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Sample records for beryllium oxide powder

  1. Specification for nuclear-grade beryllium oxide powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification defines the physical and chemical requirements of nuclear-grade beryllium oxide (BeO) powder to be used in fabricating nuclear components. 1.2 This specification does not include requirements for health and safety. , , It recognizes the material as a Class B poison and suggests that producers and users become thoroughly familiar with and comply to applicable federal, state, and local regulations and handling guidelines. 1.3 Special tests and procedures are given in Annex A1 and Annex A2. 1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  2. Notched strength of beryllium powder and ingot sheets.

    Science.gov (United States)

    Moss, R. G.

    1972-01-01

    The effects of notches in thin beryllium sheets were studied as functions of material variables and notch severity. Double edge notched samples having stress concentration factors of 1.0 to 15.4 were prepared by milling to size, etching, and electrical discharge machining the notches. Strength was not reduced greatly by sharp notches, and duller notches were more deleterious than sharp notches. The trend was for reduced strength for dull notches, increased strength for sharper notches, and reduced strength for very sharp notches. Differences in material purity or source of the sheet had little affect on notch sensitivity. The most important factors appear to be oxide content and directionality of the sheet microstructure; high oxide content and highly directional microstructure tend to give more notch sensitivity than low oxide content, and more bidirectional microstructure. Postulated causes of the change in notched/unnotched strength are given.

  3. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  4. Study of the chemical interaction between the beryllium powders of different particles size and the air in the temperature range 500-1000degC form the viewpoint of ITER safety

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, D.A. [State Scientific Center of Russian Federation, Moscow (Russian Federation); Konovalov, Y.V.; Gorokhov, V.A.; Levin, V.B.; Chekhlatov, G.M.; Khomutov, A.M.

    1998-01-01

    Under an effect of some factors characteristic for the ITER- operating condition a dense beryllium facing plasma can transit into various forms, changing its structural states. As a result of the bombardment of beryllium plasma facing components by ion fluxes, the production of a dust including the particles from a few micrometers to a few millimeters in size is possible. The specific features in the behaviour of various beryllium forms under emergency conditions are of an essential interest from the viewpoint of ITER safety. Some grades of powders of different average particles size (14-31 micron) have been produced in a given study, and their chemical interaction at high temperatures with air (500-1100degC), test duration effects simulating the emergency situation at ITER in the first approximation have been studied. The temperature dependence of beryllium powders (different particles size after disc abrased) interaction with air in the temperature range 500-1000degC at the exposure of 5 hours long for each temperature and kinetic dependence of interaction of these powders with air at 800degC for the exposure from half an hour to 7 hours long were studied. An analysis of granulometric weight fraction in the metallic and oxidized beryllium powders with different particles size has been done by the photosedimentational technique with the instrument `Analysette-20`. Construction of a mathematical model for the chemical interaction of beryllium powders with air at high temperatures have been carried out. (author)

  5. Differences in estimates of size distribution of beryllium powder materials using phase contrast microscopy, scanning electron microscopy, and liquid suspension counter techniques

    Directory of Open Access Journals (Sweden)

    Day Gregory A

    2007-02-01

    Full Text Available Abstract Accurate characterization of the physicochemical properties of aerosols generated for inhalation toxicology studies is essential for obtaining meaningful results. Great emphasis must also be placed on characterizing particle properties of materials as administered in inhalation studies. Thus, research is needed to identify a suite of techniques capable of characterizing the multiple particle properties (i.e., size, mass, surface area, number of a material that may influence toxicity. The purpose of this study was to characterize the morphology and investigate the size distribution of a model toxicant, beryllium. Beryllium metal, oxides, and alloy particles were aerodynamically size-separated using an aerosol cyclone, imaged dry using scanning electron microscopy (SEM, then characterized using phase contrast microscopy (PCM, a liquid suspension particle counter (LPC, and computer-controlled SEM (CCSEM. Beryllium metal powder was compact with smaller sub-micrometer size particles attached to the surface of larger particles, whereas the beryllium oxides and alloy particles were clusters of primary particles. As expected, the geometric mean (GM diameter of metal powder determined using PCM decreased with aerodynamic size, but when suspended in liquid for LPC or CCSEM analysis, the GM diameter decreased by a factor of two (p

  6. Mechanisms of hydrogen retention in metallic beryllium and beryllium oxide and properties of ion-induced beryllium nitride; Rueckhaltemechanismen fuer Wasserstoff in metallischem Beryllium und Berylliumoxid sowie Eigenschaften von ioneninduziertem Berylliumnitrid

    Energy Technology Data Exchange (ETDEWEB)

    Oberkofler, Martin

    2011-09-22

    In the framework of this thesis laboratory experiments on atomically clean beryllium surfaces were performed. They aim at a basic understanding of the mechanisms occurring upon interaction of a fusion plasma with a beryllium first wall. The retention and the temperature dependent release of implanted deuterium ions are investigated. An atomistic description is developed through simulations and through the comparison with calculations based on density functional theory. The results of these investigations are compared to the behaviour of hydrogen upon implantation into thermally grown beryllium oxide layers. Furthermore, beryllium nitride is produced by implantation of nitrogen into metallic beryllium and its properties are investigated. The results are interpreted with regard to the use of beryllium in a fusion reactor. (orig.)

  7. Codeposition of deuterium ions with beryllium oxide at elevated temperatures

    CERN Document Server

    Markin, A V; Gorodetsky, A E; Negodaev, M A; Rozhanskii, N V; Scaffidi-Argentina, F; Werle, H; Wu, C H; Zalavutdinov, R K; Zakharov, A P

    2000-01-01

    Deuterium-loaded BeO films were produced by sputtering the beryllium target with 10 keV Ne ions in D sub 2 gas at a pressure of approximately 1 Pa. The sputtered beryllium reacts - on the substrate surface - with the residual oxygen, thus forming a beryllium oxide layer. Biasing the substrate negatively with respect to the target provides the simultaneous bombardment of the growing film surface with D ions formed by Ne-D sub 2 collisions. Substrate potential governs the maximum energy of ions striking the growing film surface while its size governs the flux density. According to X-ray photoelectron spectroscopy (XPS), electron probe microanalysis (EPMA) and reflection high energy electron diffraction (RHEED) data, the beryllium is deposited in the form of polycrystalline hcp-BeO layers with negligible (about 1 at.%) carbon and neon retention. Thermal desorption spectroscopy (TDS) data shows a strong deuterium bonding, with a desorption peak at 950 K, in the films deposited at -50 and -400 V substrate potentia...

  8. Preparation of a sinterable beryllium oxide through decomposition of beryllium hydroxide (1963); Preparation d'un oxyde de beryllium frittable par decomposition de l'hydiloxyde (1963)

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    Bernier, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1963-07-01

    In the course of the present study, we have attempted to precise the factors which among the ones effective in the course of the preparation of the beryllium hydroxide and oxide and during the sintering have an influence on the final result: the density and homogeneity of the sintered body. Of the several varieties of hydroxides precipitated from a sulfate solution the {beta}-hydroxide only is always contaminated with beryllium sulfate and cannot be purified even by thorough washing. We noticed that those varieties of the hydroxide (gel, {alpha}, {beta}) have different decomposition rates; this behaviour is used to identify and even to dose the different species in ({alpha}, {beta}) mixtures. The various hydroxides transmit to the resulting oxides the shape they had when precipitated. Accordingly the history of the oxide is revealed by its behaviour during its fabrication and sintering. By comparing the results of the sintering operation with the various measurements performed on the oxide powders we are led to the conclusion that an oxide obtained from beryllium hydroxide is sinterable under vacuum if the following conditions are fulfilled: the particle size must lie between 0.1 and 0.2 {mu} and the BeSO{sub 4} content of the powder must be less than 0.25 per cent wt (expressed as SO{sub 3}/BeO). The best fitting is obtained with the oxide issued from an {alpha}-hydroxide precipitated as very small aggregates and with a low sulfur-content. We have observed that this is also the case for the oxide obtained by direct calcination of beryllium sulfate. (author) [French] Au cours de cette etude, nous avons cherche a preciser les facteurs qui, intervenant tout au long de la preparation de l'hydroxyde, puis de l'oxyde de beryllium et enfin du frittage, peuvent avoir une influence sur le resultat final: la densite et l'homogeneite du fritte. Parmi tous les hydroxydes precipites d'une solution de sulfate, seul l'hydroxyde {beta} est toujours

  9. Extraction of beryllium from refractory beryllium oxide with dilute ammonium bifluoride and determination by fluorescence: a multiparameter performance evaluation.

    Science.gov (United States)

    Goldcamp, Michael J; Goldcamp, Diane M; Ashley, Kevin; Fernback, Joseph E; Agrawal, Anoop; Millson, Mark; Marlow, David; Harrison, Kenneth

    2009-12-01

    Beryllium exposure can cause a number of deleterious health effects, including beryllium sensitization and the potentially fatal chronic beryllium disease. Efficient methods for monitoring beryllium contamination in workplaces are valuable to help prevent dangerous exposures to this element. In this work, performance data on the extraction of beryllium from various size fractions of high-fired beryllium oxide (BeO) particles (from Beryllium concentrations were determined by fluorescence using a hydroxybenzoquinoline fluorophore. The effects of ABF concentration and volume, extraction temperature, sample tube types, and presence of filter or wipe media were examined. Three percent ABF extracts beryllium nearly twice as quickly as 1% ABF; extraction solution volume has minimal influence. Elevated temperatures increase the rate of extraction dramatically compared with room temperature extraction. Sample tubes with constricted tips yield poor extraction rates owing to the inability of the extraction medium to access the undissolved particles. The relative rates of extraction of Be from BeO of varying particle sizes were examined. Beryllium from BeO particles in fractions ranging from less than 32 microm up to 212 microm were subjected to various extraction schemes. The smallest BeO particles are extracted more quickly than the largest particles, although at 90 degrees C even the largest BeO particles reach nearly quantitative extraction within 4 hr in 3% ABF. Extraction from mixed cellulosic-ester filters, cellulosic surface-sampling filters, wetted cellulosic dust wipes, and cotton gloves yielded 90% or greater recoveries. Scanning electron microscopy of BeO particles, including partially dissolved particles, shows that dissolution in dilute ABF occurs not just on the exterior surface but also via accessing particles' interiors due to porosity of the BeO material. Comparison of dissolution kinetics data shows that as particle diameter approximately doubles, extraction

  10. Remarkable Hydrogen Storage on Beryllium Oxide Clusters: First Principles Calculations

    CERN Document Server

    Shinde, Ravindra

    2016-01-01

    Since the current transportation sector is the largest consumer of oil, and subsequently responsible for major air pollutants, it is inevitable to use alternative renewable sources of energies for vehicular applications. The hydrogen energy seems to be a promising candidate. To explore the possibility of achieving a solid-state high-capacity storage of hydrogen for onboard applications, we have performed first principles density functional theoretical calculations of hydrogen storage properties of beryllium oxide clusters (BeO)$_{n}$ (n=2 -- 8). We observed that polar BeO bond is responsible for H$_{2}$ adsorption. The problem of cohesion of beryllium atoms does not arise, as they are an integral part of BeO clusters. The (BeO)$_{n}$ (n=2 -- 8) adsorbs 8--12 H$_{2}$ molecules with an adsorption energy in the desirable range of reversible hydrogen storage. The gravimetric density of H$_{2}$ adsorbed on BeO clusters meets the ultimate 7.5 wt% limit, recommended for onboard practical applications. In conclusion,...

  11. Preparation, certification and interlaboratory analysis of workplace air filters spiked with high-fired beryllium oxide.

    Science.gov (United States)

    Oatts, Thomas J; Hicks, Cheryl E; Adams, Amy R; Brisson, Michael J; Youmans-McDonald, Linda D; Hoover, Mark D; Ashley, Kevin

    2012-02-01

    Occupational sampling and analysis for multiple elements is generally approached using various approved methods from authoritative government sources such as the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), as well as consensus standards bodies such as ASTM International. The constituents of a sample can exist as unidentified compounds requiring sample preparation to be chosen appropriately, as in the case of beryllium in the form of beryllium oxide (BeO). An interlaboratory study was performed to collect analytical data from volunteer laboratories to examine the effectiveness of methods currently in use for preparation and analysis of samples containing calcined BeO powder. NIST SRM(®) 1877 high-fired BeO powder (1100 to 1200 °C calcining temperature; count median primary particle diameter 0.12 μm) was used to spike air filter media as a representative form of beryllium particulate matter present in workplace sampling that is known to be resistant to dissolution. The BeO powder standard reference material was gravimetrically prepared in a suspension and deposited onto 37 mm mixed cellulose ester air filters at five different levels between 0.5 μg and 25 μg of Be (as BeO). Sample sets consisting of five BeO-spiked filters (in duplicate) and two blank filters, for a total of twelve unique air filter samples per set, were submitted as blind samples to each of 27 participating laboratories. Participants were instructed to follow their current process for sample preparation and utilize their normal analytical methods for processing samples containing substances of this nature. Laboratories using more than one sample preparation and analysis method were provided with more than one sample set. Results from 34 data sets ultimately received from the 27 volunteer laboratories were subjected to applicable statistical analyses. The observed

  12. Calculated power distribution of a thermionic, beryllium oxide reflected, fast-spectrum reactor

    Science.gov (United States)

    Mayo, W.; Lantz, E.

    1973-01-01

    A procedure is developed and used to calculate the detailed power distribution in the fuel elements next to a beryllium oxide reflector of a fast-spectrum, thermionic reactor. The results of the calculations show that, although the average power density in these outer fuel elements is not far from the core average, the power density at the very edge of the fuel closest to the beryllium oxide is about 1.8 times the core avearge.

  13. Differences in estimates of size distribution of beryllium powder materials using phase contrast microscopy, scanning electron microscopy, and liquid suspension counter techniques.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Hoover, Mark D; Dickerson, Robert M; Day, Gregory A; Breysse, Patrick N; Scripsick, Ronald C

    2007-02-28

    Accurate characterization of the physicochemical properties of aerosols generated for inhalation toxicology studies is essential for obtaining meaningful results. Great emphasis must also be placed on characterizing particle properties of materials as administered in inhalation studies. Thus, research is needed to identify a suite of techniques capable of characterizing the multiple particle properties (i.e., size, mass, surface area, number) of a material that may influence toxicity. The purpose of this study was to characterize the morphology and investigate the size distribution of a model toxicant, beryllium. Beryllium metal, oxides, and alloy particles were aerodynamically size-separated using an aerosol cyclone, imaged dry using scanning electron microscopy (SEM), then characterized using phase contrast microscopy (PCM), a liquid suspension particle counter (LPC), and computer-controlled SEM (CCSEM). Beryllium metal powder was compact with smaller sub-micrometer size particles attached to the surface of larger particles, whereas the beryllium oxides and alloy particles were clusters of primary particles. As expected, the geometric mean (GM) diameter of metal powder determined using PCM decreased with aerodynamic size, but when suspended in liquid for LPC or CCSEM analysis, the GM diameter decreased by a factor of two (p particles attached to the surface of larger particles and/or particle agglomerates detach in liquid, thereby shifting the particle size distribution downward. The GM diameters of the oxide materials were similar regardless of sizing technique, but observed differences were generally significant (p aerodynamic cluster size will dictate deposition in the lung, but primary particle size may influence biological activity. The GM diameter of alloy particles determined using PCM became smaller with decreasing aerodynamic size fraction; however, when suspended in liquid for CCSEM and LPC analyses, GM particle size decreased by a factor of two (p

  14. The beryllium production at Ulba metallurgical plant (Ust-Kamenogrsk, Kazakhstan)

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Tuzov, Y.V. [Ulba Metallurgical Plant (Zavod), Ust-Kamenogorsk, Abay prospect 102 (Kazakhstan)

    1998-01-01

    The Report includes data on beryllium production of Ulba metallurgical plant, located in Ust-Kamenogorsk (Kazakhstan). Beryllium production is showed to have extended technological opportunities in manufacturing semi-products (beryllium ingots, master alloys, metallic beryllium powders, beryllium oxide) and in production of structural beryllium and its parts. Ulba metallurgical plant owns a unique technology of beryllium vacuum distillation, which allows to produce reactor grades of beryllium with a low content of metallic impurities. At present Ulba plant does not depend on raw materials suppliers. The quantity of stored raw materials and semi-products will allow to provide a 25-years work of beryllium production at a full capacity. The plant has a satisfactory experience in solving ecological problems, which could be useful in ITER program. (author)

  15. Beryllium chloride-induced oxidative DNA damage and alteration in the expression patterns of DNA repair-related genes.

    Science.gov (United States)

    Attia, Sabry M; Harisa, Gamaleldin I; Hassan, Memy H; Bakheet, Saleh A

    2013-09-01

    Beryllium metal has physical properties that make its use essential for very specific applications, such as medical diagnostics, nuclear/fusion reactors and aerospace applications. Because of the widespread human exposure to beryllium metals and the discrepancy of the genotoxic results in the reported literature, detail assessments of the genetic damage of beryllium are warranted. Mice exposed to beryllium chloride at an oral dose of 23mg/kg for seven consecutive days exhibited a significant increase in the level of DNA-strand breaking and micronuclei formation as detected by a bone marrow standard comet assay and micronucleus test. Whereas slight beryllium chloride-induced oxidative DNA damage was detected following formamidopyrimidine DNA glycosylase digestion, digestion with endonuclease III resulted in considerable increases in oxidative DNA damage after the 11.5 and 23mg/kg/day treatment as detected by enzyme-modified comet assays. Increased 8-hydroxydeoxyguanosine was also directly correlated with increased bone marrow micronuclei formation and DNA strand breaks, which further confirm the involvement of oxidative stress in the induction of bone marrow genetic damage after exposure to beryllium chloride. Gene expression analysis on the bone marrow cells from beryllium chloride-exposed mice showed significant alterations in genes associated with DNA damage repair. Therefore, beryllium chloride may cause genetic damage to bone marrow cells due to the oxidative stress and the induced unrepaired DNA damage is probably due to the down-regulation in the expression of DNA repair genes, which may lead to genotoxicity and eventually cause carcinogenicity.

  16. Synthesis and processing of monosized oxide powders

    Science.gov (United States)

    Barringer, Eric A.; Fegley, Jr., M. Bruce; Bowen, H. Kent

    1985-01-01

    Uniform-size, high-purity, spherical oxide powders are formed by hydrolysis of alkoxide precursors in dilute alcoholic solutions. Under controlled conditions (concentrations of 0.03 to 0.2 M alkoxide and 0.2 to 1.5 M water, for example) oxide particles on the order of about 0.05 to 0.7 micron can be produced. Methods of doping such powders and forming sinterable compacts are also disclosed.

  17. (Beryllium). Internal Report No. 137, Jan. 15, 1958; Le beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Mouret, P.; Rigaud, A

    1959-07-01

    After a brief summary of the physical and chemical properties of beryllium, the various chemical treatments which can be applied to beryllium minerals either directly or after a physical enrichment are discussed. These various treatments give either the hydroxide or beryllium salts, from which either beryllium oxide or metallic beryllium can easily be obtained. The purification, analysis and uses of beryllium are also briefly discussed. (author)

  18. Oxide segregation and melting behavior of transient heat load exposed beryllium

    Science.gov (United States)

    Spilker, B.; Linke, J.; Pintsuk, G.; Wirtz, M.

    2016-10-01

    In the experimental fusion reactor ITER, beryllium will be applied as first wall armor material. However, the ITER-like wall project at JET already experienced that the relatively low melting temperature of beryllium can easily be exceeded during plasma operation. Therefore, a detailed study was carried out on S-65 beryllium under various transient, ITER-relevant heat loads that were simulated in the electron beam facility JUDITH 1. Hereby, the absorbed power densities were in the range of 0.15-1.0 GW m-2 in combination with pulse durations of 1-10 ms and pulse numbers of 1-1000. In metallographic cross sections, the emergence of a transition region in a depth of ~70-120 µm was revealed. This transition region was characterized by a strong segregation of oxygen at the grain boundaries, determined with energy dispersive x-ray spectroscopy element mappings. The oxide segregation strongly depended on the maximum temperature reached at the end of the transient heat pulse in combination with the pulse duration. A threshold for this process was found at 936 °C for a pulse duration of 10 ms. Further transient heat pulses applied to specimens that had already formed this transition region resulted in the overheating and melting of the material. The latter occurred between the surface and the transition region and was associated with a strong decrease of the thermal conductivity due to the weakly bound grains across the transition region. Additionally, the transition region caused a partial separation of the melt layer from the bulk material, which could ultimately result in a full detachment of the solidified beryllium layers from the bulk armor. Furthermore, solidified beryllium filaments evolved in several locations of the loaded area and are related to the thermally induced crack formation. However, these filaments are not expected to account for an increase of the beryllium net erosion.

  19. Thermo-optical properties of beryllium containing oxide crystals as materials for high power laser systems

    Science.gov (United States)

    Pestryakov, E. V.; Petrov, V. V.; Trunov, V. I.; Kirpichnikov, A. V.; Laptev, A. V.; Matrosov, V. N.

    2007-06-01

    The elastic and thermo-optical properties of chrysoberyl, beryllium hexaaluminate and beryllium-lanthanum hexaaluminate crystals have been experimentally studied. The velocities of elastic-wave propagation in the crystals are measured by acousto-optic interference method. The values of all the independent components of elastic-constant tensor are determined and used to calculate a number of important dynamic parameters of the crystals such as the Young's and shear moduli, the modulus of volume elasticity, Poisson's ratio, the Debye temperature. Also measurements of refractive indices in 25 - 75 C temperature range in VIS spectral region were performed. Using experimental data the dispersion of thermal optical coefficients (dn/dT) was calculated, these data were employed to evaluate the thermal lens in beryllium containing laser crystals. The experimental and calculated data are compared with similar parameters for well-known laser hosts. Some of beryllium containing oxide crystals was shown to be candidates for master oscillator and amplifying stages of high power femtosecond laser systems.

  20. Physical chemistry of the powder metallurgy of beryllium: Chemical characterization of the powder in relation to its granularity

    Energy Technology Data Exchange (ETDEWEB)

    Bracconi, P.; Buisson, L. [Univ. of Burgundy, Dijon (France). Lab. for the Reactivity of Solids; Bonnet, C. [CEA, Valduc (France). Atomic Energy Board

    1996-02-01

    Combining the systematic quantitative chemical analysis of the light impurities H, C, N, and O, the quantitative thermal desorption of molecular H{sub 2}O and H{sub 2}, and X-ray diffractometry of various size fractions of a commercial Be powder (SP-65 grade from Brush-Wellman) allowed the precise determination of the mean composition and equivalent mean thickness of the surface impurity phases in the passivation-contamination layer on the surface of the particles. The overall surface stoichiometry is as follows: 0.2 BeO{sub crystallized}, 0.8 [BeO {minus} 0.59 H{sub 2}O]{sub amorphous}, 0.14 H{sub 2}O{sub ads}. The result of the elemental analysis by X-ray photoelectron spectroscopy of the unetched surface of a powder pellet is compared. Analysis of the metallic impurities reveals increased concentrations of Mg, Ca, Ti, and Cr in the finest fraction, presumably due to the liberation of fine particles of intermetallic phases by attrition

  1. Joining of Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, A

    2006-02-01

    A handbook dealing with the many aspects of beryllium that would be important for the users of this metal is currently being prepared. With an introduction on the applications, advantages and limitations in the use of this metal the following topics will be discussed in this handbook: physical, thermal, and nuclear properties; extraction from the ores; purification and casting of ingots; production and types of beryllium powders; consolidation methods, grades, and properties; mechanical properties with emphasis on the various factors affecting these properties; forming and mechanical working; welding, brazing, bonding, and fastening; machining; powder deposition; corrosion; health aspects; and examples of production of components. This report consists of ''Section X--Joining'' from the handbook. The prefix X is maintained here for the figures, tables and references. In this section the different methods used for joining beryllium and the advantages, disadvantages and limitations of each are presented. The methods discussed are fusion welding, brazing, solid state bonding (diffusion bonding and deformation bonding), soldering, and mechanical fastening. Since beryllium has a high affinity for oxygen and nitrogen with the formation of oxides and nitrides, considerable care must be taken on heating the metal, to protect it from the ambient atmosphere. In addition, mating surfaces must be cleaned and joints must be designed to minimize residual stresses as well as locations for stress concentration (notch effects). In joining any two metals the danger exists of having galvanic corrosion if the part is subjected to moisture or to any type of corroding environment. This becomes a problem if the less noble (anodic) metal has a significantly smaller area than the more noble (cathodic) metal since the ions (positive charges) from the anodic (corroding) metal must correspond to the number of electrons (negative charges) involved at the cathode. Beryllium

  2. Physical properties of beryllium oxide - Irradiation effects; Proprietes physiques et caracteristiques mecaniques de l'oxyde de beryllium fritte - Effet de l'irradiation et guerison

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    Elston, J.; Caillat, R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    This work has been carried out in view of determining several physical properties of hot-pressed beryllium oxide under various conditions and the change of these properties after irradiation. Special attention has been paid on to the measurement of the thermal conductivity coefficient and thermal diffusivity coefficient. Several designs for the measurement of the thermal conductivity coefficient have been achieved. They permit its determination between 50 and 300 deg. C, between 400 and 800 deg. C. Some measurements have been made above 1000 deg. C. In order to measure the thermal diffusivity coefficient, we heat a perfectly flat surface of a sample in such a way that the heat flux is modulated (amplitude and frequency being adjustable). The thermal diffusivity coefficient is deduced from the variations of temperature observed on several spots. Tensile strength; compressive strength; expansion coefficient; sound velocity and crystal parameters have been also measured. Some of the measurements have been carried out after neutron irradiation. Some data have been obtained on the change of the properties of beryllium oxide depending on the integrated neutron flux. (author)Fren. [French] L'objet de cette etude est la determination de plusieurs proprietes physiques de l'oxyde de beryllium fritte sous charge dans differentes conditions et l'evolution de ces proprietes apres irradiation. Une attention particuliere a ete portee sur la mesure de la conductibilite et de la diffusivite thermiques. Differents montages ont ete realises pour mesurer la conductibilite thermique. Ils permettent la determination entre 50 et 300 deg. C, entre 400 et 800 deg. C; quelques mesures ont ete faites au-dessus de 1000 deg. C. Pour la mesure du coefficient de diffusivite thermique, on realise une attaque thermique, de frequence et d'amplitude reglables d'une face parfaitement plane d'un echantillon d'oxyde de beryllium. Les variations de temperature sont

  3. JET-ISX-B beryllium limiter experiment safety analysis report and operational safety requirements

    Energy Technology Data Exchange (ETDEWEB)

    Edmonds, P.H.

    1985-09-01

    An experiment to evaluate the suitability of beryllium as a limiter material has been completed on the ISX-B tokamak. The experiment consisted of two phases: (1) the initial operation and characterization in the ISX experiment, and a period of continued operation to the specified surface fluence (10/sup 22/ atoms/cm/sup 2/) of hydrogen ions; and (2) the disassembly, decontamination, or disposal of the ISX facility. During these two phases of the project, the possibility existed for beryllium and/or beryllium oxide powder to be produced inside the vacuum vessel. Beryllium dust is a highly toxic material, and extensive precautions are required to prevent the release of the beryllium into the experimental work area and to prevent the contamination of personnel working on the device. Details of the health hazards associated with beryllium and the appropriate precautions are presented. Also described in appendixes to this report are the various operational safety requirements for the project.

  4. Reprocessing technology development for irradiated beryllium

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    Kawamura, H.; Sakamoto, N. [Oarai Research Establishment, Ibaraki-ken (Japan); Tatenuma, K. [KAKEN Co., Ibaraki-ken (Japan)] [and others

    1995-09-01

    At present, beryllium is under consideration as a main candidate material for neutron multiplier and plasma facing material in a fusion reactor. Therefore, it is necessary to develop the beryllium reprocessing technology for effective resource use. And, we have proposed reprocessing technology development on irradiated beryllium used in a fusion reactor. The preliminary reprocessing tests were performed using un-irradiated and irradiated beryllium. At first, we performed beryllium separation tests using un-irradiated beryllium specimens. Un-irradiated beryllium with beryllium oxide which is a main impurity and some other impurities were heat-treated under chlorine gas flow diluted with Ar gas. As the results high purity beryllium chloride was obtained in high yield. And it appeared that beryllium oxide and some other impurities were removed as the unreactive matter, and the other chloride impurities were separated by the difference of sublimation temperature on beryllium chloride. Next, we performed some kinds of beryllium purification tests from beryllium chloride. And, metallic beryllium could be recovered from beryllium chloride by the reduction with dry process. In addition, as the results of separation and purification tests using irradiated beryllium specimens, it appeared that separation efficiency of Co-60 from beryllium was above 96%. It is considered that about 4% Co-60 was carried from irradiated beryllium specimen in the form of cobalt chloride. And removal efficiency of tritium from irradiated beryllium was above 95%.

  5. Interaction of implanted deuterium and helium with beryllium: radiation enhanced oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Langley, R.A.

    1979-01-01

    The interaction of implanted deuterium and helium with beryllium is of significant interest in the application of first wall coatings and other components of fusion reactors. Electropolished polycrystalline beryllium was first implanted with an Xe backscatter marker at 1.98 MeV followed by either implantation with 5 keV diatomic deuterium or helium. A 2.0 MeV He beam was used to analyze for impurity buildup; namely oxygen. The oxide layer thickness was found to increase linearly with increasing implant fluence. A 2.5 MeV H/sup +/ beam was used to depth profile the D and He by ion backscattering. In addition the retention of the implant was measured as a function of the implant fluence. The mean depth of the implant was found to agree with theoretical range calculations. Scanning electron microscopy was used to observe blister formation. No blisters were observed for implanted D but for implanted He blisters occurred at approx. 1.75 x 10/sup 17/ He cm/sup -2/. The blister diameter increased with increasing implant fluence from about 0.8 ..mu..m at 10/sup 18/ He cm/sup -2/ to 5.5 ..mu..m at 3 x 10/sup 18/ He cm/sup -2/.

  6. Influence of beryllium cations on the electrochemical oxidation of methanol on stepped platinum surfaces in alkaline solution

    Science.gov (United States)

    García, Gonzalo; Stoffelsma, Chantal; Rodriguez, Paramaconi; Koper, Marc T. M.

    2015-01-01

    The role of beryllium on the oxidation of methanol on Pt stepped surfaces (Pt[(n-1) (111)x(110)]) orientation-Pt(553) with n = 5, Pt(554) n = 10, Pt(151514) n = 30), Pt(111) and Pt(110) single crystals in alkaline media was studied by cyclic voltammetry and Fourier transform infrared spectroscopy (FTIRS). The results suggest that under the conditions of the experiment, the methanol oxidation reaction follows a direct pathway with formaldehyde and formate as reaction intermediates. The combination of OHads and beryllium blocks the adsorption and oxidation of methanol on Pt(111), but appears to promote the complete oxidation of methanol to carbon dioxide/carbonate on Pt(110).

  7. Beryllium Manufacturing Processes

    Energy Technology Data Exchange (ETDEWEB)

    Goldberg, A

    2006-06-30

    This report is one of a number of reports that will be combined into a handbook on beryllium. Each report covers a specific topic. To-date, the following reports have been published: (1) Consolidation and Grades of Beryllium; (2) Mechanical Properties of Beryllium and the Factors Affecting these Properties; (3) Corrosion and Corrosion Protection of Beryllium; (4) Joining of Beryllium; (5) Atomic, Crystal, Elastic, Thermal, Nuclear, and other Properties of Beryllium; and (6) Beryllium Coating (Deposition) Processes and the Influence of Processing Parameters on Properties and Microstructure. The conventional method of using ingot-cast material is unsuitable for manufacturing a beryllium product. Beryllium is a highly reactive metal with a high melting point, making it susceptible to react with mold-wall materials forming beryllium compounds (BeO, etc.) that become entrapped in the solidified metal. In addition, the grain size is excessively large, being 50 to 100 {micro}m in diameter, while grain sizes of 15 {micro}m or less are required to meet acceptable strength and ductility requirements. Attempts at refining the as-cast-grain size have been unsuccessful. Because of the large grain size and limited slip systems, the casting will invariably crack during a hot-working step, which is an important step in the microstructural-refining process. The high reactivity of beryllium together with its high viscosity (even with substantial superheat) also makes it an unsuitable candidate for precision casting. In order to overcome these problems, alternative methods have been developed for the manufacturing of beryllium. The vast majority of these methods involve the use of beryllium powders. The powders are consolidated under pressure in vacuum at an elevated temperature to produce vacuum hot-pressed (VHP) blocks and vacuum hot-isostatic-pressed (HIP) forms and billets. The blocks (typically cylindrical), which are produced over a wide range of sizes (up to 183 cm dia. by 61

  8. Preparation of nanosized non-oxide powders using diatomaceous earth

    Directory of Open Access Journals (Sweden)

    Šaponjić A.

    2009-01-01

    Full Text Available In this paper the nanosized non-oxide powders were prepared by carbothermal reduction and subsequent nitridation of diatomaceous earth which is a waste product from coal exploitation. Our scope was to investigate the potential use of diatomaceous earth as a main precursor for low-cost nanosized non-oxide powder preparation as well as to solve an environmental problem. The influence of carbon materials (carbonized sucrose, carbon cryogel and carbon black as a reducing agent on synthesis and properties of low-cost nanosized nonoxide powders was also studied. The powders were characterized by specific surface area, X-ray and SEM investigations. It was found that by using diatomaceous earth it is was possible to produce either a mixture of non-oxide powders (Si3N4/SiC or pure SiC powders depending on temperature.

  9. Development of radiation resistant grades of beryllium for nuclear and fusion facilities

    Energy Technology Data Exchange (ETDEWEB)

    Kupriyanov, I.B.; Gorokhov, V.A.; Nikolaev, G.N. [Russia Research Institute of Inorganic Materials, Moscow (Russian Federation)

    1995-09-01

    R&D results on beryllium with high radiation resistance obtained recently are described in this report. The data are presented on nine different grades of isotropic beryllium manufactured by VNIINM and distinguished by both initial powder characteristics and properties of billets, made of these powders. The average grain size of the investigated beryllium grades varied from 8 to 26 {mu}m, the content of beryllium oxide was 0.9 - 3.9 wt.%, the dispersity of beryllium oxide - 0.04 - 0.5 {mu}m, tensile strength -- 250 - 650 MPa. All materials were irradiated in SM - 2 reactor over the temperature range 550 - 780{degrees}C. The results of the investigation showed, that HIP beryllium grades are less susceptible to swelling at higher temperatures in comparison with hot pressed and extruded grades. Beryllium samples, having the smallest grain size, demonstrated minimal swelling, which was less than 0.8 % at 750{degrees}C and Fs = 3.7 {center_dot}10{sup 21} cm{sup -2} (E>0.1 MeV). The mechanical properties, creep and microstructure parameters, measured before and after irradiation, are presented.

  10. Beryllium 1989

    Energy Technology Data Exchange (ETDEWEB)

    1989-01-01

    The Roskill report on beryllium gives information on the occurrence and reserves, production technology, geographic distribution, consumption and end-uses, stocks, prices and beryllium and health. There is an appendix on international trade statistics. (author).

  11. Accurate Electronic, Transport, and Bulk Properties of Wurtzite Beryllium Oxide (BeO)

    Science.gov (United States)

    Bamba, Cheick Oumar; Malozovsky, Yuriy; Franklin, Lashounda; Bagayoko, Diola

    We present ab-initio, self-consistent density functional theory (DFT) description of electronic, transport, and bulk properties of wurtzite Beryllium oxide (w-BeO). We used a local density approximation potential (LDA) and the linear combination of atomic orbitals (LCOA) formalism. Our implementation of the Bagayoko, Zhao, and Williams (BZW) method, as enhanced by Ekuma and Franklin (BZW-EF), ensures the full, physical content of our local density approximation (LDA) calculations - as per the derivation of DFT [AIP Advances, 4, 127104 (2014) We report the band gap, density of states, partial density of state, effective masses, and the bulk modulus. Our calculated band gap of 10.29 eV, using an experimental, room temperature lattice constant of 2.6979 A at room temperature is in agreement with the experimental value of 10.6 eV. Acknowledgments:This work was funded in part the US National Science Foundation [NSF, Award Nos. EPS-1003897, NSF (2010-2015)-RII-SUBR, and HRD-1002541], the US Department of Energy, National Nuclear Security Administration (NNSA, Award No. DE-NA0002630), LaSPACE, and LONI-SUBR.

  12. Co-administration of adjuvants along with Moringa oleifera attenuates beryllium-induced oxidative stress and histopathological alterations in rats.

    Science.gov (United States)

    Agrawal, Narottam Das; Nirala, Satendra Kumar; Shukla, Sangeeta; Mathur, Ramesh

    2015-01-01

    Moringa oleifera Lam. (Moringaceae) is a rich source of antioxidants. All parts of the plant are medicinally important and have been used as traditional medicine for a variety of human ailments in India. Therapeutic efficacy of adjuvants with M. oleifera (MO) root extract was investigated against beryllium-induced oxidative stress. Hydroalcoholic (50% v/v) root extract of M. oleifera (150 mg/kg, p.o.) alone and combinations of M. oleifera with either piperine (2.5 mg/kg, p.o.) or curcumin (5.0 mg/kg, p.o.) daily for 1 week were administered in experimental rats against beryllium toxicity (1.0 mg/kg, i.p. daily for 5 weeks). Oxidative stress parameters including blood sugar, G-6-Pase in liver, and DNA damage were analyzed. Histopathological changes in liver and kidney were also observed. Beryllium enhanced lipid peroxidation (LPO), depleted reduced glutathione (GSH) and antioxidant enzymes activities, decreased blood sugar and G-6-Pase activity, and did not damage DNA. Histologically, liver was observed with structural loss and disintegration of hepatocytes, heavy vacuolation in hepatocytes, and kidney was observed with constriction of glomeruli and hypertrophy in epithelial cells of uriniferous tubules. Therapy of M. oleifera with piperine was effective; however, combination of M. oleifera with curcumin showed better therapeutic effect by reduction of LPO, elevated GSH level, maintained antioxidant enzymes activities, restored blood sugar, and G-6-Pase activity in liver together with almost normal histoarchitecture of liver and kidney. Curcumin enhanced therapeutic efficacy of M. oleifera root extract and showed better antioxidant potential against beryllium toxicity.

  13. Electron beam niobium oxide powder deposition

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, D.S. [Centro Tecnico Aeroespacial (CTA), Sao Jose dos Campos, SP (Brazil); Nono, M.C.A. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil); Silva, C.R.M. [Universidade de Brasilia (UnB), Brasilia, DF (Brazil)

    2009-07-01

    Full text: Zirconium oxide applied by Electron Beam –Physical Vapor Deposition can produce high quality coatings for high temperature blades. In this work niobium, yttrium and zirconium oxides were applied on metallic substrates, using EB-PVD, aiming thermal conductivity reduction. Coating characterization has been performed by X-ray diffractometry and scanning electron microscopy. X-ray diffractometry shows only tetragonal phase for the composition range evaluated, with tetragonality increase for higher niobium oxide amounts. Higher amounts of niobium promote reduction of ceramic coating theoretical density and thermal conductivity. (author)

  14. Fluidized reduction of oxides on fine metal powders without sintering

    Science.gov (United States)

    Hayashi, T.

    1985-01-01

    In the process of reducing extremely fine metal particles (av. particle size or = 1000 angstroms) covered with an oxide layer, the metal particles are fluidized by a gas flow contg. H, heated, and reduced. The method uniformly and easily reduces surface oxide layers of the extremely fine metal particles without causing sintering. The metal particles are useful for magnetic recording materials, conductive paste, powder metallurgy materials, chem. reagents, and catalysts.

  15. Standard specification for nuclear-grade hafnium oxide powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification defines the physical and chemical requirements for hafnium oxide powder intended for fabrication into shapes for use in a nuclear reactor core. 1.2 The material described herein shall be particulate in nature. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  16. Oxide Dispersion Strengthened Iron Aluminide by CVD Coated Powders

    Energy Technology Data Exchange (ETDEWEB)

    Asit Biswas Andrew J. Sherman

    2006-09-25

    This I &I Category2 program developed chemical vapor deposition (CVD) of iron, aluminum and aluminum oxide coated iron powders and the availability of high temperature oxidation, corrosion and erosion resistant coating for future power generation equipment and can be used for retrofitting existing fossil-fired power plant equipment. This coating will provide enhanced life and performance of Coal-Fired Boilers components such as fire side corrosion on the outer diameter (OD) of the water wall and superheater tubing as well as on the inner diameter (ID) and OD of larger diameter headers. The program also developed a manufacturing route for readily available thermal spray powders for iron aluminide coating and fabrication of net shape component by powder metallurgy route using this CVD coated powders. This coating can also be applid on jet engine compressor blade and housing, industrial heat treating furnace fixtures, magnetic electronic parts, heating element, piping and tubing for fossil energy application and automotive application, chemical processing equipment , heat exchanger, and structural member of aircraft. The program also resulted in developing a new fabrication route of thermal spray coating and oxide dispersion strengthened (ODS) iron aluminide composites enabling more precise control over material microstructures.

  17. Research Progress on Fracture Behaviors of Powder Metallurgy Polycrystalline Beryllium at Room Temperature%粉末冶金多晶态铍室温断裂行为的研究进展

    Institute of Scientific and Technical Information of China (English)

    康慧灵; 何力军; 许德美; 钟景明; 王战宏; 孙本双; 刘霄霞

    2013-01-01

    Performances of polycrystalline beryllium and its technological process of production are introduced.Its fracture behaviors at room temperature is also reviewed,which included:fracture characteristics; influence factors of fracture performances such as size and shape of beryllium powders,process of powdered metal compacting,surface residual stress,machine-damage,and impurities (BeO,Fe,A1,Cr,Ag,Si,C,etc) embedded in grains.By authors'opinion the basic researches of beryllium in engineering may be carried out in future is forecasted at the end of the paper.%介绍了粉末冶金法生产的多晶态铍的性能、生产工艺.综述了多晶态铍室温断裂行为的研究状况,包括铍的室温断裂特征,以及诸如铍粉粒度和形态、粉末压制过程、表面残余应力,机械加工损伤、多种杂质(BeO,Fe,Al,Cr,Ag,Si,C等)对铍室温断裂性能的影响.预测了未来关于铍在工程领域可能开展的基础性研究.

  18. Beryllium thin films for resistor applications

    Science.gov (United States)

    Fiet, O.

    1972-01-01

    Beryllium thin films have a protective oxidation resistant property at high temperature and high recrystallization temperature. However, the experimental film has very low temperature coefficient of resistance.

  19. High Temperature Oxidation Behavior and Characteristic of Beryllium%铍的高温氧化行为及特性研究

    Institute of Scientific and Technical Information of China (English)

    李芳芳; 陆雷; 肖红; 陈亮; 张焕林; 白彬

    2016-01-01

    The thermal oxidation of beryllium was investigated at different tempera-tures.The oxidation process,surface state after oxidation,micro-area composition and oxidation thickness were characterized and analyzed by thermogravimetry,AES and SEM.The oxidation behavior and characteristics of beryllium at different temperatures were also discussed.The results show that in the range of room temperature to 400 ℃, the oxidation weight gain of beryllium mainly follows parabolic law,and in the range of 400 ℃ to 900 ℃,the oxidation rate generally obeys linear change.At lower tempera-tures,the passivation layer formed on the surface of beryllium shows a good protective effect,which is very resistant to corrosion.The oxidation rate of beryllium is highly affected by higher temperatures.Below 600 ℃,the oxidation rate seems to be limited by the diffusion of beryllium atoms towards the surface.Above 800 ℃,oxygen diffuses into the material through the grain boundaries and pores,and oxide films crack during thermal expansion and stress action,which results in serious oxidation corrosion.%在不同温度下对金属铍(Be)进行热氧化,采用热重、AES 和 SEM 对 Be 的热氧化过程、氧化后表面状态、微区成分和氧化层厚度进行表征和分析,探讨了不同温度下 Be 的氧化行为和氧化特性。结果表明:室温~400℃范围内,Be 样品的氧化增重主要服从抛物线规律;400~900℃范围内,主要呈线性变化。在较低温度下,Be 表面形成的钝化层具有良好的保护作用,比较耐蚀。高温对 Be 样品的氧化影响较大,认为600℃以下 Be 的氧化主要受 Be 原子向表面的热扩散控制;800℃以上,氧通过晶界和孔洞扩散进入材料体内、氧化膜受热膨胀以及应力作用开裂等,导致 Be 发生严重的氧化腐蚀。

  20. Beryllium Toxicity

    Science.gov (United States)

    ... aerospace, aircraft manufacture and maintenance, computer, dental laboratories, telecommunications, and foundries and metal reclamation. How Can I ... if exposure stops. Beryllium usually affects the respiratory system, although it can affect other parts of the ...

  1. Chronic Beryllium Disease

    Science.gov (United States)

    ... Science Education & Training Home Conditions Chronic Beryllium Disease Chronic Beryllium Disease Make an Appointment Find a Doctor ... MD, MSPH, FCCP (February 01, 2016) What is chronic beryllium disease (CBD)? Chronic beryllium disease (CBD) is ...

  2. Beryllium--important for national defense

    Science.gov (United States)

    Boland, M.A.

    2012-01-01

    Beryllium is one of the lightest and stiffest metals, but there was little industrial demand for it until the 1930s and 1940s when the aerospace, defense, and nuclear sectors began using beryllium and its compounds. Beryllium is now classified by the U.S. Department of Defense as a strategic and critical material because it is used in products that are vital to national security. The oxide form of beryllium was identified in 1797, and scientists first isolated metallic beryllium in 1828. The United States is the world's leading source of beryllium. A single mine at Spor Mountain, Utah, produced more than 85 percent of the beryllium mined worldwide in 2010. China produced most of the remainder, and less than 2 percent came from Mozambique and other countries. National stockpiles also provide significant amounts of beryllium for processing. To help predict where future beryllium supplies might be located, U.S.Geological Survey (USGS) scientists study how and where beryllium resources are concentrated in Earth's crust and use that knowledge to assess the likelihood that undiscovered beryllium resources may exist. Techniques to assess mineral resources have been developed by the USGS to support the stewardship of Federal lands and to better evaluate mineral resource availability in a global context. The USGS also compiles statistics and information on the worldwide supply of, demand for, and flow of beryllium. These data are used to inform U.S. national policymaking.

  3. Standard specification for nuclear-grade zirconium oxide powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2008-01-01

    1.1 This specification defines the physical and chemical requirements for zirconium oxide powder intended for fabrication into shapes, either entirely or partially of zirconia, for use in a nuclear reactor core. 1.2 The material described herein shall be particulate in nature. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  4. Ultrahigh Oxidation Resistance and High Electrical Conductivity in Copper-Silver Powder

    Science.gov (United States)

    Li, Jiaxiang; Li, Yunping; Wang, Zhongchang; Bian, Huakang; Hou, Yuhang; Wang, Fenglin; Xu, Guofu; Liu, Bin; Liu, Yong

    2016-12-01

    The electrical conductivity of pure Cu powder is typically deteriorated at elevated temperatures due to the oxidation by forming non-conducting oxides on surface, while enhancing oxidation resistance via alloying is often accompanied by a drastic decline of electrical conductivity. Obtaining Cu powder with both a high electrical conductivity and a high oxidation resistance represents one of the key challenges in developing next-generation electrical transferring powder. Here, we fabricate a Cu-Ag powder with a continuous Ag network along grain boundaries of Cu particles and demonstrate that this new structure can inhibit the preferential oxidation in grain boundaries at elevated temperatures. As a result, the Cu-Ag powder displays considerably high electrical conductivity and high oxidation resistance up to approximately 300 °C, which are markedly higher than that of pure Cu powder. This study paves a new pathway for developing novel Cu powders with much enhanced electrical conductivity and oxidation resistance in service.

  5. Beryllium in the ITER blanket

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M.C.

    1995-01-01

    This paper consists of viewgraphs used in a presentation on the application of beryllium in breeding blankets for ITER and JET. The paper brings together data on the physical, thermal, mechanical, and chemical properties of beryllium and beryllium oxide for this type of application, as well as issues of compatibility with construction materials, and irradiation experience. It includes the results from testing programs carried out to arrive at some of the information, including fabrication work, irradiation experiments, and sample tests performed both in and out of the irradiation piles.

  6. Reaction pathways of NO oxidation by sodium chlorite powder.

    Science.gov (United States)

    Byun, Youngchul; Ko, Kyoung Bo; Cho, Moohyun; Namkung, Won; Lee, Kiman; Shin, Dong Nam; Koh, Dong Jun

    2009-07-01

    NO oxidation is an important prerequisite step to assist selective catalytic reduction at low temperatures (sodium chlorite powder (NaClO2(s)) can oxidize NO to NO2, the injection of NaClO2(s) can be simply adapted to NO oxidation. Therefore, we explored the reaction pathways of NO oxidation by NaClO2(s). Known concentrations of NO and NO2 in N2 balance were injected into packed-bed reactor containing NaClO2(s) at 130 degreesC. NaClO2(s) oxidized NO to NO2 which reacts again with NaClO2(s) to produce OClO. Comparison of experimental data with simulation results demonstrates that each NO2 molecule removed by the reaction with NaClO2(s) generated one OClO molecule, which also oxidized NO to NO2 with the production of ClNO and ClNO2. Using these results, we conclude that the oxidation of NO by NaClO2(s) occurred by two pathways. One is through the direct reaction of NO with NaClO(s). The other is through both the reaction of NO with OlCO produced by the reaction of NO2 with NaClO2(s) and the reaction of NO with ClO produced by the reaction of NO with OClO.

  7. Cerium oxide based nanometric powders: synthesis and characterization

    Directory of Open Access Journals (Sweden)

    Ninić M.

    2007-01-01

    Full Text Available Nanometric powders of solid solutions of cerium oxide were obtained by a modified glycine nitrate procedure. Solid solutions of the host compound CeO2 with one or more dopants in the lattice were synthesized. Rare earth cations (Re=Yb, Gd and Sm were added to ceria in total concentration of x= 0.2 that was kept constant. The criterion in doping was to keep the value of lattice parameter of ceria unchanged. The lattice parameters were calculated by using the model that takes into account the existence of oxygen vacancies in the structure.

  8. OVERVIEW OF BERYLLIUM SAMPLING AND ANALYSIS

    Energy Technology Data Exchange (ETDEWEB)

    Brisson, M

    2009-04-01

    Because of its unique properties as a lightweight metal with high tensile strength, beryllium is widely used in applications including cell phones, golf clubs, aerospace, and nuclear weapons. Beryllium is also encountered in industries such as aluminium manufacturing, and in environmental remediation projects. Workplace exposure to beryllium particulates is a growing concern, as exposure to minute quantities of anthropogenic forms of beryllium may lead to sensitization and to chronic beryllium disease, which can be fatal and for which no cure is currently known. Furthermore, there is no known exposure-response relationship with which to establish a 'safe' maximum level of beryllium exposure. As a result, the current trend is toward ever lower occupational exposure limits, which in turn make exposure assessment, both in terms of sampling and analysis, more challenging. The problems are exacerbated by difficulties in sample preparation for refractory forms of beryllium, such as beryllium oxide, and by indications that some beryllium forms may be more toxic than others. This chapter provides an overview of sources and uses of beryllium, health risks, and occupational exposure limits. It also provides a general overview of sampling, analysis, and data evaluation issues that will be explored in greater depth in the remaining chapters. The goal of this book is to provide a comprehensive resource to aid personnel in a wide variety of disciplines in selecting sampling and analysis methods that will facilitate informed decision-making in workplace and environmental settings.

  9. Graphene oxide powders with different oxidation degree, prepared by synthesis variations of the Hummers method

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Contreras, Jesus; Caballero-Briones, F., E-mail: fcaballero@ipn.mx

    2015-03-01

    Graphene oxide (GO) powders with different oxidation degree estimated through the relative intensity of the infrared absorption bands related to oxygen containing groups were prepared through variations of the Hummers method. The GO powders were analyzed by Transmission Electron Microscopy, Energy dispersive spectroscopy, X-ray Photoelectron Spectroscopy, Fourier Transform Infrared Spectroscopy, Raman spectroscopy, X-ray Diffraction, UV–VIS spectroscopy and Electrical Resistance measurements. Several square micron GO sheets with low wrinkling were obtained. Oxygen to carbon ratio is around 0.2 in all the samples although a strong variance in the relative intensity of the oxygen related infrared bands is evident. Thus, the oxidation degree was estimated from the FTIR measurements using the quotient between the C–O related bands area to the total area under the spectra. FTIR shows presence of hydroxyl (–OH), epoxy (C–O–C), carboxyl (–COOH) and carbonyl (C=O) moieties and evidence of intermolecular interactions between adjacent groups. These interactions influence the exfoliation degree, the absorbance of the GO suspensions, as well as the electrical resistance, while the crystalline domain sizes, estimated from XRD and Raman do not show a noticeable behavior related with the composition and molecular structure. The results indicate that the electrical resistance is influenced mainly by the surface chemistry of the GO powders and not only by the O/C ratio. The control of the surface chemistry of GO powders would allow their use as additives in organic bulk heterojunction solar cells with enhanced photoconversion efficiency. - Highlights: • Powders of graphene oxide with different oxidation degree were prepared through variations of the Hummers method. • Raman spectroscopy and XRD demonstrated similar crystallite domain size in the samples. • Electrical resistance, exfoliation degree and optical absorption depend on the molecular structure.

  10. New processing methods to produce silicon carbide and beryllium oxide inert matrix and enhanced thermal conductivity oxide fuels

    Science.gov (United States)

    Sarma, K. H.; Fourcade, J.; Lee, S.-G.; Solomon, A. A.

    2006-06-01

    YSZ granules containing actinides could be simply dry-mixed with BeO powder and co-sintered to produce a dispersed fuel form. Alternatively, the BeO could be granulated, and the PuO2 and/or TRU oxides would fill the interstices forming a continuous minor phase that could be recycled in closed fuel cycles. Some advantages and disadvantages of these matrices are discussed.

  11. A theoretical framework for evaluating analytical digestion methods for poorly soluble particulate beryllium.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Brink, Christopher A; Dickerson, Robert M; Day, Gregory A; Brisson, Michael J; Hoover, Mark D; Scripsick, Ronald C

    2007-04-01

    Complete digestion of all chemical forms and sizes of particulate analytes in environmental samples is usually necessary to obtain accurate results with atomic spectroscopy. In the current study, we investigate the physicochemical properties of beryllium particles likely to be encountered in samples collected from different occupational environments and present a hypothesis that a dissolution theory can be used as a conceptual framework to guide development of strategies for digestion procedures. For monodisperse single-chemical constituent primary particles, such as those encountered when handling some types of beryllium oxide (BeO) powder, theory predicts that a digestion procedure is sufficient when it completely dissolves all primary particles, independent of cluster size. For polydisperse single-chemical constituent particles, such as those encountered during the handling of some types of beryllium metal powder, theory predicts that a digestion procedure is sufficient only when it completely dissolves the largest particle in the sample. For samples with unknown or multi-chemical constituent particles and with particles having undefined sizes, e.g., fume emissions from a copper-beryllium alloy furnace operation or dust from a beryl ore crushing operation, a surface area-limited and single-constituent-dependent dissolution theory may not predict complete dissolution, thereby requiring non-routine robust treatment procedures with post-digestion filtration, followed by examination of residual particulate material. Additionally, for beryllium, and likely other poorly soluble materials, particulate reference materials of various chemical forms and size distributions are needed to better evaluate and harmonize analytical digestion procedures. Figure Generation of aerosol particles during machining of beryllium oxide.

  12. Stability of zinc oxide nanofluids prepared with aggregated nanocrystalline powders.

    Science.gov (United States)

    Leonard, J P; Chung, S J; Nettleship, I; Soong, Y; Martello, D V; Chyu, M K

    2008-12-01

    Aqueous zinc oxide (ZnO) suspensions were prepared using a two-step preparation method in which an aggregated nanocrystalline ZnO powder was dispersed in water using a polyelectrolyte. The fluid showed anomalously high thermal conductivity when compared with the Maxwell and Hamilton-Crosser predictions. However, analysis of the particle size distribution showed that the fluid contained aggregated 20 nm crystallites of ZnO with a high volume fraction of particles larger than 100 nm. Sedimentation experiments revealed that particles settled out of the stationary fluid over times ranging from 0.1 hours to well over 10,000 hours. The size of the particles remaining in suspension agreed well with predictions made using Stoke's law, suggesting flocculation was not occurring in the fluids. Finally, a new concept of nanofluid stability is introduced based on the height of the fluid, sedimentation, Brownian motion and the kinetic energy of the particles.

  13. Characterization of manganese-gallium mixed oxide powders

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez Escribano, V.; Fernandez Lopez, E.; Sanchez Huidobro, P. [Universidad de Salamanca, Dept. de Quimica Inorganica (Spain); Panizza, M.; Resini, C.; Busca, G. [UNiversita di Genova, Dipt. di Ingegneria Chimica e di Processo, Genova (Italy); Resini, C. [Istituto Nazionale di Fisica della Materia, INFM (Spain); Gallardo- Amores, J.M. [Universidad Complutense, Dept. de Quimica Inorganica, Lab. Complutense de Altas Presiones, Madrid (Spain)

    2003-12-01

    Mn-Ga mixed oxides have been prepared by coprecipitation of the corresponding oxo-hydroxides as powders and have been characterized in relation to their structural and optical properties. The materials have been characterized by XRD, TG-DTA, skeletal IR and UV-visible-NIR spectroscopies. Large solubility of Mn in the diaspore type {alpha}-GaOOH oxo-hydroxide has been found. The spinel related structures of hausmannite Mn{sub 3}O{sub 4} and of {beta}-gallia present large reciprocal solubilities at least in a metastable form. At high temperature also bixbyite-type {alpha}-Mn{sub O3} solid solutions containing up to 20% at. Ga have been observed. (authors)

  14. Defense programs beryllium good practice guide

    Energy Technology Data Exchange (ETDEWEB)

    Herr, M.

    1997-07-01

    Within the DOE, it has recently become apparent that some contractor employees who have worked (or are currently working) with and around beryllium have developed chronic beryllium disease (CBD), an occupational granulomatous lung disorder. Respiratory exposure to aerosolized beryllium, in susceptible individuals, causes an immunological reaction that can result in granulomatous scarring of the lung parenchyma, shortness of breath, cough, fatigue, weight loss, and, ultimately, respiratory failure. Beryllium disease was originally identified in the 1940s, largely in the fluorescent light industry. In 1950, the Atomic Energy Commission (AEC) introduced strict exposure standards that generally curtailed both the acute and chronic forms of the disease. Beginning in 1984, with the identification of a CBD case in a DOE contractor worker, there was increased scrutiny of both industrial hygiene practices and individuals in this workforce. To date, over 100 additional cases of beryllium-specific sensitization and/or CBD have been identified. Thus, a disease previously thought to be largely eliminated by the adoption of permissible exposure standards 45 years ago is still a health risk in certain workforces. This good practice guide forms the basis of an acceptable program for controlling workplace exposure to beryllium. It provides (1) Guidance for minimizing worker exposure to beryllium in Defense Programs facilities during all phases of beryllium-related work, including the decontamination and decommissioning (D&D) of facilities. (2) Recommended controls to be applied to the handling of metallic beryllium and beryllium alloys, beryllium oxide, and other beryllium compounds. (3) Recommendations for medical monitoring and surveillance of workers exposed (or potentially exposed) to beryllium, based on the best current understanding of beryllium disease and medical diagnostic tests available. (4) Site-specific safety procedures for all processes of beryllium that is likely to

  15. Mixed metal oxide crystalline powders and method for the synthesis thereof

    Energy Technology Data Exchange (ETDEWEB)

    Joyce, I.H.; Blonski, R.P.; Maloney, J.J.; Welch, J.J.; Pipoly, R.A.; Byrne, C.J.

    1993-07-20

    A method is described for the solid state synthesis of mixed metal oxide crystalline powders comprising the steps of: preparing a raw material mixture containing at least two different metal cations; adding a template material to said mixture and blending it therewith; initiating formation of a mixed metal oxide by calcination of said mixture and said template material, whereby particles of the mixed metal oxides are formed in powder form; and thereafter recovering said mixed metal oxide particles.

  16. Some characteristics of fine beryllium particle combustion

    Science.gov (United States)

    Davydov, D. A.; Kholopova, O. V.; Kolbasov, B. N.

    2007-08-01

    Beryllium dust will be produced under plasma interaction with beryllium armor of the first wall in ITER. Exothermal reaction of this dust with water steam or air, which can leak into the reactor vacuum chamber in some accidents, gives concern in respect to reactor safety. Results of studies devoted to combustion of fine beryllium particles are reviewed in the paper. A chemically active medium and elevated temperature are prerequisite to the combustion of beryllium particles. Their ignition is hampered by oxide films, which form a diffusion barrier on the particle surface as a result of pre-flame oxidation. The temperature to initiate combustion of particles depends on flame temperature, particle size, composition of combustible mixture, heating rate and other factors. In mixtures enriched with combustible, the flame temperature necessary to ignite individual particles approaches the beryllium boiling temperature.

  17. Inherent structure features of beryllium and their influence on the performance polycrystalline metal under different conditions

    Energy Technology Data Exchange (ETDEWEB)

    Khomutov, A.M.; Mikhailov, V.S.; Pronin, V.N.; Pakhomov, Ya.D. [State Scientific Center of Russian Federation `A.A. Bochvar All-Russia Research Inst. of Inorganic Materials (VNIINM)`, Moscow (Russian Federation)

    1998-01-01

    The anisotropy of physical properties of beryllium single crystals resulting from covalent bonds in crystal lattice leads to significant residual thermal microstresses (RTM) in the polycrystalline metal. It is demonstrated experimentally that there is a simple linear dependence between the magnitude of RTM and the ultimate tensile strength. The factors controlling RTM are analysed and in the framework of powder metallurgy process the technological methods of producing beryllium with the needed properties are recommended. Primarily it is necessary to control the quantity and extent of dispersity of intergranular oxide inclusions and mean grain size in combination with the high degree of macro- and microhomogenity of the structure. The requirements to beryllium microstructure for different operating conditions including neutron fluxes and transient temperature fields are formulated. In the framework of the concept under development one can explain formerly not fully understandable effects, which are characteristic of polycrystalline beryllium such as unexpected Petch-Stro curve, the role of twinning etc., and predict new ones. In particular, it can be possible to expect the growth of ductility of high strength beryllium grades as neutron irradiated. (author)

  18. Preparation of oxide powder by continuous oxidation process from recycled Fe-77Ni alloy scrap

    Science.gov (United States)

    Yun, J. Y.; Park, D. H.; Jung, G. J.; Wang, J. P.

    2015-12-01

    The oxidation behavior of Fe-77Ni alloy scrap was studied under a 0.2 atm oxygen partial pressure at the temperature range of 400°C to 900°C. The oxidation rate was found to be increased with an increase of temperature and followed the parabolic rate law with linearly proportional to temperature. Microstructure and cross-sectional area of the oxide layer were examined by SEM, EDX, and XRD. It could be speculated that rate-limiting step was controlled by diffusion through either the spinel structure or the NiO layer, both of which were present in this alloy during oxidation at elevated temperatures. In the long run, oxide powder less than 10 μm from Fe-77Ni alloy scrap was obtained using ball-milling and sieving processes and recovery ratio approached up to 97% for 15 hours.

  19. Effect of oil droplet size on the oxidative stability of spray-dried flaxseed oil powders.

    Science.gov (United States)

    Shiga, Hirokazu; Loon Neoh, Tze; Ninomiya, Ai; Adachi, Sae; Pasten, Ignacio Lopez; Adachi, Shuji; Yoshii, Hidefumi

    2017-04-01

    The effect of the size of oil droplets on the oxidative stability of flaxseed oil in spray-dried powders was investigated. Maltodextrin with a dextrose equivalent of 25 was used as a wall material, and sodium caseinate and transglutaminase-polymerized sodium caseinate were used as emulsifiers. The oxidative stability of flaxseed oil encapsulated in the spray-dried powders was evaluated using lipid oxidation and conductometric determination tests at 105 °C. The powders containing larger oil droplets exhibited higher surface oil content after spray drying, and higher peroxide value and conductivity after storage at 105 °C. Removal of the surface oil from the powders by washing with hexane significantly decreased the conductivity. The results indicated that the surface oil of the spray-dried flaxseed oil powders affected the oxidation stability.

  20. BERYLLIUM MEASUREMENT IN COMMERCIALLY AVAILABLE WET WIPES

    Energy Technology Data Exchange (ETDEWEB)

    Youmans-Mcdonald, L.

    2011-02-18

    Analysis for beryllium by fluorescence is now an established method which is used in many government-run laboratories and commercial facilities. This study investigates the use of this technique using commercially available wet wipes. The fluorescence method is widely documented and has been approved as a standard test method by ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The procedure involves dissolution of samples in aqueous ammonium bifluoride solution and then adding a small aliquot to a basic hydroxybenzoquinoline sulfonate fluorescent dye (Berylliant{trademark} Inc. Detection Solution Part No. CH-2) , and measuring the fluorescence. This method is specific to beryllium. This work explores the use of three different commercial wipes spiked with beryllium, as beryllium acetate or as beryllium oxide and subsequent analysis by optical fluorescence. The effect of possible interfering metals such as Fe, Ti and Pu in the wipe medium is also examined.

  1. Recycling high density tungsten alloy powder by oxidization-reduction process

    Institute of Scientific and Technical Information of China (English)

    张兆森; 陈立宝; 贺跃辉; 黄伯云

    2002-01-01

    The processes of directly recycling high density tungsten alloy by oxidation-reduction technique were investigated. The particle size of recycled powder is fine, and the shape of powder particle is regular when the final reduction temperature is 850℃, in which the average size of the tungsten alloy particles reduced is about 1.5μm. The average size of the alloy particles increase to 6μm and 9μm when increasing the reduction temperature to 900℃ and 950℃, respectively. However, if the reduction temperature is higher than 900℃, the surface feature of powder is complicated. Increasing reduction temperature from 900℃ to 950℃, the content of oxygen of recycled powder decreases from 0.2314% to 0.1700%, and powder particles grow slightly. It has been also found that the chemical composition of the recycled alloy powder is the same as the initial powder.

  2. Synthesis and structure analysis of aluminum doped zinc oxide powders

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Hexagonal Al-doped zinc oxide (ZnO) powders with a nominal composition of Zn1-xAlxO (0≤x≤0.028) were synthesized by the co-precipitation method. The contents of the Al element in the samples were measured by the inductively coupled plasma-optical emission spectroscopy (ICP-OES) technique. The structures of the Zn1-xAlxO (0≤x≤0.028) compounds calcined at 1000 and 1200℃ have been deter- mined using the Rietveld full-profile analysis method. Rietveld refinements of the diffraction data indi- cated that the addition of Al initially has a considerably positive effect on the decreasing of the lattice parameters a and c of Zn1-xAlxO, but the effect becomes very slight and even negative with the further increase of the Al content. The solid solubility limit of Al in ZnO (mole fraction y) is 2.2l%, resulting in Zn0.978Al0.22O. It seems that when the Al content is excessive, Al prefers to form a ZnAl2O4 compound with ZnO, but not to incorporate into the ZnO lattice to occupy the Zn2+ cites. Two phases, [ZnO] (or Al-doped ZnO) and [ZnAl2O4], are obviously segregated in Zn1-xAlxO while the value of x is larger than 0.024. The UV-Vis absorption spectra show that the Al-doped ZnO exhibits a red-shift in the absorption edge without reduced transmission compared with pure ZnO, which also confirms that Al ions enter the ZnO lattice and form a Zn1-xAlxO solid solution.

  3. Synthesis and structure analysis of aluminum doped zinc oxide powders

    Institute of Scientific and Technical Information of China (English)

    NIE DengPan; XUE Tao; ZHANG Yu; LI XiangJun

    2008-01-01

    Hexagonal Al-doped zinc oxide (ZnO) powders with a nominal composition of Zn1-xAlxO (0≤x≤0.028) were synthesized by the co-precipitation method. The contents of the Al element in the samples were measured by the inductively coupled plasma-optical emission spectroscopy (ICP-OES) technique. The structures of the Zn1-xAlxO (0≤x≤0.028) compounds calcined at 1000 and 1200℃ have been deter-mined using the Rietveld full-profile analysis method. Rietveld refinements of the diffraction data indi-cated that the addition of Al initially has a considerably positive effect on the decreasing of the lattice parameters a and c of Zn1-xAlxO, but the effect becomes very slight and even negative with the further increase of the Al content. The solid solubility limit of Al in ZnO (mole fraction y) is 2.21%, resulting in Zn0.978Al0.22O. It seems that when the Al content is excessive, Al prefers to form a ZnAl2O4 compound with ZnO, but not to incorporate into the ZnO lattice to occupy the Zn2+ cites. Two phases, [ZnO] (or Al-doped ZnO) and [ZnAl2O4], are obviously segregated in Zn1-xAlxO while the value of x is larger than 0.024. The UV-Vis absorption spectra show that the Al-doped ZnO exhibits a red-shift in the absorption edge without reduced transmission compared with pure ZnO, which also confirms that Al ions enter the ZnO lattice and form a Zn1-xAlxO solid solution.

  4. Effect of fabrication conditions on the properties of indium tin oxide powders

    Institute of Scientific and Technical Information of China (English)

    Xie Wei

    2008-01-01

    This paper reports that indium tin oxide (ITO) crystalline powders are prepared by coprecipitation method. Fabrication conditions mainly as sintering temperature and Sn doping content are correlated with the phase, microstructure, infrared emissivity ε and powder resistivity of indium tin oxides by means of x-ray diffraction, Fourier transform infrared, and transmission electron microscope. The optimum sintering temperature of 1350℃ and Sn doping content 6~8wt% are determined. The application of ITO in the military camouflage field is proposed.

  5. Porous mandrels provide uniform deformation in hydrostatic powder metallurgy

    Science.gov (United States)

    Gripshover, P. J.; Hanes, H. D.

    1967-01-01

    Porous copper mandrels prevent uneven deformation of beryllium machining blanks. The beryllium powder is arranged around these mandrels and hot isostatically pressed to form the blanks. The mandrels are then removed by leaching.

  6. Low temperature synthesis of magnesium oxide and spinel powders by a sol-gel process

    Directory of Open Access Journals (Sweden)

    Li-Zhai Pei

    2010-09-01

    Full Text Available Magnesium oxide and magnesium aluminate (MgAl2O4 spinel (MAS powders have been synthesized by a simple aqueous sol-gel process using citrate polymeric precursors derived from magnesium chloride, aluminium nitrate and citrate. The thermal decomposition of the precursors and subsequent formation of cubic MgO and MAS were investigated by X-ray diffraction (XRD, scanning electron microscopy (SEM, thermogravimetry-differential scanning calorimetry (TG-DSC and Fourier transform infrared spectra (FTIR. The single phase cubic MgO powder and MAS powder form after heat treatment at 800 and 1200 °C, respectively. The particle size of the MgO and MAS powders is about 100 nm and several micrometers, respectively. Ball milling eliminates the size of MgO and MgAl2O4 spinel powders by decreasing the conglomeration of the powders.

  7. Synthesis of indium tin oxide powder by solid-phase reaction with microwave heating

    OpenAIRE

    Fukui, Kunihiro; Kanayama, Keiji; Katoh, Manabu; Yamamoto, Tetsuya; Yoshida, Hideto

    2009-01-01

    Indium tin oxide (ITO) powder was synthesized from indium oxide and tin oxide powders by a solid-phase method using microwave heating and conventional heating methods. Microwave heating could reduce the treatment time necessary for the completion of the solid-phase reaction by 1/30. This decrease was attributed to an increase in the diffusion rate of Sn at the local heat spot in the indium oxide formed by microwave irradiation. However, microwave heating also decreased the amount of ITO produ...

  8. Migration of Beryllium via Multiple Exposure Pathways among Work Processes in Four Different Facilities.

    Science.gov (United States)

    Armstrong, Jenna L; Day, Gregory A; Park, Ji Young; Stefaniak, Aleksandr B; Stanton, Marcia L; Deubner, David C; Kent, Michael S; Schuler, Christine R; Virji, M Abbas

    2014-01-01

    Inhalation of beryllium is associated with the development of sensitization; however, dermal exposure may also be important. The primary aim of this study was to elucidate relationships among exposure pathways in four different manufacturing and finishing facilities. Secondary aims were to identify jobs with increased levels of beryllium in air, on skin, and on surfaces; identify potential discrepancies in exposure pathways, and determine if these are related to jobs with previously identified risk. Beryllium was measured in air, on cotton gloves, and on work surfaces. Summary statistics were calculated and correlations among all three measurement types were examined at the facility and job level. Exposure ranking strategies were used to identify jobs with higher exposures. The highest air, glove, and surface measurements were observed in beryllium metal production and beryllium oxide ceramics manufacturing jobs that involved hot processes and handling powders. Two finishing and distribution facilities that handle solid alloy products had lower exposures than the primary production facilities, and there were differences observed among jobs. For all facilities combined, strong correlations were found between air-surface (rp ≥ 0.77), glove-surface (rp ≥ 0.76), and air-glove measurements (rp ≥ 0.69). In jobs where higher risk of beryllium sensitization or disease has been reported, exposure levels for all three measurement types were higher than in jobs with lower risk, though they were not the highest. Some jobs with low air concentrations had higher levels of beryllium on glove and surface wipe samples, suggesting a need to further evaluate the causes of the discrepant levels. Although such correlations provide insight on where beryllium is located throughout the workplace, they cannot identify the direction of the pathways between air, surface, or skin. Ranking strategies helped to identify jobs with the highest combined air, glove, and/or surface exposures

  9. Characterisation of oxidised aluminium powder: Validation of a new anodic oxidation bench

    Energy Technology Data Exchange (ETDEWEB)

    Gascoin, Nicolas, E-mail: Nicolas.Gascoin@univ-orleans.fr [PRISME Institute, Orleans University, 63 avenue de Lattre de Tassigny, 18020 Bourges (France); Gillard, Philippe; Baudry, Guillaume [PRISME Institute, Orleans University, 63 avenue de Lattre de Tassigny, 18020 Bourges (France)

    2009-11-15

    Aluminium powder is of major interest in many applications but it presents a risk due to its high explosibility, particularly when dispersed in air. The safety is directly linked to the particles oxidation because the Minimum Ignition Energy (MIE), which is required to initiate an Al dust explosion, increases with the oxide layer thickness. This study provides a controlled method to furnish reproducible homogeneous set of powder for such safety studies. Thanks to a new experimental bench, the influence on the oxidation rate of seven treatment parameters is investigated (current density, time of treatment, acid concentration, mass of powder, particles size, stirring, neutralisation by ammonia solution). The oxide content is plotted versus the current density, the time and the acid concentration to provide reference curves for further elaboration of oxidised powder. The particles size of sieved powder is measured before and after treatment by different methods (optical and Scanning Electron Microscopes, laser measurement). A high refinement of the powder in terms of size distribution is achieved thanks to the employed sieving. The present bench and the elaborated procedure are of great interest to provide well-calibrated oxidised powder directly available for safety studies. The time must be adjusted, depending on the wanted oxide content - from 2 to 18 wt.% - and the other treatment parameters must be kept constant: acid concentration (5 wt.%), current density (1 A dm{sup -2}), treated powder (20 g). In these conditions, the ratio of the oxide layer thickness on the particles diameter is found to be constant for a given oxide content whatever the particles size.

  10. An industrial risk: Beryllium

    Directory of Open Access Journals (Sweden)

    Emrah Çaylak

    2012-03-01

    Full Text Available Beryllium is a vocational disease factor and berylliumexposure can potentially lead to Chronic Beryllium Disease(CBD in 2-6 % of workers. While acute lymphocyticpneumonia occurred in individuals who were exposedto high doses of beryllium, low dose exposure to berylliumfollowed by a long subclinical period can cause CBDcharacterized with chronic granulomatosis. It has beenobserved that varying amounts of beryllium exposureare necessary to produce symptoms of CBD or berylliumsensitization (BeS. Genetic differences between patientsmay be the underlying cause of these dose-effects andfurther study of the differences in patients exposed to berylliummay lead to earlier diagnosis and the identificationof biomarkers of CBD. In this review, it is summarizedthe general properties of beryllium exposure, the immunopathogenesisand genetic differences of beryllium-induceddiseases, genotoxicity and the carcinogenic effectsof beryllium. J Clin Exp Invest 2012; 3(1: 141-148

  11. The structure, properties and performance of plasma-sprayed beryllium for fusion applications

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R.G.; Stanek, P.W.; Elliott, K.E. [and others

    1995-09-01

    Plasma-spray technology is under investigation as a method for producing high thermal conductivity beryllium coatings for use in magnetic fusion applications. Recent investigations have focused on optimizing the plasma-spray process for depositing beryllium coatings on damaged beryllium surfaces. Of particular interest has been optimizing the processing parameters to maximize the through-thickness thermal conductivity of the beryllium coatings. Experimental results will be reported on the use of secondary H{sub 2} gas additions to improve the melting of the beryllium powder and transferred-arc cleaning to improve the bonding between the beryllium coatings and the underlying surface. Information will also be presented on thermal fatigue tests which were done on beryllium coated ISX-B beryllium limiter tiles using 10 sec cycle times with 60 sec cooldowns and an International Thermonuclear Experimental Reactor (ITER) relevant divertor heat flux slightly in excess of 5 MW/m{sup 2}.

  12. Tailored Core Shell Cathode Powders for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Swartz, Scott [NexTech Materials, Ltd.,Lewis Center, OH (United States)

    2015-03-23

    In this Phase I SBIR project, a “core-shell” composite cathode approach was evaluated for improving SOFC performance and reducing degradation of lanthanum strontium cobalt ferrite (LSCF) cathode materials, following previous successful demonstrations of infiltration approaches for achieving the same goals. The intent was to establish core-shell cathode powders that enabled high performance to be obtained with “drop-in” process capability for SOFC manufacturing (i.e., rather than adding an infiltration step to the SOFC manufacturing process). Milling, precipitation and hetero-coagulation methods were evaluated for making core-shell composite cathode powders comprised of coarse LSCF “core” particles and nanoscale “shell” particles of lanthanum strontium manganite (LSM) or praseodymium strontium manganite (PSM). Precipitation and hetero-coagulation methods were successful for obtaining the targeted core-shell morphology, although perfect coverage of the LSCF core particles by the LSM and PSM particles was not obtained. Electrochemical characterization of core-shell cathode powders and conventional (baseline) cathode powders was performed via electrochemical impedance spectroscopy (EIS) half-cell measurements and single-cell SOFC testing. Reliable EIS testing methods were established, which enabled comparative area-specific resistance measurements to be obtained. A single-cell SOFC testing approach also was established that enabled cathode resistance to be separated from overall cell resistance, and for cathode degradation to be separated from overall cell degradation. The results of these EIS and SOFC tests conclusively determined that the core-shell cathode powders resulted in significant lowering of performance, compared to the baseline cathodes. Based on the results of this project, it was concluded that the core-shell cathode approach did not warrant further investigation.

  13. Hydrogen release from reactor-irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Klepikov, A.Kh. [Kazakh State Univ., Alma-Ata (Kazakstan); Tazhibaeva, I.L. [Kazakh State Univ., Alma-Ata (Kazakstan); Shestakov, V.P. [Kazakh State Univ., Alma-Ata (Kazakstan); Romanenko, O.G. [Kazakh State Univ., Alma-Ata (Kazakstan); Chikhray, Y.V. [Kazakh State Univ., Alma-Ata (Kazakstan); Kenzhin, E.A. [IAE NNC RK, Semipalatinsk-21 (Russian Federation); Cherepnin, Yu.S. [IAE NNC RK, Semipalatinsk-21 (Russian Federation); Tikhomirov, L.N. [IAE NNC RK, Semipalatinsk-21 (Russian Federation)

    1996-10-01

    Experiments on gas release of reactor-irradiated beryllium samples were carried out and compared to control samples. The simultaneous influence of reactor irradiation and exposure to hydrogen results in more hydrogen retention in beryllium, than if beryllium is initially irradiated and then exposed to hydrogen. Appearance of low temperature peaks at 460 K and 540 K with 0.71 eV/atom and 0.84 eV/atom desorption activation energies, respectively, assessed in a frame of a second order desorption model, is mainly responsible for the increase in hydrogen content. These peaks can be attributed to chemical hydrogen bonds with surface oxide. The simultaneous influence of hydrogen and nuclear reactor irradiation at a temperature of 1150 K was assumed to increase significantly microcrack formation near the surface of beryllium samples, resulting in an increase in low temperature peak intensities. (orig.).

  14. A experiment research of beryllium oxide induced oxidative lung injury and the protective effects of LBP in rats%氧化铍致大鼠肺氧化损伤与枸杞多糖的保护作用

    Institute of Scientific and Technical Information of China (English)

    刘志宏; 张庆锋; 王瑶; 魏丛慧; 严青; 龚爱红; 郭雄

    2015-01-01

    目的 探讨氧化铍(BeO)诱发的肺损伤及枸杞多糖(lycium barbarum polysaccharides,LBP)的保护作用.方法 选用SPF健康雄性大鼠128只,随机分为空白对照组(8只)、生理盐水组(24只)、BeO染毒组(32只,染毒剂量10 mg/kg)、BeO+LBP低剂量(10 mg/kg,32只)、BeO+LBP高剂量组(40 mg/kg,32只).动物染毒选用非暴露式气管一次注人法,LBP干预采用灌胃法.试剂盒检测大鼠肺组织中缺氧诱导因子-1(HIF-1)、血管内皮生长因子(VGEF)和血红素氧合酶(HO-1)的含量.制作肺组织病理切片观察病理改变,电子显微镜观察肺脏超微结构改变.结果 BeO染毒组大鼠肺组织出现炎性细胞浸润,间质增厚以及细胞、细胞器超微结构等病理学改变;经LBP干预后上述病理变化减轻.染毒40d,与对照组比较,BeO染毒组、BeO+LBP低剂量组HO-1的含量升高,差异有统计学意义(P<0.05或P<0.01);染毒80 d,BeO染毒组、BeO+LBP低剂量组HO-1的浓度与对照组比较降低,差异有统计学意义(P<0.05或P<0.01).染毒40 d,BeO染毒组、BeO+LBP干预组,染毒60、80 d,BeO染毒组HIF-1含量均高于对照组,差异有统计学意义(P<0.05或P<0.01);染毒40、80 d,BeO染毒组、BeO+LBP干预组,染毒60 d,BeO染毒组VEGF含量与对照组比较升高,差异有统计学意义(P<0.05或P<0.01).经LBP干预40d后,BeO+LBP高剂量组HO-1的含量低于BeO染毒组,差异有统计学意义(P<0.05);干预80 d后,BeO+LBP高剂量组HO-1的含量高于BeO染毒组,差异有统计学意义(P<0.05);干预60 d后,BeO+LBP高剂量组、干预80 d后,BeO+LBP干预组HIF-1含量低于BeO染毒组,差异有统计学意义(P<0.01);干预40 d后,BeO+LBP干预组、干预60 d后,BeO+LBP高剂量组VEGF的含量与BeO染毒组比较降低,差异有统计学意义(P<0.05或P<0.01).结论 BeO可引起大鼠肺组织中氧化损伤相关基因表达异常,LBP具有保护作用.%Objective To explore beryllium oxide induced oxidative lung

  15. Impact of sertraline salt form on the oxidative stability in powder blends.

    Science.gov (United States)

    Hsieh, Yi-Ling; Yu, Weili; Xiang, Yanqiao; Pan, Weitao; Waterman, Kenneth C; Shalaev, Evgenyi Y; Shamblin, Sheri L; Taylor, Lynne S

    2014-01-30

    Oxidation of active pharmaceutical ingredients is a common chemical degradation process occurring in solid dosage forms. The aim of this study was to investigate the tendency of various sertraline salts to oxidize in powder blends containing a basic additive. A different extent of conversion of each salt to the free base was observed to occur in the presence of the basic additive, consistent with their respective pHmax values. Sertraline was found to undergo oxidation as the unioinized form, in both solution and powder blends that incorporated an oxidizing agent. In contrast, the ionized form of sertraline remained stable in both cases. Three sertraline salts undergoing a significant extent of conversion from salt to free form in the presence of tribasic sodium phosphate were found to oxidize extensively while sertraline benzoate which had a considerably lower extent of free base formation was more resistant to oxidation. The oxidative degradants were produced through oxidation at the amine functional group of sertraline which is where sertraline is ionized as the salt form. The link between oxidation tendency and the ionization state of sertraline in powder mixtures has thus been demonstrated in this study.

  16. Beryllium: genotoxicity and carcinogenicity.

    Science.gov (United States)

    Gordon, Terry; Bowser, Darlene

    2003-12-10

    Beryllium (Be) has physical-chemical properties, including low density and high tensile strength, which make it useful in the manufacture of products ranging from space shuttles to golf clubs. Despite its utility, a number of standard setting agencies have determined that beryllium is a carcinogen. Only a limited number of studies, however, have addressed the underlying mechanisms of the carcinogenicity and mutagenicity of beryllium. Importantly, mutation and chromosomal aberration assays have yielded somewhat contradictory results for beryllium compounds and whereas bacterial tests were largely negative, mammalian test systems showed evidence of beryllium-induced mutations, chromosomal aberrations, and cell transformation. Although inter-laboratory differences may play a role in the variability observed in genotoxicity assays, it is more likely that the different chemical forms of beryllium have a significant effect on mutagenicity and carcinogenicity. Because workers are predominantly exposed to airborne particles which are generated during the machining of beryllium metal, ceramics, or alloys, testing of the mechanisms of the mutagenic and carcinogenic activity of beryllium should be performed with relevant chemical forms of beryllium.

  17. Innovative Powder Processing of Oxide Dispersion Strengthened ODS Ferritic Stainless Steels

    Energy Technology Data Exchange (ETDEWEB)

    Rieken, Joel; Anderson, Iver; Kramer, Matthew

    2011-04-01

    An innovative gas atomization reaction synthesis technique was employed as a viable method to dramatically lower the processing cost for precursor oxide dispersion forming ferritic stainless steel powders (i.e., Fe-Cr-(Hf,Ti)-Y). During this rapid solidification process the atomized powders were enveloped by a nano-metric Cr-enriched metastable oxide film. Elevated temperature heat treatment was used to dissociate this metastable oxide phase through oxygen exchange reactions with Y-(Hf,Ti) enriched intermetallic compound precipitates. These solid state reactions resulted in the formation of highly stable nano-metric mixed oxide dispersoids (i.e., Y-Ti-O or Y-Hf-O) throughout the alloy microstructure. Subsequent high temperature (1200 C) heat treatments were used to elucidate the thermal stability of each nano-metric oxide dispersoid phase. Transmission electron microscopy coupled with X-ray diffraction was used to evaluate phase evolution within the alloy microstructure.

  18. Enhancement of leaching copper by electro-oxidation from metal powders of waste printed circuit board.

    Science.gov (United States)

    Ping, Zhu; ZeYun, Fan; Jie, Lin; Qiang, Liu; Guangren, Qian; Ming, Zhou

    2009-07-30

    Oxidation leaching copper from metal powders of waste printed circuit boards (PCBs) was conducted at room temperature in sulfuric acid solution. The result showed that the copper in metal powders was oxidized by Cu(2+) to form CuCl(2)(-) in the presence of chloride ion without electrochemical oxidation. Then, CuCl(2)(-) was oxidized into CuSO(4) by oxygen derived from the air insufflated into leaching solution. The leaching rate of copper reached 100%. The whole reaction took 5.5h because it was limited by the low solubility of the air in water. In the electro-oxidation conditions, the chloride ion was electro-oxidized into ClO(-), which oxidized CuCl(2)(-) into CuSO(4) and ClO(-) was reduced into Cl(-) itself again at the same time. Since Cl(-) was recycled in the solution not only as a complexing agent but also as an oxidant, which made the reaction speed up to 3.5h to reach 100% leaching rate. Leaching solution was concentrated to crystallize CuSO(4).5H(2)O, and crystal liquor was reused to leach copper from metal powders.

  19. Characteristics of beryllium exposure to small particles at a beryllium production facility.

    Science.gov (United States)

    Virji, M Abbas; Stefaniak, Aleksandr B; Day, Gregory A; Stanton, Marcia L; Kent, Michael S; Kreiss, Kathleen; Schuler, Christine R

    2011-01-01

    Epidemiological studies have reported process-specific elevated prevalence of beryllium sensitization (BeS) and chronic beryllium disease (CBD) among workers. However, exposure-response relationships have been inconsistent, possibly due to incomplete characterization of many biologically relevant aspects of exposure, including particle size. In 1999, two surveys were conducted 3-5 months apart at a beryllium metal, oxide, and alloy production facility during which personal impactor samples (n = 198) and personal 37-mm closed-face cassette (CFC) 'total' samples (n = 4026) were collected. Among process areas, median particle mass median aerodynamic diameter ranged from 5 to 14 μm. A large fraction of the beryllium aerosol was in the nonrespirable size range. Respirable beryllium concentrations were among the highest for oxide production [geometric mean (GM) = 2.02 μg m⁻³, geometric standard deviation (GSD) = 1.3] and pebbles plant (GM = 1.05 μg m⁻³, GSD = 2.9), areas historically associated with high risk of BeS and CBD. The relationship between GM 'CFC total' and GM respirable beryllium for jobs varied by process areas; the rank order of the jobs showed high overall consistency (Spearman r = 0.84), but the overall correlation was moderate (Pearson r = 0.43). Total beryllium concentrations varied greatly within and between workers among process areas; within-worker variance was larger than between-worker variance for most processes. A review of exposure characteristics among process areas revealed variation in chemical forms and solubility. Process areas with high risk of BeS and CBD had exposure to both soluble and insoluble forms of beryllium. Consideration of biologically relevant aspects of exposure such as beryllium particle size distribution, chemical form, and solubility will likely improve exposure assessment.

  20. Beryllium Desorption from Sediments

    Science.gov (United States)

    Boschi, V.; Willenbring, J. K.

    2015-12-01

    Beryllium isotopes have provided a useful tool in the field of geochronology and geomorphology over the last 25 years. The amount of cosmogenic meteoric 10Be and native 9Be absorbed to soils often scales with the residence time and chemical weathering of sediments in a landscape, respectively. Thus, the concentrations in river sediment may be used to quantify the denudation of specific watersheds. When deposited in ocean sediment, these concentrations are thought to record the history of denudation on Earth over the last ~10 Ma. The use of both isotopes often relies on the premise of beryllium retention to sediment surfaces in order to preserve a landscape's erosion and weathering signature. Changes in setting, en route from the soil to fluvial system to the ocean, can cause beryllium desorption and may preclude some applications of the 10Be/9Be system. Four mechanisms were tested to determine the desorption potential of beryllium including a reduction in pH, an increase in ionic strength and complexation with soluble organic and inorganic species. These processes have the potential to mobilize beryllium into solution. For example, by both reducing the pH and increasing the ionic strength, competition for adsorption sites increases, potentially liberating beryllium from the sediment surface. In addition, organic and inorganic ligands can complex beryllium causing it to become mobilized. To determine which of these alterations influence beryllium desorption and to quantify the effect, we prepared separate solutions of beryllium bound to minerals and organic compounds and measured beryllium concentrations in solution before and after adjusting the pH, ionic strength, and changing inorganic and organic ligand concentrations. We conclude from our observations that overall, beryllium sorbed to organic compounds was more resistant to desorption relative to mineral-associated beryllium. Among the methods tested, a reduction in pH resulted in the greatest amount of

  1. Experimental studies and modeling of processes of hydrogen isotopes interaction with beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Tazhibaeva, I.L.; Chikhray, Y.V.; Romanenko, O.G.; Klepikov, A.Kh.; Shestakov, V.P.; Kulsartov, T.V. [Science Research Inst. of Experimental and Theoretical Physics of Kazakh State Univ., Almaty (Kazakhstan); Kenzhin, E.A.

    1998-01-01

    The objective of this work was to clarify the surface beryllium oxide influence on hydrogen-beryllium interaction characteristics. Analysis of experimental data and modeling of processes of hydrogen isotopes accumulation, diffusion and release from neutron irradiated beryllium was used to achieve this purpose as well as the investigations of the changes of beryllium surface element composition being treated by H{sup +} and Ar{sup +} plasma glowing discharge. (author)

  2. Synthesis and characterization of nanocomposite powders of calcium phosphate/titanium oxide for biomedical applications

    Energy Technology Data Exchange (ETDEWEB)

    Delima, S.A.; Camargo, N.H.A.; Souza, J.C.P.; Gemelli, E., E-mail: sarahamindelima@hotmail.com, E-mail: dem2nhac@joinville.udesc.br, E-mail: souzajulio@joinville.udesc.br, E-mail: gemelli@joinville.udesc.br [Universidade do Estado de Santa Catarina (UDESC), Joinville, SC (Brazil). Centro de Ciencias Tecnologicas

    2009-07-01

    The nanostructured bioceramics of calcium phosphate are current themes of research and they are becoming important as bone matrix in regeneration of tissues in orthopedic and dental applications. Nanocomposite powders of calcium phosphate, reinforced with nanometric particles of titanium oxide, silica oxide and alumina oxid ealpha, are being widely studied because they offer new microstructures, nanostructures and interconnected microporosity with high superficial area of micropores that contribute to osteointegration and osteoinduction processes. This study is about the synthesis of nanocomposites powders of calcium phosphate reinforced with 1%, 2%, 3% and 5% in volume of titanium oxide and its characterization through the techniques of X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Differential Thermal Analysis (DTA), Thermogravimetry (TG) and Dilatometry. (author)

  3. Efficient powder blending in support of plutonium conversion for mixed oxide fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dennison, D.K.; Brucker, J.P.; Martinez, H.E.

    1999-06-07

    This paper describes a unique system that is used to mix and blend multiple batches of plutonium oxide powder of various consistencies into an equivalent number of identical and homogeneously mixed batches. This system is being designed and built to support the Advanced Recovery and Integrated Extraction System (ARIES) at the Los Alamos TA-55 Plutonium Facility. The ARIES program demonstrates dismantlement of nuclear pits, retrieval of the plutonium components, and conversion of the plutonium into an oxide for eventual use in mixed oxide (MOX) fuel for nuclear reactors. The purpose of this powder blending work is to assure that ARIES oxide is converted into an unclassified homogeneous mixture and that consistent feed material is available for MOX fuel assembly. This blending system is being assembled in a selected glovebox a TA-55 using an LANL designed split/combine apparatus, a commercial Turbula blending unit, and several additional supporting hardware components.

  4. Cerium extraction by metallothermic reduction using cerium oxide powder injection

    Institute of Scientific and Technical Information of China (English)

    J.S. Luna A; A. Flores V; R. Mu(n)iz V; A.F. Fuentes; J. Torres; N. Rodríuez R; J.C. Ortiz; P.Orozco

    2011-01-01

    This work presented the feasibility of cerium recovery by Al-Mg alloy through the metallothermic reduction of CeO2 to obtain a master alloy Al-4%Ce. The master alloy obtained in this investigation was for the grain refinement and modification of Al-Si alloys. The reagent was incorporated into a molten alloy using the submerged powder injection technique, and metallic samples were obtained during injection. Chemical and microstructural analyses (by inductively coupled plasma (ICP) and scanning electron microscopy (SEM), respectively) confirmed the possibility of Ce uptake in the bath (0 to 4 wt.%), as CeO2 was reduced through metallothermic reactions in the molten alloys.Based on the characterization of reaction products, the sequence of the reaction was proposed.

  5. Laser surface treatment of magnesium alloys with aluminium oxide powder

    Directory of Open Access Journals (Sweden)

    L.A. Dobrzański

    2009-11-01

    Full Text Available Purpose: The aim of this paper was to improve the magnesium cast alloys surface layer by laser surface treatment and to determine the laser treatment parameters.Design/methodology/approach: The laser treatment of magnesium alloys with alloying Al2O3 powder of the particle about 80μm was carried out using a high power diode laser (HPDL. The resulting microstructure in the modified surface layer was examined using scanning electron microscopy. Phase composition was determined by the X-ray diffraction method using the XPert device. The measurements of microhardness of the modified surface layer were also studied.Findings: The alloyed region has a fine microstructure with hard carbide particles. Microhardness of laser surface alloyed layer was significantly improved as compared to an alloy without laser treatment.Research limitations/implications: The investigations were conducted for cast magnesium alloys MCMgAl12Zn1, MCMgAl9Zn1, MCMgAl6Zn1, MCMgAl3Zn1 and Al2O3 powder of the particle size about 80 μm. One has used laser power in the range from 1.2to 2.0 kW.Practical implications: The results obtained in this investigation were promising comparing with the other conventional processes. High Power Diode Laser can be used as an economical substitute of Nd: YAG and CO2 to improve the surface magnesium alloy by feeding the carbide particles.Originality/value: The value of this paper is to define the influence of laser treatment parameters on quality, microstructure and microhardness of magnesium cast alloys surface layer.

  6. Green nanochemistry: metal oxide nanoparticles and porous thin films from bare metal powders.

    Science.gov (United States)

    Redel, Engelbert; Petrov, Srebri; Dag, Omer; Moir, Jonathon; Huai, Chen; Mirtchev, Peter; Ozin, Geoffrey A

    2012-01-01

    A universal, simple, robust, widely applicable and cost-effective aqueous process is described for a controlled oxidative dissolution process of micrometer-sized metal powders to form high-purity aqueous dispersions of colloidally stable 3-8 nm metal oxide nanoparticles. Their utilization for making single and multilayer optically transparent high-surface-area nanoporous films is demonstrated. This facile synthesis is anticipated to find numerous applications in materials science, engineering, and nanomedicine.

  7. Characteristics of cerium-gadolinium oxide (CGO) suspensions as a function of dispersant and powder properties

    DEFF Research Database (Denmark)

    Phair, John; Lönnroth, Nadja; Lundberg, Mats;

    2009-01-01

    A series of concentrated suspensions ( = 0.18–0.34) of cerium-gadolinium oxide (CGO) in terpineol were prepared as a function of dispersant, powder surface area and solids concentration. The stability of the suspensions was assessed by rheological measurements including viscosity and oscillatory...

  8. Preparation of silver tin oxide powders by hydrothermal reduction and crystallization

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Silver tin oxide composite powders were synthesized by the hydrothermal method with a silver ammine solution and a Na2SnO3 solution as raw marrials. H2C2O4 was used as the co-precipitator of silver ions and tin ions. The co-precipitation conditions were investigated. The results show that the co-precipitate of Ag2C2O4 and Sn(OH)4 is available when the pH value of the solution is 4.27-8.36. Using the obtained precipitate as precursor, the reduction of Ag+ and the crystallization of tin oxide were carried out simultaneonsly by the hydrothermal method and silver tin oxide composite powders were obtained. The composite powders were characterized by X-ray diffraction (XRD) analysis, scanning electron microscope (SEM), and energy spectrum analysis. The results show that the silver tin oxide composite powders are small with a diameter of about 2 μm and with homogeneous distribution of tin.

  9. Oxidation effects during laser cladding of aluminium with SiC/Al powders

    NARCIS (Netherlands)

    Hegge, H.J.; Boetje, J.; Hosson, J.Th.M. De

    1990-01-01

    Aluminium substrates were covered with a layer of an Al-SiC powder mixture. The surface was scanned with a laser beam during which the surface was melted. The top layer of the laser tracks contained oxide plates apart from some large SiC particles. In the bottom layer a cellular network was found wi

  10. Toxicological effects of beryllium on platelets and vascular endothelium.

    Science.gov (United States)

    Togna, G; Togna, A R; Russo, P; Caprino, L

    1997-06-01

    Although ample research has described the toxic effects of the metal beryllium on the respiratory apparatus, less is known about its effects on the vascular apparatus, including pulmonary blood vessels. We investigated the in vitro effects of beryllium on endothelial vascular adenosine diphosphatase activity and prostacyclin production in bovine aortic endothelium, and on nitric oxide release in isolated rabbit arteries. Rabbit and human platelet responsiveness was also evaluated. Beryllium inhibited vascular endothelial adenosine diphosphatase activity, prostacyclin production, and nitric oxide release, thus inducing functional alterations in vascular endothelial cells. It also induced platelet hyperreactivity to arachidonic acid, as shown by a lowering of the threshold of aggregating concentration and by concurrently increasing thromboxane production. In contrast, beryllium left the response to aggregating and nonaggregating concentrations of ADP and collagen unchanged. These findings show that beryllium may impair some vascular endothelial functions and alter the interaction between platelet and endothelial mediators.

  11. SU-C-16A-02: A Beryllium Oxide (BeO) Fibre-Coupled Luminescence Dosimeter for High Dose Rate Brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Santos, A [Royal Adelaide Hospital, Adelaide, South Australia (Australia); Institute for Photonics and Advanced Sensing and School of Chem and Phys, Adelaide, South Australia (Australia); Mohammadi, M [Royal Adelaide Hospital, Adelaide, South Australia (Australia); Afshar, V.S. [Institute for Photonics and Advanced Sensing and School of Chem and Phys, Adelaide, South Australia (Australia)

    2014-06-15

    Purpose: Beryllium oxide (BeO) ceramics have an effective atomic number, zeff ∼7.1, closely matched to water, zeff ∼7.4. The purpose of this study was to evaluate the use of a beryllium oxide (BeO) ceramic fibrecoupled luminescence dosimeter, named RL/OSL BeO FOD, for high dose rate (HDR) brachytherapy dosimetry. In our dosimetry system the radioluminescence (RL) of BeO ceramics is utilized for dose-rate measurements, and the optically stimulated luminescence (OSL) can be read post exposure for accumulated dose measurements. Methods: The RL/OSL BeO FOD consists of a 1 mm diameter × 1 mm long cylinder of BeO ceramic coupled to a 15 m long silica-silica optical fibre. The optical fibre is connected to a custom developed portable RL and OSL reader, located outside of the treatment suite. The x-ray energy response was evaluated using superficial x-rays, an Ir-192 source and high energy linear accelerators. The RL/OSL BeO FOD was then characterised for an Ir-192 source, investigating the dose response and angular dependency. A depth dose curve for the Ir-192 source was also measured. Results: The RL/OSL BeO FOD shows an under-response at low energy x-rays as expected. Though at higher x-ray energies, the OSL response continued to increase, while the RL response remained relatively constant. The dose response for the RL is found to be linear up to doses of 15 Gy, while the OSL response becomes more supralinear to doses above 15 Gy. Little angular dependency is observed and the depth dose curve measured agreed within 4% of that calculated based on TG-43. Conclusion: This works shows that the RL/OSL BeO FOD can be useful in HDR dosimetry. With the RL/OSL BeO FODs current size, it is capable of being inserted into intraluminal catheters and interstitial needles to verify HDR treatments.

  12. Effects of storage time and temperature on lipid oxidation of egg powders enriched with natural antioxidants.

    Science.gov (United States)

    Matumoto-Pintro, Paula Toshimi; Murakami, Alice Eiko; Vital, Ana Carolina Pelaes; Croge, Camila; da Silva, Denise Felix; Ospina-Roja, Ivan Camilo; Guerra, Ana Flávia Quiles Garcia

    2017-08-01

    The lipid fraction of egg powder may be affected by storage conditions due to the development of oxidative rancidity caused by polyunsaturated fatty acids. This study evaluated egg powders enriched with antioxidants [tocopherol, catechin, lycopene, and butylated hydroxyanisole (BHA)] for conjugated dienes (during a 90-day period) and for malonaldehydes (during a 210-day period) at 25±2 and 4±1°C. The presence of lycopene and BHA increases the total phenolic compounds in the enriched egg powders, and BHA exhibits the most antioxidant activity, as quantified by an ABTS assay. Egg powders enriched with antioxidants do not show any reduction in conjugate diene production compared to controls, and no effect of storage temperature is observed; however, in the production of malonaldehyde, greater stability is observed at 4°C, and catechin is more effective in reducing oxidation during storage. The results show that natural antioxidants can be used in egg powder instead of synthetic compounds to reduce malonaldehyde production during storage.

  13. Formation Mechanism of Nanosized Tin Oxide (SnO2) Powder During Hydrothermal Synthesis

    OpenAIRE

    M. Ozan ÖZER; Suvaci, Ender; DOĞAN, Aydın

    2011-01-01

    Preparation of nanosized SnO2 electroceramic powders via hydrothermal synthesis was investigated as a function of initial concentration and treatment time in order to understand the formation and growth mechanisms.  SnO2 powder was successfully synthesized from the hydrous tin oxide by hydrothermal synthesis at 200°C.  Crystalline SnO2 particles with a specific surface area as high as 170 m2/g were produced in a single step without requiring any calcination process.  As ini...

  14. Dissolution of beryllium in artificial lung alveolar macrophage phagolysosomal fluid.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Virji, M Abbas; Day, Gregory A

    2011-05-01

    Dissolution of a lung burden of poorly soluble beryllium particles is hypothesized to be necessary for development of chronic beryllium lung disease (CBD) in humans. As such, particle dissolution rate must be sufficient to activate the lung immune response and dissolution lifetime sufficient to maintain chronic inflammation for months to years to support development of disease. The purpose of this research was to investigate the hypothesis that poorly soluble beryllium compounds release ions via dissolution in lung fluid. Dissolution kinetics of 17 poorly soluble particulate beryllium materials that span extraction through ceramics machining (ores, hydroxide, metal, copper-beryllium [CuBe] fume, oxides) and three CuBe alloy reference materials (chips, solid block) were measured over 31 d using artificial lung alveolar macrophage phagolysosomal fluid (pH 4.5). Differences in beryllium-containing particle physicochemical properties translated into differences in dissolution rates and lifetimes in artificial phagolysosomal fluid. Among all materials, dissolution rate constant values ranged from 10(-5) to 10(-10)gcm(-2)d(-1) and half-times ranged from tens to thousands of days. The presence of magnesium trisilicate in some beryllium oxide materials may have slowed dissolution rates. Materials associated with elevated prevalence of CBD had faster beryllium dissolution rates [10(-7)-10(-8)gcm(-2)d(-1)] than materials not associated with elevated prevalence (p<0.05).

  15. Oxidation of Ca-α-SiAlON Powders Prepared by Combustion Synthesis

    Science.gov (United States)

    Li, Jinfu; Li, Zhongmin; Wang, Enhui; Wang, Zhanjun; Yin, Xiaowei; Zhang, Zuotai

    2015-01-01

    The oxidation of Ca-α-SiAlON synthesized by the combustion synthesis (CS) method with different additives was investigated in air atmosphere using thermogravimetric (TG) analysis in a temperature range from 1453 K to 1653 K. The experimental results indicated that oxidation was controlled by mixed chemical and diffusion steps. The oxidation products by XRD analysis were composed of SiO2 and CaAl2Si2O8 at low oxidation temperature, whereas the SiO2-Al2O3-CaO ternary glassy phase was formed at elevated temperature. The deviation of oxidation resistance from each sample may be due to the morphological difference brought about by different additive additions. This study reveals the effects of additives on the oxidation resistance of synthesized Ca-α-SiAlON powders. PMID:28793657

  16. Cooperativity in beryllium bonds.

    Science.gov (United States)

    Alkorta, Ibon; Elguero, José; Yáñez, Manuel; Mó, Otilia

    2014-03-07

    A theoretical study of the beryllium bonded clusters of the (iminomethyl)beryllium hydride and (iminomethyl)beryllium fluoride [HC(BeX)=NH, X = H, F] molecules has been carried out at the B3LYP/6-311++G(3df,2p) level of theory. Linear and cyclic clusters have been characterized up to the decamer. The geometric, energetic, electronic and NMR properties of the clusters clearly indicate positive cooperativity. The evolution of the molecular properties, as the size of the cluster increases, is similar to those reported in polymers held together by hydrogen bonds.

  17. Fluorimetric method for determination of Beryllium; Determinazione fluorimetrica del berillio

    Energy Technology Data Exchange (ETDEWEB)

    Sparacino, N.; Sabbioneda, S. [ENEA, Centro Ricerche Saluggia, Vercelli (Italy). Dip. Energia

    1996-10-01

    The old fluorimetric method for the determination of Beryllium, based essentially on the fluorescence of the Beryllium-Morine complex in a strongly alkaline solution, is still competitive and stands the comparison with more modern methods or at least three reasons: in the presence of solid or gaseous samples (powders), the times necessary to finalize an analytic determination are comparable since the stage of the process which lasts the longest is the mineralization of the solid particles containing Beryllium, the cost of a good fluorimeter is by far Inferior to the cost, e. g., of an Emission Spectrophotometer provided with ICP torch and magnets for exploiting the Zeeman effect and of an Atomic absorption Spectrophotometer provided with Graphite furnace; it is possible to determine, fluorimetrically, rather small Beryllium levels (about 30 ng of Beryllium/sample), this potentiality is more than sufficient to guarantee the respect of all the work safety and hygiene rules now in force. The study which is the subject of this publication is designed to the analysis procedure which allows one to reach good results in the determination of Beryllium, chiefly through the control and measurement of the interference effect due to the presence of some metals which might accompany the environmental samples of workshops and laboratories where Beryllium is handled, either at the pure state or in its alloys. The results obtained satisfactorily point out the merits and limits of this analytic procedure.

  18. Crumpled graphene-molybdenum oxide composite powders: preparation and application in lithium-ion batteries.

    Science.gov (United States)

    Choi, Seung Ho; Kang, Yun Chan

    2014-02-01

    Crumpled graphene-MoO2 composite powders are directly prepared by means of spray pyrolysis and from a stable graphene oxide colloidal solution in the presence of Mo ions. The crumpled graphene-MoO2 composite powders are transformed into MoO3 -based composite powders after post-treatment at 300 °C. The transmission electron microscopy and dot-mapping images of the post-treatment composite powders show uniform distribution of MoO3 nanocrystals in the crumpled graphene powders. The two typical D and G bands of graphene are observed at 1350 and 1590 cm(-1) , respectively, in the Raman spectrum of the graphene-MoO3 composite. In addition, the crumpled graphene-MoO3 powders exhibit superior electrochemical behavior compared to that of pure MoO3 as an anode material for lithium-ion batteries. The initial discharge capacities of the graphene-MoO3 composite and bare MoO3 powders at a current density of 2 A g(-1) are 1490 and 1225 mA h g(-1) , respectively. The capacity retention of the graphene-MoO3 composite is 87 % after the first cycle, whereas that of bare MoO3 is 47 %, as measured after 100 cycles. The reversible discharge capacity of the graphene-MoO3 composite decreases slightly from 1228 to 845 mA h g(-1) as the current density increases from 0.5 to 3 A g(-1) .

  19. Release of beryllium into artificial airway epithelial lining fluid.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Virji, M Abbas; Day, Gregory A

    2012-01-01

    Inhaled beryllium particles that deposit in the lung airway lining fluid may dissolve and interact with immune-competent cells resulting in sensitization. As such, solubilization of 17 beryllium-containing materials (ore, hydroxide, metal, oxide, alloys, and process intermediates) was investigated using artificial human airway epithelial lining fluid. The maximum beryllium release in 7 days was 11.78% (from a beryl ore melter dust), although release from most materials was beryllium ions may be released in the respiratory tract via dissolution in airway lining fluid. Beryllium-containing particles that deposit in the respiratory tract dissolve in artificial lung epithelial lining fluid, thereby providing ions for absorption in the lung and interaction with immune-competent cells in the respiratory tract.

  20. Beryllium and copper-beryllium alloys; Beryllium und Kupfer-Beryllium-Legierungen

    Energy Technology Data Exchange (ETDEWEB)

    Nagel, Nikolaus [Materion Brush GmbH, Stuttgart (Germany). Operation and Quality/EH and S

    2017-02-15

    The light metal beryllium is a comparatively rare element, which today is primarily derived from bertrandite. It is mainly used as pure metal or in the form of copper-beryllium alloys, e.g., in automotive industry, aerospace, and electrical components. The wide range of applications is mainly attributed to the extremely high rigidity/density ratio. An overview of the history of the metal, its production, and recycling as well as the properties of CuBe alloys are given.

  1. Synthesis of yttria-doped bismuth oxide powder by carbonate coprecipitation for IT-SOFC electrolyte.

    Science.gov (United States)

    Lee, J G; Kim, S H; Yoon, H H

    2011-01-01

    Yttria-doped bismuth oxide (YBO) powders were synthesized by ammonium carbonate coprecipitation for the preparation of electrolytes of an intermediate temperature solid oxide fuel cell (IT-SOFC). The starting salts were yttrium and bismuth nitrate. The crystal structures and the morphological characteristics of the particles were analyzed by XRD and SEM, respectively. The ionic conductivity of the sintered pellet was measured by an electrochemical impedance analyzer. The size of the calcined YBO powders were in the range of 20-100 nm as measured by SEM images. The YBO pellets had a face-centered cubic structure, and their crystallite size was about 54-88 nm. The ionic conductivity of the YBO pellets sintered at 800 degrees C was observed to be 2.7 x 10(-1) Scm-(-1) at 700 degrees C. The ball-milling of the YBO powder before it was pelletized was found to have been unrequired probably because of a good sinterability of the YBO powders that was prepared via the ammonium carbonate coprecipitation method. The results showed that the ammonium carbonate coprecipitation process could be used as the cost-efficient method of producing YBO electrolytes for IT-SOFC.

  2. Investigation of structure and magnetic properties of nanocrystalline iron oxide powders for use in magnetic fluids

    Energy Technology Data Exchange (ETDEWEB)

    Lukashova, N.V.; Savchenko, A.G. [National University of Science and Technology ’’MISIS’’, 4, Leninsky pr., Moscow (Russian Federation); Yagodkin, Yu.D., E-mail: yag52@mail.ru [National University of Science and Technology ’’MISIS’’, 4, Leninsky pr., Moscow (Russian Federation); Muradova, A.G.; Yurtov, E.V. [Mendeleev University of Chemical Technology, Miusskaya sq., 9, Moscow (Russian Federation)

    2014-02-15

    Highlights: • The iron oxide nanopowders were obtained by chemical methods. • The particles of the nanopowders had different size. • The structure and magnetic behavior of the powders depend on nanoparticle size. -- Abstract: Iron oxide nanopowders with particles of different size, obtained by co-precipitation and sonochemical methods, were studied by X-ray diffraction, transmission electron microscopy and Mössbauer spectroscopy. The average size of nanoparticles obtained by a co-precipitation method, was about 10 nm. The main phase component of such nanoparticles was maghemite phase γ-Fe{sub 2}O{sub 3}. It was shown, that these nanoparticles were superparamagnetic. In contrast, the nanoparticles obtained by sonochemical method, consisted of larger particles with an average size of around 25 nm. Their main phase component was magnetite Fe{sub 3}O{sub 4}. This powder clearly showed hard magnetic properties.

  3. FORMATION MECHANISM OF NANOSIZED TIN OXIDE (SnO2 POWDER DURING HYDROTHERMAL SYNTHESIS

    Directory of Open Access Journals (Sweden)

    M. Ozan ÖZER

    2011-06-01

    Full Text Available Preparation of nanosized SnO₂ electroceramic powders via hydrothermal synthesis was investigated as a function of initial concentration and treatment time in order to understand the formation and growth mechanisms. SnO₂ powder was successfully synthesized from the hydrous tin oxide by hydro- thermal synthesis at 200°C. Crystalline SnO₂ particles with a specific surface area as high as 170 m₂/g were produced in a single step without requiring any calcination process. As initial concentration of metal cation increases from 0.0125 to 0.05 M, an Ostwald ripening type growth process was observed in the crystallite size from 3.1 to 4.6 nm. Evolution of tin oxide particles was also investigated by al- tering the treatment time from 1 to 24 h and a diffusion controlled growth behavior was observed as a function of synthesis time.

  4. Influence of superficial oxidation on the pyrophoric behaviour of uranium hydride and uranium powders in air

    Energy Technology Data Exchange (ETDEWEB)

    Ablitzer, C., E-mail: carine.ablitzer@cea.fr [CEA, DEN, DEC/SPUA/LCU, 13108 Saint-Paul lez Durance (France); Le Guyadec, F. [CEA, DEN, DTEC/SDTC, 30207 Bagnols sur Ceze (France); Raynal, J. [CEA, DEN, DEC/SPUA/LCU, 13108 Saint-Paul lez Durance (France); Genin, X. [CEA, DEN, DTEC/SDTC, 30207 Bagnols sur Ceze (France); Duhart-Barone, A. [CEA, DEN, DEC/SPUA/LCU, 13108 Saint-Paul lez Durance (France)

    2013-01-15

    Pyrophoric behaviours in air of uranium hydride and uranium powders have been studied on samples of small mass - several tens of milligrams - in a thermogravimetric device and on samples of several grams in an instrumented furnace. Results show that ignition can occur at room temperature for both materials but only in the second device and provided that powders are not superficially oxidized. Chemisorption of oxygen on particles is suspected to be responsible for ignition at room temperature. This phenomenon is not taken into account in classical theories of ignition. When ignition does not occur at room temperature, it occurs above at least 90 Degree-Sign C when heating at a rate of 5 Degree-Sign C min{sup -1}. Ignition seems then to result principally from the large increase of oxidation rates with temperature.

  5. Low temperature synthesis of magnesium oxide and spinel powders by a sol-gel process

    OpenAIRE

    Li-Zhai Pei; Wan-Yun Yin; Ji-Fen Wang; Jun Chen; Chuan-Gang Fan; Qian-Feng Zhang

    2010-01-01

    Magnesium oxide and magnesium aluminate (MgAl2O4) spinel (MAS) powders have been synthesized by a simple aqueous sol-gel process using citrate polymeric precursors derived from magnesium chloride, aluminium nitrate and citrate. The thermal decomposition of the precursors and subsequent formation of cubic MgO and MAS were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetry-differential scanning calorimetry (TG-DSC) and Fourier transform infrared spectr...

  6. Synthesis and oxidation behavior of boron-substituted carbon powders by hot filament chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Boron-substituted carbon powder, BxC1-x with x up to 0.17, has been successfully synthesized by hot filament chemical vapor deposition. The boron concentration in prepared BxC1-x samples can be controlled by varying the relative proportions of methane and diborane. X-ray diffraction, transmission electron microscopy, and electron energy loss spectrum confirm the successful synthesis of an amorphous BC5 compound, which consists of 10―20 nm particles with disk-like morphology. Thermogravimetry measurement shows that BC5 compound starts to oxidize ap-proximately at 620℃ and has a higher oxidation resistance than carbon.

  7. Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application.

    Science.gov (United States)

    Rousset, Davy; Durand, Thibaut

    2016-01-01

    Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks.

  8. Beryllium coating produced by evaporation-condensation method and some their properties

    Energy Technology Data Exchange (ETDEWEB)

    Pepekin, G.I.; Anisimov, A.B.; Chernikov, A.S.; Mozherinn, S.I.; Pirogov, A.A. [SRI SIA Lutch., Podolsk (Russian Federation)

    1998-01-01

    The method of vacuum evaporation-condensation for deposition of beryllium coatings on metal substrates, considered in the paper, side by side with a plasma-spray method is attractive fon ITER application. In particular this technique may be useful for repair the surface of eroded tiles which is operated in a strong magnetic field. The possibility of deposition of beryllium coatings with the rate of layer growth 0.1-0.2 mm/h is shown. The compatibility of beryllium coating with copper or stainless steel substrate is provided due to intermediate barrier. The results of examination of microstructure, microhardness, porosity, thermal and physical properties and stability under thermal cycling of beryllium materials are presented. The value of thermal expansion coefficient and thermal conductivity of condensed beryllium are approximately the same as for industrial grade material produced by powder mettalurgy technique. However, the condensed beryllium has higher purity (up to 99.9-99.99 % wt.). (author)

  9. Antioxidant Effectiveness of Vegetable Powders on the Lipid and Protein Oxidative Stability of Cooked Turkey Meat Patties: Implications for Health

    OpenAIRE

    Duthie, Garry; Campbell, Fiona; Bestwick, Charles; Stephen, Sylvia; Russell, Wendy

    2013-01-01

    Lipid and protein oxidation decreases the shelf-life of foods and may result in formation of end-products potentially detrimental for health. Consumer pressure to decrease the use of synthetic phenolic antioxidants has encouraged identification of alternative compounds or extracts from natural sources. We have assessed whether inclusion of dried vegetable powders improves the oxidative stability of turkey meat patties. Such powders are not only potentially-rich sources of phenolic antioxidant...

  10. The physical chemistry of nucleation of sub-micrometer non-oxide ceramic powders via sub-oxide vapor-phase reduction reaction

    Energy Technology Data Exchange (ETDEWEB)

    Jha, A. [Brunel Univ., Uxbridge (United Kingdom). Dept. of Materials Technology

    1996-10-01

    Fine ceramic powders (< 500 nm) exhibit exceptional physical and mechanical properties in engineered structural ceramics. The production of fine powders, in particular the non-oxide ceramics, via a cheaper route than the organic solvent route has been rather elusive. This paper examines the physical chemistry of sub-oxide vapor-phase reduction reaction for the nucleation of non-oxide ceramic phase. Well known vapor species eg SiO and BO in the production of technical ceramic powders (SiC, BN) are particularly discussed for understanding the nucleation process of SiC and BN ceramic phases respectively. The regimes of partial pressures and temperatures are particularly identified. The calculated nucleation rate as a function of the temperature is compared with the experimental results on powder morphology. The production of amorphous and nanocrystalline h-BN powders is discussed in the context of substrate structure and thermodynamic parameters.

  11. Influence of packaging atmosphere on the formation of cholesterol oxides in [gamma]-irradiated egg powder

    Energy Technology Data Exchange (ETDEWEB)

    Lebovics, V.K.; Gaal, O. (National Inst. of Food Hygiene and Nutrition, Budapest (Hungary)); Farkas, J.; Somogyi, L. (University of Horticulture and Food Industry, Budapest (Hungary))

    1993-09-01

    In the present work the influence of aerobic and anoxic conditions have been comparatively investigated to study the chemical changes of cholesterol in [gamma]-irradiated egg powder. The irradiation treatment was carried out with powdered egg packed under air and also under vacuum in polyethylene (PE) bags and in laminated, oxygen impermeable three-layer (polyester-aluminium-polyethylene) foil to dosage levels 2 and 4 kGy at room temperature. The cholesterol oxidation is demonstrated by thin-layer chromatograms. In the egg powder wrapped in Pe bags the predominant cholesterol derivatives -7-hydroxycholesterol isomers ([alpha] and [beta]) - accumulated in significant amounts (increasing with dose) while vacuum-packaging in laminated foil considerably suppressed the quantity of these products and prevented the formation of cholesterol 5[alpha], 6[alpha]-epoxide as well as 7-ketocholesterol. Little or no change was observed in non-irradiated (control) vacuum-packed egg powder stored at approximately 22[sup o]C for up to 5 months. Peroxide values showed changes parallel to the formation of COPs. (author).

  12. Influence of Diatomite and Mineral Powder on Thermal Oxidative Ageing Properties of Asphalt

    Directory of Open Access Journals (Sweden)

    Yongchun Cheng

    2015-01-01

    Full Text Available Ageing of asphalt affects the performances of asphalt pavement significantly. Therefore, effects of diatomite and mineral powder on ageing properties of asphalt were investigated systematically in order to improve the antiageing property of mixture. Thin film oven test (TFOT was used to conduct the short term ageing in laboratory. Softening points, penetrations, force ductility, low temperature creep properties, and viscosities of asphalt mastics were tested before and after TFOT, respectively. Results indicated that percent retained penetration (PRP increased with the increasing of fillers. Increment of softening point (ΔT, ductility retention rate (DRR, deformation energy ageing index (JAI, and viscosity ageing index (VAI of asphalt mastics nonlinearly decreased with the increasing of fillers. Ageing of asphalt was reduced by diatomite and mineral powder. And the antiageing effect of diatomite was better than that of mineral powder as a result of its porous structure. It is suggested that the mineral powder could be reasonably replaced by diatomite in order to reduce thermal oxidative ageing of asphalt mixture. The optimal content of diatomite 12.8% is also suggested for engineering.

  13. Indium tin oxide nanosized composite powder prepared using waste ITO target

    Institute of Scientific and Technical Information of China (English)

    LIU Jiaxiang; GAN Yong; ZENG Shengnan

    2005-01-01

    Indium tin oxide (TTO) nano-particles were prepared directly using waste ITO target, which had been coated by magnetron controlled sputtering. The waste ITO target was cleaned with de-ionized water, and then dissolved in acid, filtrated, neutralized, manipulated through azeotropic distillation and finally dried, and in this way the precursor of indium tin hydroxide was obtained. The nanosized ITO composite powder was prepared after the precursor heat-treated at 500C for 2h. TEM images show a narrow distribution of particle size is 5-20 nm and the particle size can be controlled. Its granule has a spherical shape and the dispersion of the particle is well. X-ray diffraction (XRD) patterns indicate the only cubic In2O3 phase in the ITO powder heat-treated at 500C. The purity of ITO composite powder is 99.9907%. The content of indium within filtrate was detected by using the EDTA titration of determination of indium in the ITO powder and ITO target. Apfully prepared by heat-treating.

  14. Purifications of calcium carbonate and molybdenum oxide powders for neutrinoless double beta decay experiment, AMoRE

    Energy Technology Data Exchange (ETDEWEB)

    Park, HyangKyu [Center for Underground Physics, Institute for Basic Science, 70, Yuseong-daero 1689-gil, Yuseong-gu, Daejeon, Korea, 305-811 (Korea, Republic of)

    2015-08-17

    The AMoRE (Advanced Mo based Rare process Experiment) collaboration is going to use calcium molybdate crystals to search for neutrinoless double beta decay of {sup 100}Mo isotope. In order to make the crystal, we use calcium carbonate and molybdenum oxide powders as raw materials. Therefore it is highly necessary to reduce potential sources for radioactive backgrounds such as U and Th in the powders. In this talk, we will present our studies for purification of calcium carbonate and molybdenum oxide powders.

  15. Synthesis and Characterization of Oxide Feedstock Powders for the Fuel Cycle R&D Program

    Energy Technology Data Exchange (ETDEWEB)

    Voit, Stewart L [ORNL; Vedder, Raymond James [ORNL; Johnson, Jared A [ORNL

    2010-09-01

    Nuclear fuel feedstock properties, such as physical, chemical, and isotopic characteristics, have a significant impact on the fuel fabrication process and, by extension, the in-reactor fuel performance. This has been demonstrated through studies with UO{sub 2} spanning greater than 50 years. The Fuel Cycle R&D Program with The Department of Energy Office of Nuclear Energy has initiated an effort to develop a better understanding of the relationships between oxide feedstock, fresh fuel properties, and in-reactor fuel performance for advanced mixed oxide compositions. Powder conditioning studies to enable the use of less than ideal powders for ceramic fuel pellet processing are ongoing at Los Alamos National Laboratory (LANL) and an understanding of methods to increase the green density and homogeneity of pressed pellets has been gained for certain powders. Furthermore, Oak Ridge National Laboratory (ORNL) is developing methods for the co-conversion of mixed oxides along with techniques to analyze the degree of mixing. Experience with the fabrication of fuel pellets using co-synthesized multi-constituent materials is limited. In instances where atomically mixed solid solutions of two or more species are needed, traditional ceramic processing methods have been employed. Solution-based processes may be considered viable synthesis options, including co-precipitation (AUPuC), direct precipitation, direct-conversion (Modified Direct Denitration or MDD) and internal/external gelation (sol-gel). Each of these techniques has various advantages and disadvantages. The Fiscal Year 2010 feedstock development work at ORNL focused on the synthesis and characterization of one batch of UO{sub x} and one batch of U{sub 80}Ce{sub 20}O{sub x}. Oxide material synthesized at ORNL is being shipped to LANL for fuel fabrication process development studies. The feedstock preparation was performed using the MDD process which utilizes a rotary kiln to continuously thermally denitrate double

  16. Historical analysis of airborne beryllium concentrations at a copper beryllium machining facility (1964-2000).

    Science.gov (United States)

    McAtee, B L; Donovan, E P; Gaffney, S H; Frede, W; Knutsen, J S; Paustenbach, D J

    2009-06-01

    Copper beryllium alloys are the most commonly used form of beryllium; however, there have been few studies assessing occupational exposure in facilities that worked exclusively with this alloy versus those where pure metal or beryllium oxide may also have been present. In this paper, we evaluated the airborne beryllium concentrations at a machining plant using historical industrial hygiene samples collected between 1964 and 2000. With the exception of a few projects conducted in the 1960s, it is believed that >95% of the operations used copper beryllium alloy exclusively. Long-term (>120 min) and short-term (machining of copper beryllium-containing parts, as well as finishing operations (e.g., deburring and polishing) and decontamination of machinery. A total of 580 beryllium air samples were analyzed (311 personal and 269 area samples). The average concentration based on area samples (1964-2000) was 0.021 microg m(-3) (SD 0.17 microg m(-3); range 0.00012-2.5 microg m(-3)); 68.8% were below the analytical limit of detection (LOD). The average airborne beryllium concentration, based on all personal samples available from 1964 through the end of 2000 (n = 311), was 0.026 microg m(-3) (SD 0.059 microg m(-3); range 0.019-0.8 microg m(-3)); 97.4% were below the LOD. Personal samples collected from machinists (n = 78) had an average airborne concentration of 0.021 microg m(-3) (SD 0.014 microg m(-3); range 0.019-0.14 microg m(-3)); 97.4% were below the LOD. Airborne concentrations were consistently below the Occupational Safety and Health Administration permissible exposure limit for beryllium (2 microg m(-3)). Overall, the data indicate that for machining operations involving copper beryllium, the airborne concentrations for >95% of the samples were below the contemporaneous occupational exposure limits or the 1999 Department of Energy action level of 0.2 microg m(-3) and, in most cases, were below the LOD.

  17. Gas atomized precursor alloy powder for oxide dispersion strengthened ferritic stainless steel

    Energy Technology Data Exchange (ETDEWEB)

    Rieken, Joel [Iowa State Univ., Ames, IA (United States)

    2011-12-13

    Gas atomization reaction synthesis (GARS) was employed as a simplified method for producing precursor powders for oxide dispersion strengthened (ODS) ferritic stainless steels (e.g., Fe-Cr-Y-(Ti,Hf)-O), departing from the conventional mechanical alloying (MA) process. During GARS processing a reactive atomization gas (i.e., Ar-O2) was used to oxidize the powder surfaces during primary break-up and rapid solidification of the molten alloy. This resulted in envelopment of the powders by an ultra-thin (t < 150 nm) metastable Cr-enriched oxide layer that was used as a vehicle for solid-state transport of O into the consolidated microstructure. In an attempt to better understand the kinetics of this GARS reaction, theoretical cooling curves for the atomized droplets were calculated and used to establish an oxidation model for this process. Subsequent elevated temperature heat treatments, which were derived from Rhines pack measurements using an internal oxidation model, were used to promote thermodynamically driven O exchange reactions between trapped films of the initial Cr-enriched surface oxide and internal Y-enriched intermetallic precipitates. This novel microstructural evolution process resulted in the successful formation of nano-metric Y-enriched dispersoids, as confirmed using high energy X-ray diffraction and transmission electron microscopy (TEM), equivalent to conventional ODS alloys from MA powders. The thermal stability of these Y-enriched dispersoids was evaluated using high temperature (1200°C) annealing treatments ranging from 2.5 to 1,000 hrs of exposure. In a further departure from current ODS practice, replacing Ti with additions of Hf appeared to improve the Y-enriched dispersoid thermal stability by means of crystal structure modification. Additionally, the spatial distribution of the dispersoids was found to depend strongly on the original rapidly solidified microstructure. To exploit this, ODS microstructures were engineered from

  18. Preparation and Characterization of Porous Yttrium Oxide Powders with High Specific Surface Area

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The porous cubic yttrium oxides with high specific surface area were prepared by the explosive decomposition of yttrium nitrate and its complex formed with methyl salicylate. The specific surface area and properties of powders synthesized at various temperatures were characterized using BET, X-ray diffraction (XRD), infrared spectra (IR), and scanning electron microscopy (SEM). The results indicate that the highest specific surface area is found to be 65.37 m2*g-1 at the calcination temperature of 600 ℃, and then decreases to 20.33 m2*g-1 with the calcination temperature rising from 600 to 900 ℃. The powders show strong surface activity for adsorping water and carbon dioxide in air, which also decreases with the rising calcination temperature. The drop both on the surface area and surface activity of samples at higher temperatures may be due to pore-narrowing(sintering) effects.

  19. Elemental mercury oxidation and adsorption on magnesite powder modified by Mn at low temperature.

    Science.gov (United States)

    Xu, Yalin; Zhong, Qin; Liu, Xinya

    2015-01-01

    Mn modified the commercial magnesite powder prepared by wet impregnation method has been shown to be effective for gas-phase elemental mercury (Hg(0)) removal at low temperatures. The prepared samples are characterized in detail across multiform techniques: XRF, BET, SEM-EDX, XRD, H2-TPR, and XPS, and all the results show that the amorphous MnO2 impregnated on magnesite powder improves the removal efficiency of Hg(0). Through further analysis by TG and in situ FTIR, the reasonable removal mechanism is also speculated. The results indicate that chemisorbed oxygen is an important reactant in the heterogeneous reaction, and gas-phase Hg(0) is adsorbed and then oxidized to solid MnHgO3 on the surface of the adsorbent.

  20. Antioxidant effectiveness of vegetable powders on the lipid and protein oxidative stability of cooked Turkey meat patties: implications for health.

    Science.gov (United States)

    Duthie, Garry; Campbell, Fiona; Bestwick, Charles; Stephen, Sylvia; Russell, Wendy

    2013-04-17

    Lipid and protein oxidation decreases the shelf-life of foods and may result in formation of end-products potentially detrimental for health. Consumer pressure to decrease the use of synthetic phenolic antioxidants has encouraged identification of alternative compounds or extracts from natural sources. We have assessed whether inclusion of dried vegetable powders improves the oxidative stability of turkey meat patties. Such powders are not only potentially-rich sources of phenolic antioxidants, but also may impart additional health benefits, as inadequate vegetable consumption is a risk factor for heart disease and several cancers. In an accelerated oxidation system, six of eleven vegetable powders significantly (p protein carbonyls (r = 0.747, p powders offers an alternative to individual antioxidants for increasing shelf-life of animal-based food products and may also provide additional health benefits associated with increased vegetable intake.

  1. Reducing retrogradation and lipid oxidation of normal and glutinous rice flours by adding mango peel powder.

    Science.gov (United States)

    Siriamornpun, Sirithon; Tangkhawanit, Ekkarat; Kaewseejan, Niwat

    2016-06-15

    Green and ripe mango peel powders (MPP) were added to normal rice flour (NRF) and glutinous rice flour (GRF) at three levels (400, 800 and 1200 ppm) and their effects on physicochemical properties and lipid oxidation inhibition were investigated. Overall, MPP increased the breakdown viscosity and reduced the final viscosity in rice flours when compared to the control. Decreasing in retrogradation was observed in both NRF and GRF with MPP added of all levels. MPP addition also significantly inhibited the lipid oxidation of all flours during storage (30 days). Retrogradation values were strongly negatively correlated with total phenolic and flavonoid contents, but not with fiber content. The hydrogen bonds and hydrophilic interactions between phenolic compounds with amylopectin molecule may be involved the decrease of starch retrogradation, especially GRF. We suggest that the addition of MPP not only reduced the retrogradation but also inhibited the lipid oxidation of rice flour.

  2. Crocin "saffron" protects against beryllium chloride toxicity in rats through diminution of oxidative stress and enhancing gene expression of antioxidant enzymes.

    Science.gov (United States)

    El-Beshbishy, Hesham A; Hassan, Memy H; Aly, Hamdy A A; Doghish, Ahmed S; Alghaithy, Abdulaziz A A

    2012-09-01

    Beryllium chloride (BeCl(2)) is a highly toxic substance that accumulates in different tissues after absorption. The purpose of this study was to investigate protective role of crocin against BeCl(2)-intoxication in rats. Male Wistar rats were used in this study and categorised into four groups (n=8). Group I served as normal control rats. Group II treated orally with BeCl(2) 86 mg/kg b.w. for five consecutive days. This dose was equivalent to experimental LD(50). Group III treated intraperitoneally with crocin 200 mg/kg b.w. for seven consecutive days. Group IV received crocin for seven consecutive days before BeCl(2) administration. Blood samples and liver and brain homogenates were obtained for haematological, biochemical and RT-PCR examinations. The haematocrit value, RBCs count and haemoglobin concentration were significantly decreased in BeCl(2)-treated rats. A significant increase was observed in rat liver and brain malondialdehyde level and protein carbonyls content in BeCl(2) exposed group compared to the control group, and these values were significantly declined upon administration of crocin. Lactate dehydrogenase levels in rat liver and brain significantly increased compared to the control group and was associated with significant decrease in catalase and superoxide dismutase activities. Reduced glutathione hepatic contents of BeCl(2)-treated rats were significantly decreased. There was significant decline in mRNA expression of catalase and superoxide dismutase genes in BeCl(2)-intoxicated rats compared to the normal rats. Crocin treatment prior to BeCl(2) intake resulted in significant increase in mRNA expressions of catalase and superoxide dismutase genes near to normalcy. The haematological and biochemical parameters were restored near to normal levels. Our results suggested that, BeCl(2) induced oxidation of cellular lipids and proteins and that administration of crocin reduced BeCl(2)-induced oxidative stress combined with initiation of m

  3. Study on Exothermic Oxidation of Acrylonitrile-butadiene-styrene (ABS Resin Powder with Application to ABS Processing Safety

    Directory of Open Access Journals (Sweden)

    Jenq-Renn Chen

    2010-08-01

    Full Text Available Oxidative degradation of commercial grade ABS (Acrylonitrile-butadiene-styrene resin powders was studied by thermal analysis. The instabilities of ABS containing different polybutadiene (PB contents with respect to temperature were studied by Differential Scanning Calorimeter (DSC. Thermograms of isothermal test and dynamic scanning were performed. Three exothermic peaks were observed and related to auto-oxidation, degradation and oxidative decomposition, respectively. Onset temperature of the auto-oxidation was determined to be around 193 °C. However, threshold temperature of oxidation was found to be as low as 140 °C by DSC isothermal testing. Another scan of the powder after degeneration in air showed an onset temperature of 127 °C. Reactive hazards of ABS powders were verified to be the exothermic oxidation of unsaturated PB domains, not the SAN (poly(styrene-acrylonitrile matrix. Heat of oxidation was first determined to be 2,800 ± 40 J per gram of ABS or 4,720 ± 20 J per gram of PB. Thermal hazards of processing ABS powder are assessed by adiabatic temperature rise at process conditions. IR spectroscopy associated with heat of oxidation verified the oxidative mechanism, and these evidences excluded the heat source from the degradation of SAN. A specially prepared powder of ABS without adding anti-oxidant was analyzed by DSC for comparing the exothermic behaviors. Exothermic onset temperatures were determined to be 120 °C and 80 °C by dynamic scanning and isothermal test, respectively. The assessment successfully explained fires and explosions in an ABS powder dryer and an ABS extruder.

  4. Low-temperature oxidation behavior of MoSi2 powders

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The oxidation behavior of molybdenum disilicide (MoSi2) powders at 400, 500, and 600℃ for 12 h in air were investigated by using X-ray diffraction (XRD) and transmission electron microscopic (TEM) techniques. Significant changes were observed in volume, mass, and color. Especially at 500℃, the volume expansion was found to be as high as 7-8 times, the color changed from black to yellow-white, and the mass gain was about 169.34% after 8 h, with SiO2 and MoO3 as main reaction products. The gains in volume and mass were less at 400 and 600℃ compared with those at 500℃, probably due to the less reaction rate at 400℃ and the formation of silica glass scale at 600℃, which would protect the matrix and restrain the diffusion of oxygen and molybdenum. Thus,the accelerated oxidation behavior of MoSi2 powder appeared at 500℃ and the volume expansion was the sign of accelerated oxidation.

  5. Influence of oxidant and fuel on the powder characteristics of LiNbO$_3$ synthesized by combustion method

    Indian Academy of Sciences (India)

    D H PIVA; H BIZ; R H PIVA; M R MORELLI

    2017-02-01

    Lithium niobate (LiNbO$_3$) is widely recognized as a promising material for replacing lead-based piezoelectric ceramics. Although the LiNbO3 synthesis by combustion method has been investigated with particular attention recently, the influence of oxidants and different fuels’ sources on the synthesized powders has not yet been thoroughly studied. In this work we investigate the influence of urea and maleic hydrazide as fuels and ammonium nitrate as an oxidant on the powder characteristics of LiNbO$_3$ synthesized by combustion method. In addition, powder characteristics and sinterability of powders prepared by combustion method are compared with those of powders prepared by solid-state reaction. The results show that the second phase LiNb$_3$O$_8$ was detected only when an oxidant agent was used in the synthesis process. Among all combustion reactions, the powders prepared with excess of urea presented better final characteristics. As a result, the sintering temperature for LiNbO$_3$ powders prepared by combustion method was appreciably lowered when compared with those prepared by solid-state reaction.

  6. Microwave synthesis of ultrafine and nanosized powders of tungsten oxide and carbide

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaenko, Irina; Kedin, Nikolay; Shveikin, Gennadii; Polyakov, Evgenii [Russian Academy of Sciences, Ekaterinburg (Russian Federation). Inst. of Solid State Chemistry

    2014-03-15

    A new method of synthesis of nanosized and ultrafine tungsten oxide and carbide powders is offered, which combines carbon carrier supported classical liquid-phase precipitation and low-temperature microwave treatment. The full range of intermediate substances obtained during thermolysis, reduction and carburization of precursors to final products is presented. It is shown that cooling of ammonium tungstate solution to 4 C and the use of carbon carrier at the precipitation stage can increase the specific surface area from 20 to 100 m{sup 2} g{sup -1}. (orig.)

  7. Standard specification for nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2003-01-01

    1.1 This specification provides the chemical and physical requirements for nuclear-grade gadolinium oxide powder intended for subsequent processing and use in nuclear fuel applications, for example, as an addition to uranium dioxide. 1.2 This specification does not include requirements for health and safety. Observance of this specification does not relieve the user of the obligation to be aware of and comply with all federal, state, and local regulations pertaining to possessing, shipping, processing, or using this material. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

  8. Effect of compaction pressure and powder grade on the microstructure, hardness and surface topography of steam oxidized sintered iron

    Energy Technology Data Exchange (ETDEWEB)

    Mello, J.D.B. de; Hutchings, I.M. [Univ. of Cambridge (United Kingdom); Binder, R. [Embraco, Joinville, S.C. (Brazil); Klein, A.N. [Labmat, UFSC, Florianopolis, S.C. (Brazil)

    2000-07-01

    Steam oxidation has proved to be an effective process to improve the properties of sintered iron components. The wear processes of such surfaces might be expected to be influenced by the presence of pores, the extent of pore closure and the nature and morphology of the oxide produced. In this paper, the influence of compaction pressure and powder grade on the microstructure, oxide content, hardness and surface topography of steam treated sintered iron is analysed. Specimens prepared from atomised powders in different sizes were compacted using 4 different pressure, sintered and then subjected to a continuous steam treatment. A clear influence of the processing parameters on porosity was highlighted. Low porosity is always associated with high compaction pressure and greater powder size. Decreasing powder size always leads to high hardness. Samples produced with smaller powder size show a continuous decrease in hardness as the compaction pressure increases although for the large powder size there is a slight increase to a constant value of ultimate hardness. For the intermediate grain size a maximum hardness is obtained as the compaction pressure increases. X-ray diffraction shows that the oxide layer is composed of magnetite and haematite. No general correlation was found between topographic features, examined using vertical scanning interferometry, and processing parameters or microstructure. (orig.)

  9. Effect of inner oxidant on self-propagating high-temperature synthesis of MnZn-ferrite powder

    Institute of Scientific and Technical Information of China (English)

    YANG Ke; GUO Zhimeng; AKHTAR Farid; ZHANG Bin; TU Yifan

    2006-01-01

    Using KClO3 as an inner oxidant, MnZn-ferrite powder was synthesized by a self-propagating high-temperature synthesis (SHS) process in normal air atmosphere. The effects of the inner oxidant on combustion temperature, combustion velocity, microstructure and the phase of the product were investigated by XRD and SEM,respectively. The results show that a highly ferritized powder can be obtained as well as the highest combustion temperature and the highest combustion velocity when the inner oxidant content m equals 5/4( k -1/6).

  10. A study of the oxide dispersion and recrystallization in NiCrAl prepared from preoxidized powder

    Science.gov (United States)

    Glasgow, T. K.

    1975-01-01

    The SAP technique of dispersion strengthening (formation of an oxide dispersion by preoxidation of metal powders) was applied to atomized powder of the alloy Ni-17Cr-5Al-0.2 Y. SAP-NiCrAl was worked by extrusion and rod rolling at 1205 C and by swaging at 760 C. A variety of annealing treatments were applied after working to determine the recrystallization response. NiCrAlY, similarly prepared from atomized powder, but without a preoxidation treatment, was examined for comparison. The SAP-NiCrAl of this study exhibited oxide particle size and spacing much larger than that usually observed in oxide dispersion strengthened alloys; nonetheless, it was possible to achieve abnormal (secondary) recrystallization in the SAP-NiCrAl as has been reported for other oxide dispersion strengthened alloys. In contrast, unoxidized NiCrAlY exhibited only primary recrystallization.

  11. Microporous Titanium through Metal Injection Moulding of Coarse Powder and Surface Modification by Plasma Oxidation

    Directory of Open Access Journals (Sweden)

    Mohammed Menhal Shbeh

    2017-01-01

    Full Text Available Titanium is one of the most attractive materials for biomedical applications due to having excellent biocompatibility accompanied by good corrosion resistance. One popular processing technique for Ti is Metal Injection Moulding (MIM. However, there are several issues associated with the use of this technique, such as the high cost of the fine powder used, the high level of contamination and consequent alteration to material properties, as well as the large volume shrinkage that occurs during sintering. In this study, the use of a relatively coarse Ti powder with a mean particle size of 75 μm to process Ti parts with the potential for biomedical applications by MIM will be examined, compared to a commercial Ti feedstock, and subsequently coated using Plasma Electrolytic Oxidation (PEO. The results show that samples produced with the coarse powder shrink 35% less and have a relative density 14% less with an average pore size three-times larger than that of the commercial feedstock. This helps increase the potential competitiveness of MIM in the production of biomedical parts, as it reduces cost, shrinkage and results in more intentionally-induced micropores, such as are desired for biomedical implants. PEO treatment of the samples yields a thick rough coating comprised of a mixture of rutile and anatase with interconnected microporous channels and openings resembling the mouth of a volcanic crater.

  12. Quality management of dispersion-strengthened beryllium-based composite alloy

    Directory of Open Access Journals (Sweden)

    Дмитро Миколайович Макаренко

    2016-05-01

    Full Text Available The article is devoted to investigation of the composition and properties of dispersion-strengthened beryllium-based composite alloy, used in various industries, including the aircraft manufacture aircraft. Analyzed the properties of these materials are analyzed to ensure their quality management. The mathematical relationship of dispersion strengthened beryllium-based composite alloy parameters from content of beryllium oxide and temperature are built

  13. Oxidative degradation of chemical warfare agents in water by bleaching powder.

    Science.gov (United States)

    Qi, Lihong; Zuo, Guomin; Cheng, Zhenxing; Zhu, Haiyan; Li, Shanmao

    2012-01-01

    Degradation of sulfur mustard (HD), S-2-(di-isopropylamino)ethyl O-ethyl methylphosphonothioate (VX) and Soman (GD) in water by bleaching powder was investigated. The degradation products were comprehensively analyzed by gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS) and ion chromatography. Degradation pathways were deduced based on the identified products. The product analysis results indicated that HD could be degraded through oxidation and chlorination reactions, and a small portion of sulfur atoms could be mineralized into SO(4)(2-) ion. Oxidative degradation of VX could finally generate O-ethyl methylphosphonate acid (EMPA), sulfonic acids, SO(4)(2-) and NO(3)(-) ions. GD would be converted into non-toxic pinacolyl methylphosphonate via nucleophilic substitution.

  14. Influence of Turmeric Rhizome Powder diets on decreasing oxidative stress caused by heat stress inbroiler model

    Directory of Open Access Journals (Sweden)

    Seyyed Javad Hosseini-Vashan

    2012-08-01

    Full Text Available Background and Aim: Production of reactive oxygen species (ROS increases during oxidative stress conditions, which stimulates diabetes, inflammatory reactions, rheumatism and anemia. Some antioxidant properties of turmeric rhizome powder (TRP were revealed by previous researchers. The present study was conducted to evaluate the influence of TRP on decreasing effects of oxidative stress resulted from heat stress in broiler chickens.   Materials and Methods: In this experimental study, two-hundred-sixty-four 1-day-old broilers were divided into 3 dietary treatments. The dietary treatments involved 0(control, 0.4 and 0.8% turmeric rhizome powder (cases. In order to create oxidative stress, the ambient temperature was daily raised from 21 to 33oc for 5 hours (11a.m-4p.m throughout the 28th-42nd days. Blood lipids, Glutathione peroxidase (GPx ,superoxide dismutase (SOD, and Tiobarbituric acid reaction score (TBARS were determined at the end of the experiment.   Results: The results revealed that total cholesterol and triglyceride were not affected. The 0.4 TRP diet decreased blood LDL (46.7±3.01 compared to basal group (52.0±2.17. HDL increased in broilers fed 0.8% TRP (74.0 ± 3.87 compared to chickens with basal diet (63.7± 2.98. Enzyme activity of GPx improved in broilers fed TRP diets (225.9± 11.52 as compared to chickens with basal diet(183.1± 8.52 however, the TRP diet did not affect enzyme activity of SOD (P > 0.05. The TBARS index decreased in broilers fed TRP (0.76 ± 0.0052 in basal vs.0.49 ± 0.0032 in 0.8% TRP.   Conclusion: The major bioactive component of TRP is Curcumin that can improve the antioxidant properties under oxidative stress and high ambient temperature.

  15. A metastable chromium carbide powder obtained by carburization of a metastable chromium oxide

    Energy Technology Data Exchange (ETDEWEB)

    Loubiere, S. [Univ. Paul-Sabatier, Toulouse (France). Lab. de Chimie des Materiaux Inorganique; Laurent, C. [Univ. Paul-Sabatier, Toulouse (France). Lab. de Chimie des Materiaux Inorganique; Bonino, J.P. [Univ. Paul-Sabatier, Toulouse (France). Lab. de Chimie des Materiaux Inorganique; Rousset, A. [Univ. Paul-Sabatier, Toulouse (France). Lab. de Chimie des Materiaux Inorganique

    1996-10-15

    A metastable Cr{sub 3}C{sub 2-x} carbide powder is prepared by carburization of a metastable chromium oxide in H{sub 2}-CH{sub 4} atmosphere under the appropriate conditions (temperature, dwell time and CH{sub 4} content). A very high specific surface area (greater than 210 m{sup 2} g{sup -1}) of the starting oxide is necessary to avoid the formation of the sole stable Cr{sub 3}C{sub 2} phase. The transformation from the stable Cr{sub 3}C{sub 2} to the metastable Cr{sub 3}C{sub 2-x} is observed for the first time. The driving force could be an epitaxial effect between Cr{sub 3}C{sub 2-x} and the surrounding graphite layer. This is consistent with the observation that the formation of graphite layers by CH{sub 4} cracking is easier in the Cr{sub 3}C{sub 2-x}-containing powders. (orig.)

  16. Beryllium contamination and exposure monitoring in an inhalation laboratory setting.

    Science.gov (United States)

    Muller, Caroline; Audusseau, Séverine; Salehi, Fariba; Truchon, Ginette; Chevalier, Gaston; Mazer, Bruce; Kennedy, Greg; Zayed, Joseph

    2010-02-01

    Beryllium (Be) is used in several forms: pure metal, beryllium oxide, and as an alloy with copper, aluminum, or nickel. Beryllium oxide, beryllium metal, and beryllium alloys are the main forms present in the workplace, with inhalation being the primary route of exposure. Cases of workers with sensitization or chronic beryllium disease challenge the scientific community for a better understanding of Be toxicity. Therefore, a toxicological inhalation study using a murine model was performed in our laboratory in order to identify the toxic effects related to different particle sizes and chemical forms of Be. This article attempts to provide information regarding the relative effectiveness of the environmental monitoring and exposure protection program that was enacted to protect staff (students and researchers) in this controlled animal beryllium inhalation exposure experiment. This includes specific attention to particle migration control through intensive housekeeping and systematic airborne and surface monitoring. Results show that the protective measures applied during this research have been effective. The highest airborne Be concentration in the laboratory was less than one-tenth of the Quebec OEL (occupational exposure limit) of 0.15 microg/m(3). Considering the protection factor of 10(3) of the powered air-purifying respirator used in this research, the average exposure level would be 0.03 x 10(- 4) microg/m(3), which is extremely low. Moreover, with the exception of one value, all average Be concentrations on surfaces were below the Quebec Standard guideline level of 3 microg/100 cm(2) for Be contamination. Finally, all beryllium lymphocyte proliferation tests for the staff were not higher than controls.

  17. The Be K-edge in beryllium oxide and chalcogenides: soft x-ray absorption spectra from first-principles theory and experiment.

    Science.gov (United States)

    Olovsson, W; Weinhardt, L; Fuchs, O; Tanaka, I; Puschnig, P; Umbach, E; Heske, C; Draxl, C

    2013-08-07

    We have carried out a theoretical and experimental investigation of the beryllium K-edge soft x-ray absorption fine structure of beryllium compounds in the oxygen group, considering BeO, BeS, BeSe, and BeTe. Theoretical spectra are obtained ab initio, through many-body perturbation theory, by solving the Bethe-Salpeter equation (BSE), and by supercell calculations using the core-hole approximation. All calculations are performed with the full-potential linearized augmented plane-wave method. It is found that the two different theoretical approaches produce a similar fine structure, in good agreement with the experimental data. Using the BSE results, we interpret the spectra, distinguishing between bound core-excitons and higher energy excitations.

  18. Investigation of Influence NH4VO3+HOCH2CH2OH Oxidation of ASD-4 Powder

    Science.gov (United States)

    Shevchenko, V.; Eselevich, D.; Krasilnikov, V.; Konyukova, A.; Ancharov, A.; Tolochko, B.; Zolotarev, K.

    The thermokinetic data on the process of oxidation, of NH4VO3 + HOCH2CH2OH modified ASD-4 powder have been obtained by the TG and DSC methods during heating in air up to 1473 K at a rate of 10 K / min. The process of phase formation was studied directly during oxidation of the modified ASD-4 powder under similar conditions by the X-ray diffraction method using a synchrotron radiation from the VEPP-3 station of Channel 4 on the basis of equipment available at ISSCM SB RAS. It was found that oxidation of the activated powders is shifted into the low temperature region. Two modifiers: NH4VO3 + HOCH2CH2OH and previously examined V2O5 nH2O were compared.

  19. Aerosols generated during beryllium machining.

    Science.gov (United States)

    Martyny, J W; Hoover, M D; Mroz, M M; Ellis, K; Maier, L A; Sheff, K L; Newman, L S

    2000-01-01

    Some beryllium processes, especially machining, are associated with an increased risk of beryllium sensitization and disease. Little is known about exposure characteristics contributing to risk, such as particle size. This study examined the characteristics of beryllium machining exposures under actual working conditions. Stationary samples, using eight-stage Lovelace Multijet Cascade Impactors, were taken at the process point of operation and at the closest point that the worker would routinely approach. Paired samples were collected at the operator's breathing zone by using a Marple Personal Cascade Impactor and a 35-mm closed-faced cassette. More than 50% of the beryllium machining particles in the breathing zone were less than 10 microns in aerodynamic diameter. This small particle size may result in beryllium deposition into the deepest portion of the lung and may explain elevated rates of sensitization among beryllium machinists.

  20. T cell recognition of beryllium.

    Science.gov (United States)

    Dai, Shaodong; Falta, Michael T; Bowerman, Natalie A; McKee, Amy S; Fontenot, Andrew P

    2013-12-01

    Chronic beryllium disease (CBD) is a granulomatous lung disorder caused by a hypersensitivity to beryllium and characterized by the accumulation of beryllium-specific CD4(+) T cells in the lung. Genetic susceptibility to beryllium-induced disease is strongly associated with HLA-DP alleles possessing a glutamic acid at the 69th position of the β-chain (βGlu69). The structure of HLA-DP2, the most prevalent βGlu69-containing molecule, revealed a unique solvent-exposed acidic pocket that includes βGlu69 and represents the putative beryllium-binding site. The delineation of mimotopes and endogenous self-peptides that complete the αβTCR ligand for beryllium-specific CD4(+) T cells suggests a unique role of these peptides in metal ion coordination and the generation of altered self-peptides, blurring the distinction between hypersensitivity and autoimmunity.

  1. Physicochemical characteristics of aerosol particles generated during the milling of beryllium silicate ores: implications for risk assessment.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Chipera, Steve J; Day, Gregory A; Sabey, Phil; Dickerson, Robert M; Sbarra, Deborah C; Duling, Mathew G; Lawrence, Robert B; Stanton, Marcia L; Scripsick, Ronald C

    2008-01-01

    Inhalation of beryllium dusts generated during milling of ores and cutting of beryl-containing gemstones is associated with development of beryllium sensitization and low prevalence of chronic beryllium disease (CBD). Inhalation of beryllium aerosols generated during primary beryllium production and machining of the metal, alloys, and ceramics are associated with sensitization and high rates of CBD, despite similar airborne beryllium mass concentrations among these industries. Understanding the physicochemical properties of exposure aerosols may help to understand the differential immunopathologic mechanisms of sensitization and CBD and lead to more biologically relevant exposure standards. Properties of aerosols generated during the industrial milling of bertrandite and beryl ores were evaluated. Airborne beryllium mass concentrations among work areas ranged from 0.001 microg/m(3) (beryl ore grinding) to 2.1 microg/m(3) (beryl ore crushing). Respirable mass fractions of airborne beryllium-containing particles were 80% in high-energy input areas (beryl melting, beryl grinding). Particle specific surface area decreased with processing from feedstock ores to drumming final product beryllium hydroxide. Among work areas, beryllium was identified in three crystalline forms: beryl, poorly crystalline beryllium oxide, and beryllium hydroxide. In comparison to aerosols generated by high-CBD risk primary production processes, aerosol particles encountered during milling had similar mass concentrations, generally lower number concentrations and surface area, and contained no identifiable highly crystalline beryllium oxide. One possible explanation for the apparent low prevalence of CBD among workers exposed to beryllium mineral dusts may be that characteristics of the exposure material do not contribute to the development of lung burdens sufficient for progression from sensitization to CBD. In comparison to high-CBD risk exposures where the chemical nature of aerosol

  2. Characterization of shocked beryllium

    Directory of Open Access Journals (Sweden)

    Papin P.A.

    2012-08-01

    Full Text Available While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. In the current work, high strain rate tests were conducted using both explosive drive and a gas gun to accelerate the material. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. Two constitutive strength (plasticity models, the Preston-Tonks-Wallace (PTW and Mechanical Threshold Stress (MTS models, were calibrated using common quasi-static and Hopkinson bar data. However, simulations with the two models give noticeably different results when compared with the measured experimental wave profiles. The experimental results indicate that, even if fractured by the initial shock loading, the Be remains sufficiently intact to support a shear stress following partial release and subsequent shock re-loading. Additional “arrested” drive shots were designed and tested to minimize the reflected tensile pulse in the sample. These tests were done to both validate the model and to put large shock induced compressive loads into the beryllium sample.

  3. Effect of Tara (Caesalpinia spinosa Pod Powder on the Oxidation and Colour Stability of Pork Meat Batter During Chilled Storage

    Directory of Open Access Journals (Sweden)

    Monika Skowyra

    2015-01-01

    Full Text Available The eff ect of dried pods of Caesalpinia spinosa, known as tara, on pH, cooking loss, lipid oxidation, colour stability and texture of model meat systems stored at 4 °C for 21 days was investigated. Tara pod powder showing a potential antioxidant activity was added at 0.02, 0.04 and 0.08 % (by mass directly to the pork batt er and compared with a synthetic antioxidant, butylated hydroxyanisole (BHA and control (no added antioxidants. The addition of tara pod powder at 0.02 % was as effective as BHA (0.02 % in retarding lipid oxidation in pork products during storage. Results showed that redness increased after the addition of tara pod powder. Specifically, 0.02 % of tara pod powder was effective in keeping the red colour of meat batter stored under illumination at 4 °C for 48 h. Hardness of pork products was the lowest in samples manufactured with tara pod powder compared with control. Results highlight the potential of using tara pod powder as natural functional ingredient in the development of pork products with enhanced quality and shelf life.

  4. Effect of Tara (Caesalpinia spinosa) Pod Powder on the Oxidation and Colour Stability of Pork Meat Batter During Chilled Storage.

    Science.gov (United States)

    Skowyra, Monika; Janiewicz, Urszula; Salejda, Anna Marietta; Krasnowska, Grażyna; Almajano, María Pilar

    2015-12-01

    The effect of dried pods of Caesalpinia spinosa, known as tara, on pH, cooking loss, lipid oxidation, colour stability and texture of model meat systems stored at 4 °C for 21 days was investigated. Tara pod powder showing a potential antioxidant activity was added at 0.02, 0.04 and 0.08% (by mass) directly to the pork batter and compared with a synthetic antioxidant, butylated hydroxyanisole (BHA) and control (no added antioxidants). The addition of tara pod powder at 0.02% was as effective as BHA (0.02%) in retarding lipid oxidation in pork products during storage. Results showed that redness increased after the addition of tara pod powder. Specifically, 0.02% of tara pod powder was effective in keeping the red colour of meat batter stored under illumination at 4 °C for 48 h. Hardness of pork products was the lowest in samples manufactured with tara pod powder compared with control. Results highlight the potential of using tara pod powder as natural functional ingredient in the development of pork products with enhanced quality and shelf life.

  5. Antioxidant Effectiveness of Vegetable Powders on the Lipid and Protein Oxidative Stability of Cooked Turkey Meat Patties: Implications for Health

    Directory of Open Access Journals (Sweden)

    Wendy Russell

    2013-04-01

    Full Text Available Lipid and protein oxidation decreases the shelf-life of foods and may result in formation of end-products potentially detrimental for health. Consumer pressure to decrease the use of synthetic phenolic antioxidants has encouraged identification of alternative compounds or extracts from natural sources. We have assessed whether inclusion of dried vegetable powders improves the oxidative stability of turkey meat patties. Such powders are not only potentially-rich sources of phenolic antioxidants, but also may impart additional health benefits, as inadequate vegetable consumption is a risk factor for heart disease and several cancers. In an accelerated oxidation system, six of eleven vegetable powders significantly (p < 0.05 improved oxidative stability of patties by 20%–30% (spinach < yellow pea < onion < red pepper < green pea < tomato. Improved lipid oxidative stability was strongly correlated with the decreased formation of protein carbonyls (r = 0.747, p < 0.01. However, improved lipid stability could not be ascribed to phenolic acids nor recognized antioxidants, such as α- and γ-tocopherol, despite their significant (p < 0.01 contribution to the total antioxidant capacity of the patties. Use of chemically complex vegetable powders offers an alternative to individual antioxidants for increasing shelf-life of animal-based food products and may also provide additional health benefits associated with increased vegetable intake.

  6. Characterization of Shocked Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Cady, Carl M [Los Alamos National Laboratory; Adams, Chris D [Los Alamos National Laboratory; Hull, Lawrence M [Los Alamos National Laboratory; Gray III, George T [Los Alamos National Laboratory; Prime, Michael B [Los Alamos National Laboratory; Addessio, Francis L [Los Alamos National Laboratory; Wynn, Thomas A [Los Alamos National Laboratory; Brown, Eric N [Los Alamos National Laboratory

    2012-08-24

    Beryllium metal has many excellent structural properties in addition to its unique radiation characteristics, including: high elastic modulus, low Poisson's ratio, low density, and high melting point. However, it suffers from several major mechanical drawbacks: 1) high anisotropy - due to its hexagonal lattice structure and its susceptibility to crystallographic texturing; 2) susceptibility to impurity-induced fracture - due to grain boundary segregation; and 3) low intrinsic ductility at ambient temperatures thereby limiting fabricability. While large ductility results from deformation under the conditions of compression, the material can exhibit a brittle behavior under tension. Furthermore, there is a brittle to ductile transition at approximately 200 C under tensile conditions. While numerous studies have investigated the low-strain-rate constitutive response of beryllium, the combined influence of high strain rate and temperature on the mechanical behavior and microstructure of beryllium has received limited attention over the last 40 years. Prior studies have focused on tensile loading behavior, or limited conditions of dynamic strain rate and/or temperature. The beryllium used in this study was Grade S200-F (Brush Wellman, Inc., Elmore, OH) material. The work focused on high strain rate deformation and examine the validity of constitutive models in deformation rate regimes, including shock, the experiments were modeled using a Lagrangian hydrocode. Two constitutive strength (plasticity) models, the Preston-Tonks-Wallace (PTW) and Mechanical Threshold Stress (MTS) models, were calibrated using the same set of quasi-static and Hopkinson bar data taken at temperatures from 77K to 873K and strain rates from 0.001/sec to 4300/sec. In spite of being calibrated on the same data, the two models give noticeably different results when compared with the measured wave profiles. These high strain rate tests were conducted using both explosive drive and a gas gun to

  7. Fabrication of dendritic silver-coated copper powders by galvanic displacement reaction and their thermal stability against oxidation

    Science.gov (United States)

    Park, Yu-Seon; An, Chang Yong; Kannan, Padmanathan Karthick; Seo, Nary; Zhuo, Kai; Yoo, Tae Kyong; Chung, Chan-Hwa

    2016-12-01

    Two steps of wet chemical processes have been developed for the preparation of core-shell nanostructures of copper and silver, which is a facile and low cost method for the production of large quantity of dendritic powders. First step involves a galvanic displacement reaction with hydrogen evolution which is the motive force of spontaneous electrochemical reaction. To achieve the core-shell structure, silver has been coated on the dendritic copper using the galvanic displacement reaction. The dendritic silver-coated copper powders exhibit high surface-area, excellent conductivity, and good oxidation resistance. It has been found that silver-coated copper powders maintain the electrical conductivity even after annealing at 150 °C for several to tens of minutes, thus it is a promising material and an alternative to pure silver powders in printed electronics application.

  8. Studies on Acetone Powder and Purified Rhus Laccase Immobilized on Zirconium Chloride for Oxidation of Phenols

    Directory of Open Access Journals (Sweden)

    Rong Lu

    2012-01-01

    Full Text Available Rhus laccase was isolated and purified from acetone powder obtained from the exudates of Chinese lacquer trees (Rhus vernicifera from the Jianshi region, Hubei province of China. There are two blue bands appearing on CM-sephadex C-50 chromatography column, and each band corresponding to Rhus laccase 1 and 2, the former being the major constituent, and each had an average molecular weight of approximately 110 kDa. The purified and crude Rhus laccases were immobilized on zirconium chloride in ammonium chloride solution, and the kinetic properties of free and immobilized Rhus laccase, such as activity, molecular weight, optimum pH, and thermostability, were examined. In addition, the behaviors on catalytic oxidation of phenols also were conducted.

  9. Particle Surface Softening as Universal Behaviour during Flash Sintering of Oxide Nano-Powders

    Directory of Open Access Journals (Sweden)

    Rachman Chaim

    2017-02-01

    Full Text Available The dissipated electric power in oxide powder compacts, subjected to flash sintering, is several hundreds of W·cm−3. This power is analyzed considering local softening/melting and transient plasma/liquid formation at the particle contacts due to thermal runaway. The sudden increase in compact electric conductivity and dissipated power referred to current percolation through the softening/liquid formed at the particle contacts, at the percolation threshold. The energy-balance and heat transfer considerations during the transient flash event are consistent with the local heating of the nanoparticle contacts to the ceramic melting temperature, or above it. The formation of the plasma by field emission of electrons is also considered.

  10. Effect of Metallic Zn Powder on Oxidation Resistance of Al2O3-C Refractories

    Institute of Scientific and Technical Information of China (English)

    LI Youqi; KE Changming; LI Yousheng; LI Nan

    2006-01-01

    Al2O3-C specimens were prepared by using tabular corundum,flaky graphite,Al,Si,and Zn powder as starting materials and phenolic formaldehyde resin as binder.Keeping the mass ratios of tabular corundum,flaky graphite,Al and Si constant,different contents of ZN(0,0.5%,1%,2%and 3%)were added respectively.The specimens were heat treated at 120-220℃ for 24h,and then fired at 1400℃ .for 3h in air atmosphere. The mass change rate, thickness of decarburization layer, apparent porosity, bulk density and microstructure of the products were determined and observed by means of SEM and EDX.The results show that the specimen with 2% Zn was characterized by minimum in thickness of decarburization layer and in apparent porosity and maximum in bulk density. Consequently, the specimen with 2% metal Zn is supposed to perform the best oxidation resistance.

  11. Beryllium metal I. experimental results on acute oral toxicity, local skin and eye effects, and genotoxicity.

    Science.gov (United States)

    Strupp, Christian

    2011-01-01

    The toxicity of soluble metal compounds is often different from that of the parent metal. Since no reliable data on acute toxicity, local effects, and mutagenicity of beryllium metal have ever been generated, beryllium metal powder was tested according to the respective Organisation for Economical Co-Operation and Development (OECD) guidelines. Acute oral toxicity of beryllium metal was investigated in rats and local effects on skin and eye in rabbits. Skin-sensitizing properties were investigated in guinea pigs (maximization method). Basic knowledge about systemic bioavailability is important for the design of genotoxicity tests on poorly soluble substances. Therefore, it was necessary to experimentally compare the capacities of beryllium chloride and beryllium metal to form ions under simulated human lung conditions. Solubility of beryllium metal in artificial lung fluid was low, while solubility in artificial lysosomal fluid was moderate. Beryllium chloride dissolution kinetics were largely different, and thus, metal extracts were used in the in vitro genotoxicity tests. Genotoxicity was investigated in vitro in a bacterial reverse mutagenicity assay, a mammalian cell gene mutation assay, a mammalian cell chromosome aberration assay, and an unscheduled DNA synthesis (UDS) assay. In addition, cell transformation was tested in a Syrian hamster embryo cell assay, and potential inhibition of DNA repair was tested by modification of the UDS assay. Beryllium metal was found not to be mutagenic or clastogenic based on the experimental in vitro results. Furthermore, treatment with beryllium metal extracts did not induce DNA repair synthesis, indicative of no DNA-damaging potential of beryllium metal. A cell-transforming potential and a tendency to inhibit DNA repair when the cell is severely damaged by an external stimulus were observed. Beryllium metal was also found not to be a skin or eye irritant, not to be a skin sensitizer, and not to have relevant acute oral

  12. Crystal structure and electrical properties of gadolinia doped bismuth oxide nanoceramic powders

    Energy Technology Data Exchange (ETDEWEB)

    Ar Latin-Small-Letter-Dotless-I , M. [Physics Department, Faculty of Sciences, Erciyes University, Kayseri (Turkey); Tasc Latin-Small-Letter-Dotless-I oglu, I.; Alt Latin-Small-Letter-Dotless-I ndal, S. [Physics Department, Faculty of Arts and Sciences, Gazi University, Ankara (Turkey); Uslu, I.; Aytimur, A. [Department of Chemistry Education, Gazi University, Ankara (Turkey); Karaaslan, T. [Physics Department, Faculty of Sciences, Erciyes University, Kayseri (Turkey); Kocyigit, S., E-mail: sergas_29@hotmail.com [Department of Chemistry Education, Gazi University, Ankara (Turkey)

    2012-10-15

    A novel method of fabrication of gadolinia doped bismuth oxide nanoceramic via the sol-gel technique is reported. Their thermal, structural and morphological properties are described by measurements of Differential Thermal Analysis/Thermal Gravimetry, X-ray Powder Diffraction and Scanning Electron Microscopy. The samples have stable high ion conductive face centered cubic {delta}-phase nanocrystalline structure. The electrical measurements of the nanoceramic powders were carried out in the temperature range of (689-1091 K) using 4-point probe technique. There is a transition between two distinct regions at 720 Degree-Sign C, which can be attributed to the order-disorder transition. This observation is supported by the differential thermal analysis measurements. The experimental results show that the value of conductivity increases with increasing temperature over linear parts characterized by two different activation energies. The conductivity data over whole measured temperature range were fitted to the Arrhenius equations of conductivity and it shows two linear regions with different slopes which correspond to low-temperature range (689-975 K) and high-temperature range (999-1091 K). The values of E{sub a1} and E{sub a2} were obtained from the slopes of ln {sigma}{sub DC} versus q/kT plot as 1.25 eV and 2.81 eV for low-temperature range and high-temperature range, respectively. -- Highlights: Black-Right-Pointing-Pointer Gadolinia doped bismuth oxide nanoceramic were produced via the sol-gel technique. Black-Right-Pointing-Pointer Structural characterizations were carried out by XRD and SEM techniques. Black-Right-Pointing-Pointer Thermal and electrical properties were evaluated by DTA/TG and 4-point probe. Black-Right-Pointing-Pointer Crystallite size was calculated using Scherrer equation. Black-Right-Pointing-Pointer The dislocation density, the microstrain and unit cell volume were calculated.

  13. Technical Basis for PNNL Beryllium Inventory

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Michelle Lynn

    2014-07-09

    The Department of Energy (DOE) issued Title 10 of the Code of Federal Regulations Part 850, “Chronic Beryllium Disease Prevention Program” (the Beryllium Rule) in 1999 and required full compliance by no later than January 7, 2002. The Beryllium Rule requires the development of a baseline beryllium inventory of the locations of beryllium operations and other locations of potential beryllium contamination at DOE facilities. The baseline beryllium inventory is also required to identify workers exposed or potentially exposed to beryllium at those locations. Prior to DOE issuing 10 CFR 850, Pacific Northwest Nuclear Laboratory (PNNL) had documented the beryllium characterization and worker exposure potential for multiple facilities in compliance with DOE’s 1997 Notice 440.1, “Interim Chronic Beryllium Disease.” After DOE’s issuance of 10 CFR 850, PNNL developed an implementation plan to be compliant by 2002. In 2014, an internal self-assessment (ITS #E-00748) of PNNL’s Chronic Beryllium Disease Prevention Program (CBDPP) identified several deficiencies. One deficiency is that the technical basis for establishing the baseline beryllium inventory when the Beryllium Rule was implemented was either not documented or not retrievable. In addition, the beryllium inventory itself had not been adequately documented and maintained since PNNL established its own CBDPP, separate from Hanford Site’s program. This document reconstructs PNNL’s baseline beryllium inventory as it would have existed when it achieved compliance with the Beryllium Rule in 2001 and provides the technical basis for the baseline beryllium inventory.

  14. Comparison between oxide-reduced and water-atomized copper powders used in making sintered wicks of heat pipe

    Institute of Scientific and Technical Information of China (English)

    Liu-Ho Chiu; Chang-Hui Wu; Pee-Yew Lee

    2007-01-01

    Oxide-reduced copper powder can be produced efficiently at low cost. The volume shrinkage, porosity, maximum pore size, permeability and thermal conductivity of wicks sintered from two oxide-reduced (OR) powders were compared with one from water-atomized (WA) powder. The green specimens were sintered at temperatures from 800 to 1000 ℃ in a tube furnace under a reduction stream of 10% hydrogen and 90% argon.The results show that the property variations of OR - 100 and WA wicks due to porosity changes have a similar tendency and range. Nine hundred degree celsius is a recommended sintering temperature for producing ideal wicks for use in heat pipes. A smaller maximum pore size can be obtained by increasing the green density.

  15. Standard test methods for chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide (Gd2O3) powder

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2006-01-01

    1.1 These test methods cover procedures for the chemical and mass spectrometric analysis of nuclear-grade gadolinium oxide powders to determine compliance with specifications. 1.2 The analytical procedures appear in the following order: Sections Carbon by Direct CombustionThermal Conductivity C1408 Test Method for Carbon (Total) in Uranium Oxide Powders and Pellets By Direct Combustion-Infrared Detection Method Total Chlorine and Fluorine by Pyrohydrolysis Ion Selective Electrode C1502 Test Method for Determination of Total Chlorine and Fluorine in Uranium Dioxide and Gadolinium Oxide Loss of Weight on Ignition 7-13 Sulfur by CombustionIodometric Titration Impurity Elements by a Spark-Source Mass Spectrographic C761 Test Methods for Chemical, Mass Spectrometric, Spectrochemical,Nuclear, and Radiochemical Analysis of Uranium Hexafluoride C1287 Test Method for Determination of Impurities In Uranium Dioxide By Inductively Coupled Plasma Mass Spectrometry Gadolinium Content in Gadolinium Oxid...

  16. Structural investigation of SiSn/(reduced graphene oxide) nanocomposite powder for Li-ion battery anode applications

    Science.gov (United States)

    Kawasaki, Masahiro; Laokawee, Viratchara; Sarakonsri, Thapanee; Hashizume, Takashi; Shiojiri, Makoto

    2016-11-01

    We synthesized SiSn/(reduced graphene oxide (rGO)) nanocomposite powder for a Li-ion battery material and characterized the structure by transmission electron microscopy (TEM) and analytical scanning transmission electron microscopy (STEM). Graphene oxide was prepared by Hummers method. The graphene oxide powder processed by heat treatment was added together with Si powder into a solution of SnCl2 ṡ 2(H2O) dissolved in N2 bubbled ethylene glycol, and the solution was reacted with NaBH4. The product had a nominal atomic ratio of Si: Sn: C = 14: 3.5: 100. High-resolution TEM/STEM analysis revealed that the powder consisted of crystalline particles of Sn, Si, and SiO as well as thin reduced graphene oxide (rGO) lamellae of amorphous-like graphite with distorted lattices that were often found in areas as local as a few nm2. The aggregated Si and SiO particles grew up to several hundred nm across. Sn particles grew as large as a few tens of nm while those as small as a few nm were scattered on the (0001) rGO surface with some epitaxial relations. Si, SiO, and Sn particles were found hanging on at the edges of the rGO lamellae. An electrochemical test was performed for this nanocomposite powder. The result suggested that the SiSn/rGO powder would be a promising anode material for lithium-ion batteries with high capacity.

  17. Modified Sol-Gel Technique as a Cost-Effective Method of Ultradispersed Metal Oxide Powders Production

    Science.gov (United States)

    Vokhmintcev, K. V.; Konstantinov, O. V.; Belousov, V. V.

    2013-05-01

    A modified sol-gel technique was developed for fabrication of ultradispersed metal oxides powders of Bi2O3, CeO2, Cr2O3, Y2O3, ZnO2 and ZrO2. Hexamethylenetetramine, monoethanolamine and acetylacetone were used for the sol formation and gel stabilization.

  18. Impact analysis of modifying the composition of the nuclear fuel of a BWR with beryllium oxide; Analisis del impacto de modificar la composicion del combustible nuclear de un BWR con oxido de berilio

    Energy Technology Data Exchange (ETDEWEB)

    Gallardo V, J. M.; Morales S, J. B., E-mail: euqrop@hotmail.com [UNAM, Facultad de Ingenieria, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

    2013-10-15

    The beryllium oxide (Be O) presents excellent physical properties, especially its high thermal conductivity that contrasts clearly with that of the uranium dioxide (UO{sub 2}) used at the present as fuel in a great number of nuclear plants. The present work models a nuclear reactor cooled by light water in boiling with two external recirculation loops (BWR/5) using the code for the transitory analysis and postulated accidents Trac-B F1, implementing a UO{sub 2} mixture and different fractions of Be O, with the objective of improving the thermal conductivity of the fuel. The numeric results and the realized analyses indicate that when adding a fraction in volume of 10% the central temperature decreases in 30.4% in stationary state, while during the large break loss of coolant accident the peak cladding temperature diminishes in 7%. Although the real interaction of the mixture has not been determined experimentally, the obtained results are promising. (Author)

  19. Temperature effect on lactose crystallization, maillard reactions, and lipid oxidation in whole milk powder.

    Science.gov (United States)

    Thomsen, Marianne K; Lauridsen, Lene; Skibsted, Leif H; Risbo, Jens

    2005-09-07

    Whole milk powder with an initial water content of 4.4% (w/w) and a water activity of 0.23 stored in hermetically sealed vials for up to 147 days below (37 and 45 degrees C) and above (55 degrees C) the glass transition temperature (T(g) determined to have the value 48 degrees C) showed a strong temperature dependence for quality deterioration corresponding to energies of activation close to 200 kJ/mol for most deteriorative processes. The glass transition was found not to cause any deviation from Arrhenius temperature dependence. Lactose crystallization, which occurred as a gradual process as monitored by isothermal calorimetry, is concluded to liberate bound water (a(w) increase to 0.46) with a modest time delay (approximately 2 days at 55 degrees C) and with concomitant surface browning as evidenced by an increasing Hunter b-value. Browning and formation of bound hydroxymethyl-furfural determined by HPLC seem to be coupled, while formation of another Maillard reaction product, furosine, occurred gradually and was initiated prior to crystallization. Initiation of lipid oxidation, as detected by lipid-derived radicals (high g-value ESR spectra), and progression of lipid oxidation, as detected by headspace GC, seem not to be affected by lactose crystallization and browning, and no indication of browning products acting as antioxidants could be determined.

  20. 国内外铍及含铍材料的研究进展%Advances in beryllium and beryllium-containing materials

    Institute of Scientific and Technical Information of China (English)

    许德美; 秦高梧; 李峰; 王战宏; 钟景明; 何季麟; 何力军

    2014-01-01

    The research progress of beryllium and beryllium-containing materials was reviewed in the past two decades in the world, and much effort in this work was focused on beryllium metallurgy, beryllium alloys, beryllium oxide, beryllium matrix composites and intermetallics. The advances of beryllium materials in both research and production techniques in China were summarized, especially in technique gap as compared to that in the developed countries. Finally, the new beryllium materials and their key techniques conforming to the requirements of industry were proposed in the next one decade in China.%综述近20年来国外铍及含铍材料的研究进展,主要包括铍的冶金制备、铍合金、铍和氧化铍金属基复合材料、铍金属间化合物等。概括我国在铍材料方面取得的研究与生产技术进展,以及与国外研发水平的差距。并展望未来10年我国铍及含铍材料需要重点发展的新材料以及突破的关键技术。

  1. Effect of surface modification and UVA photoactivation on antibacterial bioactivity of zinc oxide powder

    Science.gov (United States)

    Ann, Ling Chuo; Mahmud, Shahrom; Bakhori, Siti Khadijah Mohd; Sirelkhatim, Amna; Mohamad, Dasmawati; Hasan, Habsah; Seeni, Azman; Rahman, Rosliza Abdul

    2014-02-01

    The effects of surface modification of zinc oxide (ZnO) powder and UVA illumination on the powder towards Escherichia coli and Staphylococcus aureus were investigated. FESEM-EDS results showed that oxygen annealing increased the O:Zn ratio on the surface of ZnO-rod and ZnO-plate samples. Surface conductances of ZnO-rod and ZnO-plate pellets were reduced from 1.05 nS to 0.15 nS and 1.34 nS to 0.23 nS, respectively. Meanwhile, UVA illumination on the surface of the ZnO-rod and ZnO-plate samples was found to improve surface conductance to 7.08 nS and 6.51 nS, respectively, due to the release of charge carrier. Photoluminescence results revealed that oxygen annealing halved the UV emission intensity and green emission intensity, presumably caused by oxygen absorption in the ZnO lattice. The antibacterial results showed that oxygen-treated ZnO exhibited slightly higher growth inhibition on E. coli and S. aureus compared with unannealed ZnO. UVA illumination on ZnO causes the greatest inhibition toward E. coli and S. aureus. Under the UVA excitation, the inhibition of E. coli increased by 18% (ZnO-rod) and 13% (ZnO-plate) while the inhibition of S. aureus increased by 22% (ZnO-rod) and 21% (ZnO-plate). Release of reactive oxygen species were proposed in antibacterial mechanisms, which were aided by surface modification and UVA photoactivation. The reactive oxygen species disrupted the DNA and protein synthesis of the bacterial cell, causing bacteriostatic effects toward E. coli and S. aureus.

  2. Oxidation behavior and mechanism of powder metallurgy Rene95 nickel based superalloy between 800 and 1000 deg. C

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Lei, E-mail: zhenglei_ustb@sina.com [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 10083 (China); Zhang Maicang; Dong Jianxin [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 10083 (China)

    2010-10-01

    The oxidation behaviors of powder metallurgy (PM) Rene95 Ni-based superalloy in the temperature range of 800-1000 deg. C are investigated in air by virtue of isothermal oxidation testing, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. The results show that the oxidation kinetics follows a square power law as the time extends at each temperature. The oxidation layers are detected to be composed of Cr{sub 2}O{sub 3}, TiO{sub 2} and a small amount of NiCr{sub 2}O{sub 4}. The cross-sectional morphologies indicate that the oxidation layer consists of three parts: Cr-rich oxide layer, Cr and Ti duplex oxide layer, and oxidation affected zone. Theoretical analyses of oxidation kinetics and thicknesses of oxidation layers confirm that the activation energy of oxidation of PM Rene95 superalloy is 165.32 kJ mol{sup -1} and the oxidation process is controlled by diffusions of oxygen, Cr, and Ti. Accordingly, a diffusion-controlled mechanism is suggested to understand the oxidation behaviors of PM Rene95 superalloy at elevated temperatures.

  3. Thermal fatigue of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Deksnis, E.; Ciric, D.; Falter, H. [JET Joint undertaking, Abingdon (United Kingdom)] [and others

    1995-09-01

    Thermal fatigue life of S65c beryllium castellated to a geometry 6 x 6 x (8-10)mm deep has been tested for steady heat fluxes of 3 MW/m{sup 2} to 5 MW/m{sup 2} and under pulsed heat fluxes (10-20 MW/m{sup 2}) for which the time averaged heat flux is 5 MW/m{sup 2}. These tests were carried out in the JET neutral beam test facility A test sequence with peak surface temperatures {le} 600{degrees}C produced no visible fatigue cracks. In the second series of tests, with T{sub max} {le} 750{degrees}C evidence for fatigue appeared after a minimum of 1350 stress cycles. These fatigue data are discussed in view of the observed lack of thermal fatigue in JET plasma operations with beryllium PFC. JET experience with S65b and S65c is reviewed; recent operations with {Phi} = 25 MW/m{sup 2} and sustained melting/resolidification are also presented. The need for a failure criterion for finite element analyses of Be PFC lifetimes is discussed.

  4. Optimization of the processing parameters during internal oxidation of Cu-Al alloy powders using an artificial neural network

    Energy Technology Data Exchange (ETDEWEB)

    Song Kexing; Xing Jiandong; Dong Qiming; Liu Ping; Tian Baohong; Cao Xianjie

    2005-06-15

    Internal oxidation is a commercial method for producing oxide dispersion strengthened copper (ODS Cu). In this paper, the dilute Cu-Al alloy powders containing 0.26 wt% of Al have been internally oxidized at temperatures (T) from 700 to 1000 deg. C, for holding times (t) up to 10 h. The alumina particle size has been observed and determined by electron microscopy using the two-stage preshadowed carbon replica method. By the use of backpropagation network, the non-linear relationship between internal oxidation process parameters (T,t) and alumina particle size has been established on the base of dealing with the experimental data. The results show that the well-trained backpropagation neural network can predict the alumina particle size during internal oxidation precisely and the prediction values have sufficiently mined the basic domain knowledge of internal oxidation process. Therefore, a new way of optimizing process parameters has been provided by the authors.

  5. Measurement of Beryllium in Biological Samples by Accelerator Mass Spectrometry: Applications for Studying Chronic Beryllium Disease

    Energy Technology Data Exchange (ETDEWEB)

    Chiarappa-Zucca, M L; Finkel, R C; Martinelli, R E; McAninch, J E; Nelson, D O; Turtletaub, K W

    2004-04-15

    A method using accelerator mass spectrometry (AMS) has been developed for quantifying attomoles of beryllium (Be) in biological samples. This method provides the sensitivity to trace Be in biological samples at very low doses with the purpose of identifying the molecular targets involved in chronic beryllium disease. Proof of the method was tested by administering 0.001, 0.05, 0.5 and 5.0 {micro}g {sup 9}Be and {sup 10}Be by intraperitoneal injection to male mice and removing spleen, liver, femurs, blood, lung, and kidneys after 24 h exposure. These samples were prepared for AMS analysis by tissue digestion in nitric acid, followed by further organic oxidation with hydrogen peroxide and ammonium persulfate and lastly, precipitation of Be with ammonium hydroxide, and conversion to beryllium oxide at 800 C. The {sup 10}Be/{sup 9}Be ratio of the extracted beryllium oxide was measured by AMS and Be in the original sample was calculated. Results indicate that Be levels were dose-dependent in all tissues and the highest levels were measured in the spleen and liver. The measured {sup 10}Be/{sup 9}Be ratios spanned 4 orders of magnitude, from 10{sup -10} to 10{sup -14}, with a detection limit of 3.0 x 10{sup -14}, which is equivalent to 0.8 attomoles of {sup 10}Be. These results show that routine quantification of nanogram levels of Be in tissues is possible and that AMS is a sensitive method that can be used in biological studies to understand the molecular dosimetry of Be and mechanisms of toxicity.

  6. Manufacturing And High Temperature Oxidation Properties Of Electro-Sprayed Fe-24.5% Cr-5%Al Powder Porous Metal

    Directory of Open Access Journals (Sweden)

    Lee Kee-Ahn

    2015-06-01

    Full Text Available Fe-Cr-Al based Powder porous metals were manufactured using a new electro-spray process, and the microstructures and high-temperature oxidation properties were examined. The porous materials were obtained at different sintering temperatures (1350°C, 1400°C, 1450°C, and 1500°C and with different pore sizes (500 μm, 450 μm, and 200 μm. High-temperature oxidation experiments (TGA, Thermal Gravimetry Analysis were conducted for 24 hours at 1000°C in a 79% N2+ 21% O2, 100 mL/min. atmosphere. The Fe-Cr-Al powder porous metals manufactured through the electro-spray process showed more-excellent oxidation resistance as sintering temperature and pore size increased. In addition, the fact that the densities and surface areas of the abovementioned powder porous metals had the largest effects on the metal’s oxidation properties could be identified.

  7. The influence of particle size on the kinetics of UO 2 oxidation in aqueous powder suspensions

    Science.gov (United States)

    Roth, Olivia; Bönnemark, Tobias; Jonsson, Mats

    2006-07-01

    Previous studies have indicated that the rate of a heterogeneous liquid-solid reaction depends on the size of the solid particles. It has been suggested that both the pre-exponential factor and the activation energy depend on the particle size. The processes involved in dissolution of UO 2 have been extensively studied because of their importance for the safety analysis of a future deep repository for spent nuclear fuel and in many of these studies powder suspensions of UO 2 are used as a model system. Therefore, it is of importance to investigate and quantify the particle size effect on the kinetics of UO 2 oxidation in order to enable comparison of data from studies on different solid substrates. In this work the influence of particle size on the second order rate constant and on the activation energy of the reaction between MnO4- and UO 2 was studied using aqueous UO 2-particle suspensions of four different size distributions. A comparative study of the activation energy for the reaction using a UO 2 pellet was also performed.

  8. Surface Coating of Oxide Powders: A New Synthesis Method to Process Biomedical Grade Nano-Composites

    Directory of Open Access Journals (Sweden)

    Paola Palmero

    2014-07-01

    Full Text Available Composite and nanocomposite ceramics have achieved special interest in recent years when used for biomedical applications. They have demonstrated, in some cases, increased performance, reliability, and stability in vivo, with respect to pure monolithic ceramics. Current research aims at developing new compositions and architectures to further increase their properties. However, the ability to tailor the microstructure requires the careful control of all steps of manufacturing, from the synthesis of composite nanopowders, to their processing and sintering. This review aims at deepening understanding of the critical issues associated with the manufacturing of nanocomposite ceramics, focusing on the key role of the synthesis methods to develop homogeneous and tailored microstructures. In this frame, the authors have developed an innovative method, named “surface-coating process”, in which matrix oxide powders are coated with inorganic precursors of the second phase. The method is illustrated into two case studies; the former, on Zirconia Toughened Alumina (ZTA materials for orthopedic applications, and the latter, on Zirconia-based composites for dental implants, discussing the advances and the potential of the method, which can become a valuable alternative to the current synthesis process already used at a clinical and industrial scale.

  9. Observation of Nanometric Silicon Oxide Bifilms in a Water-Atomized Hypereutectic Cast Iron Powder

    Science.gov (United States)

    Boisvert, Mathieu; Christopherson, Denis; L'Espérance, Gilles

    2016-10-01

    This study investigated the reasons for the irregular structure of primary graphite nodules that were formed in a hypereutectic cast iron powder during water atomization. The graphite nodules contain a significant amount of micron-sized pores and multiple nanometric voids that formed from silicon oxide bifilms. The bifilms theory is often used to explain the mechanisms responsible for the presence of pores in castings. However, even if many results presented in the literature tend to corroborate the existence of bifilms, to this date, only indirect evidences of their existence were presented. The observations presented in this paper are the first to show the double-sided nature of these defects. These observations support the bifilms theory and give an explanation for the presence of porosities in castings. The bifilms were used as substrate for graphite growth during solidification. The irregular structure of the graphite nodules is a consequence of the rather random structure of the bifilms that were introduced in the melt as a result of turbulences on the surface of the melt during pouring. The confirmation of the existence of bifilms can contribute to the understanding of the mechanical properties of various metallic parts.

  10. Bioaccessibility of micron-sized powder particles of molybdenum metal, iron metal, molybdenum oxides and ferromolybdenum--Importance of surface oxides.

    Science.gov (United States)

    Mörsdorf, Alexander; Odnevall Wallinder, Inger; Hedberg, Yolanda

    2015-08-01

    The European chemical framework REACH requires that hazards and risks posed by chemicals, including alloys and metals, that are manufactured, imported or used in different products (substances or articles) are identified and proven safe for humans and the environment. Metals and alloys need hence to be investigated on their extent of released metals (bioaccessibility) in biologically relevant environments. Read-across from available studies may be used for similar materials. This study investigates the release of molybdenum and iron from powder particles of molybdenum metal (Mo), a ferromolybdenum alloy (FeMo), an iron metal powder (Fe), MoO2, and MoO3 in different synthetic body fluids of pH ranging from 1.5 to 7.4 and of different composition. Spectroscopic tools and cyclic voltammetry have been employed to characterize surface oxides, microscopy, light scattering and nitrogen absorption for particle characterization, and atomic absorption spectroscopy to quantify released amounts of metals. The release of molybdenum from the Mo powder generally increased with pH and was influenced by the fluid composition. The mixed iron and molybdenum surface oxide of the FeMo powder acted as a barrier both at acidic and weakly alkaline conditions. These findings underline the importance of the surface oxide characteristics for the bioaccessibility of metal alloys.

  11. High quality aluminium doped zinc oxide target synthesis from nanoparticulate powder and characterisation of sputtered thin films

    Energy Technology Data Exchange (ETDEWEB)

    Isherwood, P.J.M., E-mail: P.J.M.Isherwood@lboro.ac.uk [Centre for Renewable Energy Systems Technology, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); Neves, N. [Innovnano, S. A., Rua Coimbra Inovação Parque, IParque Lote 13, 3040-570 Antanhol, Coimbra (Portugal); Bowers, J.W. [Centre for Renewable Energy Systems Technology, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom); Newbatt, P. [Innovnano, S. A., Rua Coimbra Inovação Parque, IParque Lote 13, 3040-570 Antanhol, Coimbra (Portugal); Walls, J.M. [Centre for Renewable Energy Systems Technology, Loughborough University, Loughborough, Leicestershire LE11 3TU (United Kingdom)

    2014-09-01

    Nanoparticulate aluminium-doped zinc oxide powder was synthesised through detonation and subsequent rapid quenching of metallic precursors. This technique allows for precise compositional control and rapid nanoparticle production. The resulting powder was used to form sputter targets, which were used to deposit thin films by radio frequency sputtering. These films show excellent sheet resistance and transmission values for a wide range of deposition temperatures. Crystal structure analysis shows that crystals in the target have a random orientation, whereas the crystals in the films grow perpendicular to the substrate surface and propagate preferentially along the (002) axis. Higher temperature deposition reduces crystal quality with a corresponding decrease in refractive index and an increase in sheet resistance. Films deposited between room temperature and 300 °C were found to have sheet resistances equivalent to or better than indium tin oxide films for a given average transmission value. - Highlights: • Nanoparticulate AZO powder was used to produce sputter targets. • The powder synthesis technique allows for precise compositional control. • Sputtered films show excellent optical, electronic and structural properties. • High temperature films show reduced electrical and structural quality. • For a given transmission, films show equivalent sheet resistances to ITO.

  12. Release of beryllium from mineral ores in artificial lung and skin surface fluids.

    Science.gov (United States)

    Duling, Matthew G; Stefaniak, Aleksandr B; Lawrence, Robert B; Chipera, Steve J; Virji, M Abbas

    2012-06-01

    Exposure to some manufactured beryllium compounds via skin contact or inhalation can cause sensitization. A portion of sensitized persons who inhale beryllium may develop chronic beryllium disease (CBD). Little is understood about exposures to naturally occurring beryllium minerals. The purpose of this study was to assess the bioaccessibility of beryllium from bertrandite ore. Dissolution of bertrandite from two mine pits (Monitor and Blue Chalk) was evaluated for both the dermal and inhalation exposure pathways by determining bioaccessibility in artificial sweat (pH 5.3 and pH 6.5), airway lining fluid (SUF, pH 7.3), and alveolar macrophage phagolysosomal fluid (PSF, pH 4.5). Significantly more beryllium was released from Monitor pit ore than Blue Chalk pit ore in artificial sweat buffered to pH 5.3 (0.88 ± 0.01% vs. 0.36 ± 0.00%) and pH 6.5 (0.09 ± 0.00% vs. 0.03 ± 0.01%). Rates of beryllium released from the ores in artificial sweat were faster than previously measured for manufactured forms of beryllium (e.g., beryllium oxide), known to induce sensitization in mice. In SUF, levels of beryllium were below the analytical limit of detection. In PSF, beryllium dissolution was biphasic (initial rapid diffusion followed by latter slower surface reactions). During the latter phase, dissolution half-times were 1,400 to 2,000 days, and rate constants were ~7 × 10(-10) g/(cm(2)·day), indicating that bertrandite is persistent in the lung. These data indicate that it is prudent to control skin and inhalation exposures to bertrandite dusts.

  13. Study of Oxidation Behaviour of Bond Coating Nanocomposites Ni-20Cr-6Al Powder Synthesized by Mechanical Alloying

    OpenAIRE

    Akbar Salarvand; Vahid Shafi pour

    2011-01-01

    In this study, nano crystalline Ni-20Cr-6Al composite powder was produced using a high energy planetary ball milling and a two-stage process. Then the oxidation behavior of coating of that superalloy at different temperatures considered. Nanostructured Ni-20Cr-6Al coating was deposited by cold spray for application as a bond coat to thermal barrier coating on industrial gas turbine components. The paper samples synthesized were characterized by scanning electron microscopy (SEM) and transmiss...

  14. Neutron irradiation behavior of ITER candidate beryllium grades

    Energy Technology Data Exchange (ETDEWEB)

    Kupriyanov, I.B.; Gorokhov, V.A.; Nikolaev, G.N. [A.A.Bochvar All-Russia Scientific Research Inst. of Inorganic Materials (VNIINM), Moscow (Russian Federation); Melder, R.R.; Ostrovsky, Z.E.

    1998-01-01

    Beryllium is one of the main candidate materials both for the neutron multiplier in a solid breeding blanket and for the plasma facing components. That is why its behaviour under the typical for fusion reactor loading, in particular, under the neutron irradiation is of a great importance. This paper presents mechanical properties, swelling and microstructure of six beryllium grades (DshG-200, TR-30, TshG-56, TRR, TE-30, TIP-30) fabricated by VNIINM, Russia and also one - (S-65) fabricated by Brush Wellman, USA. The average grain size of the beryllium grades varied from 8 to 25 {mu}m, beryllium oxide content was 0.8-3.2 wt. %, initial tensile strength was 250-680 MPa. All the samples were irradiated in active zone of SM-3 reactor up to the fast neutron fluence (5.5-6.2) {center_dot} 10{sup 21} cm{sup -2} (2.7-3.0 dpa, helium content up to 1150 appm), E > 0.1 MeV at two temperature ranges: T{sub 1} = 130-180degC and T{sub 2} = 650-700degC. After irradiation at 130-180degC no changes in samples dimensions were revealed. After irradiation at 650-700degC swelling of the materials was found to be in the range 0.1-2.1 %. Beryllium grades TR-30 and TRR, having the smallest grain size and highest beryllium oxide content, demonstrated minimal swelling, which was no more than 0.1 % at 650-700degC and fluence 5.5 {center_dot} 10{sup 21} cm{sup -2}. Tensile and compression test results and microstructure parameters measured before and after irradiation are also presented. (author)

  15. Preparation of nanometer sized Mn doped Zn based oxides powder for DMS applications

    CSIR Research Space (South Africa)

    Das, J

    2009-01-01

    Full Text Available our novel and low cost pyrophoric reaction technique route. Microstructural (TEM) analysis of the green powder were carried out to understand the surface morphology, particle size and crystalline behavior (if any) of the green powders. It is observed...

  16. Study of Oxidation Behaviour of Bond Coating Nanocomposites Ni-20Cr-6Al Powder Synthesized by Mechanical Alloying

    Directory of Open Access Journals (Sweden)

    Akbar Salarvand

    2011-08-01

    Full Text Available In this study, nano crystalline Ni-20Cr-6Al composite powder was produced using a high energy planetary ball milling and a two-stage process. Then the oxidation behavior of coating of that superalloy at different temperatures considered. Nanostructured Ni-20Cr-6Al coating was deposited by cold spray for application as a bond coat to thermal barrier coating on industrial gas turbine components. The paper samples synthesized were characterized by scanning electron microscopy (SEM and transmission microscope (TEM. The crystallite size was found to be less than 18 nm. XRD pattern of the nanostructured Ni-20Cr-6Al milled powder consisted of two phases (Ni,Cr rich and (Ni3Al and so pure metals of Ni,Cr and Al that transferred into the coating. XRD pattern of the oxidized coating revealed that α-Al2O3 oxide was the main phase of the oxide and so Ni(Cr,Al 2O4 spinel phases despite the formation of α- Al2O3 oxide.

  17. Effect of supplementation of drumstick (Moringa oleifera) and amaranth (Amaranthus tricolor) leaves powder on antioxidant profile and oxidative status among postmenopausal women

    National Research Council Canada - National Science Library

    Kushwaha, Shalini; Chawla, Paramjit; Kochhar, Anita

    2014-01-01

    .... The objective of the present study was therefore, to analyze the effect of supplementation of drumstick and amaranth leaves powder on blood levels of antioxidant and marker of oxidative stress...

  18. In Situ Synchrotron Powder Diffraction Studies of Reduction-Oxidation (Redox) Behavior of Iron Ores and Ilmenite

    Science.gov (United States)

    Ilyushechkin, Alexander Y.; Kochanek, Mark; Tang, Liangguang; Lim, Seng

    2017-04-01

    Phase transformations of two types of iron-based oxides (iron ore and industrial-grade ilmenite) were studied using synchrotron powder diffraction of the samples processed in reducing and oxidizing atmospheres at 1173 K (900 °C) and 1223 K (950 °C), respectively. In iron ore oxidation, the disappearance of the wustite and fayalite phases was followed by hematite growth and a decrease of the magnetite phase. The magnetite phase was partially recovered by treatment in a reducing atmosphere. Ilmenite oxidation initiated decomposition of the ilmenite phase with rapid growth of hematite and gradual growth of the pseudobrookite phase. In a reducing atmosphere, ilmenite was gradually recovered from pseudobrookite with a relatively fast initial decrease in rutile and hematite content. Under reducing conditions, there was interaction of iron ore with magnesio-ferrites in iron ore-ash mixture and interaction of ilmenite with silica by the formation of fayalite.

  19. In Situ Synchrotron Powder Diffraction Studies of Reduction-Oxidation (Redox) Behavior of Iron Ores and Ilmenite

    Science.gov (United States)

    Ilyushechkin, Alexander Y.; Kochanek, Mark; Tang, Liangguang; Lim, Seng

    2017-01-01

    Phase transformations of two types of iron-based oxides (iron ore and industrial-grade ilmenite) were studied using synchrotron powder diffraction of the samples processed in reducing and oxidizing atmospheres at 1173 K (900 °C) and 1223 K (950 °C), respectively. In iron ore oxidation, the disappearance of the wustite and fayalite phases was followed by hematite growth and a decrease of the magnetite phase. The magnetite phase was partially recovered by treatment in a reducing atmosphere. Ilmenite oxidation initiated decomposition of the ilmenite phase with rapid growth of hematite and gradual growth of the pseudobrookite phase. In a reducing atmosphere, ilmenite was gradually recovered from pseudobrookite with a relatively fast initial decrease in rutile and hematite content. Under reducing conditions, there was interaction of iron ore with magnesio-ferrites in iron ore-ash mixture and interaction of ilmenite with silica by the formation of fayalite.

  20. Synthesis of A novel aminoalkoxide of iron by oxide one-pot process: Its sol-gel application to iron oxide powder

    Directory of Open Access Journals (Sweden)

    Manop Panapoy

    2009-11-01

    Full Text Available A low-cost and facile route to synthesize ferratrane complex, which can be employed as alkoxide precursor for iron oxide ordoped iron oxide via sol-gel technique, has been developed from the reaction of a very inexpensive and plentiful startingmaterials via the oxide one-pot synthesis (OOPS process. Ferratrane complex was directly synthesized from iron hydroxide,triethanolamine and ethylene glycol in the presence of triethylenetetramine as catalyst. The structure of resulting products was fully characterized using FTIR, 1H, 13C-NMR, elemental analysis, mass spectroscopy and TGA. Moreover, the influence ofcalcination temperature on the formation of iron oxide powders prepared by sol-gel route using the synthesized ferratranecomplex was investigated. The microstructure, morphology and electrical property of iron oxide obtained were also elucidated.

  1. Structural, electrochemical and optical comparisons of tungsten oxide coatings derived from tungsten powder-based sols

    Energy Technology Data Exchange (ETDEWEB)

    Isik, Dilek, E-mail: e145342@metu.edu.t [Department of Metallurgical and Materials Engineering, METU, 06531 Ankara (Turkey); Ak, Metin, E-mail: metinak@pamukkale.edu.t [Department of Chemistry, Pamukkale University, 20017 Denizli (Turkey); Durucan, Caner, E-mail: cdurucan@metu.edu.t [Department of Metallurgical and Materials Engineering, METU, 06531 Ankara (Turkey)

    2009-11-02

    Tungsten trioxide (WO{sub 3}) electrochromic coatings have been formed on indium tin oxide-coated glass substrates by aqueous routes. Coating sols are obtained by dissolving tungsten powder in acetylated (APTA) or plain peroxotungstic acid (PTA) solutions. The structural evolution and electrochromic performance of the coatings as a function of calcination temperature (250 {sup o}C and 400 {sup o}C) have been reported. Differential scanning calorimetry and X-ray diffraction have shown that amorphous WO{sub 3} films are formed after calcination at 250 {sup o}C for both processing routes; however, the coatings that calcined at 400 {sup o}C were crystalline in both cases. The calcination temperature-dependent crystallinity of the coatings results in differences in optical properties of the coatings. Higher coloration efficiencies can be achieved with amorphous coatings than could be seen in the crystalline coatings. The transmittance values (at 800 nm) in the colored state are 35% and 56% for 250 {sup o}C and 400 {sup o}C-calcined coatings, respectively. The electrochemical properties are more significantly influenced by the method of sol preparation. The ion storage capacities designating the electrochemical properties are found in the range of 1.62-2.74 x 10{sup -3} (mC cm{sup -2}) for APTA coatings; and 0.35-1.62 x 10{sup -3} (mC cm{sup -2}) for PTA coatings. As a result, a correlation between the microstructure and the electrochromic performance has been established.

  2. Preparation of Terbium Sesquisulfide and Holmium Sesquisulfide by Sulfurization of Their Oxide Powders Using CS2 Gas

    Institute of Scientific and Technical Information of China (English)

    Yuan Haibin; Michihiro Ohta; Shinji Hirai; Toshiyuki Nishimura; Kazuyoshi Shimakage

    2004-01-01

    The formation behaviors of terbium sesquisulfide(Tb2S3)and holmium sesquisulfide(Ho2S3)synthesized via the sulfurization of their oxide powders using CS2 gas in the range of temperature 673 to 1323 K were investigated. In the sulfurization of Tb4O7 powder, Tb2O3 and Tb2O2S were formed in the initial stage of reaction, and α-Tb2S3 was finally formed at higher temperature. For long sulfurization time of 8 h, single-phase α-Tb2S3 could be synthesized at 1323 K. In the sulfurization of Ho2O3 powder using CS2 gas, only Ho2O2S was formed as an intermediate product. At a sulfurization temperature above 873 K, Ho2O2S was formed in the initial stage of reaction, and single-phase δ-Ho2S3 was formed at 1323 K for 8 h instead of Ho2O2S. Furthermore, the influence of the addition of carbon black to the sulfurization of Ho2O3 powder using CS2 gas was investigated, and the result implied that the reactions were accelerated slightly by the addition of carbon black.

  3. Beryllium Related Matter

    Energy Technology Data Exchange (ETDEWEB)

    Gaylord, R F

    2008-12-23

    In recent months, LLNL has identified, commenced, and implemented a series of interim controls, compensatory measures, and initiatives to ensure worker safety, and improve safety processes with regards to potential worker exposure to beryllium. Many of these actions have been undertaken in response to the NNSA Independent Review (COR-TS-5/15/2008-8550) received by LLNL in November of 2008. Others are the result of recent discoveries, events or incidents, and lessons learned, or were scheduled corrective actions from earlier commitments. Many of these actions are very recent in nature, or are still in progress, and vary in the formality of implementation. Actions are being reviewed for effectiveness as they progress. The documentation of implementation, and review of effectiveness, when appropriate, of these actions will be addressed as part of the formal Corrective Action Plan addressing the Independent Review. The mitigating actions taken fall into the following categories: (1) Responses to specific events/concerns; (2) Development of interim controls; (3) Review of ongoing activities; and (4) Performance improvement measures.

  4. Subtask 6: Recommended practices for powder characterization. IEA Programme on Advanced Fuel Cells, Annex 2: Modelling and evaluation of Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Van Heuveln, F.H.; Huijsmans, J.P.P. [eds.

    1992-08-01

    Powders, or precursors of powders, for the fabrication of Solid Oxide Fuel Cell (SOFC) anode-, cathode-, electrolyte- and ceramic interconnect structures are the relevant products to be evaluated. The aim is to provide a standard set of powder properties which have to be measured according to recommended methods and measurement conditions. The set is based on the results of a round robin test for electrolyte powder between five laboratories. The selected powder properties to be measured are chemical composition, phase composition, specific surface, particle size distribution, particle shape, sinterability, powder density, and flowability. The laboratories involved are Cookson Group (United Kingdom), Eniricerche (Italy), Senter for Industriforskning (Norway), Alusuisse/Lonza (Switzerland), and the Netherlands Energy Research Foundation. 2 app., 8 refs.

  5. Mineral resource of the month: beryllium

    Science.gov (United States)

    ,

    2013-01-01

    The article discusses information about Beryllium. It notes that Beryllium is a light metal that has a gray color. The metal is used in the production of parts and devices including bearings, computer-chip heat sinks, and output windows of X-ray tubes. The article mentions Beryllium's discovery in 1798 by French chemist, Louis-Nicolas Vanquelin. It cites that bertrandite and beryl are the principal mineral components for the commercial production of beryllium.

  6. Biological exposure metrics of beryllium-exposed dental technicians.

    Science.gov (United States)

    Stark, Moshe; Lerman, Yehuda; Kapel, Arik; Pardo, Asher; Schwarz, Yehuda; Newman, Lee; Maier, Lisa; Fireman, Elizabeth

    2014-01-01

    Beryllium is commonly used in the dental industry. This study investigates the association between particle size and shape in induced sputum (IS) with beryllium exposure and oxidative stress in 83 dental technicians. Particle size and shape were defined by laser and video, whereas beryllium exposure data came from self-reports and beryllium lymphocyte proliferation test (BeLPT) results. Heme oxygenase-1 (HO1) gene expression in IS was evaluated by quantitative polymerase chain reaction. A high content of particles (92%) in IS >5 μ in size is correlated to a positive BeLPT risk (odds ratio [OR] = 3.4, 95% confidence interval [CI]: 0.9-13). Use of masks, hoods, and type of exposure yielded differences in the transparency of IS particles (gray level) and modulate HO1 levels. These results indicate that parameters of size and shape of particles in IS are sensitive to workplace hygiene, affect the level of oxidative stress, and may be potential markers for monitoring hazardous dust exposures.

  7. Protective Effects of Sweet Orange, Unshiu Mikan, and Mini Tomato Juice Powders on t-BHP-Induced Oxidative Stress in HepG2 Cells

    Science.gov (United States)

    Jannat, Susoma; Ali, Md Yousof; Kim, Hyeung-Rak; Jung, Hyun Ah; Choi, Jae Sue

    2016-01-01

    The aim of this study was to investigate the protective effects of juice powders from sweet orange [Citrus sinensis (L.) Osbeck], unshiu mikan (Citrus unshiu Marcow), and mini tomato (Solanum lycopersicum L.), and their major flavonoids, hesperidin, narirutin, and rutin in tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in HepG2 cells. The increased reactive oxygen species and decreased glutathione levels observed in t-BHP-treated HepG2 cells were ameliorated by pretreatment with juice powders, indicating that the hepatoprotective effects of juice powders and their major flavonoids are mediated by induction of cellular defense against oxidative stress. Moreover, pretreatment with juice powders up-regulated phase-II genes such as heme oxygenase-1 (HO-1), thereby preventing cellular damage and the resultant increase in HO-1 expression. The high-performance liquid chromatography profiles of the juice powders confirmed that hesperidin, narirutin, and rutin were the key flavonoids present. Our results suggest that these fruit juice powders and their major flavonoids provide a significant cytoprotective effect against oxidative stress, which is most likely due to the flavonoid-related bioactive compounds present, leading to the normal redox status of cells. Therefore, these fruit juice powders could be advantageous as bioactive sources for the prevention of oxidative injury in hepatoma cells. PMID:27752497

  8. The Heterogeneous Photocatalytic Oxidation of Hydrocarbons on Platinized TiO2 Powders.

    Science.gov (United States)

    1980-08-28

    presence of catalyst. Platinized anatase has a higher efficiency than plain anatase powder (see experiments 2 and 7). The results shown in experiments 3...Measurements. The photocatalytic activities of suspended platinized anatase powders were correlated with the behavior of TiO 2 single crystal electrodes in...photoelectrochemical (PEC) measurements as shown in Figure 1. The current-potential behavior of a rutile single crystal electrode was examined in an

  9. 10 CFR 850.33 - Beryllium emergencies.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Beryllium emergencies. 850.33 Section 850.33 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Specific Program Requirements § 850.33 Beryllium emergencies. (a) The responsible employer must comply with 29 CFR 1910.120(l) for...

  10. Neutron irradiation of beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S.; Ermi, R.M. [Pacific Northwest National Lab., Richland, WA (United States); Tsai, H. [Argonne National Lab., IL (United States)

    1998-03-01

    Seven subcapsules from the FFTF/MOTA 2B irradiation experiment containing 97 or 100% dense sintered beryllium cylindrical specimens in depleted lithium have been opened and the specimens retrieved for postirradiation examination. Irradiation conditions included 370 C to 1.6 {times} 10{sup 22} n/cm{sup 2}, 425 C to 4.8 {times} 10{sup 22} n/cm{sup 2}, and 550 C to 5.0 {times} 10{sup 22} n/cm{sup 2}. TEM specimens contained in these capsules were also retrieved, but many were broken. Density measurements of the cylindrical specimens showed as much as 1.59% swelling following irradiation at 500 C in 100% dense beryllium. Beryllium at 97% density generally gave slightly lower swelling values.

  11. Beryllium strain under dynamic loading

    Directory of Open Access Journals (Sweden)

    Pushkov Victor

    2015-01-01

    Full Text Available There are some data (not much on dynamic characteristics of beryllium that are important, for example, when estimating construction performance at NPP emergencies. A number of data on stress-strain curves, spall strength, shear strength, fracture and structure responses of shock loaded beryllium have obtained in US and Russian laboratories. For today the model description of this complex metal behavior does not have a reasonable agreement with the experimental data, thus a wider spectrum of experimental data is required. This work presents data on dynamic compression-test diagrams of Russian beryllium. Experiments are performed using Hopkinson bar method (SHPB. Strain rates were ε ∼ 103 s−1.

  12. Effect of grinding time of synthesized gadolinium doped ceria (GDC10 powders on the performance of solid oxide fuel cell

    Directory of Open Access Journals (Sweden)

    Fatma Aydin

    2014-03-01

    Full Text Available Ceria-based materials are prospective electrolytes for low and intermediate temperature solid oxide fuel cells. In the present work, fully dense CeO2 ceramics doped with 10 mol% gadolinium (Gd0.1Ce0.9O1.95 were prepared with a sol–gel method and commercially purchased GDC10 electrolyte powders were processed. Particle sizes of synthesized electrolyte powders were minimized by ball-milling method. Grinding of the samples were performed in different times intervals (12 h, 15 h, 18 h, 20 h, 25 h, 30 h, 35 h, 40 h and 45 h. Then, these powders were prepared to obtain of solid oxide fuel cells (SOFCs. Performances of these cells having an active area of 1 cm2 were tested using a fuel cell test station that measured in different temperatures (650 and 700 °C. In the present study, gadolinium doped ceria (GDC10 synthesiszed powders were investigated by using XRD and SEM images. Performance values of synthesized GDC10's in different temperature were compared to by commercial GDC10. Commercial GDC10's performance at 650 °C were tested, and maximum current density of 0.413 W/cm2 and maximum current density of 0.949 A/cm2 were obtained. Commercial GDC10 at 650 °C has better result. However, synthesized GDC10's performance at 700 °C demonstrated better results than commercial GDC10's. The performance tests of samples which are 20 h mill showed that they have the maximum power density of was obtained as 0.480 W/cm2 and maximum current density of as 1.231 A/cm2.

  13. Beryllium Exposure Control Program at the Cardiff Atomic Weapons Establishment in the United Kingdom.

    Science.gov (United States)

    Johnson, J S; Foote, K; McClean, M; Cogbill, G

    2001-05-01

    The Cardiff Atomic Weapons Establishment (AWE) plant, located in Cardiff, Wales, United Kingdom, used metallic beryllium in their beryllium facility during the years of operation 1961-1997. The beryllium production processes included melting and casting, powder production, pressing, machining, and heat and surface treatments. As part of Cardiff's industrial hygiene program, extensive area measurements and personal lapel measurements of airborne beryllium concentrations were collected for Cardiff workers over the 36-year period of operation. In addition to extensive air monitoring, the beryllium control program also utilized surface contamination controls, building design, engineering controls, worker controls, material controls, and medical surveillance. The electronic database includes 367,757 area sampling records at 101 locations and 217,681 personal lapel sampling records collected from 194 employees over the period 1981-1997. Similar workplace samples were collected from 1961 to 1980, but they were not analyzed because they were not available electronically. Annual personal mean sampling concentrations for all workers ranged from 0.11 to 0.72 micrograms per cubic meter (microg/m3) with 95th percentiles ranging from 0.22 to 1.89 microg/m3; foundry workers worked in the highest concentration areas with a mean of 0.87 microg/m3 and a 95th percentile of 2.9 microg/m3. Area sampling concentrations, as expected, were lower than personal sampling concentrations. Mean annual area sample concentrations for all locations ranged from 0.02 to 0.32 microg/m3. The area sample 95th percentile concentrations for all years were below 0.5 microg/m3. For the overwhelming majority of samples, airborne beryllium concentrations were below the 2.0 microg/m3 standard. Although blood lymphocyte testing for beryllium sensitization has not been routinely conducted among these workers, this metal beryllium processing facility is the only large scale beryllium facility of its kind to have

  14. Characterization of 430L porous supports obtained by powder extrusion moulding for their application in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Sotomayor, María Eugenia, E-mail: msotomay@ing.uc3m.es; Ospina, Liliana María, E-mail: lilianaospinazuluaga@hotmail.com; Levenfeld, Belén, E-mail: bll@ing.uc3m.es; Várez, Alejandro, E-mail: alvar@ing.uc3m.es

    2013-12-15

    The characterization of 430L stainless steel planar porous supports obtained by powder extrusion moulding was performed in this work. A thermoplastic multicomponent binder based on high density polyethylene and paraffin wax was selected for the process. Green supports were shaped by extrusion moulding, and subsequently the binder was removed by a thermal cycle previously optimized. Sintering was carried out at different temperatures in low vacuum. Density of sintered parts was measured by Archimedes' method and porosity was also evaluated through a microstructural analysis by optical microscopy. The porosity degree of samples sintered at low temperature was close to 35% which is a very suitable value for their application in SOFCs. Tensile tests were carried out in order to determine mechanical strength as a function of porosity degree. Based on these results, the best feedstock composition and processing parameters were selected. The oxidation behaviour in static air at high temperature was studied, and formed oxides were characterized in a scanning electron microscope equipped with energy dispersive analysis of X-rays. X-ray diffraction experiments were performed in order to identify the formed oxides based on formula Fe{sub 2−x}Cr{sub x}O{sub 3}. The results of these studies showed that this kind of ferritic stainless steel would be more suitable to be used as anodic supports where a rich hydrogen atmosphere is employed. Preliminary deposition tests allowed obtaining a homogeneous Ni–YSZ anode layer with a thickness of 10 μm on the porous metallic substrates. - Highlights: • 430L stainless steel porous supports were obtained by powder extrusion moulding. • Porosity degree was controlled sintering at different temperatures in low vacuum. • Tensile tests allowed determining mechanical strength of porous supports. • A study about its oxidation behaviour in static air at high temperature was realized. • After oxidation, formed oxides were

  15. Influence of pH-control in phosphoric acid treatment of titanium oxide and their powder properties

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Hiroaki, E-mail: onoda@kpu.ac.jp; Matsukura, Aki

    2015-06-15

    Highlights: • The photocatalytic activity was suppressed by phosphoric acid treatment. • The obtained pigment had small particles with sub-micrometer size. • By phosphoric acid treatment, the smoothness of samples improved. - Abstract: Titanium oxide that has the photocatalytic activity is used as a white pigment for cosmetics. A certain degree of sebum on the skin is decomposed by the ultraviolet radiation in sunlight. In this work, titanium oxide was shaken with phosphoric acid at various pH to synthesize a novel white pigment for cosmetics. Their chemical composition, powder properties, photocatalytic activity, color phase, and smoothness were studied. The obtained materials indicated XRD peaks of titanium oxide, however, these peak intensity became weak by phosphoric acid treatment. These samples without heating and heated at 100 °C included the small particles with sub-micrometer size. The photocatalytic activity of the obtained powders became weak by phosphoric acid treatment at pH 4 and 5 to protect the sebum on the skin.

  16. Aluminum powder metallurgy processing

    Energy Technology Data Exchange (ETDEWEB)

    Flumerfelt, J.F.

    1999-02-12

    The objective of this dissertation is to explore the hypothesis that there is a strong linkage between gas atomization processing conditions, as-atomized aluminum powder characteristics, and the consolidation methodology required to make components from aluminum powder. The hypothesis was tested with pure aluminum powders produced by commercial air atomization, commercial inert gas atomization, and gas atomization reaction synthesis (GARS). A comparison of the GARS aluminum powders with the commercial aluminum powders showed the former to exhibit superior powder characteristics. The powders were compared in terms of size and shape, bulk chemistry, surface oxide chemistry and structure, and oxide film thickness. Minimum explosive concentration measurements assessed the dependence of explosibility hazard on surface area, oxide film thickness, and gas atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization processing conditions. The GARS aluminum powders were exposed to different relative humidity levels, demonstrating the effect of atmospheric conditions on post-atomization oxidation of aluminum powder. An Al-Ti-Y GARS alloy exposed in ambient air at different temperatures revealed the effect of reactive alloy elements on post-atomization powder oxidation. The pure aluminum powders were consolidated by two different routes, a conventional consolidation process for fabricating aerospace components with aluminum powder and a proposed alternative. The consolidation procedures were compared by evaluating the consolidated microstructures and the corresponding mechanical properties. A low temperature solid state sintering experiment demonstrated that tap densified GARS aluminum powders can form sintering necks between contacting powder particles, unlike the total resistance to sintering of commercial air atomization aluminum powder.

  17. Analysis of inner filter effect on the up-conversion spectra of erbium doped yttrium oxide close-packed powders

    Science.gov (United States)

    Rakov, Nikifor; Maciel, Glauco S.

    2012-11-01

    We observed that the up-conversion (UC) emission profiles of erbium (Er3+) doped yttrium oxide (Y2O3) close-packed powders prepared by combustion synthesis are different when the luminescence reflected from the sample is compared to the luminescence transmitted through the sample (thickness: ˜0.1 mm). The effect was identified as a combination of scattering and an inner filter effect (IFE). The IFE reduces the transmitted UC luminescence bandwidths up to 50%. The IFE was suppressed by the inclusion of free-standing undoped Y2O3 particles.

  18. Reactivity test between beryllium and copper

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, H. [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan); Kato, M. [NGK Insulators, Ltd., Aichi-ken (Japan)

    1995-09-01

    Beryllium has been expected for using as plasma facing material on ITER. And, copper alloy has been proposed as heat sink material behind plasma facing components. Therefore, both materials must be joined. However, the elementary process of reaction between beryllium and copper alloy does not clear in detail. For example, other authors reported that beryllium reacted with copper at high temperature, but it was not obvious about the generation of reaction products and increasing of the reaction layer. In the present work, from this point, for clarifying the elementary process of reaction between beryllium and copper, the out-of-pile compatibility tests were conducted with diffusion couples of beryllium and copper which were inserted in the capsule filled with high purity helium gas (6N). Annealing temperatures were 300, 400, 500, 600 and 700{degrees}C, and annealing periods were 100, 300 and 1000h. Beryllium specimens were hot pressed beryllium, and copper specimens were OFC (Oxygen Free Copper).

  19. Photoluminescence enhancement from GaN by beryllium doping

    Science.gov (United States)

    García-Gutiérrez, R.; Ramos-Carrazco, A.; Berman-Mendoza, D.; Hirata, G. A.; Contreras, O. E.; Barboza-Flores, M.

    2016-10-01

    High quality Be-doped (Be = 0.19 at.%) GaN powder has been grown by reacting high purity Ga diluted alloys (Be-Ga) with ultra high purity ammonia in a horizontal quartz tube reactor at 1200 °C. An initial low-temperature treatment to dissolve ammonia into the Ga melt produced GaN powders with 100% reaction efficiency. Doping was achieved by dissolving beryllium into the gallium metal. The powders synthesized by this method regularly consist of two particle size distributions: large hollow columns with lengths between 5 and 10 μm and small platelets in a range of diameters among 1 and 3 μm. The GaN:Be powders present a high quality polycrystalline profile with preferential growth on the [10 1 bar 1] plane, observed by means of X-ray diffraction. The three characteristics growth planes of the GaN crystalline phase were found by using high resolution TEM microscopy. The optical enhancing of the emission in the GaN powder is attributed to defects created with the beryllium doping. The room temperature photoluminescence emission spectra of GaN:Be powders, revealed the presence of beryllium on a shoulder peak at 3.39 eV and an unusual Y6 emission at 3.32eV related to surface donor-acceptor pairs. Also, a donor-acceptor-pair transition at 3.17 eV and a phonon replica transition at 3.1 eV were observed at low temperature (10 K). The well-known yellow luminescence band coming from defects was observed in both spectra at room and low temperature. Cathodoluminescence emission from GaN:Be powders presents two main peaks associated with an ultraviolet band emission and the yellow emission known from defects. To study the trapping levels related with the defects formed in the GaN:Be, thermoluminescence glow curves were obtained using UV and β radiation in the range of 50 and 150 °C.

  20. Worker Environment Beryllium Characterization Study

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Environment, Safety, Health & Quality

    2009-12-28

    This report summarizes the conclusion of regular monitoring of occupied buildings at the Nevada Test Site and North Las Vegas facility to determine the extent of beryllium (Be) contamination in accordance with Judgment of Needs 6 of the August 14, 2003, “Minnema Report.”

  1. Concomitant administration of Moringa oleifera seed powder in the remediation of arsenic-induced oxidative stress in mouse.

    Science.gov (United States)

    Gupta, Richa; Dubey, D K; Kannan, G M; Flora, S J S

    2007-01-01

    Contamination of ground water by arsenic has become a cause of global public health concern. In West Bengal, India, almost 6 million people are endemically exposed to inorganic arsenic by drinking heavily contaminated groundwater through hand-pumped tube wells. No safe, effective and specific preventive or therapeutic measures for treating arsenic poisoning are available. We recently reported that some of the herbal extracts possess properties effective in reducing arsenic concentration and in restoring some of the toxic effects of arsenic in animal models. Moringa oleifera Lamarack (English: Horseradish-tree, Drumstick-tree, Hindi: Saijan, Sanskrit: Shigru) belongs to the Moringaceae family, is generally known in the developing world as a vegetable, a medicinal plant and a source of vegetable oil. The objective of the present study was to determine whether Moringa oleifera (M. oleifera) seed powder could restore arsenic induced oxidative stress and reduce body arsenic burden. Exposure to arsenic (2.5 mg/kg, intraperitoneally for 6weeks) led to a significant increase in the levels of tissue reactive oxygen species (ROS), metallothionein (MT) and thiobarbituric acid reactive substance (TBARS) which were accompanied by a decrease in the activities in the antioxidant enzymes such as superoxide dismutase (SOD), catalase and glutathione peroxidase (GPx) in mice. Arsenic exposed mice also exhibited liver injury as reflected by reduced acid phosphatase (ACP), alkaline phosphatase (ALP) and aspartate aminotransferase (AST) activities and altered heme synthesis pathway as shown by inhibited blood delta-aminolevulinic acid dehydratase (delta-ALAD) activity. Co-administration of M. oleifera seed powder (250 and 500 mg/kg, orally) with arsenic significantly increased the activities of SOD, catalase, GPx with elevation in reduced GSH level in tissues (liver, kidney and brain). These changes were accompanied by approximately 57%, 64% and 17% decrease in blood ROS, liver

  2. Stability to oxidation of spray-dried fish oil powder microencapsulated using milk ingredients

    DEFF Research Database (Denmark)

    Keogh, M.K.; O'Kennedy, B.T.; Kelly, J.;

    2001-01-01

    Microencapsulation of fish oil was achieved by spray-drying homogenized emulsions of fish oil using 3 different types of casein as emulsifier and lactose as filler. As the degree of aggregation of the casein emulsifier increased, the vacuole volume of the microencapsulated powders decreased...

  3. Phase Transformation Behavior of Oxide Particles Formed in Mechanically Alloyed Fe-5Y{sub 2}O{sub 3} Powder

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ga Eon; Choi, Jung-Sun; Noh, Sanghoon; Kang, Suk Hoon; Choi, Byoung Kwon; Kim, Tae Kyu [Korea Atomic Energy Research Institute, Deajeon (Korea, Republic of); Kim, Young Do [Hanyang University, Seoul (Korea, Republic of)

    2017-05-15

    The phase transformation behavior of the oxides formed in mechanically alloyed Fe-5Y{sub 2}O{sub 3} powder is investigated. Non-stoichiometric Y-rich and Fe-rich oxides with sizes of less than 300 nm are observed in the mechanically alloyed powder. The diffusion and redistribution reactions of the elements in these oxides during heating of the powder above 800 ℃ were observed, and these reactions result in the formation of a Y{sub 3}Fe{sub 5}O{sub 12} phase after heating at 1050 ℃. Thus, it is considered that the Y{sub 2}O{sub 3} powder and some Fe powder are formed from the non-stoichiometric Y-rich and Fe-rich oxides after the mechanical alloying process, and a considerable energy accumulated during the mechanical alloying process leads to a phase transformation of the Y-rich and Fe-rich oxides to Y{sub α}Fe{sub β}O{sub γ}-type phase during heating.

  4. Two types of radicals in whole milk powder. Effect of lactose crystallization, lipid oxidation, and browning reactions.

    Science.gov (United States)

    Thomsen, Marianne K; Lauridsen, Lene; Skibsted, Leif H; Risbo, Jens

    2005-03-09

    Whole milk powder was stored in closed vials at 60 degrees C to induce crystallization of lactose within a short time scale. After an induction period of 3-4 days simultaneous crystallization of lactose, increase of water activity, formation of browning products, and increase of radical content took place. Radicals detected before lactose crystallization were characterized by a narrow ESR spectrum (g = 2.006) and could be depleted by removal of oxygen and therefore were assigned to oxidation processes. Late-stage radicals present after crystallization of lactose gave much wider spectra (g = 2.0048) and were independent of oxygen availability and assigned to late-stage Maillard reaction products. The study indicates that the processes of lactose crystallization, browning, and formation of radical species (g = 2.0048) are strongly coupled, while lipid oxidation is less dependent on the other processes.

  5. The administration of food supplemented with cocoa powder during nutritional recovery reduces damage caused by oxidative stress in rat brain.

    Science.gov (United States)

    Barragán Mejía, Gerardo; Calderón Guzmán, David; Juárez Olguín, Hugo; Hernández Martínez, Nancy; García Cruz, Edna; Morales Ramírez, Aline; Labra Ruiz, Norma; Esquivel Jiménez, Gabriela; Osnaya Brizuela, Norma; García Álvarez, Raquel; Ontiveros Mendoza, Esperanza

    2011-12-01

    Malnutrition contributes to the development of oxidative damage in the central nervous system. The selective administration of nutrients tends to show positive results in individuals who have suffered from malnutrition. To determine the effect of the administration of cocoa powder on the peroxidation of lipids and glutathione level during the nutritional recovery in brain, rats of 21 days old were subjected to a protocol that resembles malnutrition (MN) by feeding them with 60% of the daily food consumption of the control group (WN) and later to nutritional recovery with regular rodent feed (RFR) or added with cocoa (10 g of cocoa powder/kg of regular rodent feed) (CCR). Animals fed with regular rodent food showed significant reduction in brain glutathione: RFR (84.18 ± 6.38 ng/mg protein) vs. CCR (210.61 ± 50.10 ng/mg protein) and WN (186.55 ± 33.18 ng/mg protein), but with similar level to that of MN (92.12 ± 15.60 ng/mg protein). On the contrary, lipid peroxidation in RFR-fed animals increased RFR (1.32 ± 0.2 μM malondialdehyde/g of tissue), CCR (0.86 ± 0.07 μM malondialdehyde/g of tissue), WN (0.89 ± 0.09 μM malondialdehyde/g of tissue), but their thiobarbituric acid reactive substances concentration is similar to that of MN group (1.50 ± 0.2 μM malondialdehyde/g of tissue). Consumption of cocoa powder as a source of antioxidants favors the restoration of the concentration of glutathione and reduces the damage caused by oxidative stress during nutritional recovery in rat brain.

  6. Nanostructured micro-raspberries from superparamagnetic iron oxide nanoparticles: Studying agglomeration degree and redispersibility of nanoparticulate powders via magnetisation measurements.

    Science.gov (United States)

    Stauch, Claudia; Späth, Stephan; Ballweg, Thomas; Luxenhofer, Robert; Mandel, Karl

    2017-11-01

    Surface modified superparamagnetic iron oxide nanoparticles are assembled into nanostructured micro-raspberry particles via spray drying. The micro-raspberry powder is readily redispersed to individual nanoparticles or nanostructured sub-units, depending on the initially adjusted nanoparticle modification. In this work, it is demonstrated how the technique of magnetic zero-field-cooled/field-cooled (ZFC/FC) measurements can be used to judge the degree of agglomeration, i.e. the extent of hard-agglomerates and soft-agglomerates in a system and predict the redispersibility of the powder particles. Furthermore, the uniformity of surface modification of the individual nanoparticles can be judged via this method. In addition, the technique can be applied to characterise complex nanostructured particle systems composed of iron oxide nanoparticles mixed with another type of nanoparticulate building-block. Thus, this work shows that magnetic measurement techniques are a promising approach to characterise agglomeration states of nanoparticles, their degree of surface modification and their distribution in complex particle and composite systems. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Amperometric detection of Sudan I in red chili powder samples using Ag nanoparticles decorated graphene oxide modified glassy carbon electrode.

    Science.gov (United States)

    Prabakaran, E; Pandian, K

    2015-01-01

    A simple and sensitive electrochemical method was developed to determine the concentration of Sudan I in chili powder based on silver nanoparticles decorated graphene oxide modified glassy carbon electrode (AgNPs@GO/GCE). The voltammetry behaviour of Sudan I on modified GCE was investigated in phosphate buffer medium (PBS) with various pH ranges and the electron transfer properties were studied. It is found that the AgNPs@GO/GCE can catalyse the reduction of azo group, -N=N- followed by electrochemical oxidation of (-)OH group present in Sudan I dye molecule. Quantitative detection of Sudan I present in food products was carried out by amperometry method in which reduction potential was fixed at -0.77 V vs. Ag/AgCl. The amperometry method showed an excellent performance with a sensitivity of 6.83 μA mM(-1) and a detection limit of 11.4 × 10(-7)ML(-1). A linear calibration graph was constructed in the ranging 3.90 × 10(-6) to 3.19 × 10(-5)ML(-1). The method was successfully applied for the determination of Sudan I in red chili powder samples.

  8. Effect of Al2O3 Micro-powder Additives on the Properties of Micro-arc Oxidation Coatings Formed on 6061 Aluminum Alloy

    Science.gov (United States)

    Wang, Ping; Wu, Ting; Xiao, You Tao; Pu, Jun; Guo, Xiao Yang; Huang, Jun; Xiang, Chun Lang

    2016-09-01

    Al2O3 micro-powder was suspended in the basis electrolyte to form micro-arc oxidation (MAO) coatings on 6061 aluminum alloy by MAO. During the stage of micro-arc oxidation, Al2O3 micro-powder with negative surface charge was melted by the micro-arc around the anode and incorporated into the MAO coatings. With the continuous addition of Al2O3 micro-powder, the oxidation voltages rose up firstly and then decreased. The surface and cross-sectional morphologies showed that the size of micropores decreased and the MAO coatings surface got loosened following the variation in Al2O3 micro-powder concentration. As a consequence of the changing coating structure, the corrosion resistance of the coatings decreased apparently. The micro-hardness of the coatings increased firstly and then decreased, opposite to the trend of the average friction coefficient. It revealed the minimum average friction coefficient of MAO coatings and maximum adhesion between the coatings and substrate when 2.0 g/L Al2O3 micro-powder was added into electrolyte. There were visible cracks and peelings on the coating surface merely at 4.0 g/L after thermal shock tests. The x-ray diffraction results indicated that the addition of Al2O3 micro-powder had less effect on the phase composition of MAO coatings.

  9. Facile synthesis of multi-shell structured binary metal oxide powders with a Ni/Co mole ratio of 1:2 for Li-Ion batteries

    Science.gov (United States)

    Choi, Seung Ho; Park, Sun Kyu; Lee, Jung-Kul; Kang, Yun Chan

    2015-06-01

    Multi-shell structured binary transition metal oxide powders with a Ni/Co mole ratio of 1:2 are prepared by a simple spray drying process. Precursor powder particles prepared by spray drying from a spray solution of citric acid and ethylene glycol have completely spherical shape, fine size, and a narrow size distribution. The precursor powders turn into multi-shell powders after a post heat-treatment at temperatures between 250 and 800 °C. The multi-shell structured powders are formed by repeated combustion and contraction processes. The multi-shell powders have mixed crystal structures of Ni1-xCo2O4-x and NiO phases regardless of the post-treatment temperature. The reversible capacities of the powders post-treated at 250, 400, 600, and 800 °C after 100 cycles are 584, 913, 808, and 481 mA h g-1, respectively. The low charge transfer resistance and high lithium ion diffusion rate of the multi-shell powders post-treated at 400 °C with optimum grain size result in superior electrochemical properties even at high current densities.

  10. Manganese iron oxide superparamagnetic powder by mechanochemical processing. Nanoparticles functionalization and dispersion in a nanofluid

    Energy Technology Data Exchange (ETDEWEB)

    Bellusci, M., E-mail: mariangela.bellusci@enea.it; Aliotta, C. [ENEA, CR Casaccia, Dipartimento di Chimica e Technologia dei Materiali (Italy); Fiorani, D. [ISM-CNR, Area della Ricerca (Italy); La Barbera, A.; Padella, F. [ENEA, CR Casaccia, Dipartimento di Chimica e Technologia dei Materiali (Italy); Peddis, D. [ISM-CNR, Area della Ricerca (Italy); Pilloni, M. [ENEA, CR Casaccia, Dipartimento di Chimica e Technologia dei Materiali (Italy); Secci, D. [Universita di Roma La Sapienza, Dipartimento di Chimica e Tecnologie del Farmaco (Italy)

    2012-06-15

    Manganese ferrite nanoparticles were synthesized using a High-Energy Ball-Milling mechanochemical method. After 1 h of milling, the process produces a material consisting of single crystalline domain nanoparticles having a diameter of about 8 nm. Chemical properties of the synthesized powders allow an easy functionalization with citric acid. Both as-obtained and functionalized samples show superparamagnetic behaviour at room temperature, and the functionalized powder is stably dispersible in aqueous media at physiological pH. The average hydrodynamic diameter is equal to {approx}60 nm. Nanoparticles obtained by the reported High-Energy Ball-Milling method can be synthesized with high yield and low costs and can be successfully utilized in ferrofluids development for biomedical applications.

  11. Experimental Study on Dechlorination and Leaching of Zinc-Oxide Powder%锌氧粉脱氯及浸出试验研究

    Institute of Scientific and Technical Information of China (English)

    杨体昌

    2011-01-01

    The high temperature calcination removal method of zinc - oxide powder dechlorination and defluoridation, as well as the alkaline washing dechlorination method are researched by experiment, and the direct leaching of zinc-oxide powder and using it as the neutralizer is explored too in the experiment, So the operating condition of direct leaching zinc-oxide powder by electrolyte waste liquid is proposed.%试验研究了锌氧粉脱除氟和氯的高温焙烧脱除法和碱洗除氯法;并对锌氧粉的直接浸出和作为中和剂进行了探索,提出用电解废液直接浸出锌氧粉的操作条件.

  12. Characterization of surface oxides on water-atomized steel powder by XPS/AES depth profiling and nano-scale lateral surface analysis

    Science.gov (United States)

    Chasoglou, D.; Hryha, E.; Norell, M.; Nyborg, L.

    2013-03-01

    Characterization of oxide products on the surface of water-atomized steel powder is essential in order to determine the reducing conditions required for their removal during the sintering stage which in turn will result in improved mechanical properties. Pre-alloyed powder with 3 wt% Cr and 0.5 wt% Mo was chosen as the model material. Investigation of the powder surface characteristics with regard to composition, morphology, size and distribution of surface oxides was performed using X-ray photoelectron spectroscopy, Auger electron spectroscopy and high resolution scanning electron microscopy combined with X-ray microanalysis. The analysis revealed that the powder is covered by a homogeneous (˜6 nm thick) Fe-oxide layer to ˜94% whereas the rest is covered by fine particulate features with the size below 500 nm. These particulates were further analyzed and were divided into three main categories (i) Cr-based oxides with simultaneous presence of nitrogen, (ii) Si-based oxides of "hemispherical" shape and (iii) agglomerates of the afore mentioned oxides.

  13. The decomposition behavior of as-received and oxidized TiH{sub 2} foaming-agent powder

    Energy Technology Data Exchange (ETDEWEB)

    Kennedy, A.R.; Lopez, V.H

    2003-09-25

    The decomposition behavior of as-received and oxidized TiH{sub 2} powder has been studied using differential scanning calorimetry and X-ray diffraction. It was found that the decomposition of TiH{sub 2} in argon occurs in two stages, firstly the reduction in the stoichiometry of the hydride to {delta}-TiH{sub 1.5}, and secondly, with progressive heating, decomposition of the hydride to form the {beta}- and {alpha}-phases. When heating in air, at low temperatures, oxidation of the hydride to form an oxyhydride occurs and with progressive heating, the oxidation products Ti{sub 3}O and TiO{sub 2} are formed in increasing quantities. Heat treatment, to reduce the stoichiometry of the hydride and form an oxide layer, does delay the evolution of gas when re-heated in argon. A balance between the delay in gas evolution and detrimental gas loss is best achieved for pre-heat treating to between 530 and 630 deg. C.

  14. Beryllium Lymphocyte Proliferation Test Surveillance Identifies Clinically Significant Beryllium Disease

    Science.gov (United States)

    Mroz, Margaret M.; Maier, Lisa A.; Strand, Matthew; Silviera, Lori; Newman, Lee S.

    2011-01-01

    Background Workplace surveillance identifies chronic beryllium disease (CBD) but it remains unknown over what time frame mild CBD will progress to a more severe form. Methods We examined physiology and treatment in 229 beryllium sensitization (BeS) and 171 CBD surveillance-identified cases diagnosed from 1982 to 2002. Never smoking CBD cases (81) were compared to never smoking BeS patients (83) to assess disease progression. We compared CBD machinists to non-machinists to examine effects of exposure. Results At baseline, CBD and BeS cases did not differ significantly in exposure time or physiology. CBD patients were more likely to have machined beryllium. Of CBD cases, 19.3% went on to require oral immunosuppressive therapy. At 30 years from first exposure, measures of gas exchange were significantly worse and total lung capacity was lower for CBD subjects. Machinists had faster disease progression as measured by pulmonary function testing and gas exchange. Conclusions Medical surveillance for CBD identifies individuals at significant risk of disease progression and impairment with sufficient time since first exposure. PMID:19681064

  15. Mutagenicity, carcinogenicity and teratogenicity of beryllium.

    Science.gov (United States)

    Léonard, A; Lauwerys, R

    1987-07-01

    The carcinogenicity of a number of beryllium compounds has been confirmed in experiments on laboratory animals and this metal has to be treated as a possible carcinogenic threat to man. These carcinogenic properties are associated with mutagenic activity as shown by the results of short-term tests performed in vitro with beryllium chloride and beryllium sulfate. These soluble beryllium compounds can produce some infidelity of in vitro synthesis, forward gene mutations in microorganisms and in mammalian cells. They are also able to induce cell transformation. In addition to the positive results obtained in several short-term assays beryllium compounds have been found to bind to nucleoproteins, to inhibit certain enzymes needed for DNA synthesis, to bind nucleic acids to cell membranes and to inhibit microtubule polymerization. The teratogenicity of beryllium salts is relatively unknown and needs additional investigation.

  16. Advances in identifying beryllium sensitization and disease.

    Science.gov (United States)

    Middleton, Dan; Kowalski, Peter

    2010-01-01

    Beryllium is a lightweight metal with unique qualities related to stiffness, corrosion resistance, and conductivity. While there are many useful applications, researchers in the 1930s and 1940s linked beryllium exposure to a progressive occupational lung disease. Acute beryllium disease is a pulmonary irritant response to high exposure levels, whereas chronic beryllium disease (CBD) typically results from a hypersensitivity response to lower exposure levels. A blood test, the beryllium lymphocyte proliferation test (BeLPT), was an important advance in identifying individuals who are sensitized to beryllium (BeS) and thus at risk for developing CBD. While there is no true "gold standard" for BeS, basic epidemiologic concepts have been used to advance our understanding of the different screening algorithms.

  17. Catalytic Degradation of Methylphosphonic Acid Using Iron Powder/Iron Oxides

    Science.gov (United States)

    2005-11-01

    aluminium/ aluminium oxide on the degradation of methylphosphonic acid (MPA), the final hydrolysis product of most nerve agents. EGA-FTIR provides... ALUMINIUM OXIDE ) UNDER AIR (BOTTOM). .................. 37 DSTO-TR-1849 1 1. Introduction The Convention on the Prohibition of the...as well as aluminium/ aluminium oxide , using temperature programmed EGA-FTIR. Since MPA is a Schedule II chemical the above requirement can only be

  18. Method to produce nanocrystalline powders of oxide-based phosphors for lighting applications

    Science.gov (United States)

    Loureiro, Sergio Paulo Martins; Setlur, Anant Achyut; Williams, Darryl Stephen; Manoharan, Mohan; Srivastava, Alok Mani

    2007-12-25

    Some embodiments of the present invention are directed toward nanocrystalline oxide-based phosphor materials, and methods for making same. Typically, such methods comprise a steric entrapment route for converting precursors into such phosphor material. In some embodiments, the nanocrystalline oxide-based phosphor materials are quantum splitting phosphors. In some or other embodiments, such nanocrystalline oxide based phosphor materials provide reduced scattering, leading to greater efficiency, when used in lighting applications.

  19. Photo-catalytic oxidation of acetone on a TiO2 powder: An in situ FTIR investigation

    Energy Technology Data Exchange (ETDEWEB)

    Szanyi, János; Kwak, Ja Hun

    2015-09-01

    In situ transmission infrared spectroscopy was used to investigate the photo-oxidation of acetone on a commercial, oxidized TiO2 (P25) powder catalyst under UV irradiation at ambient temperature, in the absence and presence of gas phase O2. The photochemistry of a number of organic molecules (1-butanone, methanol and acetic acid,) under the same conditions was also studied in order to identify reaction intermediates and products formed in the photo-oxidation of acetone. Under anaerobic conditions (in the absence of gas phase oxygen) limited extent of photo-oxidation of acetone took place on the oxidized TiO2 sample. In the presence of O2 in the gas phase, however, acetone was completely converted to acetates and formates, and ultimately CO2. The initial step in the sequence of photo-induced reactions is the ejection of a methyl radical, resulting in the formation of surface acetates (from the acetyl group) and formates (from the methyl radicals). Acetate ions are also converted to formates, that, in turn, photo-oxidized to CO2. Under the experimental conditions applied the accumulation of carbonates and bicarbonates were observed on the TiO2 surface as the photo-oxidation of acetone proceeded (this was also observed during the course of photo-oxidation of all the other organics studied here). When the initial radical ejection step produced hydrocarbons containing more than one C atoms (as in the case in 2-butanone and mesytil oxide), the formation of aldehydes on the catalyst surface was also observed as a result of secondary reactions. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy. JHK also acknowledges the support of this work by the 2014 Research Fund of UNIST (Ulsan National Institute of Science and Technology, Ulsan, Korea). The authors thank M

  20. MEASUREMENTS OF THE PROPERTIES OF BERYLLIUM FOIL

    Energy Technology Data Exchange (ETDEWEB)

    ZHAO,Y.; WANG,H.

    2000-03-31

    The electrical conductivity of beryllium at radio frequency (800 MHz) and liquid nitrogen temperature were investigated and measured. This summary addresses a collection of beryllium properties in the literature, an analysis of the anomalous skin effect, the test model, the experimental setup and improvements, MAFIA simulations, the measurement results and data analyses. The final results show that the conductivity of beryllium is not as good as indicated by the handbook, yet very close to copper at liquid nitrogen temperature.

  1. Inhibited solid propellant composition containing beryllium hydride

    Science.gov (United States)

    Thompson, W. W. (Inventor)

    1978-01-01

    An object of this invention is to provide a composition of beryllium hydride and carboxy-terminated polybutadiene which is stable. Another object of this invention is to provide a method for inhibiting the reactivity of beryllium hydride toward carboxy-terminated polybutadiene. It was found that a small amount of lecithin inhibits the reaction of beryllium hydride with the acid groups in carboxy terminated polybutadiene.

  2. High-temperature beryllium embrittlement

    Energy Technology Data Exchange (ETDEWEB)

    Pokrovsky, A.S. [Scientific Research Inst. of Atomic Reactors, Dimitrovgrad (Russian Federation); Fabritsiev, S.A. [D.V. Efremov Scientific Research Institute, 189631 St. Petersburg (Russian Federation); Bagautdinov, R.M. [Scientific Research Inst. of Atomic Reactors, Dimitrovgrad (Russian Federation); Goncharenko, Yu.D. [Scientific Research Inst. of Atomic Reactors, Dimitrovgrad (Russian Federation)

    1996-10-01

    The neutron irradiation effect on the mechanical properties, swelling and fracture surface structure of various beryllium grades was studied in the BOR-60 reactor at 340 to 350 C up to a fluence of 7.2 x 10{sup 21} n/cm{sup 2}. At a mechanical testing temperature of 400 C there was observed a strong anisotropy of plastic beryllium deformation depending on the direction of sample cutting relative to the pressing direction. An increase of the testing temperature up to 700 C resulted in an abrupt embrittlement of all irradiated samples. In the most part of the surface structure the intercrystallite fracture along the grain boundaries was covered entirely with large pores, 1 to 4 {mu}m in size. It was suggested that the increased rate of pore formation along the grain boundaries resulted from a high-temperature embrittlement under irradiation. (orig.).

  3. In situ X-ray powder diffraction studies of the synthesis of graphene oxide and formation of reduced graphene oxide

    DEFF Research Database (Denmark)

    Storm, Mie Møller; Johnsen, Rune E.; Norby, Poul

    2016-01-01

    Graphene oxide (GO) and reduced graphene oxide (rGO) are important materials in a wide range of fields. The modified Hummers methods, for synthesizing GO, and subsequent thermal reduction to rGO, are often employed for production of rGO. However, the mechanism behinds these syntheses methods...

  4. Direct synthesis of nanocrystalline oxide powders by wet-chemical techniques

    Directory of Open Access Journals (Sweden)

    Vladimir V. Srdić

    2010-09-01

    Full Text Available In a recent period there is a great need for increasing the knowledge of tailoring the innovative procedures for the synthesis of electroceramic nanopowders and materials with improved quality for specific application. In order to produce electroceramics with desirable microstructure and properties, synthesis of stoichiometric, ultra-fine and agglomerate free powders with narrow size distributions is one of the most important steps. Within this scope, in the present paper we summarize our recent results on direct synthesis of some important perovskites and ferrites nanopowders by wet-chemical techniques.

  5. Estabilidade oxidativa do colesterol em ovo integral em pó Oxidative stability of cholesterol in whole egg powder

    Directory of Open Access Journals (Sweden)

    Claudia Escarabajal

    2005-12-01

    Full Text Available Ovos são importantes como alimento e como matéria-prima industrial. Ao mesmo tempo, têm elevada concentração de colesterol, principalmente quando desidratado. O colesterol, por sua vez, está sujeito à oxidação durante o processamento e/ou estocagem, formando, em conseqüência, derivados oxidados com atividades tóxicas, entre as quais a aterogenicidade. Foi avaliada, neste trabalho, a estabilidade do colesterol em ovo integral em pó comercial, através da ocorrência do 7-cetocolesterol livre, quantificado por cromatografia líqüida de alta eficiência, depois da extração dos lípides totais e separação em coluna de Florisil. O 7-cetocolesterol livre ocorreu em todos os três lotes das cinco marcas analisadas de ovo integral em pó, em teor médio de 84,01±5,34 mig/g de lípides. Não foi possível indicar clara evolução da oxidação do colesterol durante a estocagem do produto por até 224 dias, à temperatura ambiente; no entanto, uma correlação significativa (r = 0,8093 pôde ser observada entre o 7-cetocolesterol livre e as substâncias reativas ao ácido tiobarbitúrico (TBARS.Eggs are important as food and also as raw material for the food industry. However they show high levels of cholesterol, mainly when they are dehydrated. Cholesterol can be oxidized during processing and/or storage to cholesterol oxides which are toxics. The oxidative stability of cholesterol in commercial whole egg powder was evaluated by the occurrence of "free" 7-ketocholesterol (free 7-k quantified by high-performance liquid chromatography, after total lipid extraction and separation on Florisil column. Free 7-k occurred in all samples analyzed (three different lots from five brands, 84,01±5,34 mug/g lipid (n=5. It was not possible to accompany cholesterol oxidation in whole egg powder stored until 224 days, at room temperature, but a significant correlation (r=0.8093 was observed between free 7-k and thiobarbituric acid reactive substances

  6. Fabrication of water-dispersible single-walled carbon nanotube powder using N-methylmorpholine N-oxide.

    Science.gov (United States)

    Choi, Hyejun; Woo, Jong Seok; Han, Joong Tark; Park, Soo-Young

    2017-09-13

    Dispersion of nanocarbon materials in liquid media is one of prerequisites for practical applications via solution processing such as spraying, printing, spinning, etc. Here we report that water-dispersible single-walled carbon nanotubes (SWCNTs) were prepared through successive treatments with chlorosulfuric acid (CSA)/H2O2 and N-methylmorpholine N-oxide (NMO) monohydrate. The powder of the CSA/H2O2- and NMO-treated SWCNTs (N-SWCNTs) could be readily redispersed in water in concentrations as high as 1 g L-1 without requiring a dispersant. The mechanism responsible for the high dispersity of the N-SWCNT powder in polar solvents, including water, was elucidated based on the high polarity of the NMO molecule. In order to highlight the wide applicability of the N-SWCNTs, they were used successfully to prepare conducting thin films by spray-coating plastic substrates with an aqueous hybrid solution containing the N-SWCNTs and Ag nanowires (NWs). In addition, a flexible, large-area thin-film heater was prepared based on the N-SWCNT/AgNW hybrid film with a transmittance of 93% and sheet resistance of 30 Ω sq-1. © 2017 IOP Publishing Ltd.

  7. Modeling of evaporation and oxidation phenomena in plasma spraying of metal powders

    Science.gov (United States)

    Zhang, Hanwei

    Plasma spraying of metals in air is usually accompanied by evaporation and oxidation of the sprayed material. Optimization of the spraying process must ensure that the particles are fully molten during their short residence time in the plasma jet and prior to hitting the substrate, but not overheated to minimize evaporation losses. In atmospheric plasma spraying (ASP), it is also clearly desirable to be able to control the extent of oxide formation. The objective of this work to develop an overall mathematical model of the oxidization and volatilization phenomena involved in the plasma-spraying of metallic particles in air atmosphere. Four models were developed to simulate the following aspects of the atmospheric plasma spraying (APS) process: (a) the particle trajectories and the velocity and temperature profiles in an Ar-H 2 plasma jet, (b) the heat and mass transfer between particles and plasma jet, (c) the interaction between the evaporation and oxidation phenomena, and (d) the oxidation of liquid metal droplets. The resulting overall model was generated by adapting the computational fluid dynamics code FIDAP and was validated by experimental measurements carried out at the collaborating plasma laboratory of the University of Limoges. The thesis also examined the environmental implications of the oxidization and volatilization phenomena in the plasma spraying of metals. The modeling results showed that the combination of the standard k-s model of turbulence and the Boussinesq eddy-viscosity model provided a more accurate prediction of plasma gas behavior. The estimated NOx generation levels from APS were lower than the U.S.E.P.A. emission standard. Either enhanced evaporation or oxidation can occur on the surface of the metal particles and the relative extent is determined by the process parameters. Comparatively, the particle size has the greatest impact on both evaporation and oxidation. The extent of particle oxidation depends principally on gas

  8. Structural and optical properties of nanocrystalline pure and indium doped tin oxide powders synthesized in a single step by flame spray pyrolysis

    Science.gov (United States)

    Silvister Raju, M. J.; Bhattacharya, S. S.

    2017-07-01

    Phase pure tin oxide (SnO2) and indium doped SnO2 nanocrystalline powders were synthesized in a single step by a flame spray pyrolysis method. The as-synthesized powders were characterized by standard techniques of x-ray diffraction, scanning and transmission electron microscopy, x-ray photoelectron spectroscopy and absorption spectroscopy. Using x-ray diffraction, it was established that the powders had the rutile (cassiterite) structure with tetragonal unit cells in the space group P42/mnm. Using the Rietveld refinement method, structural analysis was carried out in order to obtain the lattice parameters, volume and density. X-ray photoelectron spectra confirmed the presence of indium in the doped samples. Absorption spectra revealed that the powders were transparent to the visible spectrum with a sharp absorption below 350 nm. Energy bandgaps, estimated by Tauc plots, established that increasing the doping concentration reduced the bandgap.

  9. Sodium-ion storage properties of nickel sulfide hollow nanospheres/reduced graphene oxide composite powders prepared by a spray drying process and the nanoscale Kirkendall effect

    Science.gov (United States)

    Park, G. D.; Cho, J. S.; Kang, Y. C.

    2015-10-01

    Spray-drying and the nanoscale Kirkendall diffusion process are used to prepare nickel sulfide hollow nanospheres/reduced graphene oxide (rGO) composite powders with excellent Na-ion storage properties. Metallic Ni nanopowder-decorated rGO powders, formed as intermediate products, are transformed into composite powders of nickel sulfide hollow nanospheres/rGO with mixed crystal structures of Ni3S2 and Ni9S8 phases by the sulfidation process under H2S gas. Nickel sulfide/rGO composite powders with the main crystal structure of Ni3S2 are also prepared as comparison samples by the direct sulfidation of nickel acetate-graphene oxide (GO) composite powders obtained by spray-drying. In electrochemical properties, the discharge capacities at the 150th cycle of the nickel sulfide/rGO composite powders prepared by sulfidation of the Ni/rGO composite and nickel acetate/GO composite powders at a current density of 0.3 A g-1 are 449 and 363 mA h g-1, respectively; their capacity retentions, calculated from the tenth cycle, are 100 and 87%. The nickel sulfide hollow nanospheres/rGO composite powders possess structural stability over repeated Na-ion insertion and extraction processes, and also show excellent rate performance for Na-ion storage.Spray-drying and the nanoscale Kirkendall diffusion process are used to prepare nickel sulfide hollow nanospheres/reduced graphene oxide (rGO) composite powders with excellent Na-ion storage properties. Metallic Ni nanopowder-decorated rGO powders, formed as intermediate products, are transformed into composite powders of nickel sulfide hollow nanospheres/rGO with mixed crystal structures of Ni3S2 and Ni9S8 phases by the sulfidation process under H2S gas. Nickel sulfide/rGO composite powders with the main crystal structure of Ni3S2 are also prepared as comparison samples by the direct sulfidation of nickel acetate-graphene oxide (GO) composite powders obtained by spray-drying. In electrochemical properties, the discharge capacities at the

  10. Copper Benzenetricarboxylate Metal-Organic Framework Nucleation Mechanisms on Metal Oxide Powders and Thin Films formed by Atomic Layer Deposition.

    Science.gov (United States)

    Lemaire, Paul C; Zhao, Junjie; Williams, Philip S; Walls, Howard J; Shepherd, Sarah D; Losego, Mark D; Peterson, Gregory W; Parsons, Gregory N

    2016-04-13

    Chemically functional microporous metal-organic framework (MOF) crystals are attractive for filtration and gas storage applications, and recent results show that they can be immobilized on high surface area substrates, such as fiber mats. However, fundamental knowledge is still lacking regarding initial key reaction steps in thin film MOF nucleation and growth. We find that thin inorganic nucleation layers formed by atomic layer deposition (ALD) can promote solvothermal growth of copper benzenetricarboxylate MOF (Cu-BTC) on various substrate surfaces. The nature of the ALD material affects the MOF nucleation time, crystal size and morphology, and the resulting MOF surface area per unit mass. To understand MOF nucleation mechanisms, we investigate detailed Cu-BTC MOF nucleation behavior on metal oxide powders and Al2O3, ZnO, and TiO2 layers formed by ALD on polypropylene substrates. Studying both combined and sequential MOF reactant exposure conditions, we find that during solvothermal synthesis ALD metal oxides can react with the MOF metal precursor to form double hydroxy salts that can further convert to Cu-BTC MOF. The acidic organic linker can also etch or react with the surface to form MOF from an oxide metal source, which can also function as a nucleation agent for Cu-BTC in the mixed solvothermal solution. We discuss the implications of these results for better controlled thin film MOF nucleation and growth.

  11. Elimination of microcystin-LR and residual Mn species using permanganate and powdered activated carbon: Oxidation products and pathways.

    Science.gov (United States)

    Jeong, Boyoung; Oh, Min-Seok; Park, Hyun-Mee; Park, Chanhyuk; Kim, Eun-Ju; Hong, Seok Won

    2017-05-01

    The oxidation of microcystin-LR (MC-LR) in deionized water (DI) and river water using potassium permanganate (KMnO4) at a neutral pH and at 23 ± 2 °C was investigated. These two aqueous systems (i.e., DI and river water) gave comparable second-order rate constants (289.9 and 285.5 M(-1)s(-1) (r(2) > 0.99), respectively), which confirmed the effectiveness of this oxidation process for the treatment of natural surface water. The presence of either humic or fulvic acid reduced the removal efficiency of MC-LR, with the latter exhibiting a greater inhibitory effect. Monitoring of MC-LR and residual Mn(2+) levels with adding KMnO4 (1 mg/L) and powdered activated carbon (PAC, 5-20 mg L(-1)) before and during coagulation, respectively, revealed that 60 min of permanganate pre-oxidation followed by coagulant addition with PAC was the most effective approach for reducing both levels below limits stated by WHO guidelines. The MC-LR degradation products were the result of oxidation occurring at the diene and aromatic moieties of the Adda (3-amino-9-methoxy-2,6,8-trimethyl-10-phenyldeca-4,6-dienoic acid) side-chain, in addition to amine bond hydrolysis of the Mdha (N-methyldehydroalanine) moiety. Several toxic by-products with an intact Adda chain were observed during the reaction, but completely disappeared after 60 min. This further supports the conclusion that sufficient contact time with permanganate (i.e., >60 min) is essential to reducing the residual toxicity and maximizing the efficiency of MC-LR oxidation when treating raw water. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. 119Sn Mössbauer spectroscopic study of nanometric tin dioxide powders prepared by pyrolysis of organotin oxides

    Science.gov (United States)

    Pereira, A. G.; Porto, A. O.; de Lima, G. M.; Siebald, H. G. L.; Ardisson, J. D.

    2003-07-01

    This paper reports the results of 119Sn Mössbauer Spectroscopy of residues from the pyrolysis of Sn 3O 3Bu 6 ( 1) and Sn 4O 6Bu 4 ( 2) (Bu= n-butyl) in air, O 2, and N 2. The isomer shift and quadrupole splitting parameters of the samples allowed the identification of the tin oxidation states, as well as the number of non-equivalent coordinated tin sites. The result of the 119Sn Mössbauer study correlates perfectly with those of X-ray electron probe microanalysis, scanning electron microscopy and X-ray powder diffraction for the formation of pure SnO 2 from the decomposition of ( 1) and ( 2) in air or O 2. However, in N 2, evidences suggest the formation of a mixture of SnO 2 and SnO.

  13. Stability of Y-Ti-O nanoparticles during laser deposition of oxide dispersion strengthened steel powder

    Science.gov (United States)

    Euh, Kwangjun; Arkhurst, Barton; Kim, Il Hyun; Kim, Hyun-Gil; Kim, Jeoung Han

    2017-09-01

    This study investigated the feasibility of a direct energy deposition process for fabrication of oxide dispersion strengthened steel cladding. The effect of the laser working power and scan speed on the microstructural stability of oxide nanoparticles in the deposition layer was examined. Y-Ti-O type oxide nanoparticles with a mean diameter of 45 nm were successfully dispersed by the laser deposition process. The laser working power significantly affected nanoparticle size and number density. A high laser power with a low scan speed seriously induced particle coarsening and agglomeration. Compared with bulk oxide dispersion strengthened steel, the hardness of the laser deposition layer was much lower because of a relatively coarse particle and grain size. Formation mechanism of nanoparticles during laser deposition was discussed.

  14. Extraction and optical fluorescence method for the measurement of trace beryllium in soils.

    Science.gov (United States)

    Agrawal, Anoop; Cronin, John P; Agrawal, Akshay; Tonazzi, Juan C L; Adams, Lori; Ashley, Kevin; Brisson, Michael J; Duran, Brandy; Whitney, Gary; Burrell, Anthony K; McCleskey, T Mark; Robbins, James; White, Kenneth T

    2008-03-15

    Beryllium metal and beryllium oxide are important industrial materials used in a variety of applications in the electronics, nuclear energy, and aerospace industries. These materials are highly toxic, they must be disposed of with care, and exposed workers need to be protected. Recently, a new analytical method was developed that uses dilute ammonium bifluoride for extraction of beryllium and a high quantum yield optical fluorescence reagent to determine trace amounts of beryllium in airborne and surface samples. The sample preparation and analysis procedure was published by both ASTM International and the National Institute for Occupational Safety and Health (NIOSH). The main advantages of this method are its sensitivity, simplicity, use of lower toxicity materials, and low capital costs. Use of the technique for analyzing soils has been initiated to help meet a need at several of the U.S. Department of Energy legacy sites. So far this work has mainly concentrated on developing a dissolution protocol for effectively extracting beryllium from a variety of soils and sediments so that these can be analyzed by optical fluorescence. Certified reference materials (CRM) of crushed rock and soils were analyzed for beryllium content using fluorescence, and results agree quantitatively with reference values.

  15. Preparation and Anti-oxidation Property of Flaky Silver Covered Copper Powder%片状铜粉镀银及抗氧化性能研究

    Institute of Scientific and Technical Information of China (English)

    宋曰海; 马丽杰

    2013-01-01

    采用置换还原法在片状铜粉上镀银.对铜粉镀银制备过程及抗氧化性能做了研究.实验结果表明,在铜粉表面首先发生置换反应,生成点缀式银颗粒,之后银颗粒长大,不完全的包覆在铜粉表面,溶液中过量的银离子在还原剂的作用下,表面银层进一步生长,得到完全包覆银的铜粉.通过X-射线衍射分析,片状铜粉镀银层表面未见氧化物,所得粉末表层结构致密.铜粉镀银层具有良好的抗高温氧化性.%Flaky silver covered copper powder was prepared by displacement reaction.Preparation process and anti-oxidation property of the silver covered copper powder were studied.Experimental results showed that interspersed silver particles generated on the surface of copper powder by displacement reaction at first,and then the silver particles grew up and coated the copper powder incompletely.With excess silver ions in solution,silver layer grew further by reduction reaction and covered the copper powder completely.By XRD analysis,no oxide was detected on the surface of silver covered copper powder,the silver covered copper powder has dense surface structure and good high temperature oxidation resistance.

  16. Characterization of phagolysosomal simulant fluid for study of beryllium aerosol particle dissolution.

    Science.gov (United States)

    Stefaniak, A B; Guilmette, R A; Day, G A; Hoover, M D; Breysse, P N; Scripsick, R C

    2005-02-01

    A simulant of phagolysosomal fluid is needed for beryllium particle dissolution research because intraphagolysosomal dissolution is believed to be a necessary step in the cellular immune response associated with development of chronic beryllium disease. Thus, we refined and characterized a potassium hydrogen phthalate (KHP) buffered solution with pH 4.55, termed phagolysosomal simulant fluid (PSF), for use in a static dissolution technique. To characterize the simulant, beryllium dissolution in PSF was compared to dissolution in the J774A.1 murine cell line. The effects of ionic composition, buffer strength, and the presence of the antifungal agent alkylbenzyldimethylammonium chloride (ABDC) on beryllium dissolution in PSF were evaluated. Beryllium dissolution in PSF was not different from dissolution in the J774A.1 murine cell line (p = 0.78) or from dissolution in another simulant having the same pH but different ionic composition (p = 0.73). A buffer concentration of 0.01-M KHP did not appear adequate to maintain pH under all conditions. There was no difference between dissolution in PSF with 0.01-M KHP and 0.02-M KHP (p = 0.12). At 0.04-M KHP, beryllium dissolution was increased relative to 0.02-M KHP (p = 0.02). Use of a 0.02-M KHP buffer concentration in the standard formulation for PSF provided stability in pH without alteration of the dissolution rate. The presence of ABDC did not influence beryllium dissolution in PSF (p = 0.35). PSF appears to be a useful and appropriate model of in vitro beryllium dissolution when using a static dissolution technique. In addition, the critical approach used to evaluate and adjust the composition of PSF may serve as a framework for characterizing PSF to study dissolution of other metal and oxide particles.

  17. Nanostructured cobalt oxides (Co{sub 3}O{sub 4} and CoO) and metallic Co powders synthesized by the solution combustion method

    Energy Technology Data Exchange (ETDEWEB)

    Toniolo, J.C., E-mail: juliano_toniolo@hotmail.com [Department of Material Engineering, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99, 705, Downtown, 90035190 Porto Alegre, RS (Brazil); Takimi, A.S.; Bergmann, C.P. [Department of Material Engineering, Federal University of Rio Grande do Sul, Av. Osvaldo Aranha 99, 705, Downtown, 90035190 Porto Alegre, RS (Brazil)

    2010-06-15

    The combustion synthesis technique using glycine and urea as fuels and cobalt nitrate as an oxidizer is capable of producing well-crystallized Co{sub 3}O{sub 4}, CoO, as well as metallic Co powders. An interpretation based on the thermodynamic viewpoint and the measurement of the combustion temperatures during the reactions occurring for various fuel-to-oxidant ratios was proposed for a study of the nature of combustion and its correlation with the characteristics of as-synthesized powders. The largest measured specific surface area of the powders was 36 m{sup 2}/g at a 0.14 glycine-to-nitrate ratio. The crystallites were nano-sized ranging from approximately 23 to 90 nm.

  18. Beryllium particulate exposure and disease relations in a beryllium machining plant.

    Science.gov (United States)

    Kelleher, P C; Martyny, J W; Mroz, M M; Maier, L A; Ruttenber, A J; Young, D A; Newman, L S

    2001-03-01

    We examined the relationship between exposure to beryllium and the presence of beryllium sensitization (BeS) and chronic beryllium disease (CBD) in a cohort of workers in a beryllium precision machining facility. Twenty workers with BeS or CBD (cases) were compared with 206 worker-controls in a case-control study. Exposure for each job title was measured using cascade impactors placed in the workers' breathing zone to measure total beryllium exposure and exposure to particles 0.20. In conclusion, increased cumulative and LTW exposure to total and respirable beryllium was observed in workers with CBD or BeS compared with the controls. These results support efforts to control beryllium exposure in the workplace.

  19. Nuclear forensic analysis of uranium oxide powders interdicted in Victoria, Australia

    Energy Technology Data Exchange (ETDEWEB)

    Kristo, Michael Joseph [Lawrence Livermore National Laboratory, Livermore, CA (United States); Keegan, Elizabeth; Colella, Michael [Australian Nuclear Science and Technology Organisation, Kirrawee, NSW (Australia); and others

    2015-07-01

    Nuclear forensic analysis was conducted on two uranium samples confiscated during a police investigation in Victoria, Australia. The first sample, designated NSR-F-270409-1, was a depleted uranium powder of moderate purity (∝ 1000 μg/g total elemental impurities). The chemical form of the uranium was a compound similar to K{sub 2}(UO{sub 2}){sub 3}O{sub 4} . 4H{sub 2}O. While aliquoting NSR-F-270409-1 for analysis, the body and head of a Tineid moth was discovered in the sample. The second sample, designated NSR-F-270409-2, was also a depleted uranium powder. It was of reasonably high purity (∝ 380 μg/g total elemental impurities). The chemical form of the uranium was primarily UO{sub 3} . 2H{sub 2}O, with minor phases of U{sub 3}O{sub 8} and UO{sub 2}. While aliquoting NSR-F-270409-2 for analysis, a metal staple of unknown origin was discovered in the sample. The presence of {sup 236}U and {sup 232}U in both samples indicates that the uranium feed stocks for these samples experienced a neutron flux at some point in their history. The reactor burn-up calculated from the isotopic composition of the uranium is consistent with that of spent fuel from natural uranium (NU) fueled Pu production. These nuclear forensic conclusions allow us to categorically exclude Australia as the origin of the material and greatly reduce the number of candidate sources.

  20. Investigation of beryllium/steam interaction

    Energy Technology Data Exchange (ETDEWEB)

    Chekhonadskikh, A.M.; Vurim, A.D.; Vasilyev, Yu.S.; Pivovarov, O.S. [Inst. of Atomic Energy National Nuclear Center of the Republic of Kazakstan Semipalatinsk (Kazakhstan); Shestakov, V.P.; Tazhibayeva, I.L.

    1998-01-01

    In this report program on investigations of beryllium emissivity and transient processes on overheated beryllium surface attacked by water steam to be carried out in IAE NNC RK within Task S81 TT 2096-07-16 FR. The experimental facility design is elaborated in this Report. (author)

  1. Modeling of hydrogen interactions with beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Longhurst, G.R. [Lockheed Martin Idaho Technologies Co., Idaho Falls, ID (United States)

    1998-01-01

    In this paper, improved mathematical models are developed for hydrogen interactions with beryllium. This includes the saturation effect observed for high-flux implantation of ions from plasmas and retention of tritium produced from neutronic transmutations in beryllium. Use of the models developed is justified by showing how they can replicated experimental data using the TMAP4 tritium transport code. (author)

  2. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2015-01-01

    In order to validate the evaluated nuclear data on beryllium,a benchmark experiment has been performed at China Institution of Atomic Energy(CIAE).Neutron leakage spectra from pure beryllium slab samples(10cm×10cm×11cm)were measured at 61°and 121°using timeof-

  3. Diffusion-bonded beryllium aluminum optical structures

    Science.gov (United States)

    Grapes, Thomas F.

    2003-12-01

    Beryllium aluminum material can present significant advantages for optical support structures. A likely advantage of beryllium aluminum compared to aluminum or titanium for such structures is its higher specific stiffness. However, beryllium aluminum material is significantly more expensive than most competing materials. The cost problem with beryllium aluminum is exacerbated if fabrication methods that result in near net shape parts are not used. Near net shape methods result in the least amount of material "thrown away" in the fabrication process. Casting is a primary example of near net shape manufacturing that is appropriate for some optical support structures. Casting aluminum, and other materials as well, is common. Casting of beryllium aluminum is very difficult, however, and has not had significant success. Diffusion bonding - a different approach for achieving near net shape beryllium aluminum optical support structures, was pursued and accomplished. Diffusion bonding is a term used to describe the joining of solid metal pieces under high temperature and pressure, but without melting. Three different optical support structures were designed and built of beryllium aluminum using diffusion bonding. Relatively small solid beryllium aluminum pieces were arranged together and then joined under hot isostatic pressure conditions. The resulting relatively large pressure bonded part was then machined to achieve the final product. Significant cost savings as compared to machining the part from a solid block were realized. Difficulties achieving diffusion bonds in complex joints were experienced and addressed.

  4. Oxidation and the Effects of High Temperature Exposures on Notched Fatigue Life of an Advanced Powder Metallurgy Disk Superalloy

    Science.gov (United States)

    Sudbrack, Chantal K.; Draper, Susan L.; Gorman, Timothy T.; Telesman, Jack; Gab, Timothy P.; Hull, David R.

    2012-01-01

    Oxidation and the effects of high temperature exposures on notched fatigue life were considered for a powder metallurgy processed supersolvus heat-treated ME3 disk superalloy. The isothermal static oxidation response at 704 C, 760 C, and 815 C was consistent with other chromia forming nickel-based superalloys: a TiO2-Cr2O3 external oxide formed with a branched Al2O3 internal subscale that extended into a recrystallized - dissolution layer. These surface changes can potentially impact disk durability, making layer growth rates important. Growth of the external scales and dissolution layers followed a cubic rate law, while Al2O3 subscales followed a parabolic rate law. Cr- rich M23C6 carbides at the grain boundaries dissolved to help sustain Cr2O3 growth to depths about 12 times thicker than the scale. The effect of prior exposures was examined through notched low cycle fatigue tests performed to failure in air at 704 C. Prior exposures led to pronounced debits of up to 99 % in fatigue life, where fatigue life decreased inversely with exposure time. Exposures that produced roughly equivalent 1 m thick external scales at the various isotherms showed statistically equivalent fatigue lives, establishing that surface damage drives fatigue debit, not exposure temperature. Fractographic evaluation indicated the failure mode for the pre-exposed specimens involved surface crack initiations that shifted with exposure from predominately single intergranular initiations with transgranular propagation to multi-initiations from the cracked external oxide with intergranular propagation. Weakened grain boundaries at the surface resulting from the M23C6 carbide dissolution are partially responsible for the intergranular cracking. Removing the scale and subscale while leaving a layer where M23C6 carbides were dissolved did not lead to a significant fatigue life improvement, however, also removing the M23C6 carbide dissolution layer led to nearly full recovery of life, with a

  5. L{sub g} = 100 nm In{sub 0.7}Ga{sub 0.3}As quantum well metal-oxide semiconductor field-effect transistors with atomic layer deposited beryllium oxide as interfacial layer

    Energy Technology Data Exchange (ETDEWEB)

    Koh, D., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States); SEMATECH, Inc., Albany, New York 12203 (United States); Kwon, H. M. [Department of Electronics Engineering, Chungnam National University, Daejeon 305-764 (Korea, Republic of); Kim, T.-W., E-mail: dh.koh@utexas.edu, E-mail: Taewoo.Kim@sematech.org; Veksler, D.; Gilmer, D.; Kirsch, P. D. [SEMATECH, Inc., Albany, New York 12203 (United States); Kim, D.-H. [SEMATECH, Inc., Albany, New York 12203 (United States); GLOBALFOUNDRIES, Malta, New York 12020 (United States); Hudnall, Todd W. [Department of Chemistry and Biochemistry, Texas State University, San Marcos, Texas, 78666 (United States); Bielawski, Christopher W. [Department of Chemistry and Biochemistry, The University of Texas at Austin, Austin, Texas 78712 (United States); Maszara, W. [GLOBALFOUNDRIES, Santa Clara, California 95054 (United States); Banerjee, S. K. [Department of Electrical and Computer Engineering, Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

    2014-04-21

    In this study, we have fabricated nanometer-scale channel length quantum-well (QW) metal-oxide-semiconductor field effect transistors (MOSFETs) incorporating beryllium oxide (BeO) as an interfacial layer. BeO has high thermal stability, excellent electrical insulating characteristics, and a large band-gap, which make it an attractive candidate for use as a gate dielectric in making MOSFETs. BeO can also act as a good diffusion barrier to oxygen owing to its small atomic bonding length. In this work, we have fabricated In{sub 0.53}Ga{sub 0.47}As MOS capacitors with BeO and Al{sub 2}O{sub 3} and compared their electrical characteristics. As interface passivation layer, BeO/HfO{sub 2} bilayer gate stack presented effective oxide thickness less 1 nm. Furthermore, we have demonstrated In{sub 0.7}Ga{sub 0.3}As QW MOSFETs with a BeO/HfO{sub 2} dielectric, showing a sub-threshold slope of 100 mV/dec, and a transconductance (g{sub m,max}) of 1.1 mS/μm, while displaying low values of gate leakage current. These results highlight the potential of atomic layer deposited BeO for use as a gate dielectric or interface passivation layer for III–V MOSFETs at the 7 nm technology node and/or beyond.

  6. Beryllium coating on Inconel tiles

    Energy Technology Data Exchange (ETDEWEB)

    Bailescu, V.; Burcea, G.; Lungu, C.P.; Mustata, I.; Lungu, A.M. [Association EURATOM-MEC Romania, National Institute of Laser, Plasma and Radiation Physics, Bucharest (Romania); Rubel, M. [Alfven Laboratory, Royal Institute of Technology, Stockholm (Sweden); Coad, J.P. [Culham Science Centre, EURATOM-UKAEA Fusion Association, Abingdon, OX, Oxon (United Kingdom); Matthews, G.; Pedrick, L.; Handley, R. [UKAEA Fusion, Association Euratom-UKAEA, Culham Science and Engineering Centre, OX 3DB ABINGDON, Oxon (United Kingdom)

    2007-07-01

    Full text of publication follows: The Joint European Torus (JET) is a large experimental nuclear fusion device. Its aim is to confine and study the behaviour of plasma in conditions and dimensions approaching those required for a fusion reactor. The plasma is created in the toroidal shaped vacuum vessel of the machine in which it is confined by magnetic fields. In preparation for ITER a new ITER-like Wall (ILW) will be installed on Joint European Torus (JET), a wall not having any carbon facing the plasma [1]. In places Inconel tiles are to be installed, these tiles shall be coated with Beryllium. MEdC represented by the National Institute for Laser, Plasma and Radiation Physics, Magurele, Bucharest and in direct cooperation with Nuclear Fuel Plant Pitesti started to coat Inconel tiles with 8 {mu}m of Beryllium in accordance with the requirements of technical specification and fit for installation in the JET machine. This contribution provides an overview of the principles of manufacturing processes using thermal evaporation method in vacuum and the properties of the prepared coatings. The optimization of the manufacturing process (layer thickness, structure and purity) has been carried out on Inconel substrates (polished and sand blasted) The results of the optimization process and analysis (SEM, TEM, XRD, Auger, RBS, AFM) of the coatings will be presented. Reference [1] Takeshi Hirai, H. Maier, M. Rubel, Ph. Mertens, R. Neu, O. Neubauer, E. Gauthier, J. Likonen, C. Lungu, G. Maddaluno, G. F. Matthews, R. Mitteau, G. Piazza, V. Philipps, B. Riccardi, C. Ruset, I. Uytdenhouwen, R and D on full tungsten divertor and beryllium wall for JET TIER-like Wall Project, 24. Symposium on Fusion Technology - 11-15 September 2006 -Warsaw, Poland. (authors)

  7. 40 CFR 421.150 - Applicability: Description of the primary beryllium subcategory.

    Science.gov (United States)

    2010-07-01

    ... primary beryllium subcategory. 421.150 Section 421.150 Protection of Environment ENVIRONMENTAL PROTECTION... CATEGORY Primary Beryllium Subcategory § 421.150 Applicability: Description of the primary beryllium... beryllium by primary beryllium facilities processing beryllium ore concentrates or beryllium hydroxide...

  8. Direct extraction of palladium and silver from waste printed circuit boards powder by supercritical fluids oxidation-extraction process.

    Science.gov (United States)

    Liu, Kang; Zhang, Zhiyuan; Zhang, Fu-Shen

    2016-11-15

    The current study was carried out to develop an environmental benign process for direct recovery of palladium (Pd) and silver (Ag) from waste printed circuit boards (PCBs) powder. The process ingeniously combined supercritical water oxidation (SCWO) and supercritical carbon dioxide (Sc-CO2) extraction techniques. SCWO treatment could effectively enrich Pd and Ag by degrading non-metallic component, and a precious metal concentrate (PMC) could be obtained, in which the enrichment factors of Pd and Ag reached 5.3 and 4.8, respectively. In the second stage, more than 93.7% Pd and 96.4% Ag could be extracted from PMC by Sc-CO2 modified with acetone and KI-I2 under optimum conditions. Mechanism study indicated that Pd and Ag extraction by Sc-CO2 was a complicated physiochemical process, involving oxidation, complexation, anion exchange, mass transfer and migration approaches. Accordingly, this study established a benign and effective process for selective recovery of dispersal precious metals from waste materials.

  9. An in situ powder neutron diffraction study of nano-precipitate formation during processing of oxide-dispersion-strengthened ferritic steels

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Hongtao, E-mail: hongtao.zhang@materials.ox.ac.uk [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Gorley, Michael J. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Chong, Kok Boon; Fitzpatrick, Michael E. [Materials Engineering, The Open University, Walton Hall, Milton Keynes MK7 6AA (United Kingdom); Roberts, Steve G.; Grant, Patrick S. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom)

    2014-01-05

    Highlights: • In situ powder neutron diffraction to study precipitate formation in ODS steel. • First real time observation of nano-precipitate formation during processing. • Y{sub 2}O{sub 3} particles were fully dissolved into steel matrix during mechanical alloy. • The precipitation occurred during annealing of as-milled powder above 900 °C. -- Abstract: The evolution of phases in a Fe–14Cr–10Y{sub 2}O{sub 3} (wt%) oxide-dispersion-strengthened ferritic steel during mechanical alloying (MA) and subsequent annealing was studied by high resolution powder neutron diffraction, with emphasis on the kinetics of oxide-based nano-precipitate formation. Y{sub 2}O{sub 3} particles were completely dissolved into the ferritic matrix during MA. The formation of nano-precipitates was then observed by in situ thermo-diffraction experiments during annealing of as-milled powder above 900 °C, supported by scanning electron microscopy. This revealed nano-precipitate coarsening with increasing annealing temperature. Powder microhardness was measured at various processing stages, and hardness changes are discussed in terms of the measured phase fractions, crystallite size and lattice strain at different temperatures and times.

  10. Assessment of Lead and Beryllium deposition and adsorption to exposed stream channel sediments

    Science.gov (United States)

    Pawlowski, E.; Karwan, D. L.

    2016-12-01

    The fallout radionuclides Beryllium-7 and Lead-210 have been shown to be effective sediment tracers that readily bind to particles. The adsorption capacity has primarily been assessed in marine and coastal environments with an important assumption being the radionuclides' uniform spatial distribution as fallout from the atmosphere. This neglects localized storm events that may mine stratospheric reserves creating variable distributions. To test this assumption atmospheric deposition is collected at the University of Minnesota St. Paul Campus weather station during individual storm events and subsequently analyzed for Beryllium-7 and Lead-210. This provides further insight into continental effects on radionuclide deposition. The study of Beryllium-7 and Lead-210 adsorption in marine and coastal environments has provided valuable insights into the processes that influence the element's binding to particles but research has been limited in freshwater river environments. These environments have greater variation in pH, iron oxide content, and dissolved organic carbon (DOC) levels which have been shown to influence the adsorption of Beryllium and Lead in marine settings. This research assesses the adsorption of Beryllium and Lead to river sediments collected from in-channel deposits by utilizing batch experiments that mimic the stream conditions from which the deposits were collected. Soils were collected from Difficult Run, VA, and the West Swan River, MN. Agitating the soils in a controlled solution of known background electrolyte and pH while varying the level of iron oxides and DOC in step provides a better understanding of the sorption of Lead and Beryllium under the conditions found within freshwater streams. Pairing the partitioning of Lead and Beryllium with their inputs to streams via depositional processes, from this study and others, allows for their assessment as possible sediment tracers and age-dating tools within the respective watersheds.

  11. Postirradiation examination of beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)

    1998-03-01

    Postirradiation examinations of COBRA-1A beryllium pebbles irradiated in the EBR-II fast reactor at neutron fluences which generated 2700--3700 appm helium have been performed. Measurements included density change, optical microscopy, scanning electron microscopy, and transmission electron microscopy. The major change in microstructure is development of unusually shaped helium bubbles forming as highly non-equiaxed thin platelet-like cavities on the basal plane. Measurement of the swelling due to cavity formation was in good agreement with density change measurements.

  12. Technical issues for beryllium use in fusion blanket applications

    Energy Technology Data Exchange (ETDEWEB)

    McCarville, T.J.; Berwald, D.H.; Wolfer, W.; Fulton, F.J.; Lee, J.D.; Maninger, R.C.; Moir, R.W.; Beeston, J.M.; Miller, L.G.

    1985-01-01

    Beryllium is an excellent non-fissioning neutron multiplier for fusion breeder and fusion electric blanket applications. This report is a compilation of information related to the use of beryllium with primary emphasis on the fusion breeder application. Beryllium resources, production, fabrication, properties, radiation damage and activation are discussed. A new theoretical model for beryllium swelling is presented.

  13. In situ X-ray powder diffraction studies of the synthesis of graphene oxide and formation of reduced graphene oxide

    Science.gov (United States)

    Storm, Mie Møller; Johnsen, Rune E.; Norby, Poul

    2016-08-01

    Graphene oxide (GO) and reduced graphene oxide (rGO) are important materials in a wide range of fields. The modified Hummers methods, for synthesizing GO, and subsequent thermal reduction to rGO, are often employed for production of rGO. However, the mechanism behinds these syntheses methods are still unclear. We present an in situ X-ray diffraction study of the synthesis of GO and thermal reduction of GO. The X-ray diffraction revealed that the Hummers method includes an intercalation state and finally formation of additional crystalline material. The formation of GO is observed during both the intercalation and the crystallization stage. During thermal reduction of GO three stages were observed: GO, a disordered stage, and the rGO stage. The appearance of these stages depends on the heating ramp. The aim of this study is to provide deeper insight into the chemical and physical processes during the syntheses.

  14. In situ X-ray powder diffraction studies of the synthesis of graphene oxide and formation of reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Storm, Mie Møller, E-mail: mmst@dtu.dk; Johnsen, Rune E.; Norby, Poul

    2016-08-15

    Graphene oxide (GO) and reduced graphene oxide (rGO) are important materials in a wide range of fields. The modified Hummers methods, for synthesizing GO, and subsequent thermal reduction to rGO, are often employed for production of rGO. However, the mechanism behinds these syntheses methods are still unclear. We present an in situ X-ray diffraction study of the synthesis of GO and thermal reduction of GO. The X-ray diffraction revealed that the Hummers method includes an intercalation state and finally formation of additional crystalline material. The formation of GO is observed during both the intercalation and the crystallization stage. During thermal reduction of GO three stages were observed: GO, a disordered stage, and the rGO stage. The appearance of these stages depends on the heating ramp. The aim of this study is to provide deeper insight into the chemical and physical processes during the syntheses. - Graphical abstract: In situ X-ray diffraction results for of the modified Hummers synthesis and the thermal reduction of graphene oxide, revealing three stages for both syntheses as well as new GO diffraction peaks and unidentified crystalline material for the Hummers synthesis and a disordered stage for the thermal reduction of graphene oxide. Display Omitted - Highlights: • Hummers synthesis consists of three stages: dissolution, intercalation and crystal. • GO is produced early on during the synthesis and display new diffraction peaks. • An unidentified triclinic phase is observed for the Hummers synthesis. • Thermal reduction of GO display three stages: GO, a disordered stage and rGO. • In situ XRD indicate reformation of rGO even for fast heated thermal reduction.

  15. Investigation of ionic conductivity of lanthanum cerium oxide nano crystalline powder synthesized by co precipitation method

    Science.gov (United States)

    Tinwala, Hozefa; Shah, Patij; Siddhapara, Kirit; Shah, Dimple; Menghani, Jyoti

    2016-10-01

    Lanthanum (La) doped Ceria (CeO2) electrolyte has attracted considerable interest, as a candidate material for solid oxide fuel cells (SOFCs). The ionic conductivity of La doped CeO2 system (La2Ce2O7) nano-particles synthesized by the co-precipitation method has been investigated. The cubic fluorite structure was observed from the structural analysis of the material. Morphology of the sintered pellets are observed by scanning electron microscope (SEM), respectively. From the results of impedance spectroscopy from temperature range of room temperature to 400 °C, the oxide ion conductivity due to proton charge carrier was observed. Thermogravimetric analysis (TGA) was performed on the material to check stability of phase at high temperature.

  16. Supplementation of Syzygium cumini seed powder prevented obesity, glucose intolerance, hyperlipidemia and oxidative stress in high carbohydrate high fat diet induced obese rats.

    Science.gov (United States)

    Ulla, Anayt; Alam, Md Ashraful; Sikder, Biswajit; Sumi, Farzana Akter; Rahman, Md Mizanur; Habib, Zaki Farhad; Mohammed, Mostafe Khalid; Subhan, Nusrat; Hossain, Hemayet; Reza, Hasan Mahmud

    2017-06-02

    Obesity and related complications have now became epidemic both in developed and developing countries. Cafeteria type diet mainly composed of high fat high carbohydrate components which plays a significant role in the development of obesity and metabolic syndrome. This study investigated the effect of Syzygium cumini seed powder on fat accumulation and dyslipidemia in high carbohydrate high fat diet (HCHF) induced obese rats. Male Wistar rats were fed with HCHF diet ad libitum, and the rats on HCHF diet were supplemented with Syzygium cumini seed powder for 56 days (2.5% w/w of diet). Oral glucose tolerance test, lipid parameters, liver marker enzymes (AST, ALT and ALP) and lipid peroxidation products were analyzed at the end of 56 days. Moreover, antioxidant enzyme activities were also measured in all groups of rats. Supplementation with Syzygium cumini seed powder significantly reduced body weight gain, white adipose tissue (WAT) weights, blood glucose, serum insulin, and plasma lipids such as total cholesterol, triglyceride, LDL and HDL concentration. Syzygium cumini seed powder supplementation in HCHF rats improved serum aspartate amino transferase (AST), alanine amino transferase (ALT), and alkaline phosphatase (ALP) activities. Syzygium cumini seed powder supplementation also reduced the hepatic thiobarbituric acid reactive substances (TBARS) and elevated the antioxidant enzyme superoxide dismutase (SOD) and catalase (CAT) activities as well as increased glutathione (GSH) concentration. In addition, histological assessment showed that Syzygium cumini seed powder supplementation prevented inflammatory cell infiltration; fatty droplet deposition and fibrosis in liver of HCHFD fed rats. Our investigation suggests that Syzygium cumini seed powder supplementation prevents oxidative stress and showed anti-inflammatory and antifibrotic activity in liver of HCHF diet fed rats. In addition, Syzygium cumini seed powder may be beneficial in ameliorating insulin

  17. Fabrication of iridium oxide nanoparticles supported on activated carbon powder by flashlight irradiation for oxygen evolutions

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong-Hyun; Park, Sung-Hyeon [School of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Choi, Jinseong; Yi, Mi Hye [Eco Technology Center of the Hyundai Motor Company, 17-5 Mabuk-ro, Giheung-gu, Youngin-si, Gyeonggi-do 446-716 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima1774@gmail.com [School of Mechanical Engineering, Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2015-11-15

    Graphical abstract: Iridium supported on activated carbon was oxidized by flashlight irradiation at room temperature in ambient condition. - Highlights: • Ir was oxidized by flashlight irradiation at room temperature in ambient condition. • The Pt–IrO{sub 2}/C has a higher net current density than those of Pt–Ir/C and Pt/C. • During the flashlight process, an activated carbon was not damaged. • Flashlight irradiation purified an activated carbon by removing contaminants. - Abstract: In this study, iridium oxide (IrO{sub 2}) nanoparticles supported on activated carbon were fabricated for oxygen evolutions using a flashlight irradiation process at room temperature under ambient conditions within a few milliseconds. The fabricated IrO{sub 2} nanoparticles were decorated on the activated carbon surface and enlarged to 3.51 nm as average diameter from an initial value of 1.54 nm. The fabricated IrO{sub 2} nanoparticles were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and linear sweep voltammetry (LSV) for the oxygen evolution reaction.

  18. Oxidative Stress in Patients with Alzheimer's Disease: Effect of Extracts of Fermented Papaya Powder

    Science.gov (United States)

    Barbagallo, Mario; Marotta, Francesco; Dominguez, Ligia J.

    2015-01-01

    Brain tissue is particularly susceptible to oxidative stress (OS). Increased production of reactive oxygen species (ROS), reduced antioxidant systems, and decreased efficiency in repairing mechanisms have been linked to Alzheimer's disease (AD). Postmortem studies in AD patients' brains have shown oxidative damage markers (i.e., lipid peroxidation, protein oxidative damage, and glycoxidation). Fermented papaya (FPP, a product of Carica papaya Linn fermentation with yeast) is a nutraceutical supplement with favorable effects on immunological, hematological, inflammatory, and OS parameters in chronic/degenerative diseases. We studied 40 patients (age 78.2 ± 1.1 years), 28 AD patients, and 12 controls. Urinary 8-OHdG was measured to assess OS. Twenty AD patients were supplemented with FPP (Immunage, 4.5 grams/day) for 6 months, while controls did not receive any treatment. At baseline, 8-OHdG was significantly higher in patients with AD versus controls (13.7 ± 1.61 ng/mL versus 1.6 ± 0.12 ng/mL, P < 0.01). In AD patients FPP significantly decreased 8-OHdG (14.1 ± 1.7 ng/mL to 8.45 ± 1.1 ng/mL, P < 0.01), with no significant changes in controls. AD is associated with increased OS, and FPP may be helpful to counteract excessive ROS in AD patients. PMID:25944987

  19. Exposure-response analysis for beryllium sensitization and chronic beryllium disease among workers in a beryllium metal machining plant.

    Science.gov (United States)

    Madl, Amy K; Unice, Ken; Brown, Jay L; Kolanz, Marc E; Kent, Michael S

    2007-06-01

    The current occupational exposure limit (OEL) for beryllium has been in place for more than 50 years and was believed to be protective against chronic beryllium disease (CBD) until studies in the 1990s identified beryllium sensitization (BeS) and subclinical CBD in the absence of physical symptoms. Inconsistent sampling and exposure assessment methodologies have often prevented the characterization of a clear exposure-response relationship for BeS and CBD. Industrial hygiene (3831 personal lapel and 616 general area samples) and health surveillance data from a beryllium machining facility provided an opportunity to reconstruct worker exposures prior to the ascertainment of BeS or the diagnosis of CBD. Airborne beryllium concentrations for different job titles were evaluated, historical trends of beryllium levels were compared for pre- and postengineering control measures, and mean and upper bound exposure estimates were developed for workers identified as beryllium sensitized or diagnosed with subclinical or clinical CBD. Five approaches were used to reconstruct historical exposures of each worker: industrial hygiene data were pooled by year, job title, era of engineering controls, and the complete work history (lifetime weighted average) prior to diagnosis. Results showed that exposure metrics based on shorter averaging times (i.e., year vs. complete work history) better represented the upper bound worker exposures that could have contributed to the development of BeS or CBD. Results showed that beryllium-sensitized and CBD workers were exposed to beryllium concentrations greater than 0.2 microg/m3 (95th percentile), and 90% were exposed to concentrations greater than 0.4 microg/m3 (95th percentile) within a given year of their work history. Based on this analysis, BeS and CBD generally occurred as a result of exposures greater than 0.4 microg/m3 and maintaining exposures below 0.2 microg/m3 95% of the time may prevent BeS and CBD in the workplace.

  20. Solution based temperature of Perovskite-type oxide films and powders

    Energy Technology Data Exchange (ETDEWEB)

    McHale, J.M. Jr. [Temple Univ., Philadelphia, PA (United States). Dept. of Chemistry

    1995-04-01

    Conventional solid state reactions are diffusion limited processes that require high temperatures and long reaction times to reach completion. In this work, several solution based methods were utilized to circumvent this diffusion limited reaction and achieve product formation at lower temperatures. The solution methods studied all have the common goal of trapping the homogeneity inherent in a solution and transferring this homogeneity to the solid state, thereby creating a solid atomic mixture of reactants. These atomic mixtures can yield solid state products through {open_quotes}diffusionless{close_quotes} mechanisms. The effectiveness of atomic mixtures in solid state synthesis was tested on three classes of materials, varying in complexity. A procedure was invented for obtaining the highly water soluble salt, titanyl nitrate, TiO(NO{sub 3}){sub 2}, in crystalline form, which allowed the production of titanate materials by freeze drying. The freeze drying procedures yielded phase pure, nanocrystalline BaTiO{sub 3} and the complete SYNROC-B phase assemblage after ten minute heat treatments at 600{degrees}C and 1100{degrees}C, respectively. Two novel methods were developed for the solution based synthesis of Ba{sub 2}YCu{sub 3}O{sub 7-x} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}. Thin and thick films of Ba{sub 2}YCu{sub 3}O{sub 7-x} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} were synthesized by an atmospheric pressure, chemical vapor deposition technique. Liquid ammonia solutions of metal nitrates were atomized with a stream of N{sub 2}O and ignited with a hydrogen/oxygen torch. The resulting flame was used to coat a substrate with superconducting material. Bulk powders of Ba{sub 2}YCu{sub 3}O{sub 7-x} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} were synthesized through a novel acetate glass method. The materials prepared were characterized by XRD, TEM, SEM, TGA, DTA, magnetic susceptibility and electrical resistivity measurements.

  1. Solution based synthesis of perovskite-type oxide films and powders

    Energy Technology Data Exchange (ETDEWEB)

    McHale, J.M. Jr.

    1995-01-01

    Conventional solid state reactions are diffusion limited processes that require high temperatures and long reaction times to reach completion. In this work, several solution based methods were utilized to circumvent this diffusion limited reaction and achieve product formation at lower temperatures. The solution methods studied all have the common goal of trapping the homogeneity inherent in a solution and transferring this homogeneity to the solid state, thereby creating a solid atomic mixture of reactants. These atomic mixtures can yield solid state products through diffusionless mechanisms. The effectiveness of atomic mixtures in solid state synthesis was tested on three classes of materials, varying in complexity. A procedure was invented for obtaining the highly water soluble salt, titanyl nitrate, TiO(NO{sub 3}){sub 2}, in crystalline form, which allowed the production of titanate materials by freeze drying. The freeze drying procedures yielded phase pure, nanocrystalline BaTiO{sub 3} and the complete SYNROC-B phase assemblage after ten minute heat treatments at 600 C and 1,100 C, respectively. Two novel methods were developed for the solution based synthesis of Ba{sub 2}YCu{sub 3}O{sub 7{minus}x} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10}. Thin and thick films of Ba{sub 2}YCu{sub 3}O{sub 7{minus}x} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} were synthesized by an atmospheric pressure, chemical vapor deposition technique. Liquid ammonia solutions of metal nitrates were atomized with a stream of N{sub 2}O and ignited with a hydrogen/oxygen torch. The resulting flame was used to coat a substrate with superconducting material. Bulk powders of Ba{sub 2}YCu{sub 3}O{sub 7{minus}x} and Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} were synthesized through a novel acetate glass method. The materials prepared were characterized by XRD, TEM, SEM, TGA, DTA, magnetic susceptibility and electrical resistivity measurements.

  2. Recommended design correlations for S-65 beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Billone, M.C. [Argonne National Lab., IL (United States)

    1995-09-01

    The properties of tritium and helium behavior in irradiated beryllium are reviewed, along with the thermal-mechanical properties needed for ITER design analysis. Correlations are developed to describe the performance of beryllium in a fusion reactor environment. While this paper focuses on the use of beryllium as a plasma-facing component (PFC) material, the correlations presented here can also be used to describe the performance of beryllium as a neutron multiplier for a tritium breeding blanket. The performance properties for beryllium are subdivided into two categories: properties which do not change with irradiation damage to the bulk of the material; and properties which are degraded by neutron irradiation. The irradiation-independent properties described within are: thermal conductivity, specific heat capacity, thermal expansion, and elastic constants. Irradiation-dependent properties include: yield strength, ultimate tensile strength, plastic tangent modulus, uniform and total tensile elongation, thermal and irradiation-induced creep strength, He-induced swelling and tritium retention/release. The approach taken in developing properties correlations is to describe the behavior of dense, pressed S-65 beryllium -- the material chosen for ITER PFC application -- as a function of temperature. As there are essentially no data on the performance of porous and/or irradiated S-65 beryllium, the degradation of properties with as-fabricated porosity and irradiation are determined from the broad data base on S-200F, as well as other types and grades, and applied to S-65 beryllium by scaling factors. The resulting correlations can be used for Be produced by vacuum hot pressing (VHP) and cold-pressing (CP)/sintering(S)/hot-isostatic-pressing (HIP). The performance of plasma-sprayed beryllium is discussed but not quantified.

  3. Effect of Powder Type and Compaction Pressure on the Density, Hardness and Oxidation Resistance of Sintered and Steam-treated Steels

    Science.gov (United States)

    Wang, Wen-Fung

    2007-10-01

    Two types of Hoganas iron powders—sponge (NC), and highly compressible (SC) were investigated. These specimens were compacted with a pressure of 300, 400, 500, 600, and 700 MPa, before sintering in a production belt-type furnace. Steam treatment of the specimens was at 570 °C for 30 min. The sintered density and as-sintered hardness increase with increasing compaction pressure, and are significantly influenced by the powder structural characteristics. During steam treatment the type of powder and compaction pressure have an important influence on the extent of pore closure and weight gain. The maximum hardness was obtained for the components compacted at a pressure of 500 MPa for both groups of iron powders. Surface pore closure and oxidation resistance of the steam-treated components are improved with increasing compaction pressure.

  4. THE IDAHO NATIONAL LABORATORY BERYLLIUM TECHNOLOGY UPDATE

    Energy Technology Data Exchange (ETDEWEB)

    Glen R. Longhurst

    2007-12-01

    A Beryllium Technology Update meeting was held at the Idaho National Laboratory on July 18, 2007. Participants came from the U.S., Japan, and Russia. There were two main objectives of this meeting. One was a discussion of current technologies for beryllium in fission reactors, particularly the Advanced Test Reactor and the Japan Materials Test Reactor, and prospects for material availability in the coming years. The second objective of the meeting was a discussion of a project of the International Science and Technology Center regarding treatment of irradiated beryllium for disposal. This paper highlights discussions held during that meeting and major conclusions reached

  5. Metallurgical viewpoints on the brittleness of beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Lagerberg, G.

    1960-02-15

    At present the development and use of beryllium metal for structural applications is severely hampered by its brittleness. Reasons for this lack of ductility are reviewed in discussing the deformation behaviour of beryllium in relation to other hexagonal metals. The ease of fracturing in beryllium is assumed to be a consequence of a limited number of deformation modes in combination with high deformation resistance. Models for the nucleation of fracture are suggested. The relation of ductility to elastic constants as well as to grain size, texture and alloying additions is discussed.

  6. Slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry for the direct determination of metal impurities in aluminium oxide ceramic powders.

    Science.gov (United States)

    Peng, T; Chang, G; Wang, L; Jiang, Z; Hu, B

    2001-03-01

    A new analytical procedure for the direct determination of metal impurities (Cr, Cu, Fe and V) in aluminium oxide ceramic powders by slurry sampling fluorination assisted electrothermal vaporization-inductively coupled plasma-atomic emission spectrometry (ETV-ICP-AES) is reported. A polytetrafluoroethylene (PTFE) emulsion was used as a fluorinating reagent to promote the vaporization of impurity elements in aluminium oxide ceramic powders from the graphite tube. A vaporization stage with a long ramp time and a short hold time provided the possibility of temporal analyte-matrix separation. The experimental results indicated that a 10 microL 1% m/v slurry of aluminium oxide could be destroyed and vaporized completely with 600 micrograms PTFE under the selected conditions. Two aluminium oxide ceramic powder samples were used without any additional pretreatment. Analytical results obtained by using standard addition method with aqueous standard solution were checked by comparison of the results with pneumatic nebulization (PN)-ICP-AES based on the wet-chemical decomposition and analyte-matrix separation. The limits of detection (LODs) between 0.30 microgram g-1 (Fe) and 0.08 microgram g-1 (Cu) were achieved, and, the repeatability of measurements was mainly better than 10%.

  7. Effect of turmeric powder (Curcuma longa L. and ascorbic acid on antioxidant capacity and oxidative status in rabbit burgers after cooking

    Directory of Open Access Journals (Sweden)

    S. Mancini

    2016-06-01

    Full Text Available The aim of this study was to evaluate the effects of turmeric powder and ascorbic acid on lipid oxidation and antioxidant capacity in cooked rabbit burgers. The burgers were derived from 3 different formulations (C, control, with no additives; Tu with 3.5% of turmeric powder and AA with 0.1% of ascorbic acid and were stored at 4°C for 0 and 7 d and cooked. The lipid oxidation (thiobarbituric acid reactive substances [TBARS] and antioxidant capacity (2,2-azinobis-[3 ethylbenzothiazoline-6-sulfonic acid] {ABTS}, 1,1-diphenyl-2-pircydrazyl [DPPH] and ferric reducing ability [FRAP] were evaluated. A significant interaction between storage time and formulation (P<0.001 was observed for DPPH, FRAP and TBARS in cooked burgers. At day 0 and day 7, the DPPH value was higher in Tu and AA compared to C burgers. At day 0, C showed a lower level of FRAP than the Tu and AA burgers. At day 7, the FRAP values tended to decrease but remained significantly higher in Tu and AA compared to C burgers. Lipid oxidation at day 0 in Tu and AA showed lower TBARS values compared to C burgers. The addition of 3.5% turmeric powder in rabbit burgers exerts an antioxidant effect during storage and it seems more effective in controlling lipid oxidation than ascorbic acid after cooking.

  8. Efficacy of serial medical surveillance for chronic beryllium disease in a beryllium machining plant.

    Science.gov (United States)

    Newman, L S; Mroz, M M; Maier, L A; Daniloff, E M; Balkissoon, R

    2001-03-01

    There is limited information on the use of the blood beryllium lymphocyte proliferation test (BeLPT) at regular intervals in medical surveillance. Employees of a beryllium machining plant were screened with the BeLPT biennially, and new employees were screened within 3 months of hire. Of 235 employees screened from 1995 to 1997, a total of 15 (6.4%) had confirmed abnormal BeLPT results indicating beryllium sensitization; nine of these employees were diagnosed with chronic beryllium disease. Four of the 15 cases were diagnosed within 3 months of first exposure. When 187 of the 235 employees participated in biennial screening in 1997 to 1999, seven more had developed beryllium sensitization or chronic beryllium disease, increasing the overall rate to 9.4% (22 of 235). The blood BeLPT should be used serially in beryllium disease surveillance to capture new or missed cases of sensitization and disease. Beryllium sensitization and chronic beryllium disease can occur within 50 days of first exposure in modern industry.

  9. Green synthesized gold nanoparticles decorated graphene oxide for sensitive determination of chloramphenicol in milk, powdered milk, honey and eye drops.

    Science.gov (United States)

    Karthik, R; Govindasamy, Mani; Chen, Shen-Ming; Mani, Veerappan; Lou, Bih-Show; Devasenathipathy, Rajkumar; Hou, Yu-Shen; Elangovan, A

    2016-08-01

    A simple and rapid green synthesis using Bischofia javanica Blume leaves as reducing agent was developed for the preparation of gold nanoparticles (AuNPs). AuNPs decorated graphene oxide (AuNPs/GO) was prepared and employed for the sensitive amperometric determination of chloramphenicol. The green biosynthesis requires less than 40s to reduce gold salts to AuNPs. The formations of AuNPs and AuNPs/GO were evaluated by scanning electron and atomic force microscopies, UV-Visible and energy dispersive X-ray spectroscopies, X-ray diffraction studies, and electrochemical methods. AuNPs/GO composite film modified electrode was fabricated and shown excellent electrocatalytic ability towards chloramphenicol. Under optimal conditions, the amperometric sensing platform has delivered wide linear range of 1.5-2.95μM, low detection limit of 0.25μM and high sensitivity of 3.81μAμM(-1)cm(-2). The developed sensor exhibited good repeatability and reproducibility, anti-interference ability and long-term storage stability. Practical feasibility of the sensor has been demonstrated in food samples (milk, powdered milk and honey) and pharmaceutical sample (eye drops). The green synthesized AuNPs/GO composite has great potential for analysis of food samples in food safety measures.

  10. Granulation of fine powder

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ching-Fong

    2016-08-09

    A mixture of fine powder including thorium oxide was converted to granulated powder by forming a first-green-body and heat treating the first-green-body at a high temperature to strengthen the first-green-body followed by granulation by crushing or milling the heat-treated first-green-body. The granulated powder was achieved by screening through a combination of sieves to achieve the desired granule size distribution. The granulated powder relies on the thermal bonding to maintain its shape and structure. The granulated powder contains no organic binder and can be stored in a radioactive or other extreme environment. The granulated powder was pressed and sintered to form a dense compact with a higher density and more uniform pore size distribution.

  11. Adsorption of {sup 60}Co{sup 2+} on hydrous manganese oxide powder from aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Granados Correa, F. [Inst. Nacional de Investigaciones Nucleares, Mexico (Mexico); Univ. Autonoma Metropolitana Iztapalapa, Mexico (Mexico); Jimenez-Becerril, J. [Inst. Nacional de Investigaciones Nucleares, Mexico (Mexico)

    2004-07-01

    Hydrous manganese oxide (HMO) was synthesized and its ability to sorb {sup 60}Co{sup 2+} from aqueous solution was studied under static conditions as a function of contact time, cobalt concentration (10{sup -2}-10{sup -7} M), temperature (303-333 K) and pH of adsorptive solution (2.2-11.4). X-ray diffraction was used in characterization of synthesized HMO. Low concentration of {sup 60}Co{sup 2+} solution, high pH and high temperature were the most favorable conditions for the adsorption process. The results show that the removal process is complete in 40 minutes, obeys a first order rate law and can be described using the Freundlich adsorption model. The standard enthalpy of the system was {delta}H{sup 0} = 12.5 {+-} 0.2 kJ mol{sup -1} and cobalt desorption indicates that the uptake process proceeds via cation exchange. The removal of cobalt ions by HMO appears to be endothermic and irreversible. The values of calculated {delta}G{sup 0} and {delta}S{sup 0} were -17.0 {+-} 3.0 kJ mol{sup -1} and (9.8 {+-} 0.2) x 10{sup -2} kJ K{sup -1} mol{sup -1} respectively, this indicates spontaneity of the process and the degree of freedom of ions is increased by adsorption. (orig.)

  12. A kinetic study of copper(II) oxide powder reduction with hydrogen, based on thermogravimetry

    Energy Technology Data Exchange (ETDEWEB)

    Jelic, Dijana [Faculty of Medicine, Departmet of Pharmacy - Chair of Physical Chemistry, University of Banja Luka, Banja Luka, Bosnia and Herzegovina (Bosnia and Herzegowina); Tomic-Tucakovic, Biljana [Institute of General and Physical Chemistry, Studentski trg 12, 11158 Belgrade (Serbia); Mentus, Slavko, E-mail: slavko@ffh.bg.ac.rs [University of Belgrade, Faculty of Physical Chemistry, Studentski trg 12, 11185 Belgrade (Serbia)

    2011-07-10

    Highlights: {yields} The reduction of CuO by hydrogen was studied by thermogravimetry. {yields} The particle size of the samples varied inside the submicron range. {yields} The experimental data were fitted by means of a nucleation-growth model. {yields} The particle size influenced the kinetic parameters but not the reaction model. - Abstract: The reduction of powdery copper(II) oxide was carried out in a stream of gaseous mixture 25% H{sub 2} + Ar, and followed by thermogravimetry. The two samples of different history were studied: the commercial one, and that synthesized by citrate gel combustion method. The characterization of the starting materials, based on X-ray diffractometry and scanning electron microscopy, indicated equal crystal structure, but different particle size and morphology. The particle size and shape of the metallic particles obtained upon the reduction were observed by means of electron microscope. By a nonlinear regression analysis by means of a software Kinetics05, the experimental data were fitted with the nucleation-growth kinetic model, and the corresponding kinetic parameters were determined.

  13. Chronic Beryllium Disease Prevention Program Report

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S

    2012-03-29

    This document describes how Lawrence Livermore National Laboratory (LLNL) meets the requirements and management practices of federal regulation 10 CFR 850, 'Chronic Beryllium Disease Prevention Program (CBDPP).' This revision of the LLNL CBDPP incorporates clarification and editorial changes based on lessons learned from employee discussions, observations and reviews of Department of Energy (DOE) Complex and commercial industry beryllium (Be) safety programs. The information is used to strengthen beryllium safety practices at LLNL, particularly in the areas of: (1) Management of small parts and components; and (2) Communication of program status to employees. Future changes to LLNL beryllium activities and on-going operating experience will be incorporated into the program as described in Section S, 'Performance Feedback.'

  14. Synthesis and ceramization of polycarbosilane containing beryllium

    Institute of Scientific and Technical Information of China (English)

    黄小忠; 周珊; 程勇; 杜作娟; 段曦东; 王超英

    2014-01-01

    Polycarbosilane containing beryllium (BPCS) precursors was prepared by the reaction of polycarbosilane (PCS) with beryllium acetylacetone (Be (acac)2). The analysis of structures and components of BPCS demonstrates that their main structures are basically the same as PCS. Ceramization of BPCS precursors shows that BPCS precursors are organic below 600 °C and inorganic at 800 °C. At 1400 °C, BPCS precursors convert into silicon carbide ceramics. The ceramization of different beryllium content precursors were studied, which show that beryllium plays an important role in the inhibition of crystalline grain growth ofβ-SiC at high temperature and it can adjust the dielectric constant of silicon carbide ceramics.

  15. Green light emission in aluminum oxide powders doped with different terbium concentrations

    Energy Technology Data Exchange (ETDEWEB)

    Mariscal B, L; Falcony, C. [IPN, Centro de Investigacion y de Estudios Avanzados, 07360 Ciudad de Mexico (Mexico); Carmona T, S.; Murrieta, H.; Sanchez A, M. A. [UNAM, Instituto de Fisica, 04510 Ciudad de Mexico (Mexico); Vazquez A, R. [IPN, Escuela Superior de Computo, 07738 Ciudad de Mexico (Mexico); Garcia R, C. M., E-mail: mariscal2005@gmail.com [UNAM, Facultad de Ciencias, 04510 Ciudad de Mexico (Mexico)

    2016-11-01

    Different emission intensities presented in aluminum oxide phosphors corresponding to different concentrations of doping performed with terbium are analyzed. The phosphors were synthesized by the evaporation technique and were characterized by photo and cathodoluminescence, X-ray diffraction and EDS techniques for different incorporation percentages of terbium as dopant; they show characteristic transitions in 494, 543, 587 and 622 nm, corresponding to {sup 5}D{sub 4} → {sup 7}F{sub 6}, {sup 5}D{sub 4} → {sup 7}F{sub 5}, {sup 5}D{sub 4} → {sup 7}F{sub 4} and {sup 5}D{sub 4} → {sup 7}F{sub 3}, respectively when they are excited with λ{sub exc} = 380 nm wavelength at room temperature. The results of X-ray diffraction show the presence of α-Al{sub 2}O{sub 3} phases with peaks located at 2θ = 25.78, 35.34, 37.96, 43.56, 45.8, 52.74, 57.7, 61.5, 66.74, 68.44, 77.12 and 80.94, and the δ-Al{sub 2}O-3 phase 2θ = 32.82, 45.8, 61.36 and 66.74. These compounds were heat treated for two hours at 1100 degrees Celsius. EDS analyzes indicate that these compounds have close to 60% oxygen around of 40% aluminum in the presence of terbium as dopant which indicates a stoichiometry close to the expected one for alumina. (Author)

  16. Solid state bonding of beryllium-copper for an ITER first wall application

    Energy Technology Data Exchange (ETDEWEB)

    Odegard, B.C. Jr.; Cadden, C.H. [Sandia National Labs., Livermore, CA (United States)

    1998-01-01

    Several different joint assemblies were evaluated in support of a manufacturing technology for diffusion bonding a beryllium armor tile to a copper alloy heat sink for fusion reactor applications. Because beryllium reacts with all but a few elements to form intermetallic compounds, this study considered several different surface treatments as a means of both inhibiting these reactions and promoting a good diffusion bond between the two substrates. All diffusion bonded assemblies used aluminum or an aluminum-beryllium composite (AlBeMet-150) as the interfacial material in contact with beryllium. In most cases, explosive bonding was utilized as a technique for joining the copper alloy heat sink to an aluminum or AlBeMet-150 substrate, which was subsequently diffusion bonded to an aluminum coated beryllium tile. In this approach, a 250 {mu}m thick titanium foil was used as a diffusion barrier between the copper and aluminum to prevent the formation of Cu-Al intermetallic phases. In all cases, a hot isostatic pressing (HIP) furnace was used in conjunction with canned assemblies in order to minimize oxidation and apply sufficient pressure on the assembly for excellent metal-to-metal contact and subsequent bonding. Several different processing schedules were evaluated during the course of this study; bonded assemblies were produced that failed outside the bond area indicating a 100% joint efficiency. (author)

  17. Effect of nano-sized cerium-zirconium oxide solid solution on far-infrared emission properties of tourmaline powders

    Science.gov (United States)

    Guo, Bin; Yang, Liqing; Hu, Weijie; Li, Wenlong; Wang, Haojing

    2015-10-01

    Far-infrared functional nanocomposites were prepared by the co-precipitation method using natural tourmaline (XY3Z6Si6O18(BO3)3V3W, where X is Na+, Ca2+, K+, or vacancy; Y is Mg2+, Fe2+, Mn2+, Al3+, Fe3+, Mn3+, Cr3+, Li+, or Ti4+; Z is Al3+, Mg2+, Cr3+, or V3+; V is O2-, OH-; and W is O2-, OH-, or F-) powders, ammonium cerium(IV) nitrate and zirconium(IV) nitrate pentahydrate as raw materials. The reference sample, tourmaline modified with ammonium cerium(IV) nitrate alone was also prepared by a similar precipitation route. The results of Fourier transform infrared spectroscopy show that tourmaline modified with Ce and Zr has a better far-infrared emission property than tourmaline modified with Ce alone. Through characterization by transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), the mechanism for oxygen evolution during the heat process in the two composite materials was systematically studied. The XPS spectra show that Fe3+ ratio inside tourmaline modified with Ce alone can be raised by doping Zr. Moreover, it is showed that there is a higher Ce3+ ratio inside the tourmaline modified with Ce and Zr than tourmaline modified with Ce alone. In addition, XRD results indicate the formation of CeO2 and Ce1-xZrxO2 crystallites during the heat treatment and further TEM observations show they exist as nanoparticles on the surface of tourmaline powders. Based on these results, we attribute the improved far-infrared emission properties of Ce-Zr doped tourmaline to the enhanced unit cell shrinkage of the tourmaline arisen from much more oxidation of Fe2+ to Fe3+ inside the tourmaline caused by the change in the catalyst redox properties of CeO2 brought about by doping with Zr4+. In all samples, tourmaline modified with 7.14 wt.% Ce and 1.86 wt.% Zr calcined at 800∘C for 5 h has the best far-infrared emission property with the maximum emissivity value of 98%.

  18. Beryllium concentration in pharyngeal tonsils in children

    Directory of Open Access Journals (Sweden)

    Ewa Nogaj

    2014-06-01

    Full Text Available Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children’s pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2–17 years, mean 6.2 ± 2.7 years living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02–0.04 µg/g.

  19. Benchmark Experiment for Beryllium Slab Samples

    Institute of Scientific and Technical Information of China (English)

    NIE; Yang-bo; BAO; Jie; HAN; Rui; RUAN; Xi-chao; REN; Jie; HUANG; Han-xiong; ZHOU; Zu-ying

    2013-01-01

    The neutron leakage spectra were measured at 60°from pure beryllium slab samples(10 cm×10 cm×5 cm and 10 cm×10 cm×11 cm)by TOF method.The experimental results were compared with the calculated ones by MCNP5 simulation,using the evaluated data of beryllium from CENDL3.1,

  20. Beryllium concentration in pharyngeal tonsils in children.

    Science.gov (United States)

    Nogaj, Ewa; Kwapulinski, Jerzy; Misiołek, Maciej; Golusiński, Wojciech; Kowol, Jolanta; Wiechuła, Danuta

    2014-01-01

    Power plant dust is believed to be the main source of the increased presence of the element beryllium in the environment which has been detected in the atmospheric air, surface waters, groundwater, soil, food, and cigarette smoke. In humans, beryllium absorption occurs mainly via the respiratory system. The pharyngeal tonsils are located on the roof of the nasopharynx and are in direct contact with dust particles in inhaled air. As a result, the concentration levels of beryllium in the pharyngeal tonsils are likely to be a good indicator of concentration levels in the air. The presented study had two primary aims: to investigate the beryllium concentration in pharyngeal tonsils in children living in southern Poland, and the appropriate reference range for this element in children's pharyngeal tonsils. Pharyngeal tonsils were extracted from a total of 379 children (age 2-17 years, mean 6.2 ± 2.7 years) living in southern Poland. Tonsil samples were mineralized in a closed cycle in a pressure mineralizer PDS 6, using 65% spectrally pure nitric acid. Beryllium concentration was determined using the ICP-AES method with a Perkin Elmer Optima 5300DVTM. The software Statistica v. 9 was used for the statistical analysis. It was found that girls had a significantly greater beryllium concentration in their pharyngeal tonsils than boys. Beryllium concentration varies greatly, mostly according to the place of residence. Based on the study results, the reference value for beryllium in pharyngeal tonsils of children is recommended to be determined at 0.02-0.04 µg/g.

  1. Tritium release from neutron irradiated beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik

    1998-01-01

    One of the most important open issues related to beryllium for fusion applications refers to the kinetics of the tritium release as a function of neutron fluence and temperature. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating the beryllium response under neutron irradiation. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from the above mentioned irradiation experiments, trying to elucidate the tritium release controlling processes. In agreement with previous studies it has been found that release starts at about 500-550degC and achieves a maximum at about 700-750degC. The observed release at about 500-550degC is probably due to tritium escaping from chemical traps, while the maximum release at about 700-750degC is due to tritium escaping from physical traps. The consequences of a direct contact between beryllium and ceramics during irradiation, causing tritium implanting in a surface layer of beryllium up to a depth of about 40 mm and leading to an additional inventory which is usually several times larger than the neutron-produced one, are also presented and the effects on the tritium release are discussed. (author)

  2. Hydrogen release from deposited beryllium layers

    Energy Technology Data Exchange (ETDEWEB)

    Shestakov, V.P.; Klepikov, A.Kh.; Chikhray, Y.V.; Tazhibaeva, I.L. [NIIETF of Al Farabi Kazakh State Univ., Almaty (Kazakhstan)

    2000-04-01

    The analysis of hydrogen retained in deposited beryllium layers deposited by magnetron sputtering was carried out by means of thermodesorption (TDS) technique. Two hydrogen release peaks were clearly seen on the thermodesorption curves at the temperatures 760-800 K and 920-970 K. Hydrogen concentrations in the deposited beryllium layers were calculated from the gas release curves corresponding to the number of Be atoms in the beryllium layer of 100% theoretical density. Average hydrogen concentration in the beryllium samples loaded in the process of magnetron sputtering was equal to 3800{+-}200 appm. The experiments with beryllium layers, enriched with carbon, revealed the increase of retained hydrogen concentration up to 9600{+-}200 appm. Assuming that gas release can be described within the framework of model of diffusion from layer system BeO-Be-BeO, hydrogen diffusion coefficient in BeO and the trapping and detrapping constants for the traps appearing in beryllium in the process of deposition were evaluated. (orig.)

  3. Characteristics of beryllium bonds; a QTAIM study.

    Science.gov (United States)

    Eskandari, K

    2012-08-01

    The nature of beryllium bonds formed between BeX2 (X is H, F and Cl) and some Lewis bases have been investigated. The distribution of the Laplacian of electron density shows that there is a region of charge depletion around the Be atom, which, according to Laplacian complementary principal, can interact with a region of charge concentration of an atom in the base and form a beryllium bond. The molecular graphs of the investigated complexes indicate that beryllium in BeH2 and BeF2 can form “beryllium bonds” with O, N and P atoms but not with halogens. In addition, eight criteria based on QTAIM properties, including the values of electron density and its Laplacian at the BCP, penetration of beryllium and acceptor atom, charge, energy, volume and first atomic moment of beryllium atom, have been considered and compared with the corresponding ones in conventional hydrogen bonds. These bonds share many common features with very strong hydrogen bonds, however,some differences have also been observed.

  4. Occupational Exposure to Beryllium. Final rule.

    Science.gov (United States)

    2017-01-09

    The Occupational Safety and Health Administration (OSHA) is amending its existing standards for occupational exposure to beryllium and beryllium compounds. OSHA has determined that employees exposed to beryllium at the previous permissible exposure limits face a significant risk of material impairment to their health. The evidence in the record for this rulemaking indicates that workers exposed to beryllium are at increased risk of developing chronic beryllium disease and lung cancer. This final rule establishes new permissible exposure limits of 0.2 micrograms of beryllium per cubic meter of air (0.2 [mu]g/m\\3\\) as an 8-hour time-weighted average and 2.0 [mu]g/m\\3\\ as a short-term exposure limit determined over a sampling period of 15 minutes. It also includes other provisions to protect employees, such as requirements for exposure assessment, methods for controlling exposure, respiratory protection, personal protective clothing and equipment, housekeeping, medical surveillance, hazard communication, and recordkeeping. OSHA is issuing three separate standards--for general industry, for shipyards, and for construction--in order to tailor requirements to the circumstances found in these sectors.

  5. Sanitary-hygienic and ecological aspects of beryllium production

    Energy Technology Data Exchange (ETDEWEB)

    Dvinskykh, E.M.; Savchuk, V.V.; Sidorov, V.L.; Slobodin, D.B.; Tuzov, Y.V. [Ulba Metallurgical Plant, Ust-Kamenogorsk (Kazakhstan)

    1998-01-01

    The Report describes An organization of sanitary-hygienic and ecological control of beryllium production at Ulba metallurgical plant. It involves: (1) the consideration of main methods for protection of beryllium production personnel from unhealthy effect of beryllium, (2) main kinds of filters, used in gas purification systems at different process areas, (3) data on beryllium monitoring in water, soil, on equipment. This Report also outlines problems connected with designing devices for a rapid analysis of beryllium in air as well as problems of beryllium production on ecological situation in the town. (author)

  6. In Vivo Effects of Free Form Astaxanthin Powder on Anti-Oxidation and Lipid Metabolism with High-Cholesterol Diet.

    Science.gov (United States)

    Chen, Yung-Yi; Lee, Pei-Chi; Wu, Yi-Long; Liu, Li-Yun

    2015-01-01

    Astaxanthin extracted from Pomacea canaliculata eggs was made into free-form astaxanthin powder (FFAP) and its effects on lipid metabolism, liver function, antioxidants activities and astaxanthin absorption rate were investigated. 45 hamsters were split into 5 groups and fed with normal diet, high-cholesterol control (0.2% cholesterol), 1.6FFAP (control+1.6% FFAP), 3.2FFAP (control+3.2% FFAP) and 8.0FFAP (control+8.0% FFAP), respectively, for 6 weeks. FFAP diets significantly decreased the liver total cholesterol, triglyceride levels and increased liver fatty acids (C20:5n3; C22:6n3) compositions. It decreased plasma alanine aminotransferase and aspartate aminotransferase. In terms of anti-oxidative activities, we found 8.0 FFAP diet significantly decreased plasma and liver malonaldehyde (4.96±1.96 μg TEP eq./mL and 1.56±0.38 μg TEP eq./g liver) and liver 8-isoprostane levels (41.48±13.69 μg 8-ISOP/g liver). On the other hand, it significantly increased liver catalase activity (149.10±10.76 μmol/min/g liver), Vitamin C (2082.97±142.23 μg/g liver), Vitamin E (411.32±81.67 μg/g liver) contents, and glutathione levels (2.13±0.42 mg GSH eq./g liver). Furthermore, 80% of astaxanthin absorption rates in all FFAP diet groups suggest FFAP is an effective form in astaxanthin absorption. Finally, astaxanthin was found to re-distribute to the liver and eyes in a dose dependent manner. Taken together, our results suggested that the appropriate addition of FFAP into high cholesterol diets increases liver anti-oxidative activity and reduces the concentration of lipid peroxidase and therefore, it may be beneficial as a material in developing healthy food.

  7. In Vivo Effects of Free Form Astaxanthin Powder on Anti-Oxidation and Lipid Metabolism with High-Cholesterol Diet.

    Directory of Open Access Journals (Sweden)

    Yung-Yi Chen

    Full Text Available Astaxanthin extracted from Pomacea canaliculata eggs was made into free-form astaxanthin powder (FFAP and its effects on lipid metabolism, liver function, antioxidants activities and astaxanthin absorption rate were investigated. 45 hamsters were split into 5 groups and fed with normal diet, high-cholesterol control (0.2% cholesterol, 1.6FFAP (control+1.6% FFAP, 3.2FFAP (control+3.2% FFAP and 8.0FFAP (control+8.0% FFAP, respectively, for 6 weeks. FFAP diets significantly decreased the liver total cholesterol, triglyceride levels and increased liver fatty acids (C20:5n3; C22:6n3 compositions. It decreased plasma alanine aminotransferase and aspartate aminotransferase. In terms of anti-oxidative activities, we found 8.0 FFAP diet significantly decreased plasma and liver malonaldehyde (4.96±1.96 μg TEP eq./mL and 1.56±0.38 μg TEP eq./g liver and liver 8-isoprostane levels (41.48±13.69 μg 8-ISOP/g liver. On the other hand, it significantly increased liver catalase activity (149.10±10.76 μmol/min/g liver, Vitamin C (2082.97±142.23 μg/g liver, Vitamin E (411.32±81.67 μg/g liver contents, and glutathione levels (2.13±0.42 mg GSH eq./g liver. Furthermore, 80% of astaxanthin absorption rates in all FFAP diet groups suggest FFAP is an effective form in astaxanthin absorption. Finally, astaxanthin was found to re-distribute to the liver and eyes in a dose dependent manner. Taken together, our results suggested that the appropriate addition of FFAP into high cholesterol diets increases liver anti-oxidative activity and reduces the concentration of lipid peroxidase and therefore, it may be beneficial as a material in developing healthy food.

  8. Efficacy of surface sampling methods for different types of beryllium compounds.

    Science.gov (United States)

    Dufresne, A; Mocanu, T; Viau, S; Perrault, G; Dion, C

    2011-01-01

    The objective of the research work was to evaluate the efficiency of three different sampling methods (Ghost Wipe™, micro-vacuum, and ChemTest®) in the recovery of Be dust by assessing: (1) four Be compounds (beryllium acetate, beryllium chloride, beryllium oxide and beryllium aluminium), (2) three different surfaces (polystyrene, glass and aluminium) and (3) inter-operator variation. The three sampling methods were also tested on site in a laboratory of a dental school for validation purposes. The Ghost Wipe™ method showed recovery ranging from 43.3% to 85.8% for all four Be compounds and for all three quantities of Be spiked on Petri dishes, while recovery with the micro-vacuum method ranged from 0.1% to 12.4%. On polystyrene dishes with 0.4 µg Be, the recovery ranged from 48.3% to 81.7%, with an average recovery of 59.4% for Operator 1 and 68.4% for Operator 2. The ChemTest® wipe method with beryllium acetate, beryllium chloride, and AlBeMet® showed analogous results that are in line with the manufacturer's manual, but collection of beryllium oxide was negative. In the dental laboratory, Ghost Wipe™ samplings showed better recovery than the micro-vacuum method. The ratios between the recovered quantities of Be in each location where the Ghost Wipe™ was tested differed substantially, ranging from 1.45 to 64. In the dental laboratory, a faint blue color indicating the presence of Be was observed on the ChemTest® wipes used in two locations out of six. In summary, the Ghost Wipe™ method was more efficient than micro-vacuuming in collecting the Be dust from smooth, non-porous surfaces such as Petri dishes by a factor of approximately 18. The results obtained on site in a dental laboratory also showed better recovery with Ghost Wipes™. However, the ratio of Be recovered by Ghost Wipes™ versus micro-vacuuming was much lower for surfaces where a large amount of dust was present. Wet wiping is preferred over micro-vacuuming for beryllium forms, but

  9. 超声沉淀法合成氧化锌纳米粉体%Synthesis of Zinc Oxide Nanometer Powder with Precipitation under Ultrasonic Radiation

    Institute of Scientific and Technical Information of China (English)

    李东升; 王文亮; 杨文选

    2000-01-01

      分别采用超声沉淀法和沉淀法制备了氧化锌纳米粉体。借助XRD、TG-DTA、TEM及IR等技术对粉体前驱物的结构、热分解历程及粉体性能进行了研究。结果表明,超声沉淀法合成的氧化锌纳米粉体外貌呈球形,平均晶粒尺寸约为20nm,且大小均匀,分散性好,明显优于普通沉淀法所得产物。%  Zinc oxide nanometer-sized powders were prepared by precipitation under ultrasonic radiation and precipitation methods, respectively. The structure and the thermal decomposition mechanism of the predecessors, and characteristics of the powders were investigated by XRD, TG--DTA, TEM and IR techniques. The results show that the Zinc oxide nanometer powders synthesized with precipitation under ultrasonic radiation have an average diameter of 20nm with sphere-shaped and good dispersity.

  10. Charge localization in oxidized Pb2Sr2Y0.5Cu308+8 studies by electron and neutron powder diffraction

    DEFF Research Database (Denmark)

    Iversen, M.H.; Jørgensen, J.E.; Andersen, N.H.

    1998-01-01

    Oxidized Pb2Sr2Y0.5Ca0.5Cu3O8+delta was studied by electron diffraction and neutron powder diffraction. The electron diffraction diagrams showed a doubling along the b-axis and a quadruplication along the a-axis indicating that the excess oxygen is incorporated into the structure in an ordered wa...... of superconductivity in the oxidized compound. (C) 1998 Elsevier Science B.V.......Oxidized Pb2Sr2Y0.5Ca0.5Cu3O8+delta was studied by electron diffraction and neutron powder diffraction. The electron diffraction diagrams showed a doubling along the b-axis and a quadruplication along the a-axis indicating that the excess oxygen is incorporated into the structure in an ordered way....... The oxygen content was determined from refinement of the neutron data and delta = 1.2(1) was obtained. Calculation of bond valency sums for the cations shows that the bond valency sum for Cu in the CuO2 layers in Pb2Sr2Y0.5Ca0.5Cu3O8 decreases when the compound is oxidized, thereby explaining the lack...

  11. Influence of grain size on mechanical properties of isostatically pressed beryllium materials

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Six kinds of beryllium powders with different particle sizes (4 ~ 15 μm) and low oxygen prepared by impactgrinding were compacted and consolidated by cold-hot isostatic pressing (CIP-HIP). The tensile strength, yield strength,elongation and micro-yield strength(MYS) of the materials were tested and it showed that the strength of the materials,especially the yield strength and micro yield strength(MYS) increase obviously with the refinement of grain size. From theXRD and TEM, the second phase is BeO which is finely dispersed in matrix. This is considered to be the main strength-ening mechanism for CIP-HIPed beryllium materials with higher purity

  12. Mechanical performance of irradiated beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Scaffidi-Argentina, F.; Dalle-Donne, M.; Werle, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reaktortechnik

    1998-01-01

    For the Helium Cooled Pebble Bed (HCPB) Blanket, which is one of the two reference concepts studied within the European Fusion Technology Programme, the neutron multiplier consists of a mixed bed of about 2 and 0.1-0.2 mm diameter beryllium pebbles. Beryllium has no structural function in the blanket, however microstructural and mechanical properties are important, as they might influence the material behavior under neutron irradiation. The EXOTIC-7 as well as the `Beryllium` experiments carried out in the HFR reactor in Petten are considered as the most detailed and significant tests for investigating it. This paper reviews the present status of beryllium post-irradiation examinations performed at the Forschungszentrum Karlsruhe with samples from these irradiation experiments, emphasizing the effects of irradiation of essential material properties and trying to elucidate the processes controlling the property changes. The microstructure, the porosity distribution, the impurity content, the behavior under compression loads and the compatibility of the beryllium pebbles with lithium orthosilicate (Li{sub 4}SiO{sub 4}) during the in-pile irradiation are presented and critically discussed. Qualitative information on ductility and creep obtained by hardness-type measurements are also supplied. (author)

  13. Illness Absences Among Beryllium Sensitized Workers

    Science.gov (United States)

    Watkins, Janice P.; Ellis, Elizabeth D.; Girardi, David J.; Cragle, Donna L.

    2014-01-01

    Objectives. This study examined absence rates among US Department of Energy workers who had beryllium sensitization (BeS) or were diagnosed with chronic beryllium disease (CBD) compared with those of other workers. Methods. We used the lymphocyte proliferation test to determine beryllium sensitivity. In addition, we applied multivariable logistic regression to compare absences from 2002 to 2011 between workers with BeS or CBD to those without, and survival analysis to compare time to first absence by beryllium sensitization status. Finally, we examined beryllium status by occupational group. Results. Fewer than 3% of the 19 305 workers were BeS, and workers with BeS or CBD had more total absences (odds ratio [OR] = 1.31; 95% confidence interval [CI] = 1.18, 1.46) and respiratory absences (OR = 1.51; 95% CI = 1.24, 1.84) than did other workers. Time to first absence for all causes and for respiratory conditions occurred earlier for workers with BeS or CBD than for other workers. Line operators and crafts personnel were at increased risk for BeS or CBD. Conclusions. Although not considered “diseased,” workers with BeS have higher absenteeism compared with nonsensitized workers. PMID:25211750

  14. An official American Thoracic Society statement: diagnosis and management of beryllium sensitivity and chronic beryllium disease.

    Science.gov (United States)

    Balmes, John R; Abraham, Jerrold L; Dweik, Raed A; Fireman, Elizabeth; Fontenot, Andrew P; Maier, Lisa A; Muller-Quernheim, Joachim; Ostiguy, Gaston; Pepper, Lewis D; Saltini, Cesare; Schuler, Christine R; Takaro, Tim K; Wambach, Paul F

    2014-11-15

    Beryllium continues to have a wide range of industrial applications. Exposure to beryllium can lead to sensitization (BeS) and chronic beryllium disease (CBD). The purpose of this statement is to increase awareness and knowledge about beryllium exposure, BeS, and CBD. Evidence was identified by a search of MEDLINE. The committee then summarized the evidence, drew conclusions, and described their approach to diagnosis and management. The beryllium lymphocyte proliferation test is the cornerstone of both medical surveillance and the diagnosis of BeS and CBD. A confirmed abnormal beryllium lymphocyte proliferation test without evidence of lung disease is diagnostic of BeS. BeS with evidence of a granulomatous inflammatory response in the lung is diagnostic of CBD. The determinants of progression from BeS to CBD are uncertain, but higher exposures and the presence of a genetic variant in the HLA-DP β chain appear to increase the risk. Periodic evaluation of affected individuals can detect disease progression (from BeS to CBD, or from mild CBD to more severe CBD). Corticosteroid therapy is typically administered when a patient with CBD exhibits evidence of significant lung function abnormality or decline. Medical surveillance in workplaces that use beryllium-containing materials can identify individuals with BeS and at-risk groups of workers, which can help prioritize efforts to reduce inhalational and dermal exposures.

  15. Occupational and non-occupational allergic contact dermatitis from beryllium.

    Science.gov (United States)

    Vilaplana, J; Romaguera, C; Grimalt, F

    1992-05-01

    There are various references to sensitization to beryllium in the literature. Since introducing a patch testing series for patients with suspected sensitization to metals, we have found 3 cases of sensitization to beryllium. Of these 3 cases, we regard the first 2 as having relevant sensitization. Beryllium chloride (1% pet.) was positive in 3 patients and negative in 150 controls.

  16. 20 CFR 30.508 - What is beryllium sensitivity monitoring?

    Science.gov (United States)

    2010-04-01

    ... 20 Employees' Benefits 1 2010-04-01 2010-04-01 false What is beryllium sensitivity monitoring? 30... and Offsets; Overpayments Payment of Claims and Offset for Certain Payments § 30.508 What is beryllium sensitivity monitoring? Beryllium sensitivity monitoring shall consist of medical examinations to confirm...

  17. Properties and Structure of Al-doped Conductive Zinc Oxide Powder%Al掺杂纳米氧化锌导电粉的性能与结构

    Institute of Scientific and Technical Information of China (English)

    熊瑜; 郑冀; 李燕; 刘雪佳; 梁璐

    2012-01-01

    Using zinc nitrate, aluminium nitrate and urea as raw materials, basic zinc carbonate powder was prepared by homogeneous precipitation, Al-doped ZnO powders were prepared by calcining the precursor. The property was characterized by SEM, TGA, XPS and XRD. The results show that the volume resistivity of the zinc oxide decreases to 1. 05 × 10s Ω · cm when the Al3+ doping content is 1. 5% (mole fraction) , much lower than that of the conventional zinc oxide powders. Al-doped ZnO nanoparticles are wurtzite structure,and similar to ellipsoidal. The grain size distribution of doped ZnO nanopowders is narrow. Meanwhile,the conductivity of Al-doped ZnO powders was improved greatly.%以Zn( NO3)2·6H2O,Al(NO3)3·9H2O,尿素为原料,采用均相沉淀法,制备出碱式碳酸锌粉末,之后将前驱体在氢气气氛下煅烧,制得Al掺杂氧化锌导电粉.利用SEM,TGA,XPS和XRD等分析手段对材料性能进行表征,研究了Al掺杂氧化锌导电性能的影响.结果表明:随着Al3+掺杂量的增大,粉体体积电阻率先降低后升高,Al3+掺杂含量在1.5%(摩尔分数)时电阻率最低,为1.05×105Ω·cm.掺杂后的ZnO为六方纤锌矿结构,颗粒呈类椭球形,粒度分布窄,导电性能明显提高.

  18. Magnetically responsive enzyme powders

    Energy Technology Data Exchange (ETDEWEB)

    Pospiskova, Kristyna, E-mail: kristyna.pospiskova@upol.cz [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Safarik, Ivo, E-mail: ivosaf@yahoo.com [Regional Centre of Advanced Technologies and Materials, Palacky University, Slechtitelu 11, 783 71 Olomouc (Czech Republic); Department of Nanobiotechnology, Institute of Nanobiology and Structural Biology of GCRC, Na Sadkach 7, 370 05 Ceske Budejovice (Czech Republic)

    2015-04-15

    Powdered enzymes were transformed into their insoluble magnetic derivatives retaining their catalytic activity. Enzyme powders (e.g., trypsin and lipase) were suspended in various liquid media not allowing their solubilization (e.g., saturated ammonium sulfate and highly concentrated polyethylene glycol solutions, ethanol, methanol, 2-propanol) and subsequently cross-linked with glutaraldehyde. Magnetic modification was successfully performed at low temperature in a freezer (−20 °C) using magnetic iron oxides nano- and microparticles prepared by microwave-assisted synthesis from ferrous sulfate. Magnetized cross-linked enzyme powders were stable at least for two months in water suspension without leakage of fixed magnetic particles. Operational stability of magnetically responsive enzymes during eight repeated reaction cycles was generally without loss of enzyme activity. Separation of magnetically modified cross-linked powdered enzymes from reaction mixtures was significantly simplified due to their magnetic properties. - Highlights: • Cross-linked enzyme powders were prepared in various liquid media. • Insoluble enzymes were magnetized using iron oxides particles. • Magnetic iron oxides particles were prepared by microwave-assisted synthesis. • Magnetic modification was performed under low (freezing) temperature. • Cross-linked powdered trypsin and lipase can be used repeatedly for reaction.

  19. [Effects of beryllium chloride on cultured cells].

    Science.gov (United States)

    Sakaguchi, T; Sakaguchi, S; Nakamura, I; Kagami, M

    1984-05-01

    The effects of beryllium on cultured cells were investigated. Three cell-lines (HeLa-S3, Vero, HEL-R66) were used in these experiments and they were cultured in Eagle's MEM plus 5 or 10% FBS (Fetal Bovine Serum) containing beryllium in various concentrations. HeLa cells or Vero cells were able to grow in the medium with 10 micrograms Be/ml (1.1 mM). On the other hand, the growth of HEL cells were strongly inhibited, even when cultured in the medium with 1 microgram Be/ml (1.1 X 10(-1) mM) and the number of living cells showed markedly low level as compared to that of the control samples cultured in the medium without beryllium. The cytotoxic effects of beryllium on these cells, which were cultured for three days in the medium with beryllium, were observed. None of cytotoxic effects were found on HeLa cells cultured with 0.5 micrograms/ml (5.5 X 10(-2) mM) and on Vero cells cultured with 0.05 micrograms Be/ml (5.5 X 10(-3) mM), while HEL cells received cytotoxic effects even when cultured in the medium containing 0.05 micrograms Be/ml (5.5 X 10(-3) mM), and these effects on the cells appeared strong when cultured in the medium without FBS. It was revealed from these experiments that HEL cells are very sensitive in terms of toxic effects of beryllium. Therefore, there cells can be used for the toxicological study on low level concentrations of the metal.

  20. Synthesis of Uranium nitride powders using metal uranium powders

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Jae Ho; Kim, Dong Joo; Oh, Jang Soo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    Uranium nitride (UN) is a potential fuel material for advanced nuclear reactors because of their high fuel density, high thermal conductivity, high melting temperature, and considerable breeding capability in LWRs. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. The carbothermic reduction has an advantage in the production of fine powders. However it has many drawbacks such as an inevitable engagement of impurities, process burden, and difficulties in reusing of expensive N{sup 15} gas. Manufacturing concerns issued in the carbothermic reduction process can be solved by changing the starting materials from oxide powder to metals. However, in nitriding process of metal, it is difficult to obtain fine nitride powders because metal uranium is usually fabricated in the form of bulk ingots. In this study, a simple reaction method was tested to fabricate uranium nitride powders directly from uranium metal powders. We fabricated uranium metal spherical powder and flake using a centrifugal atomization method. The nitride powders were obtained by thermal treating those metal particles under nitrogen containing gas. We investigated the phase and morphology evolutions of powders during the nitriding process. A phase analysis of nitride powders was also a part of the present work.

  1. Direct determination of silicon in powdered aluminium oxide by use of slurry sampling with in situ fusion graphite-furnace atomic-absorption spectrometry.

    Science.gov (United States)

    Minami, H; Yoshida, T; Okutsu, K; Zhang, Q; Inoue, S; Atsuya, I

    2001-08-01

    A direct method for determination of silicon in powdered high-purity aluminium oxide samples, by slurry sampling with in situ fusion graphite-furnace atomic-absorption spectrometry (GF-AAS), has been established. A slurry sample was prepared by 10-min ultrasonication of a powdered sample in an aqueous solution containing both sodium carbonate and boric acid as a mixed flux. An appropriate portion of the slurry was introduced into a pyrolytic graphite furnace equipped with a platform. Silicon compounds to be determined and aluminium oxide were fused by the in situ fusion process with the flux in the furnace under optimized heating conditions, and the silicon absorbance was then measured directly. The calibration curve was prepared by use of a silicon standard solution containing the same concentration of the flux as the slurry sample. The accuracy of the proposed method was confirmed by analysis of certified reference materials. The proposed method gave statistically accurate values at the 95% confidence level. The detection limit was 3.3 microg g(-1) in solid samples, when 300 mg/20 mL slurry was prepared and a 10 microL portion of the slurry was measured. The precision of the determination (RSD for more than four separate determinations) was 14% and 2%, respectively, for levels of 10 and 100 microg g(-1) silicon in aluminium oxide.

  2. Mineral resource of the month: beryllium

    Science.gov (United States)

    Shedd, Kim B.

    2006-01-01

    Beryllium metal is lighter than aluminum and stiffer than steel. These and other properties, including its strength, dimensional stability, thermal properties and reflectivity, make it useful for aerospace and defense applications, such as satellite and space-vehicle structural components. Beryllium’s nuclear properties, combined with its low density, make it useful as a neutron reflector and moderator in nuclear reactors. Because it is transparent to most X rays, beryllium is used as X-ray windows in medical, industrial and analytical equipment.

  3. Preliminary results for explosion bonding of beryllium to copper

    Energy Technology Data Exchange (ETDEWEB)

    Butler, D.J. [Northwest Technical Industries, Inc., Sequim, WA (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States)

    1995-09-01

    This program was undertaken to determine if explosive bonding is a viable technique for joining beryllium to copper substrates. The effort was a cursory attempt at trying to solve some of the problems associated with explosive bonding beryllium and should not be considered a comprehensive research effort. There are two issues that this program addressed. Can beryllium be explosive bonded to copper substrates and can the bonding take place without shattering the beryllium? Thirteen different explosive bonding iterations were completed using various thicknesses of beryllium that were manufactured with three different techniques.

  4. Defect structure of zirconium oxide nanosized powders with Y2O3, Sc2O3, Cr2O3 impurities

    OpenAIRE

    Yurchenko, L.; I. Bykov; Vasylyev, A; Vereshchak, V.; Suchaneck, G.; Jastrabik, L.; Dejneka, A.

    2012-01-01

    Formation mechanisms of paramagnetic centers originating from Zr3+ and Cr3+ ions as well as the influence of composition of nanoparticles on thermogeneration processes of these paramagnetic centers in ZrO2 structure were studied. A set of nanosized powders of zirconium oxide was investigated by electron paramagnetic resonance method: nominally pure ZrO2; ZrO2 with Y2O3 and Sc2O3; ZrO2 with Cr2O3; ZrO2 with Y2O3 and Cr2O3. It is observed that the influence of annealing on EPR lines of Zr...

  5. Cost effective aluminum beryllium mirrors for critical optics applications

    Science.gov (United States)

    Say, Carissa; Duich, Jack; Huskamp, Chris; White, Ray

    2013-09-01

    The unique performance of aluminum-beryllium frequently makes it an ideal material for manufacturing precision optical-grade metal mirrors. Traditional methods of manufacture utilize hot-pressed powder block in billet form which is subsequently machined to final dimensions. Complex component geometries such as lightweighted, non-plano mirrors require extensive tool path programming, fixturing, and CNC machining time and result in a high buy-to-fly ratio (the ratio of the mass of raw material purchased to the mass of the finished part). This increases the cost of the mirror structure as a significant percentage of the procurement cost is consumed in the form of machining, tooling, and scrap material that do not add value to the final part. Inrad Optics, Inc. and IBC Advanced Alloys Corp. undertook a joint study to evaluate the suitability of investment-cast Beralcast® 191 and 363 aluminum-beryllium as a precision mirror substrate material. Net shape investment castings of the desired geometry minimizes machining to just cleanup stock, thereby reducing the recurring procurement cost while still maintaining performance. The thermal stability of two mirrors, (one each of Beralcast® 191 and Beralcast® 363), was characterized from -40°F to +150°F. A representative pocketed mirror was developed, including the creation of a relevant geometry and production of a cast component to validate the approach. Information from the demonstration unit was used as a basis for a comparative cost study of the representative mirror produced in Beralcast® and one machined from a billet of AlBeMet® 162 (AlBeMet® is a registered trademark of Materion Corporation). The technical and financial results of these studies will be discussed in detail.

  6. Active Gold-Ceria and Gold-Ceria/titania Catalysts for CO Oxidation. From Single-Crystal Model Catalysts to Powder Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Jose A. [Brookhaven National Lab. (BNL), Upton, NY (United States); Si, Rui [Brookhaven National Lab. (BNL), Upton, NY (United States); Evans, Jaime [Central Univ. of Venezuela, Caracas (Venezuela); Xu, Wenqian [Brookhaven National Lab. (BNL), Upton, NY (United States); Hanson, Jonathan C. [Brookhaven National Lab. (BNL), Upton, NY (United States); Tao, Jing [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhu, Yimei [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-07-23

    We studied CO oxidation on model and powder catalysts of Au-CeO2 and Au-CeOx/TiO2. Phenomena observed in Au-CeO2(1 1 1) and Au-CeO2/TiO2(1 1 0) provided useful concepts for designing and preparing highly active and stable Au-CeOx/TiO2 powder catalysts for CO oxidation. Small particles of Au dispersed on CeO2(1 1 1) displayed high catalytic activity, making Au-CeO2(1 1 1) a better CO oxidation catalyst than Au-TiO2(1 1 0) or Au-MgO(1 0 0). An excellent support for gold was found after depositing nanoparticles of ceria on TiO2(1 1 0). The CeOx nanoparticles act as nucleation centers for gold, improving dispersion of the supported metal and helping in the creation of reaction sites efficient for the adsorption of CO and the dissociation of the O2 molecule. High-surface area catalysts were prepared by depositing gold on ceria nanorods and CeOx/TiO2 powders. The samples were tested for the low-temperature (10–70 °C) oxygen-rich (1%CO/4%O2/He) CO oxidation reaction after pre-oxidation (20%O2/He, 300 °C) and pre-reduction (5%H2/He, 300 °C) treatments. Moreover, synchrotron-based operando X-ray diffraction (XRD) and X-ray absorption (XAS) spectroscopy were used to study the Au-CeO2 and Au-CeOx/TiO2 catalysts under reaction conditions. Our operando findings indicate that the most active phase of these catalysts for low-temperature CO oxidation consist of small particles of metallic Au dispersed on CeO2 or CeOx/TiO2.

  7. Investigation of damages induced by ITER-relevant heat loads during massive gas injections on Beryllium

    Directory of Open Access Journals (Sweden)

    B. Spilker

    2016-12-01

    Full Text Available Massive gas injections (MGIs will be used in ITER to mitigate the strong damaging effect of full performance plasma disruptions on the plasma facing components. The MGI method transforms the stored plasma energy to radiation that is spread across the vacuum vessel with poloidal and toroidal asymmetries. This work investigated the impact of MGI like heat loading on the first wall armor material beryllium. ITER-relevant power densities of 90-260MWm−2in combination with pulse durations of 5-10ms were exerted onto the S-65 grade beryllium specimens in the electron beam facility JUDITH 1. All tested loading conditions led to noticeable surface morphology changes and in the expected worst case scenario, a crater with thermally induced cracks with a depth of up to ∼340µm formed in the loaded area. The level of destruction in the loaded area was strongly dependent on the pulse number but also on the formation of beryllium oxide. The cyclic melting of beryllium could lead to an armor thinning mechanism under the presence of melt motion driving forces such as surface tension, magnetic forces, and plasma pressure.

  8. Effect of supplementation of drumstick (Moringa oleifera) and amaranth (Amaranthus tricolor) leaves powder on antioxidant profile and oxidative status among postmenopausal women.

    Science.gov (United States)

    Kushwaha, Shalini; Chawla, Paramjit; Kochhar, Anita

    2014-11-01

    Menopause is a gradual three-stage process that concludes with the end of periods and reproductive life. The antioxidant enzyme system get affected in postmenopause due to deficiency of estrogen, which has got antioxidant properties. The objective of the present study was therefore, to analyze the effect of supplementation of drumstick and amaranth leaves powder on blood levels of antioxidant and marker of oxidative stress. Ninety postmenopausal women aged 45-60 years were selected and divided into three groups viz. Group I, II and III having thirty subjects in each group. The subjects of group II and III were supplemented daily with 7 g drumstick leaves powder (DLP) and 9 g amaranth leaves powder (ALP), respectively for a period of 3 months in their diet. The subjects of group I was not given supplementation. Serum retinol, serum ascorbic acid, glutathione peroxidase, superoxide dismutase and malondialdehyde were analyzed before and after supplementation. Fasting blood glucose and haemoglobin level of the subjects were also analyzed. The data revealed that supplementation of DLP and ALP significantly increased serum retinol (8.8 % and 5.0 %), serum ascorbic acid (44.4 % and 5.9 %), glutathione peroxidase (18.0 % and 11.9 %), superoxide dismutase (10.4 % and 10.8) whereas decrease in marker of oxidative stress i.e. malondialdehyde (16.3 % and 9.6 %) in postmenopausal women of group II and group III, respectively. A significant (p ≤ 0.01) decrease was also observed in fasting blood glucose level (13.5 % and 10.4 %) and increase in haemoglobin (17.5 % and 5.3 %) in group II and group III, respectively. The results indicated that these plants possess antioxidant property and have therapeutic potential for the prevention of complications during postmenopause.

  9. Sn powder as reducing agents and SnO2 precursors for the synthesis of SnO2-reduced graphene oxide hybrid nanoparticles.

    Science.gov (United States)

    Chen, Mingxi; Zhang, Congcong; Li, Lingzhi; Liu, Yu; Li, Xichuan; Xu, Xiaoyang; Xia, Fengling; Wang, Wei; Gao, Jianping

    2013-12-26

    A facile approach to prepare SnO2/rGO (reduced graphene oxide) hybrid nanoparticles by a direct redox reaction between graphene oxide (GO) and tin powder was developed. Since no acid was used, it is an environmentally friendly green method. The SnO2/rGO hybrid nanoparticles were characterized by ultraviolet-visible spectroscopy, Raman spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The microstructure of the SnO2/rGO was observed with scanning electron microscopy and transmission electron microscopy. The tin powder efficiently reduced GO to rGO, and the Sn was transformed to SnO2 nanoparticles (∼45 nm) that were evenly distributed on the rGO sheets. The SnO2/rGO hybrid nanoparticles were then coated on an interdigital electrode to fabricate a humidity sensor, which have an especially good linear impedance response from 11% to 85% relative humidity.

  10. Enhancement of Antioxidant Mechanisms and Reduction of Oxidative Stress in Chickens after the Administration of Drinking Water Enriched with Polyphenolic Powder from Olive Mill Waste Waters

    Directory of Open Access Journals (Sweden)

    Aliki Papadopoulou

    2017-01-01

    Full Text Available The aim of the study was to examine the effects of a polyphenolic powder from olive mill wastewater (OMWW administered through drinking water, on chickens’ redox status. Thus, 75 chickens were divided into three groups. Group A was given just drinking water, while groups B and C were given drinking water containing 20 and 50 μg/ml of polyphenols, respectively, for 45 days. The antioxidant effects of the polyphenolic powder were assessed by measuring oxidative stress biomarkers in blood after 25 and 45 days of treatment. These markers were total antioxidant capacity (TAC, protein carbonyls (CARB, thiobarbituric acid reactive species (TBARS and superoxide dismutase activity (SOD in plasma, and glutathione (GSH and catalase activity in erythrocytes. The results showed that CARB and TBARS were decreased significantly in groups B and C, and SOD decreased in group B compared to that in group A. TAC was increased significantly in group C and GSH was increased in group B, while catalase activity was increased in groups B and C compared to that in group A. In conclusion, this is the first study showing that supplementation of chickens with polyphenols from OMWW through drinking water enhanced their antioxidant mechanisms and reduced oxidative stress-induced damage.

  11. Optical properties and structure of beryllium lead silicate glasses

    Energy Technology Data Exchange (ETDEWEB)

    Zhidkov, I. S., E-mail: i.s.zhidkov@urfu.ru [Ural Federal University, Mira Str. 19, Yekaterinburg, 620002, Russia and Institute of Metal Physics, Russian Academy of Sciences-Ural Division, S. Kovalevskoi Str. 18, 620990 Yekaterinburg (Russian Federation); Zatsepin, A. F.; Cholakh, S. O.; Kuznetsova, Yu. A. [Ural Federal University, Mira Str. 19, Yekaterinburg, 620002 (Russian Federation)

    2014-10-21

    Luminescence and optical properties and structural features of (BeO){sub x}(PbO⋅SiO{sub 2}){sub 1−x} glasses (x = 0 ÷ 0.3) are investigated by means of optical absorption and photoluminescence spectroscopy and X-ray diffraction. The regularities of the formation of the optical absorption edge and static disorder are studied. It is shown that the optical absorption and luminescence are determined by transitions between localized states of lead ions. The impact of beryllium oxide on optical and luminescence properties and electronic structure of bands tails is discussed. The presence of two different concentration ranges with various short-range order structure and band tails nature has been established.

  12. Optical properties and structure of beryllium lead silicate glasses

    Science.gov (United States)

    Zhidkov, I. S.; Zatsepin, A. F.; Cholakh, S. O.; Kuznetsova, Yu. A.

    2014-10-01

    Luminescence and optical properties and structural features of (BeO)x(PbOṡSiO2)1-x glasses (x = 0 ÷ 0.3) are investigated by means of optical absorption and photoluminescence spectroscopy and X-ray diffraction. The regularities of the formation of the optical absorption edge and static disorder are studied. It is shown that the optical absorption and luminescence are determined by transitions between localized states of lead ions. The impact of beryllium oxide on optical and luminescence properties and electronic structure of bands tails is discussed. The presence of two different concentration ranges with various short-range order structure and band tails nature has been established.

  13. Synthesis of Nanostructured Tin Oxide (SnO2 Powders and Thin Films by Sol-Gel Method

    Directory of Open Access Journals (Sweden)

    Ashok D. Bhagwat

    2015-12-01

    Full Text Available Nanocrystalline SnO2 powder was successfully prepared by using simple sol-gel technique. The sol-gel obtained was washed and calcinated at 400 C to obtain the SnO2 nano-powder. The structural property of (SnO2 nanocrystalline powder was investigated by using X-ray diffraction (XRD technique. The optical properties were studied using Uv-Vis Spectroscopy, by recording the absorbance and transmittance spectra. The XRD pattern of the as-prepared sample demonstrated the formation of a rutile structure of SnO2 nanocrystallites. The Scanning Electron Microscopic (SEM analysis showed a homogeneous distribution of quite small grains over scanned area. The Uv-Vis absorbance spectra also showed a characteristic peak of absorbance at   312 nm corresponding to SnO2. The energy band gap measurement for nanocrystalline SnO2 thin film was done from the graph of variation of (hν2 versus hν. The measured value of optical bandgap energies for SnO2 thin film is 3.78 eV. The results show that the transmittance of the synthesized SnO2 film is 78 % in the spectral range 350 nm to 800 nm.

  14. Ultra-trace determination of beryllium in occupational hygiene samples by ammonium bifluoride extraction and fluorescence detection using hydroxybenzoquinoline sulfonate.

    Science.gov (United States)

    Ashley, Kevin; Agrawal, Anoop; Cronin, John; Tonazzi, Juan; McCleskey, T Mark; Burrell, Anthony K; Ehler, Deborah S

    2007-02-19

    A highly sensitive molecular fluorescence method for measuring ultra-trace levels of beryllium has been previously described. The method entails extraction of beryllium workplace samples by 1% ammonium bifluoride (NH(4)HF(2), aqueous), followed by fluorescence detection using hydroxybenzoquinoline sulfonate (HBQS). In this work, modification of the existing procedure resulted in a significant improvement in detection power, thereby enabling ultra-trace determination of beryllium in air filter and surface wipe samples. Such low detection limits may be necessary in view of expected decreases in applicable occupational exposure limits (OELs) for beryllium. Attributes of the modified NH(4)HF(2) extraction/HBQS fluorescence method include method detection limits (MDLs) of <0.8 ng to approximately 2 ng Be per sample (depending on the fluorometer used), quantitative recoveries from beryllium oxide, a dynamic range of several orders of magnitude, and freedom from interferences. Other key advantages of the technique are field portability, relatively low cost, and high sample throughput. The method performance compares favorably with that of inductively coupled plasma-mass spectrometry (ICP-MS).

  15. Ultra-trace determination of beryllium in occupational hygiene samples by ammonium bifluoride extraction and fluorescence detection using hydroxybenzoquinoline sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Ashley, Kevin [U.S. Department of Health and Human Services, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, 4676 Columbia Parkway, M.S. R-7, Cincinnati, OH 45226-1998 (United States)]. E-mail: kashley@cdc.gov; Agrawal, Anoop [Berylliant, Inc., 4541 E. Fort Lowell Road, Tucson, AZ 85712 (United States); Cronin, John [Berylliant, Inc., 4541 E. Fort Lowell Road, Tucson, AZ 85712 (United States); Tonazzi, Juan [Berylliant, Inc., 4541 E. Fort Lowell Road, Tucson, AZ 85712 (United States); McCleskey, T. Mark [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Burrell, Anthony K. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States); Ehler, Deborah S. [Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, NM 87545 (United States)

    2007-02-19

    A highly sensitive molecular fluorescence method for measuring ultra-trace levels of beryllium has been previously described. The method entails extraction of beryllium workplace samples by 1% ammonium bifluoride (NH{sub 4}HF{sub 2}, aqueous), followed by fluorescence detection using hydroxybenzoquinoline sulfonate (HBQS). In this work, modification of the existing procedure resulted in a significant improvement in detection power, thereby enabling ultra-trace determination of beryllium in air filter and surface wipe samples. Such low detection limits may be necessary in view of expected decreases in applicable occupational exposure limits (OELs) for beryllium. Attributes of the modified NH{sub 4}HF{sub 2} extraction/HBQS fluorescence method include method detection limits (MDLs) of <0.8 ng to {approx}2 ng Be per sample (depending on the fluorometer used), quantitative recoveries from beryllium oxide, a dynamic range of several orders of magnitude, and freedom from interferences. Other key advantages of the technique are field portability, relatively low cost, and high sample throughput. The method performance compares favorably with that of inductively coupled plasma-mass spectrometry (ICP-MS)

  16. Kinetic studies on dissolution of UO{sub 2} powders in acid solutions by using cerium (IV) or chlorine dioxide as oxidants

    Energy Technology Data Exchange (ETDEWEB)

    Asano, Yuichiro; Kataoka, Makoto; Tomiyasu, Hiroshi [Tokyo Inst. of Tech. (Japan). Research Lab. for Nuclear Reactors; Ikeda, Yasuhisa

    1996-02-01

    The UO{sub 2} powders of 100-150, 150-212, 212-250, and 250-300 {mu}m were dissolved in HNO{sub 3} or HCl solutions containing strong oxidants to examine their effect on the dissolution rates. Cerium(IV) species and ClO{sub 2} were used as oxidants in HNO{sub 3} and HCl solutions, respectively. The Ce(IV) species were prepared by bubbling O{sub 3} gas into HNO{sub 3} solutions containing Ce(NO{sub 3}){sub 3}. All dissolution experiments were carried out under rapid stirring conditions which make it possible to neglect the diffusion effect. Dissolution reactions were analyzed on the assumptions that the UO{sub 2} powders are spherical particles and homogeneously dissolved from their external surface. Dissolution rate constants ({Phi}) in mol{center_dot}cm{sup -2}{center_dot}min{sup -1} were measured at various concentrations of oxidants and temperatures. Furthermore, the effect of acid concentrations on the dissolution rate was also examined. As a result, the dissolution rate constants {Phi} were found to be expressed as {Phi}=k{sub N}[Ce(IV)][H{sup +}]{sup 0.6} for HNO{sub 3} solution([HNO{sub 3}]=1-5M, Temp.{<=}30degC) and {Phi}=k{sub H}[ClO{sub 2}][H{sup +}]{sup -0.3} for HCl solution([HCl]=1-5M, Temp.{<=}30degC), respectively. Activation energies(kJ{center_dot}mol{sup -1}) for the apparent dissolution rate constants are 44.1{+-}1.9 for the HNO{sub 3} solution system and 33.5{+-}2.8 for the HCl solution system, respectively. (author).

  17. Lead Nitrate Titration Determination of Cupric Oxide in Extension of Delay Powder%硝酸铅滴定法测定延期药中氧化铜

    Institute of Scientific and Technical Information of China (English)

    王风清; 董男平; 崔丽梅; 国飞; 朱晓莉

    2014-01-01

    以硝酸和H2O2对延期药中铅化合物和氧化铜完成溶解,通过硫脲释放,采用硝酸铅滴定法测定延期药中的氧化铜。加入30 mL HNO3溶液(1+8)和15 mL六次甲基四胺控制样品溶液为pH 5~6。结果表明,方法的回收率为98.8%~99.9%,测定结果的相对标准偏差为0.12%~0.2%(n=6)。该方法准确可靠,可用于延期药中氧化铜分析。%Copper oxide and lead compounds in delay powder were dissolved by nitric acid and H2O2,and released by thiourea,then copper oxide was determined with lead nitrate titration method. Sample solution was controlled as pH 5-6 by adding 30 mL HNO3 solution (1+8) and 15 mL hexamethylenetetramine. The results showed that the recoveries were 98.8%-99.9%,and the relative standard deviations of determination results were 0.12%-0.2%(n=6). The method is accurate,reliable,and suitable to determine copper oxide in delay powder.

  18. Characterization of plasma sprayed beryllium ITER first wall mockups

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R.G.; Vaidya, R.U.; Hollis, K.J. [Los Alamos National Lab., NM (United States). Material Science and Technology Div.

    1998-01-01

    ITER first wall beryllium mockups, which were fabricated by vacuum plasma spraying the beryllium armor, have survived 3000 thermal fatigue cycles at 1 MW/m{sup 2} without damage during high heat flux testing at the Plasma Materials Test Facility at Sandia National Laboratory in New Mexico. The thermal and mechanical properties of the plasma sprayed beryllium armor have been characterized. Results are reported on the chemical composition of the beryllium armor in the as-deposited condition, the through thickness and normal to the through thickness thermal conductivity and thermal expansion, the four-point bend flexure strength and edge-notch fracture toughness of the beryllium armor, the bond strength between the beryllium armor and the underlying heat sink material, and ultrasonic C-scans of the Be/heat sink interface. (author)

  19. Quantitative method of determining beryllium or a compound thereof in a sample

    Science.gov (United States)

    McCleskey, T. Mark; Ehler, Deborah S.; John, Kevin D.; Burrell, Anthony K.; Collis, Gavin E.; Minogue, Edel M.; Warner, Benjamin P.

    2010-08-24

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  20. Quantitative method of determining beryllium or a compound thereof in a sample

    Energy Technology Data Exchange (ETDEWEB)

    McCleskey, T. Mark (Los Alamos, NM); Ehler, Deborah S. (Los Alamos, NM); John, Kevin D. (Santa Fe, NM); Burrell, Anthony K. (Los Alamos, NM); Collis, Gavin E. (Los Alamos, NM); Minogue, Edel M. (Los Alamos, NM); Warner, Benjamin P. (Los Alamos, NM)

    2010-08-24

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  1. Quantitative method of determining beryllium or a compound thereof in a sample

    Energy Technology Data Exchange (ETDEWEB)

    McCleskey, T. Mark; Ehler, Deborah S.; John, Kevin D.; Burrell, Anthony K.; Collis, Gavin E.; Minogue, Edel M.; Warner, Benjamin P.

    2006-10-31

    A method of determining beryllium or a beryllium compound thereof in a sample, includes providing a sample suspected of comprising beryllium or a compound thereof, extracting beryllium or a compound thereof from the sample by dissolving in a solution, adding a fluorescent indicator to the solution to thereby bind any beryllium or a compound thereof to the fluorescent indicator, and determining the presence or amount of any beryllium or a compound thereof in the sample by measuring fluorescence.

  2. Electronic bistability in linear beryllium chains.

    Science.gov (United States)

    Helal, Wissam; Monari, Antonio; Evangelisti, Stefano; Leininger, Thierry

    2009-04-30

    A theoretical investigation on the mixed-valence behavior (bistability) of a series of cationic linear chains composed of beryllium atoms, Be(N)(+) (with N = 6,..., 12), is presented. The calculations were performed at CAS-SCF and MR-CI levels by using an ANO basis set containing 6s4p3d2f orbitals for each atom. Our results show a consistent gradual shift between different classes of mixed-valence compounds as the number of beryllium atoms increases, from class III strong coupling toward class II valence trapped. Indeed, in the largest cases (N > 10), the cationic chains were found to be closer to class I, where the coupling vanishes. The intramolecular electron transfer parameters V(ab), E(a), and E(opt) were calculated for each atomic chain. It is shown that the decrease of V(ab) with increasing N follows an exponential pattern.

  3. Plasma cleaning of beryllium coated mirrors

    Science.gov (United States)

    Moser, L.; Marot, L.; Steiner, R.; Newman, M.; Widdowson, A.; Ivanova, D.; Likonen, J.; Petersson, P.; Pintsuk, G.; Rubel, M.; Meyer, E.; Contributors, JET

    2016-02-01

    Cleaning systems of metallic first mirrors are needed in more than 20 optical diagnostic systems from ITER to avoid reflectivity losses. Currently, plasma sputtering is considered as one of the most promising techniques to remove deposits coming from the main wall (mainly beryllium and tungsten). This work presents the results of plasma cleaning of rhodium and molybdenum mirrors exposed in JET-ILW and contaminated with typical tokamak elements (including beryllium and tungsten). Using radio frequency (13.56 MHz) argon or helium plasma, the removal of mixed layers was demonstrated and mirror reflectivity improved towards initial values. The cleaning was evaluated by performing reflectivity measurements, scanning electron microscopy, x-ray photoelectron spectroscopy and ion beam analysis.

  4. PIGE analysis of magnesium and beryllium

    Science.gov (United States)

    Fonseca, M.; Jesus, A. P.; Luís, H.; Mateus, R.; Cruz, J.; Gasques, L.; Galaviz, D.; Ribeiro, J. P.

    2010-06-01

    In this work, we present an alternative method for PIGE analysis of magnesium and beryllium in thick samples. This method is based on the ERYA - Emitted Radiation Yield Analysis - code, which integrates the nuclear reaction excitation function along the depth of the sample. For this purpose, the excitations functions of the 25Mg(p,p'γ) 25Mg ( Eγ = 585 keV) and 9Be(p,γ) 10B ( Eγ = 718 keV) reactions were employed. Calculated gamma-ray yields were compared, at several proton energy values, with experimental yields for thick samples made of inorganic compounds containing magnesium or beryllium. The agreement is better than 5%. Taking into consideration the experimental uncertainty of the measured yields and the errors related to the stopping power values, this agreement shows that effects as the beam energy straggling, ignored in the calculation, seem to play a minor role.

  5. Neutron counter based on beryllium activation

    Energy Technology Data Exchange (ETDEWEB)

    Bienkowska, B.; Prokopowicz, R.; Kaczmarczyk, J.; Paducha, M. [Institute of Plasma Physics and Laser Microfusion (IPPLM), Hery 23, 01-497 Warsaw (Poland); Scholz, M.; Igielski, A. [Institute of Nuclear Physics PAS (IFJPAN), Radzikowskiego 152, 31-342 Krakow (Poland); Karpinski, L. [Faculty of Electrical Engineering, Rzeszow University of Technology, Pola 2, 35-959 Rzeszow (Poland); Pytel, K. [National Centre for Nuclear Research (NCBJ), Soltana 7, 05-400 Otwock - Swierk (Poland)

    2014-08-21

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction {sup 9}Be(n, α){sup 6}He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, {sup 6}He, decays with half-life T{sub 1/2} = 0.807 s emitting β{sup −} particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of β–particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known β–source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5–the Monte Carlo transport code. It allowed proper application of the results of transport calculations of β{sup −} particles emitted from radioactive {sup 6}He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  6. Neutron counter based on beryllium activation

    Science.gov (United States)

    Bienkowska, B.; Prokopowicz, R.; Scholz, M.; Kaczmarczyk, J.; Igielski, A.; Karpinski, L.; Paducha, M.; Pytel, K.

    2014-08-01

    The fusion reaction occurring in DD plasma is followed by emission of 2.45 MeV neutrons, which carry out information about fusion reaction rate and plasma parameters and properties as well. Neutron activation of beryllium has been chosen for detection of DD fusion neutrons. The cross-section for reaction 9Be(n, α)6He has a useful threshold near 1 MeV, which means that undesirable multiple-scattered neutrons do not undergo that reaction and therefore are not recorded. The product of the reaction, 6He, decays with half-life T1/2 = 0.807 s emitting β- particles which are easy to detect. Large area gas sealed proportional detector has been chosen as a counter of β-particles leaving activated beryllium plate. The plate with optimized dimensions adjoins the proportional counter entrance window. Such set-up is also equipped with appropriate electronic components and forms beryllium neutron activation counter. The neutron flux density on beryllium plate can be determined from the number of counts. The proper calibration procedure needs to be performed, therefore, to establish such relation. The measurements with the use of known β-source have been done. In order to determine the detector response function such experiment have been modeled by means of MCNP5-the Monte Carlo transport code. It allowed proper application of the results of transport calculations of β- particles emitted from radioactive 6He and reaching proportional detector active volume. In order to test the counter system and measuring procedure a number of experiments have been performed on PF devices. The experimental conditions have been simulated by means of MCNP5. The correctness of simulation outcome have been proved by measurements with known radioactive neutron source. The results of the DD fusion neutron measurements have been compared with other neutron diagnostics.

  7. Beryllium induces premature senescence in human fibroblasts.

    Science.gov (United States)

    Coates, Shannon S A; Lehnert, Bruce E; Sharma, Sunil; Kindell, Susan M; Gary, Ronald K

    2007-07-01

    After cells have completed a sufficient number of cell divisions, they exit the cell cycle and enter replicative senescence. Here, we report that beryllium causes proliferation arrest with premature expression of the principal markers of senescence. After young presenescent human fibroblasts were treated with 3 microM BeSO(4) for 24 h, p21 cyclin-dependent kinase inhibitor mRNA increased by >200%. Longer periods of exposure caused mRNA and protein levels to increase for both p21 and p16(Ink4a), a senescence regulator that prevents pRb-mediated cell cycle progression. BeSO(4) also caused dose-dependent induction of senescence-associated beta-galactosidase activity (SA-beta-gal). Untreated cells had 48 relative fluorescence units (RFU)/microg/h of SA-beta-gal, whereas 3 microM BeSO(4) caused activity to increase to 84 RFU/microg/h. In chromatin immunoprecipitation experiments, BeSO(4) caused p53 protein to associate with its DNA binding site in the promoter region of the p21 gene, indicating that p53 transcriptional activity is responsible for the large increase in p21 mRNA elicited by beryllium. Forced expression of human telomerase reverse transcriptase (hTERT) rendered HFL-1 cells incapable of normal replicative senescence. However, there was no difference in the responsiveness of normal HFL-1 fibroblasts (IC(50) = 1.9 microM) and hTERT-immortalized cells (IC(50) = 1.7 microM) to BeSO(4) in a 9-day proliferation assay. The effects of beryllium resemble those of histone deacetylase-inhibiting drugs, which also cause large increases in p21. However, beryllium produced no changes in histone acetylation, suggesting that Be(2+) acts as a novel and potent pharmacological inducer of premature senescence.

  8. Computer simulation of electronic excitations in beryllium

    CERN Document Server

    Popov, A V

    2016-01-01

    An effective method for the quantitative description of the electronic excited states of polyatomic systems is developed by using computer technology. The proposed method allows calculating various properties of matter at the atomic level within the uniform scheme. A special attention is paid to the description of beryllium atoms interactions with the external fields, comparable by power to the fields in atoms, molecules and clusters.

  9. The bioinorganic chemistry and associated immunology of chronic beryllium disease.

    Science.gov (United States)

    Scott, Brian L; McCleskey, T Mark; Chaudhary, Anu; Hong-Geller, Elizabeth; Gnanakaran, S

    2008-07-07

    Chronic beryllium disease (CBD) is a debilitating, incurable, and often fatal disease that is caused by the inhalation of beryllium particulates. The growing use of beryllium in the modern world, in products ranging from computers to dental prosthetics (390 tons of beryllium in the US in the year 2000) necessitates a molecular based understanding of the disease in order to prevent and cure CBD. We have investigated the molecular basis of CBD at Los Alamos National Laboratory during the past six years, employing a multidisciplinary approach of bioinorganic chemistry and immunology. The results of this work, including speciation, inhalation and dissolution, and immunology will be discussed.

  10. The bioinorganic chemistry and associated immunology of chronic beryllium disease†

    Science.gov (United States)

    McCleskey, T. Mark; Chaudhary, Anu; Hong-Geller, Elizabeth; Gnanakaran, S.

    2013-01-01

    Chronic beryllium disease (CBD) is a debilitating, incurable, and often fatal disease that is caused by the inhalation of beryllium particulates. The growing use of beryllium in the modern world, in products ranging from computers to dental prosthetics (390 tons of beryllium in the US in the year 2000) necessitates a molecular based understanding of the disease in order to prevent and cure CBD. We have investigated the molecular basis of CBD at Los Alamos National Laboratory during the past six years, employing a multidisciplinary approach of bioinorganic chemistry and immunology. The results of this work, including speciation, inhalation and dissolution, and immunology will be discussed. PMID:18566702

  11. Possible health risks from low level exposure to beryllium.

    Science.gov (United States)

    Stange, A W; Hilmas, D E; Furman, F J

    1996-07-17

    The first case of chronic beryllium disease (CBD) at the Rocky Flats Environmental Technology Site (Rocky Flats) was diagnosed in a machinist in 1984. Rocky Flats, located 16 miles northwest of Denver, Colorado, is part of the United States Department of Energy (DOE) nuclear weapons complex. Research and development operations using beryllium began at Rocky Flats in 1953, and beryllium production operations began in 1957. Exposures could have occurred during foundry operations, casting, shearing, rolling, cutting, welding, machining, sanding, polishing, assembly, and chemical analysis operations. The Beryllium Health Surveillance Program (BHSP) was established in June 1991 at Rocky Flats to provide health surveillance for beryllium exposed employees using the Lymphocyte Proliferation Test (LPT) to identify sensitized individuals. Of the 29 cases of CBD and 76 cases of beryllium sensitization identified since 1991, several cases appear to have had only minimal opportunistic exposures to beryllium, since they were employed in administrative functions rather than primary beryllium operations. In conjunction with other health surveillance programs, a questionnaire and interview are administered to obtain detailed work and health histories. These histories, along with other data, are utilized to estimate the extent of an individual's exposure. Additional surveillance is in progress to attempt to characterize the possible risks from intermittent or brief exposures to beryllium in the workplace.

  12. A novel isomorphic phase transition in beta-pyrochlore oxide KOs{sub 2}O{sub 6}: a study using high resolution neutron powder diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Sasai, Kenzo; Kofu, Maiko; Yamaura, Jun-ichi; Hiroi, Zenji; Yamamuro, Osamu [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8581 (Japan); Ibberson, Richard M [ISIS Facility, STFC-Rutherford Appleton Laboratory, Chilton, Didcot OX11 0QX (United Kingdom); Hirota, Kazuma, E-mail: yamamuro@issp.u-tokyo.ac.j [Department of Earth and Space Science, Faculty of Science, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2010-01-13

    We have carried out adiabatic calorimetric and neutron powder diffraction experiments on the beta-pyrochlore oxide KOs{sub 2}O{sub 6}, which has a superconducting transition at T{sub c} = 9.6 K and another novel transition at T{sub p} = 7.6 K. A characteristic feature of this compound is that the K ions exhibit rattling vibrations in the cages formed by O atoms even at very low temperatures. The temperature and entropy of the T{sub p} transition is in good agreement with previous data measured using a heat relaxation method, indicating that the present sample is of high purity and the transition entropy, 0.296 J K{sup -1} mol{sup -1}, does not depend on the calorimetric method used. The neutron powder diffraction data show no peak splitting nor extra peaks over the temperature range between 2 and 295 K, suggesting that the T{sub p} transition is a rather unusual isomorphic transition. Rietveld analysis revealed an anomalous expansion of the lattice and a deformation of the O atom cage below 7.6 K. In the low-temperature phase, the distribution of scattering density corresponding to the K ions becomes broader whilst maintaining its maximum at the cage center. Based on these findings, we suggest that the T{sub p} transition is due to the expansion of the cage volume and cooperative condensation of the K ions into the ground state of the rattling motion.

  13. A novel isomorphic phase transition in β-pyrochlore oxide KOs2O6: a study using high resolution neutron powder diffraction.

    Science.gov (United States)

    Sasai, Kenzo; Kofu, Maiko; Ibberson, Richard M; Hirota, Kazuma; Yamaura, Jun-ichi; Hiroi, Zenji; Yamamuro, Osamu

    2010-01-13

    We have carried out adiabatic calorimetric and neutron powder diffraction experiments on the β-pyrochlore oxide KOs(2)O(6), which has a superconducting transition at T(c) = 9.6 K and another novel transition at T(p) = 7.6 K. A characteristic feature of this compound is that the K ions exhibit rattling vibrations in the cages formed by O atoms even at very low temperatures. The temperature and entropy of the T(p) transition is in good agreement with previous data measured using a heat relaxation method, indicating that the present sample is of high purity and the transition entropy, 0.296 J K(-1) mol(-1), does not depend on the calorimetric method used. The neutron powder diffraction data show no peak splitting nor extra peaks over the temperature range between 2 and 295 K, suggesting that the T(p) transition is a rather unusual isomorphic transition. Rietveld analysis revealed an anomalous expansion of the lattice and a deformation of the O atom cage below 7.6 K. In the low-temperature phase, the distribution of scattering density corresponding to the K ions becomes broader whilst maintaining its maximum at the cage center. Based on these findings, we suggest that the T(p) transition is due to the expansion of the cage volume and cooperative condensation of the K ions into the ground state of the rattling motion.

  14. Disposal of beryllium and cadmium from research reactors; Entsorgung von Beryllium und Cadmium aus Forschungsreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Lierse von Gostomski, C.; Remmert, A.; Stoewer, W. [Inst. fuer Radiochemie, Technische Univ. Muenchen, Garching (Germany); Bach, F.W.; Wilk, P.; Kutlu, I. [Inst. fuer Werkstoffkunde, Univ. Hannover, Hannover (Germany); Blenski, H.J.; Berthold, M. [Gesellschaft fuer Nuklear-Service mbH, Essen (Germany); Nerlich, K.D.; Plank, W. [TUeV Sueddeutschland Bau und Betrieb GmbH, Muenchen (Germany)

    2003-07-01

    Beryllium and cadmium mostly occur in metal form as radioactive special materials during the deconstruction of research reactors. Beryllium is usually used in these reactors as a neutron reflector and moderator, while cadmium is used above all as a neutron absorber. Both metals together have a high chemotoxicity as well as an inventory of radionuclides which has not been more closely characterised up to now. A high tritium content is to be expected, particularly in the case of beryllium; this tritium is due to the reaction of the metal with thermal reactor neutrons in particular. However, other nuclides which may be formed by neutron capture from impurities also contribute to the activity inventory. Up to now there is no qualified process for proper treatment, conditioning and intermediate and final repository in Germany. (orig.)

  15. Behavior of beryllium pebbles under irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Dalle-Donne, M.; Scaffidi-Argentina, F. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Inst. fuer Neutronenphysik und Reactortechnik; Baldwin, D.L.; Gelles, D.S.; Greenwood, L.R.; Kawamura, H.; Oliver, B.M.

    1998-01-01

    Beryllium pebbles are being considered in fusion reactor blanket designs as neutron multiplier. An example is the European `Helium Cooled Pebble Bed Blanket.` Several forms of beryllium pebbles are commercially available but little is known about these forms in response to fast neutron irradiation. Commercially available beryllium pebbles have been irradiated to approximately 1.3 x 10{sup 22} n/cm{sup 2} (E>1 MeV) at 390degC. Pebbles 1-mm in diameter manufactured by Brush Wellman, USA and by Nippon Gaishi Company, Japan, and 3-mm pebbles manufactured by Brush Wellman were included. All were irradiated in the below-core area of the Experimental Breeder Reactor-II in Idaho Falls, USA, in molybdenum alloy capsules containing helium. Post-irradiation results are presented on density change measurements, tritium release by assay, stepped-temperature anneal, and thermal ramp desorption tests, and helium release by assay and stepped-temperature anneal measurements, for Be pebbles from two manufacturing methods, and with two specimen diameters. The experimental results on density change and tritium and helium release are compared with the predictions of the code ANFIBE. (author)

  16. Preparation of Zn/TiO2 powder and its photocatalytic performance for oxidation of P-nitrophenol

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Zn-doped TiO2 catalysts were prepared using a sol-gel method and characterized by XPS,UV-Vis, BET,XRD in this study. Under the irradiation of simulant sunlight, the photocatalytic activity for the degradation of p-nitrophenol was studied too. After irradiation for 2.5 h, the degradation percentage of p-nitrophenol could rise to more than 80 %. The results showed that the spectrum absorption band edge of Zn/TiO2 powder does not broaden obviously comparing with pure TiO2 powder. Zinc exists as Zn (Ⅱ). When calcined at 973 K, there is a new phase as ZnTiO3 in Zn/TiO2 catalyst. The order of photocatalytic activity of Zn/TiO2 catalysts calcined at different temperatures for p-nitrophenol is 773 K > 673 K > 873 K > 573 K > 973 K and the photocatalytic activity of Zn/TiO2 catalyst calcined at 773 K is better than TiO2 catalysts heated at the same temperature, and outclasses that of commercial TiO2catalyst. It also showed that the photocatalytie degradation of p-nitrophenol follows first-order kinetics under the irradiation of simulant sunlight.

  17. Degassing measurement for beryllium exposed to D{sub 2} atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Markin, A.V.; Zakharov, A.P. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Physical Chemistry

    1998-01-01

    A possibility of the correct determination of deuterium solubility and diffusivity in Be on the basis of degassing experiments is demonstrated. It has been found that the main fraction (above 90%) of deuterium retained under D{sub 2} exposure is removed under slight electropolishing (descaling of {approx} 2-5 {mu}m) of the samples before TDS measurement. This deuterium seems to be located in the near surface oxide layers formed during the exposure as a result of interaction of beryllium with oxygen containing molecules of residual gas. In all degassing runs the diffusion of deuterium in the bulk of beryllium samples was not a limited-stage of gas release. (author)

  18. Functionally Graded Nanophase Beryllium/Carbon Composites

    Science.gov (United States)

    Choi, Michael K.

    2003-01-01

    Beryllium, beryllium alloys, beryllium carbide, and carbon are the ingredients of a class of nanophase Be/Be2C/C composite materials that can be formulated and functionally graded to suit a variety of applications. In a typical case, such a composite consists of a first layer of either pure beryllium or a beryllium alloy, a second layer of B2C, and a third layer of nanophase sintered carbon derived from fullerenes and nanotubes. The three layers are interconnected through interpenetrating spongelike structures. These Be/Be2C/C composite materials are similar to Co/WC/diamond functionally graded composite materials, except that (1) W and Co are replaced by Be and alloys thereof and (2) diamond is replaced by sintered carbon derived from fullerenes and nanotubes. (Optionally, one could form a Be/Be2C/diamond composite.) Because Be is lighter than W and Co, the present Be/Be2C/C composites weigh less than do the corresponding Co/WC/diamond composites. The nanophase carbon is almost as hard as diamond. WC/Co is the toughest material. It is widely used for drilling, digging, and machining. However, the fact that W is a heavy element (that is, has high atomic mass and mass density) makes W unattractive for applications in which weight is a severe disadvantage. Be is the lightest tough element, but its toughness is less than that of WC/Co alloy. Be strengthened by nanophase carbon is much tougher than pure or alloy Be. The nanophase carbon has an unsurpassed strength-to-weight ratio. The Be/Be2C/C composite materials are especially attractive for terrestrial and aerospace applications in which there are requirements for light weight along with the high strength and toughness of the denser Co/WC/diamond materials. These materials could be incorporated into diverse components, including cutting tools, bearings, rocket nozzles, and shields. Moreover, because Be and C are effective as neutron moderators, Be/Be2C/C composites could be attractive for some nuclear applications.

  19. Electrodeposition of Fe powder from acid electrolytes

    Directory of Open Access Journals (Sweden)

    VESNA M. MAKSIMOVIC

    2008-08-01

    Full Text Available Polarization characteristics of the electrodeposition processes of Fe powders from sulfate and chloride electrolytes and the morphology of the obtained powders were investigated. The morphology depended on the anion presence in the electrolyte but not on the current density in the investigated range. A characteristic feature of the dendritic powder with cauliflower endings obtained from sulfate electrolyte is the presence of cone-like cavities and the crystallite morphology of the powders surface. On the other hand, Fe powders electrodeposited from chloride electrolyte appear in the form of agglomerates. A soap solution treatment applied as a method of washing and drying provides good protection from oxidation of the powders.

  20. Reversal of effects of intra peritoneally administered beryllium nitrate by tiron and CaNa3DTPA alone or in combination with alpha-tocopherol.

    Science.gov (United States)

    Nirala, Satendra Kumar; Bhadauria, Monika; Upadhyay, Anil Kumar; Mathur, Ramesh; Mathur, Asha

    2009-12-01

    To evaluate therapeutic efficacy of chelating agents tiron (Sodium-4,5-dihydroxy-1,3-benzene disulphonate) and CaNa3DTPA (Calcium trisodium diethylene triamine pentaacetic acid) in presence of alpha-tocopherol against beryllium induced toxicity, adult female albino rats were exposed to beryllium nitrate for 28 days followed by therapy with tiron (471 mg/kg, i.p.) and CaNa3DTPA (35 mg/kg, i.p.) alone and in combination with alpha-tocopherol (25 mg/kg, p.o.). Results revealed non-significant fall in haemoglobin and total serum protein content while significant fall in blood sugar level and activity of serum alkaline phosphatase. On the other hand, significant rise in the activity of serum transaminases and LDH was noticed after beryllium administration. Significant increase in total and esterified cholesterol was found in liver and kidney after toxicity. Significant increase in lipid peroxidation and decreased level of reduced glutathione in both the organs showed oxidative stress due to beryllium exposure. Histopathological and ultrastructural observations of liver and kidney revealed lesions due to beryllium toxicity followed by recovery due to combined therapy. CaNa3DTPA showed moderate therapeutic efficacy; however, its effectiveness was enhanced with alpha-tocopherol to some extent. Tiron in combination with alpha-tocopherol exerted statistically more beneficial effects in reversal of beryllium induced biochemical, histopathological and ultrastructural alterations.

  1. Equation of ''state'' for thermoremanent magnetization in micron-size powders of copper oxide superconductors

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, G.; Agrawala, G.; Bhagat, S.M. (Dept. of Physics, Center for Superconductivity Research, Univ. of Maryland, College Park, MD (USA))

    1991-04-01

    We have extended previous studies on the time and temperature dependence of M{sub ZFC}, M{sub FC} and M{sub TRM} of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7} powders to encompass a variety of sizes and methods of preparation. The slow long term decays are confirmed over a wider time span. The T dependence of M{sub TRM} is well described by M{sub TRM}proportional to (1-(T/Tc)){sup q} and this ''equation of state'' is rendered plausible on the basis of a model involving thermally assisted escape of individual fluxons. (orig.).

  2. Erosion behaviour of ultrathin carbon layers and hydrogen retention in beryllium; Untersuchungen zur Erosion ultraduenner Kohlenstoffschichten und Wasserstoffrueckhaltung in Beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Reinelt, Matthias

    2008-04-16

    end of its implantation trajectory. Above a implantation fluence of 1.10{sup 17} cm{sup -2}, local supersaturation and destabilization of the beryllium lattice leads to the formation of structural modifications. Deuterium is adsorbed on the surface of nanoscaled, closes voids in these areas. Energetic considerations show, that no molecular deuterium is formed under such circumstances. The binding energies of these states are 1.06 eV and 1.14 eV with release temperatures of 440 K and 470 K respectively. Implantation at substrate temperatures above 300 K lead to the formation of increasing amounts of BeD2, which decomposes at 570 K. The influence of a thin surface oxide coverage (1-3 ML BeO) is investigated. This shows, that none of the above mentioned binding states is limited by deuterium recombination. Deuterium bound to surface oxide is released at 680 K. (orig.)

  3. Beryllium metal II. a review of the available toxicity data.

    Science.gov (United States)

    Strupp, Christian

    2011-01-01

    Beryllium metal was classified in Europe collectively with beryllium compounds, e.g. soluble salts. Toxicological equivalence was assumed despite greatly differing physicochemical properties. Following introduction of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation, beryllium metal was classified as individual substance and more investigational efforts to appropriately characterize beryllium metal as a specific substance apart from soluble beryllium compounds was required. A literature search on toxicity of beryllium metal was conducted, and the resulting literature compiled together with the results of a recently performed study package into a comprehensive data set. Testing performed under Organisation for Economic Co-Operation and Development guidelines and Good Laboratory Practice concluded that beryllium metal was neither a skin irritant, an eye irritant, a skin sensitizer nor evoked any clinical signs of acute oral toxicity; discrepancies between the current legal classification of beryllium metal in the European Union (EU) and the experimental results were identified. Furthermore, genotoxicity and carcinogenicity were discussed in the context of the literature data and the new experimental data. It was concluded that beryllium metal is unlikely to be a classical nonthreshold mutagen. Effects on DNA repair and morphological cell transformation were observed but need further investigation to evaluate their relevance in vivo. Animal carcinogenicity studies deliver evidence of carcinogenicity in the rat; however, lung overload may be a species-specific confounding factor in the existing studies, and studies in other species do not give convincing evidence of carcinogenicity. Epidemiology has been intensively discussed over the last years and has the problem that the studies base on the same US beryllium production population and do not distinguish between metal and soluble compounds. It is noted that the correlation

  4. 晶粒度对纳米铜粉抗氧能力的影响%Effect of the Grain Size on the Anti-Oxidizing Ability of Copper Nano-Powders

    Institute of Scientific and Technical Information of China (English)

    李在元; 翟玉春

    2008-01-01

    Taken KBH4 and vitamin C (VC) as reducers, CuSO4· 5H2O as a raw material, EDTA as a complex agent and polyvinyl-pyrolidone (PVP) as a protector, the copper nano-powders were prepared by the liquid reduction method. Placed the powders with different grain sizes in air for an hour, the powders were then examined by XRD, DTA-TG and TEM. The results reveal that the anti-oxidizing ability of the copper nano-powders depends on their grain sizes. When the grain size of the copper nano-powder is bigger, the anti-oxidizing ability is better. If the granularity of the powder is bigger than 75 nm, the powder will not be easily oxidized in air.The 75 nm copper nano-powder samples begin to be oxidized at 120 ℃. The melting point of the copper nano-powder is very low, so the grain will melt and grow up quickly under the TEM elec-tron beam.%以KBH4和维生素C(VC)为还原荆,以CuSO4·5H2O为原料,以EDTA为络合荆,PVP为分散剂,用液相还原法制备不同晶粒度的纳米铜粉.不同晶粒度的纳米铜粉同时在空气中放置1 h后,进行XRD、DTA-TG以及TEM检测.结果表明:不同粒度的纳米铜粉在空气中抗氧化能力不同,晶粒度越大抗氧化能力越强.晶粒度大于75 nm时在空气中放置1 h不被氧化,平均晶粒度为75 nm的纳米铜粉在120℃时开始氧化.纳米铜粉的熔点很低,进行TEM检测时,在电子束照射下颗粒熔融长大.

  5. Experimental and thermodynamic study of the hydrothermal oxidation behavior of Ti{sub 3}SiC{sub 2} powders

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.B.; Wang, X. [Applied Mineralogy, Institute for Geosciences, Eberhard-Karls-University Tuebingen, Wilhelmstrasse 56, D-72074 Tuebingen (Germany); Nickel, K.G. [Applied Mineralogy, Institute for Geosciences, Eberhard-Karls-University Tuebingen, Wilhelmstrasse 56, D-72074 Tuebingen (Germany)], E-mail: klaus.nickel@uni-tuebingen.de; Zhou, Y.C. [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2008-10-15

    The interaction of Ti{sub 3}SiC{sub 2} with H{sub 2}O at 50 MPa and 500-700 deg. C was investigated. Thermodynamic calculations were also employed to analyze the reactions. During hydrothermal oxidation, Ti and Si were selectively oxidatively extracted from Ti{sub 3}SiC{sub 2}, resulting in the formation of TiO{sub 2}, SiO{sub 2} and amorphous-sp{sup 2}-disordered carbon. This phenomenon was attributed to the unique bonding and structural characteristics of Ti{sub 3}SiC{sub 2}.

  6. Deuterium/hydrogen isotope exchange on beryllium and beryllium nitride; Deuterium/Wasserstoff-Isotopenaustausch an Beryllium und Berylliumnitrid

    Energy Technology Data Exchange (ETDEWEB)

    Dollase, Petra; Eichler, Michael; Koeppen, Martin; Dittmar, Timo; Linsmeier, Christian [Forschungszentrum Juelich GmbH, Institut fuer Energie- und Klimaforschung - Plasmaphysik (Germany)

    2016-07-01

    In the fusion experiments JET and ITER, the first wall is made up of beryllium. The use of nitrogen is discussed for radiative cooling in the divertor. This can react with the surface of the first wall to form beryllium nitride (Be{sub 3}N{sub 2}). The hydrogen isotopes deuterium and tritium, which react in the fusion reaction to helium and a neutron, are used as fuel. Since the magnetic confinement of the plasma is not perfect, deuterium and tritium ions are also found on the beryllium wall and can accumulate there. This should be avoided due to the radioactivity of tritium. Therefore the isotope exchange with deuterium is investigated to regenerate the first wall. We investigate the isotopic exchange of deuterium and protium in order to have not to work with radioactive tritium. The ion bombardment is simulated with an ion source. With voltages up to a maximum of 5 kV, deuterium and protic hydrogen ions are implanted in polycrystalline Be and Be{sub 3}N{sub 2}. The samples are then analyzed in situ using X-ray photoelectron spectroscopy (XPS) and thermal desorption spectroscopy (TDS). Subsequently, samples prepared under the same conditions are characterized ex-situ by means of nuclear reaction analysis (NRA). [German] In den Fusionsexperimenten JET und ITER besteht die erste Wand im Hauptraum aus Beryllium (Be). Zur Strahlungskuehlung im Divertor wird der Einsatz von Stickstoff diskutiert. Dieser kann mit der Oberflaeche der ersten Wand zu Berylliumnitrid (Be{sub 3}N{sub 2}) reagieren. Als Brennstoff werden die Wasserstoffisotope Deuterium und Tritium eingesetzt, die in der Fusionsreaktion zu Helium und einem Neutron reagieren. Da der magnetische Einschluss des Plasmas nicht perfekt ist, treffen auch Deuterium- und Tritiumionen auf die Berylliumwand auf und koennen sich dort anreichern. Das soll aufgrund der Radioaktivitaet von Tritium unbedingt vermieden werden. Daher wird zur Regenerierung der ersten Wand der Isotopenaustausch mit Deuterium untersucht. Wir

  7. Beryllium toxicity testing in the suspension culture of mouse fibroblasts.

    Science.gov (United States)

    Rössner, P; Bencko, V

    1980-01-01

    Suspension culture of mouse fibroblast cell line L-A 115 was used to test beryllium toxicity in the presence of magnesium ions. Beryllium added to the MEM cultivation medium was bound in a complex with sulphosalicylic acid BeSSA complex, because the use of beryllium chloride turned out to yield ineffective beryllium phosphate that formed macroscopically detectable insoluble opacities. The BeSSA complex was used in the concentration range: 10(-3)--10(-9)M, magnesium was used in 3 concentrations: 10(-1)M, 5 x 10(-2)M and 10(-2)M. Growth curve analysis revealed pronounced beryllium toxicity at the concentration of 10(-3)M, magnesium-produced toxic changes were observed only at the concentration of 10(-1)M. No competition between the beryllium and magnesium ions was recorded. It is assumed that the possible beryllium-magnesium competition was significantly modified by the use of BeSSA complex-bound beryllium.

  8. Joining of beryllium by braze welding technique: preliminary results

    Energy Technology Data Exchange (ETDEWEB)

    Banaim, P.; Abramov, E. [Ben-Gurion Univ. of the Negev, Beersheba (Israel); Zalkind, S.; Eden, S.

    1998-01-01

    Within the framework of some applications, there is a need to join beryllium parts to each other. Gas Tungsten Arc Braze Welds were made in beryllium using 0.3 mm commercially Aluminum (1100) shim preplaced at the joint. The welds exhibited a tendency to form microcracks in the Fusion Zone and Heat Affected Zone. All the microcracks were backfilled with Aluminum. (author)

  9. 10 CFR 850.20 - Baseline beryllium inventory.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Baseline beryllium inventory. 850.20 Section 850.20 Energy... Baseline beryllium inventory. (a) The responsible employer must develop a baseline inventory of the... inventory, the responsible employer must: (1) Review current and historical records; (2) Interview...

  10. Ionization energies of beryllium in strong magnetic fields

    Institute of Scientific and Technical Information of China (English)

    GUANXiao-xu; ZHANGYue-xia

    2004-01-01

    We have develop an effective frozen core approximation to calculate energy levels and ionization enegies of the beryllium atom in magnetic field strengths up to 2.35 × 105T. Systematic improvement over the Hartree-Fock results for the beryllium low-lying states has been accomplished.

  11. Ionization energies of beryllium in strong magnetic fields

    Institute of Scientific and Technical Information of China (English)

    GUAN Xiao-xu; ZHANG Yue-xia

    2004-01-01

    We have develop an effective frozen core approximation to calculate energy levels and ionization enegies of the beryllium atom in magnetic field strengths up to 2.35×105T. Systematic improvement over the Hartree-Fock results for the beryllium low-lying states has been accomplished.

  12. IRIS TOXICOLOGICAL REVIEW AND SUMMARY DOCUMENTS FOR BERYLLIUM AND COMPOUNDS

    Science.gov (United States)

    EPA's assessment of the noncancer health effects and carcinogenic potential of Beryllium was added to the IRIS database in 1998. The IRIS program is updating the IRIS assessment for Beryllium. This update will incorporate health effects information published since the last assess...

  13. MERCURY OXIDATION PROMOTED BY A SELECTIVE CATALYTIC REDUCTION CATALYST UNDER SIMULATED POWDER RIVER BASIN COAL COMBUSTION CONDITIONS

    Science.gov (United States)

    A bench-scale reactor consisting of a natural gas burner and an electrically heated reactor housing a selective catalytic reduction (SCR) catalyst was constructed for studying elemental mercury oxidation under SCR conditions. A low sulfur Power River Basin (PRB) coal combustion ...

  14. Effects of Metal Ions and EDTA on Free Radical Reaction Intermediates of Laccase-catalyzed Oxidation of Wood Powder from Szemao Pine

    Institute of Scientific and Technical Information of China (English)

    ZHOU Guanwu; DUAN Xinfang; CAO Yongjian; CHEN Yongsheng; CAO Yuanlin

    2006-01-01

    Certain activator was expected to be developed to improve the free radical intermediates relative intensity,and thus to enhance the adhesion between wood fibers when fiberboard was made by laccase treated wood fibers.Reactive oxygen species(ROS)was detected in laccase-catalyzed oxidation of wood powder using ESR spin trapping technique.The effects of five metal ions(Cu2+,K+,Fe2+,Mg2,Fe3+)and EDTA on ROS relative strengths were investigated under the condition of pH 5.6 by electron spin resonance spectrometry.The result shows that Cu2+ slightly activates the free radical reaction,and Fe2+ ion has a significant inhibitive effect on the ROS relative strength in the suspension liquid.There is a marked inhibition of the ROS relative intensity when 0.5 mmol/L EDTA is used.The metal ions that enhance laccase activity may be utilized to increase physical properties of fiberboard made by laccase oxidized wood fibers.

  15. Attenuation of lead-induced oxidative stress in rat brain, liver, kidney and blood of male Wistar rats by Moringa oleifera seed powder.

    Science.gov (United States)

    Velaga, Manoj Kumar; Daughtry, Lucius K; Jones, Angelica C; Yallapragada, Prabhakara Rao; Rajanna, Sharada; Rajanna, Bettaiya

    2014-01-01

    Moringa oleifera is a tree belonging to Moringaceae family and its leaves and seeds are reported to have ameliorative effects against metal toxicity. In the present investigation, M. oleifera seed powder was tested against lead-induced oxidative stress and compared against meso-2, 3-dimercaptosuccinic acid (DMSA) treatment. Male Wistar rats (100-120 g) were divided into four groups: control (2000 ppm of sodium acetate for 2 weeks), exposed (2000 ppm of lead acetate for 2 weeks), Moringa treated (500 mg/kg for 7 days after lead exposure), and DMSA treated (90 mg/kg for 7 days after lead exposure). After exposure and treatment periods, rats were sacrificed and the brain was separated into cerebellum, hippocampus, frontal cortex, and brain stem; liver, kidney, and blood were also collected. The data indicated a significant (poleifera restored all the parameters back to control, tissue-specifically, and also showed improvement in restoration better than DMSA treatment, indicating reduction of the negative effects of lead-induced oxidative stress.

  16. Protection of air in premises and environment against beryllium aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Bitkolov, N.Z.; Vishnevsky, E.P.; Krupkin, A.V. [Research Inst. of Industrial and Marine Medicine, St. Petersburg (Russian Federation)

    1998-01-01

    First and foremost, the danger of beryllium aerosols concerns a possibility of their inhalation. The situation is aggravated with high biological activity of the beryllium in a human lung. The small allowable beryllium aerosols` concentration in air poses a rather complex and expensive problem of the pollution prevention and clearing up of air. The delivery and transportation of beryllium aerosols from sites of their formation are defined by the circuit of ventilation, that forms aerodynamics of air flows in premises, and aerodynamic links between premises. The causes of aerosols release in air of premises from hoods, isolated and hermetically sealed vessels can be vibrations, as well as pulses of temperature and pressure. Furthermore, it is possible the redispersion of aerosols from dirty surfaces. The effective protection of air against beryllium aerosols at industrial plants is provided by a complex of hygienic measures: from individual means of breath protection up to collective means of the prevention of air pollution. (J.P.N.)

  17. Estimating occupational beryllium exposure from compliance monitoring data.

    Science.gov (United States)

    Hamm, Michele P; Burstyn, Igor

    2011-01-01

    Occupational exposure to beryllium is widespread and is a health risk. The objectives of this study were to develop plausible models to estimate occupational airborne beryllium exposure. Compliance monitoring data were obtained from the Occupational Safety and Health Administration for 12,148 personal measurements of beryllium exposure from 1979 to 2005. Industry codes were maintained as reported or collapsed based on the number of measurements per cell of a job-exposure matrix (JEM). Probability of exposure was predicted based on year, industry, job, and sampling duration. In these models, probability of exposure decreased over time, was highest in full-shift personal samples, and varied with industry and job. The probability of exposure was calculated using 6 JEMs, each providing similar rankings of the likelihood of non-negligible exposure to beryllium. These statistical models, with expert appraisal, are suitable for the assessment of the probability of elevated occupational exposure to beryllium.

  18. Preparation of reduced graphene oxide/flake carbonyl iron powders/polyaniline composites and their enhanced microwave absorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Yang [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212000 (China); Luo, Juhua, E-mail: luojuhua@163.com [School of Material Science and Engineering, Yancheng Institute of Technology, Yancheng 224051 (China); Yao, Wei; Xu, Jianguang [School of Material Science and Engineering, Yancheng Institute of Technology, Yancheng 224051 (China); Li, Tao [School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212000 (China)

    2015-07-05

    Highlights: • A novel composite of R-GO/F-CIP/PANI was prepared. • The formation mechanism of R-GO/F-CIP/PANI composites was discussed. • R-GO/F-CIP/PANI composites possessed excellent microwave absorption properties. - Abstract: The composites of reduced graphene/flake carbonyl iron powders/polyaniline (R-GO/F-CIP/PANI) were synthesized via two-step method, a green chemical route which was based on the reductive nature of the iron ion in first step and followed by the in situ polymerization of PANI on the surface of R-GO/F-CIP. The structures and morphologies were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FT-IR), and Raman spectroscopy. The results revealed that the core–shell structure of the composites of R-GO/F-CIP/PANI was successfully prepared and the shape of F-CIP had a great influence on the magnetic properties of the composites. The composites possessed the excellent microwave absorption properties in 2–18 GHz and the best microwave absorption property was obtained in 11.8 GHz with the minimum reflection loss of −38.8 dB at the thickness of 2.0 mm.

  19. ZIRCONIUM-TITANIUM-BERYLLIUM BRAZING ALLOY

    Science.gov (United States)

    Gilliland, R.G.; Patriarca, P.; Slaughter, G.M.; Williams, L.C.

    1962-06-12

    A new and improved ternary alloy is described which is of particular utility in braze-bonding parts made of a refractory metal selected from Group IV, V, and VI of the periodic table and alloys containing said metal as a predominating alloying ingredient. The brazing alloy contains, by weight, 40 to 50 per cent zirconium, 40 to 50 per cent titanium, and the balance beryllium in amounts ranging from 1 to 20 per cent, said alloy having a melting point in the range 950 to 1400 deg C. (AEC)

  20. Plasma transferred arc deposition of beryllium

    Science.gov (United States)

    Hollis, K.; Bartram, B.; Withers, J.; Storm, R.; Massarello, J.

    2006-12-01

    The exceptional properties of beryllium (Be), including low density and high elastic modulus, make it the material of choice in many defense and aerospace applications. However, health hazards associated with Be material handling limit the applications that are suited for its use. Innovative solutions that enable continued use of Be in critical applications while addressing worker health concerns are highly desirable. Plasma transferred arc solid free-form fabrication is being evaluated as a Be fabrication technique for civilian and military space-based components. Initial experiments producing Be deposits are reported here. Deposit shape, microstructure, and mechanical properties are reported.

  1. Neutron beams from protons on beryllium.

    Science.gov (United States)

    Bewley, D K; Meulders, J P; Octave-Prignot, M; Page, B C

    1980-09-01

    Measurements of dose rate and penetration in water have been made for neutron beams produced by 30--75 MeV protons on beryllium. The effects of Polythene filters added on the target side of the collimator have also been studied. A neutron beam comparable with a photon beam from a 4--8 MeV linear accelerator can be produced with p/Be neutrons plus 5 cm Polythene filtrations, with protons in the range 50--75 MeV. This is a more economical method than use of the d/Be reaction.

  2. 40 CFR 63.11166 - What General Provisions apply to primary beryllium production facilities?

    Science.gov (United States)

    2010-07-01

    ... primary beryllium production facilities? 63.11166 Section 63.11166 Protection of Environment ENVIRONMENTAL... Primary Nonferrous Metals Area Sources-Zinc, Cadmium, and Beryllium Primary Beryllium Production Facilities § 63.11166 What General Provisions apply to primary beryllium production facilities? (a) You...

  3. Hydrothermal Synthesis and Photochromism Property of Superfine Powders of Metastable Tungsten Oxide%介稳态氧化钨超微粉体的水热合成与光致变色性质研究

    Institute of Scientific and Technical Information of China (English)

    徐英明; 霍丽华; 赵辉; 高山; 赵经贵

    2005-01-01

    Under hydrothermal conditions, the superfine powders of cubic pyrochlore-type of tungsten oxide and hexagonal tungsten bronze were obtained by using Na2WO4·2H2O as the starting material. The products were characterized by XRD, TG, IR, UV and EPMA, respectively. The effects of the pH value, the acid concentration, reaction temperature and time on the structure and particle size of products were investigated in detail. The conditions for the preparation of superfine powders of tungsten oxide were optimized. The pH 2.5~4.5 of the reaction system led to the formation of a pyroehlore phase and pH 0.5~2.0 gave the hexagonal tungsten bronze structure. The photochromism property of the hexagonal tungsten bronze was studied. The results show that pyroehlore and bronze phases are decomposed at 300℃ and 450℃, respectively. With the increasing of temperature, the structure of the two oxides changes. The pyrochlore-type powder changes completely into trielinic Na2W4O13 around 500℃, while the bronze phase into a mixture of Na2W6O19 and trielinie WO3 at 550℃. The powder of the hexagonal tungsten bronze showed better photochromism property。

  4. Effect of deposited tungsten on deuterium accumulation in beryllium in contact with atomic deuterium

    Energy Technology Data Exchange (ETDEWEB)

    Sharapov, V.M.; Gavrilov, L.E. [Institute of Physical Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Kulikauskas, V.S.

    1998-01-01

    Usually ion or plasma beam is used for the experiment with beryllium which simulates the interaction of plasma with first wall in fusion devices. However, the use of thermal or subthermal atoms of hydrogen isotopes seems to be useful for that purpose. Recently, the authors have studied the deuterium accumulation in beryllium in contact with atomic deuterium. The experimental setup is shown, and is explained. By means of elastic recoil detection (ERD) technique, it was shown that in the exposure to D atoms at 740 K, deuterium is distributed deeply into the bulk, and is accumulated up to higher concentration than the case of the exposure to molecular deuterium. The depth and concentration of deuterium distribution depend on the exposure time, and those data are shown. During the exposure to atomic deuterium, oxide film grew on the side of a sample facing plasma. In order to understand the mechanism of deuterium trapping, the experiment was performed using secondary ion mass spectrometry (SIMS) and residual gas analysis (RGA). The influence that the tungsten deposit from the heated cathode exerted to the deuterium accumulation in beryllium in contact with atomic deuterium was investigated. These results are reported. (K.I.)

  5. Hot extrusion of Be–Ti powder

    Energy Technology Data Exchange (ETDEWEB)

    Kurinskiy, P., E-mail: petr.kurinskiy@kit.edu [Karlsruhe Institute of Technology, Institute for Applied Materials—Applied Materials Physics (IAM—AWP), PO Box 3640, 76021 Karlsruhe (Germany); Leiste, H. [Karlsruhe Institute of Technology, Institute for Applied Materials—Applied Materials Physics (IAM—AWP), PO Box 3640, 76021 Karlsruhe (Germany); Goraieb, A.A. [Karlsruhe Beryllium Handling Facility (KBHF GmbH), Herrmann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Mueller, S. [Extrusion Research and Development Center, TU Berlin, Sekr. TIB 4/1-2, Gustav-Meyer-Allee 25, 13355 Berlin (Germany)

    2015-10-15

    Highlights: • Extrusion in double-walled containment of Be–Ti blended powder was investigated. • Fabrication of Be–Ti rods by extrusion at 700 °C showed more satisfactory results compared to an extrusion at 900 °C. • Factors which influence homogeneous and stable metal flow during extrusion are discussed. - Abstract: Be–30.8 wt.%Ti powder mixture was extruded in copper and steel containers at 700 and 900 °C, respectively. In both cases, achieved extrusion ratio was 7:1. Investigations of microstructure of manufactured Be–Ti rods revealed that processing temperature has a great influence on the metal flow during the extrusion as well as formation of beryllide phases. The results obtained by X-ray diffraction (XRD) analysis proved that brittle intermetallic phases were formed by processing at 900 °C; while no evidence of reaction between beryllium and titanium was detected after extrusion at 700 °C. Additionally, high-temperature annealing tests of produced Be–Ti samples were performed in order to study the evolution of the phase composition after the heat treatment. The effects of different mechanical properties of core materials (beryllium and titanium) and containers on uniform deformation are discussed in this work.

  6. A simple technology for CuO/TiO2 3D interface fabrication using nanocrystalline oxide powders

    Science.gov (United States)

    Forcade, Fresnel; Snyders, Rony; Noirfalise, Xavier; González, Bernardo; Laza, Camila; Vigil, Elena

    2017-03-01

    A CuO/TiO2 interface with potential use for solar light conversion is studied. Thin films are synthesized using a mixture of commercially available nanocrystalline TiO2 and CuO powders. Samples with mass concentrations from 5 to 10% of CuO in TiO2 were prepared from a colloidal suspension using a ‘doctor blade’ technique. Heat treatment (500 °C, 1 h) was used to generate crystals necking and improve adhesion to substrates. X-ray diffraction analysis and scanning electron microscopy indicate that the CuO nanocrystals are smaller than those of TiO2. Since TiO2 does not absorb light in the spectral range where the CuO absorption edge is located, it was possible to obtain an effective CuO absorption coefficient spectra and then extract the bandgap energy. The results confirm the potential use of CuO as a TiO2 inorganic sensitizer for solar light. SEM images show a mesoporous structure for all samples that would facilitate penetration of a hole conductor and guarantee a large three-dimensional interface. Photocurrent direction with no bias confirms electron transfer from the CuO to the TiO2 when CuO/TiO2 films are used as photoelectrodes. Therefore, excited electrons in the CuO conduction band occupy levels with energy greater than the empty states in the TiO2 conduction band. Possible technological improvements to increase electron collection are discussed.

  7. Preparation of Nanostructured CoNiCrAlY Powder and Investigation on Its Oxidation Behavior%纳米结构CoNiCrAlY粉末的制备及其氧化行为

    Institute of Scientific and Technical Information of China (English)

    张林伟; 王鲁; 王全胜; 宁先进

    2012-01-01

    The nanostructured CoNiCrAlY powder was prepared using the technology of planet mechanical milling. The oxidation behavior of conventional and nanostructured powder at 1 000 C was investigated by the measures of X-ray diffraction and scanning electron microscope. The results show that the technique of planet mechanical milling could be used to prepare nanostructured powder and the average grain size of CoNiCrAlY powder is 11. 2 nm after milled for 30 h. The anti-oxidation capability of CoNiCrAlY nanostructured powder is well improved. During the static oxidation of constant temperature at 1 000 ℃ for 100 h, the nanostuructured powder forms only a single α - Al2O3 scale, while the conventional powder forms mixed oxide scale composed of a - A12O3 scale, mixed oxide and a small amount of 0- Al2O3.%利用行星球磨技术制备了纳米结构CoNiCrAlY粉末,采用XRD,SEM等方法对传统结构粉末和纳米结构粉末在1000℃时的氧化行为进行了研究.结果表明,行星球磨技术能制备出纳米结构粉末,球磨30 h后,粉末的平均晶粒尺寸为11.2 nm.纳米结构提高了CorANiClY粉末的抗氧化性能,在1000℃恒温静态氧化100 h的过程中,纳米结构粉末只生成α-Al2O3氧化膜,而传统结构粉末除α-Al2O3外还生成了尖晶石氧化物和少量θ-Al2O3.

  8. Beryllium nitrate inhibits fibroblast migration to disrupt epimorphic regeneration.

    Science.gov (United States)

    Cook, Adam B; Seifert, Ashley W

    2016-10-01

    Epimorphic regeneration proceeds with or without formation of a blastema, as observed for the limb and skin, respectively. Inhibition of epimorphic regeneration provides a means to interrogate the cellular and molecular mechanisms that regulate it. In this study, we show that exposing amputated limbs to beryllium nitrate disrupts blastema formation and causes severe patterning defects in limb regeneration. In contrast, exposing full-thickness skin wounds to beryllium only causes a delay in skin regeneration. By transplanting full-thickness skin from ubiquitous GFP-expressing axolotls to wild-type hosts, we demonstrate that beryllium inhibits fibroblast migration during limb and skin regeneration in vivo Moreover, we show that beryllium also inhibits cell migration in vitro using axolotl and human fibroblasts. Interestingly, beryllium did not act as an immunostimulatory agent as it does in Anurans and mammals, nor did it affect keratinocyte migration, proliferation or re-epithelialization, suggesting that the effect of beryllium is cell type-specific. While we did not detect an increase in cell death during regeneration in response to beryllium, it did disrupt cell proliferation in mesenchymal cells. Taken together, our data show that normal blastema organogenesis cannot occur without timely infiltration of local fibroblasts and highlights the importance of positional information to instruct pattern formation during regeneration. In contrast, non-blastemal-based skin regeneration can occur despite early inhibition of fibroblast migration and cell proliferation.

  9. Quantum molecular dynamics simulations of beryllium at high pressures

    Science.gov (United States)

    Desjarlais, Michael; Knudson, Marcus

    2008-03-01

    The phase boundaries and high pressure melt properties of beryllium have been the subject of several recent experimental and theoretical studies. The interest is motivated in part by the use of beryllium as an ablator material in inertial confinement fusion capsule designs. In this work, the high pressure melt curve, Hugoniot crossings, sound speeds, and phase boundaries of beryllium are explored with DFT based quantum molecular dynamics calculations. The entropy differences between the various phases of beryllium are extracted in the vicinity of the melt curve and agree favorably with earlier theoretical work on normal melting. High velocity flyer plate experiments with beryllium targets on Sandia's Z machine have generated high quality data for the Hugoniot, bulk sound speeds, and longitudinal sound speeds. This data provides a tight constraint on the pressure for the onset of shock melting of beryllium and intriguing information on the solid phase prior to melt. The results of the QMD calculations and the experimental results will be compared, and implications for the HCP and BCC phase boundaries of beryllium will be presented.

  10. Sarcoidosis and chronic beryllium disease: similarities and differences.

    Science.gov (United States)

    Mayer, Annyce S; Hamzeh, Nabeel; Maier, Lisa A

    2014-06-01

    Chronic beryllium disease (CBD) is a granulomatous lung disease that may be pathologically and clinically indistinguishable from pulmonary sarcoidosis, except through use of immunologic testing, such as the beryllium lymphocyte proliferation test (BeLPT). Similar to sarcoidosis, the pulmonary manifestations of CBD are variable and overlap with other respiratory diseases. Definitive diagnosis of CBD is established by evidence of immune sensitization to beryllium and diagnostic bronchoscopy with bronchoalveolar lavage and transbronchial biopsy. However, the diagnosis of CBD can also be established on a medically probable basis in beryllium-exposed patients with consistent radiographic imaging and clinical course. Beryllium workers exposed too much higher levels of beryllium in the past demonstrated a much more fulminant disease than is usually seen today. Some extrapulmonary manifestations similar to sarcoidosis were noted in these historic cohorts, although with a narrower spectrum. Extrapulmonary manifestations of CBD are rare today. Since lung-predominant sarcoidosis can very closely resemble CBD, CBD is still misdiagnosed as sarcoidosis when current or past exposure to beryllium is not recognized and no BeLPT is obtained. This article describes the similarities and differences between CBD and sarcoidosis, including clinical and diagnostic features that can help physicians consider CBD in patients with apparent lung-predominant sarcoidosis.

  11. Regulatory T cells modulate granulomatous inflammation in an HLA-DP2 transgenic murine model of beryllium-induced disease.

    Science.gov (United States)

    Mack, Douglas G; Falta, Michael T; McKee, Amy S; Martin, Allison K; Simonian, Philip L; Crawford, Frances; Gordon, Terry; Mercer, Robert R; Hoover, Mark D; Marrack, Philippa; Kappler, John W; Tuder, Rubin M; Fontenot, Andrew P

    2014-06-10

    Susceptibility to chronic beryllium disease (CBD) is linked to certain HLA-DP molecules, including HLA-DP2. To elucidate the molecular basis of this association, we exposed mice transgenic (Tg) for HLA-DP2 to beryllium oxide (BeO) via oropharyngeal aspiration. As opposed to WT mice, BeO-exposed HLA-DP2 Tg mice developed mononuclear infiltrates in a peribronchovascular distribution that were composed of CD4(+) T cells and included regulatory T (Treg) cells. Beryllium-responsive, HLA-DP2-restricted CD4(+) T cells expressing IFN-γ and IL-2 were present in BeO-exposed HLA-DP2 Tg mice and not in WT mice. Using Be-loaded HLA-DP2-peptide tetramers, we identified Be-specific CD4(+) T cells in the mouse lung that recognize identical ligands as CD4(+) T cells derived from the human lung. Importantly, a subset of HLA-DP2 tetramer-binding CD4(+) T cells expressed forkhead box P3, consistent with the expansion of antigen-specific Treg cells. Depletion of Treg cells in BeO-exposed HLA-DP2 Tg mice exacerbated lung inflammation and enhanced granuloma formation. These findings document, for the first time to our knowledge, the development of a Be-specific adaptive immune response in mice expressing HLA-DP2 and the ability of Treg cells to modulate the beryllium-induced granulomatous immune response.

  12. Angiotensin-1 converting enzyme polymorphisms in chronic beryllium disease.

    Science.gov (United States)

    Maier, L A; Raynolds, M V; Young, D A; Barker, E A; Newman, L S

    1999-04-01

    To test the hypothesis that the angiotensin converting enzyme (ACE) genotype is associated with chronic beryllium disease (CBD) and disease severity, we studied 50 cases of CBD and compared their ACE genotype to that of two different control groups, consisting of: (1) 50 participants from a beryllium machining facility; and (2) 50 participants from a non-beryllium-associated workplace. We found no statistically significant difference in the frequency of the I or D allele or of the DD genotype among cases of CBD and either control group. The odds ratio (OR) for the CBD DD genotype as compared with the non-DD genotype was 1.58 (95% confidence interval [CI]: 0.68 to 3.66, p = 0.12) for the beryllium-exposed control group, and 1.09 (95% CI: 0.48 to 2.46, p = 0.56) for the non-beryllium-exposed controls. We found an association between serum ACE activity and the ACE genotype, with DD cases having the highest median serum ACE activity (p = 0.005). We evaluated the beryllium lymphocyte proliferation test (BeLPT), bronchoalveolar lavage (BAL) cell components, chest radiography, pulmonary function test results, and exercise physiology in our CBD cases. No statistically significant associations with these disease markers were found for the CBD cases with the DD genotype. Although the difference was not statistically significant, the DD cases had a shorter median duration of exposure to beryllium before diagnosis of CBD, and tended to have a weaker response in their blood and BAL BeLPT than did the non-DD cases. These findings may indicate that the ACE genotype is important in the immune response to beryllium and in progression to beryllium disease.

  13. Multiphase and Double-Layer NiFe2O4@NiO-Hollow-Nanosphere-Decorated Reduced Graphene Oxide Composite Powders Prepared by Spray Pyrolysis Applying Nanoscale Kirkendall Diffusion.

    Science.gov (United States)

    Park, Gi Dae; Cho, Jung Sang; Kang, Yun Chan

    2015-08-05

    Multicomponent metal oxide hollow-nanosphere decorated reduced graphene oxide (rGO) composite powders are prepared by spray pyrolysis with nanoscale Kirkendall diffusion. The double-layer NiFe2O4@NiO-hollow-nanosphere decorated rGO composite powders are prepared using the first target material. The NiFe-alloy-nanopowder decorated rGO powders are prepared as an intermediate product by post-treatment under the reducing atmosphere of the NiFe2O4/NiO-decorated rGO composite powders obtained by spray pyrolysis. The different diffusion rates of Ni (83 pm for Ni(2+)) and Fe (76 pm for Fe(2+), 65 pm for Fe(3+)) cations with different radii during nanoscale Kirkendall diffusion result in multiphase and double-layer NiFe2O4@NiO hollow nanospheres. The mean size of the hollow NiFe2O4@NiO nanospheres decorated uniformly within crumpled rGO is 14 nm. The first discharge capacities of the nanosphere-decorated rGO composite powders with filled NiFe2O4/NiO and hollow NiFe2O4@NiO at a current density of 1 A g(-1) are 1168 and 1319 mA h g(-1), respectively. Their discharge capacities for the 100th cycle are 597 and 951 mA h g(-1), respectively. The discharge capacity of the NiFe2O4@NiO-hollow-nanosphere-decorated rGO composite powders at the high current density of 4 A g(-1) for the 400th cycle is 789 mA h g(-1).

  14. Tritium and helium retention and release from irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; Longhurst, G.R.; Oates, M.A.; Pawelko, R.J. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental effort to anneal irradiated beryllium specimens and characterize them for steam-chemical reactivity experiments. Fully-dense, consolidated powder metallurgy Be cylinders, irradiated in the EBR-II to a fast neutron (>0.1 MeV) fluence of {approx}6 x 10{sup 22} n/cm{sup 2}, were annealed at temperatures from 450degC to 1200degC. The releases of tritium and helium were measured during the heat-up phase and during the high-temperature anneals. These experiments revealed that, at 600degC and below, there was insignificant gas release. Tritium release at 700degC exhibited a delayed increase in the release rate, while the specimen was at 700degC. For anneal temperatures of 800degC and higher, tritium and helium release was concurrent and the release behavior was characterized by gas-burst peaks. Essentially all of the tritium and helium was released at temperatures of 1000degC and higher, whereas about 1/10 of the tritium was released during the anneals at 700degC and 800degC. Measurements were made to determine the bulk density, porosity and specific surface area for each specimen before and after annealing. These measurements indicated that annealing caused the irradiated Be to swell, by as much as 14% at 700degC and 56% at 1200degC. Kr gas adsorption measurements for samples annealed at 1000degC and 1200degC determined specific surface areas between 0.04 m{sup 2}/g and 0.1 m{sup 2}/g for these annealed specimens. The tritium and helium gas release measurements and the specific surface area measurements indicated that annealing of irradiated Be caused a porosity network to evolve and become surface-connected to relieve internal gas pressure. (author)

  15. Inhibitory effects of beryllium chloride on rat liver microsomal enzymes.

    Science.gov (United States)

    Teixeira, C F; Yasaka, W J; Silva, L F; Oshiro, T T; Oga, S

    1990-04-30

    A single i.v. dose (0.1 mmol Be2+/kg) of beryllium chloride prolonged the duration of pentobarbital-induced sleep and zoxazolamine-induced paralysis, in rats. The effects are correlated with changes of the pharmacokinetic parameters and with the in vitro inhibition of both aliphatic and aromatic hydroxylation of pentobarbital and zoxazolamine. In vitro N-demethylation of meperidine and aminopyrine was partially inhibited while O-demethylation of quinidine was unaffected by liver microsomes of rats pretreated with beryllium salt. The findings give clues that beryllium chloride inhibits some forms of cytochrome P-450, especially those responsible for hydroxylation of substrates, like pentobarbital and zoxazolamine.

  16. Beryllium Health and Safety Committee Data Reporting Task Force

    Energy Technology Data Exchange (ETDEWEB)

    MacQueen, D H

    2007-02-21

    On December 8, 1999, the Department of Energy (DOE) published Title 10 CFR 850 (hereafter referred to as the Rule) to establish a chronic beryllium disease prevention program (CBDPP) to: {sm_bullet} reduce the number of workers currently exposed to beryllium in the course of their work at DOE facilities managed by DOE or its contractors, {sm_bullet} minimize the levels of, and potential for, expos exposure to beryllium, and {sm_bullet} establish medical surveillance requirements to ensure early detection of the disease.

  17. Development of Beryllium Vacuum Chamber Technology for the LHC

    CERN Document Server

    Veness, R; Dorn, C

    2011-01-01

    Beryllium is the material of choice for the beam vacuum chambers around collision points in particle colliders due to a combination of transparency to particles, high specific stiffness and compatibility with ultra-high vacuum. New requirements for these chambers in the LHC experiments have driven the development of new methods for the manufacture of beryllium chambers. This paper reviews the requirements for experimental vacuum chambers. It describes the new beryllium technology adopted for the LHC and experience gained in the manufacture and installation.

  18. Selection of I-220H beryllium for NIRCam optical bench

    Science.gov (United States)

    Edinger, Derek J.; Nordt, Alison A.

    2005-08-01

    The Near Infrared Camera (NIRCam) for NASA's James Webb Space Telescope (JWST) is one of the four science instruments to be installed into the Integrated Science Instrument Module (ISIM) on JWST. I-220H beryllium was chosen as the optical bench material for NIRCam based on its high specific stiffness, relatively high thermal conductivity, low CTE at cryogenic temperatures, and overall thermal stability at cryogenic temperatures. Beryllium has cryogenic heritage, but development of a structural bonded joint that could survive cryogenic temperatures was required. This paper will describe the trade studies performed in which bonded, I-220H beryllium was selected.

  19. The Effect of U{sub 3}O{sub 8} Powder on the Sintered Density of UO{sub 2} Pellet I. Oxidation Temperature

    Energy Technology Data Exchange (ETDEWEB)

    Yang, C. M.; Jung, G. D.; Yoo, M. J.; Lee, J. R. [KEPCO Nuclear Fuel Co., Daejeon (Korea, Republic of); Na, S. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-05-15

    UO{sub 2} is the most widely used nuclear fuel for current nuclear power generation. In addition, the dependence of nuclear power in the total power generation is growing due to eco-friendly factors, such as the regulation of CO{sub 2} emissions. Because of the limitations of uranium reserves and an increasing use of uranium resources, uranium price is increasing. The recycling of uranium resources is environmentally friendly as well as economical. During the manufacturing process of UO{sub 2} pellets, the accompanying amount of scrap is approximately 8%. These scraps under an air atmosphere at constant temperature are recycled into U{sub 3}O{sub 8}. In general, the sintered density of UO{sub 2} pellet decreases and pore becomes coarse by the addition of U{sub 3}O{sub 8}. In other words, U{sub 3}O{sub 8} is a density controller as well as a pore-former In this study, the influence of U{sub 3}O{sub 8} powder, formed by the various oxidation temperatures, on the sintered density of CANDU-type UO{sub 2} pellet was investigated

  20. Several indicators of oxidative stress, immunity, and illness improved in trained men consuming an encapsulated juice powder concentrate for 28 weeks.

    Science.gov (United States)

    Lamprecht, Manfred; Oettl, Karl; Schwaberger, Guenther; Hofmann, Peter; Greilberger, Joachim F

    2007-12-01

    Phytonutrients from plant foods provide numerous antioxidants. We hypothesized that supplementation for 28 wk with a commercially available encapsulated juice powder concentrate (JPC) could influence indicators of oxidative stress, immunity, and illness. Trained men (n = 41; 34 +/- 5 y; maximum oxygen uptake = 55 +/- 7 mL x kg(-1) x min(-1)) from a homogenous police Special Forces unit were randomly assigned in a double blind manner to either JPC (n = 21) or placebo (n = 20). We used multiple 7-d food records to assess dietary intake and found inadequate mean daily fruit and vegetable consumption (3.2 +/- 1.2 servings). The group physician documented all duty days lost due to illness. We collected plasma at baseline and study wk 4, 8, 16, and 28 for analysis of carbonyl groups on protein (CP) and TNFalpha. Over the 28-wk investigation, CP was lower in the JPC group, with both a treatment and a time x treatment interaction (P JPC than in the placebo group (P JPC group (P = 0.068). These data suggest beneficial JPC effects with regard to reduction of duty days lost due to illness and reduction of CP and TNFalpha concentrations in this group of trained men over 28 wk.

  1. Ação promotora do berílio em catalisadores da síntese do estireno Promotor action of beryllium in catalysts for styrene production

    Directory of Open Access Journals (Sweden)

    Mário Nilo Mendes Barbosa

    1997-10-01

    Full Text Available The catalytic dehydrogenation of ethylbenzene in presence of steam is the main commercial route to produce styrene. The industrial catalysts are potassium- and chromia-doped hematite which show low surface areas leading to bad performance and short life. In order to develop catalysts with high areas, the effect of beryllium on the textural properties and on the catalytic performance of this iron oxide was studied. The influence of the amount of the dopant, the starting material and the calcination temperature were also studied. In sample preparations, iron and beryllium salts (nitrate or sulfate were hydrolyzed with ammonia and then calcinated. The experiments followed a factorial design with two variables in two levels (Fe/Be= 3 and 7; calcination temperature= 500 and 700ºC. Solids without any dopant were also prepared. Samples were characterized by elemental analysis, infrared spectroscopy, surface area and porosity measurements, X-ray diffraction, DSC and TG. The catalysts were tested in a microreactor at 524ºC and 1 atm, by using a mole ratio of steam/ ethylbenzene=10. The selectivity was measured by monitoring styrene, benzene and toluene formation. It was found that the effect of beryllium on the characteristics of hematite and on its catalytic performance depends on the starting material and on the amount of dopant. Surface areas increased due to the dopant as well as the nature of the precursor; samples produced by beryllium sulfate showed higher areas. Beryllium-doped solids showed a higher catalytic activity when compared to pure hematite, but no significant influence of the anion of starting material was noted. It can be concluded that beryllium acts as both textural and structural promoter. Samples with Fe/Be= 3, heated at 500ºC, lead to the highest conversion and were the most selective. However, catalysts prepared from beryllium sulfate are the most promising to ethylbenzene dehydrogenation due to their high surface area which

  2. REVIEW OF RECENT DEVELOPMENTS: POWER METALLURGY,

    Science.gov (United States)

    REVIEWS), (*POWDER METALLURGY, CASTING, SINTERING, COOLING, CUTTING TOOLS , TUNGSTEN ALLOYS, PIPES, DISPERSION HARDENING, NICKEL ALLOYS, COBALT ALLOYS, THORIUM COMPOUNDS, OXIDES, BERYLLIUM, POWDER ALLOYS.

  3. Photocatalytic decolorization of azo-dye with zinc oxide powder in an external UV light irradiation slurry photoreactor

    Energy Technology Data Exchange (ETDEWEB)

    Nishio, Junpei [Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, Kawagoe, Saitama 350-8585 (Japan); Tokumura, Masahiro [Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, Kawagoe, Saitama 350-8585 (Japan); Znad, Hussein T. [Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, Kawagoe, Saitama 350-8585 (Japan); Kawase, Yoshinori [Research Center for Biochemical and Environmental Engineering, Department of Applied Chemistry, Toyo University, Kawagoe, Saitama 350-8585 (Japan)]. E-mail: bckawase@mail.eng.toyo.ac.jp

    2006-11-02

    Photocatalytic decolorization of azo-dye Orange II in water has been examined in an external UV light irradiation slurry photoreactor using zinc oxide (ZnO) as a semiconductor photocatalyst. The effects of process parameters such as light intensity, initial dye concentration, photocatalyst loading and initial solution pH on the decolorization rate of Orange II have been systematically investigated. A two-stage photocatalytic decolorization of Orange II, the first stage of fast decolorization rate and the subsequent second stage of rather slow decolorization rate, was found. The efficiency of decolorization of Orange II increased as initial Orange II concentration decreased and UV light intensity increased. There was the optimal ZnO concentration being around 1000 mg L{sup -1}. The optimal pH was around 7.7, which was at the natural pH of the dye solution. The effect of aeration rate on the decolorization of Orange II has been also investigated and the enhancement of decolorization of Orange II with increasing aeration rate was found. By using a model for the light intensity profile in the external UV light irradiation slurry photoreactor, the simulation model for the decolorization of Orange II with ZnO photocatalyst has been developed. The proposed model in which the slow decolorization in the second stage as well as the initial fast decolorization is also taken into account could simulate the experimental results for UV light irradiation satisfactorily. The proposed simulation model in which the change of light intensity with time due to the decolorization of Orange II and the light scatter due to solid photocatalysts are considered will be very useful for practical engineering design of the slurry photoreactor of wastewater including textile dyes.

  4. Microwave and millimeter wave dielectric permittivity and magnetic permeability of epsilon-gallium-iron-oxide nano-powders

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Liu, E-mail: liu.chao@tufts.edu; Afsar, Mohammed N. [Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States); Ohkoshi, Shin-ichi [Department of Chemistry, School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2015-05-07

    In millimeter wave frequency range, hexagonal ferrites with high uniaxial anisotropic magnetic fields are used as absorbers. These ferrites include M-type barium ferrite (BaFe{sub 12}O{sub 19}) and strontium ferrite (SrFe{sub 12}O{sub 19}), which have natural ferromagnetic resonant frequency range from 40 GHz to 60 GHz. However, the higher frequency range lacks suitable materials that support the higher frequency ferromagnetic resonance. A series of gallium-substituted ε-iron oxides (ε-Ga{sub x}Fe{sub 2−x}O{sub 3}) are synthesized, which have ferromagnetic resonant frequencies appearing over the frequency range of 30 GHz to 150 GHz. The ε-Ga{sub x}Fe{sub 2−x}O{sub 3} is synthesized by the sol-gel method. The particle sizes are observed to be smaller than 100 nm. In this paper, in-waveguide transmission and reflection method and the free space magneto-optical approach have been employed to study these newly developed ε-Ga{sub x}Fe{sub 2−x}O{sub 3} particles in millimeter waves. These techniques enable to obtain precise transmission spectra to determine the dielectric and magnetic properties of both isotropic and anisotropic ferrites in the microwave and millimeter wave frequency range from single set of direct measurements. The complex dielectric permittivity and magnetic permeability spectra of ε-Ga{sub x}Fe{sub 2−x}O{sub 3} are shown in this paper. Strong ferromagnetic resonances at different frequencies determined by the x parameter are found.

  5. Primordial beryllium as a big bang calorimeter.

    Science.gov (United States)

    Pospelov, Maxim; Pradler, Josef

    2011-03-25

    Many models of new physics including variants of supersymmetry predict metastable long-lived particles that can decay during or after primordial nucleosynthesis, releasing significant amounts of nonthermal energy. The hadronic energy injection in these decays leads to the formation of ⁹Be via the chain of nonequilibrium transformations: Energy(h)→T, ³He→⁶He, ⁶Li→⁹Be. We calculate the efficiency of this transformation and show that if the injection happens at cosmic times of a few hours the release of O(10 MeV) per baryon can be sufficient for obtaining a sizable ⁹Be abundance. The absence of a plateau structure in the ⁹Be/H abundance down to a O(10⁻¹⁴) level allows one to use beryllium as a robust constraint on new physics models with decaying or annihilating particles.

  6. Investigation of the ion beryllium surface interaction

    Energy Technology Data Exchange (ETDEWEB)

    Guseva, M.I.; Birukov, A.Yu.; Gureev, V.M. [RRC Kurchatov Institute, Moscow (Russian Federation)] [and others

    1995-09-01

    The self -sputtering yield of the Be was measured. The energy dependence of the Be self-sputtering yield agrees well with that calculated by W. Eckstein et. al. Below 770 K the self-sputtering yield is temperature independent; at T{sub irr}.> 870 K it increases sharply. Hot-pressed samples at 370 K were implanted with monoenergetic 5 keV hydrogen ions and with a stationary plasma (flux power {approximately} 5 MW/m{sup 2}). The investigation of hydrogen behavior in beryllium shows that at low doses hydrogen is solved, but at doses {ge} 5x10{sup 22} m{sup -2} the bubbles and channels are formed. It results in hydrogen profile shift to the surface and decrease of its concentration. The sputtering results in further concentration decrease at doses > 10{sup 25}m{sup -2}.

  7. Photodesorption from copper, beryllium, and thin films

    Science.gov (United States)

    Foerster, C. L.; Halama, H. J.; Korn, G.

    Ever increasing circulating currents in electron-positron colliders and light sources demand lower and lower photodesportion (PSD) from the surfaces of their vacuum chambers and their photon absorbers. This is particularly important in compact electron storage rings and B meson factories where photon power of several kw cm(exp -1) is deposited on the surfaces. Given the above factors, we have measured PSD from 1 m long bars of solid copper and solid beryllium, and TiN, Au and C thin films deposited on solid copper bars. Each sample was exposed to about 10(exp 23) photons/m with a critical energy of 500 eV at the VUV ring of the NSLS. PSD was recorded for two conditions: after a 200 C bake-out and after an Ar glow discharge cleaning. In addition, we also measured reflected photons, photoelectrons and desorption as functions of normal, 75 mrad, 100 mrad, and 125 mrad incident photons.

  8. New facility for post irradiation examination of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Ishitsuka, Etsuo; Kawamura, Hiroshi [Oarai Research Establishment, Ibaraki-Ken (Japan)

    1995-09-01

    Beryllium is expected as a neutron multiplier and plasma facing materials in the fusion reactor, and the neutron irradiation data on properties of beryllium up to 800{degrees}C need for the engineering design. The acquisition of data on the tritium behavior, swelling, thermal and mechanical properties are first priority in ITER design. Facility for the post irradiation examination of neutron irradiated beryllium was constructed in the hot laboratory of Japan Materials Testing Reactor to get the engineering design data mentioned above. This facility consist of the four glove boxes, dry air supplier, tritium monitoring and removal system, storage box of neutron irradiated samples. Beryllium handling are restricted by the amount of tritium;7.4 GBq/day and {sup 60}Co;7.4 MBq/day.

  9. The uses and adverse effects of beryllium on health

    DEFF Research Database (Denmark)

    Cooper, Ross G.; Harrison, Adrian Paul

    2009-01-01

    Context: This review describes the health effects of beryllium exposure in the workplace and the environment. Aim: To collate information on the consequences of occupational and environmental exposure to beryllium on physiological function and well being. Materials and Methods: The criteria used...... in the current review for selecting articles were adopted from proposed criteria in The International Classification of Functioning, Disability, and Health. Articles were classified based on acute and chronic exposure and toxicity of beryllium. Results: The proportions of utilized and nonutilized articles were...... published in sources unobtainable through requests at the British Library, and some had no impact factor and were excluded. Conclusion: Beryllium has some useful but undoubtedly harmful effects on health and well-being. Measures needed to be taken to prevent hazardous exposure to this element, making its...

  10. High-temperature annealing of proton irradiated beryllium - A dilatometry-based study

    Science.gov (United States)

    Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong; Ghose, Sanjit; Savkliyildiz, Ilyas

    2016-08-01

    Ssbnd 200 F grade beryllium has been irradiated with 160 MeV protons up to 1.2 1020 cm-2 peak fluence and irradiation temperatures in the range of 100-200 °C. To address the effect of proton irradiation on dimensional stability, an important parameter in its consideration in fusion reactor applications, and to simulate high temperature irradiation conditions, multi-stage annealing using high precision dilatometry to temperatures up to 740 °C were conducted in air. X-ray diffraction studies were also performed to compliment the macroscopic thermal study and offer a microscopic view of the irradiation effects on the crystal lattice. The primary objective was to qualify the competing dimensional change processes occurring at elevated temperatures namely manufacturing defect annealing, lattice parameter recovery, transmutation 4He and 3H diffusion and swelling and oxidation kinetics. Further, quantification of the effect of irradiation dose and annealing temperature and duration on dimensional changes is sought. The study revealed the presence of manufacturing porosity in the beryllium grade, the oxidation acceleration effect of irradiation including the discontinuous character of oxidation advancement, the effect of annealing duration on the recovery of lattice parameters recovery and the triggering temperature for transmutation gas diffusion leading to swelling.

  11. Development of Biomarkers for Chronic Beryllium Disease in Mice

    Energy Technology Data Exchange (ETDEWEB)

    Gordon, Terry

    2013-01-25

    Beryllium is a strategic metal, indispensable for national defense programs in aerospace, telecommunications, electronics, and weaponry. Exposure to beryllium is an extensively documented occupational hazard that causes irreversible, debilitating granulomatous lung disease in as much as 3 - 5% of exposed workers. Mechanistic research on beryllium exposure-disease relationships has been severely limited by a general lack of a sufficient CBD animal model. We have now developed and tested an animal model which can be used for dissecting dose-response relationships and pathogenic mechanisms and for testing new diagnostic and treatment paradigms. We have created 3 strains of transgenic mice in which the human antigen-presenting moiety, HLA-DP, was inserted into the mouse genome. Each mouse strain contains HLA-DPB1 alleles that confer different magnitude of risk for chronic beryllium disease (CBD): HLA-DPB1*0401 (odds ratio = 0.2), HLA-DPB1*0201 (odds ratio = 15), HLA-DPB1*1701 (odds ratio = 240). Our preliminary work has demonstrated that the *1701 allele, as predicted by human studies, results in the greatest degree of sensitization in a mouse ear swelling test. We have also completed dose-response experiments examining beryllium-induced lung granulomas and identified susceptible and resistant inbred strains of mice (without the human transgenes) as well as quantitative trait loci that may contain gene(s) that modify the immune response to beryllium. In this grant application, we propose to use the transgenic and normal inbred strains of mice to identify biomarkers for the progression of beryllium sensitization and CBD. To achieve this goal, we propose to compare the sensitivity and accuracy of the lymphocyte proliferation test (blood and bronchoalveolar lavage fluid) with the ELISPOT test in the three HLA-DP transgenic mice strains throughout a 6 month treatment with beryllium particles. Because of the availability of high-throughput proteomics, we will also identify

  12. Nanostructured Alloys as an Alternative to Copper-Beryllium

    Science.gov (United States)

    2014-11-19

    bushing applications;  2) Nanometal/composite for high specific strength/stiffness components; and  3) Nanometal cobalt / copper enabled...performance of Integran’s Nanovate cobalt -based and nickel- cobalt metals is superior to copper beryllium (peak hardness); Mechanical Property Summary...Nanostructured Cobalt Alloy 285 ksi (1967 MPa) 225 ksi (1550 MPa) 290 ksi (2000 MPa) 18855 ksi (130 GPa) Copper Beryllium (C17200-TH04) 142 ksi

  13. Actinide/beryllium neutron sources with reduced dispersion characteristics

    Science.gov (United States)

    Schulte, Louis D.

    2012-08-14

    Neutron source comprising a composite, said composite comprising crystals comprising BeO and AmBe.sub.13, and an excess of beryllium, wherein the crystals have an average size of less than 2 microns; the size distribution of the crystals is less than 2 microns; and the beryllium is present in a 7-fold to a 75-fold excess by weight of the amount of AmBe.sub.13; and methods of making thereof.

  14. Impurities effect on the swelling of neutron irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Donne, M.D.; Scaffidi-Argentina, F. [Institut fuer Neutronenphysik und Reaktortechnik, Karlsruhe (Germany)

    1995-09-01

    An important factor controlling the swelling behaviour of fast neutron irradiated beryllium is the impurity content which can strongly affect both the surface tension and the creep strength of this material. Being the volume swelling of the old beryllium (early sixties) systematically higher than that of the more modem one (end of the seventies), a sensitivity analysis with the aid of the computer code ANFIBE (ANalysis of Fusion Irradiated BEryllium) to investigate the effect of these material properties on the swelling behaviour of neutron irradiated beryllium has been performed. Two sets of experimental data have been selected: the first one named Western refers to quite recently produced Western beryllium, whilst the second one, named Russian refers to relatively old (early sixties) Russian beryllium containing a higher impurity rate than the Western one. The results obtained with the ANFIBE Code were assessed by comparison with experimental data and the used material properties were compared with the data available in the literature. Good agreement between calculated and measured values has been found.

  15. Determination of beryllium by using X-ray fluorescence spectrometry.

    Science.gov (United States)

    Zawisza, Beata

    2008-03-01

    X-ray fluorescence spectrometry method is subject to certain difficulties and inconveniences for the elements having the atomic number 9 or less. These difficulties become progressively more severe as the atomic number decreases, and are quite serious for beryllium, which is practically indeterminable directly by XRF. Therefore, an indirect determination of beryllium that is based on the evaluation of cobalt in the precipitate is taken into consideration. In the thesis below, there is a description of a new, simple, and precise method by selective precipitation using hexamminecobalt(III) chloride and ammonium carbonate-EDTA solution as a complexing agent for the determining of a trace amount of beryllium using X-ray fluorescence spectrometry. The optimum conditions for [Co(NH(3))(6)][Be(2)(OH)(3)(CO(3))(2)(H(2)O)(2)].(3)H(2)O complex formation were studied. The complex was collected on the membrane filter, and the Co Kalpha line was measured by XRF. The method presents the advantages of the sample preparation and the elimination of the matrix effects due to the thin film obtained. The detection limit of the proposed method is 0.2 mg of beryllium. The method was successfully applied to beryllium determination in copper/ beryllium/cobalt alloys.

  16. Proton irradiation effects on beryllium - A macroscopic assessment

    Science.gov (United States)

    Simos, Nikolaos; Elbakhshwan, Mohamed; Zhong, Zhong; Camino, Fernando

    2016-10-01

    Beryllium, due to its excellent neutron multiplication and moderation properties, in conjunction with its good thermal properties, is under consideration for use as plasma facing material in fusion reactors and as a very effective neutron reflector in fission reactors. While it is characterized by unique combination of structural, chemical, atomic number, and neutron absorption cross section it suffers, however, from irradiation generated transmutation gases such as helium and tritium which exhibit low solubility leading to supersaturation of the Be matrix and tend to precipitate into bubbles that coalesce and induce swelling and embrittlement thus degrading the metal and limiting its lifetime. Utilization of beryllium as a pion production low-Z target in high power proton accelerators has been sought both for its low Z and good thermal properties in an effort to mitigate thermos-mechanical shock that is expected to be induced under the multi-MW power demand. To assess irradiation-induced changes in the thermal and mechanical properties of Beryllium, a study focusing on proton irradiation damage effects has been undertaken using 200 MeV protons from the Brookhaven National Laboratory Linac and followed by a multi-faceted post-irradiation analysis that included the thermal and volumetric stability of irradiated beryllium, the stress-strain behavior and its ductility loss as a function of proton fluence and the effects of proton irradiation on the microstructure using synchrotron X-ray diffraction. The mimicking of high temperature irradiation of Beryllium via high temperature annealing schemes has been conducted as part of the post-irradiation study. This paper focuses on the thermal stability and mechanical property changes of the proton irradiated beryllium and presents results of the macroscopic property changes of Beryllium deduced from thermal and mechanical tests.

  17. Extremely fine structured cathode for solid oxide fuel cells using Sr-doped LaMnO3 and Y2O3-stabilized ZrO2 nano-composite powder synthesized by spray pyrolysis

    Science.gov (United States)

    Shimada, Hiroyuki; Yamaguchi, Toshiaki; Sumi, Hirofumi; Nomura, Katsuhiro; Yamaguchi, Yuki; Fujishiro, Yoshinobu

    2017-02-01

    A solid oxide fuel cell (SOFC) for high power density operation was developed with a microstructure-controlled cathode using a nano-composite powder of Sr-doped LaMnO3 (LSM) and Y2O3-stabilized ZrO2 (YSZ) synthesized by spray pyrolysis. The individual LSM-YSZ nano-composite particles, formed by crystalline and amorphous nano-size LSM and YSZ particles, showed spherical morphology with uniform particle size. The use of this powder for cathode material led to an extremely fine microstructure, in which all the LSM and YSZ grains (approximately 100-200 nm) were highly dispersed and formed their own network structures. This microstructure was due to the two phase electrode structure control using the powder, namely, nano-order level in each particle and micro-order level between particles. An anode-supported SOFC with the LSM-YSZ cathode using humidified H2 as fuel and ambient air as oxidant exhibited high power densities, such as 1.29 W cm-2 under a voltage of 0.75 V and a maximum power density of 2.65 W cm-2 at 800 °C. Also, the SOFC could be stably operated for 250 h with no degradation, even at a high temperature of 800 °C.

  18. 氧化石墨烯/氧化铕复合材料粉体的光催化性能研究%Study on light catalytic performance of graphene oxide/Eu2O3 composite powder

    Institute of Scientific and Technical Information of China (English)

    王福; 李艾; 郝玉翠; 郝斌

    2016-01-01

    Graphene oxide/Eu2O3 composite powders were prepared by hydrothermal synthesis with graphene ox-ide and Eu2O3 as raw materials. Light catalytic performance of the composite powder was tested with Rhodamine B solution as model pollutant under the irradiation of UV (ultraviolet) light. Results show that the composite powder has good photocatalytic activity on Rhodamine B solution with the increasing graphene content,and it only needs 60 minutes when degradation rate closes to 100%.%以氧化石墨烯和氧化铕为原材料,利用水热法制备了氧化石墨烯/氧化铕复合粉体。以罗丹明B溶液为模拟污染物测试了所得复合粉体在紫外光照射下的光催化性能。结果表明,随着氧化石墨烯加入量的增加,复合粉体对罗丹明B溶液表现出良好的光催化性,降解率接近100%仅需要60 min。

  19. Effect of turmeric powder (Curcuma longa L.) and ascorbic acid on physical characteristics and oxidative status of fresh and stored rabbit burgers.

    Science.gov (United States)

    Mancini, Simone; Preziuso, Giovanna; Dal Bosco, Alessandro; Roscini, Valentina; Szendrő, Zsolt; Fratini, Filippo; Paci, Gisella

    2015-12-01

    The objective of this study was to evaluate the effect of Curcuma longa powder and ascorbic acid on some quality traits of rabbit burgers. The burgers (burgers control with no additives; burgers with 3.5 g of turmeric powder/100g meat; burgers with 0.1g of ascorbic acid/100g meat) were analyzed at Days 0 and 7 for pH, color, drip loss, cooking loss, fatty acid profile, TBARS, antioxidant capacity (ABTS, DPPH and FRAP) and microbial growth. The addition of turmeric powder modified the meat color, produced an antioxidant capacity similar to ascorbic acid and determined a lower cooking loss than other formulations. Turmeric powder might be considered as a useful natural antioxidant, increasing the quality and extending the shelf life of rabbit burgers.

  20. Beryllium processing technology review for applications in plasma-facing components

    Energy Technology Data Exchange (ETDEWEB)

    Castro, R.G.; Jacobson, L.A.; Stanek, P.W.

    1993-07-01

    Materials research and development activities for the International Thermonuclear Experimental Reactor (ITER), i.e., the next generation fusion reactor, are investigating beryllium as the first-wall containment material for the reactor. Important in the selection of beryllium is the ability to process, fabricate and repair beryllium first-wall components using existing technologies. Two issues that will need to be addressed during the engineering design activity will be the bonding of beryllium tiles in high-heat-flux areas of the reactor, and the in situ repair of damaged beryllium tiles. The following review summarizes the current technology associated with welding and joining of beryllium to itself and other materials, and the state-of-the-art in plasma-spray technology as an in situ repair technique for damaged beryllium tiles. In addition, a review of the current status of beryllium technology in the former Soviet Union is also included.

  1. 40 CFR 468.20 - Applicability; description of the beryllium copper forming subcategory.

    Science.gov (United States)

    2010-07-01

    ... of pollutants into publicly owned treatment works from the forming of beryllium copper alloys. ... beryllium copper forming subcategory. 468.20 Section 468.20 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS COPPER FORMING POINT SOURCE...

  2. Validation of cleaning method for various parts fabricated at a Beryllium facility

    Energy Technology Data Exchange (ETDEWEB)

    Davis, Cynthia M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-12-15

    This study evaluated and documented a cleaning process that is used to clean parts that are fabricated at a beryllium facility at Los Alamos National Laboratory. The purpose of evaluating this cleaning process was to validate and approve it for future use to assure beryllium surface levels are below the Department of Energy’s release limits without the need to sample all parts leaving the facility. Inhaling or coming in contact with beryllium can cause an immune response that can result in an individual becoming sensitized to beryllium, which can then lead to a disease of the lungs called chronic beryllium disease, and possibly lung cancer. Thirty aluminum and thirty stainless steel parts were fabricated on a lathe in the beryllium facility, as well as thirty-two beryllium parts, for the purpose of testing a parts cleaning method that involved the use of ultrasonic cleaners. A cleaning method was created, documented, validated, and approved, to reduce beryllium contamination.

  3. Controlling Beryllium Contaminated Material And Equipment For The Building 9201-5 Legacy Material Disposition Project

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, T. D.; Easterling, S. D.

    2010-10-01

    This position paper addresses the management of beryllium contamination on legacy waste. The goal of the beryllium management program is to protect human health and the environment by preventing the release of beryllium through controlling surface contamination. Studies have shown by controlling beryllium surface contamination, potential airborne contamination is reduced or eliminated. Although there are areas in Building 9201-5 that are contaminated with radioactive materials and mercury, only beryllium contamination is addressed in this management plan. The overall goal of this initiative is the compliant packaging and disposal of beryllium waste from the 9201-5 Legacy Material Removal (LMR) Project to ensure that beryllium surface contamination and any potential airborne release of beryllium is controlled to levels as low as practicable in accordance with 10 CFR 850.25.

  4. Beryllium abundances in stars hosting giant planets

    CERN Document Server

    Santos, N C; Israelian, G; Mayor, M; Rebolo, R; García-Gíl, A; Pérez de Taoro, M R; Randich, S

    2002-01-01

    We have derived beryllium abundances in a wide sample of stars hosting planets, with spectral types in the range F7V-K0V, aimed at studying in detail the effects of the presence of planets on the structure and evolution of the associated stars. Predictions from current models are compared with the derived abundances and suggestions are provided to explain the observed inconsistencies. We show that while still not clear, the results suggest that theoretical models may have to be revised for stars with Teff<5500K. On the other hand, a comparison between planet host and non-planet host stars shows no clear difference between both populations. Although preliminary, this result favors a ``primordial'' origin for the metallicity ``excess'' observed for the planetary host stars. Under this assumption, i.e. that there would be no differences between stars with and without giant planets, the light element depletion pattern of our sample of stars may also be used to further investigate and constraint Li and Be deple...

  5. Steam-chemical reactivity for irradiated beryllium

    Energy Technology Data Exchange (ETDEWEB)

    Anderl, R.A.; McCarthy, K.A.; Oates, M.A.; Petti, D.A.; Pawelko, R.J.; Smolik, G.R. [Idaho National Engineering and Environmental Lab., Idaho Falls, ID (United States)

    1998-01-01

    This paper reports the results of an experimental investigation to determine the influence of neutron irradiation effects and annealing on the chemical reactivity of beryllium exposed to steam. The work entailed measurements of the H{sub 2} generation rates for unirradiated and irradiated Be and for irradiated Be that had been previously annealed at different temperatures ranging from 450degC to 1200degC. H{sub 2} generation rates were similar for irradiated and unirradiated Be in steam-chemical reactivity experiments at temperatures between 450degC and 600degC. For irradiated Be exposed to steam at 700degC, the chemical reactivity accelerated rapidly and the specimen experienced a temperature excursion. Enhanced chemical reactivity at temperatures between 400degC and 600degC was observed for irradiated Be annealed at temperatures of 700degC and higher. This reactivity enhancement could be accounted for by the increased specific surface area resulting from development of a surface-connected porosity in the irradiated-annealed Be. (author)

  6. Report of a technical evaluation panel on the use of beryllium for ITER plasma facing material and blanket breeder material

    Energy Technology Data Exchange (ETDEWEB)

    Ulrickson, M.A. [ed.] [Sandia National Labs., Albuquerque, NM (United States); Manly, W.D. [Oak Ridge National Lab., TN (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States)] [and others

    1995-08-01

    Beryllium because of its low atomic number and high thermal conductivity, is a candidate for both ITER first wall and divertor surfaces. This study addresses the following: why beryllium; design requirements for the ITER divertor; beryllium supply and unirradiated physical/mechanical property database; effects of irradiation on beryllium properties; tritium issues; beryllium health and safety; beryllium-coolant interactions and safety; thermal and mechanical tests; plasma erosion of beryllium; recommended beryllium grades for ITER plasma facing components; proposed manufacturing methods to produce beryllium parts for ITER; emerging beryllium materials; proposed inspection and maintenance techniques for beryllium components and coatings; time table and costs; and the importance of integrating materials and manufacturing personnel with designers.

  7. Erosion of beryllium under ITER – Relevant transient plasma loads

    Energy Technology Data Exchange (ETDEWEB)

    Kupriyanov, I.B., E-mail: igkupr@gmail.com [A.A. Bochvar High Technology Research Institute of Inorganic Materials, Rogova St. 5a, 123060 Moscow (Russian Federation); Nikolaev, G.N.; Kurbatova, L.A.; Porezanov, N.P. [A.A. Bochvar High Technology Research Institute of Inorganic Materials, Rogova St. 5a, 123060 Moscow (Russian Federation); Podkovyrov, V.L.; Muzichenko, A.D.; Zhitlukhin, A.M. [TRINITI, Troitsk, Moscow reg. (Russian Federation); Gervash, A.A. [Efremov Research Institute, S-Peterburg (Russian Federation); Safronov, V.M. [Project Center of ITER, Moscow (Russian Federation)

    2015-08-15

    Highlights: • We study the erosion, mass loss/gain and surface structure evolution of Be/CuCrZr mock-ups, armored with beryllium of TGP-56FW grade after irradiation by deuterium plasma heat load of 0.5 MJ/m{sup 2} at 250 °C and 500 °C. • Beryllium mass loss/erosion under plasma heat load at 250 °C is rather small (no more than 0.2 g/m{sup 2} shot and 0.11 μm/shot, correspondingly, after 40 shots) and tends to decrease with increasing number of shots. • Beryllium mass loss/erosion under plasma heat load at 500 °C is much higher (∼2.3 g/m{sup 2} shot and 1.2 μm/shot, correspondingly, after 10 shot) and tends to decrease with increasing the number of shots (∼0.26 g/m{sup 2} pulse and 0.14 μm/shot, correspondingly, after 100 shot). • Beryllium erosion value derived from the measurements of profile of irradiated surface is much higher than erosion value derived from mass loss data. - Abstract: Beryllium will be used as a armor material for the ITER first wall. It is expected that erosion of beryllium under transient plasma loads such as the edge-localized modes (ELMs) and disruptions will mainly determine a lifetime of the ITER first wall. This paper presents the results of recent experiments with the Russian beryllium of TGP-56FW ITER grade on QSPA-Be plasma gun facility. The Be/CuCrZr mock-ups were exposed to up to 100 shots by deuterium plasma streams (5 cm in diameter) with pulse duration of 0.5 ms and heat loads range of 0.2–0.5 MJ/m{sup 2} at different temperature of beryllium tiles. The temperature of Be tiles has been maintained about 250 and 500 °C during the experiments. After 10, 40 and 100 shots, the beryllium mass loss/gain under erosion process were investigated as well as evolution of surface microstructure and cracks morphology.

  8. A Report on the Validation of Beryllium Strength Models

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, Derek Elswick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-05

    This report discusses work on validating beryllium strength models with flyer plate and Taylor rod experimental data. Strength models are calibrated with Hopkinson bar and quasi-static data. The Hopkinson bar data for beryllium provides strain rates up to about 4000 per second. A limitation of the Hopkinson bar data for beryllium is that it only provides information on strain up to about 0.15. The lack of high strain data at high strain rates makes it difficult to distinguish between various strength model settings. The PTW model has been calibrated many different times over the last 12 years. The lack of high strain data for high strain rates has resulted in these calibrated PTW models for beryllium exhibiting significantly different behavior when extrapolated to high strain. For beryllium, the α parameter of PTW has recently been calibrated to high precision shear modulus data. In the past the α value for beryllium was set based on expert judgment. The new α value for beryllium was used in a calibration of the beryllium PTW model by Sky Sjue. The calibration by Sjue used EOS table information to model the temperature dependence of the heat capacity. Also, the calibration by Sjue used EOS table information to model the density changes of the beryllium sample during the Hopkinson bar and quasi-static experiments. In this paper, the calibrated PTW model by Sjue is compared against experimental data and other strength models. The other strength models being considered are a PTW model calibrated by Shuh- Rong Chen and a Steinberg-Guinan type model by John Pedicini. The three strength models are used in a comparison against flyer plate and Taylor rod data. The results show that the Chen PTW model provides better agreement to this data. The Chen PTW model settings have been previously adjusted to provide a better fit to flyer plate data, whereas the Sjue PTW model has not been changed based on flyer plate data. However, the Sjue model provides a reasonable fit to

  9. Genetic determinants of sensitivity to beryllium in mice.

    Science.gov (United States)

    Tarantino-Hutchison, Lauren M; Sorrentino, Claudio; Nadas, Arthur; Zhu, Yiwen; Rubin, Edward M; Tinkle, Sally S; Weston, Ainsley; Gordon, Terry

    2009-06-01

    Chronic beryllium disease (CBD), an irreversible, debilitating granulomatous lung disease is caused by exposure to beryllium. This occupational hazard occurs in primary production and machining of Be-metal, BeO, beryllium - containing alloys, and other beryllium products. CBD begins as an MHC Class II-restricted, T(H)1 hypersensitivity, and the Human Leukocyte Antigen, HLA-DPB1E(69), is associated with risk of developing CBD. Because inbred strains of mice have not provided good models of CBD to date, three strains of HLA-DPB1 transgenic mice in an FVB/N background were developed; each contains a single allele of HLA-DPB1 that confers a different magnitude of risk for chronic beryllium disease: HLA-DPB1*0401 (OR approximately 0.2), HLA-DPB1*0201 (OR approximately 3), and HLA-DPB1*1701 (OR approximately 46). The mouse ear swelling test (MEST) was employed to determine if these different alleles would support a hypersensitivity response to beryllium. Mice were first sensitized on the back and subsequently challenged on the ear. In separate experiments, mice were placed into one of three groups (sensitization/challenge): C/C, C/Be, and Be/Be. In the HLA-DPB1*1701 mice, the strain with the highest risk transgene, the Be/Be group was the only group that displayed significant maximum increased ear thickness of 19.6% +/- 3.0% over the baseline measurement (p beryllium in seven inbred strains were investigated through use of the MEST, these included: FVB/N, AKR, Balb/c, C3H/HeJ, C57/BL6, DBA/2, and SJL/J. The FVB/N strain was least responsive, while the SJL/J and C57/BL6 strains were the highest responders. Our results suggest that the HLA-DPB1*1701 transgene product is an important risk factor for induction of the beryllium-sensitive phenotype. This model should be a useful tool for investigating beryllium sensitization.

  10. Identification of beryllium-dependent peptides recognized by CD4+ T cells in chronic beryllium disease.

    Science.gov (United States)

    Falta, Michael T; Pinilla, Clemencia; Mack, Douglas G; Tinega, Alex N; Crawford, Frances; Giulianotti, Marc; Santos, Radleigh; Clayton, Gina M; Wang, Yuxiao; Zhang, Xuewu; Maier, Lisa A; Marrack, Philippa; Kappler, John W; Fontenot, Andrew P

    2013-07-01

    Chronic beryllium disease (CBD) is a granulomatous disorder characterized by an influx of beryllium (Be)-specific CD4⁺ T cells into the lung. The vast majority of these T cells recognize Be in an HLA-DP–restricted manner, and peptide is required for T cell recognition. However, the peptides that stimulate Be-specific T cells are unknown. Using positional scanning libraries and fibroblasts expressing HLA-DP2, the most prevalent HLA-DP molecule linked to disease, we identified mimotopes and endogenous self-peptides that bind to MHCII and Be, forming a complex recognized by pathogenic CD4⁺ T cells in CBD. These peptides possess aspartic and glutamic acid residues at p4 and p7, respectively, that surround the putative Be-binding site and cooperate with HLA-DP2 in Be coordination. Endogenous plexin A peptides and proteins, which share the core motif and are expressed in lung, also stimulate these TCRs. Be-loaded HLA-DP2–mimotope and HLA-DP2–plexin A4 tetramers detected high frequencies of CD4⁺ T cells specific for these ligands in all HLADP2+ CBD patients tested. Thus, our findings identify the first ligand for a CD4⁺ T cell involved in metal-induced hypersensitivity and suggest a unique role of these peptides in metal ion coordination and the generation of a common antigen specificity in CBD.

  11. Behavior of carboxylic acids upon complexation with beryllium compounds.

    Science.gov (United States)

    Mykolayivna-Lemishko, Kateryna; Montero-Campillo, M Merced; Mó, Otilia; Yáñez, Manuel

    2014-07-31

    A significant acidity enhancement and changes on aromaticity were previously observed in squaric acid and its derivatives when beryllium bonds are present in those systems. In order to know if these changes on the chemical properties could be considered a general behavior of carboxylic acids upon complexation with beryllium compounds, complexes between a set of representative carboxylic acids RCOOH (formic acid, acetic acid, propanoic acid, benzoic acid, and oxalic acid) and beryllium compounds BeX2 (X = H, F, Cl) were studied by means of density functional theory calculations. Complexes that contain a dihydrogen bond or a OH···X interaction are the most stable in comparison with other possible BeX2 complexation patterns in which no other weak interactions are involved apart from the beryllium bond. Formic, acetic, propanoic, benzoic, and oxalic acid complexes with BeX2 are much stronger acids than their related free forms. The analysis of the topology of the electron density helps to clarify the reasons behind this acidity enhancement. Importantly, when the halogen atom is replaced by hydrogen in the beryllium compound, the dihydrogen bond complex spontaneously generates a new neutral complex [RCOO:BeH] in which a hydrogen molecule is lost. This seems to be a trend for carboxylic acids on complexing BeX2 compounds.

  12. Design and cooling of BESIII beryllium beam pipe

    Science.gov (United States)

    Li, Xunfeng; Ji, Quan; Wang, Li; Zheng, Lifang

    2008-01-01

    The beryllium beam pipe was restructured according to the requirements of the upgraded BESIII (Beijing Spectrometer) experiment. SMO-1 (sparking machining oil no. 1) was selected as the coolant for the central beryllium beam pipe. The cooling gap width of the beryllium beam pipe was calculated, the influence of concentrated heat load on the wall temperature of the beryllium beam pipe was studied, and the optimal velocity of the SMO-1 in the gap was determined at the maximum heat load. A cooling system for the beam pipe was developed to control the outer wall temperature of the beam pipe. The cooling system is reported in this paper with regard to the following two aspects: the layouts and the automation. The performance of the cooling system was tested on the beam pipe model with trim size. The test results show that the design of the beryllium beam pipe is reasonable and that the cooling system achieves the BESIII experimental aim. The cooling system has already passed the acceptance test and has been installed in position. It will be put into practice for the BESIII experiment in 2008.

  13. Preparation of α-Bi2O3 from bismuth powders through low-temperature oxidation%铋粉低温氧化制备α-Bi2O3

    Institute of Scientific and Technical Information of China (English)

    夏纪勇; 唐谟堂; 陈萃; 金胜明; 陈永明

    2012-01-01

    纳米金属铋粉在低于873.15 K的温度下被氧化而制备成α-Bi2O3粉体,采用XRD、SEM、TEM和HRTEM等技术表征α-Bi2O3粉体的晶体结构和形貌,通过TGA技术研究铋粉的低温氧化动力学行为.结果表明,纳米铋粉在较低的温度下熔融成铋珠,铋珠结合长大并氧化生成不规则的Bi2O3粉体,铋珠氧化机理符合核收缩模型;动力学控制步骤随着氧化时间的变化而变化,在0~10 min内,铋珠氧化动力学表现为化学反应控制,然后转化为O2内扩散控制,低温氧化表观反应活化能为55.19 kJ/mol.%α-Bi2O3 powders were prepared from nanometer Bi powders through low-temperature oxidation at less than 873.15 K.XRD,SEM,TEM and HRTEM were used to characterize the structure and morphology of Bi powders and Bi2O3 particles.Kinetic studies on the bismuth oxidation at low-temperatures were carried out by TGA method.The results show that bismuth beads should be reunited and oxidized to become irregular Bi2O3 powders.The bismuth oxidation follows shrinking core model,and its controlling mechanism varies at different reaction time.Within 0-10 min,the kinetics is controlled by chemical reaction,after that it is controlled by O2 diffusion in the solid α-Bi2O3 layer.The apparent activation energy is determined as 55.19 kJ/mol in liquid-phase oxidation.

  14. 10 CFR Appendix A to Part 850 - Chronic Beryllium Disease Prevention Program Informed Consent Form

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Chronic Beryllium Disease Prevention Program Informed Consent Form A Appendix A to Part 850 Energy DEPARTMENT OF ENERGY CHRONIC BERYLLIUM DISEASE PREVENTION PROGRAM Pt. 850, App. A Appendix A to Part 850—Chronic Beryllium Disease Prevention Program...

  15. Risk-based approach for controlling beryllium exposure in a manufacturing environment

    Energy Technology Data Exchange (ETDEWEB)

    Gilmore, W. E. (Walter E.); Clawson, C. D. (Chris D.); Ellis, K. K. (Kimberly K.)

    2003-01-01

    There are many diverse uses for beryllium in both military and industrial applications. Unfortunately, there are certain worker health risks associated with the manufacture and production of beryllium products. Respiratory illnesses due to prolonged contact with beryllium particulate are of paramount concern. However, these health risks can be controlled provided that the appropriate protective measures to prevent worker exposure from beryllium are in place. But it is no1 always a straightforward process to identify exactly what the beryllium protective measures should be in order to realize a true risk savings. Without prudent attention to a systematic inquiry and suitable evaluative criteria, a program for controlling beryllium health risks can be lacking in completeness and overall effectiveness. One approach that took into account the necessary ingredients for risk-based determination of beryllium protective measures was developed for a beryllium operation at a Department of Energy (DOE) facility. The methodological framework that was applied at this facility, as well as a discussion of the final beryllium protective measures that were determined by this approach will be presented. Regulatory aspects for working with beryllium, as well as a risk-assessment strategy for ranking beryllium-handling activities with respect to exposure potential will also be discussed. The presentation will conclude with a synopsis of lessons-learned as gleaned from this case study, as well as providing the participants with a constructive blueprint that can be adapted to other processes involving beryllium.

  16. 10 CFR 71.23 - General license: Plutonium-beryllium special form material.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false General license: Plutonium-beryllium special form material... RADIOACTIVE MATERIAL General Licenses § 71.23 General license: Plutonium-beryllium special form material. (a... form of plutonium-beryllium (Pu-Be) special form sealed sources, or to deliver Pu-Be sealed sources...

  17. Monte Carlo uncertainty analyses for integral beryllium experiments

    CERN Document Server

    Fischer, U; Tsige-Tamirat, H

    2000-01-01

    The novel Monte Carlo technique for calculating point detector sensitivities has been applied to two representative beryllium transmission experiments with the objective to investigate the sensitivity of important responses such as the neutron multiplication and to assess the related uncertainties due to the underlying cross-section data uncertainties. As an important result, it has been revealed that the neutron multiplication power of beryllium can be predicted with good accuracy using state-of-the-art nuclear data evaluations. Severe discrepancies do exist for the spectral neutron flux distribution that would transmit into significant uncertainties of the calculated neutron spectra and of the nuclear blanket performance in blanket design calculations. With regard to this, it is suggested to re-analyse the secondary energy and angle distribution data of beryllium by means of Monte Carlo based sensitivity and uncertainty calculations. Related code development work is underway.

  18. Estimation of beryllium ground state energy by Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Kabir, K. M. Ariful [Department of Physical Sciences, School of Engineering and Computer Science, Independent University, Bangladesh (IUB) Dhaka (Bangladesh); Halder, Amal [Department of Mathematics, University of Dhaka Dhaka (Bangladesh)

    2015-05-15

    Quantum Monte Carlo method represent a powerful and broadly applicable computational tool for finding very accurate solution of the stationary Schrödinger equation for atoms, molecules, solids and a variety of model systems. Using variational Monte Carlo method we have calculated the ground state energy of the Beryllium atom. Our calculation are based on using a modified four parameters trial wave function which leads to good result comparing with the few parameters trial wave functions presented before. Based on random Numbers we can generate a large sample of electron locations to estimate the ground state energy of Beryllium. Our calculation gives good estimation for the ground state energy of the Beryllium atom comparing with the corresponding exact data.

  19. Field-emission spectroscopy of beryllium atoms adsorbed on tungsten

    Energy Technology Data Exchange (ETDEWEB)

    Czyzewski, J.J.; Grzesiak, W.; Krajniak, J. (Politechnika Wroclawska (Poland))

    1981-01-01

    Field emission energy distributions (FEED) have been measured for the beryllium-tungsten (023) adsorption system over the 78-450 K temperature range. A temperature dependence of the normalized half-width, ..delta../d, of FEED peaks changed significantly due to beryllium adsorption; and the curve, ..delta../d vs p, for the Be/W adsorption system was identical in character to the calculated curve based on the free electron model in contrast to the curve for the clean tungsten surface. In the last part of this paper Gadzuk's theory of the resonance-tunneling effect is applied to the beryllium atom on tungsten. Experimental and theoretical curves of the enhancement factor as a function of energy have been discussed.

  20. Color Enhancement by Diffusion of Beryllium in Dark Blue Sapphire

    Institute of Scientific and Technical Information of China (English)

    Kyungj in Kim; Yongkil Ahn

    2016-01-01

    Diffusion of beryllium was performed on dark blue sapphire from China and Australia.The samples were heated with beryllium as a dopant in a furnace at 1 600 ℃ for 42 h in air.After beryllium diffusion,sam-ples were analyzed by UV-Vis,FTIR,and WD-XRF spectroscopy.After heat-treatment with Be as a catalyst, the irons of the ferrous state were changed to the ferric state.Therefore,reaction of Fe2+/Ti4+ IVCT was de-creased.The absorption peaks at 3 309 cm-1 attributed to OH radical were disappeared completely due to carry out heat treatment.Consequently,the intensity of absorption band was decreased in the visible region.Espe-cially,decreased absorption band in the vicinity of 570 nm was responsible for the lighter blue color.There-fore,we confirmed that the dark blue sapphires from China and Australia were changed to vivid blue.

  1. 铋蒸气氧化制备氧化铋粉体过程模拟%Simulation of the process of bismuth oxide powders produced by vapor-phase oxidation

    Institute of Scientific and Technical Information of China (English)

    胡汉祥; 丘克强

    2012-01-01

    粒子谱演变过程的数值模拟应用于粉体材料的制备过程,对于认识粒子的生成规律、优化生产条件、辅助设计制备设备具有一定的帮助作用.本文在分析制备过程特点的基础上,建立了粒子形成过程的控制方程,并利用Fluent软件对流体流动的控制方程、粒子谱演变方程及粒子的体积浓度方程构成的方程组进行了求解.模拟结果表明,氧化铋粒子的成核与凝并过程都发生在很短的时间内,较小的空间范围内,因此,所得粒子的大小受流体下游冷却系统的影响较小.在这个制备系统中,氧化铋粒子的数值浓度较低,易生成粒度较小的粒子.在反应舟区流体的径向速度较大,在炉子出口处,热迁移速度较大,氧化铋有可能在这2个地方向反应器壁沉积,造成产品产率降低.数值模拟不同制备温度下氧化铋粒度大小与实验结果基本一致.%Growth mechanisms of particles in the process of the powder preparation can well be realized and the manufacturing conditions can be optimized with the help of simulation of particle-size evolution. In this paper, the equations of controlling size growth were based on characteristics of the process and were solved by Fluent software. Numerical simulation on preparation of bismuth oxide by bismuth vapor oxidation showed that nuleation and coagulation of bismuth oxide was instantaneously complete in small spatial scope. Therefore particle size of obtained bismuth oxide was less affected by the cooling system in the downstream fluids. The ultra fine grain was easy to be prepared in this preparation system due to low concentration. The particle of bismuth oxide may be deposited on the wall at the exit of the furnace due to high velocity of thermal exchange and on the wall above the reaction boat due to high radial velocity of fluid, which resulted in a decrease in the product yield. The grain size of bismuth oxide at different temperature predicted by

  2. Method for removal of beryllium contamination from an article

    Science.gov (United States)

    Simandl, Ronald F.; Hollenbeck, Scott M.

    2012-12-25

    A method of removal of beryllium contamination from an article is disclosed. The method typically involves dissolving polyisobutylene in a solvent such as hexane to form a tackifier solution, soaking the substrate in the tackifier to produce a preform, and then drying the preform to produce the cleaning medium. The cleaning media are typically used dry, without any liquid cleaning agent to rub the surface of the article and remove the beryllium contamination below a non-detect level. In some embodiments no detectible residue is transferred from the cleaning wipe to the article as a result of the cleaning process.

  3. Relativistic and QED corrections for the beryllium atom.

    Science.gov (United States)

    Pachucki, Krzysztof; Komasa, Jacek

    2004-05-28

    Complete relativistic and quantum electrodynamics corrections of order alpha(2) Ry and alpha(3) Ry are calculated for the ground state of the beryllium atom and its positive ion. A basis set of correlated Gaussian functions is used, with exponents optimized against nonrelativistic binding energies. The results for Bethe logarithms ln(k(0)(Be)=5.750 34(3) and ln(k(0)(Be+)=5.751 67(3) demonstrate the availability of high precision theoretical predictions for energy levels of the beryllium atom and light ions. Our recommended value of the ionization potential 75 192.514(80) cm(-1) agrees with equally accurate available experimental values.

  4. CHAPTER 7. BERYLLIUM ANALYSIS BY NON-PLASMA BASED METHODS

    Energy Technology Data Exchange (ETDEWEB)

    Ekechukwu, A

    2009-04-20

    The most common method of analysis for beryllium is inductively coupled plasma atomic emission spectrometry (ICP-AES). This method, along with inductively coupled plasma mass spectrometry (ICP-MS), is discussed in Chapter 6. However, other methods exist and have been used for different applications. These methods include spectroscopic, chromatographic, colorimetric, and electrochemical. This chapter provides an overview of beryllium analysis methods other than plasma spectrometry (inductively coupled plasma atomic emission spectrometry or mass spectrometry). The basic methods, detection limits and interferences are described. Specific applications from the literature are also presented.

  5. Preparation of Highly Dispersed Antimony-doped Tin Oxide Nano-powder via Ion-exchange Hydrolysis of SnCl4 and SbCl3 and Azeotropic Drying

    Institute of Scientific and Technical Information of China (English)

    YANG Fen; ZHANG Xue-jun; TIAN Fang; WU Xu; GAN Fu-xing

    2007-01-01

    Antimony-doped tin hydroxide colloid precipitates have been synthesized by hydrolysis of SnCl4 and SbCl3 using: (1) an ion-exchange hydrolysis to remove chlorine ions, and (2) isoamyl acetate as an azeotropic solvent to obviate water. The obtained dried powder is of high dispersivity without any need for further grinding. The size and dispersivity of the final particles are investigated with the aid of TG-DTA, BET, XRD and TEM. After having calcined, the antimony-doped tin oxide nanopowder possesses a tetragonal rutile structure with high dispersivity, uniform particles and low hard agglomeration.

  6. 20 CFR 30.207 - How does a claimant prove a diagnosis of a beryllium disease covered under Part B?

    Science.gov (United States)

    2010-04-01

    ... beryllium disease covered under Part B? 30.207 Section 30.207 Employees' Benefits OFFICE OF WORKERS... Beryllium Illness Under Part B of Eeoicpa § 30.207 How does a claimant prove a diagnosis of a beryllium... employee developed a covered beryllium illness. Proof that the employee developed a covered...

  7. Extraction of beryllium sulfate by a long chain amine; Extraction du sulfate de beryllium par une amine a longue chaine

    Energy Technology Data Exchange (ETDEWEB)

    Etaix, E.S. [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

    1968-06-01

    The extraction of sulfuric acid in aqueous solution by a primary amine in benzene solution, 3-9 (diethyl) - 6-amino tri-decane (D.E.T. ) - i.e., with American nomenclature 1-3 (ethyl-pentyl) - 4-ethyl-octyl amine (E.P.O.) - has made it possible to calculate the formation constants of alkyl-ammonium sulfate and acid sulfate. The formula of the beryllium and alkyl-ammonium sulfate complex formed in benzene has next been determined, for various initial acidity of the aqueous solution. Lastly, evidence has been given of negatively charged complexes of beryllium and sulfate in aqueous solution, through the dependence of the aqueous sulfate ions concentration upon beryllium extraction. The formation constant of these anionic complexes has been evaluated. (author) [French] L'etude de l'extraction de l'acide sulfurique en solution aqueuse par une amine primaire en solution dans le benzene, le diethyl-3,9 amino-6 tridecane (D.E.T.) - autre nom americain 1-3 (ethylpentyl) - 4-ethyloctylamine (E.P.O.) a permis de calculer les constantes de formation du sulfate et de l'hydrogenosulfate d'alkyl-ammonium. La formule du complexe de sulfate de beryllium et d'alkyl-ammonium forme en solution benzenique a ete ensuite determinee pour diverses acidites initiales de la solution aqueuse. Enfin, l'influence de la concentration des ions sulfate de la phase aqueuse sur l'extraction du beryllium a mis en evidence la formation en solution aqueuse de complexes anioniques de sulfate et de beryllium dont la constante de formation a ete evaluee. (auteur)

  8. Chemistry characterization and samples beryllium process impurity determination; Caracterizacao quimica e determinacao de impurezas de amostras de processo de berilio

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, Leonel Mathry de

    1992-12-01

    Brazil is the greatest world producer of beryl (3 Be O.Al{sub 2}O{sub 3}.6SiO{sub 2}) and has recently begun to produce beryllium compounds by means of a pilot plant constructed at Governador Valadares city (Minas Gerais - Brazil). The aim of this work was the determination of trace level impurities and macro constituents in the tenth % range to support analytical control process of plant production and characterization of beryllium compounds. The impurities separations and purification process was developed by two steps procedure. The first one using EDTA complexation has separated and reduced some impurities to less than 1 {mu}g/ml level. In the second one it was used a chelating resin (Chelex 100) and the separation efficiency was about 75 to 97 % related with the element tested. High pure berylium oxide standard was obtained from purification of Be(OH)2. The R X fluorescence presented only traces of Cu and Si < 1 % Fe and Mn, Zn, Ca, Al, Na and S were completely removed. The beryllium content was determined by direct atomic emission spectroscopy in argon plasma (Dcp) and compared with classic gravimetric method as Be O. The results were in agreement (49,2+/-0,2 % and 48,3+/-0,1 % respectively) between 95 % of confidence. A low temperature gravimetric method for beryllium determination was also studied using Oxine with microwave furnace. A total of 24 elements including macro and trace level were determined by Dcp and/or spectrophotometric methods. The Be/B separation was studied using anionic resin in poly alcohols medium. A more detailed study of equilibrium conditions is necessary. This work was realized at Laboratorio de Analise Mineral (LAM) of Comissao Nacional de Energia Nuclear - Rio de Janeiro (CNEN). (author)

  9. An electrochemical cell for in operando studies of lithium/sodium batteries using a conventional x-ray powder diffractometer

    DEFF Research Database (Denmark)

    Shen, Yanbin; Pedersen, Erik Ejler; Christensen, Mogens

    2014-01-01

    An electrochemical cell has been designed for powder X-ray diffraction (PXRD) studies of lithium ion batteries (LIB) and sodium ion batteries (SIB) in operando with high time resolution using conventional powder X-ray diffractometer. The cell allows for studies of both anode and cathode electrode...... materials in reflection mode. The cell design closely mimics that of standard battery testing coin cells and allows obtaining powder X-ray diffraction patterns under representative electrochemical conditions. In addition, the cell uses graphite as the X-ray window instead of beryllium, and it is easy...

  10. Thermal Decomposition Behaviour of Zn3N2 Powder

    Institute of Scientific and Technical Information of China (English)

    ZONG Fu-Jian; ZHUANG Hui-Zhao; MA Hong-Lei; LIANG Wei; DU Wei; ZHANG Xi-Jian; XIAO Hong-Di; MA Jin; JI Feng; XUE Cheng-Shan

    2005-01-01

    @@ Thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) are employed to investigate the thermal decomposition behaviour of zinc nitride powder, which indicated that the thermal oxidation of zinc nitride powder in air follows the two-step reaction model.When the temperature is between 200 and 500℃,compact ZnO or ZnxOyNz layers in the surface of zinc nitride powder will begin to form, and prevent the interior of zinc nitride powder from the thermal oxidation.When the temperature is higher than 500 ℃, fast thermal oxidation occurs in the interior of zinc nitride powder.Over 750 ℃, all the zinc nitride will turn into zinc oxide.The x-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) of the zinc nitride powder annealed at different temperature in air are consistent with the two-step reaction model.

  11. Application of powder X-ray diffraction and the Rietveld method to the analysis of oxidation processes and products in sulphidic mine tailings

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Katerinopoulou, Anna; Edsberg, Anders

    2011-01-01

    The main strength of the Rietveld method as a tool for quantitative phase analysis lies in its ability to control and correct various parameters which influence powder diffraction patterns. The main sources of errors in this type of analysis are due to differences in properties of various constit...

  12. Consolidation of powders of the oxide superconductor YBa/sub 2/Cu/sub 3/Ox by high energy-high rate processing

    Energy Technology Data Exchange (ETDEWEB)

    Persad, C.; Lee, S.J.; Peterson, D.R.; Swinnea, J.S.; Schmerling, M.

    1988-01-01

    The consolidation response of powders of the superconducting compound YBa/sub 2/Cu/sub 3/Ox is reported. Copper, silver, tin, and Cu-based metallic glass infiltrates have also been employed in preliminary fabricability studies. The processing approach relies on short-duration (< 1s), high-current-density 10000 A/sq.cm, pulse-resistive heating of powders under applied pressures of 200 MPa to 400 MPa. Powders and fabricated disk compacts were characterized by X-ray diffraction, optical and scanning electron microscopy, and resistivity measurements. X-ray diffraction comparisons of starting powder and consolidated material show retention of the single phase 1-2-3 structure and the development of a preferred orientation. In the consolidated pure YBa/sub 2/Cu/sub 3/0x, Tc onsets of 87K were accompanied by broad transitions. Iodometric analyses indicated oxygen depletion in the as-consolidated disks. Observed oxygen-content profiles across the sample thickness had values 0.11< x <0.35. The variation in the peak processing temperature within the disk was found to correlate with the oxygen content profile.

  13. Dispersion-strengthened Aluminium Products Manufactured by Powder Blending

    DEFF Research Database (Denmark)

    Hansen, Niels

    1969-01-01

    Detailed experiments carried out to examine relationship between microstructure and mechanical properties of powder-blended aluminum products are reported; their results as well as structural studies by transmission electron microscopy and tensile-and creep- testing, are given; as dispersed phase......, various oxide powders were selected on criterion that during manufacturing no reaction must taken place between metal and oxide phase; strength of powder-blended aluminum products increases and elongation decreases with decreasing particle size of aluminum powder and with increasing concentration of oxide...

  14. Comparison of the Kinetic Behaviors of Fe{sub 2}O{sub 3} Spherical Submicron Clusters and Fe{sub 2}O{sub 3} Fine Powder Catalysts for CO Oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Seunggyun; Kim, Jinhoon; Lee, Sunghan [Yonsei Univ., Wonju (Korea, Republic of); Kim, Unho; Jung, Jinseung [Gangneung-Wonju National Univ., Gangneung (Korea, Republic of)

    2014-05-15

    α-Fe{sub 2}O{sub 3} spherical particles having an average diameter of ca. 420 nm and α-Fe{sub 2}O{sub 3} fine particles (< 10 μm particle size) were prepared to examine as catalysts for CO oxidation. Kinetic studies on the catalytic reactions were performed in a flow reactor using an on-line gas chromatography system operated at 1 atm. The apparent activation energies and the partial orders with respect to CO and O{sub 2} were determined from the rates of CO disappearance in the reaction stage showing a constant catalytic activity. In the temperature range of 150-275 .deg. C, the apparent activation energies were calculated to be 13.7 kcal/mol on the α-Fe{sub 2}O{sub 3} spherical submicron clusters and 15.0 kcal/mol on the α-Fe{sub 2}O{sub 3} fine powder. The Pco and PO{sub 2} dependencies of rate were investigated at various partial pressures of CO and O{sub 2} at 250 .deg. C. Zero-order kinetics were observed for O{sub 2} on both the catalysts, but the reaction order for CO was observed as first-order on the α-Fe{sub 2}O{sub 3} fine powder and 0.75-order on the α-Fe{sub 2}O{sub 3} spherical submicron clusters. The catalytic processes including the inhibition process by CO{sub 2} on the α-Fe{sub 2}O{sub 3} spherical submicron powder are discussed according to the kinetic results. The catalysts were characterized using XRD (X-ray powder diffraction), FE-SEM (field emission-scanning electron microscopy), HR-TEM (high resolution-transmission electron microscopy), and N{sub 2} sorption measurements.

  15. Thermal cycling tests of actively cooled beryllium copper joints

    Energy Technology Data Exchange (ETDEWEB)

    Roedig, M.; Duwe, R.; Linke, J.; Schuster, A.; Wiechers, B. [Forschungszentrum Juelich GmbH (Germany)

    1998-01-01

    Screening tests (steady state heating) and thermal fatigue tests with several kinds of beryllium-copper joints have been performed in an electron beam facility. Joining techniques under investigation were brazing with silver containing and silver-free braze materials, hot isostatic pressing (HIP) and diffusion bonding (hot pressing). Best thermal fatigue performance was found for the brazed samples. (author)

  16. On-line separation of short-lived beryllium isotopes

    CERN Document Server

    Köster, U; Catherall, R; Fedosseev, V; Georg, U; Huber, G; Jading, Y; Jonsson, O; Koizumi, M; Kratz, K L; Kugler, E; Lettry, Jacques; Mishin, V I; Ravn, H L; Sebastian, V; Tamburella, C; Wöhr, A

    1998-01-01

    With the development of a new laser ionization scheme, it became possible to ionize beryllium efficiently in the hot cavity of the ISOLDE laser ion source. The high target and ion source temperatures enable the release of short-lived beryllium isotopes. Thus all particle-stable beryllium isotopes could be extracted from a standard uranium carbide/graphite target. For the first time the short-lived isotopes /sup 12/Be and /sup 14/Be could be identified at an ISOL facility, /sup 14/Be being among the most short-lived isotopes separated so far at ISOLDE. The release time from the UC/graphite target was studied with several beryllium isotopes. Profiting from the element selectivity of laser ionization, the strong and isotopically pure beam of /sup 12/Be allowed to determine the half- life to T/sub 1/2 /=21.34(23) ms and the probability of beta-delayed neutron emission to P/sub n/=0.48/sub -0.10//sup +0.12/(23 refs).

  17. THORIUM-BERYLLIUM ALLOYS AND METHOD OF PRODUCING SAME

    Science.gov (United States)

    Spedding, F.H.; Wilhelm, H.A.; Keller, W.H.

    1959-09-01

    >The preparation is described of thorium-berylium alloys from halides of the metals by stmultaneously reducing thorium fluoride and beryllium fluoride with calcium at approximately 650 deg C and maintaining the temperature until the thorium-beryhltum alloy separates from the slag.

  18. TEM study of impurity segregations in beryllium pebbles

    Science.gov (United States)

    Klimenkov, M.; Chakin, V.; Moeslang, A.; Rolli, R.

    2014-12-01

    Beryllium is planned to be used as a neutron multiplier in the Helium-cooled Pebble Bed European concept of a breeding blanket of demonstration power reactor DEMO. In order to evaluate the irradiation performance, individual pebbles and constrained pebble beds were neutron-irradiated at temperatures typical of fusion blankets. Beryllium pebbles 1 mm in diameter produced by the rotating electrode method were subjected to a TEM study before and after irradiation at High Flux Reactor, Petten, Netherlands at 861 K. The grain size varied in a wide range from sub-micron size up to several tens of micrometers, which indicated formation bimodal grain size distribution. Based on the application of combined electron energy loss spectroscopy and energy dispersive X-ray spectroscopy methods, we suggest that impurity precipitates play an important role in controlling the mechanical properties of beryllium. The impurity elements were present in beryllium at a sub-percent concentration form beryllide particles of a complex (Fe/Al/Mn/Cr)B composition. These particles are often ordered along dislocations lines, forming several micron-long chains. It can be suggested that fracture surfaces often extended along these chains in irradiated material.

  19. Fluorometric determination of beryllium with 2-(o-hydroxylphenyl)benzoxazole

    Energy Technology Data Exchange (ETDEWEB)

    Gladilovich, D.B.; Stolyarov, K.P.

    1985-09-01

    According to the authors, of great interest for the fluorometric determination of small quantities of beryllium is 2-(o-hydroxyphenyl)benzthiazole (HPBT). In this work, 2-(o-hydroxyphenyl)benzoaxzole (HPBO), which is an analog of HPBT and differs from it in that the sulfur atom in the heterocyclic portion of the molecule is replaced by an oxygen atom, is proposed as a reagent for the fluorometric determination of beryllium. The fluorescent reaction of HPBO with beryllium is studied in this paper, in addition to the selection of the optimum conditions for the determination and the development of a procedure for the analysis of complex objects on this basis. The reaction proceeds in aqueous ethanol medium at pH 7.2-7.5. The limit of detection is 0.6 ng/ml. Methods have been developed for the determination of 10/sup -2/% beryllium in alloys based on copper and 10/sup -3/-10/sup -4/% in standard samples of silicate rocks.

  20. TEM study of impurity segregations in beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Klimenkov, M., E-mail: michael.klimenkov@kit.edu [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Chakin, V.; Moeslang, A. [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Rolli, R. [Institute for Applied Materials – Materials and Biomechanics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-12-15

    Beryllium is planned to be used as a neutron multiplier in the Helium-cooled Pebble Bed European concept of a breeding blanket of demonstration power reactor DEMO. In order to evaluate the irradiation performance, individual pebbles and constrained pebble beds were neutron-irradiated at temperatures typical of fusion blankets. Beryllium pebbles 1 mm in diameter produced by the rotating electrode method were subjected to a TEM study before and after irradiation at High Flux Reactor, Petten, Netherlands at 861 K. The grain size varied in a wide range from sub-micron size up to several tens of micrometers, which indicated formation bimodal grain size distribution. Based on the application of combined electron energy loss spectroscopy and energy dispersive X-ray spectroscopy methods, we suggest that impurity precipitates play an important role in controlling the mechanical properties of beryllium. The impurity elements were present in beryllium at a sub-percent concentration form beryllide particles of a complex (Fe/Al/Mn/Cr)B composition. These particles are often ordered along dislocations lines, forming several micron-long chains. It can be suggested that fracture surfaces often extended along these chains in irradiated material.

  1. 75 FR 80734 - Chronic Beryllium Disease Prevention Program

    Science.gov (United States)

    2010-12-23

    ... a person's immune system becomes highly responsive (allergic) to the presence of beryllium in the.... Hardcopies (2 copies) sent by regular mailing should be addressed to: Jacqueline D. Rogers, Office of Worker... to jackie.rogers@hq.doe.gov . If you have additional information, such as studies or journal articles...

  2. The uses and adverse effects of beryllium on health

    Directory of Open Access Journals (Sweden)

    Cooper Ross

    2009-01-01

    Full Text Available Context: This review describes the health effects of beryllium exposure in the workplace and the environment. Aim: To collate information on the consequences of occupational and environmental exposure to beryllium on physiological function and well being. Materials and Methods: The criteria used in the current review for selecting articles were adopted from proposed criteria in The International Classification of Functioning, Disability, and Health. Articles were classified based on acute and chronic exposure and toxicity of beryllium. Results: The proportions of utilized and nonutilized articles were tabulated. Years 2001-10 gave the greatest match (45.9% for methodological parameters, followed by 27.71% for 1991-2000. Years 1971-80 and 1981-90 were not significantly different in the information published and available whereas years 1951-1960 showed a lack of suitable articles. Some articles were published in sources unobtainable through requests at the British Library, and some had no impact factor and were excluded. Conclusion: Beryllium has some useful but undoubtedly harmful effects on health and well-being. Measures need to be taken to prevent hazardous exposure to this element, making its biological monitoring in the workplace essential.

  3. Electrical conductivity of metal powders under pressure

    Energy Technology Data Exchange (ETDEWEB)

    Montes, J.M.; Cintas, J.; Urban, P. [Universidad de Sevilla, Department of Mechanical and Materials Engineering Escuela Tecnica Superior de Ingenieria, Sevilla (Spain); Cuevas, F.G. [Universidad de Huelva, Department of Chemistry and Materials Science Escuela Tecnica Superior de Ingenieria, Palos de la Frontera (Spain)

    2011-12-15

    A model for calculating the electrical conductivity of a compressed powder mass consisting of oxide-coated metal particles has been derived. A theoretical tool previously developed by the authors, the so-called 'equivalent simple cubic system', was used in the model deduction. This tool is based on relating the actual powder system to an equivalent one consisting of deforming spheres packed in a simple cubic lattice, which is much easier to examine. The proposed model relates the effective electrical conductivity of the powder mass under compression to its level of porosity. Other physically measurable parameters in the model are the conductivities of the metal and oxide constituting the powder particles, their radii, the mean thickness of the oxide layer and the tap porosity of the powder. Two additional parameters controlling the effect of the descaling of the particle oxide layer were empirically introduced. The proposed model was experimentally verified by measurements of the electrical conductivity of aluminium, bronze, iron, nickel and titanium powders under pressure. The consistency between theoretical predictions and experimental results was reasonably good in all cases. (orig.)

  4. Determination of beryllium concentrations in UK ambient air

    Science.gov (United States)

    Goddard, Sharon L.; Brown, Richard J. C.; Ghatora, Baljit K.

    2016-12-01

    Air quality monitoring of ambient air is essential to minimise the exposure of the general population to toxic substances such as heavy metals, and thus the health risks associated with them. In the UK, ambient air is already monitored under the UK Heavy Metals Monitoring Network for a number of heavy metals, including nickel (Ni), arsenic (As), cadmium (Cd) and lead (Pb) to ensure compliance with legislative limits. However, the UK Expert Panel on Air Quality Standards (EPAQS) has highlighted a need to limit concentrations of beryllium (Be) in air, which is not currently monitored, because of its toxicity. The aim of this work was to analyse airborne particulate matter (PM) sampled onto filter papers from the UK Heavy Metals Monitoring Network for quantitative, trace level beryllium determination and compare the results to the guideline concentration specified by EPAQS. Samples were prepared by microwave acid digestion in a matrix of 2% sulphuric acid and 14% nitric acid, verified by the use of Certified Reference Materials (CRMs). The digested samples were then analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The filters from the UK Heavy Metals Monitoring Network were tested using this procedure and the average beryllium concentration across the network for the duration of the study period was 7.87 pg m-3. The highest site average concentration was 32.0 pg m-3 at Scunthorpe Low Santon, which is significantly lower than levels that are thought to cause harm. However the highest levels were observed at sites monitoring industrial point sources, indicating that beryllium is being used and emitted, albeit at very low levels, from these point sources. Comparison with other metals concentrations and data from the UK National Atmospheric Emissions Inventory suggests that current emissions of beryllium may be significantly overestimated.

  5. Unsuspected exposure to beryllium: potential implications for sarcoidosis diagnoses.

    Science.gov (United States)

    Laczniak, Andrew N; Gross, Nathan A; Fuortes, Laurence J; Field, R William

    2014-07-21

    Exposure to Beryllium (Be) can cause sensitization (BeS) and chronic beryllium disease (CBD) in some individuals.  Even relatively low exposures may be sufficient to generate an asymptomatic, or in some cases a symptomatic, immune response. Since the clinical presentation of CBD is similar to that of sarcoidosis, it is helpful to have information on exposure to beryllium in order to reduce misdiagnosis. The purpose of this pilot study is to explore the occurrence of Be surface deposits at worksites with little or no previous reported use of commercially available Be products.  The workplaces chosen for this study represent a convenience sample of businesses in eastern Iowa. One hundred thirty-six surface dust samples were collected from 27 businesses for analysis of Be. The results were then divided into categories by the amount of detected Be according to U.S. Department of Energy guidelines as described in 10 CFR 850.30 and 10 CFR 850.31. Overall, at least one of the samples at 78% of the work sites tested contained deposited Be above the analytical limit of quantitation (0.035 µg beryllium per sample).  Beryllium was detected in 46% of the samples collected. Twelve percent of the samples exceeded 0.2 µg/100 cm² and 4% of the samples exceeded a Be concentration of 3 µg/100 cm². The findings from this study suggest that there may be a wider range and greater number of work environments that have the potential for Be exposure than has been documented previously.  These findings could have implications for the accurate diagnosis of sarcoidosis.

  6. Evaluation of historical beryllium abundance in soils, airborne particulates and facilities at Lawrence Livermore National Laboratory.

    Science.gov (United States)

    Sutton, Mark; Bibby, Richard K; Eppich, Gary R; Lee, Steven; Lindvall, Rachel E; Wilson, Kent; Esser, Bradley K

    2012-10-15

    Beryllium has been historically machined, handled and stored in facilities at Lawrence Livermore National Laboratory (LLNL) since the 1950s. Additionally, outdoor testing of beryllium-containing components has been performed at LLNL's Site 300 facility. Beryllium levels in local soils and atmospheric particulates have been measured over three decades and are comparable to those found elsewhere in the natural environment. While localized areas of beryllium contamination have been identified, laboratory operations do not appear to have increased the concentration of beryllium in local air or water. Variation in airborne beryllium correlates to local weather patterns, PM10 levels, normal sources (such as resuspension of soil and emissions from coal power stations) but not to LLNL activities. Regional and national atmospheric beryllium levels have decreased since the implementation of the EPA's 1990 Clean-Air-Act. Multi-element analysis of local soil and air samples allowed for the determination of comparative ratios for beryllium with over 50 other metals to distinguish between natural beryllium and process-induced contamination. Ten comparative elemental markers (Al, Cs, Eu, Gd, La, Nd, Pr, Sm, Th and Tl) that were selected to ensure background variations in other metals did not collectively interfere with the determination of beryllium sources in work-place samples at LLNL. Multi-element analysis and comparative evaluation are recommended for all workplace and environmental samples suspected of beryllium contamination. The multi-element analyses of soils and surface dusts were helpful in differentiating between beryllium of environmental origin and beryllium from laboratory operations. Some surfaces can act as "sinks" for particulate matter, including carpet, which retains entrained insoluble material even after liquid based cleaning. At LLNL, most facility carpets had beryllium concentrations at or below the upper tolerance limit determined by sampling facilities

  7. Photo-oxidation of NO using an exterior paint--screening of various commercial titania in powder pressed and paint films.

    Science.gov (United States)

    Aguia, C; Angelo, J; Madeira, Luis M; Mendes, A

    2011-07-01

    The present work aims to evaluate the photocatalytic activity of photo-TiO(2) from various producers (Evonik, Kemira, Kronos, Millennium, Sachtleben and Tayca), in the form of powder pressed films and upon incorporation in a water-based paint, for outdoor NO abatement. The photocatalytic activity of the different samples was evaluated in terms of NO conversion and selectivity towards nitrite and nitrate ions following approximately the ISO 22197-1:2007(E) standard. The highest yields obtained for powder pressed films were achieved with VLP7000 (0.70), followed by VLP7101 (0.55) and UVLP7500 (0.55), all from Kronos. On the other hand, when incorporated in paint films, the highest yields were obtained with PC500 and PC105 from Millennium and UV100 from Sachtleben (ca. 0.15). The paint matrix plays an important role on the photocatalytic activity. In particular, the time for steady state is one or two orders of magnitude higher when the photocatalysts are incorporated in paint films in relation to the powder pressed films. The paint films were activated following the procedure recommended by the above-mentioned standard. However, the photocatalytic activity of films incorporating P25 (Evonik) was displayed only when higher power radiation and higher humidity conditions were used. This allowed for similar levels of photocatalytic activity as the other paint films. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Beryllium detection in human lung tissue using electron probe X-ray microanalysis.

    Science.gov (United States)

    Butnor, Kelly J; Sporn, Thomas A; Ingram, Peter; Gunasegaram, Sue; Pinto, John F; Roggli, Victor L

    2003-11-01

    Chronic berylliosis is an uncommon disease that is caused by the inhalation of beryllium particles, dust, or fumes. The distinction between chronic berylliosis and sarcoidosis can be difficult both clinically and histologically, as both entities can have similar presentations and exhibit nonnecrotizing granulomatous inflammation of the lungs. The diagnosis of chronic berylliosis relies on a history of exposure to beryllium, roentgenographic evidence of diffuse nodular disease, and demonstration of beryllium hypersensitivity by ancillary studies, such as lymphocyte proliferation testing. Additional support may be gained by the demonstration of beryllium in lung tissue. Unlike other exogenous particulates, such as asbestos, detection of beryllium in human lung tissue is problematic. The low atomic number of beryllium usually makes it unsuitable for conventional microprobe analysis. We describe a case of chronic berylliosis in which beryllium was detected in lung tissue using atmospheric thin-window energy-dispersive X-ray analysis (ATW EDXA). A woman with a history of occupational exposure to beryllium at a nuclear weapons testing facility presented with progressive cough and dyspnea and a nodular pattern on chest roentgenograph. Open lung biopsy showed nonnecrotizing granulomatous inflammation that was histologically indistinguishable from sarcoidosis. Scanning electron microscopy and ATW EDXA demonstrated particulates containing beryllium within the granulomas. This application of EDXA offers significant advantages over existing methods of beryllium detection in that it is nondestructive, more widely available, and can be performed using routine paraffin sections.

  9. Beryllium alters lipopolysaccharide-mediated intracellular phosphorylation and cytokine release in human peripheral blood mononuclear cells.

    Science.gov (United States)

    Silva, Shannon; Ganguly, Kumkum; Fresquez, Theresa M; Gupta, Goutam; McCleskey, T Mark; Chaudhary, Anu

    2009-12-01

    Beryllium exposure in susceptible individuals leads to the development of chronic beryllium disease, a lung disorder marked by release of inflammatory cytokine and granuloma formation. We have previously reported that beryllium induces an immune response even in blood mononuclear cells from healthy individuals. In this study, we investigate the effects of beryllium on lipopolysaccharide-mediated cytokine release in blood mononuclear and dendritic cells from healthy individuals. We found that in vitro treatment of beryllium sulfate inhibits the secretion of lipopolysaccharide-mediated interleukin 10, while the release of interleukin 1beta is enhanced. In addition, not all lipopolysaccharide-mediated responses are altered, as interleukin 6 release in unaffected upon beryllium treatment. Beryllium sulfate-treated cells show altered phosphotyrosine levels upon lipopolysaccharide stimulation. Significantly, beryllium inhibits the phosphorylation of signal transducer and activator of transducer 3, induced by lipopolysaccharide. Finally, inhibitors of phosphoinositide-3 kinase mimic the effects of beryllium in inhibition of interleukin 10 release, while they have no effect on interleukin 1beta secretion. This study strongly suggests that prior exposures to beryllium could alter host immune responses to bacterial infections in healthy individuals, by altering intracellular signaling.

  10. 铝掺杂超细氧化锌粉体的制备与性能研究%Preparation and Properties of Aluminum-Doped Zinc Oxide Ultrafine Powders

    Institute of Scientific and Technical Information of China (English)

    陈淑刚; 许林峰; 王书媚; 税安泽

    2013-01-01

    Aluminum-doped zinc oxide (AZO) ultrafine powders were synthesized by the homogeneous precipitation method with Zn( NO3)2·6H2O 和 Al( NO3) 3 ·9H2O as raw materials, and the AZO ultrafine powders were characterized by XRD, SEM, nanoparticle size analyzer and Four-point probe, resistivity. The effects of reaction temperature, calcination temperature, reactant concentration, aluminum dopant content and dispersant content on shape, size and resistivity of the AZO ultrafine powders were examined in detail. The experimental results show that the ZAO powders have the wurtzite structure; the formation of ZAO crystal phase is good at the calcination temperature 550 ℃ ; With increasing the aluminum dopant content, the resistivity of the ZAO powders decreases, and the lattice parameters decrease, however, when the dopant content exceeds 2.0 mol% , the spinel phase is produced, and the resistivity begins to increase.%本文以Zn(NO3)2·6H2O和Al(NO3)3·9H2O为原料采用均匀沉淀法制备了Al掺杂ZnO(ZAO)超细粉体,用XRD、SEM、纳米粒度分析仪及四探针电阻仪等对ZAO超细粉体进行了测试表征.研究了反应温度、煅烧温度、反应物浓度、Al掺杂量及分散剂添加量对ZAO超细粉体形貌、尺寸及电阻率的影响.研究结果表明:制备的ZAO粉体为纤锌矿结构;煅烧温度为550℃时,ZAO晶相形成很好;随着Al掺杂量的增加,ZAO粉体电阻率降低,晶格常数减小,但当Al掺杂量大于2.0 mol%时,生成尖晶石相,其电阻率反而上升.

  11. Experimental study on fluidization of micronic powders

    OpenAIRE

    Alavi, Shila; Caussat, Brigitte

    2005-01-01

    The fluidization behavior of yttrium oxide (Y2O3) powders of high density and micronic diameter belonging to the group C of Geldart’s classification has been investigated. Large interparticle forces lead to bed cracking, slugging and channelling, and cause the powder not to fluidize consistently. Different fluidization technologies have been tested, such as mechanical agitated fluidization, vibrated fluidization and addition of easyto-fluidize large particles to fine particles. The qual...

  12. Investigations of the ternary system beryllium-carbon-tungsten and analyses of beryllium on carbon surfaces; Untersuchung des ternaeren Systems Beryllium-Kohlenstoff-Wolfram und Betrachtungen von Beryllium auf Kohlenstoffoberflaechen

    Energy Technology Data Exchange (ETDEWEB)

    Kost, Florian

    2009-05-25

    Beryllium, carbon and tungsten are planned to be used as first wall materials in the future fusion reactor ITER. The aim of this work is a characterization of mixed material formation induced by thermal load. To this end, model systems (layers) were prepared and investigated, which give insight into the basic physical and chemical concepts. Before investigating ternary systems, the first step was to analyze the binary systems Be/C and Be/W (bottom-up approach), where the differences between the substrates PG (pyrolytic graphite) and HOPG (highly oriented pyrolytic graphite) were of special interest. Particularly X-ray photoelectron spectroscopy (XPS), low energy ion scattering (ISS) and Rutherford backscattering spectroscopy (RBS) were used as analysis methods. Beryllium evaporated on carbon shows an island growth mode, whereas a closed layer can be assumed for layer thicknesses above 0.7 nm. Annealing of the Be/C system induces Be{sub 2}C island formation for T{>=}770 K. At high temperatures (T{>=}1170 K), beryllium carbide dissociates, resulting in (metallic) beryllium desorption. For HOPG, carbide formation starts at higher temperatures compared to PG. Activation energies for the diffusion processes were determined by analyzing the decreasing beryllium amount versus annealing time. Surface morphologies were characterized using angle-resolved XPS (ARXPS) and atomic force microscopy (AFM). Experiments were performed to study processes in the Be/W system in the temperature range from 570 to 1270 K. Be{sub 2}W formation starts at 670 K, a complete loss of Be{sub 2}W is observed at 1170 K due to dissociation (and subsequent beryllium desorption). Regarding ternary systems, particularly Be/C/W and C/Be/W were investigated, attaching importance to layer thickness (reservoir) variations. At room temperature, Be{sub 2}C, W{sub 2}C, WC and Be{sub 2}W formation at the respective interfaces was observed. Further Be{sub 2}C is forming with increasing annealing temperatures

  13. C, N co-doped TiO2/TiC0.7N0.3 composite coatings prepared from TiC0.7N0.3 powder using ball milling followed by oxidation

    Science.gov (United States)

    Hao, Liang; Wang, Zhenwei; Zheng, Yaoqing; Li, Qianqian; Guan, Sujun; Zhao, Qian; Cheng, Lijun; Lu, Yun; Liu, Jizi

    2017-01-01

    Ball milling followed by heat oxidation was used to prepared C, N co-doped TiO2 coatings on the surfaces of Al2O3 balls from TiC0.7N0.3 powder. The as-prepared coatings were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and ultraviolet-visible spectrophotometer (UV-vis). The results show that continuous TiC0.7N0.3 coatings were formed after ball milling. C, N co-doped TiO2/TiC0.7N0.3 composite coatings were prepared after the direct oxidization of TiC0.7N0.3 coatings in the atmosphere. However, TiO2 was hardly formed in the surface layer of TiC0.7N0.3 coatings within a depth less than 10 nm during the heat oxidation of TiC0.7N0.3 coatings in carbon powder. Meanwhile, the photocatalytic activity evaluation of these coatings was conducted under the irradiation of UV and visible light. All the coatings showed photocatalytic activity in the degradation of MB no matter under the irradiation of UV or visible light. The C, N co-doped TiO2/TiC0.7N0.3 composite coatings showed the most excellent performance. The enhancement under visible light irradiation should attribute to the co-doping of carbon and nitrogen, which enhances the absorption of visible light. The improvement of photocatalytic activity under UV irradiation should attribute to the synergistic effect of C, N co-doping, the formation of rutile-anatase mixed phases and the TiO2/TiC0.7N0.3 composite microstructure.

  14. Application of powder X-ray diffraction and the Rietveld method to the analysis of oxidation processes and products in sulphidic mine tailings

    DEFF Research Database (Denmark)

    Balic Zunic, Tonci; Katerinopoulou, Anna; Edsberg, Anders

    2011-01-01

    silica were applied as proper models. The procedures developed on test mixtures result in estimated errors of determination typically lower than 2 wt%. The approach was applied to the analysis of the complex problem of estimating mass balance in oxidized mine tailings from the Nanisivik Mine, Nunavut......, Canada revealing an oxidized proportion of 9 % of total pyrite content in the well drained tailings during a period of 8 years and a negligible oxidation in the water-covered tailings....

  15. Temperature-strain rate dependence of mechanical properties of a beryllium of the DShG-200 brand

    Energy Technology Data Exchange (ETDEWEB)

    Khomutov, A.M.; Gorokhov, V.A.; Mikhailov, V.S.; Nikolaev, G.N.; Timofeev, R.Yu.; Chernov, V.M. [Vserossijskij Nauchno-Issledovatel' skij Inst. Neorganicheskikh Materialov, Moscow (Russian Federation)

    2000-04-01

    Beryllium preforms of the DShG-200 brand of improved quality were manufactured by the method of a powder metallurgy and the mechanical tests on tension in longitudinal and transversal directions in temperature range 20-600 C and strain rates of 0,02 - 20 mm/min were held. It was shown, that at an alteration of strain rate within the indicated limits the values of stresses of flow and of the relative elongation can vary by several times. Comparison testing for tension by the Russian and American procedures (GOST and ASTM) was made. The obtained results can be beneficial at calculations of thermal stresses originating in fusion reactors (FR). (orig.)

  16. Effect of Pre-Oxidation Treatment of Nano-SiC Particulates on Microstructure and Mechanical Properties of SiC/Mg-8Al-1Sn Composites Fabricated by Powder Metallurgy Combined with Hot Extrusion

    Directory of Open Access Journals (Sweden)

    Chuan-Peng Li

    2016-11-01

    Full Text Available Nano-SiC particulates (n-SiCp reinforced Mg-8Al-1Sn (AT81 composites with different pre-oxidation parameters were fabricated by powder metallurgy (P/M process combined with hot extrusion. The effects of pre-oxidization treatment of n-SiCp on the microstructure and tensile properties of 0.5 vol % n-SiCp/AT81 composites were investigated accordingly. The distribution of n-SiCp with different pre-oxidation parameters was homogeneous in the composites. Moreover, it was found that a thin MgAl2O4 layer formed at the interface when the n-SiCp were pre-oxidized at 1073 K for 2 h, while the MgAl2O4 layer became much thicker with pre-oxidization temperature increasing to 1273 K for 2 h. After an appropriate pre-oxidization treatment of n-SiCp at 1073 K for 2 h, the as-extruded 0.5 vol % n-SiCp/AT81 composites exhibited an enhanced strength. It was found that the yield strength (YS and ultimate tensile strength (UTS increased from 168 MPa and 311 MPa to 255 MPa and 393 MPa compared with the as-extruded AT81 alloy, reflecting 51.8% and 26.4% increments, respectively. The improvement of mechanical properties should be mainly attributed to the grain refinement and homogeneous distribution of n-SiCp in the composites. Moreover, a well-bonded interface and the formation of an appropriate amount of interfacial product (MgAl2O4 benefited the material’s mechanical properties.

  17. Beryllium Dust Generation in PISCES-B Due to Plasma-Material Interactions

    Science.gov (United States)

    Doerner, R.; Mays, C.; Hirooka, Y.; Luckhardt, S. C.; Sze, C. F.; Won, J.; Conn, R. W.

    1996-11-01

    The PISCES-B device has started plasma-beryllium experiments in its new location at U.C. San Diego. An improved controlled atmosphere enclosure was constructed to assure safe operation with beryllium materials. In the previous experimental campaign we found that a total of 600 mg of beryllium had been eroded during materials tests. This provided us with a unique opportunity to investigate the lost beryllium. Swipe sampling and vacuum sampling of the PISCES-B vacuum chamber revealed that 3% of the eroded beryllium resided as uniformly distributed loose dust within the vacuum chamber. An additional 33% of the eroded beryllium was coated onto the chamber wall. Filtering through a series of decreasing pore size meshes revealed a uniform distribution of particle sizes in the respirable range (between 10mm - 0.1mm), fewer larger particles (>50mm) were observed. This work is supported by USDOE under grant DE-FG03-95ER-54301.

  18. Studies on extraction of beryllium from thiocyanate solutions by quaternary ammonium halides.

    Science.gov (United States)

    El-Yamani, I S; El-Messieh, E N

    A 0.4M tricaprylmethylammonium chloride solution in n-hexane was used for the quantitative extraction of beryllium from hydrochloric acid (pH 3) and 5M potassium thiocyanate. Beryllium was stripped from the organic phase with 1M sodium hydroxide, then determined volumetrically with bismuthyl perchlorate and bromocresol green indicator. Beryllium was extracted in presence of a large number of elements which are usually associated with it in beryl and in fission products of nuclear fuel.

  19. Summary of historical beryllium uses and airborne concentration levels at Los Alamos National Laboratory.

    Science.gov (United States)

    Stefaniak, Aleksandr B; Weaver, Virginia M; Cadorette, Maureen; Puckett, Leslie G; Schwartz, Brian S; Wiggs, Laurie D; Jankowski, Mark D; Breysse, Patrick N

    2003-09-01

    Beryllium operations and accompanying medical surveillance of workers at Los Alamos National Laboratory began in the 1940s. In 1999 a Former Workers Medical Surveillance Program that includes screening for chronic beryllium disease was initiated. As part of this program, historical beryllium exposure conditions were reconstructed from archived paper and electronic industrial hygiene data sources to improve understanding of past beryllium uses and airborne concentration levels. Archived industrial hygiene sampling reports indicated beryllium was principally used in technical areas-01 and -03, primarily being machined. Beryllium was also used at 15 other technical areas in activities that ranged from explosives detonation to the manufacture of X-ray windows. A total of 4528 personal breathing zone and area air samples for beryllium, combined for purposes of calculating summary statistics, were identified during the records review phase. The geometric mean airborne beryllium concentration for the period 1949-1989 for all technical areas was 0.04 microg Be/m(3) with 97 percent of all sample below the 2.0 microg Be/m(3) occupational exposure limit (OEL). Average beryllium concentrations per decade were less than 1 microg Be/m(3) and annual geometric mean concentrations in technical area-03, the largest user of beryllium, were generally below 0.1 microg Be/m(3), indicating exposure was generally well-controlled, that is, below the OEL. Typical of many retrospective exposure assessments, not all archived data could be extracted and summarized. Despite this, we report a reasonable summary of potential beryllium uses and airborne concentration levels a worker may have encountered from 1949-1989. These data can be used to more effectively identify former worker populations at potential risk for chronic beryllium disease and to offer these workers screening as part of the Former Worker Medical Surveillance Program, and in the event that a case is diagnosed, help to understand

  20. Beryllium uptake and related biological effects studied in THP-1 differentiated macrophages.

    Science.gov (United States)

    Ding, Jian; Lin, Lin; Hang, Wei; Yan, Xiaomei

    2009-11-01

    Investigation of cellular uptake of metal compounds is important in understanding metal-related toxicity and diseases. Inhalation of beryllium aerosols can cause chronic beryllium disease, a progressive, granulomatous fibrosis of the lung. Studies in laboratory animals and cultured animal cells indicate that alveolar macrophages take up beryllium compounds and participate in a hypersensitivity immune response to a beryllium-containing antigen. In the present work, human monocyte cell line THP-1 was induced with phorbol myristate acetate to differentiate into a macrophage. This cell with characteristics of human alveolar macrophages was employed to study cellular beryllium uptake and related biological effects. Morphological changes, phagocytosis of fluorescent latex beads, and cell surface CD14 expression were used to verify the successful differentiation of THP-1 monocytes into macrophages. An improved mass spectrometry method for quantitative analysis of intracellular beryllium as opposed to the traditional radioisotopic approach was developed using ICP-MS. The influence of the solubility of beryllium compounds, exposure duration, and beryllium concentration on the incorporation of beryllium was studied. Our data indicated that the uptake of particulate BeO was much more significant than that of soluble BeSO(4), suggesting the major cellular uptake pathway is phagocytosis. Nevertheless, subsequent DAPI nuclear staining and PARP cleavage study indicated that beryllium uptake had a negligible effect on the apoptosis of THP-1 macrophages compared to the unstimulated macrophage control. Meanwhile, no substantial variation of tumour necrosis factor-alpha production was observed for THP-1 macrophages upon beryllium exposure. These data imply alveolar macrophages could have some level of tolerance to beryllium and this may explain why most Be-exposed individuals remain healthy throughout life.

  1. Minority Carrier Lifetime in Beryllium-Doped InAs/InAsSb Strained Layer Superlattices

    Science.gov (United States)

    2014-06-03

    SECURITY CLASSIFICATION OF: Minority carrier lifetimes in undoped and Beryllium -doped Type-2 Ga-free, InAs/InAsSb strained layer superlattices (SLS) with...is unlimited. Minority Carrier Lifetime in Beryllium -Doped InAs/InAsSb Strained Layer Superlattices The views, opinions and/or findings contained in...Brook University W-5510 Melville Library West Sayville, NY 11796 -3362 1 ABSTRACT Minority Carrier Lifetime in Beryllium -Doped InAs/InAsSb Strained

  2. Beryllium dimer: a bond based on non-dynamical correlation.

    Science.gov (United States)

    El Khatib, Muammar; Bendazzoli, Gian Luigi; Evangelisti, Stefano; Helal, Wissam; Leininger, Thierry; Tenti, Lorenzo; Angeli, Celestino

    2014-08-21

    The bond nature in beryllium dimer has been theoretically investigated using high-level ab initio methods. A series of ANO basis sets of increasing quality, going from sp to spdf ghi contractions, has been employed, combined with HF, CAS-SCF, CISD, and MRCI calculations with several different active spaces. The quality of these calculations has been checked by comparing the results with valence Full-CI calculations, performed with the same basis sets. It is shown that two quasi-degenerated partly occupied orbitals play a crucial role to give a qualitatively correct description of the bond. Their nature is similar to that of the edge orbitals that give rise to the quasi-degenerated singlet-triplet states in longer beryllium chains.

  3. Ultrasonic evaluation of beryllium-copper diffusion bonds

    Energy Technology Data Exchange (ETDEWEB)

    Jamieson, E.E.

    2000-06-08

    A study was performed to compare the effectiveness of several advanced ultrasonic techniques when used to determine the strength of diffusion bonded beryllium-copper, which heretofore have each been applied to only a few material systems. The use of integrated backscatter calculations, frequency domain reflection coefficients, and time-of-flight variance was compared in their ability to characterize the bond strength in a series of beryllium-copper diffusion bond samples having a wide variation in bond quality. Correlation of integrated backscatter calculations and time-of-flight variance with bond strength was good. Some correlation of the slope of the frequency based reflection coefficient was shown for medium and high strength bonds, while its Y-intercept showed moderate correlation for all bond strengths.

  4. A joint fracture toughness evaluation of hot-pressed beryllium

    Science.gov (United States)

    Conrad, H.; Sargent, G. A.; Brown, W. F., Jr.

    1977-01-01

    Fracture toughness tests at room temperature were made on three-point bend specimens cut from hot-pressed beryllium obtained from two suppliers. The test specimens had dimensions conforming to ASTM fracture toughness standard E399-72. A total of 42 specimens were machined from each batch of material. Six specimens from each batch were then distributed to seven independent laboratories for testing. The test data from the laboratories were collected and analyzed for differences between the laboratories and the two batches of material. It is concluded that ASTM 399-72 can be used as a valid test procedure for determining the fracture toughness of beryllium, providing that Kf(max) in fatigue cracking could be up to 80 percent of the K(0) value.

  5. Fabricating thin beryllium windows for X-ray applications

    Science.gov (United States)

    Truhan, John J.; Wagner, Lawrence M.

    1980-10-01

    X-ray windows for diagnostics into vacuum chambers are commonly made of beryllium, which must be as thin as possible to minimize attenuation of the X rays. The windows must be bonded to mounting flanges, and the bond must be leak-tight and able to withstand a pressure differential of one atmosphere. A solid-state bonding process can be used to attach windows of thickness from 0.025 down to 0.015 mm. The process bonds the beryllium window, a silver intermediate layer, and the mounting flange together using compression and heat. The process is not sensitive to the bonding parameters; usual ranges are: pressures of 83-172 MPa, temperatures of 750-950 K, and holding times of 5-60 min. Unsuccessful bonds can often be repaired, or parts can be salvaged for re-use. A variety of window geometries can be accommodated.

  6. Beryllium Drive Disc Characterization for Laboratory Astrophysics Experiments

    Science.gov (United States)

    Ditmar, J. R.; Drake, R. P.; Kuranz, C. C.; Grosskopf, M. J.

    2009-11-01

    Laboratory Astrophysics scales large-scale phenomena, such as core-collapse supernovae shocks, down to the sub-millimeter scale for investigation in a laboratory setting. In some experiments, targets are constructed with a 20μm thick beryllium disc attached to a polyimide tube. A shockwave is created by irradiating the Be disc with ˜ 4kJ of energy from the Omega Laser. The Be material is rolled into a 20μm sheet and then machined to a 2.5mm diameter. Characterizing the roughness and knowing if there are any major features on the initial surface could affect interpretations of data taken during experiments. Structure in the Beryllium discs could become an important parameter in future high-fidelity computer simulations. Surfaces were characterized with a Scanning Electron Microscope and an Atomic Force Microscope.

  7. VLT beryllium secondary mirror no. 1: performance review

    Science.gov (United States)

    Cayrel, Marc

    1998-08-01

    The four Very Large Telescope secondary mirrors are 1.2-m Beryllium lightweight convex mirrors. REOSC has been selected for the design and manufacturing of the optics and of their supporting system. The first mirror unit has been delivered in September, 1997. Operating from visible to near infrared, the mirror defines the telescope aperture stop and may be chopped during observation. The optical requirements are tight and a high stiffness, low weight and inertia are requested as well. Using beryllium is a technical challenge for such a large optic manufacturing, in particular regarding its stability. The requirements and design are presented, we review the mirror manufacturing steps: blank production, machining, grinding, Nickel plating, polishing, integration and testing. The optical quality control method, a problem for large convex mirrors control, is detailed. The results of acceptance testing of mirror No. 1 are summarized, we present conclusions about the mirror figure stability. The status of the three additional mirrors manufacturing is presented to conclude.

  8. Multiscale modelling of hydrogen behaviour on beryllium (0001 surface

    Directory of Open Access Journals (Sweden)

    Ch. Stihl

    2016-12-01

    Full Text Available Beryllium is proposed to be a neutron multiplier and plasma facing material in future fusion devices. Therefore, it is crucial to acquire an understanding of the microscopic mechanisms of tritium accumulation and release as a result of transmutation processes that Be undergoes under neutron irradiation. A multiscale simulation of ad- and desorption of hydrogen isotopes on the beryllium (0001 surface is developed. It consists of ab initio calculations of certain H adsorption configurations, a suitable cluster expansion approximating the energies of arbitrary configurations, and a kinetic Monte Carlo method for dynamic simulations of adsorption and desorption. The processes implemented in the kinetic Monte Carlo simulation are deduced from further ab initio calculations comprising both, static relaxation as well as molecular dynamics runs. The simulation is used to reproduce experimental data and the results are compared and discussed. Based on the observed results, proposals for a refined model are made.

  9. Nephro-protective effect of a novel formulation of unopened coconut inflorescence sap powder on gentamicin induced renal damage by modulating oxidative stress and inflammatory markers.

    Science.gov (United States)

    Jose, Svenia P; S, Asha; Im, Krishnakumar; M, Ratheesh; Santhosh, Savitha; S, Sandya; B, Girish Kumar; C, Pramod

    2017-01-01

    Fresh oyster white translucent sap obtained from the tender unopened inflorescence of coconut trees (Cocos nucifera) is identified to have great health benefits. Drug induced Nephrotoxicity is one of the major causes of renal damage in present generation. As a therapeutic agent, gentamicin imparts direct toxicity to kidney, resulting in acute tubular necrosis, glomerular and tubulointerstitial injury, haemodynamically mediated damage and obstructive nephropathy.There exists an increasing demand for safe and natural agents for the treatment and/or preventionofchronic nephrotoxicity and pathogenesis of kidney diseases. Our study shows the nephro protective/curing effect of a novel powder formulation of micronutrient enriched, unfermented coconut flower sap (CSP). The study was performed on adult male Wistar rats. The animals were grouped into three and treated separately with vehicle, gentamicin and gentamicin+CSP for 16days. Initially, gentamicin treatment significantly (pcoconut flower sap powder showed significant (p<0.05) reversal of all these biochemical parameters indicating an effective inhibition of the pathogenesis of nephrotoxicity and kidney disease.

  10. 38% Aluminum - 62% Beryllium shaped blank technology

    Science.gov (United States)

    Knapp, James T.

    2007-09-01

    Near-Net-Shape (NNS) technology for advanced engineered materials provides a number of supply chain benefits. These benefits include less input material, less machining hours and overall greater through put in comparison to conventional rectangular and round machining stock. Al-62%Be alloy has a unique combination of properties attractive for optical structures. It has a density of 0.076-lb/in3, 28-ksi minimum yield strength and 28-Msi elastic modulus. There have been significant developments with AlBe Hot Isostatic Press (HIP) consolidation technology in recent years. One key is using spherical AlBe metal powder which packs to a high density. The high packing density allows more complex can design and dimensional control to produce monolithic parts with isotropic properties. Other key success factors are HIP can design and the process to implement the near-net-shape strategy. This paper will describe an example of a process using shaped HIP cans to produce blanks approaching near-net-shape design through an iterative process. The strategy is to produce a seamless product to the next step in the supply chain as the iterations improve material utilization efficiency. The economic impact and planned future work will also be described.

  11. Beryllium, Lithium and Oxygen Abundances in F-type Stars

    CERN Document Server

    García-López, R J; Pérez de Taoro, M R; Casares, C; Rasilla, J L; Rebolo, R; Allende-Prieto, C

    1997-01-01

    Beryllium and oxygen abundances have been derived in a sample of F-type field stars for which lithium abundances had been measured previously, with the aim of obtaining observational constraints to discriminate between the different mixing mechanisms proposed. Mixing associated with the transport of angular momentum in the stellar interior and internal gravity waves within the framework of rotating evolutionary models, appear to be promising ways to explain the observations.

  12. Presence of Beryllium (Be) in urban soils: human health risk

    Energy Technology Data Exchange (ETDEWEB)

    Pena, A.; Gonzalez, M. J.; Lobo, M. C.

    2009-07-01

    Berylium (Be) is, together with As, Cd, Hg, Pb and Ti, one of the trace elements more toxic for human being (Vaessen) and Szteke, 2000; Yaman and Avci, 2006), but in spite of the exponential increment of its applications during the last decades, surprisingly there isn't hardly information about its presence and environmental distribution. The aim of this work is to evaluate the presence of Beryllium in urban soils in Alcala de Henares, (Madrid Spain).

  13. Impact of HFIR LEU Conversion on Beryllium Reflector Degradation Factors

    Energy Technology Data Exchange (ETDEWEB)

    Ilas, Dan [ORNL

    2013-10-01

    An assessment of the impact of low enriched uranium (LEU) conversion on the factors that may cause the degradation of the beryllium reflector is performed for the High Flux Isotope Reactor (HFIR). The computational methods, models, and tools, comparisons with previous work, along with the results obtained are documented and discussed in this report. The report documents the results for the gas and neutronic poison production, and the heating in the beryllium reflector for both the highly enriched uranium (HEU) and LEU HFIR configurations, and discusses the impact that the conversion to LEU may have on these quantities. A time-averaging procedure was developed to calculate the isotopic (gas and poisons) production in reflector. The sensitivity of this approach to different approximations is gauged and documented. The results show that the gas is produced in the beryllium reflector at a total rate of 0.304 g/cycle for the HEU configuration; this rate increases by ~12% for the LEU case. The total tritium production rate in reflector is 0.098 g/cycle for the HEU core and approximately 11% higher for the LEU core. A significant increase (up to ~25%) in the neutronic poisons production in the reflector during the operation cycles is observed for the LEU core, compared to the HEU case, for regions close to the core s horizontal midplane. The poisoning level of the reflector may increase by more than two orders of magnitude during long periods of downtime. The heating rate in the reflector is estimated to be approximately 20% lower for the LEU core than for the HEU core. The decrease is due to a significantly lower contribution of the heating produced by the gamma radiation for the LEU core. Both the isotopic (gas and neutronic poisons) production and the heating rates are spatially non-uniform throughout the beryllium reflector volume. The maximum values typically occur in the removable reflector and close to the midplane.

  14. The beryllium quandary: will the lower exposure limits spur new developments in sampling and analysis?

    Energy Technology Data Exchange (ETDEWEB)

    Brisson, Michael

    2013-06-03

    At the time this article was written, new rulemakings were under consideration at OSHA and the U.S. Department of Energy (DOE) that would propose changes to occupational exposure limits for beryllium. Given these developments, it’s a good time to review the tools and methods available to IHs for assessing beryllium air and surface contamination in the workplace—what’s new and different, and what’s tried and true. The article discusses limit values and action levels for beryllium, problematic aspects of beryllium air sampling, sample preparation, sample analysis, and data evaluation.

  15. Vacuum Brazing of Beryllium Copper Components for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Tyhurst, C.C.; Cunningham, M.A.

    2002-06-04

    A process for vacuum brazing beryllium copper anode assemblies was required for the Plasma Electrode Pockels Cell System, or PEPC, a component for the National Ignition Facility (NIF). Initial problems with the joint design and wettability of the beryllium copper drove some minor design changes. Brazing was facilitated by plating the joint surface of the beryllium copper rod with silver 0.0006 inch thick. Individual air sampling during processing and swipe tests of the furnace interior after brazing revealed no traceable levels of beryllium.

  16. Proteomic analysis of beryllium-induced genotoxicity in an Escherichia coli mutant model system.

    Science.gov (United States)

    Taylor-McCabe, Kirsten J; Wang, Zaolin; Sauer, Nancy N; Marrone, Babetta L

    2006-03-01

    Beryllium is the second lightest metal, has a high melting point and high strength-to-weight ratio, and is chemically stable. These unique chemical characteristics make beryllium metal an ideal choice as a component material for a wide variety of applications in aerospace, defense, nuclear weapons, and industry. However, inhalation of beryllium dust or fumes induces significant health effects, including chronic beryllium disease and lung cancer. In this study, the mutagenicity of beryllium sulfate (BeSO(4)) and the comutagenicity of beryllium with a known mutagen 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) were evaluated using a forward mutant detection system developed in Escherichia coli. In this system, BeSO(4) was shown to be weakly mutagenic alone and significantly enhanced the mutagenicity of MNNG up to 3.5-fold over MNNG alone. Based on these results a proteomic study was conducted to identify the proteins regulated by BeSO(4). Using the techniques of 2-DE and oMALDI-TOF MS, we successfully identified 32 proteins being differentially regulated by beryllium and/or MNNG in the E. coli test system. This is the first study to describe the proteins regulated by beryllium in vitro, and the results suggest several potential pathways for the focus of further research into the mechanisms underlying beryllium-induced genotoxicity.

  17. Chest wall shrapnel-induced beryllium-sensitization and associated pulmonary disease.

    Science.gov (United States)

    Fireman, E; Shai, A Bar; Lerman, Y; Topilsky, M; Blanc, P D; Maier, L; Li, L; Chandra, S; Abraham, J M; Fomin, I; Aviram, G; Abraham, J L

    2012-10-01

    Chronic beryllium disease (CBD) is an exposure-related granulomatous disease mimicking sarcoidosis. Beryllium exposure-associated disease occurs mainly via inhalation, but skin may also be a source of sensitization. A 65-year-old male with a history of war-related shrapnel wounds was initially diagnosed with pulmonary sarcoidosis. Twenty years later, the possibility of a metal-related etiology for the lung disease was raised. A beryllium lymphocyte proliferation test, elemental analysis of removed shrapnel, and genetic studies were consistent with a diagnosis of CBD. This case demonstrates that retained beryllium-containing foreign bodies can be linked to a pathophysiologic response in the lung consistent with CBD.

  18. Structure of a new high-pressure-high-temperature modification of antimony(III) oxide, γ-Sb2O3, from high-resolution synchrotron powder diffraction data.

    Science.gov (United States)

    Orosel, Denis; Dinnebier, Robert E; Blatov, Vladislav A; Jansen, Martin

    2012-02-01

    A quenchable new high-pressure-high-temperature modification of antimony(III) oxide, γ-Sb(2)O(3), has been obtained at hydrostatic pressures of 9-11 GPa and temperatures of 573-773 K. Its crystal structure has been determined from high-resolution synchrotron powder diffraction data. γ-Sb(2)O(3) consists of three-dimensionally cross-linked infinite chains of SbO(3)E units (E = lone pair) with the chains forming tetragonal rod-packing. The underlying topology of γ-Sb(2)O(3) (3,3T8) is found very rarely in inorganic structures; it is realised only for the polyanion [Si(4)O(4)N(6)](10-) that occurs in the Ce(4)(Si(4)O(4)N(6))O structure type. The structural relation to the two previously known polymorphs of Sb(2)O(3) at ambient pressure, valentinite and senarmontite is discussed.

  19. Evaluation of the controlling Pomacea canaliculata with calcium oxide, ammonium bicarbonate, Camellia oleifera powder and tea saponin%茶皂素、生石灰等防治稻田福寿螺的效果评估

    Institute of Scientific and Technical Information of China (English)

    王志高; 谭济才; 刘军; 王卫国

    2011-01-01

    Abstract: Pomacea canaliculata (Lamarck) is one of the most serious pests to the rice production area in southern China. In order to solve the problem caused by synthetic chemical molluscicides which are extremely toxic to the environment and agricultural products, we studied the efficiency of controlling P. canaliculata with four kinds of substitutes, calcium oxide, ammonium bicarbonate, Camellia oleifera powder and tea saponin, in laboratory and plot. The results indicated that the better control efficiency achieved using tea saponin, C. oleifera powder and calcium oxide. The mortality of snails achieved to 100% when the concentration of tea saponin was 40 mg/L and 50 mg/L, and treated for 48 h in laborato- ry. In the plot, mortality of snails were 100% using tea saponin at 6.0 g/m^2 with 4 days or 1.5 g/m^2 lasted 16 days. The quick-acting and lasting effect were better than those of other substitutes. Control efficiencies of C. oleifera powder at 30 g/m^2 and 45 g/m^2 and calcium oxide treatment at 45 g/m^2 are over 80% after 15 days. In addition, these three kinds of substitutes can control the Echirtochloa crusgalli (L.) Beauv effectively in the rice paddy. Ammonium bicarbonate was less effective on controlling P. canaliculata, and can promote the occurrence of E. crusgaUi. We concluded that tea saponin, C. oleifera powder and calcium oxide can be used as the substitutes of synthetic chemical molluscicides for contro- lling P. canaliculata in the rice paddy.%福寿螺已成为我国南方局部稻区严重危害水稻的有害生物,为解决常用的化学杀螺剂污染环境和农产品的问题,分别在室内和大田环境下研究了生石灰、碳酸氢铵、茶麸和茶皂素4种替代物质防治福寿螺的效果。茶皂素、茶麸和生石灰对稻田福寿螺有很好的防治作用。在室内试验中40 mg/L和50mg/L茶皂素处理在48h即达到了100%的防效;在大田试验中茶皂素6.0g/m^2的处理在第4天、1.5g/m^2

  20. Characterization of powdered fish heads for bone graft biomaterial applications.

    Science.gov (United States)

    Oteyaka, Mustafa Ozgür; Unal, Hasan Hüseyin; Bilici, Namık; Taşçı, Eda

    2013-01-01

    The aim of this study was to define the chemical composition, morphology and crystallography of powdered fish heads of the species Argyrosomus regius for bone graft biomaterial applications. Two sizes of powder were prepared by different grinding methods; Powder A (coarse, d50=68.5 µm) and Powder B (fine, d50=19.1 µm). Samples were analyzed using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM), thermogravimetry (TG), and energy dispersive X-ray spectroscopy (EDS). The powder was mainly composed of aragonite (CaCO3) and calcite (CaCO3). The XRD pattern of Powder A and B matched standard aragonite and calcite patterns. In addition, the calcium oxide (CaO) phase was found after the calcination of Powder A. Thermogravimetry analysis confirmed total mass losses of 43.6% and 47.3% in Powders A and B, respectively. The microstructure of Powder A was mainly composed of different sizes and tubular shape, whereas Powder B showed agglomerated particles. The high quantity of CaO and other oxides resemble the chemical composition of bone. In general, the powder can be considered as bone graft after transformation to hydroxyapatite phase.

  1. Calculations for electron-impact excitation and ionization of beryllium

    Science.gov (United States)

    Zatsarinny, Oleg; Bartschat, Klaus; Fursa, Dmitry V.; Bray, Igor

    2016-12-01

    The B-spline R-matrix and the convergent close-coupling methods are used to study electron collisions with neutral beryllium over an energy range from threshold to 100 eV. Coupling to the target continuum significantly affects the results for transitions from the ground state, but to a lesser extent the strong transitions between excited states. Cross sections are presented for selected transitions between low-lying physical bound states of beryllium, as well as for elastic scattering, momentum transfer, and ionization. The present cross sections for transitions from the ground state from the two methods are in excellent agreement with each other, and also with other available results based on nonperturbative convergent pseudostate and time-dependent close-coupling models. The elastic cross section at low energies is dominated by a prominent shape resonance. The ionization from the {(2s2p)}3P and {(2s2p)}1P states strongly depends on the respective term. The current predictions represent an extensive set of electron scattering data for neutral beryllium, which should be sufficient for most modeling applications.

  2. A diethylhydroxylaminate based mixed lithium/beryllium aggregate

    Energy Technology Data Exchange (ETDEWEB)

    Berger, Raphael J.F. [Paris-Lodron Universitaet Salzburg (Austria). Fachbereich fuer Materialwissenschaften und Physik; Jana, Surajit [Asansol Girls College, West-Bengal (India). Dept. of Chemistry; Froehlich, Roland [Muenster Univ. (Germany). Organisch-Chemisches Inst.; Mitzel, Norbert W. [Bielefeld Univ. (Germany). Anorganische Chemie und Strukturchemie

    2015-07-01

    A mixed lithium/beryllium diethylhydroxylaminate compound containing {sup n}butyl beryllium units of total molecular composition {sup n}Be(ONEt{sub 2}){sub 2} [(LiONEt{sub 2}){sup 2} {sup n}BuBeONEt{sub 2}]{sub 2} (1) was isolated from a reaction mixture of {sup n}butyl lithium, N,N-diethylhydroxylamine and BeCl{sub 2} in diethylether/thf. The crystal structure of 1 has been determined by X-ray diffraction. The aggregate is composed of two ladder-type subunits connected in a beryllium-centered distorted tetrahedron of four oxygen atoms. Only the lithium atoms are engaged in coordination with the nitrogen donor atoms. The DFT calculations support the positional occupation determined for Li and Be in the crystal structure. The DFT and the solid-state structure are in excellent agreement, indicating only weak intermolecular interactions in the solid state. Structural details of metal atom coordination are discussed.

  3. Transparent zinc sulfide processed from nanocrystalline powders

    Science.gov (United States)

    Gao, De; Stefanik, Todd S.

    2013-06-01

    Nanocerox produces oxide nanopowders via flame spray pyrolysis that have proven effective in the processing of a host of high quality optical ceramic materials. In order to produce LWIR windows to compete with ZnS, however, oxide materials are not suitable. Nanocerox has therefore developed aqueous synthesis techniques for the production of zinc sulfide nanopowders. The proprietary processing technique allows control of primary particle size, high purity, low levels of agglomeration, and cost effective synthesis. Crystallinity, particle size, and purity of the powders will be presented. Characterization of parts fabricated from these powders via sinter/HIP processing will also be discussed, including optical performance and microstructural characterization.

  4. Ultrafine Silver Peroxide Powders Prepared by Ozone Oxidization Method and Its Antibacterial Property%臭氧氧化法制备超细AgO粉末及其抗菌性能研究

    Institute of Scientific and Technical Information of China (English)

    沈文宁; 冯拉俊; 孔珍珍; 冯慧

    2011-01-01

    In view of the existing problems that the particle size of prepared powders is large, AgO content is low, the requirement for equipment is high and waste solution caused environmental pollution is produced in preparation process, in this paper ultrafine silver peroxide powders were prepared by chemical oxidation method using pollution-free ozone as oxidant.Effects of factors such as reaction temperature, initial pH value and ozone input time on silver peroxide content were studied.The prepared products were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and shake-flask method.The results show that ultrafine powders with a AgO content of 83.56%, a platy morphology and a thickness around 100 nm are prepared in conditions of reaction temperature 45 ℃, initial pH value 14, ozone input time 5 h.There are only Ag and O elements in powders which silver exists mainly in the forms of monoclinic AgO and little cubic Ag2O.AgO possesses strong antibacterial ability.When the concentration of antibacterial agent is 1 mg·L-1 and acting time is 30 min, the bactericidal rates of powders with a AgO content of 83.56% against S.aureus and E.coli both exceed 99.9%.And in the same condition, the bactericidal rates of AgO are 7 times higher than that of Ag2O in 5 min.%针对现有方法制备AgO粉末存在粒径大、含量低、对设备要求高、制备过程产生污染环境的废液等问题,以无污染的臭氧为氧化剂,通过化学氧化法制备超细AgO粉末.研究了反应温度、初始pH值、臭氧通入时间等因素对AgO含量的影响.利用XRD,XPS,SEM,烧瓶振荡法对制备产物进行表征.结果表明,当反应温度为45℃、初始pH值为14、臭氧通入时间为5 h时,制得形状为板状,厚度约为100 nm,AgO含量为83.56%的超细粉末;粉末中只含有Ag,O两种元素,Ag主要以单斜AgO和少量的立方Ag2O形式存在;AgO具有强的抗菌能力,1 mg·L-1AgO含量为83.56%的粉

  5. Preparation of ultrafine rhenium powders by CVD hydrogen reduction of volatile rhenium oxides%采用CVD法还原挥发性铼的氧化物制备超细铼粉

    Institute of Scientific and Technical Information of China (English)

    白猛; 刘志宏; 周乐君; 刘智勇; 张传福

    2013-01-01

    研究了一种以高铼酸铵为原料,采用化学气相沉积(CVD)制备超细铼粉的新方法.通过控制氧分压,使得NH4ReO7分解为具有挥发性的ReO4、Re2O7,再采用载气将其输运至还原区,经氢气还原生成超细铼粉.热力学计算表明,在NH4ReO7分解过程中,控制氧分压高于10-1.248 Pa时,Re2O7将不会分解为低价氧化物,DSC-TGA分析结果也证实了这一点.采用该方法制备的铼粉,粒度为100~800nm,D50为308nm,比表面积为4.37 m2/g,氧含量为0.45%.%A novel CVD process for the preparation of ultrafine rhenium powders was investigated using ammonium perrhenate as starting materials.In the process, volatile rhenium oxides,such as ReO4 and Re2O7,were vaporized under a controlled oxidizing atmosphere via the pyrolysis of ammonium perrhenate,and carried into reduction zone by carrier gas,and there reduced into rhenium powders by hydrogen gas.Thermodynamic calculations indicated that Re2O7 could be prevented from further decomposition through controlling the oxygen partial pressure higher than 10 1.248 Pa in the pyrolysis of ammonium perrhenate.This result was further validated via DSC-TGA analysis of ammonium perrhenate.The typical rhenium powders prepared by the CVD method proposed show irregular polyhedron morphology with particle size in the range of 100-800 nm and a D50 of 308 nm.The specific surface area and oxygen content were measured to be 4.37 m2/g and 0.45%,respectively.

  6. Introduction to beryllium: uses, regulatory history, and disease.

    Science.gov (United States)

    Kolanz, M E

    2001-05-01

    Beryllium is an ubiquitous element in the environment, and it has many commercial applications. Because of its strength, electrical and thermal conductivity, corrosion resistance, and nuclear properties, beryllium products are used in the aerospace, automotive, energy, medical, and electronics industries. What eventually came to be known as chronic beryllium disease (CBD) was first identified in the 1940s, when a cluster of cases was observed in workers from the fluorescent light industry. The U.S. Atomic Energy Commission recommended the first 8-hour occupational exposure limit (OEL) for beryllium of 2.0 microg/m3 in 1949, which was later reviewed and accepted by the American Conference of Governmental Industrial Hygienists (ACGIH), the American Industrial Hygiene Association (AIHA), the American National Standards Institute (ANSI), the Occupational Safety and Health Administration (OSHA), and the vast majority of countries and standard-setting bodies worldwide. The 2.0 microg/m3 standard has been in use by the beryllium industry for more than 50 years and has been considered adequate to protect workers against clinical CBD. Recently, improved diagnostic techniques, including immunological testing and safer bronchoscopy, have enhanced our ability to identify subclinical CBD cases that would have formerly remained unidentified. Some recent epidemiological studies have suggested that some workers may develop CBD at exposures less than 2.0 microg/m3. ACGIH is currently reevaluating the adequacy of the current 2.0 microg/m3 guideline, and a plethora of research initiatives are under way to provide a better understanding of the cause of CBD. The research is focusing on the risk factors and exposure metrics that could be associated with CBD, as well as on efforts to better characterize the natural history of CBD. There is growing evidence that particle size and chemical form may be important factors that influence the risk of developing CBD. These research efforts are

  7. Co-administration of monoisoamyl dimercaptosuccinic acid and Moringa oleifera seed powder protects arsenic-induced oxidative stress and metal distribution in mice.

    Science.gov (United States)

    Mishra, Deepshikha; Gupta, Richa; Pant, S C; Kushwah, Pramod; Satish, H T; Flora, S J S

    2009-02-01

    Arsenic contamination of groundwater in the West Bengal basin in India is unfolding as one of the worst natural geo-environmental disasters to date. Chelation therapy with chelating agents is considered to be the best known treatment against arsenic poisoning; however, they are compromised with certain serious drawbacks/side-effects. Efficacy of combined administration of Moringa oleifera (M. oleifera) (English: Drumstick tree) seed powder, a herbal extract, with a thiol chelator monoisoamyl DMSA (MiADMSA) post-arsenic exposure in mice was studied. Mice were exposed to 100 ppm arsenic in drinking water for 6 months, followed by 10-days treatment with M. oleifera seed powder (500 mg/kg, orally through gastric gavage, once daily), MiADMSA (50 mg/kg, intraperitoneally, once daily) either individually or in combination. Arsenic exposure caused significant decrease in blood glutathione, delta-aminolevulinic acid dehydratase (ALAD), accompanied by increased production of reactive oxygen species in blood and soft tissues. Significant inhibition of superoxide dismutase, catalase, and glutathione peroxidase activities in tissues (liver in particular) along with significant increase in thiobarbituric acid reactive substances and metallothionein levels in arsenic intoxicated mice was also noted. Combined administration of MiADMSA with M. oleifera proved better than all other treatments in the recovery of most of the above parameters accompanied by more pronounced depletion of arsenic. The results suggest that concomitant administration of M. oleifera during chelation treatment with MiADMSA might be a better treatment option than monotherapy with the thiol chelator in chronic arsenic toxicity.

  8. Pyrophoric behaviour of uranium hydride and uranium powders

    Energy Technology Data Exchange (ETDEWEB)

    Le Guyadec, F., E-mail: fabienne.leguyadec@cea.f [CEA Marcoule DEN/DTEC/SDTC, 30207 Bagnols sur Ceze, BP 17171 (France); Genin, X.; Bayle, J.P. [CEA Marcoule DEN/DTEC/SDTC, 30207 Bagnols sur Ceze, BP 17171 (France); Dugne, O. [DEN/DTEC/SGCS, 30207 Bagnols sur Ceze, BP 17171 (France); Duhart-Barone, A.; Ablitzer, C. [CEA Cadarache DEN/DEC/SPUA, 13108 St. Paul lez Durance (France)

    2010-01-31

    Thermal stability and spontaneous ignition conditions of uranium hydride and uranium metal fine powders have been studied and observed in an original and dedicated experimental device placed inside a glove box under flowing pure argon. Pure uranium hydride powder with low amount of oxide (<0.5 wt.%) was obtained by heat treatment at low temperature in flowing Ar/5%H{sub 2}. Pure uranium powder was obtained by dehydration in flowing pure argon. Those fine powders showed spontaneous ignition at room temperature in air. An in situ CCD-camera displayed ignition associated with powder temperature measurement. Characterization of powders before and after ignition was performed by XRD measurements and SEM observations. Oxidation mechanisms are proposed.

  9. 不同粒度的矾土基β-SiAlON 氧化性研究%Investigation on oxidation resistance of bauxite-basedβ-SiAlON powders with different particle size

    Institute of Scientific and Technical Information of China (English)

    朱晓燕; 刘新红; 马腾

    2014-01-01

    The oxidation characteristics of bauxite-based β-SiAlON powders with different particle size (d 50 =43.62 μm,d 50 =21.06 μm and d 50 =10.05 μm)at 20 -1400 ℃ have been studied by TG-DTA, XRD and SEM.The results show:(1 )The initial oxidation temperature of β-SiAlON powders with different particle size is about 800 ℃, while oxidation rate increases noticeably when oxidation temperature is above 1 100 ℃.The finer theβ-SiAlON particle size is,the more weight gains,indicating that the oxidation extent is high.(2)The oxidation products of β-SiAlON are cristobalite,mullite and alumina.The finer the β-SiAlON particle size is,the stronger the peaks of cristobalite,mullite and alumina are,and oxidation is more noticeable.(3 )Glass film containing needle-like mullite on the surface ofβ-SiAlON particles is formed which will retard O 2 diffusion to protect β-SiAlON from being further oxidized.%用热重分析仪(TG-DTA)、X 射线衍射仪(XRD)和扫描电子显微镜(SEM)研究了三种不同粒度(d 50=43.62μm、d 50=21.06μm 和 d 50=10.05μm)的矾土基β-SiAlON 粉体在20~1400℃温度范围内非等温氧化的特性。结果表明:(1)三种粒度的β-SiAlON 试样均从800℃开始氧化,氧化温度高于1100℃后,试样的氧化速度加快,且粒度越小,氧化增重越明显,表明氧化程度越高。(2)β-SiAlON 氧化后产物为方石英、莫来石和氧化铝。β-SiAlON 粒度越小,方石英、莫来石及氧化铝峰越强,氧化越剧烈。(3)β-SiAlON 氧化后,表面形成含针状莫来石的玻璃膜,可阻止氧气进入β-SiAlON 粒子内部,形成保护性氧化。

  10. Study of the low temperature oxidation of uranium powders and its application to the sintering of uranium oxide powders; Etude de l'oxydation des poudres dtranium a basse temperature et son application au frittage de poudres d'uranium oxyde

    Energy Technology Data Exchange (ETDEWEB)

    Conte-Albert, M. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-06-01

    The uranium oxygen reaction has been studied with a view to obtaining U-UO{sub 2} samples containing about 20 per cent by weight of UO{sub 2} starting from spherical grain uranium powder (36 {mu} < {phi} < 50 {mu}). The techniques used are micrography, thermogravimetry, sintering under pressure, radio-crystallography. At 170 deg. C in air or argon + oxygen mixtures, the uranium oxide formed is always UO{sub 2} and it is uniformly distributed around the initial uranium spheres. These mixed powders can easily be sintered under pressure in the {gamma}-phase. The density of the samples obtained is 85 to 90 per cent of the theoretical density. The influence of UO{sub 2} on the properties of uranium has been shown by the use of dilatometry and thermal cycling in the {alpha} phase. The temperatures at which the phase changes {alpha} {r_reversible} {beta} and {beta} {r_reversible} {gamma} occur are lowered, the remnant expansion is decreased. High density samples resist well to thermal cycling; the characteristic defects of uranium: high distortion, wrinkled surface, have almost disappeared. Heat treatments in a secondary vacuum at 1050 deg. C cause crystallization of UO{sub 2} in a geometrical form and the appearance of a phase of the F.C.C. crystalline type having the composition U{sub W}C{sub X}O{sub Y}N{sub Z}. This phase causes a new decrease in the {alpha} {r_reversible} {beta}, {beta} {r_reversible} {gamma} transformation temperatures for the uranium. After ten dilatometric cycles the remanent expansion of the sample is about 0.5 per cent. The resistance to thermal cycling of a low density sample which has been heat-treated is similar to that of a high density sample which has not undergone a heat treatment. (author) [French] La reaction uranium-oxygene a ete etudiee pour permettre l'obtention d'echantillons U-UO{sub 2} a 20 pour cent en poids environ d'UO{sub 2}, a partir de billes d'uranium pulverulent (36 {mu} < {phi} < 50 {mu}). Les

  11. Raman microscopy investigation of beryllium materials

    Science.gov (United States)

    Pardanaud, C.; Rusu, M. I.; Giacometti, G.; Martin, C.; Addab, Y.; Roubin, P.; Lungu, C. P.; Porosnicu, C.; Jepu, I.; Dinca, P.; Lungu, M.; Pompilian, O. G.; Mateus, R.; Alves, E.; Rubel, M.; contributors, JET

    2016-02-01

    We report for the first time on the ability of Raman microscopy to give information on the structure and composition of Be related samples mimicking plasma facing materials that will be found in ITER. For that purpose, we investigate two types of material. First: Be, W, Be1W9, and Be5W5 deposits containing a few percents of D or N, and second: a Mo mirror exposed to plasma in the main JET chamber (in the framework of the first mirror test in JET with ITER-like wall). We performed atomic quantifications using ion beam analysis for the first samples. We also did atomic force microscopy. We found defect induced Raman bands in Be, Be1W9, and Be5W5 deposits. Molybdenum oxide has been identified showing an enhancement due to a resonance effect in the UV domain.

  12. Dissolution of FB-Line Residues Containing Beryllium Metal

    Energy Technology Data Exchange (ETDEWEB)

    RUDISILL, TRACY S.; CROWDER, MARK L.

    2005-09-06

    Scrap materials containing plutonium (Pu) metal were dissolved at the Savannah River Site (SRS) as part of a program to disposition nuclear materials during the deactivation of the FB-Line facility. Some of these items contained both Pu and beryllium (Be) metal as a composite material. The Pu and Be metals were physically separated to minimize the amount of Be associated with the Pu; however, a dissolution flowsheet was required to dissolve small amounts of Be combined with the Pu metal using a dissolving solution containing nitric acid (HNO{sub 3}) and potassium fluoride (KF). Since the dissolution of Pu metal in HNO{sub 3}/fluoride (F{sup -}) solutions was well understood, the primary focus of the flowsheet development was the dissolution of Be metal. Initially, small-scale experiments were used to measure the dissolution rate of Be metal foils using conditions effective for the dissolution of Pu metal. The experiments demonstrated that the dissolution rate was nearly independent of the HNO{sub 3} concentration over the limited range of investigation and only a moderate to weak function of the F{sup -} concentration. The effect of temperature was more pronounced, significantly increasing the dissolution rate between 40 and 105 C. The offgas analysis from three Be metal foil dissolutions demonstrated that the production of hydrogen (H{sub 2}) was sensitive to the HNO{sub 3} concentration, decreasing by a factor of approximately two when the concentration was increased from 4 to 8 M. In subsequent experiments, complete dissolution of Be samples from a Pu/Be composite material was achieved in a 4 M HNO{sub 3} solution containing 0.1-0.2 M KF. Gas samples collected during each experiment showed that the maximum H{sub 2} generation rate occurred at temperatures below 70-80 C. A Pu metal dissolution experiment was performed using a 4 M HNO{sub 3}/0.1 M KF solution at 80 C to demonstrate flowsheet conditions developed for the dissolution of Be metal. As the reaction

  13. Cow dung powder poisoning

    Directory of Open Access Journals (Sweden)

    Khaja Mohideen Sherfudeen

    2015-01-01

    Full Text Available Cow dung, which has germicidal property, was used in ancient days to clean living premises in South India. Nowadays, people are using commercially available synthetic cow dung powder. It is locally known as "saani powder" in Tamil Nadu. It is freely available in homes and is sometimes accidentally consumed by children. It is available in two colors - yellow and green. Cow dung powder poisoning is common in districts of Tamil Nadu such as Coimbatore, Tirupur, and Erode. We report two cases of yellow cow dung powder poisoning from our hospital.

  14. Cow dung powder poisoning.

    Science.gov (United States)

    Sherfudeen, Khaja Mohideen; Kaliannan, Senthil Kumar; Dammalapati, Pavan Kumar

    2015-11-01

    Cow dung, which has germicidal property, was used in ancient days to clean living premises in South India. Nowadays, people are using commercially available synthetic cow dung powder. It is locally known as "saani powder" in Tamil Nadu. It is freely available in homes and is sometimes accidentally consumed by children. It is available in two colors - yellow and green. Cow dung powder poisoning is common in districts of Tamil Nadu such as Coimbatore, Tirupur, and Erode. We report two cases of yellow cow dung powder poisoning from our hospital.

  15. 20 CFR 30.615 - What type of tort suits filed against beryllium vendors or atomic weapons employers may...

    Science.gov (United States)

    2010-04-01

    ... beryllium vendors or atomic weapons employers may disqualify certain claimants from receiving benefits under... Special Provisions Effect of Tort Suits Against Beryllium Vendors and Atomic Weapons Employers § 30.615 What type of tort suits filed against beryllium vendors or atomic weapons employers may disqualify...

  16. 20 CFR 30.507 - What compensation will be provided to covered Part B employees who only establish beryllium...

    Science.gov (United States)

    2010-04-01

    ... Part B employees who only establish beryllium sensitivity under Part B of EEOICPA? 30.507 Section 30... Part B employees who only establish beryllium sensitivity under Part B of EEOICPA? The establishment of beryllium sensitivity does not entitle a covered Part B employee, or the eligible surviving beneficiary...

  17. 20 CFR 30.205 - What are the criteria for eligibility for benefits relating to beryllium illnesses covered under...

    Science.gov (United States)

    2010-04-01

    ... benefits relating to beryllium illnesses covered under Part B of EEOICPA? 30.205 Section 30.205 Employees... Relating to Covered Beryllium Illness Under Part B of Eeoicpa § 30.205 What are the criteria for eligibility for benefits relating to beryllium illnesses covered under Part B of EEOICPA? To...

  18. Proceedings of the third IEA international workshop on beryllium technology for fusion

    Energy Technology Data Exchange (ETDEWEB)

    Kawamura, Hiroshi; Okamoto, Makoto [eds.

    1998-01-01

    This report is the Proceedings of the Third International Energy Agency International Workshop on Beryllium Technology for Fusion. The workshop was held on October 22-24, 1997, at the Sangyou Kaikan in Mito City with 68 participants who attended from the Europe, the Russian Federation, the Kazakstan, the United States and Japan. The topics for papers were arranged into 9 sessions; beryllium applications for ITER, production and characterization, chemical compatibility and corrosion, forming and joining, plasma/tritium interactions, beryllium coating, first wall applications, neutron irradiation effects, health and safety. To utilize beryllium in the pebble type blanket, a series of discussions were intensified in multiple view points such as the swelling, He/T release from beryllium pebble irradiated up to high He content, effective thermal conductivity, tritium permeation and coating, and fabrication cost, and so on. As the plasma facing material, life time of beryllium and coated beryllium, dust and particle production, joining, waste treatment, mechanical properties and deformation by swelling were discussed as important issues. Especially, it was recognized throughout the discussions that the comparative study by the different researchers should be carried out to establish the reliability of the data reported in the workshop and in others. To enhance the comparative study, the world wide collaboration for the relative evaluation of the beryllium was proposed by the International Organization Committee and the proposal was approved by all of the participants. The 45 of the presented papers are indexed individually. (J.P.N.)

  19. The development and advantages of beryllium capsules for the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, D.C.; Bradley, P.A.; Hoffman, N.M. [Los Alamos National Lab., NM (United States)] [and others

    1998-02-01

    Capsules with beryllium ablators have long been considered as alternatives to plastic for the National Ignition Facility laser ; now the superior performance of beryllium is becoming well substantiated. Beryllium capsules have the advantages of relative insensitivity to instability growth, low opacity, high tensile strength, and high thermal conductivity. 3-D calculation with the HYDRA code NTIS Document No. DE-96004569 (M. M. Marinak et.al. in UCRL-LR-105821-95-3) confirm 2-D LASNEX U. B. Zimmerman and W. L. Kruer, Comments Plasmas Phys. Controlled Thermonucl. Fusion, 2, 51(2975) results that particular beryllium capsule designs are several times less sensitive than the CH point design to instability growth from DT ice roughness. These capsule designs contain more ablator mass and leave some beryllium unablated at ignition. By adjusting the level of copper dopant, the unablated mass can increase or decrease, with a corresponding decrease or increase in sensitivity to perturbations. A plastic capsule with the same ablator mass as the beryllium and leaving the same unablated mass also shows this reduced perturbation sensitivity. Beryllium`s low opacity permits the creation of 250 eV capsule designs. Its high tensile strength allows it to contain DT fuel at room temperature. Its high thermal conductivity simplifies cryogenic fielding.

  20. DETERMINING BERYLLIUM IN DRINKING WATER BY GRAPHITE FURNACE ATOMIC ABSORPTION SPECTROSCOPY

    Science.gov (United States)

    A direct graphite furnace atomic absorption spectroscopy method for the analysis of beryllium in drinking water has been derived from a method for determining beryllium in urine. Ammonium phosphomolybdate and ascorbic acid were employed as matrix modifiers. The matrix modifiers s...