Assran, Y.; Ellithi Kamel, A.; Mahmoud, M. A.; Radi, A.; Kadastik, M.; Murumaa, M.; Raidal, M.; Tiko, A.; Eerola, P.; Voutilainen, M.; Härkönen, J.; Karimäki, V.; Kinnunen, R.; Kortelainen, M. J.; Lampén, T.; Lassila-Perini, K.; Lehti, S.; Lindén, T.; Luukka, P.; Mäenpää, T.; Peltola, T.; Tuominen, E.; Tuominiemi, J.; Tuovinen, E.; Wendland, L.; Talvitie, J.; Tuuva, T.; Besancon, M.; Couderc, F.; Dejardin, M.; Denegri, D.; Fabbro, B.; Faure, J. L.; Favaro, C.; Ferri, F.; Ganjour, S.; Givernaud, A.; Gras, P.; Hamel de Monchenault, G.; Jarry, P.; Locci, E.; Malcles, J.; Rander, J.; Rosowsky, A.; Titov, M.; Baffioni, S.; Beaudette, F.; Busson, P.; Chapon, E.; Charlot, C.; Dahms, T.; Dalchenko, M.; Dobrzynski, L.; Filipovic, N.; Florent, A.; Granier de Cassagnac, R.; Mastrolorenzo, L.; Miné, P.; Naranjo, I. N.; Nguyen, M.; Ochando, C.; Ortona, G.; Paganini, P.; Regnard, S.; Salerno, R.; Sauvan, J. B.; Sirois, Y.; Veelken, C.; Yilmaz, Y.; Zabi, A.; Agram, J.-L.; Andrea, J.; Aubin, A.; Bloch, D.; Brom, J.-M.; Chabert, E. C.; Collard, C.; Conte, E.; Fontaine, J.-C.; Gelé, D.; Goerlach, U.; Goetzmann, C.; Le Bihan, A.-C.; Skovpen, K.; Van Hove, P.; Gadrat, S.; Beauceron, S.; Beaupere, N.; Bernet, C.; Boudoul, G.; Bouvier, E.; Brochet, S.; Carrillo Montoya, C. A.; Chasserat, J.; Chierici, R.; Contardo, D.; Courbon, B.; Depasse, P.; El Mamouni, H.; Fan, J.; Fay, J.; Gascon, S.; Gouzevitch, M.; Ille, B.; Kurca, T.; Lethuillier, M.; Mirabito, L.; Pequegnot, A. L.; Perries, S.; Ruiz Alvarez, J. D.; Sabes, D.; Sgandurra, L.; Sordini, V.; Vander Donckt, M.; Verdier, P.; Viret, S.; Xiao, H.; Tsamalaidze, Z.; Autermann, C.; Beranek, S.; Bontenackels, M.; Edelhoff, M.; Feld, L.; Heister, A.; Klein, K.; Lipinski, M.; Ostapchuk, A.; Preuten, M.; Raupach, F.; Sammet, J.; Schael, S.; Schulte, J. F.; Weber, H.; Wittmer, B.; Zhukov, V.; Ata, M.; Brodski, M.; Dietz-Laursonn, E.; Duchardt, D.; Erdmann, M.; Fischer, R.; Güth, A.; Hebbeker, T.; Heidemann, C.; Hoepfner, K.; Klingebiel, D.; Knutzen, S.; Kreuzer, P.; Merschmeyer, M.; Meyer, A.; Millet, P.; Olschewski, M.; Padeken, K.; Papacz, P.; Reithler, H.; Schmitz, S. A.; Sonnenschein, L.; Teyssier, D.; Thüer, S.; Cherepanov, V.; Erdogan, Y.; Flügge, G.; Geenen, H.; Geisler, M.; Haj Ahmad, W.; Hoehle, F.; Kargoll, B.; Kress, T.; Kuessel, Y.; Künsken, A.; Lingemann, J.; Nowack, A.; Nugent, I. M.; Pistone, C.; Pooth, O.; Stahl, A.; Aldaya Martin, M.; Asin, I.; Bartosik, N.; Behr, J.; Behrens, U.; Bell, A. J.; Bethani, A.; Borras, K.; Burgmeier, A.; Cakir, A.; Calligaris, L.; Campbell, A.; Choudhury, S.; Costanza, F.; Diez Pardos, C.; Dolinska, G.; Dooling, S.; Dorland, T.; Eckerlin, G.; Eckstein, D.; Eichhorn, T.; Flucke, G.; Garay Garcia, J.; Geiser, A.; Gizhko, A.; Gunnellini, P.; Hauk, J.; Hempel, M.; Jung, H.; Kalogeropoulos, A.; Karacheban, O.; Kasemann, M.; Katsas, P.; Kieseler, J.; Kleinwort, C.; Korol, I.; Krücker, D.; Lange, W.; Leonard, J.; Lipka, K.; Lobanov, A.; Lohmann, W.; Lutz, B.; Mankel, R.; Marfin, I.; Melzer-Pellmann, I.-A.; Meyer, A. B.; Mittag, G.; Mnich, J.; Mussgiller, A.; Naumann-Emme, S.; Nayak, A.; Ntomari, E.; Perrey, H.; Pitzl, D.; Placakyte, R.; Raspereza, A.; Ribeiro Cipriano, P. M.; Roland, B.; Ron, E.; Sahin, M. Ö.; Salfeld-Nebgen, J.; Saxena, P.; Schoerner-Sadenius, T.; Schröder, M.; Seitz, C.; Spannagel, S.; Vargas Trevino, A. D. R.; Walsh, R.; Wissing, C.; Blobel, V.; Centis Vignali, M.; Draeger, A. R.; Erfle, J.; Garutti, E.; Goebel, K.; Görner, M.; Haller, J.; Hoffmann, M.; Höing, R. S.; Junkes, A.; Kirschenmann, H.; Klanner, R.; Kogler, R.; Lapsien, T.; Lenz, T.; Marchesini, I.; Marconi, D.; Ott, J.; Peiffer, T.; Perieanu, A.; Pietsch, N.; Poehlsen, J.; Poehlsen, T.; Rathjens, D.; Sander, C.; Schettler, H.; Schleper, P.; Schlieckau, E.; Schmidt, A.; Seidel, M.; Sola, V.; Stadie, H.; Steinbrück, G.; Troendle, D.; Usai, E.; Vanelderen, L.; Vanhoefer, A.; Barth, C.; Baus, C.; Berger, J.; Böser, C.; Butz, E.; Chwalek, T.; De Boer, W.; Descroix, A.; Dierlamm, A.; Feindt, M.; Frensch, F.; Giffels, M.; Gilbert, A.; Hartmann, F.; Hauth, T.; Husemann, U.; Katkov, I.; Kornmayer, A.; Lobelle Pardo, P.; Mozer, M. U.; Müller, T.; Müller, Th.; Nürnberg, A.; Quast, G.; Rabbertz, K.; Röcker, S.; Simonis, H. J.; Stober, F. M.; Ulrich, R.; Wagner-Kuhr, J.; Wayand, S.; Weiler, T.; Wolf, R.; Anagnostou, G.; Daskalakis, G.; Geralis, T.; Giakoumopoulou, V. A.; Kyriakis, A.; Loukas, D.; Markou, A.; Markou, C.; Psallidas, A.; Topsis-Giotis, I.; Agapitos, A.; Kesisoglou, S.; Panagiotou, A.; Saoulidou, N.; Stiliaris, E.; Tziaferi, E.; Aslanoglou, X.; Evangelou, I.; Flouris, G.; Foudas, C.; Kokkas, P.; Manthos, N.; Papadopoulos, I.; Paradas, E.; Strologas, J.; Bencze, G.; Hajdu, C.; Hidas, P.; Horvath, D.; Sikler, F.; Veszpremi, V.; Vesztergombi, G.; Zsigmond, A. J.; Beni, N.; Czellar, S.; Karancsi, J.; Molnar, J.; Palinkas, J.; Szillasi, Z.; Makovec, A.; Raics, P.; Trocsanyi, Z. L.; Ujvari, B.; Swain, S. K.; Beri, S. B.; Bhatnagar, V.; Gupta, R.; Bhawandeep, U.; Kalsi, A. K.; Kaur, M.; Kumar, R.; Mittal, M.; Nishu, N.; Singh, J. B.; Kumar, Ashok; Kumar, Arun; Ahuja, S.; Bhardwaj, A.; Choudhary, B. C.; Kumar, A.; Malhotra, S.; Naimuddin, M.; Ranjan, K.; Sharma, V.; Banerjee, S.; Bhattacharya, S.; Chatterjee, K.; Dutta, S.; Gomber, B.; Jain, Sa.; Jain, Sh.; Khurana, R.; Modak, A.; Mukherjee, S.; Roy, D.; Sarkar, S.; Sharan, M.; Abdulsalam, A.; Dutta, D.; Kumar, V.; Mohanty, A. K.; Pant, L. M.; Shukla, P.; Topkar, A.; Aziz, T.; Banerjee, S.; Bhowmik, S.; Chatterjee, R. M.; Dewanjee, R. K.; Dugad, S.; Ganguly, S.; Ghosh, S.; Guchait, M.; Gurtu, A.; Kole, G.; Kumar, S.; Maity, M.; Majumder, G.; Mazumdar, K.; Mohanty, G. B.; Parida, B.; Sudhakar, K.; Wickramage, N.; Sharma, S.; Bakhshiansohi, H.; Behnamian, H.; Etesami, S. M.; Fahim, A.; Goldouzian, R.; Khakzad, M.; Mohammadi Najafabadi, M.; Naseri, M.; Paktinat Mehdiabadi, S.; Rezaei Hosseinabadi, F.; Safarzadeh, B.; Zeinali, M.; Felcini, M.; Grunewald, M.; Abbrescia, M.; Calabria, C.; Chhibra, S. S.; Colaleo, A.; Creanza, D.; Cristella, L.; De Filippis, N.; De Palma, M.; Fiore, L.; Iaselli, G.; Maggi, G.; Maggi, M.; My, S.; Nuzzo, S.; Pompili, A.; Pugliese, G.; Radogna, R.; Selvaggi, G.; Sharma, A.; Silvestris, L.; Venditti, R.; Verwilligen, P.; Abbiendi, G.; Benvenuti, A. C.; Bonacorsi, D.; Braibant-Giacomelli, S.; Brigliadori, L.; Campanini, R.; Capiluppi, P.; Castro, A.; Cavallo, F. R.; Codispoti, G.; Cuffiani, M.; Dallavalle, G. M.; Fabbri, F.; Fanfani, A.; Fasanella, D.; Giacomelli, P.; Grandi, C.; Guiducci, L.; Marcellini, S.; Masetti, G.; Montanari, A.; Navarria, F. L.; Perrotta, A.; Rossi, A. M.; Rovelli, T.; Siroli, G. P.; Tosi, N.; Travaglini, R.; Albergo, S.; Cappello, G.; Chiorboli, M.; Costa, S.; Giordano, F.; Potenza, R.; Tricomi, A.; Tuve, C.; Barbagli, G.; Ciulli, V.; Civinini, C.; D'Alessandro, R.; Focardi, E.; Gallo, E.; Gonzi, S.; Gori, V.; Lenzi, P.; Meschini, M.; Paoletti, S.; Sguazzoni, G.; Tropiano, A.; Benussi, L.; Bianco, S.; Fabbri, F.; Piccolo, D.; Ferretti, R.; Ferro, F.; Lo Vetere, M.; Robutti, E.; Tosi, S.; Dinardo, M. E.; Fiorendi, S.; Gennai, S.; Gerosa, R.; Ghezzi, A.; Govoni, P.; Lucchini, M. T.; Malvezzi, S.; Manzoni, R. A.; Martelli, A.; Marzocchi, B.; Menasce, D.; Moroni, L.; Paganoni, M.; Pedrini, D.; Ragazzi, S.; Redaelli, N.; Tabarelli de Fatis, T.; Buontempo, S.; Cavallo, N.; Di Guida, S.; Fabozzi, F.; Iorio, A. O. M.; Lista, L.; Meola, S.; Merola, M.; Paolucci, P.; Azzi, P.; Bacchetta, N.; Bisello, D.; Carlin, R.; Checchia, P.; Dall'Osso, M.; Dorigo, T.; Gasparini, F.; Gasparini, U.; Gozzelino, A.; Gulmini, M.; Kanishchev, K.; Lacaprara, S.; Margoni, M.; Meneguzzo, A. T.; Passaseo, M.; Pazzini, J.; Pozzobon, N.; Ronchese, P.; Simonetto, F.; Torassa, E.; Tosi, M.; Zotto, P.; Zucchetta, A.; Zumerle, G.; Gabusi, M.; Ratti, S. P.; Re, V.; Riccardi, C.; Salvini, P.; Vitulo, P.; Biasini, M.; Bilei, G. M.; Ciangottini, D.; Fanò, L.; Lariccia, P.; Mantovani, G.; Menichelli, M.; Saha, A.; Santocchia, A.; Spiezia, A.; Androsov, K.; Azzurri, P.; Bagliesi, G.; Bernardini, J.; Boccali, T.; Broccolo, G.; Castaldi, R.; Ciocci, M. A.; Dell'Orso, R.; Donato, S.; Fedi, G.; Fiori, F.; Foà, L.; Giassi, A.; Grippo, M. T.; Ligabue, F.; Lomtadze, T.; Martini, L.; Messineo, A.; Moon, C. S.; Palla, F.; Rizzi, A.; Savoy-Navarro, A.; Serban, A. T.; Spagnolo, P.; Squillacioti, P.; Tenchini, R.; Tonelli, G.; Venturi, A.; Verdini, P. G.; Vernieri, C.; Barone, L.; Cavallari, F.; D'imperio, G.; Del Re, D.; Diemoz, M.; Jorda, C.; Longo, E.; Margaroli, F.; Meridiani, P.; Micheli, F.; Organtini, G.; Paramatti, R.; Rahatlou, S.; Rovelli, C.; Santanastasio, F.; Soffi, L.; Traczyk, P.; Amapane, N.; Arcidiacono, R.; Argiro, S.; Arneodo, M.; Bellan, R.; Biino, C.; Cartiglia, N.; Casasso, S.; Costa, M.; Covarelli, R.; Degano, A.; Demaria, N.; Finco, L.; Mariotti, C.; Maselli, S.; Migliore, E.; Monaco, V.; Musich, M.; Obertino, M. M.; Pacher, L.; Pastrone, N.; Pelliccioni, M.; Pinna Angioni, G. L.; Potenza, A.; Romero, A.; Ruspa, M.; Sacchi, R.; Solano, A.; Staiano, A.; Tamponi, U.; Belforte, S.; Candelise, V.; Casarsa, M.; Cossutti, F.; Della Ricca, G.; Gobbo, B.; La Licata, C.; Marone, M.; Schizzi, A.; Umer, T.; Zanetti, A.; Chang, S.; Kropivnitskaya, A.; Nam, S. K.; Kim, D. H.; Kim, G. N.; Kim, M. S.; Kong, D. J.; Lee, S.; Oh, Y. D.; Park, H.; Sakharov, A.; Son, D. C.; Kim, T. J.; Ryu, M. S.; Kim, J. Y.; Moon, D. H.; Song, S.; Choi, S.; Gyun, D.; Hong, B.; Jo, M.; Kim, H.; Kim, Y.; Lee, B.; Lee, K. S.; Park, S. K.; Roh, Y.; Yoo, H. D.; Choi, M.; Kim, J. H.; Park, I. C.; Ryu, G.; Choi, Y.; Choi, Y. K.; Goh, J.; Kim, D.; Kwon, E.; Lee, J.; Yu, I.; Juodagalvis, A.; Komaragiri, J. R.; Md Ali, M. A. B.; Wan Abdullah, W. A. T.; Casimiro Linares, E.; Castilla-Valdez, H.; De La Cruz-Burelo, E.; Heredia-de La Cruz, I.; Hernandez-Almada, A.; Lopez-Fernandez, R.; Sanchez-Hernandez, A.; Carrillo Moreno, S.; Vazquez Valencia, F.; Pedraza, I.; Salazar Ibarguen, H. A.; Morelos Pineda, A.; Krofcheck, D.; Butler, P. H.; Reucroft, S.; Ahmad, A.; Ahmad, M.; Hassan, Q.; Hoorani, H. R.; Khan, W. A.; Khurshid, T.; Shoaib, M.; Bialkowska, H.; Bluj, M.; Boimska, B.; Frueboes, T.; Górski, M.; Kazana, M.; Nawrocki, K.; Romanowska-Rybinska, K.; Szleper, M.; Zalewski, P.; Brona, G.; Bunkowski, K.; Cwiok, M.; Dominik, W.; Doroba, K.; Kalinowski, A.; Konecki, M.; Krolikowski, J.; Misiura, M.; Olszewski, M.; Bargassa, P.; Beirão Da Cruz E Silva, C.; Faccioli, P.; Ferreira Parracho, P. G.; Gallinaro, M.; Lloret Iglesias, L.; Nguyen, F.; Rodrigues Antunes, J.; Seixas, J.; Varela, J.; Vischia, P.; Gavrilenko, M.; Golutvin, I.; Kamenev, A.; Karjavin, V.; Konoplyanikov, V.; Korenkov, V.; Kozlov, G.; Lanev, A.; Malakhov, A.; Matveev, V.; Mitsyn, V. V.; Moisenz, P.; Palichik, V.; Perelygin, V.; Shmatov, S.; Smirnov, V.; Tikhonenko, E.; Zarubin, A.; Golovtsov, V.; Ivanov, Y.; Kim, V.; Kuznetsova, E.; Levchenko, P.; Murzin, V.; Oreshkin, V.; Smirnov, I.; Sulimov, V.; Uvarov, L.; Vavilov, S.; Vorobyev, A.; Vorobyev, An.; Andreev, Yu.; Dermenev, A.; Gninenko, S.; Golubev, N.; Kirsanov, M.; Krasnikov, N.; Pashenkov, A.; Tlisov, D.; Toropin, A.; Epshteyn, V.; Gavrilov, V.; Lychkovskaya, N.; Popov, V.; Pozdnyakov, I.; Safronov, G.; Semenov, S.; Spiridonov, A.; Stolin, V.; Vlasov, E.; Zhokin, A.; Andreev, V.; Azarkin, M.; Dremin, I.; Kirakosyan, M.; Leonidov, A.; Mesyats, G.; Rusakov, S. V.; Vinogradov, A.; Belyaev, A.; Boos, E.; Dubinin, M.; Dudko, L.; Ershov, A.; Gribushin, A.; Klyukhin, V.; Kodolova, O.; Lokhtin, I.; Obraztsov, S.; Petrushanko, S.; Savrin, V.; Snigirev, A.; Azhgirey, I.; Bayshev, I.; Bitioukov, S.; Kachanov, V.; Kalinin, A.; Konstantinov, D.; Krychkine, V.; Petrov, V.; Ryutin, R.; Sobol, A.; Tourtchanovitch, L.; Troshin, S.; Tyurin, N.; Uzunian, A.; Volkov, A.; Adzic, P.; Ekmedzic, M.; Milosevic, J.; Rekovic, V.; Alcaraz Maestre, J.; Battilana, C.; Calvo, E.; Cerrada, M.; Chamizo Llatas, M.; Colino, N.; De La Cruz, B.; Delgado Peris, A.; Domínguez Vázquez, D.; Escalante Del Valle, A.; Fernandez Bedoya, C.; Fernández Ramos, J. P.; Flix, J.; Fouz, M. C.; Garcia-Abia, P.; Gonzalez Lopez, O.; Goy Lopez, S.; Hernandez, J. M.; Josa, M. I.; Navarro De Martino, E.; Pérez-Calero Yzquierdo, A.; Puerta Pelayo, J.; Quintario Olmeda, A.; Redondo, I.; Romero, L.; Soares, M. S.; Albajar, C.; de Trocóniz, J. F.; Missiroli, M.; Moran, D.; Brun, H.; Cuevas, J.; Fernandez Menendez, J.; Folgueras, S.; Gonzalez Caballero, I.; Brochero Cifuentes, J. A.; Cabrillo, I. J.; Calderon, A.; Duarte Campderros, J.; Fernandez, M.; Gomez, G.; Graziano, A.; Lopez Virto, A.; Marco, J.; Marco, R.; Martinez Rivero, C.; Matorras, F.; Munoz Sanchez, F. J.; Piedra Gomez, J.; Rodrigo, T.; Rodríguez-Marrero, A. Y.; Ruiz-Jimeno, A.; Scodellaro, L.; Vila, I.; Vilar Cortabitarte, R.; Abbaneo, D.; Auffray, E.; Auzinger, G.; Bachtis, M.; Baillon, P.; Ball, A. H.; Barney, D.; Benaglia, A.; Bendavid, J.; Benhabib, L.; Benitez, J. F.; Bloch, P.; Bocci, A.; Bonato, A.; Bondu, O.; Botta, C.; Breuker, H.; Camporesi, T.; Cerminara, G.; Colafranceschi, S.; D'Alfonso, M.; d'Enterria, D.; Dabrowski, A.; David, A.; De Guio, F.; De Roeck, A.; De Visscher, S.; Di Marco, E.; Dobson, M.; Dordevic, M.; Dorney, B.; Dupont-Sagorin, N.; Elliott-Peisert, A.; Franzoni, G.; Funk, W.; Gigi, D.; Gill, K.; Giordano, D.; Girone, M.; Glege, F.; Guida, R.; Gundacker, S.; Guthoff, M.; Hammer, J.; Hansen, M.; Harris, P.; Hegeman, J.; Innocente, V.; Janot, P.; Kousouris, K.; Krajczar, K.; Lecoq, P.; Lourenço, C.; Magini, N.; Malgeri, L.; Mannelli, M.; Marrouche, J.; Masetti, L.; Meijers, F.; Mersi, S.; Meschi, E.; Moortgat, F.; Morovic, S.; Mulders, M.; Orsini, L.; Pape, L.; Perez, E.; Petrilli, A.; Petrucciani, G.; Pfeiffer, A.; Pimiä, M.; Piparo, D.; Plagge, M.; Racz, A.; Rolandi, G.; Rovere, M.; Sakulin, H.; Schäfer, C.; Schwick, C.; Sharma, A.; Siegrist, P.; Silva, P.; Simon, M.; Sphicas, P.; Spiga, D.; Steggemann, J.; Stieger, B.; Stoye, M.; Takahashi, Y.; Treille, D.; Tsirou, A.; Veres, G. I.; Wardle, N.; Wöhri, H. K.; Wollny, H.; Zeuner, W. D.; Bertl, W.; Deiters, K.; Erdmann, W.; Horisberger, R.; Ingram, Q.; Kaestli, H. C.; Kotlinski, D.; Langenegger, U.; Renker, D.; Rohe, T.; Bachmair, F.; Bäni, L.; Bianchini, L.; Buchmann, M. A.; Casal, B.; Chanon, N.; Dissertori, G.; Dittmar, M.; Donegà, M.; Dünser, M.; Eller, P.; Grab, C.; Hits, D.; Hoss, J.; Kasieczka, G.; Lustermann, W.; Mangano, B.; Marini, A. C.; Marionneau, M.; Martinez Ruiz del Arbol, P.; Masciovecchio, M.; Meister, D.; Mohr, N.; Musella, P.; Nägeli, C.; Nessi-Tedaldi, F.; Pandolfi, F.; Pauss, F.; Perrozzi, L.; Peruzzi, M.; Quittnat, M.; Rebane, L.; Rossini, M.; Starodumov, A.; Takahashi, M.; Theofilatos, K.; Wallny, R.; Weber, H. A.; Amsler, C.; Canelli, M. F.; Chiochia, V.; De Cosa, A.; Hinzmann, A.; Hreus, T.; Kilminster, B.; Lange, C.; Ngadiuba, J.; Pinna, D.; Robmann, P.; Ronga, F. J.; Taroni, S.; Yang, Y.; Cardaci, M.; Chen, K. H.; Ferro, C.; Kuo, C. M.; Lin, W.; Lu, Y. J.; Volpe, R.; Yu, S. S.; Chang, P.; Chang, Y. H.; Chao, Y.; Chen, K. F.; Chen, P. H.; Dietz, C.; Grundler, U.; Hou, W.-S.; Liu, Y. F.; Lu, R.-S.; Miñano Moya, M.; Petrakou, E.; Tzeng, Y. M.; Wilken, R.; Asavapibhop, B.; Singh, G.; Srimanobhas, N.; Suwonjandee, N.; Adiguzel, A.; Bakirci, M. N.; Cerci, S.; Dozen, C.; Dumanoglu, I.; Eskut, E.; Girgis, S.; Gokbulut, G.; Guler, Y.; Gurpinar, E.; Hos, I.; Kangal, E. E.; Kayis Topaksu, A.; Onengut, G.; Ozdemir, K.; Ozturk, S.; Polatoz, A.; Sunar Cerci, D.; Tali, B.; Topakli, H.; Vergili, M.; Zorbilmez, C.; Akin, I. V.; Bilin, B.; Bilmis, S.; Gamsizkan, H.; Isildak, B.; Karapinar, G.; Ocalan, K.; Sekmen, S.; Surat, U. E.; Yalvac, M.; Zeyrek, M.; Albayrak, E. A.; Gülmez, E.; Kaya, M.; Kaya, O.; Yetkin, T.; Cankocak, K.; Vardarlı, F. I.; Levchuk, L.; Sorokin, P.; Brooke, J. J.; Clement, E.; Cussans, D.; Flacher, H.; Goldstein, J.; Grimes, M.; Heath, G. P.; Heath, H. F.; Jacob, J.; Kreczko, L.; Lucas, C.; Meng, Z.; Newbold, D. M.; Paramesvaran, S.; Poll, A.; Sakuma, T.; Seif El Nasr-storey, S.; Senkin, S.; Smith, V. J.; Bell, K. W.; Belyaev, A.; Brew, C.; Brown, R. M.; Cockerill, D. J. A.; Coughlan, J. A.; Harder, K.; Harper, S.; Olaiya, E.; Petyt, D.; Shepherd-Themistocleous, C. H.; Thea, A.; Tomalin, I. R.; Williams, T.; Womersley, W. J.; Worm, S. D.; Baber, M.; Bainbridge, R.; Buchmuller, O.; Burton, D.; Colling, D.; Cripps, N.; Dauncey, P.; Davies, G.; Della Negra, M.; Dunne, P.; Elwood, A.; Ferguson, W.; Fulcher, J.; Futyan, D.; Hall, G.; Iles, G.; Jarvis, M.; Karapostoli, G.; Kenzie, M.; Lane, R.; Lucas, R.; Lyons, L.; Magnan, A.-M.; Malik, S.; Mathias, B.; Nash, J.; Nikitenko, A.; Pela, J.; Pesaresi, M.; Petridis, K.; Raymond, D. M.; Rogerson, S.; Rose, A.; Seez, C.; Sharp, P.; Tapper, A.; Vazquez Acosta, M.; Virdee, T.; Zenz, S. C.; Cole, J. E.; Hobson, P. R.; Khan, A.; Kyberd, P.; Leggat, D.; Leslie, D.; Reid, I. D.; Symonds, P.; Teodorescu, L.; Turner, M.; Dittmann, J.; Hatakeyama, K.; Kasmi, A.; Liu, H.; Pastika, N.; Scarborough, T.; Wu, Z.; Charaf, O.; Cooper, S. I.; Henderson, C.; Rumerio, P.; Avetisyan, A.; Bose, T.; Fantasia, C.; Lawson, P.; Richardson, C.; Rohlf, J.; St. John, J.; Sulak, L.; Alimena, J.; Berry, E.; Bhattacharya, S.; Christopher, G.; Cutts, D.; Demiragli, Z.; Dhingra, N.; Ferapontov, A.; Garabedian, A.; Heintz, U.; Laird, E.; Landsberg, G.; Mao, Z.; Narain, M.; Sagir, S.; Sinthuprasith, T.; Speer, T.; Swanson, J.; Breedon, R.; Breto, G.; Calderon De La Barca Sanchez, M.; Chauhan, S.; Chertok, M.; Conway, J.; Conway, R.; Cox, P. T.; Erbacher, R.; Gardner, M.; Ko, W.; Lander, R.; Mulhearn, M.; Pellett, D.; Pilot, J.; Ricci-Tam, F.; Shalhout, S.; Smith, J.; Squires, M.; Stolp, D.; Tripathi, M.; Wilbur, S.; Yohay, R.; Cousins, R.; Everaerts, P.; Farrell, C.; Hauser, J.; Ignatenko, M.; Rakness, G.; Takasugi, E.; Valuev, V.; Weber, M.; Burt, K.; Clare, R.; Ellison, J.; Gary, J. W.; Hanson, G.; Heilman, J.; Ivova Rikova, M.; Jandir, P.; Kennedy, E.; Lacroix, F.; Long, O. R.; Luthra, A.; Malberti, M.; Olmedo Negrete, M.; Shrinivas, A.; Sumowidagdo, S.; Wimpenny, S.; Branson, J. G.; Cerati, G. B.; Cittolin, S.; D'Agnolo, R. T.; Holzner, A.; Kelley, R.; Klein, D.; Letts, J.; Macneill, I.; Olivito, D.; Padhi, S.; Palmer, C.; Pieri, M.; Sani, M.; Sharma, V.; Simon, S.; Tadel, M.; Tu, Y.; Vartak, A.; Welke, C.; Würthwein, F.; Yagil, A.; Zevi Della Porta, G.; Barge, D.; Bradmiller-Feld, J.; Campagnari, C.; Danielson, T.; Dishaw, A.; Dutta, V.; Flowers, K.; Franco Sevilla, M.; Geffert, P.; George, C.; Golf, F.; Gouskos, L.; Incandela, J.; Justus, C.; Mccoll, N.; Mullin, S. D.; Richman, J.; Stuart, D.; To, W.; West, C.; Yoo, J.; Apresyan, A.; Bornheim, A.; Bunn, J.; Chen, Y.; Duarte, J.; Mott, A.; Newman, H. B.; Pena, C.; Pierini, M.; Spiropulu, M.; Vlimant, J. R.; Wilkinson, R.; Xie, S.; Zhu, R. Y.; Azzolini, V.; Calamba, A.; Carlson, B.; Ferguson, T.; Iiyama, Y.; Paulini, M.; Russ, J.; Vogel, H.; Vorobiev, I.; Cumalat, J. P.; Ford, W. T.; Gaz, A.; Krohn, M.; Luiggi Lopez, E.; Nauenberg, U.; Smith, J. G.; Stenson, K.; Wagner, S. R.; Alexander, J.; Chatterjee, A.; Chaves, J.; Chu, J.; Dittmer, S.; Eggert, N.; Mirman, N.; Nicolas Kaufman, G.; Patterson, J. R.; Ryd, A.; Salvati, E.; Skinnari, L.; Sun, W.; Teo, W. D.; Thom, J.; Thompson, J.; Tucker, J.; Weng, Y.; Winstrom, L.; Wittich, P.; Winn, D.; Abdullin, S.; Albrow, M.; Anderson, J.; Apollinari, G.; Bauerdick, L. A. T.; Beretvas, A.; Berryhill, J.; Bhat, P. C.; Bolla, G.; Burkett, K.; Butler, J. N.; Cheung, H. W. K.; Chlebana, F.; Cihangir, S.; Elvira, V. D.; Fisk, I.; Freeman, J.; Gottschalk, E.; Gray, L.; Green, D.; Grünendahl, S.; Gutsche, O.; Hanlon, J.; Hare, D.; Harris, R. M.; Hirschauer, J.; Hooberman, B.; Jindariani, S.; Johnson, M.; Joshi, U.; Klima, B.; Kreis, B.; Kwan, S.; Linacre, J.; Lincoln, D.; Lipton, R.; Liu, T.; Lopes De Sá, R.; Lykken, J.; Maeshima, K.; Marraffino, J. M.; Martinez Outschoorn, V. I.; Maruyama, S.; Mason, D.; McBride, P.; Merkel, P.; Mishra, K.; Mrenna, S.; Nahn, S.; Newman-Holmes, C.; O'Dell, V.; Prokofyev, O.; Sexton-Kennedy, E.; Soha, A.; Spalding, W. J.; Spiegel, L.; Taylor, L.; Tkaczyk, S.; Tran, N. V.; Uplegger, L.; Vaandering, E. W.; Vidal, R.; Whitbeck, A.; Whitmore, J.; Yang, F.; Acosta, D.; Avery, P.; Bortignon, P.; Bourilkov, D.; Carver, M.; Curry, D.; Das, S.; De Gruttola, M.; Di Giovanni, G. P.; Field, R. D.; Fisher, M.; Furic, I. K.; Hugon, J.; Konigsberg, J.; Korytov, A.; Kypreos, T.; Low, J. F.; Matchev, K.; Mei, H.; Milenovic, P.; Mitselmakher, G.; Muniz, L.; Rinkevicius, A.; Shchutska, L.; Snowball, M.; Sperka, D.; Yelton, J.; Zakaria, M.; Hewamanage, S.; Linn, S.; Markowitz, P.; Martinez, G.; Rodriguez, J. L.; Adams, J. R.; Adams, T.; Askew, A.; Bochenek, J.; Diamond, B.; Haas, J.; Hagopian, S.; Hagopian, V.; Johnson, K. F.; Prosper, H.; Veeraraghavan, V.; Weinberg, M.; Baarmand, M. M.; Hohlmann, M.; Kalakhety, H.; Yumiceva, F.; Adams, M. R.; Apanasevich, L.; Berry, D.; Betts, R. R.; Bucinskaite, I.; Cavanaugh, R.; Evdokimov, O.; Gauthier, L.; Gerber, C. E.; Hofman, D. J.; Kurt, P.; O'Brien, C.; Sandoval Gonzalez, I. D.; Silkworth, C.; Turner, P.; Varelas, N.; Bilki, B.; Clarida, W.; Dilsiz, K.; Haytmyradov, M.; Merlo, J.-P.; Mermerkaya, H.; Mestvirishvili, A.; Moeller, A.; Nachtman, J.; Ogul, H.; Onel, Y.; Ozok, F.; Penzo, A.; Rahmat, R.; Sen, S.; Tan, P.; Tiras, E.; Wetzel, J.; Yi, K.; Anderson, I.; Barnett, B. A.; Blumenfeld, B.; Bolognesi, S.; Fehling, D.; Gritsan, A. V.; Maksimovic, P.; Martin, C.; Swartz, M.; Xiao, M.; Baringer, P.; Bean, A.; Benelli, G.; Bruner, C.; Gray, J.; Kenny, R. P., III; Majumder, D.; Malek, M.; Murray, M.; Noonan, D.; Sanders, S.; Sekaric, J.; Stringer, R.; Wang, Q.; Wood, J. S.; Chakaberia, I.; Ivanov, A.; Kaadze, K.; Khalil, S.; Makouski, M.; Maravin, Y.; Saini, L. K.; Skhirtladze, N.; Svintradze, I.; Gronberg, J.; Lange, D.; Rebassoo, F.; Wright, D.; Baden, A.; Belloni, A.; Calvert, B.; Eno, S. C.; Gomez, J. A.; Hadley, N. J.; Jabeen, S.; Kellogg, R. G.; Kolberg, T.; Lu, Y.; Mignerey, A. C.; Pedro, K.; Skuja, A.; Tonjes, M. B.; Tonwar, S. C.; Apyan, A.; Barbieri, R.; Bierwagen, K.; Busza, W.; Cali, I. A.; Di Matteo, L.; Gomez Ceballos, G.; Goncharov, M.; Gulhan, D.; Klute, M.; Lai, Y. S.; Lee, Y.-J.; Levin, A.; Luckey, P. D.; Paus, C.; Ralph, D.; Roland, C.; Roland, G.; Stephans, G. S. F.; Sumorok, K.; Velicanu, D.; Veverka, J.; Wyslouch, B.; Yang, M.; Zanetti, M.; Zhukova, V.; Dahmes, B.; Gude, A.; Kao, S. C.; Klapoetke, K.; Kubota, Y.; Mans, J.; Nourbakhsh, S.; Rusack, R.; Singovsky, A.; Tambe, N.; Turkewitz, J.; Acosta, J. G.; Oliveros, S.; Avdeeva, E.; Bloom, K.; Bose, S.; Claes, D. R.; Dominguez, A.; Gonzalez Suarez, R.; Keller, J.; Knowlton, D.; Kravchenko, I.; Lazo-Flores, J.; Meier, F.; Ratnikov, F.; Snow, G. R.; Zvada, M.; Dolen, J.; Godshalk, A.; Iashvili, I.; Kharchilava, A.; Kumar, A.; Rappoccio, S.; Alverson, G.; Barberis, E.; Baumgartel, D.; Chasco, M.; Massironi, A.; Morse, D. M.; Nash, D.; Orimoto, T.; Trocino, D.; Wang, R.-J.; Wood, D.; Zhang, J.; Hahn, K. A.; Kubik, A.; Mucia, N.; Odell, N.; Pollack, B.; Pozdnyakov, A.; Schmitt, M.; Stoynev, S.; Sung, K.; Velasco, M.; Won, S.; Brinkerhoff, A.; Chan, K. M.; Drozdetskiy, A.; Hildreth, M.; Jessop, C.; Karmgard, D. J.; Kellams, N.; Lannon, K.; Lynch, S.; Marinelli, N.; Musienko, Y.; Pearson, T.; Planer, M.; Ruchti, R.; Smith, G.; Valls, N.; Wayne, M.; Wolf, M.; Woodard, A.; Antonelli, L.; Brinson, J.; Bylsma, B.; Durkin, L. S.; Flowers, S.; Hart, A.; Hill, C.; Hughes, R.; Kotov, K.; Ling, T. Y.; Luo, W.; Puigh, D.; Rodenburg, M.; Winer, B. L.; Wolfe, H.; Wulsin, H. W.; Driga, O.; Elmer, P.; Hardenbrook, J.; Hebda, P.; Koay, S. A.; Lujan, P.; Marlow, D.; Medvedeva, T.; Mooney, M.; Olsen, J.; Piroué, P.; Quan, X.; Saka, H.; Stickland, D.; Tully, C.; Werner, J. S.; Zuranski, A.; Brownson, E.; Malik, S.; Mendez, H.; Ramirez Vargas, J. E.; Barnes, V. E.; Benedetti, D.; Bortoletto, D.; De Mattia, M.; Gutay, L.; Hu, Z.; Jha, M. K.; Jones, M.; Jung, K.; Kress, M.; Leonardo, N.; Miller, D. H.; Neumeister, N.; Primavera, F.; Radburn-Smith, B. C.; Shi, X.; Shipsey, I.; Silvers, D.; Svyatkovskiy, A.; Wang, F.; Xie, W.; Xu, L.; Zablocki, J.; Parashar, N.; Stupak, J.; Adair, A.; Akgun, B.; Ecklund, K. M.; Geurts, F. J. M.; Li, W.; Michlin, B.; Padley, B. P.; Redjimi, R.; Roberts, J.; Zabel, J.; Betchart, B.; Bodek, A.; de Barbaro, P.; Demina, R.; Eshaq, Y.; Ferbel, T.; Galanti, M.; Garcia-Bellido, A.; Goldenzweig, P.; Han, J.; Harel, A.; Hindrichs, O.; Khukhunaishvili, A.; Korjenevski, S.; Petrillo, G.; Verzetti, M.; Vishnevskiy, D.; Ciesielski, R.; Demortier, L.; Goulianos, K.; Mesropian, C.; Arora, S.; Barker, A.; Chou, J. P.; Contreras-Campana, C.; Contreras-Campana, E.; Duggan, D.; Ferencek, D.; Gershtein, Y.; Gray, R.; Halkiadakis, E.; Hidas, D.; Kaplan, S.; Lath, A.; Panwalkar, S.; Park, M.; Salur, S.; Schnetzer, S.; Sheffield, D.; Somalwar, S.; Stone, R.; Thomas, S.; Thomassen, P.; Walker, M.; Rose, K.; Spanier, S.; York, A.; Bouhali, O.; Castaneda Hernandez, A.; Dildick, S.; Eusebi, R.; Flanagan, W.; Gilmore, J.; Kamon, T.; Khotilovich, V.; Krutelyov, V.; Montalvo, R.; Osipenkov, I.; Pakhotin, Y.; Patel, R.; Perloff, A.; Roe, J.; Rose, A.; Safonov, A.; Suarez, I.; Tatarinov, A.; Ulmer, K. A.; Akchurin, N.; Cowden, C.; Damgov, J.; Dragoiu, C.; Dudero, P. R.; Faulkner, J.; Kovitanggoon, K.; Kunori, S.; Lee, S. W.; Libeiro, T.; Volobouev, I.; Appelt, E.; Delannoy, A. G.; Greene, S.; Gurrola, A.; Johns, W.; Maguire, C.; Mao, Y.; Melo, A.; Sharma, M.; Sheldon, P.; Snook, B.; Tuo, S.; Velkovska, J.; Arenton, M. W.; Boutle, S.; Cox, B.; Francis, B.; Goodell, J.; Hirosky, R.; Ledovskoy, A.; Li, H.; Lin, C.; Neu, C.; Wolfe, E.; Wood, J.; Clarke, C.; Harr, R.; Karchin, P. E.; Kottachchi Kankanamge Don, C.; Lamichhane, P.; Sturdy, J.; Belknap, D. A.; Carlsmith, D.; Cepeda, M.; Dasu, S.; Dodd, L.; Duric, S.; Friis, E.; Hall-Wilton, R.; Herndon, M.; Hervé, A.; Klabbers, P.; Lanaro, A.; Lazaridis, C.; Levine, A.; Loveless, R.; Mohapatra, A.; Ojalvo, I.; Perry, T.; Pierro, G. A.; Polese, G.; Ross, I.; Sarangi, T.; Savin, A.; Smith, W. H.; Taylor, D.; Vuosalo, C.; Woods, N.; CMS Collaboration

2016-05-01

A measurement of the ratio of the branching fractions of the Bs0 meson to J / ψf0 (980) and to J / ψϕ (1020) is presented. The J / ψ, f0 (980), and ϕ (1020) are observed through their decays to μ+μ-, π+π-, and K+K-, respectively. The f0 and the ϕ are identified by requiring |Mπ+π- - 974 MeV | < 50 MeV and |MK+K- - 1020 MeV | < 10 MeV. The analysis is based on a data sample of pp collisions at a centre-of-mass energy of 7 TeV, collected by the CMS experiment at the LHC, corresponding to an integrated luminosity of 5.3 fb-1. The measured ratio is B(Bs0 → J / ψf0) B (f0 →π+π-)/ B (Bs0 → J / ψϕ) B (ϕ →K+K-) = 0.140 ± 0.008 (stat) ± 0.023 (syst), where the first uncertainty is statistical and the second is systematic.

Potentiometric Sensor for Real-Time Remote Surveillance of Actinides in Molten Salts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Natalie J. Gese; Jan-Fong Jue; Brenda E. Serrano

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 onmore » 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.« less

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

NASA Technical Reports Server (NTRS)

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

1976-01-01

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

Supercritical Fluid Extraction and Separation of Uranium from Other Actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donna L. Quach; Bruce J. Mincher; Chien M. Wai

2014-06-01

This paper investigates the feasibility of separating uranium from other actinides by using supercritical fluid carbon dioxide (sc-CO2) as a solvent modified with tri-n-butylphosphate (TBP) for the development of an extraction and counter current stripping technique, which would be a more efficient and environmentally benign technology for used nuclear fuel reprocessing compared to traditional solvent extraction. Several actinides (U(VI), Np(VI), Pu(IV), and Am(III)) were extracted in sc-CO2 modified with TBP over a range of nitric acid concentrations and then the actinides were exposed to reducing and complexing agents to suppress their extractability. According to this study, the separation of uraniummore » from plutonium in sc-CO2 modified with TBP was successful at nitric acid concentrations of less than 3 M in the presence of acetohydroxamic acid or oxalic acid, and the separation of uranium from neptunium was successful at nitric acid concentrations of less than 1 M in the presence of acetohydroxamic acid, oxalic acid, or sodium nitrite.« less

Delocalization and occupancy effects of 5f orbitals in plutonium intermetallics using L3-edge resonant X-ray emission spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Booth, C. H.; Medling, S. A.; Jiang, Yu

2014-06-24

Although actinide (An) L3 -edge X-ray absorption near-edge structure (XANES) spectroscopy has been very effective in determining An oxidation states in insulating, ionically bonded materials, such as in certain coordination compounds and mineral systems, the technique fails in systems featuring more delocalized 5f orbitals, especially in metals. Recently, actinide L3-edge resonant X-ray emission spec- troscopy (RXES) has been shown to be an effective alternative. This technique is further demonstrated here using a parameterized partial unoccupied density of states method to quantify both occupancy and delocalization of the 5f orbital in ?-Pu, ?-Pu, PuCoGa5 , PuCoIn5 , and PuSb2. These newmore » results, supported by FEFF calculations, highlight the effects of strong correlations on RXES spectra and the technique?s ability to differentiate between f-orbital occupation and delocalization.« less

Hyperfine field, electric field gradient, quadrupole coupling constant and magnetic properties of challenging actinide digallide

NASA Astrophysics Data System (ADS)

Khan, Sajid; Yazdani-Kachoei, M.; Jalali-Asadabadi, S.; Ahmad, Iftikhar

2017-12-01

In this paper, we explore the structural and magnetic properties as well as electric field gradient (EFG), hyperfine field (HFF) and quadrupole coupling constant in actinide digallide AcGa2 (Ac = U, Np, Pu) using LDA, GGA, LDA+U, GGA+U and hybrid functional with Wu-Cohen Generalized Gradient approximation HF-WC. Relativistic effects of the electrons are considered by including spin-orbit coupling. The comparison of the calculated structural parameters and magnetic properties with the available experimental results confirms the consistency and hence effectiveness of our theoretical tools. The calculated magnetic moments demonstrate that UGa2 and NpGa2 are ferromagnetic while PuGa2 is antiferromagnetic in nature. The EFG of AcGa2 is reported for the first time. The HFF, EFG and quadrupole coupling constant in AcGa2 (Ac = U, Np, Pu) are mainly originated from f-f and p-p contributions of Ac atom and p-p contribution of Ga atom.

High Pressure Phase Transformations in Heavy Rare Earth Metals and Connections to Actinide Crystal Structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vohra, Yogesh K.; Sangala, Bagvanth Reddy; Stemshorn, Andrew K.

2008-07-01

High-pressure studies have been performed on heavy rare earth metals Terbium (Tb) to 155 GPa and Holmium (Ho) to 134 GPa in a diamond anvil cell at room temperature. The following crystal structure sequence was observed in both metals hcp {yields} Sm-type {yields} dhcp {yields} distorted fcc (hR-24) {yields} monoclinic (C2/m) with increasing pressure. The last transformation to a low symmetry monoclinic phase is accompanied by a volume collapse of 5 % for Tb at 51 GPa and a volume collapse of 3 % for Ho at 103 GPa. This volume collapse under high pressure is reminiscent of f-shell delocalizationmore » in light rare earth metal Cerium (Ce), Praseodymium (Pr), and heavy actinide metals Americium (Am) and Curium (Cm). The orthorhombic Pnma phase that has been reported in Am and Cm after f-shell delocalization is not observed in heavy rare earth metals under high pressures. (authors)« less

Measurements of branching fractions, polarizations, and direct CP-violation asymmetries in B+→ρ0K*+ and B+→f0(980)K*+ decays

NASA Astrophysics Data System (ADS)

Del Amo Sanchez, P.; Lees, J. P.; Poireau, V.; Prencipe, E.; Tisserand, V.; Garra Tico, J.; Grauges, E.; Martinelli, M.; Milanes, D. A.; Palano, A.; Pappagallo, M.; Eigen, G.; Stugu, B.; Sun, L.; Brown, D. N.; Kerth, L. T.; Kolomensky, Yu. G.; Lynch, G.; Osipenkov, I. L.; Koch, H.; Schroeder, T.; Asgeirsson, D. J.; Hearty, C.; Mattison, T. S.; McKenna, J. A.; Khan, A.; Blinov, V. E.; Buzykaev, A. R.; Druzhinin, V. P.; Golubev, V. B.; Kravchenko, E. A.; Onuchin, A. P.; Serednyakov, S. I.; Skovpen, Yu. I.; Solodov, E. P.; Todyshev, K. Yu.; Yushkov, A. N.; Bondioli, M.; Curry, S.; Kirkby, D.; Lankford, A. J.; Mandelkern, M.; Martin, E. C.; Stoker, D. P.; Atmacan, H.; Gary, J. W.; Liu, F.; Long, O.; Vitug, G. M.; Campagnari, C.; Hong, T. M.; Kovalskyi, D.; Richman, J. D.; West, C.; Eisner, A. M.; Heusch, C. A.; Kroseberg, J.; Lockman, W. S.; Martinez, A. J.; Schalk, T.; Schumm, B. A.; Seiden, A.; Winstrom, L. O.; Cheng, C. H.; Doll, D. A.; Echenard, B.; Hitlin, D. G.; Ongmongkolkul, P.; Porter, F. C.; Rakitin, A. Y.; Andreassen, R.; Dubrovin, M. S.; Mancinelli, G.; Meadows, B. T.; Sokoloff, M. D.; Bloom, P. C.; Ford, W. T.; Gaz, A.; Nagel, M.; Nauenberg, U.; Smith, J. G.; Wagner, S. R.; Ayad, R.; Toki, W. H.; Jasper, H.; Karbach, T. M.; Petzold, A.; Spaan, B.; Kobel, M. J.; Schubert, K. R.; Schwierz, R.; Bernard, D.; Verderi, M.; Clark, P. J.; Playfer, S.; Watson, J. E.; Andreotti, M.; Bettoni, D.; Bozzi, C.; Calabrese, R.; Cecchi, A.; Cibinetto, G.; Fioravanti, E.; Franchini, P.; Garzia, I.; Luppi, E.; Munerato, M.; Negrini, M.; Petrella, A.; Piemontese, L.; Baldini-Ferroli, R.; Calcaterra, A.; de Sangro, R.; Finocchiaro, G.; Nicolaci, M.; Pacetti, S.; Patteri, P.; Peruzzi, I. M.; Piccolo, M.; Rama, M.; Zallo, A.; Contri, R.; Guido, E.; Lo Vetere, M.; Monge, M. R.; Passaggio, S.; Patrignani, C.; Robutti, E.; Tosi, S.; Bhuyan, B.; Prasad, V.; Lee, C. L.; Morii, M.; Edwards, A. J.; Adametz, A.; Marks, J.; Uwer, U.; Bernlochner, F. U.; Ebert, M.; Lacker, H. M.; Lueck, T.; Volk, A.; Dauncey, P. D.; Tibbetts, M.; Behera, P. K.; Mallik, U.; Chen, C.; Cochran, J.; Crawley, H. B.; Dong, L.; Meyer, W. T.; Prell, S.; Rosenberg, E. I.; Rubin, A. E.; Gritsan, A. V.; Guo, Z. J.; Arnaud, N.; Davier, M.; Derkach, D.; Firmino da Costa, J.; Grosdidier, G.; Le Diberder, F.; Lutz, A. M.; Malaescu, B.; Perez, A.; Roudeau, P.; Schune, M. H.; Serrano, J.; Sordini, V.; Stocchi, A.; Wang, L.; Wormser, G.; Lange, D. J.; Wright, D. M.; Bingham, I.; Chavez, C. A.; Coleman, J. P.; Fry, J. R.; Gabathuler, E.; Gamet, R.; Hutchcroft, D. E.; Payne, D. J.; Touramanis, C.; Bevan, A. J.; di Lodovico, F.; Sacco, R.; Sigamani, M.; Cowan, G.; Paramesvaran, S.; Wren, A. C.; Brown, D. N.; Davis, C. L.; Denig, A. G.; Fritsch, M.; Gradl, W.; Hafner, A.; Alwyn, K. E.; Bailey, D.; Barlow, R. J.; Jackson, G.; Lafferty, G. D.; Anderson, J.; Cenci, R.; Jawahery, A.; Roberts, D. A.; Simi, G.; Tuggle, J. M.; Dallapiccola, C.; Salvati, E.; Cowan, R.; Dujmic, D.; Sciolla, G.; Zhao, M.; Lindemann, D.; Patel, P. M.; Robertson, S. H.; Schram, M.; Biassoni, P.; Lazzaro, A.; Lombardo, V.; Palombo, F.; Stracka, S.; Cremaldi, L.; Godang, R.; Kroeger, R.; Sonnek, P.; Summers, D. J.; Nguyen, X.; Simard, M.; Taras, P.; de Nardo, G.; Monorchio, D.; Onorato, G.; Sciacca, C.; Raven, G.; Snoek, H. L.; Jessop, C. P.; Knoepfel, K. J.; Losecco, J. M.; Wang, W. F.; Corwin, L. A.; Honscheid, K.; Kass, R.; Morris, J. P.; Blount, N. L.; Brau, J.; Frey, R.; Igonkina, O.; Kolb, J. A.; Rahmat, R.; Sinev, N. B.; Strom, D.; Strube, J.; Torrence, E.; Castelli, G.; Feltresi, E.; Gagliardi, N.; Margoni, M.; Morandin, M.; Posocco, M.; Rotondo, M.; Simonetto, F.; Stroili, R.; Ben-Haim, E.; Bonneaud, G. R.; Briand, H.; Calderini, G.; Chauveau, J.; Hamon, O.; Leruste, Ph.; Marchiori, G.; Ocariz, J.; Prendki, J.; Sitt, S.; Biasini, M.; Manoni, E.; Rossi, A.; Angelini, C.; Batignani, G.; Bettarini, S.; Carpinelli, M.; Casarosa, G.; Cervelli, A.; Forti, F.; Giorgi, M. A.; Lusiani, A.; Neri, N.; Paoloni, E.; Rizzo, G.; Walsh, J. J.; Lopes Pegna, D.; Lu, C.; Olsen, J.; Smith, A. J. S.; Telnov, A. V.; Anulli, F.; Baracchini, E.; Cavoto, G.; Faccini, R.; Ferrarotto, F.; Ferroni, F.; Gaspero, M.; Li Gioi, L.; Mazzoni, M. A.; Piredda, G.; Renga, F.; Hartmann, T.; Leddig, T.; Schröder, H.; Waldi, R.; Adye, T.; Franek, B.; Olaiya, E. O.; Wilson, F. F.; Emery, S.; Hamel de Monchenault, G.; Vasseur, G.; Yèche, Ch.; Zito, M.; Allen, M. T.; Aston, D.; Bard, D. J.; Bartoldus, R.; Benitez, J. F.; Cartaro, C.; Convery, M. R.; Dorfan, J.; Dubois-Felsmann, G. P.; Dunwoodie, W.; Field, R. C.; Franco Sevilla, M.; Fulsom, B. G.; Gabareen, A. M.; Graham, M. T.; Grenier, P.; Hast, C.; Innes, W. R.; Kelsey, M. H.; Kim, H.; Kim, P.; Kocian, M. L.; Leith, D. W. G. S.; Li, S.; Lindquist, B.; Luitz, S.; Luth, V.; Lynch, H. L.; Macfarlane, D. B.; Marsiske, H.; Muller, D. R.; Neal, H.; Nelson, S.; O'Grady, C. P.; Ofte, I.; Perl, M.; Pulliam, T.; Ratcliff, B. N.; Roodman, A.; Salnikov, A. A.; Santoro, V.; Schindler, R. H.; Schwiening, J.; Snyder, A.; Su, D.; Sullivan, M. K.; Sun, S.; Suzuki, K.; Thompson, J. M.; Va'Vra, J.; Wagner, A. P.; Weaver, M.; Wisniewski, W. J.; Wittgen, M.; Wright, D. H.; Wulsin, H. W.; Yarritu, A. K.; Young, C. C.; Ziegler, V.; Chen, X. R.; Park, W.; Purohit, M. V.; White, R. M.; Wilson, J. R.; Randle-Conde, A.; Sekula, S. J.; Bellis, M.; Burchat, P. R.; Miyashita, T. S.; Ahmed, S.; Alam, M. S.; Ernst, J. A.; Pan, B.; Saeed, M. A.; Zain, S. B.; Guttman, N.; Soffer, A.; Lund, P.; Spanier, S. M.; Eckmann, R.; Ritchie, J. L.; Ruland, A. M.; Schilling, C. J.; Schwitters, R. F.; Wray, B. C.; Izen, J. M.; Lou, X. C.; Bianchi, F.; Gamba, D.; Pelliccioni, M.; Bomben, M.; Lanceri, L.; Vitale, L.; Lopez-March, N.; Martinez-Vidal, F.; Oyanguren, A.; Albert, J.; Banerjee, Sw.; Choi, H. H. F.; Hamano, K.; King, G. J.; Kowalewski, R.; Lewczuk, M. J.; Lindsay, C.; Nugent, I. M.; Roney, J. M.; Sobie, R. J.; Gershon, T. J.; Harrison, P. F.; Latham, T. E.; Puccio, E. M. T.; Band, H. R.; Dasu, S.; Flood, K. T.; Pan, Y.; Prepost, R.; Vuosalo, C. O.; Wu, S. L.

2011-03-01

We present measurements of the branching fractions, longitudinal polarization, and direct CP-violation asymmetries for the decays B+→ρ0K*+ and B+→f0(980)K*+ with a sample of (467±5)×106BB¯ pairs collected with the BABAR detector at the PEP-II asymmetric-energy e+e- collider at the SLAC National Accelerator Laboratory. We observe B+→ρ0K*+ with a significance of 5.3σ and measure the branching fraction B(B+→ρ0K*+)=(4.6±1.0±0.4)×10-6, the longitudinal polarization fL=0.78±0.12±0.03, and the CP-violation asymmetry ACP=0.31±0.13±0.03. We observe B+→f0(980)K*+ and measure the branching fraction B(B+→f0(980)K*+)×B(f0(980)→π+π-)=(4.2±0.6±0.3)×10-6 and the CP-violation asymmetry ACP=-0.15±0.12±0.03. The first uncertainty quoted is statistical and the second is systematic.

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

NASA Astrophysics Data System (ADS)

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

High-pressure synthesis and characterization of new actinide borates, AnB4O8 (An=Th, U).

PubMed

Hinteregger, Ernst; Hofer, Thomas S; Heymann, Gunter; Perfler, Lukas; Kraus, Florian; Huppertz, Hubert

2013-11-18

New actinide borates ThB4O8 and UB4O8 were synthesized under high-pressure, high-temperature conditions (5.5 GPa/1100 °C for thorium borate, 10.5 GPa/1100 °C for the isotypic uranium borate) in a Walker-type multianvil apparatus from their corresponding actinide oxide and boron oxide. The crystal structure was determined on basis of single-crystal X-ray diffraction data that were collected at room temperature. Both compounds crystallized in the monoclinic space group C2/c (Z=4). Lattice parameters for ThB4O8: a=1611.3(3), b=419.86(8), c=730.6(2) pm; β=114.70(3)°; V=449.0(2) Å(3); R1=0.0255, wR2=0.0653 (all data). Lattice parameters for UB4O8: a=1589.7(3), b=422.14(8), c=723.4(2) pm; β=114.13(3)°; V=443.1(2) Å(3); R1=0.0227, wR2=0.0372 (all data). The new AnB4O8 (An=Th, U) structure type is constructed from corner-sharing BO4 tetrahedra, which form layers in the bc plane. One of the four independent oxygen atoms is threefold-coordinated. The actinide cations are located between the boron-oxygen layers. In addition to Raman spectroscopic investigations, DFT calculations were performed to support the assignment of the vibrational bands. © 2013 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This isan open access article under the terms of the Creative Commons AttributionLicense, which permits use, distribution and reproduction in any medium,provided the original work is properly cited.

Species-specific and seasonal differences in chlorophyll fluorescence and photosynthetic light response among three evergreen species in a Madrean sky island mixed conifer forest

NASA Astrophysics Data System (ADS)

Potts, D. L.; Minor, R. L.; Braun, Z.; Barron-Gafford, G. A.

2012-12-01

Unlike the snowmelt-dominated hydroclimate of more northern mountainous regions, the hydroclimate of the Madrean sky islands is characterized by snowmelt and convective storms associated with the North American Monsoon. These mid-summer storms trigger biological activity and are important drivers of primary productivity. For example, at the highest elevations where mixed conifer forests occur, ecosystem carbon balance is influenced by monsoon rains. Whereas these storms' significance is increasingly recognized at the ecosystem scale, species-specific physiological responses to the monsoon are poorly known. Prior to and following monsoon onset, we measured pre-dawn and light-adapted chlorophyll fluorescence as well as photosynthetic light response in southwestern white pine (Pinus strobiformis), ponderosa pine (Pinus ponderosa), and Douglas fir (Pseudotsuga menziesii) in a Madrean sky island mixed conifer forest near Tucson, Arizona. Photochemical quenching (qp), an indicator of the proportion of open PSII reaction centers, was greatest in P. strobiformis and least in P. menziesii and increased in response to monsoon rains (repeated-measures ANOVA; species, F2,14 = 6.17, P = 0.012; time, F2,14= 8.17, P = 0.013). In contrast, non-photochemical quenching (qN), an indicator of heat dissipation ability, was greatest in P. ponderosa and least in P. menziesii, but was not influenced by monsoon onset (repeated-measures ANOVA; species, F2,12 = 4.18, P = 0.042). Estimated from leaf area-adjusted photosynthetic light response curves, maximum photosynthetic rate (Amax) was greatest in P. ponderosa and least in P. menziesii (repeated-measures ANOVA; species, F2,8= 40.8, P = 0.001). Surprisingly, while the monsoon positively influenced Amax among P. ponderosa and P. strobiformis, Amax of P. menziesii declined with monsoon onset (repeated-measures ANOVA; species x time, F2,8 = 13.8, P = 0.002). Calculated as the initial slope of the photosynthetic light response curve, light

LLNL SFA OBER SBR FY17 Program Management and Performance Report: Subsurface Biogeochemistry of Actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kersting, Annie B.

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 anthropogenic plutonium (Pu) has accumulated 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 inmore » 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.« less

Properties of metallic glasses containing actinide metals. I. Thermal properties of U--M glasses (M = V, Cr, Mn, Fe, Co, and Ni)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giessen, B.C.; Elliott, R.O.

1978-01-01

The results of a preparative and calorimetric study forming part of a continuing investigation of the new actinide glasses are reported. Specifically, lower bounds for the composition limits of glass formation (G.F.) at moderate cooling rates have been obtained for the U-M (M = Mn, Fe, Co, Ni) systems and the thermal stabilities of glasses in these four systems as well as for a U-V glass and a U-Cr glass have been surveyed.

Isoscalar π π , K K ¯ , η η scattering and the σ , f0, f2 mesons from QCD

NASA Astrophysics Data System (ADS)

Briceño, Raul A.; Dudek, Jozef J.; Edwards, Robert G.; Wilson, David J.; Hadron Spectrum Collaboration

2018-03-01

We present the first lattice QCD study of coupled isoscalar π π ,K K ¯ ,η η S - and D -wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the light quark mass corresponding to mπ˜391 MeV . In the JP=0+ sector we find analogues of the experimental σ and f0(980 ) states, where the σ appears as a stable bound-state below π π threshold, and, similar to what is seen in experiment, the f0(980 ) manifests itself as a dip in the π π cross section in the vicinity of the K K ¯ threshold. For JP=2+ we find two states resembling the f2(1270 ) and f2'(1525 ), observed as narrow peaks, with the lighter state dominantly decaying to π π and the heavier state to K K ¯. The presence of all these states is determined rigorously by finding the pole singularity content of scattering amplitudes, and their couplings to decay channels are established using the residues of the poles.

Ultra low-level measurements of actinides by sector field ICP-MS.

PubMed

Pointurier, F; Baglan, N; Hémet, P

2004-01-01

In the present work, a double-focusing sector field inductively coupled plasma-mass spectrometer was optimised for ultra trace and isotopic analyses of actinide long-lived isotopes in low concentration solutions of the fgml(-1) to the ngml(-1) range. Sensitivities of about 3GHz/(microgml(-1)), with as low a background as 0.1cps, were obtained for U using a conventional concentric pneumatic nebuliser. Detection limits are below the fg range for 239Pu and 240Pu. With natural U, a precision lower than 0.5% RSD is currently obtained for 235U/238U isotopic ratio at the 200pgml(-1) level.

46 CFR 154.615 - Design temperature below 0 °C (32 °F) and down to −55 °C (−67 °F).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Design temperature below 0 °C (32 °F) and down to â55... LIQUEFIED GASES Design, Construction and Equipment Materials § 154.615 Design temperature below 0 °C (32 °F... tanks and secondary barriers for a design temperature below 0 °C (32 °F) and down to −55 °C (−67 °F...

46 CFR 154.615 - Design temperature below 0 °C (32 °F) and down to −55 °C (−67 °F).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Design temperature below 0 °C (32 °F) and down to â55... LIQUEFIED GASES Design, Construction and Equipment Materials § 154.615 Design temperature below 0 °C (32 °F... tanks and secondary barriers for a design temperature below 0 °C (32 °F) and down to −55 °C (−67 °F...

Ammonium iron(III) phosphate(V) fluoride, (NH4)0.5[(NH4)0.375K0.125]FePO4F, with ammonium partially substituted by potassium

PubMed Central

Wang, Lei; Zhou, Yan; Huang, Ya-Xi; Mi, Jin-Xiao

2009-01-01

The title compound, ammonium potassium iron(III) phosphate fluoride, (NH4)0.875K0.125FePO4F, is built from zigzag chains ∞ 1{[FeO4F2]7−}, with Fe3+ in a distorted octahedral coordination, extending along both the [011] and [01] directions. These chains are made up of alternating trans-[FeO4F2] and cis-[FeO4F2] octa­hedra via shared F-atom corners, and are linked by PO4 tetra­hedra, resulting in an open-framework structure with channels along the [010] and [100] directions. There are two crystallographically independent ammonium sites: one in the [010] channels and the other, partially substituted by K+ ions, in the [100] channels. The ammonium in the [010] channels is fixed to the framework via eight hydrogen bonds (six N—H⋯O and two N—H⋯F). PMID:21581466

Effect of Age on F[subscript 0] Difference Limen and Concurrent Vowel Identification

ERIC Educational Resources Information Center

Vongpaisal, Tara; Pichora-Fuller, Margaret Kathleen

2007-01-01

Purpose: To investigate the effect of age on voice fundamental frequency (F[subscript 0]) difference limen (DL) and identification of concurrently presented vowels. Method: Fifteen younger and 15 older adults with normal audiometric thresholds in the speech range participated in 2 experiments. In Experiment 1, F[subscript 0] DLs were measured for…

Species composition of and fumonisin production by the Fusarium fujikuroi species complex isolated from Korean cereals.

PubMed

Choi, Jung-Hye; Lee, Seolhee; Nah, Ju-Young; Kim, Hee-Kyoung; Paek, Ji-Seon; Lee, Soohyung; Ham, Hyeonheui; Hong, Sung Kee; Yun, Sung-Hwan; Lee, Theresa

2018-02-21

To assess the risk of fumonisin contamination in Korean cereals, we isolated colonies of the Fusarium fujikuroi species complex (FFSC) from barley, maize, rice and soybean samples from 2011 to 2015. A total of 878 FFSC strains were isolated mostly from maize and rice, and species identity of the isolates were determined using the DNA sequence of the translation elongation factor 1-α (TEF-1α) and RNA polymerase II (RPB2) genes. Fusaria recovered from Korean cereals included F. fujikuroi (317 isolates and a frequency of 36%), F. proliferatum (212 isolates and 24.1%), F. verticillioides (170 isolates and 19.4%), F. concentricum (86 strains and 9.8%), F. andiyazi (56 isolates and 6.4%), F. subglutinans (28 isolates and 3.2%), F. thapsinum (5 isolates and 0.6%), and F. circinatum (2 isolates and 0.2%). The rice samples were dominated by F. fujikuroi (47.4%), F. proliferatum (27.3%), and F. concentricum (15.1%), whereas maize samples were dominated by F. verticillioides (33.9%), F. fujikuroi (25.3%), and F. proliferatum (21.1%). A phylogenetic analysis of 70 representative isolates demonstrated that each species was resolved as genealogically exclusive in the ML tree. Fumonisin production potential was evaluated using a PCR assay for the fumonisin biosynthesis gene, FUM1 in all of the isolates. Most of the isolates tested (94%) were positive for FUM1. All of the isolates assigned to F. fujikuroi, F. proliferatum, F. verticillioides and F. thapsinum were positive for FUM1 irrespective of their host origin. Seventy-seven representative isolates positive for FUM1 were examined for fumonisin production in rice medium. The majority of F. proliferatum (26/27, 96.3%), F. verticillioides (16/17, 94.1%) and F. fujikuroi (19/25, 76.0%) produced both FB 1 and FB 2 . Notably, 16 of 19 fumonisin-producing F. fujikuroi produced >1000μg/g of fumonisins (FB 1 +FB 2 ) in rice medium, which is higher than that in previous reports. These results suggest that F. fujikuroi can produce

Actinide bioimaging in tissues: Comparison of emulsion and solid track autoradiography techniques with the iQID camera

PubMed Central

Miller, Brian W.; Van der Meeren, Anne; Tazrart, Anissa; Angulo, Jaime F.; Griffiths, Nina M.

2017-01-01

This work presents a comparison of three autoradiography techniques for imaging biological samples contaminated with actinides: emulsion-based, plastic-based autoradiography and a quantitative digital technique, the iQID camera, based on the numerical analysis of light from a scintillator screen. In radiation toxicology it has been important to develop means of imaging actinide distribution in tissues as these radionuclides may be heterogeneously distributed within and between tissues after internal contamination. Actinide distribution determines which cells are exposed to alpha radiation and is thus potentially critical for assessing absorbed dose. The comparison was carried out by generating autoradiographs of the same biological samples contaminated with actinides with the three autoradiography techniques. These samples were cell preparations or tissue sections collected from animals contaminated with different physico-chemical forms of actinides. The autoradiograph characteristics and the performances of the techniques were evaluated and discussed mainly in terms of acquisition process, activity distribution patterns, spatial resolution and feasibility of activity quantification. The obtained autoradiographs presented similar actinide distribution at low magnification. Out of the three techniques, emulsion autoradiography is the only one to provide a highly-resolved image of the actinide distribution inherently superimposed on the biological sample. Emulsion autoradiography is hence best interpreted at higher magnifications. However, this technique is destructive for the biological sample. Both emulsion- and plastic-based autoradiography record alpha tracks and thus enabled the differentiation between ionized forms of actinides and oxide particles. This feature can help in the evaluation of decorporation therapy efficacy. The most recent technique, the iQID camera, presents several additional features: real-time imaging, separate imaging of alpha particles and

Short-range order in the Ca sub 1-x La sub x F sub 2+x solid solution: 1:0:3 or 1:0:4 clusters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Laval, J.P.; Abaouz, A.; Frit, B.

1989-08-01

The defect structure of the Ca{sub 1-x}La{sub x}F{sub 2+x} solid solution (0 {le} x {le} 0.38) has been examined at room temperature by powder neutron diffraction. Two kinds of (xxx) interstitial anions, whose respective numbers increase linearly with increasing dopant cation concentration, have been found: one labeled F{sup 0} (x {approx} 0.41) is a true interstitial; the other labeled F{sup {prime}{double prime}} (x {approx} 0.31) can be considered a relaxed normal anion. Two 1:0:n defect clusters are compatible, within the experimental errors, with these results: the 1:0:3 (1V{sub F}, OF{prime}, 3F{sup {double prime}}, 2 La{sup 3+}) and the 1:0:4 (1V{submore » F}, OF{prime}, 4F{sup {double prime}}, 3La{sup 3+}) clusters. Charge balance considerations and comparisons with the homologous Ca{sub 1-x}M{sub x}{sup IV}F{sub 2+2x} solid solutions (M{sup IV} = Th, U) allow us to think that the less dense 1:0:3 cluster is present for the whole domain of both kinds of solid solutions.« less

Increased retention of americium in kidneys as compared with plutonium in an actinide wound contamination model in the rat.

PubMed

Griffiths, Nina M; Coudert, Sylvie; Molina, Thibaut; Wilk, Jean-Claude; Renault, Daniel; Berard, Philippe; Van der Meeren, Anne

2014-11-01

Americium-241 ((241)Am) presents a potential risk for nuclear industry workers associated with reactor decommissioning and aging combustible materials. The purpose of this study was to investigate Am renal retention after actinide contamination by wounding in the rat. Anesthetized rats were contaminated with Mixed Oxide (MOX) (7.1% Plutonium [Pu] by mass and containing 27% Am as % total alpha activity), Pu or Am nitrate following an incision wound of the hind leg. Times of euthanasia ranged from 2 hours to 5 months after contamination. Pu and Am levels were quantified following radiochemistry and alpha-spectrophotometry. Initial data show that over the experimental period the proportion of Am in kidneys as a fraction of total kidney alpha activity was elevated as compared to MOX powder indicating a specific retention in this organ. The percentage of Pu was similar to the powder. After MOX contamination, kidney to liver ratios appeared to increase more markedly for Am (from 0.2 at 7 days to 0.6 at 90 days) as compared with Pu (0.1 at 7 days to 0.2 at 90 days). In accordance with tissue actinide retention the dose from Am to the kidney increases with time. For comparison, the ratio of estimated equivalent doses due to Am to kidney is 1.5-fold greater than for Pu (around 90 versus 60 mSv). After actinide contamination of wounds, Am is concentrated in the kidneys as compared to Pu leading to potential exposure of renal tissue to both alpha particles and gamma radiation.

46 CFR 154.625 - Design temperature below 0 °C (32 °F) and down to −165 °C (−265 °F).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Design temperature below 0 °C (32 °F) and down to â165... LIQUEFIED GASES Design, Construction and Equipment Materials § 154.625 Design temperature below 0 °C (32 °F... process piping for a design temperature below 0 °C (32 °F) and down to −165 °C (−265 °F) must meet § 56.50...

46 CFR 154.625 - Design temperature below 0 °C (32 °F) and down to −165 °C (−265 °F).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 5 2011-10-01 2011-10-01 false Design temperature below 0 °C (32 °F) and down to â165... LIQUEFIED GASES Design, Construction and Equipment Materials § 154.625 Design temperature below 0 °C (32 °F... process piping for a design temperature below 0 °C (32 °F) and down to −165 °C (−265 °F) must meet § 56.50...

JOWOG 22/2 - Actinide Chemical Technology (July 9-13, 2012)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, Jay M.; Lopez, Jacquelyn C.; Wayne, David M.

2012-07-05

The Plutonium Science and Manufacturing Directorate provides world-class, safe, secure, and reliable special nuclear material research, process development, technology demonstration, and manufacturing capabilities that support the nation's defense, energy, and environmental needs. We safely and efficiently process plutonium, uranium, and other actinide materials to meet national program requirements, while expanding the scientific and engineering basis of nuclear weapons-based manufacturing, and while producing the next generation of nuclear engineers and scientists. Actinide Process Chemistry (NCO-2) safely and efficiently processes plutonium and other actinide compounds to meet the nation's nuclear defense program needs. All of our processing activities are done in amore » world class and highly regulated nuclear facility. NCO-2's plutonium processing activities consist of direct oxide reduction, metal chlorination, americium extraction, and electrorefining. In addition, NCO-2 uses hydrochloric and nitric acid dissolutions for both plutonium processing and reduction of hazardous components in the waste streams. Finally, NCO-2 is a key team member in the processing of plutonium oxide from disassembled pits and the subsequent stabilization of plutonium oxide for safe and stable long-term storage.« less

Unilateral incompatibility gene ui1.1 encodes an S-locus F-box protein expressed in pollen of Solanum species.

PubMed

Li, Wentao; Chetelat, Roger T

2015-04-07

Unilateral interspecific incompatibility (UI) is a postpollination, prezygotic reproductive barrier that prevents hybridization between related species when the female parent is self-incompatible (SI) and the male parent is self-compatible (SC). In tomato and related Solanum species, two genes, ui1.1 and ui6.1, are required for pollen compatibility on pistils of SI species or hybrids. We previously showed that ui6.1 encodes a Cullin1 (CUL1) protein. Here we report that ui1.1 encodes an S-locus F-box (SLF) protein. The ui1.1 gene was mapped to a 0.43-cM, 43.2-Mbp interval at the S-locus on chromosome 1, but positional cloning was hampered by low recombination frequency. We hypothesized that ui1.1 encodes an SLF protein(s) that interacts with CUL1 and Skp1 proteins to form an SCF-type (Skp1, Cullin1, F-box) ubiquitin E3 ligase complex. We identified 23 SLF genes in the S. pennellii genome, of which 19 were also represented in cultivated tomato (S. lycopersicum). Data from recombination events, expression analysis, and sequence annotation highlighted 11 S. pennellii genes as candidates. Genetic transformations demonstrated that one of these, SpSLF-23, is sufficient for ui1.1 function. A survey of cultivated and wild tomato species identified SLF-23 orthologs in each of the SI species, but not in the SC species S. lycopersicum, S. cheesmaniae, and S. galapagense, pollen of which lacks ui1.1 function. These results demonstrate that pollen compatibility in UI is mediated by protein degradation through the ubiquitin-proteasome pathway, a mechanism related to that which controls pollen recognition in SI.

46 CFR 154.610 - Design temperature not colder than 0 °C (32 °F).

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 5 2014-10-01 2014-10-01 false Design temperature not colder than 0 °C (32 °F). 154..., Construction and Equipment Materials § 154.610 Design temperature not colder than 0 °C (32 °F). Materials for cargo tanks for a design temperature not colder than 0 °C (32 °F) must meet the following: (a) The tank...

Interacting cytoplasmic loops of subunits a and c of Escherichia coli F1F0 ATP synthase gate H+ transport to the cytoplasm.

PubMed

Steed, P Ryan; Kraft, Kaitlin A; Fillingame, Robert H

2014-11-25

H(+)-transporting F1F0 ATP synthase catalyzes the synthesis of ATP via coupled rotary motors within F0 and F1. H(+) transport at the subunit a-c interface in transmembranous F0 drives rotation of a cylindrical c10 oligomer within the membrane, which is coupled to rotation of subunit γ within the α3β3 sector of F1 to mechanically drive ATP synthesis. F1F0 functions in a reversible manner, with ATP hydrolysis driving H(+) transport. ATP-driven H(+) transport in a select group of cysteine mutants in subunits a and c is inhibited after chelation of Ag(+) and/or Cd(+2) with the substituted sulfhydryl groups. The H(+) transport pathway mapped via these Ag(+)(Cd(+2))-sensitive Cys extends from the transmembrane helices (TMHs) of subunits a and c into cytoplasmic loops connecting the TMHs, suggesting these loop regions could be involved in gating H(+) release to the cytoplasm. Here, using select loop-region Cys from the single cytoplasmic loop of subunit c and multiple cytoplasmic loops of subunit a, we show that Cd(+2) directly inhibits passive H(+) transport mediated by F0 reconstituted in liposomes. Further, in extensions of previous studies, we show that the regions mediating passive H(+) transport can be cross-linked to each other. We conclude that the loop-regions in subunits a and c that are implicated in H(+) transport likely interact in a single structural domain, which then functions in gating H(+) release to the cytoplasm.

Isoscalar π π , K K ¯ , η η scattering and the σ , f 0 , f 2 mesons from QCD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Briceno, Raul A.; Dudek, Jozef J.; Edwards, Robert G.

We present the first lattice QCD study of coupled isoscalarmore » $$\\pi\\pi,K\\overline{K},\\eta\\eta$$ $S$- and $D$-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the quark mass corresponding to $$m_\\pi\\sim391$$ MeV. In the $J^P=0^+$ sector we find analogues of the experimental $$\\sigma$$ and $$f_0(980)$$ states, where the $$\\sigma$$ appears as a stable bound-state below $$\\pi\\pi$$ threshold, and, similar to what is seen in experiment, the $$f_0(980)$$ manifests itself as a dip in the $$\\pi\\pi$$ cross section in the vicinity of the $$K\\overline{K}$$ threshold. For $J^P=2^+$ we find two states resembling the $$f_2(1270)$$ and $$f_2'(1525)$$, observed as narrow peaks, with the lighter state dominantly decaying to $$\\pi\\pi$$ and the heavier state to $$K\\overline{K}$$. The presence of all these states is determined rigorously by finding the pole singularity content of scattering amplitudes, and their couplings to decay channels are established using the residues of the poles.« less

Isoscalar π π , K K ¯ , η η scattering and the σ , f 0 , f 2 mesons from QCD

DOE PAGES

Briceno, Raul A.; Dudek, Jozef J.; Edwards, Robert G.; ...

2018-03-23

We present the first lattice QCD study of coupled isoscalarmore » $$\\pi\\pi,K\\overline{K},\\eta\\eta$$ $S$- and $D$-wave scattering extracted from discrete finite-volume spectra computed on lattices which have a value of the quark mass corresponding to $$m_\\pi\\sim391$$ MeV. In the $J^P=0^+$ sector we find analogues of the experimental $$\\sigma$$ and $$f_0(980)$$ states, where the $$\\sigma$$ appears as a stable bound-state below $$\\pi\\pi$$ threshold, and, similar to what is seen in experiment, the $$f_0(980)$$ manifests itself as a dip in the $$\\pi\\pi$$ cross section in the vicinity of the $$K\\overline{K}$$ threshold. For $J^P=2^+$ we find two states resembling the $$f_2(1270)$$ and $$f_2'(1525)$$, observed as narrow peaks, with the lighter state dominantly decaying to $$\\pi\\pi$$ and the heavier state to $$K\\overline{K}$$. The presence of all these states is determined rigorously by finding the pole singularity content of scattering amplitudes, and their couplings to decay channels are established using the residues of the poles.« less

Effect of Nb and F Co-doping on Li1.2Mn0.54Ni0.13Co0.13O2 Cathode Material for High-Performance Lithium-Ion Batteries

PubMed Central

Ming, Lei; Zhang, Bao; Cao, Yang; Zhang, Jia-Feng; Wang, Chun-Hui; Wang, Xiao-Wei; Li, Hui

2018-01-01

The Li1.2Mn0.54−xNbxCo0.13Ni0.13O2−6xF6x (x = 0, 0.01, 0.03, 0.05) is prepared by traditional solid-phase method, and the Nb and F ions are successfully doped into Mn and O sites of layered materials Li1.2Mn0.54Co0.13Ni0.13O2, respectively. The incorporating Nb ion in Mn site can effectively restrain the migration of transition metal ions during long-term cycling, and keep the stability of the crystal structure. The Li1.2Mn0.54−xNbxCo0.13Ni0.13O2−6xF6x shows suppressed voltage fade and higher capacity retention of 98.1% after 200 cycles at rate of 1 C. The replacement of O2− by the strongly electronegative F− is beneficial for suppressed the structure change of Li2MnO3 from the eliminating of oxygen in initial charge process. Therefore, the initial coulombic efficiency of doped Li1.2Mn0.54−xNbxCo0.13Ni0.13O2−6xF6x gets improved, which is higher than that of pure Li1.2Mn0.54Co0.13Ni0.13O2. In addition, the Nb and F co-doping can effectively enhance the transfer of lithium-ion and electrons, and thus improving rate performance. PMID:29675405

Alimentary tract absorption (f1 values) for radionuclides in local and regional fallout from nuclear tests.

PubMed

Ibrahim, Shawki A; Simon, Steven L; Bouville, André; Melo, Dunstana; Beck, Harold L

2010-08-01

This paper presents gastrointestinal absorption fractions (f1 values) for estimating internal doses from local and regional fallout radionuclides due to nuclear tests. The choice of f1 values are based on specific circumstances of weapons test conditions and a review of reported f1 values for elements in different physical and chemical states. Special attention is given to fallout from nuclear tests conducted at the Marshall Islands. We make a distinction between the f1 values for intakes of radioactive materials immediately after deposition (acute intakes) and intakes that occur in the course of months and years after deposition, following incorporation into terrestrial and aquatic foodstuffs (chronic intakes). Multiple f1 values for different circumstances where persons are exposed to radioactive fallout (e.g., local vs. regional fallout and coral vs. continental tests) are presented when supportive information is available. In some cases, our selected f1 values are similar to those adopted by the International Commission on Radiological Protection (ICRP) (e.g., iodine and most actinides). However, f1 values for cesium and strontium derived from urine bioassay data of the Marshallese population are notably lower than the generic f1 values recommended by ICRP, particularly for acute intakes from local fallout (0.4 and 0.05 for Cs and Sr, respectively). The f1 values presented here form the first complete set of values relevant to realistic dose assessments for exposure to local or regional radioactive fallout.

Alimentary Tract Absorption (f1 Values) for Radionuclides in Local and Regional Fallout from Nuclear Tests

PubMed Central

Ibrahim, Shawki; Simon, Steven L; Bouville, André; Melo, Dunstana; Beck, Harold

2009-01-01

This paper presents gastrointestinal absorption fractions (f1 values) for estimating internal doses from local and regional fallout radionuclides due to nuclear tests. The choice of f1 values are based on specific circumstances of weapons test conditions and a review of reported f1 values for elements in different physical and chemical states. Special attention is given to fallout from nuclear tests conducted at the Marshall Islands. We make a distinction between the f1 values for intakes of radioactive materials immediately after deposition (acute intakes) and intakes that occur in the course of months and years after deposition, following incorporation into terrestrial and aquatic foodstuffs (chronic intakes). Multiple f1 values for different circumstances where persons are exposed to radioactive fallout (e.g. local vs. regional fallout and coral vs. continental tests) are presented when supportive information is available. In some cases, our selected f1 values are similar to those adopted by the ICRP (e.g. iodine and most actinides). However, f1 values for cesium and strontium derived from urine bioassay data of the Marshallese population are notably lower than the generic f1 values recommended by ICRP, particularly for acute intakes from local fallout (0.4 and 0.05 for Cs and Sr, respectively. The f1 values presented here form the first complete set of values relevant to realistic dose assessments for exposure to local or regional radioactive fallout. PMID:20622554

Mandarin-Speaking Children's Speech Recognition: Developmental Changes in the Influences of Semantic Context and F0 Contours.

PubMed

Zhou, Hong; Li, Yu; Liang, Meng; Guan, Connie Qun; Zhang, Linjun; Shu, Hua; Zhang, Yang

2017-01-01

The goal of this developmental speech perception study was to assess whether and how age group modulated the influences of high-level semantic context and low-level fundamental frequency ( F 0 ) contours on the recognition of Mandarin speech by elementary and middle-school-aged children in quiet and interference backgrounds. The results revealed different patterns for semantic and F 0 information. One the one hand, age group modulated significantly the use of F 0 contours, indicating that elementary school children relied more on natural F 0 contours than middle school children during Mandarin speech recognition. On the other hand, there was no significant modulation effect of age group on semantic context, indicating that children of both age groups used semantic context to assist speech recognition to a similar extent. Furthermore, the significant modulation effect of age group on the interaction between F 0 contours and semantic context revealed that younger children could not make better use of semantic context in recognizing speech with flat F 0 contours compared with natural F 0 contours, while older children could benefit from semantic context even when natural F 0 contours were altered, thus confirming the important role of F 0 contours in Mandarin speech recognition by elementary school children. The developmental changes in the effects of high-level semantic and low-level F 0 information on speech recognition might reflect the differences in auditory and cognitive resources associated with processing of the two types of information in speech perception.

Enhancing the actinide sciences in Europe through hot laboratories networking and pooling: from ACTINET to TALISMAN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bourg, S.; Poinssot, C.

2013-07-01

Since 2004, Europe supports the strengthening of the European actinides sciences scientific community through the funding of dedicated networks: (i) from 2004 to 2008, the ACTINET6 network of excellence (6. Framework Programme) gathered major laboratories involved in nuclear research and a wide range of academic research organisations and universities with the specific aims of funding and implementing joint research projects to be performed within the network of pooled facilities; (ii) from 2009 to 2013, the ACTINET-I3 integrated infrastructure initiative (I3) supports the cost of access of any academics in the pooled EU hot laboratories. In this continuation, TALISMAN (Trans-national Accessmore » to Large Infrastructures for a Safe Management of Actinides) gathers now the main European hot laboratories in actinides sciences in order to promote their opening to academics and universities and strengthen the EU-skills in actinides sciences. Furthermore, a specific focus is set on the development of advanced cutting-edge experimental and spectroscopic capabilities, the combination of state-of-the art experimental with theoretical first-principle methods on a quantum mechanical level and to benefit from the synergy between the different scientific and technical communities. ACTINET-I3 and TALISMAN attach a great importance and promote the Education and Training of the young generation of actinides scientists in the Trans-national access but also by organizing Schools (general Summer Schools or Theoretical User Lab Schools) or by granting students to attend International Conference on actinide sciences. (authors)« less

Variable reluctance displacement transducer temperature compensated to 650$sup 0$F

DOE Office of Scientific and Technical Information (OSTI.GOV)

Piper, T.C.; Colson, J.B.

650 deg F. Piper, T. C.; Colson, J. B. (Aerojet Nuclear Co., Idaho Falls, Idaho (USA)). Nov 1973. Contract AT(10-1)-1375. ' 16p. Dep. NTlS 00. A variable reluctnce transducer (VRT) with plus or minus 0.100- inch stroke to operate to 550 deg F is described. Specific design effort was taken to optimize the desiga to have minimum change in the VRT's null and sensitivity with rapid thermal and pressure transients. Null and sensitivity stabilities of plus or minus 0.5% and 1.8% of full scale, respectively, were obtained. Appentice; 'ineate the various effects considered in optimizing the design. (auth)

Benchmark Evaluation of Dounreay Prototype Fast Reactor Minor Actinide Depletion Measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hess, J. D.; Gauld, I. C.; Gulliford, J.

2017-01-01

Historic measurements of actinide samples in the Dounreay Prototype Fast Reactor (PFR) are of interest for modern nuclear data and simulation validation. Samples of various higher-actinide isotopes were irradiated for 492 effective full-power days and radiochemically assayed at Oak Ridge National Laboratory (ORNL) and Japan Atomic Energy Research Institute (JAERI). Limited data were available regarding the PFR irradiation; a six-group neutron spectra was available with some power history data to support a burnup depletion analysis validation study. Under the guidance of the Organisation for Economic Co-Operation and Development Nuclear Energy Agency (OECD NEA), the International Reactor Physics Experiment Evaluation Projectmore » (IRPhEP) and Spent Fuel Isotopic Composition (SFCOMPO) Project are collaborating to recover all measurement data pertaining to these measurements, including collaboration with the United Kingdom to obtain pertinent reactor physics design and operational history data. These activities will produce internationally peer-reviewed benchmark data to support validation of minor actinide cross section data and modern neutronic simulation of fast reactors with accompanying fuel cycle activities such as transportation, recycling, storage, and criticality safety.« less

Strong anisotropy effect in an iron-based superconductor CaFe0.882Co0.118AsF

NASA Astrophysics Data System (ADS)

Ma, Yonghui; Ji, Qiucheng; Hu, Kangkang; Gao, Bo; Li, Wei; Mu, Gang; Xie, Xiaoming

2017-07-01

The anisotropy of iron-based superconductors is much smaller than that of the cuprates and that predicted by theoretical calculations. A credible understanding for this experimental fact is still lacking up to now. Here we experimentally study the magnetic-field-angle dependence of electronic resistivity in the superconducting phase of an iron-based superconductor CaFe{}0.882Co{}0.118AsF, and find the strongest anisotropy effect of the upper critical field among the iron-based superconductors based on the framework of Ginzburg-Landau theory. The evidence of the energy band structure and charge density distribution from electronic structure calculations demonstrates that the observed strong anisotropic effect mainly comes from the strong ionic bonding in between the ions of Ca2+ and F-, which weakens the interlayer coupling between the layers of FeAs and CaF. This finding provides a significant insight into the nature of the experimentally-observed strong anisotropic effect of electronic resistivity, and also paves the way for designing exotic two-dimensional artificial unconventional superconductors in the future.

Electron-Transfer-Enhanced Cation-Cation Interactions in Homo- and Heterobimetallic Actinide Complexes: A Relativistic Density Functional Theory Study.

PubMed

Zheng, Ming; Chen, Fang-Yuan; Tian, Jia-Nan; Pan, Qing-Jiang

2018-04-02

To provide deep insight into cation-cation interactions (CCIs) involving hexavalent actinyl species that are major components in spent nuclear fuel and pose important implications for the effective removal of radiotoxic pollutants in the environment, a series of homo- and heterobimetallic actinide complexes supported by cyclopentadienyl (Cp) and polypyrrolic macrocycle (H 4 L) ligands were systematically investigated using relativistic density functional theory. The metal sort in both parts of (THF)(H 2 L)(OAn VI O) and (An') III Cp 3 from U to Np to Pu, as well as the substituent bonding to Cp from electron-donating Me to H to electron-withdrawing Cl, SiH 3 , and SiMe 3 , was changed. Over 0.70 electrons are unraveled to transfer from the electron-rich U III to the electron-deficient An VI of the actinyl moiety, leading to a more stable An V -U IV isomer; in contrast, uranylneptunium and uranylplutonium complexes behave as electron-resonance structures between VI-III and V-IV. These were further corroborated by geometrical and electronic structures. The energies of CCIs (i.e., O exo -An' bonds) were calculated to be -19.6 to -41.2 kcal/mol, affording those of OUO-Np (-23.9 kcal/mol) and OUO-Pu (-19.6 kcal/mol) with less electron transfer (ET) right at the low limit. Topological analyses of the electron density at the O exo -An' bond critical points demonstrate that the CCIs are ET or dative bonds in nature. A positive correlation has been built between the CCIs' strength and corresponding ET amount. It is concluded that the CCIs of O exo -An' are driven by the electrostatic attraction between the actinyl oxo atom (negative) and the actinide ion (positive) and enhanced by their ET. Finally, experimental syntheses of (THF)(H 2 L)(OU VI O)(An') III Cp 3 (An' = U and Np) were well reproduced by thermodynamic calculations that yielded negative free energies in a tetrahydrofuran solution but a positive one for their uranylplutonium analogue, which was synthetically

Prevalence, Characterization, and Mycotoxin Production Ability of Fusarium Species on Korean Adlay (Coix lacrymal-jobi L.) Seeds

PubMed Central

An, Tae Jin; Shin, Kyu Seop; Paul, Narayan Chandra; Kim, Young Guk; Cha, Seon Woo; Moon, Yuseok; Yu, Seung Hun; Oh, Sang-Keun

2016-01-01

Adlay seed samples were collected from three adlay growing regions (Yeoncheon, Hwasun, and Eumseong region) in Korea during 2012. Among all the samples collected, 400 seeds were tested for fungal occurrence by standard blotter and test tube agar methods and different taxonomic groups of fungal genera were detected. The most predominant fungal genera encountered were Fusarium, Phoma, Alternaria, Cladosporium, Curvularia, Cochliobolus and Leptosphaerulina. Fusarium species accounted for 45.6% of all species found; and, with phylogenetic analysis based on the combined sequences of two protein coding genes (EF-1α and β-tubulin), 10 Fusarium species were characterized namely, F. incarnatum (11.67%), F. kyushuense (10.33%), F. fujikuroi (8.67%), F. concentricum (6.00%), F. asiaticum (5.67%), F. graminearum (1.67%), F. miscanthi (0.67%), F. polyphialidicum (0.33%), F. armeniacum (0.33%), and F. thapsinum (0.33%). The Fusarium species were then examined for their morphological characteristics to confirm their identity. Morphological observations of the species correlated well with and confirmed their molecular identification. The ability of these isolates to produce the mycotoxins fumonisin (FUM) and zearalenone (ZEN) was tested by the ELISA quantitative analysis method. The result revealed that FUM was produced only by F. fujikuroi and that ZEN was produced by F. asiaticum and F. graminearum. PMID:27801779

Prevalence, Characterization, and Mycotoxin Production Ability of Fusarium Species on Korean Adlay (Coix lacrymal-jobi L.) Seeds.

PubMed

An, Tae Jin; Shin, Kyu Seop; Paul, Narayan Chandra; Kim, Young Guk; Cha, Seon Woo; Moon, Yuseok; Yu, Seung Hun; Oh, Sang-Keun

2016-10-27

Adlay seed samples were collected from three adlay growing regions (Yeoncheon, Hwasun, and Eumseong region) in Korea during 2012. Among all the samples collected, 400 seeds were tested for fungal occurrence by standard blotter and test tube agar methods and different taxonomic groups of fungal genera were detected. The most predominant fungal genera encountered were Fusarium , Phoma , Alternaria , Cladosporium , Curvularia , Cochliobolus and Leptosphaerulina . Fusarium species accounted for 45.6% of all species found; and, with phylogenetic analysis based on the combined sequences of two protein coding genes (EF-1α and β-tubulin), 10 Fusarium species were characterized namely, F. incarnatum (11.67%), F. kyushuense (10.33%), F. fujikuroi (8.67%), F. concentricum (6.00%), F. asiaticum (5.67%), F. graminearum (1.67%), F. miscanthi (0.67%), F. polyphialidicum (0.33%), F. armeniacum (0.33%), and F. thapsinum (0.33%). The Fusarium species were then examined for their morphological characteristics to confirm their identity. Morphological observations of the species correlated well with and confirmed their molecular identification. The ability of these isolates to produce the mycotoxins fumonisin (FUM) and zearalenone (ZEN) was tested by the ELISA quantitative analysis method. The result revealed that FUM was produced only by F. fujikuroi and that ZEN was produced by F. asiaticum and F. graminearum .

Abundance of live 244Pu in deep-sea reservoirs on Earth points to rarity of actinide nucleosynthesis

PubMed Central

Wallner, A.; Faestermann, T.; 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 remain a mystery. If continuously produced, the Interstellar Medium is expected to build-up a quasi-steady state of abundances of short-lived nuclides (with half-lives ≤100 My), including actinides produced in r-process nucleosynthesis. Their existence in today’s interstellar medium would serve as a radioactive clock and would establish that their production was recent. In particular 244Pu, a radioactive actinide nuclide (half-life=81 My), can place strong constraints on recent r-process frequency and production yield. Here we report the detection of live interstellar 244Pu, archived in Earth’s deep-sea floor during the last 25 My, at abundances lower than expected from continuous production in the Galaxy by about 2 orders of magnitude. This large discrepancy may signal a rarity of actinide r-process nucleosynthesis sites, compatible with neutron-star mergers or with a small subset of actinide-producing supernovae. PMID:25601158

Method for decontamination of nickel-fluoride-coated nickel containing actinide-metal fluorides

DOEpatents

Windt, N.F.; Williams, J.L.

In one aspect, the invention comprises contacting nickel-fluoride-coated nickel with gaseous ammonia at a temperature effecting nickel-catalyzed dissociation thereof and effecting hydrogen-reduction of the nickel fluoride. The resulting nickel is heated to form a melt and a slag and to effect transfer of actinide metals from the melt into the slag. The melt and slag are then separated. In another aspect, nickel contianing nickel oxide and actinide metals is contacted with ammonia at a temperature effecting nickel-catalyzed dissociation to effect conversion of the nickel oxide to the metal. The resulting nickel is then melted and separated as described. In another aspect nickel-fluoride-coated nickel containing actinide-metal fluorides is contacted with both steam and ammonia. The resulting nickel then is melted and separated as described. The invention is characterized by higher nickel recovery, efficient use of ammonia, a substantial decrease in slag formation and fuming, and a valuable increase in the service life of the furnace liners used for melting.

Effects of age on F0 discrimination and intonation perception in simulated electric and electroacoustic hearing.

PubMed

Souza, Pamela; Arehart, Kathryn; Miller, Christi Wise; Muralimanohar, Ramesh Kumar

2011-02-01

Recent research suggests that older listeners may have difficulty processing information related to the fundamental frequency (F0) of voiced speech. In this study, the focus was on the mechanisms that may underlie this reduced ability. We examined whether increased age resulted in decreased ability to perceive F0 using fine-structure cues provided by the harmonic structure of voiced speech sounds or cues provided by high-rate envelope fluctuations (periodicity). Younger listeners with normal hearing and older listeners with normal to near-normal hearing completed two tasks of F0 perception. In the first task (steady state F0), the fundamental frequency difference limen (F0DL) was measured adaptively for synthetic vowel stimuli. In the second task (time-varying F0), listeners relied on variations in F0 to judge intonation of synthetic diphthongs. For both tasks, three processing conditions were created: eight-channel vocoding that preserved periodicity cues to F0; a simulated electroacoustic stimulation condition, which consisted of high-frequency vocoder processing combined with a low-pass-filtered portion, and offered both periodicity and fine-structure cues to F0; and an unprocessed condition. F0 difference limens for steady state vowel sounds and the ability to discern rising and falling intonations were significantly worse in the older subjects compared with the younger subjects. For both older and younger listeners, scores were lowest for the vocoded condition, and there was no difference in scores between the unprocessed and electroacoustic simulation conditions. Older listeners had difficulty using periodicity cues to obtain information related to talker fundamental frequency. However, performance was improved by combining periodicity cues with (low frequency) acoustic information, and that strategy should be considered in individuals who are appropriate candidates for such processing. For cochlear implant candidates, this effect might be achieved by partial

Insertion of rare gas atoms into BF3 and AlF3 molecules: An ab initio investigation

NASA Astrophysics Data System (ADS)

Jayasekharan, T.; Ghanty, T. K.

2006-12-01

The structure, stability, charge redistribution, and harmonic vibrational frequencies of rare gas inserted group III-B fluorides with the general formula F -Rg-MF2 (where M =B and Al; Rg =Ar, Kr, and Xe) have been investigated using ab initio quantum chemical methods. The Rg atom is inserted in one of the M -F bond of MF3 molecules, and the geometries are optimized for ground as well as transition states using the MP2 method. It has been found that Rg inserted F -Rg-M portion is linear in both F -Rg-BF2 and F -Rg-AlF2 species. The binding energies corresponding to the lowest energy fragmentation products MF3+Rg (two-body dissociation) have been computed to be -670.4, -598.8, -530.7, -617.0, -562.1, and -494.0kJ /mol for F -Ar-BF2, F -Kr-BF2, F -Xe-BF2, F -Ar-AlF2, F -Kr-AlF2, and F -Xe-AlF2 species, respectively. The dissociation energies corresponding to MF2+Rg +F fragments (three-body dissociation) are found to be positive with respect to F -Rg-MF2 species, and the computed values are 56.3, 127.8, and 196.0kJ/mol for F -Ar-BF2, F -Kr-BF2, and F -Xe-BF2 species, respectively. The corresponding values for F -Ar-AlF2, F -Kr-AlF2, and F -Xe-AlF2 species are also found to be positive. The decomposition of F -Rg-MF2 species into the MF3+Rg (two-body dissociation) channel typically proceeds via a transition state involving F -Rg-M out-of-plane bending mode. The transition state barrier heights are 35.5, 62.7, 89.8, 22.0, 45.6, and 75.3kJ/mol for F -Ar-BF2, F -Kr-BF2, F -Xe-BF2, F -Ar-AlF2, F -Kr-AlF2, and F -Xe-AlF2 species, respectively. The calculated geometrical parameters and the energy values suggest that these species are metastable and may be prepared and characterized using low temperature matrix isolation techniques, and are possibly the next new candidates for gas phase or matrix experiments.

Accuracy Improvement of Neutron Nuclear Data on Minor Actinides

NASA Astrophysics Data System (ADS)

Harada, Hideo; Iwamoto, Osamu; Iwamoto, Nobuyuki; Kimura, Atsushi; Terada, Kazushi; Nakao, Taro; Nakamura, Shoji; Mizuyama, Kazuhito; Igashira, Masayuki; Katabuchi, Tatsuya; Sano, Tadafumi; Takahashi, Yoshiyuki; Takamiya, Koichi; Pyeon, Cheol Ho; Fukutani, Satoshi; Fujii, Toshiyuki; Hori, Jun-ichi; Yagi, Takahiro; Yashima, Hiroshi

2015-05-01

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.

Molecular dynamics simulations of the rotary motor F(0) under external electric fields across the membrane.

PubMed

Lin, Yang-Shan; Lin, Jung-Hsin; Chang, Chien-Cheng

2010-03-17

The membrane-bound component F(0), which is a major component of the F(0)F(1)-ATP synthase, works as a rotary motor and plays a central role in driving the F(1) component to transform chemiosmotic energy into ATP synthesis. We conducted molecular dynamics simulations of b(2)-free F(0) in a 1-palmitoyl-2-oleoyl-phosphatidylcholine lipid bilayer for tens of nanoseconds with two different protonation states of the cAsp-61 residue at the interface of the a-c complex in the absence of electric fields and under electric fields of +/-0.03 V/nm across the membrane. To our surprise, we observed that the upper half of the N-terminal helix of the c(1) subunit rotated about its axis clockwise by 30 degrees . An energetic analysis revealed that the electrostatic repulsion between this N-terminal helix and subunit c(12) was a major contributor to the observed rotation. A correlation map analysis indicated that the correlated motions of residues in the interface of the a-c complex were significantly reduced by external electric fields. The deuterium order parameter (S(CD)) profile calculated by averaging all the lipids in the F(0)-bound bilayer was not very different from that of the pure bilayer system, in agreement with recent (2)H solid-state NMR experiments. However, by delineating the lipid properties according to their vicinity to F(0), we found that the S(CD) profiles of different lipid shells were prominently different. Lipids close to F(0) formed a more ordered structure. Similarly, the lateral diffusion of lipids on the membrane surface also followed a shell-dependent behavior. The lipids in the proximity of F(0) exhibited very significantly reduced diffusional motion. The numerical value of S(CD) was anticorrelated with that of the diffusion coefficient, i.e., the more ordered lipid structures led to slower lipid diffusion. Our findings will help elucidate the dynamics of F(0) depending on the protonation state and electric field, and may also shed some light on the

Understanding Release from Actinide Targets -- Recent Results from RIB Development

NASA Astrophysics Data System (ADS)

Kronenberg, Andreas; Carter, H. K.; Spejewski, E. H.; Stracener, D. W.

2006-10-01

Development of ion beams of short-lived isotopes is crucial for modern nuclear structure and nuclear astrophysics. The Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory uses the ISOL (Isotope Separation Online) technique to provide radioactive ion beams. So far, uranium carbide has been used as a target to produce neutron-rich fission fragments. Thermodynamic calculations indicate the possibility of in-situ chemical side band formations of volatile species of refractory metals, such as V and Re. These elements release out of oxide targets after production in a nuclear reaction, and can occur only through in-situ formation of their volatile oxide. These have been confirmed experimentally. The results from recent, more detailed investigations of ThO2, UB4 and other actinide targets as well as conclusions from systematic studies will be presented. This research was sponsored by the NNSA under Stewardship Science Academic Alliance program through DOE Cooperative Agreement # DE-FC03-3NA00143.

Probing the 5 f electrons in Am-I by hybrid density functional theory

NASA Astrophysics Data System (ADS)

Atta-Fynn, Raymond; Ray, Asok K.

2009-11-01

The ground states of the actinides and their compounds continue to be matters of considerable controversies. Experimentally, Americium-I (Am-I) is a non-magnetic dhcp metal whereas theoretically an anti-ferromagnetic ground state is predicted. We show that hybrid density functional theory, which admixes a fraction, λ, of exact Hartree-Fock (HF) exchange with approximate DFT exchange, can correctly reproduce the ground state properties of Am. In particular, for λ=0.40, we obtain a non-magnetic ground state with equilibrium atomic volume, bulk modulus, 5 f electron population, and the density of electronic states all in good agreement with experimental data. We argue that the exact HF exchange corrects the overestimation of the approximate DFT exchange interaction.

ArF step-and-scan system with 0.75 NA for the 0.10μm node

NASA Astrophysics Data System (ADS)

Vleeming, Bert; Heskamp, Barbra; Bakker, Hans; Verstappen, Leon; Finders, Jo; Stoeten, Jan; Boerret, Rainer; Roempp, Oliver

2001-09-01

It is widely expected that 193 nm lithography will be the technology of choice for volume production of the 0.10 micrometer device generation. For this purpose the PAS5500/1100TM Step & Scan system, the second generation ArF tool, was developed. It is based on the PAS5500/900TM, the body of which has been adapted to fit the new 0.75 NA StarlithTM projection optics. This high NA enables mass manufacturing of devices following the 0.10 micrometer design rule. The system features a 10 W 2 kHz ArF laser and the AERIALTM II illuminator that can be equipped with a QUASARTM (multipole) option. In order to minimize wafer processing influences on overlay performance ATHENATM off- axis alignment with phase modulator is implemented. The usage of Reticle Blue Alignment will further improve overlay as well as increase the system stability. In this paper the PAS5500/1100TM system layout is discussed and the first imaging and overlay results are presented. Imaging performance is illustrated by SEM pictures of 0.10 micrometer dense lines, 0.15, 0.13 and 0.12 micrometer dense contact holes, 0.10 micrometer DRAM isolation patterns, image plane deviation and system distortion fingerprints. Alignment reproducibility and single machine overlay results demonstrate the overlay capability.

Prospective study of the clinical performance of three BACTEC media in a modern emergency department: Plus Aerobic/F, Plus Anaerobic/F, and Anaerobic Lytic/F.

PubMed

Rocchetti, Andrea; Di Matteo, Luigi; Bottino, Paolo; Foret, Benjamin; Gamalero, Elisa; Calabresi, Alessandra; Guido, Gianluca; Casagranda, Ivo

2016-11-01

The performance of 3 blood culture bottles (BACTEC Plus Aerobic/F, Plus Anaerobic/F, and Anaerobic Lytic/F) were analyzed with clinical specimens collected from 688 Emergency Department patients. A total of 270 strains belonging to 33 species were identified, with E. coli and S. aureus as the most frequently detected. Overall recovery rate (RR) of bacteria and yeast was equivalent in the Plus Aerobic/F vials (208 of 270 isolates; 77.0%) and Anaerobic Lytic/F vials (206 isolates; 76.3%) and significantly better than in the Plus Anaerobic/F vials (189 isolates; 70.0%). Median time to detection (TTD) was earliest with the Anaerobic Lytic/F vials (12.0h) compared with the Plus Aerobic/F (14.6h) and Plus Anaerobic/F vials (15.4h). Positivity rate (PR) was similar for Anaerobic Lytic/F vials (76.9%) and Plus Aerobic/F vials (76.5%), but better if compared with Plus Anaerobic/F vials (69.4%). The PR and TTD for the combination of Plus Aerobic/F with Anaerobic Lytic/F (94.5% and 12.3h, respectively) was significantly better than with Plus Aerobic/F with Plus Anaerobic/F (87.8% and 14.1h). Copyright © 2016 Elsevier B.V. All rights reserved.

Complexation of Nd(III) with tetraborate ion and its effect on actinide (III) solubility in WIPP brine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Borkowski, Marian; Richmann, Michael K; Reed, Donald T

2010-01-01

The potential importance of tetraborate complexation on lanthanide(III) and actinide(III) solubility is recognized in the literature but a systematic study of f-element complexation has not been performed. In neodymium solubility studies in WIPP brines, the carbonate complexation effect is not observed since tetraborate ions form a moderately strong complex with neodymium(III). The existence of these tetraborate complexes was established for low and high ionic strength solutions. Changes in neodymium(III) concentrations in undersaturation experiments were used to determine the neodymium with tetraborate stability constants as a function of NaCl ionic strength. As very low Nd(III) concentrations have to be measured, itmore » was necessary to use an extraction pre-concentration step combined with ICP-MS analysis to extend the detection limit by a factor of 50. The determined Nd(III) with borate stability constants at infinite dilution and 25 C are equal to log {beta}{sub 1} = 4.55 {+-} 0.06 using the SIT approach, equal to log {beta}{sub 1} = 4.99 {+-} 0.30 using the Pitzer approach, with an apparent log {beta}{sub 1} = 4.06 {+-} 0.15 (in molal units) at I = 5.6 m NaCl. Pitzer ion-interaction parameters for neodymium with tetraborate and SIT interaction coefficients were also determined and reported.« less

Synthesis, structure and bonding of actinide disulphide dications in the gas phase

DOE PAGES

Lucena, Ana F.; Bandeira, Nuno A. G.; Pereira, Claudia C. L.; ...

2017-01-01

Actinide disulphide dications, AnS 2 2+, were produced in the gas phase for An = Th and Np by reaction of An 2+ cations with the sulfur-atom donor COS, in a sequential abstraction process of two sulfur atoms, as examined by FTICR mass spectrometry. For An = Pu and Am, An 2+ ions were unreactive with COS and did not yield any sulphide species. High level multiconfigurational (CASPT2) calculations were performed to assess the structures and bonding of the new AnS 2 2+ species obtained for An = Th, Np, as well as for An = Pu to examine trendsmore » along the An series, and for An = U to compare with a previous experimental study and DFT computational scrutiny of US 2 2+. The CASPT2 results showed that, like in the case of uranium, the new AnS 2 2+ ions have ground states with triangular geometries, corresponding to the presence of a persulphide in the case of thorium that formally leads to a stable Th IV S 2 2+ species, while a supersulphide appears to be present in the case of U, Np and Pu, formally leading to a An IIIS 2 2+ species. Finally, the computations also revealed that linear thioactinyl structures are higher in energy, with a difference that increases fourfold upon moving from U to Pu, apparently indicating that it will be even more pronounced for Am.« less

Exploiting the Reactivity of Actinide Fluoride Bonds for the Synthesis of a New Class of Bis(azide) Uranium Complexes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erickson, Karla A.; Lichtscheidl, Alejandro G.; Monreal, Marisa Jennifer

The terminal actinide fluoride bonds in (C 5Me 5) 2ThF 2(py) (py = pyridine) and (C 5Me 5) 2UF 2(O=PR 3) (R = Me, Ph) react with two equivalents of Me 3SiN 3 in toluene to form the polymeric thorium bis(azide), [(C 5Me 5) 2Th(N 3)2] ∞, and a new class of monometallic uranium bis(azide) complexes, (C 5Me 5) 2U(N 3)2(O=PR 3), respectively. Full characterization of the novel complexes (C 5Me 5) 2ThF 2(py) and (C 5Me 5) 2UF 2(O=PR 3) are reported, including the solid-state structures of (C 5Me 5) 2ThF 2(py) and (C 5Me 5) 2U(N 3) 2(O=PPhmore » 3). Lastly, electronic absorption spectral data are also reported for (C 5Me 5) 2AnF 2(py) (An = Th, U) and (C 5Me 5) 2U(N 3) 2(O=PR 3) to confirm metal oxidation state and enable elucidation of the fluoride and azide ligand bonding in these complexes.« less

Exploiting the Reactivity of Actinide Fluoride Bonds for the Synthesis of a New Class of Bis(azide) Uranium Complexes

DOE PAGES

Erickson, Karla A.; Lichtscheidl, Alejandro G.; Monreal, Marisa Jennifer; ...

2017-11-04

The terminal actinide fluoride bonds in (C 5Me 5) 2ThF 2(py) (py = pyridine) and (C 5Me 5) 2UF 2(O=PR 3) (R = Me, Ph) react with two equivalents of Me 3SiN 3 in toluene to form the polymeric thorium bis(azide), [(C 5Me 5) 2Th(N 3)2] ∞, and a new class of monometallic uranium bis(azide) complexes, (C 5Me 5) 2U(N 3)2(O=PR 3), respectively. Full characterization of the novel complexes (C 5Me 5) 2ThF 2(py) and (C 5Me 5) 2UF 2(O=PR 3) are reported, including the solid-state structures of (C 5Me 5) 2ThF 2(py) and (C 5Me 5) 2U(N 3) 2(O=PPhmore » 3). Lastly, electronic absorption spectral data are also reported for (C 5Me 5) 2AnF 2(py) (An = Th, U) and (C 5Me 5) 2U(N 3) 2(O=PR 3) to confirm metal oxidation state and enable elucidation of the fluoride and azide ligand bonding in these complexes.« less

Aqueous and pyrochemical reprocessing of actinide fuels

NASA Astrophysics Data System (ADS)

Toth, L. Mac; Bond, Walter D.; Avens, Larry R.

1993-02-01

Processing of the nuclear fuel actinides has developed in two independent directions—aqueous processing and pyroprocessing. Similarities in the two processes, their goals, and restraints are indicated in brief parallel descriptions along with distinguishing advantages and areas of future development. It is suggested that from a technical viewpoint, the ultimate process might be a hybrid which incorporates the best steps of each process.

F1F0 ATP Synthase-Cyclophilin D Interaction Contributes to Diabetes-Induced Synaptic Dysfunction and Cognitive Decline.

PubMed

Yan, Shijun; Du, Fang; Wu, Long; Zhang, Zhihua; Zhong, Changjia; Yu, Qing; Wang, Yongfu; Lue, Lih-Fen; Walker, Douglas G; Douglas, Justin T; Yan, Shirley ShiDu

2016-11-01

Mitochondrial abnormalities are well known to cause cognitive decline. However, the underlying molecular basis of mitochondria-associated neuronal and synaptic dysfunction in the diabetic brain remains unclear. Here, using a mitochondrial single-channel patch clamp and cyclophilin D (CypD)-deficient mice (Ppif -/- ) with streptozotocin-induced diabetes, we observed an increase in the probability of Ca 2+ -induced mitochondrial permeability transition pore (mPTP) opening in brain mitochondria of diabetic mice, which was further confirmed by mitochondrial swelling and cytochrome c release induced by Ca 2+ overload. Diabetes-induced elevation of CypD triggers enhancement of F 1 F 0 ATP synthase-CypD interaction, which in turn leads to mPTP opening. Indeed, in patients with diabetes, brain cypD protein levels were increased. Notably, blockade of the F 1 F 0 ATP synthase-CypD interaction by CypD ablation protected against diabetes-induced mPTP opening, ATP synthesis deficits, oxidative stress, and mitochondria dysfunction. Furthermore, the absence of CypD alleviated deficits in synaptic plasticity, learning, and memory in diabetic mice. Thus, blockade of ATP synthase interaction with CypD provides a promising new target for therapeutic intervention in diabetic encephalopathy. © 2016 by the American Diabetes Association.

Pressure-induced phase transitions and correlation between structure and superconductivity in iron-based superconductor Ce(O(0.84)F(0.16))FeAs.

PubMed

Zhao, Jinggeng; Liu, Haozhe; Ehm, Lars; Dong, Dawei; Chen, Zhiqiang; Liu, Qingqing; Hu, Wanzheng; Wang, Nanlin; Jin, Changqing

2013-07-15

High-pressure angle-dispersive X-ray diffraction experiments on iron-based superconductor Ce(O(0.84)F(0.16))FeAs were performed up to 54.9 GPa at room temperature. A tetragonal to tetragonal isostructural phase transition starts at about 13.9 GPa, and a new high-pressure phase has been found above 33.8 GPa. At pressures above 19.9 GPa, Ce(O(0.84)F(0.16))FeAs completely transforms to a high-pressure tetragonal phase, which remains in the same tetragonal structure with a larger a-axis and smaller c-axis than those of the low-pressure tetragonal phase. The structure analysis shows a discontinuity in the pressure dependences of the Fe-As and Ce-(O, F) bond distances, as well as the As-Fe-As and Ce-(O, F)-Ce bond angles in the transition region, which correlates with the change in T(c) of this compound upon compression. The isostructural phase transition in Ce(O(0.84)F(0.16))FeAs leads to a drastic drop in the superconducting transition temperature T(c) and restricts the superconductivity at low temperature. For the 1111-type iron-based superconductors, the structure evolution and following superconductivity changes under compression are related to the radius of lanthanide cations in the charge reservoir layer.

Utilization of Minor Actinides as a Fuel Component for Ultra-Long Life Bhr Configurations: Designs, Advantages and Limitations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Pavel V. Tsvetkov

2009-05-20

This project assessed the advantages and limitations of using minor actinides as a fuel component to achieve ultra-long life Very High Temperature Reactor (VHTR) configurations. Researchers considered and compared the capabilities of pebble-bed and prismatic core designs with advanced actinide fuels to achieve ultra-long operation without refueling. Since both core designs permit flexibility in component configuration, fuel utilization, and fuel management, it is possible to improve fissile properties of minor actinides by neutron spectrum shifting through configuration adjustments. The project studied advanced actinide fuels, which could reduce the long-term radio-toxicity and heat load of high-level waste sent to a geologicmore » repository and enable recovery of the energy contained in spent fuel. The ultra-long core life autonomous approach may reduce the technical need for additional repositories and is capable to improve marketability of the Generation IV VHTR by allowing worldwide deployment, including remote regions and regions with limited industrial resources. Utilization of minor actinides in nuclear reactors facilitates developments of new fuel cycles towards sustainable nuclear energy scenarios.« less

{sup 75}As NMR study of the oriented pnictide superconducting compound NdFeAsO{sub 0.83}F{sub 0.17}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pahari, Bholanath

Magnetization and {sup 75}As nuclear magnetic resonance (NMR) measurements in the superconductor NdFeAsO{sub 0.83}F{sub 0.17} (T{sub C}~46 K) are performed in order to investigate the effect of the Nd 4f electrons in the superconducting property. The magnetization curve displays a Nd 4f moments generated Curie-Weiss signal in the field of 7 T. {sup 75}As NMR spectra in the oriented sample (H{sub 0}‖ab) are recorded at 7 T in the temperature range 10–300 K and temperature dependent {sup 75}As NMR shift, K{sub ab} has been obtained. The K{sub ab} curve shows a Curie-Weiss type contribution. The magnitude of hyperfine field, H{submore » hf} (4.4 kOe/μ{sub B}) estimated from the K{sub ab} vs χ plot indicates a non-negligible RKKY-type interaction between localized Nd 4f moments mediated by itinerant Fe 3d electrons.« less

a Chirped Pulse Fourier Transform Microwave Cp-Ftmw Spectrometer with Laser Ablation Source to Search for Actinide-Containing Molecules and Noble Metal Clusters

NASA Astrophysics Data System (ADS)

Marshall, Frank E.; Gillcrist, David Joseph; Persinger, Thomas D.; Moon, Nicole; Grubbs, G. S., II

2016-06-01

Microwave spectroscopic techniques have traditionally been part of the foundation of molecular structure and this conference. Instrumental developments by Brooks Pate and sourcing developments by Steve Cooke on these instruments have allowed for the dawning of a new era in modern microwave spectroscopic techniques. With these advances and the growth of powerful computational approaches, microwave spectroscopists can now search for molecules and/or cluster systems of actinide and noble metal-containing species with increasing certainty in molecular assignment even with the difficulties presented with spin-orbit coupling and relativistic effects. Spectrometer and ablation design will be presented along with any preliminary results on actinide-containing molecules or noble metal clusters or interactions. G. G. Brown, B. C. Dian, K. O. Douglass, S. M. Geyer, S. T. Shipman, B. H. Pate, Rev. Sci. Instrum. 79 (2008) 053103-1 - 053103-13 G. S. Grubbs II, C. T. Dewberry, K. C. Etchison, K. E. Kerr, S. A. Cooke, Rev. Sci. Instrum. 78 (2007) 096106-1 - 096106-3

Separation of Californium from other Actinides

DOEpatents

Mailen, J C; Ferris, L M

1973-09-25

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

An Approach for Validating Actinide and Fission Product Burnup Credit Criticality Safety Analyses: Criticality (k eff) Predictions

DOE PAGES

Scaglione, John M.; Mueller, Don E.; Wagner, John C.

2014-12-01

One of the most important remaining challenges associated with expanded implementation of burnup credit in the United States is the validation of depletion and criticality calculations used in the safety evaluation—in particular, the availability and use of applicable measured data to support validation, especially for fission products (FPs). Applicants and regulatory reviewers have been constrained by both a scarcity of data and a lack of clear technical basis or approach for use of the data. In this study, this paper describes a validation approach for commercial spent nuclear fuel (SNF) criticality safety (k eff) evaluations based on best-available data andmore » methods and applies the approach for representative SNF storage and transport configurations/conditions to demonstrate its usage and applicability, as well as to provide reference bias results. The criticality validation approach utilizes not only available laboratory critical experiment (LCE) data from the International Handbook of Evaluated Criticality Safety Benchmark Experiments and the French Haut Taux de Combustion program to support validation of the principal actinides but also calculated sensitivities, nuclear data uncertainties, and limited available FP LCE data to predict and verify individual biases for relevant minor actinides and FPs. The results demonstrate that (a) sufficient critical experiment data exist to adequately validate k eff calculations via conventional validation approaches for the primary actinides, (b) sensitivity-based critical experiment selection is more appropriate for generating accurate application model bias and uncertainty, and (c) calculated sensitivities and nuclear data uncertainties can be used for generating conservative estimates of bias for minor actinides and FPs. Results based on the SCALE 6.1 and the ENDF/B-VII.0 cross-section libraries indicate that a conservative estimate of the bias for the minor actinides and FPs is 1.5% of their worth within the

Combination of amino acids reduces pigmentation in B16F0 melanoma cells.

PubMed

Ishikawa, Masago; Kawase, Ichiro; Ishii, Fumio

2007-04-01

Amino acids, the building blocks of proteins, play significant roles in numerous physiological events in mammals. As the effects of amino acids on melanogenesis have yet to be demonstrated, the present study was conducted to identify whether amino acids, in particular alanine, glycine, isoleucine and leucine, influence melanogenesis in B16F0 melanoma cells. Glycine and L-isoleucine, but not D-isoleucine, reduced melanogenesis in a concentration-dependent manner without any morphological changes in B16F0 melanoma cells. L-Alanine and L-leucine, but not D-alanine and D-leucine, also reduced melanogenesis without any morphological changes in B16F0 melanoma cells. However these amino acids did not show a concentration-dependency. Combination of L-alanine and the other amino acids, particularly 4 amino acids combination, had an additive effect on the inhibition of melanogenesis compared with single treatment of L-alanine. None of the amino acids affected the activity of tyrosinase, a key enzyme in melanogenesis. These results suggest that L-alanine, glycine, L-isoleucine and L-leucine, but not the D-form amino acids, have a hypopigmenting effect in B16F0 melanoma cells, and that these effects are not due to the inhibition of tyrosinase activity. Combination of these 4 amino acids had the additive effect on hypopigmentation that was as similar as that of kojic acid.

Passivation effect of Cl, F and H atoms on CuIn0.75Ga0.25Se2 (1 1 2) surface

NASA Astrophysics Data System (ADS)

Qi, Rong-fei; Wang, Zhao-hui; Tang, Fu-ling; Agbonkina, Itohan C.; Xue, Hong-tao; Si, Feng-juan; Ma, Sheng-ling; Wang, Xiao-ka

2018-06-01

Using the first-principles calculations within the density functional-theory (DFT) framework, we theoretically investigated the surface reconstruction, surface states near the Fermi level and their passivation on CuIn0.75Ga0.25Se2 (1 1 2) (CIGS) surface by chlorine, fluorine and hydrogen. Surface reconstruction appears on CIG-terminated CIGS (1 1 2) surface and it is a self-passivation. For the locations of Cl, F and H atoms adsorbing on Se-terminated CIGS (1 1 2) surface, four high symmetry adsorption sites: top sites, bridge sites, hexagonal close-packed (hcp) sites and faced centered cubic (fcc) sites were studied respectively. With the coverage of 0.5 monolayer (ML), Cl, F and H adatoms energetically occupy the top sites on the CIGS (112) surface. The corresponding adsorption energies were -2.20 eV, -3.29 eV, -2.60 eV, respectively. The bond length and electronic properties were analyzed. We found that the surface state density near the Fermi level was markedly diminished for 0.5 ML Cl, F and H adsorption on Se-terminated CIGS (1 1 2) surface at top sites. It was also found that H can more efficiently passivate the surface state density than Cl and F atoms, and the effect of adsorption of Cl atoms is better than that of F.

Effects of age on F0-discrimination and intonation perception in simulated electric and electro-acoustic hearing

PubMed Central

Souza, Pamela; Arehart, Kathryn; Miller, Christi Wise; Muralimanohar, Ramesh Kumar

2010-01-01

Objectives Recent research suggests that older listeners may have difficulty processing information related to the fundamental frequency (F0) of voiced speech. In this study, the focus was on the mechanisms that may underlie this reduced ability. We examined whether increased age resulted in decreased ability to perceive F0 using fine structure cues provided by the harmonic structure of voiced speech sounds and/or cues provided by high-rate envelope fluctuations (periodicity). Design Younger listeners with normal hearing and older listeners with normal to near-normal hearing completed two tasks of F0 perception. In the first task (steady-state F0), the fundamental frequency difference limen (F0DL) was measured adaptively for synthetic vowel stimuli. In the second task (time-varying F0), listeners relied on variations in F0 to judge intonation of synthetic diphthongs. For both tasks, three processing conditions were created: 8-channel vocoding which preserved periodicity cues to F0; a simulated electroacoustic stimulation condition, which consisted of high-frequency vocoder processing combined with a low-pass filtered portion, and offered both periodicity and fine-structure cues to F0; and an unprocessed condition. Results F0 difference limens for steady-state vowel sounds and the ability to discern rising and falling intonations were significantly worse in the older subjects compared to the younger subjects. For both older and younger listeners scores were lowest for the vocoded condition, and there was no difference in scores between the unprocessed and electroacoustic simulation conditions. Conclusions Older listeners had difficulty using periodicity cues to obtain information related to talker fundamental frequency. However, performance was improved by combining periodicity cues with (low-frequency) acoustic information, and that strategy should be considered in individuals who are appropriate candidates for such processing. For cochlear implant candidates, that

Potential involvement of F0F1-ATP(synth)ase and reactive oxygen species in apoptosis induction by the antineoplastic agent erucylphosphohomocholine in glioblastoma cell lines : a mechanism for induction of apoptosis via the 18 kDa mitochondrial translocator protein.

PubMed

Veenman, Leo; Alten, Julia; Linnemannstöns, Karen; Shandalov, Yulia; Zeno, Sivan; Lakomek, Max; Gavish, Moshe; Kugler, Wilfried

2010-07-01

Erucylphosphohomocholine (ErPC3, Erufosine) was reported previously to induce apoptosis in otherwise highly apoptosis-resistant malignant glioma cell lines while sparing their non-tumorigenic counterparts. We also previously found that the mitochondrial 18 kDa Translocator Protein (TSPO) is required for apoptosis induction by ErPC3. These previous studies also suggested involvement of reactive oxygen species (ROS). In the present study we further investigated the potential involvement of ROS generation, the participation of the mitochondrial respiration chain, and the role of the mitochondrial F(O)F(1)-ATP(synth)ase in the pro-apoptotic effects of ErPC3 on U87MG and U118MG human glioblastoma cell lines. For this purpose, cells were treated with the ROS chelator butylated hydroxyanisole (BHA), the mitochondrial respiration chain inhibitors rotenone, antimycin A, myxothiazol, and the uncoupler CCCP. Also oligomycin and piceatannol were studied as inhibitors of the F(O) and F(1) subunits of the mitochondrial F(O)F(1)-ATP(synth)ase, respectively. BHA was able to attenuate apoptosis induction by ErPC3, including mitochondrial ROS generation as determined with cardiolipin oxidation, as well as collapse of the mitochondrial membrane potential (Deltapsi(m)). Similarly, we found that oligomycin attenuated apoptosis and collapse of the Deltapsi(m), normally induced by ErPC3, including the accompanying reductions in cellular ATP levels. Other inhibitors of the mitochondrial respiration chain, as well as piceatannol, did not show such effects. Consequently, our findings strongly point to a role for the F(O) subunit of the mitochondrial F(O)F(1)-ATP(synth)ase in ErPC3-induced apoptosis and dissipation of Deltapsi(m) as well as ROS generation by ErPC3 and TSPO.

Phase Behavior and Equations of State of the Actinide Oxides

NASA Astrophysics Data System (ADS)

Chidester, B.; Pardo, O. S.; Panero, W. R.; Fischer, R. A.; Thompson, E. C.; Heinz, D. L.; Prescher, C.; Prakapenka, V. B.; Campbell, A.

2017-12-01

The distribution of the long-lived heat-producing actinide elements U and Th in the deep Earth has important implications for the dynamics of the mantle and possibly the energy budget of Earth's core. The low shear velocities of the Large Low-Shear Velocity Provinces (LLSVPs) on the core-mantle boundary suggests that these regions are at least partially molten and may contain concentrated amounts of the radioactive elements, as well as other large cations such as the rare Earth elements. As such, by exploring the phase behavior of actinide-bearing minerals at extreme conditions, some insight into the mineralogy, formation, and geochemical and geodynamical effects of these regions can be gained. We have performed in situ high-pressure, high-temperature synchrotron X-ray diffraction experiments and calculations on two actinide oxide materials, UO2 and ThO2, to determine their phase behavior at the extreme conditions of the lower mantle. Experiments on ThO2 reached 60 GPa and 2500 K, and experiments on UO2 reached 95 GPa and 2500 K. We find that ThO2 exists in the fluorite-type structure to 20 GPa at high temperatures, at which point it transforms to the high-pressure cotunnite-type structure and remains thus up to 60 GPa. At room temperature, an anomalous expansion of the fluorite structure is observed prior to the transition, and may signal anion sub-lattice disorder. Similarly, UO2 exists in the fluorite-type structure at ambient conditions and up to 28 GPa at high temperatures. Above these pressures, we have observed a previously unidentified phase of UO2 with a tetragonal structure as the lower-temperature phase and the cotunnite-type phase at higher temperatures. Above 78 GPa, UO2 undergoes another transition or possible dissociation into two separate oxide phases. These phase diagrams suggest that the actinides could exist as oxides in solid solution with other analogous phases (e.g. ZrO2) in the cotunnite-type structure throughout much of Earth's lower mantle.

$$B^{0}_{s}$$ Lifetime Measurement in the CP-odd Decay Channel $$B^{0}_{s} \\to J/\\psi\\mbox{ }f_{0}(980)$$

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abazov, V. M.

Here, the lifetime of the B s 0 meson is measured in the decay channel B s 0→J/ψπ +π - with 880 ≤ M π+π- ≤ 1080 MeV/c 2, which is mainly a CP-odd state and dominated by the f 0(980) resonance. In 10.4 fb -1 of data collected with the D0 detector in Run II of the Tevatron, the lifetime of the B s 0 meson is measured to be τ(B s 0) = 1.70 ± 0.14(stat) ± 0.05(syst) ps. Neglecting CP violation in B s 0/more » $$\\bar{B}$$ 0 s mixing, the measurement can be translated into the width of the heavy mass eigenstate of the B s 0, Γ H = 0.59 ± 0.05(stat) ± 0.02(syst) ps -1.« less

$$B^{0}_{s}$$ Lifetime Measurement in the CP-odd Decay Channel $$B^{0}_{s} \\to J/\\psi\\mbox{ }f_{0}(980)$$

DOE PAGES

Abazov, V. M.

2016-07-06

Here, the lifetime of the B s 0 meson is measured in the decay channel B s 0→J/ψπ +π - with 880 ≤ M π+π- ≤ 1080 MeV/c 2, which is mainly a CP-odd state and dominated by the f 0(980) resonance. In 10.4 fb -1 of data collected with the D0 detector in Run II of the Tevatron, the lifetime of the B s 0 meson is measured to be τ(B s 0) = 1.70 ± 0.14(stat) ± 0.05(syst) ps. Neglecting CP violation in B s 0/more » $$\\bar{B}$$ 0 s mixing, the measurement can be translated into the width of the heavy mass eigenstate of the B s 0, Γ H = 0.59 ± 0.05(stat) ± 0.02(syst) ps -1.« less

B s 0 lifetime measurement in the C P -odd decay channel B s 0 → J / ψ f 0 ( 980 )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abazov, V. M.; Abbott, B.; Acharya, B. S.

2016-07-01

Here, the lifetime of the Bmore » $$0\\atop{S}$$ meson is measured in the decay channel B$$0\\atop{S}$$→J/ψπ +π - with 880 ≤ M π+π- ≤ 1080 MeV/c 2, which is mainly a CP-odd state and dominated by the f 0(980) resonance. In 10.4 fb -1 of data collected with the D0 detector in Run II of the Tevatron, the lifetime of the B$$0\\atop{S}$$ meson is measured to be τ(B$$0\\atop{S}$$) = 1.70 ± 0.14(stat) ± 0.05(syst) ps. Neglecting CP violation in B$$0\\atop{S}/$$\\bar{B}$ 0 s mixing, the measurement can be translated into the width of the heavy mass eigenstate of the B$$0\\atop{S}$$, Γ H = 0.59 ± 0.05(stat) ± 0.02(syst) ps -1.« less

Biochemical basis of 4-hydroxyanisole induced cell toxicity towards B16-F0 melanoma cells.

PubMed

Moridani, Majid Y

2006-11-18

In the current work we investigated for the first time the biochemical basis of 4-hydroxyanisole (4-HA) induced toxicity in B16-F0 melanoma cells. It was found that dicoumarol, a diaphorase inhibitor, and 1-bromoheptane, a GSH depleting agent, increased 4-HA induced toxicity towards B16-F0 cells whereas dithiothreitol, a thiol containing agent, and ascorbic acid (AA), a reducing agent, largely prevented 4-HA toxicity. TEMPOL and pyrogallol, free radical scavengers, did not significantly prevent 4-HA toxicity towards B16-F0 cells. GSH>AA>NADH prevented the o-quinone formation when 4-HA was metabolized by tyrosinase/O(2). 4-HA metabolism by horseradish peroxidase/H(2)O(2) was prevented more effectively by AA than NADH>GSH. We therefore concluded that quinone formation was the major pathway for 4-HA induced toxicity in B16-F0 melanoma cells whereas free radical formation played a negligible role in the 4-HA induced toxicity.

Advancing Understanding of the +4 Metal Extractant Thenoyltrifluoroacetonate (TTA-); Synthesis and Structure of MIVTTA4 (MIV = Zr, Hf, Ce, Th, U, Np, Pu) and MIII(TTA)4- (MIII = Ce, Nd, Sm, Yb).

PubMed

Cary, Samantha K; Livshits, Maksim; Cross, Justin N; Ferrier, Maryline G; Mocko, Veronika; Stein, Benjamin W; Kozimor, Stosh A; Scott, Brian L; Rack, Jeffrey J

2018-04-02

Thenoyltrifluoroacetone (HTTA)-based extractions represent popular methods for separating microscopic amounts of transuranic actinides (i.e., Np and Pu) from macroscopic actinide matrixes (e.g. bulk uranium). It is well-established that this procedure enables +4 actinides to be selectively removed from +3, + 5, and +6 f-elements. However, even highly skilled and well-trained researchers find this process complicated and (at times) unpredictable. It is difficult to improve the HTTA extraction-or find alternatives-because little is understood about why this separation works. Even the identities of the extracted species are unknown. In addressing this knowledge gap, we report here advances in fundamental understanding of the HTTA-based extraction. This effort included comparatively evaluating HTTA complexation with +4 and +3 metals (M IV = Zr, Hf, Ce, Th, U, Np, and Pu vs M III = Ce, Nd, Sm, and Yb). We observed +4 metals formed neutral complexes of the general formula M IV (TTA) 4 . Meanwhile, +3 metals formed anionic M III (TTA) 4 - species. Characterization of these M(TTA) 4 x- ( x = 0, 1) compounds by UV-vis-NIR, IR, 1 H and 19 F NMR, single-crystal X-ray diffraction, and X-ray absorption spectroscopy (both near-edge and extended fine structure) was critical for determining that Np IV (TTA) 4 and Pu IV (TTA) 4 were the primary species extracted by HTTA. Furthermore, this information lays the foundation to begin developing and understanding of why the HTTA extraction works so well. The data suggest that the solubility differences between M IV (TTA) 4 and M III (TTA) 4 - are likely a major contributor to the selectivity of HTTA extractions for +4 cations over +3 metals. Moreover, these results will enable future studies focused on explaining HTTA extractions preference for +4 cations, which increases from Np IV to Pu IV , Hf IV , and Zr IV .

Separation of actinides from lanthanides

DOEpatents

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

1988-03-31

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

Separation of actinides from lanthanides

DOEpatents

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

1989-01-01

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

Conjugates of magnetic nanoparticle-actinide specific chelator for radioactive waste separation.

PubMed

Kaur, Maninder; Zhang, Huijin; Martin, Leigh; Todd, Terry; Qiang, You

2013-01-01

A novel nanotechnology for the separation of radioactive waste that uses magnetic nanoparticles (MNPs) conjugated with actinide specific chelators (MNP-Che) is reviewed with a focus on design and process development. The MNP-Che separation process is an effective way of separating heat generating minor actinides (Np, Am, Cm) from spent nuclear fuel solution to reduce the radiological hazard. It utilizes coated MNPs to selectively adsorb the contaminants onto their surfaces, after which the loaded particles are collected using a magnetic field. The MNP-Che conjugates can be recycled by stripping contaminates into a separate, smaller volume of solution, and then become the final waste form for disposal after reusing number of times. Due to the highly selective chelators, this remediation method could be both simple and versatile while allowing the valuable actinides to be recovered and recycled. Key issues standing in the way of large-scale application are stability of the conjugates and their dispersion in solution to maintain their unique properties, especially large surface area, of MNPs. With substantial research progress made on MNPs and their surface functionalization, as well as development of environmentally benign chelators, this method could become very flexible and cost-effective for recycling used fuel. Finally, the development of this nanotechnology is summarized and its future direction is discussed.

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

NASA Astrophysics Data System (ADS)

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.

Kinetics of ATP hydrolysis catalyzed by isolated TF1 and reconstituted TF0F1 ATPase.

PubMed

Rögner, M; Gräber, P

1986-09-01

The rate of ATP hydrolysis catalyzed by isolated TF1 and reconstituted TF0F1 was measured as a function of the ATP concentration in the presence of inhibitors [ADP, Pi and 3'-O-(1-naphthoyl)ATP]. ATP hydrolysis can be described by Michaelis-Menten kinetics with Km(TF1) = 390 microM and Km (TF0F1) = 180 microM. The inhibition constants are for ADP Ki(TF1) = 20 microM and Ki(TF0F1) = 100 microM, for 3'-O-(1-naphthoyl)ATP Ki(TF1) = 150 microM and Ki(TF0F1) = 3 microM, and for Pi Ki(TF1) = 60 mM. From these results it is concluded that upon binding of TF0 to TF1 the mechanism of ATP hydrolysis catalyzed by TF1 is not changed qualitatively; however, the kinetic constants differ quantitatively.

Column Experiments for Radionuclide Adsorption Studies of the Culebra Dolomite: Retardation Parameter Estimation for Non-Eluted Actinide Species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, G.O.; Lucero, D.A.; Perkins, W.G.

formation brines. No significant changes in transport behavior were observed for changes in brine. Hydraulic characteristics (i.e., apparent porosity and apparent dispersion coefficient) for the cores were obtained via experiments using conservative tracer `Na. Elution experiments carried out over periods of a few days with tracers `*U and %Np indicated that these tracers were weakly retarded as indicated by delayed elution of these species. Elution experiments with tracers `%, 24'Pu, and 24'Ani were performed, but no elution of any of these species was observed in any flow experiment to date, including experiments of up to two years duration. However, B-Core was subjected to tomographic analysis from which a retardation factor can be inferred for%. Moreover, the fact of non- elution for 24*Pu and 24'Am after more than two years brine flow through C-Core can be coupled with the minimum detectable activity for each of these species to compute minimum retardation factors in C-Core. The retardation factors for all three species can then be coupled with the apparent hydraulic characteristics to estimate an apparent minimum solutionhock distribution coefficient, &, for each actinide. The specific radionuclide isotopes used in these experiments were chosen to facilitate analysis. Even though these isotopes are not necessarily the same as those that are most important to WIPP performance, they are isotopes of the same elements, and . their chemical and transport properties are therefore identical to those of isotopes in the WIPP inventory. The retardation factors and & values deduced from experimental results strongly support the contention that sorption in the Culebra provides an effective barrier to release of Th, Pu, and Am during the regulatory period.« less

Lanthanide/Actinide Opacities

NASA Astrophysics Data System (ADS)

Hungerford, Aimee; Fontes, Christopher J.

2018-06-01

Gravitational wave observations benefit from accompanying electromagnetic signals in order to accurately determine the sky positions of the sources. The ejecta of neutron star mergers are expected to produce such electromagnetic transients, called macronovae (e.g. the recent and unprecedented observation of GW170817). Characteristics of the ejecta include large velocity gradients and the presence of heavy r-process elements, which pose significant challenges to the accurate calculation of radiative opacities and radiation transport. Opacities include a dense forest of bound-bound features arising from near-neutral lanthanide and actinide elements. Here we present an overview of current theoretical opacity determinations that are used by neutron star merger light curve modelers. We will touch on atomic physics and plasma modeling codes that are used to generate these opacities, as well as the limited body of laboratory experiments that may serve as points of validation for these complex atomic physics calculations.

Method for digesting spent ion exchange resins and recovering actinides therefrom using microwave radiation

DOEpatents

Maxwell, III, Sherrod L.; Nichols, Sheldon T.

1999-01-01

The present invention relates to methods for digesting diphosphonic acid substituted cation exchange resins that have become loaded with actinides, rare earth metals, or heavy metals, in a way that allows for downstream chromatographic analysis of the adsorbed species without damage to or inadequate elution from the downstream chromatographic resins. The methods of the present invention involve contacting the loaded diphosphonic acid resin with concentrated oxidizing acid in a closed vessel, and irradiating this mixture with microwave radiation. This efficiently increases the temperature of the mixture to a level suitable for digestion of the resin without the use of dehydrating acids that can damage downstream analytical resins. In order to ensure more complete digestion, the irradiated mixture can be mixed with hydrogen peroxide or other oxidant, and reirradiated with microwave radiation.

Vaporisation of candidate nuclear fuels and targets for transmutation of minor actinides

NASA Astrophysics Data System (ADS)

Gotcu-Freis, P.; Hiernaut, J.-P.; Colle, J.-Y.; Nästrén, C.; Carretero, A. Fernandez; Konings, R. J. M.

2011-04-01

The thermal stability and high temperature behaviour of candidate fuels and targets for transmutation of minor actinides has been investigated. Zirconia-based solid solution, MgO-based CERCER and molybdenum-based CERMET fuels containing Am and/or Pu in various concentrations were heated up to 2700 K in a Knudsen cell coupled with a quadrupole mass spectrometer, to measure their vapour pressure and vapour composition. The results reveal that the vaporisation of the actinides from the samples is not only determined by the thermodynamics of the system but is also related to the dynamic evolution of multi-component mixtures with complex composition or microstructure.

Remarkably High Stability of Late Actinide Dioxide Cations: Extending Chemistry to Pentavalent Berkelium and Californium.

PubMed

Dau, Phuong D; Vasiliu, Monica; Peterson, Kirk A; Dixon, David A; Gibson, John K

2017-12-06

Actinyl chemistry is extended beyond Cm to BkO 2 + and CfO 2 + through transfer of an O atom from NO 2 to BkO + or CfO + , establishing a surprisingly high lower limit of 73 kcal mol -1 for the dissociation energies, D[O-(BkO + )] and D[O-(CfO + )]. CCSD(T) computations are in accord with the observed reactions, and characterize the newly observed dioxide ions as linear pentavalent actinyls; these being the first Bk and Cf species with oxidation states above IV. Computations of actinide dioxide cations AnO 2 + for An=Pa to Lr reveal an unexpected minimum for D[O-(CmO + )]. For CmO 2 + , and AnO 2 + beyond EsO 2 + , the most stable structure has side-on bonded η 2 -(O 2 ), as An III peroxides for An=Cm and Lr, and as An II superoxides for An=Fm, Md, and No. It is predicted that the most stable structure of EsO 2 + is linear [O=Es V =O] + , einsteinyl, and that FmO 2 + and MdO 2 + , like CmO 2 + , also have actinyl(V) structures as local energy minima. The results expand actinide oxidation state chemistry, the realm of the distinctive actinyl moiety, and the non-periodic character towards the end of the periodic table. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid method to determine actinides and 89/90Sr in limestone and marble samples

DOE PAGES

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

2016-04-12

A new method for the determination of actinides and radiostrontium in limestone and marble samples has been developed that utilizes a rapid sodium hydroxide fusion to digest the sample. Following rapid pre-concentration steps to remove sample matrix interferences, the actinides and 89/90Sr are separated using extraction chromatographic resins and measured radiometrically. The advantages of sodium hydroxide fusion versus other fusion techniques will be discussed. Lastly, this approach has a sample preparation time for limestone and marble samples of <4 hours.

A 0.4-2.3 GHz broadband power amplifier extended continuous class-F design technology

NASA Astrophysics Data System (ADS)

Chen, Peng; He, Songbai

2015-08-01

A 0.4-2.3 GHz broadband power amplifier (PA) extended continuous class-F design technology is proposed in this paper. Traditional continuous class-F PA performs in high-efficiency only in one octave bandwidth. With the increasing development of wireless communication, the PA is in demand to cover the mainstream communication standards' working frequencies from 0.4 GHz to 2.2 GHz. In order to achieve this objective, the bandwidths of class-F and continuous class-F PA are analysed and discussed by Fourier series. Also, two criteria, which could reduce the continuous class-F PA's implementation complexity, are presented and explained to investigate the overlapping area of the transistor's current and voltage waveforms. The proposed PA design technology is based on the continuous class-F design method and divides the bandwidth into two parts: the first part covers the bandwidth from 1.3 GHz to 2.3 GHz, where the impedances are designed by the continuous class-F method; the other part covers the bandwidth from 0.4 GHz to 1.3 GHz, where the impedance to guarantee PA to be in high-efficiency over this bandwidth is selected and controlled. The improved particle swarm optimisation is employed for realising the multi-impedances of output and input network. A PA based on a commercial 10 W GaN high electron mobility transistor is designed and fabricated to verify the proposed design method. The simulation and measurement results show that the proposed PA could deliver 40-76% power added efficiency and more than 11 dB power gain with more than 40 dBm output power over the bandwidth from 0.4-2.3 GHz.

Detection of the actinides and cesium from environmental samples

NASA Astrophysics Data System (ADS)

Snow, Mathew Spencer

Detection of the actinides and cesium in the environment is important for a variety of applications ranging from environmental remediation to safeguards and nuclear forensics. The utilization of multiple different elemental concentrations and isotopic ratios together can significantly improve the ability to attribute contamination to a unique source term and/or generation process; however, the utilization of multiple elemental "signatures" together from environmental samples requires knowledge of the impact of chemical fractionation for various elements under a variety of environmental conditions (including predominantly aqueous versus arid conditions). The research reported in this dissertation focuses on three major areas: 1. Improving the understanding of actinide-mineral interactions at ultra-low concentrations. Chapter 2 reports a batch sorption and modeling study of Np(V) sorption to the mineral goethite from attomolar to micromolar concentrations. 2. Improving the detection capabilities for Thermal Ionization Mass Spectrometry (TIMS) analyses of ultra-trace cesium from environmental samples. Chapter 4 reports a new method which significantly improves the chemical yields, purification, sample processing time, and ultimately, the detection limits for TIMS analyses of femtogram quantities of cesium from a variety of environmental sample matrices. 3. Demonstrating how actinide and cesium concentrations and isotopic ratios from environmental samples can be utilized together to determine a wealth of information including environmental transport mechanisms (e.g. aqueous versus arid transport) and information on the processes which generated the original material. Chapters1, 3 and 5 demonstrate these principles using Pu, Am, Np, and Cs concentrations and isotopic ratios from contaminated soils taken near the Subsurface Disposal Area (SDA) of Idaho National Laboratory (INL) (a low level radioactive waste disposal site in southeastern Idaho).

Theoretical Prediction of Am(III)/Eu(III) Selectivity to Aid the Design of Actinide-Lanthanide Separation Agents

DOE PAGES

Bryantsev, Vyacheslav S.; Hay, Benjamin P.

2015-03-20

Selective extraction of minor actinides from lanthanides is a critical step in the reduction of radiotoxicity of spent nuclear fuels. However, the design of suitable ligands for separating chemically similar 4f- and 5f-block trivalent metal ions poses a significant challenge. Furthermore, first-principles calculations should play an important role in the design of new separation agents, but their ability to predict metal ion selectivity has not been systematically evaluated. We examine the ability of several density functional theory methods to predict selectivity of Am(III) and Eu(III) with oxygen, mixed oxygen–nitrogen, and sulfur donor ligands. The results establish a computational method capablemore » of predicting the correct order of selectivities obtained from liquid–liquid extraction and aqueous phase complexation studies. To allow reasonably accurate predictions, it was critical to employ sufficiently flexible basis sets and provide proper account of solvation effects. The approach is utilized to estimate the selectivity of novel amide-functionalized diazine and 1,2,3-triazole ligands.« less

Enhancing BWR proliferation resistance fuel with minor actinides

NASA Astrophysics Data System (ADS)

Chang, Gray S.

2009-03-01

To reduce spent fuel for storage and enhance the proliferation resistance for the intermediate-term, there are two major approaches (a) increase the discharged spent fuel burnup in the advanced light water reactor- LWR (Gen-III Plus), which not only can reduce the spent fuel for storage, but also increase the 238Pu isotopes ratio to enhance the proliferation resistance, and (b) use of transuranic nuclides ( 237Np and 241Am) in the high burnup fuel, which can drastically increase the proliferation resistance isotope ratio of 238Pu/Pu. For future advanced nuclear systems, 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. As a result, 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. In the study, a typical boiling water reactor (BWR) fuel unit lattice cell model with UO 2 fuel pins will be used to investigate the effectiveness of minor actinide reduction approach (MARA) for enhancing proliferation resistance and improving the fuel cycle performance in the intermediate-term goal for future nuclear energy systems. To account for the water coolant density variation from the bottom (0.76 g/cm 3) to the top (0.35 g/cm 3) of the core, the axial coolant channel and fuel pin were divided to 24 nodes. The MA transmutation characteristics at different elevations were compared and their impact on neutronics criticality discussed. The concept of MARA, which involves the use of transuranic nuclides ( 237Np and/or 241Am), 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

Unconventional Superconductivity in the BiS_{2}-Based Layered Superconductor NdO_{0.71}F_{0.29}BiS_{2}.

PubMed

Ota, Yuichi; Okazaki, Kozo; Yamamoto, Haruyoshi Q; Yamamoto, Takashi; Watanabe, Shuntaro; Chen, Chuangtian; Nagao, Masanori; Watauchi, Satoshi; Tanaka, Isao; Takano, Yoshihiko; Shin, Shik

2017-04-21

We investigate the superconducting-gap anisotropy in one of the recently discovered BiS_{2}-based superconductors, NdO_{0.71}F_{0.29}BiS_{2} (T_{c}∼5  K), using laser-based angle-resolved photoemission spectroscopy. Whereas the previously discovered high-T_{c} superconductors such as copper oxides and iron-based superconductors, which are believed to have unconventional superconducting mechanisms, have 3d electrons in their conduction bands, the conduction band of BiS_{2}-based superconductors mainly consists of Bi 6p electrons, and, hence, the conventional superconducting mechanism might be expected. Contrary to this expectation, we observe a strongly anisotropic superconducting gap. This result strongly suggests that the pairing mechanism for NdO_{0.71}F_{0.29}BiS_{2} is an unconventional one and we attribute the observed anisotropy to competitive or cooperative multiple paring interactions.

Extraction Selectivity of a Quaternary Alkylammonium Salt for Trivalent Actinides over Trivalent Lanthanides: Does Extractant Aggregation Play a Role?

DOE PAGES

Knight, Andrew W.; Chiarizia, Renato; Soderholm, L.

2017-05-10

In this paper, the extraction behavior of a quaternary alkylammonium salt extractant was investigated for its selectivity for trivalent actinides over trivalent lanthanides in nitrate and thiocyanate media. The selectivity was evaluated by solvent extraction experiments through radiochemical analysis of 241Am and 152/154Eu. Solvent extraction distribution and slope-analysis experiments were performed with americium(III) and europium(III) with respect to the ligand (nitrate and thiocyanate), extractant, and metal (europium only) concentrations. Further evaluation of the equilibrium expression that governs the extraction process indicated the appropriate use of the saturation method for estimation of the aggregation state of quaternary ammonium extractants in themore » organic phase. From the saturation method, we observed an average aggregation number of 5.4 ± 0.8 and 8.5 ± 0.9 monomers/aggregate for nitrate and thiocyanate, respectively. Through a side-by-side comparison of the nitrate and thiocyanate forms, we discuss the potential role of the aggregation in the increased selectivity for trivalent actinides over trivalent lanthanides in thiocyanate media.« less

Extraction Selectivity of a Quaternary Alkylammonium Salt for Trivalent Actinides over Trivalent Lanthanides: Does Extractant Aggregation Play a Role?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knight, Andrew W.; Chiarizia, Renato; Soderholm, L.

In this paper, the extraction behavior of a quaternary alkylammonium salt extractant was investigated for its selectivity for trivalent actinides over trivalent lanthanides in nitrate and thiocyanate media. The selectivity was evaluated by solvent extraction experiments through radiochemical analysis of 241Am and 152/154Eu. Solvent extraction distribution and slope-analysis experiments were performed with americium(III) and europium(III) with respect to the ligand (nitrate and thiocyanate), extractant, and metal (europium only) concentrations. Further evaluation of the equilibrium expression that governs the extraction process indicated the appropriate use of the saturation method for estimation of the aggregation state of quaternary ammonium extractants in themore » organic phase. From the saturation method, we observed an average aggregation number of 5.4 ± 0.8 and 8.5 ± 0.9 monomers/aggregate for nitrate and thiocyanate, respectively. Through a side-by-side comparison of the nitrate and thiocyanate forms, we discuss the potential role of the aggregation in the increased selectivity for trivalent actinides over trivalent lanthanides in thiocyanate media.« less

Organic and Aqueous Redox Speciation of Cu(III) Periodate Oxidized Transuranium Actinides

DOE Office of Scientific and Technical Information (OSTI.GOV)

McCann, Kevin; Sinkov, Sergey I.; Lumetta, Gregg J.

A hexavalent group actinide separation process could streamline used nuclear fuel recycle and waste management. The limiting factor to such a process compatible with current fuel dissolution practices is obtaining and maintaining hexavalent Am, in molar nitric acid due to the high reduction potential of the Am(VI)/Am(III) couple (1.68 V vs SCE). Two strong oxidants, sodium bismuthate and Cu(III) periodate, have demonstrated quantitative oxidation of Am under molar acid conditions and better than 50% recovery by diamyl amylphosphonate (DAAP) is possible under these same conditions. This work considers the use of Cu(III) periodate to oxidize Np(V) to Np(VI) and Pu(IV)more » to Pu(VI) and recover these elements by extraction with DAAP. A metal:oxidant ratio of 1:1.2 and 1:3 was necessary to quantitatively oxidize Np(V) and Pu(IV), respectively, to the hexavalent state. Extraction of hexavalent Np, Pu, and Am by 1 M DAAP in n-dodecane was measured using UV-Vis [Pu(VI), Am (VI)] and NIR [Np(VI)]. Distribution values of Am(VI) were found to match previous tracer level studies. The organic phase spectra of Np, Pu, and Am are presented and molar absorptivities are calculated for characteristic peaks. Hexavalent Pu was found to be stable in the organic phase while Np(VI) showed some reduction to Np(V) and Am was present as Am(III), Am(V), and Am(VI) species in aqueous and organic phases during the extraction experiments. These results demonstrate, for the first time, the ability to recover macroscopic amounts of americium that would be present during fuel reprocessing and are the first characterization of Am organic phase oxidation state speciation relevant to a hexavalent group actinide separation process under acidic conditions.« less

Actinide management with commercial fast reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohki, Shigeo

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.

Pressure-induced phase transition in La 1 – x Sm x O 0.5 F 0.5 BiS 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Y.; Yazici, D.; White, B. D.

Electrical resistivity measurements on La 1–xSm xO 0.5F 0.5BiS 2 (x = 0.1, 0.3, 0.6, 0.8) have been performed under applied pressures up to 2.6 GPa from 2 K to room temperature. The superconducting transition temperature T c of each sample significantly increases at a Sm-concentration dependent pressure P t, indicating a pressure-induced phase transition from a low-T c to a high-T c phase. At ambient pressure, T c increases dramatically from 2.8 K at x = 0.1 to 5.4 K at x = 0.8; however, the T c values at P > P t decrease slightly with x andmore » P t shifts to higher pressures with Sm substitution. In the normal state, semiconducting-like behavior is suppressed and metallic conduction is induced with increasing pressure in all of the samples. Furthermore, these results suggest that the pressure dependence of T c for the BiS 2-based superconductors is related to the lattice parameters at ambient pressure and enable us to estimate the evolution of T c for SmO 0.5F 0.5BiS 2 under pressure.« less

Pressure-induced phase transition in La 1 – x Sm x O 0.5 F 0.5 BiS 2

DOE PAGES

Fang, Y.; Yazici, D.; White, B. D.; ...

2015-09-15

Electrical resistivity measurements on La 1–xSm xO 0.5F 0.5BiS 2 (x = 0.1, 0.3, 0.6, 0.8) have been performed under applied pressures up to 2.6 GPa from 2 K to room temperature. The superconducting transition temperature T c of each sample significantly increases at a Sm-concentration dependent pressure P t, indicating a pressure-induced phase transition from a low-T c to a high-T c phase. At ambient pressure, T c increases dramatically from 2.8 K at x = 0.1 to 5.4 K at x = 0.8; however, the T c values at P > P t decrease slightly with x andmore » P t shifts to higher pressures with Sm substitution. In the normal state, semiconducting-like behavior is suppressed and metallic conduction is induced with increasing pressure in all of the samples. Furthermore, these results suggest that the pressure dependence of T c for the BiS 2-based superconductors is related to the lattice parameters at ambient pressure and enable us to estimate the evolution of T c for SmO 0.5F 0.5BiS 2 under pressure.« less

Comparison of actinide production in traveling wave and pressurized water reactors

DOE Office of Scientific and Technical Information (OSTI.GOV)

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

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

Analysis and optimization of minor actinides transmutation blankets with regards to neutron and gamma sources

NASA Astrophysics Data System (ADS)

Kooymana, Timothée; Buiron, Laurent; Rimpault, Gérald

2017-09-01

Heterogeneous loading of minor actinides in radial blankets is a potential solution to implement minor actinides transmutation in fast reactors. However, to compensate for the lower flux level experienced by the blankets, the fraction of minor actinides to be loaded in the blankets must be increased to maintain acceptable performances. This severely increases the decay heat and neutron source of the blanket assemblies, both before and after irradiation, by more than an order of magnitude in the case of neutron source for instance. We propose here to implement an optimization methodology of the blankets design with regards to various parameters such as the local spectrum or the mass to be loaded, with the objective of minimizing the final neutron source of the spent assembly while maximizing the transmutation performances of the blankets. In a first stage, an analysis of the various contributors to long and short term neutron and gamma source is carried out while in a second stage, relevant estimators are designed for use in the effective optimization process, which is done in the last step. A comparison with core calculations is finally done for completeness and validation purposes. It is found that the use of a moderated spectrum in the blankets can be beneficial in terms of final neutron and gamma source without impacting minor actinides transmutation performances compared to more energetic spectrum that could be achieved using metallic fuel for instance. It is also confirmed that, if possible, the use of hydrides as moderating material in the blankets is a promising option to limit the total minor actinides inventory in the fuel cycle. If not, it appears that focus should be put upon an increased residence time for the blankets rather than an increase in the acceptable neutron source for handling and reprocessing.

Cultivar-Based Introgression Mapping Reveals Wild Species-Derived Pm-0, the Major Powdery Mildew Resistance Locus in Squash.

PubMed

Holdsworth, William L; LaPlant, Kyle E; Bell, Duane C; Jahn, Molly M; Mazourek, Michael

2016-01-01

Powdery mildew is a major fungal disease on squash and pumpkin (Cucurbita spp.) in the US and throughout the world. Genetic resistance to the disease is not known to occur naturally within Cucurbita pepo and only infrequently in Cucurbita moschata, but has been achieved in both species through the introgression of a major resistance gene from the wild species Cucurbita okeechobeensis subsp. martinezii. At present, this gene, Pm-0, is used extensively in breeding, and is found in nearly all powdery mildew-resistant C. pepo and C. moschata commercial cultivars. In this study, we mapped C. okeechobeensis subsp. martinezii-derived single nucleotide polymorphism (SNP) alleles in a set of taxonomically and morphologically diverse and resistant C. pepo and C. moschata cultivars bred at Cornell University that, by common possession of Pm-0, form a shared-trait introgression panel. High marker density was achieved using genotyping-by-sequencing, which yielded over 50,000 de novo SNP markers in each of the three Cucurbita species genotyped. A single 516.4 kb wild-derived introgression was present in all of the resistant cultivars and absent in a diverse set of heirlooms that predated the Pm-0 introgression. The contribution of this interval to powdery mildew resistance was confirmed by association mapping in a C. pepo cultivar panel that included the Cornell lines, heirlooms, and 68 additional C. pepo cultivars and with an independent F2 population derived from C. okeechobeensis subsp. martinezii x C. moschata. The interval was refined to a final candidate interval of 76.4 kb and CAPS markers were developed inside this interval to facilitate marker-assisted selection.

Cultivar-Based Introgression Mapping Reveals Wild Species-Derived Pm-0, the Major Powdery Mildew Resistance Locus in Squash

PubMed Central

Holdsworth, William L.; LaPlant, Kyle E.; Bell, Duane C.; Jahn, Molly M.; Mazourek, Michael

2016-01-01

Powdery mildew is a major fungal disease on squash and pumpkin (Cucurbita spp.) in the US and throughout the world. Genetic resistance to the disease is not known to occur naturally within Cucurbita pepo and only infrequently in Cucurbita moschata, but has been achieved in both species through the introgression of a major resistance gene from the wild species Cucurbita okeechobeensis subsp. martinezii. At present, this gene, Pm-0, is used extensively in breeding, and is found in nearly all powdery mildew-resistant C. pepo and C. moschata commercial cultivars. In this study, we mapped C. okeechobeensis subsp. martinezii-derived single nucleotide polymorphism (SNP) alleles in a set of taxonomically and morphologically diverse and resistant C. pepo and C. moschata cultivars bred at Cornell University that, by common possession of Pm-0, form a shared-trait introgression panel. High marker density was achieved using genotyping-by-sequencing, which yielded over 50,000 de novo SNP markers in each of the three Cucurbita species genotyped. A single 516.4 kb wild-derived introgression was present in all of the resistant cultivars and absent in a diverse set of heirlooms that predated the Pm-0 introgression. The contribution of this interval to powdery mildew resistance was confirmed by association mapping in a C. pepo cultivar panel that included the Cornell lines, heirlooms, and 68 additional C. pepo cultivars and with an independent F2 population derived from C. okeechobeensis subsp. martinezii x C. moschata. The interval was refined to a final candidate interval of 76.4 kb and CAPS markers were developed inside this interval to facilitate marker-assisted selection. PMID:27936008

Data appendix: F-number=1.0 EMR with a flexible back electrode

NASA Technical Reports Server (NTRS)

Mihora, D. J.

1984-01-01

A 12.5 micron Tedlar low f-number electrostatic membrane reflector was tested. The antenna reflector was designed to achieve a spherical reflector surface with a focal length to diameter ratio f(sub n) of one and a potential accuracy of 1.0 over its 4.88 m diameter. The configuration required the cutting and joining of twelve pie-shaped panels to form the reflector surface. Electrostatic forces are used to tension this preformed membrane reflector. The test data is spare-only three sets of measurements were taken due to lack of funds.

Lanthanide and actinide chemistry at high C/O ratios in the solar nebula

NASA Technical Reports Server (NTRS)

Lodders, Katharina; Fegley, Bruce, Jr.

1993-01-01

Chemical equilibrium calculations were performed to study the condensation chemistry of the REE and actinides under the highly reducing conditions which are necessary for the formation of the enstatite chondrites. Our calculations confirm that the REE and actinides condensed into oldhamite (CaS), the major REE and actinide host phase in enstatite chondrites, at a carbon-oxygen (C/O) ratio not less than 1 in an otherwise solar gas. Five basic types of REE abundance patterns, several of which are analogous to REE abundance patterns observed in the Ca, Al-rich inclusions in carbonaceous chondrites, are predicted to occur in meteoritic oldhamites. All of the reported REE patterns in oldhamites in enstatite chondrites can be interpreted in terms of our condensation calculations. The observed patterns fall into three of the five predicted categories. The reported Th and U enrichments and ratios in meteoritic oldhamites are also consistent with predictions of the condensation calculations. Pure REE sulfides are predicted to condense in the 10 exp -6 to 10 exp -9 bar range and may be found in enstatite chondrites if they formed in this pressure range.

Metal-metal bonds in f-element chemistry.

PubMed

Liddle, Stephen T; Mills, David P

2009-08-07

The molecular chemistry of the f-elements is traditionally dominated by the use of carbon-, nitrogen-, oxygen-, or halide-ligands. However, the use of metal-based fragments as ligands is underdeveloped, which contrasts to the fields of d- and p-block metal-metal complexes that have developed extensively over the last fifty years. This perspective outlines the development of compounds, which possess polarised covalent or donor-acceptor f-element-metal bonds. For this review, the f-element is defined as (i) a group 3 or lanthanide metal: scandium, yttrium, lanthanum to lutetium, or (ii) an actinide metal: thorium, or uranium, and the metal is defined as a d-block transition metal, or a group 13 (aluminium or gallium), a group 14 (silicon, germanium, or tin), or a group 15 (antimony, or bismuth) metal. Silicon, germanium, and antimony are traditionally classified as metalloids but they are included for completeness. This review focuses mainly on complexes that have been structurally authenticated by single-crystal X-ray diffraction studies and we highlight novel aspects of their syntheses, properties, and reactivities.

Supercritical fluid extraction and separation of uranium from other actinides.

PubMed

Quach, Donna L; Mincher, Bruce J; Wai, Chien M

2014-06-15

The feasibility of separating U from nitric acid solutions of mixed actinides using tri-n-butylphosphate (TBP)-modified supercritical fluid carbon dioxide (sc-CO2) was investigated. The actinides U, Np, Pu, and Am were extracted into sc-CO2 modified with TBP from a range of nitric acid concentrations, in the absence of, or in the presence of, a number of traditional reducing and/or complexing agents to demonstrate the separation of these metals from U under sc-CO2 conditions. The separation of U from Pu using sc-CO2 was successful at nitric acid concentrations of less than 3M in the presence of acetohydroxamic acid (AHA) or oxalic acid (OA) to mitigate Pu extraction, and the separation of U from Np was successful at nitric acid concentrations of less than 1M in the presence of AHA, OA, or sodium nitrite to mitigate Np extraction. Americium was not well extracted under any condition studied. Copyright © 2014 Elsevier B.V. All rights reserved.

F0 Characteristics of Newsreaders on Varied Emotional Texts in Tamil Language.

PubMed

Gunasekaran, Nishanthi; Boominathan, Prakash; Seethapathy, Jayashree

2017-12-26

The objective of this study was to profile speaking F 0 and its variations in newsreaders on varied emotional texts. This study has a prospective, case-control study design. Fifteen professional newsreaders and 15 non-newsreaders were the participants. The participants read the news bulletin that conveyed different emotions (shock, neutral, happy, and sad) in a habitual and "newsreading" voice. Speaking fundamental frequency (SFF) and F 0 variations were extracted from 1620 tokens using Praat software (version 5.2.32) on the opening lines, headlines, news stories, and closing lines of each news item. Paired t test, independent t test, and Friedman test were used for statistical analysis. Both male and female newsreaders had significantly (P ≤ 0.05) higher SFFs and standard deviations (SDs) of SFF in newsreading voice than speaking voice. Female non-newsreaders demonstrated significantly higher SFF and SD of SFF in newsreading voice, whereas no significant differences were noticed in the frequency parameters for male non-newsreaders. No significant difference was noted in the frequency parameters of speaking and newsreading voice between male newsreaders and male non-newsreaders. A significant difference in the SD of SFF was noticed between female newsreaders and female non-newsreaders in newsreading voice. Female newsreaders had a higher frequency range in both speaking voice and newsreading voice when compared with non-newsreaders. F 0 characteristics and frequency range determine the amount of frequency changes exercised by newsreaders while reading bulletins. This information is highly pedagogic for training voices in this profession. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Determination of actinides in urine and fecal samples

DOEpatents

McKibbin, Terry T.

1993-01-01

A method of determining the radioactivity of specific actinides that are carried in urine or fecal sample material is disclosed. The samples are ashed in a muffle furnace, dissolved in an acid, and then treated in a series of steps of reduction, oxidation, dissolution, and precipitation, including a unique step of passing a solution through a chloride form anion exchange resin for separation of uranium and plutonium from americium.

Determination of actinides in urine and fecal samples

DOEpatents

McKibbin, T.T.

1993-03-02

A method of determining the radioactivity of specific actinides that are carried in urine or fecal sample material is disclosed. The samples are ashed in a muffle furnace, dissolved in an acid, and then treated in a series of steps of reduction, oxidation, dissolution, and precipitation, including a unique step of passing a solution through a chloride form anion exchange resin for separation of uranium and plutonium from americium.

In-Depth Lipidomic Analysis of Molecular Species of Triacylglycerides, Diacylglycerides, Glycerophospholipids, and Sphingolipids of Buttermilk by GC-MS/FID, HPLC-ELSD, and UPLC-QToF-MS

PubMed Central

Castro-Gómez, Pilar; Montero, Olimpio; Fontecha, Javier

2017-01-01

Buttermilk, a byproduct of butter manufacturing, has gained considerable attention due to its high concentration of polar lipids as phospho- and sphingolipids from the milk fat globule membrane (MFGM). These polar lipids (PLs) are essential components of all cellular membranes and exert a variety of indispensable metabolic, neurological, and intracellular signaling processes. Despite its importance, there are few research studies that report a comprehensive characterization of the lipid molecular species of MFGM that could contribute to a better understanding of their putative healthful activities. In this study, procedures such as pressurized liquid extraction of polar and nonpolar lipids and their fractionation by flash chromatography have been carried out. The obtained fractions were submitted to an exhaustive characterization from a lipidomic point of view. The characterization includes new data about the identification and quantification of triacylglycerides (TAG), diacylglycerides (DAG), and phospho- and sphingolipids using different chromatographic techniques. The fatty acid profile was comparable to that of the milk fat but with a highly diverse composition of fatty acids. Molecular species have also been determined by using ultra-high performance liquid chromatography/quadruple-time-of-flight mass spectrometry (UPLC/QToF-MS). The TAG (16:0/16:0/6:0) and TAG (16:0/16:0/8:0) were the predominant saturated TAG species and TAG (14:0/18:1/16:0) and TAG (16:0/16:0/18:1) presented the highest content of monounsaturated TAG species. Furthermore; over 30 molecular species of phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), and phosphatidylinositol (PI) could be identified within PL, with PC (16:0/18:1) being the most abundant species. Whereas C16:0 was found to be the preferred FA in TAGs, it was C18:1 in PLs. Several ganglioside species have also been characterized with d18:1 ceramide moiety and secondary acyl chains ranging from C

RAPID DETERMINATION OF ACTINIDES IN URINE BY INDUCTIVELY-COUPLED PLASMA MASS SPECTROMETRY AND ALPHA SPECTROMETRY: A HYBRID APPROACH

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maxwell, S.; Jones, V.

2009-05-27

A new rapid separation method that allows separation and preconcentration of actinides in urine samples was developed for the measurement of longer lived actinides by inductively coupled plasma mass spectrometry (ICP-MS) and short-lived actinides by alpha spectrometry; a hybrid approach. This method uses stacked extraction chromatography cartridges and vacuum box technology to facilitate rapid separations. Preconcentration, if required, is performed using a streamlined calcium phosphate precipitation. Similar technology has been applied to separate actinides prior to measurement by alpha spectrometry, but this new method has been developed with elution reagents now compatible with ICP-MS as well. Purified solutions are splitmore » between ICP-MS and alpha spectrometry so that long- and short-lived actinide isotopes can be measured successfully. The method allows for simultaneous extraction of 24 samples (including QC samples) in less than 3 h. Simultaneous sample preparation can offer significant time savings over sequential sample preparation. For example, sequential sample preparation of 24 samples taking just 15 min each requires 6 h to complete. The simplicity and speed of this new method makes it attractive for radiological emergency response. If preconcentration is applied, the method is applicable to larger sample aliquots for occupational exposures as well. The chemical recoveries are typically greater than 90%, in contrast to other reported methods using flow injection separation techniques for urine samples where plutonium yields were 70-80%. This method allows measurement of both long-lived and short-lived actinide isotopes. 239Pu, 242Pu, 237Np, 243Am, 234U, 235U and 238U were measured by ICP-MS, while 236Pu, 238Pu, 239Pu, 241Am, 243Am and 244Cm were measured by alpha spectrometry. The method can also be adapted so that the separation of uranium isotopes for assay is not required, if uranium assay by direct dilution of the urine sample is preferred

Development of Metallic Fuels for Actinide Transmutation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hayes, Steven Lowe; Fielding, Randall Sidney; Benson, Michael Timothy

Research and development activities on metallic fuels are focused on their potential use for actinide transmutation in future sodium fast reactors. As part of this application, there is also a need for a near zero-loss fabrication process and a desire to demonstrate a multifold increase in burnup potential. The incorporation of Am and Np into the traditional U-20Pu-10Zr metallic fuel alloy was demonstrated in the US during the Integral Fast Reactor Program of the 1980’s and early 1990’s. However, the conventional counter gravity injection casting method performed under vacuum, previously used to fabricate these metallic fuel alloys, was not optimizedmore » for mitigating loss of the volatile Am constituent in the casting charge; as a result, approximately 40% of the Am casting charge failed to be incorporated into the as-cast fuel alloys. Fabrication development efforts of the past few years have pursued an optimized bottom-pour casting method to increase utilization of the melted charge to near 100%, and a differential pressure casting approach, performed under an argon overpressure, has been demonstrated to result in essentially no loss of Am due to volatilization during fabrication. In short, a path toward zero-loss fabrication of metallic fuels including minor actinides has been shown to be feasible. Irradiation testing of advanced metallic fuel alloys in the Advanced Test Reactor (ATR) has been underway since 2003. Testing in the ATR is performed inside of cadmium-shrouded positions to remove >99% of the thermal flux incident on the test fuels, resulting in an epi-thermal driven fuel test that is free from gross flux depression and producing an essentially prototypic radial temperature profile inside the fuel rodlets. To date, three irradiation test series (AFC-1,2,3) have been completed. Over 20 different metallic fuel alloys have been tested to burnups as high as 30% with constituent compositions of Pu up to 30%, Am up to 12%, Np up to 10%, and Zr

Compendium 0f Dental Residents’ Research Projects and Literature Reviews

DTIC Science & Technology

1989-05-01

slow digestion to isolate chondrocytes by incubation at 370C in Ham’s F-12 with 0.1% collagenase for 24 h. Trypan-blue dye exclusion assay was used to...characteristics of matrix vesicle proteolipids (MVP). The MV were prepared from the growth cartilages of broiler chick epiphyses (All et al, 1970). Specific

Sociological effects on vocal aging: Age related F0 effects in two languages

NASA Astrophysics Data System (ADS)

Nagao, Kyoko

2005-04-01

Listeners can estimate the age of a speaker fairly accurately from their speech (Ptacek and Sander, 1966). It is generally considered that this perception is based on physiologically determined aspects of the speech. However, the degree to which it is due to conventional sociolinguistic aspects of speech is unknown. The current study examines the degree to which fundamental frequency (F0) changes due to advanced aging across two language groups of speakers. It also examines the degree to which the speakers associate these changes with aging in a voice disguising task. Thirty native speakers each of English and Japanese, taken from three age groups, read a target phrase embedded in a carrier sentence in their native language. Each speaker also read the sentence pretending to be 20-years younger or 20-years older than their own age. Preliminary analysis of eighteen Japanese speakers indicates that the mean and maximum F0 values increase when the speakers pretended to be younger than when they pretended to be older. Some previous studies on age perception, however, suggested that F0 has minor effects on listeners' age estimation. The acoustic results will also be discussed in conjunction with the results of the listeners' age estimation of the speakers.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

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-vis spectroscopy

Sub-barrier quasifission in heavy element formation reactions with deformed actinide target nuclei

NASA Astrophysics Data System (ADS)

Hinde, D. J.; Jeung, D. Y.; Prasad, E.; Wakhle, A.; Dasgupta, M.; Evers, M.; Luong, D. H.; du Rietz, R.; Simenel, C.; Simpson, E. C.; Williams, E.

2018-02-01

Background: The formation of superheavy elements (SHEs) by fusion of two massive nuclei is severely inhibited by the competing quasifission process. Low excitation energies favor SHE survival against fusion-fission competition. In "cold" fusion with spherical target nuclei near 208Pb, SHE yields are largest at beam energies significantly below the average capture barrier. In "hot" fusion with statically deformed actinide nuclei, this is not the case. Here the elongated deformation-aligned configurations in sub-barrier capture reactions inhibits fusion (formation of a compact compound nucleus), instead favoring rapid reseparation through quasifission. Purpose: To determine the probabilities of fast and slow quasifission in reactions with prolate statically deformed actinide nuclei, through measurement and quantitative analysis of the dependence of quasifission characteristics at beam energies spanning the average capture barrier energy. Methods: The Australian National University Heavy Ion Accelerator Facility and CUBE fission spectrometer have been used to measure fission and quasifission mass and angle distributions for reactions with projectiles from C to S, bombarding Th and U target nuclei. Results: Mass-asymmetric quasifission occurring on a fast time scale, associated with collisions with the tips of the prolate actinide nuclei, shows a rapid increase in probability with increasing projectile charge, the transition being centered around projectile atomic number ZP=14 . For mass-symmetric fission events, deviations of angular anisotropies from expectations for fusion fission, indicating a component of slower quasifission, suggest a similar transition, but centered around ZP˜8 . Conclusions: Collisions with the tips of statically deformed prolate actinide nuclei show evidence for two distinct quasifission processes of different time scales. Their probabilities both increase rapidly with the projectile charge. The probability of fusion can be severely

Multidimensionally constrained relativistic mean-field study of triple-humped barriers in actinides

NASA Astrophysics Data System (ADS)

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

2015-01-01

Background: Potential energy surfaces (PES's) of actinide nuclei are characterized by a two-humped barrier structure. At large deformations beyond the second barrier, the occurrence of a third barrier was predicted by macroscopic-microscopic model calculations in the 1970s, but contradictory results were later reported by a number of studies that used different methods. Purpose: Triple-humped barriers in actinide nuclei are investigated in the framework of covariant density functional theory (CDFT). Methods: Calculations are performed using the multidimensionally constrained relativistic mean field (MDC-RMF) model, with the nonlinear point-coupling functional PC-PK1 and the density-dependent meson exchange functional DD-ME2 in the particle-hole channel. Pairing correlations are treated in the BCS approximation with a separable pairing force of finite range. Results: Two-dimensional PES's of 226,228,230,232Th and 232,235,236,238U are mapped and the third minima on these surfaces are located. Then one-dimensional potential energy curves along the fission path are analyzed in detail and the energies of the second barrier, the third minimum, and the third barrier are determined. The functional DD-ME2 predicts the occurrence of a third barrier in all Th nuclei and 238U . The third minima in 230 ,232Th are very shallow, whereas those in 226 ,228Th and 238U are quite prominent. With the functional PC-PK1 a third barrier is found only in 226 ,228 ,230Th . Single-nucleon levels around the Fermi surface are analyzed in 226Th, and it is found that the formation of the third minimum is mainly due to the Z =90 proton energy gap at β20≈1.5 and β30≈0.7 . Conclusions: The possible occurrence of a third barrier on the PES's of actinide nuclei depends on the effective interaction used in multidimensional CDFT calculations. More pronounced minima are predicted by the DD-ME2 functional, as compared to the functional PC-PK1. The depth of the third well in Th isotopes decreases

Multi-podant diglycolamides and room temperature ionic liquid impregnated resins: An excellent combination for extraction chromatography of actinides.

PubMed

Gujar, R B; Ansari, S A; Verboom, W; Mohapatra, P K

2016-05-27

Extraction chromatography resins, prepared by impregnating two multi-podant diglycolamide ligands, viz. diglycolamide-functionalized calix[4]arene (C4DGA) and tripodal diglycolamide (T-DGA) dissolved in the room temperature ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide (RTIL: C4mimTf2N) on Chromosorb-W (an inert solid support), gave excellent results for the removal of trivalent actinides from acidic waste solutions. Distribution coefficient measurements on several metal ions showed selective sorption of Am(III) over hexavalent uranyl ions and other fission product elements such as strontium and cesium. The sorbed metal ions could be efficiently desorbed with a complexing solution containing guanidine carbonate and EDTA buffer. The sorption of Am(III) on both resins followed pseudo-second order rate kinetics with rate constants of 1.37×10(-6) and 6.88×10(-7)g/cpmmin for T-DGA and C4DGA resins, respectively. The metal sorption on both resins indicated the Langmuir monolayer chemisorption phenomenon with Eu(III) sorption capacities of 4.83±0.21 and 0.52±0.05mg per g of T-DGA and C4DGA resins, respectively. The results of column studies show that these resins are of interest for a possible application for the recovery of hazardous trivalent actinides from dilute aqueous solutions. Copyright © 2016 Elsevier B.V. All rights reserved.

The Colletotrichum acutatum species complex

PubMed Central

Damm, U.; Cannon, P.F.; Woudenberg, J.H.C.; Crous, P.W.

2012-01-01

Colletotrichum acutatum is known as an important anthracnose pathogen of a wide range of host plants worldwide. Numerous studies have reported subgroups within the C. acutatum species complex. Multilocus molecular phylogenetic analysis (ITS, ACT, TUB2, CHS-1, GAPDH, HIS3) of 331 strains previously identified as C. acutatum and other related taxa, including strains from numerous hosts with wide geographic distributions, confirmed the molecular groups previously recognised and identified a series of novel taxa. Thirty-one species are accepted, of which 21 have not previously been recognised. Colletotrichum orchidophilum clusters basal to the C. acutatum species complex. There is a high phenotypic diversity within this complex, and some of the species appear to have preferences to specific hosts or geographical regions. Others appear to be plurivorous and are present in multiple regions. In this study, only C. salicis and C. rhombiforme formed sexual morphs in culture, although sexual morphs have been described from other taxa (especially as laboratory crosses), and there is evidence of hybridisation between different species. One species with similar morphology to C. acutatum but not belonging to this species complex was also described here as new, namely C. pseudoacutatum. Taxonomic novelties: New combinations - Colletotrichum limetticola (R.E. Clausen) Damm, P.F. Cannon & Crous, C. lupini (Bondar) Damm, P.F. Cannon & Crous, C. salicis (Fuckel) Damm, P.F. Cannon & Crous. New species - C. acerbum Damm, P.F. Cannon & Crous, C. australe Damm, P.F. Cannon & Crous, C. brisbanense Damm, P.F. Cannon & Crous, C. cosmi Damm, P.F. Cannon & Crous, C. costaricense Damm, P.F. Cannon & Crous, C. cuscutae Damm, P.F. Cannon & Crous, C. guajavae Damm, P.F. Cannon & Crous, C. indonesiense Damm, P.F. Cannon & Crous, C. johnstonii Damm, P.F. Cannon & Crous, C. kinghornii Damm, P.F. Cannon & Crous, C. laticiphilum Damm, P.F. Cannon & Crous, C. melonis Damm, P.F. Cannon & Crous, C

46 CFR 154.615 - Design temperature below 0 °C (32 °F) and down to −55 °C (−67 °F).

Code of Federal Regulations, 2010 CFR

2010-10-01

... (CONTINUED) CERTAIN BULK DANGEROUS CARGOES SAFETY STANDARDS FOR SELF-PROPELLED VESSELS CARRYING BULK... tanks and secondary barriers for a design temperature below 0 °C (32 °F) and down to −55 °C (−67 °F...

Variation in Phytochemical Composition Reveals Distinct Divergence of Aloe vera (L.) Burm.f. From Other Aloe Species: Rationale Behind Selective Preference of Aloe vera in Nutritional and Therapeutic Use

PubMed Central

Dey, Priyankar; Dutta, Somit; Chowdhury, Anurag; Das, Abhaya Prasad; Chaudhuri, Tapas Kumar

2017-01-01

In the present study, we have phytochemically characterized 5 different abundant Aloe species, including Aloe vera (L.) Burm.f., using silylation followed by Gas Chromatography-Mass Spectrometry technique and compared the data using multivariate statistical analysis. The results demonstrated clear distinction of the overall phytochemical profile of A vera, highlighted by its divergent spatial arrangement in the component plot. Lowest correlation of the phytochemical profiles were found between A vera and A aristata Haw. (−0.626), whereas highest correlation resided between A aristata and A aspera Haw. (0.899). Among the individual phytochemicals, palmitic acid was identified in highest abundance cumulatively, and carboxylic acids were the most predominant phytochemical species in all the Aloe species. Compared to A vera, linear correlation analysis revealed highest and lowest correlation with A aspera (R 2 = 0.9162) and A aristata (R 2 = 0.6745), respectively. Therefore, A vera demonstrated distinct spatial allocation, reflecting its greater phytochemical variability. PMID:29228808

Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kenneth L. Nash

2009-09-22

Implementation of a closed loop nuclear fuel cycle requires the utilization of Pu-containing MOX fuels with the important side effect of increased production of the transplutonium actinides, most importantly isotopes of Am and Cm. Because the presence of these isotopes significantly impacts the long-term radiotoxicity of high level waste, it is important that effective methods for their isolation and/or transmutation be developed. Furthermore, since transmutation is most efficiently done in the absence of lanthanide fission products (high yield species with large thermal neutron absorption cross sections) it is important to have efficient procedures for the mutual separation of Am andmore » Cm from the lanthanides. The chemistries of these elements are nearly identical, differing only in the slightly stronger strength of interaction of trivalent actinides with ligand donor atoms softer than O (N, Cl-, S). Research being conducted around the world has led to the development of new reagents and processes with considerable potential for this task. However, pilot scale testing of these reagents and processes has demonstrated the susceptibility of the new classes of reagents to radiolytic and hydrolytic degradation. In this project, separations of trivalent actinides from fission product lanthanides have been investigated in studies of 1) the extraction and chemical stability properties of a class of soft-donor extractants that are adapted from water-soluble analogs, 2) the application of water soluble soft-donor complexing agents in tandem with conventional extractant molecules emphasizing fundamental studies of the TALSPEAK Process. This research was conducted principally in radiochemistry laboratories at Washington State University. Collaborators at the Radiological Processing Laboratory (RPL) at the Pacific Northwest National Laboratory (PNNL) have contributed their unique facilities and capabilities, and have supported student internships at PNNL to broaden their

Complete recovery of actinides from UREX-like raffinates using a combination of hard and soft donor ligands. II. soft donor structure variation

DOE PAGES

Zalupski, Peter R.; Klaehn, John R.; Peterman, Dean R.

2015-07-30

The feasibility of simultaneous separation of uranium, neptunium, plutonium, americium, and curium from a simulated dissolved used fuel simulant adjusted to 1.0 M nitric acid is investigated using a mixture of the soft donor bis(bis-3,5-trifluoromethyl)phenyl) dithiophosphinic acid (“0”) and the hard donor synergist trioctylphosphine oxide (TOPO) dissolved in toluene. The results reported in this work are compared to our recent demonstration of a complete actinide recovery from a simulated dissolved fuel solution using a synergistic combination of bis(o-trifluoromethylphenyl)dithiophosphinic acid (“1”) and TOPO dissolved in either toluene or trifluoromethylphenyl sulfone. While the extraction efficiency of americium was enhanced for the liquid-liquidmore » system containing “0”, enabling to accomplish a trivalent An/Ln separation at 1.0 M HNO3, the extraction of neptunium was drastically diminished, relative to “1”. The partitioning behavior of curium was also negatively impacted, introducing an effective opportunity for americium/curium separation. Radiometric and spectrophotometric studies demonstrate that the complete actinide recovery using the solvent based upon “0” and TOPO is not feasible. Additionally, the importance of radiolytic degradation processes is discussed through the comparisons of extraction properties of liquid-liquid systems based on both soft donor reagents.« less

Kondoa gutianensis f.a. sp. nov., a novel ballistoconidium-forming yeast species isolated from plant leaves.

PubMed

Liu, Xin-Zhan; Groenewald, Marizeth; Boekhout, Teun; Bai, Feng-Yan

2018-01-01

Two strains, GT-165 T and GT-261, isolated from plant leaves collected from Gutian Mountain in Zhejiang province in China were identified as a novel species of the genus Kondoa by the sequence analysis of the internal transcribed spacer (ITS) region, the D1/D2 domains of the large subunit of rRNA (LSU rRNA) and the RNA polymerase II second largest subunit (RPB2), complemented by physiological tests. Phylogenetic analysis based on the concatenated sequences of ITS, D1/D2 and RPB2 showed that the closest known relatives of the new species are three undescribed Kondoa species and Kondoa thailandica. The ITS and D1/D2 sequences of the new species differ from the closely related species by 11-22% and 2-9%, respectively. The name Kondoa gutianensis f.a. sp. nov. (MB 820648, holotype = CGMCC 2.5703 T ; isotype: CBS 14811 T = CGMCC 2.5703 T ) is proposed to accommodate the new taxon.

Evidence for Electromagnetic Granularity in the Polycrystalline Iron-Based Superconductor LaO(0.89)F(0.11)FeAs

DTIC Science & Technology

2008-01-01

oriented grain-boundaries. In this work we show considerable evidence for such weak-coupling by study of the dependence of magnetization in bulk and...powdered samples. Bulk sample magnetization curves show very little hysteresis while remanent magnetization shows almost no sample size dependence...K Fig. 2 (Color online) Magnetization hysteresis loops at 5 and 20 K for the bulk LaO0.89F0.11FeAs. Inset shows the temperature dependence of

46 CFR 54.05-20 - Impact test properties for service of 0 °F and below.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 2 2012-10-01 2012-10-01 false Impact test properties for service of 0 °F and below. 54.05-20 Section 54.05-20 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE ENGINEERING PRESSURE VESSELS Toughness Tests § 54.05-20 Impact test properties for service of 0 °F and below. (a) Test energy. The impact energies of...

Measurement of the ratio $$\\mathcal{B}( \\mathrm{B}^0_{s} \\to \\mathrm{J}/\\psi\\, \\mathrm{f}_0(980))/\\mathcal{B}(\\mathrm{B}^0_{s} \\to \\mathrm{J}/\\psi\\, \\phi(1020))$$ in pp collisions at $$\\sqrt{s}$$ = 7 TeV

DOE PAGES

Khachatryan, Vardan

2016-02-17

The ratio Rf0/φ of the branching fractions of the B 0 s meson to the CP-odd eigenstate J/ψ f 0(980) and to J/ψ φ(1020) is measured, where J/ψ → µ +µ -, f 0 → π +π -, and φ → K +K -. The analysis is based on a data sample of pp collisions at a centre-of-mass energy of 7 TeV, collected by the CMS experiment, corresponding to an integrated luminosity of 5.3 fb -1 . The result is R f0/φ = 0.140 ± 0.013 ± 0.018, where the first uncertainty is statistical and the second is systematic. Thismore » result is consistent with theoretical predictions and previous measurements of R f0/ φ. It is the most precise measurement of the ratio to date.« less

Variable reluctance displacement transducer temperature compensated to 650$sup 0$F

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

In pressurized water reactor tests, compact instruments for accurate measurement of small displacements in a 650$sup 0$F environment are often required. In the case of blowdown tests such as the Loss of Fluid Test (LOFT) or Semiscale computer code development tests, not only is the initial environment water at 650$sup 0$F and 2200 psi but it undergoes a severe transient due to depressurization. Since the LOFT and Semiscale tests are run just for the purpose of obtaining data during the depressurization, instruments used to obtain the data must not give false outputs induced by the change in environment. A LOFTmore » rho v$sup 2$ probe and a Semiscale drag disk are described. Each utilizes a variable reluctance transducer (VRT) for indication of the drag-disk location and a torsion bar for drag-disk restoring force. The VRT, in addition to being thermally gain and null offset stable, is fabricated from materials known to be resistant to large nuclear radiation levels and has successfully passed a fast neutron radiation test of 2.7 x 10$sup 17$ nvt without failure. (auth)« less

Correlating Species and Spectral Diversity using Remote Sensing in Successional Fields in Virginia

NASA Astrophysics Data System (ADS)

Aneece, I.; Epstein, H. E.

2015-12-01

Conserving biodiversity can help preserve ecosystem properties and function. As the increasing prevalence of invasive plant species threatens biodiversity, advances in remote sensing technology can help monitor invasive species and their effects on ecosystems and plant communities. To assess whether we could study the effects of invasive species on biodiversity using remote sensing, we asked whether species diversity was positively correlated with spectral diversity, and whether correlations differed among spectral regions along the visible and near-infrared range. To answer these questions, we established community plots in secondary successional fields at the Blandy Experimental Farm in northern Virginia and collected vegetation surveys and ground-level hyperspectral data from 350 to 1025 nm wavelengths. Pearson correlation analysis revealed a positive correlation between spectral diversity and species diversity in the visible ranges of 350-499 nm (Pearson correlation=0.69, p=0.01), 500-589 nm (Pearson=0.64, p=0.03), and 590-674 nm (Pearson=0.70, p=0.01), slight positive correlation in the red edge range of 675-754 nm (Pearson=0.56, p=0.06), and no correlation in the near-infrared ranges of 755-924 nm (Pearson=-0.06, p=0.85) and 925-1025 nm (Pearson=0.30, p=0.34). These differences in correlations across spectral regions may be due to the elements that contribute to signatures in those regions and spectral data transformation methods. To investigate the role of pigment variability in these correlations, we estimated chlorophyll, carotenoid, and anthocyanin concentrations of five dominant species in the plots using vegetation indices. Although interspecific variability in pigment levels exceeded intraspecific variability, chlorophyll (F value=118) was more varied within species than carotenoids (F=322) and anthocyanins (F=126), perhaps contributing to the lack of correlation between species diversity and spectral diversity in the red edge region. Interspecific

Alternol induces an S-phase arrest of melanoma B16F0 cells.

PubMed

Liu, Liangliang; Zhang, Bo; Yuan, Xuan; Wang, Penglong; Sun, Xiling; Zheng, Qiusheng

2014-03-01

Alternol is a novel compound purified from the fermentation products of a microorganism in the yew tree bark. This study looks at the effects of alternol on the proliferation and cell cycle distribution of mouse melanoma cells. The inhibition of cell proliferation and changes in cell cycle distribution were analysed by sulforhodamine B and flow cytometry assays, respectively. mRNA expression of cyclin A, cyclin-dependent kinase 2 (CDK2), proliferating cell nuclear antigen (PCNA) and CDK inhibitor1A (p21) were measured by real-time reverse transcription PCR (RT-PCR). The protein levels of cyclin A, CDK2 and PCNA were analysed by Western blot analysis. p21 was measured by ELISA. Alternol treatment caused a significant decrease in the proliferation rate of B16F0 and B16F10 cells, which were significantly arrested in S phase, but this treatment had less effect on normal human embryonic kidney 293T cells. The mechanism by which alternol inhibits B16F0 proliferation in vitro may be associated with the inhibition of CDK2 and PCNA, and the activation of p21. © 2013 International Federation for Cell Biology.

Thermal conductivity of (Np0.20Pu0.50Am0.25Cm0.05)O2-x solid solutions

NASA Astrophysics Data System (ADS)

Nishi, Tsuyoshi; Takano, Masahide; Akabori, Mitsuo; Arai, Yasuo

2013-09-01

The authors prepared the sintered sample of (Np0.20Pu0.50Am0.25Cm0.05)O2-x (2 - x = 1.98, 1.96) solid solution and evaluated the dependence of the thermal conductivity on storage time and temperature. The heat capacity of (Np0.20Pu0.50Am0.25Cm0.05)O1.98 was measured between 324 and 1082 K by a drop calorimetry. The thermal diffusivity of (Np0.20Pu0.50Am0.25Cm0.05)O1.98 was measured when the storage time became 48, 216, 720 and 1584 h and that of (Np0.20Pu0.50Am0.25Cm0.05)O1.96 was measured when the storage time became 0,528 and 1386 h. In this study, the latter sample was annealed at 1423 K in vacuum with background pressure of less than 2.0 × 10-4 Pa just after the measurement on the storage time, 1386 h. The thermal diffusivity of (Np0.20Pu0.50Am0.25Cm0.05)O1.96 just after annealing returned to the values of the storage time, 0 h. This result reveals the thermal recovery behavior by annealing. The thermal conductivity of (Np0.20Pu0.50Am0.25Cm0.05)O2-x was determined from the measured thermal diffusivity, heat capacity and bulk density. The thermal conductivity of (Np0.20Pu0.50Am0.25Cm0.05)O2-x exponentially decreased with increasing storage time. This result suggested that the decrease of the thermal conductivity was attributed to the accumulation of lattice defects caused by self-irradiation. The heat capacity of (Np0.20Pu0.50Am0.25Cm0.05)O1.98 was expressed by Cp (J mol-1 K-1) = 1.7314 × 10-2T + 75.720 - 1.0579 × 106 T-2. The heat capacity at higher than 473 K was almost close to those of stoichiometric actinide dioxide within at least ±5%. The thermal diffusivity of (Np0.20Pu0.50Am0.25Cm0.05)O2-x decreased with increasing storage time in the temperature range from 473 to 573 K. The decrease of the thermal diffusivity was attributed by the lattice defect rapidly accumulated by the α-decay of 244Cm. The thermal diffusivity of (Np0.20Pu0.50Am0.25Cm0.05)O1.96 just after annealing returned to the values of the storage time, 0 h. This result reveals the thermal

F-box-like domain in the polerovirus protein P0 is required for silencing suppressor function

PubMed Central

Pazhouhandeh, Maghsoud; Dieterle, Monika; Marrocco, Katia; Lechner, Esther; Berry, Bassam; Brault, Véronique; Hemmer, Odile; Kretsch, Thomas; Richards, Kenneth E.; Genschik, Pascal; Ziegler-Graff, Véronique

2006-01-01

Plants employ small RNA-mediated posttranscriptional gene silencing as a virus defense mechanism. In response, plant viruses encode proteins that can suppress RNA silencing, but the mode of action of most such proteins is poorly understood. Here, we show that the silencing suppressor protein P0 of two Arabidopsis-infecting poleroviruses interacts by means of a conserved minimal F-box motif with Arabidopsis thaliana orthologs of S-phase kinase-related protein 1 (SKP1), a component of the SCF family of ubiquitin E3 ligases. Point mutations in the F-box-like motif abolished the P0–SKP1 ortholog interaction, diminished virus pathogenicity, and inhibited the silencing suppressor activity of P0. Knockdown of expression of a SKP1 ortholog in Nicotiana benthamiana rendered the plants resistant to polerovirus infection. Together, the results support a model in which P0 acts as an F-box protein that targets an essential component of the host posttranscriptional gene silencing machinery. PMID:16446454

Impact of concomitant Y and Mn substitution on superconductivity in La1 -yYyFe1 -xMnxAsO0.89F0.11

NASA Astrophysics Data System (ADS)

Kappenberger, Rhea; Hammerath, Franziska; Rousse, Pierre; Afrassa, Mesfin Asfaw; Haghighi, M. Hossein; Kamusella, Sirko; Prando, Giacomo; Lamura, Gianrico; Wolter, Anja U. B.; Moroni, Matteo; Sanna, Samuele; Carretta, Pietro; Hess, Christian; Grafe, Hans-Joachim; Klauss, Hans-Henning; Wurmehl, Sabine; Büchner, Bernd

2018-02-01

We discuss the impact of concomitant substitution of Fe by Mn and La by Y in optimally F-doped LaFeAsO0.89F0.11 . Mn has a known poisoning effect on superconductivity which is particularly strong in the La1111 system, where 0.2% of Mn were reported to completely suppress superconductivity. Through isovalent substitution of La by the much smaller Y we are able to inflict chemical pressure on the structure, which we show is stabilizing the superconducting state, resulting in a drastically larger amount of Mn needed to completely quench superconductivity. Interestingly, we find that the lattice parameter c changes significantly even for small amounts of Mn substitution within a series, which is unexpected taking only the differences between ionic radii into account. We discuss our findings in the light of electron localization caused by small amounts of paramagnetic Mn impurities in La1 -yYyFe1 -xMnxAsO0.89F0.11 also indicated by resistivity and Mößbauer measurements.

Improved sparse decomposition based on a smoothed L0 norm using a Laplacian kernel to select features from fMRI data.

PubMed

Zhang, Chuncheng; Song, Sutao; Wen, Xiaotong; Yao, Li; Long, Zhiying

2015-04-30

Feature selection plays an important role in improving the classification accuracy of multivariate classification techniques in the context of fMRI-based decoding due to the "few samples and large features" nature of functional magnetic resonance imaging (fMRI) data. Recently, several sparse representation methods have been applied to the voxel selection of fMRI data. Despite the low computational efficiency of the sparse representation methods, they still displayed promise for applications that select features from fMRI data. In this study, we proposed the Laplacian smoothed L0 norm (LSL0) approach for feature selection of fMRI data. Based on the fast sparse decomposition using smoothed L0 norm (SL0) (Mohimani, 2007), the LSL0 method used the Laplacian function to approximate the L0 norm of sources. Results of the simulated and real fMRI data demonstrated the feasibility and robustness of LSL0 for the sparse source estimation and feature selection. Simulated results indicated that LSL0 produced more accurate source estimation than SL0 at high noise levels. The classification accuracy using voxels that were selected by LSL0 was higher than that by SL0 in both simulated and real fMRI experiment. Moreover, both LSL0 and SL0 showed higher classification accuracy and required less time than ICA and t-test for the fMRI decoding. LSL0 outperformed SL0 in sparse source estimation at high noise level and in feature selection. Moreover, LSL0 and SL0 showed better performance than ICA and t-test for feature selection. Copyright © 2015 Elsevier B.V. All rights reserved.

Demonstration of the TRUEX process for partitioning of actinides from actual ICPP tank waste using centrifugal contactors in a shielded cell facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Law, J.D.; Brewer, K.N.; Herbst, R.S.

1996-09-01

TRUEX is being evaluated at Idaho Chemical Processing Plant (ICPP) for separating actinides from acidic radioactive waste stored at ICPP; efforts have culminated in a recent demonstration with actual tank waste. A continuous countercurrent flowsheet test was successfully completed at ICPP using waste from tank WM-183. This demonstration was performed using 24 states of 2-cm dia centrifugal contactors in the shielded hot cell at the ICPP Remote Analytical Laboratory. The flowsheet had 8 extraction stages, 5 scrub stages, 6 strip stages, 3 solvent wash stages, and 2 acid rinse stages. A centrifugal contactor stage in the scrub section was notmore » working during testing, and the scrub feed (aqueous) solution followed the solvent into the strip section, eliminating the scrub section in the flowsheet. An overall removal efficiency of 99.97% was obtained for the actinides, reducing the activity from 457 nCi/g in the feed to 0.12 nCi/g in the aqueous raffinate, well below the NRC Class A LLW requirement of 10 nCi/g for non-TRU waste.The 0.04 M HEDPA strip section back-extracted 99.9998% of the actinide from the TRUEX solvent. Removal efficiencies of >99. 90, 99.96, 99.98, >98.89, 93.3, and 89% were obtained for {sup 241}Am, {sup 238}Pu, {sup 239}Pu, {sup 235}U, {sup 238}U, and {sup 99}Tc. Fe was partially extracted by the TRUEX solvent, resulting in 23% of the Fe exiting in the strip product. Hg was also extracted by the TRUEX solvent (73%) and stripped from the solvent in the 0.25 M Na2CO3 wash section. Only 1.4% of the Hg exited with the high activity waste strip product.« less

Statistical analysis of excitation energies in actinide and rare-earth nuclei

NASA Astrophysics Data System (ADS)

Levon, A. I.; Magner, A. G.; Radionov, S. V.

2018-04-01

Statistical analysis of distributions of the collective states in actinide and rare-earth nuclei is performed in terms of the nearest-neighbor spacing distribution (NNSD). Several approximations, such as the linear approach to the level repulsion density and that suggested by Brody to the NNSDs were applied for the analysis. We found an intermediate character of the experimental spectra between the order and the chaos for a number of rare-earth and actinide nuclei. The spectra are closer to the Wigner distribution for energies limited by 3 MeV, and to the Poisson distribution for data including higher excitation energies and higher spins. The latter result is in agreement with the theoretical calculations. These features are confirmed by the cumulative distributions, where the Wigner contribution dominates at smaller spacings while the Poisson one is more important at larger spacings, and our linear approach improves the comparison with experimental data at all desired spacings.

Meson-meson scattering: K{anti K}-thresholds and f{sub 0}(980)-a{sub 0}(980) mixing

DOE Office of Scientific and Technical Information (OSTI.GOV)

O. Krehl; R. Rapp; J. Speth

1996-09-01

The authors study the influence of mass splitting between the charged and neutral pions and kaons in the Juelich meson exchange model for {pi}{pi} and {pi}{eta} scattering. The calculations are performed in the particle basis, which permits the use of physical masses for the pseudoscalar mesons and a study of the distinct thresholds associated with the neutral and the charged kaons. Within this model the authors also investigate the isospin violation which arises from the mass splitting and an apparent violation of G-parity in {pi}{pi} scattering which stems from the coupling to the K{anti K} channel. Nonvanishing cross sections formore » {pi}{pi} {r_arrow} {pi}{sup 0}{eta} indicate a mixing of the f{sub 0}(980) and a{sub 0}(980) states.« less

High-pressure polymorphism of Pb F2 to 75 GPa

NASA Astrophysics Data System (ADS)

Stan, Camelia V.; Dutta, Rajkrishna; White, Claire E.; Prakapenka, Vitali; Duffy, Thomas S.

2016-07-01

Lead fluoride, Pb F2 , was investigated experimentally in the laser-heated diamond anvil cell by x-ray diffraction to pressures of 75 GPa at room temperature and to 64.5 GPa and 2430 K, as well as through first-principles density functional theory calculations up to 70 GPa. During room temperature compression, no discontinuous changes in the x-ray diffraction pattern or volume were observed, but the lattice parameters displayed highly anomalous trends between 10-22 GPa with enhanced compressibility along the a direction and reduced or even negative compressibility along b and c . Theoretical calculations of valence electron densities at 22 GPa showed that α -Pb F2 underwent a pressure-induced isosymmetric phase transition to a postcotunnite C o2Si structure and also revealed the detailed atomic rearrangements associated with the development of an extra Pb-F bond in the high-pressure phase. Our x-ray results and theoretical calculations are consistent with an isosymmetric phase transition smoothly occurring over 10-22 GPa rather than abruptly as previously suggested. The characteristic values for the cell constants a /c and (a +c )/b , which are used to distinguish among cotunnite-, C o2Si -, and N i2In -type phases, require modification based on our results. An equation of state fit yields a bulk modulus, K0, of 72(3) GPa for the cotunnite-type, and an ambient-pressure volume, V0, of 182 (2 ) Å3 , and K0=81 (4 ) GPa for the C o2Si -type phase when fixing the pressure derivative of the bulk modulus, K0 '=4 . Upon heating above 1200 K at pressures at or above 25.9 GPa, Pb F2 partially transformed to the hexagonal N i2In -type phase but wholly or partially reverted back to C o2Si -type phase upon temperature quench. From 43-65 GPa, nearly complete transformation to the N i2In -type Pb F2 was observed at high temperature, but the material partially transformed back to the orthorhombic phase upon temperature quench. Our results show that high-pressure behavior of Pb F

Toward a stable solid-electrolyte-interfaces on nickel-rich cathodes: LiPO2F2 salt-type additive and its working mechanism for LiNi0.5Mn0.25Co0.25O2 cathodes

NASA Astrophysics Data System (ADS)

Zhao, Weimin; Zheng, Guorui; Lin, Min; Zhao, Wengao; Li, Dongjiang; Guan, Xiaoyun; Ji, Yajuan; Ortiz, Gregorio F.; Yang, Yong

2018-03-01

Although the LiNi0.5Mn0.25Co0.25O2 holds the merits of high theoretical capacities and a relatively high operating voltage, the battery performance suffers from the severe cycling decay due to the unstable solid electrolyte interface on the cathode. Herein, we present LiPO2F2 as a salt-type electrolyte additive to enhance the cycling stability of large-size crystallite LiNi0.5Mn0.25Co0.25O2 cathodes. Results demonstrate that 1 wt% LiPO2F2 can significantly improve not only the initial coulombic efficiency by 3%, but also the cycling stability and rate capability at 25 °C. Furthermore, the discharge capacity of LiNi0.5Mn0.25Co0.25O2 cathodes still maintain 156 mAh g-1 after 100 cycles even when the temperature increases to 55 °C. In-depth experimental characterization and theoretical calculation indicate that a new stable and thin (e.g. 15-20 nm) film formed on the surface of the cathodes, with composition of LiPO2F2, LiF, etc., which significantly reduces charge transfer impedance of the electrodes, and therefore significantly improves the cycling and rate performance of LiNi0.5Mn0.25Co0.25O2.

Advancing Understanding of the +4 Metal Extractant Thenoyltrifluoroacetonate (TTA –); Synthesis and Structure of M IVTTA 4 (M IV = Zr, Hf, Ce, Th, U, Np, Pu) and M III(TTA) 4 – (M III = Ce, Nd, Sm, Yb)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cary, Samantha K.; Livshits, Maksim; Cross, Justin N.

Thenoyltrifluoroacetone (HTTA)-based extractions represent popular methods for separating microscopic amounts of transuranic actinides (i.e., Np and Pu) from macroscopic actinide matrixes (e.g. bulk uranium). It is well-established that this procedure enables +4 actinides to be selectively removed from +3, + 5, and +6 f-elements. However, even highly skilled and well-trained researchers find this process complicated and (at times) unpredictable. It is difficult to improve the HTTA extraction—or find alternatives—because little is understood about why this separation works. Even the identities of the extracted species are unknown. In addressing this knowledge gap, we report in this paper advances in fundamental understandingmore » of the HTTA-based extraction. This effort included comparatively evaluating HTTA complexation with +4 and +3 metals (M IV = Zr, Hf, Ce, Th, U, Np, and Pu vs M III = Ce, Nd, Sm, and Yb). We observed +4 metals formed neutral complexes of the general formula M IV(TTA) 4. Meanwhile, +3 metals formed anionic M III(TTA) 4 – species. Characterization of these M(TTA) 4 x– (x = 0, 1) compounds by UV–vis–NIR, IR, 1H and 19F NMR, single-crystal X-ray diffraction, and X-ray absorption spectroscopy (both near-edge and extended fine structure) was critical for determining that Np IV(TTA) 4 and Pu IV(TTA) 4 were the primary species extracted by HTTA. Furthermore, this information lays the foundation to begin developing and understanding of why the HTTA extraction works so well. The data suggest that the solubility differences between M IV(TTA) 4 and M III(TTA) 4 – are likely a major contributor to the selectivity of HTTA extractions for +4 cations over +3 metals. Finally and moreover, these results will enable future studies focused on explaining HTTA extractions preference for +4 cations, which increases from Np IV to Pu IV, Hf IV, and Zr IV.« less

Advancing Understanding of the +4 Metal Extractant Thenoyltrifluoroacetonate (TTA –); Synthesis and Structure of M IVTTA 4 (M IV = Zr, Hf, Ce, Th, U, Np, Pu) and M III(TTA) 4 – (M III = Ce, Nd, Sm, Yb)

DOE PAGES

Cary, Samantha K.; Livshits, Maksim; Cross, Justin N.; ...

2018-03-21

Thenoyltrifluoroacetone (HTTA)-based extractions represent popular methods for separating microscopic amounts of transuranic actinides (i.e., Np and Pu) from macroscopic actinide matrixes (e.g. bulk uranium). It is well-established that this procedure enables +4 actinides to be selectively removed from +3, + 5, and +6 f-elements. However, even highly skilled and well-trained researchers find this process complicated and (at times) unpredictable. It is difficult to improve the HTTA extraction—or find alternatives—because little is understood about why this separation works. Even the identities of the extracted species are unknown. In addressing this knowledge gap, we report in this paper advances in fundamental understandingmore » of the HTTA-based extraction. This effort included comparatively evaluating HTTA complexation with +4 and +3 metals (M IV = Zr, Hf, Ce, Th, U, Np, and Pu vs M III = Ce, Nd, Sm, and Yb). We observed +4 metals formed neutral complexes of the general formula M IV(TTA) 4. Meanwhile, +3 metals formed anionic M III(TTA) 4 – species. Characterization of these M(TTA) 4 x– (x = 0, 1) compounds by UV–vis–NIR, IR, 1H and 19F NMR, single-crystal X-ray diffraction, and X-ray absorption spectroscopy (both near-edge and extended fine structure) was critical for determining that Np IV(TTA) 4 and Pu IV(TTA) 4 were the primary species extracted by HTTA. Furthermore, this information lays the foundation to begin developing and understanding of why the HTTA extraction works so well. The data suggest that the solubility differences between M IV(TTA) 4 and M III(TTA) 4 – are likely a major contributor to the selectivity of HTTA extractions for +4 cations over +3 metals. Finally and moreover, these results will enable future studies focused on explaining HTTA extractions preference for +4 cations, which increases from Np IV to Pu IV, Hf IV, and Zr IV.« less

The Colletotrichum boninense species complex