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Sample records for tellurium additions

  1. Tellurium

    Science.gov (United States)

    Goldfarb, Richard J.; Berger, Byron R.; George, Micheal W.; Seal, Robert R.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

    2017-12-19

    Tellurium (Te) is a very rare element that averages only 3 parts per billion in Earth’s upper crust. It shows a close association with gold and may be present in orebodies of most gold deposit types at levels of tens to hundreds of parts per million. In large-tonnage mineral deposits, such as porphyry copper and seafloor volcanogenic massive sulfide deposits, sulfide minerals may contain hundreds of parts per million tellurium, although the orebodies likely have overall concentrations of 0.1 to 1.0 parts per million tellurium. Tellurium is presently recovered as a primary ore from only two districts in the world; these are the gold-tellurium epithermal vein deposits located adjacent to one another at Dashuigou and Majiagou (Sichuan Province) in southwestern China, and the epithermal-like mineralization at the Kankberg deposit in the Skellefteå VMS district of Västerbotten County, Sweden. Combined, these two groups of deposits account for about 15 percent (about 70 metric tons) of the annual global production of between 450 and 470 metric tons of tellurium. Most of the world’s tellurium, however, is produced as a byproduct of the mining of porphyry copper deposits. These deposits typically yield concentrations of 1 to 4 percent tellurium in the anode slimes recovered during copper refining. Present production of tellurium from the United States is solely from the anode slimes at ASARCO LLC’s copper refinery in Amarillo, Texas, and may total about 50 metric tons per year. The main uses of tellurium are in photovoltaic solar cells and as an additive to copper, lead, and steel alloys in various types of machinery. The environmental data available regarding the mining of tellurium are limited; most concerns to date have focused on the more-abundant metals present in the large-tonnage deposits from which tellurium is recovered as a byproduct. Global reserves of tellurium are estimated to be 24,000 metric tons, based on the amount of tellurium likely contained in

  2. Electrophilic addition of selenium and tellurium halides to methyldiethynylsilane

    International Nuclear Information System (INIS)

    Amosova, S.V.; Penzik, M.V.; Martynov, A.V.; Zhilitskaya, L.V.; Voronkov, M.G.

    2009-01-01

    Reaction of TeCl 4 with methyldiethynylsilane (MDES) proceeds with the predominant formation of E-isomer 1,1,3,6-tetrachlorine-1-methyl-1-(methyldiethynylsiloxy)-1,4-tellurium(IV) silafulvic due to the interaction of intermediate E-isomer 4-methyl-1,1,3,6-tetrachlorine-1,4-tellurium(IV)silafulvic with MDES. TeCl 4 Reacts with MDES without reduction of Te(IV) in Te(II). Tetracoordination of tellurium atom in heterocycle was established by NMR 125 Te. Mass spectrum of heterocycle shows the presence of fragmentary ions [M-Cl 2 ] + . According elemental analysis Te:Cl=1:4 ratio proves composition of heterocycle

  3. Synthesis of Novel E-2-Chlorovinyltellurium Compounds Based on the Stereospecific Anti-addition of Tellurium Tetrachloride to Acetylene

    Directory of Open Access Journals (Sweden)

    Svetlana V. Amosova

    2012-05-01

    Full Text Available The reaction of tellurium tetrachloride with acetylene proceeds in a stereospecific anti-addition manner to afford the novel products E-2-chlorovinyltellurium trichloride and E,E-bis(2-chlorovinyltellurium dichloride. Reaction conditions for the selective preparation of each of these products were found. The latter was obtained in 90% yield in CHCl3 under a pressure of acetylene of 10–15 atm, whereas the former product was formed in up to 72% yield in CCl4 under a pressure of acetylene of 1–3 atm. Synthesis of the previously unknown E,E-bis(2-chlorovinyl telluride, E,E-bis(2-chlorovinyl ditelluride, E-2-chlorovinyl 1,2,2-trichloroethyl telluride and E,E-bis(2-chlorovinyl-tellurium dibromide is described.

  4. Analysis of tellurium thin films electrodeposition from acidic citric bath

    Energy Technology Data Exchange (ETDEWEB)

    Kowalik, Remigiusz; Kutyła, Dawid [AGH University of Science and Technology, Faculty of Non-Ferrous Metals, al. A. Mickiewicza 30, 30-059 Krakow (Poland); Mech, Krzysztof [AGH University of Science and Technology, Academic Centre for Materials and Nanotechnology, al. A. Mickiewicza 30, Krakow (Poland); Żabiński, Piotr, E-mail: rkowalik@agh.edu.pl [AGH University of Science and Technology, Faculty of Non-Ferrous Metals, al. A. Mickiewicza 30, 30-059 Krakow (Poland)

    2016-12-01

    This work presents the description of the electrochemical process of formation thin tellurium layers from citrate acidic solution. The suggested methodology consists in the preparation of stable acidic baths with high content of tellurium, and with the addition of citrate acid. In order to analyse the mechanism of the process of tellurium deposition, the electroanalytical tests were conducted. The tests of cyclic voltammetry and hydrodynamic ones were performed with the use of polycrystalline gold disk electrode. The range of potentials in which deposition of tellurium in direct four-electron process is possible was determined as well as the reduction of deposited Te° to Te{sup 2−} and its re-deposition as a result of the comproportionation reaction. On the basis of the obtained results, the deposition of tellurium was conducted by the potentiostatic method. The influence of a deposition potential and a concentration of TeO{sub 2} in the solution on the rate of tellurium coatings deposition was examined. The presence of tellurium was confirmed by X-ray spectrofluorometry and electron probe microanalysis. In order to determine the phase composition and the morphology, the obtained coatings were analysed with the use of x-ray diffraction and scanning electron microscopy.

  5. Extractive separation of tellurium(4)

    International Nuclear Information System (INIS)

    Gawali, S.B.; Shinde, V.M.

    1977-01-01

    A method is described for the extraction of tellurium (4) from hydrobromic acid media using 4-methyl-2-pentanol as an extractant. The method affords the determination of tellurium after its separation from Se, Au, Cu, Pb, Fe, Os, V and Al. (author)

  6. Quantitative analysis of tellurium in simple substance sulfur

    International Nuclear Information System (INIS)

    Arikawa, Yoshiko

    1976-01-01

    The MIBK extraction-bismuthiol-2 absorptiometric method for the quantitative analysis of tellurium was studied. The method and its limitation were compared with the atomic absorption method. The period of time required to boil the solution in order to decompose excess hydrogen peroxide and to reduce tellurium from 6 valance to 4 valance was examined. As a result of experiment, the decomposition was fast in the alkaline solution. It takes 30 minutes with alkaline solution and 40 minutes with acid solution to indicate constant absorption. A method of analyzing the sample containing tellurium less than 5 ppm was studied. The experiment revealed that the sample containing a very small amount of tellurium can be analyzed when concentration by extraction is carried out for the sample solutions which are divided into one gram each because it is difficult to treat several grams of the sample at one time. This method also is suitable for the quantitative analysis of selenium. This method showed good addition effect and reproducibility within the relative error of 5%. The comparison between the calibration curve of the standard solution of tellurium 4 subjected to the reaction with bismuthiol-2 and the calibration curve obtained from the extraction of tellurium 4 with MIBK indicated that the extraction is perfect. The result by bismuthiol-2 method and that by atom absorption method coincided quite well on the same sample. (Iwakiri, K.)

  7. Thermodynamic behaviour of tellurium at high temperatures

    International Nuclear Information System (INIS)

    Garisto, F.

    1992-09-01

    Thermodynamic calculations are used to determine the chemical speciation of tellurium in the primary heat transport system under postulated reactor accident conditions. The speciation of tellurium is determined for various values of the temperature, oxygen partial pressure, tellurium concentration and Cs/Te ratio. The effects of the Zircaloy cladding and/or cesium on tellurium speciation and volatility are of particular interest in this report. (Author) (37 refs., 14 figs., 4 tabs.)

  8. Fission product tellurium chemistry from fuel to containment

    International Nuclear Information System (INIS)

    McFarlane, J.

    1996-01-01

    Chemical equilibrium calculations were performed on the speciation of tellurium in-core and inside the primary heat transport system (PHTS) under loss-of-coolant accident conditions. Data from recent Knudsen-cell experiments on the volatilization of Cs 2 Te were incorporated into the calculation. These data were used to recalculate thermodynamic quantities for Cs 2 Te(g), including Δ f G o (298 K)= -118±9 kJ.mol -1 . The description of the condensed high-temperature cesium-tellurium phase was expanded to include Cs 2 Te 3 (c) in addition to Cs 2 Te(c). These modifications were incorporated into the database used in the equilibrium calculations; the net effect was to stabilize the condensed cesium-tellurium phase and reduce the vapour pressure of Cs 2 Te(g) between 1200 and 1600 K. The impact of tellurium speciation in containment, after release from the PHTS, is discussed along with the possible effect of tellurium on iodine chemistry. (author) 10 figs., 5 tabs., 21 refs

  9. Fission product tellurium chemistry from fuel to containment

    Energy Technology Data Exchange (ETDEWEB)

    McFarlane, J [Atomic Energy of Canada Ltd., Pinawa, MB (Canada). Whiteshell Labs.

    1996-12-01

    Chemical equilibrium calculations were performed on the speciation of tellurium in-core and inside the primary heat transport system (PHTS) under loss-of-coolant accident conditions. Data from recent Knudsen-cell experiments on the volatilization of Cs{sub 2}Te were incorporated into the calculation. These data were used to recalculate thermodynamic quantities for Cs{sub 2}Te(g), including {Delta}{sub f}G{sup o}(298 K)= -118{+-}9 kJ.mol{sup -1}. The description of the condensed high-temperature cesium-tellurium phase was expanded to include Cs{sub 2}Te{sub 3}(c) in addition to Cs{sub 2}Te(c). These modifications were incorporated into the database used in the equilibrium calculations; the net effect was to stabilize the condensed cesium-tellurium phase and reduce the vapour pressure of Cs{sub 2}Te(g) between 1200 and 1600 K. The impact of tellurium speciation in containment, after release from the PHTS, is discussed along with the possible effect of tellurium on iodine chemistry. (author) 10 figs., 5 tabs., 21 refs.

  10. Selenium and tellurium nanomaterials

    Science.gov (United States)

    Piacenza, Elena; Presentato, Alessandro; Zonaro, Emanuele; Lampis, Silvia; Vallini, Giovanni; Turner, Raymond J.

    2018-04-01

    Over the last 40 years, the rapid and exponential growth of nanotechnology led to the development of various synthesis methodologies to generate nanomaterials different in size, shape and composition to be applied in various fields. In particular, nanostructures composed of Selenium (Se) or Tellurium (Te) have attracted increasing interest, due to their intermediate nature between metallic and non-metallic elements, being defined as metalloids. Indeed, this key shared feature of Se and Te allows us the use of their compounds in a variety of applications fields, such as for manufacturing photocells, photographic exposure meters, piezoelectric devices, and thermoelectric materials, to name a few. Considering also that the chemical-physical properties of elements result to be much more emphasized when they are assembled at the nanoscale range, huge efforts have been made to develop highly effective synthesis methods to generate Se- or Te-nanomaterials. In this context, the present book chapter will explore the most used chemical and/or physical methods exploited to generate different morphologies of metalloid-nanostructures, focusing also the attention on the major advantages, drawbacks as well as the safety related to these synthetic procedures.

  11. Properties of low-alloy steel with tellurium

    International Nuclear Information System (INIS)

    Popova, L.V.; Lebedev, D.V.; Litvinenko, D.A.; Nasibov, A.G.

    1983-01-01

    The results of investigations into 09G2 and 09G2F steels alloyed with tellurium after controlled rolling are presented. 0.002-0.011% tellurium additions did not change strength and plastic properties of the steels after controlled rolling. Tellurium additions results in 40-50% increase of the steel impact strength on samples With circular and sharp cuts in brittle-viscous region. 0.002-0.003% of tellurium is considered to be the optimum content from the view point of increa=. sing steel strength. Increase of impact strength takes place at the expense of growth of both work function of crack formation and work function of crack propagation but in different temperature ranges: at the expense of firstone at 80-40 deg C, at the expense of second one at 20-40 deg C. 0.002-0.011% teilurium additions mainly at the expense of sulphide globularization bring about decrease of anisotropy of steet properties by impact strength reducing anisotropy factor from 2 to 1.5

  12. Reaction of tellurium with Zircaloy-4

    International Nuclear Information System (INIS)

    Boer, R. de; Cordfunke, E.H.P.

    1994-09-01

    Interaction of tellurium vapour with Zircaloy during the initial stage of an accident will lead to retention of tellurium in the core. For reliable estimation of the release behaviour of tellurium, it is necessary to know which zirconium tellurides are formed during this interaction. In this work the reaction of tellurium with Zircaloy-4 has been studied, using various reaction temperatures and tellurium vapour pressures. The compound ZrTe 2-x is formed on the surface of the Zircaloy in a broad range of reaction temperatures and vapour pressures. It is found that the formation of the more zirconium-rich compound Zr 5 Te 4 is favoured at high reaction temperatures is combination with low tellurium vapour pressures. (orig.)

  13. Selenium and tellurium as carbon substitutes

    International Nuclear Information System (INIS)

    Knapp, F.F. Jr.

    1980-01-01

    This review has summarized structure-activity studies with 75 Se- and /sup 123m/Te-labeled radiopharmaceuticals in which the selenium or tellurium heteroatom has been inserted between carbon-carbon bonds. The agents that have been investigated in most detail include steroids for adrenal imaging and long-chain fatty acids, and a variety of other unique agents have also been studied. Because of the great versatility of the organic chemistry of selenium and tellurium, there is continuing interest in the preparation of radiopharmaceuticals labeled with 75 Se, 73 Se, and /sup 123m/Te. There are two important factors which will determine the extent of future interest in such agents. These include the necessity of a decrease in the cost of highly enriched 122 Te to make the reactor production of /sup 123m/Te cost effective. In addition, the potential preparation of large amounts of 73 Se should stimulate the development of 73 Se-labeled radiopharmaceuticals

  14. On the resistivity of metal-tellurium alloys for low concentrations of tellurium

    International Nuclear Information System (INIS)

    Gorecki, J.

    1982-04-01

    The resistivity and thermoelectric power of metal-tellurium liquid alloys have been discussed for the case of small tellurium concentration. Nearly free electron model of conduction band has been used. The rapid increase of resistivity in transition metal-tellurium alloys has been predicted. (author)

  15. Sulfur, selenium, tellurium and polonium

    International Nuclear Information System (INIS)

    Berry, F.J.

    1987-01-01

    This chapter on the coordination compounds of sulfur, selenium, tellurium and polonium starts with an introduction to the bonding, valence and geometry of the elements. Complexes of the group VIB elements are discussed with particular reference to the halo and pseudohalide complexes, oxo acid complexes, oxygen and nitrogen donor complexes and sulfur and selenium donor complexes. There is a section on the biological properties of the complexes discussed. (UK)

  16. Electrowinning Of Tellurium From Acidic Solutions

    Directory of Open Access Journals (Sweden)

    Kowalik R.

    2015-06-01

    Full Text Available The process of electrochemical deposition of tellurium was studied. Preliminary researches embrace the voltammetry and microgravimetric measurements. According to the results the electrolysis of tellurium was conducted under potentiostatic conditions. There was no deposition of tellurium above potential −0.1 vs. Ag/AgCl electrode in 25°C. The process of deposition is observed in the range of potentials −0.1 to −0.3 V vs. Ag/AgCl. The presence of tellurium was confirmed by XRF and XRD. The obtained deposits were homogenous and compact. Below potential −0.3 V vs. Ag/AgCl the Faradaic efficiency of the tellurium deposition decreased due to reduction of Te to H2Te and hydrogen evolution.

  17. New radiohalogenated alkenyl tellurium fatty acids

    International Nuclear Information System (INIS)

    Srivastava, P.C.; Knapp, F.F. Jr.; Kabalka, G.W.

    1987-01-01

    Radiolabeled long-chain fatty acids have diagnostic value as radiopharmaceutical tools in myocardial imaging. Some applications of these fatty acids are limited due to their natural metabolic degradation in vivo with subsequent washout of the radioactivity from the myocardium. The identification of structural features that will increase the myocardial residence time without decreasing the heart uptake of long-chain fatty acids is of interest. Fatty acids containing the tellurium heteroatom were the first modified fatty acids developed that show unique prolonged myocardial retention and low blood levels. Our detailed studies with radioiodinated vinyliodide substituted tellurium fatty acids demonstrate that heart uptake is a function of the tellurium position. New techniques of tellurium and organoborane chemistry have been developed for the synthesis of a variety of radioiodinated iodoalkenyl tellurium fatty acids. 9 refs., 3 figs., 2 tabs

  18. Tellurium self-diffusion and point defects in lead telluride

    International Nuclear Information System (INIS)

    Simirskij, Yu.N.; Firsova, L.P.

    1982-01-01

    Method of radioactive indicators was used to determine factors of tellurium self-diffusion in lead telluride with different deviation of the composition from stoichiometric in the range of enrichment by tellurium. It was found that at 973 K factors of tellurium self-diffusion in lead telluride depend slightly on the vapor pressure of tellurium equilibrium with solid phase

  19. Tellurium: providing a bright future for solar energy

    Science.gov (United States)

    Goldfarb, Richard J.

    2015-01-01

    Tellurium is one of the least common elements on Earth. Most rocks contain an average of about 3 parts per billion tellurium, making it rarer than the rare earth elements and eight times less abundant than gold. Grains of native tellurium appear in rocks as a brittle, silvery-white material, but tellurium more commonly occurs in telluride minerals that include varied quantities of gold, silver, or platinum. Tellurium is a metalloid, meaning it possesses the properties of both metals and nonmetals.

  20. Tellurium in active volcanic environments: Preliminary results

    Science.gov (United States)

    Milazzo, Silvia; Calabrese, Sergio; D'Alessandro, Walter; Brusca, Lorenzo; Bellomo, Sergio; Parello, Francesco

    2014-05-01

    Tellurium is a toxic metalloid and, according to the Goldschmidt classification, a chalcophile element. In the last years its commercial importance has considerably increased because of its wide use in solar cells, thermoelectric and electronic devices of the last generation. Despite such large use, scientific knowledge about volcanogenic tellurium is very poor. Few previous authors report result of tellurium concentrations in volcanic plume, among with other trace metals. They recognize this element as volatile, concluding that volcanic gases and sulfur deposits are usually enriched with tellurium. Here, we present some results on tellurium concentrations in volcanic emissions (plume, fumaroles, ash leachates) and in environmental matrices (soils and plants) affected by volcanic emissions and/or deposition. Samples were collected at Etna and Vulcano (Italy), Turrialba (Costa Rica), Miyakejima, Aso, Asama (Japan), Mutnovsky (Kamchatka) at the crater rims by using common filtration techniques for aerosols (polytetrafluoroethylene filters). Filters were both eluted with Millipore water and acid microwave digested, and analyzed by inductively coupled plasma mass spectrometry (ICP-MS). Volcanic ashes emitted during explosive events on Etna and Copahue (Argentina) were analyzed for tellurium bulk composition and after leaching experiments to evaluate the soluble fraction of tellurium. Soils and leaves of vegetation were also sampled close to active volcanic vents (Etna, Vulcano, Nisyros, Nyiragongo, Turrialba, Gorely and Masaya) and investigated for tellurium contents. Preliminary results showed very high enrichments of tellurium in volcanic emissions comparing with other volatile elements like mercury, arsenic, thallium and bismuth. This suggests a primary transport in the volatile phase, probably in gaseous form (as also suggested by recent studies) and/or as soluble salts (halides and/or sulfates) adsorbed on the surface of particulate particles and ashes. First

  1. Investigation of biomethylation of arsenic and tellurium during composting

    International Nuclear Information System (INIS)

    Diaz-Bone, Roland A.; Raabe, Maren; Awissus, Simone; Keuter, Bianca; Menzel, Bernd; Kueppers, Klaus; Widmann, Renatus; Hirner, Alfred V.

    2011-01-01

    Though the process of composting features a high microbiological activity, its potential to methylate metals and metalloids has been little investigated so far in spite of the high impact of this process on metal(loid) toxicity and mobility. Here, we studied the biotransformation of arsenic, tellurium, antimony, tin and germanium during composting. Time resolved investigation revealed a highly dynamic process during self-heated composting with markedly differing time patterns for arsenic and tellurium species. Extraordinary high concentrations of up to 150 mg kg -1 methylated arsenic species as well as conversion rates up to 50% for arsenic and 5% for tellurium were observed. In contrast, little to no conversion was observed for antimony, tin and germanium. In addition to experiments with metal(loid) salts, composting of arsenic hyperaccumulating ferns Pteris vittata and P. cretica grown on As-amended soils was studied. Arsenic accumulated in the fronds was efficiently methylated resulting in up to 8 mg kg -1 methylated arsenic species. Overall, these studies indicate that metal(loid)s can undergo intensive biomethylation during composting. Due to the high mobility of methylated species this process needs to be considered in organic waste treatment of metal(loid) contaminated waste materials.

  2. Selenium and tellurium reagents in organic synthesis

    International Nuclear Information System (INIS)

    Comasseto, J.V.

    1984-01-01

    A review of the contribution of the University of Sao Paulo (SP, Brazil) to the organic synthesis of selenium and tellurium reagents is made. Major reactions amoung selenium compounds and insaturated substrates, phosphorus, ester enolates as well as the use of phase transference catalysed reactions to produce arylselenolate are described. For tellurium, interactions of its compounds with organic substrates and reactive intermediates (e.g. benzino diazomethane) are reported. (C.L.B.) [pt

  3. Tellurium chemistry, tellurium release and deposition during the TMI-2 accident

    International Nuclear Information System (INIS)

    Vinjamuri, K.; Sallach, R.A.; Osetek, D.J.; Hobbins, R.R.; Akers, D.W.

    1985-08-01

    This report presents the chemistry and estimated behavior of tellurium during and after the accident at Three Mile Island Unit-2. The discussion of tellurium behavior is based on all available measurement data for /sup 129 m/Te, 132 Te, stable tellurium ( 126 Te, 128 Te, and 130 Te), and best estimate calculations of tellurium release and transport. Results from Oak Ridge National Laboratory (ORNL) tests, Power Burst Facility (PBF) Severe Fuel Damage Tests at Idaho National Engineering Laboratory (INEL) and SASCHA tests from Karlsruhe, W. Germany are compared with calculated release fractions and samples taken from TMI Unit-2. It is concluded that very little tellurium was released and transported from the TMI-2 core, probably as a result of holdup by zircaloy cladding and other structural materials. 39 refs., 24 figs., 17 tabs

  4. Tellurium chemistry, tellurium release and deposition during the TMI-2 accident

    International Nuclear Information System (INIS)

    Vinjamuri, K.; Sallach, R.A.; Osetek, D.J.; Hobbins, R.R.; Akers, D.W.

    1985-01-01

    This paper presents the chemistry and estimated behavior of tellurium during and after the accident at Three Mile Island Unit-2. The discussion of tellurium behavior is based on all available measurement data for /sup 129m/Te, 132 Te, stable tellurium ( 126 Te, 128 Te, and 130 Te), and best estimate calculations of tellurium release and transport. Results from Oak Ridge National Laboratory (ORNL) tests, Power Burst Facility (PBF) Severe Fuel Damage Tests at Idaho National Engineering Laboratory (INEL) and SASCHA tests from Karlsruhe, W. Germany are compared with calculated release fractions and samples taken from TMI Unit-2. It is concluded that very little tellurium was released and transported from the TMI-2 core, probably as a result of holdup by zircaloy cladding and other structural materials. 37 refs., 12 figs., 4 tabs

  5. Tracing Tellurium and Its Nanostructures in Biology.

    Science.gov (United States)

    Zare, Bijan; Nami, Mohammad; Shahverdi, Ahmad-Reza

    2017-12-01

    Tellurium (Te) is a semimetal rare element in nature. Together with oxygen, sulfur (S), and selenium (Se), Te is considered a member of chalcogen group. Over recent decades, Te applications continued to emerge in different fields including metallurgy, glass industry, electronics, and applied chemical industries. Along these lines, Te has recently attracted research attention in various fields. Though Te exists in biologic organisms such as microbes, yeast, and human body, its importance and role and some of its potential implications have long been ignored. Some promising applications of Te using its inorganic and organic derivatives including novel Te nanostructures are being introduced. Before discovery and straightforward availability of antibiotics, Te had considered and had been used as an antibacterial element. Antilishmaniasis, antiinflammatory, antiatherosclerotic, and immuno-modulating properties of Te have been described for many years, while the innovative applications of Te have started to emerge along with nanotechnological advances over the recent years. Te quantum dots (QDs) and related nanostructures have proposed novel applications in the biological detection systems such as biosensors. In addition, Te nanostructures are used in labeling, imaging, and targeted drug delivery systems and are tested for antibacterial or antifungal properties. In addition, Te nanoparticles show novel lipid-lowering, antioxidant, and free radical scavenging properties. This review presents an overview on the novel forms of Te, their potential applications, as well as related toxicity profiles.

  6. Optimization of scintillator loading with the tellurium-130 isotope for long-term stability

    Science.gov (United States)

    Duhamel, Lauren; Song, Xiaoya; Goutnik, Michael; Kaptanoglu, Tanner; Klein, Joshua; SNO+ Collaboration

    2017-09-01

    Tellurium-130 was selected as the isotope for the SNO + neutrinoless double beta decay search, as 130Te decays to 130Xe via double beta decay. Linear alkyl benzene(LAB) is the liquid scintillator for the SNO + experiment. To load tellurium into scintillator, it is combined with 1,2-butanediol to form an organometallic complex, commonly called tellurium butanediol (TeBD). This study focuses on maximizing the percentage of tellurium loaded into scintillator and evaluates the complex's long-term stability. Studies on the effect of nucleation due to imperfections in the detector's surface and external particulates were employed by filtration and induced nucleation. The impact of water on the stability of TeBD complex was evaluated by liquid-nitrogen sparging, variability in pH and induced humidity. Alternative loading methods were evaluated, including the addition of stability-inducing organic compounds. Samples of tellurium-loaded scintillator were synthesized, treated, and consistently monitored in a controlled environment. It was found that the hydronium ions cause precipitation in the loaded scintillator, demonstrating that water has a detrimental effect on long-term stability. Optimization of loaded scintillator stability can contribute to the SNO + double beta decay search.

  7. Status of tellurium--hastelloy N studies in molten fluoride salts

    International Nuclear Information System (INIS)

    Keiser, J.R.

    1977-10-01

    Tellurium, which is a fission product in nuclear reactor fuels, can embrittle the surface grain boundaries of nickel-base structural materials. This report summarizes results of an experimental investigation conducted to understand the mechanism and to develop a means of controlling this embrittlement in the alloy Hastelloy N. The addition of a chromium telluride to salt can be used to provide small partial pressures of tellurium simulating a reactor environment where tellurium appears as a fission product. The intergranular embrittlement produced in Hastelloy N when exposed to this chromium telluride-salt mixture can be reduced by adding niobium to the Hastelloy N or by controlling the oxidation potential of the salt in the reducing range

  8. Selenium Se and tellurium Te

    International Nuclear Information System (INIS)

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

    1978-01-01

    The basic methods for determining selenium and tellurium in various objects are presented. The bichromatometric determination of Te in cadmium, zinc and mercury tellurides is based on oxidation of Te(4) to (6) in H 2 SO 4 with potassium bichromate. In steels, Te is determined photometrically with the aid of KI. The determination is hindered by Fe(3), Cu(2), Bi(3) and Se(4) ions, which must be separated. The extraction-photometric determination of Te in native sulfur is carried out with the aid of 5-mercapto-3-(naphthyl-2)-1,3,4-thiadiazolthione-2 (pH=4.8-5.0). The dyed complex is readily extracted with chloroform and benzene. The spectrophotometric determination of Te in selenium is performed with the aid of 3,5-diphenylpyrazoline-1-dithiocarbamate of sodium. Te is determined in commercial indium, arsenic and their semiconductor compounds photometrically with the aid of copper diethyldithiocarbamate. The method permits determining 5x10 -5 % Te in a weighed amount of 0.5 g. The chloride complex of Te(4) with diantipyriodolpropylmethane is quantitatively extracted with dichloroethane from hydrochloric acid solutions. Thus, any amounts of Te can be separated from Se and determined photometrically. The extraction-photometric determination of Te in commercial lead and bismuth is carried out with the aid of pyrazolone derivatives, in commercial copper with the aid of diantipyridolpropylmethane, and in ores (more than 0.01% Te) with the aid of bismuthol 2. Also described is the extraction-polarographic determination of Te in sulfide ores

  9. Speciation analysis of tellurium by solid-phase extraction in the presence of ammonium pyrrolidine dithiocarbamate and inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Chunhai; Cai, Qiantao; Guo, Zhong-Xian; Yang, Zhaoguang [Centre for Advanced Water Technology, Innovation Centre (NTU), Singapore (Singapore); Khoo, Soo Beng [Department of Chemistry, National University of Singapore (Singapore)

    2003-05-01

    Under acidic conditions tellurium(IV) formed a complex with ammonium pyrrolidine dithiocarbamate (APDC). The tellurium(IV) complex was completely retained on a non-polar Isolute silica-based octadecyl (C{sub 18}) sorbent-containing solid-phase extraction (SPE) cartridge, while the uncomplexed Te(VI) passed through the cartridge and remained as a free species in the solution. Only partial Te(IV) was retained on the SPE cartridge for samples without addition of APDC. On the basis of different retention behaviours of the complexed Te(IV) and uncomplexed Te(VI), a simple and highly sensitive method is proposed for the determination of total tellurium and Te(VI) by SPE separation and inductively coupled plasma mass spectrometry (ICP-MS) detection. The Te(IV) concentration was calculated as the difference between total tellurium and Te(VI) concentrations. The detection limit (3{sigma}) is 3 ng L{sup -1} tellurium. Factors affecting the separation and detection of tellurium species were investigated. Coexisting ions did not show significant interferences with the Te(IV)-APDC complex retention and the subsequent ICP-MS detection of Te. The method has been successfully applied to the tellurium speciation analysis in waters with spiked recoveries for Te(IV) and Te(VI) of 86.0-108% and 87.1-97.4%, respectively. (orig.)

  10. Thermoelectric properties of electrodeposited tellurium films and the sodium lignosulfonate effect

    International Nuclear Information System (INIS)

    Abad, Begoña; Rull-Bravo, Marta; Hodson, Stephen L.; Xu, Xianfan; Martin-Gonzalez, Marisol

    2015-01-01

    The effect of the addition of a surfactant, sodium lignosulfonate (SLS), on the thermoelectric properties of tellurium films prepared by electrochemical deposition is studied. The growth mechanism is found to have an important role in the thermoelectric properties since the grain size of the films is sharply reduced when the surfactant is added to the solution. For this reason, the electrical resistivity of the tellurium films when the surfactant is not added is 229 μΩ·m, which is lower than 798 μΩ·m with SLS. The Seebeck coefficient values are not influenced, with values in the vicinity of 285 μV/K for both solutions. The power factor resulted higher values than previous works, reaching values of 280 μW/m·K 2 (without SLS) and 82 μW/m·K 2 (with SLS) at room temperature. Finally, the thermal conductivity was measured by means of the Photoacoustic technique, which showed values of the order of 1 W/m·K for both solutions, which is a factor of 3 less than the bulk value of tellurium. A notable observation is that the power factor and the thermal conductivity of electrodeposited tellurium films have the same order of magnitude of bismuth telluride films grown by electrodeposition. The figure of merit is estimated to be approximately one order of magnitude higher than the bulk value, 0.09 without SLS and 0.03 with SLS, both at room temperature

  11. Facile electrochemical synthesis of tellurium nanorods and their photoconductive properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.H. [Center for Photon Manufacturing Science and Technology, School of Materials Science and Engineering, Jiangsu University, Zhenjiang - 212013 (China); Zhang, P. [Dongguan University of Technology, Dongguan-523808 (China); School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou - 510275 (China); Liang, C.L. [Instrumental Analysis and Research Center, SunYat-sen University, Guangzhou - 510275 (China); Yang, J. [School of Materials Science and Engineering, Jiangsu University, Zhenjiang - 212013 (China); Zhou, M. [Center for Photon Manufacturing Science and Technology, School of Materials Science and Engineering, Jiangsu University, Zhenjiang - 212013 (China); The State Key Laboratory of Tribology, Tsinghua University, Beijing - 10084 (China); Lu, X.H. [School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou - 510275 (China); Hope, G.A. [School of Biomolecular and Physical Sciences, Griffith University, Nathan - Qld 4111 (Australia)

    2012-10-15

    Tellurium nanorods have been successfully fabricated by template and surfactant-free electrochemical technique from an aqueous solution at room temperature. The as-prepared tellurium nanorods were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectrometry, UV-vis spectroscopy and photoluminescence spectroscopy. Films based on tellurium nanorods were constructed to study the photoresponse and I-V curves. These photoresponse measurements demonstrate that tellurium nanorods exhibited enhanced conductivity under illumination compared to in the dark measurement. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. The mineralogical characterization of tellurium in copper anodes

    Science.gov (United States)

    Chen, T. T.; Dutrizac, J. E.

    1993-12-01

    A mineralogical study of a «normal» commercial copper anode and six tellurium-rich copper anodes from the CCR Refinery of the Noranda Copper Smelting and Refining Company was carried out to identify the tellurium carriers and their relative abundances. In all the anodes, the major tellurium carrier is the Cu2Se-Cu2Te phase which occurs as a constituent of complex inclusions at the copper grain boundaries. In tellurium-rich anodes, the molar tellurium content of the Cu2Se-Cu2Te phase can exceed that of selenium. Although >85 pct of the tellurium occurs as the Cu2Se-Cu2Te phase, minor amounts are present in Cu-Pb-As-Bi-Sb oxide, Cu-Bi-As oxide, and Cu-Te-As oxide phases which form part of the grain-boundary inclusions. About 1 pct of the tellurium content of silver-rich anodes occurs in various silver alloys, but gold tellurides were never detected. Surprising is the fact that 2 to 8 pct of the total tellurium content of the anodes occurs in solid solution in the copper-metal matrix, and presumably, this form of tellurium dissolves at the anode interface during electrorefining.

  13. Comparison between selenium and tellurium clusters

    International Nuclear Information System (INIS)

    Benamar, A.; Rayane, D.; Tribollet, B.; Broyer, M.; Melinon, P.

    1991-01-01

    Selenium and tellurium clusters are produced by the inert gas condensation technique. The mass spectra of both species are completely different and reveal different properties. In selenium, a periodicity of 6-7 is observed and may be interpreted by the binding energy between small cyclic molecules. Moreover, it was very difficult to obtained large clusters probably because the binding energy between these molecules is very small. In tellurium, these periodic structures do not exist and large clusters are easily obtained in nucleation conditions where only small selenium clusters are present. These results are discussed and a simple nucleation model is used to illustrate this different behavior. Finally these clusters properties are correlated to the bulk structure of both materials. (orig.)

  14. Neutron activation analysis of high purity tellurium

    International Nuclear Information System (INIS)

    Gil'bert, Eh.N.; Verevkin, G.V.; Obrazovskij, E.G.; Shatskaya, S.S.

    1980-01-01

    A scheme of neutron activation analysis of high purity tellurium is developed. Weighed amount of Te (0.5 g) is irradiated for 20-40 hr in the flux of 2x10 13 neutron/(cm 2 xs). After decomposition of the sample impurities of gold and palladium are determined by the extraction with organic sulphides. Tellurium separation from the remaining impurities is carried out by the extraction with monothiobenzoic acid from weakly acidic HCl solutions in the presence of iodide-ions, suppressing silver extraction. Remaining impurity elements in the refined product are determined γ-spectrometrically. The method allows to determine 34 impurities with determination limits 10 -6 -10 -11 g

  15. Interaction of tellurium and tellurium-containing semiconductor compounds with solutions of HI-HNO3-H2O system

    International Nuclear Information System (INIS)

    Tomashik, V.N.; Sava, A.A.; Tomashik, Z.F.

    1994-01-01

    As a result of experimental investigations and physical-chemical simulation are established regularities of solution of semiconducting tellurium-containing compounds in HI-HNO 3 -H 2 O systems. In HNO 3 -HI system solutions enriched by HNO 3 are not used for CdTe treatment but HI enriched solution are similar in composition with I 2 -HI solutions. Solution of the given tellurium-containing materials proceeds by a chemical mechanism and is determined by tellurium oxidation with iodine

  16. Copper Tellurium Oxides - A Playground for Magnetism.

    Energy Technology Data Exchange (ETDEWEB)

    Norman, M. R.

    2018-04-15

    A variety of copper tellurium oxide minerals are known, and many of them exhibit either unusual forms of magnetism, or potentially novel spin liquid behavior. Here, I review a number of the more interesting materials with a focus on their crystalline symmetry and, if known, the nature of their magnetism. Many of these exist (so far) in mineral form only, and most have yet to have their magnetic properties studied. This means a largely unexplored space of materials awaits our exploration.

  17. Tellurium release and deposition during the TMI-2 accident

    International Nuclear Information System (INIS)

    Vinjamuri, K.; Osetek, D.J.; Hobbins, R.R.; Jessup, J.S.

    1984-09-01

    The estimated behavior of tellurium during and after the accident at the Three Mile Island Unit-2 is presented. The behavior is based on all available measurement data for /sup 129m/Te, 132 Te, stable tellurium ( 126 Te, 128 Te and 130 Te), and best estimate calculations of tellurium release and transport. The predicted release was calculated using current techniques that relate release rate to fuel temperature and holdup of tellurium in zircaloy until significant oxidation occurs. The calculated release fraction was low, approx. 7%, but the total measured release for samples analyzed to date is about 5.8%. Of the measured tellurium about 2.4, 1.8, 0.88, 0.42, 0.17 and 0.086% of core inventory were in the containment sump water, upper plenum assembly surfaces, containment solids in the sump water, makeup and purification demineralizer, containment inside surface, and the reactor primary coolant, respectively. A significant fraction (54%) of the tellurium calculated to be retained on the upper plenum surfaces (4.61% of the core inventory) was deposited during the high pressure injection of coolant at about 200 min after the reactor scram. Comparison of tellurium behavior with in-pile and out-of-pile tests strongly suggests that zircaloy holds tellurium until significant cladding oxidation occurs

  18. Tellurium behavior during and after the TMI-2 accident

    International Nuclear Information System (INIS)

    Vinjamuri, K.; Osetek, D.J.; Hobbins, R.R.

    1984-01-01

    The estimated behavior of tellurium during and after the accident at the Three Mile Island Unit-2 is presented. The behavior is based on all available measurement data for /sup 129m/Te, 132 Te and stable tellurium ( 126 Te, 128 Te and 130 Te), and best estimate calculations of tellurium release and transport. The predicted release was calculated using current techniques that relate release rate to fuel temperature and holdup of tellurium in zircaloy until significant oxidation occurs. The calculated release fraction was low, approximately 7%, but the total measured release for samples analyzed to date is about 4.0%. Of the measured tellurium about 2.4, 0.88, 0.42, 0.17 and 0.086% of core inventory were in the containment sump water, containment solids in water, makeup and purification demineralizer, containment inside surface, and the reactor primary coolant, respectively. A significant fraction (54%) of the calculated tellurium retained on the upper plenum surfaces (4.61% of the core inventory) was deposited during the high pressure injection of coolant at about 200 minutes after the reactor scram. Comparison of tellurium behavior with inpile and out-of-pile tests strongly suggests that zircaloy holds tellurium until significant cladding oxidation occurs

  19. Facile Hydrothermal Synthesis of Tellurium Nanostructures for Solar Cells

    Directory of Open Access Journals (Sweden)

    M. Panahi-Kalamuei

    2014-10-01

    Full Text Available Tellurium (Te nanostructures have been successfully synthesized via a simple hydrothermal methodfrom the reaction of a TeCl4 aqueous solution with thioglycolic acid (TGA as a reductant. TGA can be easily oxidized to the corresponding disulfide [SCH2CO2H]2, which in turn can reduce TeCl4 to Te. The obtained Te was characterized by XRD, SEM, EDS, and DRS. The effect of reducing agent on morphology and size of the products were also studied. Additionally, Te thin film was deposited on the FTO-TiO2 by Dr- blading then employed to solar cell application and measured open circuit voltage (Voc, short circuit current (Isc, and fill factor (FF were determined as well. The studies showed that particle morphology and sizes play crucial role on solar cell efficiencies.

  20. Determination of tellurium in coal samples by means of graphite furnace atomic absorption spectrometry after coprecipitation with iron(III) hydroxide

    Energy Technology Data Exchange (ETDEWEB)

    Oda, S.; Arikawa, Y. [Japan Womens University, Tokyo (Japan)

    2005-11-01

    A simple and accurate method for the determination of tellurium in coal samples was investigated by the combustion of samples under a high pressure of oxygen and coprecipitation with Fe(OH){sub 3}, followed by a measurement by graphite furnace atomic absorption spectrometry (GF-AAS). About 0.5 g of an accurately weighed ground coal sample and 0.5 g of starch were combusted in an oxygen combustion bomb filled with oxygen to 3 MPa and added with 3 ml of water as an absorbing solution. The formed tellurium trioxide TeOs dissolved in water as TeO{sub 4}{sup 2-}, which was in turn reduced to TeO{sub 3}{sup 2-} by heating. After diluting the above-mentioned solution up to about 50 ml with water, Fe(OH){sub 3} is formed upon adding Fe(NO{sub 3}){sub 3} and sodium hydroxide solutions at pH 8-9 and left standing overnight. After dissolving the precipitate by HCl, the solution was diluted to 10 ml with water and the concentration of tellurium was measured by GF-AAS at a wavelength of 214.3 nm. The standard addition method was employed for the determination of tellurium in real coal samples, because those processes for the formation of tellurium(VI) oxide and coprecipitation with Fe(OH)3 were interfered by matrices. For NIST SRM 1632c, the standard coal sample tellurium content of 0.057 {+-} 0.004 mg kg{sup -1} was in good agreement with the information value of 0.05 mg kg{sup -1} with 7% of RSD in five replicate analyses. The tellurium contents in 20 real coal samples given by Center for Coal Utilization, Japan were also determined. The tellurium contents in these samples were scattered over the narrow range between 0.032 and 0.100 mg kg{sup -1}.

  1. Rapid radiochemical ion-exchange separation of iodine from tellurium: a novel radioiodine-132 generator

    Energy Technology Data Exchange (ETDEWEB)

    Abrao, A

    1975-01-01

    Tellurium ions form a soluble cationic complex with thiourea in acid medium. The cationic tellurium-thiourea species is strongly absorbed on a cationic ion exchanger. The retention of tellurium on the resin enables many interesting separation schemes for tellurium from various ions. With special interest, the separation of iodine from tellurium was studied. An efficient and convenient iodine-132 generator is described, in which the radio-iodine is eluted with water or 9 g/1 NaCl, when desired.

  2. A rapid radiochemical ion-exchange separation of iodine from tellurium: a novel radioiodine-132 generator

    International Nuclear Information System (INIS)

    Abrao, A.

    1975-01-01

    Tellurium ions form a soluble cationic complex with thiourea in acid medium. The cationic tellurium-thiourea species is strongly absorbed on a cationic ion exchanger. The retention of tellurium on the resin enables many interesting separation schemes for tellurium from various ions. With special interest, the separation of iodine from tellurium was studied. An efficient and convenient iodine-132 generator is described, in which the radio-iodine is eluted with water or 9 g/1 NaCL, when desired

  3. Extraction-spectrophotometric method for silicon determination in high-purity substances. 1. Silicon determination in tellurium

    Energy Technology Data Exchange (ETDEWEB)

    Shaburova, V P; Yudelevich, I G [AN SSSR, Novosibirsk (USSR). Inst. Neorganicheskoj Khimii

    1989-01-01

    The extraction-spectrophotometric method for silicon determination in tellurium based on extraction isolation of the base by tributyl phosphate from hydrochloride solutions and with addition of HNO/sub 3/ and spectrophotometric silicon determination using malachite green is developed. The method permits to determine 2x10/sup -1/-3x10/sup -4/ % Si.

  4. Double beta decay of tellurium-130

    International Nuclear Information System (INIS)

    Richardson, J.F.; Manuel, O.K.; Sinha, B.; Thorpe, R.I.

    1986-01-01

    The isotopic composition of xenon is reported in four, neutron-irradiated tellurium minerals - tellurobismuthite from Boliden, Sweden, native tellurium from the Good Hope Mine of Gunnison County, Colorado, altaite from the Kirkland Lake area, Ontario, and altaite from the Mattagami Lake area, Quebec. From the amount of radiogenic 130 Xe and pile-produced 131 Xe in these samples, it is concluded that the half-life of 130 Te for ββ-decay is 21 y based on measured values of (1.0+-0.3) . 10 21 y and higher. Our results demonstrate that there has been no significant partial leakage of radiogenic 130 Xe from these minerals over geologic time. Larger values of Tsub(1/2), as indicated from some of the analysis reported here and in other studies, are attributed to recrystallization of the soft telluride minerals and complete resetting of the Te-Xe system after mineralization. The value obtained here for the half-life of 130 Te is substantiated by recent measurements on xenon in tellurides from Kalgoorlie, Western Australia. (orig.)

  5. Inclusion free cadmium zinc tellurium and cadmium tellurium crystals and associated growth method

    Science.gov (United States)

    Bolotnikov, Aleskey E [South Setauket, NY; James, Ralph B [Ridge, NY

    2010-07-20

    The present disclosure provides systems and methods for crystal growth of cadmium zinc tellurium (CZT) and cadmium tellurium (CdTe) crystals with an inverted growth reactor chamber. The inverted growth reactor chamber enables growth of single, large, high purity CZT and CdTe crystals that can be used, for example, in X-ray and gamma detection, substrates for infrared detectors, or the like. The inverted growth reactor chamber enables reductions in the presence of Te inclusions, which are recognized as an important limiting factor in using CZT or CdTe as radiation detectors. The inverted growth reactor chamber can be utilized with existing crystal growth techniques such as the Bridgman crystal growth mechanism and the like. In an exemplary embodiment, the inverted growth reactor chamber is a U-shaped ampoule.

  6. Intergranular tellurium cracking of nickel-based alloys in molten Li, Be, Th, U/F salt mixture

    Science.gov (United States)

    Ignatiev, Victor; Surenkov, Alexander; Gnidoy, Ivan; Kulakov, Alexander; Uglov, Vadim; Vasiliev, Alexander; Presniakov, Mikhail

    2013-09-01

    alloy formation with the main components of the tested alloys are not reached, that's why alloys and intermetallic compounds are not formed on the surface of the investigated chromium-nickel alloys. Under such conditions any intergranular tellurium corrosion of the selected alloys does not occur. In the fuel salt with [U(IV)/]/[U(III)] = 100 the potentials of uranium alloy formation with the main components of the tested alloys are not also reached. Under such redox conditions any traces intergranular tellurium IGC on the HN80MTY and H80M-VI alloys specimens are not found. Certain signs of incipient IGC in the form of tellurium presence on the grain boundaries in the HN80MTB and EM-721 alloys surface layer and formation of not too deep cracks on HN80MTB alloy surface were revealed at [U(IV)/]/[U(III)] = 100. With this uranium ratio in the presence of corrosion products on the surface of all of the alloys films, containing tellurium, metals of the construction alloys and carbon, are formed. In the melt with [U(IV)]/[U(III)] = 500 in all of the alloys tested the tellurium IGC took place. The HN80MTY alloy shows the maximum resistance to tellurium IGC. The intensity of tellurium IGC of the alloy (the K parameter) is by 3-5 times lower as compared to other alloys. The EM-721 alloy has the minimal resistance to tellurium IGC (K = 9200 pc m/cm, the depth of cracks is up to 434 μm). The studies have shown, that the intensity of the nickel alloys IGC is controlled by the [U(IV)]/[U(III)] ratio, and its dependence on this parameter is of threshold character. Providing the uranium ratio value's monitoring and regulation, it is possible to control the tellurium corrosion and in such a way to eliminate IGC completely or to minimize its value. The alloys strength characteristics and their structure were changed insignificantly after testing within the [U(IV)]/[U(III)] range from 0.7 tо 100. The changes are not linked with the influence of fuel salt, containing tellurium additions

  7. Peroxide coordination of tellurium in aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Mikhaylov, Alexey A.; Medvedev, Alexander G. [Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); The Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem (Israel); Churakov, Andrei V.; Grishanov, Dmitry A.; Prikhodchenko, Petr V. [Kurnakov Institute of General and Inorganic Chemistry, Russian Academy of Sciences, Moscow (Russian Federation); Lev, Ovadia [The Casali Center of Applied Chemistry, The Institute of Chemistry, The Hebrew University of Jerusalem (Israel)

    2016-02-15

    Tellurium-peroxo complexes in aqueous solutions have never been reported. In this work, ammonium peroxotellurates (NH{sub 4}){sub 4}Te{sub 2}(μ-OO){sub 2}(μ-O)O{sub 4}(OH){sub 2} (1) and (NH{sub 4}){sub 5}Te{sub 2}(μ-OO){sub 2}(μ-O)O{sub 5}(OH).1.28 H{sub 2}O.0.72 H{sub 2}O{sub 2} (2) were isolated from 5 % hydrogen peroxide aqueous solutions of ammonium tellurate and characterized by single-crystal and powder X-ray diffraction analysis, by Raman spectroscopy and thermal analysis. The crystal structure of 1 comprises ammonium cations and a symmetric binuclear peroxotellurate anion [Te{sub 2}(μ-OO){sub 2}(μ-O)O{sub 4}(OH){sub 2}]{sup 4-}. The structure of 2 consists of an unsymmetrical [Te{sub 2}(μ-OO){sub 2}(μ-O)O{sub 5}(OH)]{sup 5-} anion, ammonium cations, hydrogen peroxide, and water. Peroxotellurate anions in both 1 and 2 contain a binuclear Te{sub 2}(μ-OO){sub 2}(μ-O) fragment with one μ-oxo- and two μ-peroxo bridging groups. {sup 125}Te NMR spectroscopic analysis shows that the peroxo bridged bitellurate anions are the dominant species in solution, with 3-40 %wt H{sub 2}O{sub 2} and for pH values above 9. DFT calculations of the peroxotellurate anion confirm its higher thermodynamic stability compared with those of the oxotellurate analogues. This is the first direct evidence for tellurium-peroxide coordination in any aqueous system and the first report of inorganic tellurium-peroxo complexes. General features common to all reported p-block element peroxides could be discerned by the characterization of aqueous and crystalline peroxotellurates. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Structure and activity of tellurium-cerium oxide acrylonitrile catalysts

    International Nuclear Information System (INIS)

    Bart, J.C.J.; Giordano, N.

    1982-01-01

    Ammoxidation of propylene to acrylonitrile (ACN) was investigated over various silica-supported (Te,Ce)O catalysts at 360 and 440 0 C. The binary oxide system used consists of a single nonstoichiometric fluorite-type phase α-(Ce,Te)O 2 up to about 80 mole% TeO 2 and a tellurium-saturated solid solution β-(Ce,Te)O 2 at higher tellurium concentrations. The ACN yield varies almost linearly with the tellurium content of (Ce,Te)O 2 . The β-(Ce,Te)O 2 phase is the most active component of the system (propylene conversion and ACN selectivity at 440 C of 76.7 and 74%, respectively) and is slightly more selective to ACN than α-Te0 2 . Tellurium reduces the overoxidation properties of cerium and selective oxidation occurs through Te(IV)-bonded oxygen

  9. Selenium- or tellurium- containing bile acids and derivatives thereof

    International Nuclear Information System (INIS)

    Monks, R.; Riley, A.L.M.

    1981-01-01

    This invention relates to the preparation of selenium and tellurium derivatives, particularly γ-emitting radioactive derivatives of bile acids and bile salts. Such compounds are valuable in the examination of body function, especially small bowel function. (author)

  10. Exploring molecular and spin interactions of Tellurium adatom in reduced graphene oxide

    Energy Technology Data Exchange (ETDEWEB)

    Alegaonkar, Ashwini [Department of Chemistry, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411 007, MS (India); Alegaonkar, Prashant [Department of Applied Physics, Defence Institute of Advance Technology, Girinagar, Pune, 411 025, MS (India); Pardeshi, Satish, E-mail: skpar@chem.unipune.ac.in [Department of Chemistry, Savitribai Phule Pune University (Formerly University of Pune), Ganeshkhind, Pune, 411 007, MS (India)

    2017-07-01

    The transport of spin information fundamentally requires favourable molecular architecture and tunable spin moments to make the medium pertinent for spintronic. We report on achieving coherent molecular-spin parameters for rGO due to Tellurium (Te) adatom. Initially, GO prepared using graphite, was modified into rGO by in situ incorporation of 1 (w/w)% of Te. Both the systems were subjected to ESCA, FTIR, Raman dispersion, ESR spectroscopy, and electron microscopy. Analysis revealed that, Te substantially reacted with epoxides, carbonyl, and carboxylate groups that improved C-to-O ratio by twice. However, the spin splitting character, between Te and C, seems to be quenched. Moreover, Te altered the dynamical force constant between C-C and C=C that generated the mechanical stress within rGO network. The layer conjugation, nature of folding, symmetry, and electronic states of the edges were also affected by precipitation and entrapment of Te. The calculated dynamic molecular Raman and ESR spin parameters indicated that, Te acted as a bridging element for long range spin transport. This is particularly due to, the p-orbital moments of Te contributing, vectorially, to spin relaxation process operative at broken inversion symmetry sites. Our study suggests that, facile addition of Te in rGO is useful to achieve favourable spintronic properties. - Highlights: • Spin interactions and molecular dynamics modification due to Tellurium adatom in rGO. • Molecular level manipulation of Tellurium adatom for favourable spintronic properties. • Bychocov-Rashaba coupling are the operative channels in rGO. • Extrinsic coupling component get added vectorially by Tellurium. • Te-rGO is a viable medium for molecular spintronics.

  11. Study of distribution coefficients of admixtures in tellurium

    International Nuclear Information System (INIS)

    Kuchar, L.; Drapala, J.; Kuchar, L. jr.

    1986-01-01

    Limit areas of tellurium-admixture binary systems were studied and the values determined of steady-state distribution coefficients of admixtures. A second order polynomial was used to express equations of solidus and liquidus curves for Te-Se, Te-S, Te-Hg systems; the curves are graphically represented. The most effective method for preparing high-purity tellurium is zonal melting with material removal. (M.D.). 4 figs., 4 tabs., 16 refs

  12. Thermal neutron capture cross sections of tellurium isotopes

    International Nuclear Information System (INIS)

    Tomandl, I.; Honzatko, J.; Egidy, T. von; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.

    2003-01-01

    New values for thermal neutron capture cross sections of the tellurium isotopes 122 Te, 124 Te, 125 Te, 126 Te, 128 Te, and 130 Te are reported. These values are based on a combination of newly determined partial γ-ray cross sections obtained from experiments on targets contained natural Te and γ intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given

  13. Thermal neutron capture cross sections of tellurium isotopes

    International Nuclear Information System (INIS)

    Tomandl, I.; Honzatko, J.; Egidy, T. von; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.

    2004-01-01

    New values for thermal neutron capture cross sections of the tellurium isotopes 122Te, 124Te, 125Te, 126Te, 128Te, and 130Te are reported. These values are based on a combination of newly determined partial g-ray cross sections obtained from experiments on targets contained natural Te and gamma intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given

  14. Thermal neutron capture cross sections of tellurium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Tomandl, I.; Honzatko, J.; von Egidy, T.; Wirth, H.-F.; Belgya, T.; Lakatos, M.; Szentmiklosi, L.; Revay, Zs.; Molnar, G.L.; Firestone, R.B.; Bondarenko, V.

    2004-03-01

    New values for thermal neutron capture cross sections of the tellurium isotopes 122Te, 124Te, 125Te, 126Te, 128Te, and 130Te are reported. These values are based on a combination of newly determined partial g-ray cross sections obtained from experiments on targets contained natural Te and gamma intensities per capture of individual Te isotopes. Isomeric ratios for the thermal neutron capture on the even tellurium isotopes are also given.

  15. Tellurium quantum dots: Preparation and optical properties

    Science.gov (United States)

    Lu, Chaoyu; Li, Xueming; Tang, Libin; Lai, Sin Ki; Rogée, Lukas; Teng, Kar Seng; Qian, Fuli; Zhou, Liangliang; Lau, Shu Ping

    2017-08-01

    Herein, we report an effective and simple method for producing Tellurium Quantum dots (TeQDs), zero-dimensional nanomaterials with great prospects for biomedical applications. Their preparation is based on the ultrasonic exfoliation of Te powder dispersed in 1-methyl-2-pyrrolidone. Sonication causes the van der Waals forces between the structural hexagons of Te to break so that the relatively coarse powder breaks down into nanoscale particles. The TeQDs have an average size of about 4 nm. UV-Vis absorption spectra of the TeQDs showed an absorption peak at 288 nm. Photoluminescence excitation (PLE) and photoluminescence (PL) are used to study the optical properties of TeQDs. Both the PLE and PL peaks revealed a linear relationship against the emission and excitation energies, respectively. TeQDs have important potential applications in biological imaging and catalysis as well as optoelectronics.

  16. METHODS OF SYNTHESIS EIGHT-TELLURIUM-CONTAINING HETEROCYCLES WITH MORE HETEROATOMS

    Directory of Open Access Journals (Sweden)

    G. M. Abakarov

    2013-01-01

    Full Text Available In this article systematized and summarized data on the synthesis of neweight-embered tellurium-containing heterocycles and new preparative methods described above produce heterocyclic tellurium.

  17. Simultaneous analysis of arsenic, antimony, selenium and tellurium in environmental samples using hydride generation ICPMS

    International Nuclear Information System (INIS)

    Jankowski, L.M.; Breidenbach, R.; Bakker, I.J.I.; Epema, O.J.

    2009-01-01

    Full text: A quantitative method for simultaneous analysis of arsenic, antimony, selenium and tellurium in environmental samples is being developed using hydride generation ICPMS. These elements must be first transformed into hydride-forming oxidation states. This is particularly challenging for selenium and antimony because selenium is susceptible to reduction to the non-hydride-forming elemental state and antimony requires strong reducing conditions. The effectiveness of three reducing agents (KI, thiourea, cysteine) is studied. A comparison is made between addition of reducing agent to the sample and addition of KI to the NaBH 4 solution. Best results were obtained with the latter approach. (author)

  18. Investigation of γ-irradiation influence on the DLTS spectra in silicon diluted by tellurium

    International Nuclear Information System (INIS)

    Sultanov, N.A.; Tadzhibaev, M.; Mirzabadalov, Zh

    1997-01-01

    The influence of gamma-radiation on deep level transient spectroscopy(DLTS) spectra for silicon crystals doped with tellurium was studied. The DLTS spectra have shown that tellurium in silicon formed two deep levels with fixed ionization energy. It was shown that the presence of tellurium prevents the formation of radiation defects

  19. A recycling model of the biokinetics of systemic tellurium.

    Science.gov (United States)

    Giussani, Augusto

    2014-11-01

    To develop a compartmental model of the systemic biokinetics of tellurium required for calculating the internal dose and interpreting bioassay measurements after incorporation of radioactive tellurium. The compartmental model for tellurium was developed with the software SAAM II v. 2.0 (©The Epsilon Group, Charlottesville, Virginia, USA). Model parameters were determined on the basis of published retention and excretion data in humans and animals. The model consists of two blood compartments, one compartment each for liver, kidneys, thyroid, four compartments for bone tissues and a generic compartment for the soft tissues. The model predicts a rapid urinary excretion of systemic tellurium: 45% in the first 24 h and 84% after 50 d. Faecal excretion amounts to 0.4% after 3 d and 9% after 50 d. Whole body retention is 55% after one day, and 2.8% after 100 d. These values as well as the retained fractions in the single organs are reasonably consistent with the available human and animal data (studies with swine and guinea pigs). The proposed model gives a realistic description of the available biokinetic data for tellurium and will be adopted by the International Commission on Radiological Protection for applications in internal dosimetry.

  20. Tellurium Enrichment in Jurassic Coal, Brora, Scotland

    Directory of Open Access Journals (Sweden)

    Liam Bullock

    2017-11-01

    Full Text Available Mid-Jurassic pyritic coals exposed at the village of Brora, northern Scotland, UK, contain a marked enrichment of tellurium (Te relative to crustal mean, average world coal compositions and British Isles Carboniferous coals. The Te content of Brora coal pyrite is more than one order of magnitude higher than in sampled pyrite of Carboniferous coals. The Te enrichment coincides with selenium (Se and mercury (Hg enrichment in the rims of pyrite, and Se/Te is much lower than in pyrites of Carboniferous coals. Initial pyrite formation is attributed to early burial (syn-diagenesis, with incorporation of Te, Se, Hg and lead (Pb during later pyrite formation. The source of Te may have been a local hydrothermal system which was responsible for alluvial gold (Au in the region, with some Au in Brora headwaters occurring as tellurides. Anomalous Te is not ubiquitous in coal, but may occur locally, and is detectable by laser ablation inductively coupled plasma-mass spectrometry (LA-ICP-MS.

  1. Effect of tellurium on viscosity and liquid structure of GaSb melts

    Energy Technology Data Exchange (ETDEWEB)

    Ji Leilei [School of Material Science and Engineering, Jinan University, Jinan 250022 (China); Geng Haoran [School of Material Science and Engineering, Jinan University, Jinan 250022 (China)], E-mail: mse_genghr@ujn.edu.cn; Sun Chunjing [Key Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University, Jinan 250061 (China); Teng Xinying; Liu Yamei [School of Material Science and Engineering, Jinan University, Jinan 250022 (China)

    2008-04-03

    The behavior of GaSb melt with tellurium addition was investigated using viscometer and differential scanning calorimetry (DSC). Normally, the viscosity of all melts measured decreased with the increasing temperature. However, anomalous transition points were observed in the temperature dependence of viscosity for Ga-Sb-Te system. Corresponded with the abnormal points on the viscosity-temperature curves, there were thermal effect peaks on the DSC curves. Furthermore, viscous activation energy and flow units of these melts and their structural features were discussed in this paper.

  2. Continuous reduction of tellurite to recoverable tellurium nanoparticles using an upflow anaerobic sludge bed (UASB) reactor.

    Science.gov (United States)

    Ramos-Ruiz, Adriana; Sesma-Martin, Juan; Sierra-Alvarez, Reyes; Field, Jim A

    2017-01-01

    According to the U.S. Department of Energy and the European Union, tellurium is a critical element needed for energy and defense technology. Thus methods are needed to recover tellurium from waste streams. The objectives of this study was to determine the feasibility of utilizing upflow anaerobic sludge bed (UASB) reactors to convert toxic tellurite (Te IV ) oxyanions to non-toxic insoluble elemental tellurium (Te 0 ) nanoparticles (NP) that are amendable to separation from aqueous effluents. The reactors were supplied with ethanol as the electron donating substrate to promote the biological reduction of Te IV . One reactor was additionally amended with the redox mediating flavonoid compound, riboflavin (RF), with the goal of enhancing the bioreduction of Te IV . Its performance was compared to a control reactor lacking RF. The continuous formation of Te 0 NPs using the UASB reactors was found to be feasible and remarkably improved by the addition of RF. The presence of this flavonoid was previously shown to enhance the conversion rate of Te IV by approximately 11-fold. In this study, we demonstrated that this was associated with the added benefit of reducing the toxic impact of Te IV towards the methanogenic consortium in the UASB and thus enabled a 4.7-fold higher conversion rate of the chemical oxygen demand. Taken as a whole, this work demonstrates the potential of a methanogenic granular sludge to be applied as a bioreactor technology producing recoverable Te 0 NPs in a continuous fashion. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Analysis of tellurium-silicon alloys. Part 1. Determination of tellurium by the reduction from perchloric acid solution

    International Nuclear Information System (INIS)

    Teperek, J.

    1977-01-01

    When 100-150 mg of tellurium is dissolved in the solution containing 20 cm 3 72 wt.% of perchloric acid, the reduction of tellurium to elementary form is possible only after adding 60-100 milimoles of HCl. The reduction is performed by adding 1 cm 3 of saturated sodium pyrosulphite solution (Na 2 S 2 O 5 ) and 10 cm 3 of 10 wt.% hydrazine hydrochloride solution (N 2 H 4 .2HCl) to 80-90 cm 3 of cold solution of Te in HClO 4 -HCl mixture. The reduction is completed after 3-5 min. of boiling. When 150-200 mg sample of Te-Si alloy is dissolved in 20 cm 3 of hot 72% per chloric acid, the separation of components is reached. Tellurium can be determinated in filtrate by proposed procedure with high accuracy and precision. (author)

  4. The application of three-phase liquid-liquid extraction to the analysis of bismuth and tellurium in sulphide concentrates

    International Nuclear Information System (INIS)

    Nicholas, D.J.

    1976-01-01

    An extraction system consisting of one aqueous and two organic phases is described. Diantipyrylmethane (DAM) is used as the extractant for bismuth and tellurium, which are extracted into the smaller of the two organic phases from nitric acid and perchloric acid respectively. The extraction efficiency is in the range of 90 to 95 per cent, compensation for incomplete extraction being made by the technique of standard addition. Copper, lead, and zinc are not extracted in either procedure. When the solutions contain high concentrations of iron, thioglycolic acid is used as a masking agent for iron in the extraction of bismuth. Atomic-absorption spectrophotometry is used for the analysis of the third phase after it has been diluted with methanol. The precision for bismuth and tellurium is in the range of 3 to 4 per cent. The accuracy, as ascertained from comparative analyses of sulphide concentrates, is good

  5. METALCOMPLEXES OF TELLURIUM-CONTAINING AMINES AND AZOMETINES

    Directory of Open Access Journals (Sweden)

    G. M. Abakarov

    2014-01-01

    Full Text Available In this article methods of synthesis and reactionary ability of metalcomplexes of tellurium-containing amines, azometines, of a problem of competitive coordination with use of the principle of "soft" and "rigid" acids and the bases (R. Pearson.

  6. Tellurium Stable Isotopes as a Paleoredox Proxy

    Science.gov (United States)

    Wasserman, N.; Johnson, T. M.

    2017-12-01

    Despite arguments for variably-oxygenated shallow waters and anoxic deep marine waters, which delayed animal development until the Neoproterozoic Oxidation Event, the magnitude of atmospheric oxygen during the Proterozoic is still uncertain [1]. The evidence for low pO2 (<0.1-1% PAL) is based on geochemical and isotopic proxies, which track the mobilization of Fe and Mn on the continents. For example, large chromium isotope shifts occur at the Neoproterozoic Oxidation Event due to the initiation of Cr redox cycling, but this proxy is insensitive to fluctuations in the lower-pO2 conditions at other times during the Proterozoic. Tellurium, a metalloid with a lower threshold to oxidation, may be sensitive to pO2 shifts in a lower range. In the reduced forms, Te(-II) and Te(0), the element is insoluble and immobile. However, in the more oxidized phases, Te(IV) and Te(VI), Te can form soluble oxyanions (though it tends to adsorb to Fe-oxyhydroxides and clays) [2]. Te stable isotopes have been shown to fractionate during abiotic or biologic reduction of Te(VI) or Te(IV) to elemental Te(0) [3, 4]. Utilizing hydride generation MC-ICP-MS, we are able to obtain high precision (2σ 0.04‰) measurements of δ128Te/125Te for natural samples containing < 10 ng of Te. A suite of Phanerozoic and Proterozoic ironstones show significant variation in δ128Te/125Te (<0.5‰), suggesting that the Te redox cycle was active during the Proterozoic. Future directions will include Te isotope measurements of Precambrian paleosols to determine natural isotope variation before the Great Oxidation Event and experiments to determine fractionation during adsorption to Fe-oxyhydroxides. [1] Planavsky et al. (2014) Science 346 (6209), pp. 635-638 [2] Qin et al. (2017) Environmental Science and Technology 51 (11), pp 6027-6035 [3] Baesman et al. (2007) Applied Environmental Microbiology 73 (7), pp 2135-2143 [4] Smithers and Krause (1968) Canadian Journal of Chemistry 46(4): pp 583-591

  7. Catalytic activity of oxide cerium-molybdenum-tellurium catalysts in oxidation ammonolysis

    International Nuclear Information System (INIS)

    Dzhordano, N.; Bart, D.; Madzhori, R.

    1984-01-01

    A commercial catalyst containing a mixture of Ce-, Mo-, Te oxides deposited on SiO 2 is shown to manifest a high efficiency in oxidative ammonolysis of propylene (C 3 - ) to acrylonitrile (AN). The dependence of the catalytic properties on the catalyst composition and reaction conditions is studied. It is established that three-component mixtures are more active and selective than the systems with a lesser number of components. Using the catalyst with the optimum ratio of constituent oxides in a microreactor at 440 deg enabled one to achieve initial selectivity in terms of AN equal to 82.5% at 97% conversion of C 3 - . Acrolein, acetonitrile, HCN and nitrogen oxides are the reaction by-products. A supposition is made that the reaction proceeds via the formation of π-compleXes on the centres of Te(4). Setective oxidation occurs on oxygen atoms bonded with the Mo(6) ions. Tellurium enhances the molybdenum reducibleness due to delocalization of electrons, whereas the cerium addition to the mixture of tellurium- and molybdenum oxides increases the rate of molybdenum reoxidation and thus enhances the catalytic system stability

  8. High performance supercapacitor and non-enzymatic hydrogen peroxide sensor based on tellurium nanoparticles

    Directory of Open Access Journals (Sweden)

    M. Manikandan

    2017-04-01

    Full Text Available Tellurium nanoparticles (Te Nps were synthesized by wet chemical method and characterized by XRD, Raman, FESEM, TEM, XPS, UV–Vis and FL. The Nps were coated on graphite foil and Glassy carbon electrode to prepare the electrodes for supercapacitor and biosensor applications. The supercapacitor performance is evaluated in 2 M KOH electrolyte by both Cyclic Voltammetry (CV and galvanostatic charge-discharge method. From charge-discharge method, Te Nps show a specific capacitance of 586 F/g at 2 mA/cm2 and 100 F/g at 30 mA/cm2 as well as an excellent cycle life (100% after 1000 cycles. In addition, the H2O2 sensor performance of Te Nps modified glassy carbon electrode is checked by CV and Chronoamperometry (CA in phosphate buffer solution (PBS. In the linear range of 0.67 to 8.04 μM of hydrogen peroxide (H2O2, Te NPs show a high sensitivity of 0.83 mA mM−1 cm−2 with a correlation coefficient of 0.995. The detection limit is 0.3 μM with a response time less than 5 s. Keywords: Tellurium nanoparticles, Supercapacitor, Biosensor, Hydrogen peroxide

  9. Enrichment mechanisms of tellurium in ferromanganese crusts

    Science.gov (United States)

    Sakaguchi, A.; Sugiyama, T.; Usui, A.; Takahashi, Y.

    2012-04-01

    Marine ferromanganese crusts (FMCs) consist of iron (Fe) hydroxides and manganese (Mn) oxides with various minor and trace elements. Especially for tellurium (Te), which is recognized as one of the rare metals, it has been reported that this element is concentrated about 105 times in FMCs compared with earth's crust, and the host phase might be Fe (oxy)hydroxide (Hein et al., 2003). Actually, in our previous study, the high concentration of Te in very surface layers of FMCs was found from the top to halfway down of a seamount in the Pacific Ocean. However, the concentration of Te in surface layers through the seamount showed good correlation with that of Mn instead of Fe. In this study, we attempted to clarify the enrichment mechanism of Te in FMCs with some methods including X-ray absorption fine structure (XAFS) technique for synthesised /natural samples. Seventeen FMC samples were collected from the Takuyo-Daigo seamount, from 950 m (summit) to 3000 m in water depth, with hyper-dolphin (remotely operated vehicle) equipped with live video camera and manipulators. The growth rates of all FMC samples were estimated to be about 3 mm/Ma. Very surface layer (less than 1 mm) of all FMC was analyzed with XRD and XAFS to confirm the mineral composition and speciation of Te. Furthermore, to serve as an aid to clarify the adsorption mechanism of Te on FMCs, distribution coefficients (Kd) and oxidation states were determined through the adsorption experiments of Te(IV) and Te(VI) on ferrihydrite and δ-MnO2. In all the experiments, pH and ionic strength were adjusted to pH 7.5 and 0.7 M, respectively. The oxidation state of Te in water phase was determined with HPLC-ICP-MS. As for the analysis of oxidation and adsorption states on the solid phase, XAFS was employed. The major mineral composition of Fe and Mn had no significant variation through the water depth of Takuyo-Daigo seamount. The oxidation state of Te in all samples showed hexavalent, and there was no significant

  10. Atomic absorption determination of ultratrace tellurium in rocks utilizing high sensitivity sampling systems

    International Nuclear Information System (INIS)

    Beaty, R.D.

    1973-01-01

    The sampling boat and the graphite furnace were shown to possess the required sensitivity to detect tellurium at ultratrace levels, in a variety of sample types, by atomic absorption. In the sampling boat approach, tellurium in sample solutions is chemically separated and concentrated by extraction into methyl isobutyl ketone before measurement. For samples exhibiting extraction interferences or excessively high background absorption, a preliminary separation of tellurium by coprecipitation with selenium is described. Using this technique, tellurium can be quantitatively detected down to 5 nanograms and linear response is observed to 100 nanograms. Relative standard deviations of better than 7 percent are achieved for 50 nanograms of tellurium. For samples that have a tellurium content below the detection limits of the sampling boat, the graphite furnace is used for atomization. By this method, as little as 0.07 nanograms of tellurium can be detected, and a precision of 1 percent relative standard deviation is achievable at the 5 nanogram level. A routinely applicable procedure was developed for determining tellurium in rocks, using the graphite furnace, after a hydrofluoric acid decomposition of the sample. Using this procedure, tellurium data were obtained on 20 different rocks, and the significance of this new information is discussed. (Diss. Abstr. Int., B)

  11. Effects of tellurium concentration on the structure of melt-grown ZnSe crystals

    International Nuclear Information System (INIS)

    Atroshchenko, Lyubov V.; Galkin, Sergey N.; Rybalka, Irina A.; Voronkin, Evgeniy F.; Lalayants, Alexandr I.; Ryzhikov, Vladimir D.; Fedorov, Alexandr G.

    2005-01-01

    It has been shown that isovalent doping by tellurium positively affects the structural perfection of ZnSe crystals related to the completeness of the wurtzite-sphalerite phase transition. The optimum concentration range of tellurium in ZnSe crystals is 0.3-0.6 mass %. X-ray diffraction studies have shown that in ZnSe 1-x Te x crystals at tellurium concentrations below 0.3 mass % twinning and packing defects occur, while tellurium concentrations above 0.6 mass % lead to formation of tetragonal crystal lattice

  12. Determining arsenic in elemental antimony containing selenium and tellurium

    International Nuclear Information System (INIS)

    Mogileva, M.G.; Kozlova, E.L.

    1986-01-01

    The authors have developed a method of determining arsenic in metallic antimony containing selenium, tellurium, and mercury, in which they isolated it in elementary form for separation from the antimony and the associated elements (silicon and phosphorus), followed by colorimetric determination of the arsenic from arsenic-molbdenum blue. The reducing agents to reduce the arsenic were sodium hypophosphite and tin(II) chloride, which do not reduce antimony and which do not interfere with the determination. This method of determining arsenic in metallic antimony without preliminary separation of the selenium and tellurium is in no way inferior in accuracy to the method given in All-Union State Standard (GOST) 1367.4-83

  13. RILIS-ionized mercury and tellurium beams at ISOLDE CERN

    Energy Technology Data Exchange (ETDEWEB)

    Day Goodacre, T., E-mail: thomas.day.goodacre@cern.ch [CERN (Switzerland); Billowes, J. [The University of Manchester, School of Physics and Astronomy (United Kingdom); Chrysalidis, K. [CERN (Switzerland); Fedorov, D. V. [Petersburg Nuclear Physics Institute (Russian Federation); Fedosseev, V. N.; Marsh, B. A. [CERN (Switzerland); Molkanov, P. L. [Petersburg Nuclear Physics Institute (Russian Federation); Rossel, R. E.; Rothe, S.; Seiffert, C. [CERN (Switzerland); Wendt, K. D. A. [Johannes Gutenberg Universität, Institut für Physik (Germany)

    2017-11-15

    This paper presents the results of ionization scheme development for application at the ISOLDE Resonance Ionization Laser Ion Source (RILIS). Two new ionization schemes for mercury are presented: a three-step three-resonance ionization scheme, ionizing via an excitation to a Rydberg level and a three-step two-resonance ionization scheme, with a non-resonant final step to the ionization continuum that corresponded to a factor of four higher ionization efficiency. The efficiency of the optimal mercury ionization scheme was measured, together with the efficiency of a new three-step three resonance ionization scheme for tellurium. The efficiencies of the mercury and tellurium ionization schemes were determined to be 6 % and >18 % respectively.

  14. ELECTROCHEMICAL STUDY OF RHENIUM-TELLURIUM-COPPER SYSTEM

    OpenAIRE

    E.A.Salakhova*1, D.B.Tagiyev2, P.E.Kalantarova3 and A.M.Askerova4

    2017-01-01

    The formation of the triple alloys Re-Te-Cu on the platinum electrode at volt amperemetric cycling has been studied. The investigation was carried out from chloride acidic solution containing tellurium acid, potassium perrhenate, chloride copper. The kinetics of the processes was controlled using the measurements by the method of cyclic volt-amperometry on the device İVİUMSTAT. For the analysis of composition and structure the methods of XRD (X-ray diffraction analysis) were used, and the inv...

  15. Starting material radiation source for Moessbauer investigations of tellurium compounds

    International Nuclear Information System (INIS)

    Alexandrov, A.J.; Grushko, J.S.; Makarov, E.F.; Mishin, K.Y.; Baltrunas, D.A.J.

    1977-01-01

    A method is described of preparing a radiation source for Mossbauer investigations of tellurium compounds manufactured on the basis of 5 MgO . Te 124 O 3 . 5 MgO . Te 124 O 3 is irradiated in a reactor by means of thermal neutrons, followed by annealing at a temperature ranging from 600 0 to 1,100 0 C for a period of from 5 to 10 hours

  16. Flotation concentration for tellurium determination in industrial sewage

    International Nuclear Information System (INIS)

    Skripchuk, V.G.; Bormotova, L.V.; Lukoyanova, L.P.; Tret'yakova, M.I.

    1983-01-01

    Combination of the flotation of tellurium (4) precipitate with papaverine toluene and extraction-photometric determination of Te with butylrhodamine C allows one to determine 0.002-0.1 mg Te/l without its preliminary precipitation. Accompanying elements found in non-ferrous metallurgy sewage have no effect upon it. The duration of analysis of 10 samples is 1 to 1.5 h. Relative error is 12%. The method is introduced at the ''Uralelektromed'' plant

  17. Rutherford backscatter measurements on tellurium and cadmium implanted gallium arsenide

    International Nuclear Information System (INIS)

    Bell, E.C.

    1979-10-01

    The primary aim of the work described in this thesis was to examine implanted layers of the dopant impurities cadmium and tellurium in gallium arsenide and to experimentally assess their potential for producing electrically active layers. 1.5 MeV Rutherford backscattering measurements of lattice disorder and atom site location have been used to assess post implantation thermal annealing and elevated temperature implantations to site the dopant impurities on either gallium or arsenic lattice positions in an otherwise undisordered lattice. Pyrolitically deposited silicon dioxide was used as an encapsulant to prevent thermal dissociation of the gallium arsenide during annealing. It has been shown that high doses of cadmium and tellurium can be implanted without forming amorphous lattice disorder by heating the gallium arsenide during implantation to relatively low temperatures. Atom site location measurements have shown that a large fraction of a tellurium dose implanted at 180 0 C is located on or near lattice sites. Channeled backscatter measurements have shown that there is residual disorder or lattice strain in gallium arsenide implanted at elevated temperatures. The extent of this disorder has been shown to depend on the implanted dose and implantation temperature. The channeling effect has been used to measure annealing of the disorder. (author)

  18. Purification and in vitro antioxidant activities of tellurium-containing phycobiliproteins from tellurium-enriched Spirulina platensis

    Directory of Open Access Journals (Sweden)

    Yang F

    2014-10-01

    Full Text Available Fang Yang,1 Ka-Hing Wong,2 Yufeng Yang,3 Xiaoling Li,1 Jie Jiang,1 Wenjie Zheng,1 Hualian Wu,1 Tianfeng Chen1 1Department of Chemistry, Jinan University, Guangzhou, People’s Republic of China; 2Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, People’s Republic of China; 3Institute of Hydrobiology, College of Life Science and Technology, Jinan University, Guangzhou, People’s Republic of China Abstract: Tellurium-containing phycocyanin (Te-PC and allophycocyanin (Te-APC, two organic tellurium (Te species, were purified from tellurium-enriched Spirulina platensis by a fast protein liquid chromatographic method. It was found that the incorporation of Te into the peptides enhanced the antioxidant activities of both phycobiliproteins. With fractionation by ammonium sulfate precipitation and hydroxylapatite chromatography, Te-PC and Te-APC could be effectively separated with high purity, and Te concentrations were 611.1 and 625.3 µg g-1 protein in Te-PC and Te-APC, respectively. The subunits in the proteins were identified by using MALDI-TOF-TOF mass spectrometry. Te incorporation enhanced the antioxidant activities of both phycobiliproteins, as examined by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay. Moreover, Te-PC and Te-APC showed dose-dependent protection on erythrocytes against the water-soluble free radical initiator 2,2'-azo(2-asmidinopropanedihydrochloride-induced hemolysis. In the hepatoprotective model, apoptotic cell death and nuclear condensation induced by tert-butyl hydroperoxide in HepG2 cells was significantly attenuated by Te-PC and Te-APC. Taken together, these results suggest that Te-PC and Te-APC are promising Te-containing proteins with application potential for treatment of diseases related to oxidative stress. Keywords: tellurium, phycocyanin, allophycocyanin, purification, antioxidant activity

  19. Purification and in vitro antioxidant activities of tellurium-containing phycobiliproteins from tellurium-enriched Spirulina platensis.

    Science.gov (United States)

    Yang, Fang; Wong, Ka-Hing; Yang, Yufeng; Li, Xiaoling; Jiang, Jie; Zheng, Wenjie; Wu, Hualian; Chen, Tianfeng

    2014-01-01

    Tellurium-containing phycocyanin (Te-PC) and allophycocyanin (Te-APC), two organic tellurium (Te) species, were purified from tellurium-enriched Spirulina platensis by a fast protein liquid chromatographic method. It was found that the incorporation of Te into the peptides enhanced the antioxidant activities of both phycobiliproteins. With fractionation by ammonium sulfate precipitation and hydroxylapatite chromatography, Te-PC and Te-APC could be effectively separated with high purity, and Te concentrations were 611.1 and 625.3 μg g(-1) protein in Te-PC and Te-APC, respectively. The subunits in the proteins were identified by using MALDI-TOF-TOF mass spectrometry. Te incorporation enhanced the antioxidant activities of both phycobiliproteins, as examined by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid assay. Moreover, Te-PC and Te-APC showed dose-dependent protection on erythrocytes against the water-soluble free radical initiator 2,2'-azo(2-asmidinopropane)dihydrochloride-induced hemolysis. In the hepatoprotective model, apoptotic cell death and nuclear condensation induced by tert-butyl hydroperoxide in HepG2 cells was significantly attenuated by Te-PC and Te-APC. Taken together, these results suggest that Te-PC and Te-APC are promising Te-containing proteins with application potential for treatment of diseases related to oxidative stress.

  20. Electrodeposition of antimony, tellurium and their alloys from molten acetamide mixtures

    NARCIS (Netherlands)

    Nguyen, H.P.; Peng, X.; Murugan, G.; Vullers, R.J.M.; Vereecken, P.M.; Fransaer, J.

    2013-01-01

    We examine the electrodeposition of antimony (Sb), tellurium (Te) and their alloys from molten mixtures of acetamide - antimony chloride and tellurium chloride. The binary mixtures of acetamide with SbCl3 and TeCl 4 exhibit eutectic formation with large depressions of freezing points to below room

  1. Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

    Energy Technology Data Exchange (ETDEWEB)

    Zare, Bijan; Faramarzi, Mohammad Ali; Sepehrizadeh, Zargham [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of); Shakibaie, Mojtaba [Department of Pharmacognosy and Biotechnology, School of Pharmacy, Pharmaceutics Research Center, Kerman University of Medical Sciences, P.O. Box 76175-493 Kerman (Iran, Islamic Republic of); Rezaie, Sassan [Department of Medical Biotechnology, School of Advanced Medical Technologies, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Shahverdi, Ahmad Reza, E-mail: shahverd@sina.tums.ac.ir [Department of Pharmaceutical Biotechnology and Biotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, P.O. Box 14155-6451 Tehran (Iran, Islamic Republic of)

    2012-11-15

    Highlights: ► Biosynthesis of rod shape tellurium nanoparticles with a hexagonal crystal structure. ► Extraction procedure for isolation of tellurium nanoparticles from Bacillus sp. BZ. ► Extracted tellurium nanoparticles have good bactericidal activity against some bacteria. -- Abstract: In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm × 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates.

  2. Biosynthesis and recovery of rod-shaped tellurium nanoparticles and their bactericidal activities

    International Nuclear Information System (INIS)

    Zare, Bijan; Faramarzi, Mohammad Ali; Sepehrizadeh, Zargham; Shakibaie, Mojtaba; Rezaie, Sassan; Shahverdi, Ahmad Reza

    2012-01-01

    Highlights: ► Biosynthesis of rod shape tellurium nanoparticles with a hexagonal crystal structure. ► Extraction procedure for isolation of tellurium nanoparticles from Bacillus sp. BZ. ► Extracted tellurium nanoparticles have good bactericidal activity against some bacteria. -- Abstract: In this study, a tellurium-transforming Bacillus sp. BZ was isolated from the Caspian Sea in northern Iran. The isolate was identified by various tests and 16S rDNA analysis, and then used to prepare elemental tellurium nanoparticles. The isolate was subsequently used for the intracellular biosynthesis of elemental tellurium nanoparticles. The biogenic nanoparticles were released by liquid nitrogen and purified by an n-octyl alcohol water extraction system. The shape, size, and composition of the extracted nanoparticles were characterized. The transmission electron micrograph showed rod-shaped nanoparticles with dimensions of about 20 nm × 180 nm. The energy dispersive X-ray and X-ray diffraction spectra respectively demonstrated that the extracted nanoparticles consisted of only tellurium and have a hexagonal crystal structure. This is the first study to demonstrate a biological method for synthesizing rod-shaped elemental tellurium by a Bacillus sp., its extraction and its antibacterial activity against different clinical isolates.

  3. Reprint of “Extracellular production of tellurium nanoparticles by the photosynthetic bacterium Rhodobacter capsulatus”

    Energy Technology Data Exchange (ETDEWEB)

    Borghese, Roberto, E-mail: roberto.borghese@unibo.it [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Brucale, Marco [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Fortunato, Gianuario [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy); Lanzi, Massimiliano [Dept. of Industrial Chemistry “Toso Montanari”, University of Bologna (Italy); Mezzi, Alessio [Institute for the Study of Nanostructured Materials (CNR-ISMN), Rome (Italy); Valle, Francesco; Cavallini, Massimiliano [Institute for the Study of Nanostructured Materials (CNR-ISMN), Bologna (Italy); Zannoni, Davide [Dept. of Pharmacy and Biotechnology, University of Bologna (Italy)

    2017-02-15

    Highlights: • Tellurite is reduced by R. capsulatus as cytosolic tellurium nanoprecipitates TeNPs. • Lawsone allows R. capsulatus to produce extracellular TeNPs. • Extracellular TeNPs production depends on the carbon source used for cells growth. • Both lawsone concentration and the incubation time determine the TeNPs size. • Extracellular TeNPs are coated with extracellular polymeric substances (EPS). - Abstract: The toxic oxyanion tellurite (TeO{sub 3}{sup 2−}) is acquired by cells of Rhodobacter capsulatus grown anaerobically in the light, via acetate permease ActP2 and then reduced to Te{sup 0} in the cytoplasm as needle-like black precipitates. Interestingly, photosynthetic cultures of R. capsulatus can also generate Te{sup 0} nanoprecipitates (TeNPs) outside the cells upon addition of the redox mediator lawsone (2-hydroxy-1,4-naphtoquinone). TeNPs generation kinetics were monitored to define the optimal conditions to produce TeNPs as a function of various carbon sources and lawsone concentration. We report that growing cultures over a 10 days period with daily additions of 1 mM tellurite led to the accumulation in the growth medium of TeNPs with dimensions from 200 up to 600–700 nm in length as determined by atomic force microscopy (AFM). This result suggests that nucleation of TeNPs takes place over the entire cell growth period although the addition of new tellurium Te{sup 0} to pre-formed TeNPs is the main strategy used by R. capsulatus to generate TeNPs outside the cells. Finally, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FT-IR) analysis of TeNPs indicate they are coated with an organic material which keeps the particles in solution in aqueous solvents.

  4. Polarographic determination of selenium and tellurium in silver-gold alloys

    International Nuclear Information System (INIS)

    Gornostaeva, T.D.; Shmargun, S.V.

    1986-01-01

    The determination of selenium and tellurium is of importance in monitoring the composition of silver-gold alloys (SGA) since these elements are harmful impurities in the pure metals. Tellurium is determined in silver alloys by atomic absorption and atomic emmission methods; selenium determination is made by atomic absorption methods. This paper examines the polarographic determination of silver and tellurium in SGA containing platinum metals and copper. Copper and the bulk of the platinum and palladium were removed by precipitating selenium and tellurium with potassium hypophosphite in the elementary state from 6 M HC1. The results of an analysis of samples of SGA according to the proposed method were compared with the results obtained by the atomic absorption method. the relative deviation in the determination of 0.02-1.0% by weight selenium and tellurium does not exceed 0.12 (n = 5)

  5. Synthesis and structure of aromatic and heterocyclic compounds of tellurium

    International Nuclear Information System (INIS)

    Sadekov, I.D.; Maksimenko, A.A.; Rivkin, B.B.

    1983-01-01

    A new universal method of preparing assymmetric and symmetric diaryl-tellurium chlorides and-dibromides, based on the interaction of diarylditellurides with cations of aryl-diazonium in the presence of copper (2) halogenides is developed. High yields of diaryltellium dihalogenices (60-90 de %), the possibility of the a wide variation of the nature of substituents in both components make this reaction one of the most general methods of preparing assymmetric diaryltellurium dihalogenides. It is advisable to use aryldiazonium boron fluorides instead of halogenides in this reaction

  6. Characterization of tellurium-based films for NO2 detection

    International Nuclear Information System (INIS)

    Tsiulyanu, D.; Tsiulyanu, A.; Liess, H.-D.; Eisele, I.

    2005-01-01

    Sensing characteristics of tellurium-based thin films for NO 2 monitoring was studied systematically. The influence of contact materials, thermal treatment, temperature and thickness of the samples on the electrical conductivity and sensitivity to NO 2 with respect to scanning electron microscopy analyses is given. The possibility is shown to optimize the properties of the films for the development of a simple and stable NO 2 sensor device with rapid response/recovery time and low operating temperature. The sensing mechanism is discussed for the direct interaction of gaseous species with lone-pair electrons of chalcogen atoms

  7. Van der Waals epitaxy and photoresponse of hexagonal tellurium nanoplates on flexible mica sheets.

    Science.gov (United States)

    Wang, Qisheng; Safdar, Muhammad; Xu, Kai; Mirza, Misbah; Wang, Zhenxing; He, Jun

    2014-07-22

    Van der Waals epitaxy (vdWE) is of great interest due to its extensive applications in the synthesis of ultrathin two-dimensional (2D) layered materials. However, vdWE of nonlayered functional materials is still not very well documented. Here, although tellurium has a strong tendency to grow into one-dimensional nanoarchitecture due to its chain-like structure, we successfully realize 2D hexagonal tellurium nanoplates on flexible mica sheets via vdWE. Chemically inert mica surface is found to be crucial for the lateral growth of hexagonal tellurium nanoplates since it (1) facilitates the migration of tellurium adatoms along mica surface and (2) allows a large lattice mismatch. Furthermore, 2D tellurium hexagonal nanoplates-based photodetectors are in situ fabricated on flexible mica sheets. Efficient photoresponse is obtained even after bending the device for 100 times, indicating 2D tellurium hexagonal nanoplates-based photodetectors on mica sheets have a great application potential in flexible and wearable optoelectronic devices. We believe the fundamental understanding of vdWE effect on the growth of 2D tellurium hexagonal nanoplate can pave the way toward leveraging vdWE as a useful channel to realize the 2D geometry of other nonlayered materials.

  8. Release of tellurium and cesium from UO2 in LWR fuel rods during irradiation

    International Nuclear Information System (INIS)

    Malen, K.A.

    1983-01-01

    In this paper the release of tellurium (Te-132) and cesium (Cs-134 and Cs-137) from UO 2 -fuel is analyzed. The basis for the analysis is the experimental results from the S176 series of experiments performed at Studsvik. It seems that the model developed earlier for release of iodine applies also to tellurium and cesium. This model assumes sweeping up of the species in question by moving grain boundaries and subsequent release through grain boundary porosity. An interesting extra feature is deposition of tellurium at temperatures in the range 1500-2000 K believed to be due to condensation. (author)

  9. Review of tellurium release rates from LWR fuel elements under accident conditions

    International Nuclear Information System (INIS)

    Lorenz, R.A.; Beahm, E.C.; Wichner, R.P.

    1983-01-01

    Although fission product tellurium presents a potentially significant radiohazard, its release and transport in source-term experiments is frequently overlooked because it does not possess a readily measurable, gamma emission; moreover, a recent study emphasized noble gas, iodine and cesium release from LWR fuel elements because of the large data base that exists for these materials. Some new tests show that in some cases tellurium may be held up in core material to a greater degree than previously assumed - an observation that prompts a careful reappraisal of the existing tellurium-release data and its chemical foundation

  10. Liquid-liquid extraction of arsenic, antimony, selenium and tellurium by zinc diethyldithiocarbamate

    International Nuclear Information System (INIS)

    Bajo, S.; Wyttenbach, A.

    1978-03-01

    The authors report the solvent extraction, oxidation, reduction, extraction in the presence of iron, and reextraction of arsenic, antimony, selenium and tellurium. These processes were studied using radioactive tracers. (G.T.H.)

  11. A Magnetic Resonance Force Microscopy Quantum Computer with Tellurium Donors in Silicon

    OpenAIRE

    Berman, G. P.; Doolen, G. D.; Tsifrinovich, V. I.

    2000-01-01

    We propose a magnetic resonance force microscopy (MRFM)-based nuclear spin quantum computer using tellurium impurities in silicon. This approach to quantum computing combines the well-developed silicon technology with expected advances in MRFM.

  12. Flame and flameless atomic-absorption determination of tellurium in geological materials

    Science.gov (United States)

    Chao, T.T.; Sanzolone, R.F.; Hubert, A.E.

    1978-01-01

    The sample is digested with a solution of hydrobromic acid and bromine and the excess of bromine is expelled. After dilution of the solution to approximately 3 M in hydrobromic acid, ascorbic acid is added to reduce iron(III) before extraction of tellurium into methyl isobutyl ketone (MIBK). An oxidizing air-acetylene flame is used to determine tellurium in the 0.1-20 ppm range. For samples containing 4-200 ppb of tellurium, a carbon-rod atomizer is used after the MIBK extract has been washed with 0.5 M hydrobromic acid to remove the residual iron. The flame procedure is useful for rapid preliminary monitoring, and the flameless procedure can determine tellurium at very low concentrations. ?? 1978.

  13. DETECTION OF THE SECOND r-PROCESS PEAK ELEMENT TELLURIUM IN METAL-POOR STARS ,

    International Nuclear Information System (INIS)

    Roederer, Ian U.; Lawler, James E.; Cowan, John J.; Beers, Timothy C.; Frebel, Anna; Ivans, Inese I.; Schatz, Hendrik; Sobeck, Jennifer S.; Sneden, Christopher

    2012-01-01

    Using near-ultraviolet spectra obtained with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope, we detect neutral tellurium in three metal-poor stars enriched by products of r-process nucleosynthesis, BD +17 3248, HD 108317, and HD 128279. Tellurium (Te, Z = 52) is found at the second r-process peak (A ≈ 130) associated with the N = 82 neutron shell closure, and it has not been detected previously in Galactic halo stars. The derived tellurium abundances match the scaled solar system r-process distribution within the uncertainties, confirming the predicted second peak r-process residuals. These results suggest that tellurium is predominantly produced in the main component of the r-process, along with the rare earth elements.

  14. Simple and effective method for nuclear tellurium isomers separation from antimony cyclotron targets

    International Nuclear Information System (INIS)

    Bondarevskij, S.I.; Eremin, V.V.

    1999-01-01

    Simple and effective method of generation of tellurium nuclear isomers from irradiated on cyclotron metallic antimony is suggested. Basically this method consists in consideration of the big difference in volatilities of metallic forms of antimony, tin and tellurium. Heating of the tin-antimony alloy at 1200 K permits to separate about 90 % of produced quantity of 121m Te and 123m Te (in this case impurity of antimony radionuclides is not more than 1 % on activity) [ru

  15. Nano-Structured Crystalline Te Films by Laser Gas-Phase Pyrolysis of Dimethyl Tellurium

    Czech Academy of Sciences Publication Activity Database

    Pola, Josef; Pokorná, Veronika; Boháček, Jaroslav; Bastl, Zdeněk; Ouchi, A.

    2004-01-01

    Roč. 71, č. 2 (2004), s. 739-746 ISSN 0165-2370 R&D Projects: GA AV ČR IAA4072107; GA MŠk OC 523.60 Institutional research plan: CEZ:AV0Z4072921; CEZ:AV0Z4032918; CEZ:AV0Z4040901 Keywords : dimethyl tellurium * tellurium films * laser Subject RIV: CA - Inorganic Chemistry Impact factor: 1.352, year: 2004

  16. Kinetics and mechanism of oxidation of tellurium (IV) by periodate in alkaline medium

    International Nuclear Information System (INIS)

    Srinivas, K.; Vani, P.; Dikshitulu, L.S.A.

    1995-01-01

    Detailed kinetic study of the oxidation of tellurium (IV) by periodate in alkaline medium has been carried out to compare the mechanisms of oxidation in the acid and alkaline media. It is interesting to note that the rate step involves a two-electron transfer from tellurium (IV) to periodate in alkaline medium although the kinetic pattern is somewhat different from that in the acid medium. 7 refs., 1 tab

  17. Methods of selenium and tellurium determination in geological and enviromental materials

    International Nuclear Information System (INIS)

    Nazarenko, I.I.; Kislova, I.V.

    1988-01-01

    Atomic-absorption and atomic-emission methods of tellurium determination in ores and products of their processing are described. Flame variant with extractional concentration permits to determine tellurium with the concentration up to 6x10 -6 %, the use of graphite cuvette after preliminary concentration-up to 1x10 -6 %. Atomic-emissional method permits to determine 3x10 -4 % Te from sample of 0.5 g

  18. Formation of defects in tellurium at various levels of gravitation

    International Nuclear Information System (INIS)

    Parfen'ev, R.V.; Farbshtejn, I.I.; Shul'pina, I.L.; Yakimov, S.V.; Shalimov, V.P.; Turchaninov, A.M.

    2002-01-01

    One investigated into effect of gravitation conditions during tellurium crystallization (ranging from microgravitation up to increased gravitation - 5g 0 ) on concentration of neutral (N D ) and electrically active (N AD ) acceptor structure defects in specimens grown both under complete remelting of parent ingot and under directed recrystallization of ingot with inoculation. N AD and N D concentrations and their distribution along the specimen depth were determined on the basis of analysis of electrical characteristics (conductivity and the Hall effect) measured along ingots within 1.6-300 K temperature range. The results were compared with characteristics of specimens grown following the similar program under normal conditions. At complete remelting under microgravitation one detected attributes of strong supercooling and spontaneous crystallization, as well as, of specimen resistance oscillation by its depth caused by N D modulation [ru

  19. Tellurium adsorption on tungsten and molybdenum field emitters

    International Nuclear Information System (INIS)

    Collins, R.A.; Kiwanga, C.A.

    1977-01-01

    Studies of the adsorption of tellurium onto tungsten and molybdenum field emitters are described and the results obtained are compared with those obtained in previous work on the adsorption of silicon and selenium. The adsorption of Te onto W was found to be much more uniform than in the case of Se. Although Te is metallic in many of its properties its adsorptive behavior on field emitters is found to be similar to that of selenium and these adsorptive properties are basically common to all semiconductors. The most evident property of these adsorbates is that the work function and emission current decrease simultaneously at coverages of less than half a monolayer and the work function subsequently increases. (B.D.)

  20. Strong nonlinear photonic responses from microbiologically synthesized tellurium nanocomposites

    Science.gov (United States)

    Liao, K.-S.; Wang, Jingyuan; Dias, S.; Dewald, J.; Alley, N.J.; Baesman, S.M.; Oremland, R.S.; Blau, W.J.; Curran, S.A.

    2010-01-01

    A new class of nanomaterials, namely microbiologically-formed nanorods composed of elemental tellurium [Te(0)] that forms unusual nanocomposites when combined with poly(m-phenylenevinylene-co-2,5-dioctoxy-phenylenevinylene) (PmPV) is described. These bio-nanocomposites exhibit excellent broadband optical limiting at 532 and 1064 nm. Nonlinear scattering, originating from the laser induced solvent bubbles and microplasmas, is responsible for this nonlinear behavior. The use of bacterially-formed Te(0) when combined with an organic chemical host (e.g., PmPV) is a new green method of nanoparticle syntheses. This opens the possibilities of using unique, biologically synthesized materials to advance future nanoelectronic and nanophotonic applications. ?? 2009 Elsevier B.V. All rights reserved.

  1. Evaluation of the Content of Antimony, Arsenic, Bismuth, Selenium, Tellurium and Their Inorganic Forms in Commercially Baby Foods.

    Science.gov (United States)

    Ruiz-de-Cenzano, M; Rochina-Marco, A; Cervera, M L; de la Guardia, M

    2017-12-01

    Baby foods, from the Spanish market and prepared from meat, fish, vegetables, cereals, legumes, and fruits, were analyzed to obtain the concentration of antimony (Sb), arsenic (As), bismuth (Bi), and tellurium (Te) as toxic elements and selenium (Se) as essential element. An analytical procedure was employed based on atomic fluorescence spectroscopy which allowed to obtain accurate data at low levels of concentration. Values of 14 commercial samples, expressed in nanograms per gram fresh weight, ranged for Sb 0.66-6.9, As 4.5-242, Te 1.35-2.94, Bi 2.18-4.79, and Se 5.4-109. Additionally, speciation studies were performed based on data from a non-chromatographic screening method. It was concluded that tellurium and bismuth were mainly present as inorganic forms and selenium as organic form, and antimony and arsenic species depend on the ingredients of each baby food. Risk assessment considerations were made by comparing dietary intake of the aforementioned elements through the consumption of one baby food portion a day and recommended or tolerable guideline values.

  2. Tellurium rings as electron pair donors in cluster compounds and coordination polymers; Tellurringe als Elektronenpaardonoren in Clusterverbindungen und Koordinationspolymeren

    Energy Technology Data Exchange (ETDEWEB)

    Guenther, Anja

    2011-11-08

    In this dissertation novel and already known molecular tellurium rings are presented in cluster compounds and quasi-one-dimensional coordination polymers. The cyclic, homonuclear units are always stabilized by coordination to electron-rich transition metal atoms, with the coordinating tellurium atoms acting as two-electron donors. As a synthesis route, the solid-state reaction in quartz glass vials was used uniformly. In addition to structural determination, the focus was on the characterization of the resulting compounds. For this purpose, resistance measurements were carried out on selected compounds, the magnetic behavior and the thermal degradation reactions were investigated and accompanying quantum chemical calculations were carried out. [German] In dieser Dissertation werden neuartige sowie bereits bekannte molekulare Tellurringe in Clusterverbindungen und quasi-eindimensionalen Koordinationspolymeren vorgestellt. Die Stabilisierung der zyklischen, homonuklearen Einheiten erfolgt dabei stets durch die Koordination an elektronenreiche Uebergangsmetallatome, wobei die koordinierenden Telluratome gegenueber diesen als Zwei-Elektronendonoren fungieren. Als Syntheseroute wurde dabei einheitlich auf die Festkoerperreaktion in Quarzglasampullen zurueckgegriffen. Neben der Strukturaufklaerung stand die Charakterisierung der erhaltenden Verbindungen im Fokus der Arbeit. Dazu wurden an ausgewaehlten Verbindungen Widerstandsmessungen durchgefuehrt, das magnetische Verhalten sowie die thermischen Abbaureaktionen untersucht und begleitende quantenchemische Rechnungen durchgefuehrt.

  3. Study On Analytical Methods Of Tellurium Content In Natriiodide (Na131I) Radiopharmaceutical Solution Produced In The Dalat Nuclear Reactor

    International Nuclear Information System (INIS)

    Vo Thi Cam Hoa; Duong Van Dong; Nguyen Thi Thu; Chu Van Khoa

    2007-01-01

    This report describes the practical methods for analyzing of Tellurium content in Na 131 I solution produced at the Dalat Nuclear Research Institute. We studied analytical methods to control Tellurium content in final Na 131 I solution product used in medical purposes by three methods such as: spot test, gamma spectrometric and spectrophotometric methods. These investigation results are shown that the spot test method is suitable for controlling Tellurium trace in the final product. This spot test can be determinate Tellurium trace less than 10 ppm and are used to quality control of Na 131 I solution using in medical application. (author)

  4. Agglomeration during wet milling of LAST (lead-antimony-silver-tellurium) powders

    International Nuclear Information System (INIS)

    Hall, B.D.; Case, E.D.; Ren, F.; Johnson, J.R.; Timm, E.J.

    2009-01-01

    LAST (lead-antimony-silver-tellurium) compounds comprise a family of semiconducting materials with good thermoelectric properties. However, the as-cast form of LAST exhibits large grain size and hence low mechanical strength. Powder processing can produce a fine powder particle size that enhances fracture strength, however the powders tend to agglomerate if the individual powder diameters are less than a few microns across. Dry milling or wet milling (hexane additions of 0 cm 3 and 10 cm 3 ) produced hard agglomerates roughly 40 μm in diameter while wet milling with hexane additions of 25 cm 3 , 30 cm 3 or 50 cm 3 resulted in small, porous agglomerates roughly 20 μm in diameter. Thus, by adjusting the amount of milling liquid used while milling LAST powders, one can shift from hard to soft agglomerates, where the literature shows that soft agglomerates are less harmful to the final, sintered product. Also, in agreement with the results from the literature on other materials, wet milling of LAST powders produced smaller particle sizes but required longer times to reach the grindability limit

  5. Near threshold electron impact ionization cross section for tellurium atoms

    International Nuclear Information System (INIS)

    Chipev, F.F.; Chernyshova, I.V.; Kontros, J.E.; Shpenik, O.B.

    2004-01-01

    Full text: Up today electron-impact ionization is one of the most intensively investigated processes in atomic and molecular physics [1]. These experiments however, are associated with difficulties: high temperatures and densities are required to produce atomic beams and monochromatic intensive electron beams. A crossed electron and atomic beams scattering geometry was employed to measure the ionization efficiency curve for tellurium atoms. Our electron spectrometer comprises two serially mounted hypocycloidal electron energy analyzers [2], the first being the monochromator and the second - the scattered electron analyzer. The whole spectrometer is immersed into the homogenous magnetic field. Great care was taken in selecting the value of the extracting potential at the electrode, mounted normally to the atomic beam direction. By careful choosing this potential as low as possible (∼1.4 V), its influence on the motion of the monochromatized electrons in the collision region was minimized and the full collection of the formed ions was reached. The atom beam was produced using a compact effusion source made of the stainless steel with a microchannel exit to minimise the angular divergency of the beam. The temperature of the microchannel plate was taken about 50 K higher than that of the metal vapour in the heated reservoir. This atomic beam source enabled to produce an atomic beam with the concentration of two orders of magnitude higher than that in the case of a standard effusion source. A typical value of the electron energy spread was 0.15 eV (FWHM) in the 0.1-15 eV energy range. The primary electron beam current was equal to 10 -7 A. Such values of electron energy spread and beam current for the primary electron beam passing through the collision chamber were chosen to provide identical conditions for carrying out all the measurements. The energy scale was calibrated with the accuracy of ± 0.05 eV. The measured ionization cross-section normalized to the results

  6. Chemical Process for Treatment of Tellurium and Chromium Liquid Waste from I-131 Radioisotope Production

    International Nuclear Information System (INIS)

    Zainus-Salimin; Gunandjar; Dedy-Harsono; Hendro; Sugeng-Purnomo; Mohammad-Faruq; Zulfakhri

    2000-01-01

    The I-131 radioisotope is used in nuclear medicine for diagnosis and therapy. The I-131 radioisotope is produced by wet distillation at Bandung Nuclear Research Center and generated about 4,875 Itr of liquid waste containing 2,532.8 ppm of tellurium and 1,451.8 ppm chromium at pH 1. Considering its negative impact to the environment caused by toxic behaviour of tellurium and chromium, it is necessary to treat chemically that's liquid waste. The research of chemical treatment of tellurium and chromium liquid waste from I-131 radioisotope production has been done. The steps of process are involved of neutralisation with NaOH, coagulation-flocculation process for step I using Ca(OH) 2 coagulant for precipitation of sulphate, sulphite, oxalic, chrome Cr 3+ , and coagulation-flocculation process for step II using BaCI 2 coagulant for precipitation of chrome Cr 6+ and tellurium from the supernatant of coagulation in step I. The best result of experiment was achieved at 0.0161 ppm of chromium concentration on the supernatant from coagulation-flocculation of step I using 3.5 g Ca(OH) 2 for 100 ml of liquid waste, and 0.95 ppm of tellurium concentration on the final supernatant from coagulation-flocculation by of step II using 0.7 g BaCI 2 for supernatant from coagulation of step I. (author)

  7. Equilibrium evaporation behavior of polonium and its homologue tellurium in liquid lead-bismuth eutectic

    International Nuclear Information System (INIS)

    Ohno, Shuji; Miyahara, Shinya; Kurata, Yuji; Katsura, Ryoei; Yoshida, Shigeru

    2006-01-01

    Experimental study using the transpiration method investigates equilibrium evaporation behavior of radionuclide polonium ( 210 Po) generated and accumulated in liquid lead-bismuth eutectic (LBE) cooled nuclear systems. The experiment consists of two series of tests: preliminary evaporation tests for homologue element tellurium (Te) in LBE, and evaporation tests for 210 Po-accumulated LBE in which test specimens are prepared by neutron irradiation. The evaporation tests of Te in LBE provide the suggestion that Te exists in a chemical form of PbTe as well as the information for confirming the validity of technique and conditions of Po test. From the evaporation tests of 210 Po in LBE, we obtain fundamental data and empirical equations such as 210 Po vapor concentration in the gas phase, 210 Po partial vapor pressure, thermodynamic activity coefficients, and gas-liquid equilibrium partition coefficient of 210 Po in LBE in the temperature range from 450 to 750degC. Additionally, radioactivity concentration of 210 Po and 210m Bi vapor in a cover gas region of a typical LBE-cooled nuclear system is specifically estimated based on the obtained experimental results, and the importance of 210 Po evaporation behavior is quantitatively demonstrated. (author)

  8. Determination of tellurium in gallium by alternating current stripping voltammetry with a mercury/graphite electrode

    International Nuclear Information System (INIS)

    Berengard, I.B.; Kaplan, B. Ya.

    1986-01-01

    The analytical signal in ac stripping coltammetry (ACSV) with mercury indicator electrodes depends on the weight of the electrolytically collected analyte at the electrode surface, the depth of the collection layer being equal to the effective diffusion-layer thickness. Replacement of the static mercury drop electrode (SMDE) by the mercury/graphite electrode (MGE) is of practical interest in that the analyte detection limit can be lowered by decreasing the colume of the telluriumcontaining polarographed solution; in addition, plant laboratories find it difficult to control the SDME uniformity. The work in this article was done on a PU-1 universal polarograph in a square-wave vol tage component mode using the three-electrode cell shown. The rotating mercury/graphite electrode is found by the authors to be superior to the static mercury drop electrode in that it can lower the detection limit for tellurium in gallium to 5.10 /SUP -7percent/ , due to the smaller volume of the polarographed solution

  9. Enhanced Flexural Strength of Tellurium Nanowires/epoxy Composites with the Reinforcement Effect of Nanowires

    Science.gov (United States)

    Balguri, Praveen Kumar; Harris Samuel, D. G.; Aditya, D. B.; Vijaya Bhaskar, S.; Thumu, Udayabhaskararao

    2018-02-01

    Investigating the mechanical properties of polymer nanocomposite materials has been greatly increased in the last decade. In particular, flexural strength plays a major role in resisting bending and shear loads of a composite material. Here, one dimensional (1D) tellurium nanowires (TeNWs) reinforced epoxy composites have been prepared and the flexural properties of resulted TeNWs/epoxy nanocomposites are studied. The diameter and length of the TeNWs used to make TeNWs/epoxy nanocomposites are 21±2.5 nm and 697±87 nm, respectively. Plain and TeNWs/epoxy nanocomposites are characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). Furthermore, significant enhancement in the flexural strength of TeNWs/epoxy nanocomposite is observed in comparison to plain epoxy composite, i.e. flexural strength is increased by 65% with the addition of very little amount of TeNWs content (0.05 wt.%) to epoxy polymer. Structural details of plain and TeNWs/epoxy at micrometer scale were examined by scanning electron microscopy (SEM). We believe that our results provide a new type of semiconductor nanowires based high strength epoxy polymer nanocomposites.

  10. Gamma Radiation Dosimetry Using Tellurium Dioxide Thin Film Structures

    Directory of Open Access Journals (Sweden)

    Olga Korostynska

    2002-08-01

    Full Text Available Thin films of Tellurium dioxide (TeO2 were investigated for γ-radiation dosimetry purposes. Samples were fabricated using thin film vapour deposition technique. Thin films of TeO2 were exposed to a 60Co γ-radiation source at a dose rate of 6 Gy/min at room temperature. Absorption spectra for TeO2 films were recorded and the values of the optical band gap and energies of the localized states for as-deposited and γ-irradiated samples were calculated. It was found that the optical band gap values were decreased as the radiation dose was increased. Samples with electrical contacts having a planar structure showed a linear increase in current values with the increase in radiation dose up to a certain dose level. The observed changes in both the optical and the electrical properties suggest that TeO2 thin film may be considered as an effective material for room temperature real time γ-radiation dosimetry.

  11. Enhancement of Au-Ag-Te contents in tellurium-bearing ore minerals via bioleaching

    Science.gov (United States)

    Choi, Nag-Choul; Cho, Kang Hee; Kim, Bong Ju; Lee, Soonjae; Park, Cheon Young

    2018-03-01

    The purpose of this study was to enhance the content of valuable metals, such as Au, Ag, and Te, in tellurium-bearing minerals via bioleaching. The ore samples composed of invisible Au and Au paragenesis minerals (such as pyrite, chalcopyrite, sphalerite and galena) in combination with tellurium-bearing minerals (hessite, sylvanite and Tellurobismuthite) were studied. Indigenous microbes from mine drainage were isolated and identified as Acidithiobacillus ferrooxidans, which were used in bioleaching after adaption to copper. The effect of the microbial adaption on the bioleaching performance was then compared with the results produced by the non-adaptive process. The microbial adaption enhanced the Au-Ag-Te contents in biological leaching of tellurium-bearing ore minerals. This suggests that bioleaching with adapted microbes can be used both as a pretreatment and in the main recovery processes of valuable metals.

  12. Selective floatation-spectrophotometric determination of tellurium (4) with papaverine and butyl rhodamine B

    International Nuclear Information System (INIS)

    Skripchuk, V.G.

    1981-01-01

    It is shown, that papaverine reacts with a bromide complex of tellurium (4) to form a compound readily floated by toluene. The floatation is carried out from an aqueous solution, 5.2 M in H 2 SO 4 , 0.2 M in KBr and 5.4x10 -3 M in papaverine. The absorbance is a function of tellurium (4) concentration over a range of 5-100 μg Te/5 ml. Such a highly sensitive reagent as butylrhodamine B can be effectively substituted for papaverine. The floatation results in better selectivity. The method makes it possible to determine tellurium in blister, anodic and cathodic copper without matrix preseparation [ru

  13. The defects produced by electron irradiation in tellurium-doped germanium

    International Nuclear Information System (INIS)

    Fukuoka, Noboru; Saito, Haruo

    1989-01-01

    The nature of the irradiation induced defects in a germanium single crystal doped with tellurium was studied by DLTS and electrical measurements. The E c -0.21 eV level produced by irradiation with 1.5 MeV electrons was studied using the DLTS technique. It was found that the defect associated with this level is a divacancy. The E-center like defect (group V impurity-vacancy pair) introduces the E c -0.20 eV level in samples doped with a group V impurity. The level introduced by a tellurium (group VI impurity)-vacancy pair is deeper. The E c -0.16 eV level was generated by annealing at 430 K. A tellurium-vacancies complex is proposed as the defect associated with this level. (author)

  14. Determination of half life of tellurium isotopes: a proposal for the teaching of nuclear physics

    International Nuclear Information System (INIS)

    Ruivo, Julio C.; Zamboni, Cibele B.; Batista, Wagner F.

    2013-01-01

    This work aimed at the development of courseware for teaching nuclear physics, using experimental data of half-life measurement (T1/2) of Tellurium isotopes (A=127 and 131). The choice of Tellurium was established for providing nuclear data, which are fundamental in related investigations of nuclear structure and its use in various areas such as geochemistry, chemical and pharmaceutical industries, astrophysics etc. For evaluation of the proposal performance, the material was made available, bringing a lot of information about nuclear safety, production and storage of radioactive material and concepts of radioactive decay, subatomic particles, emission of gamma radiation, half-life, etc.

  15. Determination of half life of tellurium isotopes: a proposal for the teaching of nuclear physics

    Energy Technology Data Exchange (ETDEWEB)

    Ruivo, Julio C.; Zamboni, Cibele B.; Batista, Wagner F., E-mail: julio.ruivo.costa@usp.br, E-mail: czamboni@ipen.br, E-mail: fisicawagner@gmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    This work aimed at the development of courseware for teaching nuclear physics, using experimental data of half-life measurement (T1/2) of Tellurium isotopes (A=127 and 131). The choice of Tellurium was established for providing nuclear data, which are fundamental in related investigations of nuclear structure and its use in various areas such as geochemistry, chemical and pharmaceutical industries, astrophysics etc. For evaluation of the proposal performance, the material was made available, bringing a lot of information about nuclear safety, production and storage of radioactive material and concepts of radioactive decay, subatomic particles, emission of gamma radiation, half-life, etc.

  16. Electrochemical and antimicrobial activity of tellurium oxide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Pramod K. [Department of Applied Sciences and Humanities, Jamia Millia Islamia, New Delhi 110067 (India); Special Centre for Nanosciences, Jawaharlal Nehru University, New Delhi 110067 (India); Sharma, Prem Prakash; Sharma, Anshu [Special Centre for Nanosciences, Jawaharlal Nehru University, New Delhi 110067 (India); Khan, Zishan H., E-mail: zishan_hk@yahoo.co.in [Department of Applied Sciences and Humanities, Jamia Millia Islamia, New Delhi 110067 (India); Solanki, Pratima R., E-mail: pratimarsolanki@gmail.com [Special Centre for Nanosciences, Jawaharlal Nehru University, New Delhi 110067 (India)

    2016-09-15

    Highlights: • TeO{sub 2} NPs synthesized without using any catalyst by chemical vapour deposition method. • The growth temperature was 410 °C with continuous flow of O{sub 2.} • TeO{sub 2} NPs have anti-bacterial activity against E. coli, K. pneumoniae and S. aureus while enhances the growth of S. pyogenes. • TeO{sub 2} shows maximum redox current at pH 7 for phosphate buffer solution. - Abstract: Thin film of tellurium oxide (TeO{sub 2}) has been synthesized by chemical vapour deposition method onto indium tin oxide (ITO) coated glass substrate without using any catalyst. XRD pattern of TeO{sub 2} thin film suggests that the structure of TeO{sub 2} changes from amorphous to crystalline (paratellurite) on dispersing into deionized water. Zeta potential measurement reveals a positive surface potential of 28.8 mV. TEM images shows spherical shaped TeO{sub 2} nanoparticles having average particle size of 65 nm. Electrochemical studies of TeO{sub 2}/ITO electrode exhibit improved electron transfer owing to its inherent electron transfer property at pH 7.0 of phosphate buffer. Antimicrobial activity of TeO{sub 2} has been studied for gram-positive (Staphylococcus aureus and Streptococcus pyogenes) and gram negative (Escherichia coli and Klebsiella pneumoniae) bacterial and fungal strains (Aspergillus nizer and Candida albicans). These studies suggest that the TeO{sub 2} NPs inhibit the growth of E. coli, K. pneumoniae and S. aureus bacteria, whereas the same particles enhance the growth of S. pyogenes bacteria.

  17. Magnetic resonance force microscopy quantum computer with tellurium donors in silicon.

    Science.gov (United States)

    Berman, G P; Doolen, G D; Hammel, P C; Tsifrinovich, V I

    2001-03-26

    We propose a magnetic resonance force microscopy (MRFM)-based nuclear spin quantum computer using tellurium impurities in silicon. This approach to quantum computing combines well-developed silicon technology and expected advances in MRFM. Our proposal does not use electrostatic gates to realize quantum logic operations.

  18. Magnetic Resonance Force Microscopy Quantum Computer with Tellurium Donors in Silicon

    International Nuclear Information System (INIS)

    Berman, G. P.; Doolen, G. D.; Hammel, P. C.; Tsifrinovich, V. I.

    2001-01-01

    We propose a magnetic resonance force microscopy (MRFM)-based nuclear spin quantum computer using tellurium impurities in silicon. This approach to quantum computing combines well-developed silicon technology and expected advances in MRFM. Our proposal does not use electrostatic gates to realize quantum logic operations

  19. Electric field fluctuations in liquid tellurium alloys a hint to bond character

    NARCIS (Netherlands)

    Paulick, C.A.; Brinkmann, R.; Elwenspoek, Michael Curt; von Hartrott, M.; Kiehl, M.; Maxim, P.; Quitmann, D.

    1985-01-01

    Atomic scale electric field fluctuations in liquid tellurium alloys are detected as they induce nuclear spin relaxation rate RQ in noble gas impurity atoms, via quadrupolar interaction. Results for Xe in liquid Ag, Ga, In, Tl, Ge, Sn---Te alloys are discussed, assuming that bonding in these alloys

  20. Subnanosecond pulse measurements of 10.6 μm radiation with tellurium

    NARCIS (Netherlands)

    Haselhoff, E.H.; Bonnie, R.J.M.; Ernst, G.J.; Witteman, W.J.

    1988-01-01

    Subnanosecond infrared pulses have been measured by noncollinear secondharmonic generation in tellurium. The method is very practical because due to the high refractive index the fine tuning of the phase matching is easily obtained by rotating the crystal around the optic axis.

  1. Dismantling and chemical characterization of spent Peltier thermoelectric devices for antimony, bismuth and tellurium recovery.

    Science.gov (United States)

    Balva, Maxime; Legeai, Sophie; Garoux, Laetitia; Leclerc, Nathalie; Meux, Eric

    2017-04-01

    Major uses of thermoelectricity concern refrigeration purposes, using Peltier devices, mainly composed of antimony, bismuth and tellurium. Antimony was identified as a critical raw material by EU and resources of bismuth and tellurium are not inexhaustible, so it is necessary to imagine the recycling of thermoelectric devices. That for, a complete characterization is needed, which is the aim of this work. Peltier devices were manually dismantled in three parts: the thermoelectric legs, the alumina plates on which remain the electrical contacts and the silicone paste used to connect the plates. The characterization was performed using five Peltier devices. It includes mass balances of the components, X-ray diffraction analysis of the thermoelectric legs and elemental analysis of each part of the device. It appears that alumina represents 45% of a Peltier device in weight. The electrical contacts are mainly composed of copper and tin, and the thermoelectric legs of bismuth, tellurium and antimony. Thermoelectric legs appear to be Se-doped Bi 2 Te 3 and (Bi 0,5 Sb 1,5 )Te 3 for n type and p type semiconductors, respectively. This work shows that Peltier devices can be considered as a copper ore and that thermoelectric legs contain high amounts of bismuth, tellurium and antimony compared to their traditional resources.

  2. Determination of spins and radioactive widths of tellurium nuclear levels with capturre gamma rays

    International Nuclear Information System (INIS)

    Bianchini, F.G.

    1973-01-01

    Spins and levels widths of the tellurium, mainly 128 Te and 130 Te, were determinated by gamma spectroscopy. Measurements of inelastic and elastic scattering, angular distribution and scattering temperature dependence, were still made. Energy levels of this isotopes, were also determinated [pt

  3. Simultaneous determination of selenium and tellurium in native sulfur by atomic absorption spectrophotometry

    International Nuclear Information System (INIS)

    Arikawa, Yoshiko; Hirai, Shoji; Ozawa, Takejiro.

    1979-01-01

    A method for the determination of selenium and tellurium in native sulfur has been investigated by means of atomic absorption spectrophotometry. Native sulfur collected from around fumarole or volcanic crater is ground down into powder, a portion of which weighing 1 g is subjected to analysis. A 2.6% (w/v) sodium hydroxide solution is added by 10 ml to the sample in a teflon beaker, and the mixture is then heated on a hot plate. Sulfur is decomposed and dissolved in the form of disulfide and thiosulfate. A 30% hydrogenperoxide solution is added by 10 ml to oxidize them to sulfate. At the same time selenium and tellurium contained in the sulfur sample are also thought to be oxidized to Se(VI) and Te(VI) states. The solution is neutralized with hydrochloric acid and diluted with distilled water to 100 ml. The sample solution thus prepared is sprayed into the air-acetylene flame of the atomic absorption spectrophotometer. The absorbance is measured at 195.9 nm for selenium and 214.2 nm for tellurium. Calibration curve is prepared by measuring the absorbances of the solutions prepared as follows. One gram portions of pure sulfur (99.9999%) are decomposed as for the samples. After neutralization, standard solutions containing each same amount of selenium and tellurium (0 -- 1000 μg) are added to the sulfur solution and then diluted with water to 100 ml. The standard deviations were estimated to be 50.4 ppm for selenium at 756 ppm and 16.6 ppm for tellurium at 587 ppm. For the check of the reliability of the method, results were compared with those obtained by neutron activation analysis. Results obtained by both methods showed good agreement. (author)

  4. Large-scale synthesis of Tellurium nanostructures via galvanic displacement of metals

    Science.gov (United States)

    Kok, Kuan-Ying; Choo, Thye-Foo; Ubaidah Saidin, Nur; Rahman, Che Zuraini Che Ab

    2018-01-01

    Tellurium (Te) is an attractive semiconductor material for a wide range of applications in various functional devices including, radiation dosimeters, optical storage materials, thermoelectric or piezoelectric generators. In this work, large scale synthesis of tellurium (Te) nanostructures have been successfully carried out in different concentrations of aqueous solutions containing TeO2 and NaOH, by galvanic displacements of Zn and Al which served as the sacrificial materials. Galvanic displacement process is cost-effective and it requires no template or surfactant for the synthesis of nanostructures. By varying the concentrations of TeO2 and NaOH, etching temperatures and etching times, Te nanostructures of various forms of nanostructures were successfully obtained, ranging from one-dimensional needles and rod-like structures to more complex hierarchical structures. Microscopy examinations on the nanostructures obtained have shown that both the diameters and lengths of the Te nanostructures increased with increasing etching temperature and etching time.

  5. Equilibrium state of delta-phase with tellurium in the Sb-Bi-Te system

    International Nuclear Information System (INIS)

    Gajgukova, V.S.; Dudkin, L.D.; Erofeev, R.S.; Musaelyan, V.V.; Nadzhip, A.Eh.; Sokolov, O.B.

    1978-01-01

    A research has been carried out with a view to establish the equilibrium state of delta-phase of the composition (Sbsub(1-x)Bisub(x)) 2 Te 3 with tellurium, depending on x and temperature. The Hall effect, the thermoelectromotive force, and the electric conductivity of the samples of Sb-Bi-Te alloys have been measured, the samples being annealed at various temperatures (550 to 250 deg C). The measurement results have shown that as the Bi 2 Te 3 content in the solid solutions increases and temperature decreases, the delta-phase-Te boundary monotonously approaches the stoichiometric composition. Using the research carrid out as the basis, the general character of the equilibrium delta-phase with tellurium boundary has been rendered more precise in Sb-Bi-Te system, depending on the temperature and Bi content (up to 25 at.%)

  6. GALVANIC MAGNETIC PROPERTIES OF BISMUTH THIN FILMS DOPED WITH TELLURIUM MADE BY THERMAL VACUUM EVAPORATION

    Directory of Open Access Journals (Sweden)

    V. A. Komarov

    2013-01-01

    Full Text Available The influence of n-type impurity of tellurium (concentration range from 0.005 atomic % Te to 0.15 atomic % Te on galvanic magnetic properties (resistivity, magnetic resistance and Hall constant of Bi thin films with various thicknesses was studied. The properties were measured in temperature range from 77 to 300 K. It was established that the classical size effect in the films is significant and decreases with higher concentration of Te impurity. The analysis of experimental results was carried out in approximation of the law of Jones-Schoenberg dispersion for Bi films doped with tellurium. Calculation of concentration and mobility of charge carriers in the studied films was made.

  7. The dependence of the texture of tellurium thin films on vacuum deposition angle

    International Nuclear Information System (INIS)

    Cocks, F.H.; Peterson, M.J.; Jones, P.L.

    1980-01-01

    Vacuum-deposited tellurium thin films can show substantially different surface morphologies depending on the angle with which the vapor stream impinges on the substrate surface. These tellurium thin films have a tendency to grow as acicular crystallites but as the deposition angle is increased so that the vapor stream becomes tangential to the substrate surface the spacing between crystallites increases and approaches, at stream angles of approximately 80 0 from the normal, dimensions roughly once or twice the average wavelength of visible light. Such films may have application in solar energy collector systems because of the high absorptivity of sunlight shown by such films. Mechanisms which describe the tendency for crystallite spacing to increase with increasing angle are discussed. (Auth.)

  8. Acousto-optic measurements of ultrasound attenuation in tellurium dioxide crystal

    International Nuclear Information System (INIS)

    Voloshinov, V. B.; Lemyaskina, E. A.

    1996-01-01

    The paper is devoted to experimental investigation of ultrasound propagation in tellurium dioxide monocrystal. In particular, attenuation of slow shear acoustic modes in the crystal was measured. The measurements were performed by acousto-optic methods using probing of acoustic column by a laser beam. The paper describes measurements of acoustic attenuation coefficient for slow shear ultrasonic waves propagating at an angle =4.5 O with respect to the (110) direction in the (110) plane. The investigation was made at acoustic frequency f = 100 MHz with pulsed acoustic waves and with an optical beam of a He-Ne laser. It is found that the attenuation coefficient is α = 0.57 cm -1 ± 15 %. The attenuation at acoustic frequencies f ≥ 100 MHz influences performance characteristics of acousto-optical devices based on tellurium dioxide. As proved, spectral resolution of a quasicollinear acoustooptic filter decreases by a factor of 2 compared to a case of the attenuation absence. (authors)

  9. Evaluated phase diagrams of binary metal-tellurium systems of the D-block transition elements

    International Nuclear Information System (INIS)

    Chattopadhyay, G.; Bharadwaj, S.R.

    1989-01-01

    The binary phase diagrams of metal-tellurium systems for twenty seven d-block transition elements have been critically evaluated. Complete phase diagrams are presented for the elements, chromium, manganese, iron, cobalt, nickel, copper, molybdenum, palladium, silver, lanthanum, platinum and gold, whereas, for scandium, titanium, vanadium, yttrium, zirconium, niobium, technitium, ruthenium, rhodium, hafnium, tantalum, tungsten , rhenium, osmium and iridium, the phase diagrams are incomplete and tentative. (author). 20 refs., 27 tabs., 27 figs

  10. The effect of hydrostatic pressure on the anomalous sign reversal of the Hall coefficient in tellurium

    International Nuclear Information System (INIS)

    Balynas, V.; Dobrovolskis, Z.; Krotkus, A.; Hoerstel, W.

    1981-01-01

    In order to obtain information about the pressure behaviour of the higher lying second conduction band the dependences of the Hall coefficient of single crystalline tellurium on temperature (300 to 500 K) have been measured at atmospheric pressure and hydrostatic pressures of 500 and 800 MPa. The separation between the two conduction bands in Te decreases with increasing pressure. The anomalous sign reversal of the Hall coefficient can be well explained by a double-conduction band model

  11. Electrochemical characterization of the underpotential deposition of tellurium on Au electrode

    International Nuclear Information System (INIS)

    Zhu, W.; Yang, J.Y.; Zhou, D.X.; Bao, S.Q.; Fan, X.A.; Duan, X.K.

    2007-01-01

    Electrochemical characterization of the underpotential deposition (UPD) of tellurium on Au substrate has been performed in this paper. The mechanism of Te deposition and its voltammetry dependence on the Te ion concentration were studied, and it suggests that variations in the metal ion concentration may affect the UPD process kinetics. The effect of tellurium adsorbates on UPD behavior of Te has also been investigated. The results show that the tellurium adsorbates could be irreversibly adsorbed upon the Au substrate surface under the open-circuit conditions. Subsequent removal of the Te adsorbates was also proved to be very difficult within the Au double-layer region, and a standard electrochemical cleaning procedure is necessary to remove the Te adsorbates completely. When the potential was cycled into the Au oxidation region, a substantial loss of Te adsobates was observed, which occurs simultaneously with the Au oxidation features. Scan rate dependent cyclic voltammetry experiments reveal that the peak current in the Te UPD peak is not a linear function of the scan rate, ν, but of a 2/3 power of the scan rate, ν 2/3 . It is in good consistent with a two-dimension nucleation and growth mechanism

  12. Iodine-129 in thyroids and tellurium isotopes in meteorites by neutron activation analysis

    International Nuclear Information System (INIS)

    Ballad, R.V.

    1978-06-01

    A combination of neutron activation and mass spectrometry has been used to determine the concentration of fissiogenic 129 I and the value of the 129 I/ 127 I ratio in thyroids of man, cow, and deer from Missouri. Deer thyroids show an average value of 129 I/ 127 I = 1.8 x 10 -8 and an average concentration of 3 x 10 -3 pCi 129 I per gram of thyroid (wet weight). Thyroids of cows and humans show successively lower values for the 129 I/ 127 I ratio and the 129 I content because their diets dilute fission-produced 129 I in the natural iodine cycle with mineral iodine. The results of analyses on a few thyroids from other geographic areas are also reported. The isotopic compositions of tellurium, krypton, and xenon were determined in acid-resistant residues of the Allende meteorite. Neutron activation and γ-counting were used to determine the relative abundances of six tellurium isotopes, and mass spectrometry was used to determine the isotopic compositions of krypton and xenon in aliquots of the same residues. Nucleogenetic anomalies were observed in the isotopic compositions of these three elements. The presence of isotopically distinct components of tellurium, krypton, and xenon in these residues provides strong support for the suggestion that our solar system formed directly from the debris of a supernova

  13. Hydrogen-assisted post-growth substitution of tellurium into molybdenum disulfide monolayers with tunable compositions

    Science.gov (United States)

    Yin, Guoli; Zhu, Dancheng; Lv, Danhui; Hashemi, Arsalan; Fei, Zhen; Lin, Fang; Krasheninnikov, Arkady V.; Zhang, Ze; Komsa, Hannu-Pekka; Jin, Chuanhong

    2018-04-01

    Herein we report the successful doping of tellurium (Te) into molybdenum disulfide (MoS2) monolayers to form MoS2x Te2(1-x) alloy with variable compositions via a hydrogen-assisted post-growth chemical vapor deposition process. It is confirmed that H2 plays an indispensable role in the Te substitution into as-grown MoS2 monolayers. Atomic-resolution transmission electron microscopy allows us to determine the lattice sites and the concentration of introduced Te atoms. At a relatively low concentration, tellurium is only substituted in the sulfur sublattice to form monolayer MoS2(1-x)Te2x alloy, while with increasing Te concentration (up to ˜27.6% achieved in this study), local regions with enriched tellurium, large structural distortions, and obvious sulfur deficiency are observed. Statistical analysis of the Te distribution indicates the random substitution. Density functional theory calculations are used to investigate the stability of the alloy structures and their electronic properties. Comparison with experimental results indicate that the samples are unstrained and the Te atoms are predominantly substituted in the top S sublattice. Importantly, such ultimately thin Janus structure of MoS2(1-x)Te2x exhibits properties that are distinct from their constituents. We believe our results will inspire further exploration of the versatile properties of asymmetric 2D TMD alloys.

  14. The characterisation of vapour-phase alkali metal-tellurium-oxygen species

    International Nuclear Information System (INIS)

    Gomme, R.A.; Ogden, J.S.; Bowsher, B.R.

    1986-10-01

    Detailed assessments of hypothetical severe accidents in light water reactors require the identification of the chemical forms of the radionuclides in order to determine their transport characteristics. Caesium and tellurium are important volatile fission products in accident scenarios. This report describes detailed studies to characterise the chemical species that vaporise from heated mixtures of various alkali metal-tellurium-oxygen systems. The molecular species were characterised by a combination of quadrupole mass spectrometry and matrix isolation-infrared spectroscopy undertaken in conjunction with experiments involving oxygen-18 substitution. The resulting spectra were interpreted in terms of a vapour-phase molecule with the stoichiometry M 2 TeO 3 (M = K,Rb,Cs) for M/Te molecular ratios of ∼ 2, and polymeric species for ratios < 2. This work has demonstrated the stability of caesium tellurite. The formation of this relatively low-volatility, water-soluble species could significantly modify the transport and release of caesium and tellurium. The data presented in this report should allow more comprehensive thermodynamic calculations to be undertaken that assist in the quantification of fission product behaviour during severe reactor accidents. (author)

  15. Influence of ion beam irradiation induced defects on the structural, optical and electrical properties of tellurium nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Narinder [Department of Physics, Chaudhary Devi Lal University, Sirsa, 125055 (India); Department of Physics, Haryana College of Technology & Management, Kaithal, 136027 (India); Kumar, Rajesh [Department of Physics, RN College of Engineering & Technology, Madlauda, 132104 (India); Kumar, Sushil, E-mail: sushil_phys@rediffmail.com [Department of Physics, Chaudhary Devi Lal University, Sirsa, 125055 (India); Chakarvarti, S.K. [Research and Development, Manav Rachana International University, Faridabad, 121001 (India)

    2016-11-01

    In this study, tellurium nanowires were electrodeposited into the polymer membranes from aqueous acidic bath containing HTeO{sub 2}{sup +} ions. The field emission scanning electron microscopy (FESEM) images confirmed the formation of uniform and straight nanowires. The influence of 110 MeV Ni{sup 8+} ion irradiation induced defects on the structural, optical and electrical properties of as–deposited tellurium nanowires were examined using X-ray diffraction (XRD), UV–visible absorption spectroscopy and current–voltage (I–V) measurements. The XRD data depicted the hexagonal phase of tellurium nanowires and further revealed a variation in the intensity of diffraction peaks of ion irradiated nanowires. Williamson–Hall (WH) analysis is used for convoluting the size and microstrain contributions to the width of diffraction peaks. Tellurium nanowires exhibited a distinct absorbance band in the visible region at 686 nm, while this was absent in bulk tellurium. Electrical properties of nanowires are explored on the basis of I–V curves, which revealed a significant increase in the electrical conductivity of irradiated nanowires. A possible mechanism for the enhanced electrical conductivity is the increase in carrier concentration due to thermally excited defects. The defects produced by ion irradiation play a vital role in modifying the properties of semiconducting nanowires. - Highlights: • 110 MeV Ni{sup 8+} ion beam induced changes in tellurium nanowires have been examined. • Nanowires were prepared using template electrodeposition method. • Irradiation improved the electrical conductivity of tellurium nanowires. • Mechanism for enhanced electrical conductivity of irradiated nanowires was discussed.

  16. Chemical processes for the extreme enrichment of tellurium into marine ferromanganese oxides

    Science.gov (United States)

    Kashiwabara, Teruhiko; Oishi, Yasuko; Sakaguchi, Aya; Sugiyama, Toshiki; Usui, Akira; Takahashi, Yoshio

    2014-04-01

    Tellurium, an element of growing economic importance, is extremely enriched in marine ferromanganese oxides. We investigated the mechanism of this enrichment using a combination of spectroscopic analysis and adsorption/coprecipitation experiments. X-ray Absorption Near-Edge Structure (XANES) analysis showed that in adsorption/coprecipitation systems, Te(IV) was oxidized on δ-MnO2 and not oxidized on ferrihydrite. Extended X-ray Absorption Fine Structure (EXAFS) analysis showed that both Te(IV) and Te(VI) were adsorbed on the surface of δ-MnO2 and ferrihydrite via formation of inner-sphere complexes. In addition, Te(VI) can be structurally incorporated into the linkage of Fe octahedra through a coprecipitation process because of its molecular geometry that is similar to the Fe octahedron. The largest distribution coefficient obtained in the adsorption/coprecipitation experiments was for the Te(VI)/ferrihydrite coprecipitation system, and it was comparable to those calculated from the distribution between natural ferromanganese oxides and seawater. Our XAFS and micro-focused X-ray fluorescence (μ-XRF) mapping of natural ferromanganese oxides showed that Te was structurally incorporated as Te(VI) in Fe (oxyhydr)oxide phases. We conclude that the main process for the enrichment of Te in ferromanganese oxides is structural incorporation of Te(VI) into Fe (oxyhydr)oxide phases through coprecipitation. This mechanism can explain the unique degree of enrichment of Te compared with other oxyanions, which are mainly enriched via adsorption on the surface of the solid structures. In particular, the great contrast in the distributions of Te and Se is caused by their oxidized species: (i) the similar geometry of the Te(VI) molecule to Fe octahedron, and (ii) quite soluble nature of Se(VI). Coexisting Mn oxide phases may promote structural incorporation of Te(VI) by oxidation of Te(IV), although the surface oxidation itself may not work as the critical enrichment process as

  17. On the study of proton-irradiated Tellurium targets relevant for production of medical radioisotopes 123I and 124I

    International Nuclear Information System (INIS)

    Imam Kambali; Hari Suryanto; Daya Agung Sarwono; Cahyana Amiruddin

    2014-01-01

    The energy loss distribution and range of energetic proton beams in tellurium (Te) target have been simulated using the Stopping and Range of Ion in Matter (SRIM 2013) codes. The calculated data of the proton's range were then used to determine the optimum thickness of Te targets for future production of 123 I and 124 I from 123 Te(p,n) 123 I, 124 Te(p,n) 124 I and 124 Te(p,2n) 123 I nuclear reactions using the BATAN's Cs-30 cyclotron. It was found that for an incidence angle of 0° with respect to the target normal, the optimum thickness of 123 Te and 124 Te targets for 123 I production should be 644 µm and 1.8 mm respectively, whereas a 649 µm thick 124 Te target would be Required for 124 I production. In addition, the thickness should be decreased with increasing incidence angle. The EOB yield could theoretically reach up to 13.62 Ci of 123 I at proton energy of 22 Me V and beam current of 30 µA if the 124 Te is irradiated over a period of 3 hours. The theoretical EOB yield is comparable to the experimental data with accuracy within 10%. (author)

  18. First example of a high-level correlated calculation of the indirect spin-spin coupling constants involving tellurium

    DEFF Research Database (Denmark)

    Rusakov, Yury Yu; Krivdin, Leonid B.; Østerstrøm, Freja From

    2013-01-01

    This paper documents a very first example of a high-level correlated calculation of spin-spin coupling constants involving tellurium taking into account relativistic effects, vibrational corrections and solvent effects for the medium sized organotellurium molecules. The 125Te-1H spin-spin coupling...... constants of tellurophene and divinyl telluride were calculated at the SOPPA and DFT levels in a good agreement with experiment. A new full-electron basis set av3z-J for tellurium derived from the "relativistic" Dyall's basis set, dyall.av3z, and specifically optimized for the correlated calculations...... of spin-spin coupling constants involving tellurium, was developed. The SOPPA methods show much better performance as compared to 15 those of DFT, if relativistic effects calculated within the ZORA scheme are taken into account. Vibrational and solvent corrections are next to negligible, while...

  19. Site-specific nucleation and controlled growth of a vertical tellurium nanowire array for high performance field emitters

    International Nuclear Information System (INIS)

    Safdar, Muhammad; Zhan Xueying; Mirza, Misbah; Wang Zhenxing; Sun Lianfeng; He Jun; Niu Mutong; Zhang Jinping; Zhao Qing

    2013-01-01

    We report the controlled growth of highly ordered and well aligned one-dimensional tellurium nanostructure arrays via a one-step catalyst-free physical vapor deposition method. The density, size and fine structures of tellurium nanowires are systematically studied and optimized. Field emission measurement was performed to display notable dependence on nanostructure morphologies. The ordered nanowire array based field emitter has a turn-on field as low as 3.27 V μm −1 and a higher field enhancement factor of 3270. Our finding offers the possibility of controlling the growth of tellurium nanowire arrays and opens up new means for their potential applications in electronic devices and displays. (paper)

  20. Continuous removal and recovery of tellurium in an upflow anaerobic granular sludge bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Mal, Joyabrata, E-mail: joyabrata2006@gmail.com [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Nancharaiah, Yarlagadda V. [Biofouling and Biofilm Processes Section, Water and Steam Chemistry Division, Bhabha Atomic Research Centre, Kalpakkam, 603102, Tamil Nadu (India); Homi Bhabha National Institute, Anushakti Nagar Complex, Mumbai 400094 (India); Maheshwari, Neeraj [CNRS UMR 7338, BMBI University de Technologie Compiegne, 60200 Compiegne (France); Hullebusch, Eric D. van [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Université Paris-Est, Laboratoire Géomatériaux et Environnement (LGE), EA 4508, UPEM, 77454, Marne-la-Vallée (France); Lens, Piet N.L. [UNESCO-IHE, Westvest 7, 2611 AX Delft (Netherlands); Department of Chemistry and Bioengineering, Tampere University of Technology, P.O-Box 541, Tampere (Finland)

    2017-04-05

    Highlights: • Tellurite bioreduction coupled to recovery of biogenic Te(0) nanocrystals. • First report on continuous tellurite removal in a UASB reactor. • Biogenic Te(0) was mainly associated with loosely-bound EPS of granular sludge. • Repeated exposure to tellurite caused compositional changes in the EPS matrix. - Abstract: Continuous removal of tellurite (TeO{sub 3}{sup 2−}) from synthetic wastewater and subsequent recovery in the form of elemental tellurium was studied in an upflow anaerobic granular sludge bed (UASB) reactor operated at 30 °C. The UASB reactor was inoculated with anaerobic granular sludge and fed with lactate as carbon source and electron donor at an organic loading rate of 0.6 g COD L{sup −1} d{sup −1}. After establishing efficient and stable COD removal, the reactor was fed with 10 mg TeO{sub 3}{sup 2−} L{sup −1} for 42 d before increasing the influent concentration to 20 mg TeO{sub 3}{sup 2−} L{sup −1}. Tellurite removal (98 and 92%, respectively, from 10 and 20 mg Te L{sup −1}) was primarily mediated through bioreduction and most of the removed Te was retained in the bioreactor. Characterization using XRD, Raman spectroscopy, SEM-EDX and TEM confirmed association of tellurium with the granular sludge, typically in the form of elemental Te(0) deposits. Furthermore, application of an extracellular polymeric substances (EPS) extraction method to the tellurite reducing sludge recovered up to 78% of the tellurium retained in the granular sludge. This study demonstrates for the first time the application of a UASB reactor for continuous tellurite removal from tellurite-containing wastewater coupled to elemental Te(0) recovery.

  1. Continuous removal and recovery of tellurium in an upflow anaerobic granular sludge bed reactor

    International Nuclear Information System (INIS)

    Mal, Joyabrata; Nancharaiah, Yarlagadda V.; Maheshwari, Neeraj; Hullebusch, Eric D. van; Lens, Piet N.L.

    2017-01-01

    Highlights: • Tellurite bioreduction coupled to recovery of biogenic Te(0) nanocrystals. • First report on continuous tellurite removal in a UASB reactor. • Biogenic Te(0) was mainly associated with loosely-bound EPS of granular sludge. • Repeated exposure to tellurite caused compositional changes in the EPS matrix. - Abstract: Continuous removal of tellurite (TeO 3 2− ) from synthetic wastewater and subsequent recovery in the form of elemental tellurium was studied in an upflow anaerobic granular sludge bed (UASB) reactor operated at 30 °C. The UASB reactor was inoculated with anaerobic granular sludge and fed with lactate as carbon source and electron donor at an organic loading rate of 0.6 g COD L −1 d −1 . After establishing efficient and stable COD removal, the reactor was fed with 10 mg TeO 3 2− L −1 for 42 d before increasing the influent concentration to 20 mg TeO 3 2− L −1 . Tellurite removal (98 and 92%, respectively, from 10 and 20 mg Te L −1 ) was primarily mediated through bioreduction and most of the removed Te was retained in the bioreactor. Characterization using XRD, Raman spectroscopy, SEM-EDX and TEM confirmed association of tellurium with the granular sludge, typically in the form of elemental Te(0) deposits. Furthermore, application of an extracellular polymeric substances (EPS) extraction method to the tellurite reducing sludge recovered up to 78% of the tellurium retained in the granular sludge. This study demonstrates for the first time the application of a UASB reactor for continuous tellurite removal from tellurite-containing wastewater coupled to elemental Te(0) recovery.

  2. A new tellurium-containing amphiphilic molecule induces apoptosis in HCT116 colon cancer cells.

    Science.gov (United States)

    Du, Peng; Saidu, Nathaniel Edward Bennett; Intemann, Johanna; Jacob, Claus; Montenarh, Mathias

    2014-06-01

    Chalcogen-based redox modulators over the years have attracted considerable attention as anti-cancer agents. New selenium- and tellurium-containing compounds with a polar head group and aryl-groups of various lengths have recently been reported as biologically active in several organisms. In the present study, we used the most active of the tellurium compound DP41, and its selenium counterpart DP31 to investigate their effects on the human cancer cell line HCT116. Cells were treated with DP41 or DP31 and the formation of superoxide radicals was determined using dihydroethidium. Cell cycle analysis and apoptosis was determined by cytofluorimetry. Proteins involved in ER signaling and apoptosis were determined by Western blot analysis and fluorescence microscopy. With 50μM of DP41, we observed an increase in O2(-) formation. There was, however, no such increase in O2(-) after treatment with the corresponding selenium compound under the same conditions. In the case of DP41, the production of O2(-) radicals was followed by an up-regulation of Nrf2, HO-1, phospho-eIF2α and ATF4. CHOP was also induced and cells entered apoptosis. Unlike the cancer cells, normal retinal epithelial ARPE-19 cells did not produce elevated levels of O2(-) radicals nor did they induce the ER signaling pathway or apoptosis. The tellurium-containing compound DP41, in contrast to the corresponding selenium compound, induces O2(-) radical formation and oxidative and ER stress responses, including CHOP activation and finally apoptosis. These results indicate that DP41 is a redox modulating agent with promising anti-cancer potentials. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Light-Induced Tellurium Enrichment on CdZnTe Crystal Surfaces Detected by Raman Spectroscopy

    International Nuclear Information System (INIS)

    Hawkins, Samantha A.; Villa-Aleman, Eliel; Duff, Martine C.; Hunter, Doug B.; Burger, Arnold; Groza, Michael; Buliga, Vladimir; Black, David R.

    2008-01-01

    CdZnTe (CZT) crystals can be grown under controlled conditions to produce high-quality crystals to be used as room-temperature radiation detectors. Even the best crystal growth methods result in defects, such as tellurium secondary phases, that affect the crystal's performance. In this study, CZT crystals were analyzed by micro-Raman spectroscopy. The growth of Te rich areas on the surface was induced by low-power lasers. The growth was observed versus time with low-power Raman scattering and was observed immediately under higher-power conditions. The detector response was also measured after induced Te enrichment.

  4. LIGHT INDUCED TELLURIUM ENRICHMENT ON CDZNTE CRYSTAL SURFACES DETECTED BY RAMAN SPECTROSCOPY

    International Nuclear Information System (INIS)

    Hawkins, S; Eliel Villa-Aleman, E; Martine Duff, M; Douglas Hunter, D

    2007-01-01

    Synthetic CdZnTe or 'CZT' crystals can be grown under controlled conditions to produce high quality crystals to be used as room temperature radiation detectors. Even the best crystal growth methods result in defects, such as tellurium secondary phases, that affect the crystal's performance. In this study, CZT crystals were analyzed by micro Raman spectroscopy. The growth of Te rich areas on the surface was induced by low powered lasers. The growth was observed versus time with low power Raman scattering and was observed immediately under higher power conditions. The detector response was also measured after induced Te enrichment

  5. Vaporization studies on elemental tellurium and selenium by Knudsen effusion mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, R., E-mail: rvis1953@gmail.com; Balasubramanian, R., E-mail: rbs@igcar.gov.in; Darwin Albert Raj, D., E-mail: darwinalbertraj1953@gmail.com; Sai Baba, M., E-mail: msb@igcar.gov.in; Lakshmi Narasimhan, T.S., E-mail: tslak@igcar.gov.in

    2014-08-01

    Highlights: • A detailed KEMS study of vaporization of elemental tellurium and selenium systems. • Clusters Te{sub i}(g) (i = 2 to 7) and Se{sub i}(g) (i = 2 to 9) identified over Te(s) and Se(s). • p–T relations for Te{sub i}(g) (590 to 690 K) and Se{sub i}(g) (380 to 480 K). • Vapor phase of Te dominated by Te{sub 2}(g) (∼95%) while that of Se by Se{sub 6}(g) (∼50%) and Se{sub 5}(g) (∼25%). • Sublimation and atomization enthalpies deduced for Te{sub i}(g) and Se{sub i}(g). - Abstract: Vaporization studies on elemental tellurium and selenium were conducted by Knudsen effusion mass spectrometry in the temperature range of 590–690 K and 380–480 K, respectively. The ionic species Te{sub i}{sup +} (i = 1–7) and Se{sub i}{sup +}(g) (i = 1–9) were detected in the mass spectra over these two condensed phases. Measurement of ion intensities were performed as a function of electron impact energy and as a function of temperature (at different electron impact energies) for identifying the gaseous precursor species as well as for determining the partial pressure–temperature relations and sublimation enthalpies for these species. While the major species over elemental tellurium was confirmed to be Te{sub 2}(g) (with all other gaseous species Te{sub 3}–Te{sub 7} put together constituting less than 5%), the major species over elemental selenium was found to be Se{sub 6}(g), closely followed by Se{sub 5}(g) (with other gaseous species Se{sub 2}–Se{sub 4} and Se{sub 7}–Se{sub 9} put together also moderately constituting ∼25%). From the partial pressures, the thermodynamic data for the sublimation reactions i Te(s) = Te{sub i}(g) and i Se(s) = Se{sub i}(g) were deduced by second- and third-law methods. The atomization enthalpies of tellurium and selenium clusters were also deduced by using the recommended enthalpies of formation of monomeric species. Comparison of the findings obtained in the present study with those in previous studies revealed

  6. Characterization of tellurium-based films for NO{sub 2} detection

    Energy Technology Data Exchange (ETDEWEB)

    Tsiulyanu, D. [Technical University, Department of Physics, bul. Dacia 41, MD-2060 Kishinau (Moldova, Republic of)]. E-mail: tsiu@cni.md; Tsiulyanu, A. [Technical University, Department of Physics, bul. Dacia 41, MD-2060 Kishinau (Moldova, Republic of); Liess, H.-D. [University of the Bundeswehr Munich, Faculty of Electrical Engineering and Information Technology, Institute of Physics, D-85577 Neubiberg (Germany); Eisele, I. [University of the Bundeswehr Munich, Faculty of Electrical Engineering and Information Technology, Institute of Physics, D-85577 Neubiberg (Germany)

    2005-08-01

    Sensing characteristics of tellurium-based thin films for NO{sub 2} monitoring was studied systematically. The influence of contact materials, thermal treatment, temperature and thickness of the samples on the electrical conductivity and sensitivity to NO{sub 2} with respect to scanning electron microscopy analyses is given. The possibility is shown to optimize the properties of the films for the development of a simple and stable NO{sub 2} sensor device with rapid response/recovery time and low operating temperature. The sensing mechanism is discussed for the direct interaction of gaseous species with lone-pair electrons of chalcogen atoms.

  7. Influence of the hydrolysis conditions on the properties of tellurium coatings obtained from hydrochloric acid baths

    International Nuclear Information System (INIS)

    Bigelis, V.M.; Kim, G.N.; Navalikhin, L.V.; Kalanov, M.; Abrarov, O.A.

    1982-01-01

    The structure of tellurium coatings has been studied using the methods of activational analysis on fast neutrons, roentgenography using DRON-2. The study is carried out in electrolyte 1N TeO 2 +6NHCl+2NH 2 SO 4 at the temperatures 25 and 95 deg C in the range of current densities 10-150 mA/cm 2 with and without mixing. Atomic content of chlorine and oxygen in deposite depending on the electrolyte work is determined. Nicrohardness, density, specific resistance of the coatings investigated are determined

  8. Test of irradiation of tellurium oxide for obtaining iodine-131 by dry distillation

    International Nuclear Information System (INIS)

    Alanis M, J.

    2003-07-01

    With the purpose of optimizing to the maximum independently the work of the reactor of those mathematical calculations of irradiation that are already optimized, now it corresponds to carry out irradiation tests in the different positions with their respective neutron fluxes that it counts the reactor for samples irradiation. Then, it is necessary to carry out the irradiation of the tellurium dioxide through cycles, with the purpose of observing the activity that it goes accumulating in each cycle and this way to obtain an activity of the Iodine-131 obtained when finishing the last cycle. (Author)

  9. Direct determination of tellurium and its redox speciation at the low nanogram level in natural waters by catalytic cathodic stripping voltammetry.

    Science.gov (United States)

    Biver, Marc; Quentel, François; Filella, Montserrat

    2015-11-01

    Tellurium is one of the elements recently identified as technologically critical and is becoming a new emergent contaminant. No reliable method exists for its determination in environmental samples such as natural waters. This gap is filled by the method described here; it allows the rapid detection of trace concentrations of Te(IV) and Te(VI) in surface waters by differential pulse cathodic stripping voltammetry. It is based on the proton reduction catalysed by the absorption of Te(IV) on the mercury electrode. Under our conditions (0.1 mol L(-1) HCl) a detection limit of about 5 ng L(-1) for a deposition time of 300 s is achieved. Organic matter does not represent a problem at low concentrations; higher concentrations are eliminated by adsorptive purification. Tellurium occurs primarily as Te(IV) and Te(VI) in natural waters. Thus, determining total Te requires the reduction of Te(VI) that it is not electroactive. A number of reduction procedures have been carefully evaluated and a method based on the addition of TiCl3 to the acidified samples has been proven to reduce Te(VI) at the trace level to Te(IV) reliably and quantitatively. Therefore, the procedure described allows the direct determination of total Te and its redox speciation. It is flexible, reliable and cost effective compared to any possible alternative method based on the common preconcentration-ICPMS approach. It is readily implementable as a routine method and can be deployed in the field with relative ease. Copyright © 2015 Elsevier B.V. All rights reserved.

  10. Resource recovery from urban stock, the example of cadmium and tellurium from thin film module recycling

    Energy Technology Data Exchange (ETDEWEB)

    Simon, F.-G., E-mail: franz-georg.simon@bam.de [BAM Federal Institute for Materials Research and Testing, Division 4.3 Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205 Berlin (Germany); Holm, O.; Berger, W. [BAM Federal Institute for Materials Research and Testing, Division 4.3 Contaminant Transfer and Environmental Technologies, Unter den Eichen 87, 12205 Berlin (Germany)

    2013-04-15

    Highlights: ► The semiconductor layer on thin-film photovoltaic modules can be removed from the glass-plate by vacuum blast cleaning. ► The separation of blasting agent and semiconductor can be performed using flotation with a valuable yield of 55%. ► PV modules are a promising source for the recovery of tellurium in the future. - Abstract: Raw material supply is essential for all industrial activities. The use of secondary raw material gains more importance since ore grade in primary production is decreasing. Meanwhile urban stock contains considerable amounts of various elements. Photovoltaic (PV) generating systems are part of the urban stock and recycling technologies for PV thin film modules with CdTe as semiconductor are needed because cadmium could cause hazardous environmental impact and tellurium is a scarce element where future supply might be constrained. The paper describes a sequence of mechanical processing techniques for end-of-life PV thin film modules consisting of sandblasting and flotation. Separation of the semiconductor material from the glass surface was possible, however, enrichment and yield of valuables in the flotation step were non-satisfying. Nevertheless, recovery of valuable metals from urban stock is a viable method for the extension of the availability of limited natural resources.

  11. Ecological aspects of selenium and tellurium in human and animal health

    Energy Technology Data Exchange (ETDEWEB)

    Frost, D V; Ingvoldstad, D

    1975-01-01

    Animal and human studies indicate that selenium inadequacy, in part, underlies various chronic diseases. Epidemiologic evidence suggests that cancer and heart disease are most common where ambient Se availability is low. Plant Se uptake and Se blood levels are inverse to human cancer mortality. As the active group in glutathione peroxidase, Se/sup -2/ inhibits aberrant oxidations which lead to chronic diseases. It binds heavy metals, and with tocopherol maintains tissue integrity. Sulfur dioxide fallout from the atmosphere, resulting from fossil fuel burning, may diminish the nutritional availability of selenium by diminishing plant uptake. Intensive ruminant grazing returns unavailable Se/sup 0/ to soils. Trimethyl selenium ion, as excreted by animals, also appears to be unavailable to plants. Modern fertilization practices and the effect of buildup of sulfates in the soil, due to acid rains, both appear to lessen the availability of Se to plants. SeO/sub 2/ added to the atmosphere from combustion and volcanic activity react with SO/sub 2/ to yield Se/sup 0/. This is presumed to fall out as particles from the air. How traces of Se are otherwise carried in air, explaining its enrichment in some areas, is unknown. The New Zealand experience with Se inadequacy in animals and man may be repeated in other parts of the world. Se inadequacy is far more of a human health problem than Se toxicity. There are no known adverse health effects from tellurium, other than tellurium breath. 164 references, 5 figures, 3 tables.

  12. Determination of tellurium by hydride generation with in situ trapping flame atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Matusiewicz, H.; Krawczyk, M. [Politechn Poznanska, Poznan (Poland)

    2007-03-15

    The analytical performance of coupled hydride generation - integrated atom trap (HG-IAT) atomizer flame atomic absorption spectrometry (FAAS) system was evaluated for determination of Te in reference material (GBW 07302 Stream Sediment), coal fly ash and garlic. Tellurium, using formation of H{sub 2}Te vapors, is atomized in air-acetylene flame-heated IAT. A new design HG-IAT-FAAS hyphenated technique that would exceed the operational capabilities of existing arrangernents (a water-cooled single silica tube, double-slotted quartz tube or an 'integrated trap') was investigated. An improvement in detection limit was achieved compared with using either of the above atom trapping techniques separately. The concentration detection limit, defined as 3 times the blank standard deviation (3{sigma}), was 0.9 ng mL{sup -1} for Te. For a 2 min in situ preconcentration time (sample volume of 2 mL), sensitivity enhancement compared to flame AAS, was 222 fold, using the hydride generation atom trapping technique. The sensitivity can be further improved by increasing the collection time. The precision, expressed as RSD, was 7.0% (n = 6) for Te. The accuracy of the method was verified using a certified reference material (GBW 07302 Stream Sediment) by aqueous standard calibration curves. The measured Te contents of the reference material was in agreement with the information value. The method was successfully applied to the determination of tellurium in coal fly ash and garlic.

  13. Equilibrium evaporation test of lead-bismuth eutectic and of tellurium in lead-bismuth

    International Nuclear Information System (INIS)

    Ohno, Shuji; Nishimura, Masahiro; Hamada, Hirotsugu; Miyahara, Shinya; Sasa, Toshinobu; Kurata, Yuji

    2005-01-01

    A series of equilibrium evaporation experiment was performed to acquire the essential and the fundamental knowledge about the transfer behavior of lead-bismuth eutectic (LBE) and impurity tellurium in LBE from liquid to gas phase. The experiments were conducted using the transpiration method in which saturated vapor in an isothermal evaporation pot was transported by inert carrier gas and collected outside of the pot. The size of the used evaporation pot is 8 cm inner diameter and 15 cm length. The weight of the LBE pool in the pot is about 500 g. The investigated temperature range was 450degC to 750degC. From this experiment and discussion using the data in literature, we have obtained several instructive and useful data on the LBE evaporation behavior such as saturated vapor pressure of LBE, vapor concentration of Pb, Bi and Bi 2 in LBE saturated gas phase, and activity coefficient of Pb in the LBE. The LBE vapor pressure equation is represented as the sum of Pb, Bi and Bi 2 vapor in the temperature range between 550degC and 750degC as logP[Pa]=10.2-10100/T[k]. The gas-liquid equilibrium partition coefficient of tellurium in LBE is in the range of 10 to 100, with no remarkable temperature dependency between 450degC and 750degC. This research was founded by the Ministry of Education, Culture, Sports, Science and Technology (MEXT). (author)

  14. Improvement of physical properties of ZnO thin films by tellurium doping

    Energy Technology Data Exchange (ETDEWEB)

    Sönmezoğlu, Savaş, E-mail: svssonmezoglu@kmu.edu.tr; Akman, Erdi

    2014-11-01

    Highlights: • We report the synthesis of tellurium-doped zinc oxide (Te–ZnO) thin films using sol–gel method. • Highly c-axis oriented Te-doped ZnO thin films were grown on FTO glasses as substrate. • 1.5% Te-doping ratio could improve the physical properties of ZnO thin films. - Abstract: This investigation addressed the structural, optical and morphological properties of tellurium incorporated zinc oxide (Te–ZnO) thin films. The obtained results indicated that Te-doped ZnO thin films exhibit an enhancement of band gap energy and crystallinity compared with non-doped films. The optical transmission spectra revealed a shift in the absorption edge toward lower wavelengths. X-ray diffraction measurement demonstrated that the film was crystallized in the hexagonal (wurtzite) phase and presented a preferential orientation along the c-axis. The XRD obtained patterns indicate that the crystallite size of the thin films, ranging from 23.9 to 49.1 nm, changed with the Te doping level. The scanning electron microscopy and atomic force microscopy results demonstrated that the grain size and surface roughness of the thin films increased as the Te concentration increased. Most significantly, we demonstrate that it is possible to control the structural, optical and morphological properties of ZnO thin films with the isoelectronic Te-incorporation level.

  15. Tellurium labeled analogues of the fatty acid hexadecenoic acid for imaging of myocardial tissue

    International Nuclear Information System (INIS)

    Mills, S.L.

    1980-01-01

    Non-invasive nuclear diagnostic procedures for the evaluation of acute myocardial infarction and ischemia are currently limited by problems associated with the availablity of radiopharmaceuticals, development of imaging equipment, and inherent characteristics of radionuclides. Myocardial tissue requires high levels of substrates which provide energy for the continuous functioning of this vital organ. Of the major sources of energy, the most utilized source is fatty acids. Tellurium-123m, with excellent gamma imaging characteristics was chosen as the radionuclide. A 16 carbon fatty acid, hexadecenoic acid, was chosen as the carrier molecule. The tellurium-123m fatty acid radiopharmaceuticals were formulated either in a solution of 20 percent ethanol, two percent polysorbate 80, and brought to volume with normal saline or in 12.5 percent human serum ablumin and brought to volume with normal saline. Biodistribution was performed in three animal species: Sprague-Dawley rats (three rats per time frame), Australian white rabbits (three rabbits per time frame), and mongrel dogs (one dog per time frame). Dosimetry calculations were performed to assess the radiation dose

  16. Microbial-assisted synthesis and evaluation the cytotoxic effect of tellurium nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Forootanfar, Hamid [Herbal and Traditional Medicines Research Center, Kerman University of Medical Sciences, Kerman (Iran, Islamic Republic of); Amirpour-Rostami, Sahar; Jafari, Mandana [Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman (Iran, Islamic Republic of); Forootanfar, Amir [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Mashhad University of Medical Sciences, Mashhad (Iran, Islamic Republic of); Yousefizadeh, Zahra [The Student Research Committee, Faculty of Pharmacy, Kerman University of Medical Sciences, Kerman (Iran, Islamic Republic of); Shakibaie, Mojtaba, E-mail: shakiba@kmu.ac.ir [Pharmaceutics Research Center, Institute of Neuropharmacology, Kerman University of Medical Sciences, Kerman (Iran, Islamic Republic of)

    2015-04-01

    The present study was designed to isolate bacterial strain capable of tellurium nanorods' (Te NRs) production followed by purification and evaluation of the cytotoxic effect of Te NRs. Among 25 environmental samples collected for screening of Te NR-producer bacterial strains one bacterial colony (isolated from hot spring and identified as Pseudomonas pseudoalcaligenes strain Te) was selected and applied for biosynthesis of Te NRs. Thereafter, an organic–aqueous partitioning system was applied for the purification of the biogenic Te NRs and the purified Te NRs were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), UV–visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. The cytotoxic effect of biologically synthesized Te NRs and potassium tellurite on four cell lines of MCF-7, HT1080, HepG2 and A549 was then determined using the MTT assay method. The obtained results revealed lower toxicity for the rod-shaped biogenic tellurium nanostructures (~ 22 nm diameter by 185 nm length) compared to K{sub 2}TeO{sub 3}. - Highlights: • Te NR producing bacterial strain were isolated from hot springs. • Organic–aqueous partitioning system was applied for purification of Te nanorods. • The rod-shaped biogenic Te NPs showed lower cytotoxicity compared to K{sub 2}TeO{sub 3}.

  17. Microbial-assisted synthesis and evaluation the cytotoxic effect of tellurium nanorods

    International Nuclear Information System (INIS)

    Forootanfar, Hamid; Amirpour-Rostami, Sahar; Jafari, Mandana; Forootanfar, Amir; Yousefizadeh, Zahra; Shakibaie, Mojtaba

    2015-01-01

    The present study was designed to isolate bacterial strain capable of tellurium nanorods' (Te NRs) production followed by purification and evaluation of the cytotoxic effect of Te NRs. Among 25 environmental samples collected for screening of Te NR-producer bacterial strains one bacterial colony (isolated from hot spring and identified as Pseudomonas pseudoalcaligenes strain Te) was selected and applied for biosynthesis of Te NRs. Thereafter, an organic–aqueous partitioning system was applied for the purification of the biogenic Te NRs and the purified Te NRs were characterized using transmission electron microscopy (TEM), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), X-ray diffraction spectroscopy (XRD), UV–visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR) techniques. The cytotoxic effect of biologically synthesized Te NRs and potassium tellurite on four cell lines of MCF-7, HT1080, HepG2 and A549 was then determined using the MTT assay method. The obtained results revealed lower toxicity for the rod-shaped biogenic tellurium nanostructures (~ 22 nm diameter by 185 nm length) compared to K 2 TeO 3 . - Highlights: • Te NR producing bacterial strain were isolated from hot springs. • Organic–aqueous partitioning system was applied for purification of Te nanorods. • The rod-shaped biogenic Te NPs showed lower cytotoxicity compared to K 2 TeO 3

  18. Resource recovery from urban stock, the example of cadmium and tellurium from thin film module recycling

    International Nuclear Information System (INIS)

    Simon, F.-G.; Holm, O.; Berger, W.

    2013-01-01

    Highlights: ► The semiconductor layer on thin-film photovoltaic modules can be removed from the glass-plate by vacuum blast cleaning. ► The separation of blasting agent and semiconductor can be performed using flotation with a valuable yield of 55%. ► PV modules are a promising source for the recovery of tellurium in the future. - Abstract: Raw material supply is essential for all industrial activities. The use of secondary raw material gains more importance since ore grade in primary production is decreasing. Meanwhile urban stock contains considerable amounts of various elements. Photovoltaic (PV) generating systems are part of the urban stock and recycling technologies for PV thin film modules with CdTe as semiconductor are needed because cadmium could cause hazardous environmental impact and tellurium is a scarce element where future supply might be constrained. The paper describes a sequence of mechanical processing techniques for end-of-life PV thin film modules consisting of sandblasting and flotation. Separation of the semiconductor material from the glass surface was possible, however, enrichment and yield of valuables in the flotation step were non-satisfying. Nevertheless, recovery of valuable metals from urban stock is a viable method for the extension of the availability of limited natural resources

  19. The influence of composition of fluoride electrolytes and conditions of the electrodeposition on some properties of tellurium

    International Nuclear Information System (INIS)

    Bugelis, V.M.; Kum, G.N.; Abrarov, O.A.; Madumarov, A.; Navalikhin, L.V.; Ajnakulov, Eh.B.

    1981-01-01

    Effect of electrolytic bath content, cathode current density, illumination and temperature on specific resistance, photosensitivity, structure and chemical purity of plated tellurium coatings is studied. Deposition is realized from moderately acid fluoride electrolytes at the constant temperature with a platinum working electrode. X-ray studies of precipitates obtained are carried out

  20. Exploratory studies of element substitutions in synthetic tetrahedrite. Part II. Selenium and tellurium as anions in Zn-Fe tetrahedrites

    DEFF Research Database (Denmark)

    Karup-Møller, Sven; Makovicky, E.

    1999-01-01

    -free) compositons do not materialize. The substituted Se tetrahedrite coexists with Cu3SbSe3, (iron-bearing) Cu2-xSe, Cu3SbSe4 plus/minus low Zn-sulfide melt. Selenium does not adopt the role of cation and tellurium that of anion in the tetrahedrite structure. The explanation of the severely restricted composition...

  1. The enhancing of Au-Ag-Te content in tellurium-bearing ore mineral by bio-oxidation-leaching

    Science.gov (United States)

    Kim, PyeongMan; Kim, HyunSoo; Myung, EunJi; Kim, YoonJung; Lee, YongBum; Park*, CheonYoung

    2015-04-01

    The purpose of this study is to enhance the content of valuable metals such as Au-Ag-Te in tellurium-bearing minerals by bio-oxidation-leaching. It was confirmed that pyrite, chalcopyrite, sphalerite and galena were produced together with tellurium-bearing minerals including hessite, sylvanite and tellurobismuthite from ore minerals and concentrates through microscopic observation and SEM/EDS analysis. In a bio-oxidation-leaching experiment, with regard to Au, Ag, Te, Cu and Fe, the changes in the amount of leaching and the content of leaching residues were compared and analyzed with each other depending on the adaptation of an indigenous microbe identified as Acidithiobacillus ferrooxidans. As a result of the experiment, the Au-Ag-Te content in tellurium-bearing ore mineral was enhanced in the order of physical oxidation leaching, physical/non-adaptive bio-oxidation-leaching and physical/adaptive biological leaching. It suggests that the bio-oxidation-leaching using microbes adapted in tellurium-bearing ore mineral can be used as a pre-treatment and a main process in a recovery process of valuable metals. "This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2013R1A1A2004898)"

  2. Phenylethynyl-butyltellurium inhibits the sulfhydryl enzyme Na+, K+ -ATPase: an effect dependent on the tellurium atom.

    Science.gov (United States)

    Quines, Caroline B; Rosa, Suzan G; Neto, José S S; Zeni, Gilson; Nogueira, Cristina W

    2013-11-01

    Organotellurium compounds are known for their toxicological effects. These effects may be associated with the chemical structure of these compounds and the oxidation state of the tellurium atom. In this context, 2-phenylethynyl-butyltellurium (PEBT) inhibits the activity of the sulfhydryl enzyme, δ-aminolevulinate dehydratase. The present study investigated on the importance of the tellurium atom in the PEBT ability to oxidize mono- and dithiols of low molecular weight and sulfhydryl enzymes in vitro. PEBT, at high micromolar concentrations, oxidized dithiothreitol (DTT) and inhibited cerebral Na(+), K(+)-ATPase activity, but did not alter the lactate dehydrogenase activity. The inhibition of cerebral Na(+), K(+)-ATPase activity was completely restored by DTT. By contrast, 2-phenylethynyl-butyl, a molecule without the tellurium atom, neither oxidized DTT nor altered the Na(+), K(+)-ATPase activity. In conclusion, the tellurium atom of PEBT is crucial for the catalytic oxidation of sulfhydryl groups from thiols of low molecular weight and from Na(+), K(+)-ATPase.

  3. Electronic and atomic structures of liquid tellurium containing alkali elements

    International Nuclear Information System (INIS)

    Kawakita, Yukinobu; Yao, Makoto; Endo, Hirohisa.

    1997-01-01

    The measurements of electrical conductivity σ, density, EXAFS and neutron scattering were carried out for liquid K-Te and Rb-Te mixtures. The conductivity σ decreases rapidly with alkali concentration and a metal-semiconductor transition occurs at about 10 at.% alkali. It is found that the compositional variation of σ is nearly independent of the alkali species. The Te-Te bond length deduced from EXAFS and neutron scattering measurements is 2.8 A and changes little with alkali concentrations. The average distances from K and Rb atom to Te atoms are 3.6 A and 3.8 A, respectively. Two kinds of relaxation processes are observed in quasielastic neutron scattering for K 20 Te 80 . Upon the addition of alkali the interaction between the neighbouring Te chains, which is responsible for the metallic conduction, weaken considerably. (author)

  4. Ten Good Reasons for the Use of the Tellurium-Centered Anderson-Evans Polyoxotungstate in Protein Crystallography.

    Science.gov (United States)

    Bijelic, Aleksandar; Rompel, Annette

    2017-06-20

    Protein crystallography represents at present the most productive and most widely used method to obtain structural information on target proteins and protein-ligand complexes within the atomic resolution range. The knowledge obtained in this way is essential for understanding the biology, chemistry, and biochemistry of proteins and their functions but also for the development of compounds of high pharmacological and medicinal interest. Here, we address the very central problem in protein crystallography: the unpredictability of the crystallization process. Obtaining protein crystals that diffract to high resolutions represents the essential step to perform any structural study by X-ray crystallography; however, this method still depends basically on trial and error making it a very time- and resource-consuming process. The use of additives is an established process to enable or improve the crystallization of proteins in order to obtain high quality crystals. Therefore, a more universal additive addressing a wider range of proteins is desirable as it would represent a huge advance in protein crystallography and at the same time drastically impact multiple research fields. This in turn could add an overall benefit for the entire society as it profits from the faster development of novel or improved drugs and from a deeper understanding of biological, biochemical, and pharmacological phenomena. With this aim in view, we have tested several compounds belonging to the emerging class of polyoxometalates (POMs) for their suitability as crystallization additives and revealed that the tellurium-centered Anderson-Evans polyoxotungstate [TeW 6 O 24 ] 6- (TEW) was the most suitable POM-archetype. After its first successful application as a crystallization additive, we repeatedly reported on TEW's positive effects on the crystallization behavior of proteins with a particular focus on the protein-TEW interactions. As electrostatic interactions are the main force for TEW binding

  5. Formation of tellurium nanocrystals during anaerobic growth of bacteria that use Te oxyanions as respiratory electron acceptors

    Science.gov (United States)

    Baesman, S.M.; Bullen, T.D.; Dewald, J.; Zhang, Dongxiao; Curran, S.; Islam, F.S.; Beveridge, T.J.; Oremland, R.S.

    2007-01-01

    Certain toxic elements support the metabolism of diverse prokaryotes by serving as respiratory electron acceptors for growth. Here, we demonstrate that two anaerobes previously shown to be capable of respiring oxyanions of selenium also achieve growth by reduction of either tellurate [Te(VI)] or tellurite [Te(IV)] to elemental tellurium [Te(0)]. This reduction achieves a sizeable stable-Te-isotopic fractionation (isotopic enrichment factor [??] = -0.4 to -1.0 per ml per atomic mass unit) and results in the formation of unique crystalline Te(0) nanoarchitectures as end products. The Te(0) crystals occur internally within but mainly externally from the cells, and each microorganism forms a distinctly different structure. Those formed by Bacillus selenitireducens initially are nanorods (???10-nm diameter by 200-nm length), which cluster together, forming larger (???1,000-nm) rosettes composed of numerous individual shards (???100-nm width by 1,000-nm length). In contrast, Sulfurospirillium barnesii forms extremely small, irregularly shaped nanospheres (diameter < 50 nm) that coalesce into larger composite aggregates. Energy-dispersive X-ray spectroscopy and selected area electron diffraction indicate that both biominerals are composed entirely of Te and are crystalline, while Raman spectroscopy confirms that they are in the elemental state. These Te biominerals have specific spectral signatures (UV-visible light, Raman) that also provide clues to their internal structures. The use of microorganisms to generate Te nanomaterials may be an alternative for bench-scale syntheses. Additionally, they may also generate products with unique properties unattainable by conventional physical/chemical methods. Copyright ?? 2007, American Society for Microbiology. All Rights Reserved.

  6. Nanoscale Device Properties of Tellurium-based Chalcogenide Compounds

    Science.gov (United States)

    Dahal, Bishnu R.

    of relativistic Dirac fermions becomes relevant. This results in peculiar quantum oscillations in transport measurements which make it possible to unambiguously identify surface Dirac fermions. In order to lead us towards a better understanding of topological insulators and their applications, it is, however, necessary to develop techniques that will enable high quality materials to be obtained in a routine and reliable way. However, this has been an enormous challenge so far. Since highly volatile components are involved in most topological insulators, whether in bulk single crystal or epitaxial thin films or chemical vapor deposition grown nanoribbons, maintaining near stoichiometry has proven to be very difficult. Observing the predicted transport properties of these systems, particularly surface carriers of high mobility whilst maintaining bulk insulating states, is seriously impeded by the unintentional doping of bulk carriers. Moreover, in thin films and hetrostructures, at the all-important thickness range of a few nanometers, the additional limitation of the film-substrate lattice mismatch and the resulting strain in films is a major concern. In this thesis, we have developed a synthesis technique to obtain high quality SnTe nanoribbons, which is a topological crystalline insulator and its surface states are topologically protected by mirror symmetry of the lattice. The obtained ribbons are nearly stoichiometric and show strong semiconducting behavior with a bandgap of 240 meV. This is the first time high quality SnTe nanoribbons have been synthesized. High quality SnTe nanoribbons form a potential platform to understand the magnetic topological insulating behavior. In this thesis, it is also shown that magnetic behavior can be introduced in SnTe nanoribbons by means of chromium doping. Magnetically doped topological insulators, possessing an energy gap created at the Dirac point are predicted to exhibit exotic phenomena including the quantized anomalous Hall

  7. Intrinsic two-dimensional states on the pristine surface of tellurium

    Science.gov (United States)

    Li, Pengke; Appelbaum, Ian

    2018-05-01

    Atomic chains configured in a helical geometry have fascinating properties, including phases hosting localized bound states in their electronic structure. We show how the zero-dimensional state—bound to the edge of a single one-dimensional helical chain of tellurium atoms—evolves into two-dimensional bands on the c -axis surface of the three-dimensional trigonal bulk. We give an effective Hamiltonian description of its dispersion in k space by exploiting confinement to a virtual bilayer, and elaborate on the diminished role of spin-orbit coupling. These intrinsic gap-penetrating surface bands were neglected in the interpretation of seminal experiments, where two-dimensional transport was otherwise attributed to extrinsic accumulation layers.

  8. Calculations of energy levels and electromagnetic properties for tellurium pair isotopes, by unified method

    International Nuclear Information System (INIS)

    Teixeira, R.R.P.

    1988-01-01

    Calculations with the Unified Model (vibrator coupled to two particles), of the energy levels and the eletromagnetic properties have been performed and compared with the twelve pair isotopes from tellurium with A between 112 and 134. The results were analysed using as particles interaction: pairing and SDI (Surface Delta Interaction). The SDI and 3 fonons collective states were used in the fittings, and a syntematic comparison between the theoretical and experimental results was made. The dependence of the results with the model parameters was determined, through large variation sof them. Calculations using 4 fonons have been made, and the importance of the introduced variations in the results was discussed. Calculations have been made in the VAX Computer of the Pelletron at IFUSP. (author) [pt

  9. Studies on nickel (II and palladium (II complexes with some tetraazamacrocycles containing tellurium

    Directory of Open Access Journals (Sweden)

    Rathee Nitu

    2012-01-01

    Full Text Available The synthesis of 10-membered and 12-membered tellurium containing tetraazamacrocyclic complexes of divalent nickel and palladium by template condensation of diaryltellurium dichlorides, (aryl = p-hydroxyphenyl, 3-methyl-4-hydroxyphenyl, p-methoxyphenyl with 1,2-diaminoethane and 1,3-diaminopropane in the presence of metal dichloride is reported. The resulting complexes have been subjected to elemental analyses, magnetic measurements, electronic absorption, infra-red, and proton magnetic resonance spectral studies. The formation of proposed macrocyclic skeletons and their donor sites have been identified on the basis of spectral studies. Distorted octahedral structure for the nickel complexes in the solid state and squareplanar structure for the palladium complexes have been suggested.

  10. Effect of aging and temperature on alternating current conductivity of tellurium thin films

    Energy Technology Data Exchange (ETDEWEB)

    Tsiulyanu, D. [Technical University, Department of Physics, bul. Dacia 41, MD-2060, Chisinau (Moldova, Republic of)], E-mail: tsiu@cni.md; Marian, T.; Tiuleanu, A. [Technical University, Department of Physics, bul. Dacia 41, MD-2060, Chisinau (Moldova, Republic of); Liess, H.-D.; Eisele, I. [University of the Bundeswehr Munich, Faculty of Electrical Engineering and Information Technology, Institute of Physics, D-85577 Neubiberg (Germany)

    2009-02-27

    The impedance spectra of tellurium films with interdigital platinum electrodes were investigated in air at temperatures between 10 and 50 deg. C . Cole-Cole analysis made it possible to assess time constants, resistance, and capacitance of the film at characteristic frequencies and the dependence of these parameters on aging and temperature. Aging under normal conditions over 12 months led to a relative increase of only {approx} 5% in film impedance at the characteristic frequency. However, aging noticeably influences the electrical resistance of the film at high (> 500 kHz) frequencies, and capacitance diminished after 12 months by more than 50% throughout the spectrum. Scanning electron microscopy confirmed that the effect of aging is due to structural changes in the film. Temperature does not influence the capacitance of the film but uncommonly influences its resistance, which reaches a maximum at around 20 deg. C . This is ascribed to desorption of oxygen previously adsorbed from the environment.

  11. Effect of aging and temperature on alternating current conductivity of tellurium thin films

    International Nuclear Information System (INIS)

    Tsiulyanu, D.; Marian, T.; Tiuleanu, A.; Liess, H.-D.; Eisele, I.

    2009-01-01

    The impedance spectra of tellurium films with interdigital platinum electrodes were investigated in air at temperatures between 10 and 50 deg. C . Cole-Cole analysis made it possible to assess time constants, resistance, and capacitance of the film at characteristic frequencies and the dependence of these parameters on aging and temperature. Aging under normal conditions over 12 months led to a relative increase of only ∼ 5% in film impedance at the characteristic frequency. However, aging noticeably influences the electrical resistance of the film at high (> 500 kHz) frequencies, and capacitance diminished after 12 months by more than 50% throughout the spectrum. Scanning electron microscopy confirmed that the effect of aging is due to structural changes in the film. Temperature does not influence the capacitance of the film but uncommonly influences its resistance, which reaches a maximum at around 20 deg. C . This is ascribed to desorption of oxygen previously adsorbed from the environment

  12. Thermodynamic assessment of the palladium-tellurium (Pd-Te) system

    International Nuclear Information System (INIS)

    Gosse, S.; Gueneau, C.

    2011-01-01

    Among the fission products formed in nuclear fuels, the platinum-group metal palladium and the chalcogen element tellurium exhibit strong interaction. It is therefore of interest to be able to predict the chemical equilibria involving the Pd and Te fission products. A thermodynamic assessment is carried out using the Calphad (Calculation of Phase Diagram) method to investigate the behaviour of Pd-Te alloy system in nuclear fuels under irradiation and under waste disposal conditions. The Pd-Te binary description was optimized using experimental data found in literature including thermodynamic properties and phase diagram data. To validate the calculated phase diagram and thermodynamic properties, the results are compared with data from the literature. Both calculated and experimental phase diagrams and thermodynamic properties are in good agreement in the whole Pd-Te composition range. (authors)

  13. Melt-gas phase equilibria and state diagrams of the selenium-tellurium system

    Science.gov (United States)

    Volodin, V. N.; Trebukhov, S. A.; Burabaeva, N. M.; Nitsenko, A. V.

    2017-05-01

    The partial pressures of saturated vapor of the components in the Se-Te system are determined and presented in the form of temperature-concentration dependences from which the boundaries of the melt-gas phase transition are calculated at atmospheric pressure and vacuums of 2000 and 100 Pa. The existence of azeotropic mixtures is revealed. It is found that the points of inseparably boiling melts correspond to 7.5 at % of Se and 995°C at 101325 Pa, 10.9 at % at 673°C and 19.5 at % at 522°C in vacuums of 2000 and 100 Pa, respectively. A complete state diagram is constructed, including the fields of gas-liquid equilibria at atmospheric and low pressures, the boundaries of which allow us to assess the behavior of selenium and tellurium upon distillation fractionation.

  14. Improved selectivity for Pb(II) by sulfur, selenium and tellurium analogues of 1,8-anthraquinone-18-crown-5: synthesis, spectroscopy, X-ray crystallography and computational studies.

    Science.gov (United States)

    Mariappan, Kadarkaraisamy; Alaparthi, Madhubabu; Hoffman, Mariah; Rama, Myriam Alcantar; Balasubramanian, Vinothini; John, Danielle M; Sykes, Andrew G

    2015-07-14

    We report here a series of heteroatom-substituted macrocycles containing an anthraquinone moiety as a fluorescent signaling unit and a cyclic polyheteroether chain as the receptor. Sulfur, selenium, and tellurium derivatives of 1,8-anthraquinone-18-crown-5 (1) were synthesized by reacting sodium sulfide (Na2S), sodium selenide (Na2Se) and sodium telluride (Na2Te) with 1,8-bis(2-bromoethylethyleneoxy)anthracene-9,10-dione in a 1 : 1 ratio. The optical properties of the new compounds are examined and the sulfur and selenium analogues produce an intense green emission enhancement upon association with Pb(II) in acetonitrile. Selectivity for Pb(II) is markedly improved as compared to the oxygen analogue 1 which was also competitive for Ca(II) ion. UV-Visible and luminescence titrations reveal that 2 and 3 form 1 : 1 complexes with Pb(II), confirmed by single-crystal X-ray studies where Pb(II) is complexed within the macrocycle through coordinate covalent bonds to neighboring carbonyl, ether and heteroether donor atoms. Cyclic voltammetry of 2-8 showed classical, irreversible oxidation potentials for sulfur, selenium and tellurium heteroethers in addition to two one-electron reductions for the anthraquinone carbonyl groups. DFT calculations were also conducted on 1, 2, 3, 6, 6 + Pb(II) and 6 + Mg(II) to determine the trend in energies of the HOMO and the LUMO levels along the series.

  15. Modelling the chemical behaviour of tellurium species in the reactor pressure vessel and the reactor cooling system under severe accident conditions

    International Nuclear Information System (INIS)

    Alonso, A.; Gonzalez, C.

    1991-07-01

    This state of the art report contains information on the behaviour of tellurium and its compounds in the reactor pressure vessel and the reactor coolant system under light water reactor severe accident conditions. To characterise tellurium behaviour, it is necessary the previous knowledge of the species of tellurium released from the core, and simultaneity of its release with that of other materials which can alter the transport, for instance, control rod and structural materials. Release and transport experiments have been reviewed along with the models implemented in the codes which are used in the international community: TRAPMELT, RAFT, VICTORIA and SOPHIE. From the experiments, it can be concluded that other species different to Te 2 , such as tin telluride and cesium telluride, may be released from the fuel. That is why they must be considered in the transport phenomena. There is also experimental evidence of the strong interaction of Te 2 with Inconel 600 and stainless steel of the pipe walls and structures, however this strong interaction is in competition with the interaction of tellurium with aerosols, which under severe accident conditions may represent an area greater than that of the primary system. It is for the absence of significant tellurium species in the transport models, and also for the interaction of tellurium with aerosols, for which some codes show the greatest deficiencies

  16. In vitro and in vivo activity of an organic tellurium compound on Leishmania (Leishmania chagasi.

    Directory of Open Access Journals (Sweden)

    Isabella Aparecida Salerno Pimentel

    Full Text Available Tellurium compounds have shown several biological properties and recently the leishmanicidal effect of one organotellurane was demonstrated. These findings led us to test the effect of the organotellurium compound RF07 on Leishmania (Leishmania chagasi, the agent of visceral leishmaniasis in Latin America. In vitro assays were performed in L. (L. chagasi-infected bone marrow derived macrophages treated with different concentrations of RF07. In in vivo experiments Golden hamsters were infected with L. (L. chagasi and injected intraperitoneally with RF07 whereas control animals received either Glucantime or PBS. The effect of RF07 on cathepsin B activity of L. (L. chagasi amastigotes was assayed spectrofluorometrically using fluorogenic substrates. The main findings were: 1 RF07 showed significant leishmanicidal activity against intracellular parasites at submicromolar concentrations (IC50 of 529.7±26.5 nM, and the drug displayed 10-fold less toxicity to macrophages (CC50 of 5,426±272.8 nM; 2 kinetics assays showed an increasing leishmanicidal action of RF07 at longer periods of treatment; 3 one month after intraperitoneal injection of RF07 L. (L. chagasi-infected hamsters showed a reduction of 99.6% of parasite burden when compared to controls that received PBS; 4 RF07 inhibited the cathepsin B activity of L. (L. chagasi amastigotes. The present results demonstrated that the tellurium compound RF07 is able to destroy L. (L. chagasi in vitro and in vivo at concentrations that are non toxic to the host. We believe these findings support further study of the potential of RF07 as a possible alternative for the chemotherapy of visceral leishmaniasis.

  17. Revision and extension to the analysis of the third spectrum of tellurium: Te III

    International Nuclear Information System (INIS)

    Tauheed, A.; Naz, A.

    2011-01-01

    The spectrum of doubly ionized tellurium atom (Te III) has been investigated in the vacuum ultraviolet wavelength region. The ground configuration of Te III is 5s 2 5p 2 and the excited configurations are of the type 5s 2 5p nl. The core excitation leads to a 5s5p 3 configuration. Cowan's multi-configuration interaction code was utilized to predict the ion structure. The observed spectrum of tellurium was recorded on a 3-m normal incidence vacuum spectrograph of Antigonish Laboratory (Canada) in the wavelength region of 300 - 2000 A by using a triggered spark light source for the excitation of the spectrum. The 5s 2 5p 2 - [ 5s 2 5p (5d + 6d + 7d + 6s + 7s + 8s) + 5s5p 3 ] transition array has been analyzed. Previously reported levels by Joshi et al have been confirmed while the older analysis by Crooker and Joshi has been revised and extended to include the 5s 2 5p (5d, 6d, 7d, 6s,7s, 8s) and 5s5p 3 configurations. Least-squares- fitted parametric calculations were used to interpret the final results. One hundred and fifty spectral lines have been identified to establish 60 energy levels. Our wavelength accuracy for unblended and sharp lines is better than ±0.005 A. The ionization potential of Te III was found to be 224550 ± 300 cm -1 (27.841 ± 0.037eV).

  18. Potential for improved extraction of tellurium as a byproduct of current copper mining processes

    Science.gov (United States)

    Hayes, S. M.; Spaleta, K. J.; Skidmore, A. E.

    2016-12-01

    Tellurium (Te) is classified as a critical element due to its increasing use in high technology applications, low average crustal abundance (3 μg kg-1), and primary source as a byproduct of copper extraction. Although Te can be readily recovered from copper processing, previous studies have estimated a 4 percent extraction efficiency, and few studies have addressed Te behavior during the entire copper extraction process. The goals of the present study are to perform a mass balance examining Te behavior during copper extraction and to connect these observations with mineralogy of Te-bearing phases which are essential first steps in devising ways to optimize Te recovery. Our preliminary mass balance results indicate that less than 3 percent of Te present in copper ore is recovered, with particularly high losses during initial concentration of copper ore minerals by flotation. Tellurium is present in the ore in telluride minerals (e.g., Bi-Te-S phases, altaite, and Ag-S-Se-Te phases identified using electron microprobe) with limited substitution into sulfide minerals (possibly 10 mg kg-1 Te in bulk pyrite and chalcopyrite). This work has also identified Te accumulation in solid-phase intermediate extraction products that could be further processed to recover Te, including smelter dusts (158 mg kg-1) and pressed anode slimes (2.7 percent by mass). In both the smelter dusts and anode slimes, X-ray absorption spectroscopy indicates that about two thirds of the Te is present as reduced tellurides. In anode slimes, electron microscopy shows that the remaining Te is present in an oxidized form in a complex Te-bearing oxidate phase also containing Pb, Cu, Ag, As, Sb, and S. These results clearly indicate that more efficient, increased recovery of Te may be possible, likely at minimal expense from operating copper processing operations, thereby providing more Te for manufacturing of products such as inexpensive high-efficiency solar panels.

  19. Influence of the selected alloy additions on limiting the phase formation in Cu-Zn alloys

    OpenAIRE

    J. Kozana; St. Rzadkosz; M. Piękoś

    2010-01-01

    Influence of the selected alloy additions into copper and zinc alloys was investigated in order to find out the possibility of limiting the precipitation of unfavourable phase . The observation of microstructures and strength tests were performed. The results of metallographic and strength investigations indicate positive influence of small amounts of nickel, cobalt or tellurium. The precise determination of the influence of the selected alloy additions on limiting the gamma phase formation ...

  20. Influence of the selected alloy additions on limiting the phase formation in Cu-Zn alloys

    Directory of Open Access Journals (Sweden)

    J. Kozana

    2010-01-01

    Full Text Available Influence of the selected alloy additions into copper and zinc alloys was investigated in order to find out the possibility of limiting the precipitation of unfavourable phase . The observation of microstructures and strength tests were performed. The results of metallographic and strength investigations indicate positive influence of small amounts of nickel, cobalt or tellurium. The precise determination of the influence of the selected alloy additions on limiting the gamma phase formation will be the subject of further examinations.

  1. NMR spectroscopy of organic compounds of selenium and tellurium. Communication 8. Constants of spin-spin interaction of /sup 125/Te-/sup 1/o/sup 3/C in nmr spectra of unsaturated organtellurides

    Energy Technology Data Exchange (ETDEWEB)

    Kalabin, G.A.; Kushnarev, D.F.; Valeev, R.B. (Irkutskij Gosudarstvennyj Univ. (USSR))

    1981-06-01

    On the basis of /sup 13/C NMR spectra of a series of unsaturated and aromatic tellurium compounds the constants of spin-spin interaction (SSIC) (sup(1.2)J(Te, C)) are measured. A reliable linear relation between /sup 1/J(Te, C) and s-character of a carbon orbitale forming bond with tellurium is found. Correlation of straight SSIC of carbon with selenium and tellurium in isological compounds is established.

  2. Comparison of analytical possibilities of inversion voltammetry of tellurium with cathodic and anodic potential scanning taking layer-by-layer analysis of GaAs-Te films as example

    International Nuclear Information System (INIS)

    Kaplin, A.A.; Portnyagina, Eh.O.; Gridaev, V.F.

    1979-01-01

    Possibility of application in analytical purposes of the process of tellurium precipitation electrosolution from the surfaces of graphite and mercury-graphite electrodes at the cathode scanning of the potential is shown. As a result of comparison of direct and inversion scanning with cathodic and anodic scanning of the potential, variants of voltammetric method of tellurium determination in artificial solutions and, taking the developed method of layer-by-layer analysis of the GaAsTe films as an example, advantage of mercury-graphite electrode with cathodic scanning as compared to graphite electrode with cathode scanning of the potential is shown. Reproducibility of the GaAs film analysis results according to anodic and cathodic tellurium peaks is satisfactory. Maximum deviation from the results of analysis of oxidation peaks and tellurium peduction does not exceed 15 rel. %. Thus, for tellurium concentrations, exceeding 5x10 -6 g-ion/l, both anodic and cathodic scanning of the potential can be used, though error in tellurium determination according to cathodic peaks is 1.5-2.0 times higher. At tellurium amounts lower 5x10 -6 g-ion/l the determination should be carried out according to the peaks of tellurium anodic oxidation from the surface of graphite electrode or according to the peaks of tellurium cathodic reduction from the surface of mercury-graphite electrode

  3. Investigation of evaporation characteristics of polonium and its lighter homologues selenium and tellurium from liquid Pb-Bi-eutecticum

    CERN Document Server

    Neuhausen, J; Eichler, B

    2004-01-01

    The evaporation behaviour of polonium and its lighter homologues selenium and tellurium dissolved in liquid Pb-Bi-eutecticum (LBE) has been studied at various temperatures in the range from 482 K up to 1330 K under Ar/H2 and Ar/H2O-atmospheres using γ-ray spectroscopy. Polonium release in the temperature range of interest for technical applications is slow. Within short term (1h) experiments measurable amounts of polonium are evaporated only at temperatures above 973 K. Long term experiments reveal that a slow evaporation of polonium occurs at temperatures around 873 K resulting in a fractional polonium loss of the melt around 1% per day. Evaporation rates of selenium and tellurium are smaller than those of polonium. The presence of H2O does not enhance the evaporation within the error limits of our experiments. The thermodynamics and possible reaction pathways involved in polonium release from LBE are discussed.

  4. Deposition of tellurium films by decomposition of electrochemically-generated H{sub 2}Te: application to radiative cooling devices

    Energy Technology Data Exchange (ETDEWEB)

    Engelhard, T.; Jones, E.D.; Viney, I. [Coventry Univ. (United Kingdom). Centre for Data Storage Mater.; Mastai, Y.; Hodes, G. [Department of Materials and Interfaces, Weizmann Institute of Science, 76100, Rehovot (Israel)

    2000-07-17

    The preparation of homogenous, large area thin layers of tellurium on thin polyethylene foils is described. The tellurium was formed by room temperature decomposition of electrochemically generated H{sub 2}Te. Pre-treatment of the polyethylene substrates with KMnO{sub 4} to give a Mn-oxide layer was found to improve the Te adhesion and homogeneity. Optical characterization of the layers was performed using UV/VIS/NIR spectroscopy. Such coatings have favorable characteristics for use as solar radiation shields in radiative cooling devices. The simplicity of generation of the very unstable H{sub 2}Te was also exploited to demonstrate formation of size-quantized CdTe nanocrystals. (orig.)

  5. Total β-decay energies and masses of tin, antimony and tellurium isotopes in the vicinity of 50132Sn82

    International Nuclear Information System (INIS)

    Lund, E.; Aleklett, K.; Rudstam, G.

    1977-01-01

    Experimental β-decay energies for short-lived isotopes of tin, antimony and tellurium are presented. Mass-separated sources were produced at the on-line isotope separator OSIRIS. By applying β-γ coincidence methods, total β-decay energies have been determined for the following nuclides: 127-131 Sn, 128 130 131 134 Sb and 134 135 Te. The atomic mass excess has been derived for these nuclei, and comparisons are made with mass formula predictions. (Auth.)

  6. Solvent Extraction of Tellurium from Chloride Solutions Using Tri-n-butyl Phosphate: Conditions and Thermodynamic Data

    Directory of Open Access Journals (Sweden)

    Dongchan Li

    2014-01-01

    Full Text Available The extractive separation of tellurium (IV from hydrochloric acid media with tri-n-butyl phosphate (TBP in kerosene was investigated. The dependence on the extraction of tellurium species, concentrations of tellurium and TBP, extraction time and stage, organic/aqueous ratio, and interferences from coexist metallic ions were examined and are discussed. Besides, the stripping agent and stripping time were also studied. It was found that the extraction reaction corresponds to the neutral complex formation mechanism and the extracted species is TeCl4·3TBP and that the extraction process is exothermic. The thermodynamic parameters of enthalpy ΔH, entropy ΔS, and free energy ΔG of the extraction process were evaluated at −26.2 kJ·mol−1, −65.6 J·mol−1·K−1, and −7.0 kJ·mol−1, respectively at 293 K.

  7. Synthesis of ultra-thin tellurium nanoflakes on textiles for high-performance flexible and wearable nanogenerators

    Energy Technology Data Exchange (ETDEWEB)

    He, Wen; Van Ngoc, Huynh; Qian, Yong Teng; Hwang, Jae Seok; Yan, Ya Ping [Department of Physics and Interdisciplinary Course of Physics and Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do (Korea, Republic of); Choi, Hongsoo [Department of Robotics Engineering, Daegu Gyeongbuk Institute of Science and Technology (DGIST), 711-873, Daegu (Korea, Republic of); Kang, Dae Joon, E-mail: djkang@skku.edu [Department of Physics and Interdisciplinary Course of Physics and Chemistry, Sungkyunkwan University, 2066, Seobu-ro, Jangan-gu, Suwon 16419, Gyeoggi-do (Korea, Republic of)

    2017-01-15

    Highlights: • Ultra-thin tellurium (Te) nanoflakes were successfully grown on textile and used as an active piezoelectric material. • Te nanoflake nanogenerator device was systematically studied by bending and compressing test. • The ultra-high output power during compressing test can light up 10 LEDs without any external power source. • The device can offer a breakthrough in applying tellurium nanoflakes into high-performance flexible and wearable piezoelectric nanogenerator. - Abstract: We report that ultra-thin tellurium (Te) nanoflakes were successfully grown on a sample of a gold-coated textile, which then was used as an active piezoelectric material. An output voltage of 4 V and a current of 300 nA were obtained from the bending test under a driving frequency of 10 Hz. To test the practical applications, Te nanoflake nanogenerator (TFNG) device was attached to the subject’s arm, and mechanical energy was converted to electrical energy by means of periodic arm-bending motions. The optimized open-circuit voltage and short-circuit current density of approximately 125 V and 17 μA/cm{sup 2}, respectively, were observed when a TFNG device underwent a compression test with a compressive force of 8 N and driving frequency of 10 Hz. This high-power generation enabled the instantaneous powering of 10 green light-emitting diodes that shone without any assistance from an external power source.

  8. Effect of sample preparation methods on photometric determination of the tellurium and cobalt content in the samples of copper concentrates

    Directory of Open Access Journals (Sweden)

    Viktoriya Butenko

    2016-03-01

    Full Text Available Methods of determination of cobalt and nickel in copper concentrates currently used in factory laboratories are very labor intensive and time consuming. The limiting stage of the analysis is preliminary chemical sample preparation. Carrying out the decomposition process of industrial samples with concentrated mineral acids in open systems does not allow to improve the metrological characteristics of the methods, for this reason improvement the methods of sample preparation is quite relevant and has a practical interest. The work was dedicated to the determination of the optimal conditions of preliminary chemical preparation of copper concentrate samples for the subsequent determination of cobalt and tellurium in the obtained solution using tellurium-spectrophotometric method. Decomposition of the samples was carried out by acid dissolving in individual mineral acids and their mixtures by heating in an open system as well as by using ultrasonification and microwave radiation in a closed system. In order to select the optimal conditions for the decomposition of the samples in a closed system the phase contact time and ultrasonic generator’s power were varied. Intensification of the processes of decomposition of copper concentrates with nitric acid (1:1, ultrasound and microwave radiation allowed to transfer quantitatively cobalt and tellurium into solution spending 20 and 30 min respectively. This reduced the amount of reactants used and improved the accuracy of determination by running the process in strictly identical conditions.

  9. Non-destructive local determination of doping additions and main components in single crystals

    International Nuclear Information System (INIS)

    Ehksperiandova, L.P.; Blank, A.B.; Kukhtina, N.N.; Afanasiadi, L.I.

    1994-01-01

    Procedures for local non-destructive determination of elements in optical and scintillation single crystals are developed. They are applied for determination of the main components (in cadmium tungstate) and doping additions (tellurium in zinc selenide, europium in gadolinium silicate). The metrological characteristics of the developed micro-analysis methods are estimated. Segregation of the main components and doping additions in the objects under consideration are investigated. Tellurium is found to be distributed uniformly on the cross-sections of bulk zinc selenide single crystals. The segregation of europium along gadolinium silicate ingots is almost absent. On the cross-section surface of cadmium tungstate single crystals the microregions are found characterized by the prevailing contents of cadmium or tungsten

  10. Tellurium stable isotope fractionation in chondritic meteorites and some terrestrial samples

    Science.gov (United States)

    Fehr, Manuela A.; Hammond, Samantha J.; Parkinson, Ian J.

    2018-02-01

    New methodologies employing a 125Te-128Te double-spike were developed and applied to obtain high precision mass-dependent tellurium stable isotope data for chondritic meteorites and some terrestrial samples by multiple-collector inductively coupled plasma mass spectrometry. Analyses of standard solutions produce Te stable isotope data with a long-term reproducibility (2SD) of 0.064‰ for δ130/125Te. Carbonaceous and enstatite chondrites display a range in δ130/125Te of 0.9‰ (0.2‰ amu-1) in their Te stable isotope signature, whereas ordinary chondrites present larger Te stable isotope fractionation, in particular for unequilibrated ordinary chondrites, with an overall variation of 6.3‰ for δ130/125Te (1.3‰ amu-1). Tellurium stable isotope variations in ordinary chondrites display no correlation with Te contents or metamorphic grade. The large Te stable isotope fractionation in ordinary chondrites is likely caused by evaporation and condensation processes during metamorphism in the meteorite parent bodies, as has been suggested for other moderately and highly volatile elements displaying similar isotope fractionation. Alternatively, they might represent a nebular signature or could have been produced during chondrule formation. Enstatite chondrites display slightly more negative δ130/125Te compared to carbonaceous chondrites and equilibrated ordinary chondrites. Small differences in the Te stable isotope composition are also present within carbonaceous chondrites and increase in the order CV-CO-CM-CI. These Te isotope variations within carbonaceous chondrites may be due to mixing of components that have distinct Te isotope signatures reflecting Te stable isotope fractionation in the early solar system or on the parent bodies and potentially small so-far unresolvable nucleosynthetic isotope anomalies of up to 0.27‰. The Te stable isotope data of carbonaceous and enstatite chondrites displays a general correlation with the oxidation state and hence might

  11. Thermoelectric properties of bismuth antimony tellurium thin films through bilayer annealing prepared by ion beam sputtering deposition

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zhuang-hao [College of Physics Science and Technology, Shenzhen University, 518060 (China); Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China); Fan, Ping, E-mail: fanping308@126.com [College of Physics Science and Technology, Shenzhen University, 518060 (China); Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China); Luo, Jing-ting [College of Physics Science and Technology, Shenzhen University, 518060 (China); Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China); Cai, Xing-min; Liang, Guang-xing; Zhang, Dong-ping [College of Physics Science and Technology, Shenzhen University, 518060 (China); Ye, Fan [Shenzhen Key Laboratory of Sensor Technology, Shenzhen 518060 (China)

    2014-07-01

    Bismuth antimony tellurium is one of the most important tellurium-based materials for high-efficient thermoelectric application. In this paper, ion beam sputtering was used to deposit Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} bilayer thin films on borosilicate substrates at room-temperature. Then the bismuth antimony tellurium thin films were synthesized via post thermal treatment of the Bi{sub 2}Te{sub 3} and Sb{sub 2}Te{sub 3} bilayer thin films. The effect of annealing temperature and compositions on the thermoelectric properties of the thin films was investigated. After the thin films were annealed from 150 °C to 350 °C for 1 h in the high vacuum condition, the Seebeck coefficient changed from a negative sign to a positive sign. The X-ray diffraction results showed that the synthesized tellurium-based thermoelectric thin film exhibited various alloys phases, which contributed different thermoelectricity conductivity to the synthesized thin film. The overall Seebeck coefficient of the synthesized thin film changed from negative sign to positive sign, which was due to the change of the primary phase of the tellurium-based materials at different annealing conditions. Similarly, the thermoelectric properties of the films were also associated with the grown phase. High-quality thin film with the Seebeck coefficient of 240 μV K{sup −1} and the power factor of 2.67 × 10{sup −3} Wm{sup −1} K{sup −2} showed a single Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} phase when the Sb/Te thin film sputtering time was 40 min. - Highlights: • Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} thermoelectric thin films synthesized via bilayer annealing • The film has single Bi{sub 0.5}Sb{sub 1.5}Te{sub 3} phase with best thermoelectric performance. • The film has high thermoelectric properties comparable with other best results.

  12. Validation of a new design of tellurium dioide-irradiated target

    Energy Technology Data Exchange (ETDEWEB)

    Fllaoui, Aziz; Ghamad, Younes; Zoubir, Brahim; Ayaz, Zinel Abidine; El Morabiti, Aissam; Amayoud, Hafid [Centre National de l' Energie des Sciences et des Techniques Nucleaires, Rabat (Morocco); Chakir, El Mahjoub [Nuclear Physics Department, University Ibn Toufail, Kenitra (Morocco)

    2016-10-15

    Production of iodine-131 by neutron activation of tellurium in tellurium dioxide (TeO{sub 2}) material requires a target that meets the safety requirements. In a radiopharmaceutical production unit, a new lid for a can was designed, which permits tight sealing of the target by using tungsten inert gas welding. The leakage rate of all prepared targets was assessed using a helium mass spectrometer. The accepted leakage rate is ≤ 10 - 4 mbr.L/s, according to the approved safety report related to iodine-131 production in the TRIGA Mark II research reactor (TRIGA: Training, Research, Isotopes, General Atomics). To confirm the resistance of the new design to the irradiation conditions in the TRIGA Mark II research reactor's central thimble, a study of heat effect on the sealed targets for 7 hours in an oven was conducted and the leakage rates were evaluated. The results show that the tightness of the targets is ensured up to 600 .deg. C with the appearance of deformations on lids beyond 450 .deg. C. The study of heat transfer through the target was conducted by adopting a one-dimensional approximation, under consideration of the three transfer modes-convection, conduction, and radiation. The quantities of heat generated by gamma and neutron heating were calculated by a validated computational model for the neutronic simulation of the TRIGA Mark II research reactor using the Monte Carlo N-Particle transport code. Using the heat transfer equations according to the three modes of heat transfer, the thermal study of I-131 production by irradiation of the target in the central thimble showed that the temperatures of materials do not exceed the corresponding melting points. To validate this new design, several targets have been irradiated in the central thimble according to a preplanned irradiation program, going from 4 hours of irradiation at a power level of 0.5 MW up to 35 hours (7 h/d for 5 days a week) at 1.5 MW. The results show that the irradiated targets are

  13. Validation of a New Design of Tellurium Dioxide-Irradiated Target

    Directory of Open Access Journals (Sweden)

    Aziz Fllaoui

    2016-10-01

    Full Text Available Production of iodine-131 by neutron activation of tellurium in tellurium dioxide (TeO2 material requires a target that meets the safety requirements. In a radiopharmaceutical production unit, a new lid for a can was designed, which permits tight sealing of the target by using tungsten inert gas welding. The leakage rate of all prepared targets was assessed using a helium mass spectrometer. The accepted leakage rate is ≤ 10−4 mbr.L/s, according to the approved safety report related to iodine-131 production in the TRIGA Mark II research reactor (TRIGA: Training, Research, Isotopes, General Atomics. To confirm the resistance of the new design to the irradiation conditions in the TRIGA Mark II research reactor's central thimble, a study of heat effect on the sealed targets for 7 hours in an oven was conducted and the leakage rates were evaluated. The results show that the tightness of the targets is ensured up to 600°C with the appearance of deformations on lids beyond 450°C. The study of heat transfer through the target was conducted by adopting a one-dimensional approximation, under consideration of the three transfer modes—convection, conduction, and radiation. The quantities of heat generated by gamma and neutron heating were calculated by a validated computational model for the neutronic simulation of the TRIGA Mark II research reactor using the Monte Carlo N-Particle transport code. Using the heat transfer equations according to the three modes of heat transfer, the thermal study of I-131 production by irradiation of the target in the central thimble showed that the temperatures of materials do not exceed the corresponding melting points. To validate this new design, several targets have been irradiated in the central thimble according to a preplanned irradiation program, going from 4 hours of irradiation at a power level of 0.5 MW up to 35 hours (7 h/d for 5 days a week at 1.5 MW. The results show that the irradiated targets are

  14. Raman and DSC studies of fragility in tellurium-zinc oxide glass formers

    International Nuclear Information System (INIS)

    Stavrou, Elissaios; Kripotou, Sotiria; Raptis, Constantine; Turrell, Sylvia; Syassen, Karl

    2011-01-01

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out in four mixed (TeO 2 ) 1-x (ZnO) x (x = 0.1, 0.2, 0.3, 0.4) glasses at high temperatures (Raman and DSC through the glass transition) and high pressures (Raman) with the aim of determining the fragility of these glass forming oxides. Four different criteria, corresponding to four parameters, were applied to assess the fragility of the glasses. From the DSC studies, we have obtained the fragility parameter m which corresponds to the slopes of Arrhenius (lnQ vs. 1/T g , were Q is the heating rate) plots, and the glass transition width ΔT g . Also, from the low-frequency Raman scattering, and in particular the boson peak intensity of the glasses at T g , we have estimated the fragility ratio r R (T g ) = I min /I max whose value serves as another (empirical) fragility criterion. Finally, from high pressure Raman measurements on the glasses, we have estimated the Grueneisen parameter γ T for each glass, which constitutes the fourth fragility parameter adopted in this work. Considering the four parameters ΔT g , m, r (T g ) and γ T and the generally accepted (empirical) fragility criteria, we conclude that the mixed tellurium-zinc oxides constitute strong-to-intermediate glass formers (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  15. Structural Modeling of Djenkolic Acid with Sulfur Replaced by Selenium and Tellurium

    Directory of Open Access Journals (Sweden)

    Petr Melnikov

    2014-04-01

    Full Text Available The comparative structural modeling of djenkolic acid and its derivatives containing selenium and tellurium in chalcogen sites (Ch = Se, Te has provided detailed information about the bond lengths and bond angles, filling the gap in what we know about the structural characteristics of these aminoacids. The investigation using the molecular mechanics technique with good approximation confirmed the available information on X-ray refinements for the related compounds methionine and selenomethionine, as well as for an estimate made earlier for telluromethionine. It was shown that the Ch-C(3 and Ch-C(4 bond lengths grow in parallel with the increasing anionic radii. Although the distances C-C, C-O, and C-N are very similar, the geometry of conformers is quite different owing to the possibility of rotation about four carbon atoms, hence the remarkable variability observed in dihedral angles. It was shown that the compounds contain a rigid block with two Ch atoms connected through a methylene group. The standard program Gaussian 03 with graphical interface Gaussview 4.1.2 has proved to be satisfactory tool for the structural description of less-common bioactive compositions when direct X-ray results are absent.

  16. From Selenium- to Tellurium-Based Glass Optical Fibers for Infrared Spectroscopies

    Directory of Open Access Journals (Sweden)

    Jacques Lucas

    2013-05-01

    Full Text Available Chalcogenide glasses are based on sulfur, selenium and tellurium elements, and have been studied for several decades regarding different applications. Among them, selenide glasses exhibit excellent infrared transmission in the 1 to 15 µm region. Due to their good thermo-mechanical properties, these glasses could be easily shaped into optical devices such as lenses and optical fibers. During the past decade of research, selenide glass fibers have been proved to be suitable for infrared sensing in an original spectroscopic method named Fiber Evanescent Wave Spectroscopy (FEWS. FEWS has provided very nice and promising results, for example for medical diagnosis. Then, some sophisticated fibers, also based on selenide glasses, were developed: rare-earth doped fibers and microstructured fibers. In parallel, the study of telluride glasses, which can have transmission up to 28 µm due to its atom heaviness, has been intensified thanks to the DARWIN mission led by the European Space Agency (ESA. The development of telluride glass fiber enables a successful observation of CO2 absorption band located around 15 µm. In this paper we review recent results obtained in the Glass and Ceramics Laboratory at Rennes on the development of selenide to telluride glass optical fibers, and their use for spectroscopy from the mid to the far infrared ranges.

  17. Dibromidochlorido{2-[(dimethylaminomethyl]phenyl-κ2N,C1}tellurium(IV

    Directory of Open Access Journals (Sweden)

    Prakul Rakesh

    2012-01-01

    Full Text Available The title compound, C9H13Br2ClNTe, was synthesized by reacting [2-(dimethylaminomethylphenyl]tellurium(II chloride with Br2. As a consequence, the Cl and Br atoms are not well ordered but distributed over the three possible positions such that the overall stiochiometry is two Br atoms and one Cl atom. The scrambling of the Br and Cl atoms indicates a small energy barrier for the exchange process between the apical and equatorial positions. Overall, the Te atom geometry is slightly distorted square pyramidal (τ = 0.052 for the major component. However, there is a weak secondary interaction between the Te atoms and the disordered Br/Cl atoms of a nearby molecule. The Te—Br and Te—Cl distances in both disorder components fall into two groups; a longer distance for the Br/Cl involved in this secondary interaction [2.6945 (17 Å for Br and 2.601 (9Å for Cl] and shorter bond distances to the remaining halogen atoms, indicating that this interaction has slightly weakened the Te—X bond, as is the case in the previously reported tribromido structure [Singh et al. (1990. J. Chem. Soc. Dalton Trans. pp. 907–913]. Otherwise, the metrical parameters in the two structures are not significantly different. An intermolecular C—H...Br interaction occurs.

  18. Size Controlled Synthesis of Tellurium Nanorices by Galvanic Displacement Reaction of Aluminum

    International Nuclear Information System (INIS)

    Wu, Tingjun; Myung, Lawrence Youngjae; Zhang, Miluo; Lee, Kyu-Hwan; Lee, Yeheun Laura; Lim, Hyo-Ryong; Kim, Bum Sung; Choa, Yong-Ho; Myung, Nosang V.

    2015-01-01

    ABSTRACT: Tellurium nanostructures were synthesized by galvanic displacement reaction (GDR) of aluminum in an alkaline solution containing TeO 3 2− ions. Due to negative redox potential of Al/AlO 2 − (i.e., −2.50 V vs. sat. Ag/AgCl), TeO 3 2− (+IV) can be reduced to Te 2 2− (-I) and Te 2− (-II), which resulted in the deposition of Te (0) nanostructures in the solution via chemical reaction between Te 2 2− or Te 2− and TeO 3 2− . The deposition mechanism led to the formation of unique “rice-like” nanostructures in the solution instead of branched structures on the substrate. The sharp tips of the “rice-like” nanostructures may be attributed to the high density of surface charges at the tips. The morphology, diameter and aspect ratio of Te “rice-like” nanostructures were altered by the TeO 3 2− concentration, solution pH, reaction time and the reaction temperature. Electrochemical analytical methods, including open circuit potential (OCP) and linear polarizations (LPs), were used to investigate the reaction mechanisms. The enhancement of piezoelectric constant (d 11 ) of nanorices at small diameter was probably due to a flexoelectric effect

  19. Iron-tellurium-selenium mixed oxide catalysts for the selective oxidation of propylene to acrolein

    International Nuclear Information System (INIS)

    Patel, B.M.; Price, G.L.

    1990-01-01

    This paper reports on iron-tellurium-selenium mixed oxide catalysts prepared by coprecipitation from aqueous solution investigated for the propylene to acrolein reaction in the temperature range 543-773 K. Infrared spectroscopy, electron dispersive X-ray analysis, X-ray diffraction, and isotopic tracer techniques have also been employed to characterize this catalytic system. Properties of the Fe-Te-Se mixed oxide catalysts have been compared with Fe-Te mixed oxides in an effort to deduce the functionality of Se. The selenium in the Fe-Te-Se-O catalyst has been found to be the hydrocarbon activating site. The activation energies for the acrolein and carbon dioxide formation are 71 and 54 kJ/mol, respectively. Reactions carried out with 18 O 2 have shown lattice oxygen to be primarily responsible for the formation of both acrolein and carbon dioxide. The initial and rate-determining step for acrolein formation is hydrogen abstraction as determined by an isotope effect associated with the C 3 D 6 reaction. No isotope effect is observed for carbon dioxide formation from C 3 D 6 suggesting that CO 2 is formed by parallel, not consecutive, oxidation of propylene

  20. Study on concentration nonlinearity of interacting acoustic flows in cadmium sulfide and tellurium

    International Nuclear Information System (INIS)

    Ilisavskij, Yu.V.; Kulakova, L.A.; Yakhkind, Eh.Z.

    1976-01-01

    The ratio of an one-mode (self-action of an external monochromatic sound wave) and a many-mode (interaction of an external wave with crystal thermal phonons) concentration nonlinearity has been experimentally investigated on sound amplification in cadmium sulphide and tellurium. It has been shown that in a strong piezoelectric the main part in the nonlinear limitation of the sound amplification in a drift field is played by the wave interaction, i.e., the transfer of the sound wave energy into the crystal sound modes starts before the nonlinear self-action of a wave. In Te characterized by a large value of the electromechanical coupling constant value at the sound frequency of about 250 MHz the threshold of many-mode nonlinearity is achieved in fields much below the critical one, and corresponds to the sound intensity as low as 10 -7 W/cm 2 , as compared with 10 -2 W/cm 2 -the threshold of the one-mode nonlinearity

  1. Antiparasitic activity of 1,3-dioxolanes containing tellurium in Trichomonas vaginalis.

    Science.gov (United States)

    Sena-Lopes, Ângela; das Neves, Raquel Nascimento; Bezerra, Francisco Silvestre Brilhante; de Oliveira Silva, Mara Thais; Nobre, Patrick C; Perin, Gelson; Alves, Diego; Savegnago, Lucielli; Begnini, Karine Rech; Seixas, Fabiana Kommling; Collares, Tiago; Borsuk, Sibele

    2017-05-01

    The increased prevalence of metronidazole-resistant infections has resulted in a search for alternative drugs for the treatment of trichomoniasis. In the present study, we report the preparation and in vitro activity of three 1,3-dioxolanes that contain tellurium (PTeDOX 01, PTeDOX 02, and PTeDOX 03) against Trichomonas vaginalis. Six concentrations of these compounds were analyzed for in vitro activity against ATCC 30236 isolate of T. vaginalis. PTeDOX 01 reported a cytotoxic effect against 100% of T. vaginalis trophozoites at a final concentration of 90μM with an IC 50 of 60μM. The kinetic growth curve of trophozoites indicated that PTeDOX 01 reduced the growth by 22% at a concentration of 90μM after an exposure of 12h, and induced complete parasite death at 24h. It induced cytotoxicity of 44% at 90μM concentration but and had no effect in lower concentrations in a culture of CHO-K1 cells. These results confirmed that PTeDOX 01 is an important drug for the treatment of T. vaginalis, and should be evaluated in other infectious agents as well. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Laser resonance ionization scheme development for tellurium and germanium at the dual Ti:Sa–Dye ISOLDE RILIS

    Energy Technology Data Exchange (ETDEWEB)

    Day Goodacre, T., E-mail: thomas.day.goodacre@cern.ch [CERN, CH-1211 Geneva 23 (Switzerland); School of Physics and Astronomy, The University of Manchester, Manchester M13 9PL (United Kingdom); Fedorov, D. [Petersburg Nuclear Physics Institute, 188350 Gatchina (Russian Federation); Fedosseev, V.N.; Forster, L.; Marsh, B.A. [CERN, CH-1211 Geneva 23 (Switzerland); Rossel, R.E. [CERN, CH-1211 Geneva 23 (Switzerland); Institut für Physik, Johannes Gutenberg Universität, D-55099 Mainz (Germany); Faculty of Design, Computer Science and Media, Hochschule RheinMain, Wiesbaden (Germany); Rothe, S.; Veinhard, M. [CERN, CH-1211 Geneva 23 (Switzerland)

    2016-09-11

    The resonance ionization laser ion source (RILIS) is the principal ion source of the ISOLDE radioactive beam facility based at CERN. Using the method of in-source laser resonance ionization spectroscopy, a transition to a new autoionizing state of tellurium was discovered and applied as part of a three-step, three-resonance, photo-ionization scheme. In a second study, a three-step, two-resonance, photo-ionization scheme for germanium was developed and the ionization efficiency was measured at ISOLDE. This work increases the range of ISOLDE RILIS ionized beams to 31 elements. Details of the spectroscopy studies are described and the new ionization schemes are summarized.

  3. Laser resonance ionization scheme development for tellurium and germanium at the dual Ti:Sa–Dye ISOLDE RILIS

    CERN Document Server

    Day Goodacre, T.; Fedosseev, V.N.; Forster, L.; Marsh, B.A.; Rossel, R.E.; Rothe, S.; Veinhard, M.

    2016-01-01

    The resonance ionization laser ion source (RILIS) is the principal ion source of the ISOLDE radioactive beam facility based at CERN. Using the method of in-source laser resonance ionization spectroscopy, a transition to a new autoionizing state of tellurium was discovered and applied as part of a three-step, three-resonance, photo-ionization scheme. In a second study, a three-step, two-resonance, photo-ionization scheme for germanium was developed and the ionization efficiency was measured at ISOLDE. This work increases the range of ISOLDE RILIS ionized beams to 31 elements. Details of the spectroscopy studies are described and the new ionization schemes are summarized.

  4. Reaction of 1-bromo-3-chloropropane with tellurium and dimethyl telluride in the system of hydrazine hydrate-alkali

    International Nuclear Information System (INIS)

    Russavskaya, N.V.; Levanova, E.P.; Sukhomazova, Eh.N.; Grabel'nykh, V.A.; Elaev, A.V.; Klyba, L.V.; Zhanchipova, E.R.; Albanov, A.I.; Korotaeva, I.M.; Toryashinova, D.S.D.; Korchevin, N.A.

    2006-01-01

    A synthesis of oligomeric substance of thiocol type, the poly(trimethyleneditelluride), from 1-bromo-3-chloropropane and elemental tellurium is performed using a hydrazine hydrate-alkali system. Reductive splitting of the tellurocol followed by alkylation with methyl iodide give rise to preparation of bis(methyltelluro)propane, which was synthesized also from dimethyl telluride and 1,3-dihalopropanes using the N 2 H 4 ·H 2 O/KOH system. The reaction products were characterized by elementary analysis, NMR, and IR spectra. Mass spectra of the synthesized low molecular weight organotellurium compounds are considered [ru

  5. Luminescent Tellurium-Doped Cadmium Sulfide Electrodes as Probes of Semiconductor Excited-State Deactivation Processes in Photoelectrochemical Cells.

    Science.gov (United States)

    1980-08-12

    photocurrent and emission intensity. Whereas CdS:Te electrochemistry consisted of oxidation of an electrolyte 2+ reductant, ZnO underwent photoanodic...employed n- and 1 3 2,3 3 3,4p-type GaPl’ n-type ZnO , n-type CdS , and n- and p-type GaAs. We have focussed our attention recently on n-type, tellurium...should point out that our treatment of Or and 0x is not without precedent. Both GaP- and ZnO -based PECs have been examined in this regard.l12 The

  6. Surface studies on graphite furnace platforms covered with Pd, Rh and Ir as modifiers in graphite furnace atomic absorption spectrometry of tellurium

    Energy Technology Data Exchange (ETDEWEB)

    Pedro, Juana [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Stripekis, Jorge [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina); Departamento de Ingeniería Química, Instituto Tecnológico de Buenos Aires, Av. Eduardo Madero 399 (1106), Buenos Aires (Argentina); Bonivardi, Adrian [Area de Química Analítica, Departamento de Química, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Tudino, Mabel, E-mail: tudino@qi.fcen.uba.ar [Laboratorio de Análisis de Trazas, Departamento de Química Inorgánica, Analítica y Química Física, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina)

    2015-05-01

    The main objective of this work is the study of correlations between the efficiency of the distribution of the permanent platinum group modifiers Pd, Rh and Ir over the graphite surface with the aim of improving analytical signal of tellurium. Modifier solution was deposited onto the platform and pyrolysed after drying. In the case of Pd, the physical vaporization/deposition technique was also tested. In order to analyze the differences amongst coverings (morphology, topology and distribution), the graphite surfaces were studied with scanning electron microscopy and energy dispersive X-ray microscopy. Micrographs for physical vaporization and pyrolytic deposition of Pd were also analyzed in order to explain the lack of signal obtained for tellurium with the first alternative. Similar micrographs were obtained for pyrolytic deposition of Ir and Rh and then, compared to those of Pd. Ir showed the most homogeneous distribution on the graphite surface and the tallest and sharpest transient. With the aim of improving the analytical signal of tellurium, the correlation between the surface studies and the tellurium transient signal (height, area and shape) is discussed. - Highlights: • Distribution of Rh, Pd and Ir onto graphite furnaces is evaluated by SEM and EDX • Micrographs and spectra showed that surface distribution could influence Te signal. • Ir showed the best signal together with the most homogeneous surface distribution. • Pd-PVD micrographs revealed the absence of graphite and no signal for Te.

  7. Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions

    Science.gov (United States)

    Ramos-Ruiz, Adriana; Wilkening, Jean V.; Field, James A.; Sierra-Alvarez, Reyes

    2017-01-01

    A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. PMID:28472709

  8. Development of tellurium oxide and lead-bismuth oxide glasses for mid-wave infra-red transmission optics

    Science.gov (United States)

    Zhou, Beiming; Rapp, Charles F.; Driver, John K.; Myers, Michael J.; Myers, John D.; Goldstein, Jonathan; Utano, Rich; Gupta, Shantanu

    2013-03-01

    Heavy metal oxide glasses exhibiting high transmission in the Mid-Wave Infra-Red (MWIR) spectrum are often difficult to manufacture in large sizes with optimized physical and optical properties. In this work, we researched and developed improved tellurium-zinc-barium and lead-bismuth-gallium heavy metal oxide glasses for use in the manufacture of fiber optics, optical components and laser gain materials. Two glass families were investigated, one based upon tellurium and another based on lead-bismuth. Glass compositions were optimized for stability and high transmission in the MWIR. Targeted glass specifications included low hydroxyl concentration, extended MWIR transmission window, and high resistance against devitrification upon heating. Work included the processing of high purity raw materials, melting under controlled dry Redox balanced atmosphere, finning, casting and annealing. Batch melts as large as 4 kilograms were sprue cast into aluminum and stainless steel molds or temperature controlled bronze tube with mechanical bait. Small (100g) test melts were typically processed in-situ in a 5%Au°/95%Pt° crucible. Our group manufactured and evaluated over 100 different experimental heavy metal glass compositions during a two year period. A wide range of glass melting, fining, casting techniques and experimental protocols were employed. MWIR glass applications include remote sensing, directional infrared counter measures, detection of explosives and chemical warfare agents, laser detection tracking and ranging, range gated imaging and spectroscopy. Enhanced long range mid-infrared sensor performance is optimized when operating in the atmospheric windows from ~ 2.0 to 2.4μm, ~ 3.5 to 4.3μm and ~ 4.5 to 5.0μm.

  9. Flavoprotein-mediated tellurite reduction: structural basis and applications to the synthesis of tellurium-containing nanostructures

    Directory of Open Access Journals (Sweden)

    Mauricio Arenas-Salinas

    2016-07-01

    Full Text Available The tellurium oxyanion tellurite (TeO32- is extremely harmful for most organisms. It has been suggested that a potential bacterial tellurite resistance mechanism would consist of an enzymatic, NAD(PH-dependent, reduction to the less toxic form elemental tellurium (Te0. To date, a number of enzymes such as catalase, type II NADH dehydrogenase and terminal oxidases from the electron transport chain, nitrate reductases, and dihydrolipoamide dehydrogenase (E3, among others, have been shown to display tellurite-reducing activity. This activity is generically referred to as tellurite reductase (TR. Bioinformatic data resting on some of the abovementioned enzymes enabled the identification of common structures involved in tellurite reduction including vicinal catalytic cysteine residues and the FAD/NAD(P+-binding domain, which is characteristic of some flavoproteins. Along this line, thioredoxin reductase (TrxB, alkyl hydroperoxide reductase (AhpF, glutathione reductase (GorA, mercuric reductase (MerA, NADH: flavorubredoxin reductase (NorW, dihydrolipoamide dehydrogenase, and the putative oxidoreductase YkgC from Escherichia coli or environmental bacteria were purified and assessed for TR activity. All of them displayed in vitro TR activity at the expense of NADH or NADPH oxidation. In general, optimal reducing conditions occurred around pH 9-10 and 37 °C.Enzymes exhibiting strong TR activity produced Te-containing nanostructures (TeNS. While GorA and AhpF generated TeNS of 75 nm average diameter, E3 and YkgC produced larger structures (> 100 nm. Electron-dense structures were observed in cells over-expressing genes encoding TrxB, GorA and YkgC.

  10. Determination of gold, indium, tellurium and thallium in the same sample digest of geological materials by atomic-absorption spectroscopy and two-step solvent extraction

    Science.gov (United States)

    Hubert, A.E.; Chao, T.T.

    1985-01-01

    A rock, soil, or stream-sediment sample is decomposed with hydrofluoric acid, aqua regia, and hydrobromic acid-bromine solution. Gold, thallium, indium and tellurium are separated and concentrated from the sample digest by a two-step MIBK extraction at two concentrations of hydrobromic add. Gold and thallium are first extracted from 0.1M hydrobromic acid medium, then indium and tellurium are extracted from 3M hydrobromic acid in the presence of ascorbic acid to eliminate iron interference. The elements are then determined by flame atomic-absorption spectrophotometry. The two-step solvent extraction can also be used in conjunction with electrothermal atomic-absorption methods to lower the detection limits for all four metals in geological materials. ?? 1985.

  11. Use of Iodine-131 to Tellurium-132 Ratios for Assessing the Relationships between Human Inhaled Radioactivity and Environmental Monitoring after the Accident in Fukushima

    Directory of Open Access Journals (Sweden)

    Koji Uchiyama

    2018-03-01

    Full Text Available Significant differences in findings were seen between the intake amounts of iodine-131 that were derived from direct measurements and the estimated intake from environmental monitoring data at the Fukushima accident. To clarify these discrepancies, we have investigated the iodine-131 and tellurium-132 body burdens of five human subjects, who after being exposed to a radioactive plume, underwent 21.5 h whole body counter measurements at Fukui Prefectural Hospital, so clear intake scenario and thyroid counter measurement data were available. To determine the iodine-131 and tellurium-132 body burdens, we introduced a new method of whole body counter calibration composed of a self-consistent approach with the time-dependent correction efficiency factors concept. The ratios of iodine-131 to tellurium-132, ranging from 0.96 ± 0.05 to 2.29 ± 0.38, were consistent with results of the environmental measurements. The 24 h iodine uptake values ranging from 12.1–16.0% were within euthyroid range in Japanese people. These results suggest, even if the relatively low thyroid iodine uptake in the Japanese population was taken into consideration, that there is no doubt about the consistency between direct measurements and environmental monitoring data. Adequate intake scenario is suggested to be principally important to estimate the inhaled radioactivity in areas in or around nuclear accidents.

  12. A laser system for the spectroscopy on highly charged ions, tellurium molecules, and Rydberg states of rubidium atoms; Ein Lasersystem zur Spektroskopie von hochgeladenen Ionen, Tellurmolekuelen und Rubidium-Rydberg-Zustaenden

    Energy Technology Data Exchange (ETDEWEB)

    Albrecht, Sebastian

    2014-08-15

    Optical measuring methods allow the detection and identification of the atomic structure with extraordinary precision. Deviations to theoretical predictions can indicate unknown physical effects. Therefore, precise measurements on the atomic structure continue to be of large relevance. In this work, a laser system for precision spectroscopy on Bismuth ({sup 209}Bi{sup 82+}), Tellurium ({sup 130}Te{sub 2}) and Rydberg states of Rubidium ({sup 85}Rb) has been built and characterized. Spectroscopic measurements on Tellurium and Rubidium have been achieved with this setup. The system consists of a two-stage frequency doubled diode laser, stabilized via a cavity and an RF-offsetlock to arbitrary wavelengths with absolute high stability. The setup of the laser system will be presented and the systematic error caused by the refractive index of air inside the transfer cavity will be discussed. A stability of better then 6.14 MHz at 244 nm is obtained for planned experiments on the ground state hyperfine splitting of {sup 209}Bi{sup 82+}. This will allow an increase in precision of more then four orders of magnitude for this measurement. Further increase in precision can be achieved by using an evacuated cavity. The obtained stability is measured by comparison of the laser frequency to absorption lines of Tellurium ({sup 130}Te{sub 2}). Eight reference lines, known from literature, spanning the region from 613720.717 GHz to 616803.545 GHz have been measured. The frequency measurements of three lines, coinciding with the emission spectrum of an argon-ion-laser, show deviations with respect to the published frequencies. Further inconsistencies in literature are cleared. Part of this work is also the precise measurement of 843 Doppler-free {sup 130}Te{sub 2} reference lines spanning the frequency range from 613881.150 GHz to 616614.258 GHz at a precision of better then 4 MHz for most lines. Additionally, measurements on electromagnetically induced transparency (EIT) using

  13. Additive manufacturing.

    Science.gov (United States)

    Mumith, A; Thomas, M; Shah, Z; Coathup, M; Blunn, G

    2018-04-01

    Increasing innovation in rapid prototyping (RP) and additive manufacturing (AM), also known as 3D printing, is bringing about major changes in translational surgical research. This review describes the current position in the use of additive manufacturing in orthopaedic surgery. Cite this article: Bone Joint J 2018;100-B:455-60.

  14. Food additives

    Science.gov (United States)

    ... GO About MedlinePlus Site Map FAQs Customer Support Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Food additives URL of this page: //medlineplus.gov/ency/article/ ...

  15. Raman scattering boson peak and differential scanning calorimetry studies of the glass transition in tellurium-zinc oxide glasses.

    Science.gov (United States)

    Stavrou, E; Tsiantos, C; Tsopouridou, R D; Kripotou, S; Kontos, A G; Raptis, C; Capoen, B; Bouazaoui, M; Turrell, S; Khatir, S

    2010-05-19

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out on four mixed tellurium-zinc oxide (TeO(2))(1 - x)(ZnO)(x) (x = 0.1, 0.2, 0.3, 0.4) glasses under variable temperature, with particular attention being given to the respective glass transition region. From the DSC measurements, the glass transition temperature T(g) has been determined for each glass, showing a monotonous decrease of T(g) with increasing ZnO content. The Raman study is focused on the low-frequency band of the glasses, the so-called boson peak (BP), whose frequency undergoes an abrupt decrease at a temperature T(d) very close to the respective T(g) values obtained by DSC. These results show that the BP is highly sensitive to dynamical effects over the glass transition and provides a means for an equally reliable (to DSC) determination of T(g) in tellurite glasses and other network glasses. The discontinuous temperature dependence of the BP frequency at the glass transition, along with the absence of such a behaviour by the high-frequency Raman bands (due to local atomic vibrations), indicates that marked changes of the medium range order (MRO) occur at T(g) and confirms the correlation between the BP and the MRO of glasses.

  16. Raman scattering boson peak and differential scanning calorimetry studies of the glass transition in tellurium-zinc oxide glasses

    International Nuclear Information System (INIS)

    Stavrou, E; Tsiantos, C; Tsopouridou, R D; Kripotou, S; Kontos, A G; Raptis, C; Capoen, B; Bouazaoui, M; Turrell, S; Khatir, S

    2010-01-01

    Raman scattering and differential scanning calorimetry (DSC) measurements have been carried out on four mixed tellurium-zinc oxide (TeO 2 ) 1-x (ZnO) x (x = 0.1, 0.2, 0.3, 0.4) glasses under variable temperature, with particular attention being given to the respective glass transition region. From the DSC measurements, the glass transition temperature T g has been determined for each glass, showing a monotonous decrease of T g with increasing ZnO content. The Raman study is focused on the low-frequency band of the glasses, the so-called boson peak (BP), whose frequency undergoes an abrupt decrease at a temperature T d very close to the respective T g values obtained by DSC. These results show that the BP is highly sensitive to dynamical effects over the glass transition and provides a means for an equally reliable (to DSC) determination of T g in tellurite glasses and other network glasses. The discontinuous temperature dependence of the BP frequency at the glass transition, along with the absence of such a behaviour by the high-frequency Raman bands (due to local atomic vibrations), indicates that marked changes of the medium range order (MRO) occur at T g and confirms the correlation between the BP and the MRO of glasses.

  17. Enhancement of Thermoelectric Properties of PEDOT:PSS and Tellurium-PEDOT:PSS Hybrid Composites by Simple Chemical Treatment

    Science.gov (United States)

    Jin Bae, Eun; Hun Kang, Young; Jang, Kwang-Suk; Yun Cho, Song

    2016-01-01

    The thermoelectric properties of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and tellurium-PEDOT:PSS (Te-PEDOT:PSS) hybrid composites were enhanced via simple chemical treatment. The performance of thermoelectric materials is determined by their electrical conductivity, thermal conductivity, and Seebeck coefficient. Significant enhancement of the electrical conductivity of PEDOT:PSS and Te-PEDOT:PSS hybrid composites from 787.99 and 11.01 to 4839.92 and 334.68 S cm-1, respectively was achieved by simple chemical treatment with H2SO4. The power factor of the developed materials could be effectively tuned over a very wide range depending on the concentration of the H2SO4 solution used in the chemical treatment. The power factors of the developed thermoelectric materials were optimized to 51.85 and 284 μW m-1 K-2, respectively, which represent an increase of four orders of magnitude relative to the corresponding parameters of the untreated thermoelectric materials. Using the Te-PEDOT:PSS hybrid composites, a flexible thermoelectric generator that could be embedded in textiles was fabricated by a printing process. This thermoelectric array generates a thermoelectric voltage of 2 mV using human body heat.

  18. Acousto-optic control of internal acoustic reflection in tellurium dioxide crystal in case of strong elastic energy walkoff [Invited].

    Science.gov (United States)

    Voloshinov, Vitaly; Polikarpova, Nataliya; Ivanova, Polina; Khorkin, Vladimir

    2018-04-01

    Peculiar cases of acoustic wave propagation and reflection may be observed in strongly anisotropic acousto-optical crystals. A tellurium dioxide crystal serves as a prime example of such media, since it possesses record indexes of acoustic anisotropy. We studied one of the unusual scenarios of acoustic incidence and reflection from a free crystal-vacuum boundary in paratellurite. The directions of the acoustic waves in the (001) plane of the crystal were determined, and their basic characteristics were calculated. The carried-out acousto-optic experiment at the wavelength of light 532 nm and the acoustic frequency 73 MHz confirmed the theoretical predictions. The effects examined in the paper include the acoustic wave propagation with the record walkoff angle 74°. We also observed the incidence of the wave on the boundary at the angle exceeding 90°. Finally, we registered the close-to-back reflection of acoustic energy following the incidence. One of the stunning aspects is the distribution of energy between the incident and the back-reflected wave. The unusual features of the acoustic wave reflections pointed out in the paper are valuable for their possible applications in acousto-optic devices.

  19. Resonant ionization by laser beams: application to ions sources and to study the nuclear structure of radioactive tellurium isotopes

    International Nuclear Information System (INIS)

    Sifi, R.

    2007-07-01

    The radioactive ion beams that are produced through current isotope separators are well separated according to the A mass but not according to the Z parameter. The resonant ionization through laser beams applied to ion sources allows the production of radioactive ion beam in a very selective and efficient way by eliminating the isobaric contamination. The first chapter is dedicated to the resonant ionization by laser beams, we describe the principle, the experimental setting, the lasers used, the ionization schemes and the domain of application. The second chapter deals with the application of resonant ionization to laser ion sources for the production of radioactive ion beams. We present experimental tests performed for getting copper ion beams. Resonant ionization through laser is also used in the spectroscopy experiments performed at the Isolde (isotope separation on-line device) installation in CERN where more than 20 elements are ionized very efficiently. The technique is based on a frequency scanning around the excitation transition of the atoms in order to probe the hyperfine structure. Laser spectroscopy allows the determination of the hyperfine structure as well as the isotopic shift of atoms. In the third chapter the method is applied to the spectroscopy of tellurium atoms. First, we define the 2 parameters on which the extraction is based: charge radius and nuclear moments, then we present several theoretical models that we have used to assess our experimental results. (A.C.)

  20. Comparative Analysis of Supply Risk-Mitigation Strategies for Critical Byproduct Minerals: A Case Study of Tellurium.

    Science.gov (United States)

    Bustamante, Michele L; Gaustad, Gabrielle; Alonso, Elisa

    2018-01-02

    Materials criticality assessment is a screening framework increasingly applied to identify materials of importance that face scarcity risks. Although these assessments highlight materials for the implicit purpose of informing future action, the aggregated nature of their findings make them difficult to use for guidance in developing nuanced mitigation strategy and policy response. As a first step in the selection of mitigation strategies, the present work proposes a modeling framework and accompanying set of metrics to directly compare strategies by measuring effectiveness of risk reduction as a function of the features of projected supply demand balance over time. The work focuses on byproduct materials, whose criticality is particularly important to understand because their supplies are inherently less responsive to market balancing forces, i.e., price feedbacks. Tellurium, a byproduct of copper refining, which is critical to solar photovoltaics, is chosen as a case study, and three commonly discussed byproduct-relevant strategies are selected: dematerialization of end-use product, byproduct yield improvement, and end-of-life recycling rate improvement. Results suggest that dematerialization will be nearly twice as effective at reducing supply risk as the next best option, yield improvement. Finally, due to its infrequent use at present and its dependence upon long product lifespans, recycling end-of-life products is expected to be the least effective option despite potentially offering other benefits (e.g., cost savings and environmental impact reduction).

  1. Leaching of cadmium and tellurium from cadmium telluride (CdTe) thin-film solar panels under simulated landfill conditions.

    Science.gov (United States)

    Ramos-Ruiz, Adriana; Wilkening, Jean V; Field, James A; Sierra-Alvarez, Reyes

    2017-08-15

    A crushed non-encapsulated CdTe thin-film solar cell was subjected to two standardized batch leaching tests (i.e., Toxicity Characteristic Leaching Procedure (TCLP) and California Waste Extraction Test (WET)) and to a continuous-flow column test to assess cadmium (Cd) and tellurium (Te) dissolution under conditions simulating the acidic- and the methanogenic phases of municipal solid waste landfills. Low levels of Cd and Te were solubilized in both batch leaching tests (<8.2% and <3.6% of added Cd and Te, respectively). On the other hand, over the course of 30days, 73% of the Cd and 21% of the Te were released to the synthetic leachate of a continuous-flow column simulating the acidic landfill phase. The dissolved Cd concentration was 3.24-fold higher than the TCLP limit (1mgL -1 ), and 650-fold higher than the maximum contaminant level established by the US-EPA for this metal in drinking water (0.005mgL -1 ). In contrast, the release of Cd and Te to the effluent of the continuous-flow column simulating the methanogenic phase of a landfill was negligible. The remarkable difference in the leaching behavior of CdTe in the columns is related to different aqueous pH and redox conditions promoted by the microbial communities in the columns, and is in agreement with thermodynamic predictions. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. The use of masking agents in the determination, by hydride generation and atomic-absorption spectrophotometry, of arsenic, antimony, selenium, tellurium, and bismuth in the presence of noble metals

    International Nuclear Information System (INIS)

    Kellerman, S.P.

    1982-01-01

    The effectiveness of thiosemicarbazide, tellurium, and potassium iodide as masking agents to eliminate interferences was assessed. Thiosemicarbazide was found to be effective in eliminating or reducing the interferences on arsenic, antimony, and bismuth, and tellurium reduced the interferences on selenium. The interferences on tellurium could not be eliminated. Arsenic, antimony, selenium, and bismuth were determined in metal sulphide concentrates that were spiked with the noble metals (defined here as gold plus all the platinum-group metals except osmium). The relative standard deviations for arsenic, antimony, bismuth, and selenium were 0,061, 0,017, 0,029, and 0,145 respectively. The values obtained for all the analytes agreed favourably with the preferred values for two in-house reference samples. The laboratory method is detailed in an appendix

  3. Challenges in assessment of clean energy supply-chains based on byproduct minerals: A case study of tellurium use in thin film photovoltaics

    International Nuclear Information System (INIS)

    Bustamante, Michele L.; Gaustad, Gabrielle

    2014-01-01

    Highlights: • Byproduct mining presents unique challenges to quantifying energy security issues. • This case study shows Te scarcity is closely tied to Cu demand and production. • Material intensity changes over time have a significant impact on projections. • Recycling as a mitigation strategy is shown to have poor short-term results. - Abstract: Transitioning to a sustainable energy supply will be critical to meeting future economic and environmental goals. This transition will require optimizing and commercializing a portfolio of new clean energy technologies. However, many promising clean energy technologies are based on materials with inherent risks in their supply; these risks include scarcity, price volatility, criticality, and other potential supply-chain disruptions. Using tellurium use in CdTe photovoltaics as a case study, this paper presents analysis of some of the key challenges associated with modeling byproduct systems (a supply-chain where a key material is actually a byproduct of extraction of another material, copper in the case of tellurium). This work presents a novel modeling approach; the results of the case study are used to identify potential supply risks facing this clean technology, with a unique focus on sensitivity to changes in the preliminary lifecycle stages. Supply-chain sensitivities are connected with direct environmental impacts to frame the implications in a broader sustainability context and to emphasize the future role of recycling. Ultimately, it was shown that if historical supply and demand trends continue, supply gap conditions will emerge before the end of the current decade. However, improvements in byproduct yield, end-use recycling rate, and end-use material intensity exhibit significant leverage to minimize risk in the energy-critical tellurium supply-chain

  4. Determination of tellurium at ultra-trace levels in drinking water by on-line solid phase extraction coupled to graphite furnace atomic absorption spectrometer

    International Nuclear Information System (INIS)

    Pedro, Juana; Stripekis, Jorge; Bonivardi, Adrian; Tudino, Mabel

    2008-01-01

    In this paper, two time-based flow injection (FI) separation pre-concentration systems coupled to graphite furnace atomic absorption spectrometry (GFAAS) for tellurium determination are studied and compared. The first alternative involves the pre-concentration of the analyte onto Dowex 1X8 employed as packaging material of a micro-column inserted in the flow system. The second set-up is based on the co-precipitation of tellurium with La(OH) 3 followed by retention onto XAD resins. Both systems are compared in terms of limit of detection, linear range, RSD%, sample throughput, micro-columns lifetime and aptitude for fully automatic operation. The features of the Dowex system are: 37% efficiency of retention and an enhancement factor of 42 for a pre-concentration time of 180 seconds (sample flow rate = 3 ml min -1 ) with acetic acid elution volumes of 80 μl. The detection limit (3 s) is 7 ng l -1 and the relative standard deviation (n = 7200 ng l -1 ) is 5.8%. The analytical performance of the XAD system is: 72% efficiency of retention and an enhancement factor of 25 for a pre-concentration time of 180 s (sample flow rate = 3 ml min -1 ) with nitric acid elution volumes of 300 μl. The detection limit is 66 ng l -1 and the relative standard deviation (n = 7200 ng l -1 ) is 8.3%. Applications to the determination of tellurium in tap water and the validation of the analytical methodology employing SRM 1643e as certified reference material are shown

  5. Test of irradiation of tellurium oxide for obtaining iodine-131 by dry distillation; Prueba de irradiacion de dioxido de telurio para obtener yodo-131 por destilacion seca

    Energy Technology Data Exchange (ETDEWEB)

    Alanis M, J. [ININ, Departamento de Materiales Radiactivos, 52045 Ocoyoacac, Estado de Mexico (Mexico)

    2003-07-15

    With the purpose of optimizing to the maximum independently the work of the reactor of those mathematical calculations of irradiation that are already optimized, now it corresponds to carry out irradiation tests in the different positions with their respective neutron fluxes that it counts the reactor for samples irradiation. Then, it is necessary to carry out the irradiation of the tellurium dioxide through cycles, with the purpose of observing the activity that it goes accumulating in each cycle and this way to obtain an activity of the Iodine-131 obtained when finishing the last cycle. (Author)

  6. Stability studies of arsenic, selenium, antimony and tellurium species in water, urine, fish and soil extracts using HPLC/ICP-MS

    Energy Technology Data Exchange (ETDEWEB)

    Lindemann, T.; Prange, A.; Neidhart, B. [GKSS Research Centre, Geesthacht (Germany). Inst. of Physical and Chemical Analysis; Dannecker, W. [Hamburg Univ. (Germany). Inst. fuer Anorganische und Angewandte Chemie

    2000-10-01

    The stability of arsenic, selenium, antimony and tellurium species in water and urine (NIST SRM 2670n) as well as in extracts of fish and soil certified reference materials (DORM-2 and NIST SRM 2710) has been investigated. Stability studies were carried out with As(III), As(V), arsenobetaine, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), phenylarsonic acid (PAA), Se(IV), Se(VI), selenomethionine, Sb(III), Sb(V) and Te(VI). Speciation analysis was performed by on-line coupling of anion exchange high-performance liquid chromatography (HPLC) with inductively coupled plasma mass spectrometry (ICP-MS). Best storage of aqueous mixtures of the examined species was achieved at 3 C whereas at -20 C species transformation especially of selenomethionine and Sb(V) took place and a new selenium species appeared within a period of 30 days. Losses and species transformations during extraction processes were investigated. Extraction of the spiked fish material with methanol/water led to partial conversion of Sb(III), Sb(V) and selenomethionine to two new antimony and one new selenium species. The other arsenic, selenium and tellurium species were almost quantitatively extracted. For soil spiked with MMA, PAA, Se(IV) and Sb(III), recoveries after extraction with water and sulfuric acid (0.01 mol/L) were below 20%. (orig.)

  7. Glass formation and structure of calcium antimony phosphate glasses and those doped with tellurium oxide

    Science.gov (United States)

    Li, Jun; Zhang, Yin; Nian, Shangjiu; Wu, Zhenning; Cao, Weijing; Zhou, Nianying; Wang, Danian

    2017-03-01

    An approximate glass-forming region in the P2O5-Sb2O3-CaO ternary system was determined. The properties and structure of two compositional series of (A) (75- x)P2O5- xSb2O3-25CaO ( x = 20, 25, 30, 35 mol%) and (B) 45P2O5-30Sb2O3-(25- x)CaO- xTeO2 ( x = 5, 10, 15, 20 mol%) were studied systematically. Thermal properties were investigated by means of differential scanning calorimetry (DSC). The densities of all samples were measured by Archimedes' method using distilled water as the immersion liquid. The water durability of the glasses was described by their dissolution rate (DR) in the distilled water at 90 °C for some time periods. Density, thermal stability and water durability were improved with the addition of Sb2O3 and TeO2. Structural studies were carried out by X-ray diffraction (XRD), infrared spectroscopy and Raman spectroscopy. The phosphate chain depolymerization occurred with the increase of Sb2O3 and the Q2 structural units transformed to the Q1 and Q0 structural units with the addition of TeO2.

  8. An additive approach to low temperature zero pressure sintering of bismuth antimony telluride thermoelectric materials

    Science.gov (United States)

    Catlin, Glenn C.; Tripathi, Rajesh; Nunes, Geoffrey; Lynch, Philip B.; Jones, Howard D.; Schmitt, Devin C.

    2017-03-01

    This paper presents an additive-based approach to the formulation of thermoelectric materials suitable for screen printing. Such printing processes are a likely route to such thermoelectric applications as micro-generators for wireless sensor networks and medical devices, but require the development of materials that can be sintered at ambient pressure and low temperatures. Using a rapid screening process, we identify the eutectic combination of antimony and tellurium as an additive for bismuth-antimony-telluride that enables good thermoelectric performance without a high pressure step. An optimized composite of 15 weight percent Sb7.5Te92.5 in Bi0.5Sb1.5Te3 is scaled up and formulated into a screen-printable paste. Samples fabricated from this paste achieve a thermoelectric figure of merit (ZT) of 0.74 using a maximum processing temperature of 748 K and a total thermal processing budget of 12 K-hours.

  9. Optical properties of tellurium-doped InxGa1-xAsySb1-y epitaxial layers studied by photoluminescence spectroscopy

    International Nuclear Information System (INIS)

    Diaz-Reyes, J; Cardona-Bedoya, J A; Gomez-Herrera, M L; Herrera-Perez, J L; Riech, I; Mendoza-Alvarez, J G

    2003-01-01

    Controlled doping of quaternary alloys of In x Ga 1-x As y Sb 1-y with tellurium is fundamental to obtain the n-type layers needed for the development of optoelectronic devices based on p-n heterojunctions. InGaAsSb epitaxial layers were grown by liquid phase epitaxy and Te doping was obtained by incorporating small Sb 3 Te 2 pellets in the growth melt. The tellurium doping levels were in the range 10 16 -10 17 cm -3 . We have used low-temperature photoluminescence (PL) spectroscopy to study the influence of the Te donor levels on the radiative transitions shown in the PL spectra. The PL measurements were done by exciting the samples with the 448 nm line of an Ar ion laser with varying excitation powers in the range from 10 to 200 mW. For the low-doped sample the PL spectrum showed a narrow exciton-related peak centred at around 610 meV with a full width at half maximum (FWHM) of about 7 meV which is evidence of the good crystalline quality of the layers. For higher Te doping, the PL spectra show the presence of band-to-band and donor-to-acceptor transitions which overlap as the Te concentration increases. The peak of the PL band shifts to higher energies as Te doping increases due to a band-filling effect as the Fermi level enters into the conduction band. From the peak energy of the PL spectra, and using a model that includes the band-filling and band-shrinkage effects due to the carriers, we have estimated the effective carrier concentration due to doping with Te in the epilayers

  10. Ab-initio study of pure sup 7 sup 7 Se and sup 1 sup 2 sup 5 Te systems and of the sup 7 sup 7 Se nuclear quadrupole interaction in tellurium

    CERN Document Server

    Oh, Y K; Cho, H S

    1999-01-01

    Using the Hartree-Fock cluster procedure, we have studied the electric-field gradient tensors at the nuclear sites of sup 7 sup 7 Se and sup 1 sup 2 sup 5 Te in pure sup 1 sup 2 sup 5 Te systems and in tellurium crystalline system's with a sup 7 sup 7 Se impurity. From the results for the pure systems, sup 7 sup 7 Se in selenium and sup 1 sup 2 sup 5 Te in tellurium, using the observed quadrupole moments: Q( sup 7 sup 7 Se) 0.75 +- 0.07 barns and Q( sup 1 sup 2 sup 5 Te) = 0.35 +- 0.04 barns. Comparison is made with earlier values obtained by different methods. Using our calculated values of Q and the results of a study of the field-gradient tensors for sup 7 sup 7 Se in tellurium, the theoretical values of the quadrupole coupling constants are found to agree, within about 7 percent, with experiment. The calculated asymmetry parameters are also found to be in reasonable agreement with the experiment values, although the agreement not as close as in the case of the quadrupole -coupling constants. Directions fo...

  11. Growth of PbTe nanorods controlled by polymerized tellurium anions and metal(II) amides via composite-hydroxide-mediated approach

    Energy Technology Data Exchange (ETDEWEB)

    Wan Buyong [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); College of Physics and Information Technology, Chongqing Normal University, Chongqing 400047 (China); Hu Chenguo, E-mail: hucg@cqu.edu.cn [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China); Liu Hong [State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100 (China); Xiong Yufeng [National Center for Nanoscience and Technology, Beijing 100080 (China); Li Feiyun; Xi Yi; He Xiaoshan [Department of Applied Physics, Chongqing University, 174 Shapingba Street, Chongqing 400044 (China)

    2009-09-15

    The pure face-centered-cubic PbTe nanorods have been synthesized by the composite-hydroxide-mediated approach using hydrazine as a reducing agent. The method is based on reaction among reactants in the melts of potassium hydroxide and sodium hydroxide eutectic at 170-220 deg. C and normal atmosphere without using any organic dispersant or surface-capping agent. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy were used to characterize the structure, morphology and composition of the samples. The diameters of nanorods are almost fixed, while the lengths can be tunable under different growth time and temperatures. The growth mechanism of PbTe nanorods is investigated via UV-vis absorption, demonstrating that polymerized tellurium anions and metal(II) amides in the hydrazine hydroxide melts could control the crystallization and growth process of PbTe nanostructures. The band gap of as-synthesized PbTe nanorods has been calculated based on UV-vis-NIR optical diffuse reflectance spectra data.

  12. Growth of PbTe nanorods controlled by polymerized tellurium anions and metal(II) amides via composite-hydroxide-mediated approach

    International Nuclear Information System (INIS)

    Wan Buyong; Hu Chenguo; Liu Hong; Xiong Yufeng; Li Feiyun; Xi Yi; He Xiaoshan

    2009-01-01

    The pure face-centered-cubic PbTe nanorods have been synthesized by the composite-hydroxide-mediated approach using hydrazine as a reducing agent. The method is based on reaction among reactants in the melts of potassium hydroxide and sodium hydroxide eutectic at 170-220 deg. C and normal atmosphere without using any organic dispersant or surface-capping agent. Scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy were used to characterize the structure, morphology and composition of the samples. The diameters of nanorods are almost fixed, while the lengths can be tunable under different growth time and temperatures. The growth mechanism of PbTe nanorods is investigated via UV-vis absorption, demonstrating that polymerized tellurium anions and metal(II) amides in the hydrazine hydroxide melts could control the crystallization and growth process of PbTe nanostructures. The band gap of as-synthesized PbTe nanorods has been calculated based on UV-vis-NIR optical diffuse reflectance spectra data.

  13. Electrical properties of tellurium clusters on the void sublattice of an opal crystal the important role played by the Te-SiO$_{2}$ interface

    CERN Document Server

    Berezovets, V A; Farbshtein, I I; Nizhankovskii, V I

    2002-01-01

    The temperature dependences of electrical resistivity and of the Hall effect of nanocluster tellurium crystals obtained by filling the voids in a dielectric (opal) matrix with a melt of pure and doped Te were studied. The Hall hole concentration p/sub eff/ was found to increase anomalously (by more than two orders of magnitude) in a sample prepared from pure Te and cooled to helium temperatures. At T = 1.45 K, the hole concentration in this sample was p/sub eff/ = equivalent to 6 * 10/sup 17/ cm/sup -3/. At the same time, the Hall effect in this sample was observed to reverse sign at T equivalent to 200 K from positive for T < 200 K to negative at higher temperatures. This implies a low impurity concentration (N/sub A/ is less than at least 10/sup 15/ cm/sup -3/). A nanocluster crystal of doped Te does not exhibit this anomaly; here, we have p/sub eff/ equivalent to 6 * 10/sup 17/ cm/sup -3/ throughout the temperature region covered, as in the original Te. These features are assigned to the formation of a ...

  14. The anti-inflammatory effects of the tellurium redox modulating compound, AS101, are associated with regulation of NFκB signaling pathway and nitric oxide induction in macrophages

    Directory of Open Access Journals (Sweden)

    Sredni Benjamin

    2010-01-01

    Full Text Available Abstract Background LPS-activated macrophages produce mediators which are involved in inflammation and tissue injury, and especially those associated with endotoxic shock. The non toxic tellurium compound ammonium tri-chloro(dioxoethylene-O,O'-tellurate, AS101, has been recently shown to exert profound anti-inflammatory properties in animal models, associated with its Te(IV redox chemistry. This study explores the anti-inflammatory properties of AS101 with respect to modulation of inflammatory cytokines production and regulation of iNOS transcription and expression in activated macrophages via targeting the NFkB complex. Results AS101 decreased production of IL-6 and in parallel down-regulated LPS-induced iNOS expression and NO secretion by macrophages. AS101 reduced IkB phosphorylation and degradation, and reduced NFkB nuclear translocalization, albeit these effects were exerted at different kinetics. Chromatin immunoprecipitation assays showed that AS101 treatment attenuated p50-subunit ability to bind DNA at the NFkB consensus site in the iNOS promotor following LPS induction. Conclusions Besides AS101, the investigation of therapeutic activities of other tellurium(IV compounds is scarce in the literature, although tellurium is the fourth most abundant trace element in the human body. Since IKK and NFkB may be regulated by thiol modifications, we may thus envisage, inview of our integrated results, that Te(IV compounds, may have important roles in thiol redox biological activity in the human body and represent a new class of anti-inflammatory compounds.

  15. Reaction of 1-bromo-3-chloropropane with tellurium and dimethyl telluride in the system of hydrazine hydrate-alkali; Reaktsiya 1-brom-3-khlorpropana s tellurom i dimetilditelluridom v sisteme gidrazin-gidrat-shcheloch'

    Energy Technology Data Exchange (ETDEWEB)

    Russavskaya, N V; Levanova, E P; Sukhomazova, Eh N; Grabel' nykh, V A; Elaev, A V; Klyba, L V; Zhanchipova, E R; Albanov, A I; Korotaeva, I M; Toryashinova, D S.D.; Korchevin, N A [SO RAN, Irkutskij Inst. Khimii imeni A.E. Favorskogo, Irkutsk (Russian Federation)

    2006-05-15

    A synthesis of oligomeric substance of thiocol type, the poly(trimethyleneditelluride), from 1-bromo-3-chloropropane and elemental tellurium is performed using a hydrazine hydrate-alkali system. Reductive splitting of the tellurocol followed by alkylation with methyl iodide give rise to preparation of bis(methyltelluro)propane, which was synthesized also from dimethyl telluride and 1,3-dihalopropanes using the N{sub 2}H{sub 4}{center_dot}H{sub 2}O/KOH system. The reaction products were characterized by elementary analysis, NMR, and IR spectra. Mass spectra of the synthesized low molecular weight organotellurium compounds are considered.

  16. The Present, Mid-Term, and Long-Term Supply Curves for Tellurium; and Updates in the Results from NREL's CdTe PV Module Manufacturing Cost Model (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Woodhouse, M.; Goodrich, A.; Redlinger, M.; Lokanc, M.; Eggert, R.

    2013-09-01

    For those PV technologies that rely upon Te, In, and Ga, first-order observations and calculations hint that there may be resource constraints that could inhibit their successful deployment at a SunShot level. These are only first-order approximations, however, and the possibility for an expansion in global Te, In, and Ga supplies needs to be considered in the event that there are upward revisions in their demand and prices.In this study, we examine the current, mid-term, and long-term prospects of Tellurium (Te) for use in PV. We find that the current global supply base of Te would support <10 GW of annual traditional CdTe PV manufacturing production. But as for the possibility that the supply base for Te might be expanded, after compiling several preliminary cumulative availability curves we find that there may be significant upside potential in the supply base for this element - principally vis a vis increasing demand and higher prices. Primarily by reducing the Tellurium intensity in manufacturing and by increasing the recovery efficiency of Te in Cu refining processes, we calculate that it may prove affordable to PV manufacturers to expand the supply base for Te such that 100 GW, or greater, of annual CdTe PV production is possible in the 2030 - 2050 timeframe.

  17. Additive Manufacturing Infrared Inspection

    Science.gov (United States)

    Gaddy, Darrell; Nettles, Mindy

    2015-01-01

    The Additive Manufacturing Infrared Inspection Task started the development of a real-time dimensional inspection technique and digital quality record for the additive manufacturing process using infrared camera imaging and processing techniques. This project will benefit additive manufacturing by providing real-time inspection of internal geometry that is not currently possible and reduce the time and cost of additive manufactured parts with automated real-time dimensional inspections which deletes post-production inspections.

  18. Sequential determination of arsenic, selenium, antimony, and tellurium in foods via rapid hydride evolution and atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Fiorino, J.A.; Jones, J.W.; Capar, S.G.

    1976-01-01

    Analysis of acid digests of foods for As, Se, Sb, and Te was semiautomated. Hydrides generated by controlled addition of base stabilized NaBH 4 solution to acid digests are transported directly into a shielded, hydrogen (nitrogen diluted), entrained-air flame for atomic absorption spectrophotometric determination of the individual elements. The detection limits, based on 1 g of digested sample, are approximately 10 to 20 ng/g for all four elements. Measurement precision is 1 to 2 percent relative standard deviation for each element measured at 0.10 μg. A comparison is made of results of analysis of lyophilized fish tissues for As and Se by instrumental neutron activation (INAA), hydride generation with atomic absorption spectrometry, fluorometry, and spectrophotometry. NBS standard reference materials (orchard leaves and bovine liver) analyzed for As, Se, and Sb by this method show excellent agreement with certified values and with independent NAA values

  19. Effect of tellurium on machinability and mechanical property of CuAlMnZn shape memory alloy

    International Nuclear Information System (INIS)

    Liu Na; Li Zhou; Xu Genying; Feng Ze; Gong Shu; Zhu Lilong; Liang Shuquan

    2011-01-01

    Highlights: → A novel free-machining Cu-7.5Al-9.7Mn-3.4Zn-0.3Te (wt.%) shape memory alloy has been developed. → The size of dispersed particles with richer Te is 2-5 μm. → The CuAlMnZnTe alloy has good machinability which approached that of BZn15-24-1.5 due to the addition of Te. → Its shape memory property keeps the same as that of CuAlMnZn alloy with free Te. → The CuAlMnZn shape memory alloy with and without Te both have good ductile as annealed at 700 deg. C for 15 min. - Abstract: The microstructure transition, shape memory effect, machinability and mechanical property of the CuAlMnZn alloy with and without Te have been studied using X-ray diffraction analysis, chips observation and scanning electron microscopy (SEM), tensile strength test and differential scanning calorimeter (DSC), and semi-quantitative shape memory effect (SME) test. The particles with richer Te dispersedly distributed in grain interior and boundary with size of 2-5 μm. After the addition of Te, the CuAlMnZnTe alloy machinability has been effectively increased to approach that of BZn15-24-1.5 and its shape memory property remains the same as the one of CuAlMnZn alloy. The CuAlMnZn shape memory alloys with and without Te both have good ductility as annealed at 700 deg. C for 15 min.

  20. [Food additives and healthiness].

    Science.gov (United States)

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects.

  1. Determination of tellurium in lead and lead alloy using flow injection-hydride generation atomic absorption spectrometry

    International Nuclear Information System (INIS)

    Mesko, Marcia F.; Pozebon, Dirce; Flores, Erico M.M.; Dressler, Valderi L.

    2004-01-01

    A method based on flow injection-hydride generation atomic absorption spectrometry (FI-HG AAS) for the determination of trace amount of Te in lead and lead alloy is described. A flow injection system (FI) and related analytical parameters as well as Te determination and interference caused by Pb, Bi and Ag on Te were investigated. The Pb interference could be overcome by using a small sample volume, while the Bi interference could be overcome by thiourea. However, it was not possible to minimise the interference caused by Ag on Te. The optimised conditions for Te determination in the analysed samples were: 6 mol l -1 HCl as sample carrier solution, 0.75% (m/v) sodium tetrahydroborate as Te reductant, 40 μl of sample solution, and 200 ml min -1 Ar flow rate as carrier gas. The limit of quantification (LOQ) was 1.0 μg g -1 Te (using 250 mg of sample in 50 ml final solution), the limit of detection (LOD) was 2.5 μg l -1 and the relative standard deviation (RSD) was 6% for five consecutive measurements of sample solution. The standard addition calibration method was used. Relatively high sample throughput (ca. 45 sample runs can be performed in a working hour), reduced sample manipulation since matrix separation is not necessary, and minor waste generation are the main advantages of the proposed method for Te determination by FI-HG AAS

  2. Additives in yoghurt production

    Directory of Open Access Journals (Sweden)

    Milna Tudor

    2008-02-01

    Full Text Available In yoghurt production, mainly because of sensory characteristics, different types of additives are used. Each group, and also each substance from the same group has different characteristics and properties. For that reason, for improvement of yoghurt sensory characteristics apart from addition selection, the quantity of the additive is very important. The same substance added in optimal amount improves yoghurt sensory attributes, but too small or too big addition can reduce yoghurt sensory attributes. In this paper, characteristics and properties of mostly used additives in yoghurt production are described; skimmed milk powder, whey powder, concentrated whey powder, sugars and artificial sweeteners, fruits, stabilizers, casein powder, inulin and vitamins. Also the impact of each additive on sensory and physical properties of yoghurt, syneresis and viscosity, are described, depending on used amount added in yoghurt production.

  3. Polylactides in additive biomanufacturing.

    Science.gov (United States)

    Poh, Patrina S P; Chhaya, Mohit P; Wunner, Felix M; De-Juan-Pardo, Elena M; Schilling, Arndt F; Schantz, Jan-Thorsten; van Griensven, Martijn; Hutmacher, Dietmar W

    2016-12-15

    New advanced manufacturing technologies under the alias of additive biomanufacturing allow the design and fabrication of a range of products from pre-operative models, cutting guides and medical devices to scaffolds. The process of printing in 3 dimensions of cells, extracellular matrix (ECM) and biomaterials (bioinks, powders, etc.) to generate in vitro and/or in vivo tissue analogue structures has been termed bioprinting. To further advance in additive biomanufacturing, there are many aspects that we can learn from the wider additive manufacturing (AM) industry, which have progressed tremendously since its introduction into the manufacturing sector. First, this review gives an overview of additive manufacturing and both industry and academia efforts in addressing specific challenges in the AM technologies to drive toward AM-enabled industrial revolution. After which, considerations of poly(lactides) as a biomaterial in additive biomanufacturing are discussed. Challenges in wider additive biomanufacturing field are discussed in terms of (a) biomaterials; (b) computer-aided design, engineering and manufacturing; (c) AM and additive biomanufacturing printers hardware; and (d) system integration. Finally, the outlook for additive biomanufacturing was discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Additive and polynomial representations

    CERN Document Server

    Krantz, David H; Suppes, Patrick

    1971-01-01

    Additive and Polynomial Representations deals with major representation theorems in which the qualitative structure is reflected as some polynomial function of one or more numerical functions defined on the basic entities. Examples are additive expressions of a single measure (such as the probability of disjoint events being the sum of their probabilities), and additive expressions of two measures (such as the logarithm of momentum being the sum of log mass and log velocity terms). The book describes the three basic procedures of fundamental measurement as the mathematical pivot, as the utiliz

  5. Food Additives and Hyperkinesis

    Science.gov (United States)

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  6. Groups – Additive Notation

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2015-06-01

    Full Text Available We translate the articles covering group theory already available in the Mizar Mathematical Library from multiplicative into additive notation. We adapt the works of Wojciech A. Trybulec [41, 42, 43] and Artur Korniłowicz [25].

  7. Groups – Additive Notation

    OpenAIRE

    Coghetto Roland

    2015-01-01

    We translate the articles covering group theory already available in the Mizar Mathematical Library from multiplicative into additive notation. We adapt the works of Wojciech A. Trybulec [41, 42, 43] and Artur Korniłowicz [25].

  8. Tellurium sulfates from reactions in oleum and sulfur trioxide: syntheses and crystal structures of TeO(SO_4), Te_4O_3(SO_4)_5, and Te(S_2O_7)_2

    International Nuclear Information System (INIS)

    Logemann, Christian; Bruns, Joern; Schindler, Lisa Verena; Zimmermann, Vanessa; Wickleder, Mathias S.

    2015-01-01

    The reaction of K_2TeO_4 with fuming sulfuric acid (65 % SO_3) in sealed glass ampoules at 250 C led to colorless single crystals of TeO(SO_4) [triclinic, P anti 1, Z = 8, a = 819.89(3) pm, b = 836.95(4) pm, c = 1179.12(5) pm, α = 82.820(2) , β = 70.645(2) , γ = 81.897(2) , V = 753.11(6) x 10"6 pm"3]. A horseshoe type [Te_4O_3] fragment is the basic motif in the layer structure of the compound. The [Te_4O_3] moieties are linked to infinite chains by further oxide ions. Monomeric [Te_4O_3] horseshoes are found in the crystal structure of Te_4O_3(SO_4)_5 [trigonal, P3_221, Z = 3, a = 859.05(2) pm, c = 2230.66(7) pm, V = 1425.61(6) x 10"6 pm"3], which was obtained from TeO_2 and fuming sulfuric acid (65 % SO_3) at 200 C as colorless single crystals. By switching to neat SO_3 as reaction medium colorless crystals of Te(S_2O_7)_2 [P2_1/n, Z = 4, a = 1065.25(3) pm, b = 818.50(2) pm, c = 1206.27(3) pm, β = 102.097(1) , V = 1028.40(5) x 10"6 pm"3] form when ortho-telluric acid, H_6TeO_6, is used as the tellurium source. The compound was reported previously, however, obviously with a wrong crystallographic description. In the crystal structure the tellurium atoms are coordinated by two chelating disulfate ions. Further Te-O contacts link the [Te(S_2O_7)_2] units to an extended network. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  9. Anomalous behavior of tellurium abundances

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, B L

    1984-01-01

    The cosmic abundance of Te is larger than for any element with atomic number greater than 40, but it is one of the least abundant elements in the earth's lithosphere and it is one of the five elements never reported in sea water. On the other hand, it is the fourth most abundant element in the human body (after Fe, Zn and Rb), and is unusually abundant in human food. It is shown that the high abundance in human food combined with the low abundance in soil requires that it be picked up by plant roots very much more efficiently than any other trace element.

  10. Alternative additives; Alternative additiver

    Energy Technology Data Exchange (ETDEWEB)

    2007-08-15

    In this project a number of industrial and agricultural waste products have been characterised and evaluated in terms of alkali-getter performance. The intended use is for biomass-fired power stations aiming at reducing corrosion or slagging related problems. The following products have been obtained, characterised and evaluated: 1) Brewery draff 2) Danish de-gassed manure 3) Paper sludge 4) Moulding sand 5) Spent bleaching earth 6) Anorthosite 7) Sand 8) Clay-sludge. Most of the above alternative additive candidates are deemed unsuitable due to insufficient chemical effect and/or expensive requirements for pre-treatment (such as drying and transportation). 3 products were selected for full-scale testing: de-gassed manure, spent bleaching earth and clay slugde. The full scale tests were undertaken at the biomass-fired power stations in Koege, Slagelse and Ensted. Spent bleaching earth (SBE) and clay sludge were the only tested additive candidates that had a proven ability to react with KCl, to thereby reduce Cl-concentrations in deposits, and reduce the deposit flux to superheater tubes. Their performance was shown to nearly as good as commercial additives. De-gassed manure, however, did not evaluate positively due to inhibiting effects of Ca in the manure. Furthermore, de-gassed manure has a high concentration of heavy metals, which imposes a financial burden with regard to proper disposal of the ash by-products. Clay-sludge is a wet clay slurring, and drying and transportation of this product entails substantial costs. Spent bleaching does not require much pre-treatment and is therefore the most promising alternative additive. On the other hand, bleaching earth contains residual plant oil which means that a range of legislation relating to waste combustion comes into play. Not least a waste combustion fee of 330 DKK/tonne. For all alternative (and commercial) additives disposal costs of the increase ash by-products represents a significant cost. This is

  11. Model Additional Protocol

    International Nuclear Information System (INIS)

    Rockwood, Laura

    2001-01-01

    Since the end of the cold war a series of events has changed the circumstances and requirements of the safeguards system. The discovery of a clandestine nuclear weapons program in Iraq, the continuing difficulty in verifying the initial report of Democratic People's Republic of Korea upon entry into force of their safeguards agreement, and the decision of the South African Government to give up its nuclear weapons program and join the Treaty on the Non-Proliferation of Nuclear Weapons have all played a role in an ambitious effort by IAEA Member States and the Secretariat to strengthen the safeguards system. A major milestone in this effort was reached in May 1997 when the IAEA Board of Governors approved a Model Protocol Additional to Safeguards Agreements. The Model Additional Protocol was negotiated over a period of less than a year by an open-ended committee of the Board involving some 70 Member States and two regional inspectorates. The IAEA is now in the process of negotiating additional protocols, State by State, and implementing them. These additional protocols will provide the IAEA with rights of access to information about all activities related to the use of nuclear material in States with comprehensive safeguards agreements and greatly expanded physical access for IAEA inspectors to confirm or verify this information. In conjunction with this, the IAEA is working on the integration of these measures with those provided for in comprehensive safeguards agreements, with a view to maximizing the effectiveness and efficiency, within available resources, the implementation of safeguards. Details concerning the Model Additional Protocol are given. (author)

  12. Additive manufacturing of metals

    International Nuclear Information System (INIS)

    Herzog, Dirk; Seyda, Vanessa; Wycisk, Eric; Emmelmann, Claus

    2016-01-01

    Additive Manufacturing (AM), the layer-by layer build-up of parts, has lately become an option for serial production. Today, several metallic materials including the important engineering materials steel, aluminium and titanium may be processed to full dense parts with outstanding properties. In this context, the present overview article describes the complex relationship between AM processes, microstructure and resulting properties for metals. It explains the fundamentals of Laser Beam Melting, Electron Beam Melting and Laser Metal Deposition, and introduces the commercially available materials for the different processes. Thereafter, typical microstructures for additively manufactured steel, aluminium and titanium are presented. Special attention is paid to AM specific grain structures, resulting from the complex thermal cycle and high cooling rates. The properties evolving as a consequence of the microstructure are elaborated under static and dynamic loading. According to these properties, typical applications are presented for the materials and methods for conclusion.

  13. Additive manufactured serialization

    Science.gov (United States)

    Bobbitt, III, John T.

    2017-04-18

    Methods for forming an identifying mark in a structure are described. The method is used in conjunction with an additive manufacturing method and includes the alteration of a process parameter during the manufacturing process. The method can form in a unique identifying mark within or on the surface of a structure that is virtually impossible to be replicated. Methods can provide a high level of confidence that the identifying mark will remain unaltered on the formed structure.

  14. BWR zinc addition Sourcebook

    International Nuclear Information System (INIS)

    Garcia, Susan E.; Giannelli, Joseph F.; Jarvis, Alfred J.

    2014-01-01

    Boiling Water Reactors (BWRs) have been injecting zinc into the primary coolant via the reactor feedwater system for over 25 years for the purpose of controlling primary system radiation fields. The BWR zinc injection process has evolved since the initial application at the Hope Creek Nuclear Station in 1986. Key transitions were from the original natural zinc oxide (NZO) to depleted zinc oxide (DZO), and from active zinc injection of a powdered zinc oxide slurry (pumped systems) to passive injection systems (zinc pellet beds). Zinc addition has continued through various chemistry regimes changes, from normal water chemistry (NWC) to hydrogen water chemistry (HWC) and HWC with noble metals (NobleChem™) for mitigation of intergranular stress corrosion cracking (IGSCC) of reactor internals and primary system piping. While past reports published by the Electric Power Research Institute (EPRI) document specific industry experience related to these topics, the Zinc Sourcebook was prepared to consolidate all of the experience gained over the past 25 years. The Zinc Sourcebook will benefit experienced BWR Chemistry, Operations, Radiation Protection and Engineering personnel as well as new people entering the nuclear power industry. While all North American BWRs implement feedwater zinc injection, a number of other BWRs do not inject zinc. This Sourcebook will also be a valuable resource to plants considering the benefits of zinc addition process implementation, and to gain insights on industry experience related to zinc process control and best practices. This paper presents some of the highlights from the Sourcebook. (author)

  15. Teardrop bladder: additional considerations

    International Nuclear Information System (INIS)

    Wechsler, R.J.; Brennan, R.E.

    1982-01-01

    Nine cases of teardrop bladder (TDB) seen at excretory urography are presented. In some of these patients, the iliopsoas muscles were at the upper limit of normal in size, and additional evaluation of the perivesical structures with computed tomography (CT) was necessary. CT demonstrated only hypertrophied muscles with or without perivesical fat. The psoas muscles and pelvic width were measured in 8 patients and compared with the measurements of a control group of males without TDB. Patients with TDB had large iliopsoas muscles and narrow pelves compared with the control group. The psoas muscle width/pelvic width ratio was significantly greater (p < 0.0005) in patients with TDB than in the control group, with values of 1.04 + 0.05 and 0.82 + 0.09, respectively. It is concluded that TDB is not an uncommon normal variant in black males. Both iliopsoas muscle hypertrophy and a narrow pelvis are factors that predispose a patient to TDB

  16. Sewage sludge additive

    Science.gov (United States)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  17. Effect of increasing tellurium content on the electronic and optical properties of cadmium selenide telluride alloys CdSe{sub 1-x}Te{sub x}: An ab initio study

    Energy Technology Data Exchange (ETDEWEB)

    Reshak, Ali Hussain, E-mail: maalidph@yahoo.co.uk [Institute of Physical Biology-South Bohemia University, Nove Hrady 37333 (Czech Republic); School of Material Engineering, Malaysia University of Perlis, P.O Box 77, d/a Pejabat Pos Besar, 01007 Kangar, Perlis (Malaysia); Kityk, I.V. [Electrical Engineering Department, Technical University of Czestochowa, Al. Armii Krajowej 17/19, Czestochowa (Poland); Khenata, R. [Laboratoire de Physique Quantique et de Modelisation Mathematique de la Matiere (LPQ3 M), universite de Mascara, Mascara 29000 (Algeria); Department of Physics and Astronomy, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia); Auluck, S. [National Physical Laboratory Dr. K S Krishnan Marg, New Delhi 110012 (India)

    2011-06-16

    Highlights: > Theoretical study of effect of vary Te content on band structure, density of states, linear and nonlinear optical susceptibilities of CdSe{sub 1-x}Te{sub x}. > Increasing Te content leads to a decrease in the energy band gap. > Significant enhancement of the electronic properties as a function of tellurium concentration - Abstract: An all electron full potential linearized augmented plane wave method, within a framework of GGA (EV-GGA) approach, has been used for an ab initio theoretical study of the effect of increasing tellurium content on the band structure, density of states, and the spectral features of the linear and nonlinear optical susceptibilities of the cadmium-selenide-telluride ternary alloys CdSe{sub 1-x}Te{sub x} (x = 0.0, 0.25, 0.5, 0.75 and 1.0). Our calculations show that increasing Te content leads to a decrease in the energy band gap. We find that the band gaps are 0.95 (1.76), 0.89 (1.65), 0.83 (1.56), 0.79 (1.44) and 0.76 (1.31) eV for x = 0.0, 0.25, 0.5, 0.75 and 1.0 in the cubic structure. As these alloys are known to have a wurtzite structure for x less than 0.25, the energy gaps are 0.8 (1.6) eV and 0.7 (1.55) eV for the wurtzite structure (x = 0.0, 0.25) for the GGA (EV-GGA) exchange correlation potentials. This reduction in the energy gaps enhances the functionality of the CdSe{sub 1-x}Te{sub x} alloys, at least for these concentrations, leading to an increase in the effective second-order susceptibility coefficients from 16.75 pm/V (CdSe) to 18.85 pm/V (CdSe{sub 0.75}Te{sub 0.25}), 27.23 pm/V (CdSe{sub 0.5}Te{sub 0.5}), 32.25 pm/V (CdSe{sub 0.25}Te{sub 0.75}), and 37.70 pm/V (CdTe) for the cubic structure and from 12.65 pm/V (CdSe) to 21.11 pm/V (CdSe{sub 0.75}Te{sub 0.25}) in the wurtzite structure. We find a nonlinear relationship between the absorption/emission energies and composition, and a significant enhancement of the electronic properties as a function of tellurium concentration. This variation will help in

  18. Additive lattice kirigami.

    Science.gov (United States)

    Castle, Toen; Sussman, Daniel M; Tanis, Michael; Kamien, Randall D

    2016-09-01

    Kirigami uses bending, folding, cutting, and pasting to create complex three-dimensional (3D) structures from a flat sheet. In the case of lattice kirigami, this cutting and rejoining introduces defects into an underlying 2D lattice in the form of points of nonzero Gaussian curvature. A set of simple rules was previously used to generate a wide variety of stepped structures; we now pare back these rules to their minimum. This allows us to describe a set of techniques that unify a wide variety of cut-and-paste actions under the rubric of lattice kirigami, including adding new material and rejoining material across arbitrary cuts in the sheet. We also explore the use of more complex lattices and the different structures that consequently arise. Regardless of the choice of lattice, creating complex structures may require multiple overlapping kirigami cuts, where subsequent cuts are not performed on a locally flat lattice. Our additive kirigami method describes such cuts, providing a simple methodology and a set of techniques to build a huge variety of complex 3D shapes.

  19. Additive Manufactured Superconducting Cavities

    Science.gov (United States)

    Holland, Eric; Rosen, Yaniv; Woolleet, Nathan; Materise, Nicholas; Voisin, Thomas; Wang, Morris; Mireles, Jorge; Carosi, Gianpaolo; Dubois, Jonathan

    Superconducting radio frequency cavities provide an ultra-low dissipative environment, which has enabled fundamental investigations in quantum mechanics, materials properties, and the search for new particles in and beyond the standard model. However, resonator designs are constrained by limitations in conventional machining techniques. For example, current through a seam is a limiting factor in performance for many waveguide cavities. Development of highly reproducible methods for metallic parts through additive manufacturing, referred to colloquially as 3D printing\\x9D, opens the possibility for novel cavity designs which cannot be implemented through conventional methods. We present preliminary investigations of superconducting cavities made through a selective laser melting process, which compacts a granular powder via a high-power laser according to a digitally defined geometry. Initial work suggests that assuming a loss model and numerically optimizing a geometry to minimize dissipation results in modest improvements in device performance. Furthermore, a subset of titanium alloys, particularly, a titanium, aluminum, vanadium alloy (Ti - 6Al - 4V) exhibits properties indicative of a high kinetic inductance material. This work is supported by LDRD 16-SI-004.

  20. effects of sulphur addition on addition on and mechanical properties

    African Journals Online (AJOL)

    User

    234-8034714355. 8034714355. 1. EFFECTS OF SULPHUR ADDITION ON. ADDITION ON. 2. AND MECHANICAL PROPERTIES O. 3. 4. C. W. Onyia. 5. 1DEPT. OF METALLURGICAL AND MATERIALS. 6. 2, 4DEPT. OF METALLURGICAL ...

  1. Lasing transition at 1.06 μm emission in Nd3+ -doped borate-based tellurium calcium zinc niobium oxide glasses for high-power solid-state lasers.

    Science.gov (United States)

    Ravi, O; Prasad, K; Jain, Rajiv; Venkataswamy, M; Chaurasia, Shivanand; Deva Prasad Raju, B

    2017-08-01

    The spectroscopic properties of Tellurium Calcium Zinc Niobium oxide Borate (TCZNB) glasses of composition (in mol%) 10TeO 2  + 15CaO + 5ZnO + 10 Nb 2 O 5  + (60 - x)B 2 O 3  + Nd 2 O 3 (x = 0.1, 0.5, 1.0 or 1.5 mol%) have been investigated experimentally. The three phenomenological intensity parameters Ω 2 , Ω 4, Ω 6 have been calculated using the Judd-Ofelt theory and in turn radiative properties such as radiative transition probabilities, emission cross-sections, branching ratios and radiative lifetimes have been estimated. The trend found in the JO intensity parameter is Ω 2  > Ω 6  > Ω 4 If Ω 6  > Ω 4 , the glass system is favourable for the laser emission 4 F 3 /2  →  4 I 11 /2 in the infrared (IR) wavelength. The experimental values of branching ratio of 4 F 3 /2  →  4 I 11 /2 transition indicate favourable lasing action with low threshold power. The evaluated total radiative transition probabilities (A T ), stimulated emission cross-section (σ e ) and gain bandwidth parameters (σ e  × Δλ p ) were compared with earlier reports. An energy level analysis has been carried out considering the experimental energy positions of the absorption and emission bands. Copyright © 2016 John Wiley & Sons, Ltd.

  2. Constitutional studies in the palladium-rhodium-tellurium (-oxygen) system. A contribution to elucidate the behaviour of Pd, Rh and Te in the vitrification process of high-level waste concentrates (HLWC)

    International Nuclear Information System (INIS)

    Hartmann, T.

    1996-01-01

    In the vitrification process of high-level waste concentrates (HLWC) from the reprocessing of nuclear spent fuel elements, about 30 different elements have to be immobilized in a solid matrix consisting of an alkali borosilicate glass. Most of the waste oxides are dissolved in the alkali borosilicate melt and become structural elements of the glasses when cooled. This, however, applies only partly to the platinum metals Ru, which forms RuO 2 , and palladium and rhodium, which deposit as sparingly soluble and electrically conducting tellurides. This might considerably impair the technical process of HLWC vitrification. Therefore, constitutional studies on the Pd-Rh-Te system became necessary. The phase diagram of the Pd-Rh-Te ternary system at temperatures of 1150, 1100, 1050, 1000, 950, 900 and 750 C was determined under inertial conditions. Oxygen exerts a major influence on the system. Already under limited availability of oxygen, the rhodium contents of the solid solution phases α 1 and α 2 are clearly diminished. Rhodium of the phases becomes oxidized selectively. The three-phase field α 1 +α 2 +L is shifted to higher palladium and tellurium contents, even oxygen is available to a limited extend only. With the oxygen in the air, the extension of the three-phase space is reduced markedly. The complex process chemistry of Pf, Rh and Te during the vitrification can be described by the state of the Pd-Rh-Te ternary system after annealing in (air) oxygen for limited periods of time. (orig./MM) [de

  3. ADDITIVES USED TO OBTAIN FOOD

    Directory of Open Access Journals (Sweden)

    Dorina Ardelean

    2012-01-01

    Full Text Available Use of food additives in food is determined by the growth of contemporary food needs of the world population. Additives used in food, both natural and artificial ones, contribute to: improving the organoleptic characteristics and to preserve the food longer, but we must not forget that all these additives should not be found naturally in food products. Some of these additives are not harmful and human pests in small quantities, but others may have harmful effects on health.

  4. Color Addition and Subtraction Apps

    Science.gov (United States)

    Ruiz, Frances; Ruiz, Michael J.

    2015-01-01

    Color addition and subtraction apps in HTML5 have been developed for students as an online hands-on experience so that they can more easily master principles introduced through traditional classroom demonstrations. The evolution of the additive RGB color model is traced through the early IBM color adapters so that students can proceed step by step…

  5. How Safe Are Color Additives?

    Science.gov (United States)

    ... Linkedin Pin it Email Print Subscribe: FDA Consumer Health Information Color additives give the red tint to your fruit punch ... in Foods, Drugs, Cosmetics, and Medical Devices Color Additives: FDA's Regulatory Process and Historical Perspectives ... Health Cosmetics Dietary Supplements Drugs Food Medical Devices Nutrition ...

  6. Density measures and additive property

    OpenAIRE

    Kunisada, Ryoichi

    2015-01-01

    We deal with finitely additive measures defined on all subsets of natural numbers which extend the asymptotic density (density measures). We consider a class of density measures which are constructed from free ultrafilters on natural numbers and study a certain additivity property of such density measures.

  7. Prevalence of Food Additive Intolerance

    DEFF Research Database (Denmark)

    Madsen, Charlotte Bernhard

    1994-01-01

    The prevalence estimates vary with a factor 100. As the results vary so do the study populations. 6 If the different study populations are accounted for, a common conclusion can be drawn: Food additive intolerance is found in adults with atopic symptoms from the respiratory tract and skin. The prevalence......1 The existing prevalence estimates of food additive intolerance(1-4) are being reviewed. 2 In the EEC report the estimated frequency of food additive intolerance is 0.03% to 0.15% based on data from patient groups. 3 The British population study results in a prevalence estimate of 0.......026%. The challenged population is 81 children and adults with a history of reproducible clinical symptoms after ingestion of food additives. 4 In the Danish population study a prevalence of 1-2% is found in children age 5-16. In this study a total of 606 children mainly with atopic disease have been challenged. 5...

  8. Topology Optimization for Additive Manufacturing

    DEFF Research Database (Denmark)

    Clausen, Anders

    This PhD thesis deals with the combination of topology optimization and additive man-ufacturing (AM, also known as 3D-printing). In addition to my own works, the thesis contains a broader review and assessment of the literature within the field. The thesis first presents a classification...... of the various AM technologies, a review of relevant manufacturing materials, the properties of these materials in the additively manufactured part, as well as manufacturing constraints with a potential for design optimization. Subsequently, specific topology optimization formulations relevant for the most im...... for scalable manufacturing. In relation to interface problems it is shown how a flexible void area may be included into a standard minimum compliance problem by employing an additional design variable field and a sensitivity filter. Furthermore, it is shown how the design of coated structures may be modeled...

  9. (ICSID) ADDITIONAL FACILITY IN INTERNA

    African Journals Online (AJOL)

    Fr. Ikenga

    ... which is adopted by Article 5 of the Additional Facility Rules to guide the ... B, Barrister at Law, e-mail: kcezeibe@yahoo.com; Phone 08033950631 and .... revision and annulment which are internally available under the Washington ...

  10. Food additives: an ethical evaluation.

    Science.gov (United States)

    Mepham, Ben

    2011-01-01

    Food additives are an integral part of the modern food system, but opinion polls showing most Europeans have worries about them imply an urgent need for ethical analysis of their use. The existing literature on food ethics, safety assessment and animal testing. Food additives provide certain advantages in terms of many people's lifestyles. There are disagreements about the appropriate application of the precautionary principle and of the value and ethical validity of animal tests in assessing human safety. Most consumers have a poor understanding of the relative benefits and risks of additives, but concerns over food safety and animal testing remain high. Examining the impacts of food additives on consumer sovereignty, consumer health and on animals used in safety testing should allow a more informed debate about their appropriate uses.

  11. Understanding the influence of tellurium oxide in front Ag paste for contacting silicon solar cells with homogeneous high sheet resistance emitter

    Science.gov (United States)

    Ebong, Abasifreke; Bezawada, Nirupama; Batchu, Kartheek

    2017-08-01

    This paper investigates TeO2, one of the front Ag paste additives, to understand its role in low contact and gridline resistances for screen-printed Si solar cell. It is concluded that TeO2 aids the reduction of molten glass frit viscosity during contact co-firing. This in turn, leads to uniform flow of molten glass frit, both in the gridline bulk and interface of gridline and SiN x . Therefore, the uniform wetting and etching of SiN x and consequently larger contact area of metal to Si compared to its counterpart without TeO2. Hence, the current transport mechanism from Si to gridline can be said to be both direct and tunneling. The Raman spectra showed a blue shift in the phase of the TeO2 after contact co-firing in the gridline bulk confirming a crystalline γ-TeO2.

  12. Wide and High Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Post, Brian K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Roschli, Alex C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    The goal of this project is to develop and demonstrate the enabling technologies for Wide and High Additive Manufacturing (WHAM). WHAM will open up new areas of U.S. manufacturing for very large tooling in support of the transportation and energy industries, significantly reducing cost and lead time. As with Big Area Additive Manufacturing (BAAM), the initial focus is on the deposition of composite materials.

  13. Food additives and preschool children.

    Science.gov (United States)

    Martyn, Danika M; McNulty, Breige A; Nugent, Anne P; Gibney, Michael J

    2013-02-01

    Food additives have been used throughout history to perform specific functions in foods. A comprehensive framework of legislation is in place within Europe to control the use of additives in the food supply and ensure they pose no risk to human health. Further to this, exposure assessments are regularly carried out to monitor population intakes and verify that intakes are not above acceptable levels (acceptable daily intakes). Young children may have a higher dietary exposure to chemicals than adults due to a combination of rapid growth rates and distinct food intake patterns. For this reason, exposure assessments are particularly important in this age group. The paper will review the use of additives and exposure assessment methods and examine factors that affect dietary exposure by young children. One of the most widely investigated unfavourable health effects associated with food additive intake in preschool-aged children are suggested adverse behavioural effects. Research that has examined this relationship has reported a variety of responses, with many noting an increase in hyperactivity as reported by parents but not when assessed using objective examiners. This review has examined the experimental approaches used in such studies and suggests that efforts are needed to standardise objective methods of measuring behaviour in preschool children. Further to this, a more holistic approach to examining food additive intakes by preschool children is advisable, where overall exposure is considered rather than focusing solely on behavioural effects and possibly examining intakes of food additives other than food colours.

  14. effects of sulphur addition on addition on and mechanical properties

    African Journals Online (AJOL)

    User

    on the microstructure and mechanical properties of sand cast been investigated ... owed that the addition of sulphur to Al-12wt%Si alloy. 12wt%Si alloy .... 28 materials. 29. Element. Aluminum. Silicon. Al. Si. Ca. Fe. Cu. Zn. Mn. Mg. Cr. B. 99.71.

  15. Determination of neutron cross sections and resonance parameters for vanadium, the stable thallium isotopes, and the stable tellurium isotopes. Progress report, October 1, 1976--October 31, 1977

    International Nuclear Information System (INIS)

    Winters, R.R.

    1977-10-01

    The analysis of the neutron capture cross section data for 51 V + n has now been completed up to 215 keV. Using a few neutron widths and spin and parity assignments from the literature, the capture data has yielded estimates of radiative widths for 45 s-wave resonances and capture areas for 139 resonances. Of particular interest is the very large s-wave radiative widths for this reaction and the rather broad distribution of radiative widths. A paper describing these results is included with this report. The analysis of the neutron capture cross sections for the reaction 205 Tl(n,γ) is presently being extended to incident neutron energy 115 keV. The study of the scattered-beam sensitivity of the total energy detectors at the ORELA capture facility continues. This small but troublesome effect has now been parameterized, but the errors to be assigned to the parameterization are not yet well defined. However, in obtaining additional data for the parameterization, a series of 208 Pb(n,γ) cross section measurements were made. The analysis of these data led to results important in understanding stellar nucleosynthesis and are reported in a paper included with this report. the analysis of the Te(n,γ) data proceeds methodically but slowly

  16. Evaluation of certain food additives.

    Science.gov (United States)

    2017-01-01

    This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives, including flavouring agents. A summary follows of the Committee’s evaluations of technical, toxicological and dietary exposure data for 10 food additives (Allura Red AC; carob bean gum; lutein esters from Tagetes erecta; octenyl succinic acid (OSA)– modified gum arabic; pectin; Quinoline Yellow; rosemary extract; steviol glycosides; tartrazine; and xanthan gum) and five groups of flavouring agents (alicyclic, alicyclic-fused and aromatic-fused ring lactones; aliphatic and aromatic amines and amides; aliphatic secondary alcohols, ketones and related esters; cinnamyl alcohol and related substances; and tetrahydrofuran and furanone derivatives). Specifications for the following food additives were revised: aspartame; cassia gum; citric and fatty acid esters of glycerol (CITREM); modified starches; octanoic acid; starch sodium octenyl succinate; and total colouring matters. Annexed to the report are tables summarizing the Committee’s recommendations for dietary exposures to and toxicological evaluations of all of the food additives, including flavouring agents, considered at this meeting.

  17. Additive manufacturing of tunable lenses

    Science.gov (United States)

    Schlichting, Katja; Novak, Tobias; Heinrich, Andreas

    2017-02-01

    Individual additive manufacturing of optical systems based on 3D Printing offers varied possibilities in design and usage. In addition to the additive manufacturing procedure, the usage of tunable lenses allows further advantages for intelligent optical systems. Our goal is to bring the advantages of additive manufacturing together with the huge potential of tunable lenses. We produced tunable lenses as a bundle without any further processing steps, like polishing. The lenses were designed and directly printed with a 3D Printer as a package. The design contains the membrane as an optical part as well as the mechanical parts of the lens, like the attachments for the sleeves which contain the oil. The dynamic optical lenses were filled with an oil. The focal length of the lenses changes due to a change of the radius of curvature. This change is caused by changing the pressure in the inside of the lens. In addition to that, we designed lenses with special structures to obtain different areas with an individual optical power. We want to discuss the huge potential of this technology for several applications. Further, an appropriate controlling system is needed. Wéll show the possibilities to control and regulate the optical power of the lenses. The lenses could be used for illumination tasks, and in the future, for individual measurement tasks. The main advantage is the individuality and the possibility to create an individual design which completely fulfills the requirements for any specific application.

  18. Calcium addition in straw gasification

    DEFF Research Database (Denmark)

    Risnes, H.; Fjellerup, Jan Søren; Henriksen, Ulrik Birk

    2003-01-01

    The present work focuses on the influence of calcium addition in gasification. The inorganic¿organic element interaction as well as the detailed inorganic¿inorganic elements interaction has been studied. The effect of calcium addition as calcium sugar/molasses solutions to straw significantly...... affected the ash chemistry and the ash sintering tendency but much less the char reactivity. Thermo balance test are made and high-temperature X-ray diffraction measurements are performed, the experimental results indicate that with calcium addition major inorganic¿inorganic reactions take place very late...... in the char conversion process. Comprehensive global equilibrium calculations predicted important characteristics of the inorganic ash residue. Equilibrium calculations predict the formation of liquid salt if sufficient amounts of Ca are added and according to experiments as well as calculations calcium binds...

  19. Additive interaction in survival analysis

    DEFF Research Database (Denmark)

    Rod, Naja Hulvej; Lange, Theis; Andersen, Ingelise

    2012-01-01

    It is a widely held belief in public health and clinical decision-making that interventions or preventive strategies should be aimed at patients or population subgroups where most cases could potentially be prevented. To identify such subgroups, deviation from additivity of absolute effects...... an empirical example of interaction between education and smoking on risk of lung cancer. We argue that deviations from additivity of effects are important for public health interventions and clinical decision-making, and such estimations should be encouraged in prospective studies on health. A detailed...... is the relevant measure of interest. Multiplicative survival models, such as the Cox proportional hazards model, are often used to estimate the association between exposure and risk of disease in prospective studies. In Cox models, deviations from additivity have usually been assessed by surrogate measures...

  20. Additional disulfide bonds in insulin

    DEFF Research Database (Denmark)

    Vinther, Tine N; Pettersson, Ingrid; Huus, Kasper

    2015-01-01

    The structure of insulin, a glucose homeostasis-controlling hormone, is highly conserved in all vertebrates and stabilized by three disulfide bonds. Recently, we designed a novel insulin analogue containing a fourth disulfide bond located between positions A10-B4. The N-terminus of insulin's B......-chain is flexible and can adapt multiple conformations. We examined how well disulfide bond predictions algorithms could identify disulfide bonds in this region of insulin. In order to identify stable insulin analogues with additional disulfide bonds, which could be expressed, the Cβ cut-off distance had...... in comparison to analogues with additional disulfide bonds that were more difficult to predict. In contrast, addition of the fourth disulfide bond rendered all analogues resistant to fibrillation under stress conditions and all stable analogues bound to the insulin receptor with picomolar affinities. Thus...

  1. Aminodisulfides as additives to lubricants

    Energy Technology Data Exchange (ETDEWEB)

    Balin, A.I.; Tarasevich, V.B.; Veretenova, T.N.

    1980-01-01

    A study was carried out and tehcnology developed for producing sulfur-nitrogen containing additives of the type of aminodisulfide by interaction of beta, beta-dichlordialkyl (aryl) disulfides with diethanolamine in a medium of sulfur-diethanolamine. The 2,2'-bis-(diethanol)-dialkyl(aryl) disulfides obtained do not hydrolyze in aqueous soltuions of alkalis, exhibit rather high antiscoring properties and are recommended for tests as active additives of high pressure to SOZH and technological lubricants of the oil and emulsion types.

  2. Additive to clay drilling muds

    Energy Technology Data Exchange (ETDEWEB)

    Voytenko, V.S.; Nekrasova, V.B.; Nikitinskiy, E.L.; Ponomarev, V.N.

    1984-01-01

    The purpose of the invention is to improve the lubricating and strengthening properties of clay drilling muds. This goal is achieved because the lubricating and strengthening additive used is waste from the pulp and paper industry at the stage of reprocessing crude sulfate soap into phytosterol.

  3. The selective addition of water

    NARCIS (Netherlands)

    Resch, V.; Hanefeld, U.

    2014-01-01

    Water is omnipresent and essential. Yet at the same time it is a rather unreactive molecule. The direct addition of water to C[double bond, length as m-dash]C double bonds is therefore a challenge not answered convincingly. In this perspective we critically evaluate the selectivity and the

  4. Additive manufacturing in maxillofacial reconstruction

    Directory of Open Access Journals (Sweden)

    Dincă Luciana Laura

    2017-01-01

    Full Text Available In this paper the benefits of using additive manufacturing technologies in maxillofacial reconstruction are highlighted. Based on a real clinical case, the paper describes the manufacture of an implant prototype replacing the right zygomatic bone and a part of maxilla using additive manufacturing technologies. The face is the most expressive part of the human body that makes us unique. It was shown that the maxillofacial prostheses help to improve the psychological state of patients affected by, because low self esteem feeling appears commonly to this patients with the facial defects. The aim of this paper is to show how using additive manufacturing technologies methods within this research, the producing a surgical model will help surgeon to improve the pre-operative planning. For this we used additive manufacturing technologies such as Stereolitography to achieve the biomodel and FDM-fused deposition modelling to obtain a prototype model because these technologies make it possible to obtain prosthesis according to the physical and mechanical requirements of the region of implantation.

  5. Radiation curable Michael addition compounds

    International Nuclear Information System (INIS)

    Gruber, G.W.; Friedlander, C.B.; McDonald, W.H.; Dowbenko, R.

    1979-01-01

    Radiation polymerizable acrylyloxy-containing reaction products are provided from Michael addition reaction of an amide containing at least two acrylate groups with a primary or secondary amine. The resulting amine adducts of the amide, which contain at least one acrylate group per molecule, possesses high cure rates in air and are useful in compositions for forming coatings. (author)

  6. Additively manufactured porous tantalum implants

    NARCIS (Netherlands)

    Wauthle, Ruben; Van Der Stok, Johan; Yavari, Saber Amin; Van Humbeeck, Jan; Kruth, Jean Pierre; Zadpoor, Amir Abbas; Weinans, Harrie; Mulier, Michiel; Schrooten, Jan

    2015-01-01

    The medical device industry's interest in open porous, metallic biomaterials has increased in response to additive manufacturing techniques enabling the production of complex shapes that cannot be produced with conventional techniques. Tantalum is an important metal for medical devices because of

  7. Evaluation of certain food additives.

    Science.gov (United States)

    2012-01-01

    This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives, including flavouring agents. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for five food additives (magnesium dihydrogen diphosphate; mineral oil (medium and low viscosity) classes II and III; 3-phytase from Aspergillus niger expressed in Aspergillus niger; serine protease (chymotrypsin) from Nocardiopsis prasina expressed in Bacillus licheniformis; and serine protease (trypsin) from Fusarium oxysporum expressed in Fusarium venenatum) and 16 groups of flavouring agents (aliphatic and aromatic amines and amides; aliphatic and aromatic ethers; aliphatic hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids and related esters, sulfides, disulfides and ethers containing furan substitution; aliphatic linear alpha,beta-unsaturated aldehydes, acids and related alcohols, acetals and esters; amino acids and related substances; epoxides; furfuryl alcohol and related substances; linear and branched-chain aliphatic, unsaturated, unconjugated alcohols, aldehydes, acids and related esters; miscellaneous nitrogen-containing substances; phenol and phenol derivatives; pyrazine derivatives; pyridine, pyrrole and quinoline derivatives; saturated aliphatic acyclic branched-chain primary alcohols, aldehydes and acids; simple aliphatic and aromatic sulfides and thiols; sulfur-containing heterocyclic compounds; and sulfur-substituted furan derivatives). Specifications for the following food additives were revised: ethyl cellulose, mineral oil (medium viscosity), modified starches and titanium

  8. Protocol for ADDITION-PRO

    DEFF Research Database (Denmark)

    Johansen, Nanna Borup; Hansen, Anne-Louise Smidt; Jensen, Troels M

    2012-01-01

    disease and microvascular diabetic complications. We also require a better understanding of the mechanisms that underlie and drive early changes in cardiometabolic physiology. The ADDITION-PRO study was designed to address these issues among individuals at different levels of diabetes risk recruited from...... Danish primary care. METHODS/DESIGN: ADDITION-PRO is a population-based, longitudinal cohort study of individuals at high risk for diabetes. 16,136 eligible individuals were identified at high risk following participation in a stepwise screening programme in Danish general practice between 2001 and 2006....... All individuals with impaired glucose regulation at screening, those who developed diabetes following screening, and a random sub-sample of those at lower levels of diabetes risk were invited to attend a follow-up health assessment in 2009-2011 (n=4,188), of whom 2,082 (50%) attended. The health...

  9. Additive theory of prime numbers

    CERN Document Server

    Hua, L K

    2009-01-01

    Loo-Keng Hua was a master mathematician, best known for his work using analytic methods in number theory. In particular, Hua is remembered for his contributions to Waring's Problem and his estimates of trigonometric sums. Additive Theory of Prime Numbers is an exposition of the classic methods as well as Hua's own techniques, many of which have now also become classic. An essential starting point is Vinogradov's mean-value theorem for trigonometric sums, which Hua usefully rephrases and improves. Hua states a generalized version of the Waring-Goldbach problem and gives asymptotic formulas for the number of solutions in Waring's Problem when the monomial x^k is replaced by an arbitrary polynomial of degree k. The book is an excellent entry point for readers interested in additive number theory. It will also be of value to those interested in the development of the now classic methods of the subject.

  10. Dolomitic lime containing hydraulic additive

    International Nuclear Information System (INIS)

    Lagzdina, S.; Sedmalis, U.; Bidermanis, L.; Liepins, J.; Grosvalds, I.

    1997-01-01

    To obtain qualitative dolomitic lime the optimum calcination temperature of dolomite containing about 9 % of clayey substances is 900 deg C. The mechanical strength of dolomitic lime containing 30 % of brick waste additive after 6-9 months of hardening is 1.4-1.5 times higher than that of samples without hydraulic additive, for calcium lime - 2.2-2.6 times higher. Generally the mechanical strength of dolomitic lime is higher than that one of calcium lime. It can be explained by the active role of MgO in the hydration and hardening processes of dolomitic lime. Xray diffraction phase analysis was performed by X-ray diffractometer DPON-3M with Cu-K α emission filter

  11. Decontamination formulation with sorbent additive

    Science.gov (United States)

    Tucker; Mark D. , Comstock; Robert H.

    2007-10-16

    A decontamination formulation and method of making that neutralizes the adverse health effects of both chemical and biological compounds, especially chemical warfare (CW) and biological warfare (BW) agents, and toxic industrial chemicals. The formulation provides solubilizing compounds that serve to effectively render the chemical and biological compounds, particularly CW and BW compounds, susceptible to attack, and at least one reactive compound that serves to attack (and detoxify or kill) the compound. The formulation includes at least one solubilizing agent, a reactive compound, a bleaching activator, a sorbent additive, and water. The highly adsorbent, water-soluble sorbent additive (e.g., sorbitol or mannitol) is used to "dry out" one or more liquid ingredients, such as the liquid bleaching activator (e.g., propylene glycol diacetate or glycerol diacetate) and convert the activator into a dry, free-flowing powder that has an extended shelf life, and is more convenient to handle and mix in the field.

  12. The Frontiers of Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-03-03

    Additive manufacturing, more commonly known as 3-D printing, has become a ubiquitous tool in science for its precise control over mechanical design. For additive manufacturing to work, a 3-D structure is split into thin 2D slices, and then different physical properties, such as photo-polymerization or melting, are used to grow the sequential layers. The level of control allows not only for devices to be made with a variety of materials: e.g. plastics, metals, and quantum dots, but to also have finely controlled structures leading to other novel properties. While 3-D printing is widely used by hobbyists for making models, it also has industrial applications in structural engineering, biological tissue scaffolding, customized electric circuitry, fuel cells, security, and more.

  13. Minimum Additive Waste Stabilization (MAWS)

    International Nuclear Information System (INIS)

    1994-02-01

    In the Minimum Additive Waste Stabilization(MAWS) concept, actual waste streams are utilized as additive resources for vitrification, which may contain the basic components (glass formers and fluxes) for making a suitable glass or glassy slag. If too much glass former is present, then the melt viscosity or temperature will be too high for processing; while if there is too much flux, then the durability may suffer. Therefore, there are optimum combinations of these two important classes of constituents depending on the criteria required. The challenge is to combine these resources in such a way that minimizes the use of non-waste additives yet yields a processable and durable final waste form for disposal. The benefit to this approach is that the volume of the final waste form is minimized (waste loading maximized) since little or no additives are used and vitrification itself results in volume reduction through evaporation of water, combustion of organics, and compaction of the solids into a non-porous glass. This implies a significant reduction in disposal costs due to volume reduction alone, and minimizes future risks/costs due to the long term durability and leach resistance of glass. This is accomplished by using integrated systems that are both cost-effective and produce an environmentally sound waste form for disposal. individual component technologies may include: vitrification; thermal destruction; soil washing; gas scrubbing/filtration; and, ion-exchange wastewater treatment. The particular combination of technologies will depend on the waste streams to be treated. At the heart of MAWS is vitrification technology, which incorporates all primary and secondary waste streams into a final, long-term, stabilized glass wasteform. The integrated technology approach, and view of waste streams as resources, is innovative yet practical to cost effectively treat a broad range of DOE mixed and low-level wastes

  14. Trust Trust Me (The Additivity)

    OpenAIRE

    Mano , Ken; Sakurada , Hideki; Tsukada , Yasuyuki

    2017-01-01

    Part 4: Trust Metrics; International audience; We present a mathematical formulation of a trust metric using a quality and quantity pair. Under a certain assumption, we regard trust as an additive value and define the soundness of a trust computation as not to exceed the total sum. Moreover, we point out the importance of not only soundness of each computed trust but also the stability of the trust computation procedure against changes in trust value assignment. In this setting, we define tru...

  15. A manual on using additives

    International Nuclear Information System (INIS)

    Lee, Bong Hoon

    1991-10-01

    This book consists of five chapters, which describe plasticizer ; summary, synthesis of plasticizer, basic notion, analysis and test on plasticizer, stabilizer ; stabilizer for plastic, an antioxidant, phosphorous acid estelle, ultraviolet ray absorbent, performance of stabilizer, influence on another additives, mix case of PVC production and analysis method for stabilizer, ultraviolet ray absorbent ; basic property and ultraviolet ray absorbent maker, anti-static agent ; basics, anti-static agent of a high molecule and analysis of anti-static agent, flame retardant of plastic.

  16. Additive property of separative power

    International Nuclear Information System (INIS)

    Yamamoto, Ichiro; Kanagawa, Akira

    1980-01-01

    A separative power of a separating element, whose heads and tails separation factors are α and β, is expressed by phi sub(b)(α, β) = [α(β - 1)1n α - (α - 1)1n β]/(αβ - 1) for the unit flow of the desired material and phi sub(a)(α, β) (= phi sub(b)(β, α)) for that of undesired material. The additive properties of the functions phi sub(b) and phi sub(a) were demonstrated by calculations of various types of ideal cascades, but the origin of the property is not obvious. The present study has furnished the mathematical basis of the additivity based on the special functional equation. First, for symmetric processes (α = β), the functional equation which describes the function representing the quality of separation f(α, α) concerning the desired material was obtained and solved to give the functional form of f(α, α). The result was extented to the function f(α, β) representing the quality of asymmetric separation (α not equal β). The derived function f(α, β) was demonstrated to be equal to phi sub(b)(α, β), and it was verified that functions phi sub(b)(α, β) and phi sub(a)(α, β) have the additive property in themselves. (author)

  17. Evaluation of certain food additives.

    Science.gov (United States)

    2009-01-01

    This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives, including flavouring agents, with a view to recommending acceptable daily intakes (ADIs) and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation and assessment of intake of food additives (in particular, flavouring agents). A summary follows of the Committee's evaluations of technical, toxicological and intake data for certain food additives (asparaginase from Aspergillus niger expressed in A. niger, calcium lignosulfonate (40-65), ethyl lauroyl arginate, paprika extract, phospholipase C expressed in Pichia pastoris, phytosterols, phytostanols and their esters, polydimethylsiloxane, steviol glycosides and sulfites [assessment of dietary exposure]) and 10 groups of related flavouring agents (aliphatic branched-chain saturated and unsaturated alcohols, aldehydes, acids and related esters; aliphatic linear alpha,beta-unsaturated aldehydes, acids and related alcohols, acetals and esters; aliphatic secondary alcohols, ketones and related esters; alkoxy-substituted allylbenzenes present in foods and essential oils and used as flavouring agents; esters of aliphatic acyclic primary alcohols with aliphatic linear saturated carboxylic acids; furan-substituted aliphatic hydrocarbons, alcohols, aldehydes, ketones, carboxylic acids and related esters, sulfides, disulfides and ethers; miscellaneous nitrogen-containing substances; monocyclic and bicyclic secondary alcohols, ketones and related esters; hydroxy- and alkoxy-substituted benzyl derivatives; and substances structurally related to menthol). Specifications for the following food additives were revised: canthaxanthin; carob bean gum and carob bean gum (clarified); chlorophyllin copper complexes, sodium and potassium salts; Fast Green FCF; guar gum and guar gum (clarified

  18. Additive Manufacturing of Porous Metal

    Energy Technology Data Exchange (ETDEWEB)

    Dehoff, Ryan R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kirka, Michael M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-06-01

    Currently, helium is obtained through separation from natural gas. The current industrial process incurs significant costs and requires large energy resources to successfully achieve separation. Through utilizing Additive Manufacturing (AM) technologies it is possible to reduce both of these burdens when refining helium gas. The ability to engineer porosity levels within Inconel 718 discs for controlled separation of helium from natural gas was investigated. Arrays of samples fabricated using the electron beam melting process were analyzed for their relative porosity density. Based upon the measurements, full scale discs were fabricated, and subsequently tested to determine their effectiveness in separating helium from liquefied natural gas.

  19. Additive manufacturing of RF absorbers

    Science.gov (United States)

    Mills, Matthew S.

    The ability of additive manufacturing techniques to fabricate integrated electromagnetic absorbers tuned for specific radio frequency bands within structural composites allows for unique combinations of mechanical and electromagnetic properties. These composites and films can be used for RF shielding of sensitive electromagnetic components through in-plane and out-of-plane RF absorption. Structural composites are a common building block of many commercial platforms. These platforms may be placed in situations in which there is a need for embedded RF absorbing properties along with structural properties. Instead of adding radar absorbing treatments to the external surface of existing structures, which adds increased size, weight and cost; it could prove to be advantageous to integrate the microwave absorbing properties directly into the composite during the fabrication process. In this thesis, a method based on additive manufacturing techniques of composites structures with prescribed electromagnetic loss, within the frequency range 1 to 26GHz, is presented. This method utilizes screen printing and nScrypt micro dispensing to pattern a carbon based ink onto low loss substrates. The materials chosen for this study will be presented, and the fabrication technique that these materials went through to create RF absorbing structures will be described. The calibration methods used, the modeling of the RF structures, and the applications in which this technology can be utilized will also be presented.

  20. Mechanics of additively manufactured biomaterials.

    Science.gov (United States)

    Zadpoor, Amir A

    2017-06-01

    Additive manufacturing (3D printing) has found many applications in healthcare including fabrication of biomaterials as well as bioprinting of tissues and organs. Additively manufactured (AM) biomaterials may possess arbitrarily complex micro-architectures that give rise to novel mechanical, physical, and biological properties. The mechanical behavior of such porous biomaterials including their quasi-static mechanical properties and fatigue resistance is not yet well understood. It is particularly important to understand the relationship between the designed micro-architecture (topology) and the resulting mechanical properties. The current special issue is dedicated to understanding the mechanical behavior of AM biomaterials. Although various types of AM biomaterials are represented in the special issue, the primary focus is on AM porous metallic biomaterials. As a prelude to this special issue, this editorial reviews some of the latest findings in the mechanical behavior of AM porous metallic biomaterials so as to describe the current state-of-the-art and set the stage for the other studies appearing in the issue. Some areas that are important for future research are also briefly mentioned. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Additive versus multiplicative muon conservation

    International Nuclear Information System (INIS)

    Nemethy, P.

    1981-01-01

    Experimental elucidation of the question of muon conservation is reviewed. It is shown that neutral-current experiments have not yet yielded information about muonium-antimuonium conversion at the weak-interaction level and that all the charged-current experiments agree that there is no evidence for a multiplicative law. The best limits, from the muon-decay neutrino experiment at LAMPF and from the inverse muon-decay experiment in the CERN neutrino beam, definitely exclude multiplicative law schemes with a branching ratio R approximately 1/2. It is concluded that unless the dynamics conspire to make a multiplicative law with very small R it would appear that muon conservation obeys conserved additive lepton flavor law. (U.K.)

  2. An Additive Manufacturing Test Artifact

    Science.gov (United States)

    Moylan, Shawn; Slotwinski, John; Cooke, April; Jurrens, Kevin; Donmez, M Alkan

    2014-01-01

    A test artifact, intended for standardization, is proposed for the purpose of evaluating the performance of additive manufacturing (AM) systems. A thorough analysis of previously proposed AM test artifacts as well as experience with machining test artifacts have inspired the design of the proposed test artifact. This new artifact is designed to provide a characterization of the capabilities and limitations of an AM system, as well as to allow system improvement by linking specific errors measured in the test artifact to specific sources in the AM system. The proposed test artifact has been built in multiple materials using multiple AM technologies. The results of several of the builds are discussed, demonstrating how the measurement results can be used to characterize and improve a specific AM system. PMID:26601039

  3. Business models for additive manufacturing

    DEFF Research Database (Denmark)

    Hadar, Ronen; Bilberg, Arne; Bogers, Marcel

    2015-01-01

    Digital fabrication — including additive manufacturing (AM), rapid prototyping and 3D printing — has the potential to revolutionize the way in which products are produced and delivered to the customer. Therefore, it challenges companies to reinvent their business model — describing the logic...... of creating and capturing value. In this paper, we explore the implications that AM technologies have for manufacturing systems in the new business models that they enable. In particular, we consider how a consumer goods manufacturer can organize the operations of a more open business model when moving from...... a manufacturer-centric to a consumer-centric value logic. A major shift includes a move from centralized to decentralized supply chains, where consumer goods manufacturers can implement a “hybrid” approach with a focus on localization and accessibility or develop a fully personalized model where the consumer...

  4. Additive manufacturing with polypropylene microfibers.

    Science.gov (United States)

    Haigh, Jodie N; Dargaville, Tim R; Dalton, Paul D

    2017-08-01

    The additive manufacturing of small diameter polypropylene microfibers is described, achieved using a technique termed melt electrospinning writing. Sequential fiber layering, which is important for accurate three-dimensional fabrication, was achieved with the smallest fiber diameter of 16.4±0.2μm obtained. The collector speed, temperature and melt flow rate to the nozzle were optimized for quality and minimal fiber pulsing. Of particular importance to the success of this method is appropriate heating of the collector plate, so that the electrostatically drawn filament adheres during the direct-writing process. By demonstrating the direct-writing of polypropylene, new applications exploiting the favorable mechanical, stability and biocompatible properties of this polymer are envisaged. Copyright © 2017. Published by Elsevier B.V.

  5. Additivity of entropic uncertainty relations

    Directory of Open Access Journals (Sweden)

    René Schwonnek

    2018-03-01

    Full Text Available We consider the uncertainty between two pairs of local projective measurements performed on a multipartite system. We show that the optimal bound in any linear uncertainty relation, formulated in terms of the Shannon entropy, is additive. This directly implies, against naive intuition, that the minimal entropic uncertainty can always be realized by fully separable states. Hence, in contradiction to proposals by other authors, no entanglement witness can be constructed solely by comparing the attainable uncertainties of entangled and separable states. However, our result gives rise to a huge simplification for computing global uncertainty bounds as they now can be deduced from local ones. Furthermore, we provide the natural generalization of the Maassen and Uffink inequality for linear uncertainty relations with arbitrary positive coefficients.

  6. Tellurium purification: various techniques and limitations

    Indian Academy of Sciences (India)

    Unknown

    -chemical techniques such as vacuum distillation and zone refining are discussed. It was found that the clean environments, design, handling and cleaning of quartz ware are equally important in achieving the desired purity levels. Keywords.

  7. Tetrabromido[4-(triphenylphosphanyloxybutyl]tellurium acetonitrile monosolvate

    Directory of Open Access Journals (Sweden)

    Sari M. Närhi

    2013-02-01

    Full Text Available In the title compound, [TeBr4(C22H23OP]·CH3CN, the Te atom exhibits a square-pyramidal coordination with an apical Te—C bond and four basal Te—Br bonds. The conformation of the aliphatic C—C—C—C chain is gauche [torsion angle = −67.7 (8°]. A weak C—H...Br interaction helps to establish the conformation. In the crystal, there is a weak secondary bonding interaction [Te...N = 3.456 (11 Å] between the Te atom and the N atom of the solvent molecule, which completes a distorted TeNCBr4 octahedron. Inversion dimers linked by pairs of C—H...Br interactions are also observed.

  8. Additional Equipment for Soil Biodegradation

    Science.gov (United States)

    Vondráčková, Terezie; Kraus, Michal; Šál, Jiří

    2017-12-01

    Intensification of industrial production, increasing citizens’ living standards, expanding the consumer assortment mean in the production - consumption cycle a constantly increasing occurrence of waste material, which by its very nature must be considered as a source of useful raw materials in all branches of human activity. In addition to strict legislative requirements, a number of circumstances characterize waste management. It is mainly extensive transport associated with the handling and storage of large volumes of substances with a large assortment of materials (substances of all possible physical and chemical properties) and high demands on reliability and time coordination of follow-up processes. Considerable differences in transport distances, a large number of sources, processors and customers, and not least seasonal fluctuations in waste and strong price pressures cannot be overlooked. This highlights the importance of logistics in waste management. Soils that are contaminated with oil and petroleum products are hazardous industrial waste. Methods of industrial waste disposal are landfilling, biological processes, thermal processes and physical and chemical methods. The paper focuses on the possibilities of degradation of oil pollution, in particular biodegradation by bacteria, which is relatively low-cost among technologies. It is necessary to win the fight with time so that no ground water is contaminated. We have developed two additional devices to help reduce oil accident of smaller ranges. In the case of such an oil accident, it is necessary to carry out the permeability test of contaminated soil in time and, on this basis, to choose the technology appropriate to the accident - either in-sit biodegradation - at the site of the accident, or on-sit - to remove the soil and biodegrade it on the designated deposits. A special injection drill was developed for in-sit biodegradation, tossing and aeration equipment of the extracted soil was developed for

  9. Incommensurate crystallography without additional dimensions.

    Science.gov (United States)

    Kocian, Philippe

    2013-07-01

    It is shown that the Euclidean group of translations, when treated as a Lie group, generates translations not only in Euclidean space but on any space, curved or not. Translations are then not necessarily vectors (straight lines); they can be any curve compatible with the parameterization of the considered space. In particular, attention is drawn to the fact that one and only one finite and free module of the Lie algebra of the group of translations can generate both modulated and non-modulated lattices, the modulated character being given only by the parameterization of the space in which the lattice is generated. Moreover, it is shown that the diffraction pattern of a structure is directly linked to the action of that free and finite module. In the Fourier transform of a whole structure, the Fourier transform of the electron density of one unit cell (i.e. the structure factor) appears concretely, whether the structure is modulated or not. Thus, there exists a neat separation: the geometrical aspect on the one hand and the action of the group on the other, without requiring additional dimensions.

  10. Sustainability Characterization for Additive Manufacturing.

    Science.gov (United States)

    Mani, Mahesh; Lyons, Kevin W; Gupta, S K

    2014-01-01

    Additive manufacturing (AM) has the potential to create geometrically complex parts that require a high degree of customization, using less material and producing less waste. Recent studies have shown that AM can be an economically viable option for use by the industry, yet there are some inherent challenges associated with AM for wider acceptance. The lack of standards in AM impedes its use for parts production since industries primarily depend on established standards in processes and material selection to ensure the consistency and quality. Inability to compare AM performance against traditional manufacturing methods can be a barrier for implementing AM processes. AM process sustainability has become a driver due to growing environmental concerns for manufacturing. This has reinforced the importance to understand and characterize AM processes for sustainability. Process characterization for sustainability will help close the gaps for comparing AM performance to traditional manufacturing methods. Based on a literature review, this paper first examines the potential environmental impacts of AM. A methodology for sustainability characterization of AM is then proposed to serve as a resource for the community to benchmark AM processes for sustainability. Next, research perspectives are discussed along with relevant standardization efforts.

  11. Dynamics of ultrasonic additive manufacturing.

    Science.gov (United States)

    Hehr, Adam; Dapino, Marcelo J

    2017-01-01

    Ultrasonic additive manufacturing (UAM) is a solid-state technology for joining similar and dissimilar metal foils near room temperature by scrubbing them together with ultrasonic vibrations under pressure. Structural dynamics of the welding assembly and work piece influence how energy is transferred during the process and ultimately, part quality. To understand the effect of structural dynamics during UAM, a linear time-invariant model is proposed to relate the inputs of shear force and electric current to resultant welder velocity and voltage. Measured frequency response and operating performance of the welder under no load is used to identify model parameters. Using this model and in-situ measurements, shear force and welder efficiency are estimated to be near 2000N and 80% when welding Al 6061-H18 weld foil, respectively. Shear force and welder efficiency have never been estimated before in UAM. The influence of processing conditions, i.e., welder amplitude, normal force, and weld speed, on shear force and welder efficiency are investigated. Welder velocity was found to strongly influence the shear force magnitude and efficiency while normal force and weld speed showed little to no influence. The proposed model is used to describe high frequency harmonic content in the velocity response of the welder during welding operations and coupling of the UAM build with the welder. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Dimensionless numbers in additive manufacturing

    Science.gov (United States)

    Mukherjee, T.; Manvatkar, V.; De, A.; DebRoy, T.

    2017-02-01

    The effects of many process variables and alloy properties on the structure and properties of additively manufactured parts are examined using four dimensionless numbers. The structure and properties of components made from 316 Stainless steel, Ti-6Al-4V, and Inconel 718 powders for various dimensionless heat inputs, Peclet numbers, Marangoni numbers, and Fourier numbers are studied. Temperature fields, cooling rates, solidification parameters, lack of fusion defects, and thermal strains are examined using a well-tested three-dimensional transient heat transfer and fluid flow model. The results show that lack of fusion defects in the fabricated parts can be minimized by strengthening interlayer bonding using high values of dimensionless heat input. The formation of harmful intermetallics such as laves phases in Inconel 718 can be suppressed using low heat input that results in a small molten pool, a steep temperature gradient, and a fast cooling rate. Improved interlayer bonding can be achieved at high Marangoni numbers, which results in vigorous circulation of liquid metal, larger pool dimensions, and greater depth of penetration. A high Fourier number ensures rapid cooling, low thermal distortion, and a high ratio of temperature gradient to the solidification growth rate with a greater tendency of plane front solidification.

  13. Additive Manufacturing of Fuel Injectors

    Energy Technology Data Exchange (ETDEWEB)

    Sadek Tadros, Dr. Alber Alphonse [Edison Welding Institute, Inc., Columbus, OH (United States); Ritter, Dr. George W. [Edison Welding Institute, Inc., Columbus, OH (United States); Drews, Charles Donald [Edison Welding Institute, Inc., Columbus, OH (United States); Ryan, Daniel [Solar Turbines Inc., San Diego, CA (United States)

    2017-10-24

    Additive manufacturing (AM), also known as 3D-printing, has been shifting from a novelty prototyping paradigm to a legitimate manufacturing tool capable of creating components for highly complex engineered products. An emerging AM technology for producing metal parts is the laser powder bed fusion (L-PBF) process; however, industry manufacturing specifications and component design practices for L-PBF have not yet been established. Solar Turbines Incorporated (Solar), an industrial gas turbine manufacturer, has been evaluating AM technology for development and production applications with the desire to enable accelerated product development cycle times, overall turbine efficiency improvements, and supply chain flexibility relative to conventional manufacturing processes (casting, brazing, welding). Accordingly, Solar teamed with EWI on a joint two-and-a-half-year project with the goal of developing a production L-PBF AM process capable of consistently producing high-nickel alloy material suitable for high temperature gas turbine engine fuel injector components. The project plan tasks were designed to understand the interaction of the process variables and their combined impact on the resultant AM material quality. The composition of the high-nickel alloy powders selected for this program met the conventional cast Hastelloy X compositional limits and were commercially available in different particle size distributions (PSD) from two suppliers. Solar produced all the test articles and both EWI and Solar shared responsibility for analyzing them. The effects of powder metal input stock, laser parameters, heat treatments, and post-finishing methods were evaluated. This process knowledge was then used to generate tensile, fatigue, and creep material properties data curves suitable for component design activities. The key process controls for ensuring consistent material properties were documented in AM powder and process specifications. The basic components of the project

  14. Tellurium sulfates from reactions in oleum and sulfur trioxide: syntheses and crystal structures of TeO(SO{sub 4}), Te{sub 4}O{sub 3}(SO{sub 4}){sub 5}, and Te(S{sub 2}O{sub 7}){sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Logemann, Christian; Bruns, Joern; Schindler, Lisa Verena; Zimmermann, Vanessa; Wickleder, Mathias S. [Carl von Ossietzky University of Oldenburg, Institute of Chemistry (Germany)

    2015-04-15

    The reaction of K{sub 2}TeO{sub 4} with fuming sulfuric acid (65 % SO{sub 3}) in sealed glass ampoules at 250 C led to colorless single crystals of TeO(SO{sub 4}) [triclinic, P anti 1, Z = 8, a = 819.89(3) pm, b = 836.95(4) pm, c = 1179.12(5) pm, α = 82.820(2) , β = 70.645(2) , γ = 81.897(2) , V = 753.11(6) x 10{sup 6} pm{sup 3}]. A horseshoe type [Te{sub 4}O{sub 3}] fragment is the basic motif in the layer structure of the compound. The [Te{sub 4}O{sub 3}] moieties are linked to infinite chains by further oxide ions. Monomeric [Te{sub 4}O{sub 3}] horseshoes are found in the crystal structure of Te{sub 4}O{sub 3}(SO{sub 4}){sub 5} [trigonal, P3{sub 2}21, Z = 3, a = 859.05(2) pm, c = 2230.66(7) pm, V = 1425.61(6) x 10{sup 6} pm{sup 3}], which was obtained from TeO{sub 2} and fuming sulfuric acid (65 % SO{sub 3}) at 200 C as colorless single crystals. By switching to neat SO{sub 3} as reaction medium colorless crystals of Te(S{sub 2}O{sub 7}){sub 2} [P2{sub 1}/n, Z = 4, a = 1065.25(3) pm, b = 818.50(2) pm, c = 1206.27(3) pm, β = 102.097(1) , V = 1028.40(5) x 10{sup 6} pm{sup 3}] form when ortho-telluric acid, H{sub 6}TeO{sub 6}, is used as the tellurium source. The compound was reported previously, however, obviously with a wrong crystallographic description. In the crystal structure the tellurium atoms are coordinated by two chelating disulfate ions. Further Te-O contacts link the [Te(S{sub 2}O{sub 7}){sub 2}] units to an extended network. (Copyright copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. Resonant ionization by laser beams: application to ions sources and to study the nuclear structure of radioactive tellurium isotopes; Ionisation resonante par faisceaux laser: application aux sources d'ions et a l'etude de la structure des noyaux radioactifs de tellure

    Energy Technology Data Exchange (ETDEWEB)

    Sifi, R

    2007-07-15

    The radioactive ion beams that are produced through current isotope separators are well separated according to the A mass but not according to the Z parameter. The resonant ionization through laser beams applied to ion sources allows the production of radioactive ion beam in a very selective and efficient way by eliminating the isobaric contamination. The first chapter is dedicated to the resonant ionization by laser beams, we describe the principle, the experimental setting, the lasers used, the ionization schemes and the domain of application. The second chapter deals with the application of resonant ionization to laser ion sources for the production of radioactive ion beams. We present experimental tests performed for getting copper ion beams. Resonant ionization through laser is also used in the spectroscopy experiments performed at the Isolde (isotope separation on-line device) installation in CERN where more than 20 elements are ionized very efficiently. The technique is based on a frequency scanning around the excitation transition of the atoms in order to probe the hyperfine structure. Laser spectroscopy allows the determination of the hyperfine structure as well as the isotopic shift of atoms. In the third chapter the method is applied to the spectroscopy of tellurium atoms. First, we define the 2 parameters on which the extraction is based: charge radius and nuclear moments, then we present several theoretical models that we have used to assess our experimental results. (A.C.)

  16. Septic tank additive impacts on microbial populations.

    Science.gov (United States)

    Pradhan, S; Hoover, M T; Clark, G H; Gumpertz, M; Wollum, A G; Cobb, C; Strock, J

    2008-01-01

    Environmental health specialists, other onsite wastewater professionals, scientists, and homeowners have questioned the effectiveness of septic tank additives. This paper describes an independent, third-party, field scale, research study of the effects of three liquid bacterial septic tank additives and a control (no additive) on septic tank microbial populations. Microbial populations were measured quarterly in a field study for 12 months in 48 full-size, functioning septic tanks. Bacterial populations in the 48 septic tanks were statistically analyzed with a mixed linear model. Additive effects were assessed for three septic tank maintenance levels (low, intermediate, and high). Dunnett's t-test for tank bacteria (alpha = .05) indicated that none of the treatments were significantly different, overall, from the control at the statistical level tested. In addition, the additives had no significant effects on septic tank bacterial populations at any of the septic tank maintenance levels. Additional controlled, field-based research iswarranted, however, to address additional additives and experimental conditions.

  17. Additive conjoint measurement for multiattribute utility

    NARCIS (Netherlands)

    Maas, A.; Wakker, P.P.

    1994-01-01

    This paper shows that multiattribute utility can be simplified by methods from additive conjoint measurement. Given additive conjoint measurability under certainty, axiomatizations can be simplified, and implementation and reliability of elicitation can be improved. This also contributes to the

  18. Additive Manufacturing of Aerospace Propulsion Components

    Science.gov (United States)

    Misra, Ajay K.; Grady, Joseph E.; Carter, Robert

    2015-01-01

    The presentation will provide an overview of ongoing activities on additive manufacturing of aerospace propulsion components, which included rocket propulsion and gas turbine engines. Future opportunities on additive manufacturing of hybrid electric propulsion components will be discussed.

  19. The Philosophical Consideration about Food Additives

    OpenAIRE

    Baoyu Ma

    2015-01-01

    This study mainly analyzes the essential features of food additives technology from the angle of philosophy, explaining the essential characteristics of food additives technology. As for the attitude towards the application of food additives, it is influenced by the public's gender, age, educational level, occupation and monthly expenditure for buying non-staple food and other variables, thus, the attitude towards food additives and green food, as well as the attitude towards using artificial...

  20. The dilemma of allergy to food additives.

    Science.gov (United States)

    Bahna, Sami L; Burkhardt, Joshua G

    2018-01-01

    To provide a brief summary on food additives and to outline a practical approach for evaluating subjects suspected of having reactions to food additives. Information was derived from selected reviews and original articles published in peer-reviewed journals, supplemented by the clinical experience of the authors. Priority was given to studies that used blinded, placebo controlled, oral challenges to confirm adverse reactions to food additives. In addition, selected, appropriately evaluated case reports were included. A large number of food additives are widely used in the food industry. Allergic reactions to additives seem to be rare but are very likely underdiagnosed, primarily due to a low index of suspicion. A wide variety of symptoms to food additives have been reported, but a cause-and-effect relationship has not been well documented in the majority of cases. Reactions to food additives should be suspected in patients who report symptoms related to multiple foods or to a certain food when commercially prepared but not when home made. It is also prudent to investigate food additives in subjects considered to have "idiopathic" reactions. Except for a limited number of natural additives, there is a small role for skin tests or in vitro testing. Oral challenge, in stages, with commonly used additives is the definitive procedure for detecting the offending agent. Once the specific additive is identified, management is strict avoidance, which can be difficult.

  1. Enabling Technologies for Medium Additive Manufacturing (MAAM)

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, Bradley S. [ORNL; Love, Lonnie J. [ORNL; Chesser, Phillip C. [ORNL; Miller, Jason [Cosine Additive, Inc.; McCalip, Andrew [Cosine Additive, Inc.

    2018-02-01

    ORNL has worked with Cosine Additive, Inc. on the design of MAAM extrusion components. The objective is to improve the print speed and part quality. A pellet extruder has been procured and integrated into the MAAM printer. Print speed has been greatly enhanced. In addition, ORNL and Cosine Additive have worked on alternative designs for a pellet drying and feed system.

  2. Additive operator-difference schemes splitting schemes

    CERN Document Server

    Vabishchevich, Petr N

    2013-01-01

    Applied mathematical modeling isconcerned with solving unsteady problems. This bookshows how toconstruct additive difference schemes to solve approximately unsteady multi-dimensional problems for PDEs. Two classes of schemes are highlighted: methods of splitting with respect to spatial variables (alternating direction methods) and schemes of splitting into physical processes. Also regionally additive schemes (domain decomposition methods)and unconditionally stable additive schemes of multi-component splitting are considered for evolutionary equations of first and second order as well as for sy

  3. Biocompatibility of photopolymers for additive manufacturing

    OpenAIRE

    Leonhardt Stefan; Klare Martin; Scheer Maurice; Fischer Theresa; Cordes Burghard; Eblenkamp Markus

    2016-01-01

    To establish photopolymers for the production of class II or class III medical products by additive manufacturing it is essential to know which components of photopolymeric systems, consisting of monomers, photoinitiators and additives, are the determining factors on their biocompatible properties. In this study the leachable substances of a cured photopolymeric system were eluted and identified by HPLC-MS detection. In addition the cured photopolymer was testes for cytotoxicity and genotoxic...

  4. Harnessing the Potential of Additive Manufacturing

    Science.gov (United States)

    2016-12-01

    31 Defense AT&L: November-December 2016 Harnessing the Potential of Additive Manufacturing Bill Decker Decker is director of Technology...achieve its goal of competition throughout the acquisition life cycle. When we look at additive manufacturing , we have a much different environment. To...Titanium-6 Aluminum-4 Vanadium with Powder Bed Fusion. This specification covers additively manufactured titanium-6 aluminum-4 vanadium (Ti-6Al-4V

  5. Additives in food and their properties

    OpenAIRE

    TYLOVÁ, Kristýna

    2013-01-01

    The aim of this work is to deepen the knowledge about additives in foods, the importance of technological additives in foods, their properties and effects on human health. The aim of this work is a study of technical and scientific literature on the topic: "additives in foods and their properties" and review of the literature. Also in the practical part, implementation and evaluation of a questionnaire survey of the experimental group related to the topic: "Validation and comparison of knowle...

  6. Merits and Demerits of Food Additives

    OpenAIRE

    YANG, Xuening; ZHAN, Yong

    2014-01-01

    Food additive is a double-edged sword. It has merits and demerits. Food additives have such merits as improving sensory properties of foods, preventing deterioration and extending the shelf life, increasing varieties of foods, enhancing convenience of foods, facilitating food processing, and satisfying other demands. However, excessive and illegal use of food additives will exert adverse influence on food security. Therefore, it is required to take proper measures to bring merits of food addi...

  7. Merits and Demerits of Food Additives

    Institute of Scientific and Technical Information of China (English)

    Xuening; YANG; Yong; ZHAN

    2014-01-01

    Food additive is a double-edged sword. It has merits and demerits. Food additives have such merits as improving sensory properties of foods,preventing deterioration and extending the shelf life,increasing varieties of foods,enhancing convenience of foods,facilitating food processing,and satisfying other demands. However,excessive and illegal use of food additives will exert adverse influence on food security.Therefore,it is required to take proper measures to bring merits of food additives into full play,and get rid of their demerits.

  8. Allergic and immunologic reactions to food additives.

    Science.gov (United States)

    Gultekin, Fatih; Doguc, Duygu Kumbul

    2013-08-01

    For centuries, food additives have been used for flavouring, colouring and extension of the useful shelf life of food, as well as the promotion of food safety. During the last 20 years, the studies implicating the additives contained in foods and medicine as a causative factor of allergic reactions have been proliferated considerably. In this review, we aimed to overview all of the food additives which were approved to consume in EU and find out how common and serious allergic reactions come into existence following the consuming of food additives.

  9. 78 FR 34351 - Procurement List; Additions

    Science.gov (United States)

    2013-06-07

    .... ADDRESSES: Committee for Purchase from People Who are Blind or Severely Disabled, 1401 S. Clark Street... COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED Procurement List; Additions AGENCY: Committee for Purchase from People Who are Blind or Severely Disabled. ACTION: Additions to the...

  10. Additive Manufacturing for Low Volume Bearings

    Energy Technology Data Exchange (ETDEWEB)

    Tate, John G. [Schaeffler Group USA, Spartanburg, SC (United States); Richardson, Bradley S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Love, Lonnie J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-09-01

    ORNL worked with the Schaeffler Group USA to explore additive manufacturing techniques that might be appropriate for prototyping of bearing cages. Multiple additive manufacturing techniques were investigated, including e-beam, binder jet and multiple laser based processes. The binder jet process worked best for the thin, detailed cages printed.

  11. 48 CFR 1603.7002 - Additional guidelines.

    Science.gov (United States)

    2010-10-01

    ... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Additional guidelines. 1603.7002 Section 1603.7002 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT FEDERAL... OF INTEREST Misleading, Deceptive, or Unfair Advertising 1603.7002 Additional guidelines. Any...

  12. 18 CFR 33.10 - Additional information.

    Science.gov (United States)

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Additional information. 33.10 Section 33.10 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION... § 33.10 Additional information. The Director of the Office of Energy Market Regulation, or his designee...

  13. Additives In Meat and Poultry Products

    Science.gov (United States)

    ... Fact Sheets / Additives in Meat and Poultry Products / Additives in Meat and Poultry Products Z7_0Q0619C0JGR010IFST1G5B10H3 ... Affairs Recalls and Public Health Alerts Regulatory Compliance Regulations, Directives and Notices Rulemaking ...

  14. Feed Additives for Aquaculture and Aquarium Culture

    OpenAIRE

    Barata, Eduardo N.; Velez, Zélia

    2011-01-01

    The presente invention refers of feed additives for aquaculture and aquarium culture. These additives comprise the amino acid, 1-methyl-L-tryptophane, or its isomers with the objective of improving the attractiveness of feeds used in aquaculture and aquaria for fish, as well as other aquatic organisms, under culture conditions. Therefore, this invention has applications in the agriculture-food industry.

  15. 77 FR 41899 - Indirect Food Additives: Polymers

    Science.gov (United States)

    2012-07-17

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 177 [Docket No. FDA-2012-F-0031] Indirect Food Additives: Polymers AGENCY: Food and Drug Administration, HHS. ACTION... CFR part 177 is amended as follows: PART 177--INDIRECT FOOD ADDITIVES: POLYMERS 0 1. The authority...

  16. Photoactive devices including porphyrinoids with coordinating additives

    Science.gov (United States)

    Forrest, Stephen R; Zimmerman, Jeramy; Yu, Eric K; Thompson, Mark E; Trinh, Cong; Whited, Matthew; Diev, Vlacheslav

    2015-05-12

    Coordinating additives are included in porphyrinoid-based materials to promote intermolecular organization and improve one or more photoelectric characteristics of the materials. The coordinating additives are selected from fullerene compounds and organic compounds having free electron pairs. Combinations of different coordinating additives can be used to tailor the characteristic properties of such porphyrinoid-based materials, including porphyrin oligomers. Bidentate ligands are one type of coordinating additive that can form coordination bonds with a central metal ion of two different porphyrinoid compounds to promote porphyrinoid alignment and/or pi-stacking. The coordinating additives can shift the absorption spectrum of a photoactive material toward higher wavelengths, increase the external quantum efficiency of the material, or both.

  17. Implementation of the Additional Protocol in Japan

    International Nuclear Information System (INIS)

    Ogawa, T.

    2001-01-01

    The Additional Protocol between Japan and the IAEA entered into force in December 1999. To come into force a series of implementation trials of Additional Protocol was carried out at two Japanese representative nuclear research centers, i.e. Tokai Research Establishment of Japan Atomic Energy Research Institute (JAERI) and Oarai Engineering Center of Japan Nuclear Fuel Cycle Development Institute (JNC). These trials were proposed by Japan and were conducted in cooperation with the IAEA Secretariat. In addition, Japan amended 'the Law for the Regulation of Reactors etc.', to collect adequate information to submit to the IAEA, to arrange the surrounding for the complementary access, etc. In addition, Japan Submitted the Initial Declaration of the Additional Protocol within 180 days of the entry into force of the Protocol, in the middle of June, 2000

  18. [Effect of biochar addition on soil evaporation.

    Science.gov (United States)

    Xu, Jian; Niu, Wen Quan; Zhang, Ming Zhi; Li, Yuan; Lyu, Wang; Li, Kang-Yong; Zou, Xiao-Yang; Liang, Bo-Hui

    2016-11-18

    In order to determine the rational amount of biochar application and its effect on soil hydrological processes in arid area, soil column experiments were conducted in the laboratory using three biochar additions (5%, 10% and 15%) and four different biochar types (devaporation. The results showed that the addition of biochar could change the phreatic water recharge, soil water-holding capacity, capillary water upward movement and soil evaporation obviously. But the effects were different depending on the type of biochar raw material and the size of particle. The phreatic water recharge increased with the increasing amount of biochar addition. The addition of biochar could obviously enlarge the soil water-holding capacity and promote the capillary water upward movement rate. This effect was greater when using the material of bamboo charcoal compared with using wood charcoal, while biochar with small particle size had greater impact than that with big particle size. The biochar could effectively restrain the soil evaporation at a low addition amount (5%). But it definitely promoted the soil evaporation if the addition amount was very high. In arid area, biochar addition in appropriate amount could improve soil water retention capacity.

  19. Graphite and Hybrid Nanomaterials as Lubricant Additives

    Directory of Open Access Journals (Sweden)

    Zhenyu J. Zhang

    2014-04-01

    Full Text Available Lubricant additives, based on inorganic nanoparticles coated with organic outer layer, can reduce wear and increase load-carrying capacity of base oil remarkably, indicating the great potential of hybrid nanoparticles as anti-wear and extreme-pressure additives with excellent levels of performance. The organic part in the hybrid materials improves their flexibility and stability, while the inorganic part is responsible for hardness. The relationship between the design parameters of the organic coatings, such as molecular architecture and the lubrication performance, however, remains to be fully elucidated. A survey of current understanding of hybrid nanoparticles as lubricant additives is presented in this review.

  20. Additional symmetries of supersymmetric KP hierarchies

    International Nuclear Information System (INIS)

    Stanciu, S.

    1993-09-01

    We investigate the additional symmetries of several supersymmetric KP hierarchies: The SKP hierarchy of Manin and Radul, the SKP 2 hierarchy, and the Jacobian SKP hierarchy. The main technical tool is the supersymmetric generalisation of a map originally due to Radul between the Lie algebra of superdifferential operators and the Lie algebra of vector fields on the space of supersymmetric Lax operators. In the case of the Manin-Radul SKP hierarchy we identify additional symmetries which form an algebra isomorphic to a subalgebra of superdifferential operators; whereas in the case of the Jacobian SKP, the (additional) symmetries are identified with the algebra itself. (orig.)

  1. 78 FR 38953 - Procurement List Additions

    Science.gov (United States)

    2013-06-28

    ... Blind or Severely Disabled published notices of proposed additions to the Procurement List. After... Punch, Paper, Desktop, 3-Hole, Adjustable, 11 sheet capacity, Metallic Base, Black Grip. Coverage: A...

  2. 78 FR 12295 - Procurement List; Additions

    Science.gov (United States)

    2013-02-22

    ... published notices of proposed additions to the Procurement List. After consideration of the material..., 508 Compliant, 12 Digit, Portable, Desktop, Battery Operated NPA: MidWest Enterprises for the Blind...

  3. Laser-based additive manufacturing of metals

    CSIR Research Space (South Africa)

    Kumar, S

    2010-11-01

    Full Text Available For making metallic products through Additive Manufacturing (AM) processes, laser-based systems play very significant roles. Laser-based processes such as Selective Laser Melting (SLM) and Laser Engineered Net Shaping (LENS) are dominating processes...

  4. Additively Manufactured Ceramic Rocket Engine Components

    Data.gov (United States)

    National Aeronautics and Space Administration — HRL Laboratories, LLC, with Vector Space Systems (VSS) as subcontractor, has a 24-month effort to develop additive manufacturing technology for reinforced ceramic...

  5. 7 CFR 955.91 - Additional parties.

    Science.gov (United States)

    2010-01-01

    ... Marketing Agreement § 955.91 Additional parties. After the effective date thereof, any handler may become a... Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... then be effective as to such new contracting party. ...

  6. Non-additive measure and integral

    CERN Document Server

    Denneberg, Dieter

    1994-01-01

    Non-Additive Measure and Integral is the first systematic approach to the subject. Much of the additive theory (convergence theorems, Lebesgue spaces, representation theorems) is generalized, at least for submodular measures which are characterized by having a subadditive integral. The theory is of interest for applications to economic decision theory (decisions under risk and uncertainty), to statistics (including belief functions, fuzzy measures) to cooperative game theory, artificial intelligence, insurance, etc. Non-Additive Measure and Integral collects the results of scattered and often isolated approaches to non-additive measures and their integrals which originate in pure mathematics, potential theory, statistics, game theory, economic decision theory and other fields of application. It unifies, simplifies and generalizes known results and supplements the theory with new results, thus providing a sound basis for applications and further research in this growing field of increasing interest. It also co...

  7. Nonparametric additive regression for repeatedly measured data

    KAUST Repository

    Carroll, R. J.; Maity, A.; Mammen, E.; Yu, K.

    2009-01-01

    We develop an easily computed smooth backfitting algorithm for additive model fitting in repeated measures problems. Our methodology easily copes with various settings, such as when some covariates are the same over repeated response measurements

  8. Caustic addition system operability test procedure

    Energy Technology Data Exchange (ETDEWEB)

    Parazin, R.E.

    1994-11-01

    This test procedure provides instructions for performing operational testing of the major components of the 241-AN-107 Caustic Addition System by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E).

  9. Caustic addition system operability test procedure

    International Nuclear Information System (INIS)

    Parazin, R.E.

    1994-11-01

    This test procedure provides instructions for performing operational testing of the major components of the 241-AN-107 Caustic Addition System by WHC and Kaiser personnel at the Rotating Equipment Shop run-in pit (Bldg. 272E)

  10. 78 FR 40727 - Procurement List; Proposed Additions

    Science.gov (United States)

    2013-07-08

    ... for addition to the Procurement List for production by the nonprofit agencies listed: Products Towel.... 12/BX Cleaner, Brake Parts NSN: 6850-01-167-0678--17 oz. NPA: The Lighthouse for the Blind, St. Louis...

  11. 78 FR 35874 - Procurement List; Proposed Additions

    Science.gov (United States)

    2013-06-14

    ... proposed for addition to the Procurement List for production by the nonprofit agencies listed: Products... Cleaner NPA: Winston-Salem Industries for the Blind, Inc., Winston-Salem, NC Contracting Activity: Defense...

  12. Characterizing Polymer Powders used in Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Bajric, Sendin [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-11-16

    These are a set of slides that give the personal background of the author, information about his LANL organization, and information about his internship project at LANL about additive manufacturing and selective laser sintering (SLS).

  13. Additive Manufacturing of Magnesium (Mg) Alloys

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed work is to investigate additive manufacturing techniques for Mg alloys.  It will leverage off research being conducted at University of Florida and...

  14. 78 FR 9386 - Procurement List; Addition

    Science.gov (United States)

    2013-02-08

    ... Purchase From People Who Are Blind or Severely Disabled published notice of proposed addition to the...: Enterprise Professional Services, Inc., Austin, TX Contracting Activity: Dept of the Army, W40M USA MEDCOM...

  15. 77 FR 55195 - Procurement List; Additions

    Science.gov (United States)

    2012-09-07

    ... Purchase From People Who Are Blind or Severely Disabled published notice of proposed additions to the... Harmon Avenue, Fort Stewart, GA. NPA: Professional Contract Services, Inc., Austin, TX. Contracting...

  16. Additional symmetries of supersymmetric KP hierarchies

    International Nuclear Information System (INIS)

    Stanciu, S.

    1994-01-01

    We investigate the additional symmetries of several supersymmetric KP hierarchies: the SKP hierarchy of Manin and Radul, the SKP 2 hierarchy, and the Jacobian SKP hierarchy. In all three cases we find that the algebra of symmetries is isomorphic to the algebra of superdifferential operators, or equivalently SW 1+∞ . These results seem to suggest that despite their realization depending on the dynamics, the additional symmetries are kinematical in nature. (orig.)

  17. Additive Manufacturing in the Marine Corps

    Science.gov (United States)

    2015-06-01

    TERMS additive manufacturing, 3D printing, improving logistics 15. NUMBER OF PAGES 123 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT...One such method is ultrasonic agglomeration. The process produces compact snack items that are nutrient-dense and shelf-stable. Currently Army...possess outdated technology. Additionally, prices for the printers are dropping significantly.202 Therefore, the Marine Corps will not only have outdated

  18. Finding phosphorus containing additives in manufactured foods

    OpenAIRE

    Lloyd, Lyn; Gillanders, Lyn

    2012-01-01

    Dietary phosphorous (P) intake is associated with an increased serum phosphate level which is a risk factor for cardiovascular disease and increased mortality for people with chronic kidney disease. Dietary restriction of P is an important nutrition intervention as about 50% of daily intake of P is from P–containing food additives. Educating patients on P additives can effectively reduce serum P values over standard care. Avoidance can be achieved by reading the ingredient list to check for o...

  19. Challenges in Additive Manufacturing of Alumina

    OpenAIRE

    Gonzalez, Hugo

    2016-01-01

    Additive manufacturing is seen by many as the holy grail of manufacturing, the ability to produce parts nearly autonomously. Adding material rather than removing it would eliminate the need for expensive resources and machining. The recent expiration of key 3D printing patents has led to many advances in the field and has dramatically lowered the prices of 3D printers, making them accessible to the average individual. The one area where additive manufacturing is still in its infancy is in cer...

  20. Design and additive manufacture for flow chemistry.

    Science.gov (United States)

    Capel, Andrew J; Edmondson, Steve; Christie, Steven D R; Goodridge, Ruth D; Bibb, Richard J; Thurstans, Matthew

    2013-12-07

    We review the use of additive manufacturing (AM) as a novel manufacturing technique for the production of milli-scale reactor systems. Five well-developed additive manufacturing techniques: stereolithography (SL), multi-jet modelling (MJM), selective laser melting (SLM), laser sintering (LS) and fused deposition modelling (FDM) were used to manufacture a number of miniaturised reactors which were tested using a range of organic and inorganic reactions.

  1. Material Database for Additive Manufacturing Techniques

    Science.gov (United States)

    2017-12-01

    components in the field. II. BACKGROUND Additive manufacturing is a rapidly maturing process by which digital 3-D design data are used to build up...improves readiness by offering on-demand low-rate production [8, 9]. 3-D printing also enables rapid design iterations and complexity, which improve...abundant in additive manufacturing , allowing design freedom that is only limited by the material strength requirements. A set of eight conductive

  2. Evaluation of certain food additives and contaminants.

    Science.gov (United States)

    2013-01-01

    This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives and a food contaminant with a view to concluding as to safety concerns and to preparing specifications for identity and purity. The first part of the report contains a general discussion of the principles governing the toxicological evaluation of and assessment of dietary exposure to food additives. A summary follows of the Committee's evaluations of technical, toxicological and dietary exposure data for seven food additives (advantame; glucoamylase from Trichoderma reesei expressed in Trichoderma reesei; glycerol ester of gum rosin; glycerol ester of tall oil rosin; glycerol ester of wood rosin; nisin; and octenyl succinic acid modified gum arabic) and an assessment of dietary exposure to cadmium from cocoa and cocoa products. Specifications for the following food additives were revised: annatto extracts (solvent-extracted bixin and solvent-extracted norbixin); Benzoe tonkinensis; food additives containing aluminium and/or silicon; mineral oil (medium viscosity); modified starches; paprika extract; phosphates (analytical methods for the determination of phosphorus and revision of specifications); 3-phytase from Aspergillus niger expressed in Aspergillus niger; potassium aluminium silicate; and potassium aluminium silicate-based pearlescent pigments. Annexed to the report are tables summarizing the Committee's recommendations for dietary exposures to and toxicological evaluations of the food additives and contaminant considered.

  3. The Development of Korea Additional Protocol System

    International Nuclear Information System (INIS)

    Shim, Hye Won; Yeo, Jin Kyun

    2008-01-01

    The Agreement between the Republic of Korea (ROK) and the IAEA for the Application of Safeguards in Connection with the Treaty on the Non-Proliferation of Nuclear Weapons (the Safeguards Agreement) entered into force on 14 November 1975. The Additional Protocol to the Safeguards Agreement (the Additional Protocol) was signed on 21 June 1999 and entered into force on 19 February 2004. ROK has been submitting annual updated reports of initial declaration on every May 15th since August 2004. Additional protocol reports were submitted through Protocol Reporter provided by IAEA. Annual declarations were simply uploaded and stored in the Accounting Information Treatment System of KINAC, which did not provide data analysis and management function. There have been demands for improvement to handle ever-increasing information. KAPS (Korea Additional Protocol System) has been developed to assist and administrate the additional protocol related works effectively. The new system enables integrated management including composition of additional protocol report and version control, periodical update of related information, results of IAEA complementary access to each facility

  4. Additive effects in radiation grafting and curing

    International Nuclear Information System (INIS)

    Viengkhou, V.; Ng, L.

    1996-01-01

    Full text: Detailed studies on the accelerative effect of novel additives in radiation grafting and curing using acrylated monomer/oligomer systems have been performed in the presence of ionising radiation and UV as sources. Methyl methacrylate (MMA) is used as typical monomer for these grafting studies in the presence of the additives with model backbone polymers, cellulose and propropylene. Additives which have been found to accelerate these grafting processes are: mineral acid, occlusion compounds like urea, thermal initiators and photoinitiators as well as multifunctional monomers such as multifunctional acrylates. The results from irradiation with gamma rays have also been compared with irradiation from a 90W UV lamp. The role of the above additives in accelerating the analogous process of radiation curing has been investigated. Acrylated urethanes, epoxies and polyesters are used as oligomers together with acrylated monomers in this work with uv lamps of 300 watts/inch as radiation source. In the UV curing process bonding between film and substrate is usually due to physical forces. In the present work the presence of additives are shown to influence the occurrence of concurrent grafting during cure thus affecting the nature of the bonding of the cured film. The conditions under which concurrent grafting with UV can occur will be examined. A mechanism for accelerative effect of these additives in both grafting and curing processes has been proposed involving radiation effects and partitioning phenomena

  5. BFR Electrolyte Additive Safety and Flammability Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Allcorn, Eric [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-10-13

    Lithium-ion battery safety is a critical issue in the adoption of the chemistry to larger scale applications such as transportation and stationary storage. One of the critical components impacting the safety of lithium-ion batteries is their use of highly flammable organic electrolytes. In this work, brominated flame retardants (BFR’s) – an existing class of flame retardant materials – are incorporated as additives to lithium-ion battery electrolytes with the intention to reduce the electrolyte flammability and thereby improve safety. There are a few critical needs for a successful electrolyte additive: solubility in the electrolyte, electrochemical stability over the range of battery operation, and minimal detrimental effects on battery performance. Those detrimental effects can take the form of electrolyte specific impacts, such as a reduction in conductivity, or electrode impacts, such as SEI-layer modification or chemical instability to the active material. In addition to these needs, the electrolyte additive also needs to achieve its intended purpose, which in this case is to reduce the flammability of the electrolyte. For the work conducted as part of this SPP agreement three separate BFR materials were provided by Albemarle to be tested by Sandia as additives in a traditional lithium-ion battery electrolyte. The provided BFR materials were tribromo-neopentyl alcohol, tetrabromo bisphenol A, and tribromoethylene. These materials were incorporated as separate 4 wt.% additives into a traditional lithium-ion battery electrolyte and compared to said traditional electrolyte, designated Gen2.

  6. Additive manufacturing in production: challenges and opportunities

    Science.gov (United States)

    Ahuja, Bhrigu; Karg, Michael; Schmidt, Michael

    2015-03-01

    Additive manufacturing, characterized by its inherent layer by layer fabrication methodology has been coined by many as the latest revolution in the manufacturing industry. Due to its diversification of Materials, processes, system technology and applications, Additive Manufacturing has been synonymized with terminology such as Rapid prototyping, 3D printing, free-form fabrication, Additive Layer Manufacturing, etc. A huge media and public interest in the technology has led to an innovative attempt of exploring the technology for applications beyond the scope of the traditional engineering industry. Nevertheless, it is believed that a critical factor for the long-term success of Additive Manufacturing would be its ability to fulfill the requirements defined by the traditional manufacturing industry. A parallel development in market trends and product requirements has also lead to a wider scope of opportunities for Additive Manufacturing. The presented paper discusses some of the key challenges which are critical to ensure that Additive Manufacturing is truly accepted as a mainstream production technology in the industry. These challenges would highlight on various aspects of production such as product requirements, process management, data management, intellectual property, work flow management, quality assurance, resource planning, etc. In Addition, changing market trends such as product life cycle, mass customization, sustainability, environmental impact and localized production will form the foundation for the follow up discussion on the current limitations and the corresponding research opportunities. A discussion on ongoing research to address these challenges would include topics like process monitoring, design complexity, process standardization, multi-material and hybrid fabrication, new material development, etc.

  7. Study of zirconium-addition binary systems

    International Nuclear Information System (INIS)

    Wozniakova, B.; Kuchar, L.

    1975-01-01

    The curves are given of the solid and the liquid of binary zirconium-addition systems. Most additions reduce the melting temperature of zirconium. The only known additions to increase the melting temperature are nitrogen, oxygen and hafnium. Also given are the transformation curves of the systems and the elements are given which reduce or raise the temperature of α-β transformation. From the Mendeleev table into which are plotted the curves of the solid and the liquid of binary systems it is possible to predict the properties of unknown binary systems. For the calculations of the curves of the solid and the liquid, 1860 degC was taken as the temperature of zirconium melting. For the calculations of transformation curves, 865 degC was taken as the temperature of α-β transformation. The equations are given of the curves of the solid and the liquid and of the transformation curves of some Zr-addition systems. Also given are the calculated equilibrium distribution coefficients and the equilibrium distribution coefficients of the transformation of additions in Zr and their limit values for temperatures approximating the melting point or the temperature of the transformation of pure Zr, and the values pertaining to eutectic and peritectic or eutectoid and peritectoid temperatures. (J.B.)

  8. Laser polishing of additive manufactured Ti alloys

    Science.gov (United States)

    Ma, C. P.; Guan, Y. C.; Zhou, W.

    2017-06-01

    Laser-based additive manufacturing has attracted much attention as a promising 3D printing method for metallic components in recent years. However, surface roughness of additive manufactured components has been considered as a challenge to achieve high performance. In this work, we demonstrate the capability of fiber laser in polishing rough surface of additive manufactured Ti-based alloys as Ti-6Al-4V and TC11. Both as-received surface and laser-polished surfaces as well as cross-section subsurfaces were analyzed carefully by White-Light Interference, Confocal Microscope, Focus Ion Beam, Scanning Electron Microscopy, Energy Dispersive Spectrometer, and X-ray Diffraction. Results revealed that as-received Ti-based alloys with surface roughness more than 5 μm could be reduce to less than 1 μm through laser polishing process. Moreover, microstructure, microhardness and wear resistance of laser-polished zone was investigated in order to examine the thermal effect of laser polishing processing on the substrate of additive manufactured Ti alloys. This proof-of-concept process has the potential to effectively improve the surface roughness of additive manufactured metallic alloy by local polishing method without damage to the substrate.

  9. Terminal addition in a cellular world.

    Science.gov (United States)

    Torday, J S; Miller, William B

    2018-07-01

    Recent advances in our understanding of evolutionary development permit a reframed appraisal of Terminal Addition as a continuous historical process of cellular-environmental complementarity. Within this frame of reference, evolutionary terminal additions can be identified as environmental induction of episodic adjustments to cell-cell signaling patterns that yield the cellular-molecular pathways that lead to differing developmental forms. Phenotypes derive, thereby, through cellular mutualistic/competitive niche constructions in reciprocating responsiveness to environmental stresses and epigenetic impacts. In such terms, Terminal Addition flows according to a logic of cellular needs confronting environmental challenges over space-time. A reconciliation of evolutionary development and Terminal Addition can be achieved through a combined focus on cell-cell signaling, molecular phylogenies and a broader understanding of epigenetic phenomena among eukaryotic organisms. When understood in this manner, Terminal Addition has an important role in evolutionary development, and chronic disease might be considered as a form of 'reverse evolution' of the self-same processes. Copyright © 2017. Published by Elsevier Ltd.

  10. Non-additive Effects in Genomic Selection

    Directory of Open Access Journals (Sweden)

    Luis Varona

    2018-03-01

    Full Text Available In the last decade, genomic selection has become a standard in the genetic evaluation of livestock populations. However, most procedures for the implementation of genomic selection only consider the additive effects associated with SNP (Single Nucleotide Polymorphism markers used to calculate the prediction of the breeding values of candidates for selection. Nevertheless, the availability of estimates of non-additive effects is of interest because: (i they contribute to an increase in the accuracy of the prediction of breeding values and the genetic response; (ii they allow the definition of mate allocation procedures between candidates for selection; and (iii they can be used to enhance non-additive genetic variation through the definition of appropriate crossbreeding or purebred breeding schemes. This study presents a review of methods for the incorporation of non-additive genetic effects into genomic selection procedures and their potential applications in the prediction of future performance, mate allocation, crossbreeding, and purebred selection. The work concludes with a brief outline of some ideas for future lines of that may help the standard inclusion of non-additive effects in genomic selection.

  11. Additive Manufacturing of Metastable Beta Titanium Alloys

    Science.gov (United States)

    Yannetta, Christopher J.

    Additive manufacturing processes of many alloys are known to develop texture during the deposition process due to the rapid reheating and the directionality of the dissipation of heat. Titanium alloys and with respect to this study beta titanium alloys are especially susceptible to these effects. This work examines Ti-20wt%V and Ti-12wt%Mo deposited under normal additive manufacturing process parameters to examine the texture of these beta-stabilized alloys. Both microstructures contained columnar prior beta grains 1-2 mm in length beginning at the substrate with no visible equiaxed grains. This microstructure remained constant in the vanadium system throughout the build. The microstructure of the alloy containing molybdenum changed from a columnar to an equiaxed structure as the build height increased. Eighteen additional samples of the Ti-Mo system were created under different processing parameters to identify what role laser power and travel speed have on the microstructure. There appears to be a correlation in alpha lath size and power density. The two binary alloys were again deposited under the same conditions with the addition of 0.5wt% boron to investigate the effects an insoluble interstitial alloying element would have on the microstructure. The size of the prior beta grains in these two alloys were reduced with the addition of boron by approximately 50 (V) and 100 (Mo) times.

  12. Fuel and Additive Characterization for HCCI Combustion

    International Nuclear Information System (INIS)

    Aceves, S M; Flowers, D; Martinez-Frias, J; Espinosa-Loza, F; Pitz, W J; Dibble, R

    2003-01-01

    This paper shows a numerical evaluation of fuels and additives for HCCl combustion. First, a long list of candidate HCCl fuels is selected. For all the fuels in the list, operating conditions (compression ratio, equivalence ratio and intake temperature) are determined that result in optimum performance under typical operation for a heavy-duty engine. Fuels are also characterized by presenting Log(p)-Log(T) maps for multiple fuels under HCCl conditions. Log(p)-Log(T) maps illustrate important processes during HCCl engine operation, including compression, low temperature heat release and ignition. Log(p)-Log(T) diagrams can be used for visualizing these processes and can be used as a tool for detailed analysis of HCCl combustion. The paper also includes a ranking of many potential additives. Experiments and analyses have indicated that small amounts (a few parts per million) of secondary fuels (additives) may considerably affect HCCl combustion and may play a significant role in controlling HCCl combustion. Additives are ranked according to their capability to advance HCCl ignition. The best additives are listed and an explanation of their effect on HCCl combustion is included

  13. Excessive Additive Effect On Engine Oil Viscosity

    Directory of Open Access Journals (Sweden)

    Vojtěch Kumbár

    2014-01-01

    Full Text Available The main goal of this paper is excessive additive (for oil filling effect on engine oil dynamic viscosity. Research is focused to commercially distribute automotive engine oil with viscosity class 15W–40 designed for vans. There were prepared blends of new and used engine oil without and with oil additive in specific ratio according manufacturer’s recommendations. Dynamic viscosity of blends with additive was compared with pure new and pure used engine oil. The temperature dependence dynamic viscosity of samples was evaluated by using rotary viscometer with standard spindle. Concern was that the oil additive can moves engine oil of several viscosity grades up. It is able to lead to failure in the engine. Mathematical models were used for fitting experimental values of dynamic viscosity. Exponential fit function was selected, which was very accurate because the coefficient of determination R2 achieved high values (0.98–0.99. These models are able to predict viscosity behaviour blends of engine oil and additive.

  14. Biocompatibility of photopolymers for additive manufacturing

    Directory of Open Access Journals (Sweden)

    Leonhardt Stefan

    2016-09-01

    Full Text Available To establish photopolymers for the production of class II or class III medical products by additive manufacturing it is essential to know which components of photopolymeric systems, consisting of monomers, photoinitiators and additives, are the determining factors on their biocompatible properties. In this study the leachable substances of a cured photopolymeric system were eluted and identified by HPLC-MS detection. In addition the cured photopolymer was testes for cytotoxicity and genotoxicity according to DIN EN ISO 10993 for long time applications. The results showed that uncured residual monomers are the determining factor on the biocompatible properties of the photopolymeric system. Strategies to reduce these residual monomers in the cured photopolymer are presented.

  15. Non-additive measures theory and applications

    CERN Document Server

    Narukawa, Yasuo; Sugeno, Michio; 9th International Conference on Modeling Decisions for Artificial Intelligence (MDAI 2012)

    2014-01-01

    This book provides a comprehensive and timely report in the area of non-additive measures and integrals. It is based on a panel session on fuzzy measures, fuzzy integrals and aggregation operators held during the 9th International Conference on Modeling Decisions for Artificial Intelligence (MDAI 2012) in Girona, Spain, November 21-23, 2012. The book complements the MDAI 2012 proceedings book, published in Lecture Notes in Computer Science (LNCS) in 2012. The individual chapters, written by key researchers in the field, cover fundamental concepts and important definitions (e.g. the Sugeno integral, definition of entropy for non-additive measures) as well some important applications (e.g. to economics and game theory) of non-additive measures and integrals. The book addresses students, researchers and practitioners working at the forefront of their field.  

  16. Additive Manufacturing of Shape Memory Alloys

    Science.gov (United States)

    Van Humbeeck, Jan

    2018-04-01

    Selective Laser Melting (SLM) is an additive manufacturing production process, also called 3D printing, in which functional, complex parts are produced by selectively melting patterns in consecutive layers of powder with a laser beam. The pattern the laser beam is following is controlled by software that calculates the pattern by slicing a 3D CAD model of the part to be constructed. Apart from SLM, also other additive manufacturing techniques such as EBM (Electron Beam Melting), FDM (Fused Deposition Modelling), WAAM (Wire Arc Additive Manufacturing), LENS (Laser Engineered Net Shaping such as Laser Cladding) and binder jetting allow to construct complete parts layer upon layer. But since more experience of AM of shape memory alloys is collected by SLM, this paper will overview the potentials, limits and problems of producing NiTi parts by SLM.

  17. Effects from additives on deacetylation of chitin

    International Nuclear Information System (INIS)

    Campana Filho, Sergio P.; Signini, Roberta

    2001-01-01

    Deacetylation reactions of commercial chitin were carried out in aqueous sodium hydroxide solution at 115 deg C for 6 hours. The effect from additives (sodium borohydride or anthraquinone) and of bubbling inert gas (nitrogen or argon) on the characteristics of deacetylated samples were evaluated. Average degrees of acetylation and intrinsic viscosity were determined by 1 H NMR spectroscopy and capillary viscometry, respectively. X-ray diffraction was employed to evaluate changes in crystallinity and infrared spectroscopy was used to monitor structural changes due to deacetylation. The bubbling of inert gas during the deacetylation reaction resulted in more crystalline samples of chitosan. Deacetylation carried out without any additive produced slightly more deacetylated chitosan but they were severely depolymerized. The depolymerization process was much less important when sodium borohydride was added to the reaction medium but the addition of anthraquinone and the bubbling of nitrogen, or argon, did not have any effect, this suggests that oxygen is not required for depolymerization. (author)

  18. Additive Construction with Mobile Emplacement (ACME)

    Science.gov (United States)

    Vickers, John

    2015-01-01

    The Additive Construction with Mobile Emplacement (ACME) project is developing technology to build structures on planetary surfaces using in-situ resources. The project focuses on the construction of both 2D (landing pads, roads, and structure foundations) and 3D (habitats, garages, radiation shelters, and other structures) infrastructure needs for planetary surface missions. The ACME project seeks to raise the Technology Readiness Level (TRL) of two components needed for planetary surface habitation and exploration: 3D additive construction (e.g., contour crafting), and excavation and handling technologies (to effectively and continuously produce in-situ feedstock). Additionally, the ACME project supports the research and development of new materials for planetary surface construction, with the goal of reducing the amount of material to be launched from Earth.

  19. Evaluation of Advanced Polymers for Additive Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Rios, Orlando [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Carter, William G. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Kutchko, Cindy [PPG Industries, Pittsburgh, PA (United States); Fenn, David [PPG Industries, Pittsburgh, PA (United States); Olson, Kurt [PPG Industries, Pittsburgh, PA (United States)

    2017-09-08

    The goal of this Manufacturing Demonstration Facility (MDF) technical collaboration project between Oak Ridge National Laboratory (ORNL) and PPG Industries, Inc. (PPG) was to evaluate the feasibility of using conventional coatings chemistry and technology to build up material layer-by-layer. The PPG-ORNL study successfully demonstrated that polymeric coatings formulations may overcome many limitations of common thermoplastics used in additive manufacturing (AM), allow lightweight nozzle design for material deposition, and increase build rate. The materials effort focused on layer-by-layer deposition of coatings with each layer fusing together. The combination of materials and deposition results in an additively manufactured build that has sufficient mechanical properties to bear the load of additional layers, yet is capable of bonding across the z-layers to improve build direction strength. The formulation properties were tuned to enable a novel, high-throughput deposition method that is highly scalable, compatible with high loading of reinforcing fillers, and inherently low-cost.

  20. Transfer of Training in Simple Addition.

    Science.gov (United States)

    Chen, Yalin; Campbell, Jamie I D

    2017-04-18

    In recent years several researchers have proposed that skilled adults may solve single-digit addition problems (e.g. 3 + 1 = 4, 4 + 3 = 7) using a fast counting procedure. Practicing a procedure, often leads to transfer of learning and faster performance of unpracticed items. Such transfer has been demonstrated using a counting-based alphabet arithmetic task (e.g., B + 4 = C D E F) that indicated robust generalization of practice (i.e., RT gains) when untrained transfer problems at test had been implicitly practiced (e.g., practice B + 3, test B + 2 or B + 1). Here we constructed analogous simple addition problems (practice 4 + 3, test 4 + 2 or 4 + 1). In each of three experiments (total n = 108) participants received six practice blocks followed by two test blocks of new problems to examine generalization effects. Practice of addition identity-rule problems (i.e., 0 + N = N) showed complete transfer of RT gains made during practice to unpracticed items at test. In contrast, the addition ties (2 + 2, 3 + 3, etc.) presented large RT costs for unpracticed problems at test, but sped up substantially in the second test block. This pattern is consistent with item-specific strengthening of associative memory. The critical items were small non-tie additions (sum ≤ 10) for which the test problems would be implicitly practiced if counting was employed during practice. In all three experiments (and collectively) there was no evidence of generalization for these items in the first test block, but there was robust speed up when the items were repeated in the second test block. Thus, there was no evidence of the generalization of practice that would be expected if counting procedures mediated our participants' performance on small non-tie addition problems.

  1. Studies of alumina additions in zirconia - magnesia

    International Nuclear Information System (INIS)

    Muccillo, R.

    1987-01-01

    Ionic conductivity measurements have been carried out in the 500 0 C - 1000 0 C temperature range in Mg - PSZ (Partially Stabilized Zirconia) with 0.5 to 10 mol % alumina additions. All specimens were prepared by pressing followed by pre - and sintering at 1000 0 C/2h and1450 0 C/4h, respectively. Thermal histerysis of the ionic conductivity have been detected, probably due to phase changes in the Mg-PSZ samples. The results show that alumina additions up to 2.1% enhances densification with no major variations in electrical resistivity values. (Author) [pt

  2. Effusion plate using additive manufacturing methods

    Science.gov (United States)

    Johnson, Thomas Edward; Keener, Christopher Paul; Ostebee, Heath Michael; Wegerif, Daniel Gerritt

    2016-04-12

    Additive manufacturing techniques may be utilized to construct effusion plates. Such additive manufacturing techniques may include defining a configuration for an effusion plate having one or more internal cooling channels. The manufacturing techniques may further include depositing a powder into a chamber, applying an energy source to the deposited powder, and consolidating the powder into a cross-sectional shape corresponding to the defined configuration. Such methods may be implemented to construct an effusion plate having one or more channels with a curved cross-sectional geometry.

  3. Photogrammetry for Repositioning in Additive Manufacturing

    DEFF Research Database (Denmark)

    Jensen, Janus Nørtoft; Lyngby, Rasmus Ahrenkiel; Aanæs, Henrik

    2017-01-01

    In this preliminary work, we present our current status on how to use single camera photogrammetry to determine the orientation of an additively manufactured partly finished object that has been repositioned in the printing chamber, from a single image taken with a calibrated camera, and comparing...... this to the CAD model of the object. We describe how this knowledge can be used to update the machine code of the printer such that printing of the object can be resumed in the new location. This opens possibilities for embedding and assembling foreign parts into the additive manufacturing pipeline, adding...

  4. The structure of additive conservation laws

    International Nuclear Information System (INIS)

    Helmut Reen

    1979-01-01

    All additive conserved quantities are listed for a system with short range central force interaction between the particles: a special case shows up in Boltzmann H-theorem and his derivation of the Maxwell velocity distribution. It is concluded that in classical mechanics of mass points there are no other additive conservation laws besides of energy, momentum, angular momentum and center of mass motion. A generator is considered of a symmetry transformation defined as integral over a conserved local current density where the latter, in general, needs not be covariant under translations

  5. Synthesis and structure of aromatic and heterocyclic tellurium compounds 33. Synthesis of [2-(aryltelluro)vinyl]aldehydes and ketones and stereochemistry of nucleophilic substitution under vinyl atom of carbon

    International Nuclear Information System (INIS)

    Sadekov, I.D.; Rivkin, B.B.; Zakharov, A.V.; Minkin, V.I.

    1996-01-01

    By means of interaction of (2-vinylchlorida) carbonyl compounds and (2-acylvinyl) triethylammonium chlorides and arenetellurolate-anions certain, [2-(aryltelluro)vinyl]ketones and [2-(aryltelluro)vinyl]aldehydes have been synthesized, while by means of reaction between 2-aroylvinyl chlorides and Li 2 Te some di(2-aroylvinyl)tellurides have been prepared. Interaction of (2-vinylchloride)ketones with arenetellurolate-anions always gives rise to Z-isomers of [2-(aryltelluro)vinyl]ketones as a result of stabilization of intermediate carbanion by intramolecular coordination O→Te. Nucleophilic addition of arenetellurolate-anions to α-acetylene aldehydes and ketones occurs as trans-addition. 36 refs., 2 figs., 1 tab

  6. 77 FR 13009 - Regulation of Fuels and Fuel Additives: Identification of Additional Qualifying Renewable Fuel...

    Science.gov (United States)

    2012-03-05

    ... Regulation of Fuels and Fuel Additives: Identification of Additional Qualifying Renewable Fuel Pathways Under the Renewable Fuel Standard Program AGENCY: Environmental Protection Agency (EPA). ACTION: Withdrawal... Renewable Fuel Standard program regulations. Because EPA received adverse comment, we are withdrawing the...

  7. 42 CFR 86.20 - Additional conditions.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 1 2010-10-01 2010-10-01 false Additional conditions. 86.20 Section 86.20 Public Health PUBLIC HEALTH SERVICE, DEPARTMENT OF HEALTH AND HUMAN SERVICES OCCUPATIONAL SAFETY AND HEALTH RESEARCH AND RELATED ACTIVITIES GRANTS FOR EDUCATION PROGRAMS IN OCCUPATIONAL SAFETY AND HEALTH Occupational Safety and Health Training Grants § 86.2...

  8. 17 CFR 37.7 - Additional requirements.

    Science.gov (United States)

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Additional requirements. 37.7 Section 37.7 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION DERIVATIVES... of section 5c(c) of the Act and § 40.2 of this chapter, derivatives transaction execution facilities...

  9. Additional reactor protection system of RBMK-1500

    International Nuclear Information System (INIS)

    1999-01-01

    Analysis of anticipated transients without scram of RBMK-1500 reactor showed that additional reactor protection system is required. Data of accident analysis in the case of loose of external electric power and loose of vacuum in condensers of turbines are provided

  10. Neue Werkstoffe über additive Fertigung

    OpenAIRE

    Günther, Johannes; Niendorf, Thomas

    2016-01-01

    Über die additive Fertigung, oftmals bezeichnet als 3D-Druck, lassen sich Bauteile nahezu beliebiger geometrischer Komplexität herstellen. Gleichzeitig lassen die Prozessrandbedingungen die direkte Einstellung der Mikrostruktur in den verwendeten metallischen Werkstoffen zu. Hieraus ergeben sich weitreichende Möglichkeiten bezüglich der Eigenschaftsoptimierung aktueller Hochleistungswerkstoffe.

  11. Additive Manufacturing of Biomaterials, Tissues, and Organs

    NARCIS (Netherlands)

    Zadpoor, Amir A; Malda, Jos

    2017-01-01

    The introduction of additive manufacturing (AM), often referred to as three-dimensional (3D) printing, has initiated what some believe to be a manufacturing revolution, and has expedited the development of the field of biofabrication. Moreover, recent advances in AM have facilitated further

  12. Additive Manufacturing of Biomaterials, Tissues, and Organs

    NARCIS (Netherlands)

    Zadpoor, Amir A; Malda, Jos|info:eu-repo/dai/nl/412461099

    The introduction of additive manufacturing (AM), often referred to as three-dimensional (3D) printing, has initiated what some believe to be a manufacturing revolution, and has expedited the development of the field of biofabrication. Moreover, recent advances in AM have facilitated further

  13. Probabilistic fuzzy systems as additive fuzzy systems

    NARCIS (Netherlands)

    Almeida, R.J.; Verbeek, N.; Kaymak, U.; Costa Sousa, da J.M.; Laurent, A.; Strauss, O.; Bouchon-Meunier, B.; Yager, R.

    2014-01-01

    Probabilistic fuzzy systems combine a linguistic description of the system behaviour with statistical properties of data. It was originally derived based on Zadeh’s concept of probability of a fuzzy event. Two possible and equivalent additive reasoning schemes were proposed, that lead to the

  14. Leaching of Plastic Additives to Marine Organisms

    NARCIS (Netherlands)

    Koelmans, A.A.; Besseling, E.; Foekema, E.M.

    2014-01-01

    It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of

  15. Overview of Food Ingredients, Additives and Colors

    Science.gov (United States)

    ... In addition to maintaining the quality of the food, they help control contamination that can cause foodborne illness, including life-threatening ... still be considered safe. Regulations known as Good Manufacturing ... limit the amount of food ingredients used in foods to the amount necessary ...

  16. Polymeric additive performance in closed whitewater systems

    Science.gov (United States)

    T. H. Wegner

    1984-01-01

    “With more stringent requirements on discharge water quality and with escalating water treatment costs, water recycling within the paper mill is of growing importance. A serious problem resulting from more white-water recycling is reduced drainage and fiber or fines retention because of diminished polymeric additive performance. To provide better insight for overcoming...

  17. 76 FR 80345 - Procurement List; Additions

    Science.gov (United States)

    2011-12-23

    ... ARMY, W6QL ECC MIAMI DIV, MIAMI, FL. Service Type/Location: Industrial Laundry Service, Bureau of... Procurement List. SUMMARY: This action adds services to the Procurement List that will be provided by... concerning capability of qualified nonprofit agencies to provide the services and impact of the additions on...

  18. 78 FR 48656 - Procurement List; Proposed Additions

    Science.gov (United States)

    2013-08-09

    ... Oceanic and Atmospheric Administration, Boulder, CO. Service Type/Location: Laundry Service, US Coast... Additions to the Procurement List. SUMMARY: The Committee is proposing to add products and services to the... required to procure the products and services listed below from nonprofit agencies employing persons who...

  19. 77 FR 27736 - Procurement List Additions

    Science.gov (United States)

    2012-05-11

    ... Research Laboratory, Washington, DC. Service Type/Location: Laundry, Refurbishment, and Warehouse Services... Procurement List. SUMMARY: This action adds products and services to the Procurement List that will be... products and services and impact of the additions on the current or most recent contractors, the Committee...

  20. 77 FR 29596 - Procurement List Proposed Additions

    Science.gov (United States)

    2012-05-18

    .../Location: Laundry Service, Veterans Administration Medical Center (VAMC), (offsite: 1809 W 2nd Avenue... Additions to the Procurement List. SUMMARY: The Committee is proposing to add products and services to the... identified in this notice will be required to procure the products and services listed below from nonprofit...

  1. 75 FR 14576 - Procurement List Additions

    Science.gov (United States)

    2010-03-26

    ... Inspection Service, Minneapolis, MN. M.R. Laundry Products NSN: MR 1103--Heavy Duty Laundry Bag. NSN: MR 1104... procurement list. SUMMARY: This action adds to the Procurement List products and services to be furnished by... products and services and impact of the additions on the current or most recent contractors, the Committee...

  2. Powder Characterization and Optimization for Additive Manufacturing

    NARCIS (Netherlands)

    Cordova, Laura; Campos, Mónica; Tinga, Tiedo

    2017-01-01

    Achieving the optimal quality for Additive Manufactured (AM) parts does not only depend on setting the right process parameters. Material feedstock also plays an important role when aiming for high performance products. The metal AM processes that are most applicable to industry, Powder Bed Fusion

  3. Augmented Reality Interfaces for Additive Manufacturing

    DEFF Research Database (Denmark)

    Eiríksson, Eyþór Rúnar; Pedersen, David Bue; Frisvad, Jeppe Revall

    2017-01-01

    This paper explores potential use cases for using augmented reality (AR) as a tool to operate industrial machines. As a baseline we use an additive manufacturing system, more commonly known as a 3D printer. We implement novel augmented interfaces and controls using readily available open source...

  4. Designing for Color in Additive Manufacturing

    DEFF Research Database (Denmark)

    Eiríksson, Eyþór Rúnar; Luongo, Andrea; Frisvad, Jeppe Revall

    2016-01-01

    In this paper we present a color design pipeline for 3D printed or additively manufactured parts. We demonstrate how to characterize and calibrate a commercial printer and how to obtain its forward and backward color transformation models. We present results from our assistive color design tool...

  5. Additive Manufacturing: From Rapid Prototyping to Flight

    Science.gov (United States)

    Prater, Tracie

    2015-01-01

    Additive manufacturing (AM) offers tremendous promise for the rocket propulsion community. Foundational work must be performed to ensure the safe performance of AM parts. Government, industry, and academia must collaborate in the characterization, design, modeling, and process control to accelerate the certification of AM parts for human-rated flight.

  6. Predicting Color Output of Additive Manufactured Parts

    DEFF Research Database (Denmark)

    Eiríksson, Eyþór Rúnar; Pedersen, David Bue; Aanæs, Henrik

    2015-01-01

    In this paper we address the colorimetric performance of a multicolor additive manufacturing process. A method on how to measure and characterize color performance of said process is presented. Furthermore, a method on predicting the color output is demonstrated, allowing for previsualization...

  7. 78 FR 53734 - Procurement List; Proposed Additions

    Science.gov (United States)

    2013-08-30

    ...: Committee for Purchase From People Who Are Blind or Severely Disabled, 1401 S Clark Street, Suite 10800... COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED Procurement List; Proposed Additions AGENCY: Committee for Purchase From People Who Are Blind or Severely Disabled. ACTION: Proposed...

  8. 78 FR 77105 - Procurement List; Proposed Addition

    Science.gov (United States)

    2013-12-20

    ... People Who Are Blind or Severely Disabled, 1401 S. Clark Street, Suite 10800, Arlington, Virginia, 22202... COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED Procurement List; Proposed Addition AGENCY: Committee for Purchase From People Who Are Blind or Severely Disabled. ACTION: Proposed...

  9. 78 FR 50040 - Procurement List, Proposed Additions

    Science.gov (United States)

    2013-08-16

    ... People Who Are Blind or Severely Disabled, 1401 S Clark Street, Suite 10800, Arlington, Virginia, 22202... COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED Procurement List, Proposed Additions AGENCY: Committee for Purchase From People Who Are Blind or Severely Disabled. ACTION: Proposed...

  10. 78 FR 19248 - Procurement List; Proposed Addition

    Science.gov (United States)

    2013-03-29

    ... Purchase From People Who Are Blind or Severely Disabled, 1401 S. Clark Street, Suite 10800, Arlington... COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED Procurement List; Proposed Addition AGENCY: Committee for Purchase From People Who Are Blind or Severely Disabled. ACTION: Proposed...

  11. Power transformer additional load losses separation procedure

    Directory of Open Access Journals (Sweden)

    Kostić Miloje M.

    2011-01-01

    Full Text Available The proposed procedure is based on the fact that total transformer losses (PLL1,n, determined by short circuit test, can be separated into two components: the eddy current losses in the windings (PEC1,n and stray flux losses (PSL1,n in iron parts of construction as well as in the transformer tank walls. The total additional load losses, PLLd1 and PLLdh, are determined by short circuit test results, conducted at rated frequency (f1 and at increased harmonic frequency (fh=h*f1. Using so obtained total additional load losses, PLLd1 and PLLdh, which can be expressed in the form PLLdh=PEC1,n*h2 + PSL1,n*h, the corresponding rate additional load losses values PEC1,n and PSL1,n are derived. At the end, for given load with predefined high harmonics content, (Ih/I1n, relative to rated current, the total additional load losses value ΣPLLdh > PLLd1, is found. In such a way all harmonics up to hmax are taken into account.

  12. 19 CFR 191.103 - Additional requirements.

    Science.gov (United States)

    2010-04-01

    ... which the alcohol was withdrawn; (iv) Date of withdrawal; (v) Serial number of the tax-paid stamp or... 19 Customs Duties 2 2010-04-01 2010-04-01 false Additional requirements. 191.103 Section 191.103 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND SECURITY; DEPARTMENT OF THE...

  13. Acid Rain Analysis by Standard Addition Titration.

    Science.gov (United States)

    Ophardt, Charles E.

    1985-01-01

    The standard addition titration is a precise and rapid method for the determination of the acidity in rain or snow samples. The method requires use of a standard buret, a pH meter, and Gran's plot to determine the equivalence point. Experimental procedures used and typical results obtained are presented. (JN)

  14. Additivity properties of a Gaussian channel

    International Nuclear Information System (INIS)

    Giovannetti, Vittorio; Lloyd, Seth

    2004-01-01

    The Amosov-Holevo-Werner conjecture implies the additivity of the minimum Renyi entropies at the output of a channel. The conjecture is proven true for all Renyi entropies of integer order greater than two in a class of Gaussian bosonic channel where the input signal is randomly displaced or where it is coupled linearly to an external environment

  15. Finding phosphorus containing additives in manufactured foods

    Directory of Open Access Journals (Sweden)

    Lyn Lloyd

    2012-06-01

    This reflects manufactured foods in NZ and it is likely that these results could be generalized to countries with similar food patterns and supplies. Quantitative data in manufactured foods is unlikely to be available to guide patient choice so qualitative information of where to find P additives can be helpful.

  16. ADHD Diet: Do Food Additives Cause Hyperactivity?

    Science.gov (United States)

    ... 3 fatty acids found in certain types of fish, flaxseed and other foods. With David C. Agerter, M.D Food colours and hyperactivity. NHS Choices. http://www.nhs.uk/conditions/food-additive-intolerance/Pages/Introduction.aspx. Accessed Sept. 18, 2017. ...

  17. Additivity of quark masses in gauge theories

    International Nuclear Information System (INIS)

    Scadron, M.D.

    1987-01-01

    It is shown that, in spite of the confinement of quarks in (color-singlet) hadrons, effective quark masses of all types (dynamically generated, constituent and current masses), naturally form hadron masses in an additivity fashion. For the purposes of brevity, the discussion is limited primarily to the nonstrange flavor sector

  18. 76 FR 57719 - Procurement List; Proposed Additions

    Science.gov (United States)

    2011-09-16

    ... proposed for addition to the Procurement List for production by the nonprofit agencies listed: Products NSN: 7930-00-NIB-0583--Refills, Bathroom Cleaner and Deodorizer, Cartridge Concentrate. NSN: 7930-00-NIB-0584--Starter Kit, Bathroom Cleaner and Deodorizer, Cartridge Concentrate. NSN: 7930-00-NIB-0585...

  19. 78 FR 12296 - Procurement List; Proposed Additions

    Science.gov (United States)

    2013-02-22

    ... services are proposed for addition to the Procurement List for production by the nonprofit agencies listed... and Trailer Wash, 55 GL NSN: 7930-00-NIB-0649--Cleaner/Degreaser, Heavy Duty, Biodegradable, Car and Trucks, 5 GL NSN: 7930-00-NIB-0650--Cleaner/Degreaser, Heavy Duty, Biodegradable, Car and Trucks, 55 GL...

  20. Additive manufacturing: From implants to organs

    African Journals Online (AJOL)

    Additive manufacturing (AM) constructs 3D objects layer by layer under computer control from 3D models. 3D printing is one ... anatomical models for surgery planning, and design and construction ... production of implants, particularly to replace bony structures, is ... Manufactured organs are, however, an elusive goal.

  1. Application of Natural Mineral Additives in Construction

    Science.gov (United States)

    Linek, Malgorzata; Nita, Piotr; Wolka, Paweł; Zebrowski, Wojciech

    2017-12-01

    The article concerns the idea of using selected mineral additives in the pavement quality concrete composition. The basis of the research paper was the modification of cement concrete intended for airfield pavements. The application of the additives: metakaolonite and natural zeolite was suggested. Analyses included the assessment of basic physical properties of modifiers. Screening analysis, assessment of micro structure and chemical microanalysis were conducted in case of these materials. The influence of the applied additives on the change of concrete mix parameters was also presented. The impact of zeolite and metakaolinite on the mix density, oxygen content and consistency class was analysed. The influence of modifiers on physical and mechanical changes of the hardened cement concrete was discussed (concrete density, compressive strength and bending strength during fracturing) in diversified research periods. The impact of the applied additives on the changes of internal structure of cement concrete was discussed. Observation of concrete micro structure was conducted using the scanning electron microscope. According to the obtained lab test results, parameters of the applied modifiers and their influence on changes of internal structure of cement concrete are reflected in the increase of mechanical properties of pavement quality concrete. The increase of compressive and bending strength in case of all analysed research periods was proved.

  2. 76 FR 43988 - Procurement List; Additions

    Science.gov (United States)

    2011-07-22

    ... this work, based on applicable experience. Finally, the purpose of the JWOD Act and the responsibility... COMMITTEE FOR PURCHASE FROM PEOPLE WHO ARE BLIND OR SEVERELY DISABLED Procurement List; Additions... Procurement List. SUMMARY: This action adds products and services to the Procurement List that will be...

  3. 7 CFR 1735.18 - Additional equity.

    Science.gov (United States)

    2010-01-01

    ... AGRICULTURE GENERAL POLICIES, TYPES OF LOANS, LOAN REQUIREMENTS-TELECOMMUNICATIONS PROGRAM Loan Purposes and Basic Policies § 1735.18 Additional equity. If determined by the Administrator to be necessary for loan security, a borrower applying for an initial loan shall increase its net worth as a percentage of assets to...

  4. Sintering of magnesia: effect of additives

    Indian Academy of Sciences (India)

    Effect of different additives, namely Cr2O3, Fe2O3 and TiO2, up to 2 wt% was studied on the sinter- ing and .... mental distribution of the components is shown in figure 7. It shows ... Chiang Y M, Birniand D and Kingery W 1996 Physical ceram-.

  5. 77 FR 34026 - Procurement List; Proposed Additions

    Science.gov (United States)

    2012-06-08

    ... provide interested persons an opportunity to submit comments on the proposed actions. Additions If the..., Department of Homeland Security (DHS), Immigration and Customs Enforcement (ICE), Office of Chief Counsel... Institute, Inc., San Antonio, TX. Contracting Activity: Department of Homeland Security, U.S. Immigration...

  6. (ajst) additive main effects and multiplicative

    African Journals Online (AJOL)

    2013-08-02

    Aug 2, 2013 ... genotypes assessed by biplot analysis showed that the most stable ... biplot is a useful tool for the analysis of multi-environment trial (MET) data. ... multiplicative components, extracting first the additive ... The AMMI analysis of variance of cassava harvest index of the 8 .... wheat mega-environments in Iran.

  7. Stability issues in reconstitution by weapon addition

    Energy Technology Data Exchange (ETDEWEB)

    Canavan, G.H.

    1997-08-01

    Reconstitution of strategic forces by the unilateral uploading of additional weapons from initially symmetric modest force levels reduces first strike stability. These changes are quantified and traced to changes in first and second strike costs in a model of missile exchanges in which both strikes are optimized analytically.

  8. 76 FR 26279 - Procurement List; Proposed Additions

    Science.gov (United States)

    2011-05-06

    ...-service area; clean and sanitize food service equipment, utensil cleaning, and dishwashing; clean pots... additions to the Procurement List. SUMMARY: The Committee is proposing to add services to the Procurement... in this notice will be required to procure the services listed below from nonprofit agencies...

  9. 77 FR 60969 - Procurement List; Additions

    Science.gov (United States)

    2012-10-05

    ... Are Blind or Severely Disabled published a notice for additions to the Procurement List with the... Committee for Purchase From People Who Are Blind or Severely Disabled published notices of proposed..., Phoenix, AZ. Service Type/Location: Custodial and Grounds Maintenance Services, Austin Courthouse, 501...

  10. 27 CFR 5.33 - Additional requirements.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Additional requirements. 5.33 Section 5.33 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF DISTILLED SPIRITS Labeling Requirements for...

  11. 76 FR 41687 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Hydroxypropyl Cellulose

    Science.gov (United States)

    2011-07-15

    ... Organization and the World Health Organization (FAO/WHO) Expert Committee for Food Additives (JECFA) has... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration 21 CFR Part 172 [Docket No. FDA-2010-F-0103] Food Additives Permitted for Direct Addition to Food for Human Consumption...

  12. Additional Samples: Where They Should Be Located

    International Nuclear Information System (INIS)

    Pilger, G. G.; Costa, J. F. C. L.; Koppe, J. C.

    2001-01-01

    Information for mine planning requires to be close spaced, if compared to the grid used for exploration and resource assessment. The additional samples collected during quasimining usually are located in the same pattern of the original diamond drillholes net but closer spaced. This procedure is not the best in mathematical sense for selecting a location. The impact of an additional information to reduce the uncertainty about the parameter been modeled is not the same everywhere within the deposit. Some locations are more sensitive in reducing the local and global uncertainty than others. This study introduces a methodology to select additional sample locations based on stochastic simulation. The procedure takes into account data variability and their spatial location. Multiple equally probable models representing a geological attribute are generated via geostatistical simulation. These models share basically the same histogram and the same variogram obtained from the original data set. At each block belonging to the model a value is obtained from the n simulations and their combination allows one to access local variability. Variability is measured using an uncertainty index proposed. This index was used to map zones of high variability. A value extracted from a given simulation is added to the original data set from a zone identified as erratic in the previous maps. The process of adding samples and simulation is repeated and the benefit of the additional sample is evaluated. The benefit in terms of uncertainty reduction is measure locally and globally. The procedure showed to be robust and theoretically sound, mapping zones where the additional information is most beneficial. A case study in a coal mine using coal seam thickness illustrates the method

  13. Machinability of structural steels with calcium addition

    International Nuclear Information System (INIS)

    Pytel, S.; Zadecki, M.

    2003-01-01

    The machinability of the plain carbon and low alloy structural steels with carbon content of 0.1-0.6% is briefly discussed in the first part of the paper. In the experimental part a dependence between the addition of calcium and some changes in sulphide and oxide inclusions morphology is presented. The Volvo test for measurement of machinability index B i has been applied. Using the multiple regression methods two relationships between machinability index B i and stereological parameters of non-metallic inclusions as well as hardness of the steels have been calculated. The authors have reached the conclusion that owing to the changes in inclusion chemical composition and geometry as result of calcium addition the machinability index of the steel can be higher. (author)

  14. [Total analysis of organic rubber additives].

    Science.gov (United States)

    He, Wen-Xuan; Robert, Shanks; You, Ye-Ming

    2010-03-01

    In the present paper, after middle pressure chromatograph separation using both positive phase and reversed-phase conditions, the organic additives in ethylene-propylene rubber were identified by infrared spectrometer. At the same time, by using solid phase extraction column to maintain the main component-fuel oil in organic additves to avoid its interfering with minor compounds, other organic additves were separated and analysed by GC/Ms. In addition, the remaining active compound such as benzoyl peroxide was identified by CC/Ms, through analyzing acetone extract directly. Using the above mentioned techniques, soften agents (fuel oil, plant oil and phthalte), curing agent (benzoylperoxide), vulcanizing accelerators (2-mercaptobenzothiazole, ethyl thiuram and butyl thiuram), and antiagers (2, 6-Di-tert-butyl-4-methyl phenol and styrenated phenol) in ethylene-propylene rubber were identified. Although the technique was established in ethylene-propylene rubber system, it can be used in other rubber system.

  15. Microbial biosurfactants as additives for food industries.

    Science.gov (United States)

    Campos, Jenyffer Medeiros; Stamford, Tânia Lúcia Montenegro; Sarubbo, Leonie Asfora; de Luna, Juliana Moura; Rufino, Raquel Diniz; Banat, Ibrahim M

    2013-01-01

    Microbial biosurfactants with high ability to reduce surface and interfacial surface tension and conferring important properties such as emulsification, detergency, solubilization, lubrication and phase dispersion have a wide range of potential applications in many industries. Significant interest in these compounds has been demonstrated by environmental, bioremediation, oil, petroleum, food, beverage, cosmetic and pharmaceutical industries attracted by their low toxicity, biodegradability and sustainable production technologies. Despite having significant potentials associated with emulsion formation, stabilization, antiadhesive and antimicrobial activities, significantly less output and applications have been reported in food industry. This has been exacerbated by uneconomical or uncompetitive costing issues for their production when compared to plant or chemical counterparts. In this review, biosurfactants properties, present uses and potential future applications as food additives acting as thickening, emulsifying, dispersing or stabilising agents in addition to the use of sustainable economic processes utilising agro-industrial wastes as alternative substrates for their production are discussed. © 2013 American Institute of Chemical Engineers.

  16. The teratology testing of food additives.

    Science.gov (United States)

    Barrow, Paul C; Spézia, François

    2013-01-01

    The developmental and reproductive toxicity testing (including teratogenicity) of new foods and food additives is performed worldwide according to the guidelines given in the FDA Redbook. These studies are not required for substances that are generally recognized as safe, according to the FDA inventory. The anticipated cumulated human exposure level above which developmental or reproduction studies are required depends on the structure-alert category. For food additives of concern, both developmental (prenatal) and reproduction (multigeneration) studies are required. The developmental studies are performed in two species, usually the rat and the rabbit. The reproduction study is generally performed in the rat. The two rat studies are preferably combined into a single experimental design, if possible. The test methods described in the FDA Redbook are similar to those specified by the OECD for the reproductive toxicity testing of chemicals.

  17. [Trends in the utilization of food additives].

    Science.gov (United States)

    Szűcs, Viktória; Bánáti, Diána

    2013-11-17

    The frequent media reports on food additives weakened consumers' trust in food producers and food control authorities as well. Furthermore, consumers' uncertainty is also raised by the fact that they obtain their information from inadequate, mistrustful sources and, therefore, consumers might avoid the consumption of certain foodstuffs. While food producers may react by replacing artificial components by natural ones, they try to emphasize the favourable characteristics of their products. The authors describe the main trends and efforts related to food additives. On the basis of the overview it can be concluded that - besides taking into consideration consumers' needs - product development and research directions are promising. Food producers' efforts may help to restore consumer confidence and trust and they may help them to have informed choice.

  18. Utilization of curve offsets in additive manufacturing

    Science.gov (United States)

    Haseltalab, Vahid; Yaman, Ulas; Dolen, Melik

    2018-05-01

    Curve offsets are utilized in different fields of engineering and science. Additive manufacturing, which lately becomes an explicit requirement in manufacturing industry, utilizes curve offsets widely. One of the necessities of offsetting is for scaling which is required if there is shrinkage after the fabrication or if the surface quality of the resulting part is unacceptable. Therefore, some post-processing is indispensable. But the major application of curve offsets in additive manufacturing processes is for generating head trajectories. In a point-wise AM process, a correct tool-path in each layer can reduce lots of costs and increase the surface quality of the fabricated parts. In this study, different curve offset generation algorithms are analyzed to show their capabilities and disadvantages through some test cases and improvements on their drawbacks are suggested.

  19. Evolution of solidification texture during additive manufacturing

    Science.gov (United States)

    Wei, H. L.; Mazumder, J.; DebRoy, T.

    2015-01-01

    Striking differences in the solidification textures of a nickel based alloy owing to changes in laser scanning pattern during additive manufacturing are examined based on theory and experimental data. Understanding and controlling texture are important because it affects mechanical and chemical properties. Solidification texture depends on the local heat flow directions and competitive grain growth in one of the six preferred growth directions in face centered cubic alloys. Therefore, the heat flow directions are examined for various laser beam scanning patterns based on numerical modeling of heat transfer and fluid flow in three dimensions. Here we show that numerical modeling can not only provide a deeper understanding of the solidification growth patterns during the additive manufacturing, it also serves as a basis for customizing solidification textures which are important for properties and performance of components. PMID:26553246

  20. Additional gleaning of fusion energy development

    International Nuclear Information System (INIS)

    Yamamoto, Kenzo; Koizumi, Koichi

    2002-09-01

    This report summarizes the major topics in the history of fusion energy development in Japan from its dawn to the tokamak fusion experimental reactor, ITER. The domestic circumstances and situation in foreign countries in those days, and the details of each decision and discussion, are described. Since my previous writing, 'Forty years for Nuclear Fusion Energy Development - Big Science in Japan (1997, ERC Press. Co. Ltd.)', was a book which briefly summarize a large quantity of documents on the history, there are many points, which require additional detail explanation. This time, I selected and extracted major topics in the fusion research history, and added additional descriptions and my comments so as to supplement my previous writing. (author)

  1. Additive manufacturing technology in reconstructive surgery.

    Science.gov (United States)

    Fuller, Scott C; Moore, Michael G

    2016-10-01

    Technological advances have been part and parcel of modern reconstructive surgery, in that practitioners of this discipline are continually looking for innovative ways to perfect their craft and improve patient outcomes. We are currently in a technological climate wherein advances in computers, imaging, and science have coalesced with resulting innovative breakthroughs that are not merely limited to improved outcomes and enhanced patient care, but may provide novel approaches to training the next generation of reconstructive surgeons. New developments in software and modeling platforms, imaging modalities, tissue engineering, additive manufacturing, and customization of implants are poised to revolutionize the field of reconstructive surgery. The interface between technological advances and reconstructive surgery continues to expand. Additive manufacturing techniques continue to evolve in an effort to improve patient outcomes, decrease operative time, and serve as instructional tools for the training of reconstructive surgeons.

  2. Additive manufacturing of polymer-derived ceramics

    Science.gov (United States)

    Eckel, Zak C.; Zhou, Chaoyin; Martin, John H.; Jacobsen, Alan J.; Carter, William B.; Schaedler, Tobias A.

    2016-01-01

    The extremely high melting point of many ceramics adds challenges to additive manufacturing as compared with metals and polymers. Because ceramics cannot be cast or machined easily, three-dimensional (3D) printing enables a big leap in geometrical flexibility. We report preceramic monomers that are cured with ultraviolet light in a stereolithography 3D printer or through a patterned mask, forming 3D polymer structures that can have complex shape and cellular architecture. These polymer structures can be pyrolyzed to a ceramic with uniform shrinkage and virtually no porosity. Silicon oxycarbide microlattice and honeycomb cellular materials fabricated with this approach exhibit higher strength than ceramic foams of similar density. Additive manufacturing of such materials is of interest for propulsion components, thermal protection systems, porous burners, microelectromechanical systems, and electronic device packaging.

  3. Effects of additives on PVG dosifilm

    Energy Technology Data Exchange (ETDEWEB)

    Wenxiu, Chen; Liu, Aiguo [Beijing Normal Univ., BJ (China). Dept. of Chemistry

    1995-03-01

    Dosifilm PVG is a new radiochromic film dosimeter composed of matrix material polyvinyl butyral (PVB), leuco malachite green (LMG) and additive halogenated organic compound (RX), etc. The control of the dose range on PVG dosifilm was examined. The addition of halogenated compounds played an important role in the radiation reaction of LMG beyond the concentration of LMG. Bromide is more effective than chloride in this system, the oxidative species are X {center_dot} and X{sub 2} {center_dot} {sup -}. PVB with N-bromosuccinimide (NBS) can induce the oxidation of LMG before irradiation. The reaction mechanism of PVG was discussed. Different linear ranges of radiation response on PVG dosifilm could be controlled by alternating the relative concentrations of halogenated compounds and LMG. (author).

  4. Laser-Based Additive Manufacturing of Zirconium

    Directory of Open Access Journals (Sweden)

    Himanshu Sahasrabudhe

    2018-03-01

    Full Text Available Additive manufacturing of zirconium is attempted using commercial Laser Engineered Net Shaping (LENSTM technique. A LENSTM-based approach towards processing coatings and bulk parts of zirconium, a reactive metal, aims to minimize the inconvenience of traditional metallurgical practices of handling and processing zirconium-based parts that are particularly suited to small volumes and one-of-a-kind parts. This is a single-step manufacturing approach for obtaining near net shape fabrication of components. In the current research, Zr metal powder was processed in the form of coating on Ti6Al4V alloy substrate. Scanning electron microscopy (SEM and energy dispersive spectroscopy (EDS as well as phase analysis via X-ray diffraction (XRD were studied on these coatings. In addition to coatings, bulk parts were also fabricated using LENS™ from Zr metal powders, and measured part accuracy.

  5. Additive derivations on algebras of measurable operators

    International Nuclear Information System (INIS)

    Ayupov, Sh.A.; Kudaybergenov, K.K.

    2009-08-01

    Given a von Neumann algebra M we introduce the so-called central extension mix(M) of M. We show that mix(M) is a *-subalgebra in the algebra LS(M) of all locally measurable operators with respect to M, and this algebra coincides with LS(M) if and only if M does not admit type II direct summands. We prove that if M is a properly infinite von Neumann algebra then every additive derivation on the algebra mix(M) is inner. This implies that on the algebra LS(M), where M is a type I ∞ or a type III von Neumann algebra, all additive derivations are inner derivations. (author)

  6. Effects of additives on PVG dosifilm

    International Nuclear Information System (INIS)

    Chen Wenxiu; Liu, Aiguo

    1995-01-01

    Dosifilm PVG is a new radiochromic film dosimeter composed of matrix material polyvinyl butyral (PVB), leuco malachite green (LMG) and additive halogenated organic compound (RX), etc. The control of the dose range on PVG dosifilm was examined. The addition of halogenated compounds played an important role in the radiation reaction of LMG beyond the concentration of LMG. Bromide is more effective than chloride in this system, the oxidative species are X · and X 2 · - . PVB with N-bromosuccinimide (NBS) can induce the oxidation of LMG before irradiation. The reaction mechanism of PVG was discussed. Different linear ranges of radiation response on PVG dosifilm could be controlled by alternating the relative concentrations of halogenated compounds and LMG. (author)

  7. The addition of disilanes to cumulenes

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Yiyuan [Iowa State Univ., Ames, IA (United States)

    1997-10-08

    The syntheses of silicon-containing compounds and the studies of their rearrangements have been active research areas in the Barton research group. Previously, the addition of disilanes to acetylenes was studied in the group and an intramolecular 2S + 2A mechanism has been proposed. In this thesis, the work is focused on the addition of disilanes to cumulenes. The syntheses of the precursors are discussed and the possible mechanisms for their thermal, photochemical and catalytic rearrangements are proposed. Conjugated organic polymers have been studied in the group since 1985 because of their potential for exhibiting high electroconductivity, photoconductivity, strong non-linear optical response and intense fluorescence. In the second section of this dissertation, the synthesis and property studies of poly(phenylene vinylene) analogues are discussed.

  8. Electrolyte Additives for Phosphoric Acid Fuel Cells

    DEFF Research Database (Denmark)

    Gang, Xiao; Hjuler, H.A.; Olsen, C.A.

    1993-01-01

    , as a fuel-cell performance with the modified electrolytes. Specific conductivity measurements of some of the modified phosphoric acid electrolytes are reported. At a given temperature, the conductivity of the C4F9SO3K-modified electrolyte decreases with an increasing amount of the additive; the conductivity...... of the remains at the same value as the conductivity of the pure phosphoric acid. At a given composition, the conductivity of any modified electrolyte increases with temperature. We conclude that the improved cell performance for modified electrolytes is not due to any increase in conductivity.......Electrochemical characteristics of a series of modified phosphoric acid electrolytes containing fluorinated car on compounds and silicone fluids as additives are presented. When used in phosphoric acid fuel cells, the modified electrolytes improve the performance due to the enhanced oxygen...

  9. Femtosecond laser additive manufacturing of YSZ

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Jian; Bai, Shuang [PolarOnyx, Inc., San Jose, CA (United States)

    2017-04-15

    Laser additive manufacturing (LAM) of Yttria-Stabilized Zirconia (YSZ) is investigated using femtosecond (fs) fiber lasers. Various processing conditions are studied, which leads to desired characteristics in terms of morphology, porosity, hardness, microstructural and mechanical properties of the processed components. High-density (>99%) YSZ part with refined grain and increased hardness was obtained. Microstructure features of fabricated specimens were studied with SEM, EDX, the measured micro hardness is achieved as high as 18.84 GPa. (orig.)

  10. Selection of Additive Manufacturing (AM) Equipment

    Science.gov (United States)

    2017-04-01

    FOLLOW THE PROCEDURES IN DoD 5200.22-M, INDUSTRIAL SECURITY MANUAL, SECTION II-19 OR DoD 5200.1-R, INFORMATION SECURITY PROGRAM REGULATION...axis subtractive machining center. The hybrid approach is gaining interest in the traditionally subtractive machine tool industry as the additive...systems typically consists of a build vat, feedstock hoppers , a material spreading device, and an energy source. The material spreading device

  11. Addition of malodorants to lighter gas

    DEFF Research Database (Denmark)

    Neela, Vasu; von Solms, Nicolas

    2014-01-01

    Relevant thermodynamic and phase behavior of mixtures created by adding malodorants to lighter gas to discourage its abuse have been studied. The influence of physical factors such as temperature, pressure and concentration of the selected substances with lighter gas is studied. This work represe......-Plus-Association (CPA) - an equation of state - to model the fluid phase and solubility behavior of the mixtures formed by the various additives with butane....

  12. Object attributes combine additively in visual search

    OpenAIRE

    Pramod, R. T.; Arun, S. P.

    2016-01-01

    We perceive objects as containing a variety of attributes: local features, relations between features, internal details, and global properties. But we know little about how they combine. Here, we report a remarkably simple additive rule that governs how these diverse object attributes combine in vision. The perceived dissimilarity between two objects was accurately explained as a sum of (a) spatially tuned local contour-matching processes modulated by part decomposition; (b) differences in in...

  13. Additive Manufacturing for Affordable Rocket Engines

    Science.gov (United States)

    West, Brian; Robertson, Elizabeth; Osborne, Robin; Calvert, Marty

    2016-01-01

    Additive manufacturing (also known as 3D printing) technology has the potential to drastically reduce costs and lead times associated with the development of complex liquid rocket engine systems. NASA is using 3D printing to manufacture rocket engine components including augmented spark igniters, injectors, turbopumps, and valves. NASA is advancing the process to certify these components for flight. Success Story: MSFC has been developing rocket 3D-printing technology using the Selective Laser Melting (SLM) process. Over the last several years, NASA has built and tested several injectors and combustion chambers. Recently, MSFC has 3D printed an augmented spark igniter for potential use the RS-25 engines that will be used on the Space Launch System. The new design is expected to reduce the cost of the igniter by a factor of four. MSFC has also 3D printed and tested a liquid hydrogen turbopump for potential use on an Upper Stage Engine. Additive manufacturing of the turbopump resulted in a 45% part count reduction. To understanding how the 3D printed parts perform and to certify them for flight, MSFC built a breadboard liquid rocket engine using additive manufactured components including injectors, turbomachinery, and valves. The liquid rocket engine was tested seven times in 2016 using liquid oxygen and liquid hydrogen. In addition to exposing the hardware to harsh environments, engineers learned to design for the new manufacturing technique, taking advantage of its capabilities and gaining awareness of its limitations. Benefit: The 3D-printing technology promises reduced cost and schedule for rocket engines. Cost is a function of complexity, and the most complicated features provide the largest opportunities for cost reductions. This is especially true where brazes or welds can be eliminated. The drastic reduction in part count achievable with 3D printing creates a waterfall effect that reduces the number of processes and drawings, decreases the amount of touch

  14. Study of plutonium-addition systems

    International Nuclear Information System (INIS)

    Kuchar, L.; Wozniakova, B.

    1976-11-01

    Steady state phase diagrams and calculated values of concentrations on the solid and liquid curves, the steady state distribution coefficient and thermodynamic control are presented for temperatures ranging from the eutectic reaction temperatures to the Pu melting point temperature for binary systems plutonium-addition (Mg, Al, Si, Ti, Mn, Fe, Co, Ni, Cu, Zn, Ga, Zr, Ru, Os, Th, U, Np). (J.P.)

  15. TECHNOLOGY OF PLANT FEED ADDITIVES FOR POULTRY

    OpenAIRE

    Koshchaeva O. V.; Kalyuzhniy S. A.; Khathakumov S. S.; Likhoman A. V.

    2014-01-01

    The work on the development of technology for production of feed additives from soybean seeds and fruits of pumpkin has shown that the use of sodium bisulfate and lactic acid bacteria provide a high content of carotene in pumpkin paste (948 mg / kg and 819 mg / kg, respectively), and grinding soy before drying protein and vitamin supplements raises safety of carotene without destroying the urease

  16. Supplier Selection Using Weighted Utility Additive Method

    Science.gov (United States)

    Karande, Prasad; Chakraborty, Shankar

    2015-10-01

    Supplier selection is a multi-criteria decision-making (MCDM) problem which mainly involves evaluating a number of available suppliers according to a set of common criteria for choosing the best one to meet the organizational needs. For any manufacturing or service organization, selecting the right upstream suppliers is a key success factor that will significantly reduce purchasing cost, increase downstream customer satisfaction and improve competitive ability. The past researchers have attempted to solve the supplier selection problem employing different MCDM techniques which involve active participation of the decision makers in the decision-making process. This paper deals with the application of weighted utility additive (WUTA) method for solving supplier selection problems. The WUTA method, an extension of utility additive approach, is based on ordinal regression and consists of building a piece-wise linear additive decision model from a preference structure using linear programming (LP). It adopts preference disaggregation principle and addresses the decision-making activities through operational models which need implicit preferences in the form of a preorder of reference alternatives or a subset of these alternatives present in the process. The preferential preorder provided by the decision maker is used as a restriction of a LP problem, which has its own objective function, minimization of the sum of the errors associated with the ranking of each alternative. Based on a given reference ranking of alternatives, one or more additive utility functions are derived. Using these utility functions, the weighted utilities for individual criterion values are combined into an overall weighted utility for a given alternative. It is observed that WUTA method, having a sound mathematical background, can provide accurate ranking to the candidate suppliers and choose the best one to fulfill the organizational requirements. Two real time examples are illustrated to prove

  17. MAFJ: some simple additions to MAFCO

    International Nuclear Information System (INIS)

    Finan, C.H. III; McNamara, B.

    1976-01-01

    MAFJ is a revision of the MAFCO code which generates magnetic fields (B) resulting from collections of current elements. In addition to the original MAFCO's capabilities, MAFJ follows field lines through a region of interest and calculates integrals of functions along these lines. It can also generate three-dimensional grids of B. MAFJ runs from eight to 15 times faster than MAFCO, depending on the types of current elements chosen. 2 tables

  18. LAVA: Large scale Automated Vulnerability Addition

    Science.gov (United States)

    2016-05-23

    LAVA: Large-scale Automated Vulnerability Addition Brendan Dolan -Gavitt∗, Patrick Hulin†, Tim Leek†, Fredrich Ulrich†, Ryan Whelan† (Authors listed...released, and thus rapidly become stale. We can expect tools to have been trained to detect bugs that have been released. Given the commercial price tag...low TCN) and dead (low liveness) program data is a powerful one for vulnera- bility injection. The DUAs it identifies are internal program quantities

  19. Additional chromosome abnormalities in chronic myeloid leukemia

    Directory of Open Access Journals (Sweden)

    Hui-Hua Hsiao

    2011-02-01

    Full Text Available The Philadelphia (Ph chromosome and/or Breakpoint cluster region-Abelson leukemia virus oncogene transcript are unique markers for chronic myeloid leukemia (CML. However, CML demonstrates heterogeneous presentations and outcomes. We analyzed the cytogenetic and molecular results of CML patients to evaluate their correlation with clinical presentations and outcome. A total of 84 newly diagnosed CML patients were enrolled in the study. Patients were treated according to disease status. Bone marrow samples were obtained to perform cytogenetic and molecular studies. Clinical presentations, treatment courses, and survival were reviewed retrospectively. Among 84 patients, 72 had chronic phase and 12 had accelerated phase CML. Cytogenetic study showed 69 (82.1% with the classic Ph chromosome, 6 (7.2% with a variant Ph chromosome, and 9 (10.7% with additional chromosome abnormalities. Fifty-four (64.3% cases harbored b3a2 transcripts, 29 (34.5% had b2a2 transcript, and 1 had e19a2 transcript. There was no difference in clinical presentations between different cytogenetic and molecular groups; however, additional chromosome abnormalities were significantly associated with the accelerated phase. Imatinib therapy was an effective treatment, as measured by cytogenetic response, when administered as first- and second-line therapy in chronic phase patients. Survival analysis showed that old age, additional chromosome abnormalities, high Sokal score, and no cytogenetic response in second-line therapy had a significant poor impact (p<0.05. In conclusion, we presented the cytogenetic and molecular pattern of CML patients and demonstrated that the additional chromosome abnormality was associated with poor outcome.

  20. Thermal 18F atom addition to olefins

    International Nuclear Information System (INIS)

    Rogers, P.J.M.

    1986-01-01

    The addition of thermal 18 F atoms to olefins was investigated using various substrate molecules. The 18 F atoms were produced by the 19 F(n,2n) 18 F nuclear reaction with >10 5 eV of energy which is removed by multiple collisions with SF 6 molecules before reaction occurs with an olefin. By varying the SF 6 /substrate mole ratio it was demonstrated that the fraction of non-thermal reactions is dependent upon the frequency of non-reactive energy reducing collisions with SF 6 . The rate constants for addition and abstraction reactions with propene, cis-1-chloropropene and trans-1-chloropropene were determined. The substitution of a C1 atom for the olefinic H atom in the C 1 position does not affect the rate of 18 F bond formation but it changes the orientation of attack. The 18 F atom prefers the terminal carbon-in propene and propene-d 6 by a factor of 1.35 while the preference is less than 0.5 for the terminal carbon in cis-1-chloropropene and trans-1-chloropropene. The addition of 18 F atoms to olefins creates vibrationally excited fluoroalkyl radicals which can either decompose or stabilize by collision with another molecule. The rate constants for decomposition of excited CH 3 CHCHC1F radicals formed by 18 F addition to cis-1-chloropropene and trans-1-chloropropene are competitive with C 1 -C 2 bond rotation. The 18 F atoms add to the parent molecule with retention of geometry and a memory of the geometry persists as demonstrated by the cis-1-fluoropropene/trans-1-fluoropropene decomposition product ratio

  1. Generalized Additive Models for Nowcasting Cloud Shading

    Czech Academy of Sciences Publication Activity Database

    Brabec, Marek; Paulescu, M.; Badescu, V.

    2014-01-01

    Roč. 101, March (2014), s. 272-282 ISSN 0038-092X R&D Projects: GA MŠk LD12009 Grant - others:European Cooperation in Science and Technology(XE) COST ES1002 Institutional support: RVO:67985807 Keywords : sunshine number * nowcasting * generalized additive model * Markov chain Subject RIV: BB - Applied Statistics, Operational Research Impact factor: 3.469, year: 2014

  2. Conferences on Combinatorial and Additive Number Theory

    CERN Document Server

    2014-01-01

    This proceedings volume is based on papers presented at the Workshops on Combinatorial and Additive Number Theory (CANT), which were held at the Graduate Center of the City University of New York in 2011 and 2012. The goal of the workshops is to survey recent progress in combinatorial number theory and related parts of mathematics. The workshop attracts researchers and students who discuss the state-of-the-art, open problems, and future challenges in number theory.

  3. Ionic liquids as lubricant additives: A review

    International Nuclear Information System (INIS)

    Zhou, Yan; Qu, Jun

    2016-01-01

    In pursuit of energy efficiency and durability throughout human history, advances in lubricants have always played important roles. Ionic liquids (ILs) are room-temperature molten salts that possess unique physicochemical properties and have shown great potential in many applications with lubrication as one of the latest. While earlier work (2001–2011) primarily explored the feasibility of using ILs as neat or base lubricants, using ILs as lubricant additives has become the new focal research topic since the breakthrough in ILs’ miscibility in nonpolar hydrocarbon oils in early 2012. This work reviews the recent advances in developing ILs as additives for lubrication with an attempt to correlate among the cationic and anionic structures, oil-solubility, and other relevant physicochemical properties, and lubricating behavior. Effects of the concentration of ILs in lubricants and the compatibility between ILs and other additives in the lubricant formulation on the tribological performance are described followed by a discussion of wear protection mechanism based on tribofilm characterization. As a result, future research directions are suggested at the end.

  4. Additive Manufacturing of Biomaterials, Tissues, and Organs.

    Science.gov (United States)

    Zadpoor, Amir A; Malda, Jos

    2017-01-01

    The introduction of additive manufacturing (AM), often referred to as three-dimensional (3D) printing, has initiated what some believe to be a manufacturing revolution, and has expedited the development of the field of biofabrication. Moreover, recent advances in AM have facilitated further development of patient-specific healthcare solutions. Customization of many healthcare products and services, such as implants, drug delivery devices, medical instruments, prosthetics, and in vitro models, would have been extremely challenging-if not impossible-without AM technologies. The current special issue of the Annals of Biomedical Engineering presents the latest trends in application of AM techniques to healthcare-related areas of research. As a prelude to this special issue, we review here the most important areas of biomedical research and clinical practice that have benefited from recent developments in additive manufacturing techniques. This editorial, therefore, aims to sketch the research landscape within which the other contributions of the special issue can be better understood and positioned. In what follows, we briefly review the application of additive manufacturing techniques in studies addressing biomaterials, (re)generation of tissues and organs, disease models, drug delivery systems, implants, medical instruments, prosthetics, orthotics, and AM objects used for medical visualization and communication.

  5. Laser Additive Manufacturing of Magnetic Materials

    Science.gov (United States)

    Mikler, C. V.; Chaudhary, V.; Borkar, T.; Soni, V.; Jaeger, D.; Chen, X.; Contieri, R.; Ramanujan, R. V.; Banerjee, R.

    2017-03-01

    While laser additive manufacturing is becoming increasingly important in the context of next-generation manufacturing technologies, most current research efforts focus on optimizing process parameters for the processing of mature alloys for structural applications (primarily stainless steels, titanium base, and nickel base alloys) from pre-alloyed powder feedstocks to achieve properties superior to conventionally processed counterparts. However, laser additive manufacturing or processing can also be applied to functional materials. This article focuses on the use of directed energy deposition-based additive manufacturing technologies, such as the laser engineered net shaping (LENS™) process, to deposit magnetic alloys. Three case studies are presented: Fe-30 at.%Ni, permalloys of the type Ni-Fe-V and Ni-Fe-Mo, and Fe-Si-B-Cu-Nb (derived from Finemet) alloys. All these alloys have been processed from a blend of elemental powders used as the feedstock, and their resultant microstructures, phase formation, and magnetic properties are discussed in this paper. Although these alloys were produced from a blend of elemental powders, they exhibited relatively uniform microstructures and comparable magnetic properties to those of their conventionally processed counterparts.

  6. Microbial analyses of cement and grouting additives

    International Nuclear Information System (INIS)

    Hallbeck, L.; Jaegevall, S.; Paeaejaervi, A.; Rabe, L.; Edlund, J.; Eriksson, S.

    2012-01-01

    During sampling in the ONKALO tunnel in 2006, heavy growth of a slimy material was observed in connection with grouting. It was suggested to be microbial growth on organic additives leaching from the grout. Two sampling campaigns resulted in the isolation of several aerobic bacterial strains. Some of these strains were used in biodegradation studies of three solid cement powders, eight liquid grout additives, and six plastic drainage materials. Degradation was also studied using ONKALO groundwaters as inoculums. The isolated strains were most closely related to hydrocarbon-degrading microorganisms. The biodegradation of seven of the products was tested using microorganisms isolated from the ONKALO slime in 2006; none of these strains could degrade the tested products. When ONKALO drillhole groundwaters were used as inoculums in the degradation studies, it was demonstrated that Structuro 111X, Mighty 150, and Super-Parmix supported growth of the groundwater microorganisms. Structuro 111X is a polycarboxylate condensate while Mighty 150 and Super-Parmix are condensates with formaldehyde and naphthalene. Some of the isolated microorganisms belonged to the genus Pseudomonas, many strains of which can degrade organic molecules. None of the plastic drainage materials supported growth during the degradation studies. Microorganisms were present in two of the liquid products when delivered, GroutAid and Super-Parmix. The potential of the organic compounds in grout additives to be degraded by microorganisms, increasing the risk of biofilm formation and complexing compound production, must be considered. Microbial growth will also increase the possibility of hydrogen sulphide formation. (orig.)

  7. Culture and neuroscience: additive or synergistic?

    Science.gov (United States)

    Dapretto, Mirella; Iacoboni, Marco

    2010-01-01

    The investigation of cultural phenomena using neuroscientific methods—cultural neuroscience (CN)—is receiving increasing attention. Yet it is unclear whether the integration of cultural study and neuroscience is merely additive, providing additional evidence of neural plasticity in the human brain, or truly synergistic, yielding discoveries that neither discipline could have achieved alone. We discuss how the parent fields to CN: cross-cultural psychology, psychological anthropology and cognitive neuroscience inform the investigation of the role of cultural experience in shaping the brain. Drawing on well-established methodologies from cross-cultural psychology and cognitive neuroscience, we outline a set of guidelines for CN, evaluate 17 CN studies in terms of these guidelines, and provide a summary table of our results. We conclude that the combination of culture and neuroscience is both additive and synergistic; while some CN methodologies and findings will represent the direct union of information from parent fields, CN studies employing the methodological rigor required by this logistically challenging new field have the potential to transform existing methodologies and produce unique findings. PMID:20083533

  8. Managing water addition to a degraded core

    International Nuclear Information System (INIS)

    Kuan, P.; Hanson, D.J.; Odar, F.

    1992-01-01

    In this paper the authors present information that can be used in severe accident management by providing an improved understanding of the effects of water addition to a degraded core. This improved understanding is developed using a diagram showing a sequence of core damage states. Whenever possible, a temperature and a time after accident initiation are estimated for each damage state in the sequence diagram. This diagram can be used to anticipate the evolution of events during an accident. Possible responses of plant instruments are described to identify these damage states and the effects of water addition. The rate and amount of water addition needed (a) to remove energy from the core, (b) to stabilize the core or (c) to not adversely affect the damage progression, are estimated. Analysis of the capability to remove energy from large cohesive and particulate debris beds indicates that these beds may not be stabilized in the core region and they may partially relocate to the lower plenum of the reactor vessel

  9. How many food additives are rodent carcinogens?

    Science.gov (United States)

    Johnson, F M

    2002-01-01

    One generally assumes that chemical agents added to foods are reasonably free of risks to human health, and practically everyone consumes some additives in his or her food daily throughout life. In the United States, the 1958 Food Additives Amendment to the Federal Food, Drug and Cosmetic Act of 1938 requires food manufacturers to demonstrate the safety of food additives to the Food and Drug Administration (FDA). The Amendment contains a provision that prohibits approval of an additive if it is found to cause cancer in humans or animals. In the present study, data from the National Toxicology Program rodent bioassay (NTPRB) were used to identify a sample of approximately 50 rodent-tested additives and other chemicals added to food that had been evaluated independently of the FDA/food industry. Surprisingly, the sample shows more than 40% of these food chemicals to be carcinogenic in one or more rodent groups. If this percentage is extrapolated to all substances added to food in the United States, it would imply that more than 1000 of such substances are potential rodent carcinogens. The NTP and FDA test guidelines use similar, though not necessarily identical, rodent test procedures, including near lifetime exposures to the maximum tolerated dose. The FDA specifies that test chemicals should be administered by the oral route. However, the oral route includes three methods of delivering chemicals, that is, mixed in the food or water or delivered by stomach tube (gavage). The NTP data show only 1 of 18 food chemicals mixed in the food are rodent carcinogens, but 16 of 23 gavage-administered food chemicals are carcinogenic to rodents. The distribution suggests that among orally delivered chemicals, those administered in the feed will more likely prove to be noncarcinogens than chemicals given by gavage. The rodent data also reveal that effects may vary according to dose and genotype, as well as by route of administration, to further complicate extrapolation to humans

  10. Mechanical properties of additively manufactured octagonal honeycombs

    Energy Technology Data Exchange (ETDEWEB)

    Hedayati, R., E-mail: rezahedayati@gmail.com [Department of Mechanical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave, Tehran (Iran, Islamic Republic of); Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands); Sadighi, M.; Mohammadi-Aghdam, M. [Department of Mechanical Engineering, Amirkabir University of Technology (Tehran Polytechnic), Hafez Ave, Tehran (Iran, Islamic Republic of); Zadpoor, A.A. [Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology (TU Delft), Mekelweg 2, 2628 CD Delft (Netherlands)

    2016-12-01

    Honeycomb structures have found numerous applications as structural and biomedical materials due to their favourable properties such as low weight, high stiffness, and porosity. Application of additive manufacturing and 3D printing techniques allows for manufacturing of honeycombs with arbitrary shape and wall thickness, opening the way for optimizing the mechanical and physical properties for specific applications. In this study, the mechanical properties of honeycomb structures with a new geometry, called octagonal honeycomb, were investigated using analytical, numerical, and experimental approaches. An additive manufacturing technique, namely fused deposition modelling, was used to fabricate the honeycomb from polylactic acid (PLA). The honeycombs structures were then mechanically tested under compression and the mechanical properties of the structures were determined. In addition, the Euler-Bernoulli and Timoshenko beam theories were used for deriving analytical relationships for elastic modulus, yield stress, Poisson's ratio, and buckling stress of this new design of honeycomb structures. Finite element models were also created to analyse the mechanical behaviour of the honeycombs computationally. The analytical solutions obtained using Timoshenko beam theory were close to computational results in terms of elastic modulus, Poisson's ratio and yield stress, especially for relative densities smaller than 25%. The analytical solutions based on the Timoshenko analytical solution and the computational results were in good agreement with experimental observations. Finally, the elastic properties of the proposed honeycomb structure were compared to those of other honeycomb structures such as square, triangular, hexagonal, mixed, diamond, and Kagome. The octagonal honeycomb showed yield stress and elastic modulus values very close to those of regular hexagonal honeycombs and lower than the other considered honeycombs. - Highlights: • The octagonal

  11. Influence of Additives on Reinforced Concrete Durability

    Directory of Open Access Journals (Sweden)

    Neverkovica Darja

    2014-12-01

    Full Text Available The article presents the results of the research on carbonation and chloride induced corrosion mechanisms in reinforced concrete structures, based on three commercially available concrete admixtures: Xypex Admix C-1000, Penetron Admix and Elkem Microsilica. Carbonation takes place due to carbon dioxide diffusion, which in the required amount is present in the air. Chlorides penetrate concrete in case of the use of deicing salt or structure exploitation in marine atmosphere. Based on the implemented research, Elkem Microsilica is the recommended additive for the use in aggressive environmental conditions. Use of Xypex Admix C-1000 and Penetron Admix have only average resistance to the aggressive environmental impact.

  12. Enhanced additive manufacturing with a reciprocating platen

    Science.gov (United States)

    Lind, Randall F.; Blue, Craig A.; Love, Lonnie J.; Post, Brian K.; Lloyd, Peter D.

    2018-02-06

    An additive manufacturing extrusion head that includes a heated nozzle for accepting a feedstock and extruding the feedstock onto a substrate at a deposition plane, the nozzle having a longitudinal extrusion axis. A reciprocating platen surrounds the nozzle, the platen operable to reciprocate along the extrusion axis at or above the deposition plane as the nozzle extrudes feedstock onto the substrate; and wherein the platen flattens the extruded feedstock such that it does not protrude above the deposition plane as the extrusion head traverses over the substrate.

  13. Dust-Firing of Straw and Additives

    DEFF Research Database (Denmark)

    Wu, Hao; Glarborg, Peter; Frandsen, Flemming

    2011-01-01

    In the present work, the ash chemistry and deposition behavior during straw dust-firing were studied by performing experiments in an entrained flow reactor. The effect of using spent bleaching earth (SBE) as an additive in straw combustion was also investigated by comparing with kaolinite. During...... dust-firing of straw, the large (>∼2.5 μm) fly ash particles generated were primarily molten or partially molten spherical particles rich in K, Si, and Ca, supplemented by Si-rich flake-shaped particles. The smaller fly ash particles (...

  14. Mechanism and kinetics of addition polymerizations

    CERN Document Server

    Kucera, M

    1991-01-01

    This volume presents an up-to-date survey of knowledge concerning addition type polymerizations. It contains nine chapters, each of which covers a particular basic term. Whenever necessary, the phenomena are discussed from the viewpoint of both stationary and non-stationary state of radical, ionic (i.e. anionic and cationic) and coordination polymerization. Special attention has been paid to the propagation process. It provides not only a general overview but also information on important special cases (theoretical conditions of propagation, influence of external factors, controlled propagatio

  15. Metal-deactivating additives for liquid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Boneva, M.I. [Institute of Organic Chemistry, Sofia (Bulgaria); Ivanov, S.K.; Kalitchin, Z.D. [SciBulCom, Ltd., Sofia (Bulgaria); Tanielyan, S.K. [Seton Hall Univ., South Orange, NJ (United States); Terebenina, A.; Todorova, O.I. [Institute of Inorganic Chemistry, Sofia (Bulgaria)

    1995-05-01

    The metal-deactivating and the antioxidant properties of 1-phenyl-3-methylpyrazolone-5 derivatives have been investigated both in the model reaction of low temperature oxidation of ethylbenzene and in gasoline oxidation. The study of the ability of these derivatives to reduce the catalytic effect of copper naphthenate demonstrates that they are promising as metal deactivating additives for light fuels. Some of the pyrazolone compounds appear to be of special interest for the long-term storage of liquid fuels due to their action as multifunctional inhibitors.

  16. Additive Manufacturing of Hierarchical Porous Structures

    Energy Technology Data Exchange (ETDEWEB)

    Grote, Christopher John [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Materials Science and Technology Division. Polymers and Coatings

    2016-08-30

    Additive manufacturing has become a tool of choice for the development of customizable components. Developments in this technology have led to a powerful array of printers that t serve a variety of needs. However, resin development plays a crucial role in leading the technology forward. This paper addresses the development and application of printing hierarchical porous structures. Beginning with the development of a porous scaffold, which can be functionalized with a variety of materials, and concluding with customized resins for metal, ceramic, and carbon structures.

  17. Additive measures of travel time variability

    DEFF Research Database (Denmark)

    Engelson, Leonid; Fosgerau, Mogens

    2011-01-01

    This paper derives a measure of travel time variability for travellers equipped with scheduling preferences defined in terms of time-varying utility rates, and who choose departure time optimally. The corresponding value of travel time variability is a constant that depends only on preference...... parameters. The measure is unique in being additive with respect to independent parts of a trip. It has the variance of travel time as a special case. Extension is provided to the case of travellers who use a scheduled service with fixed headway....

  18. Additive Cellular Automata and Volume Growth

    Directory of Open Access Journals (Sweden)

    Thomas B. Ward

    2000-08-01

    Full Text Available Abstract: A class of dynamical systems associated to rings of S-integers in rational function fields is described. General results about these systems give a rather complete description of the well-known dynamics in one-dimensional additive cellular automata with prime alphabet, including simple formulæ for the topological entropy and the number of periodic configurations. For these systems the periodic points are uniformly distributed along some subsequence with respect to the maximal measure, and in particular are dense. Periodic points may be constructed arbitrarily close to a given configuration, and rationality of the dynamical zeta function is characterized. Throughout the emphasis is to place this particular family of cellular automata into the wider context of S-integer dynamical systems, and to show how the arithmetic of rational function fields determines their behaviour. Using a covering space the dynamics of additive cellular automata are related to a form of hyperbolicity in completions of rational function fields. This expresses the topological entropy of the automata directly in terms of volume growth in the covering space.

  19. Surface texture measurement for additive manufacturing

    Science.gov (United States)

    Triantaphyllou, Andrew; Giusca, Claudiu L.; Macaulay, Gavin D.; Roerig, Felix; Hoebel, Matthias; Leach, Richard K.; Tomita, Ben; Milne, Katherine A.

    2015-06-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting.

  20. Additive manufacturing of tools for lapping glass

    Science.gov (United States)

    Williams, Wesley B.

    2013-09-01

    Additive manufacturing technologies have the ability to directly produce parts with complex geometries without the need for secondary processes, tooling or fixtures. This ability was used to produce concave lapping tools with a VFlash 3D printer from 3D Systems. The lapping tools were first designed in Creo Parametric with a defined constant radius and radial groove pattern. The models were converted to stereolithography files which the VFlash used in building the parts, layer by layer, from a UV curable resin. The tools were rotated at 60 rpm and used with 120 grit and 220 grit silicon carbide lapping paste to lap 0.750" diameter fused silica workpieces. The samples developed a matte appearance on the lapped surface that started as a ring at the edge of the workpiece and expanded to the center. This indicated that as material was removed, the workpiece radius was beginning to match the tool radius. The workpieces were then cleaned and lapped on a second tool (with equivalent geometry) using a 3000 grit corundum aluminum oxide lapping paste, until a near specular surface was achieved. By using lapping tools that have been additively manufactured, fused silica workpieces can be lapped to approach a specified convex geometry. This approach may enable more rapid lapping of near net shape workpieces that minimize the material removal required by subsequent polishing. This research may also enable development of new lapping tool geometry and groove patterns for improved loose abrasive finishing.

  1. Leaching of plastic additives to marine organisms

    International Nuclear Information System (INIS)

    Koelmans, Albert A.; Besseling, Ellen; Foekema, Edwin M.

    2014-01-01

    It is often assumed that ingestion of microplastics by aquatic species leads to increased exposure to plastic additives. However, experimental data or model based evidence is lacking. Here we assess the potential of leaching of nonylphenol (NP) and bisphenol A (BPA) in the intestinal tracts of Arenicola marina (lugworm) and Gadus morhua (North Sea cod). We use a biodynamic model that allows calculations of the relative contribution of plastic ingestion to total exposure of aquatic species to chemicals residing in the ingested plastic. Uncertainty in the most crucial parameters is accounted for by probabilistic modeling. Our conservative analysis shows that plastic ingestion by the lugworm yields NP and BPA concentrations that stay below the lower ends of global NP and BPA concentration ranges, and therefore are not likely to constitute a relevant exposure pathway. For cod, plastic ingestion appears to be a negligible pathway for exposure to NP and BPA. - Highlights: • Uptake of plastic additives after plastic ingestion was modeled for worms and fish. • This was done for bisphenol A and nonylphenol. • Uncertainty was accounted for by Monte Carlo simulations. • It appeared that exposure by plastic ingestion was negligible for fish. • Plastic ingestion may occasionally be relevant for marine worms. - Leaching of nonylphenol and bisphenol A from ingested microplastic may be relevant for the lugworm, but is irrelevant for fish like cod

  2. Surface texture measurement for additive manufacturing

    International Nuclear Information System (INIS)

    Triantaphyllou, Andrew; Tomita, Ben; Milne, Katherine A; Giusca, Claudiu L; Macaulay, Gavin D; Roerig, Felix; Hoebel, Matthias; Leach, Richard K

    2015-01-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting. (paper)

  3. Surface-specific additive manufacturing test artefacts

    Science.gov (United States)

    Townsend, Andrew; Racasan, Radu; Blunt, Liam

    2018-06-01

    Many test artefact designs have been proposed for use with additive manufacturing (AM) systems. These test artefacts have primarily been designed for the evaluation of AM form and dimensional performance. A series of surface-specific measurement test artefacts designed for use in the verification of AM manufacturing processes are proposed here. Surface-specific test artefacts can be made more compact because they do not require the large dimensions needed for accurate dimensional and form measurements. The series of three test artefacts are designed to provide comprehensive information pertaining to the manufactured surface. Measurement possibilities include deviation analysis, surface texture parameter data generation, sub-surface analysis, layer step analysis and build resolution comparison. The test artefacts are designed to provide easy access for measurement using conventional surface measurement techniques, for example, focus variation microscopy, stylus profilometry, confocal microscopy and scanning electron microscopy. Additionally, the test artefacts may be simply visually inspected as a comparative tool, giving a fast indication of process variation between builds. The three test artefacts are small enough to be included in every build and include built-in manufacturing traceability information, making them a convenient physical record of the build.

  4. Emerging technologies in arthroplasty: additive manufacturing.

    Science.gov (United States)

    Banerjee, Samik; Kulesha, Gene; Kester, Mark; Mont, Michael A

    2014-06-01

    Additive manufacturing is an industrial technology whereby three-dimensional visual computer models are fabricated into physical components by selectively curing, depositing, or consolidating various materials in consecutive layers. Although initially developed for production of simulated models, the technology has undergone vast improvements and is currently increasingly being used for the production of end-use components in various aerospace, automotive, and biomedical specialties. The ability of this technology to be used for the manufacture of solid-mesh-foam monolithic and coated components of complex geometries previously considered unmanufacturable has attracted the attention of implant manufacturers, bioengineers, and orthopedic surgeons. Currently, there is a paucity of reports describing this fabrication method in the orthopedic literature. Therefore, we aimed to briefly describe this technology, some of the applications in other orthopedic subspecialties, its present use in hip and knee arthroplasty, and concerns with the present form of the technology. As there are few reports of clinical trials presently available, the true benefits of this technology can only be realized when studies evaluating the clinical and radiographic outcomes of cementless implants manufactured with additive manufacturing report durable fixation, less stress shielding, and better implant survivorship. Nevertheless, the authors believe that this technology holds great promise and may potentially change the conventional methods of casting, machining, and tooling for implant manufacturing in the future. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  5. Characterizations of additive manufactured porous titanium implants.

    Science.gov (United States)

    Basalah, Ahmad; Shanjani, Yaser; Esmaeili, Shahrzad; Toyserkani, Ehsan

    2012-10-01

    This article describes physical, chemical, and mechanical characterizations of porous titanium implants made by an additive manufacturing method to gain insight into the correlation of process parameters and final physical properties of implants used in orthopedics. For the manufacturing chain, the powder metallurgy technology was combined with the additive manufacturing to fabricate the porous structure from the pure tanium powder. A 3D printing machine was employed in this study to produce porous bar samples. A number of physical parameters such as titanium powder size, polyvinyl alcohol (PVA) amount, sintering temperature and time were investigated to control the mechanical properties and porosity of the structures. The produced samples were characterized through porosity and shrinkage measurements, mechanical compression test and scanning electron microscopy (SEM). The results showed a level of porosity in the samples in the range of 31-43%, which is within the range of the porosity of the cancelluous bone and approaches the range of the porosity of the cortical bone. The results of the mechanical test showed that the compressive strength is in the wide range of 56-509 MPa implying the effect of the process parameters on the mechanical strengths. This technique of manufacturing of Ti porous structures demonstrated a low level of shrinkage with the shrinkage percentage ranging from 1.5 to 5%. Copyright © 2012 Wiley Periodicals, Inc.

  6. Additive Manufacturing of Composites and Complex Materials

    Science.gov (United States)

    Spowart, Jonathan E.; Gupta, Nikhil; Lehmhus, Dirk

    2018-03-01

    Advanced composite materials form an important class of high-performance industrial materials used in weight-sensitive applications such as aerospace structures, automotive structures and sports equipment. In many of these applications, parts are made in small production runs, are highly customized and involve long process development times. Developments in additive manufacturing (AM) methods have helped in overcoming many of these limitations. The special topic of Additive Manufacturing of Composites and Complex Materials captures the state of the art in this area by collecting nine papers that present much novel advancement in this field. The studies under this topic show advancement in the area of AM of carbon fiber and graphene-reinforced composites with high thermal and electrical conductivities, development of new hollow glass particle-filled syntactic foam filaments for printing lightweight structures and integration of sensors or actuators during AM of metallic parts. Some of the studies are focused on process optimization or modification to increase the manufacturing speed or tuning manufacturing techniques to enable AM of new materials.

  7. Preparation of additional supplies of 244Pu

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Newman, E.; Alexander, C.W.

    1985-01-01

    In the mid-1970s, gram quantities of the man-made isotope 244 Pu were produced in high purity for basic research as a by-product of a program to prepare gram quantities of 252 Cf. Because 244 Pu is not produced in appreciable quantities in standard power reactor fuel, this nuclide has become extremely useful in the application of isotope dilution mass spectrometry (IDMS), a high-precision analytical technique, to problems of plutonium accountability in support of international safeguards agreements. Although only a small amount (a fraction of a microgram) is needed for each analysis, the present supply of certified nuclear reference standard SRM-996 is expected to last only an additional 3 to 5 years. Three options for producing additional supplies of this rare and valuable material were examined. The options encompassed the production of from 1 to 8.5 g during time spans of from 3 to 10 years. Unit costs ranged from $2300 to $7200 per mg of plutonium of >97% 244 Pu. While the paper concludes that the short-term option can be pursued along with further study of the longer-term options, this should not be regarded as an offer or a commitment on the part of the US Department of Energy (USDOE) to furnish the described material

  8. Variant Carvajal syndrome with additional dental anomalies.

    Science.gov (United States)

    Barber, Sophy; Day, Peter; Judge, Mary; Toole, Edell O'; Fayle, Stephen

    2012-09-01

    This paper aims to review the case of a girl who presented with a number of dental anomalies, in addition to unusual skin, nail and hair conditions. Tragically an undiagnosed cardiomyopathy caused unexpected sudden death. The case is discussed with reference to a number of dermatological and oral conditions which were considered as possible diagnoses. AW had been under long term dental care for prepubertal periodontitis, premature root resorption of primary teeth, soft tissue and dental anomalies, and angular cheilitis. Separately she had also been seen by several dermatologists with respect to palmar plantar keratosis, striae keratoderma, wiry hair and abnormal finger nails. Tragically the patient suffered a sudden unexpected death and the subsequent post mortem identified an undiagnosed dilated cardiomyopathy. The most likely diagnosis is that this case is a variant of Carvajal Syndrome with additional dental anomalies. To date we have been unable to identify mutations in the desoplakin gene. We aim to emphasise the importance of recognising these dental and dermatological signs when they present together as a potential risk factor for cardiac abnormalities. © 2012 The Authors. International Journal of Paediatric Dentistry © 2012 BSPD, IAPD and Blackwell Publishing Ltd.

  9. Sending more process data without additional cables

    International Nuclear Information System (INIS)

    Licht, H.; Roiha, R.; Rodych, M.

    1997-01-01

    The as-built data transmission capability in CANDU plants is fully employed. Long delays and high cost make it often not feasible to retrofit plant equipment with additional sensors and bring the data to the office. One of the reasons is the unavoidable addition of data transmission cables. This presentation describes the results of work performed in 1996/97 to network sensors using existing plant infrastructure. To provide an alternative solution, a general purpose data transmission system is being developed. It sends data over existing plant infrastructure such as power wiring and the telephone system. Its components are based on PC technology packaged in a 'black box', using special hardware and software to appear to the user as a very simple, low cost, device. Its drawback is its rather limited transmission speed. This design is in marked contrast to the complexity of present commercial data transmission systems. A point-to-point system has been demonstrated. A networked system is under development. (author)

  10. Value addition - a marketing strategy for MCL

    Energy Technology Data Exchange (ETDEWEB)

    Sagar, C.K.; Mishra, P.K.; Baranwal, P.K. [Central Mine Planning and Design Institute, Ranchi (India)

    2002-07-01

    The energy sector will remain dependent on coal because of depletion of oil reserves. With deterioration of power grade coal, the emission of greenhouse gas is going to increase thereby stressing the need of using prepared low ash coal for protection of global environment. Further, recent stipulation of MOEF imposing restriction on use of high ash coal at distant power houses and those at sensitive localities and critically polluted areas have made the aspect of marketing of coal more challenging. This has necessitated a long-term strategy for improving the quality of coal in light of national environment policy. This is more relevant in the present scenario of open market, where we need to market our coal rather simply supplying r.o.m. coal to the linked users. Mahanadi Coalfields, Limited (MCL), the youngest subsidiary of Coal India Limited bestowed with a huge reserve of inferior grade and mainly linked to power sector, is taken as a sample case study. To fulfil the demand of coal with due regard to the national environmental policy, there is need of value addition as strategy of marketing for power coal of MCL. Value addition of coal can be achieved by two distinct different ways i.e. beneficiating high ash coal at pit head or blending high ash coal with low ash coal which is a less preferred option due to non-availability of low ash coal in MCL. 7 refs., 7 tabs.

  11. Preparation of additional supplies of 244Pu

    International Nuclear Information System (INIS)

    Bigelow, J.E.; Newman, E.; Alexander, C.W.

    1985-01-01

    In the mid-1970s, gram quantities of the man-made isotope 244 Pu were produced in high purity for basic research as a by-product of a program to prepare gram quantities of 252 Cf. Because 244 Pu is not produced in appreciable quantities in standard power reactor fuel, this nuclide has become extremely useful in the application of isotope dilution mass spectrometry (IDMS), a high-precision analytical technique, to problems of plutonium accountability in support of international safeguards agreements. Although only a small amount (a fraction of a microgram) is needed for each analysis, the present supply of certified nuclear reference standard SRM-996 is expected to last only an additional 3 to 5 years. Three options for producing additional supplies of this rare and valuable material were examined. The options encompassed the production of from 1 to 8.5 g during time spans of from 3 to 10 years. Unit costs ranged from $2300 to $7200 per mg of plutonium of >97% 244 Pu. While the paper concludes that the short-term option can be pursued along with further study of the longer-term options, this should not be regarded as an offer or a commitment on the part of the U.S. Department of Energy (USDOE) to furnish the described material. (author)

  12. Additives as corrosion inhibitors in reinforced concrete

    International Nuclear Information System (INIS)

    Venegas, Ricardo; Vera, Rosa; Carvajal, Ana Maria; Villarroel, Maria; Vera, Enrique; Ortiz, Cesar

    2008-01-01

    This work studies the behavior of two additives as inhibitors of corrosion in reinforced concrete. The presence of Microsilica, a physical inhibitor, in the mixture decreases pore size in structures and improves compression. Calcium Nitrite, a chemical inhibitor, is an oxidizing agent and allows a more homogenous film to form over the steel that becomes more resistant to attacks from aggressive ions like anion chloride and others. Three pairs of concrete test pieces were used without additives and with additives with a/c ration of 0.55. The samples were exposed to an accelerated attack of chlorides, submerging them in a 4.27 M solution of NaCl for 24 hours and then drying them at room temperature for another 24 hours, completing a cycle every 48 hours. The tests were carried out at 1 cycle and 5 cycles of partial moistening and drying. The steel corrosion was evaluated with corrosion potential measurements. Conductivity, pH, chlorides and sulfate profiles were defined depending on the depth of the concrete. The composition of the corrosion products was determined using X-ray diffraction and the morphology of the film by scanning electron microscopy. The results show that for 1 test cycle, the corrosion potential of the steel in the sample with calcium nitrite was -54mV, which was a higher value than that measured in the sample with microsilica (-217.3mV) and without an additive (-159.1mV), corroborating its inhibitory power. The content of the free chlorides in the sample with micros ice allows greater capillary suction by adding high amounts of chloride to the structure (2.6% on the outside up to 2.20% near the steel); while the test pieces with calcium nitrite and without an additive had concentrations lower than 2% in all the evaluated points. After five cycles of exposing the samples to the saline solution the behavior is inverted. The measures of conductivity agreed with the previous results. Meanwhile, the pH of the solutions obtained from the powder from the

  13. Addition Table of Colours: Additive and Subtractive Mixtures Described Using a Single Reasoning Model

    Science.gov (United States)

    Mota, A. R.; Lopes dos Santos, J. M. B.

    2014-01-01

    Students' misconceptions concerning colour phenomena and the apparent complexity of the underlying concepts--due to the different domains of knowledge involved--make its teaching very difficult. We have developed and tested a teaching device, the addition table of colours (ATC), that encompasses additive and subtractive mixtures in a single…

  14. 76 FR 16285 - Food Additives Permitted for Direct Addition to Food for Human Consumption; Bacteriophage...

    Science.gov (United States)

    2011-03-23

    ... mammalian cells. (See discussion at 71 FR 47729 at 47730). As such, traditional animal testing of the... 51758 at 51759, August 25, 2000). Suitability relates to the effectiveness of the ingredient in... additive be shown to be safe prior to marketing. Under Sec. 170.3(i), a food additive is ``safe'' if...

  15. Additive phosphaturic action of parathyrin and calcitonin

    International Nuclear Information System (INIS)

    Oberleitner, H.; Lang, F.; Greger, P.; Sporer, H.; Deetjen, P.

    1980-01-01

    Parathyrin and calcitonin exert their effects on phosphate metabolism by influencing the functions of at least three organ systems, i.e. bone, gut and kidneys. To study the renal effects of these hormones under exclusion of systemic effects microinfusion studies were performed in anesthetised rats. After thyroparathyroidectomy radioactively labelled phosphate containing solutions were microinfused into single proximal convoluted tubules. The tracer recovery in the urine allowed calculation of phosphate reabsorption in the nephron segments beyond the micropuncture site. After a control period of 6 minutes the hormones were superfused to the nephron surface and tracer recovery measured during the following 36 minutes. Within few minutes both, parathyrin and calcitonin, clearly reduced phosphate reabsorption. Infusions of supramaximal doses of either hormone abolished the local action of this hormone but did not influence the effect of the other. Thus the phosphaturic actions of parathyrin and calcitonin are additive, indicating that the hormones involve different mechanisms and/or nephron sites. (author)

  16. Object attributes combine additively in visual search.

    Science.gov (United States)

    Pramod, R T; Arun, S P

    2016-01-01

    We perceive objects as containing a variety of attributes: local features, relations between features, internal details, and global properties. But we know little about how they combine. Here, we report a remarkably simple additive rule that governs how these diverse object attributes combine in vision. The perceived dissimilarity between two objects was accurately explained as a sum of (a) spatially tuned local contour-matching processes modulated by part decomposition; (b) differences in internal details, such as texture; (c) differences in emergent attributes, such as symmetry; and (d) differences in global properties, such as orientation or overall configuration of parts. Our results elucidate an enduring question in object vision by showing that the whole object is not a sum of its parts but a sum of its many attributes.

  17. Nonparametric additive regression for repeatedly measured data

    KAUST Repository

    Carroll, R. J.

    2009-05-20

    We develop an easily computed smooth backfitting algorithm for additive model fitting in repeated measures problems. Our methodology easily copes with various settings, such as when some covariates are the same over repeated response measurements. We allow for a working covariance matrix for the regression errors, showing that our method is most efficient when the correct covariance matrix is used. The component functions achieve the known asymptotic variance lower bound for the scalar argument case. Smooth backfitting also leads directly to design-independent biases in the local linear case. Simulations show our estimator has smaller variance than the usual kernel estimator. This is also illustrated by an example from nutritional epidemiology. © 2009 Biometrika Trust.

  18. Additive manufacturing techniques and their biomedical applications

    Directory of Open Access Journals (Sweden)

    Yujing Liu

    2017-12-01

    Full Text Available Additive manufacturing (AM, also known as three-dimensional (3D printing, is gaining increasing attention in medical fields, especially in dental and implant areas. Because AM technologies have many advantages in comparison with traditional technologies, such as the ability to manufacture patient-specific complex components, high material utilization, support of tissue growth, and a unique customized service for individual patients, AM is considered to have a large potential market in medical fields. This brief review presents the recent progress of 3D-printed biomedical materials for bone applications, mainly for metallic materials, including multifunctional alloys with high strength and low Young’s modulus, shape memory alloys, and their 3D fabrication by AM technologies. It describes the potential of 3D printing techniques in precision medicine and community health.

  19. Additive Feed Forward Control with Neural Networks

    DEFF Research Database (Denmark)

    Sørensen, O.

    1999-01-01

    This paper demonstrates a method to control a non-linear, multivariable, noisy process using trained neural networks. The basis for the method is a trained neural network controller acting as the inverse process model. A training method for obtaining such an inverse process model is applied....... A suitable 'shaped' (low-pass filtered) reference is used to overcome problems with excessive control action when using a controller acting as the inverse process model. The control concept is Additive Feed Forward Control, where the trained neural network controller, acting as the inverse process model......, is placed in a supplementary pure feed-forward path to an existing feedback controller. This concept benefits from the fact, that an existing, traditional designed, feedback controller can be retained without any modifications, and after training the connection of the neural network feed-forward controller...

  20. Additional investigations on the consequences of accidents

    International Nuclear Information System (INIS)

    Ehrhardt, J.; Bayer, A.; Burkart, K.

    1982-01-01

    As a first step to improve the accident consequence model of the German Risk Study within the Phase B, additional investigations on special problems and questions were performed. In detail attention is given to the following topics: emergency protective actions in the vicinity of the site; latent cancer fatalities - allocated to the population living during the nuclear accident and to persons born afterwards, within and beyond a distance of 540 km from the site, caused by radiation doses below the dose limits of the German radiation protection regulations estimated assuming a nonlinear dose response function; risk assessments of nuclear power plants with lower capacities; loss of life expectancy after accidental radiation exposure. All results are presented separately for the 8 release categories of the German Risk Study. (orig.) [de