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Sample records for hafnium 169

  1. Metallurgy of zirconium and hafnium

    International Nuclear Information System (INIS)

    Baryshnikov, N.V.; Geger, V.Eh.; Denisova, N.D.; Kazajn, A.A.; Kozhemyakin, V.A.; Nekhamkin, L.G.; Rodyakin, V.V.; Tsylov, Yu.A.

    1979-01-01

    Considered are those properties of zirconium and of hafnium, which are of practical interest for the manufacture of these elements. Systematized are the theoretical and the practical data on the procedures for thermal decomposition of zirconia and for obtaining zirconium dioxide and hafnium dioxide by a thermal decomposition of compounds and on the hydrometallurgical methods for extracting zirconium and hafnium. Zirconium and hafnium fluorides and chlorides production procedures are described. Considered are the iodide and the electrolytic methods of refining zirconium and hafnium

  2. SEPARATING HAFNIUM FROM ZIRCONIUM

    Science.gov (United States)

    Lister, B.A.J.; Duncan, J.F.

    1956-08-21

    A dilute aqueous solution of zirconyl chloride which is 1N to 2N in HCl is passed through a column of a cation exchange resin in acid form thereby absorbing both zirconium and associated hafnium impurity in the mesin. The cation exchange material with the absorbate is then eluted with aqueous sulfuric acid of a O.8N to 1.2N strength. The first portion of the eluate contains the zirconium substantially free of hafnium.

  3. Commercial production of metal hafnium and hafnium-based products

    International Nuclear Information System (INIS)

    Negodin, D.A.; Shtutsa, M.G.; Akhtonov, S.G.; Il'enko, E.V.; Kobyzev, A.M.

    2012-01-01

    Hafnium possesses a unique complex of physical and chemical properties which allow the application of products on its basis in various industries. Joint Stock Company 'Chepetsky Mechanical Plant' is the single enterprise which produces hafnium on the territory of Russia. The manufacture of metal hafnium with the total content of zirconium and hafnium, at least, 99,8 % of weights is developed at the present time at Joint Stock Company CHMZ. The weight of melted hafnium ingots is up to 1 ton. Manufacture of wide range of products from hafnium is implemented. The plates from a hafnium with thickness of 0.60 mm which are used for emergency control cartridges of VVER-440 reactors are the most critical product. It is shown that ingots and products obtained from metal hafnium correspond to the Russian and international standards for reactor materials in chemical composition, mechanical and corrosion properties.

  4. Zirconium and hafnium

    Science.gov (United States)

    Jones, James V.; Piatak, Nadine M.; Bedinger, George M.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Zirconium and hafnium are corrosion-resistant metals that are widely used in the chemical and nuclear industries. Most zirconium is consumed in the form of the main ore mineral zircon (ZrSiO4, or as zirconium oxide or other zirconium chemicals. Zirconium and hafnium are both refractory lithophile elements that have nearly identical charge, ionic radii, and ionic potentials. As a result, their geochemical behavior is generally similar. Both elements are classified as incompatible because they have physical and crystallochemical properties that exclude them from the crystal lattices of most rock-forming minerals. Zircon and another, less common, ore mineral, baddeleyite (ZrO2), form primarily as accessory minerals in igneous rocks. The presence and abundance of these ore minerals in igneous rocks are largely controlled by the element concentrations in the magma source and by the processes of melt generation and evolution. The world’s largest primary deposits of zirconium and hafnium are associated with alkaline igneous rocks, and, in one locality on the Kola Peninsula of Murmanskaya Oblast, Russia, baddeleyite is recovered as a byproduct of apatite and magnetite mining. Otherwise, there are few primary igneous deposits of zirconium- and hafnium-bearing minerals with economic value at present. The main ore deposits worldwide are heavy-mineral sands produced by the weathering and erosion of preexisting rocks and the concentration of zircon and other economically important heavy minerals, such as ilmenite and rutile (for titanium), chromite (for chromium), and monazite (for rare-earth elements) in sedimentary systems, particularly in coastal environments. In coastal deposits, heavy-mineral enrichment occurs where sediment is repeatedly reworked by wind, waves, currents, and tidal processes. The resulting heavy-mineral-sand deposits, called placers or paleoplacers, preferentially form at relatively low latitudes on passive continental margins and supply 100 percent of

  5. SEPARATION OF HAFNIUM FROM ZIRCONIUM

    Science.gov (United States)

    Overholser, L.B.; Barton, C.J. Sr.; Ramsey, J.W.

    1960-05-31

    The separation of hafnium impurities from zirconium can be accomplished by means of organic solvent extraction. The hafnium-containing zirconium feed material is dissolved in an aqueous chloride solution and the resulting solution is contacted with an organic hexone phase, with at least one of the phases containing thiocyanate. The hafnium is extracted into the organic phase while zirconium remains in the aqueous phase. Further recovery of zirconium is effected by stripping the onganic phase with a hydrochloric acid solution and commingling the resulting strip solution with the aqueous feed solution. Hexone is recovered and recycled by means of scrubbing the onganic phase with a sulfuric acid solution to remove the hafnium, and thiocyanate is recovered and recycled by means of neutralizing the effluent streams to obtain ammonium thiocyanate.

  6. Calorimetric measurements on hafnium titanate

    International Nuclear Information System (INIS)

    Kandan, R.; Prabhakara Reddy, B.; Panneerselvam, G.; Nagarajan, K.

    2012-01-01

    Owing to its desirable nuclear and mechanical properties such as good absorption cross-section for thermal neutrons (105 barns), hafnium titanate (HfTiO 4 ) finds application as control rods for nuclear reactors. An accurate knowledge of the thermo physical properties of this material is necessary for design of control rod and for modeling its performance. Heat capacity is an important thermodynamic property that determines the temperature dependent variation of all other thermodynamic properties. Hence enthalpy increments of hafnium titanate (HfTiO 4 ) were measured in the temperature range 803-1663 K by employing the method of inverse drop calorimetry using high temperature differential calorimeter

  7. Hafnium carbide formation in oxygen deficient hafnium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Rodenbücher, C. [Forschungszentrum Jülich GmbH, Peter Grünberg Institute (PGI-7), JARA-FIT, 52425 Jülich (Germany); Hildebrandt, E.; Sharath, S. U.; Kurian, J.; Komissinskiy, P.; Alff, L. [Technische Universität Darmstadt, Institute of Materials Science, 64287 Darmstadt (Germany); Szot, K. [Forschungszentrum Jülich GmbH, Peter Grünberg Institute (PGI-7), JARA-FIT, 52425 Jülich (Germany); University of Silesia, A. Chełkowski Institute of Physics, 40-007 Katowice (Poland); Breuer, U. [Forschungszentrum Jülich GmbH, Central Institute for Engineering, Electronics and Analytics (ZEA-3), 52425 Jülich (Germany); Waser, R. [Forschungszentrum Jülich GmbH, Peter Grünberg Institute (PGI-7), JARA-FIT, 52425 Jülich (Germany); RWTH Aachen, Institute of Electronic Materials (IWE 2), 52056 Aachen (Germany)

    2016-06-20

    On highly oxygen deficient thin films of hafnium oxide (hafnia, HfO{sub 2−x}) contaminated with adsorbates of carbon oxides, the formation of hafnium carbide (HfC{sub x}) at the surface during vacuum annealing at temperatures as low as 600 °C is reported. Using X-ray photoelectron spectroscopy the evolution of the HfC{sub x} surface layer related to a transformation from insulating into metallic state is monitored in situ. In contrast, for fully stoichiometric HfO{sub 2} thin films prepared and measured under identical conditions, the formation of HfC{sub x} was not detectable suggesting that the enhanced adsorption of carbon oxides on oxygen deficient films provides a carbon source for the carbide formation. This shows that a high concentration of oxygen vacancies in carbon contaminated hafnia lowers considerably the formation energy of hafnium carbide. Thus, the presence of a sufficient amount of residual carbon in resistive random access memory devices might lead to a similar carbide formation within the conducting filaments due to Joule heating.

  8. Hafnium isotope stratigraphy of ferromanganese crusts

    Science.gov (United States)

    Lee; Halliday; Hein; Burton; Christensen; Gunther

    1999-08-13

    A Cenozoic record of hafnium isotopic compositions of central Pacific deep water has been obtained from two ferromanganese crusts. The crusts are separated by more than 3000 kilometers but display similar secular variations. Significant fluctuations in hafnium isotopic composition occurred in the Eocene and Oligocene, possibly related to direct advection from the Indian and Atlantic oceans. Hafnium isotopic compositions have remained approximately uniform for the past 20 million years, probably reflecting increased isolation of the central Pacific. The mechanisms responsible for the increase in (87)Sr/(86)Sr in seawater through the Cenozoic apparently had no effect on central Pacific deep-water hafnium.

  9. Ferroelectricity in undoped hafnium oxide

    International Nuclear Information System (INIS)

    Polakowski, Patrick; Müller, Johannes

    2015-01-01

    We report the observation of ferroelectric characteristics in undoped hafnium oxide thin films in a thickness range of 4–20 nm. The undoped films were fabricated using atomic layer deposition (ALD) and embedded into titanium nitride based metal-insulator-metal (MIM) capacitors for electrical evaluation. Structural as well as electrical evidence for the appearance of a ferroelectric phase in pure hafnium oxide was collected with respect to film thickness and thermal budget applied during titanium nitride electrode formation. Using grazing incidence X-Ray diffraction (GIXRD) analysis, we observed an enhanced suppression of the monoclinic phase fraction in favor of an orthorhombic, potentially, ferroelectric phase with decreasing thickness/grain size and for a titanium nitride electrode formation below crystallization temperature. The electrical presence of ferroelectricity was confirmed using polarization measurements. A remanent polarization P r of up to 10 μC cm −2 as well as a read/write endurance of 1.6 × 10 5 cycles was measured for the pure oxide. The experimental results reported here strongly support the intrinsic nature of the ferroelectric phase in hafnium oxide and expand its applicability beyond the doped systems

  10. Study of fine structure of deformed hafnium

    International Nuclear Information System (INIS)

    Voskresenskaya, L.A.; Petukhova, A.S.; Kovalev, K.S.

    1978-01-01

    Variations in the hafnium fine structure following the cold plastic deformation have been studied. The fine structure condition has been studied through the harmonic analysis of the profile of the X-ray diffraction line, obtained at the DRON-I installation. Received has been the dependence of the crystal lattice microdistortions value on the deformation extent for hafnium. This dependence is compared with the corresponding one for zirconium. It is found out that at all the deformations the microdistortion distribution is uniform. The microdistortion value grows with the increase in the compression. During the mechanical impact higher microdistortions of the crystal lattice occur in the hafnium rather than in zirconium

  11. Hafnium - material for chemical apparatus engineering

    International Nuclear Information System (INIS)

    Jennert, D.

    1981-01-01

    This work describes - on the background of available literature - the properties of hafnium in technical quality (DIN-material No. 2.6400) as material for chemical apparatus engineering. The occurence, refining, physical and chemical properties will be described as well as the material behavior. In conclusion, it has been found that there is, at present, sufficient information for the engineering of hafnium which has to be completed by additional investigations for special applications. (orig.) [de

  12. Determination of hafnium by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Yoshida, Isao; Kobayashi, Hiroshi; Ueno, Keihei.

    1977-01-01

    Optimum conditions for atomic absorption spectrophotometric determination of hafnium were investigated by use of a Jarrel-Ash AA-1 instrument which was equipped with a premixed gas burner slotted 50 mm in length and 0.4 mm in width. Absorption of hafnium, which was atomized in an nitrous oxide-acetylene flame, was measured on a resonance line at 307.29 nm. The absorption due to hafnium was enhanced in the presence of ammonium fluoride and iron(III) ion, as shown in Figs. 2 and 3, depending on their concentration. The highest absorption was attained by the addition of (0.15 -- 0.3)M ammonium fluoride, 0.07 M of iron(III) ion and 0.05 M of hydrochloric acid. An excess of the additives decreased the absorption. The presence of zirconium, which caused a significant interference in the ordinary analytical methods, did not affect the absorption due to hafnium, if the zirconium concentration is less than 0.2 M. A standard procedure was proposed; A sample containing a few mg of hafnium was dissolved in a 25-ml volumetric flask, and ammonium fluoride, ferric nitrate and hydrochloric acid were added so that the final concentrations were 0.3, 0.07 and 0.05 M, respectively. Atomic absorption was measured on the aqueous solution in a nitrous oxide-acetylene flame and the hafnium content was calculated from the absorbance. Sensitivity was as high as 12.5 μg of Hf/ml/l% absorption. The present method is especially recommendable to the direct determination of hafnium in samples containing zirconium. (auth.)

  13. Titanium(IV), zirconium, hafnium and thorium

    International Nuclear Information System (INIS)

    Brown, Paul L.; Ekberg, Christian

    2016-01-01

    Titanium can exist in solution in a number of oxidation states. The titanium(IV) exists in acidic solutions as the oxo-cation, TiO 2+ , rather than Ti 4+ . Zirconium is used in the ceramics industry and in nuclear industry as a cladding material in reactors where its reactivity towards hydrolysis reactions and precipitation of oxides may result in degradation of the cladding. In nature, hafnium is found together with zirconium and as a consequence of the contraction in ionic radii that occurs due to the 4f -electron shell, the ionic radius of hafnium is almost identical to that of zirconium. All isotopes of thorium are radioactive and, as a consequence of it being fertile, thorium is important in the nuclear fuel cycle. The polymeric hydrolysis species that have been reported for thorium are somewhat different to those identified for zirconium and hafnium, although thorium does form the Th 4 (OH) 8 8+ species.

  14. Gravimetric determination of hafnium through its arsenate in carbide and boride of hafnium

    International Nuclear Information System (INIS)

    Rasulbekova, R.A.; Mamedov, I.A.

    1976-01-01

    A gravimetric method of determining hafnium through hydroarsenate has been recommended. The method differs from the known ones by its simplicity and by the recalculation coefficient which is more than by 50% smaller than that used in preparing a weight form of HfO 2 . Upon development of gravimetric determination of hafnium through hydro-and pyroarsenate, an investigation has been conducted with the aim to find some physico-chemical constants of hafnium hydroarsenate. The weighed amount of hafnium hydroarsenate is dissolved in sulphuric acid (2:5). The precipitate of hafnium hydroarsenate has been studied for recording infrared absorption spectra. Thermographic analysis of the precipitate has been performed. Thermogram reveals endothermal effect at 105 deg C and exothermal at 840 deg C. Water solubility of hafnium has been determined equal to 1.75x10 6 g mol/l. The corresponding solubility product of the precipitate has been calculated which is 2.1x10 -17 . It is shown that the method possesses certain selectivity, sufficient accuracy, and is rather fast. It has been established that determination can be performed in the presence of excess amounts of ions

  15. Method of separating hafnium from zirconium

    International Nuclear Information System (INIS)

    Megy, J.A.

    1980-01-01

    English. A new anhydrous method was developed for separating zirconium and hafnium, which gives higher separation factors and is more economical than previous methods. A molten phase, comprising a solution of unseparated zirconium and hafnium and a solvent metal, is first prepared. The molten metal phase is contacted with a fused salt phase which includes a zirconium salt. Zirconium and hafnium separation is effected by mutual displacement with hafnium being transported from the molten metal phase to the fused salt phase, while zirconium is transported from the fused salt phase to the molten metal phase. The solvent metal is less electropositive than zirconium. Zinc was chosen as the solvent metal, from a group which also included cadmium, lead, bismuth, copper, and tin. The fused salt phase cations are more electropositive than zirconium and were selected from a group comprising the alkali elements, the alkaline earth elements, the rare earth elements, and aluminum. A portion of the zirconium in the molten metal phase was oxidized by injecting an oxidizing agent, chlorine, to form zirconium tetrachlorid

  16. Kinetic studies on the hafnium nad deuterium

    International Nuclear Information System (INIS)

    Bing Wenzeng; Long Xinggui; Zhu Zuliang

    2009-04-01

    Through the method of reaction rate analysis in a constant volume reactor, the time dependence of the pressure drop of the hafnium deuteride formation are studied over a temperature range 573-873 K on a metal hydride thermodynamic and kinetic parameters measuring apparatus. The rate constants of the hafnium deuteride formation, which are 0.0530 s -1 , 0.0452 s -1 , 0.0319 s -1 , 0.0261 s -1 , are calculated at a serial temperatures of 573 K, 673 K, 773 K, 873 K and the initial pressure of 13 kPa. The activation energy of the reaction is (-10.1±1.5) kJ·mol -1 . Comparing the above results with those of titanium deuteride formation on the same measuring apparatus, the kinetic mechanism of the deuteride formation of hafnium and titanium is considered different. It is concluded that the reaction rate of hafnium absorbing deuterium may be controlled by phase transformation and surface oxidation. (authors)

  17. Recovery of hafnium values from loaded extraction solvent

    International Nuclear Information System (INIS)

    Abodishish, H.A.

    1989-01-01

    This patent describes an improvement in a process for recovering high purity hafnium hydroxide from a methyl isobutyl ketone organic solvent that is substantially free of sulfate ions and contains hafnium thiocyanate and thiocyanic acid. The improvement comprising reacting the organic solvent with ammonia to produce a reaction product in the form of a methyl isobutyl ketone organic solvent that is substantially free of sulfate ions and contains ammonium thiocyanite solution and hafnium hydroxide; separating the constituents of the reaction product in accordance with their respective specific gravities to produce a hafnium hydroxide sludge as one of the separation products; and removing the liquid component of the sludge to yield a high purity hafnium hydroxide ready for calcination to hafnium oxide

  18. Flotation separation of hafnium(IV) from aqueous solutions

    International Nuclear Information System (INIS)

    Downey, D.M.; Narick, C.N.; Cohen, T.A.

    1985-01-01

    A simple, rapid method for the separation of hafnium from aqueous solutions was investigated using sup(175+181)Hf tracer. Cationic hafnium complex ions were floated from dilute acid solutions with sodium lauryl sulfate (SLS) and anionic hafnium complexes were floated from basic and oxalic acid solutions with hexadecyltrimethyl ammonium bromide (HTMAB). The conditions necessary for quantitative recovery of the metal and mechanisms of flotation are described. (author)

  19. Flotation separation of hafnium(IV) from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Downey, D.M.; Narick, C.N.; Cohen, T.A.

    1985-09-01

    A simple, rapid method for the separation of hafnium from aqueous solutions was investigated using sup(175 + 181)Hf tracer. Cationic hafnium complex ions were floated from dilute acid solutions with sodium lauryl sulfate (SLS) and anionic hafnium complexes were floated from basic and oxalic acid solutions with hexadecyltrimethyl ammonium bromide (HTMAB). The conditions necessary for quantitative recovery of the metal and mechanisms of flotation are described. (author). 21 refs.; 5 figs.

  20. Titanium zirconium and hafnium coordination compounds with vanillin thiosemicarbazone

    International Nuclear Information System (INIS)

    Konunova, Ts.B.; Kudritskaya, S.A.

    1987-01-01

    Coordination compounds of titanium zirconium and hafnium tetrachlorides with vanillin thiosemicarbazone of MCl 4 x nLig composition, where n=1.5, 4 for titanium and 1, 2, 4 for zirconium and hafnium, are synthesized. Molar conductivity of ethanol solutions is measured; IR spectroscopic and thermochemical investigation are carried out. The supposition about ligand coordination via sulfur and azomethine nitrogen atoms is made. In all cases hafnium forms stable compounds than zirconium

  1. Niobium and hafnium grown on porous membranes

    International Nuclear Information System (INIS)

    Morant, C.; Marquez, F.; Campo, T.; Sanz, J.M.; Elizalde, E.

    2010-01-01

    In this work we report on a method for fabricating highly ordered nanostructures of niobium and hafnium metals by physical vapour deposition using two different templates: anodized aluminum oxide membranes (AAO) and zirconium onto AAO membranes (Zr/AAO). The growth mechanism of these metal nanostructures is clearly different depending on the material used as a template. A different morphology was obtained by using AAO or Zr/AAO templates: when the metal is deposited onto AAO membranes, nanospheres with ordered hexagonal regularity are obtained; however, when the metal is deposited onto a Zr/AAO template, highly ordered nanocones are formed. The experimental approach described in this work is simple and suitable for synthesizing nanospheres or nanoholes of niobium and hafnium metals in a highly ordered structure.

  2. Joint titrimetric determination of zirconium and hafnium

    International Nuclear Information System (INIS)

    Vazquez, Cristina; Botbol, Moises; Bianco de Salas, G.N.; Cornell de Casas, M.I.

    1980-01-01

    A method for the joint titrimetric determination of zirconium and hafnium, which are elements of similar chemical behaviour, is described. The disodic salt of the ethylendiaminetetracetic acid (EDTA) is used for titration, while xilenol orange serves as final point indicator. Prior to titration it is important to evaporate with sulfuric acid, the solution resulting from the zirconium depolymerization process, to adjust the acidity and to eliminate any interferences. The method, that allows the quick and precise determination of zirconium and hafnium in quantities comprised between 0.01 and mg, was applied to the analysis of raw materials and of intermediate and final products in the fabrication of zirconium sponge and zircaloy. (M.E.L.) [es

  3. Molten salt scrubbing of zirconium or hafnium tetrachloride

    International Nuclear Information System (INIS)

    Lee, E.D.; McLaughlin, D.F.

    1990-01-01

    This patent describes a continuous process for removing impurities of iron or aluminum chloride or both from vaporous zirconium or hafnium chloride or both. It comprises: introducing impure zirconium or hafnium chloride vapor or both into a middle portion of an absorbing column containing a molten salt phase, the molten salt phase absorbing the impurities of iron or aluminum chloride or both to produce chloride vapor stripped of zirconium or hafnium chloride; introducing sodium or potassium chloride or both into a top portion of the column; controlling the top portion of the column to between 300--375 degrees C.; heating a bottom portion of the column to 450--550 degrees C. To vaporize zirconium chloride or hafnium chloride or hafnium and zirconium chloride from the molten salt; withdrawing molten salt substantially free of zirconium and hafnium chloride from the bottom portion of the column; and withdrawing zirconium chloride or hafnium chloride or hafnium and zirconium chloride vapor substantially free of impurities of iron and aluminum chloride from the top of the column

  4. Spectroscopy of 169Ta

    International Nuclear Information System (INIS)

    Kshetri, Ritesh; Ray, I.; Ganguly, S.; Pradhan, M.K.; Raut, R.; Goswami, A.; Banerjee, P.; Mukherjee, A.; Datta Pramanik, U.; Bhattacharya, S.; Dasmahapatra, B.; Saha Sarkar, M.; Dey, G.; Ray Basu, M.; Krishichayan; Chakraborty, A.; Ghugre, S.S.; Ray, M.; Sarkar, S.

    2006-01-01

    The lifetimes of the isomeric levels of 169,171 Ta have been re-measured using the centroid shift method of electronic timing technique. Preliminary results for lifetimes are in good agreement with the adopted values. Investigations are being carried out to identify other isomeric levels

  5. Investigation of ferromagnetism in oxygen deficient hafnium oxide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, Erwin; Kurian, Jose; Krockenberger, Yoshiharu; Alff, Lambert [Institut fuer Materialwissenschaft, TU Darmstadt (Germany); Suter, Andreas [PSI, Villingen (Switzerland); Wilhelm, Fabrice; Rogalev, Andrei [ESRF, Grenoble (France)

    2008-07-01

    Oxygen deficient thin films of hafnium oxide were grown on single crystal r-cut and c-cut sapphire by reactive molecular beam epitaxy. RF-activated oxygen was used for the in situ oxidation of hafnium oxide thin films. Oxidation conditions were varied substantially in order to create oxygen deficiency in hafnium oxide films intentionally. The films were characterized by X-ray and magnetic measurements. X-ray diffraction studies show an increase in lattice parameter with increasing oxygen deficiency. Oxygen deficient hafnium oxide thin films also showed a decreasing bandgap with increase in oxygen deficiency. The magnetisation studies carried out with SQUID did not show any sign of ferromagnetism in the whole oxygen deficiency range. X-ray magnetic circular dichroism measurements also confirmed the absence of ferromagnetism in oxygen deficient hafnium oxide thin films.

  6. Preparation of hafnium carbide by chemical vapor deposition

    International Nuclear Information System (INIS)

    Hertz, Dominique.

    1974-01-01

    Hard, adhesive coatings of single-phase hafnium carbide were obtained by chemical vapor reaction in an atmosphere containing hafnium tetrachloride, methane and a large excess of hydrogen. By varying the gas phase composition and temperature the zones of formation of the different solid phases were studied and the growth of elementary hafnium and carbon deposits evaluated separately. The results show that the mechanism of hafnium carbide deposition does not hardly involve phenomene of homogeneous-phase methane decomposition or tetrachloride reduction by hydrogen unless the atmosphere is very rich or very poor in methane with respect to tetrachloride. However, hydrogen acting inversely on these two reactions, affects the stoichiometry of the substance deposited. The methane decomposition reaction is fairly slow, the reaction leading to hafnium carbide deposition is faster and that of tetrachloride reduction by hydrogen is quite fast [fr

  7. Assessing hafnium on hafnia as an oxygen getter

    International Nuclear Information System (INIS)

    O'Hara, Andrew; Demkov, Alexander A.; Bersuker, Gennadi

    2014-01-01

    Hafnium dioxide or hafnia is a wide band gap dielectric used in a range of electronic applications from field effect transistors to resistive memory. In many of these applications, it is important to maintain control over oxygen stoichiometry, which can be realized in practice by using a metal layer, specifically hafnium, to getter oxygen from the adjacent dielectric. In this paper, we employ density functional theory to study the thermodynamic stability of an interface between (100)-oriented monoclinic hafnia and hafnium metal. The nudged elastic band method is used to calculate the energy barrier for migration of oxygen from the oxide to the metal. Our investigation shows that the presence of hafnium lowers the formation energy of oxygen vacancies in hafnia, but more importantly the oxidation of hafnium through the migration of oxygen from hafnia is favored energetically

  8. Properties of filmogen solutions and films of hafnium compounds

    International Nuclear Information System (INIS)

    Sviridova, A.I.

    1986-01-01

    Study on hafnium hydrolizing compound solutions, used for hafnium oxide homogeneous layer formation, is conducted. In particular, electric conductivity, acidity and refractive index were investigated depending on the sal on ether concentration and the storage time. Oxyhafnium nitrate, hafnium chloride in ethanol, dichlorodiethoxyhafnium, hafnium oxychloride were used as initial compounds. Hydrolysis of hafnium compounds in solution occurs partially; further process occurs in the thin layer on the optical element surface; final decomposition is performed under heat treatment. It is ascertained, that alcoholic-aqueous solutions of inorganic salts can be filmogen only at definite acidity, density and viscosity (1.33-2.5 cp.). It is also ascertained that refractive index values and transmission spectral boundary of coatings, produced from alkoxy compound solutions and from chloride salt solutions, are practically the same. Transmittance boundary in ultraviolet region of spectrum of oxide films produced from nitrate and chloride solutions, varies with the heating temperature increase differently

  9. Analysis of hafnium in zirconium alloys

    International Nuclear Information System (INIS)

    Kondo, Isao; Sakai, Fumiaki; Ohuchi, Yoshifusa; Nakamura, Hisashi

    1977-01-01

    It is required to analyse alloying components and impurity elements in the acceptance analysis of zirconium alloys as the material for fuel cladding tubes and pressure tubes for advanced thermal reactors. Because of extreme similarity in chemical properties between zirconium and hafnium, about 100 ppm of hafnium is usually contained in zirconium alloys. Zircaloy-2 alloy and 2.5% Nb-zirconium with the addition of hafnium had been prepared as in-house standard samples for rapid analysis. Study was made on fluorescent X-ray analysis and emission spectral analysis to establish the analytical method. By using these in-house standard samples, acceptance analysis was successfully carried out for the fuel cladding tubes for advanced thermal reactors. Sulfuric acid solution was prepared from JAERI-Z 1, 2 and 3, the standard sample for zircaloy-2 prepared by the Analytical Committee on Nuclear Fuel and Reactor Materials, JAERI, and zirconium oxide (Hf 1 ppm/Zr). Standard Hf solution was added to the sulfuric acid solution step by step, to make up a series of the standard oxide samples by the precipitation process. By the use of these standard samples, the development of the analytical method and joint analysis were made by the three-member analytical technique research group including PNC. The analytical precision for the fluorescent X-ray analysis was improved by attaching a metallic yttrium filter to the window of an X-ray tube so as to suppress the effect due to zirconium matrix. The variation factor of the joint analysis was about 10% to show good agreement, and the indication value was determined. (Kobatake, H.)

  10. Primary hafnium metal sponge and other forms, approved standard 1973

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    A specification is presented covering virgin hafnium metal commonly designated as sponge because of its porous, sponge-like texture; it may also be in other forms such as chunklets. The specification does not cover crystal bar

  11. Investigation of colourless complexes of thorium, hafnium and zirconium

    International Nuclear Information System (INIS)

    Kiciak, S.; Stefanowicz, T.; Gontarz, H.; Swit, Z.

    1980-01-01

    The investigations conducted in the Institute of General Chemistry of Poznan Technical University in partial cooperation with Kharkhof Technical University related with thorium, hafnium and zirconium complexes are reviewed. (author)

  12. Molten salt extractive distillation process for zirconium-hafnium separation

    International Nuclear Information System (INIS)

    McLaughlin, D.F.; Stoltz, R.A.

    1989-01-01

    This patent describes an improvement in a process for zirconium-hafnium separation. It utilizes an extractive distillation column with a mixture of zirconium and hafnium tetrachlorides introduced into a distillation column having a top and bottom with hafnium enriched overheads taken from the top of the column and a molten salt solvent circulated through the column to provide a liquid phase, and with molten salt solvent containing zirconium chloride being taken from the bottom of the distillation column. The improvements comprising: utilizing a molten salt solvent consisting principally of lithium chloride and at least one of sodium, potassium, magnesium and calcium chlorides; stripping of the zirconium chloride taken from the bottom of the distillation column by electrochemically reducing zirconium from the molten salt solvent; and utilizing a pressurized reflux condenser on the top of the column to add the hafnium chloride enriched overheads to the molten salt solvent previously stripped of zirconium chloride

  13. Internal Dosimetry for Inhalation of Hafnium Tritide Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Inkret, W.C.T.; Schillaci, M.E.; Boyce, M.K.; Cheng, Y.S.; Efurd, D.W.; Little, T.T.; Miller, G.; Musgrave, J.A.; Wermer, J.R

    2001-07-01

    Metal tritides with low dissolution rates may have residence times in the lungs which are considerably longer than the biological half-time normally associated with tritium in body water, resulting in long-term irradiation of the lungs by low energy {beta} particles and bremsstrahlung X rays. Samples of hafnium tritide were placed in a lung simulant fluid to determine approximate lung dissolution rates. Hafnium hydride samples were analysed for particle size distribution with a scanning electron microscope. Lung simulant data indicated a biological dissolution half-time for hafnium tritide on the order of 10{sup 5}d. Hafnium hydride particle sizes ranged between 2 and 10 {mu}m, corresponding to activity median aerodynamic diameters of 5 to 25 {mu}m. Review of in vitro dissolution data, development of a biokinetic model, and determination of secondary limits for 1 {mu}m AMAD particles are presented and discussed. (author)

  14. New solvent extraction process for zirconium and hafnium

    International Nuclear Information System (INIS)

    Takahashi, M.; Katoh, Y.; Miyazaki, H.

    1984-01-01

    The authors' company developed a new solvent extraction process for zirconium and hafnium separation, and started production of zirconium sponge by this new process in September 1979. The process utilizes selective extraction of zirconium oxysulfate using high-molecular alkyl amine, and has the following advantages: 1. This extraction system has a separation factor as high as 10 to 20 for zirconium and hafnium in the range of suitable acid concentration. 2. In the scrubbing section, removal of all the hafnium that coexists with zirconium in the organic solvent can be effectively accomplished by using scrubbing solution containing hafnium-free zirconium sulfate. Consequently, hafnium in the zirconium sponge obtained is reduced to less than 50 ppm. 3. The extractant undergoes no chemical changes but is very stable for a long period. In particular, its solubility in water is small, about 20 ppm maximum, posing no environmental pollution problems such as are often caused by other process raffinates. At the present time, the zirconium and hafnium separation operation is very stable, and zirconium sponge made by this process can be applied satisfactorily to nuclear reactors

  15. Separation process of zirconium and hafnium

    International Nuclear Information System (INIS)

    Hure, J.; Saint-James, R.

    1955-01-01

    About the separation different processes of zirconium-hafnium, the extraction by solvent in cross-current is the most easily the process usable on an industrial scale. It uses tributyl phosphate as solvent, diluted with white spirit to facilitate the decanting. Some exploratory tests showed that nitric environment seemed the most favorable for extraction; but a lot of other factors intervene in the separation process. We studied the influence of the acidity successively, the NO 3 - ions concentration, the role of the cation coming with NO 3 - , as well as the influence of the concentration of zirconium in the solution on the separation coefficient β = α Zr / α Hf . (M.B.) [fr

  16. The interaction of fast neutrons with hafnium

    International Nuclear Information System (INIS)

    Smith, A.B.

    2002-01-01

    Elemental hafnium neutron total cross sections are measured from ∼0.75 to 4.5 MeV in steps of ∼40 keV. Differential neutron elastic-scattering cross sections are measured from ∼4.5 to 10.0 MeV in ∼0.5 MeV steps and at 40 scattering angles distributed between ∼17 and 160 deg. These data are combined with those found in the literature to construct a comprehensive experimental data base which is interpreted in terms of coupled-channels models. Physical characteristics of the resulting potentials are discussed. Comparisons are made with ENDF/B-6 (MAT 7200). A detailed report of this work is given by Smith (Smith, A., 2001. Argonne National Laboratory Report ANL/NDM-153)

  17. High temperature diffusion of hafnium in tungsten and a tungsten-hafnium carbide alloy

    International Nuclear Information System (INIS)

    Ozaki, Y.; Zee, R.H.

    1994-01-01

    Refractory metals and ceramics are used extensively in energy systems due to their high temperature properties. This is particularly important in direct conversion systems where thermal to electric conversion efficiency is a direct function of temperature. Tungsten, which has the highest melting temperature among elemental metals, does not possess sufficient creep resistance at temperature above 1,600 K. Different dispersion strengthened tungsten alloys have been developed to extend the usefulness of tungsten to higher temperatures. One of these alloys, tungsten with 0.4 mole percent of finely dispersed HfC particles (W-HfC), has the optimum properties for high temperature applications. Hafnium carbide is used as the strengthening agent due to its high chemical stability and its compatibility with tungsten. The presence of HfC particles retards the rate of grain growth as well as restricting dislocation motion. Both of which are beneficial for creep resistance. The long term behavior of this alloy depends largely on the evolution of its microstructure which is governed by the diffusion of its constituents. Data on the diffusion of carbon in tungsten and tungsten self-diffusion are available, but no direct measurements have been made on the diffusion of hafnium in tungsten. The only diffusion data available are estimated from a coarsening study and these data are highly unreliable. In this study, the diffusion behavior of hafnium in pure tungsten and in a W-HfC alloy was directly measured by means of Secondary Ion Mass Spectroscopy (SIMS). The selection of the W-HfC alloy is due to its importance in high temperature engineering applications, and its higher recrystallization temperature. The presence of HfC particles in tungsten restricts grain growth resulting in better high temperature creep resistance. The higher recrystallization temperature allows measurements to be made over a wider range of temperatures at a relatively constant grain size

  18. Preparation of Erbium-169 (169Er) Using Natural Erbium Target

    International Nuclear Information System (INIS)

    Azmairit Aziz; Nana Suherman

    2009-01-01

    The therapeutic radiopharmaceuticals which is labelled by β-particle emission are now increasingly used in nuclear medicine. Erbium-169 ('1 69 Er) is one of radioisotopes that can be used for radiation synovectomy (radio synovectomy) in the treatment of inflammatory joint diseases (arthritis) due to its β- particle emission (T 1/2 =9.4 days, E β maximum =0.34 MeV). The preliminary study on preparation of 169 Er by using natural erbium oxide (Er 2 O 3 ) target irradiated at TRIGA 2000 Bandung reactor has been carried out. The irradiated target was dissolved in hydrochloric acid solution and gentle warming. The optimum condition of 169 Er preparation was obtained by dissolution of 169 Er 2 O 3 by using 1N HCl solution. The radiochemical purity of 169 ErCl 3 was determined by paper chromatography, thin layer chromatography and paper electrophoresis techniques. The solution of 169 ErCl 3 formed was obtained with the pH of 1.5 – 2, clear, with the specific activity of 0.48 – 0.71 MBq/mg Er. The solution has the radiochemical purity of 98.32 ± 1.28% and the radionuclide purity of 99.98%. Study on the stability of 169 ErCl 3 solution showed that the solution was still stable for 4 days at room temperature with the radiochemical purity more than 95%. (author)

  19. 40 CFR 471.90 - Applicability; description of the zirconium-hafnium forming subcategory.

    Science.gov (United States)

    2010-07-01

    ... zirconium-hafnium forming subcategory. 471.90 Section 471.90 Protection of Environment ENVIRONMENTAL... POINT SOURCE CATEGORY Zirconium-Hafnium Forming Subcategory § 471.90 Applicability; description of the zirconium-hafnium forming subcategory. This subpart applies to discharges of pollutants to waters of the...

  20. 40 CFR 421.330 - Applicability: Description of the primary zirconium and hafnium subcategory.

    Science.gov (United States)

    2010-07-01

    ... primary zirconium and hafnium subcategory. 421.330 Section 421.330 Protection of Environment ENVIRONMENTAL... CATEGORY Primary Zirconium and Hafnium Subcategory § 421.330 Applicability: Description of the primary zirconium and hafnium subcategory. The provisions of this subpart are applicable to discharges resulting...

  1. Ground-state structures of Hafnium clusters

    Energy Technology Data Exchange (ETDEWEB)

    Ng, Wei Chun; Yoon, Tiem Leong [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Lim, Thong Leng [Faculty of Engineering and Technoloty, Multimedia University, Melaca Campus, 75450 Melaka (Malaysia)

    2015-04-24

    Hafnium (Hf) is a very large tetra-valence d-block element which is able to form relatively long covalent bond. Researchers are interested to search for substitution to silicon in the semi-conductor industry. We attempt to obtain the ground-state structures of small Hf clusters at both empirical and density-functional theory (DFT) levels. For calculations at the empirical level, charge-optimized many-body functional potential (COMB) is used. The lowest-energy structures are obtained via a novel global-minimum search algorithm known as parallel tempering Monte-Carlo Basin-Hopping and Genetic Algorithm (PTMBHGA). The virtue of using COMB potential for Hf cluster calculation lies in the fact that by including the charge optimization at the valence shells, we can encourage the formation of proper bond hybridization, and thus getting the correct bond order. The obtained structures are further optimized using DFT to ensure a close proximity to the ground-state.

  2. Hafnium carbide nanocrystal chains for field emitters

    International Nuclear Information System (INIS)

    Tian, Song; Li, Hejun; Zhang, Yulei; Ren, Jincui; Qiang, Xinfa; Zhang, Shouyang

    2014-01-01

    A hafnium carbide (HfC) nanostructure, i.e., HfC nanocrystal chain, was synthesized by a chemical vapor deposition (CVD) method. X-ray diffractometer, field-emission scanning electron microscope, transmission electron microscope, and energy-dispersive X-ray spectrometer were employed to characterize the product. The synthesized one-dimensional (1D) nanostructures with many faceted octahedral nanocrystals possess diameters of tens of nanometers to 500 nm and lengths of a few microns. The chain-like structures possess a single crystalline structure and preferential growth direction along the [1 0 0] crystal orientation. The growth of the chains occurred through the vapor–liquid–solid process along with a negative-feedback mechanism. The field emission (FE) properties of the HfC nanocrystal chains as the cold cathode emitters were examined. The HfC nanocrystal chains display good FE properties with a low turn-on field of about 3.9 V μm −1 and a high field enhancement factor of 2157, implying potential applications in vacuum microelectronics.

  3. Use of hafnium in control bars of nuclear reactors

    International Nuclear Information System (INIS)

    Ramirez S, J.R.; Alonso V, G.

    2003-01-01

    Recently the use of hafnium as neutron absorber material in nuclear reactors has been reason of investigation by virtue of that this material has nuclear properties as to the neutrons absorption and structural that can prolong the useful life of the control mechanisms of the nuclear reactors. In this work some of those more significant hafnium properties are presented like nuclear material. Also there are presented calculations carried out with the HELIOS code for fuel cells of uranium oxide and of uranium and plutonium mixed oxides under controlled conditions with conventional bars of boron carbide and also with similar bars to which are substituted the absorbent material by metallic hafnium, the results are presented in this work. (Author)

  4. Analytical study of zirconium and hafnium α-hydroxy carboxylates

    International Nuclear Information System (INIS)

    Terra, V.R.

    1991-01-01

    The analytical study of zirconium and hafnium α-hydroxy carboxylates was described. For this purpose dl-mandelic, dl-p-bromo mandelic, dl-2-naphthyl glycolic, and benzilic acids were prepared. These were used in conjunction with glycolic, dl-lactic, dl-2-hydroxy isovaleric, dl-2-hydroxy hexanoic, and dl-2-hydroxy dodecanoic acids in order to synthesize the zirconium(IV) and hafnium(IV) tetrakis(α-hydroxy carboxylates). The compounds were characterized by melting point determination, infrared spectroscopy, thermogravimetric analysis, calcination to oxides and X-ray diffractometry by the powder method. (C.G.C)

  5. High temperature evaporation of titanium, zirconium and hafnium carbides

    International Nuclear Information System (INIS)

    Gusev, A.I.; Rempel', A.A.

    1991-01-01

    Evaporation of cubic nonstoichiometric carbides of titanium, zirconium and hafnium in a comparatively low-temperature interval (1800-2700) with detailed crystallochemical sample certification is studied. Titanium carbide is characterized by the maximum evaporation rate: at T>2300 K it loses 3% of sample mass during an hour and at T>2400 K titanium carbide evaporation becomes extremely rapid. Zirconium and hafnium carbide evaporation rates are several times lower than titanium carbide evaporation rates at similar temperatures. Partial pressures of metals and carbon over the carbides studied are calculated on the base of evaporation rates

  6. Preparation of complexes of zirconium and hafnium tetrachlorides with phosphorus oxychloride

    International Nuclear Information System (INIS)

    McLaughlin, D.F.

    1989-01-01

    This patent describes an improvement in a method for separating hafnium tetrachloride from zirconium tetrachloride where a complex of zirconium-hafnium tetrachlorides and phosphorus oxychloride is prepared from zirconium-hafnium tetrachlorides and the complex of zirconium-hafnium tetrachlorides and phosphorus oxychloride is introduced into a distillation column, which distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and where a hafnium tetrachloride enriched stream is taken from the top of the column and a zirconium enriched tetrachloride stream is taken from the bottom of the column. The improvement comprising: prepurifying the zirconium-hafnium tetrachlorides, prior to preparation of the complex and introduction of the complex into a distillation column, to substantially eliminate iron chloride from the zirconium hafnium tetrachlorides, whereby buildup or iron chloride in the distillation column and in the reboiler is substantially eliminated and the column can be operated in a continuous, stable and efficient manner

  7. Separation process of zirconium and hafnium; Procede de separation du zirconium et du hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Hure, J; Saint-James, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    About the separation different processes of zirconium-hafnium, the extraction by solvent in cross-current is the most easily the process usable on an industrial scale. It uses tributyl phosphate as solvent, diluted with white spirit to facilitate the decanting. Some exploratory tests showed that nitric environment seemed the most favorable for extraction; but a lot of other factors intervene in the separation process. We studied the influence of the acidity successively, the NO{sub 3}{sup -} ions concentration, the role of the cation coming with NO{sub 3}{sup -}, as well as the influence of the concentration of zirconium in the solution on the separation coefficient {beta} = {alpha}{sub Zr} / {alpha}{sub Hf}. (M.B.) [French] Des differents procedes de separation zirconium-hafnium, l'extraction par solvant en contre-courant est le procede le plus facilement utilisable a l'echelle industrielle. On utilise comme solvant le phosphate de tributyle, dilue avec du white spirit pour faciliter les decantations. Des essais preliminaires ont montre que le milieu nitrique semblait le plus favorable a l'extraction; mais beaucoup d'autres facteurs interviennent dans le processus de separation. Nous avons etudie successivement l'influence de l'acidite, celle de la concentration en ions NO{sub 3}{sup -}, le role du cation accompagnant NO{sub 3}{sup -}, ainsi que l'influence de la concentration en zirconium de la solution sur le coefficient de separation {beta} = {alpha}{sub Zr} / {alpha}{sub Hf}. (MB)

  8. Separation of zirconium and hafnium using paper distribution chromatography

    International Nuclear Information System (INIS)

    Lebedeva, G.G.; Viktorova, M.E.

    1981-01-01

    A method is suggested of chromatographic separation of zirconium and hafnium in a CCl 4 -tributyl phosphate system (1:9) containing KCl as a salting-out agent in 5 M HNO 3 at 28-30 deg C. Zr and Hf are deterfmined in articiial mixtures under optimal chromatography conditions using visual colorimetry [ru

  9. X-Ray Photoemission Study of the Oxidation of Hafnium

    International Nuclear Information System (INIS)

    Chourasia, R.; Hickman, J.L.; Miller, R.L.; Nixon, G.A.; Seabolt, M.A.

    2011-01-01

    About 20 angstrom of hafnium were deposited on silicon substrates using the electron beam evaporation technique. Two types of samples were investigated. In one type, the substrate was kept at the ambient temperature. After the deposition, the substrate temperature was increased to 100, 200, and 300 degree C. In the other type, the substrate temperature was held fixed at some value during the deposition. For this type, the substrate temperatures used were 100, 200, 300, 400, 500, 550, and 600 degree C. The samples were characterized in situ by the technique of X-ray photoelectron spectroscopy. No trace of elemental hafnium is observed in the deposited overlayer. Also, there is no evidence of any chemical reactivity between the overlayer and the silicon substrate over the temperature range used. The hafnium overlayer shows a mixture of the dioxide and the suboxide. The ratio of the suboxide to dioxide is observed to be more in the first type of samples. The spectral data indicate that hafnium has a strong affinity for oxygen. The overlayer gets completely oxidized to form HfO 2 at substrate temperature around 300 degree C for the first type of samples and at substrate temperature greater than 550 degree C for the second type

  10. X-Ray Photoemission Study of the Oxidation of Hafnium

    Directory of Open Access Journals (Sweden)

    A. R. Chourasia

    2009-01-01

    Full Text Available About 20 Å of hafnium were deposited on silicon substrates using the electron beam evaporation technique. Two types of samples were investigated. In one type, the substrate was kept at the ambient temperature. After the deposition, the substrate temperature was increased to 100, 200, and 300∘C. In the other type, the substrate temperature was held fixed at some value during the deposition. For this type, the substrate temperatures used were 100, 200, 300, 400, 500, 550, and 600∘C. The samples were characterized in situ by the technique of X-ray photoelectron spectroscopy. No trace of elemental hafnium is observed in the deposited overlayer. Also, there is no evidence of any chemical reactivity between the overlayer and the silicon substrate over the temperature range used. The hafnium overlayer shows a mixture of the dioxide and the suboxide. The ratio of the suboxide to dioxide is observed to be more in the first type of samples. The spectral data indicate that hafnium has a strong affinity for oxygen. The overlayer gets completely oxidized to form HfO2 at substrate temperature around 300∘C for the first type of samples and at substrate temperature greater than 550∘C for the second type.

  11. 46 CFR 169.569 - Fire axes.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fire axes. 169.569 Section 169.569 Shipping COAST GUARD... Firefighting Equipment Firefighting Equipment § 169.569 Fire axes. (a) Each vessel must carry at least the number of fire axes set forth in Table 169.569(a). The Officer in Charge, Marine Inspection may require...

  12. Modelling of Zirconium and Hafnium separation using continuous annular chromatography

    International Nuclear Information System (INIS)

    Moch-Setyadji; Endang Susiantini

    2014-01-01

    Nuclear degrees of zirconium in the form of a metal alloy is the main material for fuel cladding of NPP. Zirconium is also used as sheathing UO 2 kernel in the form of ZrC as a substitute of SiC in the fuel elements of High Temperature Reactor (HTR). Difficulty separating hafnium from zirconium because it has a lot of similarities in the chemical properties of Zr and Hf. Annular chromatography is a device that can be used for separating of zirconium and hafnium to obtain zirconium nuclear grade. Therefore, it is necessary to construct the mathematical modelling that can describe the separation of zirconium and hafnium in the annular chromatography containing anion resin dowex-1X8. The aim of research is to perform separation simulation by using the equilibrium model and mass transfer coefficient resulted from research. Zr and Hf feed used in this research were 26 and 1 g/l, respectively. Height of resin (L), angular velocity (ω) and the superficial flow rate (uz) was varied to determine the effect of each parameter on the separation of Zr and Hf. By using Kd and Dv values resulted previous research. Simulation results showed that zirconium and hafnium can be separated using a continuous annular chromatography with high resin (long bed) 50 cm, superficial flow rate of 0.001 cm/s, the rotation speed of 0.006 rad/min and 20 cm diameter annular. In these conditions the results obtained zirconium concentration of 10,303.226 g/m 3 and hafnium concentration of 12.324 g/m 3 (ppm). (author)

  13. Hafnium Resonance Parameter Analysis Using Neutron Capture and Transmission Experiments

    International Nuclear Information System (INIS)

    MJ Trbovich; DP Barry; RE Slovacck; Y Danon; RC Block; JA Burke; NJ Drindak; G Leinweber; RV Ballad

    2004-01-01

    The focus of this work is to determine resonance parameters for stable hafnium isotopes in the 0.005-200 eV region, with special emphasis on the overlapping 176 Hf and 178 Hf resonances near 8 eV. The large neutron cross section of hafnium, combined with its corrosion resistance and excellent mechanical properties, make it a useful material for controlling nuclear reactions. Experiments measuring neutron capture and transmission were performed at the Rensselaer Polytechnic Institute (RPI) electron linear accelerator (LINAC) using the time of flight method. 6 Li glass scintillation detectors were used for transmission experiments at flight path lengths of 15 and 25 m. Capture experiments were done using a sixteen section NaI(Tl) multiplicity detector at a flight path length of 25 m. These experiments utilized various thicknesses of metallic and isotopically-enriched liquid samples. The liquid samples were designed to provide information on the 176 Hf and 178 Hf contributions to the 8 eV doublet without saturation. Data analysis was done using the R-matrix Bayesian code SAMMY version M6 beta. SAMMY is able to account for experimental resolution effects for each of the experimental setups at the RPI LINAC, and also can correct for multiple scattering effects in neutron capture yield data. The combined capture and transmission data analysis yielded resonance parameters for all hafnium isotopes from 0.005-200 eV. Resonance integrals were calculated along with errors for each hafnium isotope using the NJOY [1] and INTER [2] codes. The isotopic resonance integrals calculated were significantly different than previously published values; however the calculated elemental hafnium resonance integral changed very little

  14. 46 CFR 169.559 - Fire pumps.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fire pumps. 169.559 Section 169.559 Shipping COAST GUARD... Firefighting Equipment Firefighting Equipment § 169.559 Fire pumps. (a) Each sailing school vessel must be equipped with fire pumps as required in Table 169.559(a). Table 169.559(a)—Fire Pumps Length Exposed and...

  15. Electronic properties of hafnium oxide: A contribution from defects and traps

    Energy Technology Data Exchange (ETDEWEB)

    Gritsenko, Vladimir A., E-mail: grits@isp.nsc.ru; Perevalov, Timofey V.; Islamov, Damir R., E-mail: damir@isp.nsc.ru

    2016-02-15

    In the present article, we give a review of modern data and latest achievements pertaining to the study of electronic properties of oxygen vacancies in hafnium oxide. Hafnium oxide is a key dielectric for use in many advanced silicon devices. Oxygen vacancies in hafnium oxide largely determine the electronic properties of the material. We show that the electronic transitions between the states due to oxygen vacancies largely determine the optical absorption and luminescent properties of hafnium oxide. We discuss the role of oxygen vacancies as traps that facilitate charge transport in hafnium oxide films. Also, we demonstrate the fact that the electrical conductivity in hafnium oxide is controlled by the phonon-assisted tunnelling of charge carriers between traps that were identified as oxygen vacancies.

  16. Method of purifying zirconium tetrachloride and hafnium tetrachloride in a vapor stream

    International Nuclear Information System (INIS)

    Snyder, T.S.; Stolz, R.A.

    1992-01-01

    This patent describes a method of purifying zirconium tetrachloride and hafnium tetrachloride in a vapor stream from a sand chlorinator in which the silicon and metals present in sand fed to the chlorinator are converted to chlorides at temperatures over about 800 degrees C. It comprises cooling a vapor stream from a sand chlorinator, the vapor stream containing principally silicon tetrachloride, zirconium tetrachloride, and hafnium tetrachloride contaminated with ferric chloride, to a temperature of from about 335 degrees C to about 600 degrees C; flowing the vapor stream through a gaseous diffusion separative barrier to produce a silicon tetrachloride-containing vapor stream concentrated in zirconium tetrachloride and hafnium tetrachloride and a silicon tetrachloride-containing vapor stream depleted in zirconium tetrachloride and hafnium tetrachloride; adsorbing the ferric chloride in the separative barrier; and recovering the silicon tetrachloride stream concentrated in zirconium tetrachloride and hafnium tetrachloride separately from the silicon tetrachloride stream depleted in zirconium tetrachloride and hafnium tetrachloride

  17. Synthesis of Hafnium-Based Ceramic Materials for Ultra-High Temperature Aerospace Applications

    Science.gov (United States)

    Johnson, Sylvia; Feldman, Jay

    2004-01-01

    This project involved the synthesis of hafnium (Hf)-based ceramic powders and Hf-based precursor solutions that were suitable for preparation of Hf-based ceramics. The Hf-based ceramic materials of interest in this project were hafnium carbide (with nominal composition HE) and hafnium dioxide (HfO2). The materials were prepared at Georgia Institute of Technology and then supplied to research collaborators Dr. Sylvia Johnson and Dr. Jay Feldman) at NASA Ames Research Center.

  18. Elaboration and characterisation of yttrium oxide and hafnium oxide powders by the sol-gel process

    International Nuclear Information System (INIS)

    Hours, T.

    1988-01-01

    The two classical sol-gel processes, colloidal and polymeric are studied for the preparation of yttrium oxide and hafnium oxide high performance powders. In the colloidal process, controlled and reproducible conditions for the preparation of yttrium oxide and hafnium oxide sols from salts or alkoxides are developed and the hydrothermal synthesis monodisperse hafnium oxide colloids is studied. The polymeric process is studied with hafnium ethyl-hexylate, hydrolysis kinetics for controlled preparation of sols and gels is investigated. Each step of preparation is detailed and powders obtained are characterized [fr

  19. Design and fabrication of hafnium tube to control the power of the irradiation test fuel in HANARO

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D. H.; Lee, C. B.; Kim, Y. M.; Yang, Y. S.; Jung, Y. H

    2003-05-01

    For the irradiation test at HANARO, non-instrumentation capsule was manufactured and hafnium tube was used to control LHGR of HANARO. Hafnium tube can control the irradiation condition of HANARO similar to that of commercial reactor. Hafnium tube thickness was determined by the LHGR calculated at OR-4 irradiation hole to be installed the non-instrumented capsule. To fabricate the hafnium tube with hafnium plate, the fabrication method was determined by using the hafnium mechanical properties. And the tensile strength of hafnium was confirmed by tensile test. This report is confirmed the LHGR control at the OR-4 and the Hafnium fabrication for in used which the AFPCAP non-instrumented irradiation capsule.

  20. Pentamethylcyclopentadienyl Zirconium and Hafnium Polyhydride Complexes : Synthesis, Structure, and Reactivity

    NARCIS (Netherlands)

    Visser, Cindy; Hende, Johannes R. van den; Meetsma, Auke; Hessen, Bart; Teuben, Jan H.

    2001-01-01

    The half-sandwich zirconium and hafnium N,N-dimethylaminopropyl complexes Cp*M[(CH2)3NMe2]Cl2 (Cp* = η5-C5Me5, M = Zr, 1; Hf, 2) and Cp*M[(CH2)3NMe2]2Cl (M = Zr, 3; Hf, 4) were synthesized by mono- or dialkylation of Cp*MCl3 with the corresponding alkyllithium and Grignard reagents. Hydrogenolysis

  1. Separation of zirconium from hafnium by ion exchange

    Energy Technology Data Exchange (ETDEWEB)

    Felipe, Elaine C.B.; Palhares, Hugo G.; Ladeira, Ana Claudia Q., E-mail: elainecfelipe@yahoo.com.br, E-mail: hugopalhares@gmail.com, E-mail: ana.ladeira@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2013-07-01

    Zirconium and hafnium are two of the most important metals for the nuclear industry. Hafnium occurs in all zirconium ores usually in the range 2 - 3%. However, for the most nuclear industry applications, it is necessary to use a zirconium of extremely pure level. The current work consists in the separation of zirconium and hafnium by the ion exchange method in order to obtain a zirconium concentrate of high purity. The zirconium and hafnium liquors were produced from the leaching of the Zr(OH){sub 4} and Hf(OH){sub 4} with nitric acid for 24 hours. From these two liquors it was prepared one solution containing 7.5 x 10{sup -2} mol L{sup -1} of Zr and 5.8 x 10{sup -3} mol L{sup -1} of Hf with acidity of 1 M. Ion exchange experiments were carried out in batch with the resins Dowex 50WX4, Dowex 50WX8 100, Dowex 50WX8 50, Amberlite IR-120 and Marathon C at constant temperature 28 deg C. Other variables such as, acidity and agitation were kept constant. The data were adjusted to Langmuir equation in order to calculate the maximum loading capacity (q{sub max}) of the resins, the distribution coefficient (K{sub d}) for Zr and Hf and the separation factor (α{sub Hf}{sup Zr} ). The results of maximum loading capacity (q{sub max}) for Zr and Hf, in mmol g{sup -}1, showed that the most suitable resins for columns experiments are: Dowex 50WX4 50 (q{sub max} Z{sub r} = 2.21, Hf = 0.18), Dowex 50WX8 50 (q{sub max} Zr = 1.89, Hf = 0.13) and Amberlite (q{sub max} Zr = 1.64, Hf = 0.12). However, separations factors, α{sub Hf}{sup Zr}, showed that the resins are not selective. (author)

  2. Evolution of the hafnium isotopic composition in the RBMK reactor

    International Nuclear Information System (INIS)

    Jurkevicius, A.; Remeikis, V.

    2002-01-01

    The isotopic composition of hafnium in the radial neutron flux sensor of the RBMK-1500 reactor, the rates of the neutron absorption on Hf isotopes and the neutron spectrum in the sensor were numerically modeled. The sequence SAS2 (Shielding Analysis Sequence) program from the package SCALE 4.4A and the HELIOS code system were used for calculations. It has been obtained that the overall neutron absorption rates in hafnium for the sensors located in the 2.4 % and 2.6 % enrichment uranium-erbium nuclear fuel assemblies are by 16 % and 19 % lower than in the 2.0 % enrichment uranium nuclear fuel assemblies. The overall neutron absorption rate in hafnium decreases 2.70-2.75 times due to the sensor burnup to 5800 MW d. The sensitivity of the Hf sensors to the thermal neutron flux increases twice due to the nuclear fuel assembly burnup to 3000 MW d. The corrective factors ξ d (I) at the different integral current I of the sensors and ξ td (E) at the different burnup E of the nuclear fuel assemblies were calculated. The obtained dependence ξ d (I) calculated numerically was compared to the experimental one determined by comparing signals of the fresh sensor and the sensor with the integral current I and by processing repeated calibration results of Hf sensors in RBMK-1500 reactors. The relative relationship coefficients K T (T FA ) were found for all RBMK-1500 nuclear fuel types. (author)

  3. Recovery of hafnium radioisotopes from a proton irradiated tantalum target

    International Nuclear Information System (INIS)

    Taylor, W.A.; Garcia, J.G.; Hamilton, V.T.; Heaton, R.C.; Jamriska, D.J.; Ott, M.A.; Philips, D.R.; Radzinski, S.D.

    1998-01-01

    The 178m2 Hf nucleus, with its long half-life (31 y) and high-spin isomeric state (16 + ) is desired for new and exotic nuclear physics studies. The Los Alamos Radioisotope Program irradiated a kilogram of natural tantalum at the Los Alamos Meson Physics Facility in early 1981. After fifteen years of decay, this target was ideal for the recovery of 178m2 Hf. There was more than a millicurie of 178m2 Hf produced during this irradiation and there has been a sufficient period of time for most of the other hafnium radioisotopes to decayed away. Traditionally, separation techniques for recovering hafnium isotopes from tantalum targets employ solvent extractions with reagents that are considered hazardous. These techniques are no longer condoned because they generate a mixed-waste (radioactive and hazardous components) that can not be treated for disposal. In this paper we describe a new and unique procedure for the recovery of hafnium radioisotopes from a highly radioactive, proton irradiated, tantalum target using reagents that do not contribute a hazardous waste component. (author)

  4. 46 CFR 169.112 - Special consideration.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Special consideration. 169.112 Section 169.112 Shipping... Provisions § 169.112 Special consideration. In applying the provisions of this part, the Officer in Charge, Marine Inspection, may give special consideration to departures from the specific requirements when...

  5. 46 CFR 169.688 - Power supply.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Power supply. 169.688 Section 169.688 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Electrical Installations on Vessels of 100 Gross Tons and Over § 169.688 Power supply. (a) The...

  6. 14 CFR 169.5 - FAA determination.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false FAA determination. 169.5 Section 169.5 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRPORTS EXPENDITURE OF FEDERAL FUNDS FOR NONMILITARY AIRPORTS OR AIR NAVIGATION FACILITIES THEREON § 169.5 FAA...

  7. 46 CFR 169.239 - Hull.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Hull. 169.239 Section 169.239 Shipping COAST GUARD... Certification Inspections § 169.239 Hull. At each inspection for certification and periodic inspection, the vessel must be afloat and ready for the following tests and inspections of the hull structure and its...

  8. 46 CFR 169.689 - Demand loads.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Demand loads. 169.689 Section 169.689 Shipping COAST... Electrical Electrical Installations on Vessels of 100 Gross Tons and Over § 169.689 Demand loads. Demand loads must meet § 111.60-7 of this chapter except that smaller demand loads for motor feeders are...

  9. 46 CFR 169.609 - Exhaust systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Exhaust systems. 169.609 Section 169.609 Shipping COAST... Electrical Internal Combustion Engine Installations § 169.609 Exhaust systems. Engine exhaust installations... Yacht Council, Inc. Standard P-1, “Safe Installation of Exhaust Systems for Propulsion and Auxiliary...

  10. 46 CFR 169.642 - Vital systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Vital systems. 169.642 Section 169.642 Shipping COAST... Electrical Piping Systems § 169.642 Vital systems. For the purpose of this part, the following are considered vital systems— (a) A marine engineering system identified by the OCMI as being crucial to the survival...

  11. 21 CFR 169.115 - French dressing.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false French dressing. 169.115 Section 169.115 Food and... § 169.115 French dressing. (a) Description. French dressing is the separable liquid food or the..., lecithin, or polyglycerol esters of fatty acids. (d) Nomenclature. The name of the food is “French dressing...

  12. 46 CFR 169.654 - Bilge pumps.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Bilge pumps. 169.654 Section 169.654 Shipping COAST... Electrical Bilge Systems § 169.654 Bilge pumps. (a) Vessels of less than 65 feet in length must have a portable hand bilge pump having a maximum capacity of 5 gpm. (b) In addition to the requirements of...

  13. 46 CFR 169.311 - Fire protection.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fire protection. 169.311 Section 169.311 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction and Arrangement Hull Structure § 169.311 Fire protection. (a) The general construction of the vessel...

  14. 46 CFR 169.668 - Batteries.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Batteries. 169.668 Section 169.668 Shipping COAST GUARD... § 169.668 Batteries. (a) Each battery must be in a location that allows the gas generated in charging to... this section, a battery must not be located in the same compartment with a gasoline tank or gasoline...

  15. 46 CFR 169.723 - Safety belts.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Safety belts. 169.723 Section 169.723 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.723 Safety belts. Each vessel must carry a harness type safety belt conforming to Offshore Racing Council (ORC) standards for each person on watch or...

  16. 28 CFR 16.9 - Appeals.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Appeals. 16.9 Section 16.9 Judicial Administration DEPARTMENT OF JUSTICE PRODUCTION OR DISCLOSURE OF MATERIAL OR INFORMATION Procedures for Disclosure of Records Under the Freedom of Information Act § 16.9 Appeals. (a) Appeals of adverse...

  17. 10 CFR 16.9 - Hearing.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Hearing. 16.9 Section 16.9 Energy NUCLEAR REGULATORY... § 16.9 Hearing. (a) Request for hearing. (1) An employee shall file a petition for a hearing in... creditor agency, a hearing may be requested by filing a written petition stating why the employee disputes...

  18. 46 CFR 169.329 - Storm rails.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Storm rails. 169.329 Section 169.329 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction and Arrangement Rails and Guards § 169.329 Storm rails. Suitable storm rails or hand grabs must be...

  19. 46 CFR 169.619 - Reliability.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Reliability. 169.619 Section 169.619 Shipping COAST... Electrical Steering Systems § 169.619 Reliability. (a) Except where the OCMI judges it impracticable, the... be below that necessary for the safe navigation of the vessel. (c) The strength and reliability of...

  20. Zirconium and hafnium in the southeastern Atlantic States

    Science.gov (United States)

    Mertie, J.B.

    1958-01-01

    The principal source of zirconium and hafnium is zircon, though a minor source is baddeleyite, mined only in Brazil. Zircon is an accessory mineral in igneous, metamorphic, and sedimentary rocks, but rarely occurs in hardrock in minable quantities. The principal sources of zircon are therefore alluvial deposits, which are mined in many countries of five continents. The principal commercial deposits in the United States are in Florida, though others exist elsewhere in the southeastern Coastal Plain. The evidence indicates that conditions for the accumulation of workable deposits of heavy minerals were more favorable during the interglacial stages of the Pleistocene epoch than during Recent time. Therefore detrital ores of large volume and high tenor are more likely to be found in the terrace deposits than along the present beaches. Other concentrations of heavy minerals, however, are possible at favored sites close to the Fall Line where the Tuscaloosa formation rests upon the crystalline rocks of the Piedmont province. A score of heavy and semiheavy minerals occur in the detrital deposits of Florida, but the principal salable minerals are ilmenite, leucoxene, rutile, and zircon, though monazite and staurolite are saved at some mining plants. Commercial deposits of heavy minerals are generally required to have a tenor of 4 percent, though ores with a lower tenor can be mined at a profit if the content of monazite is notably high. The percentages of zircon in the concentrates ranges from 10 to 16 percent, and in eastern Florida from 13 to 15 percent. Thus the tenor in zircon of the ore-bearing sands ranges from 0.4 to 0.6 percent. The content of hafnium in zircon is immaterial for many uses, but for some purposes very high or very low tenors in hafnium are required. Alluvial zircon cannot be separated into such varieties, which, if needed, must be obtained from sources in bedrock. It thus becomes necessary to determine the Hf : Zr ratios in zircon from many kinds of

  1. On the stabilization of niobium(V) solutions by zirconium(IV) and hafnium(IV)

    DEFF Research Database (Denmark)

    Sørensen, E.; Bjerre, A.B.

    1992-01-01

    Niobium cannot be separated from zirconium or hafnium when these elements occur together in solution with common anions such as chloride and sulphate. This is ascribed to the co-polymerization of niobium(V) and the hydrolysed ionic species of zirconium(IV) and hafnium(IV) to form colloidal...

  2. Use of X-ray fluorescence analysis for the determination of hafnium in zircalloys

    International Nuclear Information System (INIS)

    Sato, I.M.; Salvador, V.L.R.; Lordello, A.R.

    1985-01-01

    The determination of hafnium at trace levels (ppm) in the presence of zirconium by X-ray fluorescence technique is presented. The samples were prepared in the form of double-layer pellets, with boric acid as the binding material. The most sensitive first order line of hafnium HfLα (0.157 nm), which is used analyticaly, has approximately 67% overlapping with second order line of zirconium ZrKα 1 , (0.079 nm). As the excitation potencial of zirconium is larger than hafnium, the best condition was selected, so that the interference of zirconium intensity would not be significant in hafnium analytical line. The method allowed the determination of hafnium above 5.0 ppm (LLd = 1.5 ppm) with an accuracy of less than 10%. (Author) [pt

  3. Preparation of complexes of zirconium and hafnium tetrachlorides with phosphorus oxychloride

    International Nuclear Information System (INIS)

    Snyder, T.S.; Stoltz, R.A.

    1989-01-01

    This patent describes an improvement in a method for separating hafnium chloride from zirconium chloride using a distillation column, with a hafnium chloride enriched vapor stream taken from the top of the column and a zirconium enriched chloride stream taken from the bottom of the column. The improvement comprising: purifying the zirconium-hafnium chloride in a molten salt purification vessel prior to or after introduction into the distillation column to substantially eliminate iron chloride from the zirconium-hafnium chloride by at least periodically removing iron chloride from the molten salt purification vessel by electrochemically plating iron onto an electrode in the molten salt purification vessel. The molten salt in the molten salt purification vessel consisting essentially of a mixture of chlorides selected from the group consisting of alkali metals, alkaline earth metals, zirconium, hafnium, aluminum, manganese, and zinc

  4. Properties of neutron-rich hafnium high-spin isomers

    CERN Multimedia

    Tungate, G; Walker, P M; Neyens, G; Billowes, J; Flanagan, K; Koester, U H; Litvinov, Y

    It is proposed to study highly-excited multi-quasiparticle isomers in neutron-rich hafnium (Z=72) isotopes. Long half-lives have already been measured for such isomers in the storage ring at GSI, ensuring their accessibility with ISOL production. The present proposal focuses on:\\\\ (i) an on-line experiment to measure isomer properties in $^{183}$Hf and $^{184}$Hf, and\\\\ (ii) an off-line molecular breakup test using REXTRAP, to provide Hf$^{+}$ beams for future laser spectroscopy and greater sensitivity for the future study of more neutron-rich isotopes.

  5. Studies on Optical and Electrical Properties of Hafnium Oxide Nanoparticles

    Science.gov (United States)

    Jayaraman, Venkatachalam; Sagadevan, Suresh; Sudhakar, Rajesh

    2017-07-01

    In this paper, the synthesis and physico-chemical properties of hafnium oxide nanoparticles (HfO2 NPs) are analyzed and reported. The synthesis was carried out by the precipitation route by using hafnium tetrachloride (HfCl4) as precursor material with potassium hydroxide (KOH) dissolved in Millipore water. In the precipitation technique, the chemical reaction is comparatively simple, low-cost and non-toxic compared to other synthetic methods. The synthesized HfO2 NPs were characterized by using powder x-ray diffraction (PXRD), ultraviolet-visible (UV-Vis) spectroscopy, Raman analysis, and high-resolution transmission electron microscopy (HRTEM). The monoclinic structure of the HfO2 NPs was resolved utilizing x-ray diffraction (XRD). The optical properties were studied from the UV-Vis absorption spectrum. The optical band gap of the HfO2NPs was observed to be 5.1 eV. The Raman spectrum shows the presence of HfO2 NPs. The HRTEM image showed that the HfO2 NPs were of spherical shape with an average particle size of around 28 nm. The energy-dispersive x-ray spectroscopy (EDS) spectrum obviously demonstrated the presence of HfO2 NPs. Analysis and studies on the dielectric properties of the HfO2 NPs such as the dielectric constant, the dielectric loss, and alternating current (AC) conductivity were carried out at varying frequencies and temperatures.

  6. Corrosion potentials of hafnium in molten alkaline-earth metal chlorides

    International Nuclear Information System (INIS)

    Kovalik, O.Yu.; Tkhaj, V.D.

    2000-01-01

    Corrosion potentials of hafnium in molten calcium, strontium and barium chlorides are measured and their temperature dependences are determined. It is stated that the corrosion potential of hafnium becomes more electropositive with an increase of the environment temperature. If the temperature is the same the potential shifts to the interval of more electronegative values in the row of CaCl 2 , SrCl 2 , BaCl 2 which corresponds to a lesser corrosion rate in environments positioned from left to right. the comparison of hafnium corrosion potentials with previously measured values for titanium and zirconium shows that a metal activity decrease results in a more electronegative corrosion potential [ru

  7. Hafnium-Based Contrast Agents for X-ray Computed Tomography.

    Science.gov (United States)

    Berger, Markus; Bauser, Marcus; Frenzel, Thomas; Hilger, Christoph Stephan; Jost, Gregor; Lauria, Silvia; Morgenstern, Bernd; Neis, Christian; Pietsch, Hubertus; Sülzle, Detlev; Hegetschweiler, Kaspar

    2017-05-15

    Heavy-metal-based contrast agents (CAs) offer enhanced X-ray absorption for X-ray computed tomography (CT) compared to the currently used iodinated CAs. We report the discovery of new lanthanide and hafnium azainositol complexes and their optimization with respect to high water solubility and stability. Our efforts culminated in the synthesis of BAY-576, an uncharged hafnium complex with 3:2 stoichiometry and broken complex symmetry. The superior properties of this asymmetrically substituted hafnium CA were demonstrated by a CT angiography study in rabbits that revealed excellent signal contrast enhancement.

  8. 10 CFR 26.169 - Reporting Results.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Reporting Results. 26.169 Section 26.169 Energy NUCLEAR... specific gravity test. (4) For a specimen that has an invalid result, the laboratory shall contact the MRO... transmission and ensure only authorized access to any data transmission, storage, and retrieval system. (f) For...

  9. 25 CFR 169.27 - Power projects.

    Science.gov (United States)

    2010-04-01

    ... 25 Indians 1 2010-04-01 2010-04-01 false Power projects. 169.27 Section 169.27 Indians BUREAU OF... projects. (a) The Act of March 4, 1911 (36 Stat. 1253), as amended by the Act of May 27, 1952 (66 Stat. 95... on any project for the generation of electric power, or the transmission or distribution of...

  10. 46 CFR 169.605 - General.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false General. 169.605 Section 169.605 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical... engine cooling water temperature, exhaust cooling water temperature and engine lubricating oil pressure...

  11. 46 CFR 169.717 - Fireman's outfit.

    Science.gov (United States)

    2010-10-01

    ... helmet that provides effective protection against impact; and (8) Protective clothing. (b) Each vessel... 46 Shipping 7 2010-10-01 2010-10-01 false Fireman's outfit. 169.717 Section 169.717 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel...

  12. Solvent extraction of zirconium and hafnium using MIBK-HSCN-HCL process

    International Nuclear Information System (INIS)

    Borges, J.A.L.; Cunha, O.G.C. da

    1985-01-01

    The separation process of zirconium and hafnium, using MIBK as extractant in a set of mixer-settler is described. The chemical analysis was done by X-ray fluorescence and emission spectrography. (Author) [pt

  13. Hafnium as a prospective absorber for VVER-1000 reactors of Ukraine

    International Nuclear Information System (INIS)

    Afanas'ev, A.A.; Konotop, Yu.F.; Odejchuk, N.L.

    2000-01-01

    Nuclear-physical parameters of hafnium having in mind its use as an absorber, are considered. Technical aspects of Hf production are exposed. Use of B 4 C/Hf absorber is twice cheaper than a standard one

  14. Spectrofluorimetric determination of hafnium and zirconium with 3,7-dihydroxyflavone

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Takushi; Suzuki, Osamu; Seuzuki, Tetsuo; Murata, Akira

    1986-04-01

    The absorptive and fluorescent characteristics of the hafnium and zirconium complexes of 3-hydroxyflavone and its 12 hydroxy and methoxy derivatives have been studied. The fluorescence of the 1:1 hafnium - 3,7-dihydroxyflavone complex (lambdasub(ex.)397 nm,lambdasub(em.) 465 nm) in 3 M hydrochloric acid has been used to determine 2-40 ng ml/sup -1/ of hafnium. The fluorescence of the 1:1 zirconium - 3,7-dihydroxyflavone complex (lambdasub(ex.) 395 nm, lambda sub(em.) 465 nm) at pH 2.0 in 0.02 M sulphate solution has been used to determine 2-40 ng ml/sup -1/ of zirconium. These methods are very sensitive and can be used for the simultaneous determination of hafnium and zirconium with an error of about 5%.

  15. Electronic structure of pentacene on hafnium studied by ultraviolet photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Kang, Seong Jun; Yi, Yeon Jin; Kim, Chung Yi; Whang, Chung Nam

    2005-01-01

    The electronic structure of pentacene on hafnium, which is a low work function metal, was analyzed by using ultraviolet photoelectron spectroscopy. The energy level alignment was studied by using the onset of the highest occupied molecular orbital level and the shift of the vacuum level of the pentacene layer, which was deposited on a clean hafnium surface in a stepwise manner. The measured onset of the highest occupied molecular orbital energy level was 1.52 eV from the Fermi level of hafnium. The vacuum level was shifted 0.28 eV toward higher binding energy with additional pentacene layers, which means an interfacial dipole exists at the interface between pentacene and hafnium. We confirm that a small electron injection barrier can be achieved by inserting a low work function metal in a pentacene thin-film transistor.

  16. Compositional characterization of hafnium alloy used as control rod material in nuclear reactor

    International Nuclear Information System (INIS)

    Sharma, P.K.; Bassan, M.K.T.; Avhad, D.K.; Singhal, R.K.

    2014-01-01

    Hafnium (Hf) is a heavy, steel-gray metal in the reactive metals group that is very closely related to zirconium (Zr) and forms a continuous solid-solution at all concentrations of zirconium and hafnium. Hafnium occurs naturally with zirconium at a ratio of approximately 1:50 and is produced exclusively as a co-product of nuclear-grade zirconium. It is used in a variety of applications where few substitutes are available. Thus with its relatively high thermal neutron absorption cross-section, hafnium's biggest application is as control rod material in nuclear reactors. During this work, major (Zirconium (Zr), Cobalt (Co) and Molybdenum (Mo)) and trace ((Iron (Fe), Nickel (Ni) and Titanium (Ti)) elements were measured in the bulk matrices of Hf. These materials are also associated with other impurities such as O, N, H etc.

  17. Evaluation of thermodynamic data on zirconium and hafnium halides and oxyhalides by means of transport experiments

    International Nuclear Information System (INIS)

    Dittmer, G.; Niemann, U.

    1987-01-01

    A consistent set of thermodynamic data for zirconium and hafnium halides, oxides and oxyhalides was achieved. It was found that formation enthalpies of gaseous compounds could be derived from solubility measurements together with theoretical estimations and a revision of literature data. Free energy functions were calculated employing statistical mechanics. Data for liquid and solid compounds were obtained via sublimation and vaporization data. Chemical equilibria of zirconium and hafnium with halogens are discussed. 51 refs.; 16 figs.; 14 tabs

  18. Investigation of chlorination of zirconium and hafnium and their compounds in discharge from hollow cathode

    International Nuclear Information System (INIS)

    Ioffe, R.B.; Korovin, Yu.I.

    1978-01-01

    The possibility is investigated of chlorinating various zirconium and hafnium compounds (metal, oxide, carbide) in a hot discharge from a hollow cathode with various chlorinating reagents: copper monochloride, nickel chloride, magnesium chloride, for the purpose of accelerating their entrance into the excitation zone. It has been shown thermodynamically and experimentally that chlorination of metal zirconium and hafnium and their carbides with copper monochloride in hot hollow cathode conditions provides a sharp increase in the intensity of the lines of these elements

  19. Knight shift in scandium and its alloys with hafnium and titanium

    International Nuclear Information System (INIS)

    Chachkhiani, Z.B.; Chechernikov, V.I.; Martynova, L.F.; Nidel'ko, V.I.; Chachkhiani, L.G.; Georgadze, G.S.

    1981-01-01

    Results of the investigation of NMR on 45 Sc nuclei and magnetic susceptibility of scandium and its solid solutions with titanium and hafnium are presented. It is shown that the existing hybridization of S and d zones in pure scandium and its alloys with titanium and hafnium affects the Knight shift reducing the value of the contact contribution. The temperature behaviour of the Knight shift from the temperature dependence and spin susceptibility of collectivized d electrons [ru

  20. Application of hafnium hydride control rod to large sodium cooled fast breeder reactor

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Kazumi, E-mail: kazumi_ikeda@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc., 34-17, Jingumae 2-Chome, Shibuya-ku, Tokyo 150-0001 (Japan); Moriwaki, Hiroyuki, E-mail: hiroyuki_moriwaki@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc., 34-17, Jingumae 2-Chome, Shibuya-ku, Tokyo 150-0001 (Japan); Ohkubo, Yoshiyuki, E-mail: yoshiyuki_okubo@mfbr.mhi.co.jp [Mitsubishi FBR Systems, Inc., 34-17, Jingumae 2-Chome, Shibuya-ku, Tokyo 150-0001 (Japan); Iwasaki, Tomohiko, E-mail: tomohiko.iwasaki@qse.tohoku.ac.jp [Department of Quantum Science and Energy Engineering, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai-shi, Miyagi-ken 980-8579 (Japan); Konashi, Kenji, E-mail: konashi@imr.tohoku.ac.jp [Institute for Materials Research, Tohoku University, Narita-cho, Oarai-machi, Higashi-Ibaraki-gun, Ibaraki-ken 311-1313 (Japan)

    2014-10-15

    Highlights: • Application of hafnium hydride control rod to large sodium cooled fast breeder reactor. • This paper treats application of an innovative hafnium hydride control rod to a large sodium cooled fast breeder reactor. • Hydrogen absorption triples the reactivity worth by neutron spectrum shift at H/Hf ratio of 1.3. • Lifetime of the control rod quadruples because produced daughters of hafnium isotopes are absorbers. • Nuclear and thermal hydraulic characteristics of the reactor are as good as or better than B-10 enriched boron carbide. - Abstract: This study treats the feasibility of long-lived hafnium hydride control rod in a large sodium-cooled fast breeder reactor by nuclear and thermal analyses. According to the nuclear calculations, it is found that hydrogen absorption of hafnium triples the reactivity by the neutron spectrum shift at the H/Hf ratio of 1.3, and a hafnium transmutation mechanism that produced daughters are absorbers quadruples the lifetime due to a low incineration rate of absorbing nuclides under irradiation. That is to say, the control rod can function well for a long time because an irradiation of 2400 EFPD reduces the reactivity by only 4%. The calculation also reveals that the hafnium hydride control rod can apply to the reactor in that nuclear and thermal characteristics become as good as or better than 80% B-10 enriched boron carbide. For example, the maximum linear heat rate becomes 3% lower. Owing to the better power distribution, the required flow rate decreases approximately by 1%. Consequently, it is concluded on desk analyses that the long lived hafnium hydride control rod is feasible in the large sodium-cooled fast breeder reactor.

  1. Dielectric response and ac conductivity analysis of hafnium oxide nanopowder

    International Nuclear Information System (INIS)

    Karahaliou, P K; Xanthopoulos, N; Krontiras, C A; Georga, S N

    2012-01-01

    The dielectric response of hafnium oxide nanopowder was studied in the frequency range of 10 -2 -10 6 MHz and in the temperature range of 20-180 °C. Broadband dielectric spectroscopy was applied and the experimental results were analyzed and discussed using the electric modulus (M*) and alternating current (ac) conductivity formalisms. The analyses of the dc conductivity and electric modulus data revealed the presence of mechanisms which are thermally activated, both with almost the same activation energy of 1.01 eV. A fitting procedure involving the superposition of the thermally activated dc conductivity, the universal dielectric responce and the near constant loss terms has been used to describe the frequency evolution of the real part of the specific electrical conductivity. The conductivity master curve was obtained, suggesting that the time-temperature superposition principle applies for the studied system, thus implying that the conductivity mechanisms are temperature independent.

  2. Amorphous Hafnium-Indium-Zinc Oxide Semiconductor Thin Film Transistors

    Directory of Open Access Journals (Sweden)

    Sheng-Po Chang

    2012-01-01

    Full Text Available We reported on the performance and electrical properties of co-sputtering-processed amorphous hafnium-indium-zinc oxide (α-HfIZO thin film transistors (TFTs. Co-sputtering-processed α-HfIZO thin films have shown an amorphous phase in nature. We could modulate the In, Hf, and Zn components by changing the co-sputtering power. Additionally, the chemical composition of α-HfIZO had a significant effect on reliability, hysteresis, field-effect mobility (μFE, carrier concentration, and subthreshold swing (S of the device. Our results indicated that we could successfully and easily fabricate α-HfIZO TFTs with excellent performance by the co-sputtering process. Co-sputtering-processed α-HfIZO TFTs were fabricated with an on/off current ratio of ~106, higher mobility, and a subthreshold slope as steep as 0.55 V/dec.

  3. Determination of hafnium with the inductively coupled plasma (ICP)

    International Nuclear Information System (INIS)

    Wuensch, G.; Pose, K.

    1985-01-01

    The relative intensities of 198 hafnium lines in the Ar-ICP are listed. Spectral interference tables are given for the 9 analytically best lines, covering the range of +-60 pm around the Hf-lines. They include measured (not calculated) data of the interferent equivalent concentrations (IEC) and the critical concentration ratios (CCR) for 115 lines of all 34 possibly interfering elements. In many cases, these IEC- or CCR-data differ by 1 or 2 orders of magnitude from those calculated from intensities observed in the NBS-copper arc. Since no intense Hf-line is free from spectral interferences, examples are given for the calculation of the most suitable line for a known matrix. (orig.) [de

  4. Separation of zirconium--hafnium by nitride precipitation

    International Nuclear Information System (INIS)

    Anderson, R.N.; Parlee, N.A.

    1977-01-01

    A method is described for the separation of a light reactive metal (e.g., zirconium) from a heavy reactive metal (e.g., hafnium) by forming insoluble nitrides of the metals in a molten metal solvent (e.g., copper) inert to nitrogen and having a suitable density for the light metal nitride to form a separate phase in the upper portion of the solvent and for the heavy metal nitride to form a separate phase in the lower portion of the solvent. Nitriding is performed by maintaining a nitrogen-containing atmosphere over the bath. The light and heavy metals may be an oxide mixture and carbothermically reduced to metal form in the same bath used for nitriding. The nitrides are then separately removed and decomposed to form the desired separate metals. 16 claims, 1 figure

  5. Systematic investigation of electromagnetic properties of all stable hafnium isotopes

    International Nuclear Information System (INIS)

    Napiorkowski, T.J.; Choinski, J.; Czosnyka, T.; Iwanicki, J.; Kownacki, J.; Zemlo, L.; Srebrny, J.; Starosta, K.; Boer, J. de.; Gollwitzer, A.; Loewe, M.; Wuerkner, M.; Guenther, C.; Weber, T.; Hagemann, G.; Sletten, G.

    1996-01-01

    In a systematic investigation of the electromagnetic structure of hafnium stable isotopes enriched targets of 176, 177, 178, 179, 180 Hf were Coulomb exciting using: 67 MeV 19 F beam from NBITAL FN Tandem, 125 MeV 32 S beam from MP Tandem in Accelerator Laboratory LMU and TU Munich, 225 MeV 58 Ni beam from NBITAL FN Tandem plus 2 Liniac Boosters complex. Scattered particle-gamma as well as p-γ-γ coincidence were registered. A further simultaneous analysis of Coulomb excitation cross section as a function of scattering angle of 19 F, 32 S, 58 Ni projectiles should be sufficient to deduce reduced probabilities of E2 transitions in ground state band

  6. Synthesis and characterization of hafnium oxide for luminescent applications

    International Nuclear Information System (INIS)

    Guzman Mendoza, J.; Aguilar Frutis, M.A.; Flores, G. Alarcon; Garcia Hipolito, M.; Azorin Nieto, J.; Rivera Montalvo, T.; Falcony, C.

    2008-01-01

    Full text: Hafnium oxide (HfO 2 ) is a material with a wide range of possible technological applications because it's chemical and physical properties such as high melting point, high chemical stability, high refraction index, high dielectric constant and hardness near to diamond in the tetragonal phase. The large energy gap and low phonon frequencies of the HfO 2 makes it appropriate as a host matrix for been doped with rare earth activators. Efficient luminescent materials find wide application in electroluminescent flat panel displays; color plasma displays panels, scintillators, cathode ray tubes, fluorescent lamps, lasers, etc. In recent years the study of luminescent materials based on HfO 2 has been intensified. Some groups have studied the optical properties of doped and undoped HfO 2 . In this contribution, Hafnium Oxide (HfO 2 ) films were prepared using the spray pyrolysis deposition technique. The material was synthesized using chlorides as raw materials in deionised water as solvent and deposited on Corning glass substrates at temperatures from 300 deg C to 600 deg C. For substrate temperatures lower than 400 deg C, the deposited films are amorphous, while for substrate temperatures higher than 450 deg C, the monoclinic phase of HfO 2 appears. Scanning electron microscopy with microprobe analysis was use to observe the microstructure and obtain the chemical composition of the films; rough surfaces with spherical particles were appreciated. UV and low energy X Ray radiations were used in order to achieve the thermoluminescent characterization of the films as a function of the deposition temperature

  7. 21 CFR 169.181 - Vanilla-vanillin flavoring.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Vanilla-vanillin flavoring. 169.181 Section 169... Dressings and Flavorings § 169.181 Vanilla-vanillin flavoring. (a) Vanilla-vanillin flavoring conforms to... ingredients prescribed for vanilla-vanillin extract by § 169.180, except that its content of ethyl alcohol is...

  8. 21 CFR 169.180 - Vanilla-vanillin extract.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Vanilla-vanillin extract. 169.180 Section 169.180... Dressings and Flavorings § 169.180 Vanilla-vanillin extract. (a) Vanilla-vanillin extract conforms to the... § 169.3(c), contained therein, the article also contains not more than 1 ounce of added vanillin. (b...

  9. Pyroelectricity of silicon-doped hafnium oxide thin films

    Science.gov (United States)

    Jachalke, Sven; Schenk, Tony; Park, Min Hyuk; Schroeder, Uwe; Mikolajick, Thomas; Stöcker, Hartmut; Mehner, Erik; Meyer, Dirk C.

    2018-04-01

    Ferroelectricity in hafnium oxide thin films is known to be induced by various doping elements and in solid-solution with zirconia. While a wealth of studies is focused on their basic ferroelectric properties and memory applications, thorough studies of the related pyroelectric properties and their application potential are only rarely found. This work investigates the impact of Si doping on the phase composition and ferro- as well as pyroelectric properties of thin film capacitors. Dynamic hysteresis measurements and the field-free Sharp-Garn method were used to correlate the reported orthorhombic phase fractions with the remanent polarization and pyroelectric coefficient. Maximum values of 8.21 µC cm-2 and -46.2 µC K-1 m-2 for remanent polarization and pyroelectric coefficient were found for a Si content of 2.0 at%, respectively. Moreover, temperature-dependent measurements reveal nearly constant values for the pyroelectric coefficient and remanent polarization over the temperature range of 0 ° C to 170 ° C , which make the material a promising candidate for IR sensor and energy conversion applications beyond the commonly discussed use in memory applications.

  10. Hafnium oxide nanoparticles: toward an in vitro predictive biological effect?

    International Nuclear Information System (INIS)

    Marill, Julie; Anesary, Naeemunnisa Mohamed; Zhang, Ping; Vivet, Sonia; Borghi, Elsa; Levy, Laurent; Pottier, Agnes

    2014-01-01

    Hafnium oxide, NBTXR3 nanoparticles were designed for high dose energy deposition within cancer cells when exposed to ionizing radiation. The purpose of this study was to assess the possibility of predicting in vitro the biological effect of NBTXR3 nanoparticles when exposed to ionizing radiation. Cellular uptake of NBTXR3 nanoparticles was assessed in a panel of human cancer cell lines (radioresistant and radiosensitive) by transmission electron microscopy. The radioenhancement of NBTXR3 nanoparticles was measured by the clonogenic survival assay. NBTXR3 nanoparticles were taken up by cells in a concentration dependent manner, forming clusters in the cytoplasm. Differential nanoparticle uptake was observed between epithelial and mesenchymal or glioblastoma cell lines. The dose enhancement factor increased with increase NBTXR3 nanoparticle concentration and radiation dose. Beyond a minimum number of clusters per cell, the radioenhancement of NBTXR3 nanoparticles could be estimated from the radiation dose delivered and the radiosensitivity of the cancer cell lines. Our preliminary results suggest a predictable in vitro biological effect of NBTXR3 nanoparticles exposed to ionizing radiation

  11. Studies of high-K isomers in hafnium nuclei

    International Nuclear Information System (INIS)

    Sletten, G.; Gjoerup, N.L.

    1991-01-01

    K-isomeric states built on high-Ω Nilsson orbitals from deformation-aligned high-j levels near the Fermi surface are found to cluster in the neutron rich Hf, W and Os nuclei. It has been shown that some of the high seniority states of this type have decay properties that indicate strong mixing of configurations and that in Osmium nuclei γ-softness cause strong deviations from the well established K-selection rule. Also in the Hafnium nuclei is the expected forbiddenness in isomeric decays an order of magnitude smaller than expected from the K-selection rule. A new 9 quasiparticle isomer has been discovered in 175 Hf at I=57/2. This isomer has the anomalous decay as the dominant mode. Other lower seniority states are also identified. At spin 35/2 and 45/2 the deformation aligned states become yrast, but the structure of the yrast line to even higher spins is not yet understood. (author)

  12. Luminescent determination of zirconium and hafnium with myricetin

    International Nuclear Information System (INIS)

    Talipov, Sh.T.; Zel'tser, L.E.; Morozova, L.A.; Tashkhodzhaev, A.T.

    1978-01-01

    Reaction of formation of 3, 5, 7, 3', 4', 5' - hexaoxiflavone - myricetin complexes with zirconium and hafnium ions has been the basis for development of luminescent method of determining these elements. Optimum conditions for complexing have been determined. For Hf they are : 8-9 HCl concentration, maximum fluorescence wave length (lambda fl.)of 520 nm, wave length of exciting light (lambda el) of 436 nm, for Zr lambda fl = 536nm, lambda el = 436 nm. Stable fluorescence establishes after 25 min. for Zr and after 15 min for Hf in the presence of 40% ethanol. Usage of various camouflage agents has permitted to attain high selectivity of the method. Possibility for determination of Zr with myricetin in the presence of a 10-time excess of Hf, Cr, Cu, 50-time excess of Mo and Ti is shown. Sensitivity of Zr determination is 2.0x10 μg -2 /ml, for Hf it is 9.0x10 μg -3 and mineral waters

  13. Composition and microstructure of zirconium and hafnium germanates obtained by different chemical routes

    International Nuclear Information System (INIS)

    Utkin, A.V.; Prokip, V.E.; Baklanova, N.I.

    2014-01-01

    The phase composition and morphology of zirconium and hafnium germanates synthesized by ceramic and co-precipitation routes were studied. The products were characterized using high-temperature X-ray diffraction analysis (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and thermal (TG/DTA) analysis. To investigate the phase composition and stoichiometry of compounds the unit cell parameters were refined by full-profile Rietveld XRD analysis. The morphology of products and its evolution during high-temperature treatment was examined by SEM analysis. It was stated that there is the strong dependence of the phase composition and morphology of products on the preparation route. The ceramic route requires a multi-stage high-temperature treatment to obtain zirconium and hafnium germanates of 95% purity or more. Also, there are strong diffusion limitations to obtain hafnium germanate Hf 3 GeO 8 by ceramic route. On the contrary, the co-precipitation route leads to the formation of nanocrystalline single phase germanates of stoichiometric composition at a relatively low temperatures (less than 1000 °C). The results of quantitative XRD analysis showed the hafnium germanates are stoichiometric compounds in contrast to zirconium germanates that form a set of solid solutions. This distinction may be related to the difference in the ion radii of Zr and Hf. - Graphical abstract: The phase composition and morphology of zirconium and hafnium germanates synthesized by ceramic and co-precipitation routes were studied. It was stated that there is the strong dependence of the phase composition and morphology of products on the preparation route. Display Omitted - Highlights: • Zr and Hf germanates were synthesized by ceramic and co-precipitation routes. • The morphology of products depends on the synthesis parameters. • Zirconium germanates forms a set of solid solutions. • Hafnium germanates are stoichiometric compounds

  14. 46 CFR 169.101 - Purpose.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS General Provisions § 169.101 Purpose. The regulations in this part set forth uniform requirements which are suited to the particular characteristics and specialized operations of sailing school vessels as defined in Title 46...

  15. 46 CFR 169.739 - Lifeboats.

    Science.gov (United States)

    2010-10-01

    ..., Miscellaneous Systems, and Equipment Markings § 169.739 Lifeboats. (a) The name and port of the vessel marked on... thwarts, side benches and footings of lifeboats must be painted or otherwise colored international orange. The area in way of the red mechanical disengaging gear control lever, from the keel to the side bench...

  16. 46 CFR 169.563 - Firehose.

    Science.gov (United States)

    2010-10-01

    ..., DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Lifesaving and Firefighting Equipment Firefighting Equipment § 169.563 Firehose. (a) One length of firehose must be provided... protection is afforded to the hose, it may be temporarily removed from the hydrant in heavy weather and...

  17. Bond formation in hafnium atom implantation into SiC induced by high-energy electron irradiation

    International Nuclear Information System (INIS)

    Yasuda, H.; Mori, H.; Sakata, T.; Naka, M.; Fujita, H.

    1992-01-01

    Bilayer films of Hf (target atoms)/α-SiC (substrate) were irradiated with 2 MeV electrons in an ultra-high voltage electron microscope (UHVEM), with the electron beam incident on the hafnium layer. As a result of the irradiation, hafnium atoms were implanted into the SiC substrate. Changes in the microstructure and valence electronic states associated with the implantation were studied by a combination of UHVEM and Auger valence electron spectroscopy. The implantation process is summarized as follows. (1) Irradiation with 2 MeV electrons first induces a crystalline-to-amorphous transition in α-SiC. (2) Hafnium atoms which have been knocked-off from the hafnium layer by collision with the 2 MeV electrons are implanted into the resultant amorphous SiC. (3) The implanted hafnium atoms make preferential bonding to carbon atoms. (4) With continued irradiation, the hafnium atoms repeat the displacement along the beam direction and the subsequent bonding with the dangling hybrids of carbon and silicon. The repetition of the displacement and subsequent bonding lead to the deep implantation of hafnium atoms into the SiC substrate. It is concluded that implantation successfully occurs when the bond strength between a constituent atom of a substrate and an injected atom is stronger than that between constituent atoms of a substrate. (Author)

  18. Determination of hafnium, molybdenum, and vanadium in niobium and niobium-based alloys by atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Ide, Kunikazu; Kobayashi, Takeshi; Sudo, Emiko.

    1985-01-01

    The analytical procedure is as follows: Weigh 1 g of a sample and put it into a 100 cm 3 PTFE beaker. Add 5 ml of distilled water and 5 ml of hydrofluoric acid, and then heat the solution on a hot plate, adding 3 ml of nitric acid dropwise. Dilute the solution to 100 cm 3 with distilled water. When hafnium is determined, add 2 g of diammonium titanium hexafluoride ((NH 4 ) 2 TiF 6 )) before dilution. Working standard solutions are prepared by adding the stock standard solutions of hafnium, molybdenum, and vanadium into niobium solutions. When hafnium is determined, add 2 g of (NH 4 ) 2 TiF 6 and the alloying elements in amounts corresponding to those in sample solutions into the working standard solutions. The tolerable amounts of hydrofluoric acid were 2.9 M, 2.1 M, and 3.1 M and those of nitric acid were 1.0 M, 1.6 M, and 1.6 M for hafnium, molybdenum, and vanadium, respectively. It was found that (NH 4 ) 2 TiF 6 greatly increased the sensitivity for hafnium determination. Niobium showed minus effect for hafnium and plus effect for molybdenum and vanadium. The atomic absorption of molybdenum and vanadium were not influenced by the presence of 20 % of each alloying element, while the atomic absorption of hafnium was given plus effect by 20 % of zirconium, iron, cobalt, nickel, manganese, chromium or vanadium and minus effect by 20 % tungsten. The analytical values of hafnium, molybdenum, and vanadium in niobium-based alloys by this method showed a good agreement with those by X-ray fluorescence analysis. The lower limits of determination (S/N=2) were 0.05, 0.001, and 0.002 % and the relative standard deviation were 3, 1, and 1.5 % for hafnium, molybdenum, and vanadium, respectively. (author)

  19. Separation of zirconium and hafnium from acompanying elements by paper chromatography in the systems of alcohol-acid

    International Nuclear Information System (INIS)

    Lebedeva, G.G.; Viktorova, M.E.

    1980-01-01

    Solvents have been chosen and investigated which provide expressed separation of zirconium and hafnium at the analysis of mineral raw materials by paper chromatography. The systems with HNO 3 and HCl containing methyl, ethyl, propyl and butyl alcohols have been studied as mobile phases for separation of zirconium and hafnium. It has been shown that alcohol contents and solvent acidity affect the Rsub(f) value of these elements. The C 2 H 5 OH-5MHCl and C 2 H 5 OH-5MHNO 3 systems are most optimal for pre-concentration of zirconium and hafnium

  20. ENTIRELY AQUEOUS SOLUTION-GEL ROUTE FOR THE PREPARATION OF ZIRCONIUM CARBIDE, HAFNIUM CARBIDE AND THEIR TERNARY CARBIDE POWDERS

    Directory of Open Access Journals (Sweden)

    Zhang Changrui

    2016-07-01

    Full Text Available An entirely aqueous solution-gel route has been developed for the synthesis of zirconium carbide, hafnium carbide and their ternary carbide powders. Zirconium oxychloride (ZrOCl₂.8H₂O, malic acid (MA and ethylene glycol (EG were dissolved in water to form the aqueous zirconium carbide precursor. Afterwards, this aqueous precursor was gelled and transformed into zirconium carbide at a relatively low temperature (1200 °C for achieving an intimate mixing of the intermediate products. Hafnium and the ternary carbide powders were also synthesized via the same aqueous route. All the zirconium, hafnium and ternary carbide powders exhibited a particle size of ∼100 nm.

  1. Plasma spraying of zirconium carbide – hafnium carbide – tungsten cermets

    Czech Academy of Sciences Publication Activity Database

    Brožek, Vlastimil; Ctibor, Pavel; Cheong, D.-I.; Yang, S.-H.

    2009-01-01

    Roč. 9, č. 1 (2009), s. 49-64 ISSN 1335-8987 Institutional research plan: CEZ:AV0Z20430508 Keywords : Plasma spraying * cermet coatings * microhardness * zirconium carbide * hafnium carbide * tungsten * water stabilized plasma Subject RIV: JH - Ceramics, Fire-Resistant Materials and Glass

  2. Titanium, zirconium- and hafnium containing initiators in the polymerization of acrylic monomers to ''living'' polymers

    International Nuclear Information System (INIS)

    Farnham, W.B.; Hertler, W.R.

    1988-01-01

    This patent describes a process for preparing ''living'' polymer. The process comprises contacting one or more acrylic monomers under polymerizing conditions with a polymerization-initiating amount of a tetra-coordinate organotitanium, organozirconium or organo-hafnium polymerization initiator, and ''living'' polymers produced thereby

  3. Vapor pressure, heat capacities, and phase transitions of tetrakis(tert-butoxy)hafnium

    Czech Academy of Sciences Publication Activity Database

    Fulem, Michal; Růžička, K.

    2011-01-01

    Roč. 311, Dec. (2011), s. 25-29 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z10100521 Keywords : tetrakis(tert-butoxy)hafnium * MO precursor * vapor pressure * heat capacity * vaporization enthalpy * enthalpy of fusion Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.139, year: 2011

  4. Separation of hafnium from zirconium in sulfuric acid solutions using pressurized ion exchange

    International Nuclear Information System (INIS)

    Hurst, F.J.

    1981-01-01

    High-resolution pressurized ion exchange has been used successfully to study and separate hafnium and zirconium sulfate complexes by chromatographic elution from Dowex 50W-X8 (15 to 25 μm) resin with sulfuric acid solutions. Techniques were developed to continuously monitor the column effluents for zirconium and hafnium by reaction with fluorometric and colorimetric reagents. Since neither reagent was specific for either metal ion, peak patterns were initially identified by using the stable isotopes 90 Zr and 180 Hf as fingerprints of their elution position. Distribution ratios for both zirconium and hafnium decrease as the inverse fourth power of the sulfuric acid concentration below 2N and as the inverse second power at higher acid concentration. The hafnium-to-zirconium separation factor is approximately constant (approx. 8) over the 0.5 to 3N range. Under certain conditions, an unseparated fraction was observed that was not retained by the resin. The amount of this fraction which is thought to be a polymeric hydrolysis product appears to be a function of metal and sulfuric acid concentrations. Conditions are being sought to give the highest zirconium concentration and the lowest acid concentration that can be used as a feed material for commercial scale-up in the continuous annular chromatographic (CAC) unit without formation of the polymer

  5. The corrosion behavior of hafnium in high-temperature-water environments

    Energy Technology Data Exchange (ETDEWEB)

    Rishel, D.M.; Smee, J.D.; Kammenzind, B.F.

    1999-10-01

    The high-temperature-water corrosion performance of hafnium is evaluated. Corrosion kinetic data are used to develop correlations that are a function of time and temperature. The evaluation is based on corrosion tests conducted in out-of-pile autoclaves and in out-of-flux locations of the Advanced Test Reactor (ATR) at temperatures ranging from 288 to 360 C. Similar to the corrosion behavior of unalloyed zirconium, the high-temperature-water corrosion response of hafnium exhibits three corrosion regimes: pretransition, posttransition, and spalling. In the pretransition regime, cubic corrosion kinetics are exhibited, whereas in the posttransition regime, linear corrosion kinetics are exhibited. Because of the scatter in the spalling regime data, it is not reasonable to use a best fit of the data to describe spalling regime corrosion. Data also show that neutron irradiation does not alter the corrosion performance of hafnium. Finally, the data illustrate that the corrosion rate of hafnium is significantly less than that of Zircaloy-2 and Zircaloy-4.

  6. 21 CFR 169.182 - Vanilla-vanillin powder.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Vanilla-vanillin powder. 169.182 Section 169.182... Dressings and Flavorings § 169.182 Vanilla-vanillin powder. (a) Vanilla-vanillin powder conforms to the... § 169.3(c) contained therein, the article also contains not more than 1 ounce of added vanillin. (b) The...

  7. 46 CFR 169.613 - Gasoline fuel systems.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Gasoline fuel systems. 169.613 Section 169.613 Shipping... Machinery and Electrical Fuel Systems § 169.613 Gasoline fuel systems. (a) Except as provided in paragraph (b) each gasoline fuel system must meet the requirements of § 56.50-70 of this chapter (b) Each...

  8. 46 CFR 169.236 - Inspection and testing required.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Inspection and testing required. 169.236 Section 169.236... Inspection and Certification Repairs and Alterations § 169.236 Inspection and testing required. (a) The... involving riveting, welding, burning, or other fire-producing actions may be made— (1) Within or on the...

  9. 46 CFR 169.725 - First aid kit.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false First aid kit. 169.725 Section 169.725 Shipping COAST... Control, Miscellaneous Systems, and Equipment § 169.725 First aid kit. Each vessel must carry an approved first aid kit, constructed and fitted in accordance with subpart 160.041 of this chapter. ...

  10. 36 CFR 406.161-406.169 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false [Reserved] 406.161-406.169 Section 406.161-406.169 Parks, Forests, and Public Property AMERICAN BATTLE MONUMENTS COMMISSION... BATTLE MONUMENTS COMMISSION §§ 406.161-406.169 [Reserved] ...

  11. 46 CFR 169.817 - Master to instruct ship's company.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Master to instruct ship's company. 169.817 Section 169.817 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.817 Master to instruct ship's company. The master shall conduct drills and give instructions as necessary to insure that al...

  12. 46 CFR 169.743 - Portable magazine chests.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Portable magazine chests. 169.743 Section 169.743... Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.743 Portable magazine chests. Portable magazine chests must be marked in letters at least 3 inches high: “PORTABLE MAGAZINE CHEST...

  13. 28 CFR 39.161-39.169 - [Reserved

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false [Reserved] 39.161-39.169 Section 39.161-39.169 Judicial Administration DEPARTMENT OF JUSTICE ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE DEPARTMENT OF JUSTICE §§ 39.161-39.169 [Reserved] ...

  14. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

  15. 46 CFR 169.713 - Engineroom communication system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Engineroom communication system. 169.713 Section 169.713... Vessel Control, Miscellaneous Systems, and Equipment § 169.713 Engineroom communication system. An efficient communication system must be provided between the principal steering station and the engineroom on...

  16. 46 CFR 169.703 - Cooking and heating.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Cooking and heating. 169.703 Section 169.703 Shipping... Control, Miscellaneous Systems, and Equipment § 169.703 Cooking and heating. (a) Cooking and heating... cooking, heating or lighting is prohibited on all vessels. (c) The use of liquefied petroleum gas (LPG) or...

  17. 45 CFR 2490.161-2490.169 - [Reserved

    Science.gov (United States)

    2010-10-01

    ... 45 Public Welfare 4 2010-10-01 2010-10-01 false [Reserved] 2490.161-2490.169 Section 2490.161-2490.169 Public Welfare Regulations Relating to Public Welfare (Continued) JAMES MADISON MEMORIAL... CONDUCTED BY THE JAMES MADISON MEMORIAL FELLOWSHIP FOUNDATION §§ 2490.161-2490.169 [Reserved] ...

  18. 46 CFR 169.666 - Generators and motors.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Generators and motors. 169.666 Section 169.666 Shipping... of Less Than 100 Gross Tons § 169.666 Generators and motors. (a) Each vessel of more than 65 feet in...) Each generator and motor must be in a location that is accessible, adequately ventilated, and as dry as...

  19. 49 CFR 28.161-28.169 - [Reserved

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false [Reserved] 28.161-28.169 Section 28.161-28.169 Transportation Office of the Secretary of Transportation ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY THE DEPARTMENT OF TRANSPORTATION §§ 28.161-28.169 [Reserved] ...

  20. 46 CFR 169.677 - Equipment protection and enclosure.

    Science.gov (United States)

    2010-10-01

    ... Vessels of Less Than 100 Gross Tons § 169.677 Equipment protection and enclosure. (a) Except as provided... 46 Shipping 7 2010-10-01 2010-10-01 false Equipment protection and enclosure. 169.677 Section 169.677 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL...

  1. Reinforcement against crack propagation of PWR absorbers by development of boron-carbon-hafnium composites

    International Nuclear Information System (INIS)

    Provot, B.; Herter, P.

    2000-01-01

    In order to improve the mechanical behaviour of materials used as neutron absorbers in nuclear reactors, we have developed CERCER or CERMET composites with boron and hafnium. Thus a new composite B 4 C/HfB 2 has been especially studied. We have identified three kinds of degradation under irradiation (thermal gradient, swelling due to fission products and accidental corrosion) that induce imposed deformations cracking phenomena. Mechanical behaviour and crack propagation resistance have been studied by ball-on-three-balls and double torsion tests. A special device was developed to enable crack propagation and associated stress intensity factor measurements. Effects of structure and of a second phase are underline. First results show that these materials present crack initiation and propagation resistance much higher than pure boron carbide or hafnium diboride. We observe R-Curves effects, crack bridging or branching, crack arrests, and toughness increases that we can relate respectively to the composite structures. (author)

  2. Synthesis and characterization of hafnium oxide films for thermo and photoluminescence applications

    International Nuclear Information System (INIS)

    Guzman Mendoza, J.; Aguilar Frutis, M.A.; Flores, G. Alarcon; Garcia Hipolito, M.; Maciel Cerda, A.; Azorin Nieto, J.; Rivera Montalvo, T.; Falcony, C.

    2010-01-01

    Hafnium oxide (HfO 2 ) films were deposited by the ultrasonic spray pyrolysis process. The films were synthesized from hafnium chloride as raw material in deionized water as solvent and were deposited on corning glass substrates at temperatures from 300 to 600 deg. C. For substrate temperatures lower than 400 deg. C the deposited films were amorphous, while for substrate temperatures higher than 450 deg. C, the monoclinic phase of HfO 2 appeared. Scanning electron microscopy showed that the film's surface resulted rough with semi-spherical promontories. The films showed a chemical composition close to HfO 2 , with an Hf/O ratio of about 0.5. UV radiation was used in order to achieve the thermoluminescent characterization of the films; the 240 nm wavelength induced the best response. In addition, preliminary photoluminescence spectra, as a function of the deposition temperatures, are shown.

  3. Synthesis and characterization of Ho3+ doped hafnium oxide TLD for radiation dosimeter

    International Nuclear Information System (INIS)

    Sekar, Nandakumar; Ganesan, Bharanidharan; Sahib, Hajee Reyaz Ali; Aruna, Prakasarao; Ganesan, Singaravelu; Thamilkumar, P.; Rai, R.R.

    2017-01-01

    Cancer is a dreaded disease which is treated by Radiotherapy, Chemotherapy and Surgery. Radiotherapy plays a vital role in treatment of cancer and recently measurements of invivo radiation dosimetric in patient is of great interest due to high dose gradients in advanced technology like IMRT, IGRT etc. Hence, for the last few decades, a great degree of interest has been shown for the hafnium oxide for radiation dosimetric applications, due to its high dielectric constant, wide band gap and better interface properties such as chemical stability, conduction band offset and thermodynamic stability. In the present study, Synthesis and characterization of Ho 3+ doped Hafnium oxide were carried out and its applications towards radiation dosimeter were investigated

  4. Self-cleaning and surface chemical reactions during hafnium dioxide atomic layer deposition on indium arsenide.

    Science.gov (United States)

    Timm, Rainer; Head, Ashley R; Yngman, Sofie; Knutsson, Johan V; Hjort, Martin; McKibbin, Sarah R; Troian, Andrea; Persson, Olof; Urpelainen, Samuli; Knudsen, Jan; Schnadt, Joachim; Mikkelsen, Anders

    2018-04-12

    Atomic layer deposition (ALD) enables the ultrathin high-quality oxide layers that are central to all modern metal-oxide-semiconductor circuits. Crucial to achieving superior device performance are the chemical reactions during the first deposition cycle, which could ultimately result in atomic-scale perfection of the semiconductor-oxide interface. Here, we directly observe the chemical reactions at the surface during the first cycle of hafnium dioxide deposition on indium arsenide under realistic synthesis conditions using photoelectron spectroscopy. We find that the widely used ligand exchange model of the ALD process for the removal of native oxide on the semiconductor and the simultaneous formation of the first hafnium dioxide layer must be significantly revised. Our study provides substantial evidence that the efficiency of the self-cleaning process and the quality of the resulting semiconductor-oxide interface can be controlled by the molecular adsorption process of the ALD precursors, rather than the subsequent oxide formation.

  5. Zirconium and hafnium tetrachloride separation by extractive distillation with molten zinc chloride lead chloride solvent

    International Nuclear Information System (INIS)

    McLaughlin, D.F.; Stoltz, R.A.

    1988-01-01

    In an extractive distillation method for separating hafniuim tetrachloride from zirconium tetrachloride of the type wherein a mixture of zirconium and hafnium tetrachlorides is introduced into an extractive distillation column, which extractive distillation column has a reboiler connected at the bottom and a reflux condenser connected at the top and wherein a molten salt solvent is circulated into the reflux condenser and through the column to provide a liquid phase, and wherein molten salt solvent containing zirconium tetrachloride is taken from the reboiler and run through a stripper to remove zirconium tetrachloride product from the molten salt solvent and the stripped molten salt solvent is returned to the reflux condenser and hafnium tetrachloride enriched vapor is taken as product from the reflux condenser, the improvement is described comprising: the molten salt having a composition of at least 30 mole percent zinc chloride and at least 10 mole percent of lead chloride

  6. Preparation of hafnium metal by calciothermic reduction of HfO2

    International Nuclear Information System (INIS)

    Sharma, I.G.; Vijay, P.L.; Sehra, J.C.; Sundaram, C.V.

    1975-01-01

    Hafnium metal powder has been produced by the calciothermic reduction of hafnium oxide. The influence of various experimental parameters - such as amount of calcium in excess of stoichiometric requirement, temperature, and time of reduction - on the yield and purity of the metal has been studied. The metal powder obtained by reduction at 960 0 C (two hours) with a calcium excess of 70% analysed 600 ppm of oxygen and 147 ppm of nitrogen. A reduction efficiency of 96% has been achieved under these conditions. The refining of the powder by electron beam melting, fused salt electrolysis, and iodide process has been studied. The oxygen content in the metal could be brought down from 6900 to 148 ppm by electron beam melt-refining. (author)

  7. On-line separation of refractory hafnium and tantalum isotopes at the ISOCELE separator

    CERN Document Server

    Liang, C F; Obert, J; Paris, P; Putaux, J C

    1981-01-01

    By chemical evaporation technique, neutron deficient hafnium nuclei have been on-line separated at the ISOCELE facility, from the isobar rare-earth elements, in the metal-fluoride HfF/sub 3//sup +/ ion form. Half-lives of /sup 162-165/Hf have been measured. Similarly, tantalum has been selectively separated on the TaF/sub 4//sup +/ form. (4 refs) .

  8. Complexonometric determination of hafnium (4) in the presence of europium(3) or tantalum(5)

    International Nuclear Information System (INIS)

    Oziashvili, E.D.; Ehsakiya, K.E.; Sirakanyan, N.M.

    1986-01-01

    Complexonometric determination of hafnium in the presence of Ta or Eu in samples which can be decomposed by acids, i.e. in double borides has been investigated. Initial solutions are prepared by fusing with K 2 S 2 O 8 excess, the fusion was leached by hot water, H 2 SO L 4 was added and Hf was titrated by complexone 3 in the presence of xylenol orange

  9. Simplified method for gravimetric determination of zirconium or hafnium with α-hydroxy carboxylic acids

    International Nuclear Information System (INIS)

    Barbieri, R.S.; Rocha, J.C.; Terra, V.R.; Marques Netto, A.

    1989-01-01

    The conditions for gravimetric determination of zirconium or hafnium by glicoloc acids derivatives were studied by thermogravimetric analysis. The method utilized shownd that after precipitation, washing and drying of precipitates at 150 o C, the resulting solid was weighed in the form of [M (RCH(OH)COO) 4 ] (M = Zr, Hf; R + C 6 H 5 , β-C 10 H 7 , p-BrC 6 H 4 ). (author)

  10. Modified method for zirconium or hafnium gravimetric determination with glycolic acid derivatives

    International Nuclear Information System (INIS)

    Barbieri, R.S.; Rocha, J.C.; Terra, V.R.; Marques Neto, A.

    1989-01-01

    The conditions for gravimetric determination of zirconium or hafnium by glicolic acid derivatives were studied by thermogravimetric analysis. The method utilized shown that after precipitation, washing and drying of precipitates at 150 0 C, the resulting solid was weighed in the form of [M{RCH(OH)COO} 4 ] (M = Zr,Hf;R = C 6 H 5 , β-C 10 H 7 ,p-BrC 6 H 4 ). (author) [pt

  11. Electrodeposition in molten salts of metals used in nuclear industry: hafnium and uranium

    International Nuclear Information System (INIS)

    Serrano, K.

    1998-01-01

    The aim of this work is to study the electrodeposition in molten salts of metals used in nuclear industry: hafnium and uranium. The experiment is carried out in a molten alkaline halogenide medium in a temperature range between 670 and 750 degrees Celsius. The first part of this work concerns more particularly the electrochemical behaviour of the hafnium and uranium ions in the electrolytic solution. The reduction mechanisms of these ions have been studied by the use of three methods: cyclic voltametry, chrono-potentiometry and square wave voltametry. Results have shown that the process of metal deposition is difficult to explain because secondary reactions (as for instance: adsorption phenomena or cathodic deposit dissolution) occur. The uranium germination has then been studied by modelling of chrono-amperograms. The experiments have shown that the deposition is the result of the initial uranium crystal growth and depends on the electrolyte diffusion. The second part of this work deals with the implementation of hafnium and uranium deposition taking into account the preceding mechanistic studies. Depositions have all been observed by physical methods as for instance scanning electron microscopy. Particular experimental solutions (soluble anode, addition of fluoride ions to the electrolyte) have been used. The obtained deposition of hafnium is smooth and adheres very well to the substrate. The uranium depositions have been implemented with the use of a soluble anode. Uranium is deposited in a dendritic shape to the cathode. It has also been shown that the electro-kinetic parameters (temperature, uranium ions concentration, current density) have not an important influence on the dendritic morphology of the deposition. This morphology could be the consequence of particular convection movements to the surface of the cathode. (O.M.)

  12. Rhodium and Hafnium Influence on the Microstructure, Phase Composition, and Oxidation Resistance of Aluminide Coatings

    OpenAIRE

    Maryana Zagula-Yavorska; Małgorzata Wierzbińska; Jan Sieniawski

    2017-01-01

    A 0.5 μm thick layer of rhodium was deposited on the CMSX 4 superalloy by the electroplating method. The rhodium-coated superalloy was hafnized and aluminized or only aluminized using the Chemical vapour deposition method. A comparison was made of the microstructure, phase composition, and oxidation resistance of three aluminide coatings: nonmodified (a), rhodium-modified (b), and rhodium- and hafnium-modified (c). All three coatings consisted of two layers: the additive layer and the interdi...

  13. Radiation effects on the electrical properties of hafnium oxide based MOS capacitors.

    Energy Technology Data Exchange (ETDEWEB)

    Petrosky, J. C. (Air Force Institute of Technology, Wright-Patterson Air Force Base, OH); McClory, J. W. (Air Force Institute of Technology, Wright-Patterson Air Force Base, OH); Bielejec, Edward Salvador; Foster, J. C. (Air Force Institute of Technology, Wright-Patterson Air Force Base, OH)

    2010-10-01

    Hafnium oxide-based MOS capacitors were investigated to determine electrical property response to radiation environments. In situ capacitance versus voltage measurements were analyzed to identify voltage shifting as a result of changes to trapped charge with increasing dose of gamma, neutron, and ion radiation. In situ measurements required investigation and optimization of capacitor fabrication to include dicing, cleaning, metalization, packaging, and wire bonding. A top metal contact of 200 angstroms of titanium followed by 2800 angstroms of gold allowed for repeatable wire bonding and proper electrical response. Gamma and ion irradiations of atomic layer deposited hafnium oxide on silicon devices both resulted in a midgap voltage shift of no more than 0.2 V toward less positive voltages. This shift indicates recombination of radiation induced positive charge with negative trapped charge in the bulk oxide. Silicon ion irradiation caused interface effects in addition to oxide trap effects that resulted in a flatband voltage shift of approximately 0.6 V also toward less positive voltages. Additionally, no bias dependent voltage shifts with gamma irradiation and strong oxide capacitance room temperature annealing after ion irradiation was observed. These characteristics, in addition to the small voltage shifts observed, demonstrate the radiation hardness of hafnium oxide and its applicability for use in space systems.

  14. On the phase formation of sputtered hafnium oxide and oxynitride films

    International Nuclear Information System (INIS)

    Sarakinos, K.; Music, D.; Mraz, S.; Baben, M. to; Jiang, K.; Nahif, F.; Braun, A.; Zilkens, C.; Schneider, J. M.; Konstantinidis, S.; Renaux, F.; Cossement, D.; Munnik, F.

    2010-01-01

    Hafnium oxynitride films are deposited from a Hf target employing direct current magnetron sputtering in an Ar-O 2 -N 2 atmosphere. It is shown that the presence of N 2 allows for the stabilization of the transition zone between the metallic and the compound sputtering mode enabling deposition of films at well defined conditions of target coverage by varying the O 2 partial pressure. Plasma analysis reveals that this experimental strategy facilitates control over the flux of the O - ions which are generated on the oxidized target surface and accelerated by the negative target potential toward the growing film. An arrangement that enables film growth without O - ion bombardment is also implemented. Moreover, stabilization of the transition sputtering zone and control of the O - ion flux without N 2 addition is achieved employing high power pulsed magnetron sputtering. Structural characterization of the deposited films unambiguously proves that the phase formation of hafnium oxide and hafnium oxynitride films with the crystal structure of HfO 2 is independent from the O - bombardment conditions. Experimental and theoretical data indicate that the presence of vacancies and/or the substitution of O by N atoms in the nonmetal sublattice favor the formation of the cubic and/or the tetragonal HfO 2 crystal structure at the expense of the monoclinic HfO 2 one.

  15. Correlations between nuclear data and integral slab experiments: the case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Palau, J.M

    1999-07-01

    The aim of this work was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular 'mock-up' reactor.In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods together with Monte Carlo- type simulations enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent's efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author)

  16. Correlations between nuclear data and integral slab experiments: the case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Palau, J M

    1999-07-01

    The aim of this work was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular 'mock-up' reactor.In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods together with Monte Carlo- type simulations enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent's efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author)

  17. Correlations between nuclear data and results of integral slab experiments. Case of hafnium; Correlations entre donnees nucleaires et experiences integrales a plaques: le cas du hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Palau, J M

    1997-10-22

    The aim of this thesis was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular `mock-up` reactor. In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods (APOLLO2 code) together with Monte Carlo- type simulations (TRIPOLI4 code) enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope {sup 177}Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent`s efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author) 128 refs.

  18. Development and characterization of ultrathin hafnium titanates as high permittivity gate insulators

    Science.gov (United States)

    Li, Min

    High permittivity or high-kappa materials are being developed for use as gate insulators for future ultrascaled metal oxide semiconductor field effect transistors (MOSFETs). Hafnium containing compounds are the leading candidates. Due to its moderate permittivity, however, it is difficult to achieve HfO2 gate structures with an EOT well below 1.0 nm. One approach to increase HfO2 permittivity is combining it with a very high-kappa material, such as TiO2. In this thesis, we systematically studied the electrical and physical characteristics of high-kappa hafnium titanates films as gate insulators. A series of HfxTi1-xO2 films with well-controlled composition were deposited using an MOCVD system. The physical properties of the films were analyzed using a variety of characterization techniques. X-ray micro diffraction indicates that the Ti-rich thin film is more immune to crystallization. TEM analysis showed that the thick stoichiometric HfTiO 4 film has an orthorhombic structure and large anisotropic grains. The C-V curves from the devices with the hafnium titanates films displayed relatively low hysteresis. In a certain composition range, the interfacial layer (IL) EOT and permittivity of HfxTi1-x O2 increases linearly with increasing Ti. The charge is negative for HfxTi1-xO2/IL and positive for Si/IL interface, and the magnitude increases as Hf increases. For ultra-thin films (less than 2 nm EOT), the leakage current increases with increasing HE Moreover, the Hf-rich sample has weaker temperature dependence of the current. In the MOSFET devices with the hafnium titanates films, normal transistor characteristics were observed, also electron mobility degradation. Next, we investigated the effects that different pre-deposition surface treatments, including HF dipping, NH3 surface nitridation, and HfO2 deposition, have on the electrical properties of hafnium titanates. Surface nitridation shows stronger effect than the thin HfO2 layer. The nitrided samples displayed a

  19. Low-voltage bendable pentacene thin-film transistor with stainless steel substrate and polystyrene-coated hafnium silicate dielectric.

    Science.gov (United States)

    Yun, Dong-Jin; Lee, Seunghyup; Yong, Kijung; Rhee, Shi-Woo

    2012-04-01

    The hafnium silicate and aluminum oxide high-k dielectrics were deposited on stainless steel substrate using atomic layer deposition process and octadecyltrichlorosilane (OTS) and polystyrene (PS) were treated improve crystallinity of pentacene grown on them. Besides, the effects of the pentacene deposition condition on the morphologies, crystallinities and electrical properties of pentacene were characterized. Therefore, the surface treatment condition on dielectric and pentacene deposition conditions were optimized. The pentacene grown on polystyrene coated high-k dielectric at low deposition rate and temperature (0.2-0.3 Å/s and R.T.) showed the largest grain size (0.8-1.0 μm) and highest crystallinity among pentacenes deposited various deposition conditions, and the pentacene TFT with polystyrene coated high-k dielectric showed excellent device-performance. To decrease threshold voltage of pentacene TFT, the polystyrene-thickness on high-k dielectric was controlled using different concentration of polystyrene solution. As the polystyrene-thickness on hafnium silicate decreases, the dielectric constant of polystyrene/hafnium silicate increases, while the crystallinity of pentacene grown on polystyrene/hafnium silicate did not change. Using low-thickness polystyrene coated hafnium silicate dielectric, the high-performance and low voltage operating (pentacene thin film transistor (μ: ~2 cm(2)/(V s), on/off ratio, >1 × 10(4)) and complementary inverter (DC gains, ~20) could be fabricated.

  20. Extraction of zirconium and hafnium thiocyanates by CH3COCH2CH.(CH3)2-HSCN solvent from chloride medium

    International Nuclear Information System (INIS)

    Okada, A.T.

    1982-01-01

    A zirconium-hafnium separation process for application in nuclear industry is presented. The extraction of zirconium and hafnium thiocyanates in chloride medium by hexone-HSCN solvent was studied. The extraction process was developed, varying the parameters, such as, concentrations of the metals, the thiocyanate ion, the sulphate ion and free acidity in aqueous phase. (Author) [pt

  1. Development of Yb-169 radiation source for new nondestructive inspection

    International Nuclear Information System (INIS)

    Yamabayashi, Hisamichi

    1994-01-01

    As the nondestructive inspection method for large structures, there has been radiography, and X-ray and γ-ray have been used as the radiation. The transmissivity of radiation through materials changes by the energy of the radiation and the density and thickness of the materials. At present about 880 γ-ray radiography apparatuses are used in Japanese private enterprises, and about 70% of them use 192 Ir γ-ray sources, and about 30% use 60 Co or 137 Cs sources. Recently the defect inspection for the worlded parts of thin wall small tubes and so on have become to be regarded as important, and the 169 Yb source that emits lower energy γ-ray is suitable to the purpose. There are many reports that 169 Yb radiography was applied successfully. As the 169 Yb radiation source, pellets and balls are on the market. 169 Yb is made by the neutron irradiation of 168 Yb in nuclear reactors. The characteristics of 169 Yb, the manufacture of 169 Yb radiation sources and the applicability of 169 Yb radiation sources to nondestructive inspection are reported. Also in Japan, many basic experiments on 169 Yb radiation sources have been carried out, and the irradiation apparatuses are small and light, and the control area can be set small. (K.I.)

  2. 21 CFR 169.176 - Concentrated vanilla extract.

    Science.gov (United States)

    2010-04-01

    ... content of ethyl alcohol is not less than 35 percent by volume. (b) The specified name of the food is... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Concentrated vanilla extract. 169.176 Section 169.176 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED...

  3. 46 CFR 169.315 - Ventilation (other than machinery spaces).

    Science.gov (United States)

    2010-10-01

    ... section is satisfied, a vessel having only a natural ventilation system must satisfy the following: V/A≥1... 46 Shipping 7 2010-10-01 2010-10-01 false Ventilation (other than machinery spaces). 169.315... SCHOOL VESSELS Construction and Arrangement Hull Structure § 169.315 Ventilation (other than machinery...

  4. 46 CFR 169.313 - Means of escape.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Means of escape. 169.313 Section 169.313 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction... apart, uniform for the length of the ladder; (3) At least 3 inches from the nearest permanent object in...

  5. 46 CFR 169.685 - Electric heating and cooking equipment.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Electric heating and cooking equipment. 169.685 Section... More on Vessels of Less Than 100 Gross Tons § 169.685 Electric heating and cooking equipment. (a) Each...) All electric cooking equipment, attachments, and devices, must be of rugged construction and so...

  6. 46 CFR 169.683 - Overcurrent protection, general.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Overcurrent protection, general. 169.683 Section 169.683 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS... reaches a value that causes an excessive or dangerous temperature in the conductor or conductor insulation...

  7. 46 CFR 169.565 - Fixed carbon dioxide system.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Fixed carbon dioxide system. 169.565 Section 169.565 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS... cylinder storage area must be properly ventilated and the temperature inside must not exceed 130 °F. (g...

  8. 46 CFR 169.627 - Compartments containing diesel fuel tanks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compartments containing diesel fuel tanks. 169.627... SCHOOL VESSELS Machinery and Electrical Ventilation § 169.627 Compartments containing diesel fuel tanks. Unless they are adequately ventilated, enclosed compartments or spaces containing diesel fuel tanks and...

  9. 12 CFR 410.161-410.169 - [Reserved

    Science.gov (United States)

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false [Reserved] 410.161-410.169 Section 410.161-410.169 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES ENFORCEMENT OF NONDISCRIMINATION ON THE BASIS OF HANDICAP IN PROGRAMS OR ACTIVITIES CONDUCTED BY EXPORT-IMPORT BANK OF THE UNITED STATES §§ 410...

  10. Solvent extraction of titanium(IV), zirconium(IV) and hafnium(IV) salicylates using liquid ion exchangers

    Energy Technology Data Exchange (ETDEWEB)

    Sundaramurthi, N M; Shinde, V M

    1989-02-01

    A solvent extraction method is proposed for the extraction of quadrivalent titanium, zirconium an hafnium from salicylate media using liquid ion exchangers such as Aliquat 336 and trioctylamine dissolved in xylene. The optimum conditions were evaluated from a critical study of the following: pH, salicylate concentration, amine concentration, diluent and period of equilibration. The method allows the separation of titanium, zirconium and hafnium from binary mixtures containing commonly associated metal ions and is applicable to the analysis of real samples such as BCS-CRM 387 nimonic 901, BCS-CRM 243/4 ferro-titanium, BCS-CRM 307 magnesium alloy and BCS-CRM 388 zircon. Titanium is determined either with hydrogen peroxide or by atomic absorption spectrometry whereas zirconium and hafnium are determined spectrophotometrically with Alizarin Red S and Zylenol Orange, respectively. The results of both separation and analysis are reported. The method is precise, accurate and fast.

  11. Use of hafnium in control bars of nuclear reactors; Uso de hafnio en barras de control de reactores nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Ramirez S, J.R.; Alonso V, G. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)]. e-mail: jrrs@nuclear.inin-mx

    2003-07-01

    Recently the use of hafnium as neutron absorber material in nuclear reactors has been reason of investigation by virtue of that this material has nuclear properties as to the neutrons absorption and structural that can prolong the useful life of the control mechanisms of the nuclear reactors. In this work some of those more significant hafnium properties are presented like nuclear material. Also there are presented calculations carried out with the HELIOS code for fuel cells of uranium oxide and of uranium and plutonium mixed oxides under controlled conditions with conventional bars of boron carbide and also with similar bars to which are substituted the absorbent material by metallic hafnium, the results are presented in this work. (Author)

  12. Strong influence of polymer architecture on the microstructural evolution of hafnium-alkoxide-modified silazanes upon ceramization.

    Science.gov (United States)

    Papendorf, Benjamin; Nonnenmacher, Katharina; Ionescu, Emanuel; Kleebe, Hans-Joachim; Riedel, Ralf

    2011-04-04

    The present study focuses on the synthesis and ceramization of novel hafnium-alkoxide-modified silazanes as well as on their microstructure evolution at high temperatures. The synthesis of hafnia-modified polymer-derived SiCN ceramic nanocomposites is performed via chemical modification of a polysilazane and of a cyclotrisilazane, followed by cross-linking and pyrolysis in argon atmosphere. Spectroscopic investigation (i.e., NMR, FTIR, and Raman) shows that the hafnium alkoxide reacts with the N-H groups of the cyclotrisilazane; in the case of polysilazane, reactions of N-H as well as Si-H groups with the alkoxide are observed. Consequently, scanning and transmission electron microscopy studies reveal that the ceramic nanocomposites obtained from cyclotrisilazane and polysilazane exhibited markedly different microstructures, which is a result of the different reaction pathways of the hafnium alkoxide with cyclotrisilazane and with polysilazane. Furthermore, the two prepared ceramic nanocomposites are unexpectedly found to exhibit extremely different high-temperature behavior with respect to decomposition and crystallization; this essential difference is found to be related to the different distribution of hafnium throughout the ceramic network in the two samples. Thus, the homogeneous distribution of hafnium observed in the polysilazane-derived ceramic leads to an enhanced thermal stability with respect to decomposition, whereas the local enrichment of hafnium within the matrix of the cyclotrisilazane-based sample induces a pronounced decomposition upon annealing at high temperatures. The results indicate that the chemistry and architecture of the precursor has a crucial effect on the microstructure of the resulting ceramic material and consequently on its high-temperature behavior. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Hafnium at subduction zones: isotopic budget of input and output fluxes; L'hafnium dans les zones de subduction: bilan isotopique des flux entrant et sortant

    Energy Technology Data Exchange (ETDEWEB)

    Marini, J.Ch

    2004-05-15

    Subduction zones are the primary regions of mass exchanges between continental crust and mantle of Earth through sediment subduction toward the earth's mantle and by supply of mantellic magmas to volcanic arcs. We analyze these mass exchanges using Hafnium and Neodymium isotopes. At the Izu-Mariana subduction zone, subducting sediments have Hf and Nd isotopes equivalent to Pacific seawater. Altered oceanic crust has Hf and Nd isotopic compositions equivalent to the isotopic budget of unaltered Pacific oceanic crust. At Luzon and Java subduction zones, arc lavas present Hf isotopic ratios highly radiogenic in comparison to their Nd isotopic ratios. Such compositions of the Luzon and Java arc lavas are controlled by a contamination of their sources by the subducted oceanic sediments. (author)

  14. Atomic layer deposition of calcium oxide and calcium hafnium oxide films using calcium cyclopentadienyl precursor

    International Nuclear Information System (INIS)

    Kukli, Kaupo; Ritala, Mikko; Sajavaara, Timo; Haenninen, Timo; Leskelae, Markku

    2006-01-01

    Calcium oxide and calcium hafnium oxide thin films were grown by atomic layer deposition on borosilicate glass and silicon substrates in the temperature range of 205-300 o C. The calcium oxide films were grown from novel calcium cyclopentadienyl precursor and water. Calcium oxide films possessed refractive index 1.75-1.80. Calcium oxide films grown without Al 2 O 3 capping layer occurred hygroscopic and converted to Ca(OH) 2 after exposure to air. As-deposited CaO films were (200)-oriented. CaO covered with Al 2 O 3 capping layers contained relatively low amounts of hydrogen and re-oriented into (111) direction upon annealing at 900 o C. In order to examine the application of CaO in high-permittivity dielectric layers, mixtures of Ca and Hf oxides were grown by alternate CaO and HfO 2 growth cycles at 230 and 300 o C. HfCl 4 was used as a hafnium precursor. When grown at 230 o C, the films were amorphous with equal amounts of Ca and Hf constituents (15 at.%). These films crystallized upon annealing at 750 o C, showing X-ray diffraction peaks characteristic of hafnium-rich phases such as Ca 2 Hf 7 O 16 or Ca 6 Hf 19 O 44 . At 300 o C, the relative Ca content remained below 8 at.%. The crystallized phase well matched with rhombohedral Ca 2 Hf 7 O 16 . The dielectric films grown on Si(100) substrates possessed effective permittivity values in the range of 12.8-14.2

  15. A study of a production process for hafnium-free zirconium from zircon

    International Nuclear Information System (INIS)

    Ratanalert, N.

    1985-01-01

    The purpose of this experiment was to extract and purify the zirconium from zircon. The effects of time of extraction and stripping of zirconium, concentration of feed solution, concentration of hydrochloric acid in stripping process, equilibrium curve of extraction of zirconium and hafnium and equilibrium curve of stripping zirconium or scrubbing hafnium were studied from standard zirconium and hafnium. The results, subsequently were applied to the extraction procedures for zirconium from zircon. Minus 100 mesh zircon was fused with sodium hydroxide in the ratio of 1 : 6 at 700 degree C for l hour. After fusion the zirconate was leached with water and dissolved in hot concentrated hydrochloric acid. Zirconyl chloride octahydrate crystallized out when the solution was cooled. An agueons solution of zirconyl chloride was used as the feed to the hexone - thiocyanate solvent extraction process. This was prepared by dissolving zirconyl chloride octahydrate crystal in waster. This zirconium feed solution in 1 M HCl and 1 M N H 4 CNS was extracted with 2.7 m N H 4 CNS in hexone and then stripped with 3.6 M HCl the aqueous phase was got rid of thiocyanate ion by extracting with pure hexone, then the zirconium in aqueous phase was precipitated with sulfuric acid and ammonium hydroxide at pH 1.8 - 2.0 and zirconium oxide was obtained by ignition at 700 degree C. The process could be modified to improve the purity of zirconium by using cation exchange resin to get rid of thiocyanate ion after solvent extraction process

  16. Laser coating of hafnium on Ti6Al4 for biomedical applications

    CSIR Research Space (South Africa)

    Phume, L

    2012-12-01

    Full Text Available Al4V FOR BIOMEDICAL APPLICATIONS Lerato Phume 1, 2, S.L. Pityana 1, 2, C. Meacock 1, A.P.I Popoola 2 1. National Laser Centre, Council for Scientific and Industrial Research, P.O. Box 395, Pretoria, 0001, South Africa 2. Department of Chemical... and Metallurgical Engineering, Tshwane University of Technology, Private Bag X 680, Pretoria, 0001, South Africa (b) (c) (e) To investigate laser surface coating of Ti6Al4V with preplaced Hafnium powder, to determine the influence of the energy density...

  17. Improvement of aging kinetics and precipitate size refinement in Mg–Sn alloys by hafnium additions

    Energy Technology Data Exchange (ETDEWEB)

    Behdad, S. [Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States); Zhou, L. [Department of Materials Science and Engineering and Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, FL 32816 (United States); Henderson, H.B.; Manuel, M.V. [Department of Materials Science and Engineering, University of Florida, Gainesville, FL 32611 (United States); Sohn, Y. [Department of Materials Science and Engineering and Advanced Materials Processing and Analysis Center, University of Central Florida, Orlando, FL 32816 (United States); Agarwal, A. [Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States); Boesl, B., E-mail: bboesl@fiu.edu [Department of Mechanical and Materials Engineering, Florida International University, Miami, FL 33174 (United States)

    2016-01-10

    Two Mg–Sn alloys were microalloyed by addition of Hafnium and their age-hardening response was studied at 200 °C. Time to reach peak hardness was significantly reduced and improved by Hf addition. TEM study showed Hf clusters in the close vicinity and at the surface of Mg{sub 2}Sn precipitates, which confirms that Hf clusters act as additional nucleation centers for Mg{sub 2}Sn precipitate formation. Our results support the validity of thermokinetic criterion proposed by Mendis for selection of microalloying elements in order to refine precipitate size, accelerate aging kinetics and enhance peak hardness.

  18. Critical evaluation of the determination of zirconium and hafnium by instrumental and radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Burger, Mario; Kraehenbuehl, Urs

    1991-01-01

    Neutron activation analysis (instrument or radiochemical) is suitable for the determination of zirconium and hafnium in samples of geochemical origin only when sufficient attention is paid to inter-fering nuclides. The size of the necessary correction for INAA depends on the composition of the sample; this problem is discussed. The radio-chemical technique which is recommended involves separation of the samples, precipitations and anion-exchange separation. Results are given for various standard reference materials and for meteorites. (author). 12 refs.; 1 fig.; 9 tabs

  19. High temperature thermodynamics of solutions of oxygen in zirconium and hafnium

    International Nuclear Information System (INIS)

    Boureau, G.; Gerdanian, P.

    1984-01-01

    The Tian-Calvet microcalorimetric method has been applied to the determination at 1323 Kelvin of ΔH(O 2 ), the partial molar enthalpy of mixing of oxygen in zirconium and in hafnium. No measurable departure from Henry's law has been found for dilute solutions (ratio oxygen over metal smaller than 0.1). For concentrated solutions repulsive interactions are found in agreement with the existence of ordered structures at lower temperatures. The domain of homogeneity of zirconium has been found larger than previously assumed. (author)

  20. Complexing of zirconium and hafnium with ortho-aminobenzoic acid and paraaminobenzoic acid

    International Nuclear Information System (INIS)

    Alekseeva, I.I.; Nemzer, I.I.; Yuranova, L.I.; Borisova, V.V.; Prozorovskaya, Z.N.

    1977-01-01

    Formation of complexes between zirconium and hafnium and ortho- and para-aminobenzoic acids has been studied by the kinetic method. It has been found that at pH=1.3-2.0 and concentrations of metals 10 -5 -10 -6 mole complex compounds are formed with composition Me:L=1:2 and 1:1 (Me=Zr, Hf; L=ortho- or para-aminobenzoic acids). Stepwise constants and overall effective constants of complex formation have been calculated

  1. Investigation of interaction of zirconium and hafnium tetrafluorides with strontium fluoride

    International Nuclear Information System (INIS)

    Ratnikova, I.D.; Korenev, Yu.M.; Novoselova, A.V.

    1980-01-01

    Diagrams of the condensated state of systems SrF 2 -EF 4 have been plotted, where E represents Zr, Hf. In these systems, three intermediate compounds of Sr 3 EF 10 , Sr 2 EF 8 and Sr EF 6 compositions are formed. All those compounds melt incongruently at temperatures of 982, 865 and 750 deg C, respectively - zirconium salt; at temperatures of 1000, 900 and 820 deg C - hafnium salts. Fluoro-metallates of composition 2:1, and 1:1, exist in two polymorphic forms. Tetrafluorides were found to dissolve in strontium fluoride: they form solid solutions having fluorite structure

  2. Near net shape processing of zirconium or hafnium metals and alloys

    International Nuclear Information System (INIS)

    Evans, S.C.

    1992-01-01

    This patent describes a process for producing a metal shape. It comprises: plasma arc melting a metal selected from zirconium, hafnium and alloys thereof comprising at least about 90 w/o of these metals to form a liquid pool; pouring the metal form the pool into a mold to form a near net shape; and reducing the metal from its near net shape to a final size while maintaining the metal temperature below the alpha-beta transition temperature throughout the size reducing step

  3. Thermal behaviour of hafnium diethylenetriaminepentaacetate studied using the perturbed angular correlation technique

    Energy Technology Data Exchange (ETDEWEB)

    Chain, Cecilia Y. [Universidad Nacional de La Plata (Argentina). Dept. de Fisica; Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), La Plata (Argentina). IFLP-CCT; Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Rivas, Patricia [Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), La Plata (Argentina). IFLP-CCT; Consejo Nacional de Investigaciones Cientificas y Tecnicas, Buenos Aires (Argentina); Universidad Nacional de La Plata (Argentina). Facultad de Ciencias Agrarias y Forestales; Pasquevich, Alberto F. [Universidad Nacional de La Plata (Argentina). Dept. de Fisica; Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET), La Plata (Argentina). IFLP-CCT; Comision de Investigaciones Cientificas de la Provincia de Buenos Aires (CIC-PBA) (Argentina)

    2014-07-01

    Polyaminecarboxilic ligands like diethylenetriaminepentaacetic acid form stable complexes with many heavy metal ions, excelling as cation chelants especially in the field of radiopharmacy. The aim of this work is to characterize, by using the Time Differential Perturbed Angular Correlations (TDPAC) technique, the hyperfine interactions at hafnium sites in hafnium diethylenetriaminepentaacetate and to investigate their evolution as temperature increases. TDPAC results for KHfDTPA.3H{sub 2}O obtained by chemical synthesis yield a well defined and highly asymmetric interaction of quadrupole frequency ω{sub Q} = 141 Mrad/s, which is consistent with the existence of a unique site for the metal in the crystal lattice. The thermal behaviour of the chelate is investigated by means of differential scanning calorimetry and thermogravimetrical analyses revealing that an endothermic dehydration of KHfDTPA.3H{sub 2}O takes place in one step between 80 C and 180 C. The anhydrous KHfDTPA thus arising is characterized by a fully asymmetric and well defined interaction of quadrupole frequency ω{sub Q} = 168 Mrad/s. (orig.)

  4. Rare-earth hafnium oxide materials for magnetohydrodynamic (MHD) generator application

    Energy Technology Data Exchange (ETDEWEB)

    Marchant, D. D; Bates, J. L.

    1979-01-01

    Several ceramic materials based on rare-earth hafnium oxides have been identified as potential high-temperature electrodes and low-temperature current leadouts for open cycle coal-fired MHD generator channels. The electrode-current leadouts combination must operate at temperatures between 400 and 2000K with an electrical conductivity greater than 10/sup -2/ ohm/sup -1/ cm/sup -1/. The electrodes will be exposed to flowing (linear flow rates up to 100 m/s) potassium seeded coal combustion gases (plasma core temperatures between 2400 to 3200/sup 0/K) and coal slag. During operation the electrodes must conduct direct electric current at densities near 1.5 amp/cm/sup 2/. Consequently, the electrodes must be resistant to electrochemical decompositions and interactions with both the coal slag and potassium salts (e.g., K/sub 2/SO/sub 4/, K/sub 2/CO/sub 3/). The current leadout materials are placed between the hot electrodes and the water-cooled copper structural members and must have electrical conductivities greater than 10/sup -2/ ohm/sup -1/ cm/sup -1/ between 1400 and 400/sup 0/K. The current leadouts must be thermally and electrochemically compatible with the electrode, copper, and potassium salts. Ideally, the electrodes and current leadouts should exhibit minimal ionic conductivity. The fabrication, electrical conductivity, and electrochemical corrosion of rare-earth hafnium oxide materials are discussed. (WHK)

  5. Thermal behaviour of hafnium diethylenetriaminepentaacetate studied using the perturbed angular correlation technique

    International Nuclear Information System (INIS)

    Chain, Cecilia Y.; Rivas, Patricia

    2014-01-01

    Polyaminecarboxilic ligands like diethylenetriaminepentaacetic acid form stable complexes with many heavy metal ions, excelling as cation chelants especially in the field of radiopharmacy. The aim of this work is to characterize, by using the Time Differential Perturbed Angular Correlations (TDPAC) technique, the hyperfine interactions at hafnium sites in hafnium diethylenetriaminepentaacetate and to investigate their evolution as temperature increases. TDPAC results for KHfDTPA.3H 2 O obtained by chemical synthesis yield a well defined and highly asymmetric interaction of quadrupole frequency ω Q = 141 Mrad/s, which is consistent with the existence of a unique site for the metal in the crystal lattice. The thermal behaviour of the chelate is investigated by means of differential scanning calorimetry and thermogravimetrical analyses revealing that an endothermic dehydration of KHfDTPA.3H 2 O takes place in one step between 80 C and 180 C. The anhydrous KHfDTPA thus arising is characterized by a fully asymmetric and well defined interaction of quadrupole frequency ω Q = 168 Mrad/s. (orig.)

  6. Preparation, structure and properties of hafnium compounds in the system Hf-C-N-O

    International Nuclear Information System (INIS)

    Brundiers, G.D.

    1975-08-01

    Highly dense, homogenous and single phase hafnium carbonitride samples (with low oxygen content) were prepared in the whole concentration range of the ternary cubic carbonitrides. Stoichiometric hafnium oxicarbides were also prepared within the range of solubility. The procedure involved the hot pressing of powders of HfC, HfN, Hf, Hf-Oxide and carbon at temperatures of 3,000 0 C and pressures up to 550 kpf/cm 2 using a novel technique. Small single crystals of slightly substoichiometric HfN were also repared. The densification of the powders was studied as a function of the non-metal concentration. Carbonitrides with N/Hf ratio of 0.37 were prepared in a high temperature autoclave operating at medium pressures by the reaction of HfC with nitrogen. All the samples were characterized by density measurements, chemical, X-ray and metallographic analysis and in some cases with the aid of quantitative metallography and microprobe analysis. Typical properties investigated were lattice parameter, thermal expansion, microhardness and electrical resistivity as function of the non-metal content. For specific concentrations extreme values in the properties are attained. With the aid of the valence electron concentration (VEC) parameter, the properties can be correlated with the density of states of electrons at the Fermi level. (orig./HK) [de

  7. Titrimetric determination of thiocyanate in solutions of the hafnium-zirconium separation process

    International Nuclear Information System (INIS)

    Vazquez, Cristina; Botbol, Moises; Hernandez, M.H.

    1980-01-01

    The control of the thiocyanate concentration is necessary during the process of separating hafnium from zirconium by the hexone-thiocyanate method. Said control is carried out by titrimetric determination of thiocyanate in aqueous and organic solutions containing hydrochloric acid and ammonium thiocyanate in presence or absence of zirconium and/or hafnium. The method consists in a redox volumetric analysis using a cerium (IV) salt as titrating agent, and ferroine as the final point indicator. Owing to the instability of thiocyanate in an acid medium it is necessary to know previously if the decomposition of solutions with different concentration of ammonium thiocyanate and hydrochloric acid may have an influence upon the analytic results or may even invalidate them. In order to obtain reliable results, it must be taken into account that the stability of the solutions depends on the thiocyanate concentration, the acidity and the time elapsed from the moment the sample is taken until the test is performed. The decomposition process can be slowed down by cooling the solutions. This method allows to control the plant and does not require any special equipment. (M.E.L) [es

  8. Molecular structure, vibrational, HOMO-LUMO, MEP and NBO analysis of hafnium selenite

    Science.gov (United States)

    Yankova, Rumyana; Genieva, Svetlana; Dimitrova, Ginka

    2017-08-01

    In hydrothermal condition hafnium selenite with estimated chemical composition Hf(SeO3)2·n(H2O) was obtained and characterized by powder X-Ray diffraction, IR spectroscopy and thermogravimetrical analysis. The composition of the obtained crystalline phase was established as dihydrate of tetraaqua complex of the hafnium selenite [Hf(SeO3)2(H2O)4]·2H2O. The results of the thermogravimetrical analysis are shown that the two hydrated water molecules are released in the temperature interval 80-110°C, while the four coordinated water molecules - at 210-300°C. By DFT method, with Becke's three parameter exchange-functional combined with gradient-corrected correlation functional of Lee, Yang and Parr and 6-31G(d), 6-311 + G(d,p) basis sets and LANL2DZ for Hf atom were calculated the molecular structure, vibrational frequencies and thermodynamic properties of the structure. The UV-Vis spectra and electronic properties are presented. The energy and oscillator strength calculated by time-dependent density functional theory corresponds well with the experimental ones. Molecular electrostatic potential (MEP) was performed. Mulliken population analysis on atomic charges was also calculated. The stability and intramolecular interactions are interpreted by NBO analysis.

  9. Correlations between nuclear data and results of integral slab experiments. Case of hafnium

    International Nuclear Information System (INIS)

    Palau, J.M.

    1997-01-01

    The aim of this thesis was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular 'mock-up' reactor. In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods (APOLLO2 code) together with Monte Carlo- type simulations (TRIPOLI4 code) enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope 177 Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent's efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author)

  10. Correlations between nuclear data and integral slab experiments: the case of hafnium

    International Nuclear Information System (INIS)

    Palau, J.M.

    1999-01-01

    The aim of this work was to evaluate how much integral slab experiments can both reduce discrepancies between experimental results and calculations, and improve the knowledge of hafnium isotopes neutronic parameters by an adapted sensitivity and uncertainty method. A statistical approach, based on the generalized least squares method and perturbation theory, has been incorporated into our calculation system in order to deduce microscopic cross-section adjustments from observed integral measurements on this particular 'mock-up' reactor.In this study it has been established that the correlations between integral parameters and hafnium capture cross-sections enable specific variations in the region of resolved resonances at the level of multigroup and punctual cross-sections recommended data (JEF-2.2 evaluation) to be highlighted. The use of determinist methods together with Monte Carlo- type simulations enabled a depth analysis of the modelling approximations to be carried out. Furthermore, the sensitivity coefficient validation technique employed leads to a reliable assessment of the quality of the new basic nuclear data. In this instance, the adjustments proposed for certain isotope 177 Hf resonance parameters reduce, after error propagation, by 3 to 5 per cent the difference between experimental results and calculations related to this absorbent's efficiency. Beyond this particular application, the qualification methodology integrated in our calculation system should enable other basic sizing parameters to be treated (chemical / geometric data or other unexplored nuclear data) to make technological requirements less stringent. (author)

  11. Highly substituted zirconium and hafnium cyclopentadienyl bifunctional β-diketiminate complexes – Synthesis, structure, and catalytic activity towards ethylene polymerization

    Czech Academy of Sciences Publication Activity Database

    Havlík, A.; Lamač, Martin; Pinkas, Jiří; Varga, Vojtěch; Růžička, A.; Olejník, R.; Horáček, Michal

    2015-01-01

    Roč. 786, JUN 2015 (2015), s. 71-80 ISSN 0022-328X R&D Projects: GA ČR GAP106/10/0924 Institutional support: RVO:61388955 Keywords : Zirconium * Hafnium * Cyclopentadienyl Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.336, year: 2015

  12. Differential perturbed angular correlation: use of physico-chemical study of some hafnium complexes derivates of hydroxy acids and EDTA

    International Nuclear Information System (INIS)

    Silveira, J.G. da.

    1981-01-01

    Measures of quadrupolar interaction to nucleus level of the metal, in some hafnium complexes are presented, including the analysis by combustion, microanalysis, infrared spectroscopy and thermogravimetry. The hyperfine interaction parameters, the temperature effects and the thermal neutrons capture effects over the irradiated Hf Y (Y = EDTA) are also studied. (author)

  13. 46 CFR 169.253 - Miscellaneous systems and equipment.

    Science.gov (United States)

    2010-10-01

    ... VESSELS Inspection and Certification Inspections § 169.253 Miscellaneous systems and equipment. (a) At each inspection for certification and periodic inspection all items in the ship's outfit, such as...

  14. Analysis of n+165Ho and 169Tm reactions

    International Nuclear Information System (INIS)

    Young, P.G.; Arthur, E.D.; Philis, C.; Nagel, P.; Collin, M.

    1982-09-01

    Experimental data for neutron-induced reactions on 165 Ho and 169 Tm have been theoretically analyzed in preparation for calculations on the unstable isotopes of Tm. A set of deformed optical model parameters was determined from measurements of s- and p-wave neutron strength functions, total cross sections, elastic angular distributions, and 16-MeV proton scattering to the 165 Ho ground and first excited states. The parameters for the 165 Ho and 169 Tm nuclei were linked by means of an isospin term in the real and imaginary well depths, together with adjustment of the ν 2 and ν 4 deformation parameters based on systematics in this mass region. Transmission coefficients from this analysis were used in Hauser-Feshbach statistical model calculations of the 169 Tm(n,ν) cross section as well as the 169 Tm(n,2n) and (n,3n) cross sections to 23 MeV, after application of suitable preequilibrium corrections. The results of these calculations are in good agreement with most of the available experimental data on 165 Ho and 169 Tm

  15. A thermally robust and thickness independent ferroelectric phase in laminated hafnium zirconium oxide

    Directory of Open Access Journals (Sweden)

    S. Riedel

    2016-09-01

    Full Text Available Ferroelectric properties in hafnium oxide based thin films have recovered the scaling potential for ferroelectric memories due to their ultra-thin-film- and CMOS-compatibility. However, the variety of physical phenomena connected to ferroelectricity allows a wider range of applications for these materials than ferroelectric memory. Especially mixed HfxZr1-xO2 thin films exhibit a broad compositional range of ferroelectric phase stability and provide the possibility to tailor material properties for multiple applications. Here it is shown that the limited thermal stability and thick-film capability of HfxZr1-xO2 can be overcome by a laminated approach using alumina interlayers.

  16. Surface State Capture Cross-Section at the Interface between Silicon and Hafnium Oxide

    Directory of Open Access Journals (Sweden)

    Fu-Chien Chiu

    2013-01-01

    Full Text Available The interfacial properties between silicon and hafnium oxide (HfO2 are explored by the gated-diode method and the subthreshold measurement. The density of interface-trapped charges, the current induced by surface defect centers, the surface recombination velocity, and the surface state capture cross-section are obtained in this work. Among the interfacial properties, the surface state capture cross-section is approximately constant even if the postdeposition annealing condition is changed. This effective capture cross-section of surface states is about 2.4 × 10−15 cm2, which may be an inherent nature in the HfO2/Si interface.

  17. Thermal expansion studies on Hafnium titanate (HfTiO4)

    International Nuclear Information System (INIS)

    Panneerselvam, G.; Subramanian, G.G.S.; Antony, M.P.

    2006-01-01

    The lattice thermal expansion characteristics of hafnium titanate (HfTiO 4 ) have been studied by measuring the lattice parameter as a function of temperature by high temperature X-ray diffraction technique (HT-XRD) in the temperature range 298-1973K. Percentage linear thermal expansion and mean linear thermal expansion coefficients were computed from the lattice parameter data. The thermal expansion of HfTiO 4 is highly anisotropic. The expansivity along 'a' axis is large; as compared to the expansivity along 'b' axis which is negative below 1073 K. The percentage linear thermal expansion in the temperature range 298-1973 K along a, b and c axis are 2.74, 0.901 and 1.49 respectively. Thermal expansion values obtained in the present study are in reasonable agreement with the existing thermal expansion data. (author)

  18. Density and surface tension of melts of zirconium and hafnium fluorides with lithium fluoride

    International Nuclear Information System (INIS)

    Katyshev, S.F.; Artemov, V.V.; Desyatnik, V.N.

    1988-01-01

    A study was conducted to determine the temperature dependence of the density and surface tension of melts of LiF-ZrF 4 and LiF-HfF 4 . Density and surface tension were determined by the method of maximum pressure in an argon bubble. On the basis of experimental data over the entire concentration range the molar volumes and their relative deviations from the additive molar volumes were calculated for 1100 0 K. The positive deviations of the molar volumes from additivity in the LiF-HfF 4 system (22.45%) were greater than in the LiF-ZrF 4 system (15.75%). This indicated that the reaction with lithium fluoride is intensified with the switch to the hafnium fluoride. Results also demonstrated that the fluorides are surface-active components in the molten mixtures

  19. Extraction of hafnium with chelating agents from aqueous-alcoholic solutions

    International Nuclear Information System (INIS)

    Hala, J.; Prihoda, J.

    1975-01-01

    The extraction was studied of hafnium into solutions of N-benzoyl-N-phenylhydroxylamine, 2-thenoyltrifluoroacetone and di-n-butylphosphoric acid in benzene, toluene, chloroform and tetrachloromethane from aqueous alcoholic solutions with a formal acidity of 2M-HClO 4 . Methyl-, ethyl-, n- and isopropyl- and tert-butyl alcohol were used as organic components in the mixed aqueous-organic phase. In the extraction into N-benzoyl-N-phenylhydroxylamine the presence of the alcohols resulted in synergic effects analogous to the previously described extraction by substituted benzoylpyrazolone. With the other two extractants, the effect of the alcohols was antagonistic, due to the interaction of alcohol or water with the reagent in the organic phase, and to the decrease in the reagent distribution constant. (author)

  20. Interface and oxide traps in high-κ hafnium oxide films

    International Nuclear Information System (INIS)

    Wong, H.; Zhan, N.; Ng, K.L.; Poon, M.C.; Kok, C.W.

    2004-01-01

    The origins of the interface trap generation and the effects of thermal annealing on the interface and bulk trap distributions are studied in detail. We found that oxidation of the HfO 2 /Si interface, removal of deep trap centers, and crystallization of the as-deposited film will take place during the post-deposition annealing (PDA). These processes will result in the removal of interface traps and deep oxide traps and introduce a large amount of shallow oxide traps at the grain boundaries of the polycrystalline film. Thus, trade-off has to be made in considering the interface trap density and oxide trap density when conducting PDA. In addition, the high interface trap and oxide trap densities of the HfO 2 films suggest that we may have to use the SiO 2 /HfO 2 stack or hafnium silicate structure for better device performance

  1. Wake-up effects in Si-doped hafnium oxide ferroelectric thin films

    International Nuclear Information System (INIS)

    Zhou, Dayu; Xu, Jin; Li, Qing; Guan, Yan; Cao, Fei; Dong, Xianlin; Müller, Johannes; Schenk, Tony; Schröder, Uwe

    2013-01-01

    Hafnium oxide based ferroelectric thin films have shown potential as a promising alternative material for non-volatile memory applications. This work reports the switching stability of a Si-doped HfO 2 film under bipolar pulsed-field operation. High field cycling causes a “wake-up” in virgin “pinched” polarization hysteresis loops, demonstrated by an enhancement in remanent polarization and a shift of negative coercive voltage. The rate of wake-up is accelerated by either reducing the frequency or increasing the amplitude of the cycling field. We suggest de-pinning of domains due to reduction of the defect concentration at bottom electrode interface as origin of the wake-up

  2. Atom-vacancy ordering and magnetic susceptibility of nonstoichiometric hafnium carbide

    International Nuclear Information System (INIS)

    Gusev, A.I.; Zyryanova, A.N.

    1999-01-01

    Experimental results on magnetic susceptibility of nonstoichiometric hafnium carbide HfC y (0.6 0.71 , HfC 0.78 and HfC 0.83 in the range of 870-930 K the anomalies are revealed which are associated with superstructure short-range ordering in a non-metallics sublattice. It is shown that a short-range order in HfC 0.71 and HfC 0.78 carbides corresponds to Hf 3 C 2 ordered phase, and in HfC 0.83 carbide - to Hf 6 C 5 ordered phase. HfC 0.78 carbide is found to possesses zero magnetic susceptibility in temperature range 910-980 K [ru

  3. Sub-10 nm low current resistive switching behavior in hafnium oxide stack

    Energy Technology Data Exchange (ETDEWEB)

    Hou, Y., E-mail: houyi@pku.edu.cn, E-mail: lfliu@pku.edu.cn [Institute of Microelectronics, Peking University, 100871 Beijing (China); IMEC, Kapeldreef 75, B-3001 Heverlee (Belgium); Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee (Belgium); Celano, U.; Xu, Z.; Vandervorst, W. [IMEC, Kapeldreef 75, B-3001 Heverlee (Belgium); Department of Physics and Astronomy, KU Leuven, Celestijnenlaan 200D, B-3001 Heverlee (Belgium); Goux, L.; Fantini, A.; Degraeve, R.; Youssef, A.; Jurczak, M. [IMEC, Kapeldreef 75, B-3001 Heverlee (Belgium); Liu, L., E-mail: houyi@pku.edu.cn, E-mail: lfliu@pku.edu.cn; Cheng, Y.; Kang, J. [Institute of Microelectronics, Peking University, 100871 Beijing (China)

    2016-03-21

    In this letter, a tip-induced cell relying on the conductive atomic force microscope is proposed. It is verified as a referable replica of an integrated resistive random access memory (RRAM) device. On the basis of this cell, the functionality of sub-10 nm resistive switching is confirmed in hafnium oxide stack. Moreover, the low current switching behavior in the sub-10 nm dimension is found to be more pronounced than that of a 50 × 50 nm{sup 2} device. It shows better ON/OFF ratio and low leakage current. The enhanced memory performance is ascribed to a change in the shape of the conductive filament as the device dimensions are reduced to sub-10 nm. Therefore, device downscaling provides a promising approach for the resistance optimization that benefits the RRAM array design.

  4. Solvent extraction of hafnium(IV) by dinonylnaphthalene sulfonic acid from mixed aqueous-organic media

    International Nuclear Information System (INIS)

    Hala, J.; Piperkovova, H.

    1979-01-01

    The extraction of hafnium(IV) by heptane and toluene solutions of dinonylnaphthalene sulfonic acid (HD) from mixed aqueous-organic solutions has been studied. Alcohols, ketones, carboxylic acids, cyclic ethers, dimethylsulfoxide and dimethylformamide were used as the organic component of the mixed phase. Methanol, ethanol, formic acid and dioxane increased the extractability of Hf(IV) whereas other solvents showed only an antagonistic effect. The results were discussed from the point of view of the changes in micellar structure of HD, and compared with the uptake of Hf(IV) by resinous cation exchangers. The solubilization by HD of alcohols, carboxylic acids and dimethylsulfoxide was demonstrated by using the corresponding 14 C and 35 S labelled compounds. (author)

  5. Study of bulk Hafnium oxide (HfO2) under compression

    Science.gov (United States)

    Pathak, Santanu; Mandal, Guruprasad; Das, Parnika

    2018-04-01

    Hafnium oxide (HfO2) is a technologically important material. This material has K-value of 25 and band gap 5.8 eV. A k value of 25-30 is preferred for a gate dielectric [1]. As it shows good insulating and capacitive properties, HfO2 is being considered as a replacement to SiO2 in microelectronic devices as gate dielectrics. On the other hand because of toughening mechanism due to phase transformation induced by stress field observed in these oxides, HFO2 has been a material of investigations in various configurations for a very long time. However the controversies about phase transition of HfO2 under pressure still exists. High quality synchrotron radiation has been used to study the structural phase transition of HfO2 under pressure.

  6. Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, A B; Kudyakov, V Ya; Smirnov, M V; Moskalenko, N I [AN SSSR, Sverdlovsk. Inst. Ehlektrokhimii

    1984-08-01

    The coefficient of HfCl/sub 4/ and ZrCl/sub 4/ separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl/sub 4/+HfCl/sub 4/). HfCl/sub 4/ and ZrCl/sub 4/ are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl.

  7. Separation of hafnium from zirconium in their tetrachloride solution in molten alkali metal chlorides

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Kudyakov, V.Ya.; Smirnov, M.V.; Moskalenko, N.I.

    1984-01-01

    The coefficient of HfCl 4 and ZrCl 4 separation in the process of vapour sublimation from their solutions in molten NaCl, KCl, CsCl, NaCl-KCl and NaCl-CsCl equimolar mixtures is found to vary in the series from approximately 1.10 to approximately 1.22 and practically not to depend on the temperature (in the 600-910 deg) range and concentration (2-25 mol.% ZrCl 4 +HfCl 4 ). HfCl 4 and ZrCl 4 are shown to form almost perfect solutions with each other, which in their turn form imperfect solutions with molten alkali metal chlorides, with the strength of hafnium complex chloride anions increasing higher than that of zirconium in the series from NaCl to CsCl

  8. Influence of plastic deformation on nitriding of a molybdenum-hafnium alloy

    International Nuclear Information System (INIS)

    Lakhtin, Yu.M.; Kogan, Ya.D.; Shashkov, D.P.; Likhacheva, T.E.

    1982-01-01

    The influence of a preliminary plastic strain on the structure and properties of molybdenum alloy with 0.2 wt.% Hf upon nitriding in the ammonia medium at 900-1200 deg C during 1-6 h is investigated. The study of microhardness distribution across the nitrided layer thickness has shown that with increase of the degree of preliminary plastic strain up to 50 % the nitrided layer hardness decreases and with further reduction growth up to 90 % - increases. Nitriding sharply (hundred times) increases wear resistance of molybdenum alloy with hafnium addition. At the reduction degree 25 % the wear resistance is less than at other values of percentage reduction in area owing to the minimum thickness of the nitride zone. The alloy strained before nitriding by 25 % has shown the best results during heat resistance testing

  9. Hafnium at subduction zones: isotopic budget of input and output fluxes

    International Nuclear Information System (INIS)

    Marini, J.Ch.

    2004-05-01

    Subduction zones are the primary regions of mass exchanges between continental crust and mantle of Earth through sediment subduction toward the earth's mantle and by supply of mantellic magmas to volcanic arcs. We analyze these mass exchanges using Hafnium and Neodymium isotopes. At the Izu-Mariana subduction zone, subducting sediments have Hf and Nd isotopes equivalent to Pacific seawater. Altered oceanic crust has Hf and Nd isotopic compositions equivalent to the isotopic budget of unaltered Pacific oceanic crust. At Luzon and Java subduction zones, arc lavas present Hf isotopic ratios highly radiogenic in comparison to their Nd isotopic ratios. Such compositions of the Luzon and Java arc lavas are controlled by a contamination of their sources by the subducted oceanic sediments. (author)

  10. Rapid screening of nuclear grade zirconium silicate without separation of hafnium from the bulk matrix

    International Nuclear Information System (INIS)

    Venkatesh, Manisha; Sharma, P.K.; Avhad, D.K.; Basu, H.; Singhal, R.K.; Reddy, A.V.R.

    2014-01-01

    Zirconium silicate, also zirconium orthosilicate, (ZrSiO 4 ) is a chemical compound, and occurs in nature as zircon, a silicate mineral. The concentration of Hafnium in nuclear grade Zirconium must be less than 0.2% w/w of Zr. In view of this it must be accurately chemically characterized before issuing a certification for export under non nuclear category. As the chemistry of Zr and Hf is similar, it is difficult to separate Hf by direct wet chemical method. During this work, concentration of Hf in zirconium silicate was measured by Field Portable X-ray Fluorescence (FPXRF) and results obtained were validated by using detailed chemical method. FPXRF spectrometry has become a common analytical technique for on-site screening and fast turnaround analysis of contaminant elements in environmental samples

  11. Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyralozone from aqueous-alcoholic solutions

    International Nuclear Information System (INIS)

    Hala, J.; Prihoda, J.

    1975-01-01

    Extraction of hafnium by 1-phenyl-3-methyl-4-benzoyl-5-pyrazolone (HL) in benzene, toluene, chloroform and tetrachloromethane from aqueous-alcoholic solutions of the formal acidity of 2M-HClO 4 was studied. Methyl, ethyl, n- and isopropyl, tert-butyl and allyl alcohol as well as ethylene glycol monomethyl ether and propylene glycol were used as organic components of the mixed aqueous-organic phase. Their presence in some cases resulted in a synergic increase in the distribution ratio of hafnium. The increase is interpreted using the results of a slope analysis and measurements of the alcohol distribution and the relative permittivity of the organic phase. It is suggested that HfL 4 molecules were solvated by alcohol molecules in the organic phase. At high alcohol concentration synergism changed into antagonism. This was caused by changes in the distribution of HL and its interaction with the alcohol in the organic phase. (author)

  12. Hafnium isotope evidence for a transition in the dynamics of continental growth 3.2 Gyr ago.

    Science.gov (United States)

    Næraa, T; Scherstén, A; Rosing, M T; Kemp, A I S; Hoffmann, J E; Kokfelt, T F; Whitehouse, M J

    2012-05-30

    Earth's lithosphere probably experienced an evolution towards the modern plate tectonic regime, owing to secular changes in mantle temperature. Radiogenic isotope variations are interpreted as evidence for the declining rates of continental crustal growth over time, with some estimates suggesting that over 70% of the present continental crustal reservoir was extracted by the end of the Archaean eon. Patterns of crustal growth and reworking in rocks younger than three billion years (Gyr) are thought to reflect the assembly and break-up of supercontinents by Wilson cycle processes and mark an important change in lithosphere dynamics. In southern West Greenland numerous studies have, however, argued for subduction settings and crust growth by arc accretion back to 3.8 Gyr ago, suggesting that modern-day tectonic regimes operated during the formation of the earliest crustal rock record. Here we report in situ uranium-lead, hafnium and oxygen isotope data from zircons of basement rocks in southern West Greenland across the critical time period during which modern-like tectonic regimes could have initiated. Our data show pronounced differences in the hafnium isotope-time patterns across this interval, requiring changes in the characteristics of the magmatic protolith. The observations suggest that 3.9-3.5-Gyr-old rocks differentiated from a >3.9-Gyr-old source reservoir with a chondritic to slightly depleted hafnium isotope composition. In contrast, rocks formed after 3.2 Gyr ago register the first additions of juvenile depleted material (that is, new mantle-derived crust) since 3.9 Gyr ago, and are characterized by striking shifts in hafnium isotope ratios similar to those shown by Phanerozoic subduction-related orogens. These data suggest a transitional period 3.5-3.2 Gyr ago from an ancient (3.9-3.5 Gyr old) crustal evolutionary regime unlike that of modern plate tectonics to a geodynamic setting after 3.2 Gyr ago that involved juvenile crust generation by plate

  13. Results for heterogeneous poisoning of the critical HTR-test facility KAHTER using absorber elements containing hafnium and boron

    International Nuclear Information System (INIS)

    Drueke, V.; Filges, D.; Nabi, R.; Neef, R.D.; Paul, N.; Schaal, H.

    1979-10-01

    Experiments and checking computations for investigating the initial-core poisoning of the pebble bed high temperature reactor are described. Following the example of the THTR-300, THTR absorber elements poisoned with hafnium/boron were added to the THTR fuel- and graphite elements of the KAHTER core. Three different hafnium-boron poisoned core loadings, corresponding to 2.7, 5.3 and 8% reactivity compensation, were used in the experiments. For purposes of comparison, two cores exclusively boron poisoned were also studied. The poisoning of these cores correspond to 2.7 and 8% reactivity compensation. The experiments and checking computations should serve to test the accuracy of the theoretical models and data sets in modeling the reactivity effects of absorber poisoned elements in the THTR. In particular, the applicability of the nuclear data of hafnium and the treatment of resonance calculations should be verified. In addition, to determining critical masses and ksub(eff), special emphasis was placed in the experiments on the exact determination of all reactivity effects. In some cases, repeated loading of a configuration also provided a measure of the reproducibility of ksub(eff). The experiments were checked computationally using the GAMTEREX code package and the program system RSYST. These two computation packages contain different data bases, - although the hafnium data are identical -, and the computing models differ in certain phases of the calculations. Both code systems compute ksub(eff) values to within the present accuracy requirements, whereas the program system RSYST gives better agreement with experimental measurements. (orig.) 891 RW/orig. 892 RDG [de

  14. Ion-bombardment-induced reduction in vacancies and its enhanced effect on conductivity and reflectivity in hafnium nitride films

    Energy Technology Data Exchange (ETDEWEB)

    Gu, Zhiqing; Wang, Jiafu; Hu, Chaoquan; Zhang, Xiaobo; Dang, Jianchen; Gao, Jing; Zheng, Weitao [Jilin University, School of Materials Science and Engineering, Key Laboratory of Mobile Materials, MOE, and State Key Laboratory of Superhard Materials, Changchun (China); Zhang, Sam [Nanyang Technological University, School of Mechanical and Aerospace Engineering, Singapore (Singapore); Wang, Xiaoyi [Chinese Academy of Sciences, Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Changchun (China); Chen, Hong [Jilin University, Department of Control Science and Engineering, Changchun (China)

    2016-08-15

    Although the role of ion bombardment on electrical conductivity and optical reflectivity of transition metal nitrides films was reported previously, the results were controversial and the mechanism was not yet well explored. Here, we show that proper ion bombardment, induced by applying the negative bias voltage (V{sub b}), significantly improves the electrical conductivity and optical reflectivity in rocksalt hafnium nitride films regardless of level of stoichiometry (i.e., in both near-stoichiometric HfN{sub 1.04} and over-stoichiometric HfN{sub 1.17} films). The observed improvement arises from the increase in the concentration of free electrons and the relaxation time as a result of reduction in nitrogen and hafnium vacancies in the films. Furthermore, HfN{sub 1.17} films have always much lower electrical conductivity and infrared reflectance than HfN{sub 1.04} films for a given V{sub b}, owing to more hafnium vacancies because of larger composition deviation from HfN exact stoichiometry (N:Hf = 1:1). These new insights are supported by good agreement between experimental results and theoretical calculations. (orig.)

  15. 25 CFR 169.4 - Permission to survey.

    Science.gov (United States)

    2010-04-01

    ... application shall adequately describe the proposed project, including the purpose and general location, and it shall be accompanied by the written consents required by § 169.3, by satisfactory evidence of the good... an application, provided the company issuing the surety bond is licensed to do business in the State...

  16. 46 CFR 169.231 - Definitions relating to hull examinations.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Definitions relating to hull examinations. 169.231... hull examinations. As used in the part— (a) Drydock examination means hauling out a vessel or placing a... and all through-hull fittings, sea chests, sea valves, sea strainers, and valves for the emergency...

  17. 21 CFR 133.169 - Pasteurized process cheese.

    Science.gov (United States)

    2010-04-01

    ...) FOOD FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE PRODUCTS Requirements for Specific Standardized Cheese and Related Products § 133.169 Pasteurized process cheese. (a)(1) Pasteurized process cheese is... two or more varieties, except cream cheese, neufchatel cheese, cottage cheese, lowfat cottage cheese...

  18. 7 CFR 3015.169 - Equipment management requirements.

    Science.gov (United States)

    2010-01-01

    ... following requirements (including replacement equipment) until such actions as transfer, replacement or... transfer, replacement, or disposal of the equipment. (b) Every two years, at a minimum, a physical... 7 Agriculture 15 2010-01-01 2010-01-01 false Equipment management requirements. 3015.169 Section...

  19. 7 CFR 457.169 - Mint crop insurance provisions.

    Science.gov (United States)

    2010-01-01

    ... type designated in the actuarial documents. The price elections you choose for each type must have the... CORPORATION, DEPARTMENT OF AGRICULTURE COMMON CROP INSURANCE REGULATIONS § 457.169 Mint crop insurance... produces new mint plants at its tips or nodes. Type. A category of mint identified as a type in the Special...

  20. Nano-scale Radiotherapy-NBTXR3 Hafnium Oxide Nanoparticles as Promising Cancer Therapy

    International Nuclear Information System (INIS)

    Maggiorella, L.; Barouch, G.; Devaux, C.; Pottier, A.; Levy, L.; Deutsch, E.; Bourhis, J.; Borghi, E.

    2011-01-01

    Complete text of publication follows: Background: There is considerable interest in approaches that could improve the therapeutic window of radiotherapy, which represents a crucial modality of treatment in oncology. We present the rationale for designing NBTXR3 nanoparticles activated by radiotherapy and validate the concept. We performed the Monte Carlo calculations for the first time based on the 'local model' simulation that showed a dose enhancement of radiation to tumour cells of approximately nine-fold. NBTXR3 was shown to deposit high energy when the ionizing radiation source is 'on' and to have chemically inert behavior in cellular and subcellular systems demonstrated by very good systemic tolerance, thus decreasing potential health hazards. Material and Methods: We used conventional methods, implemented in different ways, to explore interactions of high Z matter and ionizing radiation with biological systems. In addition, microtomography was performed to explore the nanoparticle volume occupancy inside the tumour and its persistence overtime in mouse tumour models. The antitumour activity of NBTXR3 and tolerance were evaluated in Ewing tumour (A673) and fibrosarcoma (HT1080) using high energy source. Results and Conclusion: We created and developed NBTXR3 nanoparticles with a crystalline hafnium oxide core which provide high electron density structure and inert behavior in biological media. NBTXR3 nanoparticles' characteristics, size, charge and shape, allow for efficient interaction with biological entities, cell membrane binding and cellular uptake. The nanoparticles were shown to form clusters at the subcellular level in tumour models. Of most importance, we show NBTXR3 intra-tumour bioavailability with dispersion of nanoparticles in the three dimensions and persistence within the tumour structure, supporting the use of NBTXR3 as effective antitumour therapeutic agent. Antitumour activity of NBTXR3 showed marked advantage in terms of survival, tumour

  1. Hafnium-doped hydroxyapatite nanoparticles with ionizing radiation for lung cancer treatment.

    Science.gov (United States)

    Chen, Min-Hua; Hanagata, Nobutaka; Ikoma, Toshiyuki; Huang, Jian-Yuan; Li, Keng-Yuan; Lin, Chun-Pin; Lin, Feng-Huei

    2016-06-01

    Recently, photodynamic therapy (PDT) is one of the new clinical options by generating cytotoxic reactive oxygen species (ROS) to kill cancer cells. However, the optical approach of PDT is limited by tissue penetration depth of visible light. In this study, we propose that a ROS-enhanced nanoparticle, hafnium-doped hydroxyapatite (Hf:HAp), which is a material to yield large quantities of ROS inside the cells when the nanoparticles are bombarded with high penetrating power of ionizing radiation. Hf:HAp nanoparticles are generated by wet chemical precipitation with total doping concentration of 15mol% Hf(4+) relative to Ca(2+) in HAp host material. The results show that the HAp particles could be successfully doped with Hf ions, resulted in the formation of nano-sized rod-like shape and with pH-dependent solubility. The impact of ionizing radiation on Hf:HAp nanoparticles is assessed by using in-vitro and in-vivo model using A549 cell line. The 2',7'-dichlorofluorescein diacetate (DCFH-DA) results reveal that after being exposed to gamma rays, Hf:HAp could significantly lead to the formation of ROS in cells. Both cell viability (WST-1) and cytotoxicity (LDH) assay show the consistent results that A549 lung cancer cell lines are damaged with changes in the cells' ROS level. The in-vivo studies further demonstrate that the tumor growth is inhibited owing to the cells apoptosis when Hf:HAp nanoparticles are bombarded with ionizing radiation. This finding offer a new therapeutic method of interacting with ionizing radiation and demonstrate the potential of Hf:HAp nanoparticles in tumor treatment, such as being used in a palliative treatment after lung surgical procedure. Photodynamic therapy (PDT) is one of the new clinical options by generating cytotoxic reactive oxygen species (ROS) to kill cancer cells. Unfortunately, the approach of PDT is usually limited to the treatment of systemic disease and deeper tumor, due to the limited tissue penetration depth of visible

  2. Characterization of hafnium oxide resistive memory layers deposited on copper by atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, B.D.; Bishop, S.M. [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States); Leedy, K.D. [Air Force Research Laboratory, 2241 Avionics Circle, Wright Patterson Air Force Base, Dayton, OH 45433 (United States); Cady, N.C., E-mail: ncady@albany.edu [SUNY College of Nanoscale Science and Engineering, 255 Fuller Road, Albany, NY 12203 (United States)

    2014-07-01

    Hafnium oxide-based resistive memory devices have been fabricated on copper bottom electrodes. The HfO{sub x} active layers in these devices were deposited by atomic layer deposition (ALD) at 250 °C with tetrakis(dimethylamido)hafnium(IV) as the metal precursor and an O{sub 2} plasma as the reactant. Depth profiles of the HfO{sub x} by X-ray photoelectron spectroscopy and secondary ion mass spectroscopy revealed a copper concentration on the order of five atomic percent throughout the HfO{sub x} film. In addition to the Cu doped HfO{sub x}, a thin layer (20 nm) of Cu{sub x}O is present at the surface. This surface layer is believed to have formed during the ALD process, and greatly complicates the analysis of the switching mechanism. The resistive memory structures fabricated from the ALD HfO{sub x} exhibited non-polar resistive switching, independent of the top metal electrode (Ni, Pt, Al, Au). Resistive switching current voltage (I–V) curves were analyzed using Schottky emission and ionic hopping models to gain insight into the physical mechanisms underpinning the device behavior. During the forming process it was determined that, at voltages in excess of 2.5 V, an ionic hopping model is in good agreement with the I–V data. The extracted ion hopping distance ∼ 4 Å was within the range of interatomic spacing of HfO{sub 2} during the forming process consistent with ionic motion of Cu{sup 2+} ions. Lastly the on state I–V data was dominated at larger voltages by Schottky emission with an estimated barrier height of ∼ 0.5 eV and a refractive index of 2.59. The consequence of the Schottky emission analysis indicates the on state resistance to be a product of a Pt/Cu{sub 2}O/Cu filament(s)/Cu{sub 2}O/Cu structure. - Highlights: • HfO{sub 2} was grown via atomic layer deposition at 250 and 100 °C on Cu substrates. • A Cu{sub 2}O surface layer and Cu doping were observed in post-deposition of HfO{sub 2}. • Resistive memory devices were fabricated and

  3. Yrast spectroscopy in the neutron-deficient nucleus 169Os

    International Nuclear Information System (INIS)

    Joss, D.T.; Simpson, J.; Appelbe, D.E.; Warner, D.D.; Page, R.D.; King, S.L.; Amzal, N.; Cullen, D.M.; Greenlees, P.T.; Keenan, A.; Baeck, T.; Cederwall, B.; Wyss, R.; Bentley, M.A.; Williams, S.J.; Cocks, J.F.C.; Helariutta, K.; Jones, P.M.; Julin, R.; Juutinen, S.

    2002-01-01

    Excited states in the neutron-deficient isotope 169 Os have been identified for the first time in an experiment using the Jurosphere γ-ray spectrometer in conjunction with the Ritu gas-filled recoil separator. The problems associated with identifying neutron-deficient isotopes produced with low fusion cross sections against a high background of competing channels, including fission, have been overcome by using the recoil-decay tagging technique. The band structures observed in 169 Os are interpreted in the context of the systematics of neighboring nuclei and the predictions of cranked Woods-Saxon calculations. The systematics of the second (i 13/2 ) 2 neutron alignment in this region are discussed

  4. Recoil Induced Room Temperature Stable Frenkel Pairs in a-Hafnium Upon Thermal Neutron Capture

    Science.gov (United States)

    Butz, Tilman; Das, Satyendra K.; Dey, Chandi C.; Ghoshal, Shamik

    2013-11-01

    Ultrapure hafnium metal (110 ppm zirconium) was neutron activated with a thermal neutron flux of 6:6 · 1012 cm-2s-1 in order to obtain 181Hf for subsequent time differential perturbed angular correlation (TDPAC) experiments using the nuclear probe 181Hf(β-) 181Ta. Apart from the expected nuclear quadrupole interaction (NQI) signal for a hexagonal close-packed (hcp) metal, three further discrete NQIs were observed with a few percent fraction each. The TDPAC spectra were recorded for up to 11 half lives with extreme statistical accuracy. The fitted parameters vary slightly within the temperature range between 248 K and 373 K. The signals corresponding to the three additional sites completely disappear after `annealing' at 453 K for one minute. Based on the symmetry of the additional NQIs and their temperature dependencies, they are tentatively attributed to Frenkel pairs produced by recoil due to the emission of a prompt 5:694 MeV -ray following thermal neutron capture and reported by the nuclear probe in three different positions. These Frenkel pairs are stable up to at least 373 K.

  5. The energy landscape of glassy dynamics on the amorphous hafnium diboride surface

    Science.gov (United States)

    Nguyen, Duc; Mallek, Justin; Cloud, Andrew N.; Abelson, John R.; Girolami, Gregory S.; Lyding, Joseph; Gruebele, Martin

    2014-11-01

    Direct visualization of the dynamics of structural glasses and amorphous solids on the sub-nanometer scale provides rich information unavailable from bulk or conventional single molecule techniques. We study the surface of hafnium diboride, a conductive ultrahigh temperature ceramic material that can be grown in amorphous films. Our scanning tunneling movies have a second-to-hour dynamic range and single-point current measurements extend that to the millisecond-to-minute time scale. On the a-HfB2 glass surface, two-state hopping of 1-2 nm diameter cooperatively rearranging regions or "clusters" occurs from sub-milliseconds to hours. We characterize individual clusters in detail through high-resolution (single cluster vertical displacements, we can reconstruct the local free energy landscape of individual clusters, complete with activation barrier height, a reaction coordinate in nanometers, and the shape of the free energy landscape basins between which hopping occurs. The experimental images are consistent with the compact shape of α-relaxors predicted by random first order transition theory, whereas the rapid hopping rate, even taking less confined motion at the surface into account, is consistent with β-relaxations. We make a proposal of how "mixed" features can show up in surface dynamics of glasses.

  6. Characteristics of laser produced plasmas of hafnium and tantalum in the 1-7 nm region

    Science.gov (United States)

    Li, Bowen; Otsuka, Takamitsu; Sokell, Emma; Dunne, Padraig; O'Sullivan, Gerry; Hara, Hiroyuki; Arai, Goki; Tamura, Toshiki; Ono, Yuichi; Dinh, Thanh-Hung; Higashiguchi, Takeshi

    2017-11-01

    Soft X-ray (SXR) spectra from hafnium and tantalum laser produced plasmas were recorded in the 1-7 nm region using two Nd:YAG lasers with pulse lengths of 170 ps and 10 ns, respectively, operating at a range of power densities. The maximum focused peak power density was 2. 3 × 1014 W cm-2 for 170 ps pulses and 1. 8 × 1012 W cm-2 for 10 ns pulses, respectively. Two intense quasicontinuous intensity bands resulting from n = 4 - n = 4 and n = 4 - n = 5 unresolved transition arrays (UTAs) dominate both sets of experimental spectra. Comparison with calculations performed with the Cowan suite of atomic structure codes as well as consideration of previous experimental and theoretical results aided identification of the most prominent features in the spectra. For the 10 ns spectrum, the highest ion stage that could be identified from the n = 4 - n = 5 arrays were lower than silver-like Hf25+ and Ta26+ (which has a 4 d 104 f ground configuration) indicating that the plasma temperature attained was too low to produce ions with an outermost 4 d subshell, while for the 170 ps plasmas the presence of significantly higher stages was deduced and lines due to 4 d-5 p transitions were clearly evident. Furthermore, we show an enhancement of emission from tantalum using dual laser irradiation, and the effect of pre-pulse durations and delay times between two pulses are demonstrated.

  7. Ferroelectric transistors with monolayer molybdenum disulfide and ultra-thin aluminum-doped hafnium oxide

    Science.gov (United States)

    Yap, Wui Chung; Jiang, Hao; Liu, Jialun; Xia, Qiangfei; Zhu, Wenjuan

    2017-07-01

    In this letter, we demonstrate ferroelectric memory devices with monolayer molybdenum disulfide (MoS2) as the channel material and aluminum (Al)-doped hafnium oxide (HfO2) as the ferroelectric gate dielectric. Metal-ferroelectric-metal capacitors with 16 nm thick Al-doped HfO2 are fabricated, and a remnant polarization of 3 μC/cm2 under a program/erase voltage of 5 V is observed. The capability of potential 10 years data retention was estimated using extrapolation of the experimental data. Ferroelectric transistors based on embedded ferroelectric HfO2 and MoS2 grown by chemical vapor deposition are fabricated. Clockwise hysteresis is observed at low program/erase voltages due to slow bulk traps located near the 2D/dielectric interface, while counterclockwise hysteresis is observed at high program/erase voltages due to ferroelectric polarization. In addition, the endurances of the devices are tested, and the effects associated with ferroelectric materials, such as the wake-up effect and polarization fatigue, are observed. Reliable writing/reading in MoS2/Al-doped HfO2 ferroelectric transistors over 2 × 104 cycles is achieved. This research can potentially lead to advances of two-dimensional (2D) materials in low-power logic and memory applications.

  8. Silicon-doped hafnium oxide anti-ferroelectric thin films for energy storage

    Science.gov (United States)

    Ali, Faizan; Liu, Xiaohua; Zhou, Dayu; Yang, Xirui; Xu, Jin; Schenk, Tony; Müller, Johannes; Schroeder, Uwe; Cao, Fei; Dong, Xianlin

    2017-10-01

    Motivated by the development of ultracompact electronic devices as miniaturized energy autonomous systems, great research efforts have been expended in recent years to develop various types of nano-structural energy storage components. The electrostatic capacitors characterized by high power density are competitive; however, their implementation in practical devices is limited by the low intrinsic energy storage density (ESD) of linear dielectrics like Al2O3. In this work, a detailed experimental investigation of energy storage properties is presented for 10 nm thick silicon-doped hafnium oxide anti-ferroelectric thin films. Owing to high field induced polarization and slim double hysteresis, an extremely large ESD value of 61.2 J/cm3 is achieved at 4.5 MV/cm with a high efficiency of ˜65%. In addition, the ESD and the efficiency exhibit robust thermal stability in 210-400 K temperature range and an excellent endurance up to 109 times of charge/discharge cycling at a very high electric field of 4.0 MV/cm. The superior energy storage performance together with mature technology of integration into 3-D arrays suggests great promise for this recently discovered anti-ferroelectric material to replace the currently adopted Al2O3 in fabrication of nano-structural supercapacitors.

  9. Hafnium Films and Magnetic Shielding for TIME, A mm-Wavelength Spectrometer Array

    Science.gov (United States)

    Hunacek, J.; Bock, J.; Bradford, C. M.; Butler, V.; Chang, T.-C.; Cheng, Y.-T.; Cooray, A.; Crites, A.; Frez, C.; Hailey-Dunsheath, S.; Hoscheit, B.; Kim, D. W.; Li, C.-T.; Marrone, D.; Moncelsi, L.; Shirokoff, E.; Steinbach, B.; Sun, G.; Trumper, I.; Turner, A.; Uzgil, B.; Weber, A.; Zemcov, M.

    2018-04-01

    TIME is a mm-wavelength grating spectrometer array that will map fluctuations of the 157.7-μm emission line of singly ionized carbon ([CII]) during the epoch of reionization (redshift z ˜ 5-9). Sixty transition-edge sensor (TES) bolometers populate the output arc of each of the 32 spectrometers, for a total of 1920 detectors. Each bolometer consists of gold absorber on a ˜ 3 × 3 mm silicon nitride micro-mesh suspended near the corners by 1 × 1 × 500 μm silicon nitride legs targeting a photon-noise-dominated NEP ˜ 1 × 10^{-17} W/√{Hz} . Hafnium films are explored as a lower-T_c alternative to Ti (500 mK) for TIME TESs, allowing thicker support legs for improved yield. Hf T_c is shown to vary between 250 and 450 mK when varying the resident Ar pressure during deposition. Magnetic shielding designs and simulations are presented for the TIME first-stage SQUIDs. Total axial field suppression is predicted to be 5 × 10^7.

  10. Tuning the magnetic properties of pure hafnium by high pressure torsion

    International Nuclear Information System (INIS)

    Cepeda-Jiménez, C.M.; Beltrán, J.I.; Hernando, A.; García, M.A.; Ynduráin, F.; Zhilyaev, A.; Pérez-Prado, M.T.

    2017-01-01

    This work demonstrates that room temperature (RT) ferromagnetism might be triggered in pure hafnium (Hf), a classic paramagnet, by severe plastic deformation (SPD) via high pressure torsion (HPT). The origin of this phenomenon is elucidated by a combined approach including density functional theory (DFT) calculations and transmission electron microscopy (TEM). In particular, it is shown that the elastic lattice distorsions induced in pure Hf as a consequence of grain refinement down to the nanocrystalline regime by HPT lead to the development of a new monoclinic crystalline structure that exhibits a spontaneous magnetization at RT. DFT calculations are utilized to prove that local stretching of the original pure Hf hexagonal close packed (hcp) lattice along specific pyramidal directions, due to the presence of internal stresses in the deformed nanostructure, may give rise to the emergence of the monoclinic phase, which is endowed with a net magnetic moment. An excellent agreement is found between DFT calculations and experimental TEM observations, which provide a first evidence of the presence of the pure Hf monoclinic crystal lattice. This work shows that SPD may constitute a viable, yet widely unexplored, strategy to tune the magnetic properties and, in particular, to induce RT ferromagnetism in bulk non-magnetic metals.

  11. Liposomal encapsulated Zn-DTPA for removing intracellular 169Yb

    International Nuclear Information System (INIS)

    Blank, M.L.; Cress, E.A.; Byrd, B.L.; Washburn, L.C.; Snyder, F.

    1980-01-01

    Multilamellar liposomes possessing neutral positive or negative charges were tested for their capacity to encapsulate sodium ethylenediaminetetraacetate (EDTA) and for their selectivity in depositing in specific tissues after being injected into rats. Negative-charged liposomes had the greatest trapping efficiency over a wide range of lipid-to-aqueous phase ratios. In contrast, except for lung, liposomal charge had no significant effect on the tissue distribution of encapsulated EDTA; liver and spleen exhibited the highest uptake with all preparations. The proportion of encapsulated EDTA taken up by the liver decreased as the amount of injected liposomes was increased. Free zinc diethylenetriaminepentaacetate (Zn-DTPA) and multilamellar liposomes containing entrapped Zn-DTPA were administered to rats that had been injected with 169 Yb-citrate 24 hr earlier. At doses of 14 mg Zn-DTPA per kg body weight, both free Zn-DPTA and the liposomal-bound Zn-DTPA caused increased removal of 169 Yb from the animals. However, treatment with the liposomal Zn-DTPA caused significantly more of the 169 Yb to be removed than did the free Zn-DTPA treatment by itself. Our data indicate that lipophilic forms of chelators can effectively increase the removal rates of heavy metal contamination in tissues. (author)

  12. β decays on the rotational levels of the 5/2+[642] 169Yb band

    International Nuclear Information System (INIS)

    Dzhelepov, B.S.; Zhukovskij, N.N.; Shestopalova, S.A.

    1993-01-01

    Competing 169 Lu β decays into rotational levels of 5/2 + [642] 169 Yb band are considered. Schemes of resolved β decay into 3 levels of deformed nucleus rotational bands, γ transitions linked with excitation and discharge of 169 Yb 5/2, 7/2, 9/2, 5/2 + [642] levels are presented. Matrix elements of axial-vector decay are determined. Data on 12 γ transitions in 169 Lu are presented

  13. 46 CFR 169.831 - Emergency position indicating radio beacon (EPIRB).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Emergency position indicating radio beacon (EPIRB). 169.831 Section 169.831 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS... radio beacon (EPIRB). The master shall ensure that— (a) The EPIRB required in § 169.555 of this...

  14. In-Pile Experiment of a New Hafnium Aluminide Composite Material to Enable Fast Neutron Testing in the Advanced Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Donna Post Guillen; Douglas L. Porter; James R. Parry; Heng Ban

    2010-06-01

    A new hafnium aluminide composite material is being developed as a key component in a Boosted Fast Flux Loop (BFFL) system designed to provide fast neutron flux test capability in the Advanced Test Reactor. An absorber block comprised of hafnium aluminide (Al3Hf) particles (~23% by volume) dispersed in an aluminum matrix can absorb thermal neutrons and transfer heat from the experiment to pressurized water cooling channels. However, the thermophysical properties, such as thermal conductivity, of this material and the effect of irradiation are not known. This paper describes the design of an in-pile experiment to obtain such data to enable design and optimization of the BFFL neutron filter.

  15. Rapid formation of nanocrystalline HfO2 powders from amorphous hafnium hydroxide under ultrasonically assisted hydrothermal treatment

    International Nuclear Information System (INIS)

    Meskin, Pavel E.; Sharikov, Felix Yu.; Ivanov, Vladimir K.; Churagulov, Bulat R.; Tretyakov, Yury D.

    2007-01-01

    Peculiarities of hafnium hydroxide hydrothermal decomposition were studied by in situ heat flux calorimetry for the first time. It was shown that this process occurs in one exothermal stage (ΔH = -17.95 kJ mol -1 ) at 180-250 deg. C resulting in complete crystallization of amorphous phase with formation of pure monoclinic HfO 2 . It was found that the rate of m-HfO 2 formation can be significantly increased by combining hydrothermal treatment with simultaneous ultrasonic activation

  16. Study on the eγ coincidences in the 169Lu decay

    International Nuclear Information System (INIS)

    Batsev, S.; Bonch-Osmolovskaya, N.A.; Budzyak, A.; Kuznetsov, V.V.; Usmanov, R.R.

    1979-01-01

    The 169 Lu→ 169 Yb decay scheme was analyzed on the basis of measurements of eγ coincidence. The 169 Lu sources were obtained by irradiating a tantalum target by 660 MeV protons. The eγ-coincidence spectra were measured by an ironless β-spectrometer with a toroidal magnetic field and a detector. The γ-ray and eγ-coincidence spectra were processed by a computer. The results of processing the 169 Lu coincidence spectra are tabulated. No excited states of 169 Yb not confirmed by γγ and eγ coincidences (except for the head level of the 3/2 + (651) 720 keV band) remain in the 169 Lu decay scheme proposed. Weak transitions with the total intensity of no more than 3.3% per a 169 Lu decay have remained unarranged, they should discharge weakly excited levels of 169 Yb. Probabilities of the 169 Yb level population per a 169 Lu decay and the corresponding values of probabilities of transitions in them are presented. As a whole, the 169 Lu decay scheme involves 60 levels, 31 states of them are new

  17. The energy landscape of glassy dynamics on the amorphous hafnium diboride surface

    International Nuclear Information System (INIS)

    Nguyen, Duc; Girolami, Gregory S.; Mallek, Justin; Cloud, Andrew N.; Abelson, John R.; Lyding, Joseph; Gruebele, Martin

    2014-01-01

    Direct visualization of the dynamics of structural glasses and amorphous solids on the sub-nanometer scale provides rich information unavailable from bulk or conventional single molecule techniques. We study the surface of hafnium diboride, a conductive ultrahigh temperature ceramic material that can be grown in amorphous films. Our scanning tunneling movies have a second-to-hour dynamic range and single-point current measurements extend that to the millisecond-to-minute time scale. On the a-HfB 2 glass surface, two-state hopping of 1–2 nm diameter cooperatively rearranging regions or “clusters” occurs from sub-milliseconds to hours. We characterize individual clusters in detail through high-resolution (<0.5 nm) imaging, scanning tunneling spectroscopy and voltage modulation, ruling out individual atoms, diffusing adsorbates, or pinned charges as the origin of the observed two-state hopping. Smaller clusters are more likely to hop, larger ones are more likely to be immobile. HfB 2 has a very high bulk glass transition temperature T g , and we observe no three-state hopping or sequential two-state hopping previously seen on lower T g glass surfaces. The electronic density of states of clusters does not change when they hop up or down, allowing us to calibrate an accurate relative z-axis scale. By directly measuring and histogramming single cluster vertical displacements, we can reconstruct the local free energy landscape of individual clusters, complete with activation barrier height, a reaction coordinate in nanometers, and the shape of the free energy landscape basins between which hopping occurs. The experimental images are consistent with the compact shape of α-relaxors predicted by random first order transition theory, whereas the rapid hopping rate, even taking less confined motion at the surface into account, is consistent with β-relaxations. We make a proposal of how “mixed” features can show up in surface dynamics of glasses

  18. Materials properties of hafnium and zirconium silicates: Metal interdiffusion and dopant penetration studies

    Science.gov (United States)

    Quevedo Lopez, Manuel Angel

    Hafnium and Zirconium based gate dielectrics are considered potential candidates to replace SiO2 or SiON as the gate dielectric in CMOS processing. Furthermore, the addition of nitrogen into this pseudo-binary alloy has been shown to improve their thermal stability, electrical properties, and reduce dopant penetration. Because CMOS processing requires high temperature anneals (up to 1050°C), it is important to understand the diffusion properties of any metal associated with the gate dielectric in silicon at these temperatures. In addition, dopant penetration from the doped polysilicon gate into the Si channel at these temperatures must also be studied. Impurity outdiffusion (Hf, Zr) from the dielectric, or dopant (B, As, P) penetration through the dielectric into the channel region would likely result in deleterious effects upon the carrier mobility. In this dissertation extensive thermal stability studies of alternate gate dielectric candidates ZrSixOy and HfSixO y are presented. Dopant penetration studies from doped-polysilicon through HfSixOy and HfSixOyNz are also presented. Rutherford Backscattering Spectroscopy (RBS), Heavy Ion RBS (HI-RBS), X-ray Photoelectron Spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HR-TEM), and Time of Flight and Dynamic Secondary Ion Mass Spectroscopy (ToF-SIMS, D-SIMS) methods were used to characterize these materials. The dopant diffusivity is calculated by modeling of the dopant profiles in the Si substrate. In this disseration is reported that Hf silicate films are more stable than Zr silicate films, from the metal interdiffusion point of view. On the other hand, dopant (B, As, and P) penetration is observed for HfSixO y films. However, the addition of nitrogen to the Hf - Si - O systems improves the dopant penetration properties of the resulting HfSi xOyNz films.

  19. Protective coatings of hafnium dioxide by atomic layer deposition for microelectromechanical systems applications

    Energy Technology Data Exchange (ETDEWEB)

    Berdova, Maria, E-mail: maria.berdova@aalto.fi [Aalto University, Department of Materials Science and Engineering, 02150, Espoo (Finland); Wiemer, Claudia; Lamperti, Alessio; Tallarida, Grazia; Cianci, Elena [Laboratorio MDM, IMM CNR, Via C. Olivetti 2, 20864, Agrate Brianza, MB (Italy); Lamagna, Luca; Losa, Stefano; Rossini, Silvia; Somaschini, Roberto; Gioveni, Salvatore [STMicroelectronics, Via C. Olivetti 2, 20864, Agrate Brianza, MB (Italy); Fanciulli, Marco [Laboratorio MDM, IMM CNR, Via C. Olivetti 2, 20864, Agrate Brianza, MB (Italy); Università degli studi di Milano Bicocca, Dipartimento di Scienza dei Materiali, 20126, Milano (Italy); Franssila, Sami, E-mail: sami.franssila@aalto.fi [Aalto University, Department of Materials Science and Engineering, 02150, Espoo (Finland)

    2016-04-15

    Graphical abstract: - Highlights: • Atomic layer deposition of HfO{sub 2} from (CpMe){sub 2}Hf(OMe)Me or Hf(NMeEt){sub 4} and ozone for potential applications in microelectromechanical systems. • ALD HfO{sub 2} protects aluminum substrates from degradation in moist environment and at the same time retains good reflectance properties of the underlying material. • The resistance of hafnium dioxide to moist environment is independent of chosen precursors. - Abstract: This work presents the investigation of HfO{sub 2} deposited by atomic layer deposition (ALD) from either HfD-CO4 or TEMAHf and ozone for microelectromechanical systems (MEMS) applications, in particular, for environmental protection of aluminum micromirrors. This work shows that HfO{sub 2} films successfully protect aluminum in moist environment and at the same time retain good reflectance properties of underlying material. In our experimental work, the chemical composition, crystal structure, electronic density and roughness of HfO{sub 2} films remained the same after one week of humidity treatment (relative humidity of 85%, 85 °C). The reflectance properties underwent only minor changes. The observed shift in reflectance was only from 80–90% to 76–85% in 400–800 nm spectral range when coated with ALD HfO{sub 2} films grown with Hf(NMeEt){sub 4} and no shift (remained in the range of 68–83%) for films grown from (CpMe){sub 2}Hf(OMe)Me.

  20. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-Gonzá lez, R.; Garcí a-Cerda, L. A.; Alshareef, Husam N.; Gnade, Bruce E.; Quevedo-Ló pez, Manuel Angel Quevedo

    2010-01-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  1. Study of hafnium (IV) oxide nanoparticles synthesized by polymerized complex and polymer precursor derived sol-gel methods

    KAUST Repository

    Ramos-González, R.

    2010-03-01

    This work reports the preparation and characterization of hafnium (IV) oxide (HfO2) nanoparticles grown by derived sol-gel routes that involves the formation of an organic polymeric network. A comparison between polymerized complex (PC) and polymer precursor (PP) methods is presented. For the PC method, citric acid (CA) and ethylene glycol (EG) are used as the chelating and polymerizable reagents, respectively. In the case of PP method, poly(acrylic acid) (PAA) is used as the chelating reagent. In both cases, different precursor gels were prepared and the hafnium (IV) chloride (HfCl4) molar ratio was varied from 0.1 to 1.0 for the PC method and from 0.05 to 0.5 for the PP method. In order to obtain the nanoparticles, the precursors were heat treated at 500 and 800 °C. The thermal characterization of the precursor gels was carried out by thermogravimetric analysis (TGA) and the structural and morphological characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The XRD patterns of the samples obtained by both methods shows the formation of HfO2 at 500 °C with monoclinic crystalline phase. The PC method exhibited also the cubic phase. Finally, the HfO2 nanoparticles size (4 to 11 nm) was determined by TEM and XRD patterns. © (2010) Trans Tech Publications.

  2. Corrosion resistant surface for vanadium nitride and hafnium nitride layers as function of grain size

    Science.gov (United States)

    Escobar, C. A.; Caicedo, J. C.; Aperador, W.

    2014-01-01

    In this research it was studied vanadium nitride (VN) and hafnium nitride (HfN) film, which were deposited onto silicon (Si (100)) and AISI 4140 steel substrates via r.f. magnetron sputtering technique in Ar/N2 atmosphere with purity at 99.99% for both V and Hf metallic targets. Both films were approximately 1.2±0.1 μm thick. The crystallography structures that were evaluated via X-ray diffraction analysis (XRD) showed preferential orientations in the Bragg planes VN (200) and HfN (111). The chemical compositions for both films were characterized by EDX. Atomic Force Microscopy (AFM) was used to study the morphology; the results reveal grain sizes of 78±2 nm for VN and 58±2 nm for HfN and roughness values of 4.2±0.1 nm for VN and 1.5±0.1 nm for HfN films. The electrochemical performance in VN and HfN films deposited onto steel 4140 were studied by Tafel polarization curves and impedance spectroscopy methods (EIS) under contact with sodium chloride at 3.5 wt% solution, therefore, it was found that the corrosion rate decreased about 95% in VN and 99% for HfN films in relation to uncoated 4140 steel, thus demonstrating, the protecting effect of VN and HfN films under a corrosive environment as function of morphological characteristics (grain size). VN(grain size)=78±2.0 nm, VN(roughness)=4.2±0.1 nm, VN(corrosion rate)=40.87 μmy. HfN(grain size)=58±2.0 nm, HfN(roughness)=1.5±0.1 nm, HfN(corrosion rate)=0.205 μmy. It was possible to analyze that films with larger grain size, can be observed smaller grain boundary thus generating a higher corrosion rate, therefore, in this work it was found that the HfN layer has better corrosion resistance (low corrosion rate) in relation to VN film which presents a larger grain size, indicating that the low grain boundary in (VN films) does not restrict movement of the Cl- ion and in this way the corrosion rate increases dramatically.

  3. Synthesis and characterization of hafnium carbide microcrystal chains with a carbon-rich shell via CVD

    International Nuclear Information System (INIS)

    Tian, Song; Li, Hejun; Zhang, Yulei; Liu, Sen; Fu, Yangxi; Li, Yixian; Qiang, Xinfa

    2013-01-01

    Graphical abstract: Novel HfC microcrystal chains have been synthesized via a catalyst-assisted chemical vapor deposition process. SEM results show the chains have a periodically changing diameter and a nanoscale sharpening tip. Analysis of TEM/SAED/EELS/EDX data shows the single-crystal chains grow along a [0 0 1] direction and consist of a HfC core and a thin carbon-rich shell with embedded HfC nanocrystallites surrounding the core. This work achieves the controllable preparation of nanoscale HfC sharpening tips for application as a point electron emission source and facilitates the application of HfC ultrafast laser-triggered tips in attosecond science. Highlights: •HfC microcrystal chains were synthesized by a catalyst-assisted CVD. •The chains grow along a [0 0 1] direction and have a periodically changing diameter. •Single-crystal HfC core is sheathed by a thin carbon-rich shell. •A growth mechanism model is proposed to explain the growth of microcrystal chians. •This work achieves the controllable preparation of nanoscale HfC sharpening tips. -- Abstract: Novel hafnium carbide (HfC) microcrystal chains, with a periodically changing diameter and a nanoscale sharpening tip at the chain end, have been synthesized via a catalyst-assisted chemical vapor deposition (CVD) process. The as-synthesized chains with many octahedral microcrystals have diameters of between several hundreds of nm and 6 μm and lengths of ∼500 μm. TEM diffraction studies show that the chains are single-crystalline HfC and preferentially grow along a [0 0 1] crystal orientation. TEM/EELS/EDX analysis proves the chains are composed of a HfC core and a thin (several tens of nm to 100 nm) carbon-rich shell with the embedded HfC nanocrystallites (typically below 10 nm) surrounding the core. The growth mechanism model for the chains based on the vapor–liquid–solid process, the vapor–solid process, and the HfC crystal growth characteristics is discussed

  4. Hafnium in peralkaline and peraluminous boro-aluminosilicate glass, and glass subcomponents: a solubility study

    International Nuclear Information System (INIS)

    Davis, Linda L.; Darab, John G.; Qian, Maoxu; Zhao, Donggao; Palenik, Christopher S.; Li, Hong; Strachan, Denis M.; Li, Liyu

    2003-01-01

    A relationship between the solubility of hafnia (HfO2) and the host glass composition was explored by determining the solubility limits of HfO2 in peralkaline and peraluminous borosilicate glasses in the system SiO2-Al2O3-B2O3-Na2O, and in glasses in the system SiO2-Na2O-Al2O3 in air at 1450 C. The only Hf-bearing phase to crystallize in the peralkaline borosilicate melts is hafnia, while in the boron-free melts sodium-hafnium silicates crystallize. All peraluminous borosilicate melts crystallize hafnia, but the slightly peraluminous glasses also have sector-zoned hafnia crystals that contain Al and Si. The more peraluminous borosilicate glasses also crystallize a B-containing mullite. The general morphology of the hafnia crystals changes as peralkalinity (Na2O/(Na2O+Al2O3)) decreases, as expected in melts with increasing viscosity. In all of the glasses with Na2O > Al2O3, the solubility of hafnia is linearly and positively correlated with Na2O/(Na2O + Al2O3) or Na2O - Al2O3 (excess sodium), despite the presence of 5 to 16 mol% B2O3. The solubility of hafnia is higher in the sodium-aluminum borosilicate glasses than in the sodium-aluminosilicate glasses, suggesting that the boron is enhancing the effect that excess sodium has on the incorporation of Hf into the glass structure. The results of this solubility study are compared to other studies of high-valence cation solubility in B-free silicate melts. From this, for peralkaline B-bearing glasses, it is shown that, although the solubility limits are higher, the solution behavior of hafnia is the same as in B-free silicate melts previously studied. By comparison, also, it is shown that in peraluminous melts, there must be a different solution mechanism for hafnia: different than for peralkaline sodium-aluminum borosilicate glasses and different than for B-free silicate melts studied by others

  5. Nano-crystals of cerium–hafnium binary oxide: Their size-dependent structure

    Energy Technology Data Exchange (ETDEWEB)

    Raitano, Joan M. [Department of Applied Physics and Applied Mathematics, Materials Science and Engineering Program, Columbia University, New York, NY 10027 (United States); Khalid, Syed [National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973 (United States); Marinkovic, Nebojsa [Chemical Engineering Department, Columbia University, 500 W 120th St, Mudd 801, New York, NY 10027 (United States); Chan, Siu-Wai, E-mail: sc174@columbia.edu [Department of Applied Physics and Applied Mathematics, Materials Science and Engineering Program, Columbia University, New York, NY 10027 (United States)

    2015-09-25

    Highlights: • (1 − x)CeO{sub 2}–xHfO{sub 2} was precipitated (0 < x < 1) and calcined in air. • For x ⩽ 0.14, crystallites ⩽140 nm in size exhibit only the fluorite structure. • This low hafnia solubility is attributable to no auto-reduction (Ce{sup 3+} = 0). • The low solubility is also due to the high temperature required for homogenization. • Coarsening is lessened as Hf{sup 4+} ions slow cation diffusion in these crystallites. - Abstract: Cerium oxide (CeO{sub 2}, “ceria”) and hafnium oxide (HfO{sub 2}, “hafnia”) were aqueously co-precipitated and subsequently calcined to allow for homogenization. The size of the (1−x)CeO{sub 2}–xHfO{sub 2} crystallites, determined by the Scherrer equation, varied from 140 nm for x = 0 to 15 nm for x = 0.73. For x ⩽ 0.14, only cubic structures are visible in X-ray diffractograms, and the lattice parameters are consistent with the values expected for structurally cubic solid solutions of hafnia in ceria. At x = 0.26, tetragonal and monoclinic phases nucleated with the former not being observed in the bulk phase diagram for ceria–hafnia. Therefore, the solubility limit of the cubic structure is between x = 0.14 and x = 0.26 for 40–61 nm crystallites, the sizes of these respective compositions. More specifically, for the 40 nm crystallites of x = 0.26 (1 − x)CeO{sub 2}–xHfO{sub 2}, 15% of the hafnia remains in a structurally cubic solid solution with ceria based on the observed cubic lattice parameter. The compositional domain for the cubic fluorite structure in this study is narrower than other nanostructured (1 − x)CeO{sub 2}–xHfO{sub 2} studies, especially studies with crystallite sizes less than 10 nm, but wider than observed in the bulk and helps to expand the size regime over which the relationship between crystallite size and phase stability is known. The extent of this cubic-structure domain is mainly attributable to the intermediate crystallite size and the roughly zero Ce{sup 3

  6. A search for long-lived radionuclides produced by fast-neutron irradiations of copper, silver, europium, terbium, and hafnium

    International Nuclear Information System (INIS)

    Meadows, J.W.; Smith, D.L.; Ikeda, Y.; Konno, C.

    1990-01-01

    Identical sample packets, each containing samples of elemental copper, silver, europium, terbium, and hafnium, as well as titanium, iron and nickel as dosimeters, have been irradiated in three distinct accelerator neutron fields (at Argonne National Laboratory and Los Alamos National Laboratory in the U.S.A., and Japan Atomic Energy Research Institute, Tokai, Japan) as part of an interlaboratory research collaboration to search for the production of long-lived radionuclides for fusion waste disposal applications. This paper is a progress report on this project. To date, we have detected the following activities, and have obtained preliminary experimental cross section values for several of these: Ag-106m,108m,110m; Eu-150m,152g,154; Tb-158,160; and Hf-175,178m2,179m2,181. (author). 11 refs, 1 fig., 4 tabs

  7. Improved DC performance of AlGaN/GaN high electron mobility transistors using hafnium oxide for surface passivation

    International Nuclear Information System (INIS)

    Liu, Chang; Chor, Eng Fong; Tan, Leng Seow

    2007-01-01

    Improved DC performance of AlGaN/GaN high electron mobility transistors (HEMTs) have been demonstrated using reactive-sputtered hafnium oxide (HfO 2 ) thin film as the surface passivation layer. Hall data indicate a significant increase in the product of sheet carrier concentration (n s ) and electron mobility (μ n ) in the HfO 2 -passivated HEMTs, compared to the unpassivated HEMTs. This improvement in electron carrier characteristics gives rise to a 22% higher I Dmax and an 18% higher g mmax in HEMTs with HfO 2 passivation relative to the unpassivated devices. On the other hand, I gleak of the HEMTs decreases by nearly one order of magnitude when HfO 2 passivation is applied. In addition, drain current is measured in the subthreshold regime. Compared to the unpassivated HEMTs, HfO 2 -passivated HEMTs exhibit a much smaller off-state I D , indicating better turn-off characteristics

  8. About the structure and stability of complex carbonates of thorium (IV), cerium (IV), zirconium (IV), hafnium (IV)

    International Nuclear Information System (INIS)

    Dervin, Jacqueline

    1972-01-01

    This research thesis addressed the study of complex carbonates of cations of metals belonging to the IV A column, i.e. thorium (IV), zirconium (IV), hafnium (IV), and also cerium (IV) and uranium (VI), and more particularly focused on ionic compounds formed in solution, and also on the influence of concentration and nature of cations on stability and nature of the formed solid. The author first presents methods used in this study, discusses their precision and scope of validity. She reports the study of the formation of different complex ions which have been highlighted in solution, and the determination of their formation constants. She reports the preparation and study of the stability domain of solid complexes. The next part reports the use of thermogravimetric analysis, IR spectrometry, and crystallography for the structural study of these compounds

  9. Tribo-electrochemical characterization of hafnium multilayer systems deposited on nitride/vanadium nitride AISI 4140 steel

    Science.gov (United States)

    Mora, M.; Vera, E.; Aperador, W.

    2016-02-01

    In this work is presented the synergistic behaviour among corrosion/wear (tribocorrosion) of the multilayer coatings hafnium nitride/vanadium nitride [HfN/VN]n. The multilayers were deposited on AISI 4140 steel using the technique of physical vapor deposition PVD magnetron sputtering, the tests were performed using a pin-on-disk tribometer, which has an adapted potentiostat galvanostat with three-electrode electrochemical cell. Tribocorrosive parameters such as: Friction coefficient between the coating and the counter body (100 Cr6 steel ball); Polarization resistance by means of electrochemical impedance spectroscopy technique and corrosion rate by polarization curves were determined. It was observed an increase in the polarization resistance, a decrease in the corrosion rate and a low coefficient of friction in comparison with the substrate, due to an increase on the number of bilayers.

  10. Tribo-electrochemical characterization of hafnium multilayer systems deposited on nitride/vanadium nitride AISI 4140 steel

    International Nuclear Information System (INIS)

    Mora, M; Vera, E; Aperador, W

    2016-01-01

    In this work is presented the synergistic behaviour among corrosion/wear (tribocorrosion) of the multilayer coatings hafnium nitride/vanadium nitride [HfN/VN]n. The multilayers were deposited on AISI 4140 steel using the technique of physical vapor deposition PVD magnetron sputtering, the tests were performed using a pin-on-disk tribometer, which has an adapted potentiostat galvanostat with three-electrode electrochemical cell. Tribocorrosive parameters such as: Friction coefficient between the coating and the counter body (100 Cr6 steel ball); Polarization resistance by means of electrochemical impedance spectroscopy technique and corrosion rate by polarization curves were determined. It was observed an increase in the polarization resistance, a decrease in the corrosion rate and a low coefficient of friction in comparison with the substrate, due to an increase on the number of bilayers. (paper)

  11. The interfacial orientation relationship of oxide nanoparticles in a hafnium-containing oxide dispersion-strengthened austenitic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Yinbin, E-mail: miao2@illinois.edu [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Mo, Kun [Nuclear Engineering Division, Argonne National Laboratory, Lemont, IL 60493 (United States); Cui, Bai [Department of Mechanical and Materials Engineering, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States); Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Chen, Wei-Ying [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Miller, Michael K.; Powers, Kathy A. [Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States); McCreary, Virginia; Gross, David [Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Almer, Jonathan [X-ray Science Division, Argonne National Laboratory, Lemont, IL 60493 (United States); Robertson, Ian M. [Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, WA 53706 (United States); Department of Material Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Stubbins, James F. [Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States)

    2015-03-15

    This work reports comprehensive investigations on the orientation relationship of the oxide nanoparticles in a hafnium-containing austenitic oxide dispersion-strengthened 316 stainless steel. The phases of the oxide nanoparticles were determined by a combination of scanning transmission electron microscopy–electron dispersive X-ray spectroscopy, atom probe tomography and synchrotron X-ray diffraction to be complex Y–Ti–Hf–O compounds with similar crystal structures, including bixbyite Y{sub 2}O{sub 3}, fluorite Y{sub 2}O{sub 3}–HfO{sub 2} solid solution and pyrochlore (or fluorite) Y{sub 2}(Ti,Hf){sub 2−x}O{sub 7−x}. High resolution transmission electron microscopy was used to characterize the particle–matrix interfaces. Two different coherency relationships along with one axis-parallel relation between the oxide nanoparticles and the steel matrix were found. The size of the nanoparticles significantly influences the orientation relationship. The results provide insight into the relationship of these nanoparticles with the matrix, which has implications for interpreting material properties as well as responses to radiation. - Highlights: • The oxide nanoparticles in a hafnium-containing austenitic ODS were characterized. • The nanoparticles are Y–Hf–Ti–O enriched phases according to APT and STEM–EDS. • Two coherency and an axis-parallel orientation relationships were found by HR-TEM. • Particle size has a prominent effect on the orientation relationship (OR). • Formation mechanism of the oxide nanoparticles was discussed based on the ORs.

  12. 46 CFR 169.679 - Wiring for power and lighting circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Wiring for power and lighting circuits. 169.679 Section... SCHOOL VESSELS Machinery and Electrical Electrical Installations Operating at Potentials of 50 Volts Or More on Vessels of Less Than 100 Gross Tons § 169.679 Wiring for power and lighting circuits. Wiring...

  13. 46 CFR 169.755 - Draft marks and draft indicating systems.

    Science.gov (United States)

    2010-10-01

    ... Section 169.755 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Vessel Control, Miscellaneous Systems, and Equipment Markings § 169.755 Draft marks and... projections of the marks onto a vertical plane are of uniform height equal to the vertical spacing between...

  14. 46 CFR 169.555 - Emergency position indicating radio beacon (EPIRB).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Emergency position indicating radio beacon (EPIRB). 169.555 Section 169.555 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS... Emergency position indicating radio beacon (EPIRB). (a) Each vessel certificated for exposed waters must...

  15. 46 CFR 169.744 - Emergency position indicating radio beacon (EPIRB).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Emergency position indicating radio beacon (EPIRB). 169.744 Section 169.744 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS... position indicating radio beacon (EPIRB). Each EPIRB must be marked with the vessel's name. ...

  16. 46 CFR 169.631 - Separation of machinery and fuel tank spaces from accommodation spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Separation of machinery and fuel tank spaces from accommodation spaces. 169.631 Section 169.631 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED... machinery and fuel tank spaces from accommodation spaces. (a) Machinery and fuel tank spaces must be...

  17. 46 CFR 169.629 - Compartments containing gasoline machinery or fuel tanks.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Compartments containing gasoline machinery or fuel tanks. 169.629 Section 169.629 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL... gasoline machinery or fuel tanks. Spaces containing gasoline machinery or fuel tanks must have natural...

  18. Implantation of titanium, chromium, yttrium, molybdenum, silver, hafnium, tantalum, tungsten and platinum ions generated by a metal vapor vacuum ion source into 440C stainless steel

    International Nuclear Information System (INIS)

    Sasaki, Jun; Hayashi, Kazunori; Sugiyama, Kenji; Ichiko, Osami; Hashiguchi, Yoshihiro

    1992-01-01

    Titanium, yttrium, molybdenum, silver, chromium, hafnium, tantalum, tungsten and platinum ions generated by a metal vapor vacuum arc (MEVVA) ion source were implanted into 440C stainless steel in the dose region 10 17 ions cm -2 with extraction voltages of up to 70 kV. Glow discharge spectroscopy (GDS), friction coefficient, and Vickers microhardness of the specimens were studied. Grooves made by friction tests were investigated by electron probe microanalysis (EPMA). GDS showed incorporation of carbon in the yttrium, hafnium, tantalum, tungsten and platinum implanted specimens, as well as titanium implanted samples. A large amount of oxygen was observed in the yttrium implanted specimen. The friction coefficient was measured by reciprocating sliding of an unimplanted 440C ball without lubricant at a load of 0.245 N. The friction decreased and achieved a stable state after implantation of titanium, hafnium and tantalum. The friction coefficient of the platinum implanted specimen showed a gradual decrease after several cycles of sliding at high friction coefficient. The yttrium implanted sample exhibited a decreased but slightly unstable friction coefficient. Results from EPMA showed that the implanted elements, which gave decreased friction, remained even after sliding of 200 cycles. Implantation of chromium, molybdenum, silver and tungsten did not provide a decrease in friction and the implants were gone from the wear grooves after the sliding tests. (orig.)

  19. Elongated Hypocotyl 5-Homolog (HYH Negatively Regulates Expression of the Ambient Temperature-Responsive MicroRNA Gene MIR169

    Directory of Open Access Journals (Sweden)

    Phanu T. Serivichyaswat

    2017-12-01

    Full Text Available Arabidopsis microRNA169 (miR169 is an ambient temperature-responsive microRNA that plays an important role in stress responses and the floral transition. However, the transcription factors that regulate the expression of MIR169 have remained unknown. In this study, we show that Elongated Hypocotyl 5-Homolog (HYH directly binds to the promoter of MIR169a and negatively regulates its expression. Absolute quantification identified MIR169a as the major locus producing miR169. GUS reporter assays revealed that the deletion of a 498-bp fragment (–1,505 to –1,007, relative to the major transcriptional start site of MIR169a abolished its ambient temperature-responsive expression. DNA-affinity chromatography followed by liquid chromatography-mass spectrometry analysis identified transcription factor HYH as a trans-acting factor that binds to the 498-bp promoter fragment of pri-miR169a. Electrophoretic mobility shift assays and chromatin immunoprecipitation–quantitative PCR demonstrated that the HYH.2 protein, a predominant isoform of HYH, directly associated with a G-box-like motif in the 498-bp fragment of pri-miR169a. Higher enrichment of HYH.2 protein on the promoter region of MIR169a was seen at 23°C, consistent with the presence of more HYH.2 protein in the cell at the temperature. Transcript levels of pri-miR169a increased in hyh mutants and decreased in transgenic plants overexpressing HYH. Consistent with the negative regulation of MIR169a by HYH, the diurnal levels of HYH mRNA and pri-miR169a showed opposite patterns. Taken together, our results suggest that HYH is a transcription factor that binds to a G-box-like motif in the MIR169a promoter and negatively regulates ambient temperature-responsive expression of MIR169a at higher temperatures in Arabidopsis.

  20. Interferon-Inducible CD169/Siglec1 Attenuates Anti-HIV-1 Effects of Alpha Interferon

    Science.gov (United States)

    Akiyama, Hisashi; Ramirez, Nora-Guadalupe Pina; Gibson, Gregory; Kline, Christopher; Watkins, Simon; Ambrose, Zandrea

    2017-01-01

    ABSTRACT A hallmark of human immunodeficiency virus type 1 (HIV-1) infection in vivo is chronic immune activation concomitant with type I interferon (IFN) production. Although type I IFN induces an antiviral state in many cell types, HIV-1 can replicate in vivo via mechanisms that have remained unclear. We have recently identified a type I IFN-inducible protein, CD169, as the HIV-1 attachment factor on dendritic cells (DCs) that can mediate robust infection of CD4+ T cells in trans. Since CD169 expression on macrophages is also induced by type I IFN, we hypothesized that type I IFN-inducible CD169 could facilitate productive HIV-1 infection in myeloid cells in cis and CD4+ T cells in trans and thus offset antiviral effects of type I IFN. In support of this hypothesis, infection of HIV-1 or murine leukemia virus Env (MLV-Env)-pseudotyped HIV-1 particles was enhanced in IFN-α-treated THP-1 monocytoid cells, and this enhancement was primarily dependent on CD169-mediated enhancement at the virus entry step, a phenomenon phenocopied in HIV-1 infections of IFN-α-treated primary monocyte-derived macrophages (MDMs). Furthermore, expression of CD169, a marker of type I IFN-induced immune activation in vivo, was enhanced in lymph nodes from pigtailed macaques infected with simian immunodeficiency virus (SIV) carrying HIV-1 reverse transcriptase (RT-SHIV), compared to uninfected macaques, and interestingly, there was extensive colocalization of p27gag and CD169, suggesting productive infection of CD169+ myeloid cells in vivo. While cell-free HIV-1 infection of IFN-α-treated CD4+ T cells was robustly decreased, initiation of infection in trans via coculture with CD169+ IFN-α-treated DCs restored infection, suggesting that HIV-1 exploits CD169 in cis and in trans to attenuate a type I IFN-induced antiviral state. IMPORTANCE HIV-1 infection in humans causes immune activation characterized by elevated levels of proinflammatory cytokines, including type I interferons (IFN

  1. 46 CFR 169.849 - Posting placards containing instructions for launching and inflating inflatable liferafts.

    Science.gov (United States)

    2010-10-01

    ... Inspections § 169.849 Posting placards containing instructions for launching and inflating inflatable... accessible to the ship's company and guests approved placards containing instructions for launching and... determined by the Officer in Charge, Marine Inspection. ...

  2. Mechanistic Studies of Hafnium-Pyridyl Amido-Catalyzed 1-Octene Polymerization and Chain Transfer Using Quench-Labeling Methods.

    Science.gov (United States)

    Cueny, Eric S; Johnson, Heather C; Anding, Bernie J; Landis, Clark R

    2017-08-30

    Chromophore quench-labeling applied to 1-octene polymerization as catalyzed by hafnium-pyridyl amido precursors enables quantification of the amount of active catalyst and observation of the molecular weight distribution (MWD) of Hf-bound polymers via UV-GPC analysis. Comparison of the UV-detected MWD with the MWD of the "bulk" (all polymers, from RI-GPC analysis) provides important mechanistic information. The time evolution of the dual-detection GPC data, concentration of active catalyst, and monomer consumption suggests optimal activation conditions for the Hf pre-catalyst in the presence of the activator [Ph 3 C][B(C 6 F 5 ) 4 ]. The chromophore quench-labeling agents do not react with the chain-transfer agent ZnEt 2 under the reaction conditions. Thus, Hf-bound polymeryls are selectively labeled in the presence of zinc-polymeryls. Quench-labeling studies in the presence of ZnEt 2 reveal that ZnEt 2 does not influence the rate of propagation at the Hf center, and chain transfer of Hf-bound polymers to ZnEt 2 is fast and quasi-irreversible. The quench-label techniques represent a means to study commercial polymerization catalysts that operate with high efficiency at low catalyst concentrations without the need for specialized equipment.

  3. An Auger electron spectroscopy study on the anodization process of high-quality thin-film capacitors made of hafnium

    International Nuclear Information System (INIS)

    Noya, Atsushi; Sasaki, Katsutaka; Umezawa, Toshiji

    1989-01-01

    Formation process of the anodic oxide film of hafnium for use as a thin-film capacitor has been examined by the current-voltage characteristics of the anodization and the in-depth analysis of formed oxide using Auger electron spectroscopy. It is found that the oxide growth obeys three different rate laws such as the linear rate law at first and next the parabolic rate law during the constant current anodization, and then the reciprocal logarithmic rate law during the constant voltage anodization following after the constant current process. From the Auger electron spectroscopy analysis, it is found that the shape of the compositional depth profile of the grown oxide film varies associating with the rate law of oxidation obeyed. The variation of depth profile correlating with the rate law is discussed with respect to each elementary process such as the transport and/or the reaction of chemical species interpreted from the over-all behavior of anodization process. It is revealed that the stoichiometric film having an interface with sharp transition, which is favorable for obtaining excellent electrical properties of the capacitor, can be obtained under the condition that the phase-boundary reaction is the rate-determining step of the anodization. The constant voltage anodization process also satisfies such circumstances and therefore can be favorable method for preparing highquality thin-film capacitors. (author)

  4. Evaluation and Enhancement of the Oxygen Reduction Reaction Activity on Hafnium Oxide Nanoparticles Assisted by L(+)-lysine

    International Nuclear Information System (INIS)

    Chisaka, Mitsuharu; Itagaki, Noriaki

    2016-01-01

    Evaluation of the oxygen reduction reaction (ORR) on oxide compounds is difficult owing to the insulating nature of oxides. In this study, various amounts of L(+)-lysine were added to the precursor dispersion for the hydrothermal synthesis of hafnium oxide nanoparticles on reduced graphene oxide sheets (HfO_x–rGO) to coat the HfO_x catalysts with layers of carbon, thereby increasing the conductivity and number of active sites. When the mass ratio of L(+)-lysine to GO, R, was above 26, carbon layers were formed and the amount monotonically increased with increasing R, as noted by cyclic voltammogrametry. X-ray photoelectron spectroscopy and rotating disk electrode analyses revealed that pyrolysis produced ORR-active oxygen defects, whose formation was proposed to involve carbothermal reduction. When 53 ≤ R ≤ 210, HfO_x–rGO contained a similar amount of oxygen defects and ORR activity, as represented by an onset potential of 0.9 V versus the reversible hydrogen electrode in 0.1 mol dm"−"3 H_2SO_4. However, the number of active sites depended on R due to the amount of L(+)-lysine-derived carbon layers that increased both the number of active sites and resistivity towards oxygen diffusion.

  5. IER-297 CED-2: Final Design for Thermal/Epithermal eXperiments with Jemima Plates with Polyethylene and Hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, A. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Percher, C. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Zywiec, W. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Heinrichs, D. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2018-01-11

    This report presents the final design (CED-2) for IER-297, and focuses on 15 critical configurations using highly enriched uranium (HEU) Jemima plates moderated by polyethylene with and without hafnium diluent. The goal of the U.S. Nuclear Criticality Safety Program’s Thermal/Epithermal eXperiments (TEX) is to design and conduct new critical experiments to address high priority nuclear data needs from the nuclear criticality safety and nuclear data communities, with special emphasis on intermediate energy (0.625 eV – 100 keV) assemblies that can be easily modified to include various high priority diluent materials. The TEX (IER 184) CED-1 Report [1], completed in 2012, demonstrated the feasibility of meeting the TEX goals with two existing NCSP fissile assets, plutonium Zero Power Physics Reactor (ZPPR) plates and highly enriched uranium (HEU) Jemima plates. The first set of TEX experiments will focus on using the plutonium ZPPR plates with polyethylene moderator and tantalum diluents.

  6. Trap state passivation improved hot-carrier instability by zirconium-doping in hafnium oxide in a nanoscale n-metal-oxide semiconductor-field effect transistors with high-k/metal gate

    International Nuclear Information System (INIS)

    Liu, Hsi-Wen; Tsai, Jyun-Yu; Liu, Kuan-Ju; Lu, Ying-Hsin; Chang, Ting-Chang; Chen, Ching-En; Tseng, Tseung-Yuen; Lin, Chien-Yu; Cheng, Osbert; Huang, Cheng-Tung; Ye, Yi-Han

    2016-01-01

    This work investigates the effect on hot carrier degradation (HCD) of doping zirconium into the hafnium oxide high-k layer in the nanoscale high-k/metal gate n-channel metal-oxide-semiconductor field-effect-transistors. Previous n-metal-oxide semiconductor-field effect transistor studies demonstrated that zirconium-doped hafnium oxide reduces charge trapping and improves positive bias temperature instability. In this work, a clear reduction in HCD is observed with zirconium-doped hafnium oxide because channel hot electron (CHE) trapping in pre-existing high-k bulk defects is the main degradation mechanism. However, this reduced HCD became ineffective at ultra-low temperature, since CHE traps in the deeper bulk defects at ultra-low temperature, while zirconium-doping only passivates shallow bulk defects.

  7. Affinity of 169Yb, 67Ga and 111In for malignant tumor, (1)

    International Nuclear Information System (INIS)

    Ando, Itsuko

    1975-01-01

    The tumor affinity of 169 Yb-citrate, 67 Ga-citrate and 111 In-citrate was examined by using Yoshida sarcoma-bearing rats, and the affinity of these compounds for inflammation was also tested using rats with inflammation induced by croton oil injection. In this investigation there was no great difference in uptake by the tumor tissue of these compounds, but a great difference was observed in the retention value of the blood and uptake rate in the bone. 169 Yb-citrate was cleared rapidly from the blood and was taken mostly into the bone. So the retention values in the soft tissues became very small. On the other hand, 111 In-citrate was slowly and only slightly taken into the bone from the blood, so the retention values in the soft tissue remained relatively high. 67 Ga-citrate showed the intermediate value between the bone uptake rate of 169 Yb-citrate and that of 111 In-citrate. In the following experiments, 169 Yb-citrate and 67 Ga-citrate were compared in four strains: Yoshida sarcoma, Walker carcinosarcoma 256, Sarcoma 180, and Ehrlich tumor. The uptake rate of 169 Yb in tumor tissue was much larger than that of 67 Ga in Ehrlich tumor-bearing mice, but the value of 169 Yb was slightly smaller than those of 67 Ga in Yoshida sarcoma-bearing rats, Walker carcinosarcoma 256-bearing rats and Sarcoma 180-bearing mice. Tumor to organ ratios of 169 Yb, which were most important for tumor scanning, were much larger than those of 67 Ga in all four strains except tumor to bone ratios of 169 Yb. From the above-described facts, it was shown that 169 Yb-citrate had a stronger tumor affinity than 67 Ga-citrate and that the tumor affinity of 169 Yb-citrate was similar in these four strains of tumor bearing animals. These three compounds had a relatively strong affinity with the inflammatory tissue. (auth.)

  8. Comparison of radiation shielding requirements for HDR brachytherapy using 169Yb and 192Ir sources

    International Nuclear Information System (INIS)

    Lymperopoulou, G.; Papagiannis, P.; Sakelliou, L.; Georgiou, E.; Hourdakis, C. J.; Baltas, D.

    2006-01-01

    169 Yb has received a renewed focus lately as an alternative to 192 Ir sources for high dose rate (HDR) brachytherapy. Following the results of a recent work by our group which proved 169 Yb to be a good candidate for HDR prostate brachytherapy, this work seeks to quantify the radiation shielding requirements for 169 Yb HDR brachytherapy applications in comparison to the corresponding requirements for the current 192 Ir HDR brachytherapy standard. Monte Carlo simulation (MC) is used to obtain 169 Yb and 192 Ir broad beam transmission data through lead and concrete. Results are fitted to an analytical equation which can be used to readily calculate the barrier thickness required to achieve a given dose rate reduction. Shielding requirements for a HDR brachytherapy treatment room facility are presented as a function of distance, occupancy, dose limit, and facility workload, using analytical calculations for both 169 Yb and 192 Ir HDR sources. The barrier thickness required for 169 Yb is lower than that for 192 Ir by a factor of 4-5 for lead and 1.5-2 for concrete. Regarding 169 Yb HDR brachytherapy applications, the lead shielding requirements do not exceed 15 mm, even in highly conservative case scenarios. This allows for the construction of a lead door in most cases, thus avoiding the construction of a space consuming, specially designed maze. The effects of source structure, attenuation by the patient, and scatter conditions within an actual treatment room on the above-noted findings are also discussed using corresponding MC simulation results

  9. George de Hevesy (1885-1966). Discoverer of hafnium, founder of radioanalytical chemistry and X-ray fluorescence analysis and father of nuclear medicine

    International Nuclear Information System (INIS)

    Niese, Siegfried

    2017-01-01

    George de Hevesy known as discoverer of hafnium, founder of radioanalytical chemistry and X-ray fluorescence analysis and father of nuclear medicine has done important research work in inorganic, physical and radioanalytical and physiological chemistry as well as in geochemistry, radiation biology and medicine. When he must flee for political reasons from a country he must change his colleagues, his equipments, and the topic of his work. It is extremely surprising that he could receive important results under such circumstances even at an advanced age. (author)

  10. A spanish mineral of zirconium and hafnium. Separation of the two elements by liquid-liquid extraction, using tributyl phosphate as chelating agent

    International Nuclear Information System (INIS)

    Ruiz Sanchez, F.; Cruz Castillo, F. de la; Fernandez Cellini, R.

    1962-01-01

    The zirconium and Hafnium oxides are obtained from a Spanish mineral of zircon with an average contest of 55% in ZrO 2 -HfO 2 . An alkaline fusion to open the mineral, followed by a purification by crystallization as (Zr O-Hf O)Cl 2 H 2 O or as (Zr-Hf) (SO 4 ) 2 . 4H 2 O, is used. A discussion of the best experimental conditions for opening the mineral and of the purification method is made. (Author) 45 refs

  11. Whole-body retention studies of /sup 169/Yb-citrate. Estimation of radiation dose to humans from /sup 169/Yb-citrate

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Mori, H; Ando, I; Hisada, K

    1977-09-01

    For purpose of the estimation of the radiation dose to humans from /sup 169/Yb-citrate, the whole-body retention studies using five rats were carried out. Following intravenous administration of /sup 169/Yb-citrate, the whole-body activity was monitored for 40 days by the animal counter. The whole-body retention curve consisted of three components: the first with a 3.6 hours effective half-time, the second with an 154 hours effective half-time and the third with a 29.9 days effective half-time. Therefore it was assumed that 32% of the administered /sup 169/Yb-citrate clears from the kidney with a short biologic half-time (3.6 hours), 18% remains in the liver and other soft tissues with a relatively long biologic half-time (194 hours) and 50% remains in the bone with a long biologic half-time (850 days). Based on these biological data and the MIRD Committee method, the average dose to the bone and whole-body were 20.8 rads/mCi and 4.5 rads/mCi respectively.

  12. Study of subcellular distribution of /sup 169/Yb and /sup 111/In in tumor and liver

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Takeshita, M; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Ando, Itsuko; Hisada, Kinichi

    1977-03-01

    Rats were implanted with Yoshida sarcoma and hepatoma AH109A; and mice were implanted with Ehrlich tumor. /sup 169/Yb-citrate and /sup 111/In-citrate were injected into the rats intravenously and into the mice intraperitoneally. Ten minutes to 48 hours after the administration of /sup 169/Yb-citrate and /sup 111/In-citrate, the animals were sacrificed and the tumor tissues and liver were excised. Subcellular fractionation of tumor tissues and liver was carried out according to the method of Hogeboom and Schneider. The /sup 169/Yb and /sup 111/In of each fraction were counted by a well type scintillation counter, and the protein of each fraction was measured according to Lowry's method. In Yoshida sarcoma and Ehrlich tumor, most of the radioactivity was localized in the supernatant fraction, and a small amount of radioactivity was accumulated in the mitochondrial fraction (lysosome is contained in this fraction). But, in the liver, most of the radioactivity was concentrated in the mitochondrial fraction, and the radioactivity of this fraction was increased with the passage of time after administration. Twenty-four hours later, about 50% of the total radioactivity was accumulated in this fraction. In the case of hepatoma AH109A, radioactivity of the mitochondrial fraction was increased with time after administration, and about 30% of total radioactivity was concentrated in this fraction 24 hours after administration. From these results it is concluded that the lysosome does not play an important role in the concentration of /sup 169/Yb and /sup 111/In in the tumor, and that the lysosome plays an important role in the concentration of /sup 169/Yb and /sup 111/In in the liver. In the case of hepatoma AH109A it is presumed that the lysosome plays a very important role in the concentration of /sup 169/Yb and /sup 111/In, in the tumor as hepatoma AH109A retains some nature of liver.

  13. Tumor Necrosis Factor-Mediated Survival of CD169+ Cells Promotes Immune Activation during Vesicular Stomatitis Virus Infection

    DEFF Research Database (Denmark)

    Shinde, Prashant V; Xu, Haifeng C; Maney, Sathish Kumar

    2018-01-01

    Innate immune activation is essential to mount an effective antiviral response and to prime adaptive immunity. Although a crucial role of CD169(+) cells during vesicular stomatitis virus (VSV) infections is increasingly recognized, factors regulating CD169(+) cells during viral infections remain...... stomatitis virus infection, phagocytes produce tumor necrosis factor (TNF) which signals via TNFR1 and promote "enforced virus replication" in CD169(+) macrophages. Consequently, lack of TNF or TNFR1 resulted in defective immune activation and VSV clearance....

  14. Comet 169P/NEAT(=2002EX12): More Dead Than Alive

    Science.gov (United States)

    Kasuga, T.; Balam, D. D.; Wiegert, P. A.

    2011-10-01

    The Jupiter family comet 169P/NEAT (previously known as asteroid 2002 EX12) has a dynamical association with the ?-Capriconid meteoroid stream. In this paper, we present photometric observations of comet 169P/NEAT to further investigate the physical characters of its disintegration state related to the stream. The comet shows a point-like surface brightness profile limiting contamination due to coma emission at ˜ 4% at most, indicating no evidence of outgassing. An upper limit on the fraction of the surface that could be sublimating water ice of disintegration of the parent at every return.

  15. Does a selective 5-hydroxytryptamine antagonist (ICI 169, 369) lower blood pressure in hypertensive patients?

    OpenAIRE

    Scott, A K; Roy-Chaudhury, P; Webster, J; Petrie, J C

    1989-01-01

    1. The effect of single doses (10, 30 and 50 mg) of a selective 5-HT2 receptor antagonist, ICI 169, 369, on blood pressure, heart rate and the electrocardiogram was studied using a double-blind, placebo-controlled, within subject design in hypertensive patients. 2. ICI 169, 369 did not reduce blood pressure or increase QT interval as has been reported with ketanserin. This suggests that it is the other properties of ketanserin which are responsible for its antihypertensive effect. 3. Plasma c...

  16. A fast response hafnium selective polymeric membrane electrode based on N,N'-bis(α-methyl-salicylidene)-dipropylenetriamine as a neutral carrier

    International Nuclear Information System (INIS)

    Rezaei, B.; Meghdadi, S.; Zarandi, R. Fazel

    2008-01-01

    In this study a new hafnium selective sensor was fabricated from polyvinylchloride (PVC) matrix membrane containing neutral carrier N,N'-bis(α-methyl-salicylidene)-dipropylenetriamine (Mesaldpt) as a new ionophore, sodium tetraphenyl borate (NaTPB) as anionic discriminator and dioctyl phthalate (DOP) as plasticizing solvent mediator in tetrahydrofuran solvent. The electrode exhibits Nernstian response for Hf 4+ (Hafnium(IV)) over a wide concentration range (2.0 x 10 -7 to 1.0 x 10 -1 M) with the determination coefficient of 0.9966 and slope of 15.1 ± 0.1 mV decades -1 . The limit of detection is 1.9 x 10 -7 M. The electrode has a fast response time of 18 s and a working pH range of 4-8. The proposed membrane shows excellent discriminating ability towards Hf 4+ ion with regard to several alkali, alkaline earth transition and heavy metal ions. It can be used over a period of 1.5 months with good reproducibility. It is successfully applied for direct determination of Hf 4+ in solutions by standard addition method for real sample analysis

  17. A fast response hafnium selective polymeric membrane electrode based on N,N'-bis({alpha}-methyl-salicylidene)-dipropylenetriamine as a neutral carrier

    Energy Technology Data Exchange (ETDEWEB)

    Rezaei, B. [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)], E-mail: rezaei@cc.iut.ac.ir; Meghdadi, S.; Zarandi, R. Fazel [Department of Chemistry, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2008-08-30

    In this study a new hafnium selective sensor was fabricated from polyvinylchloride (PVC) matrix membrane containing neutral carrier N,N'-bis({alpha}-methyl-salicylidene)-dipropylenetriamine (Mesaldpt) as a new ionophore, sodium tetraphenyl borate (NaTPB) as anionic discriminator and dioctyl phthalate (DOP) as plasticizing solvent mediator in tetrahydrofuran solvent. The electrode exhibits Nernstian response for Hf{sup 4+} (Hafnium(IV)) over a wide concentration range (2.0 x 10{sup -7} to 1.0 x 10{sup -1} M) with the determination coefficient of 0.9966 and slope of 15.1 {+-} 0.1 mV decades{sup -1}. The limit of detection is 1.9 x 10{sup -7} M. The electrode has a fast response time of 18 s and a working pH range of 4-8. The proposed membrane shows excellent discriminating ability towards Hf{sup 4+} ion with regard to several alkali, alkaline earth transition and heavy metal ions. It can be used over a period of 1.5 months with good reproducibility. It is successfully applied for direct determination of Hf{sup 4+} in solutions by standard addition method for real sample analysis.

  18. 46 CFR 169.680 - Installation of wiring for power and lighting circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Installation of wiring for power and lighting circuits... SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Electrical Installations Operating at Potentials of 50 Volts Or More on Vessels of Less Than 100 Gross Tons § 169.680 Installation of wiring for power...

  19. 46 CFR 169.673 - Installation of wiring for power and lighting circuits.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Installation of wiring for power and lighting circuits... SCHOOLS SAILING SCHOOL VESSELS Machinery and Electrical Electrical Installations Operating at Potentials of Less Than 50 Volts on Vessels of Less Than 100 Gross Tons § 169.673 Installation of wiring for...

  20. 32 CFR Appendix D to Part 169a - Commercial Activities Management Information System (CAMIS)

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Commercial Activities Management Information... to Part 169a—Commercial Activities Management Information System (CAMIS) Each DoD Component shall... American Standard Code Information Interchange text file format on a MicroSoft-Disk Operating System...

  1. 33 CFR 169.102 - Who is the shore-based authority?

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Who is the shore-based authority... (CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Establishment of Two Mandatory Ship Reporting Systems for the Protection of Northern Right Whales § 169.102 Who is the shore-based authority? The U.S...

  2. 46 CFR 169.721 - Storm sails and halyards (exposed and partially protected waters only).

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Storm sails and halyards (exposed and partially... § 169.721 Storm sails and halyards (exposed and partially protected waters only). (a) Unless clearly unsuitable, each vessel must have one storm trysail of appropriate size. It must be sheeted independently of...

  3. Preparation and radiopharmaceutical control of 169Yb EDTA an agent for kidney function and scintigraphy

    International Nuclear Information System (INIS)

    Gulbaba, G.; Ozker; Tomek, F.

    1976-01-01

    169 Yb was produced by thermal neutron irradiation of Yb 2 O 3 in 1 MW research reactor at Cekmece Nuclear Research Center. 169 Yb-EDTA complex was then prepared with a sodium salt of EDTA. Radionuclidic and radiochemical purities of the compound were determined by gama spectral analysis and radiochromatography-electrophoresis following preparation. Ionic Yb(III) which accumulates at bone and liver was not observed on the radiochromatographic and electrophoretic analysis of the final compound. There was no separation of the label for two months of examination in order to determine stability of the compound. In conclusion, the labeled compound has been prepared for use in the external scanning of kidney and determining the glomerular filtration rate. The label appears to be firmly bound so that the agent can be stored for a reasonably long period as 31 days half-life of 169 Yb permits. Administration of the compound is safe from the stand point of radiation dose since a 30 micro-Ci 169 Yb-EDTA for a glomerular filtration study delivers no more than 0.4 mrad whole-body and 5 mrad kidney dose. (author)

  4. 25 CFR 169.18 - Tenure of approved right-of-way grants.

    Science.gov (United States)

    2010-04-01

    ..., and public utility water pipelines (including pumping stations and appurtenant facilities), electric... 169.18 Indians BUREAU OF INDIAN AFFAIRS, DEPARTMENT OF THE INTERIOR LAND AND WATER RIGHTS-OF-WAY OVER... sanitary and storm sewer lines including sewage disposal and treatment plants, water control and use...

  5. In Vivo Activity of the Benzothiazinones PBTZ169 and BTZ043 against Nocardia brasiliensis.

    Directory of Open Access Journals (Sweden)

    Norma Alejandra González-Martínez

    Full Text Available Mycetoma is a neglected, chronic, and deforming infectious disease caused by fungi and actinomycetes. In Mexico, N. brasiliensis is the predominant etiologic agent. Therapeutic alternatives are necessary because the current drug regimens have several disadvantages. Benzothiazinones (BTZ are a new class of candidate drugs that inhibit decaprenyl-phosphoribose-epimerase (DprE1, an essential enzyme involved in the cell wall biosynthesis of Corynebacterineae.In this study, the in vitro activity of the next generation BTZ, PBTZ169, was tested against thirty Nocardia brasiliensis isolates. The MIC50 and MIC90 values for PBTZ169 were 0.0075 and 0.03 μg/mL, respectively. Because Nocardia is a potential intracellular bacterium, a THP-1 macrophage monolayer was infected with N. brasiliensis HUJEG-1 and then treated with PBTZ169, resulting in a decrease in the number of colony-forming units (CFUs at a concentration of 0.25X the in vitro value. The in vivo activity was evaluated after infecting female BALB/c mice in the right hind food-pad. After 6 weeks, treatment was initiated with PBTZ169 and its activity was compared with the first generation compound, BTZ043. Both BTZ compounds were administered at 100 mg/kg twice daily by gavage, and sulfamethoxazole/trimethoprim (SXT, at 100 mg/kg sulfamethoxazole, was used as a positive control. After 22 weeks of therapy, only PBTZ169 and SXT displayed statistically significant activity.These results indicate that DprE1 inhibitors may be useful for treating infections of Nocardia and may therefore be active against other actinomycetoma agents. We must test combinations of these compounds with other antimicrobial agents, such as linezolid, tedizolid or SXT, that have good to excellent in vivo activity, as well as new DprE1 inhibitors that can achieve higher plasma levels.

  6. In Vivo Activity of the Benzothiazinones PBTZ169 and BTZ043 against Nocardia brasiliensis.

    Science.gov (United States)

    González-Martínez, Norma Alejandra; Lozano-Garza, Hector Gerardo; Castro-Garza, Jorge; De Osio-Cortez, Alexandra; Vargas-Villarreal, Javier; Cavazos-Rocha, Norma; Ocampo-Candiani, Jorge; Makarov, Vadim; Cole, Stewart T; Vera-Cabrera, Lucio

    2015-01-01

    Mycetoma is a neglected, chronic, and deforming infectious disease caused by fungi and actinomycetes. In Mexico, N. brasiliensis is the predominant etiologic agent. Therapeutic alternatives are necessary because the current drug regimens have several disadvantages. Benzothiazinones (BTZ) are a new class of candidate drugs that inhibit decaprenyl-phosphoribose-epimerase (DprE1), an essential enzyme involved in the cell wall biosynthesis of Corynebacterineae. In this study, the in vitro activity of the next generation BTZ, PBTZ169, was tested against thirty Nocardia brasiliensis isolates. The MIC50 and MIC90 values for PBTZ169 were 0.0075 and 0.03 μg/mL, respectively. Because Nocardia is a potential intracellular bacterium, a THP-1 macrophage monolayer was infected with N. brasiliensis HUJEG-1 and then treated with PBTZ169, resulting in a decrease in the number of colony-forming units (CFUs) at a concentration of 0.25X the in vitro value. The in vivo activity was evaluated after infecting female BALB/c mice in the right hind food-pad. After 6 weeks, treatment was initiated with PBTZ169 and its activity was compared with the first generation compound, BTZ043. Both BTZ compounds were administered at 100 mg/kg twice daily by gavage, and sulfamethoxazole/trimethoprim (SXT), at 100 mg/kg sulfamethoxazole, was used as a positive control. After 22 weeks of therapy, only PBTZ169 and SXT displayed statistically significant activity. These results indicate that DprE1 inhibitors may be useful for treating infections of Nocardia and may therefore be active against other actinomycetoma agents. We must test combinations of these compounds with other antimicrobial agents, such as linezolid, tedizolid or SXT, that have good to excellent in vivo activity, as well as new DprE1 inhibitors that can achieve higher plasma levels.

  7. Phosphorylation of the centrosomal protein, Cep169, by Cdk1 promotes its dissociation from centrosomes in mitosis.

    Science.gov (United States)

    Mori, Yusuke; Inoue, Yoko; Taniyama, Yuki; Tanaka, Sayori; Terada, Yasuhiko

    2015-12-25

    Cep169 is a centrosomal protein conserved among vertebrates. In our previous reports, we showed that mammalian Cep169 interacts and collaborates with CDK5RAP2 to regulate microtubule (MT) dynamics and stabilization. Although Cep169 is required for MT regulation, its precise cellular function remains largely elusive. Here we show that Cep169 associates with centrosomes during interphase, but dissociates from these structures from the onset of mitosis, although CDK5RAP2 (Cep215) is continuously located at the centrosomes throughout cell cycle. Interestingly, treatment with purvalanol A, a Cdk1 inhibitor, nearly completely blocked the dissociation of Cep169 from centrosomes during mitosis. In addition, mass spectrometry analyses identified 7 phosphorylated residues of Cep169 corresponding to consensus phosphorylation sequence for Cdk1. These data suggest that the dissociation of Cep169 from centrosomes is controlled by Cdk1/Cyclin B during mitosis, and that Cep169 might regulate MT dynamics of mitotic spindle. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. 78 FR 18314 - Foreign-Trade Zone 169-Manatee County, Florida; Application for Production Authority; ASO, LLC...

    Science.gov (United States)

    2013-03-26

    ... located within Subzone 169A, in Sarasota, Florida. The facility is used for the production of plastic and... County, Florida; Application for Production Authority; ASO, LLC; Subzone 169A (Textile Fabric Adhesive Bandage Coating and Production); Sarasota, Florida An application has been submitted to the Foreign-Trade...

  9. Relationship between strains of tumor-bearing animals and the tumor affinity of /sup 169/Yb and /sup 67/Ga

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Hisada, K; Ando, I; Ugiie, T

    1975-02-01

    It is well a well-known fact that ytterbium-169 is a strong bone seeking element. We have already reported that this element was concentrated in nonosseous tumor tissues and that its tumor affinity was stronger than that of gallium-67 in our previous experiment using Yoshida sarcoma-bearing rats. Ytterbium-169 citrate and gallium-67 citrate were compared in four strains of tumor-bearing rats and mice. The uptake rate of ytterbium-169 in tumor tissues was much larger than that of gallium-67 in Ehrlich cancer-bearing mice, but these values of ytterbium-169 were slightly smaller than those of gallium-67 in Yoshida sarcoma-bearing rats, Walker carcinosarcoma 256-bearing rats and sarcoma 180-bearing mice. Tumor to organ ratios of ytterbium-169, which were most important for tumor scanning agents, were much larger than those of gallium-67 in all four strains except for the tumor to bone ratio of ytterbium-169. From the above-described facts, it was shown that ytterbium-169 citrate had a stronger tumor affinity than did gallium-67 citrate and that the tumor affinity of ytterbium-169 citrate was similar in each of these four strains of tumor-bearing animals.

  10. 78 FR 62708 - 169th Meeting of the Advisory Council on Employee Welfare and Pension Benefit Plans; Notice of...

    Science.gov (United States)

    2013-10-22

    ... DEPARTMENT OF LABOR Employee Benefits Security Administration 169th Meeting of the Advisory Council on Employee Welfare and Pension Benefit Plans; Notice of Meeting Pursuant to the authority... 169th open meeting of the Advisory Council on Employee Welfare and Pension Benefit Plans (also known as...

  11. Metallorganic chemical vapor deposition and atomic layer deposition approaches for the growth of hafnium-based thin films from dialkylamide precursors for advanced CMOS gate stack applications

    Science.gov (United States)

    Consiglio, Steven P.

    To continue the rapid progress of the semiconductor industry as described by Moore's Law, the feasibility of new material systems for front end of the line (FEOL) process technologies needs to be investigated, since the currently employed polysilicon/SiO2-based transistor system is reaching its fundamental scaling limits. Revolutionary breakthroughs in complementary-metal-oxide-semiconductor (CMOS) technology were recently announced by Intel Corporation and International Business Machines Corporation (IBM), with both organizations revealing significant progress in the implementation of hafnium-based high-k dielectrics along with metal gates. This announcement was heralded by Gordon Moore as "...the biggest change in transistor technology since the introduction of polysilicon gate MOS transistors in the late 1960s." Accordingly, the study described herein focuses on the growth of Hf-based dielectrics and Hf-based metal gates using chemical vapor-based deposition methods, specifically metallorganic chemical vapor deposition (MOCVD) and atomic layer deposition (ALD). A family of Hf source complexes that has received much attention recently due to their desirable properties for implementation in wafer scale manufacturing is the Hf dialkylamide precursors. These precursors are room temperature liquids and possess sufficient volatility and desirable decomposition characteristics for both MOCVD and ALD processing. Another benefit of using these sources is the existence of chemically compatible Si dialkylamide sources as co-precursors for use in Hf silicate growth. The first part of this study investigates properties of MOCVD-deposited HfO2 and HfSixOy using dimethylamido Hf and Si precursor sources using a customized MOCVD reactor. The second part of this study involves a study of wet and dry surface pre-treatments for ALD growth of HfO2 using tetrakis(ethylmethylamido)hafnium in a wafer scale manufacturing environment. The third part of this study is an investigation of

  12. Mechanism of tumor and liver concentration of /sup 111/In and /sup 169/Yb: /sup 111/In and /sup 169/Yb binding substances in tumor tissues and liver

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Ando, I; Hiraki, T; Takeshita, M; Hisada, K

    1982-07-01

    Tumor-bearing animals were injected with /sup 111/In- and /sup 169/Yb-citrate. Tumor homogenates, from which the nuclear fraction was removed, and the mitochondrial fractions of the host livers were digested with pronase P. After digestion, the supernatants of the reaction mixtures were applied to Sephadex G-100 columns. The resultant eluates were analyzed for radioactivity, protein, uronic acid, and sialic acids. Three peaks of radioactivity were obtained by gel filtration. The first peak, eluted the void volume, contained a species whose molecular weight exceeded 40000. The second peak consisted of substances with molecular weights of 9400-40000. Radioactivity in the third peak was liberated /sup 111/In and /sup 169/Yb. These two nuclides in the second peak were bound to acid mucopolysaccharide and/or the sulfated carbohydrate chain of sulfated glycorprotein. It was thought that the nuclides in the first peak might be bound to some acid mucopolysaccharides. The second peak nuclides seemed to be bound to acid mucopolysaccharide that contained no uronic acids, and/or to the sulfated carbohydrate chain of sulfated glycoprotein. It was concluded that they were bound to the acid mucopolysaccharides and/or the sulfated carbohydrate chain of sulfated glycoprotein in tumor tissues and liver lysosomes.

  13. Glomerular filtration in kidney recipients measured by plasma clearance of 169Yb-DTPA

    International Nuclear Information System (INIS)

    Stribrna, J.; Oppelt, A.; Jirickova, E.; Janata, V.; Kocandrle, V.; Sup, I.; Woller, P.; Franke, W.G.

    1986-01-01

    Values of 169 Yb-DTPA clearance (C DTPA ) calculated after a single injection were compared in 26 recipients of kidneys with renal clearance of inulin (C in ), polyfructosan S (C pf ) and creatinine (C cr ). In 21 patients the examinations were made simultaneously, in 5 patients C DTPA was measured within a short interval after the examination of renal clearance. The mean C DTPA values did not significantly differ from C cr but were significantly higher (p in and C pf (by 33% on average). Investigation of changes in C DTPA as compared with C in and C pf showed no significant difference in glomerular filtration (GF). This was measured using inulin and polyfructosan. The results showed that the differing molecular weight of inulin and polyfructosan S had no detectable effect on the GF of kidney recipients. The plasma clearance of 169 Yb-DTPA similarly to C cr overestimates the GF measured by inulin and polyfructosan clearance. (author)

  14. Radio metal (169Yb) uptake in normal and tumour cells in vitro. Influence of metabolic cell activity and complex structure

    International Nuclear Information System (INIS)

    Franke, W.G.; Kampf, G.

    1996-01-01

    Trivalent radio metal tracers have been used for tumour imaging and metastatic pain palliation. For better understanding their tumour accumulation, basic model studies of uptake of different 169 Yb complexes into cultured normal and tumour cells were performed. Whereas the uptake of 169 Yb citrate is strongly dependent on the metabolic activity and is not tumour-cell pacific, the uptake of 169 Yb complexed with amino carbonic acid (NTA, EDTA, DTPA) does not correlate to the metabolic activities. These complexes are taken up to a greater amount by the tumour cells (by a factor of about 2). Uptake of both complex types leads to a stable association to cellular compounds, 169 Yb is not releasable by the strong complexing agent DTPA. Protein binding of the 169 Yb complexes shows great influence on their cellular uptake. The bound proportion is no more available,for cellular uptake. The results indicate that i 0 uptake of 169 Yb citrate is an active cellular transport process which i not tumor-specific, ii) the 169 Yb amino carbonic acid complexes show a weak favouring by the tumour cells, iii) different from earlier acceptions the Yb complexes studied are not taken up by the cells in protein-bound form. The structure of the Yb complex is decisive for its protein binding and cellular uptake. (author). 13 refs., 6 figs

  15. Genome Sequence of an Endophytic Fungus, Fusarium solani JS-169, Which Has Antifungal Activity.

    Science.gov (United States)

    Kim, Jung A; Jeon, Jongbum; Park, Sook-Young; Kim, Ki-Tae; Choi, Gobong; Lee, Hyun-Jung; Kim, Yangsun; Yang, Hee-Sun; Yeo, Joo-Hong; Lee, Yong-Hwan; Kim, Soonok

    2017-10-19

    An endophytic fungus, Fusarium solani strain JS-169, isolated from a mulberry twig, showed considerable antifungal activity. Here, we report the draft genome sequence of this strain. The assembly comprises 17 scaffolds, with an N 50 value of 4.93 Mb. The assembled genome was 45,813,297 bp in length, with a G+C content of 49.91%. Copyright © 2017 Kim et al.

  16. Analysis of the radiobiology of ytterbium-169 and iodine-125 permanent brachytherapy implants

    Energy Technology Data Exchange (ETDEWEB)

    Lazarescu, G.R. [Windsor Regional Cancer Center, Ontario Cancer Treatment and Research Foundation, Windsor, Canada N8W 2X3 (Canada); Battista, J.J. [London Regional Cancer Center, Ontario Cancer Treatment and Research Foundation, Dept. of Oncology and Dept. of Medical Biophysics, University of Western Ontario, London, Canada N6A 4L6 (Canada)

    1997-09-01

    Recently, Yb-169 has been considered as a potential replacement for I-125 and Pd-103 in permanent implants. In spite of the uncertainties in the parameters necessary for an accurate radiobiological modelling, the linear quadratic model can be useful in the comparative evaluation of the radiotherapeutic merit of similar implants. In order to find out if a Yb-169 permanent implant can be made biologically 'equivalent' to an I-125 implant, we studied the dependence of local control on the tumour cell radiosensitivity and on the balance between the rate of tumour cell killing and tumour cell proliferation, for rapidly and slowly proliferating tumours. The extrapolated response dose (ERD) has been calculated for tumour and late reacting normal tissue for both types of implants and the possible biological restrictions due to the normal tissue tolerance have been discussed. Our theoretical analysis is consistent with the clinical results published for I-125 permanent implants in prostate tumours and meningiomas. It predicts that Yb-169, which has only recently been used in human tumours, can provide comparable tumour control for permanent implants in slowly proliferating tumours with an initial dose rate of 13 cGy h{sup -1}. Control might be extended to rapidly proliferating tumours by increasing the initial dose rate within a range consistent with an acceptable level of normal tissue late reaction. (author)

  17. PRODUCTION OF HAFNIUM METAL

    Science.gov (United States)

    Elger, G.W.; Boubel, R.W.

    1963-01-01

    This patent deals with a process of producing pure Hf metal from oxygen- contaminated gaseous Hf chloride. The oxygen compounds in the chioride gas are halogenated by contacting the gas at elevated temperature with Cl/sub 2/ in the presence of C. The Hf chloride, still in gaseous form, is contacted with molten Mg whereby Hf metal is formed and condensed on the Mg. (AEC)

  18. ILO Convention no. 169 Concerning Indigenous and Tribal Peoples in Independent Countries 1989-2009 : an overview / Athanasios Yupsanis

    Index Scriptorium Estoniae

    Yupsanis, Athanasios

    2010-01-01

    Ülevaade ja kriitika ILO iseseisvates riikides elavate põlisrahvaste ja hõimude konventsiooni kohta (Convention concerning Indigenous and Tribal Peoples in Independent Countries, 1989, nr 169, jõustus 1991)

  19. Effects of oxygen partial pressure and annealing temperature on the residual stress of hafnium oxide thin-films on silicon using synchrotron-based grazing incidence X-ray diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Biswas, Debaleen [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India); Sinha, Anil Kumar [ISU, Raja Ramanna Centre for Advanced Technology, Indore 452 013 (India); Homi Bhabha National Institute, BARC, Mumbai 400 094 (India); Chakraborty, Supratic, E-mail: supratic.chakraborty@saha.ac.in [Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700 064 (India)

    2016-10-30

    Highlights: • Residual stress estimation thin hafnium oxide film with thickness of <10 nm. • A mathematical expression is proposed for stress estimation of thin-film using GIXRD. • Residual stress varies with argon content in Ar/O{sub 2} plasma and annealing temperature. • Variation of stress is explained by IL swelling and enhanced structural relaxation. - Abstract: Synchrotron radiation-based grazing incidence X-ray diffraction (GI-XRD) technique is employed here to estimate the residual stress of < 10 nm thin hafnium oxide film deposited on Si (100) substrate at different argon/oxygen ratios using reactive rf sputtering. A decrease in residual stress, tensile in nature, is observed at higher annealing temperature for the samples deposited with increasing argon ratio in the Ar/O{sub 2} plasma. The residual stress of the films deposited at higher p{sub Ar} (Ar:O{sub 2} = 4:1) is also found to be decreased with increasing annealing temperature. But the stress is more or less constant with annealing temperature for the films deposited at lower Ar/O{sub 2} (1:4) ratio. All the above phenomena can be explained on the basis of swelling of the interfacial layer and enhanced structural relaxation in the presence of excess Hf in hafnium oxide film during deposition.

  20. The End of the Lines for OX 169: No Binary Broad-Line Region

    Science.gov (United States)

    Halpern, J. P.; Eracleous, M.

    2000-03-01

    We show that unusual Balmer emission-line profiles of the quasar OX 169, frequently described as either self-absorbed or double peaked, are actually neither. The effect is an illusion resulting from two coincidences. First, the forbidden lines are quite strong and broad. Consequently, the [N II] λ6583 line and the associated narrow-line component of Hα present the appearance of twin Hα peaks. Second, the redshift of 0.2110 brings Hβ into coincidence with Na I D at zero redshift, and ISM absorption in Na I D divides the Hβ emission line. In spectra obtained over the past decade, we see no substantial change in the character of the line profiles and no indication of intrinsic double-peaked structure. The Hγ, Mg II, and Lyα emission lines are single peaked, and all of the emission-line redshifts are consistent once they are correctly attributed to their permitted and forbidden-line identifications. A systematic shift of up to 700 km s-1 between broad and narrow lines is seen, but such differences are common and could be due to gravitational and transverse redshift in a low-inclination disk. Stockton & Farnham had called attention to an apparent tidal tail in the host galaxy of OX 169 and speculated that a recent merger had supplied the nucleus with a coalescing pair of black holes that was now revealing its existence in the form of two physically distinct broad-line regions. Although there is no longer any evidence for two broad emission-line regions in OX 169, binary black holes should form frequently in galaxy mergers, and it is still worthwhile to monitor the radial velocities of emission lines that could supply evidence of their existence in certain objects.

  1. Experimental stress analysis for four 24-in. ANSI standard B16.9 tees

    International Nuclear Information System (INIS)

    Hayes, J.K.; Moore, S.E.

    1976-01-01

    The experimental stress analysis and low cycle fatigue tests of four tees tested by Combustion Engineering, Inc. (E-E) under subcontract to Union Carbide Nuclear Division are described. These tests are part of the ORNL Design Criteria for Piping and Nozzles Program which is being conducted for the development of design criteria for nuclear power plant service piping components. The test assemblies were fabricated at C-E from commercially obtained ANSI B16.9 tees and matching diameter steel pipes welded to the tees, with suitable and closures and fixtures for applying the loads

  2. The Aalborg case - GPS tracking of 169 young adults in a Danish central city area

    DEFF Research Database (Denmark)

    Harder, Henrik; Bro, Peter; Knudsen, Anne-Marie

    Recent developments in the global positioning system (GPS) and the global system for mobile communications, or third generation technology (GSM/3G), have enabled an increasingly simple and cost-effective tracking of human activity in urban areas through the use of mobile telephony...... was based on a unique sample of movement data gleaned from 169 young adults aged 16 to 20 years. Each person was GPS-tracked over a period of seven days in 2008-2009 to record their movements in and uses of spaces in the central city area of Aalborg, which is Denmark’s fourth-largest city, with 122 461...

  3. Contribution towards ALD and MOCVD of rare earth oxides and hafnium oxide. From precursor evaluation to process development and thin film characterization

    International Nuclear Information System (INIS)

    Xu, Ke

    2013-01-01

    elements for ALD applications. A possible synthesis route is the salt metatheses route. It could be expected that the monodentate guanidine ligand would provide increased reactivity towards water, where the bulky guanidine ligands will shield the RE center providing self-limiting growth behavior. In Chapter 4 and 7, ALD of rare earth oxides and hafnium oxide using corresponding guanidinate precursors are in detail investigated. According to the measurements, these processes are true ALD processes with broad ALD windows, high growth per cycle in the saturated area. Furthermore, the rare earth guanidinate and hafnium guanidinate precursors exhibit matching ALD window in the temperature range of 200 - 225 C. This motivated us to deposite trinary oxide thin films (HfREOx) using corresponding precursor combinations.

  4. Ytterbium 169 citrate in the diagnosis of lung opacities of cancerous origin

    International Nuclear Information System (INIS)

    Peltier, Patrick.

    1976-01-01

    Lung scintigraphy for tumour exploration has been widely studied for some years, but unfortunately with the many radioisotopes used at present this examination is not entirely reliable. It seemed interesting therefore to investigate a new tracer, 169 Yb citrate, the properties of which were demonstrated recently by HISADA. To estimate the specificity of this tracer we chose 62 records of different bronchopulmonary diseases. After an introductory review of various diagnostic methods the physical and physiological characteristics of ytterbium citrate and its method of use are described, then the records examined are presented and our thoughts and conclusions discussed. 169 Yb citrate possesses excellent biophysical properties for tumour scintigraphy but this isotope, though causing no radioactive pollution, delivers an appreciable irradiation dose to the patient examined. It has a positive tropism for pathological lung images. The fixation index of the documents taken separately, apart from that of the 14th day, cannot distinguish between benign and malignant diseases. This is possible with the kinetic uptake curve and the index ratios for the 2nd and 14th days. With these diagnostic criteria the overall results are better than those obtained with other commonly used radioisotopes: true positives 70%, false negatives 11%, false positives 4.5% [fr

  5. Design of an Yb-169 source optimized for gold nanoparticle-aided radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Reynoso, Francisco J.; Manohar, Nivedh [Nuclear/Radiological Engineering and Medical Physics Programs, Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0405 (United States); Krishnan, Sunil [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States); Cho, Sang Hyun, E-mail: scho@mdanderson.org [Department of Radiation Physics and Department of Imaging Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas 77030 (United States)

    2014-10-15

    Purpose: To find an optimum design of a new high-dose rate ytterbium (Yb)-169 brachytherapy source that would maximize the dose enhancement during gold nanoparticle-aided radiation therapy (GNRT), while meeting practical constraints for manufacturing a clinically relevant brachytherapy source. Methods: Four different Yb-169 source designs were considered in this investigation. The first three source models had a single encapsulation made of one of the following materials: aluminum, titanium, and stainless steel. The last source model adopted a dual encapsulation design with an inner aluminum capsule surrounding the Yb-core and an outer titanium capsule. Monte Carlo (MC) simulations using the Monte Carlo N-Particle code version 5 (MCNP5) were conducted initially to investigate the spectral changes caused by these four source designs and the associated variations in macroscopic dose enhancement across the tumor loaded with gold nanoparticles (GNPs) at 0.7% by weight. Subsequent MC simulations were performed using the EGSnrc and NOREC codes to determine the secondary electron spectra and microscopic dose enhancement as a result of irradiating the GNP-loaded tumor with the MCNP-calculated source spectra. Results: Effects of the source filter design were apparent in the current MC results. The intensity-weighted average energy of the Yb-169 source varied from 108.9 to 122.9 keV, as the source encapsulation material changed from aluminum to stainless steel. Accordingly, the macroscopic dose enhancement calculated at 1 cm away from the source changed from 51.0% to 45.3%. The sources encapsulated by titanium and aluminum/titanium combination showed similar levels of dose enhancement, 49.3% at 1 cm, and average energies of 113.0 and 112.3 keV, respectively. While the secondary electron spectra due to the investigated source designs appeared to look similar in general, some differences were noted especially in the low energy region (<50 keV) of the spectra suggesting the

  6. Lys169 of human glucokinase is a determinant for glucose phosphorylation: implication for the atomic mechanism of glucokinase catalysis.

    Directory of Open Access Journals (Sweden)

    Jian Zhang

    Full Text Available Glucokinase (GK, a glucose sensor, maintains plasma glucose homeostasis via phosphorylation of glucose and is a potential therapeutic target for treating maturity-onset diabetes of the young (MODY and persistent hyperinsulinemic hypoglycemia of infancy (PHHI. To characterize the catalytic mechanism of glucose phosphorylation by GK, we combined molecular modeling, molecular dynamics (MD simulations, quantum mechanics/molecular mechanics (QM/MM calculations, experimental mutagenesis and enzymatic kinetic analysis on both wild-type and mutated GK. Our three-dimensional (3D model of the GK-Mg(2+-ATP-glucose (GMAG complex, is in agreement with a large number of mutagenesis data, and elucidates atomic information of the catalytic site in GK for glucose phosphorylation. A 10-ns MD simulation of the GMAG complex revealed that Lys169 plays a dominant role in glucose phosphorylation. This prediction was verified by experimental mutagenesis of GK (K169A and enzymatic kinetic analyses of glucose phosphorylation. QM/MM calculations were further used to study the role of Lys169 in the catalytic mechanism of the glucose phosphorylation and we found that Lys169 enhances the binding of GK with both ATP and glucose by serving as a bridge between ATP and glucose. More importantly, Lys169 directly participates in the glucose phosphorylation as a general acid catalyst. Our findings provide mechanistic details of glucose phorphorylation catalyzed by GK, and are important for understanding the pathogenic mechanism of MODY.

  7. Effect of Advanced Plasma Source bias voltage on properties of HfO2 films prepared by plasma ion assisted electron evaporation from metal hafnium

    International Nuclear Information System (INIS)

    Zhu, Meiping; Yi, Kui; Arhilger, Detlef; Qi, Hongji; Shao, Jianda

    2013-01-01

    HfO 2 films, using metal hafnium as starting material, are deposited by plasma-ion assisted electron evaporation with different Advanced Plasma Source (APS) bias voltages. The refractive index and extinction coefficient are calculated, the chemical state and composition, as well as the stress and aging behavior is investigated. Laser induced damage threshold (LIDT) and damage mechanism are also evaluated and discussed. Optical, structural, mechanical and laser induced damage properties of HfO 2 films are found to be sensitive to APS bias voltage. The film stress can be tuned by varying the APS bias voltage. Damage morphologies indicate the LIDT of the HfO 2 films at 1064 nm and 532 nm are dominated by the nodular-defect density in coatings, while the 355 nm LIDT is dominated by the film absorption. HfO 2 films with higher 1064 nm LIDT than samples evaporated from hafnia are achieved with bias voltage of 100 V. - Highlights: • HfO 2 films are evaporated with different Advanced Plasma Source (APS) bias voltages. • Properties of HfO 2 films are sensitive to APS bias voltage. • With a bias voltage of 100 V, HfO 2 coatings without any stress can be achieved. • Higher 1064 nm laser induced damage threshold is achieved at a bias voltage of 100 V

  8. Design of an Extractive Distillation Column for the Environmentally Benign Separation of Zirconium and Hafnium Tetrachloride for Nuclear Power Reactor Applications

    Directory of Open Access Journals (Sweden)

    Le Quang Minh

    2015-09-01

    Full Text Available Nuclear power with strengthened safety regulations continues to be used as an important resource in the world for managing atmospheric greenhouse gases and associated climate change. This study examined the environmentally benign separation of zirconium tetrachloride (ZrCl4 and hafnium tetrachloride (HfCl4 for nuclear power reactor applications through extractive distillation using a NaCl-KCl molten salt mixture. The vapor–liquid equilibrium behavior of ZrCl4 and HfCl4 over the molten salt system was correlated with Raoult’s law. The molten salt-based extractive distillation column was designed optimally using a rigorous commercial simulator for the feasible separation of ZrCl4 and HfCl4. The molten salt-based extractive distillation approach has many potential advantages for the commercial separation of ZrCl4 and HfCl4 compared to the conventional distillation because of its milder temperatures and pressure conditions, smaller number of required separation trays in the column, and lower energy requirement for separation, while still taking the advantage of environmentally benign feature by distillation. A heat-pump-assisted configuration was also explored to improve the energy efficiency of the extractive distillation process. The proposed enhanced configuration reduced the energy requirement drastically. Extractive distillation can be a promising option competing with the existing extraction-based separation process for zirconium purification for nuclear power reactor applications.

  9. A silicon doped hafnium oxide ferroelectric p–n–p–n SOI tunneling field–effect transistor with steep subthreshold slope and high switching state current ratio

    Directory of Open Access Journals (Sweden)

    Saeid Marjani

    2016-09-01

    Full Text Available In this paper, a silicon–on–insulator (SOI p–n–p–n tunneling field–effect transistor (TFET with a silicon doped hafnium oxide (Si:HfO2 ferroelectric gate stack is proposed and investigated via 2D device simulation with a calibrated nonlocal band–to–band tunneling model. Utilization of Si:HfO2 instead of conventional perovskite ferroelectrics such as lead zirconium titanate (PbZrTiO3 and strontium bismuth tantalate (SrBi2Ta2O9 provides compatibility to the CMOS process as well as improved device scalability. By using Si:HfO2 ferroelectric gate stack, the applied gate voltage is effectively amplified that causes increased electric field at the tunneling junction and reduced tunneling barrier width. Compared with the conventional p–n–p–n SOI TFET, the on–state current and switching state current ratio are appreciably increased; and the average subthreshold slope (SS is effectively reduced. The simulation results of Si:HfO2 ferroelectric p–n–p–n SOI TFET show significant improvement in transconductance (∼9.8X enhancement at high overdrive voltage and average subthreshold slope (∼35% enhancement over nine decades of drain current at room temperature, indicating that this device is a promising candidate to strengthen the performance of p–n–p–n and conventional TFET for a switching performance.

  10. L2₁ and XA Ordering Competition in Hafnium-Based Full-Heusler Alloys Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb).

    Science.gov (United States)

    Wang, Xiaotian; Cheng, Zhenxiang; Wang, Wenhong

    2017-10-20

    For theoretical designing of full-Heusler based spintroinc materials, people have long believed in the so-called Site Preference Rule (SPR). Very recently, according to the SPR, there are several studies on XA-type Hafnium-based Heusler alloys X₂YZ, i.e., Hf₂VAl, Hf₂CoZ (Z = Ga, In) and Hf₂CrZ (Z = Al, Ga, In). In this work, a series of Hf₂-based Heusler alloys, Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb), were selected as targets to study the site preferences of their atoms by first-principle calculations. It has been found that all of them are likely to exhibit the L2₁-type structure instead of the XA one. Furthermore, we reveal that the high values of spin-polarization of XA-type Hf₂VZ (Z = Al, Ga, In, Tl, Si, Ge, Sn, Pb) alloys have dropped dramatically when they form the L2₁-type structure. Also, we prove that the electronic, magnetic, and physics nature of these alloys are quite different, depending on the L2₁-type or XA-type structures.

  11. Structure of states and reduced probabilities of electromagnetic transitions in 169Yb

    International Nuclear Information System (INIS)

    Bonch-Osmolovskaya, N.A.; Morozov, V.A.; Khudajberdyev, Eh.N.

    1988-01-01

    The effect of accounting the Pauli principle on the structure and energy of nonrotational states of 169 Yb deformed nucleus as well as on reduced probabilities of E2-transitions B(E2) is studied within the framework of the quasiparticle-phonon model (QPM). The amplitudes of states mixing due to Coriolis interaction and reduced probabilities of gamma transition within the framework of nonadiabatic rotation model are also calculated. The results are compared with calculations made within QPM with account of Coriolis interaction but excluding the Pauli principle in the wave state function. It is shown that to describe correctly both the level structure and reduced probabilities B(E2) it is necessary to include all types of interaction : quasiparticle interaction with phonons with account of the Pauli principle in the wave state functions and Coriolis interactions. Now no uniform theoretical approach exists

  12. Comet 169P/NEAT(=2002 EX12): The Parent Body of the α-Capricornid Meteoroid Stream

    Science.gov (United States)

    Kasuga, Toshihiro; Balam, David D.; Wiegert, Paul A.

    2010-12-01

    The Jupiter-family comet 169P/NEAT (previously known as asteroid 2002 EX12) has a dynamical association with the α-Capricornid meteoroid stream. In this paper, we present photometric observations of comet 169P/NEAT to further investigate the physical characters of its disintegration state related to the stream. The comet shows a point-like surface brightness profile limiting contamination due to coma emission to ~4% at most, indicating no evidence of outgassing. An upper limit on the fraction of the surface that could be sublimating water ice of disintegration of the parent at every return.

  13. Cep169, a Novel Microtubule Plus-End-Tracking Centrosomal Protein, Binds to CDK5RAP2 and Regulates Microtubule Stability.

    Directory of Open Access Journals (Sweden)

    Yusuke Mori

    Full Text Available The centrosomal protein, CDK5RAP2, is a microcephaly protein that regulates centrosomal maturation by recruitment of a γ-tubulin ring complex (γ-TuRC onto centrosomes. In this report, we identified a novel human centrosomal protein, Cep169, as a binding partner of CDK5RAP2, a member of microtubule plus-end-tracking proteins (+TIPs. Cep169 interacts directly with CDK5RAP2 through CM1, an evolutionarily conserved domain, and colocalizes at the pericentriolar matrix (PCM around centrioles with CDK5RAP2. In addition, Cep169 interacts with EB1 through SxIP-motif responsible for EB1 binding, and colocalizes with CDK5RAP2 at the microtubule plus-end. EB1-binding-deficient Cep169 abolishes EB1 interaction and microtubule plus-end attachment, indicating Cep169 as a novel member of +TIPs. We further show that ectopic expression of either Cep169 or CDK5RAP2 induces microtubule bundling and acetylation in U2OS cells, and depletion of Cep169 induces microtubule depolymerization in HeLa cells, although Cep169 is not required for assembly of γ-tubulin onto centrosome by CDK5RAP2. These results show that Cep169 targets microtubule tips and regulates stability of microtubules with CDK5RAP2.

  14. Affinity of /sup 169/Yb, /sup 67/Ga and /sup 111/In for malignant tumor. II. Comparison of tumor affinity among /sup 169/Yb, /sup 67/Ga, and /sup 111/In

    Energy Technology Data Exchange (ETDEWEB)

    Ando, I [Kanazawa Univ. (Japan). School of Medicine

    1975-10-01

    Comparisons of biological behavior of /sup 169/Yb-citrate and /sup 111/In-citrate and /sup 67/Ga-citrate in tumor tissue were performed by macro-autoradiography as well as by subcellular fractionation according to the method of Hogeboom and Schneider, using Yoshida sarcoma-bearing rats and Ehrlich tumor-bearing mice. The uptake of /sup 169/Yb, /sup 67/Ga and /sup 111/In into the tumor and various organs was assayed at 10, 30, 60 and 120 minutes after intravenous injection, using the rats subcutaneously transplanted with Yoshida sarcoma. Autoradiographical findings showed that the uptake of these nuclides was predominant in viable tumor tissue rather than in necrotic tumor tissue. Among subcellular fractions of Ehrlich tumor, most of the radioactivity was localized in the supernatant fraction and a small amount of radioactivity was found in the nuclear, mitochondria and microsome fractions. In Yoshida sarcoma, the results were almost similar in the three nuclides. And the specific activities of protein (cpm/mg) of these four fractions were not greatly different in the three nuclides. After intravenous injection of these nuclides, they were rapidly taken up into the tumor, and not excreted out of the tumor. It is a well-known fact that /sup 169/Yb, /sup 67/Ga and /sup 111/In are not sulfur coordinators, but weak nitrogen coordinators. Considering the above-described facts, it is presumed that the chemical bond of these elements is not a chelate ring, but anionic bond. From an in vitro adsorption test of these nuclides with the hydroxy-apatite crystal and cation exchange resin, it is presumed that the reason for the strong affinity of /sup 169/Yb to the bone is attributed to the fact that /sup 169/Yb stays mostly in cation form in the blood.

  15. Effect of Propionibacterium acidipropionici P169 on the rumen and faecal microbiota of beef cattle fed a maize-based finishing diet.

    Science.gov (United States)

    Azad, E; Narvaez, N; Derakhshani, H; Allazeh, A Y; Wang, Y; McAllister, T A; Khafipour, E

    2017-10-13

    Direct fed microbial supplementation with lactic acid utilising bacteria (i.e. Propionibacterium acidipropionici P169) has been shown to alleviate the severity of subacute ruminal acidosis in high-grain fed beef cattle. This study was carried out to explore the impact of P169 supplementation on modulating rumen and hindgut microbiota of high-grain fed steers. Seven ruminally-canulated high-grain fed steers were randomly assigned to two treatment groups: control diet (n=3) and the same diet supplemented with P169 added at a rate of 1×10 11 cfu/head/d (n=4). Samples were collected every 28 days for a 101 d period (5 time points) and subjected to qPCR quantification of P169 and high-throughput sequencing of bacterial V4 16S rRNA genes. Ruminal abundance of P169 was maintained at elevated levels (P=0.03) both in liquid and solid fractions post supplementation. Concomitant with decreased proportion of amylolytic (such as Prevotella) and key lactate-utilisers (such as Veillonellaceae and Megasphaera), the proportions of cellulolytic bacterial lineages (such as Ruminococcaceae, Lachnospiraceae, Clostridiaceae, and Christensenellaceae) were enriched in the rumen microbiota of P169-supplemented steers. These, coupled with elevated molar proportions of branched-chain fatty acids and increased concentration of ammonia in the rumen content of P169-supplemented steers, indicated an improved state of fibrolytic and proteolytic activity in response to P169 supplementation. Further, exploring the hindgut microbiota of P169-supplemented steers revealed enrichment of major amylolytic bacterial lineages, such as Prevotella, Blautia, and Succinivibrionaceae, which might be indicative of an increased availability of carbohydrates in the hindgut ecosystem following P169 supplementation. Collectively, the present study provides insights into the microbiota dynamics that underlie the P169-associated shifts in the rumen fermentation profile of high-grain fed steers.

  16. 32 CFR 169a.8 - Inventory and review schedule (Report Control Symbol DD-P&L(A)).

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 1 2010-07-01 2010-07-01 false Inventory and review schedule (Report Control... OF DEFENSE DEFENSE CONTRACTING COMMERCIAL ACTIVITIES PROGRAM PROCEDURES Procedures § 169a.8 Inventory and review schedule (Report Control Symbol DD-P&L(A)). (a) Information in each DoD Component's...

  17. 33 CFR 165.169 - Safety and Security Zones: New York Marine Inspection Zone and Captain of the Port Zone.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Safety and Security Zones: New... Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) PORTS AND WATERWAYS SAFETY... Areas First Coast Guard District § 165.169 Safety and Security Zones: New York Marine Inspection Zone...

  18. Impedance Characterization of the Capacitive field-Effect pH-Sensor Based on a thin-Layer Hafnium Oxide Formed by Atomic Layer Deposition

    Directory of Open Access Journals (Sweden)

    Michael LEE

    2014-05-01

    Full Text Available As a sensing element, silicon dioxide (SiO2 has been applied within ion-sensitive field effect transistors (ISFET. However, a requirement of increasing pH-sensitivity and stability has observed an increased number of insulating materials that obtain high-k gate being applied as FETs. The increased high-k gate reduces the required metal oxide layer and, thus, the fabrication of thin hafnium oxide (HfO2 layers by atomic layer deposition (ALD has grown with interest in recent years. This metal oxide presents advantageous characteristics that can be beneficial for the advancements within miniaturization of complementary metal oxide semiconductor (CMOS technology. In this article, we describe a process for fabrication of HfO2 based on ALD by applying water (H2O as the oxygen precursor. As a first, electrochemical impedance spectroscopy (EIS measurements were performed with varying pH (2-10 to demonstrate the sensitivity of HfO2 as a potential pH sensing material. The Nyquist plot demonstrates a high clear shift of the polarization resistance (Rp between pH 6-10 (R2 = 0.9986, Y = 3,054X + 12,100. At acidic conditions (between pH 2-10, the Rp change was small due to the unmodified oxide gate (R2 = 0.9655, Y = 2,104X + 4,250. These preliminary results demonstrate the HfO2 substrate functioned within basic to neutral conditions and establishes a great potential for applying HfO2 as a dielectric material for future pH measuring FET sensors.

  19. Synergistic effect of carbon nanotube as sintering aid and toughening agent in spark plasma sintered molybdenum disilicide-hafnium carbide composite

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, Biswajyoti; Asiq Rahman, O.S.; Sribalaji, M [Materials Science and Engineering, Indian Institute of Technology Patna, Bihta Kanpa Road, Bihta, Patna, Bihar 801103 (India); Bakshi, Srinivasa Rao [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Keshri, Anup Kumar, E-mail: anup@iitp.ac.in [Materials Science and Engineering, Indian Institute of Technology Patna, Bihta Kanpa Road, Bihta, Patna, Bihar 801103 (India)

    2016-12-15

    Hafnium carbide (HfC) along with sintering aids was consolidated at a relatively lower temperature i.e. 1600 °C (i.e. T=~0.41 T{sub m}) under a uniaxial load of 50 MPa by spark plasma sintering. Two different sintering aids such as molybdenum disilicide (MoSi{sub 2}) and carbon nanotube (CNT) were added to enhance the densification and lower the extent of grain growth in the sintered pellets. Density of the sintered pellet increased from 96.0±0.8% in HfC +5 wt% MoSi{sub 2} (HM) to 99.0±0.5% with the addition of 2 wt% CNT in HfC+5 wt% MoSi{sub 2} (HMC) at sintering temperature of 1600 °C. Further, the extent of grain growth drastically reduced from 204% in HM to 50% in HMC. Analysis of linear shrinkage during densification revealed that CNT addition increased densification rate and decreased the time required to reach the density of 99.0±0.5% at 1600 °C. Increased densification and lower degree of grain growth could be due to the synergistic effect offered by the CNT, which are as follows: (i) Lubrication effect of CNT, (ii) Lower activation energy for grain boundary diffusion (iii) Reduction in liquid phase sintering temperature and (iv) Grain boundary pinning. Fracture toughness of the sintered HM and HMC composite was obtained using indentation technique. By the addition of 2 wt% CNT in HM, drastic increase of 91% in fracture toughness was seen. This significant improvement in fracture toughness was due to the enhanced densification and relatively lower grain size of HMC. Also crack bridging, crack deflection, crack arrest, CNT and graphene sheet pull-out and swording played major role in toughening of HMC pellet.

  20. Technical Note: A simulation study on the feasibility of radiotherapy dose enhancement with calcium tungstate and hafnium oxide nano- and microparticles.

    Science.gov (United States)

    Sherck, Nicholas J; Won, You-Yeon

    2017-12-01

    To assess the radiotherapy dose enhancement (RDE) potential of calcium tungstate (CaWO 4 ) and hafnium oxide (HfO 2 ) nano- and microparticles (NPs). A Monte Carlo simulation study was conducted to gauge their respective RDE potentials relative to that of the broadly studied gold (Au) NP. The study was warranted due to the promising clinical and preclinical studies involving both CaWO 4 and HfO 2 NPs as RDE agents in the treatment of various types of cancers. The study provides a baseline RDE to which future experimental RDE trends can be compared to. All three materials were investigated in silico with the software Penetration and Energy Loss of Positrons and Electrons (PENELOPE 2014) developed by Francesc Salvat and distributed in the United States by the Radiation Safety Information Computational Center (RSICC) at Oak Ridge National Laboratory. The work utilizes the extensively studied Au NP as the "gold standard" for a baseline. The key metric used in the evaluation of the materials was the local dose enhancement factor (DEF loc ). An additional metric used, termed the relative enhancement ratio (RER), evaluates material performance at the same mass concentrations. The results of the study indicate that Au has the strongest RDE potential using the DEF loc metric. HfO 2 and CaWO 4 both underperformed relative to Au with lower DEF loc of 2-3 × and 4-100 ×, respectively. The computational investigation predicts the RDE performance ranking to be: Au > HfO 2 > CaWO 4 . © 2017 American Association of Physicists in Medicine.

  1. Members of miR-169 family are induced by high salinity and transiently inhibit the NF-YA transcription factor

    Directory of Open Access Journals (Sweden)

    Lin Hongxuan

    2009-04-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are endogenously expressed small RNAs with a length of about 21 nt. MiRNAs silence their target genes at the post-transcriptional level. In plants, miRNAs play various developmental and physiological roles by cleavaging mRNAs predominantly. Drought and high salinity are the most severe environmental abiotic stresses and cause crop losses all over the world. Results In this study, we identified miR-169g and miR-169n (o as high salinity-responsive miRNAs in rice. MiR-169n and miR169o were in a miRNA cluster with a distance of 3707 base pairs (bp. The high degree of conservation and close phylogenic distance of pre-miR-169n and pre-miR-169o indicated that they were derived from a very recent tandem duplication evolutionary event. The existence of a cis-acting abscisic acid responsive element (ABRE in the upstream region of miR-169n (o suggested that miR-169n (o may be regulated by ABA. In our previous study, we found that miR-169g was induced by the osmotic stress caused by drought via a dehydration-responsive element (DRE. Thus, our data showed that there were both overlapping and distinct responses of the miR-169 family to drought and salt stresses. We also showed that these miR-169 members selectively cleaved one of the NF-YA genes, Os03g29760, which is a CCAAT-box binding transcription factor and participates in transcriptional regulation of large number genes. Finally, we found one or more ath-miR-169 member that was also induced by high salinity. Conclusion We identified members of the miR-169 family as salt-induced miRNAs and analyzed their evolution, gene organization, expression, transcriptional regulation motif and target gene. Our data also indicated that the salt-induction of some miR-169 members was a general property in plants.

  2. Members of miR-169 family are induced by high salinity and transiently inhibit the NF-YA transcription factor.

    Science.gov (United States)

    Zhao, Botao; Ge, Liangfa; Liang, Ruqiang; Li, Wei; Ruan, Kangcheng; Lin, Hongxuan; Jin, Youxin

    2009-04-08

    MicroRNAs (miRNAs) are endogenously expressed small RNAs with a length of about 21 nt. MiRNAs silence their target genes at the post-transcriptional level. In plants, miRNAs play various developmental and physiological roles by cleavaging mRNAs predominantly. Drought and high salinity are the most severe environmental abiotic stresses and cause crop losses all over the world. In this study, we identified miR-169g and miR-169n (o) as high salinity-responsive miRNAs in rice. MiR-169n and miR169o were in a miRNA cluster with a distance of 3707 base pairs (bp). The high degree of conservation and close phylogenic distance of pre-miR-169n and pre-miR-169o indicated that they were derived from a very recent tandem duplication evolutionary event. The existence of a cis-acting abscisic acid responsive element (ABRE) in the upstream region of miR-169n (o) suggested that miR-169n (o) may be regulated by ABA. In our previous study, we found that miR-169g was induced by the osmotic stress caused by drought via a dehydration-responsive element (DRE). Thus, our data showed that there were both overlapping and distinct responses of the miR-169 family to drought and salt stresses. We also showed that these miR-169 members selectively cleaved one of the NF-YA genes, Os03g29760, which is a CCAAT-box binding transcription factor and participates in transcriptional regulation of large number genes. Finally, we found one or more ath-miR-169 member that was also induced by high salinity. We identified members of the miR-169 family as salt-induced miRNAs and analyzed their evolution, gene organization, expression, transcriptional regulation motif and target gene. Our data also indicated that the salt-induction of some miR-169 members was a general property in plants.

  3. Thermodynamic and kinetic studies in the systems alkali chloride-zinconium (or hafnium) tetrachloride: Part I. Vapour pressure measurements over hexachloro compounds and use of vapour pressure data in fractional decomposition

    International Nuclear Information System (INIS)

    Ray, H.S.; Bhat, B.G.; Reddy, G.S.; Biswas, A.K.

    1978-01-01

    A molten tin isoteniscope has been used to measure the vapour pressures over ZrCl 4 , HfCl 4 and the hexachlore zirconates (M 2 ZrCl 6 ) and the hexachloro hafnates (M 2 HfCl 6 ) of four alkali metals (M = Na,K,Rb,Cs). The method of preparation of these compounds and the effect of small amounts of residual alkali chlorides on the their vapour pressure are discussed. The pressure-temperature plots are examined in the light of some theoretical postulates. A scheme for separation of hafnium from zirconoium by multistage fractional decomposition of the hexachlore compounds of any alkali metal is described. The scheme, which is analogous to rectification in liquid-vapour systems, employs a countercurrent flow of Zr(Hf)Cl 4 in a gas stream and a moving bed of alkali chlorides. The separation is based on the difference in the dissociation equilibrium for zirconium and hafnium compounds. Stage calculations for such a scheme and the main conclusions of a computational work are presented. (author)

  4. Low-energy nuclear reaction of the 14N+169Tm system: Incomplete fusion

    Science.gov (United States)

    Kumar, R.; Sharma, Vijay R.; Yadav, Abhishek; Singh, Pushpendra P.; Agarwal, Avinash; Appannababu, S.; Mukherjee, S.; Singh, B. P.; Ali, R.; Bhowmik, R. K.

    2017-11-01

    Excitation functions of reaction residues produced in the 14N+169Tm system have been measured to high precision at energies above the fusion barrier, ranging from 1.04 VB to 1.30 VB , and analyzed in the framework of the statistical model code pace4. Analysis of α -emitting channels points toward the onset of incomplete fusion even at slightly above-barrier energies where complete fusion is supposed to be one of the dominant processes. The onset and strength of incomplete fusion have been deduced and studied in terms of various entrance channel parameters. Present results together with the reanalysis of existing data for various projectile-target combinations conclusively suggest strong influence of projectile structure on the onset of incomplete fusion. Also, a strong dependence on the Coulomb effect (ZPZT) has been observed for the present system along with different projectile-target combinations available in the literature. It is concluded that the fraction of incomplete fusion linearly increases with ZPZT and is found to be more for larger ZPZT values, indicating significantly important linear systematics.

  5. Subcellular distribution of 111In and 169Yb in tumor and liver

    International Nuclear Information System (INIS)

    Ando, A.; Ando, I.; Takeshita, M.; Hiraki, T.; Hisada, K.

    1981-01-01

    Subcellular distribution of 111 In and 169 Yb was quantitatively determined to evaluate the role of the lysosome in accumulation of these nuclides in malignant tumor tissue and in the liver using three different tumor models and the host liver. In Yoshida sarcoma and Ehrlich tumor, most of the radioactivity of these nuclides was localized in the supernatant fraction, and only a small amount of radioactivity was localized in the mitochondrial fraction, which contains lysosomes. In the liver, most of the radioactivity was concentrated in the mitochondrial fraction. The radioactivity of this fraction increased with time after the administration of these nuclides and reached approximately 50% of the total radioactivity within 24 h. In the case of hepatoma AH109A, radioactivity of the mitochondrial fraction increased with time after administration, and about 30% of the total radioactivity was concentrated in this fraction after 24 h. It is concluded that the lysosome does not play a major role in the tumor concentration of these nuclides, although it may play an important role in their liver concentration. In the case of hepatoma AH109A, it is pressumed that lysosome plays a considerably important role in the tumor concentration of these nuclides, hepatoma AH109A possessing some residual features of the liver. (orig.)

  6. Violence as a public health problem: an ecological study of 169 countries.

    Science.gov (United States)

    Wolf, Achim; Gray, Ron; Fazel, Seena

    2014-03-01

    Individual level risk factors for violence have been widely studied, but little is known about country-level determinants, particularly in low and middle-income countries. We hypothesized that income inequality, through its detrimental effects on social cohesion, would be related to an increase in violence worldwide, and in low and middle-income countries in particular. We examined country-level associations of violence with socio-economic and health-related factors, using crime statistics from the United Nations Office on Drugs and Crime, and indicators from the Human Development Report published by the United Nations Development Programme. Using regression models, we measured relationships between country-level factors (age, education, measures of income, health expenditure, and alcohol consumption) and four violent outcomes (including measures of violence-related mortality and morbidity) in up to 169 countries. We stratified our analyses comparing high with low and middle-income countries, and analysed longitudinal data on homicide and income inequality in high-income countries. In low and middle-income countries, income inequality was related to homicide, robbery, and self-reported assault (all p's public policy interventions reducing alcohol consumption may contribute to reducing violence rates. Our main finding was that income inequality was related to violence in low and middle-income countries. Public health should advocate for global action to moderate income inequality to reduce the global health burden of violence. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Subcellular distribution of /sup 111/In and /sup 169/Yb in tumor and liver

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Ando, I; Takeshita, M; Hiraki, T; Hisada, K

    1981-05-01

    Subcellular distribution of /sup 111/In and /sup 169/Yb was quantitatively determined to evaluate the role of the lysosome in accumulation of these nuclides in malignant tumor tissue and in the liver using three different tumor models and the host liver. In Yoshida sarcoma and Ehrlich tumor, most of the radioactivity of these nuclides was localized in the supernatant fraction, and only a small amount of radioactivity was localized in the mitochondrial fraction, which contains lysosomes. In the liver, most of the radioactivity was concentrated in the mitochondrial fraction. The radioactivity of this fraction increased with time after the administration of these nuclides and reached approximately 50% of the total radioactivity within 24 h. In the case of hepatoma AH109A, radioactivity of the mitochondrial fraction increased with time after administration, and about 30% of the total radioactivity was concentrated in this fraction after 24 h. It is concluded that the lysosome does not play a major role in the tumor concentration of these nuclides, although it may play an important role in their liver concentration. In the case of hepatoma AH109A, it is pressumed that lysosome plays a considerably important role in the tumor concentration of these nuclides, hepatoma AH109A possessing some residual features of the liver.

  8. Four phosphoproteins with common amino termini are encoded by human cytomegalovirus AD169

    International Nuclear Information System (INIS)

    Wright, D.A.; Staprans, S.I.; Spector, D.H.

    1988-01-01

    In this report, the authors identify the proteins encoded by the 2.2-kilobase class of early transcripts arising from a region of the strain AD169 human cytomegalovirus genome (map units 0.682 to 0.713) which contains cell-related sequences. These transcripts, encoded by adjacent EcoRI fragments R and d, have a complex spliced structure with 5' and 3' coterminal ends. Antiserum directed against a synthetic 11-amino-acid peptide corresponding to the predicted amino terminus of the proteins was generated and found to immunoprecipitate four-infected-cell proteins of 84, 50, 43, and 34 kilodaltons. These proteins were phosphorylated and were associated predominantly with the nuclei of infected cells. The 43-kilodalton protein was the most abundant of the four proteins, and its level of expression remained relatively constant throughout the infection. Expression of the other proteins increased as the infection progressed. Pulse-chase analysis failed to show a precursor-product relationship between any of the proteins. A comparison of the [ 35 S]methionine-labeled tryptic peptide maps of the four proteins from infected cells and an in vitro-generated polypeptide derived from the putative first exon showed that all four infected-cell proteins were of viral origin and contained a common amino-terminal region

  9. IGHV1-69 B cell chronic lymphocytic leukemia antibodies cross-react with HIV-1 and hepatitis C virus antigens as well as intestinal commensal bacteria.

    Directory of Open Access Journals (Sweden)

    Kwan-Ki Hwang

    Full Text Available B-cell chronic lymphocytic leukemia (B-CLL patients expressing unmutated immunoglobulin heavy variable regions (IGHVs use the IGHV1-69 B cell receptor (BCR in 25% of cases. Since HIV-1 envelope gp41 antibodies also frequently use IGHV1-69 gene segments, we hypothesized that IGHV1-69 B-CLL precursors may contribute to the gp41 B cell response during HIV-1 infection. To test this hypothesis, we rescued 5 IGHV1-69 unmutated antibodies as heterohybridoma IgM paraproteins and as recombinant IgG1 antibodies from B-CLL patients, determined their antigenic specificities and analyzed BCR sequences. IGHV1-69 B-CLL antibodies were enriched for reactivity with HIV-1 envelope gp41, influenza, hepatitis C virus E2 protein and intestinal commensal bacteria. These IGHV1-69 B-CLL antibodies preferentially used IGHD3 and IGHJ6 gene segments and had long heavy chain complementary determining region 3s (HCDR3s (≥21 aa. IGHV1-69 B-CLL BCRs exhibited a phenylalanine at position 54 (F54 of the HCDR2 as do rare HIV-1 gp41 and influenza hemagglutinin stem neutralizing antibodies, while IGHV1-69 gp41 antibodies induced by HIV-1 infection predominantly used leucine (L54 allelic variants. These results demonstrate that the B-CLL cell population is an expansion of members of the innate polyreactive B cell repertoire with reactivity to a number of infectious agent antigens including intestinal commensal bacteria. The B-CLL IGHV1-69 B cell usage of F54 allelic variants strongly suggests that IGHV1-69 B-CLL gp41 antibodies derive from a restricted B cell pool that also produces rare HIV-1 gp41 and influenza hemagglutinin stem antibodies.

  10. SU-F-T-54: Determination of the AAPM TG-43 Brachytherapy Dosimetry Parameters for A New Titanium-Encapsulated Yb-169 Source by Monte Carlo Calculations

    Energy Technology Data Exchange (ETDEWEB)

    Reynoso, F [UT MD Anderson Cancer Center, Houston, TX (United States); Washington University School of Medicine, St. Louis, MO (United States); Munro, J [Source Production & Equipment Co., Inc., St. Rose, LA (United States); Cho, S [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To determine the AAPM TG-43 brachytherapy dosimetry parameters of a new titanium-encapsulated Yb-169 source designed to maximize the dose enhancement during gold nanoparticle-aided radiation therapy (GNRT). Methods: An existing Monte Carlo (MC) model of the titanium-encapsulated Yb-169 source, which was described in the current investigators’ published MC optimization study, was modified based on the source manufacturer’s detailed specifications, resulting in an accurate model of the titanium-encapsulated Yb-169 source that was actually manufactured. MC calculations were then performed using the MCNP5 code system and the modified source model, in order to obtain a complete set of the AAPM TG-43 parameters for the new Yb-169 source. Results: The MC-calculated dose rate constant for the new titanium-encapsulated Yb-169 source was 1.05 ± 0.03 cGy per hr U, indicating about 10% decrease from the values reported for the conventional stainless steel-encapsulated Yb-169 sources. The source anisotropy and radial dose function for the new source were found similar to those reported for the conventional Yb-169 sources. Conclusion: In this study, the AAPM TG-43 brachytherapy dosimetry parameters of a new titanium-encapsulated Yb-169 source were determined by MC calculations. The current results suggested that the use of titanium, instead of stainless steel, to encapsulate the Yb-169 core would not lead to any major change in the dosimetric characteristics of the Yb-169 source, while it would allow more low energy photons being transmitted through the source filter thereby leading to an increased dose enhancement during GNRT. Supported by DOD/PCRP grant W81XWH-12-1-0198 This investigation was supported by DOD/PCRP grant W81XWH-12-1- 0198.

  11. Structure of the semi-decoupled π 1/2[411] band in odd proton nucleus 169Ta

    International Nuclear Information System (INIS)

    Song Hai; Deng Fuguo; Shao Liqin; Zhou Hongyu; Sun Huibin; Lu Jingbin; Zhao Guangyi; Yin Lichang; Liu Yunzuo

    2003-01-01

    High spin states of the odd proton-nucleus 169 Ta have been populated in the reaction 155 Gd( 19 F, 5 n) with beam energies of 97 MeV. Rotational band based on d 3/2 proton 1/2[411] Nilsson state has been pushed up to 39/2 + in the α=1/2 decay sequence. Its signature partner, the α=-1/2 decay sequence with four link transitions has been established and 1/2[411] band in 169 Ta was reassigned to be a semi-decoupled band. The systematics of the signature splitting in the K=1/2 bands in the rear-earth region and the accidental degeneracy conclusion given by the angular projection shell model were discussed

  12. Evolution of E 2 transition strength in deformed hafnium isotopes from new measurements on 172Hf,174Hf, and 176Hf

    Science.gov (United States)

    Rudigier, M.; Nomura, K.; Dannhoff, M.; Gerst, R.-B.; Jolie, J.; Saed-Samii, N.; Stegemann, S.; Régis, J.-M.; Robledo, L. M.; Rodríguez-Guzmán, R.; Blazhev, A.; Fransen, Ch.; Warr, N.; Zell, K. O.

    2015-04-01

    Background: The available data for E 2 transition strengths in the region between neutron-deficient hafnium and platinum isotopes are far from complete. More and precise data are needed to enhance the picture of structure evolution in this region and to test state-of-the-art nuclear models. In a simple model, the maximum collectivity is expected at the middle of the major shell. However, for actual nuclei, particularly in heavy-mass regions, which should be highly complex, this picture may no longer be the case, and one should use a more realistic nuclear-structure model. We address this point by studying the spectroscopy of Hf as a representative case. Purpose: We remeasure the 21+ half-lives of 172,174,176Hf, for which there is some disagreement in the literature. The main goal is to measure, for the first time, the half-lives of higher-lying states of the rotational band. The new results are compared to a theoretical calculation for absolute transition strengths. Method: The half-lives were measured using γ -γ and conversion-electron-γ delayed coincidences with the fast timing method. For the determination of half-lives in the picosecond region, the generalized centroid difference method was applied. For the theoretical calculation of the spectroscopic properties, the interacting boson model is employed, whose Hamiltonian is determined based on microscopic energy-density functional calculations. Results: The measured 21+ half-lives disagree with results from earlier γ -γ fast timing measurements, but are in agreement with data from Coulomb excitation experiments and other methods. Half-lives of the 41+ and 61+ states were measured, as well as a lower limit for the 81+ states. Conclusions: This work shows the importance of a mass-dependent effective boson charge in the interacting boson model for the description of E 2 transition rates in chains of nuclei. It encourages further studies of the microscopic origin of this mass dependence. New experimental

  13. Violence as a public health problem: An ecological study of 169 countries☆

    Science.gov (United States)

    Wolf, Achim; Gray, Ron; Fazel, Seena

    2014-01-01

    Individual level risk factors for violence have been widely studied, but little is known about country-level determinants, particularly in low and middle-income countries. We hypothesized that income inequality, through its detrimental effects on social cohesion, would be related to an increase in violence worldwide, and in low and middle-income countries in particular. We examined country-level associations of violence with socio-economic and health-related factors, using crime statistics from the United Nations Office on Drugs and Crime, and indicators from the Human Development Report published by the United Nations Development Programme. Using regression models, we measured relationships between country-level factors (age, education, measures of income, health expenditure, and alcohol consumption) and four violent outcomes (including measures of violence-related mortality and morbidity) in up to 169 countries. We stratified our analyses comparing high with low and middle-income countries, and analysed longitudinal data on homicide and income inequality in high-income countries. In low and middle-income countries, income inequality was related to homicide, robbery, and self-reported assault (all p's income countries, urbanicity was significantly associated with official assault (p = 0.002, β = 0.716) and robbery (p = 0.011, β = 0.587) rates; income inequality was related to homicide (p = 0.006, β = 0.670) and self-reported assault (p = 0.020, β = 0.563), and longitudinally with homicide (p = 0.021). Worldwide, alcohol consumption was associated with self-reported assault rates (p income inequality was related to violence in low and middle-income countries. Public health should advocate for global action to moderate income inequality to reduce the global health burden of violence. PMID:24581081

  14. Radiosynoviorthesis of acromioclavicular joint using 169Er-citrate: prospective evaluation of efficacy.

    Science.gov (United States)

    Vereb, Marika; Liepe, Knut; Fischer, Manfred; Kaliska, Lucia; Noskovicova, Lucia; Balogova, Sona

    2018-01-01

    There is a clinical need for therapeutic alternative in patients with persisting painful arthritis of AC-joint and failure of previous treatments. However, no radiopharmaceutical is currently explicitly approved for radiosynoviorthesis of acromioclavicular joint. The aim of our study was to prospectively assess the efficacy and safety of radiosynoviorthesis of acromioclavicular joint using erbium-169 citrate. Radiosynoviorthesis of acromioclavicular joint was performed in 51 consecutive patients (18 males, 33 females) mean age 64.3 (range 43.8-82.6, median 63.6) years with clinically confirmed arthritis of 85 acromioclavicular joints. The efficacy of RSO was reported by patients according to 10-step visual analogue scale of pain (VAS) (0 = no pain, 10 = most severe pain) at 6 months after radiosynoviorthesis and by ranking the global therapeutic effect of RSO in 4 categories (1 = the best effect, 4 = no change). To assess the variation of blood perfusion in treated joints, the efficacy of RSO was also evaluated by variation of target (acromioclavicular joint)/non-target (soft tissue) uptake ratio (T/NTR) of metylendiphosphonate (99mTc) measured as number of counts over region of interest on blood pool phase of two-phase bone scintigraphy performed before and 6 months after RSO. Radiosynoviorthesis was followed by significant decrease in VAS, mean - 3.1 (-47%). Excellent, good, moderate and bad response was observed in 57 (67%), 25 (29%), 1 (1%) and in 2 (2%) of acromioclavicular joints respectively. A significant correlation between decrease of T/NTR and variation of VAS in % (ρ = 0.532, p acromioclavicular joint in whom previous line(s) of treatment did not lead to satisfactory pain relief.

  15. Loss of the nodule-specific cysteine rich peptide, NCR169, abolishes symbiotic nitrogen fixation in the Medicago truncatula dnf7 mutant.

    Science.gov (United States)

    Horváth, Beatrix; Domonkos, Ágota; Kereszt, Attila; Szűcs, Attila; Ábrahám, Edit; Ayaydin, Ferhan; Bóka, Károly; Chen, Yuhui; Chen, Rujin; Murray, Jeremy D; Udvardi, Michael K; Kondorosi, Éva; Kaló, Péter

    2015-12-08

    Host compatible rhizobia induce the formation of legume root nodules, symbiotic organs within which intracellular bacteria are present in plant-derived membrane compartments termed symbiosomes. In Medicago truncatula nodules, the Sinorhizobium microsymbionts undergo an irreversible differentiation process leading to the development of elongated polyploid noncultivable nitrogen fixing bacteroids that convert atmospheric dinitrogen into ammonia. This terminal differentiation is directed by the host plant and involves hundreds of nodule specific cysteine-rich peptides (NCRs). Except for certain in vitro activities of cationic peptides, the functional roles of individual NCR peptides in planta are not known. In this study, we demonstrate that the inability of M. truncatula dnf7 mutants to fix nitrogen is due to inactivation of a single NCR peptide, NCR169. In the absence of NCR169, bacterial differentiation was impaired and was associated with early senescence of the symbiotic cells. Introduction of the NCR169 gene into the dnf7-2/NCR169 deletion mutant restored symbiotic nitrogen fixation. Replacement of any of the cysteine residues in the NCR169 peptide with serine rendered it incapable of complementation, demonstrating an absolute requirement for all cysteines in planta. NCR169 was induced in the cell layers in which bacteroid elongation was most pronounced, and high expression persisted throughout the nitrogen-fixing nodule zone. Our results provide evidence for an essential role of NCR169 in the differentiation and persistence of nitrogen fixing bacteroids in M. truncatula.

  16. Overcoring rock stress measurements in drillholes ONK-PP169 and ONK-PP170 Olkiluoto

    International Nuclear Information System (INIS)

    Berg, S.; Sjoeberg, J.

    2009-03-01

    Three-dimensional overcoring rock stress measurements were conducted in drillholes ONK-PP169 and ONK-PP170 at the 230 m depth level in the ONKALO site ramp. The measurements were performed during the spring of 2008. The objective of the measurements was to obtain better understanding of the in situ stress field for the measured depth levels. Another objective was to increase the confidence and reliability and to diminish the uncertainties concerning the state of stress at shallow depth of ONKALO. Due to problems with bonding of strain gauges, which may have been caused by a thin layer/coating of unknown material on the pilot hole wall, stress measurements results were only achieved in drillhole ONK-PP170 at -230 m level. The initial plan was to conduct measurements at three depth levels, -120 m, -180 m and -220 m levels, in the ONKALO ramp. Two (2) of the conducted measurements could be rated as successful (rating a) two (2) measurement were partly successful (rating b). The results from the measurements assuming isotropic condition, the major principal stress is plunging between 18deg and 35deg and trending between S and WSW. Stress magnitudes (for σ 1 ) varied between 12 and 16 MPa except for test 2:3:3 where a much higher value (47 MPa) was obtained. The orientation of the major principal stress are similar for test 2:3:3 and 2:4:3 (WSW), but are different from the orientation of the major principal stress for test 2:5:1 and 2:6:1 (S). Likewise, the horizontal stresses have the highest values for test 2:3:3 but in this case the orientation is similar to test 2:5:1 and 2:4:3. The horizontal stress magnitudes of test 2:4:3, 2:5:1 and 2:6:1 are similar but the orientation for test 2:6:1 are different from the other three tests. The results from two of the measurements assuming transversely isotropic conditions, the major principal stress is 12.3 MPa and 12.7 MPa, trending WSW and S, plunging 30 deg. (orig.)

  17. 6-Peroxo-6-zirconium crown and its hafnium analogue embedded in a triangular polyanion: [M6(O2)6(OH)6(gamma-SiW10O36)3]18- (M = Zr, Hf).

    Science.gov (United States)

    Bassil, Bassem S; Mal, Sib Sankar; Dickman, Michael H; Kortz, Ulrich; Oelrich, Holger; Walder, Lorenz

    2008-05-28

    We have synthesized and structurally characterized the unprecedented peroxo-zirconium(IV) containing [Zr6(O2)6(OH)6(gamma-SiW10O36)3]18- (1). Polyanion 1 comprises a cyclic 6-peroxo-6-zirconium core stabilized by three decatungstosilicate units. We have also prepared the isostructural hafnium(IV) analogue [Hf6(O2)6(OH)6(gamma-SiW10O36)3]18- (2). We investigated the acid/base and redox properties of 1 by UV-vis spectroscopy and electrochemistry studies. Polyanion 1 represents the first structurally characterized Zr-peroxo POM with side-on, bridging peroxo units. The simple, one-pot synthesis of 1 and 2 involving dropwise addition of aqueous hydrogen peroxide could represent a general procedure for incorporating peroxo groups into a large variety of transition metal and lanthanide containing POMs.

  18. Hafnium and neodymium isotopes and REY distribution in the truly dissolved, nanoparticulate/colloidal and suspended loads of rivers in the Amazon Basin, Brazil

    Science.gov (United States)

    Merschel, Gila; Bau, Michael; Schmidt, Katja; Münker, Carsten; Dantas, Elton L.

    2017-09-01

    Radiogenic isotopes in river sediments and river waters have been widely used in provenance studies, as these samples naturally integrate the geology/chemistry of the entire catchment. While the Hf and Nd isotope systems are coupled during igneous processes, they are decoupled during supergene processes at the Earth's surface, which is reflected by the isotope composition of riverine sediments. We present the first data for both Hf and Nd isotope compositions of the dissolved (0.2 μm-filtrates rich in nanoparticles and colloids, NPCs) and the truly dissolved (1 kDa-ultrafiltrates) load of rivers. Hafnium and Nd isotope compositions and concentrations of the Rare Earths and Yttrium (REY) and Hf were determined for suspended particles (>0.2 μm) as well as for the dissolved and the truly dissolved load of the Rio Solimões, the Amazon's largest tributary draining the Andes, and of the Rio Negro, an organic NPC- and particle-rich river draining the rainforest of northern Amazonia. We also analyzed the Nd isotope compositions of suspended sediments and 0.2 μm-filtered water samples from the Amazon River and its tributaries Rio Tapajos, Rio Xingu and Rio Jari. Our novel results clearly show that the decoupling of the Hf and Nd isotope systems is related to incongruent weathering processes on the continent, as this decoupling can already be observed in the different Hf and Nd pools, i.e. in the particulate, the NPC-dominated dissolved and the truly dissolved load of rivers. In the Rio Negro and Rio Solimões, a strong particle size-dependent difference in Hf isotope composition is observed. Values of εHf become more radiogenic as filter poresize decreases, which can be related to the density- and size-dependent distribution of Hf-rich minerals, e.g. zircons, and their absence from the truly dissolved pool. In contrast, the Nd isotope composition of Amazonian river waters reflects that of their catchment geology. Tributaries draining the Precambrian Brazilian and

  19. Analyzing power measurements for n-p scattering between 13.5 and 16.9 MeV

    International Nuclear Information System (INIS)

    Tornow, W.; Lisowski, P.W.; Byrd, R.C.; Walter, R.L.

    1980-01-01

    The analyzing power A%sub(Y)(theta) for neutron-proton scattering has been measured for theta = 90 0 (c.m.) from 13.5 to 16.9 MeV and from theta = 50 0 to 145 0 (c.m.) at 16.9 MeV. Extensive Monte Carlo calculations have been made to correct for multiple scattering effects. Overall uncertainties are about +- 0.002. All the A%sub(Y)(theta) data, but primarily those at 16.9 MeV, disagree with predictions based on the phase-shift sets which have been derived previously by way of global analyses of nucleon-nucleon scattering data. Data for the product delta(theta)A%sub(Y)(theta) have been fitted with an expansion of the form (sin theta)(a 0 + a 1 cos theta + a 2 cos 2 theta). For the first time the need for a non-zero a 2 has been illustrated for energies below 20 MeV. This parameter is shown to be related to the nucleon-nucleon F-state spin-orbit phase parameter. In addition, the P, D, and F spin-orbit phase parameter values derived from the present data differ significantly from the ones based on the Yale-IV and Livermore-X global analyses. The derived D and F spin-orbit phase parameters also differ from those obtained in the recent analysis of nucleon-nucleon scattering data by Arndt et al. (orig.)

  20. COMET 169P/NEAT(=2002 EX12): THE PARENT BODY OF THE α-CAPRICORNID METEOROID STREAM

    International Nuclear Information System (INIS)

    Kasuga, Toshihiro; Wiegert, Paul A.; Balam, David D.

    2010-01-01

    The Jupiter-family comet 169P/NEAT (previously known as asteroid 2002 EX 12 ) has a dynamical association with the α-Capricornid meteoroid stream. In this paper, we present photometric observations of comet 169P/NEAT to further investigate the physical characters of its disintegration state related to the stream. The comet shows a point-like surface brightness profile limiting contamination due to coma emission to ∼4% at most, indicating no evidence of outgassing. An upper limit on the fraction of the surface that could be sublimating water ice of -4 is obtained with an upper limit to the mass loss of ∼10 -2 kg s -1 . The effective radius of nucleus is found to be 2.3 ± 0.4 km. Red filter photometry yields a rotational period of 8.4096 ± 0.0012 hr, and the range of the amplitude 0.29 ± 0.02 mag is indicative of a moderately spherical shape having a projected axis ratio ∼1.3. The comet shows redder colors than the Sun, being compatible with other dead comet candidates. The calculated lost mass per revolution is ∼10 9 kg. If it has sustained this mass loss over the estimated 5000 yr age of the α-Capricornid meteoroid stream, the total mass loss from 169P/NEAT (∼10 13 kg) is consistent with the reported stream mass (∼10 13 -10 15 kg), suggesting that the stream is the product of steady disintegration of the parent at every return.

  1. Zirconium Zr and hafnium Hf

    International Nuclear Information System (INIS)

    Busev, A.I.; Tiptsova, V.G.; Ivanov, V.M.

    1978-01-01

    The basic methods for extracting and determining Zr(4) and Hf(4) are described. Diantipyrinemethane and its alkyl homologs selectively extract Zr and Hf from HNO 3 solutions in the presence of nitrates. Zr is selectively extracted with tetraethyldiamide of heptyl phosphoric acid (in benzene) as well as with 2-thenoyltrifluoroacetone (in an acid). The latter reagents is suitable for rapid determination of 95 Zr in a mixture with 95 Nb and other fragments. The complexometric determination of Zr is based on formation of a stable complex of Zr with EDTA. The titration is carried out in the presence of n-sulfobenzene-azo-pyrocatechol, eriochrome black T. The determination is hindered by Hf, fluoride-, phosphate-, oxalate- and tartrate-ions. The method is used for determining Zr in zircon and eudialyte ore. Zr is determined photometrically with the aid of xylenol orange, arsenazo 3 and pyrocatechol violet (in phosphorites). Hf is determined in the presence of Zr photometrically with the aid of xylenol orange or methyl-thymol blue. The method is based on Zr being masked with hydrogen peroxide in the presence of sulfate-ions

  2. Cathodoluminescence of Irradiated Hafnium Dioxide

    Science.gov (United States)

    2011-03-01

    Martin and Michael Rhoby for their hard work in fixing assorted problems that cropped up during the course of my thesis work. Emily A. Purcell...Cathodoluminescence Microscopy of Inorganic Solids. New York: Plenum Press, 1990. [13] D. Drouin, A. R. Couture, D. Joly , X. Tastet, V. Aimez and R. Gauvin

  3. Alkali metal hafnium oxide scintillators

    Science.gov (United States)

    Bourret-Courchesne, Edith; Derenzo, Stephen E.; Taylor, Scott Edward

    2018-05-08

    The present invention provides for a composition comprising an inorganic scintillator comprising an alkali metal hafnate, optionally cerium-doped, having the formula A2HfO3:Ce; wherein A is an alkali metal having a valence of 1, such as Li or Na; and the molar percent of cerium is 0% to 100%. The alkali metal hafnate are scintillators and produce a bright luminescence upon irradiation by a suitable radiation.

  4. Influence of radiation damage evolution on hyperfine interactions of implanted impurities: 169Tm and 175Lu in Fe

    International Nuclear Information System (INIS)

    Thome, L.; Bernas, H.; Meunier, R.

    1978-01-01

    The hyperfine interaction of 169 Tm and 175 Lu implanted in Fe and annealed, or implanted at high temperatures, was studied by time-integral and time-differential perturbed angular correlation experiments. The heat treatment was performed in order to modify the impurity-radiation damage interaction in the sample. Comparison of our results with other hyperfine interaction results on rare earths implanted in iron shows that after room-temperature implantation, all the implanted nuclei experience the same hyperfine interaction. The annealing-and implantation-temperature dependences of the fraction of nuclei experiencing this hyperfine interaction are significantly different. The results are interpreted in terms of precipitation of an increasing proportion of implanted impurities. A discussion of their relation to the implanted impurity lattice location is presented in a companion paper

  5. Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of N'-(furan-3-ylmethylene)-2-(4-methoxyphenylamino)acetohydrazide.

    Science.gov (United States)

    Emam, Sanaa M; El-Saied, Fathy A; Abou El-Enein, Saeyda A; El-Shater, Heba A

    2009-03-01

    Cobalt(II), nickel(II), copper(II), zinc(II) and hafnium(IV) complexes of furan-2-carbaldehyde 4-methoxy-N-anilinoacetohydrazone were synthesized and characterized by elemental and thermal (TG and DTA) analyses, IR, UV-vis and (1)H NMR spectra as well as magnetic moment and molar conductivity. Mononuclear complexes are obtained with 1:1 molar ratio except complexes 3 and 9 which are obtained with 1:2 molar ratios. The IR spectra of ligand and metal complexes reveal various modes of chelation. The ligand behaves as a neutral bidentate one and coordination occurs via the carbonyl oxygen atom and azomethine nitrogen atom. The ligand behaves also as a monobasic tridentate one and coordination occurs through the enolic oxygen atom, azomethine nitrogen atom and the oxygen atom of furan ring. Moreover, the ligand behaves as a neutral tridentate and coordination occurs via the carbonyl oxygen, azomethine nitrogen and furan oxygen atoms as well as a monobasic bidentate and coordination occurs via the enolic oxygen atom and azomethine nitrogen atom. The electronic spectra and magnetic moment measurements reveal that all complexes possess octahedral geometry except the copper complex 10 possesses a square planar geometry. The thermal studies showed the type of water molecules involved in metal complexes as well as the thermal decomposition of some metal complexes.

  6. Determination of hafnium at the 10−4% level (relative to zirconium content) using neutron activation analysis, inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry

    International Nuclear Information System (INIS)

    Smolik, Marek; Polkowska-Motrenko, Halina; Hubicki, Zbigniew; Jakóbik-Kolon, Agata; Danko, Bożena

    2014-01-01

    Graphical abstract: -- Highlights: •We worked out ICP-MS method of Hf determination in Zr and Zr compounds. •We used NAA method as reference one. •We obtained pure zirconium matrix by ion exchange (Diphonix ® resin). •These permit to determine ≥1 × 10 −4 % Hf in Zr sample by ICP MS with good precision and accuracy. -- Abstract: Hafnium at the very low level of 1–8 ppm (in relation to zirconium) was determined in zirconium sulfate solutions (originating from investigations of the separation of ca. 44 ppm Hf from zirconium by means of the ion exchange method) by using three independent methods: inductively coupled plasma mass spectrometry (ICP MS), neutron activation analysis (NAA) and inductively coupled plasma atomic emission spectrometry (ICP-AES). The results of NAA and ICP MS determinations were consistent with each other across the entire investigated range (the RSD of both methods did not exceed 38%). The results of ICP-AES determination were more diverse, particularly at less than 5 ppm Hf (RSD was significantly higher: 29–253%). The ion exchange method exploiting Diphonix ® resin proved sufficient efficiency in Zr–Hf separation when the initial concentration ratio of the elements ([Zr] 0 /[Hf] 0 ) ranged from 1200 to ca. 143,000

  7. Study of distribution of /sup 169/Yb, /sup 67/Ga and /sup 111/In in tumor tissue by macroautoradiography. Comparison between viable tumor tissue and necrotic tumor tissue

    Energy Technology Data Exchange (ETDEWEB)

    Ando, A; Sanada, S; Hiraki, T [Kanazawa Univ. (Japan). School of Paramedicine; Doishita, K; Ando, I

    1977-01-01

    The localization of /sup 169/Yb, /sup 67/Ga and /sup 111/In in tumor tissues was determined macroautoradiographically. /sup 169/Yb-citrate, /sup 67/Ga-citrate and /sup 111/In-citrate were injected intravenously into rats which had received subcutaneously transplantations of Yoshida sarcoma, and were injected intraperitoneally to the mice which had received subcutaneous transplantations of Ehrlich tumor. These animals were sacrificed 3, 24 and 48 hours after injection. The tumor tissues were frozen in n-hexane (-70/sup 0/C) cooled with dry ice-acetone. After this, the frozen tumor tissues were cut into thin serial sections (10 ..mu..m) in a cryostat (-20/sup 0/C). One of these sections was then placed on x-ray film, and this film was developed after exposure of several days. The next slice of each of these sections were stained using the hematoxylin and eosin. From the observations of these autoradiogram and H-E stained slice, the following results were obtained. Concentration of /sup 169/Yb, /sup 67/Ga and /sup 111/In was predominant in viable tumor tissue rather than in necrotic tumor tissue, regardless of time after administration. /sup 67/Ga and /sup 111/In were distributed uniformly in viable tumor tissue, but there was greater deposition of /sup 169/Yb in viable tumor tissue neighboring the necrotic tumor.

  8. Elastic moduli of normal and pathological human breast tissues: an inversion-technique-based investigation of 169 samples

    International Nuclear Information System (INIS)

    Samani, Abbas; Zubovits, Judit; Plewes, Donald

    2007-01-01

    Understanding and quantifying the mechanical properties of breast tissues has been a subject of interest for the past two decades. This has been motivated in part by interest in modelling soft tissue response for surgery planning and virtual-reality-based surgical training. Interpreting elastography images for diagnostic purposes also requires a sound understanding of normal and pathological tissue mechanical properties. Reliable data on tissue elastic properties are very limited and those which are available tend to be inconsistent, in part as a result of measurement methodology. We have developed specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples including fat and fibroglandular tissue as well as a range of benign and malignant breast tumour types. Results show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness. Fibrocystic disease and malignant tumours exhibited a 3-6-fold increased stiffness with high-grade invasive ductal carcinoma exhibiting up to a 13-fold increase in stiffness compared to fibrogalndular tissue. A statistical analysis showed that differences between the elastic modulus of the majority of those tissues were statistically significant. Implications for the specificity advantages of elastography are reviewed

  9. Elastic moduli of normal and pathological human breast tissues: an inversion-technique-based investigation of 169 samples

    Energy Technology Data Exchange (ETDEWEB)

    Samani, Abbas [Department of Medical Biophysics/Electrical and Computer Engineering, University of Western Ontario, Medical Sciences Building, London, Ontario, N6A 5C1 (Canada); Zubovits, Judit [Department of Anatomic Pathology, Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5 (Canada); Plewes, Donald [Department of Medical Biophysics, University of Toronto, 2075 Bayview Avenue, Toronto, Ontario, M4N 3M5 (Canada)

    2007-03-21

    Understanding and quantifying the mechanical properties of breast tissues has been a subject of interest for the past two decades. This has been motivated in part by interest in modelling soft tissue response for surgery planning and virtual-reality-based surgical training. Interpreting elastography images for diagnostic purposes also requires a sound understanding of normal and pathological tissue mechanical properties. Reliable data on tissue elastic properties are very limited and those which are available tend to be inconsistent, in part as a result of measurement methodology. We have developed specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples including fat and fibroglandular tissue as well as a range of benign and malignant breast tumour types. Results show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness. Fibrocystic disease and malignant tumours exhibited a 3-6-fold increased stiffness with high-grade invasive ductal carcinoma exhibiting up to a 13-fold increase in stiffness compared to fibrogalndular tissue. A statistical analysis showed that differences between the elastic modulus of the majority of those tissues were statistically significant. Implications for the specificity advantages of elastography are reviewed.

  10. Elastic moduli of normal and pathological human breast tissues: an inversion-technique-based investigation of 169 samples

    Science.gov (United States)

    Samani, Abbas; Zubovits, Judit; Plewes, Donald

    2007-03-01

    Understanding and quantifying the mechanical properties of breast tissues has been a subject of interest for the past two decades. This has been motivated in part by interest in modelling soft tissue response for surgery planning and virtual-reality-based surgical training. Interpreting elastography images for diagnostic purposes also requires a sound understanding of normal and pathological tissue mechanical properties. Reliable data on tissue elastic properties are very limited and those which are available tend to be inconsistent, in part as a result of measurement methodology. We have developed specialized techniques to measure tissue elasticity of breast normal tissues and tumour specimens and applied them to 169 fresh ex vivo breast tissue samples including fat and fibroglandular tissue as well as a range of benign and malignant breast tumour types. Results show that, under small deformation conditions, the elastic modulus of normal breast fat and fibroglandular tissues are similar while fibroadenomas were approximately twice the stiffness. Fibrocystic disease and malignant tumours exhibited a 3-6-fold increased stiffness with high-grade invasive ductal carcinoma exhibiting up to a 13-fold increase in stiffness compared to fibrogalndular tissue. A statistical analysis showed that differences between the elastic modulus of the majority of those tissues were statistically significant. Implications for the specificity advantages of elastography are reviewed.

  11. Experimental stress analysis and fatigue tests of five 24-in. NPS ANSI Standard B16.9 tees

    International Nuclear Information System (INIS)

    Moore, S.E.; Hayes, J.K.; Weed, R.A.

    1985-03-01

    Experimental stress analyses and low-cycle fatigue tests of five 24-in. nominal pipe size American National Standards Institute (ANSI) Standard B16.9 forged tees are documented in this report. The tees, designated as Oak Ridge National Laboratory tees T10, T11, T12, T13, and T16, were tested under subcontract at Combustion Engineering, Inc. in Chattanooga, Tennessee. Experimental stress analyses were conducted for 12 individual loadings on each tee. Each test model was instrumented with approx. 225, 1/8-in. three-gage, 45 0 strain rosettes on the inside and outside surfaces; and 6 linear variable differential transformers mounted on special nonflexible holding frames for measuring deflections and rotations of the pipe extensions. Following completion of the strain-gate tests, each tee was fatigue tested to failure with either a fully reversed displacement controlled in-plane bending moment on the branch or a cyclic internal pressure that ranged from a value slightly above zero to about 90% of the nominal yield pressure of the pipe extensions

  12. A spanish mineral of zirconium and hafnium. Separation of the two elements by liquid-liquid extraction, using tributyl phosphate as chelating agent; Beneficio de un mineral espanol de circonio-hafnio. Separacion de ambos elementos por extraccion liquido-liquido, empleando fosfato de tributilo como agente de quelacion

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz Sanchez, F; Cruz Castillo, F. de la; Fernandez Cellini, R

    1962-07-01

    The zirconium and Hafnium oxides are obtained from a Spanish mineral of zircon with an average contest of 55% in ZrO{sub 2}-HfO{sub 2}. An alkaline fusion to open the mineral, followed by a purification by crystallization as (Zr O-Hf O)Cl{sub 2} H{sub 2}O or as (Zr-Hf) (SO{sub 4}){sub 2}. 4H{sub 2}O, is used. A discussion of the best experimental conditions for opening the mineral and of the purification method is made. (Author) 45 refs.

  13. Effects of ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA) derivatives on penetration of /sup 169/Yb and /sup 144/Ce into the rat offspring

    Energy Technology Data Exchange (ETDEWEB)

    Baltrukiewicz, Z; Burakowski, T; Derecki, J

    1976-01-01

    Penetration of radioactive ytterbium-169 and cerium-144 into fetuses was determined at the end of pregnancy and penetration into suckling rats was studied during feeding with the milk of exposed mothers when EDTA or DTPA derivatives were being administered. Injection of ytterbium-169 as a complex with EDTA or DTPA or injection of Na/sub 2/Ca EDTA or Na/sub 3/Ca DTPA 1h after administration of cerium-144 to mothers reduced penetration of both radionuclides into offsprings in relation to the animals receiving no complex compounds. It was observed that the action of DTPA was stronger than that of EDTA. Passage of ytterbium with milk and across the placenta was greater than the passage of cerium.

  14. Effects of ethylenediaminetetraacetic acid (EDTA)and diethylenetriaminepentaacetic acid (DTPA) derivatives on penetration of ytterbium-169 and cerium-144 into the rat offspring

    Energy Technology Data Exchange (ETDEWEB)

    Baltrukiewicz, Z; Burakowski, T; Derecki, J [Wojskowy Inst. Higieny i Epidemiologii, Warsaw (Poland)

    1976-01-01

    Penetration of radioactive ytterbum-169 and cerium-144 into fetuses was determined at the end of pregnancy and penetration into the organism of suckling rats was studied during feeding with the milk of exposed mothers when EDTA or DTPA derivatives were being administered. Injection of ytterbum-169 as a complex with EDTA or DTPA or injection of Na/sub 2/Ca EDTA or Na/sub 3/Ca DTPA 1h after administration of cerium-144 to mothers reduced penetration of both radionuclides into offsprings in relation to the animals receiving no complex compounds. It was observed that the action of DTPA was stronger than that of EDTA. Passage of ytterbium with milk and across the placenta was greater than the passage of cerium.

  15. Measurements of the 169Tm(n,2n)168Tm cross section between 9.0 and 17.5 MeV

    Science.gov (United States)

    Soter, J.; Bhike, Megha; Krishichayan, Fnu; Finch, S. W.; Tornow, W.

    2016-09-01

    Measurements of the 169Tm(n,2n)168Tm cross section have been performed in 0.5 MeV intervals for neutron energies ranging from 9.0 MeV to 17.5 MeV in order to resolve discrepancies in the current literature data. The neutron activation technique was used with 90Zr and 197Au as monitor foils. After irradiation, de-excitation gamma rays were recorded off-line with High-Purity Germanium (HPGE) detectors in TUNL's Low-Background Counting Facility. In addition, data for the 169Tm(n,3n)167Tm reaction have also been obtained from 15.5 MeV to 17.5 MeV. The results of these measurements provide the basis for investigating properties of the interial confinement fusion plasma in deuterium-tritium (DT) capsules at the National Ignition Facility located at Lawrence Livermore National Laboratory.

  16. Cross-Section Measurement of the 169Tm(n,3n)167Tm Reaction and Constraining the Branching Ratio of 167Tm

    Science.gov (United States)

    Champine, Brian; Gooden, Matthew; Thomas, Keenan; Krishichayan, F.; Norman, Eric; Scielzo, Nick; Tonchev, Anton; Tornow, Werner

    2015-10-01

    The cross section of the 169Tm(n,3n)167Tm reaction has been measured from 17.5 to 21.5 MeV using activation technique. This energy region was chosen to resolve the two different trends of the previous (n,3n) cross section measurements on 169Tm. In addition, the branching ratio of the 207.8 keV γ-ray line stemming from electron capture of 167Tm was measured to be 0.419(16). The result of these measurements provide more accurate diagnostic estimation of the so called reaction-in-flight neutrons produced via the internal confinement fusion plasma in deuterium-tritium capsules at the National Ignition Facility.

  17. Structural Determination of the Broadly Reactive Anti-IGHV1-69 Anti-idiotypic Antibody G6 and Its Idiotope.

    Science.gov (United States)

    Avnir, Yuval; Prachanronarong, Kristina L; Zhang, Zhen; Hou, Shurong; Peterson, Eric C; Sui, Jianhua; Zayed, Hatem; Kurella, Vinodh B; McGuire, Andrew T; Stamatatos, Leonidas; Hilbert, Brendan J; Bohn, Markus-Frederik; Kowalik, Timothy F; Jensen, Jeffrey D; Finberg, Robert W; Wang, Jennifer P; Goodall, Margaret; Jefferis, Roy; Zhu, Quan; Kurt Yilmaz, Nese; Schiffer, Celia A; Marasco, Wayne A

    2017-12-12

    The heavy chain IGHV1-69 germline gene exhibits a high level of polymorphism and shows biased use in protective antibody (Ab) responses to infections and vaccines. It is also highly expressed in several B cell malignancies and autoimmune diseases. G6 is an anti-idiotypic monoclonal Ab that selectively binds to IGHV1-69 heavy chain germline gene 51p1 alleles that have been implicated in these Ab responses and disease processes. Here, we determine the co-crystal structure of humanized G6 (hG6.3) in complex with anti-influenza hemagglutinin stem-directed broadly neutralizing Ab D80. The core of the hG6.3 idiotope is a continuous string of CDR-H2 residues starting with M53 and ending with N58. G6 binding studies demonstrate the remarkable breadth of binding to 51p1 IGHV1-69 Abs with diverse CDR-H3, light chain, and antigen binding specificities. These studies detail the broad expression of the G6 cross-reactive idiotype (CRI) that further define its potential role in precision medicine. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  18. Structural Determination of the Broadly Reactive Anti-IGHV1-69 Anti-idiotypic Antibody G6 and Its Idiotope

    Directory of Open Access Journals (Sweden)

    Yuval Avnir

    2017-12-01

    Full Text Available The heavy chain IGHV1-69 germline gene exhibits a high level of polymorphism and shows biased use in protective antibody (Ab responses to infections and vaccines. It is also highly expressed in several B cell malignancies and autoimmune diseases. G6 is an anti-idiotypic monoclonal Ab that selectively binds to IGHV1-69 heavy chain germline gene 51p1 alleles that have been implicated in these Ab responses and disease processes. Here, we determine the co-crystal structure of humanized G6 (hG6.3 in complex with anti-influenza hemagglutinin stem-directed broadly neutralizing Ab D80. The core of the hG6.3 idiotope is a continuous string of CDR-H2 residues starting with M53 and ending with N58. G6 binding studies demonstrate the remarkable breadth of binding to 51p1 IGHV1-69 Abs with diverse CDR-H3, light chain, and antigen binding specificities. These studies detail the broad expression of the G6 cross-reactive idiotype (CRI that further define its potential role in precision medicine.

  19. Efficient UV-emitting X-ray phosphors: octahedral Zr(PO4)6 luminescence centers in potassium hafnium-zirconium phosphates K2Hf1-xZrx(PO4)2 and KHf2(1-x)Zr2x(PO4)3

    International Nuclear Information System (INIS)

    Torardi, C.C.; Miao, C.R.; Li, J.

    2003-01-01

    Potassium hafnium-zirconium phosphates, K 2 Hf 1-x Zr x (PO 4 ) 2 and KHf 2(1-x) Zr 2x (PO 4 ) 3 , are broad-band UV-emitting phosphors. At room temperature, they have emission peak maxima at approximately 322 and 305 nm, respectively, under 30 kV peak molybdenum X-ray excitation. Both phosphors demonstrate luminescence efficiencies that make them up to ∼60% as bright as commercially available CaWO 4 Hi-Plus. The solid-state and flux synthesis conditions, and X-ray excited UV luminescence of these two phosphors are discussed. Even though the two compounds have different atomic structures, they contain zirconium in the same active luminescence environment as that found in highly efficient UV-emitting BaHf 1-x Zr x (PO 4 ) 2 . All the three materials have hafnium and zirconium in octahedral coordination via oxygen-atom corner sharing with six separate PO 4 tetrahedra. This octahedral Zr(PO 4 ) 6 moiety appears to be an important structural element for efficient X-ray excited luminescence, as are the edge-sharing octahedral TaO 6 chains for tantalate emission

  20. Radial dose functions for 103Pd, 125I, 169Yb and 192Ir brachytherapy sources: an EGS4 Monte Carlo study

    International Nuclear Information System (INIS)

    Mainegra, E.

    2000-01-01

    Radial dose functions g(r) in water around 103 Pd, 125 I, 169 Yb and 192 Ir brachytherapy sources were estimated by means of the EGS4 simulation system and extensively compared with experimental as well as with theoretical results. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. Use of the point source approach produces reasonably accurate values of the radial dose function only at distances beyond 0.5 cm for 103 Pd sources. It is shown that binding corrections for Compton scattering have a negligible effect on radial dose function for 169 Yb and 192 Ir seeds and for 103 Pd seeds under 5.0 cm from the source centre and for the 125 I seed model 6702 under 8.0 cm. Beyond those limits there is an increasing influence of binding corrections on radial dose function for 103 Pd and 125 I sources. Results in solid water medium underestimate radial dose function for low-energy sources by as much as 6% for 103 Pd and 2.5% for 125 I already at 2 cm from source centre resulting in a direct underestimation of absolute dose rate values. It was found necessary to consider medium boundaries when comparing results for the radial dose function of 169 Yb and 192 Ir sources to avoid discrepancies due to the backscattering contribution in the phantom medium. Values of g(r) for all source types studied are presented. Uncertainties lie under 1% within one standard deviation. (author)

  1. Discrepancies between global nucleon-nucleon phase shifts and new data for n-p scattering at 16.9 MeV

    International Nuclear Information System (INIS)

    Tornow, W.; Lisowski, P.W.; Byrd, R.C.; Walter, R.L.

    1977-01-01

    Data for the analyzing power A/sub y/(theta) for n-p scattering at 16.9 MeV have been measured for the range from 50 to 145 0 (c.m.). Eleven values are reported to an accuracy of about +- 0.002, the highest overall precision ever obtained in any fast-neutron polarization experiment. Predictions based on phase-shift sets obtained from global analyses of nucleon-nucleon scattering disagree significantly with the new data. The data are sufficiently precise to show a dependence on the f-wave spin-orbit phase parameter

  2. IGHV1-69-Encoded Antibodies Expressed in Chronic Lymphocytic Leukemia React with Malondialdehyde-Acetaldehyde Adduct, an Immunodominant Oxidation-Specific Epitope

    DEFF Research Database (Denmark)

    Que, Xuchu; Widhopf Ii, George F; Amir, Shahzada

    2013-01-01

    The immunoglobulins expressed by chronic lymphocytic leukemia (CLL) B cells are highly restricted, suggesting they are selected for binding either self or foreign antigen. Of the immunoglobulin heavy-chain variable (IGHV) genes expressed in CLL, IGHV1-69 is the most common, and often is expressed...... are products of enhanced lipid peroxidation and a major target of innate natural antibodies. Specifically, CLL69C bound immunodominant OSE adducts termed MAA (malondialdehyde-acetaldehyde-adducts), which are found on apoptotic cells, inflammatory tissues, and atherosclerotic lesions. It also reacted...

  3. Overexpression of miR169o, an Overlapping microRNA in Response to Both Nitrogen Limitation and Bacterial Infection, Promotes Nitrogen Use Efficiency and Susceptibility to Bacterial Blight in Rice.

    Science.gov (United States)

    Chao, Yu; Chen, Yutong; Cao, Yaqian; Chen, Huamin; Wang, Jichun; Bi, Yong-Mei; Tian, Fang; Yang, Fenghuan; Rothstein, Steven J; Zhou, Xueping; He, Chenyang

    2018-03-15

    Limiting nitrogen (N) supply contributes to improved resistance to bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) in susceptible rice (Oryza sativa). To understand the regulatory roles of microRNAs in this phenomenon, sixty-three differentially-expressed overlapping miRNAs in response to Xoo infection and N-limitation stress in rice were identified through deep RNA-sequence and stem loop qRT-PCR. Among these, miR169o was further assessed as a typical overlapping miRNA through the overexpression of the miR169o primary gene. Osa-miR169o-OX plants were taller, and had more biomass accumulation with significantly increased nitrate and total amino acid contents in roots than wild type (WT). Transcript level assays showed that under different N supply conditions miR169o opposite regulated NRT2 which is reduced under normal N supply condition but remarkably induced under N limiting stress. On the other hand, osa-miR169o-OX plants also displayed increased disease lesion lengths and reduced transcriptional levels of defense gene (PR1b, PR10a, PR10b and PAL) compared with WT after inoculation with Xoo. In addition, miR169o impeded Xoo-mediated NRT transcription. Therefore, the overlapping miR169o contributes to increase N use efficiency and negatively regulates the resistance to bacterial blight in rice. Consistently, transient expression of NF-YAs in rice protoplast promoted the transcripts of PR genes and NRT2 genes, while reduced the transcripts of NRT1 genes. Our results provide novel and additional insights into the coordinated regulatory mechanisms of crosstalk between Xoo infection and N-deficiency responses in rice.

  4. Dose rate constants for 125I, 103Pd, 192Ir and 169Yb brachytherapy sources: an EGS4 Monte Carlo study

    International Nuclear Information System (INIS)

    Mainegra, Ernesto; Capote, Roberto; Lopez, Ernesto

    1998-01-01

    An exhaustive revision of dosimetry data for 192 Ir, 125 I, 103 Pd and 169 Yb brachytherapy sources has been performed by means of the EGS4 simulation system. The DLC-136/PHOTX cross section library, water molecular form factors, bound Compton scattering and Doppler broadening of the Compton-scattered photon energy were considered in the calculations. The absorbed dose rate per unit contained activity in a medium at 1 cm in water and air-kerma strength per unit contained activity for each seed model were calculated, allowing the dose rate constant (DRC) Λ to be estimated. The influence of the calibration procedure on source strength for low-energy brachytherapy seeds is discussed. Conversion factors for 125 I and 103 Pd seeds to obtain the dose rate in liquid water from the dose rate measured in a solid water phantom with a detector calibrated for dose to water were calculated. A theoretical estimate of the DRC for a 103 Pd model 200 seed equal to 0.669±0.002 cGy h -1 U -1 is obtained. Comparison of obtained DRCs with measured and calculated published results shows agreement within 1.5% for 192 Ir, 169 Yb and 125 I sources. (author)

  5. Side chain requirements for affinity and specificity in D5, an HIV-1 antibody derived from the VH1-69 germline segment.

    Science.gov (United States)

    Stewart, Alex; Harrison, Joseph S; Regula, Lauren K; Lai, Jonathan R

    2013-04-08

    Analysis of factors contributing to high affinity antibody-protein interactions provides insight into natural antibody evolution, and guides the design of antibodies with new or enhanced function. We previously studied the interaction between antibody D5 and its target, a designed protein based on HIV-1 gp41 known as 5-Helix, as a model system [Da Silva, G. F.; Harrison, J. S.; Lai, J. R., Biochemistry, 2010, 49, 5464-5472]. Antibody D5 represents an interesting case study because it is derived from the VH1-69 germline segment; this germline segment is characterized by a hydrophobic second heavy chain complementarity determining region (HCDR2) that constitutes the major functional paratope in D5 and several antibodies derived from the same progenitor. Here we explore side chain requirements for affinity and specificity in D5 using phage display. Two D5-based libraries were prepared that contained diversity in all three light chain complementarity determining regions (LCDRs 1-3), and in the third HCDR (HCDR3). The first library allowed residues to vary among a restricted set of six amino acids (Tyr/Ala/Asp/Ser/His/Pro; D5-Lib-I). The second library was designed based on a survey of existing VH1-69 antibody structures (D5-Lib-II). Both libraries were subjected to multiple rounds of selection against 5-Helix, and individual clones characterized. We found that selectants from D5-Lib-I generally had moderate affinity and specificity, while many clones from D5-Lib-II exhibited D5-like properties. Additional analysis of the D5-Lib-II functional population revealed position-specific biases for particular amino acids, many that differed from the identity of those side chains in D5. Together these results suggest that there is some permissiveness for alternative side chains in the LCDRs and HCDR3 of D5, but that replacement with a minimal set of residues is not tolerated in this scaffold for 5-Helix recognition. This work provides novel information about this high

  6. Passive behaviour of zirconium, hafnium and niobium

    International Nuclear Information System (INIS)

    Hornkjoel, S.

    1990-01-01

    The paper deals mainly with the results of stationary and transient polarization measurements together with capacitance measurements on passive electrodes of Zr, Hf and Nb over the entire pH-scale. The passive current densities are exstremely low, and essentially both pH and potential independent, exept for Nb at high pH. The extrapolated potential of zero inverse capacitance seems to be different from the extrapolated potential of zero film thickness for Zr and Hf, but not for Nb. The potential versus time curves at constant current show a downwards bending for Zr and Hf. It is shown that the pitting potentials of Zr and Hf are dependent of the concentration of halide ions and the type of halide ion, but not on pH. It is also shown that the pitting induction is second-order stimulated by chloride ions and first-order hindered by sulphate ions. Results from electron transfer reactions on passive niobium are reported. 9 refs

  7. Nanomechanical properties of hafnium nitride coating

    International Nuclear Information System (INIS)

    Chen Yao; Laha, Tapas; Balani, Kantesh; Agarwal, Arvind

    2008-01-01

    Nanomechanical properties of plasma-sprayed HfN coating with and without hot isostatic pressing (HIP) treatment were evaluated using nanoindentation. For HIPed HfN coating, the elastic modulus (E) and yield strength increase whereas the hardness (H), H/E ratio and fraction of the elastic work decrease. HIPed HfN coating shows a larger pile-up around the indent as compared to as-sprayed HfN. HIPing causes densification and improvement in inter-splat bonding which subsequently lead to increase in nanomechanical properties

  8. High-pressure torsion of hafnium

    International Nuclear Information System (INIS)

    Edalati, Kaveh; Horita, Zenji; Mine, Yoji

    2010-01-01

    Pure Hf (99.99%) is processed by high-pressure torsion (HPT) under pressures of 4 and 30 GPa to form an ultrafine-grained structure with a gain size of ∼180 nm. X-ray diffraction analysis shows that, unlike Ti and Zr, no ω phase formation is detected after HPT processing even under a pressure of 30 GPa. A hydride formation is detected after straining at the pressure of 4 GPa. The hydride phase decomposes either by application of a higher pressure as 30 GPa or by unloading for prolong time after HPT processing. Microhardness, tensile and bending tests show that a high hardness (360 Hv) and an appreciable ductility (8%) as well as high tensile and bending strength (1.15 and 2.75 GPa, respectively) are achieved following the high-pressure torsion.

  9. MPT0B169, a New Antitubulin Agent, Inhibits Bcr-Abl Expression and Induces Mitochondrion-Mediated Apoptosis in Nonresistant and Imatinib-Resistant Chronic Myeloid Leukemia Cells.

    Directory of Open Access Journals (Sweden)

    Shuit-Mun Wong

    Full Text Available Chronic myeloid leukemia (CML is a clonal disorder of hematopoietic stem/progenitor cells that is caused by the Bcr-Abl oncoprotein. Clinical resistance to the Bcr-Abl inhibitor imatinib is a critical problem in treating CML. This study investigated the antitumor effect and mechanism of MPT0B169, a new antitubulin agent, in K562 CML cells and their derived imatinib-resistant cells, IMR2 and IMR3. IMR2 and IMR3 cells showed complete resistance to imatinib-induced growth inhibition and apoptosis. Resistance involved ERK1/2 overactivation and MDR1 overexpression. MPT0B169 inhibited the growth of K562, IMR2, and IMR3 cells in a dose- and time-dependent manner. MPT0B169 substantially inhibited the mRNA and protein levels of Bcr-Abl, followed by its downstream pathways including Akt, ERK1/2, and STAT3 in these cells. MPT0B169 treatment resulted in a decrease in the polymer form of tubulin according to Western blot analysis. It triggered cell cycle arrest at the G2/M phase before apoptosis, which was related to the upregulation of the mitotic marker MPM2 and the cyclin B1 level, and a change in the phosphorylation of Cdk1. MPT0B169 induced apoptosis in nonresistant and imatinib-resistant cells via a mitochondrion-mediated caspase pathway. Further study showed that the agent led to a decrease in the antiapoptotic proteins Bcl-2, Bcl-xL, and Mcl-1 and an increase in the apoptotic protein Bax. Taken together, our results suggest that MPT0B169 might be a promising agent for overcoming imatinib resistance in CML cells.

  10. Dosimetric characterization of the GammaClip™{sup 169}Yb low dose rate permanent implant brachytherapy source for the treatment of nonsmall cell lung cancer postwedge resection

    Energy Technology Data Exchange (ETDEWEB)

    Currier, Blake [Medical Physics, University of Massachusetts Lowell, 1 University Avenue, Lowell, Massachusetts 01854 (United States); Munro, John J. III [Source Production and Equipment Co., Inc., 113 Teal Street, St. Rose, Louisiana 70087 (United States); Medich, David C. [Department of Physics, Worcester Polytechnic Institute, 100 Institute Road, Worcester, Massachusetts 01609 (United States)

    2013-08-15

    Purpose: A novel {sup 169}Yb low dose rate permanent implant brachytherapy source, the GammaClip™, was developed by Source Production and Equipment Co. (New Orleans, LA) which is designed similar to a surgical staple while delivering therapeutic radiation. In this report, the brachytherapy source was characterized in terms of “Dose calculation for photon-emitting brachytherapy sources with average energy higher than 50 keV: Report of the AAPM and ESTRO” by Perez-Calatayud et al. [Med. Phys. 39, 2904–2929 (2012)] using the updated AAPM Task Group Report No. 43 formalism.Methods: Monte Carlo calculations were performed using Monte Carlo N-Particle 5, version 1.6 in water and air, the in-air photon spectrum filtered to remove photon energies below 10 keV in accordance with TG-43U1 recommendations and previously reviewed {sup 169}Yb energy cutoff levels [D. C. Medich, M. A. Tries, and J. M. Munro, “Monte Carlo characterization of an Ytterbium-169 high dose rate brachytherapy source with analysis of statistical uncertainty,” Med. Phys. 33, 163–172 (2006)]. TG-43U1 dosimetric data, including S{sub K}, D-dot (r,θ), Λ, g{sub L}(r), F(r, θ), φ{sub an}(r), and φ{sub an} were calculated along with their statistical uncertainties. Since the source is not axially symmetric, an additional set of calculations were performed to assess the resulting axial anisotropy.Results: The brachytherapy source's dose rate constant was calculated to be (1.22 ± 0.03) cGy h{sup −1} U{sup −1}. The uncertainty in the dose to water calculations, D-dot (r,θ), was determined to be 2.5%, dominated by the uncertainties in the cross sections. The anisotropy constant, φ{sub an}, was calculated to be 0.960 ± 0.011 and was obtained by integrating the anisotropy factor between 1 and 10 cm using a weighting factor proportional to r{sup −2}. The radial dose function was calculated at distances between 0.5 and 12 cm, with a maximum value of 1.20 at 5.15 ± 0.03 cm. Radial dose

  11. Measurement of the 169Tm (n ,3 n ) 167Tm cross section and the associated branching ratios in the decay of 167Tm

    Science.gov (United States)

    Champine, B.; Gooden, M. E.; Krishichayan, Norman, E. B.; Scielzo, N. D.; Stoyer, M. A.; Thomas, K. J.; Tonchev, A. P.; Tornow, W.; Wang, B. S.

    2016-01-01

    The cross section for the 169Tm(n ,3 n ) 167Tm reaction was measured from 17 to 22 MeV using quasimonoenergetic neutrons produced by the 2H(d ,n ) 3He reaction. This energy range was studied to resolve the discrepancy between previous (n ,3 n ) cross-section measurements. In addition, the absolute γ -ray branching ratios following the electron-capture decay of 167Tm were measured. These results provide more reliable nuclear data for an important diagnostic that is used at the National Ignition Facility to estimate the yield of reaction-in-flight neutrons produced via the inertial-confinement-fusion plasma in deuterium-tritium capsules.

  12. Fast neutron capture cross sections of /sup 169/Tm, /sup 191/Ir, /sup 193/Ir, and /sup 175/Lu for 3 less than or equal to E/sub n/ less than or equal to 2000 keV

    Energy Technology Data Exchange (ETDEWEB)

    Macklin, R.L.; Drake, D.M.; Malanify, J.J.

    1977-11-01

    Fast neutron capture cross sections of /sup 169/Tm, /sup 191/Ir, /sup 193/Ir, and /sup 175/Lu, and the /sup 6/Li(n,..cap alpha..)/sup 3/H cross sections to which they are normalized are presented in tabular form for neutron energies between 3 and 2000 keV.

  13. Susceptibility of 169 USA300 methicillin-resistant Staphylococcus aureus isolates to two copper-based biocides, CuAL42 and CuWB50.

    Science.gov (United States)

    Luna, Vicki Ann; Hall, Tony J; King, Debbie S; Cannons, Andrew C

    2010-05-01

    To test the activity of two copper-based biocides, CuAL42 and CuWB50, and benzalkonium chloride against 169 isolates of methicillin-resistant Staphylococcus aureus (MRSA) pulsotype USA300, a virulent, multiply resistant, widespread clone in the USA. Tests including MIC, MBC and time-kill studies were performed multiple times. The MIC range, MIC(50) and MIC(90) (0.59-18.75, 4.69 and 4.69 ppm, respectively) and the MBC range, MBC(50) and MBC(90) (1.17-18.75, 4.69 and 9.38 ppm, respectively) for CuAL42 were identical with those obtained with CuWB50, except that the MBC range for CuWB50 was wider (0.59-37.5 ppm). In time-kill studies, a 6 log(10) reduction of cfu was achieved within 1 h (150 ppm) and 0.5 h (300 ppm) for CuAL42, and 1.5 h (150 ppm) and 0.75 h (300 ppm) for CuWB50. Both copper-based biocides can effectively kill USA300 MRSA and may facilitate the eradication of the organism from healthcare settings.

  14. Comparative decay analysis of 179Re* and 189Au* formed in the reactions 20Ne+159Tb, 169Tm with Elab=8 MeV/A

    International Nuclear Information System (INIS)

    Manpreet Kaur; Singh, BirBikram

    2016-01-01

    The heavy ion induced reactions lead to the formation of composite systems, which subsequently decay because of high excitation energy and angular momentum. The study of decaying composite system facilitates to explore the number of nuclear characteristics and the reaction dynamics. The medium mass composite systems 164 Yb*, 176,182,188,196 Pt* and 200,202 Pb* have been studied successfully within the framework of dynamical cluster decay model (DCM). These studies show the emission of light particles, LP (or evaporation residues, ER), intermediate mass fragments, IMF, heavy mass fragments, HMF and symmetric fragments, SF along with signatures of quasi-fission, qf, process in their decay path. The decay of medium mass composite system 179 Re* has also been studied within DCM. In the present work, we investigate the comparative decay of two medium mass composite systems 179 Re* and 189 Au formed in the reactions with same projectile ( 20 Ne) having same E lab (or same E/A) on two different targets 159 Tb and 169 Tm, for which the experimental data is available

  15. Processing of thyrotropin-releasing hormone prohormone (pro-TRH) generates a biologically active peptide, prepro-TRH-(160-169), which regulates TRH-induced thyrotropin secretion

    International Nuclear Information System (INIS)

    Bulant, M.; Vaudry, H.; Roussel, J.P.; Astier, H.; Nicolas, P.

    1990-01-01

    Rat thyrotropin-releasing hormone (TRH) prohormone contains five copies of the TRH progenitor sequence Gln-His-Pro-Gly linked together by connecting sequences whose biological activity is unknown. Both the predicted connecting peptide prepro-TRH-(160-169) (Ps4) and TRH are predominant storage forms of TRH precursor-related peptides in the hypothalamus. To determine whether Ps4 is co-released with TRH, rat median eminence slices were perfused in vitro. Infusion of depolarizing concentrations of KCl induced stimulation of release of Ps4- and TRH-like immunoreactivity. The possible effect of Ps4 on thyrotropin release was investigated in vitro using quartered anterior pituitaries. Infusion of Ps4 alone had no effect on thyrotropin secretion but potentiated TRH-induced thyrotropin release in a dose-dependent manner. In addition, the occurrence of specific binding sites for 125 I-labeled Tyr-Ps4 in the distal lobe of the pituitary was demonstrated by binding analysis and autoradiographic localization. These findings indicate that these two peptides that arise from a single multifunctional precursor, the TRH prohormone, act in a coordinate manner on the same target cells to promote hormonal secretion. These data suggest that differential processing of the TRH prohormone may have the potential to modulate the biological activity of TRH

  16. SU-E-T-359: Emulation of Yb-169 Gamma-Ray Spectrum Using Metal-Filtered 250 KVp X-Rays for Pre-Clinical Studies of Gold Nanoparticle-Aided Radiation Therapy

    International Nuclear Information System (INIS)

    Reynoso, F; Cho, S

    2015-01-01

    Purpose: To develop an external beam surrogate of the Yb-169 brachytherapy source applying a filter-based spectrum modulation technique to 250 kVp x-rays. In-vitro/vivo studies performed with the modulated 250 kVp beam will help gauge the benefits of implementing gold nanoparticle-aided radiotherapy with the Yb-169 source. Methods: A previously validated MCNP5 model of the Phillips RT-250 orthovoltage unit was used to obtain the percentage depth dose (PDD) and filtered photon spectra for a variety of filtration and irradiation conditions. Photon spectra were obtained using the average flux F4 tally in air right after all collimation. A 30 x 30 x 30 cm 3 water phantom was used to compute the PDD along the central axis (CAX) under the standards conditions of a 10 x 10 cm 2 field size at 50 cm SSD. Cylindrical cells of 4 cm in diameter and the energy deposition F6 tally were used along the CAX to score the doses down to 20 cm depth. The number of particle history was set to 2 x 10 8 in order to keep the relative uncertainty within each cell < 0.3%. The secondary electron spectrum within a gold-loaded tissue due to each photon spectrum was also calculated using EGSnrc and compared with that due to Yb-169 gamma rays. Results: Under the practical constraints for the spectrum modulation task, 250 kVp x-rays filtered by a 0.25 mm Erbium (Er) foil produced the best match with Yb-169 gamma rays, in terms of PDD and, more importantly, secondary electron spectrum. Conclusion: Modulation of 250kVp x-ray spectrum by an Er-filter was found effective in emulating the gamma ray spectrum of Yb-169. Possible benefits as predicted from the current MC model such as enhanced radiosensitization with the Er-filtered beam (as a surrogate of Yb-169) was confirmed with a separate in-vitro study. Supported by DOD/PCRP grant W81XWH-12-1-0198

  17. TU-H-CAMPUS-TeP3-04: Probing the Dose Enhancement Due to a Clinically-Relevant Concentration of Gold Nanoparticles and Yb-169 Gamma Rays Using PRESAGE Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Cho, J [UT MD Anderson Cancer Center, Houston, TX (United States); Oklahoma State University, Stillwater, OK (United States); Alqathami, M; Cho, S [UT MD Anderson Cancer Center, Houston, TX (United States); Reynoso, F [UT MD Anderson Cancer Center, Houston, TX (United States); Washington University School of Medicine, St. Louis, MO (United States)

    2016-06-15

    Purpose: To probe physical evidences of the dose enhancement due to a low/clinically-relevant concentration of gold nanoparticles (GNPs) and Yb-169 gamma rays using PRESAGE dosimeters. Methods: A PRESAGE cuvette was placed at approximately 2 mm above the plane containing three novel Yb-169 brachytherapy seeds (3.2, 3.2, and 5.3 mCi each). Two types of PRESAGE dosimeters were used – plain PRESAGEs (controls) and PRESAGEs loaded with 0.02 wt. % of GNPs (GNP-PRESAGEs). Each PRESAGE dosimeter was irradiated with different time durations (0 to 24 hours) to deliver 0, 4, 8, 16 and 24 Gy of dose. For a reference/comparison, both types of PRESAGEs were also irradiated using 250 kVp x-rays with/without Er-filter to deliver 0, 3, 10, and 30 Gy of dose. Er-filter was used to emulate Yb-169 spectrum using 250 kVp x-rays. The absorption spectra of PRESAGEs were measured using a UV spectrophotometer and used to determine the corresponding optical densities (ODs). Results: GNP-PRESAGEs exposed to Yb-169 sources showed ∼65% increase in ODs compared with controls. When exposed to Er-filtered and unfiltered 250 kVp x-rays, they produced smaller increases in ODs, ∼41% and ∼37%, respectively. There was a linear relationship between ODs and delivered doses with a goodness-of-fit (R2) greater than 0.99. Conclusion: A notable increase in the ODs (∼65%) was observed for GNP-PRESAGEs irradiated by Yb-169 gamma rays. Considering the observed OD increases, it was highly likely that Yb-169 gamma rays were more effective than both Er-filtered and unfiltered 250 kVp x-rays, in terms of producing the dose enhancement. Due to several unknown factors (e.g., possible difference in the dose response of GNP-PRESAGEs vs. PRESAGEs), however, a further investigations is necessary to establish the feasibility of quantifying the exact amount of macroscopic or microscopic/local GNP-mediated dose enhancement using PRESAGE or similar volumetric dosimeters. Supported by DOD/PCRP grant W81XWH-12

  18. Separation of zirconium and hafnium; Separation du zirconium et de l'hafnium

    Energy Technology Data Exchange (ETDEWEB)

    Saint-James, D [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    This account is more chemical than metallurgical in character. The reason for this is that so-called 'nuclear metal' must fulfil standards of purity which only chemical processes can attain. This paper must therefore be considered as a preliminary study, from which the metallurgists can form an idea of the treatments leading to the production of the metal. (author) [French] Cet expose a un caractere chimique plutot que metallurgique. La raison en est que le metal dit 'nucleaire' a des exigences de purete que seuls des processus chimiques peuvent satisfaire. Il faut donc considerer cet expose comme un preliminaire, permettant de donner une idee aux metallurgistes des traitements qui aboutissent a l'elaboration du metal. (auteur)

  19. Vegetation - Point Reyes [ds169

    Data.gov (United States)

    California Natural Resource Agency — The National Park Service (NPS), in conjunction with the Biological Resources Division (BRD) of the U.S. Geological Survey (USGS), has implemented a program to...

  20. 166 - 169_Yakubu and Babatunde

    African Journals Online (AJOL)

    User

    Yakubu, I.* and Babatunde, B. H.. Department of Geography Bayero University, PMB 3011, Kano. *Corresponding author: ibyakubu2006@yahoo.com. ABSTRACT. Soil nutrient decline has become a major issue of concern to researchers in the semi-arid region of. Nigeria. This condition is further exacerbated by worsening ...

  1. Absorbed dose profiles for 32P, 90Y, 188Re, 177Lu, 51Cr, 153Sm and 169Er: radionuclides used in radiosynoviortheses treatment

    International Nuclear Information System (INIS)

    Torres, M.; Ayra, E.; Albuerne, O.; Delgado, M.

    2008-01-01

    The remarkable advances in the design and synthesis of radiopharmaceuticals has created the opportunity of generating new agents for the treatment of radiosynoviortheses (RSV) which exhibit a minimum leakage from the synovial joint reducing, this way, the non desired absorbed doses to non target organs such as liver, spleen, kidney. Nowadays, the variety of beta emitters used in RSV ranges between 0.34 MeV - 0.33 mm penetration in tissue ( 169 Er) and 2.27 MeV - 3.6 mm penetration in tissue ( 90 Y). The half life of these isotopes goes from 2.3 hours ( 165 Dy) to 27.8 days ( 51 Cr). The selection criterion on which radionuclide should be used, in modern clinics, depends on which joints are to be treated. Thus, the smaller the joint, the lowest should be the energy of the beta emitted and the penetration in soft tissue of these particles. This leads to the use of fixed radionuclides and doses for each kind of joint. In the Isotopes Centre, we've been carrying on studies for the development of radiopharmaceuticals for the radiosynoviortheses treatment and focused our attention in the following radionuclides: 32 P, 90 Y, 188 Re, 177 Lu, 51 Cr, 153 Sm and 169 Er. The main objective of this paper was to obtain the absorbed dose profiles for radionuclides of frequent or potential use in radiosynoviortheses. These profiles reveal the absorbed dose imparted per unit activity of injected radionuclide (Gy/h*MBq) in the synovial membrane and the articular cartilage. The researched radionuclides were those previously mentioned. Also were calculated the therapeutic range of each radionuclides in synovial tissue. The therapeutic range is defined as the deepness at which the absorbed dose equals the 10 % of the maximum dose deposited in the synovial surface. This range determines the synovial thickness that can be sufficiently irradiated and thus successfully treated. The synovial membrane model consisted on a cylinder with the source uniformly distributed in its volume. This

  2. Primary cutaneous B-cell lymphoma is associated with somatically hypermutated immunoglobulin variable genes and frequent use of VH1-69 and VH4-59 segments.

    Science.gov (United States)

    Perez, M; Pacchiarotti, A; Frontani, M; Pescarmona, E; Caprini, E; Lombardo, G A; Russo, G; Faraggiana, T

    2010-03-01

    Accurate assessment of the somatic mutational status of clonal immunoglobulin variable region (IgV) genes is relevant in elucidating tumour cell origin in B-cell lymphoma; virgin B cells bear unmutated IgV genes, while germinal centre and postfollicular B cells carry mutated IgV genes. Furthermore, biases in the IgV repertoire and distribution pattern of somatic mutations indicate a possible antigen role in the pathogenesis of B-cell malignancies. This work investigates the cellular origin and antigenic selection in primary cutaneous B-cell lymphoma (PCBCL). We analysed the nucleotide sequence of clonal IgV heavy-chain gene (IgVH) rearrangements in 51 cases of PCBCL (25 follicle centre, 19 marginal zone and seven diffuse large B-cell lymphoma, leg-type) and compared IgVH sequences with their closest germline segment in the GenBank database. Molecular data were then correlated with histopathological features. We showed that all but one of the 51 IgVH sequences analysed exhibited extensive somatic hypermutations. The detected mutation rate ranged from 1.6% to 21%, with a median rate of 9.8% and was independent of PCBCL histotype. Calculation of antigen-selection pressure showed that 39% of the mutated IgVH genes displayed a number of replacement mutations and silent mutations in a pattern consistent with antigenic selection. Furthermore, two segments, VH1-69 (12%) and VH4-59 (14%), were preferentially used in our case series. Data indicate that neoplastic B cells of PBCBL have experienced germinal centre reaction and also suggest that the involvement of IgVH genes is not entirely random in PCBCL and that common antigen epitopes could be pathologically relevant in cutaneous lymphomagenesis.

  3. α and p emission before, during, and after fission of the fusion nucleus 169Ta: Nuclear deformation, field emission, and nuclear shadow

    International Nuclear Information System (INIS)

    Brucker, A.

    1986-01-01

    In the asymmetric system 318 MeV 28 Si + 141 Pr the angular and energy distributions of α particles and protons were measured in coincidence with fission fragments. Identification and separation of the sources of sequential emission before (CN) and after (F) fission of the compound-nucleus 169 Ta yields following multiplicities: M CN α =0.38±0.04, M CN p =0.6±0.15; M F α =0.16±0.03, M F p =0.54±0.15. Measurement of the cross sections δ ER =(608±81) mb and δ F =(679±159) mb for residual nucleus formation respectively fission fixes the mean angular momentum for fission l F =(94±7)ℎ and the maximal angular momentum l F,max =(110±10)ℎ (sharp cut-off model). From the angular correlation relative to the spin direction of the compound-nucleus an anisotropy parameter of A α =6.7±0.8 and A p =1.3±0.2 for α respectively proton emission from the compound-nucleus is measured, and by means of the semiclassical model of Dossing a quadrupole deformation parameter of the compound-nucleus of vertical strokeδvertical stroke=0.43±0.05 consistent within the uncertainties of the analysis determined. Apart from pre-equilibrium emission under small angles to the beam significant deviations from sequential emission are observed only in the α emission and detailedly studied by means of angular correlation and energy spectra: (I) an strong nuclear shadowing of the fragment emission of 1/7 of its sequential value in a narrow angular range (≅40 0 (FWHM)) in the direction of the detected fission fragment. From this a mean lifetime of the compound nucleus τ CN =(140-240).10 -22 s is obtained. (II) A perpendicularly to the scission axis strongly pronounced surplus M SC α =(1.7±0.4).10 -2 and an observed deficit of equal magnitude in direction of the scission axis. (orig./HSI) [de

  4. Utility of radioisotopic filtration markers in chronic renal insufficiency: Simultaneous comparison of 125I-iothalamate, 169Yb-DTPA, 99mTc-DTPA, and inulin. The Modification of Diet in Renal Disease Study

    International Nuclear Information System (INIS)

    Perrone, R.D.; Steinman, T.I.; Beck, G.J.; Skibinski, C.I.; Royal, H.D.; Lawlor, M.; Hunsicker, L.G.

    1990-01-01

    Assessment of glomerular filtration rate (GFR) with inulin is cumbersome and time-consuming. Radioisotopic filtration markers have been studied as filtration markers because they can be used without continuous intravenous (IV) infusion and because analysis is relatively simple. Although the clearances of 99mTc-DTPA, 169Yb-DTPA, and 125I-iothalamate have each been compared with inulin, rarely has the comparability of radioisotopic filtration markers been directly evaluated in the same subject. To this purpose, we determined the renal clearance of inulin administered by continuous infusion and the above radioisotopic filtration markers administered as bolus injections, simultaneously in four subjects with normal renal function and 16 subjects with renal insufficiency. Subjects were studied twice in order to assess within-study and between-study variability. Unlabeled iothalamate was infused during the second half of each study to assess its effect on clearances. We found that renal clearance of 125I-iothalamate and 169Yb-DTPA significantly exceeded clearance of inulin in patients with renal insufficiency, but only by several mL.min-1.1.73m-2. Overestimation of inulin clearance by radioisotopic filtration markers was found in all normal subjects. No differences between markers were found in the coefficient of variation of clearances either between periods on a given study day (within-day variability) or between the two study days (between-day variability). The true test variability between days did not correlate with within-test variability. We conclude that the renal clearance of 99mTc-DTPA, 169Yb-DTPA, or 125I-iothalamate administered as a single IV or subcutaneous injection can be used to accurately measure GFR in subjects with renal insufficiency; use of the single injection technique may overestimate GFR in normal subjects

  5. Production techniques and quality control of sealed radioactive sources of palladium-103, iodine-125, iridium-192 and ytterbium-169. Final report of a coordinated research project 2001-2005

    International Nuclear Information System (INIS)

    2006-06-01

    Radioisotopes have been used extensively for many years for several medical and industrial applications either in the form of an open source or encapsulated in an appropriate metallic container (sealed source). The design and technology for the preparation of radioactive sealed sources is an area of continuous development to satisfy an ever increasing demand for a larger variety of shapes, sizes, type of radioisotope and levels of radioactivity required for newer and specialized applications. In medicine, sealed sources using the radioisotopes of 125 I, 192 Ir and 103 Pd are commonly used for brachytherapy for the treatment of malignant diseases, and for bone density measurements. In industry, they are widely used for non-destructive testing (NDT), radiation processing, 'on-line' process control systems and on-line elemental analysis of mineral resources. Some well-known examples of such sources are 60 Co for industrial nucleonic gauges, 192 Ir sources for industrial radiography, 241 Am sources for smoke detectors and chemical analysers and, more recently, 169 Yb for NDT measurements of thin metallic tubes and plates. The current challenges in development include the production of miniature size sources with a high level of activity, a high degree of uniformity in the distribution of the radioactivity and the highest degree of safety, requiring stringent quality control methods. The IAEA has been promoting and supporting activities designed to increase the utilization of radiation and radioisotopes in several areas. In particular, in view of the proven benefits of, and an increasing demand for radioactive sealed sources for medical and industrial applications, upon the recommendation of several experts, a Coordinated Research Project (CRP) on Development of Radioactive Sources for Emerging Therapeutic and Industrial Applications was begun in 2002. The aim of the CRP was the optimization and testing of procedures and methods for the fabrication and quality control

  6. Compton polarimetry detection of small circularly and linearly polarized impurities in Mössbauer 8.4 keV (3/2-1/2) M1 γ-transition of {sup 169}Tm

    Energy Technology Data Exchange (ETDEWEB)

    Tsinoev, V.; Cherepanov, V.; Shuvalov, V.; Balysh, A.; Gabbasov, R., E-mail: graul@list.ru [National Research Centre “Kurchatov Institute” (Russian Federation)

    2016-12-15

    The arrangement of an experiment to detect the P−odd and P, T−odd polarized part of the Mössbauer ({sup +}3/2– {sup +}1/2) gamma transition of a deformed {sup 169}Tm nucleus with an energy of 8.4 keV by Compton polarimetry is discussed. Tm {sub 2}O{sub 3} single crystal with a quadrupolarly split Mössbauer spectrum is proposed as a resonance polarizer. A Be-scatterer-based Compton polarimeter and a synchronously detecting system will be used to measure the P-odd circular polarization P{sub C}and P, T-odd linear polarization P{sub L}.The expected accuracy of measuring the relative magnitude of the P, T-odd contribution is about 1% of the magnitude of usual weak nucleon–nucleon interaction.

  7. SU-F-T-15: Evaluation of 192Ir, 60Co and 169Yb Sources for High Dose Rate Prostate Brachytherapy Inverse Planning Using An Interior Point Constraint Generation Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Mok Tsze Chung, E; Aleman, D [University of Toronto, Toronto, Ontario (Canada); Safigholi, H; Nicolae, A; Davidson, M; Ravi, A; Song, W [Odette Cancer Centre, Sunnybrook Health Sciences Centre, Toronto, Ontario (Canada)

    2016-06-15

    Purpose: The effectiveness of using a combination of three sources, {sup 60}Co, {sup 192}Ir and {sup 169}Yb, is analyzed. Different combinations are compared against a single {sup 192}Ir source on prostate cancer cases. A novel inverse planning interior point algorithm is developed in-house to generate the treatment plans. Methods: Thirteen prostate cancer patients are separated into two groups: Group A includes eight patients with the prostate as target volume, while group B consists of four patients with a boost nodule inside the prostate that is assigned 150% of the prescription dose. The mean target volume is 35.7±9.3cc and 30.6±8.5cc for groups A and B, respectively. All patients are treated with each source individually, then with paired sources, and finally with all three sources. To compare the results, boost volume V150 and D90, urethra Dmax and D10, and rectum Dmax and V80 are evaluated. For fair comparison, all plans are normalized to a uniform V100=100. Results: Overall, double- and triple-source plans were better than single-source plans. The triple-source plans resulted in an average decrease of 21.7% and 1.5% in urethra Dmax and D10, respectively, and 8.0% and 0.8% in rectum Dmax and V80, respectively, for group A. For group B, boost volume V150 and D90 increased by 4.7% and 3.0%, respectively, while keeping similar dose delivered to the urethra and rectum. {sup 60}Co and {sup 192}Ir produced better plans than their counterparts in the double-source category, whereas {sup 60}Co produced more favorable results than the remaining individual sources. Conclusion: This study demonstrates the potential advantage of using a combination of two or three sources, reflected in dose reduction to organs-at-risk and more conformal dose to the target. three sources, reflected in dose reduction to organs-at-risk and more conformal dose to the target. Our results show that {sup 60}Co, {sup 192}Ir and {sup 169}Yb produce the best plans when used simultaneously and

  8. Hafnium isotope ratios of nine GSJ reference samples

    International Nuclear Information System (INIS)

    Hanyu, Takeshi; Nakai, Shun'ichi; Tatsuta, Riichiro

    2005-01-01

    176 Hf/ 177 Hf ratios of nine geochemical reference rocks from the Geological Survey of Japan, together with BIR-1 and BCR-2, were determined using multi-collector inductively coupled plasma mass spectrometry. Our data for BIR-1, BCR-2 and JB-1 are in agreement with those previously reported, demonstrating the appropriateness of the chemical procedure and isotopic measurement employed in this study. The reference rocks have a wide range of 176 Hf/ 177 Hf covering the field defined by various volcanic rocks, such as mid-ocean ridge basalts, ocean island basalts, and subduction related volcanic rocks. They are therefore suitable as rock standards for Hf isotope measurement of geological samples. (author)

  9. Control of the hafnium content in Co samples by SSMS

    International Nuclear Information System (INIS)

    Lukaszew, R.A.; Cretella, R.F.

    1989-01-01

    The production of 60 Co requires a strict control of the chemical composition of the cobalt before irradiation in order to avoid the activation of some undesirable elements and to constrain the presence of slow neutron poisons. A methodology by SSMS for the survey analysis of metallic Co prior to its irradiation in the nuclear reactor at Embalse (Cdba., Argentina) is described. The low detection limit attained for Hf (below 0.5 ppm) is outlined. The results obtained for some other impurities without a standard reference are compared with atomic emission spectrographic data and show satisfactory agreement. (orig.)

  10. Production of long-lived hafnium isomers in reactor irradiations

    Czech Academy of Sciences Publication Activity Database

    Adam, Jindřich

    -, - (2006), s. 48-56 ISSN 1574-1818 R&D Projects: GA MŠk 1P04LA213 Institutional research plan: CEZ:AV0Z10480505 Keywords : production * Hf Subject RIV: BG - Nuclear, Atomic and Molecular Physics, Colliders

  11. Hafnium Isotopic Variations in Central Atlantic Intraplate Volcanism

    Science.gov (United States)

    Geldmacher, J.; Hanan, B. B.; Hoernle, K.; Blichert-Toft, J.

    2008-12-01

    Although one of the geochemically best investigated volcanic regions on Earth, almost no Hf isotopic data have been published from the broad belt of intraplate seamounts and islands in the East Atlantic between 25° and 36° N. This study presents 176Hf/177Hf ratios from 61 representative samples from the Canary, Selvagen and Madeira Islands and nearby large seamounts, encompassing the full range of different evolutionary stages and geochemical endmembers. The majority of samples have mafic, mainly basaltic compositions with Mg-numbers within or near the range of magmas in equilibrium with mantle olivine (68-75). No correlation was found between Mg-number and 176Hf/177Hf ratios in the data set. In comparison to observed Nd isotope variations published for this volcanic province (6 ɛNd units), 176Hf/177Hf ratios span a larger range (14 ɛHf units). Samples from the Madeira archipelago have the most radiogenic compositions (176Hf/177Hfm= 0.283132-0.283335), widely overlapping the field for central Atlantic N-MORB. They form a relatively narrow, elongated trend (stretching over >6 ɛHf units) between a radiogenic MORB-like endmember and a composition located on the Nd-Hf mantle array. In contrast, all Canary Islands samples plot below the mantle array (176Hf/177Hfm = 0.282943-0.283067) and, despite being from an archipelago that stretches over a much larger geographic area, form a much denser cluster with less compositional variation (~4 ɛHf units). All samples from the seamounts NE of the Canaries, proposed to belong to the same Canary hotspot track (e.g. Geldmacher et al., 2001, JVGR 111; Geldmacher et al., 2005, EPSL 237), fall within the Hf isotopic range of this cluster. The cluster largely overlaps the composition of the proposed common mantle endmember 'C' (Hanan and Graham, 1996, Science 272) but spans a space between a more radiogenic (depleted) composition and a HIMU-type endmember. Although samples of Seine and Unicorn seamounts, attributed to the Madeira hotspot track, show less radiogenic Hf and Nd isotope ratios than Madeira, their isotopic compositions lie along an extension of the Madeira trend in plots of Hf versus Sr, Nd, Pb isotopes. The new Hf isotope ratios confirm the existence of at least two geochemically distinct volcanic provinces (Canary and Madeira) in the East Atlantic as previously proposed.

  12. Electric field cycling behavior of ferroelectric hafnium oxide.

    Science.gov (United States)

    Schenk, Tony; Schroeder, Uwe; Pešić, Milan; Popovici, Mihaela; Pershin, Yuriy V; Mikolajick, Thomas

    2014-11-26

    HfO2 based ferroelectrics are lead-free, simple binary oxides with nonperovskite structure and low permittivity. They just recently started attracting attention of theoretical groups in the fields of ferroelectric memories and electrostatic supercapacitors. A modified approach of harmonic analysis is introduced for temperature-dependent studies of the field cycling behavior and the underlying defect mechanisms. Activation energies for wake-up and fatigue are extracted. Notably, all values are about 100 meV, which is 1 order of magnitude lower than for conventional ferroelectrics like lead zirconate titanate (PZT). This difference is mainly atttributed to the one to two orders of magnitude higher electric fields used for cycling and to the different surface to volume ratios between the 10 nm thin films in this study and the bulk samples of former measurements or simulations. Moreover, a new, analog-like split-up effect of switching peaks by field cycling is discovered and is explained by a network model based on memcapacitive behavior as a result of defect redistribution.

  13. Elastic and Thermodynamic Properties of Zirconium and Hafnium ...

    Indian Academy of Sciences (India)

    65

    Here Rh3V is chosen as the parent binary compound and the doping ..... Grüneisen parameter ζ [44] are two key quantities in solid state problems due to their .... The authors wish to thank DRDO (ER & IPR), New Delhi for the financial support.

  14. Electronic structure of hafnium: A Compton profile study

    Indian Academy of Sciences (India)

    To extract the true Compton profile from the raw data, the raw data were cor- rected for ... For the present sample and experimental conditions, the contribution of .... are in better agreement with the simple renormalized free atom calculations for.

  15. Hafnium(IV) complexation with oxalate at variable temperatures

    Energy Technology Data Exchange (ETDEWEB)

    Friend, Mitchell T.; Wall, Nathalie A. [Washington State Univ., Pullmanm, WA (United States). Dept. of Chemistry

    2017-08-01

    Appropriate management of fission products in the reprocessing of spent nuclear fuel (SNF) is crucial in developing advanced reprocessing schemes. The addition of aqueous phase complexing agents can prevent the co-extraction of these fission products. A solvent extraction technique was used to study the complexation of Hf(IV) - an analog to fission product Zr(IV) - with oxalate at 15, 25, and 35 C in 1 M HClO{sub 4} utilizing a {sup 175+181}Hf radiotracer. The mechanism of the solvent extraction system of 10{sup -5} M Hf(IV) in 1 M HClO{sub 4} to thenoyltrifluoroacetone (TTA) in toluene demonstrated a 4{sup th}-power dependence in both TTA and H{sup +}, with Hf(TTA){sub 4} the only extractable species. The equilibrium constant for the extraction of Hf(TTA){sub 4} was determined to be log K{sub ex}=7.67±0.07 (25±1 C, 1 M HClO{sub 4}). The addition of oxalate to the aqueous phase decreased the distribution ratio, indicating aqueous Hf(IV)-oxalate complex formation. Polynomial fits to the distribution data identified the formation of Hf(ox){sup 2+} and Hf(ox){sub 2(aq)} and their stability constants were measured at 15, 25, and 35 C in 1 M HClO{sub 4}. van't Hoff analysis was used to calculate Δ{sub r}G, Δ{sub r}H, and Δ{sub r}S for these species. Stability constants were observed to increase at higher temperature, an indication that Hf(IV)-oxalate complexation is endothermic and driven by entropy.

  16. Iron(3) chloride interaction with zirconium and hafnium tetrahalides

    International Nuclear Information System (INIS)

    Berdonosov, S.; Kharisov, B.I.; Melikhov, I.V.

    1988-01-01

    Using FeCl 3 , labelled with 36 Cl radionuclide, it is shown, that during reaction between FeCl 3 and MCl (M=Zr, Hf) resulting in Cl 2 splitting-off and FeMCl 6 formation, chlorine is splitted from MCl 4 . From the analysis of Moessbauer spectra and visual observations it follows, that reaction between FeCl 3 and MBr 4 starts at 50 deg C temperature, whereupon bromine and FeMCl 3 Br 3 compounds are formed. Considerations about the possible mechanism of reactions between FeCl 3 and MCl 4 or MBr 4 are proposed

  17. Cesium hafnium chloride scintillator coupled with an avalanche photodiode photodetector

    Czech Academy of Sciences Publication Activity Database

    Kurosawa, S.; Kodama, S.; Yokota, Y.; Horiai, T.; Yamaji, A.; Shoji, Y.; Král, Robert; Pejchal, Jan; Ohashi, Y.; Kamada, K.; Nikl, Martin; Yoshikawa, A.

    2017-01-01

    Roč. 12, Feb (2017), s. 1-8, č. článku C02042. ISSN 1748-0221 Grant - others:AV ČR(CZ) JSPS-17-18 Program:Bilaterální spolupráce Institutional support: RVO:68378271 Keywords : gamma detectors * scintillators and scintillating fibres * scintillators * scintillation and light emission processes Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 1.220, year: 2016

  18. Spectroscopy of very neutron-deficient hafnium and tungsten isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Dracoulis, G D; Fabricius, B; Davidson, P M [Australian National Univ., Canberra, ACT (Australia). Dept. of Nuclear Physics; Macchiavelli, A O; Oliviera, J; Burde, J; Stephens, F; Deleplanque, M A [Lawrence Berkeley Lab., CA (United States)

    1992-08-01

    Level schemes of the very neutron-deficient isotopes {sup 158}Hf and {sup 162}W have been identified, and that for {sup 164}W extended. Alignment of the H{sub 9/2} neutrons is suggested. (author). 12 refs., 7 figs.

  19. Neutron Detection Utilizing Gadolinium Doped Hafnium Oxide Films

    National Research Council Canada - National Science Library

    Blasy, Bryan D

    2008-01-01

    ... retains monoclinic local symmetery for all levels of doping. Current as a function of voltage experiments identified the films as having poor diode characteristics with high leakage current in the forward bias region...

  20. Crystal structures of superconducting sodium intercalates of hafnium nitride chloride

    International Nuclear Information System (INIS)

    Oro-Sole, J.; Frontera, C.; Beltran-Porter, D.; Lebedev, O.I.; Van Tendeloo, G.; Fuertes, A.

    2006-01-01

    Sodium intercalation compounds of HfNCl have been prepared at room temperature in naphtyl sodium solutions in tetrahydrofuran and their crystal structure has been investigated by Rietveld refinement using X-ray powder diffraction data and high-resolution electron microscopy. The structure of two intercalates with space group R3-bar m and lattice parameters a=3.58131(6)A, c=57.752(6)A, and a=3.58791(8)A, c=29.6785(17)A is reported, corresponding to the stages 2 and 1, respectively, of Na x HfNCl. For the stage 2 phase an ordered model is presented, showing two crystallographically independent [HfNCl] units with an alternation of the Hf-Hf interlayer distance along the c-axis, according with the occupation by sodium atoms of one out of two van der Waals gaps. Both stages 1 and 2 phases are superconducting with critical temperatures between 20 and 24K, they coexist in different samples with proportions depending on the synthesis conditions, and show a variation in c spacing that can be correlated with the sodium stoichiometry. High-resolution electron microscopy images of the host and intercalated samples show bending of the HfNCl bilayers as well as stacking faults in some regions, which coexist in the same crystal with ordered domains

  1. Elastic and thermodynamic properties of zirconium- and hafnium ...

    Indian Academy of Sciences (India)

    2018-02-02

    Feb 2, 2018 ... ties. The volume optimization curves (both LDA and GGA) for binary Rh3V, Rh3Zr and Rh3Hf compounds are shown in ... the strength of covalent bonding of the given material. ..... Bulk modulus is correlated with binding energy or cohesive energy of atoms, since it is a measure of average atomic bond.

  2. Identification of a novel PMS2 alteration c.505C>G (R169G) in trans with a PMS2 pathogenic mutation in a patient with constitutional mismatch repair deficiency.

    Science.gov (United States)

    Mork, Maureen E; Borras, Ester; Taggart, Melissa W; Cuddy, Amanda; Bannon, Sarah A; You, Y Nancy; Lynch, Patrick M; Ramirez, Pedro T; Rodriguez-Bigas, Miguel A; Vilar, Eduardo

    2016-10-01

    Constitutional mismatch repair deficiency syndrome (CMMRD) is a rare autosomal recessive predisposition to colorectal polyposis and other malignancies, often childhood-onset, that is caused by biallelic inheritance of mutations in the same mismatch repair gene. Here, we describe a patient with a clinical diagnosis of CMMRD based on colorectal polyposis and young-onset endometrial cancer who was identified to have two alterations in trans in PMS2: one known pathogenic mutation (c.1831insA; p.Ile611Asnfs*2) and one novel variant of uncertain significance (c.505C>G; p.Arg169Glu), a missense alteration. We describe the clinical and molecular features in the patient harboring this novel alteration c.505C>G, who meets clinical criteria for CMMRD and exhibits molecular evidence supporting a diagnosis of CMMRD. Although experimental validation is needed to confirm its pathogenicity, PMS2 c.505C>G likely has functional consequences that contributes to our patient's phenotype based on the patient's clinical presentation, tumor studies, and bioinformatics analysis.

  3. 32 CFR 169a.21 - Reporting requirements.

    Science.gov (United States)

    2010-07-01

    ... Accounting Office (GAO), OSD, and others. The CAMIS is divided into two parts. Part I contains data on CAs... activity by the most efficient Government organization; a statement indicating the life of the contract... contractors during the preceding fiscal year, include the estimated number of work years for the in-house...

  4. 32 CFR 169.5 - Responsibilities.

    Science.gov (United States)

    2010-07-01

    ... employee displaced because of a contract entered into with a contractor for performance of a commercial... decide how best to use the CA program to accomplish the mission. Minimally, as prescribed by P.L. 100-180... comparison of those commercial activities selected for conversion to contractor performance under OMB...

  5. 29 CFR 1910.169 - Air receivers.

    Science.gov (United States)

    2010-07-01

    ... and equipment used on transportation vehicles such as steam railroad cars, electric railway cars, and... therein are easily accessible. Under no circumstances shall an air receiver be buried underground or...

  6. 21 CFR 169.140 - Mayonnaise.

    Science.gov (United States)

    2010-04-01

    ... ingredients. (1) Any vinegar or any vinegar diluted with water to an acidity, calculated as acetic acid, of..., any blend of two or more vinegars is considered to be a vinegar. (2) Lemon juice and/or lime juice in any appropriate form, which may be diluted with water to an acidity, calculated as citric acid, of not...

  7. 21 CFR 169.150 - Salad dressing.

    Science.gov (United States)

    2010-04-01

    ... ingredients. (1) Any vinegar or any vinegar diluted with water, or any such vinegar or diluted vinegar mixed... purpose of this paragraph, any blend of two or more vinegars is considered to be a vinegar. (2) Lemon juice and/or lime juice in any appropriate form, which may be diluted with water. (c) Egg yolk...

  8. 46 CFR 169.686 - Shore power.

    Science.gov (United States)

    2010-10-01

    ... requirements: (a) A shore power connection box or receptacle and a cable connecting this box or receptacle to... power cable must be provided with a disconnect means located on or near the main distribution panel...

  9. 169 DIFFERENT RITUAL SYMBOLS IN IGBO TRADITIONAL ...

    African Journals Online (AJOL)

    (Moslem) fixed feasts in relation to the appearance of the moon. It is very important because it ... this states that “Before an Igbo man carves Ikenga or Ofo, or both, he first intends imagines, .... Ofo and Cross. Gestural and Physical Movement.

  10. Search Results | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Nurses are the largest single group of health professionals who influence the ... Existing intellectual property regimes protect individual rights for the purpose of ... a vehicle that allows teachers to develop scientific content aimed at simplifying ...

  11. 32 CFR 169a.15 - Special considerations.

    Science.gov (United States)

    2010-07-01

    ... labor organization accorded exclusive recognition under 5 U.S.C. 7111, consultation with representatives... supported by current, accurate, complete information and be readily available for the independent reviewing... purchased services. (H) Overhead costs shall be computed only when such costs will not continue in the event...

  12. 26 CFR 1.169-2 - Definitions.

    Science.gov (United States)

    2010-04-01

    ... facility which (i) is used to abate or control water or atmospheric pollution or contamination by removing... serves no function other than the abatement or control of water or atmospheric pollution. (ii) For... atmospheric pollution if, for example, equipment is acquired for the abatement or control of water or...

  13. 32 CFR 169a.17 - Solicitation considerations.

    Science.gov (United States)

    2010-07-01

    ... occurs within the first year of contract performance, the following procedures apply: (1) If the... Government that might result from making more than one award. The decision to group commercial activities... economies of administering multifunction vs. single function contracts, including cost risks associated with...

  14. Publications | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC works with developing-country researchers and institutions to build local capacity ... Openness and quality in Asian distance education : sub-project 5; ... of Arts in Nursing (MAN) students enrolled in their first clinical course entitled ...

  15. Reference: 169 [Arabidopsis Phenome Database[Archive

    Lifescience Database Archive (English)

    Full Text Available e M et al. 2005 Mar. Plant J. 41(5):744-54. The recessive Arabidopsis thalianafumonisin B1-resistant (fbr6) ...opment and sensitivity to fumonisin B1. 5 744-54 15703061 2005 Mar The Plant journal Liang Xinwen|Nekl Emily R|Stiers Justin J|Stone Julie M

  16. 23_163 - 169_Mohammed_Psidium

    African Journals Online (AJOL)

    pc

    S analysis. The TLC chromatogram revealed 3, 4 and 6 bands respectiv ... range of medicinal plant parts is used for extrac raw drugs .... plant extracts. RESULT AND DISCUSSION. The result of the thin layer chromatography of the aqueous, ethanolic and chloroform extract of P. guajava is presented in (Table 1). According ...

  17. Search Results | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Unemployment is one of the main economic, social and political problems facing ... through simple resource-based activities: oil, minerals, tourism and labour migrati. Project. -. Creating an International Network of Democracy Builders.

  18. 40 CFR 169.1 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... of causes beyond the control and without the fault or negligence of such person. Such causes may... the control and without the fault or negligence of said person. (e) Producer. The term “producer...

  19. 169 CONTENT NORMATIVITY AND THE INTERDEPENDENCY OF ...

    African Journals Online (AJOL)

    Tracie1

    INTERDEPENDENCY OF BELIEF AND DESIRE. Seyed Ali ... attriЛutions are constitutively normative since “it is a condition on ... the concept of Лelief is constitutively normative since .... according to the definition (14) the concept of content.

  20. 46 CFR 169.107 - Definitions.

    Science.gov (United States)

    2010-10-01

    ... circumstances. Headquarters means the Office of the Commandant, United States Coast Guard, Washington, DC 20593... exclusively for the purposes of sailing instruction. Ship's Company means the officers and crew of a sailing...

  1. 32 CFR 169.3 - Definitions.

    Science.gov (United States)

    2010-07-01

    ... determining whether or not a cost comparison will be conducted. Commercial Source. A business or other non... employees and comparing it, in accordance with the requirements in DoD Instruction 4100.33 to the cost of... resources on Federal Property; direction of intelligence and counterintelligence operations; and regulation...

  2. 32 CFR 169a.3 - Definitions.

    Science.gov (United States)

    2010-07-01

    .... A business or other non-Federal activity located in the United States, its territories and... process of developing an estimate of the cost of performance of a CA by DoD employees and comparing it, in... intelligence and counterintelligence operations; and regulation of industry and commerce, including food and...

  3. 46 CFR 169.317 - Accommodations.

    Science.gov (United States)

    2010-10-01

    ... vessel than a vertical plane located at 5 percent of the vessel's loadline length abaft the forward side... are to be odorproof. (c) All quarters are to be properly drained, odorproof and protected from heat... reasonably smooth surface. There must be a minimum vertical distance between bunks of 24 inches. (f) A means...

  4. 25 CFR 169.23 - Railroads.

    Science.gov (United States)

    2010-04-01

    ..., individually owned and Government-owned land, except in the State of Oklahoma, for railroads, station buildings... proposed railroad is parallel to, and within 10 miles of, a railroad already built or in course of..., to construct and maintain passenger and freight stations for each Government townsite, and to permit...

  5. 25 CFR 169.1 - Definitions.

    Science.gov (United States)

    2010-04-01

    ... against alienation or encumbrance. (c) Tribe means a tribe, band, nation, community, group or pueblo of... alienation or encumbrance, and includes such land reserved for Indian Bureau administrative purposes. The...

  6. 32 CFR 169a.4 - Policy.

    Science.gov (United States)

    2010-07-01

    ... assistance to employees whose Federal jobs are eliminated through CA competitions. (h) Permit interim-in... Department of Defense OFFICE OF THE SECRETARY OF DEFENSE DEFENSE CONTRACTING COMMERCIAL ACTIVITIES PROGRAM... shall consider the overall DoD mission and the defense objective of maintaining readiness and...

  7. 46 CFR 169.567 - Portable extinguishers.

    Science.gov (United States)

    2010-10-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS... permit the use of any approved fire extinguishers, including semiportable extinguishers, which provide equivalent fire protection. (c) All portable fire extinguishers installed on vessels must be of an approved...

  8. Development of multi-dimensional thermal-hydraulic modeling using mixing factors for wire wrapped fuel pin bundles in fast reactors. Validation through a sodium experiment of 169-pin fuel subassembly

    International Nuclear Information System (INIS)

    Nishimura, M.; Kamide, H.; Miyake, Y.

    1997-04-01

    Temperature distributions in fuel subassemblies of fast reactors interactively affect heat transfer from center to outer region of the core (inter-subassembly heat transfer) and cooling capability of an inter-wrapper flow, as well as maximum cladding temperature. The prediction of temperature distribution in the subassembly is, therefore one of the important issues for the reactor safety assessment. Mixing factors were applied to multi-dimensional thermal-hydraulic code AQUA to enhance the predictive capability of simulating maximum cladding temperature in the fuel subassemblies. In the previous studies, this analytical method had been validated through the calculations of the sodium experiments using driver subassembly test rig PLANDTL-DHX with 37-pin bundle and blanket subassembly test rig CCTL-CFR with 61-pin bundle. The error of the analyses were comparable to the error of instrumentation's. Thus the modeling was capable of predicting thermal-hydraulic field in the middle scale subassemblies. Before the application to large scale real subassemblies with more than 217 pins, accuracy of the analytical method have to be inspected through calculations of sodium tests in a large scale pin bundle. Therefore, computations were performed on sodium experiments in the relatively large 169-pin subassembly which had heater pins sparsely within the bundle. The analysis succeeded to predict the experimental temperature distributions. The errors of temperature rise from inlet to maximum values were reduced to half magnitudes by using mixing factors, compared to those of analyses without mixing factors. Thus the modeling is capable of predicting the large scale real subassemblies. (author)

  9. Measurements of the total cross-section difference ΔδL (np) at 1.39, 1.69, 1.89 and 1.99 GeV

    International Nuclear Information System (INIS)

    Sharov, V.I.; Anishchenko, N.G.; Antonenko, V.G.

    2004-01-01

    New accurate results of the neutron-proton spin-dependent total cross-section difference Δδ L (np) at the neutron beam kinetic energies of 1.39, 1.69, 1.89 and 1.99 GeV are presented. In general these data complete the measurements of energy dependence of Δδ L (np) over the Dubna Synchrophasotron energy region. The quasi-monochromatic neutron beam was produced by break-up of extracted polarized deuterons. The deuteron (and hence neutron) polarization direction was flipped every accelerator burst. The neutron vertical direction of polarization was rotated onto the neutron beam direction and longitudinally (L) polarized neutrons were transmitted through the large proton L-polarized target. The longitudinal target polarization direction was inverted after 1-2 days of measurements. Four different combinations of the beam and target parallel and antiparallel polarization directions, both oriented along the neutron beam momentum, were used at each energy. A fast decrease of - Δδ L (np) with increasing energy above 1.1 GeV and a structure in the energy dependence around 1.8 GeV, first observed from our previous data, seem to be well revealed. The new results are also compared with model predictions and with phase shift analysis fits. The Δδ L quantities for isosinglet state I = 0, deduced from the measured Δδ L (np) values and known Δδ L (pp) data, are also given. The results of the measurements of unpolarized total cross sections δ 0tot (np) at 1.3, 1.4 and 1.5 GeV and δ 0tot (nC) at 1.4 and 1.5 GeV are presented as well. These data were obtained using the same apparatus and high intensity unpolarized deuteron beams extracted either from the Synchrophasotron, or from the Nuclotron

  10. Determination of Glomerular Filtration Rate with {sup 51}Cr, {sup 58}Co, {sup 114m}In, {sup 115m}In and {sup 169}Yb- Labelled EDTA and DTPA Complexes

    Energy Technology Data Exchange (ETDEWEB)

    Molnar, Gy.; Pal, I.; Stuetzel, M.; Jaky, L. [Third Department of Medicine, University Medical School and Institute of Isotopes of the Hungarian Academy of Sciences, Budapest (Hungary)

    1971-02-15

    Some metal complexes are suitable for determination of the glomerular filtration rate (GFR). A series of labelled EDTA and DTPA complexes have been produced during the last two years by the Isotope Institute of the Hungarian Academy of Sciences. The common property of EDTA and DTPA complexes is their great stability, which is a major advantage over the iodinated compounds. We have demonstrated that none of the complexes used by us combine with plasma proteins or penetrate into the red blood cells. There is evidence that EDTA and DTPA leave the body exclusively by way of glomerular filtration. The results of more than 600 cases are presented. {sup 169}Yb EDTA was used in 315, {sup 51}Cr EDTA in 126, {sup 114m}In EDTA in 83, {sup 58}Co DTPA in 72 and {sup 115m}In EDTA in 28 cases for determination of GFR. The injected activity was 0.3 -4.0 {mu}Ci/kg body weight. In most cases the result has been compared with the 24-h endogenous creatine clearance, and in 50 cases with inulin clearance also. In general the single-shot method was used. Blood samples were taken about the first and the second hour after injection of the isotope. A formula is given for calculating GFR. In a few cases we administered the isotope in the same way as inulin (priming dose and constant plasma concentration sustained by an infusion pump). Our results show that the single-shot method is a very suitable one in routine clinical practice either in states of normal or reduced kidney function. Using the single-shot method for GFR determination is especially important in those cases where the collection of urine is impossible without using a catheter, which always entails the risk of infection. Results are reliable even in disorders of the urinary tract. During or after the procedure no side effects could be observed. (author)

  11. Measurement of the np total cross section difference Δ σ L(np) at 1.39, 1.69, 1.89 and 1.99 GeV

    Science.gov (United States)

    Sharov, V. I.; Anischenko, N. G.; Antonenko, V. G.; Averichev, S. A.; Azhgirey, L. S.; Bartenev, V. D.; Bazhanov, N. A.; Belyaev, A. A.; Blinov, N. A.; Borisov, N. S.; Borzakov, S. B.; Borzunov, Yu T.; Bushuev, Yu P.; Chernenko, L. P.; Chernykh, E. V.; Chumakov, V. F.; Dolgii, S. A.; Fedorov, A. N.; Fimushkin, V. V.; Finger, M.; Finger, M.; Golovanov, L. B.; Gurevich, G. M.; Janata, A.; Kirillov, A. D.; Kolomiets, V. G.; Komogorov, E. V.; Kovalenko, A. D.; Kovalev, A. I.; Krasnov, V. A.; Krstonoshich, P.; Kuzmin, E. S.; Ladygin, V. P.; Lazarev, A. B.; Lehar, F.; de Lesquen, A.; Liburg, M. Yu; Livanov, A. N.; Lukhanin, A. A.; Maniakov, P. K.; Matafonov, V. N.; Matyushevsky, E. A.; Moroz, V. D.; Morozov, A. A.; Neganov, A. B.; Nikolaevsky, G. P.; Nomofilov, A. A.; Panteleev, Tz; Pilipenko, Yu K.; Pisarev, I. L.; Plis, Yu A.; Polunin, Yu P.; Prokofiev, A. N.; Prytkov, V. Yu; Rukoyatkin, P. A.; Schedrov, V. A.; Schevelev, O. N.; Shilov, S. N.; Shindin, R. A.; Slunečka, M.; Slunečková, V.; Starikov, A. Yu; Stoletov, G. D.; Strunov, L. N.; Svetov, A. L.; Usov, Yu A.; Vasiliev, T.; Volkov, V. I.; Vorobiev, E. I.; Yudin, I. P.; Zaitsev, I. V.; Zhdanov, A. A.; Zhmyrov, V. N.

    2004-09-01

    New accurate results of the neutron-proton spin-dependent total cross section difference Δσ_L(np) at the neutron beam kinetic energies 1.39, 1.69, 1.89 and 1.99 GeV are presented. Measurements were carried out in 2001 at the Synchrophasotron of the Veksler and Baldin Laboratory of High Energies of the Joint Institute for Nuclear Research. A quasi-monochromatic neutron beam was produced by break-up of extracted polarized deuterons. The deuteron (and hence neutron) polarization direction was flipped every accelerator burst. The vertical neutron polarization direction was rotated onto the neutron beam direction and longitudinally (L) polarized neutrons were transmitted through a large proton L-polarized target. The target polarization vector was inverted after 1-2 days of measurements. The data were recorded for four different combinations of the beam and target parallel and antiparallel polarization directions at each energy. A fast decrease of Δσ_L(np) with increasing energy above 1.1 GeV was confirmed. The structure in the Δσ_L(np) energy dependence around 1.8 GeV, first observed from our previous data, seems to be well pronounced. The new results are also compared with model predictions and with phase shift analysis fits. The Δσ_L quantities for isosinglet state I = 0, deduced from the measured Δσ_L(np) values and the known Δσ_L(pp) data, are also given. The results were completed by the measurements of unpolarized total cross sections σ_{0tot}(np) at 1.3, 1.4 and 1.5 GeV and σ_{0tot}(nC) at 1.4 and 1.5 GeV. These data were obtained using the same apparatus and high intensity unpolarized deuteron beams were extracted either from the Synchrophasotron, or from the Nuclotron.

  12. Measurements of the Total-Cross-Section Difference ΔσL(np) at 1.39, 1.69, 1.89, and 1.99 GeV

    International Nuclear Information System (INIS)

    Sharov, V.I.; Anischenko, N.G.; Averichev, S.A.; Bartenev, V.D.; Blinov, N.A.; Borzunov, Yu.T.; Chernykh, E.V.; Chumakov, V.F.; Dolgii, S.A.; Fimushkin, V.V.; Golovanov, L.B.; Kirillov, A.D.; Komogorov, E.V.; Kovalenko, A.D.; Krasnov, V.A.; Ladygin, V.P.; Liburg, M.Yu.; Livanov, A.N.; Maniakov, P.K.; Matyushevsky, E.A.

    2005-01-01

    New accurate data of the neutron-proton spin-dependent total-cross-section difference Δσ L (np) at the neutron-beam kinetic energies 1.39, 1.69, 1.89, and 1.99 GeV are presented. In general, these data complete the measurements of energy dependence of Δσ L (np) over the Dubna Synchrophasotron energy region. Measurements were carried out at the Synchrophasotron of the Veksler and Baldin Laboratory of High Energies of the Joint Institute for Nuclear Research. The quasi-monochromatic neutron beam was produced by breakup of extracted polarized deuterons. The deuteron (and hence neutron) polarization direction was flipped every accelerator burst. The initial transverse (with respect to beam momentum) neutron polarization was changed to a longitudinal one and longitudinally polarized neutrons were transmitted through the large proton longitudinally polarized target. The target polarization direction was inverted after one to two days of measurements. Four different combinations of the beam and target parallel and antiparallel polarization directions, both oriented along the neutron-beam momentum, were used at each energy. A fast decrease in -Δσ L (np) with increasing energy above 1.1 GeV and a structure in the energy dependence around 1.8 GeV, first observed from our previous data, seem to be well revealed. The new results are also compared with model predictions and with phase-shift analysis fits. The Δσ L quantities for isosinglet state I = 0, deduced from the measured Δσ L (np) values and known Δσ L (pp) data, are also given. The results of the measurements of unpolarized total cross sections σ 0tot (np) at 1.3, 1.4, and 1.5 GeV and σ 0tot (nC) at 1.4 and 1.5 GeV are presented as well. These data were obtained using the same apparatus and high-intensity unpolarized deuteron beams extracted either from the Synchrophasotron or from the Nuclotron

  13. Separation of magnesium from magnesium chloride and zirconium and/or hafnium subchlorides in the production of zirconium and/or hafnium sponge metal

    International Nuclear Information System (INIS)

    Abodishish, H.A.M.; Adams, R.J.; Kearl, S.R.

    1992-01-01

    This patent describes the producing of a refractory metal wherein a sponge refractory metal is produced as an intermediate product by the use of magnesium with the incidental production of magnesium chloride, and wherein residual magnesium is separated from the magnesium chloride and from refractory metal to a vacuum distillation step which fractionally distills the magnesium, the magnesium chloride, and the metal sub-chlorides; the steps of: recovering fractionally distilled vapors of magnesium chloride and metal sub-chlorides from a sponge refractory metal; separately condensing the vapors as separately recovered; and recycling the separately recovered magnesium at a purity of at least about 96%

  14. Measurement of the 209Bi(n ,4 n )206Bi and 169Tm(n ,3 n )167Tm cross sections between 23.5 and 30.5 MeV relevant to reaction-in-flight neutron studies at the National Ignition Facility

    Science.gov (United States)

    Gooden, M. E.; Bredeweg, T. A.; Champine, B.; Combs, D. C.; Finch, S.; Hayes-Sterbenz, A.; Henry, E.; Krishichayan, Rundberg, R.; Tornow, W.; Wilhelmy, J.; Yeamans, C.

    2017-08-01

    At the National Ignition Facility, experiments are being performed to measure charged-particle stopping powers in the previously unexplored warm dense plasma regime. These measurements are done using reaction-in-flight (RIF) neutrons from an inertial confinement fusion system. RIF neutrons are produced with a continuum of energies up to 30 MeV. By making activation measurements utilizing threshold reactions for neutrons in the energy range of 15 169Tm(n ,3 n )167Tm reaction has been used. However, in an effort to provide a secondary complimentary measurement, efforts are underway to make use of the 209Bi(n ,4 n )206Bi reaction, with a threshold of 22.5 MeV. The cross sections were measured at the 10 MV tandem Van De Graaff accelerator at the Triangle Universities Nuclear Laboratory with quasimonoenergetic neutrons between 23.5 and 30.5 MeV, where few previous measurements have been made. Cross-section data are compared to calculations and other available measurements.

  15. Dicty_cDB: AFG169 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available --LMKNLN*twllihhhc*krnrqryqrkislrrprl*s*nanccliisprkiiritrr sshhhr**tfplprsplptitlrygiswyprnhl*lhhem*c*yp*rf...rnrqryqrkislrrprl*s*nanccliisprkiiritrr sshhhr**tfplprsplptitlrygiswyprnhl*lhhem*c*yp*rfirqcrliwwyny vpryc*s

  16. 46 CFR 169.115 - Incorporation by reference.

    Science.gov (United States)

    2010-10-01

    ...—Design and Construction” (1981) A-1-78—“Marine LPG—Liquefied Petroleum Gas Systems” A-3-70—“Recommended Practices and Standards Covering Galley Stoves” A-22-78—“Marine CNG—Compressed Natural Gas Systems” (2...—“Pleasure and Commercial Motor Craft,” Chapter 6 (1980) 306—“Control of Gas Hazards on Vessels” (1980) 70...

  17. 46 CFR 169.682 - Distribution and circuit loads.

    Science.gov (United States)

    2010-10-01

    ... the rating of the overcurrent protective device, computed using the greater of— (1) The lamp sizes to be installed; or (2) 50 watts per outlet. (b) Circuits supplying electrical discharge lamps must be...

  18. 46 CFR 169.323 - Furniture and furnishings.

    Science.gov (United States)

    2010-10-01

    ... of fire resistant materials. (b) Existing solid wooden furniture may be retained on existing vessels. (c) Draperies must be fabricated of fire resistant fabrics. (d) Rugs and carpets must be of wool or other material having equivalent fire resistant qualities. (e) Trash receptacles must be constructed of...

  19. What we do | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Cost of Conflicts in the Common Market for Eastern and Southern Africa ... impact of HIV/AIDS on agriculture and food production in rural sub-Saharan Africa. ... Middle East, Central Asia, Far East Asia, South Asia, Peru, South Africa. PROJECT ...

  20. 46 CFR 169.529 - Description of lifeboat equipment.

    Science.gov (United States)

    2010-10-01

    ...) Lantern. The lantern must contain sufficient oil to burn for at least 9 hours, and be ready for immediate..., Standard Color Card of America). Rigging must consist of galvanized wire rope not less than three...

  1. 46 CFR 169.807 - Notice of casualty.

    Science.gov (United States)

    2010-10-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS... to mariners, radiograms sent and received, the radio log, and crew, sailing school student... jurisdiction of the Coast Guard, the person in charge of the vessel shall report the accident to the nearest...

  2. What we do | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC supports research in developing countries to create real and lasting change. ... financial resources, advice, and training to find solutions to local problems; ... the elderly and young people, sports clubs, labour unions, parents' committees, ...

  3. 46 CFR 169.675 - Generators and motors.

    Science.gov (United States)

    2010-10-01

    ... COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS... designed for an ambient temperature of 50 degrees C. (122 degrees F.). (g) A generator or motor may be designed for an ambient temperature of 40 degrees C. (104 degrees F.) if the vessel is designed so that the...

  4. South of Sahara | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    South of Sahara. Sud du Sahara. Read more about Ecohealth Chair on Urban Air Pollution and Non-Communicable Respiratory Diseases (West Africa). Language English. Read more about Analyse des flux financiers des économies émergentes vers les pays en développement. Language French. Read more about An ...

  5. All projects related to | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    Region: South Asia, Bangladesh, Sri Lanka, India, Nepal, Pakistan ... Social Policy, POLICY MAKING, RESEARCH NETWORKS, SOCIAL INEQUALITY ... Gender and Enterprise Development in Africa: A Cross-Country Comparative Study.

  6. Capture cross section and resonance parameters of thulium-169

    International Nuclear Information System (INIS)

    Arbo, J.C.; Felvinci, J.P.; Melkonian, E.; Havens, W.W. Jr.

    1975-01-01

    The previously analyzed energy range for thulium capture resonance parameters is extended from 1 keV to 2 keV. In addition, point and group averaged thulium cross section curves are extended to above 2 keV and 181 Ta impurity levels are discussed. (SDF)

  7. 21 CFR 73.169 - Grape color extract.

    Science.gov (United States)

    2010-04-01

    ...-dextrin. (2) Color additive mixtures for food use made with grape color extract may contain only those... part per million. (c) Uses and restrictions. Grape color extract may be safely used for the coloring of... promulgated under section 401 of the act, unless the use of added color is authorized by such standards. (d...

  8. Evaluation of the Ion Torrent™ HID SNP 169-plex

    DEFF Research Database (Denmark)

    Børsting, Claus; Fordyce, Sarah L; Olofsson, Jill Katharina

    2014-01-01

    The Ion Torrent™ HID SNP assay amplified 136 autosomal SNPs and 33 Y-chromosome markers in one PCR and the markers were subsequently typed using the Ion PGM™ second generation sequencing platform. A total of 51 of the autosomal SNPs were selected from the SNPforID panel that is routinely used...... in our ISO 17025 accredited laboratory. Concordance between the Ion Torrent™ HID SNP assay and the SNPforID assay was tested by typing 44 Iraqis twice with the Ion Torrent™ HID SNP assay. The same samples were previously typed with the SNPforID assay and the Y-chromosome haplogroups of the individuals...

  9. Dicty_cDB: VHM169 [Dicty_cDB

    Lifescience Database Archive (English)

    Full Text Available one) Homo sapiens full open reading fra... 76 2e-12 AF134593_1( AF134593 |pid:none) Homo sapiens L-pipecolic...06_1( BC114006 |pid:none) Bos taurus L-pipecolic acid oxidas... 76 2e-12 protein

  10. What we do | Page 169 | IDRC - International Development ...

    International Development Research Centre (IDRC) Digital Library (Canada)

    IDRC supports research in developing countries to create real and lasting change. This knowledge can be used as a tool for addressing pressing global challenges. ... Historically, the cooperative sector in Latin America has contributed to job ...

  11. Quantitative microanalysis of hafnium - zirconium system by X-ray fluorescence

    International Nuclear Information System (INIS)

    Majid, C.A.; Hussain, M.A.; Saeed, K.

    1986-01-01

    X-ray fluorescence technique has been used for the analysis of Hf in the presence of Zr by developing a method. In this method the spectral interference of Hf lines by Zr is eliminated completely and the Hf detection is accomplished using the most efficient Li line of its L-series. The principle of the method is based on the extinction properties of crystals for some orders of reflection. Ge(III) is used as the analyzing crystal. This method can be used accurately to detect Hf in any concentration of Zr at least from about 20 ppm to 100%. Also no information about the expected range of the analyte sample, is required in advance. (authors)

  12. X-Ray fluorescence of microquantities of hafnium in zirconium by precipitation as thin film

    International Nuclear Information System (INIS)

    Vigoda de Leyt, Dora; Caridi, A.F.; Deibe, Jorge

    1988-01-01

    The importance of Zr and Hf in the nuclear industry represents and increasing need for the development of reliable chemical methods to determine Hf traces in Zr matrix. A precipitation method in amoniacal medium was developed. A thin film is obtained where matrix effects are absent or minimized. Hf in the range of 5-70.10 -9 Kg in a 5.10 -6 Kg Zr matrix was studied. Fluorescence Hf Lα and Hf Lβ X-rays are excited by a W-anode tube 17 kV-25mA and 50kV-25mA. Radiation scattered by the tube was used as internal standard. Bartlett criterion was used for the regression analysis. Determination limit was fixed in 5±4. 10 -9 Kg Hf at a 95 % probability. (Author) [es

  13. Hafnium-tungsten chronometry of angrites and the earliest evolution of planetary objects

    DEFF Research Database (Denmark)

    Markowski, A.; Quitté, G.; Kleine, T.

    2007-01-01

    Angrites are amongst the oldest basalts in the solar system and their origins are enigmatic, some even proposing the planet Mercury as the parent body (APB). Whatever their exact provenance their chronometry provides insights into early stages of planetary melting and differentiation. We present...... various short-lived chronometers provides evidence that Al, Mn and Hf were homogeneously distributed in the solar nebula, although we cannot rule out the possibility of local small heterogeneities. Contrary to recent proposals, the data are also consistent with the previously determined age of the solar...... for such late melting and core formation are unclear. Quenched angrites are coeval with non-magmatic IAB iron meteorites and CB chondrules at ~ 4562 Ma. However, demonstration of a genetic link between angrite melting and impact events must await the acquisition of still higher resolution chronometry....

  14. Pressure-dependence of the phase transitions and thermal expansion in zirconium and hafnium pyrovanadate

    Energy Technology Data Exchange (ETDEWEB)

    Gallington, Leighanne C.; Hester, Brett R.; Kaplan, Benjamin S. [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332‐0400 (United States); Wilkinson, Angus P., E-mail: angus.wilkinson@chemistry.gatech.edu [School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332‐0400 (United States); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA 30332‐0245 (United States)

    2017-05-15

    Low or negative thermal expansion (NTE) has been previously observed in members of the ZrP{sub 2}O{sub 7} family at temperatures higher than their order-disorder phase transitions. The thermoelastic properties and phase behavior of the low temperature superstructure and high temperature negative thermal expansion phases of ZrV{sub 2}O{sub 7} and HfV{sub 2}O{sub 7} were explored via in situ variable temperature/pressure powder x-ray diffraction measurements. The phase transition temperatures of ZrV{sub 2}O{sub 7} and HfV{sub 2}O{sub 7} exhibited a very strong dependence on pressure (∼700 K GPa), with moderate compression suppressing the formation of their NTE phases below 513 K. Compression also reduced the magnitude of the coefficients of thermal expansion in both the positive and negative thermal expansion phases. Additionally, the high temperature NTE phase of ZrV{sub 2}O{sub 7} was found to be twice as stiff as the low temperature positive thermal expansion superstructure (24 and 12 GPa respectively). - Graphical abstract: The temperature at which ZrV{sub 2}O{sub 7} transforms to a phase displaying negative thermal expansion is strongly pressure dependent. The high temperature form of ZrV{sub 2}O{sub 7} is elastically stiffer than the low temperature form. - Highlights: • The order-disorder phase transition temperatures in ZrV{sub 2}O{sub 7} and HfV{sub 2}O{sub 7} are strongly pressure dependent (∼700 K.GPa). • The high temperature (disordered) phase of ZrV{sub 2}O{sub 7} is much stiffer than the ambient temperature (ordered) phase. • Compression reduces the magnitude of the negative thermal expansion in the high temperature phase of ZrV{sub 2}O{sub 7}.

  15. Interaction of chelate cyclopentadienyl compounds of zirconium and hafnium with bromine

    International Nuclear Information System (INIS)

    Brajnina, Eh.M.; Minacheva, M.Kh.

    1975-01-01

    Interaction of bromine with Zr and Hf dibenzoylmethane (DBM) compounds of following type: (DBM) 4 M, CpM(DBM) 3 and Cp 2 M(DBM) 2 leads to the formation of (DBM) 2 MBr 2 , (DBM) 3 MBr and CpZr(DBM) 2 Br in the rations which depend on the conditions of the reaction (Cp=C 5 H 5 )

  16. Investigation of Hafnium oxide/Copper resistive memory for advanced encryption applications

    Science.gov (United States)

    Briggs, Benjamin D.

    The Advanced Encryption Standard (AES) is a widely used encryption algorithm to protect data and communications in today's digital age. Modern AES CMOS implementations require large amounts of dedicated logic and must be tuned for either performance or power consumption. A high throughput, low power, and low die area AES implementation is required in the growing mobile sector. An emerging non-volatile memory device known as resistive memory (ReRAM) is a simple metal-insulator-metal capacitor device structure with the ability to switch between two stable resistance states. Currently, ReRAM is targeted as a non-volatile memory replacement technology to eventually replace flash. Its advantages over flash include ease of fabrication, speed, and lower power consumption. In addition to memory, ReRAM can also be used in advanced logic implementations given its purely resistive behavior. The combination of a new non-volatile memory element ReRAM along with high performance, low power CMOS opens new avenues for logic implementations. This dissertation will cover the design and process implementation of a ReRAM-CMOS hybrid circuit, built using IBM's 10LPe process, for the improvement of hardware AES implementations. Further the device characteristics of ReRAM, specifically the HfO2/Cu memory system, and mechanisms for operation are not fully correlated. Of particular interest to this work is the role of material properties such as the stoichiometry, crystallinity, and doping of the HfO2 layer and their effect on the switching characteristics of resistive memory. Material properties were varied by a combination of atomic layer deposition and reactive sputtering of the HfO2 layer. Several studies will be discussed on how the above mentioned material properties influence switching parameters, and change the underlying physics of device operation.

  17. Influence of the oxygen/argon ratio on the properties of sputtered hafnium oxide

    International Nuclear Information System (INIS)

    Pereira, L.; Barquinha, P.; Fortunato, E.; Martins, R.

    2005-01-01

    In this work we have focused our attention on the role of the gas mixture (O 2 /Ar) used during HfO 2 thin film processing by r.f. magnetron sputtering, to produce dielectrics with suitable characteristics to be used as gate dielectric. Increasing the O 2 /Ar ratio from 0 to 0.2, the films properties (optical gap, permittivity, resistivity and compactness) are improved. At these conditions, films with a band gap around 5 eV were produced, indicating a good stoichiometry. Also the flat band voltage has a reduction of almost three times indicating also a reduction of the same order on the fixed charge density at the semiconductor-insulator interface. The dielectric constant is around 16 which is very good, since the surface of the silicon where the HfO 2 films were deposited contains a SiO 2 layer of about 3 nm that gives an effective dielectric constant above 20, close to the HfO 2 stoichiometric value (∼25). Further increase on the O 2 /Ar ratio does not produce significant improvements

  18. Structure and Optical Properties of Nanocrystalline Hafnium Oxide Thin Films (PostPrint)

    Science.gov (United States)

    2014-09-01

    sputter-deposition. A large band gap coupled with low absorption provide optical transparency over a broad range in the electromagnetic spectrum; HfO2...k) in the middle of the visible spec- trum, and C influences n(k) to a greater extent in shorter wave - lengths [31]. Note that this principle behind...Approved for publicnanocrystalline HfO2 films crystallize in monoclinic structure. Fur - thermore, increasing Ts results in improved structural order and

  19. The Juvenile Hafnium Isotope Signal as a Record of Supercontinent Cycles

    Science.gov (United States)

    Gardiner, Nicholas J.; Kirkland, Christopher L.; van Kranendonk, Martin J.

    2016-12-01

    Hf isotope ratios measured in igneous zircon are controlled by magmatic source, which may be linked to tectonic setting. Over the 200-500 Myr periodicity of the supercontinent cycle - the principal geological phenomenon controlling prevailing global tectonic style - juvenile Hf signals, i.e. most radiogenic, are typically measured in zircon from granites formed in arc settings (crustal growth), and evolved zircon Hf signals in granites formed in continent-collision settings (crustal reworking). Interrogations of Hf datasets for excursions related to Earth events commonly use the median value, however this may be equivocal due to magma mixing. The most juvenile part of the Hf signal is less influenced by crustal in-mixing, and arguably a more sensitive archive of Earth’s geodynamic state. We analyze the global Hf dataset for this juvenile signal, statistically correlating supercontinent amalgamation intervals with evolved Hf episodes, and breakup leading to re-assembly with juvenile Hf episodes. The juvenile Hf signal is more sensitive to Pangaea and Rodinia assembly, its amplitude increasing with successive cycles to a maximum with Gondwana assembly which may reflect enhanced subduction-erosion. We demonstrate that the juvenile Hf signal carries important information on prevailing global magmatic style, and thus tectonic processes.

  20. As-cast structure refinement of Ti-46Al alloy by hafnium and boron additions

    Directory of Open Access Journals (Sweden)

    Zhang Li

    2009-05-01

    Full Text Available The infl uence of Hf and B on the solidifi cation structure of cast Ti-46Al alloys was investigated. The results show that the coupling effect of Hf and B changes the solidifi cation structure morphology and strongly refi nes the grain size. When the Hf+B contents were increased from 0 + 0.0 to 3 + 0.2, 5 + 0.6 and 7 + 1.0 (in at. %, the solidification structure morphology changed from coarse columnar dendrite to fine columnar dendrite, then to equiaxed dendrite, and further to fi ne near granular grain whilst the average grain size decreased to 20 μm. It is concluded that the columnar dendrite refinement is due to the effect of Hf and B on the decrease of Al diffusion coeffi cient in the melt. The fi ne near granular grain formation is attributed to the combined constitutional supercooling formed by Al and B segregation that is strengthened by Hf and B additions at the solid/liquid interface during solidifi cation, and the TiB2 precipitates acting as heterogeneous nuclei

  1. Metal-Element Compounds of Titanium, Zirconium, and Hafnium as Pyrotechnic Fuels

    Science.gov (United States)

    2015-05-04

    59 Ti3O5 (s, 59.9), K (g, 19.9), N2 (g, 8.2), H2O (g, 5.2), KOH (g, 4.0) TiB2 2868 26 / 74 TiO2 (l, 16.3), Ti2O3 (l, 8.7), KBO2 (g, 56.0), N2 (g...Borate Glasses – Structural Studies with NMR and Raman Spectroscopies. J. Phys. Chem. 100, 16720-16728. 9. Massis, T. M. (1996) New Explosive

  2. Characterization of the superconducting state in hafnium hydride under high pressure

    Science.gov (United States)

    Duda, A. M.; Szewczyk, K. A.; Jarosik, M. W.; Szcześniak, K. M.; Sowińska, M. A.; Szcześniak, D.

    2018-05-01

    The hydrogen-rich compounds at high pressure may exhibit notably high superconducting transition temperatures. In the paper, we have calculated the basic thermodynamic parameters of the superconducting state in two selected phases of HfH2 hydride under high-pressure respectively at 180 GPa for Cmma and 260 GPa for P21 / m . Calculations has been conducted in the framework of the Eliashberg formalism. In particular, we have determined the values of the critical temperature (TC) to be equal to 8 K and 13 K for the Cmma and P21 / m phases, respectively. Moreover, we have estimated other thermodynamic properties such as the order parameter (Δ (T)) , the thermodynamic critical field (HC (T)) , and the specific heat for the normal (CN) and superconducting (CS) state. Finally, we have shown that the characteristic ratios: RΔ = 2 Δ (0) /kBTC and RC = ΔC (TC) /CN (TC) , which are related to the above thermodynamic functions, slightly differ from the predictions of the Bardeen-Cooper-Schrieffer theory due to the strong-coupling and retardation effects.

  3. Structure and property evaluation of a vacuum plasma sprayed nanostructured tungsten-hafnium carbide bulk composite

    International Nuclear Information System (INIS)

    Rea, K.E.; Viswanathan, V.; Kruize, A.; Hosson, J.Th.M. de; O'Dell, S.; McKechnie, T.; Rajagopalan, S.; Vaidyanathan, R.; Seal, S.

    2008-01-01

    Vacuum plasma spray (VPS) forming of tungsten-based metal matrix nanocomposites (MMCs) has shown to be a cost effective and time saving method for the formation of bulk monolithic nanostructured thermo-mechanical components. Spray drying of powder feedstock appears to have a significant effect on the improved mechanical properties of the bulk nanocomposite. The reported elastic modulus of the nanocomposite nearly doubles due to the presence of HfC nano particulates in the W matrix. High resolution transmission electron microscopy (HRTEM) revealed the retention of nanostructures at the select process conditions and is correlated with the enhanced mechanical properties of the nanocomposite

  4. Spectroscopic and structural investigation of undoped and Er{sup 3+} doped hafnium silicate layers

    Energy Technology Data Exchange (ETDEWEB)

    Khomenkova, L., E-mail: khomen@ukr.net [CIMAP CEA/CNRS/ENSICAEN/UCBN, 6 Blvd. Maréchal Juin, 14050 Caen Cedex 4 (France); V. Lashkaryov Institute of Semiconductor Physics at NASU, 41 Pr. Nauky, Kyiv 03028 (Ukraine); An, Y.-T. [CIMAP CEA/CNRS/ENSICAEN/UCBN, 6 Blvd. Maréchal Juin, 14050 Caen Cedex 4 (France); Khomenkov, D. [Taras Shevchenko National University of Kyiv, Faculty of Physics, 4 Pr. Hlushkov, Kyiv 03022 (Ukraine); Portier, X.; Labbé, C.; Gourbilleau, F. [CIMAP CEA/CNRS/ENSICAEN/UCBN, 6 Blvd. Maréchal Juin, 14050 Caen Cedex 4 (France)

    2014-11-15

    This paper demonstrates the functionality of radio-frequency magnetron sputtering for the fabrication of undoped and Er-doped Si-rich-HfO{sub 2} films with specific structural and spectroscopic properties. The effect of post-deposition treatment on film properties was investigated by means of Fourier-transform infrared spectroscopy, Raman scattering and photoluminescence methods, as well as Transmission Electron microscopy. It was observed that annealing treatment at 850–1000 °C causes phase separation process and the formation of HfO{sub 2}, SiO{sub 2} and pure Si phases. This process stimulates also an intense light emission in the 700–950-nm spectral range under broad band excitation. The phase separation mechanism as well as the nature of radiative transitions were discussed. Photoluminescence was ascribed to carrier recombination in silicon clusters and host defects. The appearance of silicon clusters was also confirmed by the comparison of luminescent properties of pure HfO{sub 2}, SiO{sub 2}, Si-rich-HfO{sub 2} and Si-rich-SiO{sub 2} films. Additional argument for Si clusters’ formation was obtained under investigation of Er-doped Si-rich HfO{sub 2} films. These latter demonstrated 1.54-µm Er{sup 3+} luminescence under non-resonant excitation originating from an energy transfer from Si clusters towards Er{sup 3+} ions.

  5. Electric field and temperature scaling of polarization reversal in silicon doped hafnium oxide ferroelectric thin films

    International Nuclear Information System (INIS)

    Zhou, Dayu; Guan, Yan; Vopson, Melvin M.; Xu, Jin; Liang, Hailong; Cao, Fei; Dong, Xianlin; Mueller, Johannes; Schenk, Tony; Schroeder, Uwe

    2015-01-01

    HfO 2 -based binary lead-free ferroelectrics show promising properties for non-volatile memory applications, providing that their polarization reversal behavior is fully understood. In this work, temperature-dependent polarization hysteresis measured over a wide applied field range has been investigated for Si-doped HfO 2 ferroelectric thin films. Our study indicates that in the low and medium electric field regimes (E < twofold coercive field, 2E c ), the reversal process is dominated by the thermal activation on domain wall motion and domain nucleation; while in the high-field regime (E > 2E c ), a non-equilibrium nucleation-limited-switching mechanism dominates the reversal process. The optimum field for ferroelectric random access memory (FeRAM) applications was determined to be around 2.0 MV/cm, which translates into a 2.0 V potential applied across the 10 nm thick films

  6. The Rayleigh law in silicon doped hafnium oxide ferroelectric thin films

    International Nuclear Information System (INIS)

    Guan, Yan; Liu, Xiaohua; Zhou, Dayu; Xu, Jin; Cao, Fei; Dong, Xianlin; Mueller, Johannes; Schenk, Tony; Schroeder, Uwe

    2015-01-01

    A wealth of studies have confirmed that the low-field hysteresis behaviour of ferroelectric bulk ceramics and thin films can be described using Rayleigh relations, and irreversible domain wall motion across the array of pining defects has been commonly accepted as the underlying micro-mechanism. Recently, HfO 2 thin films incorporated with various dopants were reported to show pronounced ferroelectricity, however, their microscopic domain structure remains unclear till now. In this work, the effects of the applied electric field amplitude, frequency and temperature on the sub-coercive polarization reversal properties were investigated for 10 nm thick Si-doped HfO 2 thin films. The applicability of the Rayleigh law to ultra-thin ferroelectric films was first confirmed, indicating the existence of a multi-domain structure. Since the grain size is about 20-30 nm, a direct observation of domain walls within the grains is rather challenging and this indirect method is a feasible approach to resolve the domain structure. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  7. Structure and property evaluation of a vacuum plasma sprayed nanostructured tungsten-hafnium carbide bulk composite

    NARCIS (Netherlands)

    Rea, K. E.; Viswanathan, V.; Kruize, A.; De Hosson, J. Th. M.; O'Dell, S.; McKechnie, T.; Rajagopalan, S.; Vaidyanathan, R.; Seal, S.; O’Dell, S.

    2008-01-01

    Vacuum plasma spray (VPS) forming of tungsten-based metal matrix nanocomposites (MMCs) has shown to be a cost effective and time saving method for the formation of bulk monolithic nanostructured then no-mechanical components. Spray drying of powder feedstock appears to have a significant effect on

  8. Radiation Effects on the Electrical Properties of Hafnium Oxide Based MOS Capacitors

    Science.gov (United States)

    2011-03-01

    evaporator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 12. Copper crucible . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21...picture shows the chamber, controls, and pumps. Figure 12. A copper crucible held a cylindrical pellet of the contact metal. An electron beam evaporated

  9. The Rayleigh law in silicon doped hafnium oxide ferroelectric thin films

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Yan; Liu, Xiaohua [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian (China); Zhou, Dayu [Key Laboratory of Materials Modification by Laser, Ion, and Electron Beams (Ministry of Education), School of Materials Science and Engineering, Dalian University of Technology, Dalian (China); State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu (China); Xu, Jin [Department of Electronic Engineering, Dalian Neusoft University of Information, Dalian (China); Cao, Fei; Dong, Xianlin [Key Laboratory of Inorganic Functional Materials and Devices, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai (China); Mueller, Johannes [Fraunhofer IPMS-CNT, Dresden (Germany); Schenk, Tony; Schroeder, Uwe [NaMLab gGmbH/TU Dresden (Germany)

    2015-10-15

    A wealth of studies have confirmed that the low-field hysteresis behaviour of ferroelectric bulk ceramics and thin films can be described using Rayleigh relations, and irreversible domain wall motion across the array of pining defects has been commonly accepted as the underlying micro-mechanism. Recently, HfO{sub 2} thin films incorporated with various dopants were reported to show pronounced ferroelectricity, however, their microscopic domain structure remains unclear till now. In this work, the effects of the applied electric field amplitude, frequency and temperature on the sub-coercive polarization reversal properties were investigated for 10 nm thick Si-doped HfO{sub 2} thin films. The applicability of the Rayleigh law to ultra-thin ferroelectric films was first confirmed, indicating the existence of a multi-domain structure. Since the grain size is about 20-30 nm, a direct observation of domain walls within the grains is rather challenging and this indirect method is a feasible approach to resolve the domain structure. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Corrosion of Fe-25 Cr Alloy with microconstituent additions of hafnium and platinum

    International Nuclear Information System (INIS)

    Srinivasan, V.

    1989-01-01

    The study reported was performed with a view to understanding the effects of minor additions of Hf and Pt on the corrosion behavior of a model chromia former, Fe-25Cr. Bulk addition of Hf or Pt was made at 1 wt.% level to the base alloy, Fe-25 Cr, and the experimental alloys were made by an ingot metallurgy route. Coupons were machined from the as-cast rods or forged prismatic bars, and metallographically polished to 1 μ alumina. Multiple samples were exposed to an H 2 /H 2 S/H 2 O/Ar gas mixture at 700 degrees C for times up to 192 hrs. Planar and cross-sections of scales formed on the substrate alloys were examined using a scanning electron microscope with an energy dispersive x-ray spectrometer (SEM/EDAX). A uniform chromia scale formed initially. This scale was broken down locally and slowly by the overgrowth of sulfide rich nodules. The effects of minor additions of Hf or Pt on the growth and breakdown of protective chromia scales are discussed in this paper

  11. High temperature strengthening mechanism of hafnium carbide in a tungsten-rhenium matrix

    International Nuclear Information System (INIS)

    Luo, A.; Shin, K.S.; Jacobson, D.L.

    1991-01-01

    The interrelationship between the testing temperature and HfC strength increment of an arc-melted W-3.6Re-0.4HfC was determined from 1950 K to 2980 K in a vacuum of better than 1.3x10 -5 Pa (10 -7 torr). The present research was focused on the characteristic temperature at which the rapid coarsening of HfC particles occurred and the effect of the second-phase particle size on the high temperature strength properties of this material. It was found that the HfC particle strengthening was effective in a W-Re matrix up to a characteristic temperature of 2450 K in the short-term tensile test. Carbon was found to be the rate-limiting solute in the HfC particle growth. The strength of HfC strengthened alloy at temperature above 0.5 T m is proportional to the square root of particle volume fraction. The yield strengths of W-3.6Re-0.26HfC calculated based on the particle statistical distribution had good agreement with the experimental values from 1950 K to 2980 K. Besides, an addition of 0.26 percent HfC in tungsten resulted in about 28 percent increase in the activation energy of plastic deformation at high temperatures

  12. Precise simultaneous determination of zirconium and hafnium in silicate rocks, meteorites and lunar samples. [Neutron reactions

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, P A; Garg, A N; Ehmann, W D [Kentucky Univ., Lexington (USA). Dept. of Chemistry

    1977-01-01

    A precise, sensitive and rapid analytical technique has been developed for the simultaneous determination of Zr and Hf in natural silicate matrices. The technique is based on radiochemical neutron activation analysis and employs a rapid fusion dissolution of the sample and simultaneous precipitation of the Zr-Hf pair with p-hydroxybenzene arsenic acid in an acidic medium. The indicator radionuclides, /sup 95/Zr and /sup 181/Hf, are counted and the /sup 95/Zr activity is corrected for the contribution from U fission. The chemical yields of the radiochemical separation are based on Hf carrier. The yield is determined by reactivation of the processed samples and standards with a /sup 252/Cf isotopic neutron source and by counting the 18.6 sec half-life sup(179m)Hf. The RNAA procedure for Zr and Hf has been shown to be precise and accurate for natural silicate samples, based on replicate analyses of samples containing Zr in the range of 1 ..mu..g/g to over 600 ..mu..g/g. The procedure is relatively rapid with a total chemical processing time of approximately 3 hours. At least 4 samples are processed simultaneously. Ten additional elements (Fe, Cr, Co, Sc, Eu, La, Lu, Ce, Th and Tb) can be determined by direct Ge(Li) spectrometry (INAA) on the samples prior to dissolution for the RNAA determination of Zr and Hf. Corrections for the U fission contribution can be made on the basis of the known U content or from the INAA Th content, based on the relatively constant natural Th/U ratio.

  13. CONVERSION OF D-XYLOSE INTO FURFURAL WITH ALUMINUM AND HAFNIUM PILLARED CLAYS AS CATALYST

    Directory of Open Access Journals (Sweden)

    WILLIAM CORTÉS

    2013-01-01

    Full Text Available El proceso industrial utilizado para la producción de furfural es la deshidratación de pentosas, la cual se lleva a cabo por medio de ácidos minerales, altamente corrosivos y contaminantes como catalizadores. Debido a los efectos ecológicos y toxicológicos asociados a este proceso, y a la dificultad en la separación del producto, el desarrollo de nuevos catalizadores sólidos ácidos ha tenido una significativa expansión en los últimos años. El presente trabajo de investigación se enfocó en la producción de furfural a partir de D-xilosa empleando como catalizadores sólidos ácidos, arcillas pilarizadas con aluminio y hafnio. Después de 4 h de reacción a temperaturas entre 140 y 170 °C, los resultados evidenciaron una conversión entre el 50 y el 80%, mientras que los niveles de selectividad alcanzados estuvieron entre el 40 y el 65%. Finalmente, la estabilidad de los catalizadores fue evaluada por medio de un tratamiento térmico, antes de usarlo de nuevo. En cuatro reacciones consecutivas no fue observada una disminución significativa en la selectividad. En conclusión, las arcillas pilarizadas evidencian ser catalizadores activos, selectivos y estables para la deshidratación de pentosas.

  14. Early history of Earth's crust-mantle system inferred from hafnium isotopes in chondrites

    DEFF Research Database (Denmark)

    Bizzarro, Martin; Haack, Henning; Rosing, M.

    2003-01-01

    for the chondrite-forming event. This ¿176 value indicates that Earth's oldest minerals were derived from melts of a mantle source with a time-integrated history of depletion rather than enrichment. The depletion event must have occurred no later than 320 Myr after planetary accretion, consistent with timing......The Lu to Hf decay series has been widely used to understand the nature of Earth's early crust-mantle system. The interpretation, however, of Lu-Hf isotope data requires accurate knowledge of the radioactive decay constant of Lu (¿176), as well as bulk-Earth reference parameters. A recent...

  15. Cavitation resistance of 45 and 2H13 steels laser enriched with silicon carbides and hafnium

    International Nuclear Information System (INIS)

    Skodo, M.; Giren, B.; Cenian, A.

    1999-01-01

    Cavitation resistance of 45 and H13 steels with surface layers enriched with Hf and SiC compounds was investigated. All contamination elements were spread over the samples surfaces and subsequently alloyed with core material by CO 2 laser beam. Cavitation tests carried out at the rotating disk facility revealed multiple - 5 to 10 times - increase of erosion resistance of the processed materials during the incubation period of the destruction. This effect was found not to be decisively linked to obtained microhardness changes. (author)

  16. Excess hafnium-176 in meteorites and the early Earth zircon record

    DEFF Research Database (Denmark)

    Bizzarro, Martin; Connelly, James; Thrane, Kristine

    2012-01-01

    The long-lived Lu-to- Hf decay system is a powerful tool to understand ancient chemical fractionation events associated with planetary differentiation. Detrital Hadean zircons (>3.8 Gyr) from the Jack Hills metasedimentary belt of Western Australia record extremely enriched Hf-isotope signals sug...... crust prior to ~4.4 Gyr. This new view suggests continuous juvenile crustal growth and recycling throughout the Hadean and Archean eras, perhaps analogous to modern plate tectonics....

  17. Iron modified titanium–hafnium binary oxides as catalysts in total oxidation of ethyl acetate

    Czech Academy of Sciences Publication Activity Database

    Tsoncheva, T.; Ivanova, R.; Henych, Jiří; Velinov, N.; Kormunda, M.; Dimitrov, M.; Paneva, D.; Slušná, Michaela; Mitov, I.; Štengl, Václav

    2016-01-01

    Roč. 81, JUN (2016), s. 14-19 ISSN 1566-7367 R&D Projects: GA MŠk LM2015073 Institutional support: RVO:61388980 Keywords : Titania–hafnia binary oxide s * Iron modifications * Support effect * Ethyl acetate oxydation Subject RIV: CA - Inorganic Chemistry Impact factor: 3.330, year: 2016

  18. Creep and Oxidation of Hafnium Diboride Based Ultra High Temperature Ceramics at 1500C

    Science.gov (United States)

    2015-12-01

    word ceramic comes from the Greek word keramos, meaning pottery, but now refers to many classes of materials, including clays , abrasives......these situations, the viscosity of the grain boundary becomes an important factor for the creep rate. 25 When grain elongation accompanies grain

  19. Plasma arc cutting: Microstructural modifications of hafnium cathodes during first cycles

    Energy Technology Data Exchange (ETDEWEB)

    Rotundo, F., E-mail: fabio.rotundo@unibo.it [Dept. of Mechanical Engineering (DIEM), Alma Mater Studiorum, Universita di Bologna, Via Saragozza 8, 40123 Bologna (Italy); Martini, C.; Chiavari, C.; Ceschini, L. [Dept. of Metals Science, Electrochemistry and Chemical Techniques (SMETEC), Alma Mater Studiorum, Universita di Bologna, Viale Risorgimento 4, 40136 Bologna (Italy); Concetti, A.; Ghedini, E.; Colombo, V. [Dept. of Mechanical Engineering (DIEM), Alma Mater Studiorum, Universita di Bologna, Via Saragozza 8, 40123 Bologna (Italy); Dallavalle, S. [Cebora S.p.A., Via Andrea Costa 24, 40057 Cadriano di Granarolo (Italy)

    2012-06-15

    In the present work, the microstructural modifications of the Hf insert in plasma arc cutting (PAC) electrodes operating at 250 A were experimentally investigated during first cycles, in order to understand those phenomena occurring on and under the Hf emissive surface and involved in the electrode erosion process. Standard electrodes were subjected to an increasing number of cutting cycles (CCs) on mild steel plates in realistic operative conditions, with oxygen/air as plasma/shield gas. Microstructural analysis was performed for each electrode at different erosion stages by means of scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS) and Raman spectroscopy. Electrodes cross sections were also observed by means of optical microscopy (both in bright field and in reflected polarised light) after chemical etching. In the insert, three typical zones were found after cutting: monoclinic HfO{sub 2} layer; thermally-modified transition zone with O{sub 2}-Hf solid solution; unmodified Hf. The erosion cavity and the oxide layer thickness increase with the number of cutting cycles. Macrocracking was observed in the oxide layer, while microcracking and grain growth were detected in the remelted Hf. Moreover, detachment was found at the Hf/Cu interface. Based on thermodynamics and kinetics of the Hf high temperature oxidation, conclusions can be drawn on the erosion mechanism involved. - Highlights: Black-Right-Pointing-Pointer Hf microstructural modifications in cathodes after plasma arc cutting cycles investigated. Black-Right-Pointing-Pointer 3 zones identified after cutting: HfO{sub 2} layer; remelted zone with O{sub 2}-Hf solid solution; unmodified Hf. Black-Right-Pointing-Pointer Hf-based ejections both in arc-on and arc-off phases; erosion cavity deepens with cutting cycles. Black-Right-Pointing-Pointer Detachment at the Hf/Cu interfaces, worsening heat dissipation and oxidation/erosion phenomena. Black-Right-Pointing-Pointer The use of a different current ramp at subsequent erosion stages is suggested.

  20. Population of Metastable States in Stable Hafnium and Ytterbium Nuclei via Beam Break-up

    International Nuclear Information System (INIS)

    Malwela, T.; Ntshangase, S.S.; Shirinda, O.; Bark, R.A.; Gueorguieva, E.; Lawrie, J.J.; Mullins, S.M.; Murray, S.H.T.; Sharpey-Schafer, J.F.; Gal, J.; Kalinka, G.; Krasznahorkay, A.; Molnar, J.; Nyako, B.M.; Timar, J.; Zolnai, L.; Hlatshwayo, T.; Juhasz, K.; Komati, F.S.; Scheurer, J.N.

    2005-01-01

    The ''Chessboard'' section of the DIAMANT charged-particle array has been coupled with the AFRODITE γ-ray spectrometer at the iThemba Laboratory for Accelerator Based Sciences. Charged-particle-γ-ray coincidence data were recorded during the bombardment of a 176Yb target with a 13C beam at an energy of 90 MeV. The purpose of the investigation was to study the population of metastable states in hafium nuclei via incomplete fusion reactions in which the beam breaks up due to its α-cluster character. Of note was the observation of the band based on the Kπ = 16+, T1/2 = 31 year isomer in 178Hf to its 19+ member. Also, decays from the high-K isomeric states in 174Yb and 176Yb. which were populated via 3αxn channels, indicative of complete break-up of the 13C beam

  1. Evaluation of Cross-Section Data from Threshold to 40 MeV for some Neutron Reactions Important for Fusion Dosimetry Applications. Part 2 Evaluation of the Excitation Functions for the 59Co(n,3n)57Co, 89Y(n,2n)88Y, 93Nb(n,2n)92mNb, 169Tm(n,2n)168Tm and 209Bi(n,3n)207Bi Reactions

    International Nuclear Information System (INIS)

    Zolotarev, K.I.

    2010-11-01

    Evaluations of cross sections and their associated covariance matrices have been carried out for five dosimetry reactions: excitation functions were re-evaluated for the 89 Y(n,2n) 88 Y, 93 Nb(n,2n) 92 mNb and 169 Tm(n,2n) 168 Tm reactions over the neutron energy range from threshold up to 40 MeV; excitation functions were re-evaluated for the 59 Co(n,3n) 57 Co and 209 Bi(n,3n) 207 Bi reactions over the neutron energy range from threshold to 85 and 45 MeV, respectively. Uncertainties in the cross sections for all of those reactions were also derived in the form of relative covariance matrices. Benchmark calculations performed for 235 U thermal fission and 252 Cf spontaneous fission neutron spectra show that the integral cross sections calculated from the newly evaluated excitation functions exhibit improved agreement with related experimental data when compared with the equivalent data from the IRDF-2002 library. (author)

  2. Evaluation of Some (n,n'), (n,γ), (n,p), (n,2n) and (n,3n) Reaction Excitation Functions for Fission and Fusion Reactor Dosimetry Applications; Evaluation of the Excitation Functions for the 54Fe(n,p)54Mn, 58Ni(n,2n)57Ni, 67Zn(n,p)67Cu, 92Mo(n,p)92mNb, 93Nb(n,γ)94Nb, 113In(n,n')113mIn, 115In(n,γ) 116mIn, and 169Tm(n,3n)167Tm Reactions. Progress Report on Research Contract No 16242

    International Nuclear Information System (INIS)

    Zolotarev, K.I.; Zolotarev, P.K.

    2013-12-01

    Cross section data for the 54 Fe(n,p) 54 Mn, 58 Ni(n,2n) 57 Ni, 67 Zn(n,p) 67 Cu, 92 Mo(n,p) 92m Nb, 93 Nb(n,γ) 94 Nb, 113 In(n,n') 113m In, 115 In(n,γ) 116m In, 169 Tm(n,3n) 167 Tm reactions are needed to solve a wide spectrum of scientific and technical tasks. Activation detectors based on these reactions may be used in the field of reactor dosimetry. Furthermore, the 54 Fe(n,p) 54 Mn reaction is often used in experimental nuclear physics as a monitor reaction for measurements of unknown cross sections by means of the activation method over the neutron energy range from 5 to 15 MeV. The 93 Nb(n,γ) 94 Nb reaction is also very promising for using in retrospective neutron dosimetry for determination of total neutron fluence during a campaign of a reactor. In the existing version of the International Reactor Dosimetry File and the new extended version named as IRDFF data for excitation functions of 67 Zn(n,p) 67 Cu, 92 Mo(n,p) 92m Nb, 113 In(n,n') 113m In, and 169 Tm(n,3n) 167 Tm reactions are absent. Data for these reactions are also absent in the JENDL/D-99 dosimetry file. Excitation functions of 67 Zn(n,p) 67 Cu and 169 Tm(n,3n) 167 Tm are presented in the TENDL-2012, EAF-2010, JENDL-4.0, JEFF-3.1/A, MENDL-2 libraries. Cross section data for the 67 Zn(n,p) 67 Cu reaction up to 20 MeV are given also in the JENDL/HE-2007 library. Excitation functions of the 92 Mo(n,p) 92m Nb and 113 In(n,n') 113m In reactions are evaluated in the EAF-2010 and JEFF-3.1/A libraries. Cross section data for the 113 In(n,n') 113m In reaction are given also in the TENDL-2010 library. It is necessary to note that neutron data in the JEFF-3.1/A and JENDL-4.0 libraries were evaluated up to 20 MeV. Neutron data in the TENDL-2012, EAF-2010, MENDL-2 and TENDL-2010 libraries had been evaluated up to 30 MeV, 60 MeV, 100 MeV and 200 MeV, respectively. Neutron cross sections in the MENDL-2, TENDL-2010 and TENDL-2012 libraries had been obtained on the basis of pure theoretical model calculations

  3. X-ray detection capabilities of plastic scintillators incorporated with hafnium oxide nanoparticles surface-modified with phenyl propionic acid

    Science.gov (United States)

    Hiyama, Fumiyuki; Noguchi, Takio; Koshimizu, Masanori; Kishimoto, Shunji; Haruki, Rie; Nishikido, Fumihiko; Yanagida, Takayuki; Fujimoto, Yutaka; Aida, Tsutomu; Takami, Seiichi; Adschiri, Tadafumi; Asai, Keisuke

    2018-01-01

    We synthesized plastic scintillators incorporated with HfO2 nanoparticles as detectors for X-ray synchrotron radiation. Nanoparticles with sizes of less than 10 nm were synthesized with the subcritical hydrothermal method. The detection efficiency of high-energy X-ray photons improved by up to 3.3 times because of the addition of the nanoparticles. Nanosecond time resolution was successfully achieved for all the scintillators. These results indicate that this method is applicable for the preparation of plastic scintillators to detect X-ray synchrotron radiation.

  4. Reduction of the interfacial trap density of indium-oxide thin film transistors by incorporation of hafnium and annealing process

    Directory of Open Access Journals (Sweden)

    Meng-Fang Lin

    2015-01-01

    Full Text Available The stable operation of transistors under a positive bias stress (PBS is achieved using Hf incorporated into InOx-based thin films processed at relatively low temperatures (150 to 250 °C. The mobilities of the Hf-InOx thin-film transistors (TFTs are higher than 8 cm2/Vs. The TFTs not only have negligible degradation in the mobility and a small shift in the threshold voltage under PBS for 60 h, but they are also thermally stable at 85 °C in air, without the need for a passivation layer. The Hf-InOx TFT can be stable even annealed at 150 °C for positive bias temperature stability (PBTS. A higher stability is achieved by annealing the TFTs at 250 °C, originating from a reduction in the trap density at the Hf-InOx/gate insulator interface. The knowledge obtained here will aid in the realization of stable TFTs processed at low temperatures.

  5. Process stabilization by peak current regulation in reactive high-power impulse magnetron sputtering of hafnium nitride

    International Nuclear Information System (INIS)

    Shimizu, T; Villamayor, M; Helmersson, U; Lundin, D

    2016-01-01

    A simple and cost effective approach to stabilize the sputtering process in the transition zone during reactive high-power impulse magnetron sputtering (HiPIMS) is proposed. The method is based on real-time monitoring and control of the discharge current waveforms. To stabilize the process conditions at a given set point, a feedback control system was implemented that automatically regulates the pulse frequency, and thereby the average sputtering power, to maintain a constant maximum discharge current. In the present study, the variation of the pulse current waveforms over a wide range of reactive gas flows and pulse frequencies during a reactive HiPIMS process of Hf-N in an Ar–N 2 atmosphere illustrates that the discharge current waveform is a an excellent indicator of the process conditions. Activating the reactive HiPIMS peak current regulation, stable process conditions were maintained when varying the N 2 flow from 2.1 to 3.5 sccm by an automatic adjustment of the pulse frequency from 600 Hz to 1150 Hz and consequently an increase of the average power from 110 to 270 W. Hf–N films deposited using peak current regulation exhibited a stable stoichiometry, a nearly constant power-normalized deposition rate, and a polycrystalline cubic phase Hf-N with (1 1 1)-preferred orientation over the entire reactive gas flow range investigated. The physical reasons for the change in the current pulse waveform for different process conditions are discussed in some detail. (paper)

  6. Separation of zirconium (Zr) and hafnium (Hf) using solvent mixture of TBP-D_2EHPA and amberlite XAD-16

    International Nuclear Information System (INIS)

    Dwi Biyantoro; I Made Sukarna; Agus Suyanto

    2017-01-01

    The aims of this research were to determine the composition (ratio of extractant and resin) of the SIR which is effective for the separation of Zr and Hf, knowing adsorption equilibrium models Zr and Hf using the SIR, and knowing the most effective adsorption results from SIR weight ratio. The research was conducted by using the SIR method that is impregnating the extractant into the resin. Extractant used is a mixture of TBP and D_2EHPA (1 : 3), the resin used is XAD-16, and the feed used is ZOC. This research was conducted by varying the composition of the SIR, after the result of effective SIR variation. Adsorption process is then performed using the ZOC with SIR. Then filtered, the filtrate was analyzed by XRF. While solids SIR adsorption product was desorbed using sulfuric acid. Then the desorption results were analyzed using XRF spectrometer. Based on calculations, the results of the most effective SIR composition for the separation of Zr-Hf are comparison extractant and resin = 5:5 either for the dry method and wet method, the equilibrium equations for Zr approaching Langmuir equilibrium models while the equilibrium equation for Hf approaching Freundlich equilibrium models which the most effective adsorption results that bait comparison with the SIR = 10 mL : 5 g with β = 0.1831; η Zr = 26.39 % and η Hf = 66.19 % for dry method and β = 0.1557; η Zr = 25.17 % and η Hf = 68.36 % for wet method. From result desorption process was 2 M H_2SO_4. (author)

  7. Effects of carbon and hafnium concentrations in wrought powder-metallurgy superalloys based on nasa 2b-11 alloy

    International Nuclear Information System (INIS)

    Miner, R.V. Jr.

    1976-01-01

    A candidate alloy for advanced-temperature turbine engine disks and four modifications of that alloy with various C and Hf concentrations were produced as cross-rolled disks from prealloyed powder that was hot isostatically compacted. The mechanical properties, microstructures, and phase relations of the alloys are discussed in terms of their C and Hf concentrations. A low-C and high-Hf modification of IIB-11 had the best balance of mechanical properties for service below about 750 C. Because of their finer grain sizes, none of the powder-metallurgy alloys produced had the high-temperature rupture strength of conventionally cast and wrought IIB-11. (Author)

  8. New constraints on the sources and behavior of neodymium and hafnium in seawater from Pacific Ocean ferromanganese crusts

    Science.gov (United States)

    van de Flierdt, T.; Frank, M.; Lee, D.-C.; Halliday, A.N.; Reynolds, B.C.; Hein, J.R.

    2004-01-01

    The behavior of dissolved Hf in the marine environment is not well understood due to the lack of direct seawater measurements of Hf isotopes and the limited number of Hf isotope time-series obtained from ferromanganese crusts. In order to place better constraints on input sources and develop further applications, a combined Nd-Hf isotope time-series study of five Pacific ferromanganese crusts was carried out. The samples cover the past 38 Myr and their locations range from sites at the margin of the ocean to remote areas, sites from previously unstudied North and South Pacific areas, and water depths corresponding to deep and bottom waters. For most of the samples a broad coupling of Nd and Hf isotopes is observed. In the Equatorial Pacific ENd and EHf both decrease with water depth. Similarly, ENd and EHf both increase from the South to the North Pacific. These data indicate that the Hf isotopic composition is, in general terms, a suitable tracer for ocean circulation, since inflow and progressive admixture of bottom water is clearly identifiable. The time-series data indicate that inputs and outputs have been balanced throughout much of the late Cenozoic. A simple box model can constrain the relative importance of potential input sources to the North Pacific. Assuming steady state, the model implies significant contributions of radiogenic Nd and Hf from young circum-Pacific arcs and a subordinate role of dust inputs from the Asian continent for the dissolved Nd and Hf budget of the North Pacific. Some changes in ocean circulation that are clearly recognizable in Nd isotopes do not appear to be reflected by Hf isotopic compositions. At two locations within the Pacific Ocean a decoupling of Nd and Hf isotopes is found, indicating limited potential for Hf isotopes as a stand-alone oceanographic tracer and providing evidence of additional local processes that govern the Hf isotopic composition of deep water masses. In the case of the Southwest Pacific there is evidence that decoupling may have been the result of changes in weathering style related to the buildup of Antarctic glaciation. Copyright ?? 2004 Elsevier Ltd.

  9. Synthesis and spectral properties of axially substituted zirconium(IV) and hafnium(IV) water soluble phthalocyanines in solutions

    International Nuclear Information System (INIS)

    Gerasymchuk, Y.S.; Volkov, S.V.; Chernii, V.Ya.; Tomachynski, L.A.; Radzki, St.

    2004-01-01

    Methods of synthesis of novel water soluble axially substituted Zr(IV) and Hf(IV) phthalocyanines with gallic, 5-sulfosalicyllic, oxalic acids, and methyl ester of gallic acid as axial ligands coordinated to the central atom metal of phthalocyanine are presented. The absorption spectra of complex solutions in various solvents were characterized. The dependence of the spectral red shift from Reichardt's empirical polarity parameter is described. The deviation from the linearity of Beer-Bouguer-Lambert law was investigated for the range of concentration 5x10 -6 to 10x10 -5 M. Fluorescent properties of axially substituted phthalocyaninato metal complexes in DMSO solutions were investigated

  10. High temperature oxidation behavior of hafnium modified NiAl bond coat in EB-PVD thermal barrier coating system

    Energy Technology Data Exchange (ETDEWEB)

    Guo Hongbo; Sun Lidong; Li Hefei [Department of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, No.37 Xueyuan Road, Beijing 100083 (China); Gong Shengkai [Department of Material Science and Engineering, Beijing University of Aeronautics and Astronautics, No.37 Xueyuan Road, Beijing 100083 (China)], E-mail: gongsk@buaa.edu.cn

    2008-06-30

    NiAl coatings doped with 0.5 at.% and 1.5 at.% Hf were produced by co-evaporation of NiAl and Hf ingots by electron beam physical vapor deposition (EB-PVD), respectively. The addition of 0.5 at.% Hf significantly improved the cyclic oxidation resistance of the NiAl coating. The TGO layer in the 1.5 at.% Hf doped NiAl coating is straight; while that in the 0.5 at.% Hf doped coating became undulated after thermal cycling. The doped NiAl thermal barrier coatings (TBCs) revealed improved thermal cycling lifetimes at 1423 K, compared to the undoped TBC. Failure of the 0.5 at.% Hf doped TBC occurred by cracking at the interface between YSZ topcoat and bond coat, while the 1.5 at.% Hf doped TBC cracked at the interface between bond coat and substrate.

  11. Radiochemical separations of hafnium, tantalum, and germanium from tungsten and selenium irradiated by 14 MeV neutrons

    International Nuclear Information System (INIS)

    Blachot, J.; Benabed, A.; Herment, J.; Monnand, E.

    1968-01-01

    Radiochemical separations of Hf, Ta and Ge from W and Se respectively, after 14 MeV-neutron irradiation. A new isotope: 79 Ge with a half-live of 50 ± 5 s and emitter of a 230 keV γ transition is observed. (authors) [fr

  12. Study of the heat conductivity of double and triple disordered solid solutions in the titanium-zirconium-hafnium system

    Energy Technology Data Exchange (ETDEWEB)

    Zarichnyak, Yu.P.; Lisnenko, T.A.

    1977-10-01

    Measurements are presented of the heat physical properties of trinary alloys in the system Ti-Zr-Hf. The possibility is shown of summarizing the results of the measurement and prediction of the heat conductivity of trinary continuous disordered solid solutions. Comparison of calculated results with experimental data shows that the method of modeling of the structure and prediction of heat conductivity suggested yields good qualitative and quantitative agreement throughout the entire range of change of concentration of the components. The maximum disagreement between calculated and experimental results is about 10%. 8 references, 2 figures, 1 table.

  13. Isospecific propylene polymerization with in situ generated bis(phenoxy-amine)zirconium and hafnium single site catalysts.

    Science.gov (United States)

    Makio, Haruyuki; Prasad, Aitha Vishwa; Terao, Hiroshi; Saito, Junji; Fujita, Terunori

    2013-07-07

    Bis(phenoxy-imine) Zr and Hf complexes were activated with (i)Bu3Al or (i)Bu2AlH in conjunction with Ph3CB(C6F5)4 and tested as catalysts for propylene polymerization with emphasis on the enantioselectivity of the isospecific species and the single site polymerization characteristics. The isoselective species was identified as the in situ generated bis(phenoxy-amine) complex whose isoselectivity was sensitive to subtle changes in ligand structure. By employing specific substituents at certain key positions the isotacticity reached an extremely high level comparable to high-end commercial isotactic polypropylenes (Tm > 160 °C). Single site polymerization characteristics depended upon the efficiency and selectivity of the in situ imine reduction which is sensitive to the substituent on the imine nitrogen and the reaction conditions. By using (i)Bu2AlH as a reducing agent, quantitative imine reduction can be achieved with a stoichiometric amount of the reducing agent. This lower alkylaluminum loading is beneficial for the catalyst and significantly enhances the polymerization activity and the molecular weight of the resultant polymer.

  14. Measurements of 14-MeV neutron cross-sections for the production of isomeric states in hafnium isotopes

    International Nuclear Information System (INIS)

    Patrick, B.H.; Sowerby, M.G.; Wilkins, C.G.; Russen, L.C.

    1990-01-01

    The cross sections for the production of isomeric states in the reactions 179 Hf(n,2n) 178m2 Hf, 180 Hf(n,2n) 179m2 Hf, 179 Hf(n,n') 179m2 Hf with 14 MeV neutrons have been measured and compared with the theoretical ones. 4 refs, 3 figs, 4 tabs

  15. Processing, Structure and High Temperature Oxidation Properties of Polymer-Derived and Hafnium Oxide Based Ceramic Systems

    Science.gov (United States)

    Terauds, Kalvis

    Demands for hypersonic aircraft are driving the development of ultra-high temperature structural materials. These aircraft, envisioned to sustain Mach 5+, are expected to experience continuous temperatures of 1200--1800°C on the aircraft surface and temperatures as high as 2800°C in combustion zones. Breakthroughs in the development of fiber based ceramic matrix composites (CMCs) are opening the door to a new class of high-tech UHT structures for aerospace applications. One limitation with current carbon fiber or silicon carbide fiber based CMC technology is the inherent problem of material oxidation, requiring new approaches for protective environmental barrier coatings (EBC) in extreme environments. This thesis focuses on the development and characterization of SiCN-HfO2 based ceramic composite EBC systems to be used as a protective layer for silicon carbide fiber based CMCs. The presented work covers three main architectures for protection (i) multilayer films, (ii) polymer-derived HfSiCNO, and (iii) composite SiCN-HfO 2 infiltration. The scope of this thesis covers processing development, material characterization, and high temperature oxidation behavior of these three SiCN-HfO2 based systems. This work shows that the SiCN-HfO 2 composite materials react upon oxidation to form HfSiO4, offering a stable EBC in streaming air and water vapor at 1600°C.

  16. The effect of hafnium content on the transformation temperatures of Ni49Ti51-xHfx shape memory alloys

    International Nuclear Information System (INIS)

    Angst, D.R.; Thoma, P.E.; Kao, M.Y.

    1995-01-01

    Ternary alloys of NiTiHf, having higher transformation temperatures than binary NiTi shape memory alloys, have been produced and analyzed. Beginning with a base composition of Ni 49 Ti 51 , Hf was substituted for Ti up to 30 atomic percent. Differential scanning calorimetry was used to determine the transformation temperatures of the as-cast alloys. The peak martensite temperature of the Ni 49 Ti 51 alloy was 69 C and increased to 525 C for the Ni 49 Ti 21 Hf 30 alloy. The peak austenite temperature of the Ni 49 Ti 51 alloy was 114 C and increased to 622 C for the Ni 49 Ti 21 Hf 30 alloy. An apparent minimum in the peak transformation temperatures occurred between 0 and 3 atomic percent Hf. Preliminary experiments were also conducted to determine the effect of thermomechanical processing on the shape memory properties of the Ni 49 Ti 41 Hf 10 . Data are presented on the effect of cold work and heat treatment on the transformation temperatures of this alloy. (orig.)

  17. NUCLEOSYNTHETIC TUNGSTEN ISOTOPE ANOMALIES IN ACID LEACHATES OF THE MURCHISON CHONDRITE: IMPLICATIONS FOR HAFNIUM-TUNGSTEN CHRONOMETRY

    Energy Technology Data Exchange (ETDEWEB)

    Burkhardt, Christoph; Wieler, Rainer [Institute of Geochemistry and Petrology, Clausiusstrasse 25, ETH Zurich, CH-8092 Zurich (Switzerland); Kleine, Thorsten [Institut fuer Planetologie, Westfaelische Wilhelms-Universitaet Muenster, Wilhelm-Klemm-Strasse 10, D-48149 Muenster (Germany); Dauphas, Nicolas, E-mail: burkhardt@erdw.ethz.ch [Origins Laboratory, Department of the Geophysical Sciences and Enrico Fermi Institute, University of Chicago, 5734 South Ellis Avenue, Chicago, IL 60637 (United States)

    2012-07-01

    Progressive dissolution of the Murchison carbonaceous chondrite with acids of increasing strengths reveals large internal W isotope variations that reflect a heterogeneous distribution of s- and r-process W isotopes among the components of primitive chondrites. At least two distinct carriers of nucleosynthetic W isotope anomalies must be present, which were produced in different nucleosynthetic environments. The co-variation of {sup 182}W/{sup 184}W and {sup 183}W/{sup 184}W in the leachates follows a linear trend that is consistent with a mixing line between terrestrial W and a presumed s-process-enriched component. The composition of the s-enriched component agrees reasonably well with that predicted by the stellar model of s-process nucleosynthesis. The co-variation of {sup 182}W/{sup 184}W and {sup 183}W/{sup 184}W in the leachates provides a means for correcting the measured {sup 182}W/{sup 184}W and {sup 182}W/{sup 183}W of Ca-Al-rich inclusions (CAI) for nucleosynthetic anomalies using the isotopic variations in {sup 183}W/{sup 184}W. This new correction procedure is different from that used previously, and results in a downward shift of the initial {epsilon}{sup 182}W of CAI to -3.51 {+-} 0.10 (where {epsilon}{sup 182}W is the variation in 0.01% of the {sup 182}W/{sup 183}W ratio relative to Earth's mantle). This revision leads to Hf-W model ages of core formation in iron meteorite parent bodies that are {approx}2 Myr younger than previously calculated. The revised Hf-W model ages are consistent with CAI being the oldest solids formed in the solar system, and indicate that core formation in some planetesimals occurred within {approx}2 Myr of the beginning of the solar system.

  18. ZIRCONIUM—HAFNIUM ISOTOPE EVIDENCE FROM METEORITES FOR THE DECOUPLED SYNTHESIS OF LIGHT AND HEAVY NEUTRON-RICH NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Akram, W.; Schönbächler, M. [School of Earth, Atmospheric and Environmental Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL (United Kingdom); Sprung, P. [Institut für Planetologie, Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Vogel, N. [Institute for Geochemistry and Petrology, ETH, Clausiusstrasse 25, 8092 Zürich (Switzerland)

    2013-11-10

    Recent work based on analyses of meteorite and terrestrial whole-rock samples showed that the r- and s- process isotopes of Hf were homogeneously distributed throughout the inner solar system. We report new Hf isotope data for Calcium-Aluminum-rich inclusions (CAIs) of the CV3 carbonaceous chondrite Allende, and novel high-precision Zr isotope data for these CAIs and three carbonaceous chondrites (CM, CO, CK). Our Zr data reveal enrichments in the neutron-rich isotope {sup 96}Zr (≤1ε in {sup 96}Zr/{sup 90}Zr) for bulk chondrites and CAIs (∼2ε). Potential isotope effects due to incomplete sample dissolution, galactic and cosmic ray spallation, and the nuclear field shift are assessed and excluded, leading to the conclusion that the {sup 96}Zr isotope variations are of nucleosynthetic origin. The {sup 96}Zr enrichments are coupled with {sup 50}Ti excesses suggesting that both nuclides were produced in the same astrophysical environment. The same CAIs also exhibit deficits in r-process Hf isotopes, which provides strong evidence for a decoupling between the nucleosynthetic processes that produce the light (A ≤ 130) and heavy (A > 130) neutron-rich isotopes. We propose that the light neutron-capture isotopes largely formed in Type II supernovae (SNeII) with higher mass progenitors than the supernovae that produced the heavy r-process isotopes. In the context of our model, the light isotopes (e.g. {sup 96}Zr) are predominantly synthesized via charged-particle reactions in a high entropy wind environment, in which Hf isotopes are not produced. Collectively, our data indicates that CAIs sampled an excess of materials produced in a normal mass (12-25 M{sub ☉}) SNII.

  19. Interaction of zirconium and hafnium tetrachlorides with cesium, rubidium and potassium chlorides and Raman spectra of reaction products

    International Nuclear Information System (INIS)

    Salyulev, A.B.; Vovkotrub, Eh.G.; Strekalovskij, V.N.

    2008-01-01

    Raman spectroscopy was used to reveal the formation of novel complexes involving [Zr 2 Cl 9 ] - and [Hf 2 Cl 9 ] - anions in molten mixtures of ZrCl 4 and HfCl 4 with CsCl, RbCl, and KCl. A prediction is made about the presence of the above-mentioned complex anions in poorly investigated melts of the corresponding binary systems at high concentrations of ZrCl 4 or HfCl 4 [ru

  20. Determination of rare earth elements, hafnium and cadmium in sintered pellets of mixed thorium and uranium oxides by neutron activation

    International Nuclear Information System (INIS)

    Cardoso, S.N.M.

    1987-01-01

    This work shows the development of a method for determination of the rare-earth elements (Eu, Sm, Dy and Gd), Hf and Cd contents in sinterized U and Th mixed oxides by neutron activation analysis. The sample is dissolved in nitric/fluoridric (0,1% HF) medium, to dryness and redissolved in 6N HCl solution. The Hf is extracted into organic phase (0,5 M TTA/benzene), irradiated and analysed through 181 Hf isotope energy peak. The aqueous phase is treated with NH 4 OH for the precipitation of hidroxides. Then, these are dissolved in 6N HNO 3 solution. The extraction of U and Th is made in two steps, one with TBP/CCl 4 and another with 0,5 M TTA/C 6 H 6 . Then the rare-earth elements and Cd are irradiated and determined by gamma spectrometry. (author) [pt